679 research outputs found
Acute and Chronic Effects of Exercise on Appetite, Energy Intake, and Appetite-Related Hormones: The Modulating Effect of Adiposity, Sex, and Habitual Physical Activity.
Exercise facilitates weight control, partly through effects on appetite regulation. Single bouts of exercise induce a short-term energy deficit without stimulating compensatory effects on appetite, whilst limited evidence suggests that exercise training may modify subjective and homeostatic mediators of appetite in directions associated with enhanced meal-induced satiety. However, a large variability in responses exists between individuals. This article reviews the evidence relating to how adiposity, sex, and habitual physical activity modulate exercise-induced appetite, energy intake, and appetite-related hormone responses. The balance of evidence suggests that adiposity and sex do not modify appetite or energy intake responses to acute or chronic exercise interventions, but individuals with higher habitual physical activity levels may better adjust energy intake in response to energy balance perturbations. The effect of these individual characteristics and behaviours on appetite-related hormone responses to exercise remains equivocal. These findings support the continued promotion of exercise as a strategy for inducing short-term energy deficits irrespective of adiposity and sex, as well as the ability of exercise to positively influence energy balance over the longer term. Future well-controlled studies are required to further ascertain the potential mediators of appetite responses to exercise
Defining linkage to care following human immunodeficiency virus (HIV) diagnosis for public health monitoring in Europe
Prompt linkage to human immunodeficiency virus
(HIV) care after diagnosis is crucial to ensure optimal patient outcomes. However, few countries monitor this important public health marker and different
definitions have been applied, making country and
study comparisons difficult. This article presents an
expert-agreed, standard definition of linkage to care
for a pragmatic approach to public health monitoring,
appropriate to the European context. Here, linkage to
care is defined as patient entry into specialist HIV care
after diagnosis, measured as the time between the HIV
diagnosis date and one of the following markers: either
the first clinic attendance date, first CD4+ cell count or
viral load date, or HIV treatment start date, depending
on data availability; Linkage is considered prompt if
within 3 months of diagnosis. Application of this definition by researchers and public health professionals
when reporting surveillance or research data relating
to linkage to care after HIV diagnosis will enable reliable comparisons across countries, better assessment
of the success of health services programmes aimed
at improving peoples access to HIV treatment and care
and the identification of barriers limiting access to HIV
care across Europe
MOLA: a bootable, self-configuring system for virtual screening using AutoDock4/Vina on computer clusters
<p>Abstract</p> <p>Background</p> <p>Virtual screening of small molecules using molecular docking has become an important tool in drug discovery. However, large scale virtual screening is time demanding and usually requires dedicated computer clusters. There are a number of software tools that perform virtual screening using AutoDock4 but they require access to dedicated Linux computer clusters. Also no software is available for performing virtual screening with Vina using computer clusters. In this paper we present MOLA, an easy-to-use graphical user interface tool that automates parallel virtual screening using AutoDock4 and/or Vina in bootable non-dedicated computer clusters.</p> <p>Implementation</p> <p>MOLA automates several tasks including: ligand preparation, parallel AutoDock4/Vina jobs distribution and result analysis. When the virtual screening project finishes, an open-office spreadsheet file opens with the ligands ranked by binding energy and distance to the active site. All results files can automatically be recorded on an USB-flash drive or on the hard-disk drive using VirtualBox. MOLA works inside a customized Live CD GNU/Linux operating system, developed by us, that bypass the original operating system installed on the computers used in the cluster. This operating system boots from a CD on the master node and then clusters other computers as slave nodes via ethernet connections.</p> <p>Conclusion</p> <p>MOLA is an ideal virtual screening tool for non-experienced users, with a limited number of multi-platform heterogeneous computers available and no access to dedicated Linux computer clusters. When a virtual screening project finishes, the computers can just be restarted to their original operating system. The originality of MOLA lies on the fact that, any platform-independent computer available can he added to the cluster, without ever using the computer hard-disk drive and without interfering with the installed operating system. With a cluster of 10 processors, and a potential maximum speed-up of 10x, the parallel algorithm of MOLA performed with a speed-up of 8,64× using AutoDock4 and 8,60× using Vina.</p
Feasibility and acceptability of point of care HIV testing in community outreach and GUM drop-in services in the North West of England: A programmatic evaluation
Background: In Liverpool, injecting drug users (IDUs), men-who-have-sex-with-men (MSM) and UK Africans experience a disproportionate burden of HIV, yet services do not reach out to these groups and late presentations continue. We set out to: increase testing uptake in targeted marginalized groups through a community and genitourinary medicine (GUM)-based point of care testing (POCT) programme; and conduct a process evaluation to examine service provider inputs and document service user perceptions of the programme.
