Reflecting Solutions of High Order Elliptic Differential Equations in Two Independent Variables Across Analytic Arcs

Consideration is given specifically to sixth order elliptic partial differential equations in two independent real variables x, y such that the coefficients of the highest order terms are real constants. It is assumed that the differential operator has distinct characteristics and that it can be factored as a product of second order operators. By analytically continuing into the complex domain and using the complex characteristic coordinates of the differential equation, it is shown that its solutions, u, may be reflected across analytic arcs on which u satisfies certain analytic boundary conditions. Moreover, a method is given whereby one can determine a region into which the solution is extensible. It is seen that this region of reflection is dependent on the original domain of difinition of the solution, the arc and the coefficients of the highest order terms of the equation and not on any sufficiently small quantities; i.e., the reflection is global in nature. The method employed may be applied to similar differential equations of order 2n

Labor force participation: a stimulus to fertility in Puerto Rico?

Includes bibliographyPublicado en Demography, vol. 2, 196

Computational Models of Adult Neurogenesis

Experimental results in recent years have shown that adult neurogenesis is a significant phenomenon in the mammalian brain. Little is known, however, about the functional role played by the generation and destruction of neurons in the context of and adult brain. Here we propose two models where new projection neurons are incorporated. We show that in both models, using incorporation and removal of neurons as a computational tool, it is possible to achieve a higher computational efficiency that in purely static, synapse-learning driven networks. We also discuss the implication for understanding the role of adult neurogenesis in specific brain areas.Comment: To appear Physica A, 7 page

Lattice results for the decay constant of heavy-light vector mesons

We compute the leptonic decay constants of heavy-light vector mesons in the quenched approximation. The reliability of lattice computations for heavy quarks is checked by comparing the ratio of vector to pseudoscalar decay constant with the prediction of Heavy Quark Effective Theory in the limit of infinitely heavy quark mass. Good agreement is found. We then calculate the decay constant ratio for B mesons: $f_{B^*}/f_B= 1.01(0.01)(^{+0.04}_{-0.01})$. We also quote quenched $f_{B^*}=177(6)(17)$ MeV.Comment: 11 pages, 3 postscript figs., revtex; two references adde

Sub-mm detection of a high redshift Type 2 QSO

We report on the first SCUBA detection of a Type 2 QSO at z=3.660 in the Chandra Deep Field South. This source is X-ray absorbed, shows only narrow emission lines in the optical spectrum and is detected in the sub-mm: it is the ideal candidate in an evolution scheme for AGN (e.g. Fabian (1999); Page et al. (2004)) of an early phase corresponding to the main growth of the host galaxy and formation of the central black hole. The overall photometry (from the radio to the X-ray energy band) of this source is well reproduced by the spectral energy distribution (SED) of NGC 6240, while it is incompatible with the spectrum of a Type 1 QSO (3C273) or a starburst galaxy (Arp 220). Its sub-mm (850 \mu m) to X-ray (2 keV) spectral slope (alpha_SX) is close to the predicted value for a Compton-thick AGN in which only 1% of the nuclear emission emerges through scattering. Using the observed flux at 850 \mu m we have derived a SFR=550--680 M$_odot/yr and an estimate of the dust mass, M$_dust=4.2 10^8 M_odotComment: 6 Pages, 5 Figures, accepted for publication in MNRA

Developmental arrest of T cells in RpL22-deficient mice is dependent upon multiple p53 effectors

available in PMC 2012 July 15alpha beta and gamma delta lineage T cells are thought to arise from a common CD4–CD8– progenitor in the thymus. However, the molecular pathways controlling fate selection and maturation of these two lineages remain poorly understood. We demonstrated recently that a ubiquitously expressed ribosomal protein, Rpl22, is selectively required for the development of alpha beta lineage T cells. Germline ablation of Rpl22 impairs development of alpha beta lineage, but not gamma delta lineage, T cells through activation of a p53-dependent checkpoint. In this study, we investigate the downstream effectors used by p53 to impair T cell development. We found that many p53 targets were induced in Rpl22−/− thymocytes, including miR-34a, PUMA, p21waf, Bax, and Noxa. Notably, the proapoptotic factor Bim, while not a direct p53 target, was also strongly induced in Rpl22−/− T cells. Gain-of-function analysis indicated that overexpression of miR-34a caused a developmental arrest reminiscent of that induced by p53 in Rpl22-deficient T cells; however, only a few p53 targets alleviated developmental arrest when individually ablated by gene targeting or knockdown. Co-elimination of PUMA and Bim resulted in a nearly complete restoration of development of Rpl22−/− thymocytes, indicating that p53-mediated arrest is enforced principally through effects on cell survival. Surprisingly, co-elimination of the primary p53 regulators of cell cycle arrest (p21waf) and apoptosis (PUMA) actually abrogated the partial rescue caused by loss of PUMA alone, suggesting that the G1 checkpoint protein p21[superscript waf] facilitates thymocyte development in some contexts.National Institutes of Health (U.S.) ( (NIH) Grant R01AI073920)National Institutes of Health (U.S.) (NIH Core Grant P01CA06927)National Institutes of Health (U.S.) ( (NIH) Grant R21CA141194)National Institutes of Health (U.S.) ( NIH Center Grant P30-DK-50306)Pennsylvania (appropriation)Fox Chase Cancer Center (NIH Postdoctoral Training Grant T32 CA00903534)Fox Chase Cancer Center (NIH Postdoctoral Training Grant F32 AI089077-01A1

