An Effective Field Theory for Jet Processes

Processes involving narrow jets receive perturbative corrections enhanced by logarithms of the jet opening angle and the ratio of the energies inside and outside the jets. Analyzing cone-jet processes in effective field theory, we find that in addition to soft and collinear fields their description requires degrees of freedom which are simultaneously soft and collinear to the jets. These collinear-soft particles can resolve individual collinear partons, leading to a complicated multi-Wilson-line structure of the associated operators at higher orders. Our effective field theory provides, for the first time, a factorization formula for a cone-jet process, which fully separates the physics at different energy scales. Its renormalization-group equations control all logarithmically enhanced higher-order terms, in particular also the non-global logarithms.Comment: 9 pages, 1 figure. v2: PRL versio

Factorization and N^3LL_p+NNLO Predictions for the Higgs Cross Section with a Jet Veto

We have recently derived a factorization formula for the Higgs-boson production cross section in the presence of a jet veto, which allows for a systematic resummation of large Sudakov logarithms of the form alpha_s^n ln^m(p_T^veto/m_H), along with the large virtual corrections known to affect also the total cross section. Here we determine the ingredients entering this formula at two-loop accuracy. Specifically, we compute the dependence on the jet-radius parameter R, which is encoded in the two-loop coefficient of the collinear anomaly, by means of a direct, fully analytic calculation in the framework of soft-collinear effective theory. We confirm the result obtained by Banfi et al. from a related calculation in QCD, and demonstrate that factorization-breaking, soft-collinear mixing effects do not arise at leading power in p_T^veto/m_H, even for R=O(1). In addition, we extract the two-loop collinear beam functions numerically. We present detailed numerical predictions for the jet-veto cross section with partial next-to-next-to-next-to-leading logarithmic accuracy, matched to the next-to-next-to-leading order cross section in fixed-order perturbation theory. The only missing ingredients at this level of accuracy are the three-loop anomaly coefficient and the four-loop cusp anomalous dimension, whose numerical effects we estimate to be small.Comment: 43 pages, 12 figures; minor changes, references updated; version published in JHE

Per oral substitution with 300000 IU vitamin D (Cholecalciferol) reduces bone turnover markers in HIV-infected patients

BACKGROUND: Osteoporosis and bone fractures seem to be higher in HIV-infected Patients compared to the general populations. Moreover, bone turnover markers are increased in patients on antiretroviral therapy and vitamin D deficiency is prevalent in HIV-infected patients. However, the influence of per oral cholecalciferol on bone metabolism in HIV infected patients is not well understood. METHODS: We measured the bone turnover markers in 96 HIV-infected patients: Bone specific alkaline phosphatase (BSAP), Pyridinoline (PYR), Desoxypyridinoline (DPD) and 25-OH vitamin D. If 25-OH vitamin D was below 75 nnol/L (87/96 patients), 300000 IU cholecalciferol was given per os. 25OH-vitamin D and bone turn over markers were determinded 3 month later. 25 OH-vitamin D was corrected for circannual rythm [Formula: see text] , whereas bone turnover markers were not corrected. The paired students t-Test was used to compare the two periods. No calcium supplementation or biphosphonate therapy was given. RESULTS: Corrected 25OH-vitamin D levels increased significantly after supplementation (42.7 ± 26.61 vs. 52.85 ± 21.8 nmol/L, p < 0.001). After supplementation, bone turnover markers were significantly lower. The values decreased for BSAP from 21.31 ± 14.32 to 17.53 ± 8.17 μg/L (p < 0.001), PYR from 74.57 ± 36.83 to 54.82 ± 21.43 nmol/mmol creatinine (p < 0.001) and DPD from 15.17 ± 8.34 to 12.61 ± 5.02 nmol/mmol creatinine (p = 0.01). CONCLUSIONS: After per oral substitution with cholecalciferol, bone formation as well as bone resorption markers decreased significant. We postulate a protective effect on bone structure with cholecalciferol supplementation

