Efectos de los métodos de procesado y de las condiciones de almacenamiento comercial en los índices de calidad del aceite virgen extra

The effect of machinery groups, packing materials and light intensities was ascertained on indices of oxidative deterioration, peroxide value, and extinction coefficient K232 and K270 of extra virgin olive oil for one season of olive harvesting in an effort to simulate commercial storage conditions. It was revealed that during the storage of olive oil the peroxide value was significantly affected by the type of extraction machinery, packing material and light intensity. It is significant that oil exposed to diffused daylight and artificial light attained maximum PV in the second or third month of storage and de creased thereafter, while samples stored in the dark attained their maximum PV during the sixth month of storage. Oil samples extracted using the centrifugal type of machines and kept in glass containers in the dark had higher peroxide values than those extracted by the classic method. The rate of changes of the PV and the two indices K232 and K270 was also affected similarly by the type of machinery, packing material and light intensity.El efecto de la maquinaria, el material de envasado y la intensidad de luz fue relacionado con los índices de deterioración oxidativa, índice de peróxidos (IP) y coeficientes de extinción K232 y K270 del aceite de oliva virgen extra durante una campaña de cosecha de aceituna en un esfuerzo por simular las condiciones de almacenamiento comercial. Esto reveló que durante el almacenamiento del aceite de oliva el índice de peróxidos fue afectado significativamente por el tipo de maquinaria de extracción, el material de envasado y la intensidad de luz. Es significativo que el aceite expuesto a la luz diaria difusa y a la artificial alcanzara el máximo IP en el segundo o tercer mes de almacenamiento, decreciendo a partir de este momento, mientras que las muestras almacenadas en oscuridad no alcanzaban su máximo IP hasta el sexto mes de conservación. Las muestras de aceite extraídas con centrífuga y mantenidas en contenedores vidrio en la oscuridad alcanzaron un IP mayor que las extraídas por el sistema clásico. Las velocidades de cambio del IP y de los K232 y K270 fueron también afectadas por el tipo de maquinaria extractora empleada, el material de envasado utilizado y la intensidad de luz recibida por el aceite durante su conservación

Investigating the KNDy hypothesis in humans by co-administration of kisspeptin, neurokinin B and naltrexone in men

Context: A subpopulation of hypothalamic neurons co-localise three neuropeptides namely kisspeptin, neurokinin B (NKB) and dynorphin collectively termed KNDy neurons. Animal studies suggest they interact to affect pulsatile GnRH release (KNDy hypothesis); kisspeptin stimulates, NKB modulates and dynorphin (an opioid) inhibits. Objective: To investigate the KNDy hypothesis in humans, we assessed for the first time the effects of co-administration of kisspeptin-54, NKB and an opioid receptor antagonist, naltrexone on LH pulsatility (surrogate marker for GnRH pulsatility) and gonadotropin release. Design, setting and participants: Ethically approved prospective, single-blinded placebo-controlled study. Healthy male volunteers (n=5/group) attended our research facility for 8 study visits. Intervention and main outcome measure: After 1h baseline blood sampling, participants received a different intervention at each visit: oral 50mg naltrexone (NAL), 8h intravenous infusions of vehicle, 2.56nmol/kg/h NKB (NKB), 0.1nmol/kg/h kissspeptin-54 (KP) alone and in combination. Frequent blood sampling to measure plasma gonadotropins and sex steroids was conducted and LH pulsatility was determined using blinded deconvolution analysis. Results: All kisspeptin and naltrexone containing groups potently increased LH and LH pulsatility (p<0.001 vs vehicle). NKB alone did not affect gonadotropins. NKB+KP had significantly lower increases in gonadotropins compared with kisspeptin alone (p<0.01). NAL+KP was the only group to significantly increase LH pulse amplitude (p<0.001 vs vehicle). Conclusions: Our results suggest significant interactions between the KNDy neuropeptides on LH pulsatility and gonadotropin release in humans. This has important implications for improving our understanding of GnRH pulse generation in humans

Indicators for the Sea-floor Integrity of the Hellenic Seas under the European Marine Strategy Framework Directive: establishing the thresholds and standards for Good Environmental Status

