Avoidance of reporter assay distortions from fused dual reporters

Positioning test sequences between fused reporters permits monitoring of both translation levels and framing, before and after the test sequence. Many studies, including those on recoding such as productive ribosomal frameshifting and stop codon readthrough, use distinguishable luciferases or fluorescent proteins, as reporters. Occasional distortions, due to test sequence product interference with the individual reporter activities or stabilities, are here shown to be avoidable by the introduction of tandem StopGo sequences (2A) flanking the test sequence. Using this new vector system (pSGDluc), we provide evidence for the use of a 3’ stem loop stimulator for $\textit{ACP2}$ readthrough, but failed to detect the reported $\textit{VEGFA}$ readthrough.This work was supported by grants from Science Foundation Ireland (12/IP/1492 and 13/1A/1853 to J.F.A.), National Institutes of Health (R01GM114291 and R21ES022716 to M.T.H.), Wellcome Trust (106207 to A.E.F.) and the European Research Council (646891 to A.E.F.)

The neurochemistry of agitation in Alzheimer's disease: a systematic review

OBJECTIVE: To provide an up-to-date systematic review of the characteristics, methodology and findings of studies that have investigated the neurochemistry of agitation in Alzheimer's disease (AD). METHODS: Electronic databases were searched for published peer-reviewed articles which provided data on any neurotransmitter system in relation to agitation in AD. Screening of titles and abstracts and data extraction from full texts were conducted in duplicate. RESULTS: Forty-five studies were included. Monoamines (serotonin, dopamine and noradrenaline) were most commonly investigated. A variety of methods were used to investigate the neurochemistry underlying agitation in AD and, although there were several conflicting findings, there was evidence of serotonergic deficit, relatively preserved dopaminergic function and compensatory overactivity of postsynaptic noradrenergic neurons in agitation in AD. CONCLUSIONS: Disruption of the dynamic balance between multiple neurotransmitter systems could impair functional neural networks involved in affective regulation and executive function. Differences in study design and methodology may have contributed to conflicting findings. Future studies that overcome these limitations (e.g. using standardized criteria to define agitation) and employ neuroimaging methods such as MRI/PET to investigate specific neural networks are needed to clarify the role of neurotransmitter alterations in these patients

Computer-Generated Ovaries to Assist Follicle Counting Experiments

Precise estimation of the number of follicles in ovaries is of key importance in the field of reproductive biology, both from a developmental point of view, where follicle numbers are determined at specific time points, as well as from a therapeutic perspective, determining the adverse effects of environmental toxins and cancer chemotherapeutics on the reproductive system. The two main factors affecting follicle number estimates are the sampling method and the variation in follicle numbers within animals of the same strain, due to biological variability. This study aims at assessing the effect of these two factors, when estimating ovarian follicle numbers of neonatal mice. We developed computer algorithms, which generate models of neonatal mouse ovaries (simulated ovaries), with characteristics derived from experimental measurements already available in the published literature. The simulated ovaries are used to reproduce in-silico counting experiments based on unbiased stereological techniques; the proposed approach provides the necessary number of ovaries and sampling frequency to be used in the experiments given a specific biological variability and a desirable degree of accuracy. The simulated ovary is a novel, versatile tool which can be used in the planning phase of experiments to estimate the expected number of animals and workload, ensuring appropriate statistical power of the resulting measurements. Moreover, the idea of the simulated ovary can be applied to other organs made up of large numbers of individual functional units

A sound-sensitive source of alpha oscillations in human non-primary auditory cortex

