3,240 research outputs found

    Trispyrazolylborate Ligands Supported on Vinyl Addition Polynorbornenes and Their Copper Derivatives as Recyclable Catalysts

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    Polynorbornenes prepared by vinyl addition poly- merization and bearing pendant alkenyl groups serve as skeletons to support trispyrazolylborate ligands (Tpx) built at those alkenyl sites. Reaction with CuI in acetonitrile led to VA-PNB–TpxCu(NCMe) (VA-PBN = vinyl addition polynorbor- nene) with a 0.8–1.4 mmol incorporation of Cu per gram of polymer. The presence of tetracoordinated copper(I) ions was been assessed by FTIR studies on the corresponding VA-PNB-TpxCu(CO) adducts, in agreement with those on discrete TpxCu(CO). The new materials were employed as heteroge- neous catalysts in several carbene- and nitrene-transfer reac- tions, showing a behavior similar to that of the homogene- ous counterparts but also being recycled several times main- taining a high degree of activity and selectivity. This is the first example of supported Tpx ligands onto polymeric sup- ports with catalytic applications.MINECO (CTQ2017-82893-C2-1-R, CTQ2016-80913-P and Red Intecat CTQ2016-81923-REDC)Junta de Castilla y León (VA051P17, VA062G18)European Union (CHAOS COST ACTION CA-15106)

    La migración desde la mirada de los empleadores de una agroindustria de los Altos de Jalisco, México

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    En los Altos de Jalisco, México, la migra- ción y la actividad agropecuaria son acti- vidades tradicionales con impacto econó- mico y social en la cotidianidad. Por ello se llevó a cabo un estudio cualitativo so- bre la percepción y experiencia de nueve empleadores de una empresa agroindus- trial respecto al fenómeno migratorio en la región, así como los costos y benefi cios que asocian al mismo. Los empleadores observan la disminución de emigrantes y el aumento de deportados. Identifi can un aumento de mujeres e hijos jóvenes ingre- sando a trabajar en la empresa. Como im- pacto negativo destacan: difi cultades de adaptación de los retornados, adquisición de costumbres diferentes, distanciamien- to o abandono familiar y falta de envío de remesas. Aprecian el desarrollo de nuevas cualidades y mayores exigencias hacia la empresa en los trabajadores migrantes de retorno

    Reactivation of Paleozoic structures during Cenozoic deformation in the Cordón del Plata and Southern Precordillera ranges (Mendoza, Argentina)

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    The tectonic style of the eastern morphostructural units of the Central Andes between 32°20´ and 33°20´S is strongly influenced by pre- Andean structures, especially those developed during the late Carboniferous-Early Permian San Rafael orogeny of the Gondwanan orogenic cycle. Moreover, in the study area pre-Carboniferous rocks were deformed in Late Devonian-early Carboniferous times by the Chanic orog­eny. In this paper we argue that the Cordón del Plata and the Southern Precordillera ranges, first order features of the eastern ranges of the Andes, have been shaped in large part by the Permian event. Our data suggest that the double verging character of the Andean Precordillera fold- thrust belt is mainly the result of the reactivation of Gondwanan structures which conform a fold-thrust belt with distinct characteristics north and south of 33°S. The northern sector of this belt corresponds to a bivergent system, while the southern sector had a widespread east vergence. The vergence of the Chanic structures is more difficult to determine, but we infer a westward vergence in the Frontal Cordillera and western sector of Precordillera, and an eastern vergence in the eastern sector of the Precordillera. The sharp disappearance of the Precordillera morphostructural unit south of 33°S is inferred here to be related to the distribution of inherited Permian structures.El estilo tectónico del sector oriental de las unidades morfoestructurales de los Andes Centrales entre los 32°20´y 33°20´S se encuentra fuertemente influenciado por estructuras pre-andinas, especialmente aquellas desarrolladas durante el Carbonífero superior-Pérmico Inferior y asociadas al orógeno San Rafael del ciclo orogénico Gondwánico. Además, en el área de estudio, las rocas pre-carboníferas se deformaron durante el Devónico Superior y Carbonífero inferior, en relación con la orogenia Chánica. En este trabajo discutimos los rasgos de primer orden del sector oriental de los Andes, que comprende al Cordón del Plata y a la Precordillera Austral, fueron en gran parte modelados a partir del evento pérmico. Nuestros datos sugieren que la doble vergencia de una faja plegada y corrida en la Precordillera Andina es el resultado principalmente de la reactivación de estructuras gondwánicas que conformaron una faja plegada y corrida con características distintivas al norte y sur de los 33°S. El sector norte de la faja corresponde a un sistema bivergente, mientras que el sector sur posee una vergencia predo­minantemente oriental. La vergencia de las estructuras chánicas es más difícil de predecir, pero se sugiere aquí una vergencia hacia el oeste para las estructuras de la Cordillera Frontal y el sector occidental de la Precordillera y otra hacia el este para las estructuras del sector oriental de la Precordillera. Se infiere que la marcada desaparición de la Precordillera como unidad morfoestructural andina al sur de los 33° está relacionada a la distribución de estructuras chánicas y gondwánicas

