On the discrete spectrum of quantum layers

Consider a quantum particle trapped between a curved layer of constant width built over a complete, non-compact, $\mathcal C^2$ smooth surface embedded in $\mathbb{R}^3$. We assume that the surface is asymptotically flat in the sense that the second fundamental form vanishes at infinity, and that the surface is not totally geodesic. This geometric setting is known as a quantum layer. We consider the quantum particle to be governed by the Dirichlet Laplacian as Hamiltonian. Our work concerns the existence of bound states with energy beneath the essential spectrum, which implies the existence of discrete spectrum. We first prove that if the Gauss curvature is integrable, and the surface is weakly $\kappa$-parabolic, then the discrete spectrum is non-empty. This result implies that if the total Gauss curvature is non-positive, then the discrete spectrum is non-empty. We next prove that if the Gauss curvature is non-negative, then the discrete spectrum is non-empty. Finally, we prove that if the surface is parabolic, then the discrete spectrum is non-empty if the layer is sufficiently thin.Comment: Clarifications and corrections to previous version, conjecture from previous version is proven here (Theorem 1.5), additional references include

Markov Chain Monte Carlo methods for assigning larvae to natal sites using natural geochemical tags

Author Posting. © Ecological Society of America, 2008. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 18 (2008): 1901–1913, doi:10.1890/07-1792.1.Geochemical signatures deposited in otoliths are a potentially powerful means of identifying the origin and dispersal history of fish. However, current analytical methods for assigning natal origins of fish in mixed-stock analyses require knowledge of the number of potential sources and their characteristic geochemical signatures. Such baseline data are difficult or impossible to obtain for many species. A new approach to this problem can be found in iterative Markov Chain Monte Carlo (MCMC) algorithms that simultaneously estimate population parameters and assign individuals to groups. MCMC procedures only require an estimate of the number of source populations, and post hoc model selection based on the deviance information criterion can be used to infer the correct number of chemically distinct sources. We describe the basics of the MCMC approach and outline the specific decisions required when implementing the technique with otolith geochemical data. We also illustrate the use of the MCMC approach on simulated data and empirical geochemical signatures in otoliths from young-of-the-year and adult weakfish, Cynoscion regalis, from the U.S. Atlantic coast. While we describe how investigators can use MCMC to complement existing analytical tools for use with otolith geochemical data, the MCMC approach is suitable for any mixed-stock problem with a continuous, multivariate data.J. W. White was supported by NSF Predoctoral, UC Regents, and UCSB Affiliates fellowships

Perspectives of Social Justice Activists: Advocating Against Native-themed Mascots, Nicknames, and Logos

This study investigated perspectives of social justice activists who directly advocate for the elimination of Native-themed mascots, nicknames, and logos. Using Consensual Qualitative Research methodology, the research team analyzed transcripts of interviews conducted with eleven social justice activists to generate themes, categories, and domains within the data. Five domains emerged: (a) deleterious impact of Native-themed mascots, nicknames, and logos; (b) components of identity preservation among supporters; (c) reasons why some American Indians might support Native-themed mascots, nicknames, logos; (d) frontline advocacy efforts; and (e) coping strategies for advocates. Results provided insights into the sociopsychological processes which operate—among both non-Indians and Indians—to allow the misappropriation of American Indian culture, symbols, and imagery in sport to continue to exist in society. Findings can help counseling psychologists better understand the lived experience of social justice activists, while also highlighting ways that our field can support efforts to eliminate race-based mascots, nicknames, and logos

Histamine stimulates the proliferation of small and large cholangiocytes by activation of both IP3/Ca2+ and cAMP-dependent signaling mechanisms

