833 research outputs found
Cytoplasmic human TDP-43 mislocalization induces widespread dendritic spine loss in mouse upper motor neurons
Amyotrophic lateral sclerosis (ALS) is defined by the destruction of upper- and lowermotor neurons. Post-mortem, nearly all ALS cases are positive for cytoplasmic aggregates containingthe DNA/RNA binding protein TDP-43. Recent studies indicate that this pathogenic mislocalizationof TDP-43 may participate in generating hyperexcitability of the upper motor neurons, the earliestdetectable change in ALS patients, yet the mechanisms driving this remain unclear. We investigatedhow mislocalisation of TDP-43 could initiate network dysfunction in ALS. We employed a tetracyclineinducible system to express either human wildtype TDP-43 (TDP-43WT) or human TDP-43 that cannotenter the nucleus (TDP-43∆NLS) in excitatory neurons (Camk2α promoter), crossed Thy1-YFPH miceto visualize dendritic spines, the major site of excitatory synapses. In comparison to both TDP-43WTand controls, TDP-43∆NLS drove a robust loss in spine density in all the dendrite regions of theupper motor neurons, most affecting thin spines. This indicates that TDP-43 is involved in thegeneration of network dysfunction in ALS likely through impacting the formation or durability ofexcitatory synapses. These findings are relevant to the vast majority of ALS cases, and providesfurther evidence that upper motor neurons may need to be protected from TDP-43 mediated synapticexcitatory changes early in disease
Determining the Contribution of Epidermal Cell Shape to Petal Wettability Using Isogenic Antirrhinum Lines
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
Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales
Most of the matter in the universe is not luminous and can be observed
directly only through its gravitational effect. An emerging technique called
weak gravitational lensing uses background galaxies to reveal the foreground
dark matter distribution on large scales. Light from very distant galaxies
travels to us through many intervening overdensities which gravitationally
distort their apparent shapes. The observed ellipticity pattern of these
distant galaxies thus encodes information about the large-scale structure of
the universe, but attempts to measure this effect have been inconclusive due to
systematic errors. We report the first detection of this ``cosmic shear'' using
145,000 background galaxies to reveal the dark matter distribution on angular
scales up to half a degree in three separate lines of sight. The observed
angular dependence of this effect is consistent with that predicted by two
leading cosmological models, providing new and independent support for these
models.Comment: 18 pages, 5 figures: To appear in Nature. (This replacement fixes tex
errors and typos.
Talking about sex after traumatic brain injury: perceptions and experiences of multidisciplinary rehabilitation professionals
Purpose: Research indicates that although 50–60% of people who have had a traumatic brain injury (TBI) experience changes in sexual functioning, sexuality issues remain largely unaddressed in rehabilitation. This study aimed to explore rehabilitation professionals’ perceptions and experiences of discussing sexuality with service-users who have had a TBI.
Method: Purposeful sampling was used to recruit 24 participants from two local National Health Service trusts and from a national charity. Four focus groups were conducted with pre-existing groups of professionals, using a semi-structured interview schedule. Focus group data were transcribed verbatim and analysed using thematic analysis.
Results: Six main themes were derived from the analysis: (1) sexuality after TBI is a specialist issue; (2) sexuality is a sensitive subject; (3) practicalities of discussing sexuality; (4) roles and responsibilities; (5) dilemmas about risk and vulnerabilities; and (6) organisational and structural issues.
