草食性小型哺乳动物的食粪行为

食粪行为广泛存在于草食性中小型哺乳动物中,是特指动物取食由盲肠内容物所形成的粪便的行为。这些动物具有特殊的结肠分离机制,能够产生两种不同的粪便。食粪行为延长了食物在消化道中的平均滞留时间;提高了对高纤维食物的消化率;弥补了食物中氨基酸和维生素的缺乏,满足了动物对这些营养物质的需求;是动物消化过程中的一个特殊组成部分。食粪行为的节律性是动物对取食和食粪的风险权衡的结果。食粪行为的发展是与动物草食性的特点紧密相关的,是动物对身体较小、食物质量低和天敌威胁等不利因素适应的结果。本对这些方面的研究进展进行了综述。     

Occupational low-level exposure to hard metals: cobalt and tungsten biomonitoring as an effective tool to evaluate the effectiveness of industrial hygiene interventions for risk management

Abstract

Purpose: The aim of the study was to assess the exposure to Cobalt (Co) and Tungsten (W) in a group of hard metal tool sharpeners through a combined approach of air and biological monitoring, and to evaluate the effectiveness of a control and improvement intervention carried out in collaboration with the medical officers of the local Health Protection Agency, by biomonitoring.

Methods: We enrolled 132 workers from 17 companies of the province of Brescia, northern Italy. The study was performed in two phases: (1) an environmental and biomonitoring survey to assess the workers’ exposure to Co and W at their usual working conditions; (2) a further biomonitoring survey 3?months after the enforcement of a control and improvement intervention, to assess its effectiveness.

Results: Workers were found to be exposed to low concentration of airborne dust containing Co and W but after the intervention we recorded a significant decrease of the urinary concentrations of both Co and W. The extent of the decrease was correlated to the number of preventive industrial hygiene interventions that were carried out.

Conclusions: Biological monitoring of Co and W in the hard metal tools manufacturing industry is a sensitive and effective method to evaluate the effectiveness of prevention practices.     

A machine vision system to detect and count laying hens in battery cages

Manually counting hens in battery cages on large commercial poultry farms is a challenging task: time-consuming and often inaccurate. Therefore, the aim of this study was to develop a machine vision system that automatically counts the number of hens in battery cages. Automatically counting hens can help a regulatory agency or inspecting officer to estimate the number of living birds in a cage and, thus animal density, to ensure that they conform to government regulations or quality certification requirements. The test hen house was 87 m long, containing 37 battery cages stacked in 6-story high rows on both sides of the structure. Each cage housed 18 to 30 hens, for a total of approximately 11 000 laying hens. A feeder moves along the cages. A camera was installed on an arm connected to the feeder, which was specifically developed for this purpose. A wide-angle lens was used in order to frame an entire cage in the field of view. Detection and tracking algorithms were designed to detect hens in cages; the recorded videos were first processed using a convolutional neural network (CNN) object detection algorithm called Faster R-CNN, with an input of multi-angular view shifted images. After the initial detection, the hens’ relative location along the feeder was tracked and saved using a tracking algorithm. Information was added with every additional frame, as the camera arm moved along the cages. The algorithm count was compared with that made by a human observer (the ‘gold standard’). A validation dataset of about 2000 images achieved 89.6% accuracy at cage level, with a mean absolute error of 2.5 hens per cage. These results indicate that the model developed in this study is practicable for obtaining fairly good estimates of the number of laying hens in battery cages.     

Past and present forest vegetation in NE Slovenia derived from old maps

Abstract. Using old military and cadastral maps and modern vegetation maps, the changes in land use over the past 230 yr were followed. The following maps were used: the military map from the second half of the 18th century, the cadastral map of the ‘Economic cadastral survey for regulation of land taxes’ from the first half of the 19th century, and a field map made in the 1980s. A vegetation map of the area was made on the basis of satellite images. We used basic classification techniques combined with extensive field inspections and aerial photographs. The output of this procedure was verified in the field. Additionally, a comparison of statistical data about land use categories is presented. It was established that the last remaining areas of inundated riverine forest disappeared 200 yr ago, and since then only minor changes in land use have occurred.     

Premolar microwear and tooth use in Australopithecus afarensis

The mandibular third premolar (P₃) of Australopithecus afarensis is notable for extensive morphological variability (e.g., metaconid presence/absence, closure of the anterior fovea, root number) and temporal trends in crown length and shape change over its 700 Ka time range. Hominins preceding A. afarensis have unicuspid, mesiodistally elongated P₃s with smaller talonids, and subsequent australopiths have bicuspid, more symmetrically-shaped P₃ crowns with expanded talonids. For these features, A. afarensis is intermediate and, thus, evinces the incipient stages of P₃ molarization. Here, we examine A. afarensis P₃ Phase II microwear and compare it with that of Australopithecus africanus and Cercocebus atys, an extant hard-object specialist, to assess whether the role of the P₃ in food processing changed over time in A. afarensis. Premolar Phase II microwear textures are also compared with those of the molars to look for evidence of functional differentiation along the tooth row (i.e., that foods with different mechanical properties were processed by separate regions of the postcanine battery). Microwear textures were also examined along the mesial protoconid crest, the site of occlusion with the maxillary canine, of the A. afarensis P₃ and compared with the same region in Pan troglodytes to determine whether microwear can be useful for identifying changes in the occlusal relationship between the P₃ and maxillary canine in early Australopithecus. Finally, temporal trends in P₃ Phase II and mesial microwear are considered. Results indicate that 1) both the P₃ and molar Phase II facets of A. afarensis have less complex microwear textures than in A. africanus or C. atys; 2) A. afarensis P₃ and molar Phase II textures differ, though not to the extent seen in taxa that eat hard and tough items; 3) microwear along the A. afarensis mesial protoconid crest is clearly distinct from that of the P. troglodytes, indicating that there is no honing equivalent in A. afarensis; and 4) there is little evidence of change over time in A. afarensis P₃ microwear on either the mesial or Phase II facet. In sum, these results provide no evidence that A. afarensis routinely loaded either its premolars or molars to process hard objects or that A. afarensis P₃ function changed over time.     

