bluuebunny/crossref_metadata_2025_split huggingface dataset:
Astrophysical gyrokinetics: turbulence in pressure-anisotropic plasmas at ion scales and beyond
Authors: Kunz M. W. , Abel I. G. , Klein K. G. , Schekochihin A. A. 
Published: April 2018

We present a theoretical framework for describing electromagnetic kinetic turbulence in a multi-species, magnetized, pressure-anisotropic plasma. The turbulent fluctuations are assumed to be small compared to the mean field, to be spatially anisotropic with respect to it and to have frequencies small compared to the ion cyclotron frequency. At scales above the ion-Larmor radius, the theory reduces to the pressure-anisotropic generalization of kinetic reduced magnetohydrodynamics (KRMHD) formulated by Kunz et al. (J. Plasma Phys., vol. 81, 2015, 325810501). At scales at and below the ion-Larmor radius, three main objectives are achieved. First, we analyse the linear response of the pressure-anisotropic gyrokinetic system, and show it to be a generalization of previously explored limits. The effects of pressure anisotropy on the stability and collisionless damping of Alfvénic and compressive fluctuations are highlighted, with attention paid to the spectral location and width of the frequency jump that occurs as Alfvén waves transition into kinetic Alfvén waves. Secondly, we derive and discuss a very general gyrokinetic free-energy conservation law, which captures both the KRMHD free-energy conservation at long wavelengths and dual cascades of kinetic Alfvén waves and ion entropy at sub-ion-Larmor scales. We show that non-Maxwellian features in the distribution function change the amount of phase mixing and the efficiency of magnetic stresses, and thus influence the partitioning of free energy amongst the cascade channels. Thirdly, a simple model is used to show that pressure anisotropy, even within the bounds imposed on it by firehose and mirror instabilities, can cause order-of-magnitude variations in the ion-to-electron heating ratio due to the dissipation of Alfvénic turbulence. Our theory provides a foundation for determining how pressure anisotropy affects turbulent fluctuation spectra, the differential heating of particle species and the ratio of parallel and perpendicular phase mixing in space and astrophysical plasmas.
Nanoencapsulation of benznidazole in calcium carbonate increases its selectivity to Trypanosoma cruzi
Authors: Tessarolo Louise Donadello , de Menezes Ramon Róseo Paula Pessoa Bezerra , Mello Clarissa Perdigão , Lima Dânya Bandeira , Magalhães Emanuel Paula , Bezerra Eveline Matias , Sales Francisco Adilson Matos , Barroso Neto Ito Liberato , Oliveira Maria de Fátima , dos Santos Ricardo Pires , Albuquerque Eudenilson L. , Freire Valder Nogueira , Martins Alice Maria 
Published: April 2018

AbstractChagas disease is a public health problem, affecting about 7 million people worldwide. Benznidazole (BZN) is the main treatment option, but it has limited effectiveness and can cause severe adverse effects. Drug delivery through nanoparticles has attracted the interest of the scientific community aiming to improve therapeutic options. The aim of this study was to evaluate the cytotoxicity of benznidazole-loaded calcium carbonate nanoparticles (BZN@CaCO3) on Trypanosoma cruzi strain Y. It was observed that BZN@CaCO3 was able to reduce the viability of epimastigote, trypomastigote and amastigote forms of T. cruzi with greater potency when compared with BZN. The amount of BZN necessary to obtain the same effect was up to 25 times smaller when loaded with CaCO3 nanoparticles. Also, it was observed that BZN@CaCO3 enhanced the selectivity index. Furthermore, the cell-death mechanism induced by both BZN and BZN@CaCO3 was evaluated, indicating that both substances caused necrosis and changed mitochondrial membrane potential.
The reduced genome of Candidatus Kinetoplastibacterium sorsogonicusi, the endosymbiont of Kentomonas sorsogonicus (Trypanosomatidae): loss of the haem-synthesis pathway
Authors: Silva Flávia M. , Kostygov Alexei Y. , Spodareva Viktoria V. , Butenko Anzhelika , Tossou Regis , Lukeš Julius , Yurchenko Vyacheslav , Alves João M. P. 
Published: April 2018

AbstractTrypanosomatids of the genera Angomonas and Strigomonas (subfamily Strigomonadinae) have long been known to contain intracellular beta-proteobacteria, which provide them with many important nutrients such as haem, essential amino acids and vitamins. Recently, Kentomonas sorsogonicus, a divergent member of Strigomonadinae, has been described. Herein, we characterize the genome of its endosymbiont, Candidatus Kinetoplastibacterium sorsogonicusi. This genome is completely syntenic with those of other known Ca. Kinetoplastibacterium spp., but more reduced in size (~742 kb, compared with 810–833 kb, respectively). Gene losses are not concentrated in any hot-spots but are instead distributed throughout the genome. The most conspicuous loss is that of the haem-synthesis pathway. For long, removing haemin from the culture medium has been a standard procedure in cultivating trypanosomatids isolated from insects; continued growth was considered as an evidence of endosymbiont presence. However, we demonstrate that, despite bearing the endosymbiont, K. sorsogonicus cannot grow in culture without haem. Thus, the traditional test cannot be taken as a reliable criterion for the absence or presence of endosymbionts in trypanosomatid flagellates. It remains unclear why the ability to synthesize such an essential compound was lost in Ca. K. sorsogonicusi, whereas all other known bacterial endosymbionts of trypanosomatids retain them.
CYP51 as drug targets for fungi and protozoan parasites: past, present and future
Authors: Lepesheva Galina I. , Friggeri Laura , Waterman Michael R. 
Published: April 2018

AbstractThe efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.
Azealia Banks: ‘Chasing Time’, erotics, and body politics
Authors: Hansen Kai Arne , Hawkins Stan 
Published: April 2018

AbstractDuring the 2010s a new generation of queer hip hop artists emerged, providing an opportunity to engage with a set of politics defined by art, fashion, lyrics and music. A leading proponent of this movement was Azealia Banks, the controversial rapper, artist and actress from New York. This study instigates a critical investigation of her performance strategies in the track and video, ‘Chasing Time’ (2014), offering up various perspectives that probe into queer agency. It is suggested that techniques of sonic styling necessitate a consideration of subjectivity alongside genre and style. Employing audiovisual methods of analysis, we reflect on the relationship between gendered subjectivity and modalities of queerness as a means for demonstrating how aesthetics are staged and aligned to advanced techniques of production. It is argued that the phenomenon of eroticised agency, through hyperembodied display, is central to understanding body politics. This article opens a space for problematising issues of black female subjectivity in a genre that is traditionally relegated to the male domain.
Gold-nanofève surface-enhanced Raman spectroscopy visualizes hypotaurine as a robust anti-oxidant consumed in cancer survival
Authors: Shiota Megumi , Naya Masayuki , Yamamoto Takehiro , Hishiki Takako , Tani Takeharu , Takahashi Hiroyuki , Kubo Akiko , Koike Daisuke , Itoh Mai , Ohmura Mitsuyo , Kabe Yasuaki , Sugiura Yuki , Hiraoka Nobuyoshi , Morikawa Takayuki , Takubo Keiyo , Suina Kentaro , Nagashima Hideaki , Sampetrean Oltea , Nagano Osamu , Saya Hideyuki , Yamazoe Shogo , Watanabe Hiroyuki , Suematsu Makoto 
Published: April 2018

AbstractGold deposition with diagonal angle towards boehmite-based nanostructure creates random arrays of horse-bean-shaped nanostructures named gold-nanofève (GNF). GNF generates many electromagnetic hotspots as surface-enhanced Raman spectroscopy (SERS) excitation sources, and enables large-area visualization of molecular vibration fingerprints of metabolites in human cancer xenografts in livers of immunodeficient mice with sufficient sensitivity and uniformity. Differential screening of GNF-SERS signals in tumours and those in parenchyma demarcated tumour boundaries in liver tissues. Furthermore, GNF-SERS combined with quantum chemical calculation identified cysteine-derived glutathione and hypotaurine (HT) as tumour-dominant and parenchyma-dominant metabolites, respectively. CD44 knockdown in cancer diminished glutathione, but not HT in tumours. Mechanisms whereby tumours sustained HT under CD44-knockdown conditions include upregulation of PHGDH, PSAT1 and PSPH that drove glycolysis-dependent activation of serine/glycine-cleavage systems to provide one-methyl group for HT synthesis. HT was rapidly converted into taurine in cancer cells, suggesting that HT is a robust anti-oxidant for their survival under glutathione-suppressed conditions.
Pathogen-derived extracellular vesicles mediate virulence in the fatal human pathogen Cryptococcus gattii
Authors: Bielska Ewa , Sisquella Marta Arch , Aldeieg Maha , Birch Charlotte , O’Donoghue Eloise J. , May Robin C. 
Published: April 2018