Conclusions: Our findings suggest that a more proactive approach to addressing sexuality issues be taken by incorporating sexuality into assessments and by having sexuality information available for service-users. Support for professionals is also needed in the form of the development of policy, on-going training and supervision
Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden
We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the δ13C and δ15N values for animal references from Västerås. This research (Bäckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
A systematic analysis of host factors reveals a Med23-interferon-λ regulatory axis against herpes simplex virus type 1 replication
Herpes simplex virus type 1 (HSV-1) is a neurotropic virus causing vesicular oral or genital skin lesions, meningitis and other diseases particularly harmful in immunocompromised individuals. To comprehensively investigate the complex interaction between HSV-1 and its host we combined two genome-scale screens for host factors (HFs) involved in virus replication. A yeast two-hybrid screen for protein interactions and a RNA interference (RNAi) screen with a druggable genome small interfering RNA (siRNA) library confirmed existing and identified novel HFs which functionally influence HSV-1 infection. Bioinformatic analyses found the 358 HFs were enriched for several pathways and multi-protein complexes. Of particular interest was the identification of Med23 as a strongly anti-viral component of the largely pro-viral Mediator complex, which links specific transcription factors to RNA polymerase II. The anti-viral effect of Med23 on HSV-1 replication was confirmed in gain-of-function gene overexpression experiments, and this inhibitory effect was specific to HSV-1, as a range of other viruses including Vaccinia virus and Semliki Forest virus were unaffected by Med23 depletion. We found Med23 significantly upregulated expression of the type III interferon family (IFN-λ) at the mRNA and protein level by directly interacting with the transcription factor IRF7. The synergistic effect of Med23 and IRF7 on IFN-λ induction suggests this is the major transcription factor for IFN-λ expression. Genotypic analysis of patients suffering recurrent orofacial HSV-1 outbreaks, previously shown to be deficient in IFN-λ secretion, found a significant correlation with a single nucleotide polymorphism in the IFN-λ3 (IL28b) promoter strongly linked to Hepatitis C disease and treatment outcome. This paper describes a link between Med23 and IFN-λ, provides evidence for the crucial role of IFN-λ in HSV-1 immune control, and highlights the power of integrative genome-scale approaches to identify HFs critical for disease progression and outcome
Complaints handling in hospitals: an empirical study of discrepancies between patients' expectations and their experiences
<p>Abstract</p> <p>Background</p> <p>Many patients are dissatisfied with the way in which their complaints about health care are dealt with. This study tested the assumption that this dissatisfaction consists – in part at least – of unmet expectations.</p> <p>Methods</p> <p>Subjects were 279 patients who lodged a complaint with the complaints committees of 74 hospitals in the Netherlands. They completed two questionnaires; one on their expectations at the start of the complaints handling process, and one on their experiences after the complaints procedure (pre-post design; response 50%). Dependent variables are patients' satisfaction and their feeling that justice was done; independent variables are the association between patients' expectations and their experiences.</p> <p>Results</p> <p>Only 31% of the patients felt they had received justice from the complaints process.</p> <p>Two thirds of the patients were satisfied with the conduct of the complaints committee, but fewer were satisfied with the conduct of the hospital or the medical professional (29% and 18%). Large discrepancies between expectations and experiences were found in the case of doctors not admitting errors when errors had been made, and of hospital managements not providing information on corrective measures that were taken. Discrepancies collectively explained 51% of patients' dissatisfaction with the committee and one third of patients' dissatisfaction with the hospital and the professional. The feeling that justice was done was influenced by the decision on the complaint (well-founded or not), but also by the satisfaction with the conduct of the committee, the hospital management and the professional involved.</p> <p>Conclusion</p> <p>It is disappointing to observe that less than one third of the patients felt that justice had been done through the complaints handling process. This study shows that the feeling that justice had been done is not only influenced by the judgement of the complaints committee, but also by the response of the professional. Furthermore, hospitals and professionals should communicate on how they are going to prevent a recurrence of the events that led to the complaint.</p
The multiple roles of myelin protein genes during the development of the oligodendrocyte
It has become clear that the products of several of the earliest identified myelin protein genes perform functions that extend beyond the myelin sheath. Interestingly, these myelin proteins, which comprise proteolipid protein, 2′,3′-cyclic nucleotide 3′-phosphodiesterase and the classic and golli MBPs (myelin basic proteins), play important roles during different stages of oligodendroglial development. These non-myelin-related functions are varied and include roles in the regulation of process outgrowth, migration, RNA transport, oligodendrocyte survival and ion channel modulation. However, despite the wide variety of cellular functions performed by the different myelin genes, the route by which they achieve these many functions seems to converge upon a common mechanism involving Ca2+ regulation, cytoskeletal rearrangements and signal transduction. In the present review, the newly emerging functions of these myelin proteins will be described, and these will then be discussed in the context of their contribution to oligodendroglial development
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