Although large cholangiocytes exert their functions by activation of cyclic adenosine 3',5'-monophosphate (cAMP), Ca(2+)-dependent signaling regulates the function of small cholangiocytes. Histamine interacts with four receptors, H1-H4HRs. H1HR acts by Gαq activating IP(3)/Ca(2+), whereas H2HR activates Gα(s) stimulating cAMP. We hypothesize that histamine increases biliary growth by activating H1HR on small and H2HR on large cholangiocytes. The expression of H1-H4HRs was evaluated in liver sections, isolated and cultured (normal rat intrahepatic cholangiocyte culture (NRIC)) cholangiocytes. In vivo, normal rats were treated with histamine or H1-H4HR agonists for 1 week. We evaluated: (1) intrahepatic bile duct mass (IBDM); (2) the effects of histamine, H1HR or H2HR agonists on NRIC proliferation, IP(3) and cAMP levels and PKCα and protein kinase A (PKA) phosphorylation; and (3) PKCα silencing on H1HR-stimulated NRIC proliferation. Small and large cholangiocytes express H1-H4HRs. Histamine and the H1HR agonist increased small IBDM, whereas histamine and the H2HR agonist increased large IBDM. H1HR agonists stimulated IP(3) levels, as well as PKCα phosphorylation and NRIC proliferation, whereas H2HR agonists increased cAMP levels, as well as PKA phosphorylation and NRIC proliferation. The H1HR agonist did not increase proliferation in PKCα siRNA-transfected NRICs. The activation of differential signaling mechanisms targeting small and large cholangiocytes is important for repopulation of the biliary epithelium during pathologies affecting different-sized bile ducts

Soil Microbiome Dynamics During Pyritic Mine Tailing Phytostabilization: Understanding Microbial Bioindicators of Soil Acidification

Challenges to the reclamation of pyritic mine tailings arise from in situ acid generation that severely constrains the growth of natural revegetation. While acid mine drainage (AMD) microbial communities are well-studied under highly acidic conditions, fewer studies document the dynamics of microbial communities that generate acid from pyritic material under less acidic conditions that can allow establishment and support of plant growth. This research characterizes the taxonomic composition dynamics of microbial communities present during a 6-year compost-assisted phytostabilization field study in extremely acidic pyritic mine tailings. A complementary microcosm experiment was performed to identify successional community populations that enable the acidification process across a pH gradient. Taxonomic profiles of the microbial populations in both the field study and microcosms reveal shifts in microbial communities that play pivotal roles in facilitating acidification during the transition between moderately and highly acidic conditions. The potential co-occurrence of organoheterotrophic and lithoautotrophic energy metabolisms during acid generation suggests the importance of both groups in facilitating acidification. Taken together, this research suggests that key microbial populations associated with pH transitions could be used as bioindicators for either sustained future plant growth or for acid generation conditions that inhibit further plant growth.National Institute of Environmental and Health Sciences (NIEHS) Superfund Research Program (SRP) [P42 ES004940]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The β-isoform of BCCIP promotes ADP release from the RAD51 presynaptic filament and enhances homologous DNA pairing

Homologous recombination (HR) is a template-driven repair pathway that mends DNA double-stranded breaks (DSBs), and thus helps to maintain genome stability. The RAD51 recombinase facilitates DNA joint formation during HR, but to accomplish this task, RAD51 must be loaded onto the single-stranded DNA. DSS1, a candidate gene for split hand/split foot syndrome, provides the ability to recognize RPA-coated ssDNA to the tumor suppressor BRCA2, which is complexed with RAD51. Together BRCA2-DSS1 displace RPA and load RAD51 onto the ssDNA. In addition, the BRCA2 interacting protein BCCIP normally colocalizes with chromatin bound BRCA2, and upon DSB induction, RAD51 colocalizes with BRCA2-BCCIP foci. Down-regulation of BCCIP reduces DSB repair and disrupts BRCA2 and RAD51 foci formation. While BCCIP is known to interact with BRCA2, the relationship between BCCIP and RAD51 is not known. In this study, we investigated the biochemical role of the β-isoform of BCCIP in relation to the RAD51 recombinase. We demonstrate that BCCIPβ binds DNA and physically and functionally interacts with RAD51 to stimulate its homologous DNA pairing activity. Notably, this stimulatory effect is not the result of RAD51 nucleoprotein filament stabilization; rather, we demonstrate that BCCIPβ induces a conformational change within the RAD51 filament that promotes release of ADP to help maintain an active presynaptic filament. Our findings reveal a functional role for BCCIPβ as a RAD51 accessory factor in HR

