Th Ages for Metal-Poor Stars

With a sample of 22 metal-poor stars, we demonstrate that the heavy element abundance pattern (Z > 55) is the same as the r-process contributions to the solar nebula. This bolsters the results of previous studies that there is a universal r-process production pattern. We use the abundance of thorium in five metal-poor stars, along with an estimate of the initial Th abundance based on the abundances of stable r-process elements, to measure their ages. We have four field red giants with errors of 4.2 Gyr in their ages and one M92 giant with an error of 5.6 Gyr, based on considering the sources of observational error only. We obtain an average age of 11.4 Gyr, which depends critically on the assumption of an initial production ratio of Th/Eu of 0.496. If the Universe is 15 Gyr old, then the initial Th/Eu value should be 0.590, in agreement with some theoretical models of the r-process.Comment: 26 pages, to be published in Ap

Can physical activity be used to maintain cognitive function in nursing home residents with dementia? A literature review

Background: Dementia is a noncommunicable disease with no effective prevention, treatment or cure. Evidence is emerging for the use of exercise to decelerate cognitive decline; however, few studies exist among nursing home residents and an optimum exercise protocol is yet to be determined. Objectives: To determine the effectiveness of physical activity in maintaining cognitive function in nursing home residents with dementia. Methods: Databases searched included CINAHL, MEDLINE complete, SPORTDiscus and ScienceDirect. Six relevant studies were identified and critically appraised using the Effective Public Health Practice Project Quality Assessment Tool. Results: All trials included different exercise programmes with various activity types and duration; all control interventions were social activities. Three studies demonstrated improved cognition in the intervention group, whilst one study observed a slower decline. Four studies found statistically significant cognitive decline in the control groups. Two studies observed no significant changes in either the intervention or control groups. Overall, there is moderate-to-moderate evidencestrong evidence that physical activity can effectively maintain cognitive function in nursing home residents with dementia. Conclusions: All interventions had a favourable effect on cognition. Results suggest that aerobic exercise of longer duration may be most effective for those with mild-to-moderate cognitive impairment; whilst multimodal programmes may be most effective for moderate-to-severe dementia. Combining an exercise programme with standard daily activities appears no more effective than exercise alone. Future research should aim to determine an optimum exercise protocol and whether the positive effects on cognition can be maintained long term with continued exercise

Novel mass spectrometric approaches for the analysis of modern oil paint media and organic additives in paintings

Modern unvarnished oil paints in paintings show degradation problems such as bleeding, efflorescence and solvent sensitivity1 which are related to specific lipidic media and additives in the paint. Micro-analytical techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography/Mass spectrometry (GCMS) are routinely used for detection of organic materials in oil paints. The type of oil may be determined based on characteristic peak ratios of mainly palmitic and stearic acid, using GCMS. However, the techniques are less specific if other lipidic components are present. Moreover, using standard preparation techniques GCMS provides only limited information about important parameters which reflect the original composition and the state of ageing or degradation through oxidation, hydrolysis and soap formation. In general, a combination of analytical techniques and/or extensive sample pretreatment is required to obtain such information.2,3 This paper discusses 20th C oil paint technology and the organic components that may be present in fresh and dried oil paints. An overview is given of novel mass spectrometric techniques which can be used for detection of these original materials and their drying and degradation products, and compared to GCMS techniques which involve pretreatment and derivatisation procedures

Pollutants Increase Song Complexity and the Volume of the Brain Area HVC in a Songbird

Environmental pollutants which alter endocrine function are now known to decrease vertebrate reproductive success. There is considerable evidence for endocrine disruption from aquatic ecosystems, but knowledge is lacking with regard to the interface between terrestrial and aquatic ecosystems. Here, we show for the first time that birds foraging on invertebrates contaminated with environmental pollutants, show marked changes in both brain and behaviour. We found that male European starlings (Sturnus vulgaris) exposed to environmentally relevant levels of synthetic and natural estrogen mimics developed longer and more complex songs compared to control males, a sexually selected trait important in attracting females for reproduction. Moreover, females preferred the song of males which had higher pollutant exposure, despite the fact that experimentally dosed males showed reduced immune function. We also show that the key brain area controlling male song complexity (HVC) is significantly enlarged in the contaminated birds. This is the first evidence that environmental pollutants not only affect, but paradoxically enhance a signal of male quality such as song. Our data suggest that female starlings would bias their choice towards exposed males, with possible consequences at the population level. As the starling is a migratory species, our results suggest that transglobal effects of pollutants on terrestrial vertebrate physiology and reproduction could occur in birds

