fMRI mapping of cortical centers following visual stimulation in postnatal pigs of different ages

Classical studies have demonstrated that the visual centers in primates consist of cortical areas V1, V2 and V4 and their branches. However, nothing is known about how these visual areas change in postnatal development. In the present studies, therefore, pigs aged 2, 4, and 6 months old, were stimulated visually with a colored checker board and the active sites in the cortex, cerebellum and brainstem recorded using functional magnetic resonance imaging (fMRI). In pigs aged 2 months old, visual stimulation induced an increase in activation of sites in the V2 and V4 cortical areas, as well as in the areas of the inferior aspect of the parietal and middle aspect of the temporal cortices, but not in the medial and caudal occipital cortex (V1 area). At 4 months old, the V1 area was also activated, and by 6 months old, an inferior sector in the prefrontal cortex was also activated. As the pigs aged, functional active sites were further demonstrated in the cerebellum and the brainstem, which probably had to do with action memory, and the control of the ocular muscles, respectively. It is concluded that the visual pathway of the pig mainly involves cortical areas that mature at 6 months of age.     

Determination of adipocyte size by computer image analysis

Methods that allow rapid and accurate determination of adipocyte size are important to studies of energy and glucose metabolism. The direct measurement of adipocyte size by microscopy is widely used, although the method is tedious and time consuming. Computer-assisted image analysis can overcome most of the disadvantages associated with this technique. We report a new method for determining adipocyte size by measuring the cross-sectional area of adipocytes with computer image analysis. This method allows a large number of adipocytes to be measured rapidly with computer hardware and software that are readily available.     

Local visual homing by matched-filter descent in image distances

In natural images, the distance measure between two images taken at different locations rises smoothly with increasing distance between the locations. This fact can be exploited for local visual homing where the task is to reach a goal location that is characterized by a snapshot image: descending in the image distance will lead the agent to the goal location. To compute an estimate of the spatial gradient in the distance measure, its value must be sampled at three noncollinear points. An animal or robot would have to insert exploratory movements into its home trajectory to collect these samples. Here we suggest a method based on the matched-filter concept that allows one to estimate the gradient without exploratory movements. Two matched filters – optical flow fields resulting from translatory movements in the horizontal plane – are used to predict two images in perpendicular directions from the current location. We investigate the relation to differential flow methods applied to the local homing problem and show that the matched-filter approach produces reliable homing behavior on image databases. Two alternative methods that only require a single matched filter are suggested. The matched-filter concept is also applied to derive a home-vector equation for a Fourier-based parameter method.     

Perception of spatial orientation in different g-levels

Spatial orientation perception was examined in experiments on the MIR94 mission, during parabolic flight, and in ground control experiments. Space flight subjects were asked to remember their initial orientation, then turned and, with eyes closed, signal the ceiling direction. Ground-based control subjects were asked to indicate their original starting position while rotating on their backs. Results indicate a sensory conflict related to the vestibular system can lead to spatial disorientation.     

Ventilatory functions of normal rats of different ages

1. Lung volume, respiratory mechanics and flow-volume curve were measured in 96 male Wistar rats weighing from 102 to 521 g. Their ages ranged from 31 to 137 days and therefore, most of them were in the rapidly growing phase. 2. Data except for functional residual capacity were obtained under conditions of artificial ventilation. 3. Total lung capacity and the fractions of lung volume of these animals were found to relate linearly with their body weights. 4. Most of the parameters concerning respiratory mechanics and flow-volume curve also changed generally in proportion to their body weights, but those standardized for lung volume were not constant but varied depending on the weights. 5. These results suggest that the mechanical properties of lungs of young rats are age-related and comparisons of ventilatory functions among those animals should be carefully done.     

