184 research outputs found
Effects of environmental variability and offspring growth on the movement ecology of breeding Scopoli's shearwater Calonectris diomedea
Abstract
Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be located far from the colony, and return to the colony regularly. In this context, flexibility in movement behavior may be crucial for breeding success. During chick-rearing, Procellariformes species can alternate short trips lasting 1–4 days for chick provisioning with longer trips for self-provisioning in what has been called a dual-foraging strategy. We analyzed foraging trips from 136 Scopoli's shearwaters from three Mediterranean colonies tracked with GPS during 6 chick-rearing seasons to assess whether the adoption of a dual foraging strategy depends on the quality of habitat surrounding the colony. We found a marked dual-foraging strategy only in birds from the Linosa colony which was the largest colony in terms of breeding pairs and was characterized by having a lower marine habitat quality. Birds from this colony performed foraging trips that extended up to 369 km from the nest and lasted more than 10 days. In general, the decision to perform long lasting trips was triggered by lower values of primary production and higher offspring weight. Contrary to expectation, the decision to feed far from the colony was not related to the parents' weight. At the same time, despite the higher productivity offered by distant areas, the higher proportion of long trips performed by birds breeding in poor areas was not sufficient to maintain the same body mass as the ones breeding in richer areas
Force calculation on walls and embedded particles in multiparticle collision dynamics simulations
Colloidal solutions posses a wide range of time and length scales, so that it
is unfeasible to keep track of all of them within a single simulation. As a
consequence some form of coarse-graining must be applied. In this work we use
the Multi-Particle Collision Dynamics scheme. We describe a particular
implementation of no-slip boundary conditions upon a solid surface, capable of
providing correct force s on the solid bypassing the calculation of the
velocity profile or the stre ss tensor in the fluid near the surface. As an
application we measure the friction on a spherical particle, when it is placed
in a bulk fluid and when it is confined in a slit. We show that the
implementation of the no-slip boundary conditions leads to an enhanced Ensko g
friction, which can be understood analytically. Because of the long-range
nature of hydrodynamic interactions, the Stokes friction obtained from the
simulations is sensitive of the simulation box size. We address this topic for
the slit geometry, showing that that the dependence on the system size differs
very much from what is expected in a 3D system, where periodic boundary
conditions are used in all directions.Comment: To appear in Physical Review
Validity and everyday clinical applicability of lumbar muscle fatigue assessment methods in patients with chronic non-specific low back pain: a systematic review
Purpose: This systematic literature review aimed at examining the validity and applicability in everyday clinical rehabilitation practise of methods for the assessment of back muscle fatiguability in patients with chronic non-specific low back pain (CNSLBP).
Methods: Extensive research was performed in MEDLINE, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Embase, Physiotherapy Evidence Database (PEDro) and Cochrane Central Register of Controlled Trials (CENTRAL) databases from their inception to September 2014. Potentially relevant articles were also manually looked for in the reference lists of the identified publications. Studies examining lumbar muscle fatigue in people with CNSLBP were selected. Two reviewers independently selected the articles, carried out the study quality assessment and extracted the results. A modified Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale was used to evaluate the scientific rigour of the selected works.
Results: Twenty-four studies fulfilled the selection criteria and were included in the systematic review. We found conflicting data regarding the validity of methods used to examine back muscle fatigue. The Biering-Sorensen test, performed in conjunction with surface electromyography spectral analysis, turned out to be the most widely used and comparatively, the most optimal modality currently available to assess objective back muscle fatigue in daily clinical practise, even though critical limitations are discussed.
Conclusions: Future research should address the identification of an advanced method for lower back fatigue assessment in patients with CNSLBP which, eventually, might provide physical therapists with an objective and reliable test usable in everyday clinical practise
Female mating tactics in lekking fallow deer (Dama dama): experience explains inter-individual variability more than costs
Sex-mediated changes in foraging behaviour according to breeding stage in a monomorphic seabird adapted to rural habitats
In contrast to sexually size-dimorphic species, monomorphic ones rarely show sexual differences in foraging behaviour as such variations have been primarily attributed to dissimilar body size. To investigate this aspect, we analysed foraging behaviour in breeding gull-billed terns, Gelochelidon nilotica, a monomorphic seabird adapted to rural habitats. We equipped 19 breeding birds with GPS devices and assessed differences in foraging behaviour and habitat use according to sex and breeding stage. Foraging trip distance and duration and daily frequencies were influenced by both breeding stage and sex, with females, but not males, performing closer, more frequent and shorter duration trips during chick rearing than incubation. Females, but not males, increased the repeatability of foraging metrics from incubation to chick rearing, while both sexes increased individual foraging site fidelity between the two breeding stages. Agricultural fields were the most exploited habitat for both sexes, but females made more use of aquatic habitats than males, especially during chick rearing. By foraging in different ways and in different habitats, the breeding pair can provide a wider range of prey types to their offspring, maximizing the chances of delivering high quantity and quality of food items under different environmental conditions. Our work provides new additional evidence of sex differences in foraging behaviour of monomorphic species, while highlighting the need to better understand underlying mechanisms driving foraging niche divergence and the consequences for fitness
Theranostics in Boron neutron capture therapy