The use of sewage treatment works as foraging sites by insectivorous bats

Sewage treatment works with percolating filter beds are known to provide profitable foraging areas for insectivorous birds due to their association with high macroinvertebrate densities. Fly larvae developing on filter beds at sewage treatment works may similarly provide a valuable resource for foraging bats. Over the last two decades, however, there has been a decline in filter beds towards a system of “activated sludge”. Insects and bat activity were surveyed at 30 sites in Scotland employing these two different types of sewage treatment in order to assess the possible implications of these changes for foraging bats. Bat activity (number of passes) recorded from broad-band bat detectors was quantified at three points within each site. The biomass of aerial insects, sampled over the same period as the detector surveys, was measured using a suction trap. The biomass of insects and activity of Pipistrellus spp. was significantly higher at filter beds than at activated sludge sites. In addition, whilst foraging activity of Pipistrellus spp. at filter beds was comparable to that of adjacent “good” foraging habitat, foraging at activated sludge sites was considerably lower. This study indicates the high potential value of an anthropogenic process to foraging bats, particularly in a landscape where their insect prey has undergone a marked decline, and suggests that the current preference for activated sludge systems is likely to reduce the value of treatment works as foraging sites for bats

HPLC-DAD and HPLC-ESI-Q-ToF characterisation of early 20th century lake and organic pigments from Lefranc archives

The characterisation of atelier materials and of the historical commercial formulation of paint materials has recently gained new interest in the field of conservation science applied to modern and contemporary art, since modern paint materials are subjected to peculiar and often unpredictable degradation and fading processes. Assessing the composition of the original materials purchased by artists can guide not only their identification in works of art, but also their restoration and conservation. Advances in characterisation methods and models for data interpretation are particularly important in studying organic coloring materials in the transition period corresponding to the late 19th-early 20th century, when many such variants or combinations were hypothetically possible in their formulations. There is thus a need for reliable databases of materials introduced in that period and for gaining chemical knowledge at a molecular level related to modern organic pigments, by state-of-the-art protocols. This paper reports on the results of a study on 44 samples of historical colorants in powder and paint tubes, containing both lake pigments and synthetic organic pigments dating from 1890 to 1926. The samples were collected at the Lefranc Archive in Le Mans (France) as a part of Project Futurahma "From Futurism to Classicism (1910-1922). Research, Art History and Material Analysis", (FIRB2012, Italian Ministry of University and Research), and were investigated using an analytical approach based on chromatographic and mass spectrometric techniques. The focus of the chemical analyses was to reveal the composition of the historical organic lake pigments including minor components, to discriminate between different recipes for the extraction of chromophore-containing molecules from the raw materials, and ultimately to distinguish between different formulations and recipes. High performance liquid chromatography (HPLC) with diode array detector (DAD) or electrospray-Quadrupole-Time of Flight tandem mass spectrometry detector (ESI-Q-ToF) were chosen given their considerable capacity to identify such complex and widespread organic materials. Although the inorganic components of the pigments were not taken into account in this survey, the specific molecular profiles provided invaluable information on the extraction procedures or synthetic strategy followed by the different producers, at different times. For instance, the use of Kopp's purpurin and garancine was highlighted, and synthetic by-products were identified. The results provided evidence that the addition of synthetic organic pigments to paint mixtures started from 1910 onwards, but they also suggest that in the formulation of high quality (surfin) colorants, natural products were still preferred. Moreover, in one of the samples the use of murexide as the colouring material was confirmed. This paper presents the first systematic and comprehensive survey on organic lakes and pigments belonging to an historical archive, by both HPLC-DAD and HPLC-ESI-Q-ToF. Specific by-products of synthetic production of pigments, which can act as specific molecular markers for dating or locating a work of art, were also identified for the first time

Placing the library at the heart of plagiarism prevention: The University of Bradford experience.

yesPlagiarism is a vexed issue for Higher Education, affecting student transition, retention and attainment. This paper reports on two initiatives from the University of Bradford library aimed at reducing student plagiarism. The first initiative is an intensive course for students who have contravened plagiarism regulations. The second course introduces new students to the concepts surrounding plagiarism with the aim to prevent plagiarism breaches. Since the Plagiarism Avoidance for New Students course was introduced there has been a significant drop in students referred to the disciplinary programme. This paper discusses the background to both courses and the challenges of implementation

