Experimental evidence of parametric decay processes in the variable specific impulse magnetoplasma rocket (VASIMR) helicon plasma source

Decay waves have been observed in the megahertz range in the helium plasma generated by the variable specific impulse magnetoplasma rocket magnetoplasma thruster. They are measured using one of the tips of a triple probe connected to a 50 Ω input of a spectrum analyzer via a dc block (a small capacitor). The maximum amplitude of all waves is in the center of the plasma and does not appear correlated to the radial electron density or temperature profiles. The waves seem to be generated close to the helicon antenna that was 91 cm “upstream” from the measuring Langmuir probe. A possible explanation is parametric decay of the large amplitude helicon wave that also generates the plasma.This project was proudly supported by the International Science Linkages programme established under the Australian Government’s innovation statement Backing Australia’s Ability

Triplet Exciton Generation in Bulk-Heterojunction Solar Cells based on Endohedral Fullerenes

Organic bulk-heterojunctions (BHJ) and solar cells containing the trimetallic nitride endohedral fullerene 1-[3-(2-ethyl)hexoxy carbonyl]propyl-1-phenyl-Lu3N@C80 (Lu3N@C80-PCBEH) show an open circuit voltage (VOC) 0.3 V higher than similar devices with [6,6]-phenyl-C[61]-butyric acid methyl ester (PC61BM). To fully exploit the potential of this acceptor molecule with respect to the power conversion efficiency (PCE) of solar cells, the short circuit current (JSC) should be improved to become competitive with the state of the art solar cells. Here, we address factors influencing the JSC in blends containing the high voltage absorber Lu3N@C80-PCBEH in view of both photogeneration but also transport and extraction of charge carriers. We apply optical, charge carrier extraction, morphology, and spin-sensitive techniques. In blends containing Lu3N@C80-PCBEH, we found 2 times weaker photoluminescence quenching, remainders of interchain excitons, and, most remarkably, triplet excitons formed on the polymer chain, which were absent in the reference P3HT:PC61BM blends. We show that electron back transfer to the triplet state along with the lower exciton dissociation yield due to intramolecular charge transfer in Lu3N@C80-PCBEH are responsible for the reduced photocurrent

Diagnosis and treatment of obstetric anal sphincter injuries: new evidence and perspectives

Perineal injury during childbirth is a common event with important morbidity associated in particular with third-and-fourth degree perineal tears (also referred to as obstetric anal sphincter injuries-OASIS). Early diagnosis of these damages is mandatory to define a prompt therapeutic strategy and thus avoid the development of late-onset consequences, such as faecal incontinence. For this purpose, various diagnostic exams can be performed after a thorough clinical examination. The management of OASIS includes several measures and should be individualized according to the timing and features of the clinical presentation

Hybrid plasma simulations of a magnetically shielded Hall thruster

Numerical simulations of a magnetically shielded Hall effect thruster with a centrally mounted cathode are performed with an axisymmetric hybrid particle-in-cell/fluid code and are partially validated with experimental data. A full description of the plasma discharge inside the thruster chamber and in the near plume is presented and discussed, with the aim of highlighting those features most dependent on the magnetic configuration and the central cathode. Compared to traditional magnetic configurations, the acceleration region is mainly outside the thruster, whereas high plasma densities and low temperatures are found inside the thruster. Thus, magnetic shielding does not decrease plasma currents to the walls, but reduces significantly the energy fluxes, yielding low heat loads and practically no wall erosion. The injection of neutrals at the central cathode generates a secondary plasma plume that merges with the main one and facilitates much the drift of electrons toward the chamber. Once inside, the magnetic topology is efficient in channeling electron current away from lateral walls. Current and power balances are analyzed to assess performances in detail

Cryptosporidium infections in sheep farms from Italy

Cryptosporidiosis is recognized as being a significant cause of gastrointestinal illness due to its wide range of vertebrate hosts, including humans. Infection with Cryptosporidium spp. is especially common in young domestic ruminants (calves, lambs and goat kids) and has been associated with economic losses worldwide. In contrast to cattle, to date, detailed studies on Cryptosporidium infections in sheep from Europe are still limited; thus, their importance as reservoirs of Cryptosporidium species with implications on animal and public health still needs to be clarified. This study evaluates the prevalence and zoonotic potential of Cryptosporidium spp. in sheep farms in Italy. A total of 915 individual faecal samples divided into three different animal categories were collected from 61 sheep farms. Each sample was examined by microscopy of faecal smears stained by modified Ziehl-Neelsen and by biomolecular techniques. Cryptosporidium oocysts were detected in 10.1% of the animals examined and in 34.4% of the farms. The prevalence of Cryptosporidium spp. was significantly higher (χ2 = 51.854; P < 0.001) in diarrhoeic samples than in pasty or normal faeces. Genotype analyses showed the presence of two Cryptosporidium species: C. parvum and C. ubiquitum. Subtyping analysis of C. parvum isolates revealed the presence of subtypes IIa15G2R1 and IIdA20G1 and of subtype XIIa for C. ubiquitum. These findings have public health implications since both Cryptosporidium species identified are considered zoonotic, and C. parvum is the second-most common Cryptosporidium species infecting humans. Our data reveal that lambs, especially those excreting diarrhoeic faeces, may be important reservoirs of Cryptosporidium. We also highlight the need to establish adequate control and monitoring programmes for the control of this infection in sheep farms primarily through coprological monitoring

Localization and Broadband Follow-Up of the Gravitational-Wave Transient GW150914

