Effects of Enriched Physical and Social Environments on Motor Performance, Associative Learning, and Hippocampal Neurogenesis in Mice.

We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice.

Long-term treatment with insulin induces apoptosis in brown adipocytes: role of oxidative stress

Trying to define the precise role played by insulin regulating the survival of brown adipocytes, we have used rat fetal brown adipocytes maintained in primary culture. The effect of insulin on apoptosis and the mechanisms involved were assessed. Different from the known effects of insulin as a survival factor, we have found that long-term treatment (72 h) with insulin induces apoptosis in rat fetal brown adipocytes. This process is dependent on the phosphatidylinositol 3-kinase/mammalian target of rapamycin/p70 S6 kinase pathway. Short-term treatment with the conditioned medium from brown adipocytes treated with insulin for 72 h mimicked the apoptotic effect of insulin. During the process, caspase 8 activation, Bid cleavage, cytochrome c release, and activation of caspases 9 and 3 are sequentially produced. Treatment with the caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (Z-VAD), prevents activation of this apoptotic cascade. The antioxidants, ascorbic acid and superoxide dismutase, also impair this process of apoptosis. Moreover, generation of reactive oxygen species (ROS), probably through reduced nicotinamide adenine dinucleotide phosphate oxidases, and a late decrease in reduced glutathione content are produced. According to this, antioxidants prevent caspase 8 activation and Bid cleavage, suggesting that ROS production is an important event mediating this process of apoptosis. However, the participation of uncoupling protein-1, -2, and -3 regulating ROS is unclear because their levels remain unchanged upon insulin treatment for 72 h. Our data suggest that the prolonged hyperinsulinemia might cause insulin resistance through the loss of brown adipose tissue.

Optimized exosome isolation protocol for cell culture supernatant and human plasma.

Extracellular vesicles represent a rich source of novel biomarkers in the diagnosis and prognosis of disease. However, there is currently limited information elucidating the most efficient methods for obtaining high yields of pure exosomes, a subset of extracellular vesicles, from cell culture supernatant and complex biological fluids such as plasma. To this end, we comprehensively characterize a variety of exosome isolation protocols for their efficiency, yield and purity of isolated exosomes. Repeated ultracentrifugation steps can reduce the quality of exosome preparations leading to lower exosome yield. We show that concentration of cell culture conditioned media using ultrafiltration devices results in increased vesicle isolation when compared to traditional ultracentrifugation protocols. However, our data on using conditioned media isolated from the Non-Small-Cell Lung Cancer (NSCLC) SK-MES-1 cell line demonstrates that the choice of concentrating device can greatly impact the yield of isolated exosomes. We find that centrifuge-based concentrating methods are more appropriate than pressure-driven concentrating devices and allow the rapid isolation of exosomes from both NSCLC cell culture conditioned media and complex biological fluids. In fact to date, no protocol detailing exosome isolation utilizing current commercial methods from both cells and patient samples has been described. Utilizing tunable resistive pulse sensing and protein analysis, we provide a comparative analysis of 4 exosome isolation techniques, indicating their efficacy and preparation purity. Our results demonstrate that current precipitation protocols for the isolation of exosomes from cell culture conditioned media and plasma provide the least pure preparations of exosomes, whereas size exclusion isolation is comparable to density gradient purification of exosomes. We have identified current shortcomings in common extracellular vesicle isolation methods and provide a potential standardized method that is effective, reproducible and can be utilized for various starting materials. We believe this method will have extensive application in the growing field of extracellular vesicle research.

Why evolution matters for species conservation: perspectives from three case studies of plant metapopulations

We advocate the advantage of an evolutionary approach to conservation biology that considers evolutionary history at various levels of biological organization. We review work on three separate plant taxa, spanning from one to multiple decades, illustrating extremes in metapopulation functioning. We show how the rare endemics Centaurea corymbosa (Clape Massif, France) and Brassica insularis in Corsica (France) may be caught in an evolutionary trap: disruption of metapopulation functioning due to lack of colonization of new sites may have counterselected traits such as dispersal ability or self-compatibility, making these species particularly vulnerable to any disturbance. The third case study concerns the evolution of life history strategies in the highly diverse genus Leucadendron of the South African fynbos. There, fire disturbance and the recolonization phase after fires are so integral to the functioning of populations that recruitment of new individuals is conditioned by fire. We show how past adaptation to different fire regimes and climatic constraints make species with different life history syndromes more or less vulnerable to global changes. These different case studies suggest that management strategies should promote evolutionary potential and evolutionary processes to better protect extant biodiversity and biodiversification.

