NNLL resummation for s-channel single top quark production

I present the next-to-next-to-leading-logarithm (NNLL) resummation of soft and collinear gluon corrections to single top quark production in the s channel. Attaining NNLL accuracy involves the calculation of the two-loop soft anomalous dimension for the partonic subprocesses. Finite-order expansions of the resummed cross section are calculated through next-to-next-to-leading order (NNLO). Numerical results are presented for s-channel single top quark production at the Tevatron and the LHC, including the dependence of the cross sections on the top quark mass and the uncertainties in the theoretical prediction. The higher-order corrections are significant for energies at both colliders and they decrease the theoretical uncertainty.Comment: 17 pages, 12 figures; added figures and discussio

Effective affinities in microarray data

In the past couple of years several studies have shown that hybridization in Affymetrix DNA microarrays can be rather well understood on the basis of simple models of physical chemistry. In the majority of the cases a Langmuir isotherm was used to fit experimental data. Although there is a general consensus about this approach, some discrepancies between different studies are evident. For instance, some authors have fitted the hybridization affinities from the microarray fluorescent intensities, while others used affinities obtained from melting experiments in solution. The former approach yields fitted affinities that at first sight are only partially consistent with solution values. In this paper we show that this discrepancy exists only superficially: a sufficiently complete model provides effective affinities which are fully consistent with those fitted to experimental data. This link provides new insight on the relevant processes underlying the functioning of DNA microarrays.Comment: 8 pages, 6 figure

Caseness and comorbidity of probable (complex) post-traumatic stress disorder and depression in survivors of genocide against Tutsi in Rwanda: the role of social determinants

Numerous studies have been conducted among survivors of the genocide against the Tutsi on the prevalence of depression and post-traumatic stress disorder. However, thus far, no studies provide information on the frequency of comorbidity of these disorders, the prevalence of the new trauma-related diagnostic disorder known as complex post-traumatic stress disorder, and the role of social determinants, such as age, sex, marital status, employment category, education, and location, in the occurrence of these disorders. The present study was conducted to address these gaps. Genocide survivors ( N = 261 participants; M = 46.30, SD = 11.95, females = 52.9%) took part in the study. They completed the International Trauma Questionnaire, the Public Health Depression Questionnaire, and the Harvard Trauma Questionnaire. Descriptive statistical analyses, bivariate analyses with two-tailed chi-square tests, and logistic regression were used to determine the prevalence of the above-mentioned disorders, comorbidity, and the associations between the social determinants and the assessed psychopathologies. Of the total sample, 47.1% presented with at least one of the assessed probable mental health disorders: 15.3% ( n = 40) met the criteria for probable post-traumatic stress disorder, 15.3% ( n = 40) for probable complex post-traumatic stress disorder, and 38.7% ( n = 101) for probable depression. Of the participants with probable post-traumatic stress disorder and complex post-traumatic stress disorder, nearly half met the criteria for probable depression. Being married but not living with the partner was associated with probable complex post-traumatic stress disorder, and unemployment was associated with probable depression. Our findings suggest to clinicians and policymakers that they should consider comorbidity and social determinants in their interventions

Dependence of α-synuclein aggregate morphology on solution conditions

α-Synuclein is the major component of Lewy bodies and Lewy neurites, which are granular and filamentous protein inclusions that are the defining pathological features of several neurodegenerative conditions such as Parkinson's disease. Fibrillar aggregates formed from α-synuclein in vitro resemble brain-derived material, but the role of such aggregates in the etiology of Parkinson's disease and their relation to the toxic molecular species remain unclear. In this study, we investigated the effects of pH and salt concentration on the in vitro assembly of human wild-type α-synuclein, particularly with regard to aggregation rate and aggregate morphology. Aggregates formed at pH 7.0 and pH 6.0 in the absence of NaCl and MgCl, were fibrillar; the pH 6.0 fibrils displayed a helical twist, as clearly evident by scanning force and electron microscopy. Incubations at pH 7.0 remained transparent during the process of aggregation and exhibited strong thioflavin-T and weak 8-anilino-1-naphthalene-sulfonate (ANS) binding; furthermore, they were efficient in seeding fibrillization of fresh solutions. In contrast, incubating α-synuclein at low pH (pH 4.0 or pH 5.0) resulted in the rapid formation of turbid suspensions characterized by strong ANS binding, reduced thioflavin-T binding and reduced seeding efficiency. At pH 4.0, fibril formation was abrogated; instead, very large aggregates (dimensions similar to100 mum) of amorphous appearance were visible by light microscopy. As with acidic conditions, addition of 0.2 M NaCl or 10 mM MgCl, to pH 7.0 incubations led to a shorter aggregation lag time and formation of large, amorphous aggregates. These results demonstrate that the morphology of α-synuclein aggregates is highly sensitive to solution conditions, implying that the fibrillar state does not necessarily represent the predominant or most functionally significant aggregated state under physiological conditions. (C) 2002 Elsevier Science Ltd. All rights reserved