Adults can be trained to acquire synesthetic experiences

Synesthesia is a condition where presentation of one perceptual class consistently evokes additional experiences in different perceptual categories. Synesthesia is widely considered a congenital condition, although an alternative view is that it is underpinned by repeated exposure to combined perceptual features at key developmental stages. Here we explore the potential for repeated associative learning to shape and engender synesthetic experiences. Non-synesthetic adult participants engaged in an extensive training regime that involved adaptive memory and reading tasks, designed to reinforce 13 specific letter-color associations. Following training, subjects exhibited a range of standard behavioral and physiological markers for grapheme-color synesthesia; crucially, most also described perceiving color experiences for achromatic letters, inside and outside the lab, where such experiences are usually considered the hallmark of genuine synesthetes. Collectively our results are consistent with developmental accounts of synesthesia and illuminate a previously unsuspected potential for new learning to shape perceptual experience, even in adulthood

Physical Phenomenology of Phyllotaxis

We propose an evolutionary mechanism of phyllotaxis, regular arrangement of leaves on a plant stem. It is shown that the phyllotactic pattern with the Fibonacci sequence has a selective advantage, for it involves the least number of phyllotactic transitions during plant growth

For a history of Brazilian higher education evaluation: analysis of PARU, CNRES, GERES and PAIUB documents

Com o Provão, em 1996, e depois com o SINAES, em 2004, a avaliação passou a ser um elemento central na política de educação superior brasileira. Apesar das influências dos modelos internacionais as duas principais concepções adotadas (a da avaliação com uma visão formativa/emancipatória e a de regulação/controle) foram delineadas pelos acadêmicos participantes de comissões governamentais do Ministério da Educação durante as décadas de 1980 e 1990. No artigo, analisam-se essas duas concepções e algumas das suas implicações nas políticas atuais. São considerados os documentos oficiais: "Programa de Avaliação da Reforma Universitária" (1983); "Relatório da Comissão Nacional de Avaliação do Ensino Superior" "Uma Nova Política para a Educação Superior Brasileira" (1985), "Relatório do Grupo Executivo para a Reformulação da Educação Superior" (1986). e "Programa de Avaliação Institucional das Universidades Brasileiras" (1993).Evaluation became a central element in higher education policy in Brazil, first in 1996 with ENC-Provão and, then, in 2004, with SINAES. Despite the influences of international models, the two main conceptions adopted (the formative and the regulatory evaluation) were outlined by the academics who participated in government commissions at the Ministry of Education, during 80's and 90's. In this paper, these two concepts and some of their implications in current policies are analyzed. The official documents "Evaluation Program of the University Reform" (1983); "A New Policy for the Brazilian Higher Education" (1985); "Report of the Executive Group for Higher Education Revision" (1986) and "Institutional Evaluation Program of the Brazilian Universities" (1993.) are considered

Nanotoxicology: a perspective and discussion of whether or not in vitro testing is a valid alternative

Despite the many proposed advantages related to nanotechnology, there are increasing concerns as to the potential adverse human health and environmental effects that the production of, and subsequent exposure to nanoparticles (NPs) might pose. In regard to human health, these concerns are founded upon the plethora of knowledge gained from research relating to the effects observed following exposure to environmental air pollution. It is known that increased exposure to environmental air pollution can cause reduced respiratory health, as well as exacerbate pre-existing conditions such as cardiovascular disease and chronic obstructive pulmonary disease. Such disease states have also been associated with exposure to the NP component contained within environmental air pollution, raising concerns as to the effects of NP exposure. It is not only exposure to accidentally produced NPs however, which should be approached with caution. Over the past decades, NPs have been specifically engineered for a wide range of consumer, industrial and technological applications. Due to the inevitable exposure of NPs to humans, owing to their use in such applications, it is therefore imperative that an understanding of how NPs interact with the human body is gained. In vivo research poses a beneficial model for gaining immediate and direct knowledge of human exposure to such xenobiotics. This research outlook however, has numerous limitations. Increased research using in vitro models has therefore been performed, as these models provide an inexpensive and high-throughput alternative to in vivo research strategies. Despite such advantages, there are also various restrictions in regard to in vitro research. Therefore, the aim of this review, in addition to providing a short perspective upon the field of nanotoxicology, is to discuss (1) the advantages and disadvantages of in vitro research and (2) how in vitro research may provide essential information pertaining to the human health risks posed by NP exposur

Subspecies typing of Streptococcus agalactiae based on ribosomal subunit protein mass variation by MALDI-TOF MS

