90 research outputs found

    Building up active membership in cooperatives

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    Abstract Active membership is crucial for agricultural cooperatives as it engenders better performance. It even is the key for cooperative competitiveness. Active membership, however, decreases in many cooperatives. Thus, it is important to know what galvanizes members to become active members. The cooperative’s value and the cooperative’s offers motivate some members to become active members, but certainly not all of them. Therefore, more work needs to be done to understand the social attributes that transform members into active members. In this paper the incentives that sustain members’ participation over time and the contribution of members’ active participation in the cooperative’s competitive advantage are studied. Empirical evidence is provided via a questionnaire completed by 241 cooperative members of a Dutch feed supply cooperative and interviews with cooperative experts. Results show that active membership builds on social attributes, such as cooperative culture, open communication, trust, involvement, and the willingness to be active. It is explained that these social attributes create benefits for both the cooperative and its members. Finally, suggestions are presented to stimulate active cooperative membership. Key-words: agricultural cooperatives, participation, social indicators

    A learning theory of attachment: Unraveling the black box of attachment development

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    Attachment is an inborn behavioral system that is biologically driven and essential for survival. During child development, individual differences in (in)secure attachment emerge. The development of different attachment behaviors has been traditionally explained as a process during which experiences with (lack of) responsive and supportive care are internalized into working models of attachment. However, this idea has been criticized for being vague and even untestable. With the aim of unraveling this black box, we propose to integrate evidence from conditioning research with attachment theory to formulate a Learning Theory of Attachment. In this review, we explain how the development of individual differences in attachment security at least partly follows the principles of classical and operant conditioning. We combine observed associations between attachment and neurocognitive and endocrinological (cortisol, oxytocin, and dopamine) processes with insights in conditioning dynamics to explain the development of attachment. This may contribute to the explanation of empirical observations in attachment research that are insufficiently accounted for by traditional attachment theory

    No side-effects of single intranasal oxytocin administration in middle childhood.

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    Development Psychopathology in context: famil

    Combining oxytocin and cognitive bias modification training in a randomized controlled trial:Effects on trust in maternal support

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    Background and objectives: Research on the social effects of intranasal oxytocin in children is scarce. Oxytocin has been proposed to have clearer beneficial effects when added to social learning paradigms. The current study tested this proposition in middle childhood by assessing effects of cognitive bias modification (CBM) training and oxytocin on trust in maternal support. Methods: Children (N = 100, 8–12 years) were randomly assigned to one of two training conditions: CBM training aimed at increasing trust or neutral placebo training. Within each training condition, half the participants received oxytocin and half a placebo. Main and interaction effects were assessed on measures of trust-related interpretation bias and trust. We explored whether child characteristics moderated intervention effects. Results: Children in the CBM training were faster to interpret maternal behaviour securely versus insecurely. Effects did not generalize to interpretation bias measures or trust. There were no main or interaction effects of oxytocin. Exploratory moderation analyses indicated that combining CBM training with oxytocin had less positive effects on trust for children with more internalizing problems. Limitations: As this was the first study combining CBM and oxytocin, replication of the results is needed. Conclusions: This study combined a social learning paradigm with oxytocin in children. CBM training was effective at an automatic level of processing. Oxytocin did not enhance CBM effects or independently exert effects. Research in larger samples specifying when oxytocin might have beneficial effects is necessary before oxytocin can be used as intervention option in children

    Methods to create a stringent selection system for mammalian cell lines

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    The efficient establishment of high protein producing recombinant mammalian cell lines is facilitated by the use of a stringent selection system. Here, we describe two methods to create a stringent selection system based on the Zeocin resistance marker. First, we cloned increasingly longer stretches of DNA, encoding a range of 8–131 amino acids immediately upstream of the Zeocin selection marker gene. The DNA stretches were separated from the open reading frame of the selection marker gene by a stopcodon. The idea behind this was that the translation machinery will first translate the small peptide, stop and then restart at the AUG of the Zeocin marker. This process, however, will become less efficient with increasingly longer stretches of DNA upstream of the Zeocin marker that has to be translated first. This would result in lower levels of the Zeocin selection marker protein and thus a higher selection stringency of the system. Secondly, we performed a genetic screen to identify PCR induced mutations in the Zeocin selection protein that functionally impair the selection marker protein. Both the insertion of increasingly longer peptides and several Zeocin selection protein mutants resulted in a decreasing number of stably transfected colonies that concomitantly displayed higher protein expression levels. When the Zeocin mutants were combined with very short small peptides (8–14 amino acids long), this created a flexible, high stringency selection system. The system allows the rapid establishment of few, but high protein producing mammalian cell lines