Emergent geomorphic-vegetation interactions on a subalpine alluvial fan

Following perturbation, an ecosystem (flora, fauna, soil) should evolve as a function of time at a rate conditioned by external variables (relief, climate, geology). More recently, biogeomorphologists have focused upon the notion of co-development of geomorphic processes with ecosystems over very short through to very long (evolutionary) timescales. Alpine environments have been a particular focus of this co-development. However, work in this field has tended to adopt a simplified view of the relationship between perturbation and succession, including: how the landform and ecosystem itself conditions the impact of a perturbation to create a complex spatial response impact; and how perturbations are not simply ecosystem destroyers but can be a significant source of ecosystem resources. What this means is that at the within landform scale, there may well be a complex and dynamic topographic and sedimentological template that co-develops with soil, flora and fauna. Here, we present and test a conceptual model of this template for a subalpine alluvial fan. We combine detailed floristic inventory with soil inventory, determination of edaphic variables and analysis of historical aerial imagery. Spatial variation in the probability of perturbation of sites on the fan surface was associated with down fan variability in the across-fan distribution of fan ages, fan surface channel characteristics and fan surface sedimentology. Floristic survey confirmed that these edaphic factors distinguished site floristic richness and plant communities up until the point that the soil-vegetation system was sufficiently developed to sustain plant communities regardless of edaphic conditions. Thus, the primary explanatory variable was the estimated age of each site, which could be tied back into perturbation history and its spatial expression due to the geometry of the fan: distinct plant communities were emergent both across fan and down fan, a distribution maintained by the way in which the fan dissipates potentially perturbing events.

Narcolepsy-Associated HLA Class I Alleles Implicate Cell-Mediated Cytotoxicity.

STUDY OBJECTIVES: Narcolepsy with cataplexy is tightly associated with the HLA class II allele DQB1*06:02. Evidence indicates a complex contribution of HLA class II genes to narcolepsy susceptibility with a recent independent association with HLA-DPB1. The cause of narcolepsy is supposed be an autoimmune attack against hypocretin-producing neurons. Despite the strong association with HLA class II, there is no evidence for CD4+ T-cell-mediated mechanism in narcolepsy. Since neurons express class I and not class II molecules, the final effector immune cells involved might include class I-restricted CD8+ T-cells. METHODS: HLA class I (A, B, and C) and II (DQB1) genotypes were analyzed in 944 European narcolepsy with cataplexy patients and in 4,043 control subjects matched by country of origin. All patients and controls were DQB1*06:02 positive and class I associations were conditioned on DQB1 alleles. RESULTS: HLA-A*11:01 (OR = 1.49 [1.18-1.87] P = 7.0*10(-4)), C*04:01 (OR = 1.34 [1.10-1.63] P = 3.23*10(-3)), and B*35:01 (OR = 1.46 [1.13-1.89] P = 3.64*10(-3)) were associated with susceptibility to narcolepsy. Analysis of polymorphic class I amino-acids revealed even stronger associations with key antigen-binding residues HLA-A-Tyr(9) (OR = 1.32 [1.15-1.52] P = 6.95*10(-5)) and HLA-C-Ser(11) (OR = 1.34 [1.15-1.57] P = 2.43*10(-4)). CONCLUSIONS: Our findings provide a genetic basis for increased susceptibility to infectious factors or an immune cytotoxic mechanism in narcolepsy, potentially targeting hypocretin neurons.

Expanding to institutionally different countries. Reasons, Firm International Experience, and Entry Mode Choice

We examine entry mode choice and its consequences when a multinational enterprise (MNE) expands into an institutionally different country. We argue that discussions of entry mode should distinguish between informal (e.g., culture) and formal (e.g., laws) institutions, and should take into account not just the home country of the MNE and its distance to the focal host country, but the MNE's overall footprint and experience across the world in general, especially in countries with an institutional structure that is similar to that of the focal host country. Specifically, we argue that firms with experience in countries with different informal institutions will be more likely to enter via acquisitions than firms without such experience, that such experience will not matter as much in the case of formal institutions, and that such firms will exit more quickly when they enter via equity alliances than through full acquisitions. We also distinguish between balanced and unbalanced alliances and argue that balanced alliances will be more enduring, but only when the host country is culturally (not legally) different from the other countries where the MNE has experience. Our arguments suggest that entry mode should be conditioned on a firm's experience in other markets, and that intercountry differences in formal versus informal institutions have distinct influences on entry mode.