Methods: Mixed quantitative, qualitative and process evaluation methods were used. Service providers were trained to use fourth generation rapid antibody/antigen HIV tests. Existing outreach services incorporated POCT into routine practice. Clients completed a semi-structured questionnaire and focus group discussions (FGDs) were
held with service providers.
Results: Between September 2009 and June 2010, 953 individuals underwent POCT (GUM: 556 [59%]; communitybased
sites: 397 [42%]). Participants in the community were more likely to be male (p = 0.028), older (p < 0.001), of UK African origin (p < 0.001) and IDUs (p < 0.001) than participants from the GUM clinic. Seventeen new HIV diagnoses were confirmed (prevalence = 1.8%), 16 of whom were in risk exposure categories (prevalence: 16/517,
3.1%). Questionnaires and FGDs showed that clients and service providers were supportive of POCT, highlighting
benefits of reaching out to marginalised communities and incorporating HIV prevention messages.
Conclusions: Community and GUM clinic-based POCT for HIV was feasible and acceptable to clients and service
providers in a low prevalence setting. It successfully reached target groups, many of whom would not have
otherwise tested. We recommend POCT be considered among strategies to increase the uptake of HIV testing
among groups who are currently underserved
Left ventricular twist mechanics during incremental cycling and knee extension exercise in healthy men
Purpose: The objective of the present study was to investigate left ventricular (LV) twist mechanics in response to incremental cycling and isometric knee extension exercises. Methods: Twenty-six healthy male participants (age = 30.42 ± 6.17 years) were used to study peak twist mechanics at rest and during incremental semi-supine cycling at 30 and 60% work rate maximum (W) and during short duration (15 s contractions) isometric knee extension at 40 and 75% maximum voluntary contraction (MVC), using two-dimensional speckle tracking echocardiography. Results: Data presented as mean ± standard deviation or median (interquartile range). LV twist increased from rest to 30% W (13.21° ± 4.63° to 20.04° ± 4.76°, p 0.05), whilst twisting velocity increased (rest 89.15° ± 21.77° s to 75% MVC 124.32° ± 34.89° s, p 0.05) then increased from 40 to 75% MVC [−98.44 (43.54)° s to −138.42 (73.29)° s, p < 0.01]. Apical rotations and rotational velocities were greater than basal during all conditions and intensities (all p < 0.01). Conclusion: Cycling increased LV twist to 30% W which then remained unchanged thereafter, whereas twisting velocities showed further increases to greater intensities. A novel finding is that LV twist was unaffected by incremental knee extension, yet systolic and diastolic twisting velocities augmented with isometric exercise
Dusty Planetary Systems
Extensive photometric stellar surveys show that many main sequence stars show
emission at infrared and longer wavelengths that is in excess of the stellar
photosphere; this emission is thought to arise from circumstellar dust. The
presence of dust disks is confirmed by spatially resolved imaging at infrared
to millimeter wavelengths (tracing the dust thermal emission), and at optical
to near infrared wavelengths (tracing the dust scattered light). Because the
expected lifetime of these dust particles is much shorter than the age of the
stars (>10 Myr), it is inferred that this solid material not primordial, i.e.
the remaining from the placental cloud of gas and dust where the star was born,
but instead is replenished by dust-producing planetesimals. These planetesimals
are analogous to the asteroids, comets and Kuiper Belt objects (KBOs) in our
Solar system that produce the interplanetary dust that gives rise to the
zodiacal light (tracing the inner component of the Solar system debris disk).
