Gyrofluid analysis of electron β e effects on collisionless reconnection

The linear and nonlinear evolutions of the tearing instability in a collisionless plasma with a strong guide field are analysed on the basis of a two-field Hamiltonian gyrofluid model. The model is valid for a low ion temperature and a finite. The finite effect implies a magnetic perturbation along the guide field direction, and electron finite Larmor radius effects. A Hamiltonian derivation of the model is presented. A new dispersion relation of the tearing instability is derived for the case and tested against numerical simulations. For the equilibrium electron temperature is seen to enhance the linear growth rate, whereas we observe a stabilizing role when electron finite Larmor radius effects become more relevant. In the nonlinear phase, stall phases and faster than exponential phases are observed, similarly to what occurs in the presence of ion finite Larmor radius effects. Energy transfers are analysed and the conservation laws associated with the Casimir invariants of the model are also discussed. Numerical simulations seem to indicate that finite effects do not produce qualitative modifications in the structures of the Lagrangian invariants associated with Casimirs of the model

Noncollisional plasmoid instability based on a gyrofluid and gyrokinetic integrated approach

In this work, the development of two-dimensional current sheets with respect to tearing-modes, in collisionless plasmas with a strong guide field, is analysed. During their non-linear evolution, these thin current sheets can become unstable to the formation of plasmoids, which allows the magnetic reconnection process to reach high reconnection rates. We carry out a detailed study of the impact of a finite $\beta_e$, which also implies finite electron Larmor radius effects, on the collisionless plasmoid instability. This study is conducted through a comparison of gyrofluid and gyrokinetic simulations. The comparison shows in general a good capability of the gyrofluid models in predicting the plasmoid instability observed with gyrokinetic simulations. We show that the effects of $\beta_e$ promotes the plasmoid growth. The impact of the closure applied during the derivation of the gyrofluid model is also studied through the comparison of the energy variation

The Role of Exosomal miR-181c-3p Within the Ovarian Tumor Microenvironment

https://openworks.mdanderson.org/sumexp22/1034/thumbnail.jp

ULTRASONOGRAPHIC FEATURES OF ADRENAL GLAND LESIONS IN DOGS CAN AID IN DIAGNOSIS

BACKGROUND: Ultrasonography to visualize adrenal gland lesions and evaluate incidentally discovered adrenal masses in dogs has become more reliable with advances in imaging techniques. However, correlations between sonographic and histopathological changes have been elusive. The goal of our study was to investigate which ultrasound features of adrenal gland abnormalities could aid in discriminating between benign and malignant lesions. To this end, we compared diagnosis based on ultrasound appearance and histological findings and evaluated ultrasound criteria for predicting malignancy. RESULTS: Clinical records of 119 dogs that had undergone ultrasound adrenal gland and histological examination were reviewed. Of these, 50 dogs had normal adrenal glands whereas 69 showed pathological ones. Lesions based on histology were classified as cortical adrenal hyperplasia (n = 67), adenocarcinoma (n = 17), pheochromocytoma (n = 10), metastases (n = 7), adrenal adenoma (n = 4), and adrenalitis (n = 4). Ultrasonographic examination showed high specificity (100%) but low sensitivity (63.7%) for identifying the adrenal lesions, which improved with increasing lesion size. Analysis of ultrasonographic predictive parameters showed a significant association between lesion size and malignant tumors. All adrenal gland lesions >20 mm in diameter were histologically confirmed as malignant neoplasms (pheochromocytoma and adenocarcinoma). Vascular invasion was a specific but not sensitive predictor of malignancy. As nodular shape was associated with benign lesions and irregular enlargement with malignant ones, this parameter could be used as diagnostic tool. Bilaterality of adrenal lesions was a useful ultrasonographic criterion for predicting benign lesions, as cortical hyperplasia. CONCLUSIONS: Abnormal appearance of structural features on ultrasound images (e.g., adrenal gland lesion size, shape, laterality, and echotexture) may aid in diagnosis, but these features alone were not pathognomic. Lesion size was the most direct ultrasound predictive criterion. Large and irregular masses seemed to be better predictors of malignant neoplasia and lesions <20 mm in diameter and nodular in shape were often identified as cortical hyperplastic nodules or adenomas

Fluid circulation pattern inside La Soufrière volcano (Guadeloupe) inferred from combined electrical resistivity tomography, self-potential, soil temperature and diffuse degassing measurements

