Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai–Tibetan Plateau          下载免费PDF全文

J. Cao  Y. Gong  E. T. Yeh  N. M. Holden  J. F. Adamowski  R. C. Deo  M. Liu  J. Zhou  J. Zhang  W. Zhang  S. Zhang  D. Sheng  S. Yang  X. Xu  M. Li  Q. Feng 《Soil Use and Management》2017,33(4):663-671

Carbon storage in the soils on the Qinghai–Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi‐household management pattern (MMP: grassland shared by several households without enclosures) and a single‐household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai–Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 Mg C/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31 × 10⁷ and 6.15 × 10⁷ Mg C/yr across the Qinghai–Tibetan Plateau relative to MMP, which more closely resembles pre‐1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai–Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai–Tibetan Plateau but also other grazing regions globally where such practices may exist.  相似文献   

Correction to: Predation on glass eels of Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis> in the Tone River Estuary,Japan     

Yoichi Miyake  Aigo Takeshige  Hikaru Itakura  Hajime Itoh  Hiroaki Onda  Akira Yamaguchi  Akihito Yoneta  Kohma Arai  Yulina V. Hane  Shingo Kimura 《Fisheries Science》2018,84(6):1015-1016

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Letter from the Editor     

P. C. Struik 《Potato Research》2009,52(4):273-273

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牦牛病毒性腹泻/粘膜病的防制研究   总被引：10，自引：0，他引：10  

刘亚刚  殷中琼  刘世贵  韩鹏  华莎  余勇  石谦  丁晓涛  刘晓钢  于若飞 《中国预防兽医学报》2003,25(6):487-490

20世纪80年代以来，我国牦牛群中陆续发现牛病毒性腹泻／粘膜病(BVD／MD)，血清阳性率在30％～42．4％之间，病死率在30％左右，本研究先后从四川、西藏等地牦牛中分离出病毒，并对其进行各种生物学特征鉴定后，表明该病毒与标准毒属同一种，所不同的是四川牦牛病毒株属非致细胞病变型，即属NCP型。但回归本动物能复制出典型病例。目前尚无国产牛粘膜病疫苗用于生产。本研究依据猪瘟病毒与牛病毒性腹泻／粘膜病病毒具有交叉免疫性的原理，用猪瘟弱毒苗对牦牛病毒性腹泻／粘膜病进行预防，试验证明用猪瘟弱毒苗可以预防牛病毒性腹泻／粘膜病，且安全可靠，具有实用价值。  相似文献   

银川地区羊肝中阿苯达唑(丙硫苯咪唑)残留情况的调查   总被引：1，自引：0，他引：1  

倪泽成刘辛赟  武占银马立均夏国振  蒋安文张惠英李春和  沙涌波 《中国动物检疫》2004,21(9):29-30

阿苯达唑又称丙硫苯咪唑或丙硫咪唑，有时又称抗蠕敏，是目前国内常用的驱虫效果好、范围广、毒性较低的兽用驱虫药。随着家庭舍饲养羊规模的不断扩大，饲养者为了减少因寄生虫导致的死亡并增加育肥效果，常把阿苯达唑作为育肥前预防驱虫或寄生虫病治疗的首选药，出现了滥用或超剂量使用的现  相似文献   

Versuche zur Zyklussynchronisation bei Kühen aus Beständen rnit Fertilitätsproblemen und bei Hybriden zwischen Wisent und Rind mit der PRID-Spirale*     

