首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14篇
  免费   1篇
  2020年   2篇
  2019年   1篇
  2016年   3篇
  2013年   6篇
  2011年   1篇
  2003年   1篇
  1995年   1篇
排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
2.
Abstract

Horses have played an important economic, military and cultural role in South African history. However, disease has always posed a threat to their survival. Horsesickness, a viral infection transmitted by midges from the genus culicoides, is endemic in much of the country but has historically assumed epizootic proportions in certain years. In the lowveld and Zululand nagana (trypanosomosis), spread by tsetse flies, has killed both horses and cattle and affected the distribution of human settlement and agricultural activities. In addition, much of South Africa is very arid, yet has rich floral taxa. Several plants, such as Senecio spp. are highly toxic to horses, but in times of drought and fodder shortages, equines are faced with the choice of starvation or potentially succumbing to toxicosis by eating poisonous weeds. This paper considers the environmental impact of these three types of horse diseases in South Africa and explores the scientific and ecological investigations undertaken since the late nineteenth century to try to control them. Research into horse diseases brought together the laboratory and the field and raised important questions about the part played by environmental factors, as opposed to just germs, in the distribution of livestock infections and the ability of farmers and scientists to tackle them effectively.  相似文献   
3.
4.
Mesofossil assemblages from several Cretaceous and Cenozoic units across Australia and New Zealand provide new evidence of insect and annelid behaviour. The earliest scale insects (Diaspididae, Coccoidea) from Australasia are described and represented by three scale morphotypes. The mesofossil assemblages also reveal clitellate annelid cocoon morphotypes, three morphotypes of arthropod coprolites and several insect piercement structures on gymnosperm leaf or stem fragments, possibly related to feeding or more likely oviposition. This research offers a new avenue for detecting cryptic terrestrial invertebrate groups and their interactions, particularly with plants, in the fossil record. The fossils demonstrate that insect/invertebrate activity can be preserved and identified in mesofossil suites, that such traces and exoskeleton fragments are relatively common in acid-extracted mesofossil suites, and that recognizable categories occur on multiple landmasses and at various ages.  相似文献   
5.
Cai, C.-y. & Wang, B., 2013. The oldest silken fungus beetle from the Early Cretaceous of southern China (Coleoptera: Cryptophagidae: Atomariinae). Alcheringa 37, 1–4. ISSN 0311-5518

Atomaria cretacea sp. nov., a new silken fungus beetle, is described and figured based on an impression fossil from the Lower Cretaceous Shixi Formation at a locality near Qingxi Town, Jiangxi Province, southern China. The new species can be referred to the extant family Cryptophagidae as supported by the tiny body size, the clubbed antenna with dilated antennomere 1, closely spaced antennal insertions, and abdominal ventrite 1 being longer than the remaining ventrites. It is placed in the extant subfamily Atomariinae based on the presence of a frontoclypeal suture and the absence of gular sutures; and tentatively in Atomaria based on its body size, sub-parallel body shape, and the presence of a frontoclypeal suture.

Chen-Yang Cai [caichenyang1988@163.com], Bo Wang [savantwang@gmail.com], State Key Laboratory of Palaeobiology and Stratigraphy; Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China. Received 11.11.2012; revised 26.1.2013; accepted 31.1.2013.  相似文献   
6.
Cai, C., Clarke, D.J., Huang, D. & Nel, A., 2014. A new genus and species of Steninae from the late Eocene of France (Coleoptera, Staphylinidae). Alcheringa 38, 557–562. ISSN 0311-5518.

A remarkable new genus and species of rove beetle, Eocenostenus fossilis gen. et sp. nov., is described and figured based on one well-preserved specimen from the late Eocene of Monteils (near Alès, Gard, France). Eocenostenus is definitively placed in the extant subfamily Steninae, based on the combination of dense and coarse body punctation, globular and protruding eyes, exposed and closely spaced antennal insertions on the vertex, and six visible abdominal terga. Eocenostenus differs from the two extant stenine genera Stenus and Dianous most notably in the structure of the prothorax, which is strongly transverse and with unusual anterolateral projections, and in the anteriorly placed antennal insertions. This new discovery highlights the palaeodiversity of a genus-poor subfamily and suggests that the early diversification of Steninae is probably complicated.

Chenyang Cai [] and Diying Huang [], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Rd., Nanjing 210008, PR China; Dave J Clarke [], Integrative Research Center, Field Museum of Natural History, 1400 S Lake Shore Drive, Chicago, IL 60605, USA; and André Nel [], Muséum National d’Histoire Naturelle, Institut de Systématique, Evolution, Biodiversité, ISYEB, UMR 7205 CNRS UPMC EPHE, CP50, 45 rue Buffon, F-75005 Paris, France. Received 23.1.2014; revised 2.5.2014; accepted 12.5.2014.  相似文献   
7.
Prehistoric field systems sometimes encompass excavated, pit‐like features which are difficult to classify due to the complex stratigraphies resulting from reuse, infilling and collapse. They are frequently classified as wells and watering holes, but other potential uses for excavated depressions are rarely cited. We argue the need for environmental archaeology in the interpretation of features of this nature, and present a case study from a Bronze Age site at Pode Hole, near Peterborough (UK), where fossil insect material clearly contradicts the archaeological interpretation. We present empirical evidence for a sealed context filled with dung which cannot be interpreted as a water source. This evidence strongly contrasts with other superficially similar features at the site.  相似文献   
8.
Insects are present in most archaeological contexts as a result of both natural and cultural processes. Insect data can be used to address a number of issues, including environmental reconstruction, forensics, identification of domesticates, taphonomy, and diet. This paper focuses on the archaeology of insect use in antiquity: their collection, processing, and storage and the archaeological manifestations of those activities. Consideration also is given to the incorporation of insect data into settlement/subsistence models.  相似文献   
9.
10.
Abstract

This article concerns the relationship between Abraham Lincoln's natural right argument against slavery and contemporary Darwinian biology. It is frequently supposed that the latter undermines the former. I argue to the contrary that natural right has been rediscovered independently by modern Darwinian biology, and that it largely confirms Lincoln's understanding of human nature.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号