近58a长江源地区不同等级降水的变化特征分析

利用长江源地区1962～2019年逐日降水资料,运用数理统计的方法,分析不同等级降水量、降水日数和降水强度的变化特征.结果 表明:近58a长江源地区年降水量、年降日数和降水强度均呈增加趋势,年降水量和年降水日数增加趋势明显,降水强度增加趋势不明显;小雨、中雨降水量(降水日数)呈显著增加趋势,大到暴雨降水量(降水日数)呈...     

气候变化对内蒙古荒漠草原牧草气候生产力的影响

根据内蒙古荒漠草原1961~2007年11个气象站点的年平均气温、年降水量资料,采用Thornthwaite Me-morial模型计算牧草气候生产力,运用气候诊断分析、相关分析等方法分析荒漠草原年平均气温、年降水量、牧草气候生产力的时空变化特征及趋势,并探讨了不同气候变化情景对内蒙古荒漠草原牧草气候生产力的影响。结果表明:(1)近47年来内蒙古荒漠草原年平均气温呈极显著的上升趋势,荒漠草原东北部和西部增温幅度相对较大;年降水量总体变化趋势不明显,但东北部地区年降水量明显减少。(2)牧草气候生产力总体为不显著的线性增加趋势,其中荒漠草原中部牧草气候生产力增加显著。(3)未来"暖湿型"气候可使牧草气候生产力提高,"暖干型"气候使牧草气候生产力降低,"冷湿型"气候也有利于牧草气候生产力的增长。(4)年降水量与牧草气候生产力有极其显著的相关性,降水是影响内蒙古荒漠草原牧草气候生产力的关键因子。     

近56年乌鲁木齐市青草期水热气候条件时空变化

基于乌鲁木齐市及其周边10个气象站1961-2016年逐日气象资料,以日平均气温稳定≥5℃的初、终日分别作为天然草地青草期初、终日指标,使用线性趋势分析以及ArcGIS的空间插值技术对近56年乌鲁木齐市青草期初、终日、青草期日数、平均气温、≥5℃积温、降水量和干湿指数等水热气候要素的时空变化规律进行了分析。结果表明,乌鲁木齐市天然草地青草期初日的空间分布具有"平原荒漠类草地早、山地草原和草甸类草地晚"的特点;青草期终日与初日相反,呈现"平原荒漠类草地晚、山地草原和草甸类草地早"的特点;青草期日数、平均气温、≥5℃积温均为"平原荒漠类草地多(高)、山地草原和草甸类草地少(低)",青草期降水量表现为"山地草甸和山地草原多、高寒草甸和平原荒漠类草地少",青草期干湿指数随海拔的升高而增大。1961-2016年,乌鲁木齐市青草期初日以每10年-0.424d的倾向率呈不显著(P0.05)的提早趋势,青草期终日以1.455d·10a-1的倾向率呈显著(P0.01)的推迟趋势,青草期日数、平均气温、≥5℃积温、降水量以及干湿指数分别以每10年1.879d、0.16℃、61.14℃·d、6.93mm和0.015的倾向率呈显著(P0.05)的增多或上升趋势,但上述变化具有区域性差异。近26年(1991-2016年)较前30年(1961-1990年),除青草期初日提早幅度的空间差异不明显外,青草期终日的推迟幅度以及青草期日数、平均气温、≥5℃积温等要素的增多幅度表现出"平原荒漠类草地多、山地草原和草甸类草地少"的特点,青草期降水量和干湿指数增大幅度的空间分布呈现"平原荒漠类草地少、山地草原和草甸类草地多"的特点。     

内蒙古化德地区1961—2010年风沙天气变化分析

根据内蒙古化德县气象站1961—2010年的气温、降水、风沙（大风、沙尘暴）气象资料,分析了化德地区近50年与风沙有关的气象要素。结果表明,该地区50年来年平均气温呈明显上升趋势;年总降水量变化趋势不明显;大风日数、沙尘暴日数呈减少趋势。     

不同降水条件对干旱矿区土壤表层种子库的激活效应

近年来,随着国家煤炭开发产业逐渐西移,干旱荒漠矿区的生态恢复工作愈发受到重视。然而在干旱矿区水资源稀缺的背景下,针对土壤种子库(特别是持久土壤种子库)在天然降水条件下激活情况的研究依然匮乏。本研究以内蒙古乌海市新星露天煤矿周边0-5 cm表层土壤种子库为研究对象,采用人工模拟降水条件下种子库中种子短期萌发试验的方法,对矿区周边持久土壤种子库在不同降水量处理下的萌发进程以及不同日降水量、年降水量对土壤种子库的激活效应进行研究。结果表明：1)不同日降水量对土壤种子库的激活效应存在差异,随着日降水量的增加,激活的土壤种子库物种数和种子萌发数均呈先增加后降低趋势,其中5 mm日降水萌发的种子数最多,10 mm日降水萌发的物种数最多;2)不同植物种子对不同日降水量的响应状态不同,种子萌发数量最多的小画眉草(Eragrostis minor)、冷蒿(Artemisia frigida)在3～20 mm日降水均能被激活,而红砂(Reaumuria songarica)、猫头刺(Oxytropis aciphylla)等灌木种子需在10 mm以上降水量才能被激活;3)在50～150 mm年降水量范围,...     

