Inverted orbital polarization in strained correlated oxide films

Manipulating the orbital occupation of valence electrons via epitaxial strain in an effort to induce new functional properties requires considerations of how changes in the local bonding environment affect the band structure at the Fermi level. Using synchrotron radiation to measure the x-ray linear dichroism of epitaxially strained films of the correlated oxide CaFeO3, we demonstrate that the orbital polarization of the Fe valence electrons is opposite from conventional understanding. Although the energetic ordering of the Fe 3d orbitals is confirmed by multiplet ligand field theory analysis to be consistent with previously reported strain-induced behavior, we find that the nominally higher energy orbital is more populated than the lower. We ascribe this inverted orbital polarization to an anisotropic bandwidth response to strain in a compound with nearly filled bands. These findings provide an important counterexample to the traditional understanding of strain-induced orbital polarization and reveal a new method to engineer otherwise unachievable orbital occupations in correlated oxides

Book Reviews

Science and Learning in France. With a Survey of Opportunities for American Students in French Universities. An Appreciation by American Scholars. The Society for American Fellowships in France, 1917; PP. xxxviii, 454

Book Reviews

Science of Legal Method. Select Essays by Various Authors. Translation by Ernest Bruncken, Washington, D. C. and Layton B. Register of the University of Pennsylvania Law School. With Introductions by Henry N. Sheldon, Former justice of the Supreme Judicial Court of Massachusetts and by John W. Salmond, Solicitor General of New Zealand. Boston: The Boston Book Company, I917; pp. lxxxvi, 593

Effect of Flibanserin Treatment on Body Weight in Premenopausal and Postmenopausal Women with Hypoactive Sexual Desire Disorder: A Post Hoc Analysis.

Background: Flibanserin, a 5-HT1A agonist and 5-HT2A antagonist, is indicated for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. This post hoc analysis evaluated the effect of flibanserin treatment on body weight in premenopausal and postmenopausal women with HSDD. Materials and Methods: This analysis included three 24-week, double-blind, placebo-controlled studies of flibanserin 100 mg each bedtime (qhs) in premenopausal women, a similarly designed study in postmenopausal women, and a 52-week, open-label extension study in premenopausal women. Results: In a pooled analysis of premenopausal women, mean baseline body mass index (BMI) was 27.0 kg/m2 in the flibanserin group (n = 1227) and 26.8 kg/m2 in the placebo group (n = 1238). Among patients who completed 24 weeks of treatment, least squares (LS) mean weight change was −1.4 kg in the flibanserin group (n = 1010) and −0.1 kg in the placebo group (n = 1066; p \u3c 0.0001). Weight loss ≥5% from baseline was reported in 21.0% of patients who received flibanserin and 7.8% of patients who received placebo; weight loss ≥10% was reported in 3.8% and 2.0% of patients, respectively. In postmenopausal women, mean baseline BMI was 27.7 kg/m2 in the flibanserin group (n = 467) and 27.3 kg/m2 in the placebo group (n = 480). LS mean weight change at week 24 was −1.8 kg in the flibanserin group (n = 385) and −0.1 kg in the placebo group (n = 425; p \u3c 0.0001), with weight loss ≥5% reported in 24.7% and 7.3% of patients, respectively, and weight loss ≥10% reported in 5.2% and 1.7%, respectively. In HSDD patients with \u3e12 months (n = 880) and \u3e18 months (n = 637) of exposure to flibanserin, mean weight change was −1.0 and −1.2 kg, respectively; 25.4% and 26.9% of patients, respectively, experienced weight loss ≥5% from baseline, and 7.8% and 8.4%, respectively, experienced weight loss ≥10%. Conclusions: Women treated with flibanserin for HSDD may experience weight loss

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study. We measured mortality and morbidity among 114 patients assigned randomly to home hemodialysis (HD) and home intermittent peritoneal dialysis (IPD). Data were collected during the time of home training and for 12 months after initiation of home dialysis. Training time was shorter for the IPD than for the HD patients (P < 0.001) with median time 1.8 months for IPD and 3.9 months for HD. Switching to the alternative mode of treatment was more frequent for the IPD group (29/59 vs. 5/55, P < 0.001). Survival time was not different, perhaps because of the modality change. More IPD patients were hospitalized in the first 6 months (20 for IPD vs. 9 for HD, P = 0.02), but they had fewer troublesome cardiovascular events in the first year (0 vs. 12, P < 0.001). The HD patients maintained better nutritional status as reflected in body weight and arm muscle circumference and possibly in urea appearance rate. Thus, these data suggest that for most patients, IPD is a less satisfactory form of therapy than HD, but certain advantages of IPD did emerge. Applications of this information to the currently more popular mode of CAPD await further study.Comparaison contrôlée entre l'hémodialyse et la dialyse péritonéale: Étude multicentrique de l'Administration des Veterans. Nous avons mesuré la mortalité et la morbidité chez 114 malades, pris au hasard, en hémodialyse à domicile (HD) ou en dialyse péritonéale intermittente à domicile (IPD). Les données ont été recueillies pendant l'entrainement à domicile et pendant les 12 mois suivant le début de la dialyse à domicile. La durée d'entrainement était plus brève pour les malades en IPD que pour ceux en HD (P < 0,001), avec un temps médian de 1,8 mois pour l'IPD et de 3,9 mois pour l'HD. Le changement pour l'autre mode de traitement était plus fréquent pour le groupe IPD (29/59 contre 5/55, P < 0,001). La durée de suivi n'était pas différente, peut-être à cause du changement de modalité. Plus de malades en IPD ont été hospitalisés dans les 6 premiers mois (20 en IPD, contre 9 en HD, P = 0,02), mais ils ont eu moins d'ennuis cardiovasculaires gênants au cours de la première année (0 contre 12, P < 0,001). Les malades HD conservaient un meilleur état nutritionnel, reflété par le poids corporel, la circonférence musculaire du bras, et probablement la vitesse d'apparition de l'urée. Ainsi ces données suggèrent que pour la plupart des malades, l'IPD est une forme de traitement moins satisfaisante que l'HD, mais certains avantages de l'IPD sont apparus. Les applications de cette information au mode actuellement le plus répandu de CAPD requièrent d'autres études