String Breaking in Lattice Quantum Chromodynamics

The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or string, which should break in the presence of light quark-antiquark pairs. This expected zero temperature phenomenon has proven elusive in simulations of lattice QCD. We present simulation results that show that the string does break in the confining phase at nonzero temperature.Comment: 11 pages RevTeX, including 4 encapsulated Postscript figures. version2: minor corrections to reference

Zero temperature string breaking in lattice quantum chromodynamics

The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or "string", which should break in the presence of light quark-antiquark pairs. This expected zero-temperature phenomenon has proven elusive in simulations of lattice QCD. We study mixing between the string state and the two-meson decay channel in QCD with two flavors of dynamical sea quarks. We confirm that mixing is weak and find that it decreases at level crossing. While our study does not show direct effects of internal quark loops, our results, combined with unitarity, give clear confirmation of string breaking.Comment: 20 pages, 7 figures. With small clarifications and two additions to references. Submitted to Phys. Rev.

Skin and Soft Tissue Infections Caused by Methicillin-Resistant Staphylococcus aureus USA300 Clone

An increase in SSTIs suggests that USA300 is becoming more virulent with a greater propensity to cause SSTIs

Trouble with the curve: the 90–9-1 rule to measure volitional participation inequalities among Royal Canadian Mounted Police cadets during training

ObjectiveThe Royal Canadian Mounted Police (RCMP) Study includes longitudinal multimodal assessments of RCMP cadets from pre-training (i.e., starting the Cadet Training Program [CTP]) to post-deployment and for five years thereafter. The data allow for investigating the multidimensionality of volitional participation in digital health data collection frameworks within serial data collection platforms and the impact of participation inequalities by classifying cadets using the 90–9-1 rule. By classifying cadets as Lurkers, Contributors, and Superusers formally described by the 90–9-1 rule, where 90% of actors do not participate, 9% seldom contribute, and 1% contribute substantially allows for the assessing of relationships between participation inequalities in self-monitoring behaviors as well as whether mental health disorder symptoms at pre-training (i.e., starting the CTP) were associated with subsequent participation.MethodsParticipants were asked to complete a Full Assessment prior to their training at CTP, as well as short daily surveys throughout their training. Participation frequency was described using a process where participants were rank ordered by the number of daily surveys completed and classified into one of three categories. Full assessment surveys completed prior to their training at CTP included screening tools for generalized anxiety disorder (GAD), major depressive disorder (MDD), posttraumatic stress disorder (PTSD), alcohol use disorder (AUD), and panic disorder (PD). The Kruskal-Wallis H test was used to assess differences in participation rates between mental health disorder symptom screening groups for each measure at pre-training, and Spearman’s Rho was used to test for associations amongst self-reported Full Assessment screening tool responses and the number of daily surveys completed during CTP.ResultsThere were 18557 daily survey records collected from 772 participants. The rank-ordering of cadets by the number of daily surveys completed produced three categories in line with the 90–9-1 rule: Superusers who were the top 1% of cadets (n=8) and produced 6.4% of all recordings; Contributors who were the next 9% of cadets (n=68) and produced 49.2% of the recordings; and Lurkers who were the next 90% of cadets (n=695) and produced 44.4% of daily survey recordings. Lurkers had the largest proportion of positive screens for self-reported mental health disorders at pre-training.ConclusionThe creation of highly individualized, population-based mental health injury programs has been limited by an incomplete understanding of the causal relationships between protective factors and mental health. Disproportionate rates of disengagement from persons who screen positive for mental health disorders further compounds the difficulty in understanding the relationships between training programs and mental health. The current results suggest persons with mental health challenges may be less likely to engage in some forms of proactive mental health training. The current results also provide useful information about participation, adherence, and engagement that can be used to inform evidence-based paradigm shifts in health-related data collection in occupational populations