Boron neutron capture therapy (BNCT) has the potential to specifically destroy tumor cells without damaging the tissues infiltrated by the tumor. BNCT is a binary treatment method based on the combination of two agents that have no effect when applied individually:10B and thermal neutrons. Exclusively, the combination of both produces an effect, whose extent depends on the amount of10B in the tumor but also on the organs at risk. It is not yet possible to determine the10B concentration in a specific tissue using non-invasive methods. At present, it is only possible to measure the10B concentration in blood and to estimate the boron concentration in tissues based on the assumption that there is a fixed uptake of10B from the blood into tissues. On this imprecise assumption, BNCT can hardly be developed further. A therapeutic approach, combining the boron carrier for therapeutic purposes with an imaging tool, might allow us to determine the10B concentration in a specific tissue using a non-invasive method. This review provides an overview of the current clinical protocols and preclinical experiments and results on how innovative drug development for boron delivery systems can also incorporate concurrent imaging. The last section focuses on the importance of proteomics for further optimization of BNCT, a highly precise and personalized therapeutic approach
Theranostics in Boron neutron capture therapy
Boron neutron capture therapy (BNCT) has the potential to specifically destroy tumor cells without damaging the tissues infiltrated by the tumor. BNCT is a binary treatment method based on the combination of two agents that have no effect when applied individually:B and thermal neutrons. Exclusively, the combination of both produces an effect, whose extent depends on the amount ofB in the tumor but also on the organs at risk. It is not yet possible to determine theB concentration in a specific tissue using non-invasive methods. At present, it is only possible to measure theB concentration in blood and to estimate the boron concentration in tissues based on the assumption that there is a fixed uptake ofB from the blood into tissues. On this imprecise assumption, BNCT can hardly be developed further. A therapeutic approach, combining the boron carrier for therapeutic purposes with an imaging tool, might allow us to determine theB concentration in a specific tissue using a non-invasive method. This review provides an overview of the current clinical protocols and preclinical experiments and results on how innovative drug development for boron delivery systems can also incorporate concurrent imaging. The last section focuses on the importance of proteomics for further optimization of BNCT, a highly precise and personalized therapeutic approach.E.H.-H. and M.K. gratefully acknowledge support from the DFG (HE 1376/38-1); L.S. received funding from GEFLUC Grenoble Dauphiné Savoie
Context-dependent foraging habitat selection in a farmland raptor along an agricultural intensification gradient
Gradients of agricultural intensification in agroecosystems may determine uneven resource availability for
predators relying on these man-made habitats. In turn, these variations in resource availability may affect
predators’ habitat selection patterns, resulting in context-dependent habitat selection. We assessed the effects of
gradients of landscape composition and configuration on habitat selection of a colonial farmland bird of prey, the
lesser kestrel (Falco naumanni), relying on 76 GPS-tracked nestling-rearing individuals from 10 populations
scattered along an agricultural intensification gradient. Analyses were conducted considering two ecological
levels of aggregation (the population and the individual) and two spatial scales of habitat availability (the colony
surroundings and the individual home-range). Overall, non-irrigated croplands and semi-natural grasslands were
the most preferred habitats at both spatial scales. At the colony scale, lesser kestrels showed a preference for
grassland compared to non-irrigated crops, whereas the opposite was the case within individual home-ranges.
Conversely, croplands were positively selected with comparable intensity at both spatial scales. Strong selection
for grassland at the colony scale highlights the importance of this semi-natural habitat for the species. The
weaker preference for grassland at the home-range scale is likely due to the phenology and structure of the
vegetation in the late breeding season. Spatial scale differences in selection patterns may thus derive from spatiotemporal
changes in resource availability through the breeding season. The strength of selection for the two most
used habitats varied markedly among individuals. At the spatial scale of the colony, individual selection strength
for grasslands increased with decreasing compositional diversity of the surrounding landscape, suggesting that
agroecosystem heterogeneity may at least partly buffer the loss of semi-natural habitats. At the within homerange
scale, higher cropland availability reduced the strength of individual preference for this habitat, suggesting
a negative functional response possibly related to density-dependent processes acting on foraging
movements. Our study provides evidence that farmland species show context-dependent habitat selection patterns
in response to landscape gradients shaped by agricultural intensification as well as by intrinsic characteristics
and habitat availability. Our findings highlight the importance of addressing both individual and
population-level variability and considering multiple spatial scales in studies of habitat selection to inform
species’ management and conservation
Theranostics in Boron Neutron Capture Therapy
Boron neutron capture therapy (BNCT) has the potential to specifically destroy tumor cells without damaging the tissues infiltrated by the tumor. BNCT is a binary treatment method based on the combination of two agents that have no effect when applied individually: B-10 and thermal neutrons. Exclusively, the combination of both produces an effect, whose extent depends on the amount of B-10 in the tumor but also on the organs at risk. It is not yet possible to determine the B-10 concentration in a specific tissue using non-invasive methods. At present, it is only possible to measure the B-10 concentration in blood and to estimate the boron concentration in tissues based on the assumption that there is a fixed uptake of B-10 from the blood into tissues. On this imprecise assumption, BNCT can hardly be developed further. A therapeutic approach, combining the boron carrier for therapeutic purposes with an imaging tool, might allow us to determine the B-10 concentration in a specific tissue using a non-invasive method. This review provides an overview of the current clinical protocols and preclinical experiments and results on how innovative drug development for boron delivery systems can also incorporate concurrent imaging. The last section focuses on the importance of proteomics for further optimization of BNCT, a highly precise and personalized therapeutic approach
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