Differential effect of denervation on free radical scavenging enzymes in slow and fast muscle of rat

To determine the effect of denervation on the free radical scavenging systems in relation to the mitochondrial oxidative metabolism in the slow twitch soleus and fast twitch extensor digitorum longus (EDL) muscles, the sciatic nerve of the rat was crushed in the mid-thigh region and the muscle tissue levels of 5 enzymes were studied 2 and 5 weeks following crush. Radioimmunoassays were utilized for the selective measurement of cuprozinc (cytosolic) and mangano (mitochondrial) superoxide dismutases. These data represent the first systematic report of free radical scavening systems in slow and fast muscles in response to denervation. Selective modification of cuprozinc and manganosuperoxide dismutases and differential regulation of GSH-peroxidase was demonstrated in slow and fast muscle

Piscivorous Bird Use of Aquaculture and Natural Water Bodies in Mississippi

Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these species on aquaculture and naturally occurring water bodies using aerial surveys from October through April of 2015–2016, 2016–2017, and 2017–2018. We modeled the proportion of each species on aquaculture as a function of year, date, and weather-related variables using quasi binomial generalized linear models. Egrets used aquaculture consistently more than what was proportionally available to them and use was not influenced by any of the variables we measured. Proportional use of aquaculture by cormorants was lowest during October through January but steadily increased through April, indicating a distribution shift toward aquaculture in the months immediately prior to their migration. The highest proportional use of aquaculture by cormorants occurred in 2016, a year when lethal control measures were not allowed against cormorants. Conversely, the least proportion of cormorants on aquaculture was in 2015 when cormorants could be lethally controlled under authority of an Aquaculture Depredation Order. This trend highlights the potential influence of changes in mortality risk, caused by changes in policy regarding lethal take of cormorants, on cormorant distribution between foraging option

Subitizing with Variational Autoencoders

Numerosity, the number of objects in a set, is a basic property of a given visual scene. Many animals develop the perceptual ability to subitize: the near-instantaneous identification of the numerosity in small sets of visual items. In computer vision, it has been shown that numerosity emerges as a statistical property in neural networks during unsupervised learning from simple synthetic images. In this work, we focus on more complex natural images using unsupervised hierarchical neural networks. Specifically, we show that variational autoencoders are able to spontaneously perform subitizing after training without supervision on a large amount images from the Salient Object Subitizing dataset. While our method is unable to outperform supervised convolutional networks for subitizing, we observe that the networks learn to encode numerosity as basic visual property. Moreover, we find that the learned representations are likely invariant to object area; an observation in alignment with studies on biological neural networks in cognitive neuroscience

Spatio-Temporal Interpolation Is Accomplished by Binocular Form and Motion Mechanisms

Spatio-temporal interpolation describes the ability of the visual system to perceive shapes as whole figures (Gestalts), even if they are moving behind narrow apertures, so that only thin slices of them meet the eye at any given point in time. The interpolation process requires registration of the form slices, as well as perception of the shape's global motion, in order to reassemble the slices in the correct order. The commonly proposed mechanism is a spatio-temporal motion detector with a receptive field, for which spatial distance and temporal delays are interchangeable, and which has generally been regarded as monocular. Here we investigate separately the nature of the motion and the form detection involved in spatio-temporal interpolation, using dichoptic masking and interocular presentation tasks. The results clearly demonstrate that the associated mechanisms for both motion and form are binocular rather than monocular. Hence, we question the traditional view according to which spatio-temporal interpolation is achieved by monocular first-order motion-energy detectors in favour of models featuring binocular motion and form detection

'It seemed churlish not to': How living non-directed kidney donors construct their altruism

Our objective was to explore how prospective altruistic kidney donors construct their decision to donate. Using a qualitative design and biographical-narrative semistructured interviews, we aimed to produce text for analysis on two levels: the social implications for subjectivity and practice and a tentative psychodynamic explanation of the participants’ psychological investment in the discourses they used. A total of six prospective altruistic kidney donors were interviewed. A psychosocial approach to the analysis was taken. In-depth discourse analysis integrated Foucauldian with psychodiscursive approaches and psychodynamic theory was applied to sections of text in which participants seemed to have particular emotional investment. Analysis generated three major discursive themes: other-oriented, rational and self-oriented discourses. The desire to donate was experienced as compelling by participants. Participants used discourses to position themselves as concerned with the needs of the recipient, to resist questioning and criticism, and to manage difficult feelings around mortality. Participants tended to reject personal motivations for altruistic donation, positioning relatives’ disapproval as selfish and illogical. These results suggest that the term ‘altruistic’ for living non-directed organ donation constrains available discourses, severely limiting what can be said, felt, thought and done by donors, clinicians and the public. A more useful approach would acknowledge potential psychological motives and gains for the donor

An Introduction to Statistical Issues and Methods in Metrology for Physical Science and Engineering

This article provides an overview of the interplay between statistics and measurement. Measurement quality affects inference from data collected and analyzed using statistical methods while appropriate data analysis quantifies the quality of measurements. This article brings material on statistics and measurement together in one place as a resource for practitioners. Both frequentist and Bayesian methods are discussed

Rigour in moderation processes is more important than the choice of method

doi: 10.1080/02602938.2016.1236183 AbstractProcesses for moderating assessments are much debated in higher education. The myriad approaches to the task vary in their demands on staff time and expertise, and also in how valid, reliable and fair to students they appear. Medical education, with its diverse range of assessments and assessors across clinical and academic domains presents additional challenges to moderation. The current review focuses on medical education, considering double-marking and benchmarking as two broad classes of moderation procedure, and argues that it is the process more than the type of procedure which is crucial for successful moderation. The advantages and disadvantages of each class of procedure are discussed in the light of our medical school?s current practices, and with respect to the limited empirical evidence within medical education assessment. Consideration of implementation is central to ensuring valid and reliable moderation. The reliability of assessor judgements depends more on the consistency of assessment formats and the application of clear and agreed assessment criteria than on the moderation process itself. This article considers these factors in relation to their impact on the reliability of moderation, and aims to help assessors and students appreciate the diversity of these factors by facilitating their consideration in the assessment process.AbstractProcesses for moderating assessments are much debated in higher education. The myriad approaches to the task vary in their demands on staff time and expertise, and also in how valid, reliable and fair to students they appear. Medical education, with its diverse range of assessments and assessors across clinical and academic domains presents additional challenges to moderation. The current review focuses on medical education, considering double-marking and benchmarking as two broad classes of moderation procedure, and argues that it is the process more than the type of procedure which is crucial for successful moderation. The advantages and disadvantages of each class of procedure are discussed in the light of our medical school?s current practices, and with respect to the limited empirical evidence within medical education assessment. Consideration of implementation is central to ensuring valid and reliable moderation. The reliability of assessor judgements depends more on the consistency of assessment formats and the application of clear and agreed assessment criteria than on the moderation process itself. This article considers these factors in relation to their impact on the reliability of moderation, and aims to help assessors and students appreciate the diversity of these factors by facilitating their consideration in the assessment process