S. Zdu&#x;czyk  A. Domaszewski  Z. Giiejewski  T. Janowski  A. Zebracki 《Reproduction in domestic animals》1989,24(1):1-7

Inhalt: An 81 Versuchs- und 92 Kontrolltieren der Rasse “Potnische Schwarzbunte” aus 3 Problembetrieben wurde ein Versuch zur Sterilitätsprophylaxe rnit der PRID-Spirale durchgeführt. Anhand klinischer Befunde und Milchprogesteronwerten wurde die Untergruppe aus Kühen mit Ovardystrophie (18 Versuchs- und 22 Kontrolltiere) gebildet und extra ausgewertet. Der Behandlungsbeginn lag zwischen 60 und 80 Tage post partum. Die Versuchstiere wurden mit der PRID-Spirale 12 Tage lang behandelt, die Kontrolltiere erhielten Injcktionen rnit Kochsalzlösung und solche rnit Ovardystrophie wurden zusätzlich mit einer Eierstocksmassage behandelt. Die Versuchstiere wurden 56 und 72 Stunden nach Entfernung der Spirale blind besamt. Die Brunstin-duktionsrate betrug insgesamt 90,1%, bei denen rnit Ovardystrophie 77,7%. Die An-wendung der PRID-Spirale führte zur Verbesserung der Fertilitätslage. Die Gesamt-trächtigkeitsrate lag mit 87,6% bei den Versuchskühenüber derjenigen der Kontrollkü-he mit 79,3%. Die Behandlung der Tiere rnit Ovardystrophie erbrachte eine Gesamt-trächtigkeitsrate von 88,8% bei den Versuchs- und 72,7% bei den Kontrolltieren. Die Zwischentragezeit betrug bei den Versuchstieren 101,2 Tage und bei den Kontrolltieren 113,3 Tage (p ≤ 0,05). Bei den azyklischen Tieren lag die Zwischentragezeit bei 104,6 Tage bzw. 134,7 Tage (p ≤ 0,05). In einem anderen Versuch wurde 20 Hybriden zwischen Wisent und Hausrind rwecks Zyklussynchronisation die PRID-Spirale verabreicht. Die Brunstinduktionsrate betrug 66,6%, das Erstbesamungsergebnis nach Doppelbesamung 30%, die Gesamtträchtig-keitsrate nach dem Decken der umrindernden Kreuzungstiere rnit einem Bullen 90%. Die Deckperiode konnte verkürzt werden. Contents: Investigations on the synchronization of estrus cycle in cattle from farms with fertility problems and in cross-breeds between bison and cattle with a PRID-de-vice In 81 experimental and 92 control animals of the “Polish Black and White” breed derived from 3 farms with fertility problems an investigation was carried out for sterility prophylaxis using the PRID-device. Based on clinical findings and milk progesterone values cattle with ovarian dystrophy (18 experimental and 22 control animals) from a special group were used. The begin of treatment was between 60 and 80 days post partum. All experimental animals had received a PRID-device for a duration of 12 days. Control animals were injected with physiological saline solution and animals with ovarian dystrophy were treated additionally with ovarian massage. Experimental animals were inseminated 56 and 72 hrs after removal of the device. All animals taken, estrus was induced in 90.1% of the animals, while only 77.7% of animals with ovarian dystrophy came to estrus. Application of the PRID-device led to an improvement of fertility. Pregnancy rates in experimental animals were 87.6%, while only 79.3% of the control animals were pregnant. Treatment of animals with ovarian dystrophy resulted in 88.8% pregnancies for treated and 72.7% for control animals. Experimental animals were non-pregnant for a duration of 101.2 days, while control animals remained non-pregnant for 113.3 days (p < 0.05). Acyclic cattle had a non-pregnant period of 104.6 days and 134.7 days (p < 0.05) respectively. In a second experiment 20 cross-breeds between bison and domestic cattle were treated with a PRID-device for synchronization of the estrus cycle. The rate of estrus induction was 66.6%, the fertility after double insemination 30%, the total pregnancy rate improved after mating with a bull of animals that had not conceived to 90%.  相似文献   

Anaplasmosis in Uganda. I. Use of dried blood on filter papers and serum samples for serodiagnosis of anaplasmosis—A comparative study     

G. S. Z. Ssenyonga  I. Kakoma  Sonia Montenegro-James  R. Hansen 《Tropical animal health and production》1992,24(1):2-8

Summary The suitability of blood collected on filter papers in comparison with corresponding conventional serum samples in the diagnosis of bovine anaplasmosis was studied using the complement fixation test, DOT-ELISA, Western immunoblot and rapid card agglutination test. Dried blood on Whatman filter paper no. 1 was eluted in PBS 0·05% Tween 20 giving an initial dilution of 1∶10. The reactivity of the eluted samples in both DOT-ELISA and Western immunoblotting were similar to those obtained with the corresponding straight serum sample dilutions. Filter paper samples gave lower reactivity in the remaining tests when compared with corresponding serum samples. There was no significant difference in the reactivity between the eluates from filter papers stored at temperatures ranging between 15·5 and 24°C and those kept refrigerated. Storage at 15·5 to 24°C did not significantly affect reactivity for up to six months. Eluates from filter papers stored for six months at 15·5 to 24°C continued to give similar reactivity as those from freshly prepared filter papers in both DOT-ELISA and Western blot, and in the rapid card agglutination test. It is concluded that collecting blood on filter papers is a suitable technique for large scale seroepidemiological studies on anaplasmosis and offers many advantages in developing countries where transport and cold chain facilities are a major constraint.

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Resumen Se estudió la efectividad de muestras de sangre colectadas en papel filtro, en comparación con las correspondientes muestras convencionales du suero, en el diagnóstico de anaplasmosis bovina, utilizando fijación de complemento, DOT-ELISA, Western, immunoblot y la prueba rápida de la tarjeta. La sangre seca en papel Whatman N^o 1 fue removida con PBS 0·05% entre 20, dando una dilución inicial de 1∶10. La reactividad de las muestras removidas de papel filtro, en la prueba de DOT-ELISA y Western immunoblotting, fueron similares a la obtenida con la correspondiente muestra de suero. Las muestras de papel filtro reaccionaron menos en las otras pruebas, cuando se compararon con las correspondients muestras du suero. No hubo diferencia significativa en la reactividad entre los lavados del papel filtro guardados a temperaturas entre 15·5 y 24°C y aquellos guardados en refrigeración. El almacenaje entre 15·5 y 24°C, no afectó la reactividad hastas seis meses. Los lavados de papel filtro guardados por seis meses entre 15·5 y 24°C, dieron la misma reactividad como los lavados frescos, en la prueba DOT-ELISA y Western blot, lo mismo que en la prueba de aglutinación rápida de tarjeta. Se concluye, qu la colección de sangre en papel filtro, es una buena técnica para estudios epidemiológicos de cierta magnitud, sobre anaplasmosis, ofreciendo ventajas considerables en paises en desarrollo en donde las cadenas de frío son deficientes.

