Nuclear Structure of Bound States of Asymmetric Dark Matter

Models of Asymmetric Dark Matter (ADM) with a sufficiently attractive and long-range force gives rise to stable bound objects, analogous to nuclei in the Standard Model, called nuggets. We study the properties of these nuggets and compute their profiles and binding energies. Our approach, applicable to both elementary and composite fermionic ADM, utilizes relativistic mean field theory, and allows a more systematic computation of nugget properties, over a wider range of sizes and force mediator masses, compared to previous literature. We identify three separate regimes of nugget property behavior corresponding to (1) non-relativistic and (2) relativistic constituents in a Coulomb-like limit, and (3) saturation in an anti-Coulomb limit when the nuggets are large compared to the force range. We provide analytical descriptions for nuggets in each regime. Through numerical calculations, we are able to confirm our analytic descriptions and also obtain smooth transitions for the nugget profiles between all three regimes. We also find that over a wide range of parameter space, the binding energy in the saturation limit is an ${\cal O}(1)$ fraction of the constituent's mass, significantly larger than expectations in the non-relativistic case. In a companion paper, we apply our results to synthesis of ADM nuggets in the early Universe.Comment: 20 pages, 8 figures, 1 appendi

Fraud Risk Factor Of The Fraud Triangle Assessing The Likelihood Of Fraudulent Financial Reporting

This research examines risk factors of the fraud triangle, core of all fraud auditing standards, for assessing likelihood of fraudulent financial reporting. Significant variables, including analyst’s forecast error, debt ratio, directors’ and supervisors’ stock pledged ratio, percentage of sales related party transaction, number of historical restatements, and number of auditor switch, belong to pressure/incentive, opportunity and attitude/rationalization. Results indicate fraudulent reporting positively correlated to one of the following conditions: more financial pressure of a firm or supervisor of a firm, higher percentage of complex transactions of a firm, more questionable integrity of a firm’s managers, or more deterioration in relation between a firm and its auditor. A simple logistic model based on examples of fraud risk factors of ISA 240 and SAS 99 gauges the likelihood of fraudulent financial reporting and can benefit practitioners

Fraudulent Statements Disclosure And Financial Distress: A Discrete-Time Survival Analysis

This study uses discrete-time survival analysis (DTSA) to examine the influence of fraudulent statements disclosure on the probability of financial distress not only in the initial period subsequent to disclosure, but future periods as well. Evidence indicates DTSA is superior to logistic regression and extends a richer depiction of the probability after a first-time fraudulent statement disclosure. After fraudulent statements disclosure, 24% of the reporting firms experienced financial distress in Year 1, with the hazard function declines progressively in subsequent years. We find total liability to total assets, directors and supervisors’ stock pledged ratio, and CPA (Certified Public Accountant) change are definitely linked to financial distress probability (p-value <0.05). A DTSA model not only includes financial ratios, but also considers corporate governance variables to produce more accurate classification than those of alternative models

Approximate perturbed direct homotopy reduction method: infinite series reductions to two perturbed mKdV equations

An approximate perturbed direct homotopy reduction method is proposed and applied to two perturbed modified Korteweg-de Vries (mKdV) equations with fourth order dispersion and second order dissipation. The similarity reduction equations are derived to arbitrary orders. The method is valid not only for single soliton solution but also for the Painlev\'e II waves and periodic waves expressed by Jacobi elliptic functions for both fourth order dispersion and second order dissipation. The method is valid also for strong perturbations.Comment: 8 pages, 1 figur

Psychosocial risk factors associated with falls among Chinese community-dwelling older adults in Hong Kong

This study examined the relationship between psychosocial factors and falls among community-dwelling older adults in the Hong Kong Special Administrative Region of China. The study included 1573 adults aged 60 or above who lived at home and who were applying for long-term care services. These participants were part of a large cross-sectional survey carried out between 2003 and 2004 in which they completed the Hong Kong Chinese version of the Resident Assessment Instrument-Home Care (RAI-HC) assessment. Of those persons who were surveyed, 516 (32.8%, 95% CI 30.5% to 35.2%) had fallen in the previous 90 days. Bivariate analyses showed that five psychosocial factors (depressive symptoms, fear of falling, a decline in social activities, the number of hours of informal care support during weekdays and living alone) were significantly associated with falls (. P <. 0.05). Logistic regression analysis showed living alone (odds ratio (OR) = 0.62; 95% CI 0.44 to 0.86) was the only psychosocial factor significantly associated with falls, after adjusting for the known significant factors related to falls. It was also found that more elders who lived with others had environmental hazards than those who lived alone (71.0% vs 29.0%, 2 = 4.80, . P = 0.028). These findings suggested that living with others may not be as safe as we assume. Interventions to increase awareness of home safety and to seek co-operation with family members in falls prevention are recommended. Fall preventive strategies should be educated to family members who are living with frail older adults. On the other hand, Chinese older adults who live alone often receive support from relatives or friends. Social support seems to be crucial to prevent them from falls and this measure is recommended to be continued in the community. © 2010 Blackwell Publishing Ltd.postprin

