Stress transfer quantification in gelatin-matrix natural composites with tunable optical properties

© 2015 American Chemical Society.This work reports on the preparation and characterization of natural composite materials prepared from bacterial cellulose (BC) incorporated into a gelatin matrix. Composite morphology was studied using scanning electron microscopy and 2D Raman imaging revealing an inhomogeneous dispersion of BC within the gelatin matrix. The composite materials showed controllable degrees of transparency to visible light and opacity to UV light depending on BC weight fraction. By adding a 10 wt % fraction of BC in gelatin, visible (= 550 nm) and UV (= 350 nm) transmittances were found to decrease by ∼35 and 40%, respectively. Additionally, stress transfer occurring between the gelatin and BC fibrils was quantified using Raman spectroscopy. This is the first report for a gelatin-matrix composite containing cellulose. As a function of strain, two distinct domains, both showing linear relationships, were observed for which an average initial shift rate with respect to strain of -0.63 ± 0.2 cm-1%-1 was observed, followed by an average shift rate of -0.25 ± 0.03 cm-1%-1. The average initial Raman band shift rate value corresponds to an average effective Youngs modulus of 39 ± 13 GPa and 73 ± 25 GPa, respectively, for either a 2D and 3D network of BC fibrils embedded in the gelatin matrix. As a function of stress, a linear relationship was observed with a Raman band shift rate of -27 ± 3 cm-1GPa-1. The potential use of these composite materials as a UV blocking food coating is discussed

Asistencia a las urgencias psiquiátricas en Albacete.

Se han examinado las características de los pacientes atendidos en la Unidad de Urgencias Psiquiátricas de Albacete durante el año 1990. De los datos obtenidos destacan: 1) Los trastornos por alcohol y opiáceos fueron el grupo más numeroso, con casi un tercio de las urgencias. 2) Casi los dos tercios de las urgencias estuvieron entre las edades de 15 a 40 años. 3) Casi la cuarta parte de las mismas se quedaron ingresadas en la Unidad de Hospitalización Psiquiátrica. Y 4) La escasa incidencia de las urgencias enviadas por el juez

Asistencia a las urgencias psiquiátricas en Albacete.

Se han examinado las características de los pacientes atendidos en la Unidad de Urgencias Psiquiátricas de Albacete durante el año 1990. De los datos obtenidos destacan: 1) Los trastornos por alcohol y opiáceos fueron el grupo más numeroso, con casi un tercio de las urgencias. 2) Casi los dos tercios de las urgencias estuvieron entre las edades de 15 a 40 años. 3) Casi la cuarta parte de las mismas se quedaron ingresadas en la Unidad de Hospitalización Psiquiátrica. Y 4) La escasa incidencia de las urgencias enviadas por el juez

The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang

Evolution in the measured rest frame ultraviolet spectral slope and ultraviolet to optical flux ratios indicate a rapid evolution in the dust obscuration of galaxies during the first 3 billion years of cosmic time (z>4). This evolution implies a change in the average interstellar medium properties, but the measurements are systematically uncertain due to untested assumptions, and the inability to measure heavily obscured regions of the galaxies. Previous attempts to directly measure the interstellar medium in normal galaxies at these redshifts have failed for a number of reasons with one notable exception. Here we report measurements of the [CII] gas and dust emission in 9 typical (~1-4L*) star-forming galaxies ~1 billon years after the big bang (z~5-6). We find these galaxies have >12x less thermal emission compared with similar systems ~2 billion years later, and enhanced [CII] emission relative to the far-infrared continuum, confirming a strong evolution in the interstellar medium properties in the early universe. The gas is distributed over scales of 1-8 kpc, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z<3 and being comparable to local low-metallicity systems.Comment: Submitted to Nature, under review after referee report. 22 pages, 4 figures, 4 Extended Data Figures, 5 Extended Data table

Structural Determinants of the Dictyostatin Chemotype for Tubulin Binding Affinity and Antitumor Activity Against Taxane- and Epothilone-Resistant Cancer Cells

A combined biochemical, structural, and cell biology characterization of dictyostatin is described, which enables an improved understanding of the structural determinants responsible for the high-affinity binding of this anticancer agent to the taxane site in microtubules (MTs). The study reveals that this macrolide is highly optimized for MT binding and that only a few of the structural modifications featured in a library of synthetic analogues resulted in small gains in binding affinity. The high efficiency of the dictyostatin chemotype in overcoming various kinds of clinically relevant resistance mechanisms highlights its potential for therapeutic development for the treatment of drug-resistant tumors. A structural explanation is advanced to account for the synergy observed between dictyostatin and taxanes on the basis of their differential effects on the MT lattice. The X-ray crystal structure of a tubulin−dictyostatin complex and additional molecular modeling have allowed the rationalization of the structure−activity relationships for a set of synthetic dictyostatin analogues, including the highly active hybrid 12 with discodermolide. Altogether, the work reported here is anticipated to facilitate the improved design and synthesis of more efficacious dictyostatin analogues and hybrids with other MT-stabilizing agents.We thank Peter T. Northcote for peloruside A, W.-S. Fang for Flutax-2, K. H. Altmann for epothilone D, Dr. Paraskevi Giannakakou (Weill Cornell Medical Center, New York) for the 1A9, PTX10, PTX22, and A8 cell lines, and Prof. Richard Ludueñ a (University of Texas) for the HeLa βIII-transfected cells. We thank Matadero INCOVA (Segovia) for the calf brains for tubulin purification. This work was supported in part by grants BIO2013-42984-R (J.F.D.) and SAF2012-39760-C02-02 (F.G.) from Ministerio de Economia y Competitividad, grant S2010/ ́ BMD-2457 BIPEDD2 from Comunidad Autonoma de Madrid ́ (F.G. and J.F.D.), and the Swiss National Science Foundation grants 310030B_138659 and 31003A_166608 (M.O.S.). The authors acknowledge networking contribution by the COST Action CM1407 “Challenging organic syntheses inspired by naturefrom natural products chemistry to drug discovery” and the COST action CM1470. I.P. thanks the EPSRC and AstraZeneca for funding, Dr. John Leonard (AstraZeneca) for useful discussions, Dr. Stuart Mickel (Novartis) for the provision of chemicals, and the EPSRC UK National Mass Spectrometry Facility at Swansea University for mass spectra

