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Sino-French War

The Sino-French War, also known as the Tonkin War, was a limited conflict fought from August 1884 to April 1885 between the French Third Republic and Qing China for influence in Vietnam. There was no declaration of war.

The Chinese armies performed better than in their other nineteenth-century wars. Although French forces emerged victorious from most engagements, the Chinese scored noteworthy successes on land, notably forcing the French to hastily withdraw from occupied Lạng Sơn in the late stages of the war, thus regaining control of the town and its surroundings. However, a lack of foreign support, French naval supremacy, and northern threats posed by Russia and Japan forced China to enter negotiations.

China ceded to France its sphere of influence over Northern and Central Vietnam, which respectively became the protectorates of Tonkin and Annam. Both sides ratified the Treaty of Tientsin and no diplomatic gain was reaped by either nation. On another note, the war strengthened the dominance of Empress Dowager Cixi over the Chinese government but France securing its strategic objective did not prevent the collapse of French Prime Minister Jules Ferry's government for whom the Tonkin Affair was ignominious.

Prelude
French interest in northern Vietnam dated from the late 18th century, when the political Catholic priest Pigneau de Behaine recruited French volunteers to fight for Nguyễn Ánh and help begin the Nguyễn dynasty, in an attempt to gain privileges for France and for the Roman Catholic Church. France began its colonial campaign in 1858, annexing several southern provinces in 1862 to form the colony of Cochinchina.

French explorers followed the course of the Red River through northern Vietnam to its source in Yunnan, arousing hopes for a profitable trade route with China that could bypass the treaty ports of the Chinese coastal provinces. The main obstacle to this idea, the Black Flag Army – a well-organized private army led by the formidable Liu Yongfu – was levying exorbitant "taxes" on Red River trade between Sơn Tây and Lào Cai on the Yunnan border.

In 1873, a small French force commanded by Lieutenant de Vaisseau Francis Garnier, exceeding his instructions, attacked northern Vietnam. Following a series of French victories against the Vietnamese, the Vietnamese government called on Liu Yongfu's Black Flags, who defeated Garnier's force beneath the walls of Hanoi. Garnier was killed in this battle, and the French government later disavowed his expedition.

Henri Rivière's expedition in Tonkin

In 1881, French Commandant Henri Rivière was sent with a small military force to Hanoi to investigate Vietnamese complaints about the activities of French merchants. In defiance of the instructions of his superiors, Rivière stormed the citadel of Hanoi on 25 April 1882. Although Rivière subsequently returned the citadel to Vietnamese control, his recourse to force provoked alarm both in Vietnam and in China.

The Vietnamese government, unable to confront Rivière with its own ramshackle army, once again enlisted the help of Liu Yongfu, whose well-trained and seasoned Black Flag soldiers would prove a thorn in the side of the French. The Vietnamese also bid for Chinese support. Vietnam had long been a tributary state of China, and China agreed to arm and support the Black Flags, and to covertly oppose French operations in Tonkin.

The Qing court also sent a strong signal to the French that China would not allow Tonkin to fall under French control. In the summer of 1882, troops of the Chinese Yunnan Army and Guangxi Army crossed the border into Tonkin, occupying Lạng Sơn, Bắc Ninh, Hưng Hóa and other towns. The French minister to China, Frédéric Bourée, was so alarmed by the prospect of war with China that in November and December he negotiated a deal with the Chinese statesman Li Hongzhang to divide Tonkin into French and Chinese spheres of influence. Neither of the parties to these negotiations consulted the Vietnamese.

Rivière, disgusted at the deal cut by Bourée, decided early in 1883 to force the issue. He had recently been sent a battalion of marine infantry from France, giving him just enough men to venture beyond Hanoi. On 27 March 1883, to secure his line of communications from Hanoi to the coast, Rivière captured the citadel of Nam Định with a force of 520 French soldiers under his personal command. During his absence at Nam Định, the Black Flags and Vietnamese made an attack on Hanoi, but Chef de Bataillon Berthe de Villers repulsed them in the Battle of Gia Cuc (Gia Quất) on 28 March. Rivière jubilantly reacted: 'This will force them to take forward their Tonkin Question!'

Rivière had perfect timing. He had expected to be cashiered for his capture of Nam Định; instead he found himself the hero of the hour. There had recently been a change of government in France, and the new administration of Jules Ferry strongly favoured colonial expansion. It therefore decided to back Rivière. Ferry and Foreign Minister Paul-Armand Challemel-Lacour denounced Bourée's agreement with Li Hongzhang and recalled the hapless French minister. They also made it clear to the Chinese that they were determined to place Tonkin under French protection. In April 1883, realising that the Vietnamese lacked the means of resisting the French effectively, the Chinese civil Mandarin Tang Jingsong (唐景崧) persuaded Liu Yongfu to take the field against Rivière with the Black Flag Army. This resulted in a year of Liu Yongfu's forces fighting an unconventional war.

On 10 May 1883 Liu Yongfu challenged the French to battle in a taunting message widely placarded on the walls of Hanoi. On 19 May Rivière confronted the Black Flags in the Battle of Paper Bridge, and the French suffered a disastrous defeat. Rivière's small force (around 450 men) attacked a strong Black Flag defensive position near the village of Cầu Giấy, a few miles to the west of Hanoi, known to the French as Paper Bridge (Pont de Papier). After initial successes the French were eventually enveloped on both wings; only with difficulty could they regroup and fall back to Hanoi. Rivière, Berthe de Villers and several other senior officers were killed in this action.

French intervention in Tonkin
Rivière's death produced an angry reaction in France. Reinforcements were rushed to Tonkin, a threatened attack by the Black Flags on Hanoi was averted, and the military situation was stabilised.

Protectorate over Tonkin
On 20 August 1883 Admiral Amédée Courbet, who had recently been appointed to the command of the newly formed Tonkin Coasts Naval Division, stormed the forts which guarded the approaches to the Vietnamese capital Huế in the Battle of Thuận An, and forced the Vietnamese government to sign the Treaty of Huế, placing Tonkin under French protection.

At the same time the new commander of the Tonkin expeditionary corps, General Bouët, attacked the Black Flag positions on the Day River. Although the French mauled the Black Flag Army in the Battle of Phủ Hoài (15 August) and the Battle of Palan (1 September), they were unable to capture all of Liu Yongfu's positions, and in the eyes of the world the battles were tantamount to French defeats. Bouët was widely held to have failed in his mission, and resigned in September 1883. In the event, severe flooding eventually forced Liu Yongfu to abandon the line of the Day River and fall back to the fortified city of Sơn Tây, several miles to the west.

Confrontation between France and China
The French prepared for a major offensive at the end of the year to annihilate the Black Flags, and tried to persuade China to withdraw its support for Liu Yongfu, while attempting to win the support of the other European powers for the projected offensive. However, negotiations in Shanghai in July 1883 between the French minister Arthur Tricou and Li Hongzhang were terminated by the Qing government on receipt of a naively optimistic assessment by Marquis Zeng Jize, the Chinese minister to Paris, that the French government had no stomach for a full-scale war with China. Jules Ferry and the French foreign minister Paul-Armand Challemel-Lacour met a number of times in the summer and autumn of 1883 with Marquis Zeng in Paris, but these parallel diplomatic discussions also proved abortive. The Chinese stood firm, and refused to withdraw substantial garrisons of Chinese regular troops from Sơn Tây, Bắc Ninh and Lạng Sơn, despite the likelihood that they would be shortly engaged in battle against the French. As war with China seemed increasingly likely, the French persuaded the German government to delay the release of Dingyuan and Zhenyuan, two modern battleships then being constructed in German shipyards for China's Beiyang Fleet. Meanwhile, the French consolidated their hold on the Delta by establishing posts at Quảng Yên, Hưng Yên and Ninh Bình.

The growing tension between France and China gave rise to anti-foreign demonstrations inside China during the autumn of 1883. The most serious incidents took place in Guangdong province, where Europeans were most prominent. Attacks were made on the property of European merchants in Guangzhou and on Shamian island. Several European powers, including France, sent gunboats to Guangzhou to protect their nationals.

Sơn Tây and Bac Ninh
The French accepted that an attack on Liu Yongfu would probably result in an undeclared war with China, but calculated that a quick victory in Tonkin would force the Chinese to accept a fait accompli. Command of the Tonkin Campaign was entrusted to Courbet, who attacked Sơn Tây in December 1883. The Sơn Tây Campaign was the fiercest campaign the French had yet fought in Tonkin. Although the Chinese and Vietnamese contingents at Son Tay played little part in the defence, Liu Yongfu's Black Flags fought ferociously to hold the city. On 14 December the French assaulted the outer defences of Sơn Tây at Phù Sa, but were thrown back with heavy casualties. Hoping to exploit Courbet's defeat, Liu Yongfu attacked the French lines the same night, but the Black Flag attack also failed disastrously. After resting his troops on 15 December, Courbet again assaulted the defences of Sơn Tây on the afternoon of 16 December. This time the attack was thoroughly prepared by artillery, and delivered only after the defenders had been worn down. At 5 p.m. a Foreign Legion battalion and a battalion of marine fusiliers captured the western gate of Sơn Tây and fought their way into the town. Liu Yongfu's garrison withdrew to the citadel, and evacuated Sơn Tây under cover of darkness several hours later. Courbet had achieved his objective, but at considerable cost. French casualties at Sơn Tây were 83 dead and 320 wounded. The fighting at Sơn Tây also took a terrible toll of the Black Flags, and in the opinion of some observers broke them once and for all as a serious fighting force. Liu Yongfu felt that he had been deliberately left to bear the brunt of the fighting by his Chinese and Vietnamese allies, and determined never again to expose his troops so openly.