Six NSCL/P loci show associations with normal-range craniofacial variation

Objectives: Orofacial clefting is one of the most prevalent craniofacial malformations. Previous research has demonstrated that unaffected relatives of patients with non-syndromic cleft lip with/without cleft palate (NSCL/P) show distinctive facial features, which can be an expression of underlying NSCL/P susceptibility genes. These results support the hypothesis that genes involved in the occurrence of a cleft also play a role in normal craniofacial development. In this study, we investigated the influence of genetic variants associated with NSCL/P on normal-range variation in facial shape. Methods: A literature review of genome wide association studies (GWAS) investigating the genetic etiology of NSCL/P was performed, resulting in a list of 75 single nucleotide polymorphisms (SNPs) located in 38 genetic loci. Genotype data were available for 65 of these selected SNPs in three datasets with a combined sample size of 7,418 participants of European ancestry, whose 3D facial images were also available. The effect of each SNP was tested using a multivariate canonical correlation analysis (CCA) against 63 hierarchically-constructed facial segments in each of the three datasets and meta-analyzed. This allowed for the investigation of associations between SNPs known to be involved in NSCL/P and normal-range facial shape variations in a global-to-local perspective, without preselecting specific facial shape features or characteristics. Results: Six NSCL/P SNPs showed significant associations with variation in normal-range facial morphology. rs6740960 showed significant effects in the chin area (p = 3.71 × 10−28). This SNP lies in a non-coding area. Another SNP, rs227731 near the NOG gene, showed a significant effect in the philtrum area (p = 1.96 × 10−16). Three SNPs showed significant effects on the shape of the nose. rs742071 (p = 8.71 × 10−14), rs34246903 (p = 6.87 × 10−12), and rs10512248 (p = 8.4 × 10−9). Respectively, these SNPs are annotated to PAX7, MSX1, and PTCH1. Finally, rs7590268, an intron variant of THADA, showed an effect in the shape of the supraorbital ridge (p = 3.84 × 10−7). Conclusions: This study provides additional evidence NSCL/P-associated genetic variants influence normal-range craniofacial morphology, with significant effects observed for the chin, the nose, the supraorbital ridges and the philtrum area

Extending cognitive-behavioural theory and therapy to medically unexplained symptoms and long term conditions:a hybrid transdiagnostic/problem specific approach

Medically unexplained symptoms (MUS) are not only common and distressing, but are also typically poorly managed in general medical settings. Those suffering from these problems tend to incur significantly higher health costs than the general population. There are many effective treatments for different MUS; these are almost entirely based on cognitive-behavioural approaches. However, the wide range of treatment protocols tend to be ‘syndrome specific’. As such, they do not generalise well in terms of training and application, making them expensive and difficult to disseminate, suggesting the desirability of developing a transdiagnostic approach. The general basis of such a CBT grounded transdiagnostic approach is considered, and the particular need to incorporate cognitive elements of both anxiety or health anxiety (threat) and depression (loss) is highlighted. Key empirically grounded and evidence-based processes (both specific and general) previously identified as underpinning the maintenance of MUS are delineated. The way in which these can be combined in a transdiagnostic model that accounts for most MUS presentations is presented and linked to a formulation-driven transdiagnostic treatment strategy, which is described. However, the need to take more syndrome-specific issues into account in treatment is identified, suggesting that the optimum treatment may be a hybrid transdiagnostic/specific approach with formulation, shared understanding, belief change strategies, and behavioural experiments at its heart. The generalisation of such approaches to psychological problems occurring in the context of ‘long-term conditions’ is identified as a further important development that is now within reach

