170 resultados para OVIS


Relevância:

10.00% 10.00%

Publicador:

Resumo:

兔属物种的形态特征差异甚微,其分类地位长期存在争议。本研究论文来用线粒体DNA标记从分子水平对兔属物种的系统发育,分类地位以及历史生物地理学进行探讨。我们应用四个线粒体DNA标记:细胞色素b和125基因全序列,ND4和控制区部分序列构建中国野兔和世界范围内的其它兔属物种间的系统发育关系。系统发育关系的构建以鼠兔为外群,采用三种方法:最大简约法(淤),最大似然法(ML)和贝叶斯方法(Bl)。分析结果显示:中国野兔并不是一个单系群。世界范围内的兔属动物形成一个单系,并以地理分布可分为相应的三个种组:北美种组(NortoAmericanspeciesgroup),欧亚种组①urasionspeciesgroP)和非洲种组(S。uthAfricanspeciesgroup)。兔属动物鉴定的29个种可能多于该属的有效种。历史生物地理学的祖先地分析表明:兔属动物起源于北美大陆,通过白令大陆桥扩散到欧亚大陆,最后到达非洲大陆。Brooks简约分析(BPA)揭示兔属物种形成是在扩散事件之后,在不同的地理区域适应当时的生态环境导致种的发生。兔属动物经历了一个快速扩散和种发生的过程。贝叶斯放松分子钟方法估计种组内的分化时间显示:兔属物种的形成是在上新世早期(Plioceneepoch:4.29-5.39MyA)。云南兔(L.comusGAllen1927)是仅分布于云贵高原上的唯一一种兔属物种。我们应用线粒体DNA控制区第一高变区检测云南兔的群体遗传结构和系统地理结构模式,评价地理隔离,如高山、河流等对该物种的群体结构和系统地理模式的影响。分子变异分析显示(AMOVA)不同的地理区域间遗传差异明显,而且成对遗传差异与相应的地理距离成线性关系。错配核普酸分析(Mismatchanalysis)表明云南兔群体近期没有群体扩张。系统地理学的嵌套分析法揭示云南兔现有的群体遗传结构和遗传分化与云南高原复杂的地形地貌相关。高山、河流等地理隔离导致群体间有限的基因流形成了现有云南兔群体的分布。云南兔不同地理区域单倍型的分子系统分析以及明显的群体分化建议云南兔两个亚种的划分(L.c.comusandL.c.peni)。雪兔种组(thetimidusspeciescomplex)是生活于北半球高纬度区域的兔属物种。我们以该种组为模型,采用快速进化的mtDNA控制区序列对它们的系统地理结构进行比较研究。结果表明:雪兔种组以白令海峡为地理隔离存在显著的系变异为7.7%,变异范围从2.4%一11.5%。分子系统分析的最大简约树显示:来自乌孜别克斯坦的两个亚种(seertzoviandnikr枷ontana)首先发生遗传上的分化。之后盘羊祖先群体的扩散导致在中国某些地理区域可能有三个进化谱系的分化。盘羊祖先群体的扩散可能起始于亚洲大陆的西部通过中亚高原向南扩散。分布于中国的盘羊亚种中,阿尔金亚种(O.a.dalai-lamae)与西藏亚种(O.a.hodsoni)有着比蒙古亚种(aa.da附ino较近的系统进化关系。而来自乌孜别克斯坦的两个亚种(servertzoviandnigrimontana)与中国的盘羊亚种有着显著的遗传差异。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1. Plateau pikas Ochotona curzoniae are considered a pest species on the Tibetan Plateau because they compete with livestock for forage and their burrowing could contribute to soil erosion. The effectiveness of pest control programmes in Tibet has not been measured, and it is not known whether changes in livestock management have exacerbated problems with plateau pikas or compromised their control. This study measured the impact of control programmes and livestock management for forage conservation on populations of plateau pikas in alpine meadow in Naqu District, central Tibet, during 2004 and 2005.2. Current techniques for controlling plateau pikas in spring cause large reductions in abundance, but high density-dependent rates of increase result in no differences between treated and untreated populations by the following autumn. Rates of increase from spring to autumn are not influenced by standing plant biomass or concurrent grazing by yaks Bos grunniens and Tibetan sheep Ovis aries.3. In autumn there was significantly lower biomass outside fenced areas with year-round livestock grazing compared with inside fenced areas with equivalent or higher numbers of plateau pikas but predominantly winter grazing by livestock. Inside fenced areas, control of plateau pikas in spring produced no detectable effect on standing plant biomass at the end of the following summer compared with uncontrolled populations of plateau pikas.4. Regardless of their initial density, populations of plateau pikas declined rapidly over winter outside fenced areas where there was very low standing plant biomass in autumn. However, inside fenced areas with higher plant biomass in autumn, low-density populations of plateau pikas declined more slowly than high-density populations.5. Synthesis and applications. Current control programmes have limited effect because populations of plateau pikas can recover in one breeding season. There was no apparent increase in forage production in areas where plateau pikas were controlled. However, plateau pikas appear to benefit from changes in grazing management, with low-density populations declining less over winter inside fenced areas than elsewhere. It was not evident that control programmes are warranted or that they will improve the livelihoods of Tibetan herders.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