A data set of 625 samples of benthic macroinvertebrates collected from the Hellenic Seas (Ionian and Aegean) was used to establish thresholds and reference standards for two of the indicators addressing the descriptors of Sea-floor Integrity under the Marine Strategy Framework Directive (MSFD): species diversity and richness and the ratio of sensitive species to tolerant species. The dataset was categorised according to the baseline ecological status assessment of the respective water bodies under the Water Framework Directive (WFD). Species diversity and richness were characterised using the Shannon diversity and species richness indices, respectively, and were analysed for three pre-defined substrate types, three depth zones and three sample-size categories, and the significant categories were statistically validated. Good Environmental Status (GEnS) threshold and reference values were established for the valid combinations of categories denoted as ‘ecotypes’ through the use of a boxplot and an analysis of variance. The limitations and specifications for an overall GEnS assessment using the above indices are highlighted based on the WFD experience. For the ratio of sensitive species to tolerant species, the BENTIX index classification scale is proposed for GEnS assessment, and an integrated approach to the assessment of diversity and species richness is suggested. Finally, the regionality of the tested indices in relation to the two Mediterranean sub-regions, including the Hellenic area, was tested

Students' Experiences of Interdisciplinary Learning while Building Scientific Video Games

Game jams, hackathons and similar group game creation events have become increasingly popular over the past decade (Fowler et al., 2015). They provide new and exciting opportunities for education and research. They foster creative thinking and innovation (Preston et al., 2012), and strengthen project management and communication skills (Smith & Bowers, 2016); all of which are essential skills for working in industry (Pirker et al., 2016)

Taylor-Couette instability in disk suspensions: Experimental observation and theory

Using the well-known hydrodynamic theory for dilute suspensions of spheroids, we have previously predicted the destabilization of Taylor-Couette flow due to anisotropic viscous stresses induced by suspended disk-shaped particles [Gillissen and Wilson, Phys. Rev. Fluids 3, 113903 (2018)]. Here we provide experimental evidence for the destabilization mechanism using suspensions of mica flakes. There is good qualitative agreement between the experiment and theory in the mica concentration dependence of the critical speed for instability onset and of the axial wavelength of the corresponding Taylor vortices. Quantitative differences are attributed to hydrodynamic interactions between the disks, which we account for in the theory in an ad hoc fashion using rotary diffusion

Colored Non-Crossing Euclidean Steiner Forest

Given a set of $k$-colored points in the plane, we consider the problem of finding $k$ trees such that each tree connects all points of one color class, no two trees cross, and the total edge length of the trees is minimized. For $k=1$, this is the well-known Euclidean Steiner tree problem. For general $k$, a $k\rho$-approximation algorithm is known, where $\rho \le 1.21$ is the Steiner ratio. We present a PTAS for $k=2$, a $(5/3+\varepsilon)$-approximation algorithm for $k=3$, and two approximation algorithms for general~$k$, with ratios $O(\sqrt n \log k)$ and $k+\varepsilon$

Nanosecond and femtosecond ablation of La0.6Ca0.4CoO3: a comparison between plume dynamics and composition of the films

Thin films of La0.6Ca0.4CoO3 were grown by pulsed laser ablation with nanosecond and femtosecond pulses. The films deposited with femtosecond pulses (248nm, 500fs pulse duration) exhibit a higher surface roughness and deficiency in the cobalt content compared to the films deposited with nanosecond pulses (248nm, 20ns pulse duration). The origin of these pronounced differences between the films grown by ns and fs ablation has been studied in detail by time-resolved optical emission spectroscopy and imaging. The plumes generated by nanosecond and femtosecond ablation were analyzed in vacuum and in a background pressure of 60 Pa of oxygen. The ns-induced plume in vacuum exhibits a spherical shape, while for femtosecond ablation the plume is more elongated along the expansion direction, but with similar velocities for ns and fs laser ablation. In the case of ablation in the background gas similar velocities of the plume species are observed for fs and ns laser ablation. The different film compositions are therefore not related to different kinetic energies and different distributions of various species in the plasma plume which has been identified as the origin of the deficiency of species for other material