In March 1884, the French renewed their offensive under the command of General Charles-Théodore Millot, who took over responsibility for the land campaign from Courbet after the fall of Sơn Tây. Reinforcements from France and the African colonies had now raised the strength of the Tonkin Expeditionary Corps to over 10,000 men, and Millot organised this force into two brigades. The 1st Brigade was commanded by General Louis Brière de l'Isle, who had earlier made his reputation as governor of Senegal, and the 2nd Brigade was commanded by the charismatic young Foreign Legion general François de Négrier, who had recently quelled a serious Arab rebellion in Algeria. The French target was Bắc Ninh, garrisoned by a strong force of regular Chinese troops of the Guangxi Army. The Bắc Ninh Campaign was a walkover for the French. Morale in the Chinese army was low, and Liu Yongfu was careful to keep his experienced Black Flags out of danger. Millot bypassed Chinese defences to the southwest of Bắc Ninh, and assaulted the city on 12 March from the southeast, with complete success. The Guangxi Army put up a feeble resistance, and the French took the city with ease, capturing large quantities of ammunition and a number of brand new Krupp cannon.

The Tientsin Accord and the Treaty of Huế
The defeat at Bắc Ninh, coming close on the heels of the fall of Sơn Tây, strengthened the hand of the moderate element in the Chinese government and temporarily discredited the extremist 'Purist' party led by Zhang Zhidong, which was agitating for a full-scale war against France. Further French successes in the spring of 1884, including the Capture of Hưng Hóa and Thái Nguyên, convinced the Empress Dowager Cixi that China should come to terms, and an accord was reached between France and China in May. The negotiations took place in Tianjin (Tientsin). Li Hongzhang, the leader of the Chinese moderates, represented China; and Captain François-Ernest Fournier, commander of the French cruiser Volta, represented France. The Tientsin Accord, concluded on 11 May 1884, provided for Chinese recognition of the French protectorate over Annam and Tonkin and withdrawal of Chinese troops from Tonkin, in return for a comprehensive treaty that would settle details of trade and commerce between France and China and provide for the demarcation of its disputed border with Vietnam.

On 6 June the French followed up their accord with China by concluding a fresh Treaty of Huế with the Vietnamese, which established a French protectorate over both Annam and Tonkin and allowed the French to station troops at strategic points in Vietnamese territory and to install residents in the main towns. The signature of the treaty was accompanied by an important symbolic gesture. The seal presented by the emperor of China several decades earlier to the Vietnamese emperor Gia Long was melted down in the presence of the French and Vietnamese plenipotentiaries, betokening the renunciation by Vietnam of its traditional links with China.

Fournier was not a professional diplomat, and the Tientsin Accord contained several loose ends. Crucially, it failed to explicitly state a deadline for the Chinese troop withdrawal from Tonkin. The French asserted that the troop withdrawal was to take place immediately, while the Chinese argued that the withdrawal was contingent upon the conclusion of the comprehensive treaty. In fact, the Chinese stance was an ex post facto rationalisation, designed to justify their unwillingness or inability to put the terms of the accord into effect. The accord was extremely unpopular in China, and provoked an immediate backlash. The war party called for Li Hongzhang's impeachment, and his political opponents intrigued to have orders sent to the Chinese troops in Tonkin to hold their positions.

The Bắc Lệ ambush
Li Hongzhang hinted to the French that there might be difficulties in enforcing the accord, but nothing specific was said. The French assumed that the Chinese troops would leave Tonkin as agreed, and made preparations for occupying the border towns of Lạng Sơn, Cao Bằng and Thất Khê. In early June 1884 a French column under the command of Lieutenant-Colonel Alphonse Dugenne advanced to occupy Lạng Sơn. On 23 June, near the small town of Bắc Lệ, the French encountered a strong detachment of the Guangxi Army ensconced in a defensive position behind Thương River. In view of the diplomatic significance of this discovery, Dugenne should have reported the presence of the Chinese force to Hanoi and waited for further instructions. Instead, he gave the Chinese an ultimatum, and on their refusal to withdraw resumed his advance. The Chinese opened fire on the advancing French, precipitating a two-day battle in which Dugenne's column was encircled and seriously mauled. Dugenne eventually fought his way out of the Chinese encirclement and extricated his small force.

When news of the Bắc Lệ ambush reached Paris, there was fury at what was perceived as blatant Chinese treachery. Ferry's government demanded an apology, an indemnity, and the immediate implementation of the terms of the Tianjin Accord. The Chinese government agreed to negotiate, but refused to apologise or pay any indemnity. The mood in France was against compromise, and although negotiations continued throughout July, Courbet was ordered to take his squadron to Fuzhou (Foochow). He was instructed to prepare to attack the Chinese Fujian Fleet in the harbour and to destroy the Foochow Navy Yard. Meanwhile, as a preliminary demonstration of what would follow if the Chinese were recalcitrant, Rear Admiral Sébastien Lespès destroyed three Chinese shore batteries in the port of Keelung in northern Formosa (Taiwan) by naval bombardment on 5 August. The French put a landing force ashore to occupy Keelung and the nearby coal mines at Pei-tao (Pa-tou), as a 'pledge' (gage) to be bargained against a Chinese withdrawal from Tonkin, but the arrival of a large Chinese army under the command of the imperial commissioner Liu Mingchuan forced it to re-embark on 6 August.

Fuzhou and the Min River

Negotiations between France and China broke down in mid-August, and on 22 August Courbet was ordered to attack the Chinese fleet at Fuzhou. In the Battle of Fuzhou (also known as the Battle of the Pagoda Anchorage) on 23 August 1884, the French took their revenge for the Bắc Lệ Ambush. In a two-hour engagement watched with professional interest by neutral British and American vessels (the battle was one of the first occasions on which the spar torpedo was successfully deployed), Courbet's Far East Squadron annihilated China's outclassed Fujian fleet and severely damaged the Foochow Navy Yard (which, ironically, had been built under the direction of the French administrator Prosper Giquel). Nine Chinese ships were sunk in less than an hour, including the corvette Yangwu, the flagship of the Fujian fleet. Chinese losses may have amounted to 3,000 dead, while French losses were minimal. Courbet then successfully withdrew down the Min River to the open sea, destroying several Chinese shore batteries from behind as he took the French squadron through the Min'an and Jinpai passes.

Riots in Hong Kong
The French attack at Fuzhou effectively ended diplomatic contacts between France and China. Although neither country declared war, the dispute would now be settled on the battlefield. The news of the destruction of the Fujian fleet was greeted by an outbreak of patriotic fervour in China, marred by attacks on foreigners and foreign property. There was considerable sympathy for China in Europe, and the Chinese were able to hire a number of British, German and American army and navy officers as advisers.

Patriotic indignation spread to the British colony of Hong Kong. In September 1884 dock workers in Hong Kong refused to repair the French ironclad La Galissonnière, which had suffered shell damage in the August naval engagements. The strike collapsed at the end of September, but the dock workers were prevented from resuming their business by other groups of Chinese workers, including longshoremen, sedan chair carriers and rickshawmen. An attempt by the British authorities to protect the dock workers against harassment resulted in serious rioting on 3 October, during which at least one rioter was shot dead and several Sikh constables were injured. The British suspected, with good reason, that the disturbances had been fomented by the Chinese authorities in Guangdong province.

French occupation of Keelung

Meanwhile, the French decided to put pressure on China by landing an expeditionary corps in northern Formosa to seize Keelung and Tamsui, redeeming the failure of 6 August and finally winning the 'pledge' they sought. On 1 October Lieutenant-Colonel Bertaux-Levillain landed at Keelung with a force of 1,800 marine infantry, forcing the Chinese to withdraw to strong defensive positions which had been prepared in the surrounding hills. The French force was too small to advance beyond Keelung, and the Pei-tao coal mines remained in Chinese hands. Meanwhile, after an ineffective naval bombardment on 2 October, Lespès attacked the Chinese defences at Tamsui with 600 sailors from his squadron's landing companies on 8 October, but was decisively repulsed by forces under the command of the Fujianese general Sun Kaihua (孫開華). As a result, French control over Formosa was limited to the town of Keelung, far short of what had been hoped for.

Blockade of Taiwan
Towards the end of 1884 the French were able to enforce a limited blockade of the northern Formosan ports of Keelung and Tamsui and the prefectural capital Taiwan (now Tainan) and the southern port Takow (Kaohsiung). In early January 1885 the Formosa expeditionary corps, now under the command of Colonel Jacques Duchesne, was substantially reinforced with two battalions of infantry, bringing its total strength to around 4,000 men. Meanwhile, drafts from the Hunan Army and Anhui Army had brought the strength of Liu Mingchuan's defending army to around 25,000 men. Although severely outnumbered, the French captured a number of minor Chinese positions to the southeast of Keelung at the end of January 1885, but were forced to halt offensive operations in February due to incessant rain.

The blockade succeeded in part because the northern Beiyang Fleet, commanded by Li Hongzhang, denied help to the southern Nanyang Fleet. No Beiyang ships were sent to battle the French. This led the Navy to fail. The most advanced ships were reserved for the northern Chinese fleet by Li Hongzhang, he did not even "consider" using this well equipped fleet to attack the French, since he wanted to make sure it was always under his command. China's north and south had rivalries and the government was split into different parties. China did not have a single admiralty in command of the navy and the northern and southern fleets refused to cooperate, guaranteeing French control of the seas during the war. Tianjin's northern naval academy also drained southern China of potential sailors, since they enlisted in northern China instead.

Shipu Bay, Zhenhai Bay and the rice blockade

Although the Formosa expeditionary corps remained confined in Keelung, the French scored important successes elsewhere in the spring of 1885. Courbet's squadron had been reinforced substantially since the start of the war, and he now had considerably more ships at his disposal than in October 1884. In early February 1885 part of his squadron left Keelung to head off a threatened attempt by part of the Chinese Nanyang Fleet (Southern Seas fleet) to break the French blockade of Formosa. On 11 February Courbet's task force met the cruisers Kaiji, Nanchen and Nanrui, three of the most modern ships in the Chinese fleet, near Shipu Bay, accompanied by the frigate Yuyuan and the composite sloop Chengqing. The Chinese scattered at the French approach, and while the three cruisers successfully made their escape, the French succeeded in trapping Yuyuan and Chengqing in Shipu Bay. On the night of 14 February, in the Battle of Shipu, the French attacked the Chinese vessels with two torpedo launches. During a brief engagement inside the bay, Yuyuan was seriously damaged by torpedoes and Chengqing was hit by Yuyuan's fire. Both ships were subsequently scuttled by the Chinese. The French torpedo launches escaped almost without loss.