Non-Equilibrium Statistical Physics of Currents in Queuing Networks

We consider a stable open queuing network as a steady non-equilibrium system of interacting particles. The network is completely specified by its underlying graphical structure, type of interaction at each node, and the Markovian transition rates between nodes. For such systems, we ask the question ``What is the most likely way for large currents to accumulate over time in a network ?'', where time is large compared to the system correlation time scale. We identify two interesting regimes. In the first regime, in which the accumulation of currents over time exceeds the expected value by a small to moderate amount (moderate large deviation), we find that the large-deviation distribution of currents is universal (independent of the interaction details), and there is no long-time and averaged over time accumulation of particles (condensation) at any nodes. In the second regime, in which the accumulation of currents over time exceeds the expected value by a large amount (severe large deviation), we find that the large-deviation current distribution is sensitive to interaction details, and there is a long-time accumulation of particles (condensation) at some nodes. The transition between the two regimes can be described as a dynamical second order phase transition. We illustrate these ideas using the simple, yet non-trivial, example of a single node with feedback.Comment: 26 pages, 5 figure

Range expansion and the origin of USA300 north american epidemic methicillin-resistant Staphylococcus aureus

The USA300 North American epidemic (USA300-NAE) clone of methicillin-resistant Staphylococcus aureus has caused a wave of severe skin and soft tissue infections in the United States since it emerged in the early 2000s, but its geographic origin is obscure. Here we use the population genomic signatures expected from the serial founder effects of a geographic range expansion to infer the origin of USA300-NAE and identify polymorphisms associated with its spread. Genome sequences from 357 isolates from 22 U.S. states and territories and seven other countries are compared. We observe two significant signatures of range expansion, including decreases in genetic diversity and increases in derived allele frequency with geographic distance from the Pennsylvania region. These signatures account for approximately half of the core nucleotide variation of this clone, occur genome wide, and are robust to heterogeneity in temporal sampling of isolates, human population density, and recombination detection methods. The potential for positive selection of a gyrA fluoroquinolone resistance allele and several intergenic regions, along with a 2.4 times higher recombination rate in a resistant subclade, is noted. These results are the first to show a pattern of genetic variation that is consistent with a range expansion of an epidemic bacterial clone, and they highlight a rarely considered but potentially common mechanism by which genetic drift may profoundly influence bacterial genetic variation. IMPORTANCE The process of geographic spread of an origin population by a series of smaller populations can result in distinctive patterns of genetic variation. We detect these patterns for the first time with an epidemic bacterial clone and use them to uncover the clone’s geographic origin and variants associated with its spread. We study the USA300 clone of methicillin-resistant Staphylococcus aureus, which was first noticed in the early 2000s and subsequently became the leading cause of skin and soft tissue infections in the United States. The eastern United States is the most likely origin of epidemic USA300. Relatively few variants, which include an antibiotic resistance mutation, have persisted during this clone’s spread. Our study suggests that an early chapter in the genetic history of this epidemic bacterial clone was greatly influenced by random subsampling of isolates during the clone’s geographic spread

A Statistically Rigorous Method for Determining Antigenic Switching Networks

Many vector-borne pathogens rely on antigenic variation to prolong infections and increase their likelihood of onward transmission. This immune evasion strategy often involves mutually exclusive switching between members of gene families that encode functionally similar but antigenically different variants during the course of a single infection. Studies of different pathogens have suggested that switching between variant genes is non-random and that genes have intrinsic probabilities of being activated or silenced. These factors could create a hierarchy of gene expression with important implications for both infection dynamics and the acquisition of protective immunity. Inferring complete switching networks from gene transcription data is problematic, however, because of the high dimensionality of the system and uncertainty in the data. Here we present a statistically rigorous method for analysing temporal gene transcription data to reconstruct an underlying switching network. Using artificially generated transcription profiles together with in vitro var gene transcript data from two Plasmodium falciparum laboratory strains, we show that instead of relying on data from long-term parasite cultures, accuracy can be greatly improved by using transcription time courses of several parasite populations from the same isolate, each starting with different variant distributions. The method further provides explicit indications about the reliability of the resulting networks and can thus be used to test competing hypotheses with regards to the underlying switching pathways. Our results demonstrate that antigenic switch pathways can be determined reliably from short gene transcription profiles assessing multiple time points, even when subject to moderate levels of experimental error. This should yield important new information about switching patterns in antigenically variable organisms and might help to shed light on the molecular basis of antigenic variation

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table