卡拉麦里山有蹄类自然保护区是世界著名的荒漠有蹄类自然保护区, 区内有蒙古野驴(E. hemionus)、鹅喉羚(G. subgutturosa)、盘羊(Ovis ammon)以及近期野放的普氏野马(E. przewalski)。经过多年有效保护和管理,区内蒙古野驴及鹅喉羚种群得到恢复并有较大增长。从2006年开始,我们在该保护区开展了蒙古野驴和鹅喉羚的食性构成、社群结构、种群密度、卧息及采食生境利用、季节性栖息地利用等方面的研究。主要结果如下: 采用粪样显微分析技术研究了蒙古野驴、鹅喉羚与家羊、家马和家骆驼3种家养动物春季、秋季和冬季食性组成及食物生态位。结果发现:(1) 该区域的蒙古野驴、鹅喉羚和家畜所采食的植物科数和种数都不相同,针茅、驼绒藜、蒿和梭梭在各自食谱中所占的比例不同, 但蒙古野驴、鹅喉羚和家畜主要采食针茅、驼绒藜、蒿和梭梭;(2) 春季、秋季和冬季这些野生与家养草食动物两两之间的食物生态位重叠均在0.8以上,最低为0.832(冬季:鹅喉羚和家马),最高达到0.986(秋季:蒙古野驴和家羊;秋季:家马和家羊)。五种有蹄类之间的食物生态位重叠度也达到了0.3以上。表明在卡拉麦里山有蹄类自然保护区,上述野生动物及季节性进入该自然保护区的家畜之间均存在食物竞争。冬季积雪深,食物短缺, 荒漠有蹄类易因冻饿及疾病等造成死亡。因此,应采取限制秋冬季进入该自然保护区家畜数量及调整放牧区域等保护管理措施,对该区域荒漠有蹄类实施有效保护。 对蒙古野驴和鹅喉羚的集群行为进行了初步研究。将鹅喉羚或蒙古野驴集群划分为雌性群、雄性群、母仔群、雌雄混群和独羚或独驴5种类型。共统计蒙古野驴556群次,计8235匹次。其中,雌雄混群223群次, 占40%, 为最多的集群类型;其余为雄性群(24%)、独驴(19%)、雌性群(11%)和母仔群(6% )。不同集群大小的比例差异极显著 (P=0.000)。其中2-30匹的集群占69%,独驴占18%,其余为13%。最大集群为266匹。除独驴外,其余4种集群类型的集群大小存在极显著差异。独驴作为一种特殊的集群类型,其占雄性个体的比例达63%,说明雄性个体比雌性更容易形成独驴。观察记录到鹅喉羚1286群次,计9148只次。其中,雌雄混群459群次, 占35%,为最多的集群类型;其余为独羚(18%)、母仔群(18%)、雄性群(17%)和雌性群(12%)。不同大小集群的比例差异极显著(P=0.000),其中2一15头的集群占73%, 16头以上集群占42%,独羚仅占3%,不同集群大小差异也极为显著(P=0.000)。除独羚外,其余4种集群类型的集群大小存在极显著差异。独羚作为一种特殊的集群类型,其雌性个体的比例占到55%,因此, 不能说明雄性比雌性更容易形成独羚。 分四个季节采用截线取样法,用DISTANCE5.0估计了蒙古野驴、鹅喉羚的密度和遇见率。根据DISTANCE5.0计算,该区域春季蒙古野驴种群密度为0.55±0.14匹/km2 (平均数±标准差,下同),夏季为0.60±0.13匹/km2,秋季为0.78±0.19匹/km2和冬季为0.54±0.14匹/km2。春季、夏季、秋季和冬季的鹅喉羚种群密度分别为1.14± 0.18头/km2,0.95±0.12头/km2,1.08±0.18头/km2和1.54±0.31头/km2。将这些结果与本区域不同时期及不同地域的蒙古野驴、鹅喉羚密度和遇见率数据进行了比较对比。截线取样法为研究干旱地区的有蹄类动物提供了一种标准方法,本研究结果为卡拉麦里自然保护区蒙古野驴和鹅喉羚的长期监测提供了基础数据。 采用样方法研究了鹅喉羚夏季和冬季卧息生境选择。夏季测定了49个卧迹样方,36个对照样方;冬季测定了75个卧迹样方,75个对照样方。研究发现,春季鹅喉羚主要选择平滩、下坡位和无坡位、海拔高度910米以上、与水源距离较远、远离道路、远离居民点、隐蔽级高、中低植被密度和中高草本密度的区域作为卧息生境;而冬季则主要选择山坡、阳坡和半阴半阳坡、中上坡位和下坡位、海拔900~1000m范围、离道路501~1000m以及大于2000m的距离、靠近居民点、中低隐蔽级、中厚度(1.1-3cm)雪深、中高植被密度和中高草本密度的区域作为卧息生境。主成分分析表明,卡拉麦里山鹅喉羚夏季季卧息样方前4个主成分的累积贡献率达到86.57%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅密度、至最近居民点距离、至永久水源最近距离和海拔。冬季该区域鹅喉羚卧息样方前4个主成分的累积贡献率达到73.88%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅密度和坡度。 通过设立样方研究了蒙古野驴的采食生境。研究发现,夏季和秋季两个季节蒙古野驴主要在平滩和山沟采食。集中在无坡向的平滩、1001m以上的海拔高度、与水源距离较近、远离道路、远离矿区等人类活动点、植被盖度高、草本盖度高、植物多样性高、草本多样性高(P<0.05)的区域采食。主成分分析表明,夏季影响蒙古野驴采食生境选择的环境因子是植物盖度、草本盖度、针茅盖度、植物密度、草本密度、针茅密度、植物种类、草本种类和禾本科种类。秋季影响蒙古野驴采食生境选择的环境因子是海拔、植物盖度、草本盖度、针茅盖度、植物密度、草本密度、针茅密度、植物种类、草本种类和禾本科种类。 利用卡山保护区不同季节野外种群调查数据,以3S技术为手段,评价了蒙古野驴和鹅喉羚季节性栖息地适宜性。首先把各季节蒙古野驴和鹅喉羚分布点图层,分别和固定水源点图层、道路图层、固定冬牧点图层和矿点图层进行叠加和距离查询,用Vanderploeg & Scavia’s选择指数(Ei*)分析了蒙古野驴和鹅喉羚季节性栖息地选择及其主要影响因素,建立了固定水源点、植被、道路、固定冬牧点和矿点对蒙古野驴和鹅喉羚栖息地影响强度的评价标准。通过缓冲区分析,分别研究了固定水源点、道路、固定冬牧点、矿点对蒙古野驴和鹅喉羚季节性栖息地的影响。通过缓冲区分析,综合研究了与人类活动有关的道路、固定冬牧点和矿点因子对蒙古野驴和鹅喉羚季节性栖息地的影响。最后将固定水源点、植被、道路、固定冬牧点和矿点等5个因子结合起来通过地图综合查询研究分析了这些因子对蒙古野驴和鹅喉羚季节性栖息地的综合影响,在固定水源点较适宜以上范围给出了该保护区蒙古野驴和鹅喉羚季节性不同适宜等级的生境面积。 我们建议采取以下积极措施来保护卡山保护区荒漠生态系统多样性以有效保护该区域内栖息的蒙古野驴和鹅喉羚:提高保护区周边社区政府的认识,提高公众参与自然资源和生物多样性保护的意识;加强水源地建设,积极采取飞播等措施,恢复植被,提高栖息生境质量;逐步限制进入卡拉麦里山越冬渡春的家畜数量;严格进入卡山保护区采矿制度,取缔非法矿业;加强草原围栏生态通道建设;与蒙古国合作建立跨国界的国际自然保护区;建立卡山自然保护区自然资源有偿使用机制;开展长期蒙古野驴和鹅喉羚种群监测。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Extradomain A from fibronectin (EDA) has an immunomodulatory role as fusion protein with viral and tumor antigens, but its effect when administered with bacteria has not been assessed. Here, we investigated the adjuvant effect of EDA in mice immunizations against Salmonella enterica subspecies enterica serovar Enteritidis (Salmonella Enteritidis). Since lipopolysaccharide (LPS) is a major virulence factor and the LPS O-polysaccharide (O-PS) is the immunodominant antigen in serological diagnostic tests, Salmonella mutants lacking O-PS (rough mutants) represent an interesting approach for developing new vaccines and diagnostic tests to differentiate infected and vaccinated animals (DIVA tests). Here, antigenic preparations (hot-saline extracts and formalin-inactivated bacterins) from two Salmonella Enteritidis rough mutants, carrying either intact (SE Delta waaL) or deep-defective (SE Delta gal) LPS-Core, were used in combination with EDA. Biotinylated bacterins, in particular SE Delta waaL bacterin, decorated with EDAvidin (EDA and streptavidin fusion protein) improved the protection conferred by hot-saline or bacterins alone and prevented significantly the virulent infection at least to the levels of live attenuated rough mutants. These findings demonstrate the adjuvant effect of EDAvidin when administered with biotinylated bacterins from Salmonella Enteritidis lacking O-PS and the usefulness of BEDA-SE Delta waaL as non-live vaccine in the mouse model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Livestock production contributes substantially to the livelihoods of poor rural farmers in Pakistan; strengthening pastoral communities plays an imperative role in the country’s thrive for poverty alleviation. Intestinal helminths constitute a major threat for pastoral livestock keepers in the whole country because chronic infestation leads to distinct losses in livestock productivity, particularly the growth of young animals. Synthetic anthelmintics have long been considered the only effective way of controlling this problem but high prices, side effects and chemical residues/toxicity problems, or development of resistance, lead to their very limited use in many pastoral systems. Additionally, poor pastoralists in remote areas of Pakistan hardly have access to appropriate anthelmintic drugs, which are also relatively expensive due to the long routes of transportation. The search for new and more sustainable ways of supporting livestock keepers in remote areas has given rise to studies of ethno-botanicals or traditional plant-based remedies to be used in livestock health care. Plant-based remedies are cheap or free of cost, environmentally safe and generally create no problem of drug resistance; they thus might substitute allopathic drugs. Furthermore, these remedies are easily available in remote areas and simple to prepare and/or administer. Cholistan desert is a quite poor region of Pakistan and the majority of its inhabitants are practicing a nomadic life. The region’s total livestock population (1.29 million heads) is almost twice that of the human population. Livestock husbandry is the primordial occupation of the communities and traditionally wealth assessment was based on the number of animals, especially goats and sheep, owned by an individual. Fortunately, about 60% of this desert region is richly endowed with highly adapted grasses, shrubs and trees. This natural flora has a rich heritage of scientifically unexplored botanical pharmacopoeia. Against this background, the present research project that was conducted under the umbrella of the International Center for Development and Decent Work at Kassel University, focused on a development aspect: in the Cholistan desert region it was firstly examined how pastoralists manage their livestock, which major health problems they face for the different animal species, and which of the naturally occurring plants they use for the treatment of animal diseases (Chapter 2). For this purpose, a baseline survey was carried out across five locations in Cholistan, using a structured questionnaire to collect data from 100 livestock farmers (LF) and 20 local healers (LH). Most of LF and LH were illiterate (66%; 70%). On average, LH had larger herds (109 animals) than LF (85 animals) and were more experienced in livestock husbandry and management. On average LF spent about 163 Euro per year on the treatment of