Courbet followed up this success on 1 March by locating Kaiji, Nanchen and Nanrui, which had taken refuge with four other Chinese warships in Zhenhai Bay, near the port of Ningbo. Courbet considered forcing the Chinese defences, but after testing its defenses finally decided to guard the entrance to the bay to keep the enemy vessels bottled up there for the duration of hostilities. A brief and inconclusive skirmish between the French cruiser Nielly and the Chinese shore batteries on 1 March enabled the Chinese general Ouyang Lijian (歐陽利見), charged with the defence of Ningbo, to claim the so-called 'Battle of Zhenhai' as a defensive victory.

In February 1885, under diplomatic pressure from China, Britain invoked the provisions of the 1870 Foreign Enlistment Act and closed Hong Kong and other ports in the Far East to French warships. The French government retaliated by ordering Courbet to implement a 'rice blockade' of the Yangzi River, hoping to bring the Qing court to terms by provoking serious rice shortages in northern China. The rice blockade severely disrupted the transport of rice by sea from Shanghai and forced the Chinese to carry it overland, but the war ended before the blockade seriously affected China's economy.

French victories in the delta

Meanwhile, the French army in Tonkin was also putting severe pressure on the Chinese forces and their Black Flag allies. General Millot, whose health was failing, resigned as general-in-chief of the Tonkin expeditionary corps in early September 1884 and was replaced by General Brière de l'Isle, the senior of his two brigade commanders. Brière de l'Isle's first task was to beat off a major Chinese invasion of the Red River Delta. In late September 1884, large detachments of the Guangxi Army advanced from Langson and probed into the Lục Nam valley, announcing their presence by ambushing the French gunboats Hache and Massue on 2 October. Brière de l'Isle responded immediately, transporting nearly 3,000 French soldiers to the Lục Nam valley aboard a flotilla of gunboats and attacking the Chinese detachments before they could concentrate. In the Kép Campaign, (2 to 15 October 1884), three French columns under the overall command of General de Négrier fell upon the separated detachments of the Guangxi Army and successively defeated them in engagements at Lam Cốt (6 October), Kép (8 October) and Chũ (10 October). The second of these battles was marked by bitter close-quarter fighting between French and Chinese troops, and de Négrier's soldiers suffered heavy casualties storming the fortified village of Kép. The exasperated victors shot or bayoneted scores of wounded Chinese soldiers after the battle, and reports of French atrocities at Kép shocked public opinion in Europe. In fact, prisoners were rarely taken by either side during the Sino-French War, and the French were equally shocked by the Chinese habit of paying a bounty for severed French heads.

In the wake of these French victories the Chinese fell back to Bắc Lệ and Đồng Sông, and de Négrier established important forward positions at Kép and Chũ, which threatened the Guangxi Army's base at Lạng Sơn. Chũ was only a few miles southwest of the Guangxi Army's advanced posts at Đồng Sông, and on 16 December a strong Chinese raiding detachment ambushed two companies of the Foreign Legion just to the east of Chũ, at Hà Hồ. The legionnaires fought their way out of the Chinese encirclement, but suffered a number of casualties and had to abandon their dead on the battlefield. De Négrier immediately brought up reinforcements and pursued the Chinese, but the raiders made good their retreat to Đồng Sông.

Shortly after the October engagements against the Guangxi Army, Brière de l'Isle took steps to resupply the western outposts of Hưng Hóa, Thái Nguyên and Tuyên Quang, which were coming under increasing threat from Liu Yongfu's Black Flags and Tang Jingsong's Yunnan Army. On 19 November, in the Battle of Yu-Oc, a column making for Tuyên Quang under the command of Duchesne was ambushed in the Yu-Oc gorge by the Black Flags but was able to fight its way through to the beleaguered post. The French also sealed off the eastern Delta from raids by Chinese guerillas based in Guangdong by occupying Tiên Yên, Đông Triều and other strategic points, and by blockading the Cantonese port of Beihai (Pak-Hoi). They also conducted sweeps along the lower course of the Red River to dislodge Annamese guerilla bands from bases close to Hanoi. These operations enabled Brière de l'Isle to concentrate the bulk of the Tonkin expeditionary corps around Chũ and Kép at the end of 1884, to advance on Lạng Sơn as soon as the word was given.

Lạng Sơn Campaign

French strategy in Tonkin was the subject of a bitter debate in the Chamber of Deputies in late December 1884. The army minister General Jean-Baptiste-Marie Campenon argued that the French should consolidate their hold on the Delta. His opponents urged an all-out offensive to throw the Chinese out of northern Tonkin. The debate culminated in Campenon's resignation and his replacement as army minister by the hawkish General Jules Louis Lewal, who immediately ordered Brière de l'Isle to capture Lạng Sơn. The campaign would be launched from the French forward base at Chũ, and on 3 and 4 January 1885 General de Négrier attacked and defeated a substantial detachment of the Guangxi Army that had concentrated around the nearby village of Núi Bop to try to disrupt the French preparations. De Nègrier's victory at Núi Bop, won at odds of just under one to ten, was regarded by his fellow-officers as the most spectacular professional triumph of his career.

It took the French a month to complete their preparations for the Lạng Sơn Campaign. Finally, on 3 February 1885, Brière de l'Isle began his advance from Chũ with a column of just under 7,200 troops, accompanied by 4,500 coolies. In ten days the column advanced to the outskirts of Lang Son. The troops were burdened with the weight of their provisions and equipment, and had to march through extremely difficult country. They also had to fight fierce actions to overrun stoutly defended Chinese positions, at Tây Hòa (4 February), Hạ Hòa (5 February) and Đồng Sông (6 February). After a brief pause for breath at Đồng Sông, the expeditionary corps pressed on towards Lạng Sơn, fighting further actions at Quao Pass (9 February), and Vy village (11 February). On 12 February, in a costly but successful battle, the Turcos and marine infantry of Colonel Laurent Giovanninelli's 1st Brigade stormed the main Chinese defences at Bắc Việt, several kilometres to the south of Lạng Sơn. On 13 February, the French column entered Lạng Sơn which the Chinese abandoned after fighting a token rearguard action at the nearby village of Kỳ Lừa.

Siege and relief of Tuyên Quang

The capture of Lang Son allowed substantial French forces to be diverted further west to relieve the small and isolated French garrison in Tuyên Quang, which had been placed under siege in November 1884 by Liu Yongfu's Black Flag Army and Tang Jingsong's Yunnan Army. The Siege of Tuyên Quang was the most evocative confrontation of the Sino-French War. The Chinese and Black Flags sapped methodically up to the French positions, and in January and February 1885 breached the outer defences with mines and delivered seven separate assaults on the breach. The Tuyên Quang garrison, 400 legionnaires and 200 Tonkinese auxiliaries under the command of chef de bataillon Marc-Edmond Dominé, beat off all attempts to storm their positions, but lost over a third of their strength (50 dead and 224 wounded) sustaining a heroic defence against overwhelming odds. By mid-February it was clear that Tuyên Quang would fall unless it was relieved immediately.

Leaving de Négrier at Lang Son with the 2nd Brigade, Brière de l'Isle personally led Giovanninelli's 1st Brigade back to Hanoi, and then upriver to the relief of Tuyên Quang. The brigade, reinforced at Phủ Doãn, on 24 February by a small column from Hưng Hóa under the command of Lieutenant-Colonel de Maussion, found the route to Tuyên Quang blocked by a strong Chinese defensive position at Hòa Mộc. On 2 March 1885 Giovanninelli attacked the left flank of the Chinese defensive line. The Battle of Hòa Mộc was the most fiercely fought action of the war. Two French assaults were decisively repulsed, and although the French eventually stormed the Chinese positions, they suffered very high casualties (76 dead and 408 wounded). Nevertheless, their costly victory cleared the way to Tuyên Quang. The Yunnan Army and the Black Flags raised the siege and drew off to the west, and the relieving force entered the beleaguered post on 3 March. Brière de l'Isle praised the courage of the hard-pressed garrison in a widely quoted order of the day. 'Today, you enjoy the admiration of the men who have relieved you at such heavy cost. Tomorrow, all France will applaud you!'

Bang Bo, Kỳ Lừa and the retreat from Lạng Sơn
Before his departure for Tuyên Quang, Brière de l'Isle ordered de Négrier to press on from Lạng Sơn towards the Chinese border and expel the battered remnants of the Guangxi Army from Tonkinese soil. After resupplying the 2nd Brigade with food and ammunition, de Négrier defeated the Guangxi Army at the Battle of Đồng Đăng on 23 February 1885 and cleared it from Tonkinese territory. For good measure, the French crossed briefly into Guangxi province and blew up the 'Gate of China', an elaborate Chinese customs building on the Tonkin-Guangxi border. They were not strong enough to exploit this victory, however, and the 2nd Brigade returned to Lạng Sơn at the end of February.

By early March, in the wake of the French victories at Hoà Mộc and Đồng Đăng, the military situation in Tonkin had reached a temporary stalemate. Giovanninelli's 1st Brigade faced Tang Qingsong's Yunnan Army around Hưng Hóa and Tuyên Quang, while de Négrier's 2nd Brigade at Lạng Sơn faced Pan Dingxin's Guangxi Army. Neither Chinese army had any realistic prospect of launching an offensive for several weeks, while the two French brigades that had jointly captured Lạng Sơn in February were not strong enough to inflict a decisive defeat on either Chinese army separately. Meanwhile, the French government was pressuring Brière de l'Isle to send the 2nd Brigade across the border into Guangxi province, in the hope that a threat to Chinese territory would force China to sue for peace. Brière de l'Isle and de Négrier examined the possibility of a campaign to capture the major Chinese military depot at Longzhou (Lung-chou, 龍州), 60 kilometres beyond the border, but on 17 March Brière de l'Isle advised the army ministry in Paris that such an operation was beyond his strength. Substantial French reinforcements reached Tonkin in the middle of March, giving Brière de l'Isle a brief opportunity to break the stalemate. He moved the bulk of the reinforcements to Hưng Hóa to reinforce the 1st Brigade, intending to attack the Yunnan Army and drive it back beyond Yen Bay. While he and Giovanninelli drew up plans for a western offensive, he ordered de Négrier to hold his positions at Lang Son.