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser InterferometerGravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimatesof the time, significance, and sky location of the event were shared with 63 teams of observers covering radio,optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter wedescribe the low-latency analysis of the GW data and present the sky localization of the first observed compactbinary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-rayCoordinates Network circulars, giving an overview of the participating facilities, the GW sky localizationcoverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger,there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadbandcampaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broadcapabilities of the transient astronomy community and the observing strategies that have been developed to pursueneutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-upcampaign are being disseminated in papers by the individual teams

Feeding habits of Cocobolo Andinoacara pulcher in the cienaga Grande de Lorica, Colombia

ABSTRACT Objective. The feeding habits of Cocobolo (Andinoacara pulcher) in the cienaga Grande de Lorica, Sinu river basin, were studied. Materials and methods. The stomach content was analyzed using the Proportion of empty stomachs, Grade of digestion, Frequency of occurrence, numerical Frequency, Gravimetry, relative importance Index (RII) and the gut length-total length relationship. Results. 39.8% of stomachs were empty, 47.1% of preys were fresh and five food groups were identified. Vegetable remains was the most frequent group (63.8%) and the prey with greatest composition in weight (33.5%), while Rest of fishes was the most abundant group (34.7%). It was observed that in low and rising waters, fishes was the most consumed prey, while that in high and falling waters the most consumed prey was vegetable remains. Vegetable remains, detritus and fishes were food groups of secondary relative importance, while Insects and Others were circumstantial or incidental groups. Conclusions. The results achieved indicate that Cocobolo is a fish with omnivores feeding habits with a preference for fishes and vegetable remains. RESUMEN Objetivo. Se estudiaron los hábitos alimentarios de Cocobolo (Andinoacara pulcher) en la ciénaga Grande de Lorica, cuenca del río Sinú, Colombia. Materiales y Métodos. El contenido estomacal se evaluó con el Coeficiente de vacuidad, Grado de llenado, Grado de digestión, Frecuencia de ocurrencia, Frecuencia numérica, Gravimetría, Índice de importancia relativa y la relación longitud intestinal- longitud total. Resultados. El 39.8% de los estómagos se encontró vacío, el 47.1% de las presas en estado fresco y se identificaron cinco grupos alimentarios. Material vegetal fue el grupo más frecuente (63.8%) y con mayor composición por peso (33.5%), mientras que Restos de peces fue el más abundante (34.7%). Se observó que en aguas bajas y en aguas ascendentes, peces fue la presa más consumida, mientras que en aguas altas y aguas descendentes, fue material vegetal. Material vegetal, detritos y restos de peces fueron grupos alimentarios de importancia relativa secundaria, mientras que insectos y otros fueron circunstanciales o incidentales. Conclusiones. Los resultados alcanzados indican que Cocobolo es un pez de hábitos alimentarios omnívoros con preferencia por peces y material vegetal

Polymorphism AGT2 (rs4762) is involved in the development of dermatologic events: Proof-of-concept in hepatocellular carcinoma patients treated with sorafenib

BACKGROUND Dermatologic adverse events (DAEs) are associated with a better outcome in patients with hepatocellular carcinoma (HCC) irrespective of the therapeutic agent received. The exact mechanisms associated with the development of DAEs are unknown although several studies point to direct toxicity of tyrosine kinase inhibitors (TKIs) to the skin or an immune-mediated reaction triggered by the oncologic treatment. As is the case in other conditions, individual genetic variants may partially explain a higher risk of DAEs. AIM To evaluate the contribution of several gene variants to the risk of developing DAEs in HCC patients treated with TKIs. METHODS We first analyzed 27 single-nucleotide polymorphisms (SNPs) from 12 genes selected as potential predictors of adverse event (AE) development in HCC patients treated with sorafenib [Barcelona Clinic Liver Cancer 1 (BCLC1) cohort]. Three additional cohorts were analyzed for AGT1 (rs699) and AGT2 (rs4762) polymorphisms-initially identified as predictors of DAEs: BCLC2 (n= 79), Northern Italy (n= 221) and Naples (n= 69) cohorts, respectively. The relation between SNPs and DAEs and death were assessed by univariate and multivariate Cox regression models, and presented with hazard ratios and their 95% confidence intervals (95%CI). RESULTS The BCLC1 cohort showed that patients with arterial hypertension (AHT) (HR = 1.61; P value = 0.007) and/or AGT SNPs had an increased risk of DAEs. Thereafter, AGT2 (rs4762) AA genotype was found to be linked to a statistically significant increased probability of DAEs (HR = 5.97; P value = 0.0201, AA vs GG) in the Northern Italy cohort by multivariate analysis adjusted for BCLC stage, ECOG-PS, diabetes and AHT. The value of this genetic marker was externally validated in the cohort combining the BCLC1, BCLC2 and Naples cohorts [HR = 3.12 (95%CI: 1.2-8.14), P value = 0.0199, AGT2 (rs4762) AA vs AG genotype and HR = 2.73 (95%CI: 1.18-6.32) P value = 0.0188, AGT2 (rs4762) AA vs GG genotype]. None of the other gene variants tested were found to be associated with the risk of DAE development. CONCLUSION DAE development in HCC patients receiving TKIs could be explained by the AGT2 (rs4762) gene variant. If validated in other anti-oncogenic treatments, it might be considered a good prognosis marker

The European Solar Telescope

The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Telescope Heliographique pour l'etude du Magnetisme et des Instabilites Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems