Voluntary participation in an active learning exercise leads to a better understanding of physiology

Students learn best when they are focused and thinking about the subject at hand. To teach physiology, we must offer opportunities for students to actively participate in class. This approach aids in focusing their attention on the topic and thus generating genuine interest in the mechanisms involved. This study was conducted to determine if offering voluntary active learning exercises would improve student understanding and application of the material covered. To compare performance, an anonymous cardiorespiratory evaluation was distributed to two groups of students during the fall (control, n = 168) and spring (treatment, n = 176) semesters. Students in both groups were taught by traditional methods, and students in the treatment group had the option to voluntary participate in two additional active learning exercises: 1) a small group discussion, where students would discuss a physiology topic with their Teaching Assistant before running BIOPAC software for the laboratory exercise and 2) a free response question, where students anonymously responded to one short essay question after the laboratory exercise. In these formative assessments, students received feedback about their present state of learning from the discussion with their peers and also from the instructor comments regarding perceived misconceptions. As a result of the participation in these activities, students in the treatment group had a better overall performance [χ(2) (degree of freedom = 1) = 31.2, P < 0.001] on the evaluation (treatment group: 62% of responses correct and control group: 49%) with an observed difference of 13% (95% confidence interval: 8, 17). In conclusion, this study presents sufficient evidence that when the opportunity presents itself, students become active participants in the learning process, which translates into an improvement in their understanding and application of physiological concepts.     

Settlement decisions by the two-spotted spider mite Tetranychus urticae

In silk-spinning arthropods, silk can be used for web building, protection, and communication. Silk is an informative material about the presence of conspecifics. It can therefore inform on habitat suitability and hence assist in habitat choice. In this context, we investigated the influence of silk on microhabitat choice by the two-spotted spider mite, Tetranychus urticae. Three factors that could potentially influence habitat choice were manipulated: the strain, number, and the stage of mites. Our study showed that these factors all influence the choice of microhabitat. The tendency of whether to settle on a silk-covered area was influenced by the origin of mites (strain effect). Adult females showed a higher tendency to settle on an area covered with the silk laid by numerous congeners (number effect). Moreover, larvae seemed to be more responsive to the presence of silk than adults (stage effect). This suggests that individuals use silk as a social cue in selecting their microhabitat and that the spatial organization and group behaviour seem to be shaped by the individuals’ response to social cues, such as the amount of silk already present.     

Concealing of facial expressions by a wild Barbary macaque (Macaca sylvanus)

Behavioural research on non-vocal communication among non-human primates and its possible links to the origin of human language is a long-standing research topic. Because human language is under voluntary control, it is of interest whether this is also true for any communicative signals of other species. It has been argued that the behaviour of hiding a facial expression with one’s hand supports the idea that gestures might be under more voluntary control than facial expressions among non-human primates, and it has also been interpreted as a sign of intentionality. So far, the behaviour has only been reported twice, for single gorilla and chimpanzee individuals, both in captivity. Here, we report the first observation of concealing of facial expressions by a monkey, a Barbary macaque (Macaca sylvanus), living in the wild. On eight separate occasions between 2009 and 2011 an adult male was filmed concealing two different facial expressions associated with play and aggression (“play face” and “scream face”), 22 times in total. The videos were analysed in detail, including gaze direction, hand usage, duration, and individuals present. This male was the only individual in his group to manifest this behaviour, which always occurred in the presence of a dominant male. Several possible interpretations of the function of the behaviour are discussed. The observations in this study indicate that the gestural communication and cognitive abilities of monkeys warrant more research attention.     

Human Breath Analysis May Support the Existence of Individual Metabolic Phenotypes

The metabolic phenotype varies widely due to external factors such as diet and gut microbiome composition, among others. Despite these temporal fluctuations, urine metabolite profiling studies have suggested that there are highly individual phenotypes that persist over extended periods of time. This hypothesis was tested by analyzing the exhaled breath of a group of subjects during nine days by mass spectrometry. Consistent with previous metabolomic studies based on urine, we conclude that individual signatures of breath composition exist. The confirmation of the existence of stable and specific breathprints may contribute to strengthen the inclusion of breath as a biofluid of choice in metabolomic studies. In addition, the fact that the method is rapid and totally non-invasive, yet individualized profiles can be tracked, makes it an appealing approach.     

