Spectral Inversion of Multi-Line Full-Disk Observations of Quiet Sun Magnetic Fields

Spectral inversion codes are powerful tools to analyze spectropolarimetric observations, and they provide important diagnostics of solar magnetic fields. Inversion codes differ by numerical procedures, approximations of the atmospheric model, and description of radiative transfer. Stokes Inversion based on Response functions (SIR) is an implementation widely used by the solar physics community. It allows to work with different atmospheric components, where gradients of different physical parameters are possible, e.g., magnetic field strength and velocities. The spectropolarimetric full-disk observations were carried out with the Stokesmeter of the Solar Telescope for Operative Predictions (STOP) at the Sayan Observatory on 3 February 2009, when neither an active region nor any other extended flux concentration was present on the Sun. In this study of quiet Sun magnetic fields, we apply the SIR code simultaneously to 15 spectral lines. A tendency is found that weaker magnetic field strengths occur closer to the limb. We explain this finding by the fact that close to the limb, we are more sensitive to higher altitudes in an expanding flux tube, where the field strength should be smaller since the magnetic flux is conserved with height. Typically, the inversions deliver two populations of magnetic elements: (1) high magnetic field strengths (1500-2000 G) and high temperatures (5500-6500 K) and (2) weak magnetic fields (50-150 G) and low temperatures (5000-5300 K).Comment: 10 pages, 6 figures, accepted for Solar Physic

Managing acute malnutrition in infants aged less than six months: a qualitative assessment in Niger public hospitals

Quality management of severe acute malnutrition (SAM) in infants < 6 months of age is a key strategy within the “1000 days window of opportunity”. It prevents early child death, secures optimal growth and forms a foundation for full adulthood potentials. Most studies to date on management of SAM in infants relied on informants from Non-Governmental Organizations staff or government public health officials but little is known from hospital practitioners. From June to August 2013, a qualitative appraisal of hospital practitioners’ views on the current quality of care for malnourished infants was conducted in the eight main hospitals of Niger. These eight hospitals included two National Referral Hospitals (Lamordé and Zinder) and six Regional Referral Hospitals (Poudrière, Dosso, Tahoua, Maradi, Diffa and Agadez). Authorization for the review was given by the Ministry of Health of Niger. Health workers (HW) present during surveyors’ visits were included in the study. Two (2) specific objectives were considered: 1) Determine HW perceptions and current use of the Supplemental Suckling Technique (SST) and 2) Collect HW propositions on feasibility to organize outpatient treatment of SAM in infants less than six months. Self-designed interview guide was used. Data were analysed manually and saturation in the occurrence of responses were the criteria used to retain items. The Supplemental Suckling Technique (SST), though firmly recommended by national guidelines to ensure continuation of breastfeeding and adequate nutrients intake from supplemental milks especially in a small infant, was rarely used. Main reasons advanced by staff were work overload, inadequate training, and lack of compliance from mothers. Before being discharged from hospital, mothers were counseled on continuation of treatment, follow up visits at peripheral health center (PHC) and feeding options at home. However, hospital staff had no indication whether mothers were seen at the referred PHC, nor if counseling was practiced at home. The proposed outpatient treatment model for selected cases without medical complications should relieve hospital caseloads, strengthen referral and improve breastfeeding support to mothers after discharge from hospital.Keywords: Malnutrition, infant feeding, inpatient treatment, qualitative assessment, Nige

An efficient and versatile chemical synthesis of bioactive glyco-glycerolipids

Synthesis of b-glyco-1,2-diacylglycerols is achieved by a versatile and simple procedure based on trichloro-acetimidate methodology and use of peracetate sugar substrates. The chemical strategy was tested through stereoselective preparation of b-galacto- and b-gluco-lipid derivatives capable to trigger immune system response. The synthetic approach is designed to obtain enantiomerically pure regioand stereo-isomers including derivatives containing poly-unsaturated fatty acids

Biosynthetic Studies Through Feeding Experiments in Marine Organisms

This chapter deals with feeding experiments in biosynthetic studies of secondary metabolites from marine organisms. The evolution of the field is traced through a critical report of both review papers published from the 1980s and selected studies published in the latest years. The progress in the methodologies, from simple modification of advanced precursors, through incorporation of substrates with radioactive or stable isotopes, to recent extensive use of molecular genetic techniques, served as a main guideline for the preparation of this overview. Finally, after a section dedicated to the methodologies, the biosynthesis of oxylipins from diatoms and propionates from Mediterranean sacoglossans, recently conducted in the authors’ institute, will be discussed with more detail

Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration

Introduction: Status epilepticus (SE) is an epileptic condition that can cause cerebellar atrophy and loss of Purkinje cells in both humans and research animals. Cerebellum is a region rich in γ-amino butyric acid (GABA) and glutamate, and some studies have shown that their concentrations may be altered after convulsions. However, there are no studies showing the effect of seizures on different cerebellar regions in developing rats. Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration. Methods: SE was induced using the lithium-pilocarpine model; control rats were injected with saline solution. At 6 hours, 24 hours, and 1 month after SE o saline injection, rats were anaesthetised with pentobarbital and decapitated, and cerebella were extracted. The vermis and hemispheres were dissected and homogenised in 0.1 M perchloric acid containing 4 mM sodium bisulfite. Homogenates were centrifuged and supernatant was used to quantify GABA, and glutamate tissue concentrations by HPLC coupled with fluorometric detection. Results: SE did not alter GABA and glutamate tissue concentration in the cerebellar vermis and hemispheres. Conclusion: The developing rat cerebellum is resistant to both short- and long-term neurochemical changes induced by SE. Resumen: Introducción: El status epilepticus (SE) es un tipo de actividad epiléptica que causa atrofia cerebelar y pérdida de células de Purkinje en humanos y en animales de experimentación. El cerebelo es una región con alto contenido de ácido γ-aminobutírico (GABA) y glutamato, y algunos estudios refieren cambios en su concentración después de las convulsiones. Sin embargo, hasta la fecha no existen estudios que hayan analizado su efecto en diferentes regiones cerebelares en ratas en desarrollo. El objetivo del presente estudio fue realizar un curso temporal del efecto del SE inducido en ratas Wistar de 14 días de edad (P14) sobre el contenido tisular de GABA y glutamato en el vermis y los hemisferios cerebelares. Métodos: El SE se indujo con el modelo de litio-pilocarpina; las ratas control se inyectaron con salina. Seis h, 24 h o 30 días después del inicio del SE o de la aplicación de solución salina, las ratas se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Las ratas de ambos grupos se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Ambas regiones se homogeneizaron (ácido perclórico 0,1 M conteniendo metabisulfito de sodio 4 mM) y centrifugaron, y el sobrenadante se empleó para cuantificar la concentración tisular de GABA y glutamato por cromatografía de líquidos de alta resolución acoplada a un detector fluorométrico. Resultados: El SE no modificó la concentración de GABA y glutamato a los diferentes tiempos de análisis ni en el vermis ni en los hemisferios cerebelares. Conclusiones: El cerebelo en desarrollo es resistente a los cambios neuroquímicos a corto y largo plazo producidos por el SE. Keywords: Status epilepticus, Cerebellum, γ-Amino butyric acid, Glutamate, Palabras clave: Status epilepticus, Cerebelo, Ácido γ-aminobutírico, Glutamat

Evaluación temporal del efecto del status epilepticus inducido en la rata en desarrollo en la concentración cerebelar de ácido γ-aminobutírico y glutamato

Resumen: Introducción: El status epilepticus (SE) es un tipo de actividad epiléptica que causa atrofia cerebelar y pérdida de células de Purkinje en humanos y en animales de experimentación. El cerebelo es una región con alto contenido de ácido γ-aminobutírico (GABA) y glutamato, y algunos estudios refieren cambios en su concentración después de las convulsiones. Sin embargo, hasta la fecha no existen estudios que hayan analizado su efecto en diferentes regiones cerebelares en ratas en desarrollo. El objetivo del presente estudio fue realizar un curso temporal del efecto del SE inducido en ratas Wistar de 14 días de edad (P14) sobre el contenido tisular de GABA y glutamato en el vermis y los hemisferios cerebelares. Métodos: El SE se indujo con el modelo de litio-pilocarpina; las ratas control se inyectaron con salina. Seis h, 24 h o 30 días después del inicio del SE o de la aplicación de solución salina, las ratas se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Las ratas de ambos grupos se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Ambas regiones se homogeneizaron (ácido perclórico 0,1 M conteniendo metabisulfito de sodio 4 mM) y centrifugaron, y el sobrenadante se empleó para cuantificar la concentración tisular de GABA y glutamato por cromatografía de líquidos de alta resolución acoplada a un detector fluorométrico. Resultados: El SE no modificó la concentración de GABA y glutamato a los diferentes tiempos de análisis ni en el vermis ni en los hemisferios cerebelares. Conclusiones: El cerebelo en desarrollo es resistente a los cambios neuroquímicos a corto y largo plazo producidos por el SE. Abstract: Introduction: Status epilepticus (SE) is an epileptic condition that can cause cerebellar atrophy and loss of Purkinje cells in both humans and research animals. Cerebellum is a region rich in γ-aminobutyric acid (GABA) and glutamate, and some studies have shown that their concentrations may be altered after convulsions. However, there are no studies showing the effect of seizures on different cerebellar regions in developing rats. Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration. Methods: SE was induced using the lithium-pilocarpine model; control rats were injected with saline solution. At 6 h, 24 h, and 1 month after SE o saline injection, rats were anaesthetised with pentobarbital and decapitated, and cerebella were extracted. The vermis and hemispheres were dissected and homogenised in 0.1 M perchloric acid containing 4 mM sodium bisulfite. Homogenates were centrifuged and supernatant was used to quantify GABA, and glutamate tissue concentrations by HPLC coupled with fluorometric detection. Results: SE did not alter GABA and glutamate tissue concentration in the cerebellar vermis and hemispheres. Conclusion: The developing rat cerebellum is resistant to both short- and long-term neurochemical changes induced by SE. Palabras clave: Status epilepticus, Cerebelo, Ácido γ-aminobutírico, Glutamato, Keywords: Status epilepticus, Cerebellum, γ-amino butyric acid, Glutamat