    Is the association between health-related quality of life and fatigue mediated by depression in patients with multiple sclerosis? A Spanish cross-sectional study

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    OBJECTIVES: To determine the mediating effects of depression on health-related quality of life and fatigue in individuals with multiple sclerosis (MS). DESIGN: A cross-sectional study. SETTING: Tertiary urban hospital. PARTICIPANTS: One hundred and eight patients (54% women) with MS participated in this study. OUTCOME MEASURES: Demographic and clinical data (weight, height, medication and neurological impairment), fatigue (Fatigue Impact Scale), depression (Beck Depression Inventory-II) and health-related quality of life (Short-Form Health Survey 36) were collected. RESULTS: Fatigue was significantly associated with bodily pain, physical function, mental health and depression. Depression was associated with bodily pain and mental health. The path analysis found direct effects from physical function, bodily pain and depression to fatigue (all, P<0.01). The path model analysis revealed that depression exerted a mediator effect from bodily pain to fatigue (B=-0.04, P<0.01), and from mental health to fatigue (B=-0.16, P<0.01). The amount of fatigue explained by all predictors in the path model was 37%. CONCLUSIONS: This study found that depression mediates the relationship between some health-related quality of life domains and fatigue in people with MS. Future longitudinal studies focusing on proper management of depressive symptoms in individuals with MS will help determine the clinical implications of these finding

    Active video games improve muscular fitness and motor skills in children with overweight or obesity

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    (1) Background: Childhood obesity is an important public health problem. Children with overweight or obesity often tend to show the pediatric inactivity triad components; these involve exercise deficit disorder, pediatric dynapenia, and physical illiteracy. The aim of the study was to examine the influence of an active video games (AVG) intervention combined with multicomponent exercise on muscular fitness, physical activity (PA), and motor skills in children with overweight or obesity. (2) Methods: A total of 29 (13 girls) children (10.07 ± 0.84 years) with overweight or obesity were randomly allocated in the intervention group (AVG group; n = 21) or in the control group (CG; n = 8). The intervention group performed a 5-month AVG training using the Xbox 360® with the Kinect, the Nintendo Wii®, dance mats, and the BKOOL® interactive cycling simulator, combined with multicomponent exercise, performing three sessions per week. The control group continued their daily activities without modification. Weight, PA using accelerometers, and motor competence using the Test of Gross Motor Development 3rd edition were measured. Muscular fitness was evaluated through the Counter Movement Jump height, maximal isometric strength of knee extension and handgrip strength, and lean mass using Dual-energy X-ray Absorptiometry. Mann–Whitney U and Wilcoxon signed rank tests were performed. The biserial correlation coefficients (r) were calculated. Spearman’s correlation coefficients among PA, muscular fitness, and motor competence variables were also calculated. (3) Results: The AVG group significantly increased their knee extension maximal isometric strength (4.22 kg; p < 0.01), handgrip strength (1.93 kg; p < 0.01), and jump height (1.60 cm; p < 0.01), while the control group only increased the knee extension maximal isometric strength (3.15 kg; p < 0.01). The AVG group improved motor competence and light physical activity (p < 0.05) and decreased sedentary time (p < 0.05). Lean mass improved in both AVG group and CG (p < 0.05). Lastly, the percentage of improvement of motor skills positively correlated with the percentage of improvement in vigorous PA (r = 0.673; p = 0.003) and the percentage of improvement in CMJ (r = 0.466; p = 0.039). (4) Conclusions: A 5-month intervention combining AVG with multicomponent training seems to have positive effects on muscle fitness, motor competence, and PA in children with overweight or obesity