Body segment differences in surface area, skin temperature and 3D displacement and the estimation of heat balance during locomotion in hominins

The conventional method of estimating heat balance during locomotion in humans and other hominins treats the body as an undifferentiated mass. This is problematic because the segments of the body differ with respect to several variables that can affect thermoregulation. Here, we report a study that investigated the impact on heat balance during locomotion of inter-segment differences in three of these variables: surface area, skin temperature and rate of movement. The approach adopted in the study was to generate heat balance estimates with the conventional method and then compare them with heat balance estimates generated with a method that takes into account inter-segment differences in surface area, skin temperature and rate of movement. We reasoned that, if the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement affect heat balance during locomotion is correct, the estimates yielded by the two methods should be statistically significantly different. Anthropometric data were collected on seven adult male volunteers. The volunteers then walked on a treadmill at 1.2 m/s while 3D motion capture cameras recorded their movements. Next, the conventional and segmented methods were used to estimate the volunteers' heat balance while walking in four ambient temperatures. Lastly, the estimates produced with the two methods were compared with the paired t-test. The estimates of heat balance during locomotion yielded by the two methods are significantly different. Those yielded by the segmented method are significantly lower than those produced by the conventional method. Accordingly, the study supports the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement impact heat balance during locomotion. This has important implications not only for current understanding of heat balance during locomotion in hominins but also for how future research on this topic should be approached.     

Illusionary pattern detection in habitual gamblers

Does problem gambling arise from an illusion that patterns exist where there are none? Our prior research suggested that “hot hand,” a tendency to perceive illusory streaks in sequences, may be a human universal, tied to an evolutionary history of foraging for clumpy resources. Like other evolved propensities, this tendency might be expressed more stongly in some people than others, leading them to see luck where others see only chance. If the desire to gamble is enhanced by illusory pattern detection, such individual differences could be predictive of gambling risk. While previous research has suggested a potential link between cognitive strategies and propensity to gamble, no prior study has directly measured gamblers' cognitive strategies using behavioral choice tasks, and linked them to risk taking or gambling propensities. Using a computerized sequential decision-making paradigm that directly measured subjects' predictions of sequences, we found evidence that subjects who have a greater tendency to gamble also have a higher tendency to perceive illusionary patterns, as measured by their preferences for a random slot machine over a negatively autocorrelated one. Casino gamblers played the random slot machine significantly more often even though a training phase and a history of outcomes were provided. Additionally, we found a marginally significant group difference between gamblers and matched community members in their slot-machine choice proportions. Performance on our behavioral choice task correlated with subjects' risk attitudes toward gambling and their frequency of play, as well as the selection of choice strategies in gambling activities.     

RNA interference in the termite Reticulitermes flavipes through ingestion of double-stranded RNA

RNA interference (RNAi) represents a breakthrough technology for conducting functional genomics research in non-model organisms and for the highly targeted control of insect pests. This study investigated RNAi via voluntary feeding in the economically important pest termite, Reticulitermes flavipes. We used a high-dose double-stranded (ds) RNA feeding approach to silence two termite genes: one encoding an endogenous digestive cellulase enzyme and the other a caste-regulatory hexamerin storage protein. Contrary to results from previous low-dose studies that examined injection-based RNAi, high-dose silencing of either gene through dsRNA feeding led to significantly reduced group fitness and mortality. Hexamerin silencing in combination with ectopic juvenile hormone treatments additionally led to lethal molting impacts and increased differentiation of presoldier caste phenotypes (a phenotype that is not capable of feeding). These results provide the first examples of insecticidal effects from dsRNA feeding in a termite. Additionally, these results validate a high-throughput bioassay approach for use in (i) termite functional genomics research, and (ii) characterizing target sites of conventional and novel RNAi-based termiticides.     

Telomere length measurement-caveats and a critical assessment of the available technologies and tools

Studies of telomeres and telomere biology often critically rely on the detection of telomeric DNA and measurements of the length of telomere repeats in either single cells or populations of cells. Several methods are available that provide this type of information and it is often not clear what method is most appropriate to address a specific research question. The major variables that need to be considered are the material that is or can be made available and the accuracy of measurements that is required. The goal of this review is to provide a comprehensive summary of the most commonly used methods and discuss the advantages and disadvantages of each. Methods that start with genomic DNA include telomere restriction fragment (TRF) length analysis, PCR amplification of telomere repeats relative to a single copy gene by Q-PCR or MMQPCR and single telomere length analysis (STELA), a PCR-based approach that accurately measures the full spectrum of telomere lengths from individual chromosomes. A different set of methods relies on fluorescent in situ hybridization (FISH) to detect telomere repeats in individual cells or chromosomes. By including essential calibration steps and appropriate controls these methods can be used to measure telomere repeat length or content in chromosomes and cells. Such methods include quantitative FISH (Q-FISH) and flow FISH which are based on digital microscopy and flow cytometry, respectively. Here the basic principles of various telomere length measurement methods are described and their strengths and weaknesses are highlighted. Some recent developments in telomere length analysis are also discussed. The information in this review should facilitate the selection of the most suitable method to address specific research question about telomeres in either model organisms or human subjects.     