AbstractThe Pacific Northwest outbreak of cryptococcosis, caused by a near-clonal lineage of the fungal pathogen Cryptococcus gattii, represents the most significant cluster of life-threatening fungal infections in otherwise healthy human hosts currently known. The outbreak lineage has a remarkable ability to grow rapidly within human white blood cells, using a unique ‘division of labour’ mechanism within the pathogen population, where some cells adopt a dormant behaviour to support the growth of neighbouring cells. Here we demonstrate that pathogenic ‘division of labour’ can be triggered over large cellular distances and is mediated through the release of extracellular vesicles by the fungus. Isolated vesicles released by virulent strains are taken up by infected host macrophages and trafficked to the phagosome, where they trigger the rapid intracellular growth of non-outbreak fungal cells that would otherwise be eliminated by the host. Thus, long distance pathogen-to-pathogen communication via extracellular vesicles represents a novel mechanism to control complex virulence phenotypes in Cryptococcus gattii and, potentially, other infectious species.
The molecular basis of JAK/STAT inhibition by SOCS1
Authors: Liau Nicholas P. D. , Laktyushin Artem , Lucet Isabelle S. , Murphy James M. , Yao Shenggen , Whitlock Eden , Callaghan Kimberley , Nicola Nicos A. , Kershaw Nadia J. , Babon Jeffrey J. 
Published: April 2018

AbstractThe SOCS family of proteins are negative-feedback inhibitors of signalling induced by cytokines that act via the JAK/STAT pathway. SOCS proteins can act as ubiquitin ligases by recruiting Cullin5 to ubiquitinate signalling components; however, SOCS1, the most potent member of the family, can also inhibit JAK directly. Here we determine the structural basis of both these modes of inhibition. Due to alterations within the SOCS box domain, SOCS1 has a compromised ability to recruit Cullin5; however, it is a direct, potent and selective inhibitor of JAK catalytic activity. The kinase inhibitory region of SOCS1 targets the substrate binding groove of JAK with high specificity and thereby blocks any subsequent phosphorylation. SOCS1 is a potent inhibitor of the interferon gamma (IFNγ) pathway, however, it does not bind the IFNγ receptor, making its mode-of-action distinct from SOCS3. These findings reveal the mechanism used by SOCS1 to inhibit signalling by inflammatory cytokines.
Domain imaging across the magneto-structural phase transitions in Fe1+yTe
Authors: Warmuth Jonas , Bremholm Martin , Hofmann Philip , Wiebe Jens , Wiesendanger Roland 
Published: April 2018

AbstractThe investigation of the magnetic phase transitions in the parent compounds of Fe-based superconductors is regarded essential for an understanding of the pairing mechanism in the related superconducting compounds. Even though the chemical and electronic properties of these materials are often strongly inhomogeneous on a nanometer length scale, studies of the magnetic phase transitions using spatially resolved experimental techniques are still scarce. Here, we present a real space spin-resolved scanning tunneling microscopy investigation of the surface of Fe1+yTe single crystals with different excess Fe content, y, which are continuously driven through the magnetic phase transition. For Fe1.08Te, the transition into the low-temperature monoclinic phase is accompanied by the appearance of a chevron-patterned structural ordering due to the four 90° rotational domains of the monoclinic lattice. Each of the structural domains contains locally commensurate nanoscale diagonal double stripe antiferromagnetic spin order domains with π-phase slips accross domain boundaries. In the low-temperature phase of Fe1.12Te, on the other hand, the chevron pattern gets rather narrow and less well-defined, and an additional 90° rotated component of the spin-order with local plaquette order emerges. The simultaneous imaging of spin and structural order we show here gives valuable insights into the nature of the magneto-structural domains of Fe1+yTe near the tricritical point, which presumably add to the understanding of the mechanism of superconductivity in the related Fe1+yTe
x
Se1−x material.
Entrainment of theta, not alpha, oscillations is predictive of the brightness enhancement of a flickering stimulus
Authors: Bertrand Jennifer K. , Wispinski Nathan J. , Mathewson Kyle E. , Chapman Craig S. 
Published: April 2018

