1,825 research outputs found

    Cooperation sustainability in small groups:Exogenous and endogenous dynamics of the sustainability of cooperation

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    Cooperation sustainability presents a complex social phenomenon. Two common approaches have been used to study the sustainability of cooperation in small groups: endogenous processes (dynamic) and exogenous factors (static approaches). The present study integrates existing research by investigating how the interplay between exogenous and endogenous conditions affects cooperation in small groups. To uncover endogenous group dynamics in an online Public Goods experiment (n = 353), we performed multilevel latent Markov models on Bayesian estimation that allowed us to estimate latent classes on the level of rounds, individuals, and groups. We studied exogenous factors by investigating the effects of situational tightness versus looseness, and monetary versus symbolic frames on cooperation sustainability. Our key findings show that both endogenous and exogenous factors are critical to explain the variation of cooperation sustainability between groups. Second, groups exposed to tight situations reveal higher levels of cooperation sustainability than groups exposed to loose situations. Money primes did not have an impact. Among the control variables, collective intentionality showed the strongest association with cooperation. Future research may develop a more sophisticated measure of tight versus loose situations and examine the causal relationship between collective intentionality and cooperation

    Shared understanding and task-interdependence in nursing interns’ collaborative relations:A social network study of vocational health care internships in the Netherlands

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    Shared understanding among collaborators is a key element of delivering successful interprofessional care and a main challenge for professional education concerns nurturing such understanding among students. We assessed how nursing students perceived different levels of shared understanding in their collaborations with others in clinical internships. We analyse the collaborative networks of interns to examine whether individual factors (attitudes, perceptions of collaborative cultures, and motivation) or relational factors among collaborators (task-interdependence, cooperation frequency, and interprofessional and hierarchical roles) affect shared understanding among 150 Dutch nursing interns and their collaborators (n = 865). Theoretically, we stress the importance of focusing on collaborative relations in interprofessional care settings. Multilevel models distinguish two levels in explaining the variation in shared understanding, nesting collaborative relationships within individuals. Results indicate merely 37.4% of found variation of shared understanding could be attributed to individual-level factors (variation between interns), while 62.6% of variation is found within interns, showing that shared understanding differs substantially between the collaborations one intern engages in. Multilevel models reveal that task-interdependence strongly predicts shared understanding in inter- and intraprofessional collaborations. We conclude that focusing on collaborative relations is essential to foster shared understanding in vocational internship programmes, and that health care organisations should pay explicit attention to task-interdependence in interns’ collaborations

    Noise-robust method for image segmentation

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    Segmentation of noisy images is one of the most challenging problems in image analysis and any improvement of segmentation methods can highly influence the performance of many image processing applications. In automated image segmentation, the fuzzy c-means (FCM) clustering has been widely used because of its ability to model uncertainty within the data, applicability to multi-modal data and fairly robust behaviour. However, the standard FCM algorithm does not consider any information about the spatial linage context and is highly sensitive to noise and other imaging artefacts. Considering above mentioned problems, we developed a new FCM-based approach for the noise-robust fuzzy clustering and we present it in this paper. In this new iterative algorithm we incorporated both spatial and feature space information into the similarity measure and the membership function. We considered that spatial information depends on the relative location and features of the neighbouring pixels. The performance of the proposed algorithm is tested on synthetic image with different noise levels and real images. Experimental quantitative and qualitative segmentation results show that our method efficiently preserves the homogeneity of the regions and is more robust to noise than other FCM-based methods

    Involvement of Plasmodium falciparum protein kinase CK2 in the chromatin assembly pathway

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    <p>Abstract</p> <p>Background</p> <p>Protein kinase CK2 is a pleiotropic serine/threonine protein kinase with hundreds of reported substrates, and plays an important role in a number of cellular processes. The cellular functions of <it>Plasmodium falciparum </it>CK2 (PfCK2) are unknown. The parasite's genome encodes one catalytic subunit, PfCK2α, which we have previously shown to be essential for completion of the asexual erythrocytic cycle, and two putative regulatory subunits, PfCK2ÎČ1 and PfCK2ÎČ2.</p> <p>Results</p> <p>We now show that the genes encoding both regulatory PfCK2 subunits (PfCK2ÎČ1 and PfCK2ÎČ2) cannot be disrupted. Using immunofluorescence and electron microscopy, we examined the intra-erythrocytic stages of transgenic parasite lines expressing hemagglutinin (HA)-tagged catalytic and regulatory subunits (HA-CK2α, HA-PfCK2ÎČ1 or HA-PfCK2ÎČ2), and localized all three subunits to both cytoplasmic and nuclear compartments of the parasite. The same transgenic parasite lines were used to purify PfCK2ÎČ1- and PfCK2ÎČ2-containing complexes, which were analyzed by mass spectrometry. The recovered proteins were unevenly distributed between various pathways, with a large proportion of components of the chromatin assembly pathway being present in both PfCK2ÎČ1 and PfCK2ÎČ2 precipitates, implicating PfCK2 in chromatin dynamics. We also found that chromatin-related substrates such as nucleosome assembly proteins (Naps), histones, and two members of the Alba family are phosphorylated by PfCK2α <it>in vitro</it>.</p> <p>Conclusions</p> <p>Our reverse-genetics data show that each of the two regulatory PfCK2 subunits is required for completion of the asexual erythrocytic cycle. Our interactome study points to an implication of PfCK2 in many cellular pathways, with chromatin dynamics being identified as a major process regulated by PfCK2. This study paves the way for a kinome-wide interactomics-based approach to elucidate protein kinase function in malaria parasites.</p