Comments on recent reports on infrared spectral detection of disease markers in blood components

The search for disease markers in whole blood, or easily accessible blood components by spectral methods is a highly important aspect in the field of biophotonic research for disease diagnostics and screening, since it promises a minimally invasive approach to assess an individual's state of health. Fourier transform infrared spectroscopy, in particular, promises to be a fast, inexpensive method to search for markers of disease, since it detects variation in the proteome, lipidome and metabolome of biofluids, or activation of immune cells. However, the analysis of any materials by spectral methods is confounded by external factors such as those related to sample deposition and data acquisition, and by inherent variations in blood plasma concentration of small molecules (lactate, carbonate, phosphate, glucose) that varies between individual subjects and even for a given individual, as a function of time. Furthermore, observed differences in spectral patterns between patient samples and the control group may be due to the body's immune response (in particular, to the albumin to globulin ratio) and therefore, may not be specific to disease. These factors need to be accounted for in any effort to reliably detect much smaller variations in the concentration of disease‐specific markers.     

大尺度不透水面遥感估算方法比较——以京津唐为例

城市不透水面既是常用的城市化程度指标,也是衡量环境质量的重要指标。采用遥感技术准确提取城市不透水面并分析其空间扩张过程,对生态城市建设具有重要意义。基于Landsat 5 TM影像,采用NDVI二元法和线性光谱分解法,分别提取北京、天津和唐山3个城市不透水面信息,并将不透水面估算结果与近同期的ALOS影像提取结果对比验证。结果表明,线性光谱分解法获取的不透水面结果较好,RMSE为20.6%,能有效提取大范围的不透水面信息。     

The Fiftieth Anniversary of Soviet Psychophysiology

It must be generally recognized today that areas "contiguous" to a particular science have great theoretical and practical importance, which arises during contact of various sciences in some important objective. This is particularly true with respect to such a complex research objective as the thinking human brain. We find the ancients already beginning to speculate about the question of the relation of the "soul" to the body and about which body organ has the closest relation to psychological activity. Gradually this question became more concrete and was broken down into a group of more particular problems on which many scholars have been working. The early "classical" psychophysiology was primarily concerned with study of the relation of the senses and perception to the physical properties of stimuli and to the anatomical-physiological apparatuses of the peripheral sense organs. Currently, the main emphasis is shifting more and more to a study of the central mechanisms of psychological processes. This fundamental shift in approach to the traditional "psychophysical" problem (now frequently referred to as the psychophysiological problem) first took place in the area of studying the mechanisms of association, and was subsequently spread over studies of perception, emotion, voluntary movements, cognitive processes, and, finally, individual psychological differences.     

Group choice and individual choices: modeling human social behavior with the Ideal Free Distribution

Group choice describes the behavioral phenomenon in which a group of individuals chooses between two behavioral alternatives over time and the Ideal Free Distribution (IFD) [Acta Biotheor. 19 (1970) 16] describes group choice analogous to individual choice and the matching law. Our experiments investigated the usefulness of IFD analyses of human group choice based on a procedure reported in Sokolowski et al. [Psych. Bull. Rev. 6 (1999) 157]. A group of humans distributed into two subgroups to receive points that could earn cash prizes. The participants aligned themselves into subgroups by choosing between two rows of chairs, two different colored cards, or two cyber-subgroups. Different methods of distributing points to participants showed that IFD matching was dependent on the method (i.e. sharing points evenly produced near IFD matching, but probabilistic point distribution produced more undermatching). In addition, the sensitivity measures of individual choices in the groups differed from the sensitivity of the groups' choices.     

案例教学法结合多媒体教学法在超声专业教学中的应用研究

目的:研究案例教学法结合多媒体教学法在超声专业教学中的应用效果。方法:选择2015年3月到2017年3月在我院超声科实习的112名医学院学生进行研究,按照随机数字表法将医学生分成观察组及对照组,各56例,对照组采用传统教学法实施教学,观察组则采用案例教学法以及多媒体教学法实施综合教学,在每学期末,统计并对比两组学生理论成绩和实践成绩,以及两组学生对教学方式的满意度。结果:观察组的理论成绩和实践成绩各项目分值均分别明显高于对照组,差异均有统计学意义(均P0.05)。观察组学生对教学方式的满意度为98.21%,明显高于对照组的87.50%,差异有统计学意义(P0.05)。结论:案例教学法与多媒体教学法的综合应用能够有效提升超声专业学生的理论成绩和实践成绩,还可改善其对教学方式的满意度,效果较好,临床超声教学可考虑将此种教学方式进行广泛推广,从而更有利于培养专业人才。     

Radio Frequency Identification and Motion-sensitive Video Efficiently Automate Recording of Unrewarded Choice Behavior by Bumblebees