内蒙古不同类型草地NPP时空动态特征及其气候影响因素分析

为揭示内蒙古不同类型草地净初级生产力(NPP)时空动态,探究其与气候因子的相关性,利用2001～2016年遥感数据,气象数据和20世纪80年代中国草地分类数据,采用光能利用率(CASA)模型,模拟获取2001～2016年内蒙古草地NPP,并分析了不同类型草地NPP的时空动态及其对气候因子的响应。结果表明:(1)2001～2016年,内蒙古草地年均NPP为163.9 gC/(m^2·a),空间上呈现东北部高西南部低的特征,年均NPP总量为31.6 TgC/a(1Tg=10¹²g);(2)试验的16年,内蒙古草地年均NPP呈增加趋势增加量为2.1 gC/(m^2·a),年际波动较大;(3)温性草甸草原、热性草丛、低地草甸、山地草甸和沼泽的年均NPP呈显著增加趋势,其他5类呈显著减少趋势;(4)NPP与年均温和年总降水量的相关系数分别为-0.01和0.4;(5)除温性荒漠草原和温性草原化荒漠外,其他类型草地NPP均与温度呈负相关关系,所有类型草地NPP与降水量均呈正相关关系。降水是影响内蒙古草地NPP最主要的气候因子。     

模拟降水对短花针茅荒漠草原土壤养分的影响

为了探究降水对短花针茅荒漠草原土壤养分的影响,在内蒙古四子王旗荒漠草原采用完全随机区组设计开展了模拟降水试验,试验设4个不同模拟降水梯度(减少自然降水50%、自然降水、增加自然降水50%和增加自然降水100%),在不同水分梯度下用直径3.5cm土钻钻取表层土样,测定土壤养分(全碳、全氮、全钾、全磷、有机碳、铵态氮、硝态氮、速效钾和速效磷)含量。结果表明:随着降水量的增加,土壤有机碳、全碳、全氮和硝态氮的含量呈显著降低趋势(P<0.05);减少降水能够使土壤养分积累;过高的降水量会导致土壤养分淋溶,造成养分流失;降水处理对土壤钾元素和磷元素含量没有显著性影响。     

不同模拟降水量下草地早熟禾根系形态与解剖结构的动态变化

以草地早熟禾为研究对象,采用人工控水模拟降水量的方法,比较对照组(浇水量为小雨组的60%),小雨组(24 h内的降水量小于10 mm)、中雨组(24 h内降水量为10~25 mm)、大雨组(24 h内降水量为25~50 mm)根系形态与解剖结构的差异,以探究不同模拟降水量对草地早熟禾根系发育的影响机制。结果表明,总体上处理组与对照组相比差异较为显著。在试验进程中,中雨组水分条件下草地早熟禾根系生长全程均良好。在根系构型方面,根长、根表面积、根总体积、根平均直径与根分叉数均显著增加,比根长与根干重密度较为稳定,各项根系构型数据均显示草地早熟禾在中雨组的水分处理下生长状况优于其他处理。在根系解剖方面,到生长第50 天时,对照组继续受干旱的影响,根系结构受损,中柱和导管直径显著变小,占根系直径比例减小;小雨组出现轻微干旱情况;中雨组根系解剖结构正常;大雨组出现水淹情况。以上结果表明,中雨组为最适合草地早熟禾生长的水分条件。     

内蒙古草地生态系统近10年NPP时空变化及其与气候的关系

植被净初级生产力(net primary productivity, NPP)及其对气候变化的响应研究是全球变化的核心内容之一。通过改进的光能利用率模型(CASA模型),利用MODIS NDVI数据、土地覆盖分类数据、气象数据等,逐像元模拟2001-2010 年内蒙古草地生态系统NPP的时空变化,分析其对气候因子变化的响应关系。结果表明,1)2001-2010年内蒙古草地多年平均NPP为281.3 g C/(m²·a),空间分布呈由西南向东北递增的趋势,草甸草原、典型草原和荒漠草原平均NPP分别为431.8,288.7和123.5 g C/(m²·a);2) 2001-2010年间内蒙古草地NPP总体上呈上升趋势。NPP上升趋势最明显的草地主要分布在毛乌素沙地、浑善达克沙地、科尔沁沙地、呼伦贝尔盟和大兴安岭南麓地区,而下降趋势最明显的草地主要分布在阴山山脉和锡林郭勒盟中部的典型草原区;3) 总体而言,降水量是内蒙古草地净初级生产力的主要影响因素。草甸草原NPP与降水量、温度的关系均很密切,而且与温度的相关性更强;典型草原和荒漠草原NPP则主要受降水量控制,其中荒漠草原NPP与降水量的关系更密切。     