    How to Escape Local Optima in Black Box Optimisation: When Non-elitism Outperforms Elitism

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    Escaping local optima is one of the major obstacles to function optimisation. Using the metaphor of a fitness landscape, local optima correspond to hills separated by fitness valleys that have to be overcome. We define a class of fitness valleys of tunable difficulty by considering their length, representing the Hamming path between the two optima and their depth, the drop in fitness. For this function class we present a runtime comparison between stochastic search algorithms using different search strategies. The ((Formula presented.)) EA is a simple and well-studied evolutionary algorithm that has to jump across the valley to a point of higher fitness because it does not accept worsening moves (elitism). In contrast, the Metropolis algorithm and the Strong Selection Weak Mutation (SSWM) algorithm, a famous process in population genetics, are both able to cross the fitness valley by accepting worsening moves. We show that the runtime of the ((Formula presented.)) EA depends critically on the length of the valley while the runtimes of the non-elitist algorithms depend crucially on the depth of the valley. Moreover, we show that both SSWM and Metropolis can also efficiently optimise a rugged function consisting of consecutive valleys

    Hypoxia and adipose tissue function and dysfunction in obesity

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    The rise in the incidence of obesity has led to a major interest in the biology of white adipose tissue. The tissue is a major endocrine and signalling organ, with adipocytes, the characteristic cell type, secreting a multiplicity of protein factors – the adipokines. Increases in the secretion of a number of adipokines occurs in obesity, underpinning inflammation in white adipose tissue and the development of obesity-associated diseases. There is substantial evidence, particularly from animal studies, that hypoxia develops in adipose tissue as the tissue mass expands, and the reduction in pO2 is considered to underlie the inflammatory response. Exposure of white adipocytes to hypoxic conditions in culture induces changes in the expression of >1,000 genes. The secretion of inflammation-related adipokines is up-regulated by hypoxia, and there is a switch from oxidative metabolism to anaerobic glycolysis. Glucose utilisation is increased in hypoxic adipocytes with corresponding increases in lactate production. Importantly, hypoxia induces insulin resistance in fat cells and leads to the development of adipose tissue fibrosis. Many of the responses of adipocytes to hypoxia are initiated at pO2 levels above the normal physiological range for adipose tissue. The other cell types within the tissue also respond to hypoxia, with the differentiation of preadipocytes to adipocytes being inhibited and preadipocytes being transformed into leptin-secreting cells. Overall, hypoxia has pervasive effects on the function of adipocytes and appears to be a key factor in adipose tissue dysfunction in obesity

    The role of viral and host microRNAs in the Aujeszky's disease virus during the infection process

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    Porcine production is a primary market in the world economy. Controlling swine diseases in the farm is essential in order to achieve the sector necessities. Aujeszky's disease is a viral condition affecting pigs and is endemic in many countries of the world, causing important economic losses in the swine industry. microRNAs (miRNAs) are non-coding RNAs which modulates gene expression in animals, plants and viruses. With the aim of understanding miRNA roles during the Aujeszky's disease virus [ADV] (also known as suid herpesvirus type 1 [SuHV-1]) infection, the expression profiles of host and viral miRNAs were determined through deep sequencing in SuHV-1 infected porcine cell line (PK-15) and in an animal experimental SuHV-1 infection with virulent (NIA-3) and attenuated (Begonia) strains. In the in vivo approach miR-206, miR-133a, miR-133b and miR-378 presented differential expression between virus strains infection. In the in vitro approach, most miRNAs were down-regulated in infected groups. miR-92a and miR-92b-3p were up-regulated in Begonia infected samples. Functional analysis of all this over expressed miRNAs during the infection revealed their association in pathways related to viral infection processes and immune response. Furthermore, 8 viral miRNAs were detected by stem loop RT-qPCR in both in vitro and in vivo approaches, presenting a gene regulatory network affecting 59 viral genes. Most described viral miRNAs were related to Large Latency Transcript (LLT) and to viral transcription activators EP0 and IE180, and also to regulatory genes regarding their important roles in the host-pathogen interaction during viral infection
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