Pressure dependence of the Shubnikov-de Haas oscillation pectrum of beta''-(BEDT-TTF)4(NH4)[Cr(C2O4)3].DMF

The Shubnikov-de Haas (SdH) oscillation spectra of the beta''-(BEDT-TTF)4(NH4)[Cr(C2O4)\_3].DMF organic metal have been studied in pulsed magnetic fields of up to either 36 T at ambient pressure or 50 T under hydrostatic pressures of up to 1 GPa. The ambient pressure SdH oscillation spectra can be accounted for by up to six fundamental frequencies which points to a rather complex Fermi surface (FS). A noticeable pressure-induced modification of the FS topology is evidenced since the number of frequencies observed in the spectra progressively decreases as the pressure increases. Above 0.8 GPa, only three compensated orbits are observed, as it is the case for several other isostructural salts of the same family at ambient pressure. Contrary to other organic metals, of which the FS can be regarded as a network of orbits, no frequency combinations are observed for the studied salt, likely due to high magnetic breakdown gap values or (and) high disorder level evidenced by Dingle temperatures as large as about 7 K.Comment: To be published in European Physical Journal

Of the Repository: Poetics in a Networked Digital Milieu

This doctoral dissertation is a material and cultural analysis of the entwined histories of the three major North American digital repositories of contemporary avant-garde and experimental poetry: the Electronic Poetry Center at the State University of New York at Buffalo, Kenneth Goldsmith’s UbuWeb, and PennSound at the University of Pennsylvania. The dissertation takes up a media-historical methodology to document the actors, publics, discourses, aesthetics, institutional environments, technological infrastructures, and social relations involved in the production of these open online repositories. The research begins from the premise that, in the study of what writing is, has been, and might be, the discourse of poetics and the figure of the archive fuse together. If, as Kate Eichhorn (2003) argues, “[t]o write in a digital age is to write in the archive,” in this research I ask: What can the composition of archives – their materials, contexts, protocols, and interfaces – teach us about poetics today? Since the mid-1990s, these three repositories have served as a primary means for extending the purview and program of poetics as a contemporary institutional formation. In doing so, the creators of these repositories have utilized them as important media infrastructures for the publication, dissemination, and storage of poetic works and critical analysis on the contemporary production of poetry. Each digital repository is an argument for a specific poetics. Their entwined histories and cultural-technical infrastructures articulate numerous affinities, yet each is distinct in the way it casts a new light on certain critical terms for literary studies. Approaching each in terms of its emphasis on, respectively, access, circulation, and format enables a detailed engagement with the aesthetic, institutional, legal, and technological concerns of the digital repository. Here, this dissertation develops a unique methodology for addressing these complicated structures called digital repositories by emphasizing each case study’s particular bias. Such an engagement opens on to a more general consideration of language, writing, and textuality in networked milieus, and emphasizes the particular affordances that make the digital repository a significant, yet underkacknowledged, archival genre

de Haas-van Alphen oscillations in the underdoped cuprate YBa2_2Cu3_3O6.5_{6.5}

The de Haas-van Alphen effect was observed in the underdoped cuprate YBa$_2$Cu$_3$O$_{6.5}$ via a torque technique in pulsed magnetic fields up to 59 T. Above an irreversibility field of $\sim$30 T, the magnetization exhibits clear quantum oscillations with a single frequency of 540 T and a cyclotron mass of 1.76 times the free electron mass, in excellent agreement with previously observed Shubnikov-de Haas oscillations. The oscillations obey the standard Lifshitz-Kosevich formula of Fermi-liquid theory. This thermodynamic observation of quantum oscillations confirms the existence of a well-defined, close and coherent, Fermi surface in the pseudogap phase of cuprates.Comment: published versio

Shubnikov-de Haas oscillations in YBa_2Cu_4O_8

We report the observation of Shubnikov-de Haas oscillations in the underdoped cuprate superconductor YBa$_2$Cu$_4$O$_8$ (Y124). For field aligned along the c-axis, the frequency of the oscillations is $660\pm 30$ T, which corresponds to $\sim 2.4$ % of the total area of the first Brillouin zone. The effective mass of the quasiparticles on this orbit is measured to be $2.7\pm0.3$ times the free electron mass. Both the frequency and mass are comparable to those recently observed for ortho-II YBa$_2$Cu$_3$O$_{6.5}$ (Y123-II). We show that although small Fermi surface pockets may be expected from band structure calculations in Y123-II, no such pockets are predicted for Y124. Our results therefore imply that these small pockets are a generic feature of the copper oxide plane in underdoped cuprates.Comment: v2: Version of paper accepted for publication in Physical Review Letters. Only minor changes to the text and reference

Distribution and biology of the Blackmouth catshark Galeus melastomus in the Strait of Sicily (Central Mediterranean Sea)