Consequences of warming and resource quality on the stoichiometry and nutrient cycling of a stream shredder

As a result of climate change, streams are warming and their runoff has been decreasing in most temperate areas. These changes can affect consumers directly by increasing their metabolic rates and modifying their physiology and indirectly by changing the quality of the resources on which organisms depend. In this study, a common stream detritivore (Echinogammarus berilloni Catta) was reared at two temperatures (15 and 20°C) and fed Populus nigra L. leaves that had been conditioned either in an intermittent or permanent reach to evaluate the effects of resource quality and increased temperatures on detritivore performance, stoichiometry and nutrient cycling. The lower quality (i.e., lower protein, soluble carbohydrates and higher C:P and N:P ratios) of leaves conditioned in pools resulted in compensatory feeding and lower nutrient retention capacity by E. berilloni. This effect was especially marked for phosphorus, which was unexpected based on predictions of ecological stoichiometry. When individuals were fed pool-conditioned leaves at warmer temperatures, their growth rates were higher, but consumers exhibited less efficient assimilation and higher mortality. Furthermore, the shifts to lower C:P ratios and higher lipid concentrations in shredder body tissues suggest that structural molecules such as phospholipids are preserved over other energetic C-rich macromolecules such as carbohydrates. These effects on consumer physiology and metabolism were further translated into feces and excreta nutrient ratios. Overall, our results show that the effects of reduced leaf quality on detritivore nutrient retention were more severe at higher temperatures because the shredders were not able to offset their increased metabolism with increased consumption or more efficient digestion when fed pool-conditioned leaves. Consequently, the synergistic effects of impaired food quality and increased temperatures might not only affect the physiology and survival of detritivores but also extend to other trophic compartments through detritivore-mediated nutrient cycling.

La investigación didáctica: hacia la interdisciplinariedad y la cooperación

This article aims to explain the main references that characterize the educational research in our context. This requires assessing the main external influences and the way how are you we have been conditioned. Briefly describes the trajectory of specific teaching in Spain give to his creation to the present moment, to understand the passage of its constitution to create the research and its effects. Highlights the emerging methodologies and proposed findings that point to new perspectives on the proposed interdisciplinary teaching compared

Quantificação de sulfadimetoxina em leite por cromatografia líquida de alta eficiência

A method for HPLC determination of sulfadimethoxyne in milk is presented. The analyte isolation and concentration were performed by solid-phase extraction through a C-8 cartridge, pre-conditioned with hexane, methanol and water and eluted with MeOH. The recovery determination was done with a spiked solution of 20, 50 or 100 µg L-1. In this concentration range, the recovery was 83.2% with a RDS of 15.4%. For quantification, a Zorbax Eclipse XDB-C8 (4.6 mm x 150 mm, 5 µm), a mobile phase of MeCN: 0.01 mol L-1 KH2PO4 aq. (1:4), and a variable wavelength detector (275 nm) were used.

La gestió del regadiu a Catalunya: plans, actors i reptes de futur

Irrigation has traditionally constituted one of the most characteristic and emblematic agricultural mosaics of the Mediterranean as a key factor of socio-economic dynamism of the territorial matrix. In recent years there has been an important scientific, intellectual and social environment mobilization around water uses and, in particular, around the main socio-economic use of resource: irrigation, which is undergoing an intense and accelerated transformation process. Thus, in parallel with the decline of traditional irrigation systems, located in areas with natural availability of water, fertile soil and appropriate topographic conditions, the socio-economic changes in the last decade have stimulated the appearance of new irrigated areas with environmental, social and economic disparate characteristics. As a result, the irrigation management model has been conditioned to respond to the new parameters of water scarcity and resource efficiency. In addition, policies and actors have evolved over time as a consequence of disparate priorities –and often conflicting– in terms of irrigation, making necessary the gear of different discourses. In this context, the Model of social commitment of irrigation proposed by the Institutional and Social Innovations in Irrigation Mediterranean Management (ISIIMM) can become a starting example

Pla de màrqueting per al llançament d'un nou producte en el mercat dels motors elèctrics per a bancs de proves