On 23 and 24 March the 2nd Brigade, only 1,500 men strong, fought a fierce action with over 25,000 troops of the Guangxi Army entrenched near Zhennanguan on the Chinese border. The Battle of Bang Bo (named by the French from the Vietnamese pronunciation of Hengpo, a village in the centre of the Chinese position where the fighting was fiercest), is normally known as the Battle of Zhennan Pass in China. The French took a number of outworks on 23 March, but failed to take the main Chinese positions on 24 March and were fiercely counterattacked in their turn. Although the French made a fighting withdrawal and prevented the Chinese from piercing their line, casualties in the 2nd Brigade were relatively heavy (70 dead and 188 wounded) and there were ominous scenes of disorder as the defeated French regrouped after the battle. As the brigade's morale was precarious and ammunition was running short, de Négrier decided to fall back to Lạng Sơn.

The coolies abandoned the French who were already suffering supply issues. The Chinese advanced slowly in pursuit, and on 28 March de Négrier fought a battle at Kỳ Lừa in defence of Lạng Sơn. Rested, recovered and fighting behind breastworks, the French successfully held their positions and inflicted crippling casualties on the Guangxi Army. French casualties at Kỳ Lừa were 7 men killed and 38 wounded. The Chinese left 1,200 corpses on the battlefield, and a further 6,000 Chinese soldiers may have been wounded.

Towards the end of the battle de Négrier was seriously wounded in the chest while scouting the Chinese positions. He was forced to hand over command to his senior regimental commander, Lieutenant-Colonel Paul-Gustave Herbinger. Herbinger was a noted military theoretician who had won a respectable battlefield reputation during the Franco-Prussian War, but was quite out of his depth as a field commander in Tonkin. Several French officers had already commented scathingly on his performance during the Lạng Sơn campaign and at Bang Bo, where he had badly bungled an attack on the Chinese positions.

Upon assuming command of the brigade, Herbinger panicked. Despite the evidence that the Chinese had been decisively defeated and were streaming back in disarray towards the Chinese frontier, he convinced himself that they were preparing to encircle Lạng Sơn and cut his supply line. Disregarding the appalled protests of some of his officers, he ordered the 2nd Brigade to abandon Lạng Sơn on the evening of 28 March and retreat to Chũ. The retreat from Lạng Sơn was conducted without loss and with little interference from the Chinese, but Herbinger set an unnecessarily punishing pace and abandoned considerable quantities of food, ammunition and equipment. When the 2nd Brigade eventually rallied at Chũ, its soldiers were exhausted and demoralised. Meanwhile, the Chinese general Pan Dingxin (潘鼎新), informed by sympathisers in Lạng Sơn that the French were in full retreat, promptly turned his battered army around and reoccupied Lạng Sơn on 30 March. The Chinese were in no condition to pursue the French to Chũ, and contented themselves with a limited advance to Đồng Sông. The retreat was seen as a Chinese victory.

There was also bad news for the French from the western front. On 23 March, in the Battle of Phu Lam Tao, a force of Chinese regulars and Black Flags surprised and routed a French zouave battalion that had been ordered to scout positions around Hưng Hóa in preparation for Giovanninelli's projected offensive against the Yunnan Army.

Collapse of Ferry's government

Neither reverse was serious, but in the light of Herbinger's alarming reports Brière de l'Isle believed the situation to be much worse than it was, and sent an extremely pessimistic telegram back to Paris on the evening of 28 March. The political effect of this telegram was momentous. Ferry's immediate reaction was to reinforce the army in Tonkin, and indeed Brière de l'Isle quickly revised his estimate of the situation and advised the government that the front could soon be stabilised. However, his second thoughts came too late. When his first telegram was made public in Paris there was an uproar in the Chamber of Deputies. A motion of no confidence was tabled, and Ferry's government fell on 30 March. The 'Tonkin Affair', as this humiliating blow to French policy in Tonkin was immediately dubbed, effectively ended Ferry's distinguished career in French politics. He would never again become Premier, and his political influence during the rest of his career would be severely limited. His successor, Henri Brisson, promptly concluded peace with China. The Chinese government agreed to implement the Tientsin Accord (implicitly recognising the French protectorate over Tonkin), and the French government dropped its demand for an indemnity for the Bắc Lệ ambush. A peace protocol ending hostilities was signed on 4 April, and a substantive peace treaty was signed on 9 June at Tianjin by Li Hongzhang and the French minister Jules Patenôtre.

Japan and Russia's threat to join the war against China and the Northern fleet
Japan had taken advantage of China's distraction with France to intrigue in the Chinese protectorate state of Korea. In December 1884 the Japanese sponsored the 'Gapsin Coup', bringing Japan and China to the brink of war. Thereafter the Qing court considered that the Japanese were a greater threat to China than the French. In January 1885 the Empress Dowager directed her ministers to seek an honourable peace with France. Secret talks between the French and Chinese were held in Paris in February and March 1885, and the fall of Ferry's ministry removed the last remaining obstacles to a peace.

The Korean issue led to Japan and Russia having deteriorating relations with China, and in northern China Japan potentially threatened to join the war with France against China. North China was menaced by the prospect of Japan and Russia joining in the war which led to China seeking a peace deal even though Chinese forces defeated the French on land.

Throughout the war Li Hongzhang rejected pleas he deploy the Beiyang fleet against the French, citing the Korean issue and threat of Japanese intervention. In truth, Li Hongzhang wanted to maintain direct control of the fleet by keeping it anchored in northern China and away from combat where it could potentially slip out of his personal control.

Final engagements
Ironically, while the war was being decided on the battlefields of Tonkin and in Paris, the Formosa expeditionary corps won two spectacular victories in March 1885. In a series of actions fought between 4 and 7 March, Duchesne broke the Chinese encirclement of Keelung with a flank attack delivered against the east of the Chinese line, capturing the key position of La Table and forcing the Chinese to withdraw behind the Keelung River. Duchesne's victory sparked a brief panic in Taipei, but the French were not strong enough to advance beyond their bridgehead. The Keelung Campaign now reached a point of equilibrium. The French were holding a virtually impregnable defensive perimeter around Keelung but could not exploit their success, while Liu Mingchuan's army remained in presence just beyond their advanced positions.

However, the French had one card left to play. Duchesne's victory enabled Courbet to detach a marine infantry battalion from the Keelung garrison to capture the Pescadores Islands in late March. Strategically, the Pescadores campaign was an important victory, which would have prevented the Chinese from further reinforcing their army in Formosa, but it came too late to affect the outcome of the war. Future French operations were cancelled on the news of Herbinger's retreat from Lạng Sơn on 28 March, and Courbet was on the point of evacuating Keelung to reinforce the Tonkin expeditionary corps, leaving only a minimum garrison at Makung in the Pescadores, when hostilities were ended in April by the conclusion of preliminaries of peace.

The news of the peace protocol of 4 April did not reach the French and Chinese forces in Tonkin for several days, and the final engagement of the Sino-French War took place on 14 April 1885 at Kép, where the French beat off a half-hearted Chinese attack on their positions. Meanwhile, Brière de l'Isle had reinforced the key French posts at Hưng Hóa and Chũ, and when hostilities ended in the third fortnight of April the French were standing firm against both the Guangxi and Yunnan armies. Although Brière de l'Isle was planning to attack the Yunnan Army at Phu Lam Tao to avenge the defeat of 23 March, many French officers doubted whether this offensive would have succeeded. At the same time, the Chinese armies had no prospect whatsoever of driving the French from Hưng Hóa or Chũ. Militarily, the war in Tonkin ended in a stalemate.

The peace protocol of 4 April required the Chinese to withdraw their armies from Tonkin, and the French continued to occupy Keelung and the Pescadores for several months after the end of hostilities, as a surety for Chinese good faith. Courbet fell seriously ill during this occupation, and on 11 June died aboard his flagship Bayard in Makung harbour. Meanwhile, the Chinese punctiliously observed the terms of the peace settlement, and by the end of June 1885 both the Yunnan and Guangxi armies had evacuated Tonkin. Liu Yongfu's Black Flag Army also withdrew from Tonkinese territory.

Continuation of insurgency
Liu Yongfu's Chinese Black Flag forces continued to harass and fight the French in Tonkin after the end of the Sino-French War.

With support from China, Vietnamese and Chinese freebooters fought against the French in Lạng Sơn in the 1890s. They were labelled "pirates" by the French. The Black Flags and Liu Yongfu in China received requests for assistance from Vietnamese anti-French forces.

In 1891, Goldthwaite's Geographical Magazine, Volumes 1–2 wrote, "FOUR months ago, a band of 500 pirates attacked the French residency at Chobo, in 'l'onkin. They beheaded the French resident, ransacked and burned the town, and killed many of the people." In 1906 the "Decennial Reports on the Trade, Navigation, Industries, Etc., of the Ports Open to Foreign Commerce in China and Corea, and on the Condition and Development of the Treaty Port Provinces ..., Volume 2" said "Piracy on the Tonkin border was very prevalent in the early years of the decade. Fortified frontier posts were established in 1893 by the Tonkin Customs at the most dangerous passes into China, for the purpose of repressing contraband, the importation of arms and ammunition, and specially the illicit traflic of women, children, and cattle, which the pirates raided in Tonkin and carried beyond the Chinese mountains with impunity. These posts were eventually handed over to the military authorities." In 1894, Around Tonkin and Siam wrote, "This, in my view, is too pessimist an estimate of the situation, a remark which also applies to the objection that these new roads facilitate the circulation of pirates. Defective as they may be, these roads must, it seems to me, be of service to cultivation and trade, and, therefore, in the long run to the pacification of the country." In 1893 "The Medical World, Volume 11" said ''"Captain Hugot, of the Zouaves, was inclose pursuit of the infamous Thuyết, one of the most redoubtable, ferocious, and cunning of the Black Flag (Annamite pirates) leaders, the man who prepared and executed the ambuscade at Hue. The captain was just about to seize the person of the young pretender Hàm-Nghi, whom the Black Flags had recently proclaimed sovereign of Armani, when he was struck by several arrows, discharged by the body-guard of Hàm-Nghi. The wounds were all light, scarcely more than scratches, and no evil effect was feared at the time. After a few days, however, in spite of every care, the captain grew weaker, and it became apparent that he was suffering from the effects of arrow poison. He was removed as quickly and as tenderly as possible to Tánh-Hóa, where he died in horrible agony a few days later, in spite of the most scientific treatment and the most assiduous attention."— National Druggist. The 1892 "The Imperial and Asiatic Quarterly Review and Oriental and Colonial Record" said "The French port of Yến Long was surprised by Chinese and Annamite pirates and the troops driven out with loss."''