We present two methods for observing bumblebee choice behavior in an enclosed testing space. The first method consists of Radio Frequency Identification (RFID) readers built into artificial flowers that display various visual cues, and RFID tags (i.e., passive transponders) glued to the thorax of bumblebee workers. The novelty in our implementation is that RFID readers are built directly into artificial flowers that are capable of displaying several distinct visual properties such as color, pattern type, spatial frequency (i.e., “busyness” of the pattern), and symmetry (spatial frequency and symmetry were not manipulated in this experiment). Additionally, these visual displays in conjunction with the automated systems are capable of recording unrewarded and untrained choice behavior. The second method consists of recording choice behavior at artificial flowers using motion-sensitive high-definition camcorders. Bumblebees have number tags glued to their thoraces for unique identification. The advantage in this implementation over RFID is that in addition to observing landing behavior, alternate measures of preference such as hovering and antennation may also be observed. Both automation methods increase experimental control, and internal validity by allowing larger scale studies that take into account individual differences. External validity is also improved because bees can freely enter and exit the testing environment without constraints such as the availability of a research assistant on-site. Compared to human observation in real time, the automated methods are more cost-effective and possibly less error-prone.     

Organelle association visualized by three-dimensional ultrastructural imaging of the yeast cell

This study was aimed at a better understanding of organelle organization in the yeast Saccharomyces cerevisiae with special emphasis on the interaction and physical association of organelles. For this purpose, a computer aided method was employed to generate three-dimensional ultrastructural reconstructions of chemically and cryofixed yeast cells. This approach showed at a high level of resolution that yeast cells were densely packed with organelles that had a strong tendency to associate at a distance of <30 nm. The methods employed here also allowed us to measure the total surface area and volume of organelles, the number of associations between organelles, and the ratio of associations between organelles per surface area. In general, the degree of organelle associations was found to be much higher in chemically fixed cells than in cryofixed cells, with endoplasmic reticulum/plasma membrane, endoplasmic reticulum/mitochondria and lipid particles/nuclei being the most prominent pairs of associated fractions. In cryofixed cells, similar preferences for organelle association were seen, although at lower frequency. The occurrence of specific organelle associations is believed to be important for intracellular translocation and communication. Membrane contact as a possible means of interorganelle transport of cellular components, especially of lipids, is discussed.     

Anchor profiles of HLA-specific peptides: analysis by a novel affinity scoring method and experimental validation

The study of intermolecular interactions is a fundamental research subject in biology. Here we report on the development of a quantitative structure-based affinity scoring method for peptide-protein complexes, named PepScope. The method operates on the basis of a highly specific force field function (CHARMM) that is applied to all-atom structural representations of peptide-receptor complexes. Peptide side-chain contributions to total affinity are scored after detailed rotameric sampling followed by controlled energy refinement. A de novo approach to estimate dehydration energies was developed, based on the simulation of individual amino acids in a solvent box filled with explicit water molecules. Transferability of the method was demonstrated by its application to the hydrophobic HLA-A2 and -A24 receptors, the polar HLA-A1, and the sterically ruled HLA-B7 receptor. A combined theoretical and experimental study on 39 anchor substitutions in FxSKQYMTx/HLA-A2 and -A24 complexes indicated a prediction accuracy of about two thirds of a log-unit in Kd. Analysis of free energy contributions identified a great role of desolvation and conformational strain effects in establishing a given specificity profile. Interestingly, the method rightly predicted that most anchor profiles are less specific than so far assumed. This suggests that many potential T-cell epitopes could be missed with current prediction methods. The results presented in this work may therefore significantly affect T-cell epitope discovery programs applied in the field of peptide vaccine development.     

河流生态系统健康及其评价

概括了河流生态系统健康概念的涵义,详细介绍了以着重藻类、无脊椎动物、鱼类为主要指示生物的河流生态系统健康的评价方法,并就其评价管理将这些方法分为预测模型法（predictive models）和多指标法（multimetrics两大类,提出了河流健康评价方法的发展方向,以及我国应尽快开展的研究工作。     

Remote Guidance of Untrained Turtles by Controlling Voluntary Instinct Behavior

Recently, several studies have been carried out on the direct control of behavior in insects and other lower animals in order to apply these behaviors to the performance of specialized tasks in an attempt to find more efficient means of carrying out these tasks than artificial intelligence agents. While most of the current methods cause involuntary behavior in animals by electronically stimulating the corresponding brain area or muscle, we show that, in turtles, it is also possible to control certain types of behavior, such as movement trajectory, by evoking an appropriate voluntary instinctive behavior. We have found that causing a particular behavior, such as obstacle avoidance, by providing a specific visual stimulus results in effective control of the turtle''s movement. We propose that this principle may be adapted and expanded into a general framework to control any animal behavior as an alternative to robotic probes.