141 research outputs found
The Threat of Long-Arm Jurisdiction to Electronic Commerce
Unfortunately for those whose businesses rely on the Internet, an increasing amount of legal conflict is also arising in reaction to this new business medium. As attorneys and the courts attempt to sort out the Internet’s legal status quo, both are considering such pressing substantive issues as electronic contracts, privacy, trademark, copyright, defamation, computer crimes, censorship, and taxation. It is imperative that information system professionals become aware of how evolving Internet law will affect the medium they are charged with administrating. An informed IS community is also much more capable of mounting legal and political challenges to law that might thwart continued development of e-commerce
Precision constraints on radiative neutrino decay with CMB spectral distortion
We investigate the radiative decay of the cosmic neutrino background, and its
impact on the spectrum of the cosmic microwave background (CMB) that is known
to be a nearly perfect black body. We derive exact formulae for the decay of a
heavier neutrino into a lighter neutrino and a photon, , and of absorption as its inverse, , by
accounting for the precise form of the neutrino momentum distribution. Our
calculations show that if the neutrinos are heavier than eV,
the exact formulae give results that differ by 50%, compared with
approximate ones where neutrinos are assumed to be at rest. We also find that
spectral distortion due to absorption is more important for heavy neutrino
masses (by a factor of 10 going from a neutrino mass of 0.01 eV to 0.1
eV). By analyzing the CMB spectral data measured with COBE-FIRAS, we obtain
lower limits on the neutrino lifetime of s
(95% C.L.) for the smaller mass splitting and s for the larger mass splitting. These represent up to one order of
magnitude improvement over previous CMB constraints. With future CMB
experiments such as PIXIE, these limits will improve by roughly 4 orders of
magnitude. This translates to a projected upper limit on the neutrino magnetic
moment (for certain neutrino masses and decay modes) of , where is the Bohr magneton. Such constraints would
make future precision CMB measurements competitive with lab-based constraints
on neutrino magnetic moments.Comment: 14 pages, 9 figures. v2: Added a number of references and
clarifications. Matches version published in PR
Економіко-правове забезпечення формування та реалізації соціальної політики держави, регіону, міста
У статті визначено потребу послідовного правового забезпечення формування та реалізації соціальної політики в багаторівневій системі управління. Обґрунтовано зміст та особливості соціальної політики залежно від рівня управління. Сформульовано пропозиції з удосконалення соціальної політики держави та її регіонів, виконано їх правову регламентацію
Cocrystal structure of a class-I preQ1 riboswitch reveals a pseudoknot recognizing an essential hypermodified nucleobase
Riboswitches are mRNA domains that bind metabolites and modulate gene expression in cis. We report cocrystal structures of a remarkably compact riboswitch (34 nucleotides suffice for ligand recognition) from Bacillus subtilis selective for the essential nucleobase preQ1 (7-aminomethyl-7-deazaguanine). These reveal a previously unrecognized pseudoknot fold, and suggest a conserved gene-regulatory mechanism whereby ligand binding promotes sequestration of an RNA segment that otherwise assembles into a transcriptional anti-terminator
An analysis of benign human prostrate offers insight into the mechanism of apocrine secretion and the origin of prostasomes
The structure and function of normal human prostate is still not fully understood. Herein, we concentrate on the different cell types present in normal prostate, describing some previously unreported types and provide evidence that prostasomes are primarily produced by apocrine secretion. Patients (n = 10) undergoing TURP were prospectively consented based on their having a low risk of harbouring CaP. Scanning electron microscopy and transmission electron microscopy was used to characterise cell types and modes of secretion. Zinc levels were determined using Inductively Coupled Plasma Mass Spectrometry. Although merocrine secretory cells were noted, the majority of secretory cells appear to be apocrine; for the first time, we clearly show high-resolution images of the stages of aposome secretion in human prostate. We also report a previously undescribed type of epithelial cell and the first ultrastructural image of wrapping cells in human prostate stroma. The zinc levels in the tissues examined were uniformly high and X-ray microanalysis detected zinc in merocrine cells but not in prostasomes. We conclude that a significant proportion of prostasomes, possibly the majority, are generated via apocrine secretion. This finding provides an explanation as to why so many large proteins, without a signal peptide sequence, are present in the prostatic fluid
Analysis of Inducible Nitric Oxide Synthase Gene Polymorphisms in Vitiligo in Han Chinese People
Background: Vitiligo is a chronic depigmented skin disorder with regional melanocytes depletion. The pathogenesis was not completely clarified. Recently, more and more evidence suggested that polymorphisms of some genes are associated with vitiligo risk. Here, we want to examine the association between the inducible nitric oxide synthase (iNOS) gene polymorphisms and the risk of vitiligo in Chinese populations. Methods and Principal Findings: In a hospital-based case-control study of 749 patients with vitiligo and 763 age- and sexmatched healthy controls, three polymorphisms of iNOS gene were genotyped by using the PCR-restriction fragment length polymorphism (PCR-RFLP) and mutagenically separated PCR (MS-PCR) methods, respectively. We found the iNOS-954 polymorphism was associated with a significantly higher risk of vitiligo (adjusted OR = 1.36, 95 % CI = 1.02–1.81). Furthermore, this association is more pronounced in vulgaris vitiligo, active vitiligo and vitiligo without other autoimmune diseases in the stratification study. Analysis of haplotypes showed increased risk for the C-1173C-954CEx16+14 (OR = 1.44, 95% CI = 1.01–1.74). In addition, the serum iNOS activity is significantly associated with iNOS-954 combined genotype (GC+CC) and is much higher in vitiligo patients than in the controls (P,0.01). Logistic regression analysis of iNOS activity showed increased risk between higher activity and iNOS-954 GRC variant genotype carriers (Ptrend,0.001). Conclusions and Significance: INOS gene polymorphisms may play an important role in the genetic susceptibility to th
Critical phenomena and universal dynamics in one-dimensional driven diffusive systems with two species of particles
Recent work on stochastic interacting particle systems with two particle
species (or single-species systems with kinematic constraints) has demonstrated
the existence of spontaneous symmetry breaking, long-range order and phase
coexistence in nonequilibrium steady states, even if translational invariance
is not broken by defects or open boundaries. If both particle species are
conserved, the temporal behaviour is largely unexplored, but first results of
current work on the transition from the microscopic to the macroscopic scale
yield exact coupled nonlinear hydrodynamic equations and indicate the emergence
of novel types of shock waves which are collective excitations stabilized by
the flow of microscopic fluctuations. We review the basic stationary and
dynamic properties of these systems, highlighting the role of conservation laws
and kinetic constraints for the hydrodynamic behaviour, the microscopic origin
of domain wall (shock) stability and the coarsening dynamics of domains during
phase separation.Comment: 72 pages, 6 figures, 201 references (topical review for J. Phys. A:
Math. Gen.
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