French attempts to secure an alliance with Japan

The French were well aware of China's sensitivities regarding Japan, and as early as June 1883, in the wake of Rivière's death at Paper Bridge, began angling for an alliance with Japan to offset their precarious military position in Tonkin. The French foreign minister Paul Challemel-Lacour believed that France "ought not to disdain the support which, at an appropriate moment, the attitude of Japan would be able to supply to our actions". In order to court the Japanese government, France offered to support Japan's pleas for revision of the unequal treaties of the Bakumatsu era, which provided extra-territoriality and advantageous tariffs to foreigners. Japan welcomed the offer of French support, but was reluctant to be drawn into a military alliance. Japan was in effect quite worried of the military might China represented, at least on paper, at that time. As the situation in Annam deteriorated however, France was even more anxious to obtain Japanese help.

After French difficulties in Taiwan, new attempts at negotiating an alliance were made with the Minister General Campenon meeting with General Miura Gorō, but Gorō remained ambiguous, encouraging France to continue to support Japan's drive for Treaty revision. Hopes for an alliance were reawakened in December 1884 when a clash occurred between China and Japan in Korea, when Japan supported the Gapsin coup d'état by Kim Ok-gyun against the pro-Chinese Korean government, prompting Ferry to request the French ambassador in Japan Sienkiewicz to approach the Japanese government with an offer. Sienkiewicz however remained extremely negative to the point of refraining from communicating Ferry's proposal. French interest faded in 1885 as the campaign in Tonkin progressed, while, on the contrary Japanese interest increased as the Japanese government and public opinion started to favour open conflict with China. The Sino-French War ended however without an alliance coming to fruition.

Political situation

Li Hongzhang and Zeng Jize were key Chinese officials in the negotiations between China, France, and Vietnam. At the time, Li was the viceroy of Zhili and chief minister of Beiyang. Zeng was the Chinese ambassador to France. Li favoured a quick settlement but Zeng talked of prolonging the war. The peace treaty of June 1885 gave the French control of Annam, the contested area of Indochina. They were obliged to evacuate Formosa and the Pescadores Islands (which Courbet had wanted to retain as a French counterweight to British Hong Kong), but the Chinese withdrawal from Tonkin left the way clear for them to reoccupy Lạng Sơn and to advance up the Red River to Lào Cai on the Yunnan–Tonkin border. In the years that followed the French crushed a vigorous Vietnamese resistance movement and consolidated their hold on Annam and Tonkin. In 1887, Cochinchina, Annam and Tonkin (the territories which comprise the modern state of Vietnam) and Cambodia were incorporated into French Indochina. They were joined a few years later by Laos, ceded to France by Siam at the conclusion of the Franco-Siamese crisis of 1893. France dropped demands for an indemnity from China.

Domestically, the unsatisfactory conclusion to the Sino-French War dampened enthusiasm for colonial conquest. The war had already destroyed Ferry's career, and his successor Henri Brisson also resigned in the wake of the acrimonious 'Tonkin Debate' of December 1885, in which Clemenceau and other opponents of colonial expansion nearly succeeded in securing a French withdrawal from Tonkin. In the end, the Chamber voted the 1886 credits to support the Tonkin expeditionary corps by 274 votes to 270.

Land
There are different interpretations for the significance of the military campaign on land. According to Bruce A. Elleman, the Chinese forces outnumbered the French, their weapons were modern, but their training was largely inferior. Although the Qing troops suffered initial losses, they also won victories (though fewer in number) and managed to push back French forces. The French withdrawal from Lang Són was seen by many as the result of panic and Qing forces captured Lang Són and its surrounding territory by early April 1885. Fighting ended on 4 April 1885 as a result of peace negotiations due to the Qing court's concerns about the economy, French naval supremacy, lack of foreign support, and northern threats posed by Russia and Japan. The call for peace seemed unbelievable to some Chinese contemporaries given the Chinese successes immediately prior. Ban Zhao, a front-line commander, reported that his subordinates begged for them to continue their attack. Many other commanders and officers in the south as well as the governor-general of Guangdong-Guangxi, Zhang Zhidong, protested the end of the war. In Taiwan, the French succeeded in occupying Keelung in the north but failed to advance any further after seven months. Henri Cordier described both Keelung and Tamsui as worthless places.

Chinese sources often condemn the final peace agreement and emphasize the Chinese successes that preceded the peace. According to Loyd Eastman, this interpretation fails to account for the overall situation of China, which had to contend with Russian and Japanese threats in the north, the critical situation in Taiwan, and weak supply lines in the south. Eastman claims that fear of conflict with Japan was the deciding factor in the Qing court's decision to sue for peace. Elleman states that although "China's forces in Tonkin achieved some notable land victories against the French," it became clear China would not receive any foreign assistance, and this forced Beijing to open negotiations. In the final treaty on 9 June 1885, China affirmed Annam's status as a French protectorate and allowed French firms to trade directly in China's southern provinces, promising to open five ports in the following years. Although no indemnity was paid, China accrued 20 million taels in debt for the war effort, and lost another 100 million taels in economic losses. As a result, Elleman deemed China to have lost the war by any modern standard.

Jane E. Elliott suggests that contemporary Chinese and foreign analysts may have been correct in finding the final peace treaty amusing as the Chinese seemed to be ascendant. Elliott notes that Western scholarly sources fail to give straightforward reasons and detailed descriptions of Chinese victories. Chinese victories were attributed to French mismanagement or misjudgement, the climate, and the difficulties of logistics. However the same problems also existed for the Chinese. Francis Garnier, Henri Rivière, and many senior French officers died in the war. In some instances, the French were only able to momentarily hold on to forts in Vietnam and Taiwan. The French succeeded in capturing Keelung in Taiwan but failed to take Tamsui for example. These mixed results may have appeared to indicate both French victory in France and French defeat in China. Elliott notes that contemporary European sources were averse to reporting French losses and glossed over mistakes made on the French side. Accounts of battles were manipulated to consistently portray the French as superior and never definitively losing, so that the Chinese never won except in instances of French error. Even recent work "perpetuates the myth that the French defeated the Chinese easily." The land campaign of the Sino-French War has been described by Chung-yam Po and Katherine Hui-yi Tseng as a French defeat and a Chinese victory.

Navy
Historians have judged the Qing dynasty's vulnerability and weakness to foreign imperialism in the 19th century to be based mainly on its maritime naval weakness, the historian Edward L. Dreyer said that "Meanwhile, new but not exactly modern Chinese armies suppressed the mid century rebellions, bluffed Russia into a peaceful settlement of disputed frontiers in Central Asia, and defeated the French forces on land in the Sino-French War (1884–85). However the defeat of the fleet, and the resulting threat to steamship traffic to Taiwan, forced China to conclude peace on unfavorable terms."

Modern sources

title: Sino-French War


text:
Nepetalactone

Nepetalactone is a name for multiple iridoid analog stereoisomers. Nepetalactones are produced by Nepeta cataria (catnip) and many other plants belonging to the genus Nepeta, in which they protect these plants from herbivorous insects by functioning as insect repellents. They are also produced by many aphids, in which they are sex pheromones. Nepetalactones are cat attractants, and cause the behavioral effects that catnip induces in domestic cats. However, they affect visibly only about two thirds of adult cats. They produce similar behavioral effects in many other felids, especially in lions and jaguars. In 1941, the research group of Samuel M. McElvain was the first to determine the structures of nepetalactones and several related compounds.

Structure and properties
Nepetalactone has three chiral centers, two at the fusion of the two rings, and one where the methyl group attaches to the cyclopentane ring. Thus, it has eight (23) stereoisomers. The terms cis and trans are used to refer to the relative stereochemistry at the ring fusion, and also to the methyl group as compared to the lactone on the cyclopentane.

(cis,trans)-Nepetalactone is a colorless oil. Its boiling point is 71 °C at 0.05 mmHg. At 25 °C, its density is 1.0663 g/mL and refractive index 1.4859.

Natural occurrence
Plants belonging to the Nepeta genus produce 4 different nepetalactone stereoisomers: (cis,cis)-, (cis,trans)-, (trans,cis)- and (trans,trans)-nepetalactone. Their relative occurrence varies among plant species. Small amounts of (cis,trans)- and (trans,cis)-nepetalactone also occur in the wood of Lonicera tatarica, but its cat attractant effects are assumed to be caused by actinidine, which occurs in it in higher concentrations.

Nepetalactones are also produced by many aphids, in which they function as sex pheromones. The most common isomer in aphids is (cis,trans)-nepetalactone. Aphids also commonly produce a structurally related (1R,4aS,7S,7aR)-nepetalactol, which is also an aphid sex pheromone. Relative concentrations of these two compounds varies among aphid species.

Biosynthesis
Nepetalactone is a bicyclic monoterpene produced through the terpenoid pathway in the genus Nepeta using its starting compound, geranyl pyrophosphate (GPP). There are three isomers of nepetalactone and it is suggested their stereochemistry is produced using different enzymes. Geranyl pyrophosphate undergoes hydrolysis and several oxidations to form 8-oxogeranial which can undergo a canonical activation–cyclation step in iridoid biosynthesis. Uncanonically, 8-oxogeranial will be reduced to create an 8-oxocitronellyl enol intermediate. Through a Diels–Alder reaction with a group of cyclases known as nepetalactone-related short-chain dehydrogenase enzymes (NEPS), the different stereoisomers of nepetalactone are biosynthesized.

