282 research outputs found
Neural circuits underlying nest building in male zebra finches
SDH thanks SICB for financial support and the work described here was conducted with the support of EASTBIO DTP from the Biotechnology and Biological Sciences Research Council (BBSRC, to SE), the School of Biology and NSERC (to ZJH), MARIE CURIE (Ares(2016)5869884 to EI), and BBSRC Roslin Institute strategic grant funding (BB/P013759/1, to SLM). EN was supported by the Erasmus Plus student exchange program to SLM.Nest building consists of a series of motor actions, which are concomitant with activity in regions of the anterior motor pathway, the social behaviour network and the reward circuity in nest building adult male zebra finches (Taeniopygia guttata). It is not clear, however, whether this activity is due to nest building, collection and/or manipulation of nest material. To identify which areas of the brain are specifically involved, we used immunohistochemistry to quantify the immediate early gene c-fos in male zebra finches that were nest building (Building), birds given a nestbox but could interact only with tied down nest material (Fixed), and birds that were not given a nestbox or nest material (Control). We investigated the following brain regions: the anterior motor pathway (anterior ventral mesopallium (AMV), anterior nidopallium (AN), anterior striatium (ASt)), areas of the social behaviour network (bed nucleus of the stria terminalis, dorsomedial sub division (BSTmd), lateral septum (LS)), the dopaminergic reward circuitry (ventral tegmental area (VTA)) and the cerebellum. We found that there was greater Fos-ir expression in the BSTmd, LS and AMV with increased material deposition; in LS, AMV ASt and folia VI with increased material carrying; in LS, AMV and ASt with increased nest material tucking; and in LS and all folia (except folium VIII) with increased tugging at tied down material. These data confirm a functional role for areas of the anterior motor pathway, social behaviour network and the cerebellum in nest material collection and manipulation by birdsPostprintPeer reviewe
Using computer algorithms to elucidate zebra finch reproductive behaviour
Birds that experience variation in climatic conditions must maintain a stable nest temperature during incubation for successful hatching of offspring. Varying nest structure and incubation behaviour may be the methods birds use to regulate nest temperature. We used a modeling approach to investigate how birds adjust incubation behaviour to ambient temperature.
Hidden Markov Models (HMM) have been used previously to predict the spatial distribution of animals based on the models’ ability to classify movement behaviour. We used a HMM to predict zebra finch (Taeniopygia guttata) incubation behaviour and nest structure from a nest temperature data set. The full data set consisted of data logger nest temperature records and video recordings of incubation behaviour in two different temperature conditions. Nest temperature from data loggers was used to obtain predictions about the timing, duration and frequency of incubation which could then be compared to video recordings of incubation behaviour and the structure of nests. Predicted results would be that zebra finches in a colder temperature would incubate for longer periods of time than warmer temperatures, and that experience at those temperatures would play a role in how successful their breeding attempt will be.
This research explores new uses of computational techniques in animal behaviour, animal cognition, and behavioural ecology, provides new information about behavioural regulation of nest temperature during incubation, and develops practical techniques for inferring behaviour from data loggers in the field and in the lab
MFGE8 does not influence chorio-retinal homeostasis or choroidal neovascularization in vivo
Purpose: Milk fat globule-epidermal growth factor-factor VIII (MFGE8) is necessary for diurnal outer segment phagocytosis and promotes VEGF-dependent neovascularization. The prevalence of two single nucleotide polymorphisms (SNP) in MFGE8 was studied in two exsudative or “wet” Age-related Macular Degeneration (AMD) groups and two corresponding control groups. We studied the effect of MFGE8 deficiency on retinal homeostasis with age and on choroidal neovascularization (CNV) in mice.
Methods: The distribution of the SNP (rs4945 and rs1878326) of MFGE8 was analyzed in two groups of patients with “wet” AMD and their age-matched controls from Germany and France. MFGE8-expressing cells were identified in Mfge8+/− mice expressing ß-galactosidase. Aged Mfge8+/− and Mfge8−/− mice were studied by funduscopy, histology, electron microscopy, scanning electron microscopy of vascular corrosion casts of the choroid, and after laser-induced CNV.
Results: rs1878326 was associated with AMD in the French and German group. The Mfge8 promoter is highly active in photoreceptors but not in retinal pigment epithelium cells. Mfge8−/− mice did not differ from controls in terms of fundus appearance, photoreceptor cell layers, choroidal architecture or laser-induced CNV. In contrast, the Bruch's membrane (BM) was slightly but significantly thicker in Mfge8−/− mice as compared to controls.
Conclusions: Despite a reproducible minor increase of rs1878326 in AMD patients and a very modest increase in BM in Mfge8−/− mice, our data suggests that MFGE8 dysfunction does not play a critical role in the pathogenesis of AMD
Influence of acute fasting on pain tolerance in healthy subjects: a randomised crossover study
BackgroundAlthough chronic pain and obesity are global health crises with substantial healthcare costs, little is known about the relationship between pain perception and eating behaviours. Food consumption has been reported to provide an analgesic effect by the release of neurotransmitters modulating the pain network. However, whether short-term (acute) fasting affects pain perception remains unclear.PurposeThis study aimed to investigate the effect of acute fasting on pain perception and whether attention and mood changes drove the observed changes.Patients and methodsThe cold pressor test (CPT) was used to investigate the pain tolerance of 25 healthy participants in both non-fasting and 12-h fasting sessions. They were randomised to either session with a crossover to the other after at least 24 h, with the experimenter blinded to the sessions. The pain tolerance was measured using a Stroop task in both attentive and distracted states. The Profile of Mood States (POMS) questionnaire was used to capture the mood, and a 10-point hunger scale was used to measure hunger. Mixed-effects models were used to investigate the influence of fasting and distraction on pain perception, accounting for the repeated measures.ResultsFasting reduced CPT pain tolerance, with fasting participants twice as likely to withdraw their hands early (hazard ratio = 2.4, 95% CI: 1.3–4.5). Though men tolerated CPT pain longer than women, there was no evidence that men responded to fasting differently than women (p = 0.9). In addition, no evidence supporting that fasting affected attention or mood was found. Nonetheless, it increased hunger scores by 2.7 points on a 10-point scale (95% CI: 1.2–4.2) and decreased blood glucose concentration levels by 0.51 mmol/L (95% CI: 0.19–0.84).ConclusionAcute fasting reduces pain tolerance in the healthy participants, and this effect is independent of gender and attention or mood changes
Equine Amplification and Virulence of Subtype IE Venezuelan Equine Encephalitis Viruses Isolated during the 1993 and 1996 Mexican Epizootics
To assess the role of horses as amplification hosts during the 1993 and 1996 Mexican Venezuelan equine encephalitis (VEE) epizootics, we subcutaneously infected 10 horses by using four different equine isolates. Most horses showed little or no disease and low or nonexistent viremia. Neurologic disease developed in only 1 horse, and brain histopathologic examination showed meningeal lymphocytic infiltration, perivascular cuffing, and focalencephalitis. Three animals showed mild meningoencephalitis without clinical disease. Viral RNA was detected in the brain of several animals 12-14 days after infection. These data suggest that the duration and scope of the recent Mexican epizootics were limited by lack of equine amplification characteristic of previous, more extensive VEE outbreaks. The Mexican epizootics may have resulted from the circulation of a more equine-neurotropic, subtype IE virus strain or from increased transmission to horses due to amplification by other vertebrate hosts or transmission by more competent mosquito vectors
Building democracy from below : lessons from Western Uganda
How to achieve democratisation in the neopatrimonial and agrarian environments that predominate in sub-Saharan Africa continues to present a challenge for both development theory and practice. Drawing on intensive fieldwork in Western Uganda, this paper argues that Charles Tilly’s ‘democratisation as process’ provides us with the framework required to explain the ways in which particular kinds of association can advance democratisation from below. Moving beyond the current focus on how elite-bargaining and certain associational forms may contribute to liberal forms of democracy, this approach helps identify the intermediate mechanisms involved in building democracy from below, including the significance of challenging categorical inequalities, notably through the role of producer groups, and of building trust networks, cross-class alliances and synergistic relations between civil and political society. The evidence and mode of analysis deployed here help suggest alternative routes for supporting local efforts to build democracy from below in sub-Saharan Africa
High Target Homology Does Not Guarantee Inhibition: Aminothiazoles Emerge as Inhibitors of \u3ci\u3ePlasmodium falciparum\u3c/i\u3e
In this study, we identified three novel compound classes with potent activity against Plasmodium falciparum, the most dangerous human malarial parasite. Resistance of this pathogen to known drugs is increasing, and compounds with different modes of action are urgently needed. One promising drug target is the enzyme 1-deoxy-D-xylulose-5- phosphate synthase (DXPS) of the methylerythritol 4-phosphate (MEP) pathway for which we have previously identified three active compound classes against Mycobacterium tuberculosis. The close structural similarities of the active sites of the DXPS enzymes of P. falciparum and M. tuberculosis prompted investigation of their antiparasitic action, all classes display good cell-based activity. Through structure−activity relationship studies, we increased their antimalarial potency and two classes also show good metabolic stability and low toxicity against human liver cells. The most active compound 1 inhibits the growth of blood-stage P. falciparum with an IC50 of 600 nM. The results from three different methods for target validation of compound 1 suggest no engagement of DXPS. All inhibitor classes are active against chloroquine-resistant strains, confirming a new mode of action that has to be further investigated
Caring for quality of care: symbolic violence and the bureaucracies of audit.
BACKGROUND: This article considers the moral notion of care in the context of Quality of Care discourses. Whilst care has clear normative implications for the delivery of health care it is less clear how Quality of Care, something that is centrally involved in the governance of UK health care, relates to practice. DISCUSSION: This paper presents a social and ethical analysis of Quality of Care in the light of the moral notion of care and Bourdieu's conception of symbolic violence. We argue that Quality of Care bureaucracies show significant potential for symbolic violence or the domination of practice and health care professionals. This generates problematic, and unintended, consequences that can displace the goals of practice. SUMMARY: Quality of Care bureaucracies may have unintended consequences for the practice of health care. Consistent with feminist conceptions of care, Quality of Care 'audits' should be reconfigured so as to offer a more nuanced and responsive form of evaluation
New Mass and Radius Constraints on the LHS 1140 Planets -- LHS 1140 b is Either a Temperate Mini-Neptune or a Water World
The two-planet transiting system LHS 1140 has been extensively observed since
its discovery in 2017, notably with , HST, TESS, and ESPRESSO, placing
strong constraints on the parameters of the M4.5 host star and its small
temperate exoplanets, LHS 1140 b and c. Here, we reanalyse the ESPRESSO
observations of LHS 1140 with the novel line-by-line framework designed to
fully exploit the radial velocity content of a stellar spectrum while being
resilient to outlier measurements. The improved radial velocities, combined
with updated stellar parameters, consolidate our knowledge on the mass of LHS
1140 b (5.600.19 M) and LHS 1140 c (1.910.06 M)
with unprecedented precision of 3%. Transits from , HST, and TESS are
jointly analysed for the first time, allowing us to refine the planetary radii
of b (1.7300.025 R) and c (1.2720.026 R).
Stellar abundance measurements of refractory elements (Fe, Mg and Si) obtained
with NIRPS are used to constrain the internal structure of LHS 1140 b. This
planet is unlikely to be a rocky super-Earth as previously reported, but rather
a mini-Neptune with a 0.1% H/He envelope by mass or a water world with a
water-mass fraction between 9 and 19% depending on the atmospheric composition
and relative abundance of Fe and Mg. While the mini-Neptune case would not be
habitable, a water-abundant LHS 1140 b potentially has habitable surface
conditions according to 3D global climate models, suggesting liquid water at
the substellar point for atmospheres with relatively low CO concentration,
from Earth-like to a few bars.Comment: 31 pages, 18 figures, accepted for publication in ApJ
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