their livestock, with a huge variability in expenditures. Eighty-six traditional remedies based on 64 plants belonging to 43 families were used. Capparaceae was the botanical family with the largest number of species used (4), followed by Chenopodiaceae, Poaceae, Solanaceae and Zygophyllaceae (3). The plants Capparis decidua (n=55 mentions), Salsola foetida (n=52), Suaeda fruticosa (n=46), Haloxylon salicornicum (n=42) and Haloxylon recurvum (n=39) were said to be most effective against the infestations with gastrointestinal parasites. Aerial parts (43%), leaves (26%), fruits (9%), seeds and seed oils (9%) were the plant parts frequently used for preparation of remedies, while flowers, roots, bulbs and pods were less frequently used (<5%). Common preparations were decoction, jaggery and ball drench; oral drug administration was very common. There was some variation in the doses used for different animal species depending on age, size and physical condition of the animal and severity of the disease. In a second step the regionally most prevalent gastrointestinal parasites of sheep and goats were determined (Chapter 3) in 500 animals per species randomly chosen from pastoral herds across the previously studied five localities. Standard parasitological techniques were applied to identify the parasites in faecal samples manually collected at the rectum. Overall helminth prevalence was 78.1% across the 1000 animals; pure nematode infestations were most prevalent (37.5%), followed by pure trematode (7.9%), pure cestode (2.6%) and pure protozoa infestations (0.8%). Mixed infestations with nematodes and trematodes occurred in 6.4% of all animals, mixed nematode-cestode infestations in 3.8%, and all three groups were found in 19.1% of the sheep and goats. In goats more males (81.1%) than females (77.0%) were infested, the opposite was found in sheep (73.6% males, 79.5% females). Parasites were especially prevalent in suckling goats (85.2%) and sheep (88.5%) and to a lesser extent in young (goats 80.6%, sheep 79.3%) and adult animals (goats 72.8%, sheep 73.8%). Haemonchus contortus, Trichuris ovis and Paramphistomum cervi were the most prevalent helminths. In a third step the in vitro anthelmintic activity of C. decidua, S. foetida, S. fruticosa, H. salicornicum and H. recurvum (Chapter 2) was investigated against adult worms of H. contortus, T. ovis and P. cervi (Chapter 3) via adult motility assay (Chapter 4). Various concentrations ranging from 7.8 to 500 mg dry matter/ml of three types of extracts of each plant, i.e. aqueous, methanol, and aqueous-methanol (30:70), were used at different time intervals to access their anthelmintic activity. Levamisol (0.55 mg/ml) and oxyclozanide (30 mg/ml) served as positive and phosphate-buffered saline as negative control. All extracts exhibited minimum and maximum activity at 2 h and 12 h after parasite exposure; the 500 mg/ml extract concentrations were most effective. Plant species (P<0.05), extract type (P<0.01), parasite species (P<0.01), extract concentration (P<0.01), time of exposure (P<0.01) and their interactions (P<0.01) had significant effects on the number of immobile/dead helminths. From the comparison of LC50 values it appeared that the aqueous extract of C. decidua was more potent against H. contortus and T. ovis, while the aqueous extract of S. foetida was effective against P. cervi. The methanol extracts of H. recurvum were most potent against all three types of parasites, and its aqueous-methanol extract was also very effective against T. ovis and P. cervi. Based on these result it is concluded that the aqueous extract of C. decidua, as well as the methanol and aqueous-methanol extract of H. recurvum have the potential to be