Influencia de la frecuencia de ordeñes en el nivel de producción y composición láctea en ovejas de la raza pampinta

Con el objetivo de determinar la influencia que tiene la frecuencia de ordeñe en el rendimiento y composición láctea de ovejas de la raza Pampinta, se realizó un ensayo en el que se siguió un diseño completamente aleatorizado con un factor (tipo de ordeñe) con dos tratamientos (un ordeñe diario contra dos ordeñes diarios) y con medidas repetidas en el tiempo (tres fechas para la variable producción y dos fechas para la variable composición láctea). Se utilizaron cinco animales por tratamiento (n=5) y cada animal se mantuvo identificado para poder hacerle un seguimiento en tiempo. La suma de los tres controles lecheros dio una producción total de 16,66 litros para el tratamiento doble ordeñe contra 13,83 litros del tratamiento único ordeñe, Los valores promedio de los dos tratamientos fueron los siguientes: 0,922 Its/día para el tratamiento único ordeñe y 1,11° Its/día para el tratamiento doble ordene. Si bien en este trabajo no se encontraron diferencias con significancia estadística entre los tratamientos, existen dos factores fundamentales que afectan la magnitud de la respuesta al doble ordeñe como son, el potencial lechero y la etapa de la curva de lactación. Animales con alto potencial lechero responden en menor grado que aquellos con bajo potencial y a medida que avanzamos en la lactancia tenemos menos respuesta al doble ordeñe. Tampoco se encontraron diferencias significativas estadísticamente entre los tratamientos en lo que respecta a composición láctea, tanto para los contenidos de grasa como para los contenidos de extracto seco.Director: Ing. Agr. Gustavo D. Fernández e Ing. Agr. Abel E. Zuccari. Cátedra de Zootecnia Especial 1

1,3-Bis[(naphthalen-2-ylsulfan­yl)meth­yl]benzene

Mol­ecules of the title compound, C28H22S2, are located on a crystallographic mirror plane with one half-mol­ecule in the asymmetric unit. The dihedral angle between the phenyl ring and the naphthyl unit is 83.14 (7)°. In the crystal, mol­ecules are inter­connected by C—H⋯S and C—H⋯π inter­actions

Effect of angiotensin II and small GTPase Ras signaling pathway inhibition on early renal changes in a murine model of obstructive nephropathy

This is an open access article distributed under the Creative Commons Attribution License.Tubulointerstitial fibrosis is a major feature of chronic kidney disease. Unilateral ureteral obstruction (UUO) in rodents leads to the development of renal tubulointerstitial fibrosis consistent with histopathological changes observed in advanced chronic kidney disease in humans. The purpose of this study was to assess the effect of inhibiting angiotensin II receptors or Ras activation on early renal fibrotic changes induced by UUO. Animals either received angiotensin II or underwent UUO. UUO animals received either losartan, atorvastatin, and farnesyl transferase inhibitor (FTI) L-744,832, or chaetomellic acid A (ChA). Levels of activated Ras, phospho-ERK1/2, phospho-Akt, fibronectin, and α-smooth muscle actin were subsequently quantified in renal tissue by ELISA, Western blot, and/or immunohistochemistry. Our results demonstrate that administration of angiotensin II induces activation of the small GTPase Ras/Erk/Akt signaling system, suggesting an involvement of angiotensin II in the early obstruction-induced activation of renal Ras. Furthermore, upstream inhibition of Ras signalling by blocking either angiotensin AT1 type receptor or by inhibiting Ras prenylation (atorvastatin, FTI o ChA) reduced the activation of the Ras/Erk/Akt signaling system and decreased the early fibrotic response in the obstructed kidney. This study points out that pharmacological inhibition of Ras activation may hold promise as a future strategy in the prevention of renal fibrosis.This study was supported by grants from Ministerio de Economía y Competitividad (Grant SAF2010-15881 and Red de Investigacion Cooperativa en Enfermedades Renales REDINREN RD12/0021/0032), Junta de Castilla y León (Grant SA 001/C05 and Excellence Group GR100), and REDINREN which is an initiative of the Instituto de Salud Carlos III of Spain supported by FEDER funds. When performing the present study, Ana B. Rodríguez-Pena was a fellow of the Fundacion Renal “Iñigo Ávarez de Toledo” and Neil G. Docherty was a fellow ofThe Marie Curie Programme, EU.Peer Reviewe