The process starts with geraniol synthase (GES) hydrolyzing GPP to form geraniol which is oxidized into 8-hydrogeraniol by geraniol-8-hydroxylase (G8H) (scheme 1). Geraniol-8-hydroxylase is further oxidized by 8-hydroxygeraniol oxidoreductase (8OG) to produce 8-oxo-geranial which is reduced by iridoid synthase (ISY) and NADPH to form the intermediate 8-oxocitronellyl enol (scheme 2). This intermediate leads to cyclization by a gene cluster which utilizes ISY and major latex-protein-like genes (MLPL) or NEPS homologs. 8-oxocitronellyl enol is cyclized into (cis,trans)-nepetalactol by MLPL, NEPS1, or NEPS2 and then oxidized by NEPS5 and the cofactor NAD+ to yield (cis,trans)-nepetalactone (scheme 3). The process can be repeated with 8-oxocitronellyl enol cyclizing into (cis,cis)-nepetalactol by NEPS3 and oxidation by NEPS1 or NEPS5 and NAD+ to yield (cis,cis)-nepetalactone (scheme 4). 8-Oxocitronellyl enol can also be cyclized into (trans,cis)-nepetalactol by NEPS4 and then oxidized by NEPS1 into (trans,cis)-nepetalactone (scheme 5). It is suggested that the lack of the NEPS1 leads to decay and formation of (trans,cis)-iridodial.

Duration and efficacy variation
Nepetalactones affect domestic cats via nasal mucosa. Oral ingestion has no effects. They induce noticeable behavioral effects in about two thirds of adult cats. However, all cats are probably affected by them, but the effects in one third of adult cats are less visible. Nepetalactones do not noticeably affect kittens that are less than three months old. Their effects also tend to be less pronounced in neutered cats in comparison to non-neutered cats, but not significantly.

The effects of nepetalactones begin quickly in domestic cats, and last for 5 to 15 minutes. Cats develop drug tolerance towards nepetalactones after exposure. The tolerance lasts for a few hours.

Lions (Panthera leo) and jaguars (Panthera onca) are sensitive to nepetalactones. Their effects can last in them for up to 60 minutes. They also affect leopards (Panthera pardus). Species exhibiting overall lesser to no sensitivity include tigers (Panthera tigris), bobcats (Lynx rufus), cougars (Puma concolor) or oncillas (Leopardus tigrinus).

Effects
Two thirds of adult domestic cats begin to lick, sniff, eat, scratch or roll over the nepetalactone source after being exposed to it. They may also begin pawing, shaking their heads, rubbing their cheeks, licking themselves or vocalizing. About one third of adult cats react more passively to nepetalactones, and may assume a sphinx-like posture, decrease vocalization or decrease movement. The effects of nepetalactones are similar in other Felidae.

Mechanism of action
Felidae olfactory receptor exposure to nepetalactones or nepetalactols induces β-endorphin secretion in the blood; this endorphin release in turn activates μ-opioid receptors as an agonist, thus working in a similar manner as morphine or other opioids. Naloxone, a μ-opioid receptor antagonist, is known to block the effects of nepetalactones and nepetalactols in domestic cats, which supports this endorphin related mechanism of action. Repeated exposure to nepetalactones or nepetalactols does not induce opioid withdrawals in Felidae, probably because endogenous β-endorphin secretion is controlled. (cis,trans)- and (trans,cis)-nepetalactones have both been shown to function as cat attractants in domestic cats in studies of poor quality. Both isomers occur in catnip for example, but the (cis,trans)-isomer is the major one.

Evolutionary reasons for the effects
Felidae react to plants that contain nepetalactones by licking them and rubbing them in their fur. Nepetalactones and nepetalactols repel some disease-causing insects. For example, nepetalactols are able to repel Aedes albopictus. The cats typically hunt other animals by stalking them. This requires being still or slow movements, which allow insects to bite the cat more easily. This would make evolutionary pressure select for the behavior of rubbing of natural insect repellent. This was proposed to be the reason for this widely preserved behavioral trait in Felidae in a paper published in 2021.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Nepetalactone


text:
De Branges's theorem

In complex analysis, de Branges's theorem, or the Bieberbach conjecture, is a theorem that gives a necessary condition on a holomorphic function in order for it to map the open unit disk of the complex plane injectively to the complex plane. It was posed by and finally proven by.

The statement concerns the Taylor coefficients $$a_n$$ of a univalent function, i.e. a one-to-one holomorphic function that maps the unit disk into the complex plane, normalized as is always possible so that $$a_0=0$$ and $$a_1=1$$. That is, we consider a function defined on the open unit disk which is holomorphic and injective (univalent) with Taylor series of the form

 * $$f(z)=z+\sum_{n\geq 2} a_n z^n.$$

Such functions are called schlicht. The theorem then states that

 * $$ |a_n| \leq n \quad \text{for all }n\geq 2.$$

The Koebe function (see below) is a function for which $$a_n=n$$ for all $$n$$, and it is schlicht, so we cannot find a stricter limit on the absolute value of the $$n$$th coefficient.

Schlicht functions
The normalizations

 * $$a_0=0 \ \text{and}\ a_1=1$$

mean that

 * $$ f(0)=0\ \text{and}\ f'(0)=1 . $$

This can always be obtained by an affine transformation: starting with an arbitrary injective holomorphic function $$g$$ defined on the open unit disk and setting

 * $$f(z)=\frac{g(z)-g(0)}{g'(0)}.$$

Such functions $$g$$ are of interest because they appear in the  Riemann mapping theorem.

A schlicht function is defined as an analytic function $$f$$ that is one-to-one and satisfies $$f(0)=0$$ and $$f'(0)=1$$. A family of schlicht functions are the rotated Koebe functions

 * $$f_\alpha(z)=\frac{z}{(1-\alpha z)^2}=\sum_{n=1}^\infty n\alpha^{n-1} z^n$$

with $$\alpha$$ a complex number of absolute value $$1$$. If $$f$$ is a schlicht function and $$|a_n|=n$$ for some $$n\geq 2$$, then $$f$$ is a rotated Koebe function.

The condition of de Branges' theorem is not sufficient to show the function is schlicht, as the function
 * $$f(z)=z+z^2 = (z+1/2)^2 - 1/4$$

shows: it is holomorphic on the unit disc and satisfies $$|a_n|\leq n$$ for all $$n$$, but it is not injective since $$f(-1/2+z) = f(-1/2-z)$$.

History
A survey of the history is given by Koepf (2007).

proved $$|a_2|\leq 2$$, and stated the conjecture that $$|a_n|\leq n$$. and  independently proved the conjecture for starlike functions. Then Charles Loewner proved $$|a_3|\leq 3$$, using the Löwner equation. His work was used by most later attempts, and is also applied in the theory of Schramm–Loewner evolution.

proved that $$|a_n|\leq en$$ for all $$n$$, showing that the Bieberbach conjecture is true up to a factor of $$e=2.718\ldots$$ Several authors later reduced the constant in the inequality below $$e$$. If $$f(z)=z+\cdots$$ is a schlicht function then $$\varphi(z) = z(f(z^2)/z^2)^{1/2}$$ is an odd schlicht function. showed that its Taylor coefficients satisfy $$ b_k\leq 14$$ for all $$k$$. They conjectured that $$14$$ can be replaced by $$1$$ as a natural generalization of the Bieberbach conjecture. The Littlewood–Paley conjecture easily implies the Bieberbach conjecture using the Cauchy inequality, but it was soon disproved by, who showed there is an odd schlicht function with $$b_5=1/2+\exp(-2/3)=1.013\ldots$$, and that this is the maximum possible value of $$b_5$$. Isaak Milin later showed that $$14$$ can be replaced by $$1.14$$, and Hayman showed that the numbers $$b_k$$ have a limit less than $$1$$ if $$f$$ is not a Koebe function (for which the $$b_{2k+1}$$ are all $$1$$). So the limit is always less than or equal to $$1$$, meaning that Littlewood and Paley's conjecture is true for all but a finite number of coefficients. A weaker form of Littlewood and Paley's conjecture was found by.

The Robertson conjecture states that if

 * $$\phi(z) = b_1z+b_3z^3+b_5z^5+\cdots$$

is an odd schlicht function in the unit disk with $$b_1=1$$ then for all positive integers $$n$$,
 * $$\sum_{k=1}^n|b_{2k+1}|^2\le n.$$

Robertson observed that his conjecture is still strong enough to imply the Bieberbach conjecture, and proved it for $$n=3$$. This conjecture introduced the key idea of bounding various quadratic functions of the coefficients rather than the coefficients themselves, which is equivalent to bounding norms of elements in certain Hilbert spaces of schlicht functions.

There were several proofs of the Bieberbach conjecture for certain higher values of $$n$$, in particular proved $$|a_4|\leq 4$$,  and  proved $$|a_6|\leq 6$$, and  proved $$|a_5|\leq 5$$.

proved that the limit of $$a_n/n$$ exists, and has absolute value less than $$1$$ unless $$f$$ is a Koebe function. In particular this showed that for any $$f$$ there can be at most a finite number of exceptions to the Bieberbach conjecture.

The Milin conjecture states that for each schlicht function on the unit disk, and for all positive integers $$n$$,
 * $$\sum^n_{k=1} (n-k+1)(k|\gamma_k|^2-1/k)\le 0$$

where the logarithmic coefficients $$\gamma_n$$ of $$f$$ are given by

 * $$\log(f(z)/z)=2 \sum^\infty_{n=1}\gamma_nz^n.$$

showed using the Lebedev–Milin inequality that the Milin conjecture (later proved by de Branges) implies the Robertson conjecture and therefore the Bieberbach conjecture.

Finally proved $$|a_n|\leq n$$ for all $$n$$.

