BPS black holes, quantum attractor flows and automorphic forms

We propose a program for counting microstates of four-dimensional BPS black holes in N >= 2 supergravities with symmetric-space valued scalars by exploiting the symmetries of timelike reduction to three dimensions. Inspired by the equivalence between the four dimensional attractor flow and geodesic flow on the three-dimensional scalar manifold, we radially quantize stationary, spherically symmetric BPS geometries. Connections between the topological string amplitude, attractor wave function, the Ooguri-Strominger-Vafa conjecture and the theory of automorphic forms suggest that black hole degeneracies are counted by Fourier coefficients of modular forms for the three-dimensional U-duality group, associated to special "unipotent" representations which appear in the supersymmetric Hilbert space of the quantum attractor flow.Comment: 9 pages, revtex; v2: references added and typos correcte

RNA:protein ratio of the unicellular organism as a characteristic of phosphorous and nitrogen stoichiometry and of the cellular requirement of ribosomes for protein synthesis

Background Mean phosphorous:nitrogen (P:N) ratios and relationships of P:N ratios with the growth rate of organisms indicate a surprising similarity among and within microbial species, plants, and insect herbivores. To reveal the cellular mechanisms underling this similarity, the macromolecular composition of seven microorganisms and the effect of specific growth rate (SGR) on RNA:protein ratio, the number of ribosomes, and peptide elongation rate (PER) were analyzed under different conditions of exponential growth. Results It was found that P:N ratios calculated from RNA and protein contents in these particular organisms were in the same range as the mean ratios reported for diverse organisms and had similar positive relationships with growth rate, consistent with the growth-rate hypothesis. The efficiency of protein synthesis in microorganisms is estimated as the number of active ribosomes required for the incorporation of one amino acid into the synthesized protein. This parameter is calculated as the SGR:PER ratio. Experimental and theoretical evidence indicated that the requirement of ribosomes for protein synthesis is proportional to the RNA:protein ratio. The constant of proportionality had the same values for all organisms, and was derived mechanistically from the characteristics of the protein-synthesis machinery of the cell (the number of nucleotides per ribosome, the average masses of nucleotides and amino acids, the fraction of ribosomal RNA in the total RNA, and the fraction of active ribosomes). Impairment of the growth conditions decreased the RNA:protein ratio and increased the overall efficiency of protein synthesis in the microorganisms. Conclusion Our results suggest that the decrease in RNA:protein and estimated P:N ratios with decrease in the growth rate of the microorganism is a consequence of an increased overall efficiency of protein synthesis in the cell resulting from activation of the general stress response and increased transcription of cellular maintenance genes at the expense of growth related genes. The strong link between P:N stoichiometry, RNA:protein ratio, ribosomal requirement for protein synthesis, and growth rate of microorganisms indicated by the study could be used to characterize the N and P economy of complex ecosystems such as soils and the oceans

Perioperative adjuvant corticosteroids for post-operative analgesia in knee arthroplasty – A meta-analysis of 1396 knees

Background and purpose — Immediate postoperative pain management offered in knee arthroplasty is suboptimal in up to onethird of patients resulting in high opiate consumption and delayed discharge. In this meta-analysis we investigate the analgesic effect and safety of perioperative adjuvant corticosteroids in knee arthroplasty. Methods — Databases Medline, Embase, and Central were searched for randomized studies comparing the analgesic effect of adjuvant perioperative corticosteroids in knee arthroplasty. Our primary outcome was pain score at 24 hours postoperatively. Secondary outcomes included pain at 12, 48, and 72 hours, opiate consumption, postoperative nausea and vomiting, infection, and discharge time. Systemic (intravenous) and local (intra-articular) corticosteroids were analyzed separately. Results — 14 randomized controlled trials (1,396 knees) were included. Mean corticosteroid dosages were predominantly 50–75mg oral prednisolone equivalents for both systemic and local routes. Systemic corticosteroids demonstrated statistically signifi cant and clinically modest reductions in pain at 12 hours by –1.1 points (95%CI –2.2 to 0.02), 24 hours by –1.3 points (CI –2.3 to –0.26) and 48 hours by –0.4 points (CI –0.67 to –0.04). Local corticosteroids did not reduce pain. Opiate consumption, postoperative nausea and vomiting, infection, or time till discharge were similar between groups. Interpretation — Corticosteroids modestly reduce pain postoperatively at 12 and 24 hours when used systemically without any increase in associated risks for dosages between 50 and 75 mg oral prednisolone equivalents

Sex differential in mortality trends of old-aged Danes: a nation wide study of age, period and cohort effects