Aspectos microbiológicos e epidemiológicos dos surtos causados por Salmonella sp em criações não industriais de Gallus gallus domesticus no Estado do Paraná

Orientador: Yasuyoshi HayashiDissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias AgrariasCom o objetivo de verificar a participação de Salmonella sp como causa de mortalidade entre as aves domésticas das criações caseiras no Estado do Paraná, foram analisadas, no período de 1987 a 1991, 671 amostras de aves, obtendo-se 7,0% de isolamento positivo, totalizando 47 cepas do microrganismo. Foram encontrados três sorovares causando doença, entre os quais, S.gallinarum (82,9%) responsável pela maioria dos surtos, seguido pela S.pullorum (12,7%) e S.enteritidis (4,2%). Vale ressaltar que o sorovar S.pullorum afetou somente as aves adultas. As 47 cepas de Salmonella pertenciam ao sorogrupo D1 , apresentando semelhante sensibilidade e resistência aos antibióticos e quimioterápicos quando testados "in vitro". Comprovou-se estatisticamente correlação entre o isolamento dos três sorovares citados com a morbidade e mortalidade ocorridas. Quanto ao sorovar S.gallinarum, as taxas médias de morbidade e mortalidade observadas nas aves consideradas jovens adultas (duas a oito semanas de idade) e adultas (mais de oito semanas de idade), situaram-se em 17 ,8%, 34,3% e 17,3%, 33,6%, respectivamente. No que se refere à S.pullorum as mesmas faixas etárias em relação a morbidade foram de 3,2% e 26,9% e mortalidade de 3,2% e 24,8%. S.enteritidis causou índices de morbidade de 23,8% e mortalidade de 22,6% somente na faixa etária das aves consideradas adultas. As aves jovens (1 a 14 dias de idade) não foram afetadas pela doença. Os percentuais de letalidade em relação à S.gallinarum, S.pullorum e S.enteritidis, foram de 97 ,9%, 93,3% e 95,0%, respectivamente. Observou-se ainda que a salmonelose ocorreu em todos os meses do ano. No entanto, quando distribuídos nas estações do ano, a primavera (31,9%) concentrou maior número de surtos, seguido do outono (25,5%), verão (23,4%) e inverno (19,1%)In order to check the role of the Salmonella as the cause of mortality of non commercial flocks of chicken in the State of Parana - Brazil, between 1987 and 1991, 671 samples were analyzed. The percentage of positive cases was 7,0%, comprising 47 different strains of the microorganism. Three serovars of Salmonella affected the birds. S.gallinarum was present in 82,9% of the outbreaks, S.pullorum in 12,7%, and S.enteritidis in only 4,2% of them. It is important to notice that S.pullorum affected only adult animals. When tested "in vitro" all the 47 strains of Salmonella belonged to the D1 serogroup, and showed similar resistance and sensitivity to antibacterial drugs. There is statistically significant correlation between the isolated serovars and the occurrence of morbidity and mortality .The mean rates of morbidity and mortality caused by the S.gallinarum serovar were respectively 17,8% and 34,3%, for young adults (two to eight weeks) and 17,3% and 33,6%, for adults (more than eight weeks). For the same are groups, the mean rates related to morbidity and mortality caused by S.pullorum was 3,2% and 26,9%, and 3,2% and 24,8%, respectively .The S.enteritidis affected only adult birds, causing 23,8% of morbidity and 22,6% of mortality. The group of young birds (one to 14 days) did not show morbidity or mortality .The lethality caused by S.gallinarum, S.pullorum and S.enteritidis was 97,9%, 93,3% and 95,0%, respectively. The salmonellosis was observed in all months of the year, with the greater number of outbreaks in the spring (31,9%). The percentages for the other seasons were 25,5%,23,4% and 19,1%, for the fallt, summer and winter, respectivel