Demersal fish assemblages associated with hard bottom habitat in the South Atlantic Bight of the U.S.A.

Synopsis Demersal fish communities associated with hard bottom habitats in the South Atlantic Bight were investigated in three depth zones (inner, middle and outer shelf) between 30° and 33°N latitudes. Fishes were sampled with trawls and baited fishing gear, and were observed by remotely operated underwater television. Most demersal hard bottom fishes demonstrated seasonal differences in abundance in each depth zone, especially at the inner and outer shelf stations. Diversity values from trawl catches were higher in winter than summer at inner and outer shelf stations, but lower in winter at middle shelf stations. Species richness was higher in summer than in winter at most stations, but H' diversity patterns were more influenced by community evenness. Diversity values were higher than those reported for similar depths in the Middle Atlantic Bight. Mean biomass of demersal teleosts for all stations combined was slightly greater in winter than in summer. There was no significant difference in biomass between stations in summer, however, middle shelf stations had significantly greater biomass than inner or outer shelf stations in winter. Biomass estimates from the hard bottom areas studied were considerably higher than those reported in the literature for sand bottom areas in the South Atlantic Bight, but less than those reported for tropical reefs. Cluster analysis revealed differences in community composition between day and night trawl tows at all stations, and greater seasonal differences in species composition at inner and outer shelf stations than at middle shelf depths. Underwater television provided useful complementary data to trawl catches, documented the presence of large fishes which avoided the trawl, and provided information on the community composition at high relief stations which could not be trawled.     

Physiological and genetic correlates of boldness: characterising the mechanisms of behavioural variation in rainbow trout, Oncorhynchus mykiss

Bold, risk-taking animals have previously been putatively linked with a proactive stress coping style whereas it is suggested shyer, risk-averse animals exhibit a reactive coping style. The aim of this study was to investigate whether differences in the expression of bold-type behaviour were evident within and between two lines of rainbow trout, Oncorhynchus mykiss, selectively bred for a low (LR) or high (HR) endocrine response to stress, and to link boldness and stress responsiveness with the expression of related candidate genes. Boldness was determined in individual fish over two trials by measuring the latency to approach a novel object. Differences in plasma cortisol concentrations and the expression of eight novel candidate genes previously identified as being linked with divergent behaviours or stress were determined. Bold and shy individuals, approaching the object within 180 s or not approaching within 300 s respectively, were evident within each line, and this was linked with activity levels in the HR line. Post-stress plasma cortisol concentrations were significantly greater in the HR line compared with the LR line, and six of the eight tested genes were upregulated in the brains of LR fish compared with HR fish. However, no direct relationship between boldness and either stress responsiveness or gene expression was found, although clear differences in stress physiology and, for the first time, gene expression could be identified between the lines. This lack of correlation between physiological and molecular responses and behavioural variation within both lines highlights the complexity of the behavioural-physiological complex.     

Neural signatures for sustaining object representations attributed to others in preverbal human infants

A major feat of social beings is to encode what their conspecifics see, know or believe. While various non-human animals show precursors of these abilities, humans perform uniquely sophisticated inferences about other people''s mental states. However, it is still unclear how these possibly human-specific capacities develop and whether preverbal infants, similarly to adults, form representations of other agents'' mental states, specifically metarepresentations. We explored the neurocognitive bases of eight-month-olds'' ability to encode the world from another person''s perspective, using gamma-band electroencephalographic activity over the temporal lobes, an established neural signature for sustained object representation after occlusion. We observed such gamma-band activity when an object was occluded from the infants'' perspective, as well as when it was occluded only from the other person (study 1), and also when subsequently the object disappeared, but the person falsely believed the object to be present (study 2). These findings suggest that the cognitive systems involved in representing the world from infants'' own perspective are also recruited for encoding others'' beliefs. Such results point to an early-developing, powerful apparatus suitable to deal with multiple concurrent representations, and suggest that infants can have a metarepresentational understanding of other minds even before the onset of language.     

给药对象特征对医药用途发明权利要求的影响 ——以百时美施贵宝公司与正大天晴公司专利纠纷一案为例

给药对象等给药特征对医药用途发明权利要求是否具备限定作用,在新颖性和创造性评判时是否予以考虑,一直存在不同见解。 通过对百时美施贵宝公司与正大天晴公司专利纠纷一案的缘由、审理过程进行介绍,并对其中所涉及的问题进行分析,探讨给药对象特 征对医药用途发明权利要求的影响。