基于高通量测序的不同年龄恒河猴肠道菌群结构差异分析

目的观察不同年龄恒河猴肠道菌群结构和丰度的变化。方法 50只恒河猴,分为成年(5～10岁)、老年(10岁以上)2组,其中成年组33只,老年组17只。采集动物的新鲜直肠粪便,提取DNA后使用Illumina高通量测序平台对样本中细菌16S rDNA-V3区进行测序,定量分析肠道菌群的结构和丰度。结果老年组和成年组获得的优化序列数差异无显著性(P> 0.05)。α-多样性分析,老年组恒河猴肠道菌群的Chao1指数(P=0.0174)、Simpson指数(P=0.0258)、ACE指数(P=0.0121)与成年组比较降低,Shannon指数与成年组比较升高(P=0.0132)。老年组与成年组相比,在门水平,拟杆菌门(Bacteroidetes)相对丰度升高(P=0.0013),厚壁菌门(Firmicutes)、螺旋体门(Spirochaetes)、疣微菌门(Verrucomicrobia)、粘胶球形菌门(Lentisphaerae)相对丰度降低(P=0.0283,P=0.0002,P=0.0482,P=0.0242)。在科水平,Prevotellaceae相对丰度升高(P=0.0001),Ruminococcaceae、Clostridiales、Spirochaetaceae、Christensenellaceae相对丰度降低(P=0.0039,P=0.0080,P=0.0002,P=0.0021)。在属水平,老年组unidentified_Prevotellaceae相对丰度升高(P=0.0001),乳杆菌属(Lactobacillus)、八迭球菌(Sarcina)、unidentified_Spirochaetaceae相对丰度降低(P=0.0114,P=0.0227,P=0.0028)。β-多样性分析,老年组肠道菌群与成年组分布在不同区域,差异有显著性(P=0.003)。LEfSe分析,在成年组,链球菌属(Streptococcus)、布赫纳氏菌属(buchnera)、乳杆菌属(lactobacillus)是具有统计学意义的生物标记物。结论恒河猴肠道菌群的结构随年龄增长而改变。丰度降低,多样性增高。     

Hydrocarbons in haemolymph of cockroaches of different ages

Gas chromatography has been adapted to the analysis of hydrocarbons in the supernatant of cockroach haemolymph. Samples of only 1–2 μl are required. A qualitative and quantitative difference was found in the principal hydrocarbons that occur in several genera of cockroaches. The totals and the relative quantities of the principal hydrocarbons in the American cockroach (Periplaneta americana (L.)) and in the German cockroach (Blattella germanica (L.)) are not exclusively sex-dependent but they also fluctuate with age.     

A program for at-risk high school students informed by evolutionary science

Improving the academic performance of at-risk high school students has proven difficult, often calling for an extended day, extended school year, and other expensive measures. Here we report the results of a program for at-risk 9th and 10th graders in Binghamton, New York, called the Regents Academy that takes place during the normal school day and year. The design of the program is informed by the evolutionary dynamics of cooperation and learning, in general and for our species as a unique product of biocultural evolution. Not only did the Regents Academy students outperform their comparison group in a randomized control design, but they performed on a par with the average high school student in Binghamton on state-mandated exams. All students can benefit from the social environment provided for at-risk students at the Regents Academy, which is within the reach of most public school districts.     

Health status of cloned cattle at different ages

The procedure of somatic cloning is associated with important losses during pregnancy and in the perinatal period, reducing the overall efficacy to less than 5% in most cases. A mean of 30% of the cloned calves die before reaching 6 months of age with a wide range of pathologies, including, for the most common, respiratory failure, abnormal kidney development, liver steatosis. Heart and liver weight in relation to body weight are also increased. Surviving animals, although mostly clinically normal, differ from controls obtained by artificial insemination (AI) within the first 1-2 months, to become undistinguishable from them thereafter. Hemoglobin concentrations, for instance, are lower, and leptin concentrations are elevated. In response to the lack of prospective studies addressing the health of adult clones, a long-term, 3-4-year study is currently being conducted to assess the health of mature bovine clones at INRA. Preliminary results over 1 year of study do not show any statistical difference between groups for hematological parameters.     

Impact of commuting distance and school timing on sleep of school students

Sleep and Biological Rhythms - The insufficiency of sleep has become a widespread problem. The global development and rise of megacities have resulted in a drastic change in the life style of...