AbstractFrequency-dependent brightness enhancement, where a flickering light can appear twice as bright as an equiluminant constant light, has been reported to exist within the alpha (8–12 Hz) band. Could oscillatory neural activity be driving this perceptual effect? Here, in two experiments, human subjects reported which of two flickering stimuli were brighter. Strikingly, 4 Hz stimuli were reported as brighter more than 80% of the time when compared to all other tested frequencies, even though all stimuli were equiluminant and of equal temporal length. Electroencephalography recordings showed that inter-trial phase coherence (ITC) of theta (4 Hz) was: (1) Significantly greater than alpha, contralateral to the flickering stimulus; (2) Enhanced by the presence of a second ipsilateral 4 Hz flickering stimulus; and (3) Uniquely lateralized, unlike the alpha band. Importantly, on trials with two identical stimuli (i.e. 4 Hz vs 4 Hz), the brightness discrimination judgment could be predicted by the hemispheric balance in the amount of 4 Hz ITC. We speculate that the theta rhythm plays a distinct information transfer role, where its ability to share information between hemispheres via entrainment promotes a better processing of visual information to inform a discrimination decision.
Clinicopathological and prognostic significance of high circulating lymphocyte ratio in patients receiving neoadjuvant chemotherapy for advanced gastric cancer
Authors: Li Yang , Wei Yao , He Qi , Wang Xulin , Fan Chaogang , Li Guoli 
Published: April 2018

AbstractThis study was designed to investigate the prognostic value of circulating blood cell counts and subsets for patients with advanced gastric cancer (AGC) treated with neoadjuvant chemotherapy (NAC) and the factors determining pathological complete response (pCR). In 112 patients with AGC, we retrospectively examined the ratios of lymphocyte, monocyte, and neutrophil during and after NAC before surgery, and the percentages of CD3+, CD3+ CD4+, CD3+ CD8+ and CD4+/CD8+ lymphocytes as well. We also investigated their associations with the pCR rate and overall survival (OS). The ratios of lymphocyte taken before and after NAC were significantly greater in forty-four pCR cases than that in sixty-eight non-pCR cases. During NAC, the proportion of lymphocyte and the percentages of CD3+, CD3+ CD4+, and CD3+ CD8+ lymphocytes were dramatically increased in pCR group. The lymphocyte ratio showed an independent association with pCR by multivariate analysis and maintained at a relatively high level in pCR cases. By mean of 31.53% lymphocyte ratio before-NAC and 41.68% after-NAC, cases with high lymphocyte ratio showed significantly better outcome in OS. High circulating lymphocyte ratios, both before and after NAC, are positively associated with pCR and improved OS in advanced gastric cancer, which may be considered as a new prognostic biomarker.
Association between radiological parameters and clinical and molecular characteristics in human somatotropinomas
Authors: Alhambra-Expósito María R. , Ibáñez-Costa Alejandro , Moreno-Moreno Paloma , Rivero-Cortés Esther , Vázquez-Borrego Mari C. , Blanco-Acevedo Cristóbal , Toledano-Delgado Álvaro , Lombardo-Galera María S. , Vallejo-Casas Juan A. , Gahete Manuel D. , Castaño Justo P. , Gálvez María A. , Luque Raúl M. 
Published: April 2018