Objective Over the last half century the mortality rates in Denmark for females above age 80 have declined dramatically whereas the decline for males have been modest, resulting in a change in sex-ratio for centenarians from 2 to 5. Here we investigate whether this mortality pattern is mainly explained by period effects, cohort effects or both. This can provide clues for where to search for causes behind the changes in sex differential in mortality seen in many Western countries during the last decades. Methods Age-period-cohort study of mortality for all Danish women and men aged 79–98 during the period 1949–2006. Outcome measures Relative risks for deaths and second order differences for exploration of the nonlinear variation. Results Both the overall trends in mortality differences and the fluctuations in mortality for both men and women were better explained by period effects than by cohort effects. The observed rates were better described by the age, period and cohort model than by other models. Conclusions Our results suggest that causes for both the overall increased difference in mortality and the short term fluctuations in mortality rates are primarily to be found in the period dimension. Cohort effects on the mortality of the oldest Danish women and men played a significant but minor role compared to period effects

Massive Spin 3/2 Electrodynamics

We study the general non-minimally coupled charged massive spin 3/2 model both for its low energy phenomenological properties and for its unitarity, causality and degrees of freedom behaviour. When the model is viewed as an effective theory, its parameters (after ensuring the correct excitation count) are related to physical characteristics, such as the magnetic moment g factor, by means of low energy theorems. We also provide the corresponding higher spin generalisation. Separately, we consider both low and high energy unitarity, as well as the causality aspects of our models. None (including truncated N=2 supergravity) is free of the minimal model's acausality.Comment: 23 pages, 1 figure, LaTeX and axodraw.sty, novel Majorana-type term included; results unaltere

Abusive Supervision, Upward Maintenance Communication, and Subordinates\u27 Psychological Distress

This study reanalyzes data from Tepper\u27s (2000) two-wave study regarding the effects of subordinates\u27 perceptions of supervisory abuse to assess previously unexamined relationships. As predicted, we found that subordinates who more rather than less strongly perceived that they had been abused by supervisors tended to use regulative maintenance tactics with higher frequency. Further, the positive relationship between abusive supervision and subordinates\u27 psychological distress was exacerbated by subordinates\u27 use of regulative maintenance communications, and that relationship was reduced by subordinates\u27 use of direct maintenance communication. Theoretical and practical implications are discussed

The road to deterministic matrices with the restricted isometry property

The restricted isometry property (RIP) is a well-known matrix condition that provides state-of-the-art reconstruction guarantees for compressed sensing. While random matrices are known to satisfy this property with high probability, deterministic constructions have found less success. In this paper, we consider various techniques for demonstrating RIP deterministically, some popular and some novel, and we evaluate their performance. In evaluating some techniques, we apply random matrix theory and inadvertently find a simple alternative proof that certain random matrices are RIP. Later, we propose a particular class of matrices as candidates for being RIP, namely, equiangular tight frames (ETFs). Using the known correspondence between real ETFs and strongly regular graphs, we investigate certain combinatorial implications of a real ETF being RIP. Specifically, we give probabilistic intuition for a new bound on the clique number of Paley graphs of prime order, and we conjecture that the corresponding ETFs are RIP in a manner similar to random matrices.Comment: 24 page

A case of projectile trauma from the medieval Poulton Chapel, Cheshire, the United Kingdom

Excavations at the medieval cemetery of Poulton Chapel, Cheshire, have uncovered over 900 articulated human skeletal remains, with numbers predicted to reach as high as 1500 as excavations continue. The demographics of this archaeological site is typical of a medieval rural assemblage. However, SK535 provides a glimpse into some of the traumatic aspects of medieval life. The excavation of SK535 revealed a middle‐aged adult male around 168 cm in stature. His position of burial was typical of Christian burials with an east‐west orientation, but the positioning of his arms identified that this was not a typical burial. His right arm was flexed at the elbow crossing the thorax, whereas the left arm was in the extended position. This is different from the other arm positions observed at Poulton Chapel. A metal object, identified here as a Type M7 bodkin arrowhead, was recovered from underneath the right arm, from within the thorax. This arrowhead was potentially armour piercing, and the type was commonly used during the 12th–13th century. Radiocarbon dates obtained for SK535 coincide with the time of the use of this arrowhead. Following the initial assessment, the only other instance of trauma identified in SK535 was a healed transverse fracture to the right distal ulna. Due to the location of Poulton Chapel in Cheshire, SK535 could have been wounded by an arrow carrying the M7 bodkin during English‐Welsh border skirmishes, which occurred frequently during this time period. The demographic profile of this individual indicates a possible professional fighter of the medieval period; however, no firm skeletal evidence of occupation could be provided. Nonetheless, this case study not only highlights the violence experienced during the medieval period but also indicates the ability for the survival of some traumas