De Branges's proof
The proof uses a type of Hilbert space of entire functions. The study of these spaces grew into a sub-field of complex analysis and the spaces have come to be called de Branges spaces. De Branges proved the stronger  Milin conjecture  on logarithmic coefficients. This was already known to imply the Robertson conjecture about odd univalent functions,  which in turn was known to imply  the Bieberbach conjecture about schlicht functions. His proof uses the Loewner equation, the Askey–Gasper inequality about Jacobi polynomials, and the Lebedev–Milin inequality on exponentiated power series.

De Branges reduced the conjecture to some inequalities for Jacobi polynomials, and verified the first few by hand. Walter Gautschi verified more of these inequalities by computer for de Branges (proving the Bieberbach conjecture for the first 30 or so coefficients) and then asked Richard Askey whether he knew of any similar inequalities. Askey pointed out that had proved the necessary inequalities eight years before, which allowed de Branges to complete his proof. The first version was very long and had some minor mistakes which caused some skepticism about it, but these were corrected with the help of members of the Leningrad seminar on Geometric Function Theory (Leningrad Department of Steklov Mathematical Institute) when de Branges visited in 1984.

De Branges proved the following result, which for $$\nu=0$$ implies the Milin conjecture (and therefore the Bieberbach conjecture). Suppose that $$\nu > -3/2$$ and $$\sigma_n$$ are real numbers for positive integers $$n$$ with limit $$0$$ and such that
 * $$ \rho_n=\frac{\Gamma(2\nu+n+1)}{\Gamma(n+1)}(\sigma_n-\sigma_{n+1}) $$

is non-negative, non-increasing, and has limit $$0$$. Then for all Riemann mapping functions $$F(z)=z+\cdots$$ univalent in the unit disk with
 * $$\frac{F(z)^\nu-z^\nu} {\nu}= \sum_{n=1}^{\infty} a_nz^{\nu+n}$$

the maximum value of
 * $$\sum_{n=1}^\infty(\nu+n)\sigma_n|a_n|^2$$

is achieved by the Koebe function $$z/(1-z)^2$$.

A simplified version of the proof was published in 1985 by Carl FitzGerald and Christian Pommerenke, and an even shorter description by Jacob Korevaar.

title: De Branges's theorem


text:
Gδ set

In the mathematical field of topology, a Gδ set is a subset of a topological space that is a countable intersection of open sets. The notation originated from the German nouns open set and  intersection. Historically Gδ sets were also called inner limiting sets, but that terminology is not in use anymore. Gδ sets, and their dual, F$\sigma$ sets, are the second level of the Borel hierarchy.

Definition
In a topological space a Gδ set is a countable intersection of open sets. The Gδ sets are exactly the level Π$0 2$ sets of the Borel hierarchy.

Examples

 * Any open set is trivially a Gδ set.
 * The irrational numbers are a Gδ set in the real numbers $$\R$$. They can be written as the countable intersection of the open sets $$\{ q \}^{c}$$ (the superscript denoting the complement) where $$q$$ is rational.
 * The set of rational numbers $$\Q$$ is a Gδ set in $$\R$$.  If $$\Q$$ were the intersection of open sets $$A_n$$ each $$A_n$$ would be dense in $$\R$$ because $$\Q$$ is dense in $$\R$$.  However, the construction above gave the irrational numbers as a countable intersection of open dense subsets.  Taking the intersection of both of these sets gives the empty set as a countable intersection of open dense sets in $$\R$$, a violation of the Baire category theorem.
 * The continuity set of any real valued function is a Gδ subset of its domain (see the "Properties" section for a more general statement).
 * The zero-set of a derivative of an everywhere differentiable real-valued function on $$\R$$ is a Gδ set; it can be a dense set with empty interior, as shown by Pompeiu's construction.
 * The set of functions in $$C([0,1])$$ not differentiable at any point within $[0, 1]$ contains a dense Gδ subset of the metric space $$C([0,1])$$. (See .)

Properties
The notion of Gδ sets in metric (and topological) spaces is related to the notion of completeness of the metric space as well as to the Baire category theorem. See the result about completely metrizable spaces in the list of properties below. $$\mathrm {G_\delta}$$ sets and their complements are also of importance in real analysis, especially measure theory.

Basic properties

 * The complement of a Gδ set is an Fσ set, and vice versa.
 * The intersection of countably many Gδ sets is a Gδ set.
 * The union of many Gδ sets is a Gδ set.
 * A countable union of Gδ sets (which would be called a Gδσ set) is not a Gδ set in general. For example, the rational numbers $$\Q$$ do not form a Gδ set in $$\R$$.
 * In a topological space, the zero set of every real valued continuous function $$f$$ is a (closed) Gδ set, since $$f^{-1}(0)$$ is the intersection of the open sets $$\{x \in X : -1/n < f(x) < 1/n\}$$, $$(n = 1, 2, \ldots)$$.
 * In a metrizable space, every closed set is a Gδ set and, dually, every open set is an Fσ set. Indeed, a closed set $$F \subseteq X$$ is the zero set of the continuous function $$f(x) = d(x, F)$$, where $$d$$ indicates the distance from a point to a set.  The same holds in pseudometrizable spaces.
 * In a first countable T1 space, every singleton is a Gδ set.
 * A subspace of a completely metrizable space $$X$$ is itself completely metrizable if and only if it is a Gδ set in $$X$$.
 * A subspace of a Polish space $$X$$ is itself Polish if and only if it is a Gδ set in $$X$$. This follows from the previous result about completely metrizable subspaces and the fact that every subspace of a separable metric space is separable.
 * A topological space $$X$$ is Polish if and only if it is homeomorphic to a Gδ subset of a compact metric space.

Continuity set of real valued functions
The set of points where a function $$f$$ from a topological space to a metric space is continuous is a $$\mathrm {G_\delta}$$ set. This is because continuity at a point $$p$$ can be defined by a $$\Pi^0_2$$ formula, namely: For all positive integers $$n,$$ there is an open set $$U$$ containing $$p$$ such that $$d(f(x), f(y)) < 1/n$$ for all $$x, y$$ in $$U$$. If a value of $$n$$ is fixed, the set of $$p$$ for which there is such a corresponding open $$U$$ is itself an open set (being a union of open sets), and the universal quantifier on $$n$$ corresponds to the (countable) intersection of these sets. As a consequence, while it is possible for the irrationals to be the set of continuity points of a function (see the popcorn function), it is impossible to construct a function that is continuous only on the rational numbers.

In the real line, the converse holds as well; for any Gδ subset $$A$$ of the real line, there is a function $$f : \R \to \R$$ that is continuous exactly at the points in $$A$$.

Gδ space
A Gδ space is a topological space in which every closed set is a Gδ set. A normal space that is also a Gδ space is called perfectly normal. For example, every metrizable space is perfectly normal.

title: Gδ set


text:
Windows Driver Model

In computing, the Windows Driver Model (WDM) –  also known at one point as the Win32 Driver Model –  is a framework for device drivers that was introduced with Windows 98 and Windows 2000 to replace VxD, which was used on older versions of Windows such as Windows 95 and Windows 3.1, as well as the Windows NT Driver Model.

Overview
WDM drivers are layered in a stack and communicate with each other via I/O request packets (IRPs). The Microsoft Windows Driver Model unified driver models for the Windows 9x and Windows NT product lines by standardizing requirements and reducing the amount of code that needed to be written. WDM drivers will not run on operating systems earlier than Windows 98 or Windows 2000, such as Windows 95 (before the OSR2 update that sideloads the WDM model), Windows NT 4.0 and Windows 3.1. By conforming to WDM, drivers can be binary compatible and source-compatible across Windows 98, Windows 98 Second Edition, Windows Me, Windows 2000, Windows XP, Windows Server 2003 and Windows Vista (for backwards compatibility) on x86-based computers. WDM drivers are designed to be forward-compatible so that a WDM driver can run on a version of Windows newer than what the driver was initially written for, but doing that would mean that the driver cannot take advantage of any new features introduced with the new version. WDM is generally not backward-compatible, that is, a WDM driver is not guaranteed to run on any older version of Windows. For example, Windows XP can use a driver written for Windows 2000 but will not make use of any of the new WDM features that were introduced in Windows XP. However, a driver written for Windows XP may or may not load on Windows 2000.

WDM exists in the intermediary layer of Windows 2000 kernel-mode drivers and was introduced to increase the functionality and ease of writing drivers for Windows. Although WDM was mainly designed to be binary and source compatible between Windows 98 and Windows 2000, this may not always be desired and so specific drivers can be developed for either operating system.

Device kernel-mode drivers
With the Windows Drivers Model (WDM) for devices Microsoft implements an approach to kernel mode drivers that is unique to Windows operating systems. WDM implements a layered architecture for device drivers, and every device of a computer is served by a stack of drivers. However, every driver in that stack can chain isolate hardware-independent features from the driver above and beneath it. So drivers in the stack do not need to interact directly with one another. WDM defines architecture and device procedures for a range of devices, such as display and the network card, known as Network Driver Interface Specification (NDIS). In the NDIS architecture the layered network drivers include lower-level drivers that manage the hardware and upper-level drivers that implement network data transport, such as the Transmission Control Protocol (TCP).

While WDM defines three types of device drivers, not all driver stacks for a given device contain all types of device drivers. The three WDM device driver types are:

Bus driver: For every bus on the mainboard there is a one bus driver, with the primary responsibility for the identification of all devices connected to that bus and responding to plug and play events. Microsoft will provide bus drivers as part of the operating system, such as PCI, PnPISA, SCSI, USB and FireWire.

Function driver: this is the principal driver for a device and it provides the operational interface for a device by handling read and write operations. Function drivers are written by the device vendors, and for their interaction with the hardware they depend on a specific bus driver being present in the Windows operating system.

Filter driver: This driver is optional, and can modify the behaviour of a device, such as input and output requests. These drivers can be implemented as lower-level and upper-level filter drivers.

Object-oriented driver stack
Function drivers and bus drivers are often implemented as driver/minidriver pairs, which in practice is either a class or miniclass, or a port or miniport pair.