Background: A ribosomal subunit protein (rsp)-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method was developed for fast subspecies-level typing of Streptococcus agalactiae (Group B Streptococcus, GBS), a major cause of neonatal sepsis and meningitis. Methods: A total of 796 GBS whole genome sequences, covering the genetic diversity of the global GBS population, were used to in silico predict molecular mass variability of 28 rsp and to identify unique rsp mass combinations, termed “rsp-profiles”. The in silico established GBS typing scheme was validated by MALDI-TOF MS analysis of GBS isolates at two independent research sites in Europe and South East Asia. Results: We identified in silico 62 rsp-profiles, with the majority (>80%) of the 796 GBS isolates displaying one of the six rsp-profiles 1-6. These dominant rsp-profiles classify GBS strains in high concordance with the core-genome based phylogenetic clustering. Validation of our approach by in-house MALDI-TOF MS analysis of 248 GBS isolates and external analysis of 8 GBS isolates showed that across different laboratories and MALDI-TOF MS platforms, the 28 rsp were detected reliably in the mass spectra, allowing assignment of clinical isolates to rsp-profiles at high sensitivity (99%) and specificity (97%). Our approach distinguishes the major phylogenetic GBS genotypes, identifies hyper-virulent strains, predicts the probable capsular serotype and surface protein variants and distinguishes between GBS genotypes of human and animal origin. Conclusion: We combine the information depth of whole genome sequences with the highly cost efficient, rapid and robust MALDI-TOF MS approach facilitating high-throughput, inter-laboratory, large-scale GBS epidemiological and clinical studies based on pre-defined rsp-profiles

Intensive care 1980-1995: change in patient characteristics, nursing workload and outcome

Objective: To assess temporal changes in patient characteristics, nursing workload and outcome of the patients and to compare the actual amount of available nursing staff with the estimated needs in a medical-surgical ICU. Design: Retrospective analysis of prospectively collected data. Setting: A medical-surgical adult intensive care unit (ICU) in a Swiss university hospital. Patients: Data of all patients staying in the ICU between January 1980 and December 1995 were included. Interventions: None. Measurements and results: The estimated number of nurses needed was defined according to the Swiss Society of Intensive Care Medicine (SGI) grading system: category I=one nurse/patient/shift (=8 h), category II=one nurse/two patients/shift, category III=one nurse/three patients/shift. An intervention score (IS) was obtained, based on a number of specific activities in the ICU. There was a total of 35,327 patients (32 % medical and 68 % postoperative/trauma patients). Over time, the number of patients per year increased (1980/1995:1,825/2,305, p70 years (19 %/28 %,p<0.001), and a decrease in the number of patients<60 years (58 % /41 %, p<0.001). During the same time period, the IS increased two-fold. Measurement of nursing workload showed an increase over time. The number of nursing days per year increased (1980/1995: 7454/8681, p<0.019), as did the relative amount of patients in category I (49 %/71 %, p<0.001), whereas the portion of patients in category II (41 %/28 %,p< 0.019) and category III (10 %/0 %) decreased. During the same time period, mortality at ICU discharge decreased (9.0 %/ 7.0 %,p< 0.002). Conclusions: During the last 16 years, there has been a marked increase in workload at this medical-surgical ICU. Despite an increase in the number of severely sick patients (as defined by the nursing grading system) and patient age, ICU mortality and LOS declined from 1980 to 1995. This may be ascribed to improved patient treatment or care. Whether an increasingly liberal discharge policy (transfer to newly opened intermediate care units, transfer of patients expected to die to the ward) or a more rigorous triage (denying admission to patients with a very poor prognosis) are confounding factors cannot be answered by this investigation. The present data provide support for the tenet that there is a trend toward more complex therapies in increasingly older patients in tertiary care ICUs. Calculations for the number or nurses needed in an ICU should take into account the increased turnover of patients and the changing patient characteristic

Conformal lattice of magnetic bubble domains in garnet film

We report experimental observations of magnetic bubble domain arrays with no apparent translational symmetry. Additionally the results of comparative numerical studies are discussed. Our goal is to present experimental evidence for natural occurence of conformal structures.Comment: 7 pages, 2 figures, LaTeX2e, accepted as paper E090 at JEMS'01 (Joint European Magnetic Symposia, formerly EMMA + MRM), August 28th to September 1st, 2001, Grenoble, Franc