Consistent discretizations: the Gowdy spacetimes

We apply the consistent discretization scheme to general relativity particularized to the Gowdy space-times. This is the first time the framework has been applied in detail in a non-linear generally-covariant gravitational situation with local degrees of freedom. We show that the scheme can be correctly used to numerically evolve the space-times. We show that the resulting numerical schemes are convergent and preserve approximately the constraints as expected.Comment: 10 pages, 8 figure

Out of Place, Out of Mind: Schema-Driven False Memory Effects for Object-Location Bindings

Events consist of diverse elements, each processed in specialized neocortical networks, with temporal lobe memory systems binding these elements to form coherent event memories. We provide a novel theoretical analysis of an unexplored consequence of the independence of memory systems for elements and their bindings, 1 that raises the paradoxical prediction that schema-driven false memories can act solely on the binding of event elements despite the superior retrieval of individual elements. This is because if 2, or more, schema-relevant elements are bound together in unexpected conjunctions, the unexpected conjunction will increase attention during encoding to both the elements and their bindings, but only the bindings will receive competition with evoked schema-expected bindings. We test our model by examining memory for object-location bindings in recognition (Study 1) and recall (Studies 2 and 3) tasks. After studying schema-relevant objects in unexpected locations (e.g., pan on a stool in a kitchen scene), participants who then viewed these objects in expected locations (e.g., pan on stove) at test were more likely to falsely remember this object-location pairing as correct, compared with participants that viewed a different unexpected object-location pairing (e.g., pan on floor). In recall, participants were more likely to correctly remember individual schema-relevant objects originally viewed in unexpected, as opposed to expected locations, but were then more likely to misplace these items in the original room scene to expected places, relative to control schema-irrelevant objects. Our theoretical analysis and novel paradigm provide a tool for investigating memory distortions acting on binding processes

A new web-based genomics resource for bioinformatics analysis of Rhipicephalus (Boophilus) microplus: CattleTickBase

No abstract availabl

A Study of Gaussianity in CMB band maps

The detection of non-Gaussianity in the CMB data would rule out a number of inflationary models. A null detection of non-Gaussianity, instead, would exclude alternative models for the early universe. Thus, a detection or non-detection of primordial non-Gaussianity in the CMB data is crucial to discriminate among inflationary models, and to test alternative scenarios. However, there are various non-cosmological sources of non-Gaussianity. This makes important to employ different indicators in order to detect distinct forms of non-Gaussianity in CMB data. Recently, we proposed two new indicators to measure deviation from Gaussianity on large angular scales, and used them to study the Gaussianity of the raw band WMAP maps with and without the KQ75 mask. Here we extend this work by using these indicators to perform similar analyses of deviation from Gaussianity of the foreground-reduced Q, V, and W band maps. We show that there is a significant deviation from Gaussianity in the considered full-sky maps, which is reduced to a level consistent with Gaussianity when the KQ75 mask is employed.Comment: 5 pages, 2 PS figures, uses ws-ijmpd.cls ; to be published in the International Journal of Modern Physics

Leadership in Sport Organizations

First paragraph: The ability to lead, inspire and motivate people is an important human characteristic. Indeed, it has been suggested that leadership is vital for effective organizational and societal functioning (Antonakis, Cianciolo, & Sternberg, 2004), with great or poor organizational, military, or sport performances frequently credited to great leadership or lack thereof. Therefore, it is not surprising that leadership has become one of the most studied topics within the social sciences (Antonakis et al., 2004). Leadership has been studied from a number of different perspectives (e.g., trait, behavioural, contingency, relational, skeptic, information-processing based approaches) which has resulted in a large number of different theories and models of leadership. Indeed, as long ago as 1971, Fiedler (1971) stated that, “there are almost as many definitions of leadership as there are theories of leadership - and there almost as many theories of leadership as there are psychologists working in the field” (p. 1)

Microarray evidence for off target effects in tick RNA interference experiments, and the lack of strong correlation between DSRNA and antibody phenotypes in tick In vitro treatments for vaccine candidate screening

