1,332 research outputs found
Isospin dependence of 6He+p optical potential and the symmetry energy
A consistent folding analysis of the elastic p(6He,6He)p scattering and
charge exchange p(6He,6Li*)n reaction data measured at Elab=41.6A MeV has been
performed within the coupled channels formalism. We have used the isovector
coupling to link the isospin dependence of 6He+p optical potential to the cross
section of p(6He,6Li*)n reaction exciting the 0+ isobaric analog state (IAS) at
3.563 MeV in 6Li. Based on these results and the Hartree-Fock calculation of
asymmetric nuclear matter using the same isospin-dependent effective
nucleon-nucleon interaction, we were able to confirm that the most realistic
value of the symmetry energy Esym is around 31 MeV. Our analysis has also shown
that the measured charge exchange p(6He,6Li*)n data are quite sensitive to the
halo tail of the 6He density used in the folding calculation and the IAS of 6Li
is likely to have a halo structure similar to that established for the ground
state of 6He.Comment: Accepted for publication in Phys. Rev.
Wigner-Seitz cells in neutron star crust with finite range interactions
The structure of Wigner-Seitz cells in the inner crust of neutron stars is
investigated using a microcospic Hartree-Fock-BCS approach with finite range
D1S and M3Y-P4 interactions. Large effects on the densities are found compared
to previous predictions using Skyrme interactions. Pairing effects are found to
be small, and they are attenuated by the use of finite range interactions in
the mean field.Comment: 11 pages, 5 figure
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The Public-Private Divide in Prosecutions and Obtaining of Evidence: Towards a Code?
In English law, in spite of the existence of the Crown Prosecution Service, every person still has the right to bring a criminal prosecution. Nowadays, this right is little used by individuals acting in a personal capacity, but private prosecutions have become much more common in recent years as corporations have attempted to use them to protect their commercial interests, and as some law firms have encouraged individuals and corporations to bring them as a means of obtaining redress. In 1977, Lord Diplock stated that the right to bring a private prosecution is âa useful constitutional safeguard against capricious, corrupt or biased failure or refusal of [the relevant state] authorities to prosecute offenders against the criminal law.â1 However, there is more recent judicial authority for the view that the right to prosecute privately is a historical anomaly of little worth, and potentially dangerous.2
It is with both of these judicial views in mind that we examine the relationship between certain organisations which exist solely to protect the commercial interests of particular corporations, and English and Welsh state agencies such as police authorities and local councils, which have a duty to consider the public interest but which sometimes work in partnership with such organisations.We argue that this relationship raises serious concerns about the potential abuse of state power by private organisations, and that a specific code of conduct may be required to guard against such abuse
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Private prosecution: a useful constitutional safeguard or potentially dangerous historical anomaly?
In the light of recent English cases concerning the right of individuals to bring private prosecutions, this article argues that this right should be removed or circumscribed more closely. In particular, we advocate three reforms here if the power to launch private prosecutions is to remain
MECHANOMYOGRAPHIC ANALYSIS OF EXERCISE HYPERTROPHY - THE EFFECT ON MUSCLE CONTRACTILE PROPERTIES
This study investigated mechanomyographic (MMG) derived muscle changes during biceps brachii hypertrophy. Healthy participants (age: 23.73+- 2.67, n=19) performed unilateral biceps curls for 8 weeks (nondominant limb; treatment, dominant limb; control). Significant differences (
Prothonotary warbler demography and nest site selection in natural and artificial cavities in bottomland forests of Arkansas, USA [DĂ©mographie et sĂ©lection du site de nidification de la paruline orangĂ©e dans des cavitĂ©s naturelles et artificielles en forĂȘts sur terres basses de l\u27Arkansas, Ă.-U.]
Anthropogenic alterations to bottomland forests in the United States that occurred post-European settlement likely negatively affected many avian species. The Prothonotary Warbler (Protonotaria citrea), a secondary cavity nester that breeds predominantly in these forests, has steadily declined over the past 60 years, and our ability to mitigate this trend is partially limited by a lack of basic biological data. Although much research has been devoted to Prothonotary Warblers, most studies have focused on local breeding populations that use nest boxes; we lack information about habitat selection behavior and demographic parameters of individuals that use natural cavities, which includes the vast majority of the global population. We studied warblers nesting both in boxes and natural cavities in central Arkansas, USA. We aimed to evaluate: (1) microhabitat features important for nest site selection, (2) relationships between these features and nest survival, and (3) demographic parameters of individuals breeding in natural cavities versus nest boxes. We hypothesized (1) selected nest site characteristics are associated with nest survival, and (2) natural cavities and nest boxes provide similar nest features related to clutch size and number fledged, but that predation protection differs. We found that warblers preferred nesting in dead trees with cavities that were higher and shallower than available random cavities, and that canopy cover within 5 m of nests was inversely related to nest survival. Demographic parameters did not differ between natural cavities and nest boxes; however, when excluding flooded nests, boxes experienced lower rates of nest depredation. We believe that forest management strategies that increase the number of suitable dead nest trees and restore the natural hydrology of these ecosystems would create and improve habitat for this iconic species. We advocate multiscale experimental canopy cover manipulation to explore the causal mechanism(s) of the relationship we found between canopy cover and nest survival
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes.
For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy.
Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagyrelated protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field
Discrete element simulation of wet granular materials: plastic compression
We use Discrete Element Method (DEM) simulations in three dimensions (3D) to study the quasistatic response of very loose assemblies of frictional spherical grains to an isotropic compression in the presence of a small amount of an interstitial liquid, which gives rise to capillary menisci and attractive forces. Previous results obtained in 2D [8] are generalized to systems that may be observed in the laboratory. We study the influence of the initial assembling process and of various micromechanical parameters on the plastic
compression curves, from very loose states assembled at low Pâ to maximally compressed ones in which capillary cohesion is negligible at large Pâ. We also show how the plastic response along those compression curves is influenced by rolling resistance in contacts
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