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Résumé La fiabilité du sang récolté sur papier filtre comparée à celle des prélèvements conventionnels de sérum pour le diagnostic de l'anaplasmose a été étudiée à l'aide des tests suivants: fixation du complément, ELISA, immunoblot de Western, test rapide d'agglutination sur carte. Du sang séché sur papier filtre Whatman N^o 1 a fait l'object d'une élution dans une solution de PBS à 0,05 p. 100 (Tween 20) pour donner une dilution de base au dilution de base au 1∶10. Le réactivité des échantillons, autant avec le test ELISA que l'immunoblot Western, a été identique à celle obtenue par dilution directe de sérums homologue. Les échantillons sur papier filtre ont donné une réactivité plus faible pour les autres tests, comparée à celle des échantillons de sérum semblables. Aucune différence significative n'a été décelée quant à leur réactivité les éluats provenant de papiers filtres stockés à des températures comprises entre 15,5 et 24°C at ceux conservés au réfrigérateur. Le stockage entre 15,5 et 24°C n'a pas non plus affecté la réactivité de fa?on significative; les éluats conservés à partir des papiers filtres, à cette même température durant 6 mois, ont montré des réactions identiques que ceux provenant de papiers filtres fra?chement préparés, à la fois avec le test ELISA, celui de Western Blot et le test d'agglutination rapide sur carte. On peut conclure que la collecte du sang sur papier filtre est une technique adaptée à l'étude épidémiologique de l'anaplasmose à grande échelle. Elle offre de nombreux avantages dans les pays en développement où offre de nombreux avantages dans les pays en développement où les moyens de transports et la cha?ne du froid constituent des contraintes majeures.

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高效预应力混凝土框架的试验研究     

廖莎 《湖南农业大学学报(自然科学版)》1996,23(6)

通过２榀预应力混凝土叠合框架１：３比例的模型试验，了解了叠合梁框架在竖向荷载作用下的受力性能。讨论了叠合梁截面应变分布特点，并分析了梁的配筋率这一主要参数对框架极限承载力和破坏形态的影响。  相似文献   

Effect of Split Nitrogen Application on Growth and Yield of Wheat (T. aestivum L.) Genotypes with Different N-Assimilation Potential     

M. Z. Abdin    K. C. Bansal  Y. P. Abrol 《Journal of Agronomy and Crop Science》1996,176(2):83-90

A field experiment was conducted with different nitrogen regimes to assess the growth and yield performance of wheat genotypes which differ in nitrate assimilation potential. Genotypic differences in biomass accumulation were observed at different growth stages. The nitrogen treatment had little effect on biomass accumulation at early stages of growth, while at later stages of growth there was enhanced biomass accumulation when N was applied in more than two splits. On an average, genotypes with high nitrate reductase activity (the 'HNR' genotypes) accumulated 14.2 % more biomass than the genotypes with low nitrate reductase activity ('LNR' genotypes) when an extra dose (40 kg N ha⁻¹) of nitrogen was given at the time of anthesis. The application of nitrogen in more than two splits increased grain yield of both 'HNR' and 'LNR' genotypes mainly by increasing grain weight per ear. The application of an extra dose of nitrogen (40 kg N ha⁻¹) at the time of anthesis increased grain yield of 'HNR' genotypes by 38.5 % as compared to 'LNR' genotypes.  相似文献   

Seroprevalence of porcine and human influenza A virus antibodies in pigs between 1986 and 1988 in Hassia     

X M Zhang  W Herbst  H Lange-Herbst  T Schliesser 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(10):765-770

1,268 sera collected from slaughtered pigs in Hassia (FRG) from 1986 to 1988 were tested for antibodies against porcine and human influenza A virus strains using the single radial haemolysis test (SRHT). Antibodies against the porcine strains (subtype H1N1) A/Swine/Arnsberg/1/81, A/Swine/Iowa/15/30 and A/New Jersey/7/76 were detected in 411 (32.4%), 318 (25.1%) and 304 (24.0%) of sera, respectively. Up to 1988 a slight increase (10%) in the seroprevalence to A/Swine/Arnsberg/1/81 was noticed, whereas the results obtained with the other strains showed little variation. Antibodies against the human H1N1 strain A/Singapore/6/86 were only found in sera collected 1987 and 1988 in rates of 1.6% and 3.0%. Serological indication of infections with the human H3N2 strains A/Victoria/1/75, A/Hong Kong/1/68 and A/Philippines/2/82 could be shown in 286 (22.6%), 178 (14.4%) and 135 (10.6%) of the serum samples. Within the three year period the rate of sera positive for antibodies against A/Philippines/2/82 increased from 6.5% to 23.0%, whereas no variation in the rates were found using the other H3N2 strains. Antibodies simultaneously against porcine (H1N1) and human (H3N2) virus strains were detected in 9.9% of all sera tested.  相似文献