Free-space subcarrier wave quantum communication

We experimentally demonstrate quantum communication in 10 dB loss outdoor atmospheric channel with 5 kbit/s bitrate using subcarrier wave coding method. Free-space link was organized by telescoping system with symmetric fiber-optic collimators

Geometry and symmetries of multi-particle systems

The quantum dynamical evolution of atomic and molecular aggregates, from their compact to their fragmented states, is parametrized by a single collective radial parameter. Treating all the remaining particle coordinates in d dimensions democratically, as a set of angles orthogonal to this collective radius or by equivalent variables, bypasses all independent-particle approximations. The invariance of the total kinetic energy under arbitrary d-dimensional transformations which preserve the radial parameter gives rise to novel quantum numbers and ladder operators interconnecting its eigenstates at each value of the radial parameter. We develop the systematics and technology of this approach, introducing the relevant mathematics tutorially, by analogy to the familiar theory of angular momentum in three dimensions. The angular basis functions so obtained are treated in a manifestly coordinate-free manner, thus serving as a flexible generalized basis for carrying out detailed studies of wavefunction evolution in multi-particle systems.Comment: 37 pages, 2 eps figure

Stable longitudinal associations of family income with children's hippocampal volume and memory persist after controlling for polygenic scores of educational attainment

Despite common notion that the correlation of socioeconomic status with child cognitive performance may be driven by both environmentally- and genetically-mediated transactional pathways, there is a lack of longitudinal and genetically informed research that examines these postulated associations. The present study addresses whether family income predicts associative memory growth and hippocampal development in middle childhood and tests whether these associations persist when controlling for DNA-based polygenic scores of educational attainment. Participants were 142 6-to-7-year-old children, of which 127 returned when they were 8-to-9 years old. Longitudinal analyses indicated that the association of family income with children's memory performance and hippocampal volume remained stable over this age range and did not predict change. On average, children from economically disadvantaged background showed lower memory performance and had a smaller hippocampal volume. There was no evidence to suggest that differences in memory performance were mediated by differences in hippocampal volume. Further exploratory results suggested that the relationship of income with hippocampal volume and memory in middle childhood is not primarily driven by genetic variance captured by polygenic scores of educational attainment, despite the fact that polygenic scores significantly predicted family income

Characteristics of health and well-being in former Jehovah’s Witnesses in Austria, Germany, and Switzerland

Background: This study collected quantifiable data on the characteristics, health, and well-being of individuals who left or were expelled from a fundamentalist Christian faith community in Austria, Germany, or Switzerland. Methods: Data were collected using an online survey. Results: This study assessed a sample of former Jehovah’s Witnesses (N = 424, Mage = 42.14, SDage = 12.57, 65% female). Most participants (66%) were born into this faith community. Half the sample left voluntarily, 21% were expelled, and 31% left due to having experienced abuse or maltreatment. One third reported suicidal thoughts; 10% had attempted suicide. The sample (especially women) reported relatively high levels of child maltreatment, moderate current health, clinically significant symptoms, high levels of stress, and low quality of life. Participants who left due to abuse or maltreatment reported more symptoms and child maltreatment. Discussion: Women and survivors of child maltreatment may represent particularly vulnerable sub-groups of former Jehovah’s Witnesses