    Quality of Life in Men With Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency

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    Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is a disorder of adrenal steroid biosynthesis, leading to hypocortisolism, hypoaldosteronism, and hyperandrogenism. Impaired quality of life (QoL) has been demonstrated in women with CAH, but data on men with CAH are scarce. We hypothesized that disease severity and poor treatment control are inversely associated with QoL. In this study, 109 men (16-68 years) with 21OHD were included. The WHOQOL-BREF questionnaire was used to measure self-reported QoL domain scores on a 0-100 scale, where higher scores reflect better QoL. QoL domain scores were compared to published data on healthy and chronically ill reference populations from France, Germany, the Netherlands, and the United Kingdom. Differences in QoL scores among groups of disease severity and treatment control were tested within the study population. Overall, the men with CAH in this study appeared to rate their QoL as good. Median domain scores were 78.6 (IQR: 67.9-85.7) for physical health, 79.2 (IQR: 66.7-87.5) for psychological health, 75.0 (IQR: 58.3-83.3) for social relationships, and 81.3 (IQR: 71.9-90.6) for environment. In general, these scores were similar to WHOQOL-BREF domain scores in healthy references and higher compared to chronically ill reference populations. The domain scores did not differ among genotype groups, but patients with undertreatment or increased 17-hydroxyprogestrone concentrations scored higher on several QoL domains (p<0.05). Patients treated with dexamethasone or prednisone scored higher on the physical health, psychological health, and social relationships domains, but not on the environmental domain. In conclusion, QoL domain scores appeared to be comparable to healthy reference populations and higher compared to patients with a chronic illness. QoL was not influenced by genotype, but undertreatment and use of dexamethasone or prednisone were associated with higher QoL

    The Use of a Stringent Selection System Allows the Identification of DNA Elements that Augment Gene Expression

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    The use of high stringency selection systems often results in the induction of very few recombinant mammalian cell lines, which limits the ability to isolate a cell line with favorable characteristics. The employment of for instance STAR elements in DNA constructs elevates the induced number of colonies and also the protein expression levels in these colonies. Here, we describe a method to systematically identify genomic DNA elements that are able to induce many stably transfected mammalian cell lines. We isolated genomic DNA fragments upstream from the human Rb1 and p73 gene loci and cloned them around an expression cassette that contains a very stringent selection marker. Due to the stringency of the selection marker, hardly any colony survives without flanking DNA elements. We tested fourteen ~3500 bp DNA stretches from the Rb1 and p73 loci. Only two ~3500 bp long DNA fragments, called Rb1E and Rb1F, induced many colonies in the context of the stringent selection system and these colonies displayed high protein expression levels. Functional analysis showed that the Rb1 DNA fragments contained no enhancer, promoter, or STAR activity. Our data show the potential of a methodology to identify novel gene expression augmenting DNA elements in an unbiased manner

    Genomic Characterization of Methanomicrobiales Reveals Three Classes of Methanogens

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    BACKGROUND:Methanomicrobiales is the least studied order of methanogens. While these organisms appear to be more closely related to the Methanosarcinales in ribosomal-based phylogenetic analyses, they are metabolically more similar to Class I methanogens. METHODOLOGY/PRINCIPAL FINDINGS:In order to improve our understanding of this lineage, we have completely sequenced the genomes of two members of this order, Methanocorpusculum labreanum Z and Methanoculleus marisnigri JR1, and compared them with the genome of a third, Methanospirillum hungatei JF-1. Similar to Class I methanogens, Methanomicrobiales use a partial reductive citric acid cycle for 2-oxoglutarate biosynthesis, and they have the Eha energy-converting hydrogenase. In common with Methanosarcinales, Methanomicrobiales possess the Ech hydrogenase and at least some of them may couple formylmethanofuran formation and heterodisulfide reduction to transmembrane ion gradients. Uniquely, M. labreanum and M. hungatei contain hydrogenases similar to the Pyrococcus furiosus Mbh hydrogenase, and all three Methanomicrobiales have anti-sigma factor and anti-anti-sigma factor regulatory proteins not found in other methanogens. Phylogenetic analysis based on seven core proteins of methanogenesis and cofactor biosynthesis places the Methanomicrobiales equidistant from Class I methanogens and Methanosarcinales. CONCLUSIONS/SIGNIFICANCE:Our results indicate that Methanomicrobiales, rather than being similar to Class I methanogens or Methanomicrobiales, share some features of both and have some unique properties. We find that there are three distinct classes of methanogens: the Class I methanogens, the Methanomicrobiales (Class II), and the Methanosarcinales (Class III)
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