developed into plant-based drugs for treatment against H. contortus, T. ovis and P. cervi infestations. Further studies are now needed to investigate the in vivo anthelmintic activity of these plants and plant extracts, respectively, in order to develop effective, cheap and locally available anthelmintics for pastoralists in Cholistan and neighboring desert regions. This will allow developing tangible recommendations for plant-based anthelminthic treatment of sheep and goat herds, and by this enable pastoralists to maintain healthy and productive flocks at low costs and probably even manufacture herbal drugs for marketing on a regional scale.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Analizar la explosión docente y discente, provocada por las necesidades educativas de una población en pleno crecimiento y con acelerado desarrollo y por las ansias culturales que la época presente suscita. La situación de la enseñanza en Avilés a lo largo del siglo XX. Se analiza la situación a principios de siglo, el número de escuelas en Avilés en 1910 y la Enseñanza General Básica en el curso 76-77. Monografías, libros de Historia Local y de Pedagogía, estudios socio-económicos. La ley Moyano, aprobada el 9 de septiembre de 1857, se ocupó de estructurar la enseñanza en cada municipio, fijando el número de distritos y clases que correspondían teniendo en cuenta la población y su estructura de poblamiento. Como consecuencia de esta Ley y de las propuestas posteriores de las inspecciones de Primera Enseñanza, el Partido Judicial de Avilés quedaba repartido en 55 escuelas, número 81 veces menor que las unidades que tiene Avilés solamente en 1976. En el curso 1976-77, Avilés cuenta con 22 colegios, 10 centros incompletos, 421 unidades, 455 profesores y 14046 alumnos matriculados, a lo que hay que sumar 35 unidades de Preescolar con 1283 alumnos y 35 profesores, 27 unidades de Educación Especial con 230 alumnos y 27 profesores, 5 unidades de Educación Permanente con 150 alumnos y 5 profesores, 3 institutos de Bachillerato, una escuela de FP, un colegio técnico y una escuela de Artes y Oficios. La enseñanza en Avilés puede considerarse que está atendida en la EGB en forma satisfactoria y que aún se seguirán construyendo nuevos colegios en sustitución de los viejos, así como institutos de Bachillerato, centros profesionales y politécnicos. Todo esto, junto con la Casa de Cultura, Biblioteca Pública Municipal y otras bibliotecas de entidades, favorecerán y estimularán el afán de aprender. Se puede señalar a Avilés como uno de los municipios donde la inteligencia tiene el máximo aprecio y su cultura un interés primordial, tanto para las autoridades como para los vecinos.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

La sepsis es un evento inflamatorio generalizado del organismo inducido por un daño causado generalmente por un agente infeccioso. El patógeno más frecuentemente asociado con esta entidad es el Staphylococcus aureus, responsable de la inducción de apoptosis en células endoteliales debida a la producción de ceramida. Se ha descrito el efecto protector de la proteína C activada (PCA) en sepsis y su relación con la disminución de la apoptosis de las células endoteliales. En este trabajo se analizó la activación de las quinasas AKT, ASK1, SAPK/JNK y p38 en un modelo de apoptosis endotelial usando las técnicas de Western Blotting y ELISA. Las células endoteliales (EA.hy926), se trataron con C2-ceramida (130μM) en presencia de inhibidores químicos de cada una de estas quinasas y PCA. La supervivencia de las células en presencia de inhibidores químicos y PCA fue evaluada por medio de ensayos de activación de las caspasas 3, 7 y 9, que verificaban la muerte celular por apoptosis. Los resultados evidencian que la ceramida reduce la activación de AKT y aumenta la activación de las quinasas ASK, SAPK/JNK y p38, en tanto que PCA ejerce el efecto contrario. Adicionalmente se encontró que la tiorredoxina incrementa la activación/fosforilación de AKT, mientras que la quinasa p38 induce la defosforilación de AKT.