No abstract availabl

Stability of Actinolite on Venus

Venus currently has a hostile surface environment with temperatures of ~460 C, pres-sures near 92 bars, and an atmosphere composed of super critical CO2 hosting a myriad of other potentially reactive gases (e.g., SO2, HCl, HF). However, it has been proposed that its surface may not have always been so harsh. Models suggest there may have been billions of years of clement conditions allowing an Earth-like environment with liquid water oceans. If such conditions existed, it is possible Venus formed a similar array of hydrous or aqueous minerals as seen on other planets with liquid surface water (e.g., Mars, Earth). Based on thermodynamic modeling, many of these phases would not be stable under the current atmospheric conditions on Venus, dehydrating due to the high temperatures and low concentration of H2O in the atmosphere. However, the rate of decomposition of these phases may allow them to remain present on the surface over geologic time. For example, experiments on the reaction rate of tremolite (Ca2Mg5Si8O22(OH)2) show a 50% decomposition time of 2.7 Gyr for micrometer sized grains in unreactive atmospheres (i.e., without SO2) at 740 K, and a 50% decomposition time of 70 Gyr for crystals several millimeters to centimeters in size. If hydrous minerals can remain on the surface of Venus over geologic time, it has implications for our detection of evidence of these past environments, and also for the overall water budget of the planet. If after surficial dehydration the planet was able to still store water in its crust, possible processes such as subduction or metamorphism could still have operated using stored water long after liquid surface water evaporated. Several previous studies have focused on experimental investigations of mineral stability on Venus. In particular, the works of studied the decomposition rate of tremolite under conditions relevant to Venus. As their focus was on decomposition of the mineral due to lack of water in the atmosphere, their experiments were undertaken using only CO2 or N2 gas at atmospheric pressure. Re-cent experiments have examined reactivity of other minerals with the Venusian atmosphere using more complex gas compositions at similar pressures to those seen on Venus. These studies show reaction of silicate minerals with atmospheric components on relatively short timescales (i.e., on the order of days). The reported reactions of silicate materials in both studies produced iron oxides, Ca sulfates, and Na sulfates. These ions are present in many amphiboles, and Ca was proposed by Johnson and Fegley to potentially have an important role in the decomposition mechanism for tremolite, with the Ca-O bond being the first to break during decomposition. The potential involvement of Ca in both processes raises the question of whether or not the reaction to form a secondary mineral phase will influence the rate of amphibole break-down (e.g., discussion in for tremolite). Additionally, reaction of Ca with atmospheric gases may result in a different secondary mineral assemblage than simple amphibole decomposition, which will need to be recognized when searching for evidence of past hydrated minerals on the Venusian surface. In order to understand the effect of this reaction on the overall preservation potential of amphibole on the surface of Venus, we are conducting experiments in both reactive and nonreactive atmospheres using the mineral actinolite (Ca2(Mg,Fe)5Si8O22(OH)2), an amphibole with similar crystal structure to tremolite that contains both Ca and Fe

A Randomized Prospective Study of Cefepime Plus Metronidazole with Imipenem-Cilastatin in the Treatment of Intra-abdominal Infections

Abstract : Background: : Presumptive antimicrobial therapy is an important aspect of the management of intra-abdominal infections. Together with surgery, antimicrobial combinations are still widely used to achieve the required spectrum of activity. The aim of this study was to evaluate the efficacy of parenteral cefepime + metronidazole vs imipenemcilastatin for the treatment of intra-abdominal infections in adult patients. Methods: : Patients with a clinically confirmed diagnosis of intra-abdominal infection were randomized to one of two treatment regimens: cefepime 2 g iv/12 h plus metronidazole 500 mg/8 h or imipenem-cilastatin 500 mg iv/6 h. The primary measure of clinical response was the decline of pre-treatment signs and symptoms of infection. The duration of follow-up was 30 days. Treatment failure was defined as either a lack of improvement or a worsening of pre-treatment signs and symptoms of infection. Surgical management of the infection was determined by the surgeon-in-charge. Results: : Of the 122 intended-to-treat patients included in the study, 60 patients (33 men) were randomized to cefepime + metronidazole and 61 (27 men) to imipenemcilastatin. Cefepime + metronidazole treatment was successful in 52 (87%) patients and imipenem-cilastatin in 44 (72%) patients (p = 0.004). Microbiological eradication was established in similar proportions in both groups (cefepime + metronidazole, 43; imipenem-cilastatin, 38). Conclusion: : Further studies are warranted to confirm the better results with the cefepime + metronidazole regimen for the treatment of intra-abdominal infection

Electric Charge Quantization

Experimentally it has been known for a long time that the electric charges of the observed particles appear to be quantized. An approach to understanding electric charge quantization that can be used for gauge theories with explicit $U(1)$ factors -- such as the standard model and its variants -- is pedagogically reviewed and discussed in this article. This approach uses the allowed invariances of the Lagrangian and their associated anomaly cancellation equations. We demonstrate that charge may be de-quantized in the three-generation standard model with massless neutrinos, because differences in family-lepton--numbers are anomaly-free. We also review the relevant experimental limits. Our approach to charge quantization suggests that the minimal standard model should be extended so that family-lepton--number differences are explicitly broken. We briefly discuss some candidate extensions (e.g. the minimal standard model augmented by Majorana right-handed neutrinos).Comment: 18 pages, LaTeX, UM-P-92/5