Magnetism and stability interplay : Correlations in simple BCC-based Fe intermetallic compounds

In this work, we present an ab initio study of a large set of simple, highly symmetrical ordered Fe-compounds (superlattices of the body-centered cubic structure, BCC), in order to analyze the role of the magnetism in the phase stability of these compounds. Our results, confirm that ferromagnetism and compound stability can be related. That is, the highest magnetic moments are observed for the least stable compounds. We also show that compounds have qualitatively different behavior as regards stability, according to whether their nature is ferromagnetic or non-magnetic.Instituto de Física La PlataDepartamento de Electrotecni

Magnetism and stability interplay : Correlations in simple BCC-based Fe intermetallic compounds

In this work, we present an ab initio study of a large set of simple, highly symmetrical ordered Fe-compounds (superlattices of the body-centered cubic structure, BCC), in order to analyze the role of the magnetism in the phase stability of these compounds. Our results, confirm that ferromagnetism and compound stability can be related. That is, the highest magnetic moments are observed for the least stable compounds. We also show that compounds have qualitatively different behavior as regards stability, according to whether their nature is ferromagnetic or non-magnetic.Instituto de Física La PlataDepartamento de Electrotecni

Superconductivity in Te-deficient ZrTe2_2

We present structural, electrical, and thermoelectric potential measurements on high-quality single crystals of ZrTe$_{1.8}$ grown from isothermal chemical vapor transport. These measurements show that the Te-deficient ZrTe$_{1.8}$, which forms the same structure as the non-superconducting ZrTe$_2$, is superconducting below 3.2\,K. The temperature dependence of the upper critical field (H$_{c2}$) deviates from the behavior expected in conventional single-band superconductors, being best described by an electron-phonon two-gap superconducting model with strong intraband coupling. For the ZrTe$_{1.8}$ single crystals, the Seebeck potential measurements suggest that the charge carriers are predominantly negative, in agreement with the ab initio calculations. Through first-principles calculations within DFT, we show that the slight reduction of Te occupancy in ZrTe$_2$ unexpectedly gives origin to density of states peaks at the Fermi level due to the formation of localized Zr-$d$ bands, possibly promoting electronic instabilities at the Fermi level and an increase at the critical temperature according to the standard BCS theory. These findings highlight that the Te deficiency promotes the electronic conditions for the stability of the superconducting ground state, suggesting that defects can fine-tune the electronic structure to support superconductivity

Magnetism and stability interplay : Correlations in simple BCC-based Fe intermetallic compounds

In this work, we present an ab initio study of a large set of simple, highly symmetrical ordered Fe-compounds (superlattices of the body-centered cubic structure, BCC), in order to analyze the role of the magnetism in the phase stability of these compounds. Our results, confirm that ferromagnetism and compound stability can be related. That is, the highest magnetic moments are observed for the least stable compounds. We also show that compounds have qualitatively different behavior as regards stability, according to whether their nature is ferromagnetic or non-magnetic.Instituto de Física La PlataDepartamento de Electrotecni

Assessment techniques, database design and software facilities for thermodynamics and diffusion

The purpose of this article is to give a set of recommendations to producers of assessed thermodynamic data, who may be involved in either the critical evaluation of limited chemical systems or the creation and dissemination of larger thermodynamic databases. Also, it is hoped that reviewers and editors of scientific publications in this field will find some of the information useful. Good practice in the assessment process is essential, particularly as datasets from many different sources may be combined together into a single database. With this in mind, we highlight some problems that can arise during the assessment process and we propose a quality assurance procedure. It is worth mentioning at this point, that the provision of reliable assessed thermodynamic data relies heavily on the availability of high quality experimental information. The different software packages for thermodynamics and diffusion are described here only briefly