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Desarrollar el modelo dialéctico-crítico como planteamiento alternativo a los enfoques técnicos y prácticos en 3 campos interrelacionados: ciencia, conciencia y práctica. Profundizar en teorías psicológicas, pedagógicas, epistemológicas, sociológicas y antropológicas para desarrollarlas en el marco general del modelo dialéctico-crítico y observar sus implicaciones en el desarrollo de actuaciones concretas de aula. Elaborar instrumentos de trabajo en el aula mediante procedimientos de investigación-acción. Experimentar un nuevo sistema de formación permanente del profesorado. (Enumeran varios objetivos específicos). 38 docentes de niveles comprendidos entre Preescolar de 4 años hasta estudios de Doctorado. Se constituyen 5 grupos de profesores para el desarrollo de la investigación: 1. Grupo de lenguaje. 2. Grupo de educación infantil. 3. Grupo de orientación. 4. Grupo de ciencias experimentales. 5. Grupo de educación universitaria. Aplican una metodología de investigación-acción en 4 fases: planificación, acción, estudio y reflexión. Los objetivos son sustituidos por 15 principios de procedimiento, que cumplen la doble función de orientar la actividad de los individuos y servir de criterios referenciales en la evaluación periódica del trabajo. Para elaborar las fases de forma cooperativa se establecen una serie de instrumentos a 3 niveles: individual, de grupo, y del conjunto de los grupos (grupos asociados). Igualmente están previstas una serie de actividades complementarias. Encuentros, plenarios, actas, dossiers, proyecto de investigación, estudios cuantitativos, coordinadoras, diario, proyecto de investigación. 1. El desarrollo del modelo dialéctico-crítico se ha realizado en sus aspectos más generales. Durante la investigación se han planteado elementos de avance tanto en la caracterización de la relación sociedad-educación, como en lo que se refiere a la relación conocimiento-educación. 2. Se ha profundizado en las fuentes teóricas propias del modelo, desarrollando además algunas de ellas en su vertiente curricular, es decir, en cuanto a sus posibilidades prácticas para el trabajo de aula. Entre estas teorías destacan: procesos de comprensión y expresión a partir de algunos planteamientos vigotskianos; desarrollos curriculares de la teoría de la actividad; modelo de orientación; el currículum orientado hacia una democracia radical; el pensamiento y la obra de Paulo Freire; diseño de instrucción de temas de carácter sociopolítico. 3. Se han encontrado elementos que pueden ser parte de proyectos curriculares o de intervención. 4. El sistema de formación permanente establece unas pautas organizativas concretas para aquellos grupos de profesores que deseen abordar tareas similares.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Taphonomic studies regularly employ animal analogues for human decomposition due to ethical restrictions relating to the use of human tissue. However, the validity of using animal analogues in soil decomposition studies is still questioned. This study compared the decomposition of skeletal muscle tissues (SMTs) from human (Homo sapiens), pork (Sus scrofa), beef (Bos taurus), and lamb (Ovis aries) interred in soil microcosms. Fixed interval samples were collected from the SMT for microbial activity and mass tissue loss determination; samples were also taken from the