The Blackmouth catshark, Galeus melastomus, Rafinesque, 1810 (Carcharhiniformes; Scyliorhinidae), is a common, although at present discarded, by- catch of the bottom trawl fisheries in the Strait of Sicily. Given its ecological interest, data gathered in experimental bottom trawl surveys were analysed in order to describe its distribution and main biological traits. The Blackmouth catshark was sampled almost exclusively on the upper slope (200-800), showing the highest frequency of occurrence (69-100%), biomass (BI; 10-85 kg*km-2) and density (DI; 54-506 N*km-2) indexes in the deeper (501-800m) grounds. Individual size (total length, TL, mm) were between 70-590 and 90-510 in females and males, respectively. The sex ratio (SR) was around 0.5. The SR by size showed a gradual decrease till 450 mm class size, followed by an increase up 1 after 500 mm. Virginal/immature specimens represented the bulk of the samples in both females (77%) and males (65%); the length at 50% of sexual maturity (Lm50%) and corresponding maturity range (Lm25% - Lm75% ) was 433 (423-443) and 380 (366-394) mm, respectively

Cell cultures harbouring constructs of different pig promoter polymorphisms show different transcriptional efficiency in gene reporter systems

AbstractProduction traits variability among and within breeds, differences among developmental stages or the response to different environments are in part due to genetic factors that affect gene expression. Within the context of an Italian FIRB project, whose objective is to identify genes and molecular mechanisms affecting meat quality and production traits in pig, we studied the promoter regions of candidate genes selected on the basis of their physiological role in animal tissue development or composition. Genomic DNA was isolated from liver or muscle tissue of individuals belonging to Large White and Casertana breed. PCR primers were designed to amplify 5' upstream region of SCD (Stearoyl-CoA Desaturase), LDLR (Low Density Lipoprotein Receptor), LEP (Leptin), MSTN (Myostatin), ACTA1 (Alpha-actin) and HFABP (Heart Fatty Acid Binding Protein) genes using sequences available at NCBI. A total of 19 single nucleotide polymorphisms (SNPs) not previously described were characterised. Some haplotypes, harbou..

Postoperative Non-steroidal Anti-inflammatory Drugs and Risk of Bleeding in Pediatric Intracapsular Tonsillectomy

Tonsillectomy with or without adenoidectomy is one of the most frequently performed surgeries in the United States, with over 500,000 performed annually. Post-tonsillectomy hemorrhage is one of the most feared complications; thus, medications that could increase the risk of postoperative bleeding traditionally have been avoided. With recent FDA guidelines encouraging a departure from codeine-based medications in pediatric patients undergoing tonsillectomy, we examined the use of ibuprofen for post-tonsillectomy pain control. The records of 449 children who underwent tonsillectomy and received ibuprofen for postoperative pain control were reviewed and compared to a cohort of 1731 children who received codeine for pain postoperatively. Outcomes measured included rates of secondary post-tonsillectomy hemorrhage (PTH), secondary PTH requiring operative control, and emergency room evaluation for dehydration. Use of ibuprofen after pediatric intracapsular tonsillectomy was found to be associated with a statistically significant increase in secondary PTH and secondary PTH requiring operative control; however, ibuprofen was found to provide pain control that is at least equivalent to narcotic. Rates of secondary PTH with postoperative ibuprofen use remain within the national average. We propose that, despite the increased risk of bleeding, the use of ibuprofen is appropriate for use postoperatively in pediatric tonsillectomy patients, given its ability to control pain and lack of respiratory depression effects

Molecular targets of developmental exposure to bisphenol A in diabesity: a focus on endoderm-derived organs

Several studies associate foetal human exposure to bisphenol A (BPA) to metabolic/endocrine diseases, mainly diabesity. They describe the role of BPA in the disruption of pancreatic beta cell, adipocyte and hepatocyte functions. Indeed, the complexity of the diabesity phenotype is due to the involvement of different endoderm-derived organs, all targets of BPA. Here, we analyse this point delineating a picture of different mechanisms of BPA toxicity in endoderm-derived organs leading to diabesity. Moving from epidemiological data, we summarize the in vivo experimental data of the BPA effects on endoderm-derived organs (thyroid, pancreas, liver, gut, prostate and lung) after prenatal exposure. Mainly, we gather molecular data evidencing harmful effects at low-dose exposure, pointing to the risk to human health. Although the fragmentation of molecular data does not allow a clear conclusion to be drawn, the present work indicates that the developmental exposure to BPA represents a risk for endoderm-derived organs development as it deregulates the gene expression from the earliest developmental stages. A more systematic analysis of BPA impact on the transcriptomes of endoderm-derived organs is still missing. Here, we suggest in vitro toxicogenomics approaches as a tool for the identification of common mechanisms of BPA toxicity leading to the diabesity in organs having the same developmental origin