AbstractAcromegaly is a rare but severe disease, originated in 95% of cases by a growth hormone-secreting adenoma (somatotropinoma) in the pituitary. Magnetic resonance imaging (MRI) is a non-invasive technique used for the diagnosis and prognosis of pituitary tumours. The aim of this study was to determine whether the use of T2-weighted signal intensity at MRI could help to improve the characterisation of somatotropinomas, by analysing its relationship with clinical/molecular features. An observational study was implemented in a cohort of 22 patients (mean age = 42.1 ± 17.2 years; 59% women; 95% size>10 mm). Suprasellar-extended somatotropinomas presented larger diameters vs. non-extended tumours. T2-imaging revealed that 59% of tumours were hyperintense and 41% isointense adenomas, wherein hyperintense were more invasive (according to Knosp-score) than isointense adenomas. A higher proportion of hyperintense somatotropinomas presented extrasellar-growth, suprasellar-growth and invasion of the cavernous sinus compared to isointense adenomas. Interestingly, somatostatin receptor-3 and dopamine receptor-5 (DRD5) expression levels were associated with extrasellar and/or suprasellar extension. Additionally, DRD5 was also higher in hyperintense adenomas and its expression was directly correlated with Knosp-score and with tumour diameter. Hence, T2-weighted MRI on somatotropinomas represents a potential tool to refine their diagnosis and prognosis, and could support the election of preoperative treatment, when required.
Perineuronal Net Protein Neurocan Inhibits NCAM/EphA3 Repellent Signaling in GABAergic Interneurons
Authors: Sullivan Chelsea S. , Gotthard Ingo , Wyatt Elliott V. , Bongu Srihita , Mohan Vishwa , Weinberg Richard J. , Maness Patricia F. 
Published: April 2018

AbstractPerineuronal nets (PNNs) are implicated in closure of critical periods of synaptic plasticity in the brain, but the molecular mechanisms by which PNNs regulate synapse development are obscure. A receptor complex of NCAM and EphA3 mediates postnatal remodeling of inhibitory perisomatic synapses of GABAergic interneurons onto pyramidal cells in the mouse frontal cortex necessary for excitatory/inhibitory balance. Here it is shown that enzymatic removal of PNN glycosaminoglycan chains decreased the density of GABAergic perisomatic synapses in mouse organotypic cortical slice cultures. Neurocan, a key component of PNNs, was expressed in postnatal frontal cortex in apposition to perisomatic synapses of parvalbumin-positive interneurons. Polysialylated NCAM (PSA-NCAM), which is required for ephrin-dependent synapse remodeling, bound less efficiently to neurocan than mature, non-PSA-NCAM. Neurocan bound the non-polysialylated form of NCAM at the EphA3 binding site within the immunoglobulin-2 domain. Neurocan inhibited NCAM/EphA3 association, membrane clustering of NCAM/EphA3 in cortical interneuron axons, EphA3 kinase activation, and ephrin-A5-induced growth cone collapse. These studies delineate a novel mechanism wherein neurocan inhibits NCAM/EphA3 signaling and axonal repulsion, which may terminate postnatal remodeling of interneuron axons to stabilize perisomatic synapses in vivo.
Identification of QTL controlling domestication-related traits in cowpea (Vigna unguiculata L. Walp)
Authors: Lo Sassoum , Muñoz-Amatriaín María , Boukar Ousmane , Herniter Ira , Cisse Ndiaga , Guo Yi-Ning , Roberts Philip A. , Xu Shizhong , Fatokun Christian , Close Timothy J. 
Published: April 2018

AbstractCowpea (Vigna unguiculata L. Walp) is a warm-season legume with a genetically diverse gene-pool composed of wild and cultivated forms. Cowpea domestication involved considerable phenotypic changes from the wild progenitor, including reduction of pod shattering, increased organ size, and changes in flowering time. Little is known about the genetic basis underlying these changes. In this study, 215 recombinant inbred lines derived from a cross between a cultivated and a wild cowpea accession were used to evaluate nine domestication-related traits (pod shattering, peduncle length, flower color, days to flowering, 100-seed weight, pod length, leaf length, leaf width and seed number per pod). A high-density genetic map containing 17,739 single nucleotide polymorphisms was constructed and used to identify 16 quantitative trait loci (QTL) for these nine traits. Based on annotations of the cowpea reference genome, genes within these regions are reported. Four regions with clusters of QTL were identified, including one on chromosome 8 related to increased organ size. This study provides new knowledge of the genomic regions controlling domestication-related traits in cowpea as well as candidate genes underlying those QTL. This information can help to exploit wild relatives in cowpea breeding programs.