The presence of these "debris disks" around stars with a wide range of masses,
luminosities, and metallicities, with and without binary companions, is
evidence that planetesimal formation is a robust process that can take place
under a wide range of conditions. This chapter is divided in two parts. Part I
discusses how the study of the Solar system debris disk and the study of debris
disks around other stars can help us learn about the formation, evolution and
diversity of planetary systems by shedding light on the frequency and timing of
planetesimal formation, the location and physical properties of the
planetesimals, the presence of long-period planets, and the dynamical and
collisional evolution of the system. Part II reviews the physical processes
that affect dust particles in the gas-free environment of a debris disk and
their effect on the dust particle size and spatial distribution.Comment: 68 pages, 25 figures. To be published in "Solar and Planetary
Systems" (P. Kalas and L. French, Eds.), Volume 3 of the series "Planets,
Stars and Stellar Systems" (T.D. Oswalt, Editor-in-chief), Springer 201
Geometry sensing by dendritic cells dictates spatial organization and PGE2-induced dissolution of podosomes
Assembly and disassembly of adhesion structures such as focal adhesions (FAs) and podosomes regulate cell adhesion and differentiation. On antigen-presenting dendritic cells (DCs), acquisition of a migratory and immunostimulatory phenotype depends on podosome dissolution by prostaglandin E2 (PGE2). Whereas the effects of physico-chemical and topographical cues have been extensively studied on FAs, little is known about how podosomes respond to these signals. Here, we show that, unlike for FAs, podosome formation is not controlled by substrate physico-chemical properties. We demonstrate that cell adhesion is the only prerequisite for podosome formation and that substrate availability dictates podosome density. Interestingly, we show that DCs sense 3-dimensional (3-D) geometry by aligning podosomes along the edges of 3-D micropatterned surfaces. Finally, whereas on a 2-dimensional (2-D) surface PGE2 causes a rapid increase in activated RhoA levels leading to fast podosome dissolution, 3-D geometric cues prevent PGE2-mediated RhoA activation resulting in impaired podosome dissolution even after prolonged stimulation. Our findings indicate that 2-D and 3-D geometric cues control the spatial organization of podosomes. More importantly, our studies demonstrate the importance of substrate dimensionality in regulating podosome dissolution and suggest that substrate dimensionality plays an important role in controlling DC activation, a key process in initiating immune responses
Effect of valdecoxib pretreatment on pain and secondary hyperalgesia: a randomized controlled trial in healthy volunteers [ISRCTN05282752, NCT00260325]
BACKGROUND: Induction of the COX-2 isoenzyme appears to play a major role in the genesis of central sensitization after nociceptive stimulation. This study aimed to investigate the efficacy of a single, oral dose of the specific COX-2 inhibitor-valdecoxib in attenuating the central sensitization – induced secondary hyperalgesia in a heat/capsaicin pain model in healthy volunteers. METHODS: The study was a randomized, double blind, placebo controlled, crossover, single dose efficacy trial using 20 healthy volunteers. Two hours following placebo or 40 mg, PO valdecoxib, participants underwent skin sensitization with heat/capsaicin, as well as supra-threshold pain and re-kindling measurements according to an established, validated pain model. Subjects rated pain intensity and unpleasantness on a visual analog scale and the area of secondary hyperalgesia was serially mapped. RESULTS: The area of secondary hyperalgesia produced after 40 mg of valdecoxib was no different than that after placebo. Furthermore, there were no significantly relevant differences when volunteers were treated with valdecoxib or placebo in relation to either cold- or hot pain threshold or the intensity of pain after supra-threshold, thermal pain stimulation. CONCLUSION: We demonstrated that a single, oral dose of valdecoxib when does not attenuate secondary hyperalgesia induced by heat/capsaicin in a cutaneous sensitization pain model in healthy volunteers
The Main Belt Comets and ice in the Solar System
We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies
Investigating Agrobacterium-Mediated Transformation of Verticillium albo-atrum on Plant Surfaces
Background: Agrobacterium tumefaciens has long been known to transform plant tissue in nature as part of its infection process. This natural mechanism has been utilised over the last few decades in laboratories world wide to genetically manipulate many species of plants. More recently this technology has been successfully applied to non-plant organisms in the laboratory, including fungi, where the plant wound hormone acetosyringone, an inducer of transformation, is supplied exogenously. In the natural environment it is possible that Agrobacterium and fungi may encounter each other at plant wound sites, where acetosyringone would be present, raising the possibility of natural gene transfer from bacterium to fungus. Methodology/Principal Findings: We investigate this hypothesis through the development of experiments designed to replicate such a situation at a plant wound site. A. tumefaciens harbouring the plasmid pCAMDsRed was co-cultivated with the common plant pathogenic fungus Verticillium albo-atrum on a range of wounded plant tissues. Fungal transformants were obtained from co-cultivation on a range of plant tissue types, demonstrating that plant tissue provides sufficient vir gene inducers to allow A. tumefaciens to transform fungi in planta. Conclusions/Significance: This work raises interesting questions about whether A. tumefaciens may be able to transform organisms other than plants in nature, or indeed should be considered during GM risk assessments, with furthe
- …