New variable separation approach: application to nonlinear diffusion equations

The concept of the derivative-dependent functional separable solution, as a generalization to the functional separable solution, is proposed. As an application, it is used to discuss the generalized nonlinear diffusion equations based on the generalized conditional symmetry approach. As a consequence, a complete list of canonical forms for such equations which admit the derivative-dependent functional separable solutions is obtained and some exact solutions to the resulting equations are described.Comment: 19 pages, 2 fig

Note on the hydrodynamic description of thin nematic films: strong anchoring model

We discuss the long-wave hydrodynamic model for a thin film of nematic liquid crystal in the limit of strong anchoring at the free surface and at the substrate. We rigorously clarify how the elastic energy enters the evolution equation for the film thickness in order to provide a solid basis for further investigation: several conflicting models exist in the literature that predict qualitatively different behaviour. We consolidate the various approaches and show that the long-wave model derived through an asymptotic expansion of the full nemato-hydrodynamic equations with consistent boundary conditions agrees with the model one obtains by employing a thermodynamically motivated gradient dynamics formulation based on an underlying free energy functional. As a result, we find that in the case of strong anchoring the elastic distortion energy is always stabilising. To support the discussion in the main part of the paper, an appendix gives the full derivation of the evolution equation for the film thickness via asymptotic expansion

Rapid Evolution of BRCA1 and BRCA2 in Humans and Other Primates

The maintenance of chromosomal integrity is an essential task of every living organism and cellular repair mechanisms exist to guard against insults to DNA. Given the importance of this process, it is expected that DNA repair proteins would be evolutionarily conserved, exhibiting very minimal sequence change over time. However, BRCA1, an essential gene involved in DNA repair, has been reported to be evolving rapidly despite the fact that many protein-altering mutations within this gene convey a significantly elevated risk for breast and ovarian cancers. Results: To obtain a deeper understanding of the evolutionary trajectory of BRCA1, we analyzed complete BRCA1 gene sequences from 23 primate species. We show that specific amino acid sites have experienced repeated selection for amino acid replacement over primate evolution. This selection has been focused specifically on humans and our closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). After examining BRCA1 polymorphisms in 7 bonobo, 44 chimpanzee, and 44 rhesus macaque (Macaca mulatta) individuals, we find considerable variation within each of these species and evidence for recent selection in chimpanzee populations. Finally, we also sequenced and analyzed BRCA2 from 24 primate species and find that this gene has also evolved under positive selection. Conclusions: While mutations leading to truncated forms of BRCA1 are clearly linked to cancer phenotypes in humans, there is also an underlying selective pressure in favor of amino acid-altering substitutions in this gene. A hypothesis where viruses are the drivers of this natural selection is discussed.National Institutes of Health R01-GM-093086, 8U42OD011197-13National Science Foundation BCS-07115972Burroughs Wellcome FundMolecular Bioscience

Identification of a Genomic Reservoir for New TRIM Genes in Primate Genomes

Tripartite Motif (TRIM) ubiquitin ligases act in the innate immune response against viruses. One of the best characterized members of this family, TRIM5α, serves as a potent retroviral restriction factor with activity against HIV. Here, we characterize what are likely to be the youngest TRIM genes in the human genome. For instance, we have identified 11 TRIM genes that are specific to humans and African apes (chimpanzees, bonobos, and gorillas) and another 7 that are human-specific. Many of these young genes have never been described, and their identification brings the total number of known human TRIM genes to approximately 100. These genes were acquired through segmental duplications, most of which originated from a single locus on chromosome 11. Another polymorphic duplication of this locus has resulted in these genes being copy number variable within the human population, with a Han Chinese woman identified as having 12 additional copies of these TRIM genes compared to other individuals screened in this study. Recently, this locus was annotated as one of 34 “hotspot” regions that are also copy number variable in the genomes of chimpanzees and rhesus macaques. Most of the young TRIM genes originating from this locus are expressed, spliced, and contain signatures of positive natural selection in regions known to determine virus recognition in TRIM5α. However, we find that they do not restrict the same retroviruses as TRIM5α, consistent with the high degree of divergence observed in the regions that control target specificity. We propose that this recombinationally volatile locus serves as a reservoir from which new TRIM genes arise through segmental duplication, allowing primates to continually acquire new antiviral genes that can be selected to target new and evolving pathogens