The functional organization of human auditory cortex can be probed by characterizing responses to various classes of sound at different anatomical locations. Along with histological studies this approach has revealed a primary field in posteromedial Heschl's gyrus (HG) with pronounced induced high-frequency (70-150 Hz) activity and short-latency responses that phase-lock to rapid transient sounds. Low-frequency neural oscillations are also relevant to stimulus processing and information flow, however their distribution within auditory cortex has not been established. Alpha activity (7-14 Hz) in particular has been associated with processes that may differentially engage earlier versus later levels of the cortical hierarchy, including functional inhibition and the communication of sensory predictions. These theories derive largely from the study of occipitoparietal sources readily detectable in scalp electroencephalography. To characterize the anatomical basis and functional significance of less accessible temporal-lobe alpha activity we analyzed responses to sentences in seven human adults (four female) with epilepsy who had been implanted with electrodes in superior temporal cortex. In contrast to primary cortex in posteromedial HG, a non-primary field in anterolateral HG was characterized by high spontaneous alpha activity that was strongly suppressed during auditory stimulation. Alpha-power suppression decreased with distance from anterolateral HG throughout superior temporal cortex, and was more pronounced for clear compared to degraded speech. This suppression could not be accounted for solely by a change in the slope of the power spectrum. The differential manifestation and stimulus-sensitivity of alpha oscillations across auditory fields should be accounted for in theories of their generation and function.SIGNIFICANCE STATEMENTTo understand how auditory cortex is organized in support of perception, we recorded from patients implanted with electrodes for clinical reasons. This allowed measurement of activity in brain regions at different levels of sensory processing. Oscillations in the alpha range (7-14 Hz) have been associated with functions including sensory prediction and inhibition of regions handling irrelevant information, but their distribution within auditory cortex is not known. A key finding was that these oscillations dominated in one particular non-primary field, anterolateral Heschl's gyrus, and were suppressed when subjects listened to sentences. These results build on our knowledge of the functional organization of auditory cortex and provide anatomical constraints on theories of the generation and function of alpha oscillations

Sequence learning modulates neural responses and oscillatory coupling in human and monkey auditory cortex

Learning complex ordering relationships between sensory events in a sequence is fundamental for animal perception and human communication. While it is known that rhythmic sensory events can entrain brain oscillations at different frequencies, how learning and prior experience with sequencing relationships affect neocortical oscillations and neuronal responses is poorly understood. We used an implicit sequence learning paradigm (an “artificial grammar”) in which humans and monkeys were exposed to sequences of nonsense words with regularities in the ordering relationships between the words. We then recorded neural responses directly from the auditory cortex in both species in response to novel legal sequences or ones violating specific ordering relationships. Neural oscillations in both monkeys and humans in response to the nonsense word sequences show strikingly similar hierarchically nested low-frequency phase and high-gamma amplitude coupling, establishing this form of oscillatory coupling—previously associated with speech processing in the human auditory cortex—as an evolutionarily conserved biological process. Moreover, learned ordering relationships modulate the observed form of neural oscillatory coupling in both species, with temporally distinct neural oscillatory effects that appear to coordinate neuronal responses in the monkeys. This study identifies the conserved auditory cortical neural signatures involved in monitoring learned sequencing operations, evident as modulations of transient coupling and neuronal responses to temporally structured sensory input

Three deeply divided lineages of the freshwater mussel genus Anodonta in western North America

Abstract The surprising diversity and recent dramatic decline of freshwater mussels in North America have been well documented, although inventory efforts to date have been concentrated in the eastern United States. Unlike their eastern counterparts, western freshwater mussels have received comparatively little attention. The accurate identity of western lineages is a necessary component for future inventory, monitoring, and ecological work involving these taxa. Here we initiate a study involving the most speciose genus (Anodonta) in western North America, incorporating information about type localities and type specimen morphology and describing the discovery of three highly divergent lineages among four western Anodonta species. In a limited phylogenetic analysis, we find (1) that A. californiensis/nuttalliana and A.oregonensis/kennerlyi are distinct, highly divergent clades, and (2) that A. beringiana is more closely allied with A. woodiana, an Asian species, than either of the other two western North American clades. We were largely unable to resolve the placement of these three clades with respect to other anodontines, and suggest the need for a broader phylogenetic framework. We recommend, however, that the existence of these three deeply divergent groups be considered in the development of regional monitoring, conservation and research plans despite the taxonomic uncertainty