    DEVELOPMENT OF COMPLEX TECHNOLOGIES FOR PROCESSING OF RICE BRAN WITH OBTAINING OF THERAPEUTIC OIL AND MEDICINE – PHYTIN

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    In this article, showed effectiveness of obtaining therapeutic, edible oil and medicine-phytin and researched the viability of using waste generated during processing of rice - rice bran. Carried out research on the qualitative and physical - chemical characteristics of rice bran and defined quantitative content of phytin in raw materials and substances

    DEVELOPMENT OF COMPLEX TECHNOLOGIES FOR PROCESSING OF RICE BRAN WITH OBTAINING OF THERAPEUTIC OIL AND MEDICINE – PHYTIN

    Get PDF
    In this article, showed effectiveness of obtaining therapeutic, edible oil and medicine-phytin and researched the viability of using waste generated during processing of rice - rice bran. Carried out research on the qualitative and physical - chemical characteristics of rice bran and defined quantitative content of phytin in raw materials and substances

    Social media revenge: A typology of online consumer revenge

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    The main purpose of this study is to present a detailed typology of online revenge behaviors that identifies the differential factors affecting this behavior in terms of triggers, channels, and emotional outcomes across two countries: Jordan and Britain. Based on a qualitative approach from a sample of Jordanian and British customers who had previously committed acts of online revenge (N = 73), this study identified four main types of online avengers: materialistic, ego-defending, aggressive, and rebellious. The findings show that British consumers were motivated by core service malfunction failures and employee failures. In contrast, Jordanian consumers’ acts of revenge were triggered by wasta service failures and contract breach failures. Moreover, Jordanian consumers tended to employ more aggressive and sometimes illegal ways to get revenge, whereas British consumers often used social media platforms and review websites. The findings have implications for the prevalence of online consumer revenge acts and for extending theoretical understanding of why and how consumers employ the Internet for revenge after a service failure in addition to how to respond to each avenger

    On the Hausdorff volume in sub-Riemannian geometry

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    For a regular sub-Riemannian manifold we study the Radon-Nikodym derivative of the spherical Hausdorff measure with respect to a smooth volume. We prove that this is the volume of the unit ball in the nilpotent approximation and it is always a continuous function. We then prove that up to dimension 4 it is smooth, while starting from dimension 5, in corank 1 case, it is C^3 (and C^4 on every smooth curve) but in general not C^5. These results answer to a question addressed by Montgomery about the relation between two intrinsic volumes that can be defined in a sub-Riemannian manifold, namely the Popp and the Hausdorff volume. If the nilpotent approximation depends on the point (that may happen starting from dimension 5), then they are not proportional, in general.Comment: Accepted on Calculus and Variations and PD

    Adaptation of the LIGNUM model for simulations of growth and light response in Jack pine

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    LIGNUM is a whole tree model, developed for Pinus sylvestris in Finland, that combines tree metabolism with a realistic spatial distribution of morphological parts. We hypothesize that its general concepts, which include the pipe model, functional balance, yearly carbon budget, and a set of architectural growth rules, are applicable to all trees. Adaptation of the model to Pinus banksiana, a widespread species of economic importance in North America, is demonstrated. Conversion of the model to Jack pine entailed finding new values for 16 physiological and morphological parameters, and three growth functions. Calibration of the LIGNUM Jack pine model for open grown trees up to 15 years of age was achieved by matching crown appearance and structural parameters (height, foliage biomass, aboveground biomass) with those of real trees. A sensitivity study indicated that uncertainty in the photosynthesis and respiration parameters will primarily cause changes to the net annual carbon gain, which can be corrected through calibration of the growth rate. The effect of a decrease in light level on height, biomass, total tree branch length, and productivity were simulated and compared with field data. Additional studies yielded insight into branch pruning, carbon allocation patterns, crown structure, and carbon stress. We discuss the value of the LIGNUM model as a tool for understanding tree growth and survival dynamics in natural and managed forests
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