underlying soil for pH, electrical conductivity, and nutrient (potassium, phosphate, ammonium, and nitrate) analysis. The overall patterns of nutrient fluxes and chemical changes in nonhuman SMT and the underlying soil followed that of human SMT. Ovine tissue was the most similar to human tissue in many of the measured parameters. Although no single analogue was a precise predictor of human decomposition in soil, all models offered close approximations in decomposition dynamics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A controlled laboratory experiment is described, in principle and practice, which can be used for the of determination the rate of tissue decomposition in soil. By way of example, an experiment was conducted to determine the effect of temperature (12°C, 22°C) on the aerobic decomposition of skeletal muscle tissue (Organic Texel × Suffolk lamb (Ovis aries)) in a sandy loam soil. Measurements of decomposition processes included muscle tissue mass loss, microbial CO2 respiration, and muscle tissue carbon (C) and nitrogen (N). Muscle tissue mass loss at 22°C always was greater than at 12°C (p < 0.001). Microbial respiration was greater in samples incubated at 22°C for the initial 21 days of burial (p < 0.01). All buried muscle tissue samples demonstrated changes in C and N content at the end of the experiment. A significant correlation (p < 0.001) was demonstrated between the loss of muscle tissue-derived C (C1) and microbially-respired C (Cm) demonstrating CO2 respiration may be used to predict mass loss and hence biodegradation. In this experiment Q10 (12°C - 22°C) = 2.0. This method is recommended as a useful tool in determining the effect of environmental variables on the rate of decomposition of various tissues and associated materials.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the present study, the validation of an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of canine brucellosis is described. Two different antigenic extracts, obtained by heat or ultrasonic homogenization of microbial antigens from a wild isolate of Brucella canis bacteria, were compared by ELISA and Western blot (WB). A total of 145 canine sera were used to define sensitivity, specificity and accuracy of the ELISA as follows: (1) sera from 34 animals with natural B. canis infection, confirmed by blood culture and PCR, as well as 51 sera samples from healthy dogs with negative results by the agar-gel immunodiffusion (ACID) test for canine brucellosis, were used as the control panel for B. cants infection; and (2) to scrutinize the possibility of cross reactions with other common dog infections in the same geographical area in Brazil, 60 sera samples from dogs harboring known infections by Leptospira sp., Ehrlichia canis, canine distemper virus (CDV), Neospora caninum, Babesia canis and Leishmania chagasi (10 in each group) were included in the study. The ELISA using heat soluble bacterial extract (HE-antigen) as antigen showed the best values of sensitivity (91.18%), specificity (100%) and accuracy (96.47%). In the WB analyses, the HE-antigen showed no cross-reactivity with sera from dogs with different infections, while the B. canis sonicate had various protein bands identified by those sera. The performance of the ELISA standardized with the heat soluble B. canis antigen indicates that this assay can be used as a reliable and practical method to confirm infection by this microorganism, as well as a tool for seroepidemiological studies. (C) 2010 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of São Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'Associação Paulista de Criadores de Ovinos' (ASPACO; São Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.