Structural Determinants of the Dictyostatin Chemotype for Tubulin Binding Affinity and Antitumor Activity Against Taxane- and Epothilone-Resistant Cancer Cells

A combined biochemical, structural, and cell biology characterization of dictyostatin is described, which enables an improved understanding of the structural determinants responsible for the high-affinity binding of this anticancer agent to the taxane site in microtubules (MTs). The study reveals that this macrolide is highly optimized for MT binding and that only a few of the structural modifications featured in a library of synthetic analogues resulted in small gains in binding affinity. The high efficiency of the dictyostatin chemotype in overcoming various kinds of clinically relevant resistance mechanisms highlights its potential for therapeutic development for the treatment of drug-resistant tumors. A structural explanation is advanced to account for the synergy observed between dictyostatin and taxanes on the basis of their differential effects on the MT lattice. The X-ray crystal structure of a tubulin−dictyostatin complex and additional molecular modeling have allowed the rationalization of the structure−activity relationships for a set of synthetic dictyostatin analogues, including the highly active hybrid 12 with discodermolide. Altogether, the work reported here is anticipated to facilitate the improved design and synthesis of more efficacious dictyostatin analogues and hybrids with other MT-stabilizing agents.We thank Peter T. Northcote for peloruside A, W.-S. Fang for Flutax-2, K. H. Altmann for epothilone D, Dr. Paraskevi Giannakakou (Weill Cornell Medical Center, New York) for the 1A9, PTX10, PTX22, and A8 cell lines, and Prof. Richard Ludueñ a (University of Texas) for the HeLa βIII-transfected cells. We thank Matadero INCOVA (Segovia) for the calf brains for tubulin purification. This work was supported in part by grants BIO2013-42984-R (J.F.D.) and SAF2012-39760-C02-02 (F.G.) from Ministerio de Economia y Competitividad, grant S2010/ ́ BMD-2457 BIPEDD2 from Comunidad Autonoma de Madrid ́ (F.G. and J.F.D.), and the Swiss National Science Foundation grants 310030B_138659 and 31003A_166608 (M.O.S.). The authors acknowledge networking contribution by the COST Action CM1407 “Challenging organic syntheses inspired by naturefrom natural products chemistry to drug discovery” and the COST action CM1470. I.P. thanks the EPSRC and AstraZeneca for funding, Dr. John Leonard (AstraZeneca) for useful discussions, Dr. Stuart Mickel (Novartis) for the provision of chemicals, and the EPSRC UK National Mass Spectrometry Facility at Swansea University for mass spectra

Mental health care for irregular migrants in Europe: Barriers and how they are overcome

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Experimental Size‐Selective Harvesting Affects Behavioral Types of a Social Fish

In most fisheries, larger fish experience substantially higher mortality than smaller fish. Body length, life-history and behavioral traits often correlate, such that fisheries-induced changes in size or life-history can also alter behavioural traits. However, empirical evidence regarding how size-selective harvesting alters the evolution of behavioural traits in exploited stocks is scarce. We used experimental lines of zebrafish (Danio rerio) that were exposed to positive, negative or random size-selective harvest over five generations. Our aim was to investigate whether simulated fishing changed the mean personality of the surviving females five generations after initial harvesting halted. We found that mean boldness, activity, and sociability were significantly altered relative to a randomly harvested control line. Harvestinduced changes in individual-level personality were only detected in the negatively sizeselected line. By contrast, we did not detect harvest-induced evolution of personality in the positively size-selected line. We conclude that size-selective harvesting alters individual fish personality in a social fish.peerReviewe

A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions

Conservation agriculture involves reduced tillage, permanent soil cover and crop rotations to enhance soil fertility and to supply food from a dwindling land resource. Recently, conservation agriculture has been promoted in Southern Africa, mainly for maize-based farming systems. However, maize yields under rain-fed conditions are often variable. There is therefore a need to identify factors that influence crop yield under conservation agriculture and rain-fed conditions. Here, we studied maize grain yield data from experiments lasting 5 years and more under rain-fed conditions. We assessed the effect of long-term tillage and residue retention on maize grain yield under contrasting soil textures, nitrogen input and climate. Yield variability was measured by stability analysis. Our results show an increase in maize yield over time with conservation agriculture practices that include rotation and high input use in low rainfall areas. But we observed no difference in system stability under those conditions. We observed a strong relationship between maize grain yield and annual rainfall. Our meta-analysis gave the following findings: (1) 92% of the data show that mulch cover in high rainfall areas leads to lower yields due to waterlogging; (2) 85% of data show that soil texture is important in the temporal development of conservation agriculture effects, improved yields are likely on well-drained soils; (3) 73% of the data show that conservation agriculture practices require high inputs especially N for improved yield; (4) 63% of data show that increased yields are obtained with rotation but calculations often do not include the variations in rainfall within and between seasons; (5) 56% of the data show that reduced tillage with no mulch cover leads to lower yields in semi-arid areas; and (6) when adequate fertiliser is available, rainfall is the most important determinant of yield in southern Africa. It is clear from our results that conservation agriculture needs to be targeted and adapted to specific biophysical conditions for improved impact