短花针茅荒漠草原植物群落组成对模拟降水的响应

为了阐明降水变化对荒漠草原植物群落组成的影响,在短花针茅荒漠草原进行了模拟增加降水和减少降水的试验。试验有 4 种处理,分别是减少 50% 自然降水量(P1)、自然降水量(P2)、增加 50% 自然降水量(P3)、增加 100% 自然降水量(P4)。结果表明：(1)增加 50% 降水量对土壤含水量没有显著影响,增加 100% 降水量时土壤含水量明显增加,减少 50% 降水量使土壤含水量显著降低(P ＜ 0. 05);(2)群落物种丰富度和多样性指数没有随着降水增加而增加,但是群落内部的组成却发生了变化,多年生杂类草和一、二年生草本的比例显著增加(P＜0. 05),而减少降水使得一、二年生草本显著减少(P＜0. 05)。试验结果有助于更好地预测植物群落组成对降水变化的响应,制定合理的草原保护措施来提高草原的生态系统稳定性,从而应对降水变化的影响。     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

2019年我国兽用抗菌药物使用情况分析研究

对2019年国内兽用抗菌药物销量数据进行了统计分析,按照兽用抗菌药销售量等同于使用量的评价指标,结果发现,国内兽药使用总量为37159.12吨;其中,使用量最大的是四环素类,占比36.56%;促生长用抗菌药的用量为14871.05吨,占比48.12%;每吨动物产品兽用抗菌药使用量为160 g。与2018年相比,兽用抗菌药物使用量略有上升,每吨动物产品使用的抗菌药物量也同比增加,这提示我国兽用抗菌药物使用管理不能放松,减抗政策需继续实施,久久为功。     

Meiosis in bovine oocytes matured in vitro and in vivo

Meiosis in bovine oocytes has; been studied after maturation in vitro or in vivo. Oocytes for in vitro maturation were collected from the ovaries of slaughtered cattle without regard to the phase of the estrous cycle while in vivo maturation was studied in oocytes from gonadotrophin-stimulated heifers at times varying between 6 and 36 h after the beginning of behavioural estrus. Oocytes from slaughtered cattle were classified according to their cumulus complex and ooplasm and were cultured for 6, 12, 18, 24, 36 or 48 h in modified Krebs-Ringer bicarbonate buffer before fixation) for cytogenetic analysis. Oocytes from stimulated heifers were aspirated from follicles or flushed from the oviducts, classified according to cumulus and ooplasm, and fixed within 6 h of collection. Nuclear maturation was more rapid in vitro than in vivo. The largest proportion of oocytes reached maturity (Mil) after 12 to 18 h in culture or 30 to 36 h after the onset of behavioural estrus. Oocytes devoid of cumulus cells or showing signs of vacuolation or degeneration had virtually no capacity for nuclear maturation.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Malaria in cynomolgus monkeys used in toxicity studies in Japan

Plasmodium spp. protozoa cause malaria and are known to infect humans and a variety of animal species including macaque monkeys. Here we report both our experience with malaria recrudescence in cynomolgus monkeys (Macaca fascicularis) in a toxicity study and the results of a survey on Plasmodium infection in cynomolgus monkeys imported to Japan for laboratory use. A cynomolgus monkey from the toxicity study presented with severe anemia and Plasmodium protozoa in erythrocytes on a thin blood smear and was subsequently diagnosed with symptomatic malaria. In this animal, congestion and accumulation of hemozoin (malaria pigment) in macrophages were noted in the enlarged and darkly discolored spleen. As a follow-up for the experience, spleen sections from 800 cynomolgus monkeys in toxicity studies conducted between 2003 and 2013 were retrospectively examined for hemozoin deposition as a marker of Plasmodium infection. The origin of the animals included Cambodia, China, Indonesia, and Vietnam. Hemozoin deposition was confirmed in 44% of all examined monkeys. Monkeys from Indonesia showed the highest incidence of hemozoin deposition (approx. 80%). A high prevalence of Plasmodium infection in laboratory monkeys was also confirmed with polymerase chain reaction (PCR) by using Plasmodium genus-specific primers. Although Japan is not a country with endemic malaria, it is important to be aware of the prevalence and potential impact of background infection with Plasmodium spp. and recrudescence of symptomatic malaria in imported laboratory monkeys on pharmaceutical toxicity studies.     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).