Bus drivers for devices attached to a bus are implemented as class drivers and are hardware-agnostic. They will support the operations of a certain type of device. Windows operating systems include a number of class drivers, such as the kbdclass.sys driver for keyboards. Miniclass drivers on the other hand are supplied by the vendor of a device, and only support device specific operations, for a particular device of a given class.

Port drivers support general input/output (I/O) operations for a peripheral hardware interface. The core functionality of port drivers is mandated by the operating system, and Windows operating systems integrate a variety of port drivers. For example, the i8042prt.sys port driver for the 8042 microcontroller connects PS/2 keyboards to the mainboard peripheral bus. The miniport drivers, like the miniclass drivers, are supplied by the hardware vendors and support only device specific operations of peripheral hardware that is connected to a port on the mainboard.

Each driver that processes an I/O request for a device has a corresponding object, which is loaded into main memory. A device object is created by the Windows operating system from the associated device class. Device objects contain structures of type DEVICE_OBJECT, which store pointers to their driver. At run time these pointers are used to locate a driver's dispatch routine and member functions. In the WDM driver stack, the filter driver device object, known as the upper filter, will receive an I/O request packet (IRP) for a device from the I/O manager. If the upper filter driver can not serve the request, it will locate the object of the driver one step down in the driver stack. The IRP is passed down the driver stack by calling the function IoCallDrive, and processed by the function driver device object, also known as functional device object. The function driver device object in turn may pass the IRP to the lower filter, another filter device object. Then the IRP may be passed down to the bus driver, which operates as the physical device object. The bus driver object is at the bottom of the driver stack, and interacts with the hardware abstraction layer, which is part of the Windows operating system kernel and allows Windows operating systems to run on a variety of processors, different memory management unit architectures, and a variety of computer systems with different I/O bus architectures. The execution of an IRP is finished when any of the driver objects in the stack returns the request back to the I/O manager, with the result and a status flag.

Device drivers for different Windows operating systems
The WDM framework was developed by Microsoft to simplify the communication between the operating system and drivers inside the kernel. In Windows operating systems, drivers are implemented as Dynamic Link Libraries .DLL or .SYS files. WDM compliant drivers must follow rules of design, initialisation, plug-and-play, power management and memory allocation. In practice WDM driver programmers reuse large pieces of code when building new object-oriented drivers. This means that drivers in the WDM stack may contain residual functionality, which is not documented in specifications. Drivers that have passed the Microsoft quality test are digitally signed by Microsoft. The Microsoft Hardware Compatibility Tests and the Driver Development Kit include reliability and stress tests.

A device driver that is not designed for a specific hardware component may allow another device to function. This is because the basic functionality of a hardware device class is similar. The functionality of the video card class, for example, allows the Microsoft Basic Display Adapter driver to work with a wide variety of video cards. However, installing the wrong driver for a device will mean that the full functionality of the device can not be used, and may result in poor performance and the destabilization of the Windows operating system. Hardware device vendors may release updated device drivers for particular Windows operating systems, to improve performance, add functionality or fix bugs. If a device is not working as expected the latest device drivers should be downloaded from the vendor website and installed.

Device drivers are designed for particular Windows operating system versions, and device drivers for a previous version of Windows may not work correctly or at all with other versions. Because many device drivers run in kernel mode installing drivers for a previous operating system version may destabilise the Windows operating system. Migrating a computer to a higher version of a Windows operating system therefore requires that new device drivers are installed for all hardware components. Finding up to date device drivers and installing them for Windows 10 has introduced complications into the migration process.

Common device driver compatibility issues include: a 32-bit device driver is required for a 32-bit Windows operating system, and a 64-bit device driver is required for a 64-bit Windows operating system. 64-bit device drivers must be signed by Microsoft, because they run in kernel mode and have unrestricted access to the computer hardware. For operating systems prior to Windows 10 Microsoft allowed vendors to sign their 64-bit drivers themselves, assuming vendors had undertaken compatibility tests. However, Windows 10 64-bit drivers now need to be signed by Microsoft. Therefore, device vendors have to submit their drivers to Microsoft for testing and approval. The driver installation package includes all files in the .inf directory, and all files in the package need to be installed, otherwise the installation of the device driver may fail. For operating system versions before Windows 10 not all files necessary for the driver installation were included in the package, as this requirement was not consistently enforced. Some device driver installers have a user interface GUI, often requiring user configuration input. The absence of a user interface does not mean that the installation of the device driver is not successful. Besides, Windows 10 device drivers are not allowed to include a user interface. The Network Driver Interface Specification (NDIS) 10.x is used for network devices by the Windows 10 operating system. Network device drivers for Windows XP use NDIS 5.x and may work with subsequent Windows operating systems, but for performance reasons network device drivers should implement NDIS 6.0 or higher. Similarly, WDDM is the driver model for Windows Vista and up, which replaces XPDM used in graphics drivers.

Device Manager
The Device Manager is a Control Panel applet in Microsoft Windows operating systems. It allows users to view and control the hardware attached to the computer. It allows users to view and modify hardware device properties, and is also the primary tool to manage device drivers.

Criticism
The Windows Driver Model, while a significant improvement over the VxD and Windows NT Driver Model used before it, has been criticised by driver software developers, most significantly for the following:
 * Interactions with power management events and plug and play are difficult. This can lead to situations where Windows machines cannot enter or exit sleep modes correctly due to bugs in driver code.
 * I/O cancellation is difficult to get right.
 * Complex boilerplate support code is required for every driver.
 * There is no support for writing pure user-mode drivers.

There were also a number of concerns about the quality of documentation and samples that Microsoft provided.

Because of these issues, Microsoft has released a new set of frameworks on top of WDM, called the Windows Driver Frameworks (WDF; formerly Windows Driver Foundation), which includes Kernel-Mode Driver Framework (KMDF) and User-Mode Driver Framework (UMDF). Windows Vista supports both pure WDM and the newer WDF. KMDF is also available for download for Windows XP and even Windows 2000, while UMDF is available for Windows XP and above.

title: Windows Driver Model


text:
IRP

IRP may mean any of the following in:

Science and technology

 * NIH Intramural Research Program
 * I/O request packet, in Microsoft Windows
 * Iron Removal Plant, in water treatment
 * Iron-responsive element-binding protein or iron regulatory protein

Political and international organizations

 * Initiative of the Republic of Poland, a former Polish political party
 * International Recovery Platform, a joint initiative of United Nations agencies, international financial institutions, national and local governments, and non-governmental organizations engaged in disaster recovery
 * Institute of Revolutionary Practice, educational institution affiliated with the Kuomintang
 * International Registration Plan of transportation carriers in North America
 * The International Reporting Project, funds independent journalistic coverage
 * International Resource Panel, for sustainable use of natural resources
 * International Responsa Project, a Schlesinger Institute project concerning medical issues and Jewish law
 * Islamic Renaissance Party of Tajikistan
 * Islamic Republic of Pakistan
 * Islamic Republic Party, former Iranian political party

Other

 * IRP, IATA code for Matari Airport
 * Irp., Irpinian dialect
 * Indianapolis Raceway Park, a short track in Indianapolis, Indiana
 * Individual'nyi Ratsion Pitaniya (IRP) (Индивидуальный рацион питания (ИРП)), Russian military rations
 * Integrated resource planning, a method for long-term utility planning
 * Integrated Rail Plan for the North and Midlands, UK government plan for its railways
 * Integrated Resource Plan, used in South Africa and by United States energy utilities

title: IRP


text:
Sexual norm

A sexual norm can refer to a personal or a social norm. Most cultures have social norms regarding sexuality, and define normal sexuality to consist only of certain sex acts between individuals who meet specific criteria of age, consanguinity (e.g. incest), race/ethnicity (e.g. interracial relationships), and/or social role and socioeconomic status.

In most societies, the term normal identifies a range or spectrum of behaviors. Rather than each act being simply classified as "acceptable" or "not acceptable", many acts are viewed as "more or less accepted" by different people, and the opinion on how normal or acceptable they are greatly depends on the individual making the opinion as well as the culture itself. Based on information gained from sexological studies, a great many ordinary people's sex lives are very often quite different from popular beliefs about normal, in private.

If non-restrictive sexual norms are regarded positively, they may be called "sexual freedom", "sexual liberation" or "free love". If they are regarded negatively, they may be called "sexual licence" or "licentiousness". Restrictive social norms, if judged negatively, are called sexual oppression. If the restrictive norms are judged positively, they may be regarded as encouraging chastity, "sexual self-restraint" or "sexual decency", and negative terms are used for the targeted sexuality, e.g. sexual abuse and perversion.

Social attitudes
In the West, some people have relaxed the traditional definitions of normality, choosing instead to define normal sexuality as any sexual practice which does not involve what are regarded as sexual perversions. However, using this definition makes use of a long list of sexual perversions which themselves show up hidden assumptions about cultural norms. Recently, in Western society, consensual paraphilias are becoming more acceptable, in particular "any activity, not otherwise illegal, performed between consenting adults in private."

This liberalization of attitudes has resulted in the decriminalisation of homosexuality in many countries, following the ground-breaking Wolfenden report in the United Kingdom.

There is a tendency in Western countries towards serial monogamy as a normal heterosexual lifestyle. There is also a movement towards recognizing long-term homosexual relationships (see same-sex marriage).

There is also greater acceptance of sexual relationships (partnerships) without requiring the sanction of a form of marriage recognised by the church, state or legal system.

These liberalizing trends can be contrasted with conservative social trends that seek to reverse these patterns of behaviour, with encouragement for young people to choose traditionally accepted roles, beliefs and behaviors, and to exercise sexual abstinence or non-promiscuous lifestyles before marriage.

There is an opposing trend in reaction, that views such changes as a socially destructive force, and is opposed to them. It is often, though not exclusively, associated with people who have religious feelings, and is prevalent in much of Christianity in America, as well as Islam in the Middle East and Asia, and other devout religious groups such as Haredi Jews in Israel. In such countries there is often strong criticism of non-traditional sexualities and sexual liberation.

Some social unrest in both Eastern and Western cultures is due to this conflict between these two trends, and views upon acceptability and control of social and sexual norms.

title: Sexual norm