Genotypic and phenotypic consequences of reintroduction history in the black-footed ferret (Mustela nigripes)

Abstract Population augmentation with translocated individuals has been shown to alleviate the effects of bottlenecks and drift. The first step to determine whether restoration for genetic considerations is warranted is to genetically monitor reintroduced populations and compare results to those from the source. To assess the need for genetic restoration, we evaluated genetic diversity and structure of reintroduced (n = 3) and captive populations of the endangered black-footed ferret (Mustela nigripes). We measured genotypic changes among populations using seven microsatellite markers and compared phenotypic changes with eight morphometric characters. Results indicated that for the population which rapidly grew postreintroduction, genetic diversity was equivalent to the captive, source population. When growth languished, only the population that was augmented yearly maintained diversity. Without augmentation, allelic diversity declined precipitously and phenotypic changes were apparent. Ferrets from the genetically depaupertate population had smaller limbs and smaller overall body size than ferrets from the two populations with greater diversity. Population divergence (F ST = 0.10 ± 0.01) was surprisingly high given the common source of populations. Thus, it appears that 5-10 years of isolation resulted in both genotypic divergence and phenotypic changes to populations. We recommend translocation of 30-40 captive individuals per annum to reintroduction sites which have not become established quickly. This approach will maximize the retention of genetic diversity, yet maintain the beneficial effects of local adaptation without being swamped by immigration

Fundamental limitations for quantum and nano thermodynamics

The relationship between thermodynamics and statistical physics is valid in the thermodynamic limit - when the number of particles becomes very large. Here, we study thermodynamics in the opposite regime - at both the nano scale, and when quantum effects become important. Applying results from quantum information theory we construct a theory of thermodynamics in these limits. We derive general criteria for thermodynamical state transformations, and as special cases, find two free energies: one that quantifies the deterministically extractable work from a small system in contact with a heat bath, and the other that quantifies the reverse process. We find that there are fundamental limitations on work extraction from nonequilibrium states, owing to finite size effects and quantum coherences. This implies that thermodynamical transitions are generically irreversible at this scale. As one application of these methods, we analyse the efficiency of small heat engines and find that they are irreversible during the adiabatic stages of the cycle.Comment: Final, published versio

Scientists Want More Children

Scholars partly attribute the low number of women in academic science to the impact of the science career on family life. Yet, the picture of how men and women in science – at different points in the career trajectory – compare in their perceptions of this impact is incomplete. In particular, we know little about the perceptions and experiences of junior and senior scientists at top universities, institutions that have a disproportionate influence on science, science policy, and the next generation of scientists. Here we show that having fewer children than wished as a result of the science career affects the life satisfaction of science faculty and indirectly affects career satisfaction, and that young scientists (graduate students and postdoctoral fellows) who have had fewer children than wished are more likely to plan to exit science entirely. We also show that the impact of science on family life is not just a woman's problem; the effect on life satisfaction of having fewer children than desired is more pronounced for male than female faculty, with life satisfaction strongly related to career satisfaction. And, in contrast to other research, gender differences among graduate students and postdoctoral fellows disappear. Family factors impede talented young scientists of both sexes from persisting to research positions in academic science. In an era when the global competitiveness of US science is at risk, it is concerning that a significant proportion of men and women trained in the select few spots available at top US research universities are considering leaving science and that such desires to leave are related to the impact of the science career on family life. Results from our study may inform university family leave policies for science departments as well as mentoring programs in the sciences

Do Interventions Designed to Support Shared Decision-Making Reduce Health Inequalities? : A Systematic Review and Meta-Analysis

Copyright: © 2014 Durand et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Increasing patient engagement in healthcare has become a health policy priority. However, there has been concern that promoting supported shared decision-making could increase health inequalities. Objective: To evaluate the impact of SDM interventions on disadvantaged groups and health inequalities. Design: Systematic review and meta-analysis of randomised controlled trials and observational studies.Peer reviewe