Identidad étnica y redes personales entre jóvenes de Sarajevo

After fieldwork conducted among young people in Sarajevo, we found a relation between the discourses sustained by them and the ethnic categories they use to classify people and to identify themselves. Also we have found that people self-affiliated as "Bosnians" play an important role in the network of multiethnic relationships, in which strong ties, surprisingly, are still very important. Finally we found a relationship between the composition of personal networks and the ethnic discourses that are maintained.Después de un trabajo de campo realizado con un grupo de jóvenes en Sarajevo, hemos constatado la existencia de una relación entre los discursos que sostienen y las categorías étnicas que utilizan tanto para clasificar a los demás como para auto-identificarse. Asimismo hemos encontrado que los jóvenes que se autodenominan "Bosnios" juegan un rol importante en la red de relaciones multiétnicas, en la que los lazos fuertes, sorprendentemente, son muy importantes. Finalmente hemos hallado una relación entre la composición de las redes personales y los discursos étnicos que se sostienen. Vivimos, o creemos vivir, en múltiples "comunidades", imaginadas o no. Al mismo tiempo, el individuo y no el lugar, la familia o el grupo, se sitúa en el centro de la vida social y de las comunicaciones (Cf. Wellman, 2001). En este contexto, inducido por el avance del capitalismo flexible (Castells, 1996), pensamos que para entender adecuadamente la identidad o identidades postuladas por los individuos es necesario estudiar las redes personales y su dinámica. Desde esta perspectiva no podemos hablar de "etnias" o "multietnicidad" sin más precisiones, pues son conceptos basados en una concepción esencialista y estática de la identidad individual. El concepto de "sociedad multiétnica" es utilizado de una manera engañosamente progresista y objetiva, pues lo que en realidad legitima es la existencia de diferencias esenciales entre personas, alejando en lugar de acercar. Sin embargo, somos plenamente conscientes que los discursos esencialistas de la identidad étnica son omnipresentes, con enormes efectos políticos e individuales. Que planteemos que la concepción esencialista de la identidad sea inapropiada desde un punto de vista académico, no significa que ésta no se utilice políticamente y por lo tanto tenga consecuencias formidables en las relaciones sociales. Precisamente el estudio de las redes personales nos permite situarnos en una perspectiva que no utiliza con pretensiones analíticas conceptos "folk", como son los de "etnia", "pueblo" o "nación", sino que los sitúa en el terreno de los discursos sustentados por los actores (y los estados y medios de comunicación) y nos permite contextualizarlos mediante conceptos etic, es decir, impuestos por los investigadores. Sólo así podemos superar las tautologías que abundan en los discursos étnicos

Study of behaviour on simulated daylight ageing of artists¿ acrylic and poly(vinyl acetate) paint films

[EN] This work proposes a multi-method approach that combines advanced microscopy (SEM/EDX, AFM) and spectroscopy (UV-vis and FTIR) techniques. This approach not only characterises the behaviour of the additives of two commercial poly(vinyl acetate) (PVAc) and acrylic emulsion paints but also simultaneously characterises the changes in chemical composition and morphology observed in the paint films as a result of ageing due to the paints being exposed to an intense source of simulated daylight. In parallel, a series of mechanical tests were performed that correlate the chemical changes in composition and the changes observed in the films' mechanical properties. This work was a comparative study between both types of acrylic and PVAc paints. The results obtained are of great interest for the modern paint conservation field as they provide valuable information on the mid- and long-term behaviours of these synthetic paints.Financial support is gratefully acknowledged from the Spanish "I+D+I MICINN" project CTQ2008-06727-C03-01/BQU supported by ERDEF funds and from the "Generalitat Valenciana" I+D project ACOMP/2009/171 and the AP2006-3223 project ascribed to the Predoctoral Stages Programme of Universitary Researchers in Spanish Universities and Research Centres from the Spanish Ministry of Science and Innovation (MICINN). The authors wish to thank Mr. Manuel Planes i Insausti and Dr. Jose Luis Moya Lopez, the technical supervisors responsible for the Electron Microscopy Service at the Polytechnic University of Valencia.Domenech Carbo, MT.; Silva, MF.; Aura Castro, E.; Fuster López, L.; Kröner ., SU.; Martínez Bazán, ML.; Mas Barberà, X.... (2011). Study of behaviour on simulated daylight ageing of artists¿ acrylic and poly(vinyl acetate) paint films. Analytical and Bioanalytical Chemistry. 399:2921-2937. https://doi.org/10.1007/s00216-010-4294-3S2921293739