Ningú no dubte ja del canvi de mentalitat que s’ha produït en els darrers anys en els compradors pel què fa al mercat de l’automòbil. La seguretat i el respecte per el medi ambient, són actualment dos dels factors claus que el consumidor té en compte a l’hora de comprar un vehicle. D’altra banda en els darrers anys la Unió Europea, ha fixat tota una sèrie normatives per tal de reduir les emissions nocives a l’atmosfera. Així doncs, més seguretat i menys emissions, signifiquen vehicles que incorporin components i sistemas cada cop més sofisticats, els quals, a la vegada, necessiten de bancs d’assaig i equips de test per tal de ser validats. Aquest fet ha provocat una revolució dins dels sistemes de test per a vehicles, per als quals han augmentat enormement les exigències en quan a precisions i repetibilitat per tal d’intentar reproduir, amb la màxima fiabilitat possible, les condicions de treball que hauran de suportar els components durant el seu ús real. Les característiques dels motors elèctrics, resulten ideals per a accionar aquest tipus d’aplicacions, ja que permeten un control del parell molt acurat i una repetibilitat quasi perfecte enfront d’altres sistemas utilitzats fins no fa massa temps. Aquesta demanda creixent d’aquest tipus de màquines elèctriques, obra una nova oportunitat de negoci per a les empreses fabricants de motors elèctrics. L’objectiu principal d’aquest treball és identificar i satisfer les necessitats dels clients, dins d’un mercat industrial concret: el mercat dels motors elèctrics per a bancs de proves de components per a la indústria de l’automoció. La fita és doncs la de proporcionar les eines necessàries per tal de que una empresa, fabricant de motors elèctrics de velocitat variable, pugui realitzar el disseny, desenvolupament i llançament comercial d’un nou tipus de motor, específicament pensat per aquest mercat, amb les màximes garanties d’èxit. Com a principal conclusió, el treball argumenta que el nou producte representa una oportunitat de negoci força atractiva i rendible per a l’empresa, i permetrà diversificar la oferta de la companyia cap a un nou sector fins ara no explotat.

Periodismo y dispositivos móviles de lecto-escritura. Introducción al diseño de contenidos para tabletas

El lanzamiento de las tabletas, especialmente la iPad de Apple en 2010, abrió la competencia entre las compañías de comunicación en el sentido de hacer disponible el contenido para este entorno de medios emergentes. La fuga de lectores de periódicos impresos y la consecuente caída en las ganancias por publicidad, forzó a las compañías periodísticas a que buscaran los otros medios de mantener sus negocios. La diversificación de productos y la penetración de los periódicos en dispositivos móviles constituyen un escenario prometedor para el medio. El vertiginoso volumen de ventas de las tabletas indica que en 2012 serán comercializadas más de 140 millones de unidades en el mundo. El diseño de los periódicos en tabletas está íntimamente ligado al diseño de la versión impresa por la fuerza de su metáfora. El desafío es encontrar un diseño de páginas propio, aprovechando el potencial multimedia sin interferir negativamente en la legibilidad y en el carácter intrínseco de informar.

Mental Health of Expatriates in Finnish Enterprises in Brazil

Expatriation has become increasingly common due to the global trade expansion. Many large companies base their production facilities in far-flung countries, where experts are sent from their own countries to launch the operations. Working in a foreign environment demands from so-called expatriates considerable adaptability. This study aimed to investigate if following expatriation mental health difficulties were experienced by the employees themselves or their family members. This study investigated by a questionnaire and interviews how expatriate employees in Finnish companies operating in different regions of Brazil and their families adjusted. Investigated employees were required to be at least 6 months in expatriation. Data were collected in Brazil during their stay at least 3 months after the arrival. The survey covered 121 expatriate employees, that operated in 17 different companies, from which 71 employees from 10 different companies responded to the questionnaire. All the employees from the two largest enterprises and their spouses were invited to focus groups; in total 43 persons (22 employees and 21 employees’ spouses) participated in a group or individual interviews. No significant mental health difficulties were found among the expatriate employees. Only a tenth of the expatriate employees reported strain. The experience of strain symptoms was found to be related to long working days, intense working rhythm and lack of friends. Work satisfaction seemed to be an important mediator in the coping process. While abroad, the expatriate employees were highly recognized for their work. Due to the immature organization of work they could often use their creative capacities to improve the work flow. The opportunity to see the effects of their own contribution with their own eyes to the development of the enterprise made them feel good. The association between the expatriate employees’ adjustment and that of their spouses’ was evident. The spouses’ situation was markedly different than that of the expatriate employees’ themselves. Expatriation changed the family members’ previous division of tasks considerably. The expatriate spouses had to change their roles more than the expatriate employees themselves; since most of them were highly educated women, who were leaded through an identity crisis due to at least temporary renunciation of own work and career.

Is contextual-potentiated eating dependent on caloric density of food?

One experiment tested whether a specific context could elicit eating in rats as a result of Pavlovian conditioning and whether this effect depended on the caloric density of food. Thirty two deprived rats experienced two contexts. They had access to food in context A, but no food was available in context B. During conditioning, half of the animals received high density caloric food (HD groups) whereas the other half, low density caloric food (LD groups). Then, half of the rats in each type of food group was tested in context A and the other half in context B. The results demonstrated an effect of context conditioning only in HD groups. These findings suggest the relevance of both contextual conditioning and caloric density of food in eating behaviour. Implications for the aetiology of binge eating will be discussed.