International audienceAfter a drastic decline in 1983, hydrothermal activity at La Soufrière lava dome (Guadeloupe, Lesser Antilles) has been progressively increasing in the summit area since 1992, raising the threat of a renewed eruptive activity. To better constrain the geometry of the hydrothermal system, an extensive high-resolution self-potential survey was performed on the dome and three multi-method profiles combining electrical resistivity tomography, self-potential, ground thermometry and soil CO 2 diffuse degassing measurements were carried out to cover its southern periphery in January 2011. Results indicate that hydrothermal ascending flows are currently restricted to a proximal area including the dome and its very vicinity. The extension of hydrothermal alteration inferred from electrical resistivity tomography reflects the presence of a heat source just below the dome. A first-order correction of topography-related self-potential variations allows the identification of major hydrothermal fluid circulations pathways, as well as significant meteoric infiltration zones. Local shifting of hydrothermal fluids towards the dome periphery is favored by the presence of major axes. The regional La Ty fault appears as the major axis draining large volumes of hydrothermal and magmatic fluids. However hydrothermal activity remains confined inside a collapse structure surrounding the dome, that formed in the last 9000 years as a result of recurrent edifice collapses, the latest occurring at the onset of the 1530 AD eruption. The combination of these qualitative results with structural analysis leads to a synthetic model of magmatic and hydrothermal fluids circulation inside the dome, which may be useful for the assessment of potential hazards associated with a renewal of fluid pres-surization, and a possibly associated partial flank-failure

Spatially Resolved Transcriptomics Identified Distinct Tumor-Stroma Crosstalk Networks Associated With Chemoresistance in Ovarian Cancer

https://openworks.mdanderson.org/sumexp21/1135/thumbnail.jp

Difusión del Corn Stunt Spiroplasma del maíz (Spiroplasma kunkelii) y del vector (Dalbulus maidis) en la República Argentina

Among the most important diseases that affect the corn crops (Zea mays L.) is “Corn Stunt Spiroplasm” (CSS). It is caused by Spiroplasm kunkelii and transmitted by a cicadelid Dalbulus maidis (De Long &amp; Wolcott, 1923), the only vector known up to the present in Argentina. Corn crop were monitored in 10 provinces of Argentina during 1991/1992, 1994/1995, 1996/2000. This provided information about the growth of this disease since its detection in the year 1990/1991 up to the present in Argentina as well as the distribution of D. maidis, its vector. The detection of the pathogen was performed on plants with symptoms that are characteristic of CSS using the technique of NC-ELISA. The vector was captured by sweeping plants of corn with symptoms. A increase in the areas affected by CSS was shown in the provinces of Jujuy, Salta, Tucumán, Catamarca, Chaco, Corrientes and Santiago del Estero as well as its recent detection in the provinces of Córdoba, San Luis and La Pampa. Based on the 83 places monitored, D. maidis was present in 80 % of the samples and the pathogen was detected in 96%. In the provinces Corrientes, Córdoba, San Luis and La Pampa, D. maidis was not registered.Entre las enfermedades más importantes que afectan al cultivo de maíz (Zea mays L.), se encuentra el achaparramiento o Corn Stunt Spiroplasma (CSS), causado por Spiroplasma kunkelii, trasmitido por el cicadélido Dalbulus maidis (De Long & Wolcott, 1923), único vector conocido hasta el presente en Argentina. Sobre la base de monitoreos realizados en lotes cultivados de maíz en 10 provincias de Argentina durante las campañas 1991/1992; 1994/1995; 1996/2000 se aporta información de esta enfermedad y del agente vector desde su detección en el año 1990/1991. La identificación del patógeno se realizó sobre plantas con síntomas característicos del CSS mediante la técnica de NCELISA. La presencia del vector se registró mediante capturas con red entomológica de arrastre sobre plantas de maíz con síntomas. Se demostró un incremento de la superficie afectada por el Corn Stunt Spiroplasma en las provincias de Jujuy, Salta, Tucumán, Catamarca, Chaco, Corrientes, Santiago del Estero y la reciente aparición en las provincias de Córdoba, San Luis y La Pampa. De las 83 localidades monitoreadas, D. maidis estuvo presente en 80 % de las localidades y en 96% se detectó el patógeno. En las provincias de Corrientes, Córdoba, San Luis y La Pampa no se registró a D. maidis