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Direct Contribution (direct + contribution)
Selected AbstractsThe Origins and Influence of Land Property Rights in VietnamDEVELOPMENT POLICY REVIEW, Issue 3 2008Denise Hare Vietnam's 1993 Land Law was intended not only to increase the security of farmers'usage rights to their land, but also to facilitate land transfers. Despite potential benefits, the actual issuance of land-use rights certificates to farmers (as specified by the law) proceeded rather slowly in some regions. This article seeks to identify factors that explain the emergence of this form of property right as well as to measure its effect on agricultural production. The results suggest that the certificate's direct contribution may be rather small in the absence of the appropriate supporting conditions and institutions. [source] The antimicrobial activity of CCL28 is dependent on C-terminal positively-charged amino acidsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2010Bin Liu Abstract Several chemokines have been shown to act as antimicrobial proteins, suggesting a direct contribution to innate immune protection. Based on the study of defensins and other antimicrobial peptides, it has been proposed that cationic amino acids in these proteins play a key role in their antimicrobial activity. The primary structure requirements necessary for the antimicrobial activity of chemokines, however, have not yet been elucidated. Using mouse CCL28, we have identified a C-terminal region of highly-charged amino acids (RKDRK) that is essential to the antimicrobial activity of the murine chemokine. Additionally, other positively-charged amino acids in the C-terminus of the protein contribute to the observed antimicrobial effect. Charge reversal and deletion mutations support our hypothesis that C-terminal positively-charged amino acids are essential for the antimicrobial activity of CCL28. Results also demonstrate that although the C-terminal region of the chemokine is essential, it is not sufficient for full antimicrobial activity of CCL28. [source] The role of mineral and organic components in phenanthrene and dibenzofuran sorption by soilEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2006R. Celis Summary Improved predictions of sorption of hydrophobic organic compounds (HOCs) in soil require a better knowledge of the relative contribution of inorganic and organic soil constituents to the sorption process. In this paper, sorption of a three-ring polycyclic aromatic hydrocarbon (phenanthrene) and a three-ring heterocyclic,aromatic compound (dibenzofuran) by six agricultural soils, their clay-size fractions, and a series of single, binary, and ternary model sorbents was evaluated to elucidate the relative role of soil mineral and organic components in the retention of these two model HOCs. The sorption coefficients for phenanthrene and dibenzofuran on purified soil organic materials (Kd = 821,9080 litre kg,1) were two orders of magnitude greater than those measured on mineral model sorbents (Kd = 0,114 litre kg,1). This, along with the strong correlation between sorption and the organic C content of the soil clay fractions (r = 0.99, P < 0.01), indicated a primary role of soil organic matter in the retention of both compounds. However, weak relationships between phenanthrene and dibenzofuran sorption coefficients and the organic C content of the bulk soils and variability of Koc values among soils, clay fractions, and model sorbents (1340,21020 litre kg,1 C for phenanthrene and 1685,7620 litre kg,1 C for dibenzofuran) showed that sorption was not predictable exclusively from the organic C content of the materials. Organic matter heterogeneity and domain blockage arising from organic matter,clay interactions and associated pH shifts were identified as the most likely causes of the different organic C-normalized sorption capacities of the soils. A direct contribution from minerals to the sorption of phenanthrene and dibenzofuran by the soils studied was likely to be small. Our results suggested that suitable descriptors for the extent of organic matter,mineral interactions would help to improve current Koc -based sorption predictions and subsequently the assessment of risk associated with the presence of HOCs in soil. [source] Neutrophil influx during non-typhoidal salmonellosis: who is in the driver's seat?FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2006Çagla Tükel Abstract A massive neutrophil influx in the intestine is the histopathological hallmark of Salmonella enterica serovar Typhimurium-induced enterocolitis in humans. Two major hypotheses on the mechanism leading to neutrophil infiltration in the intestinal mucosa have emerged. One hypothesis suggests that S. enterica serovar Typhimurium takes an active role in triggering this host response by injecting proteins, termed effectors, into the host cell cytosol which induce a proinflammatory gene expression profile in the intestinal epithelium. The second hypothesis suggests a more passive role for the pathogen by proposing that bacterial invasion stimulates the innate pathways of inflammation because the pathogen-associated molecular patterns of S. enterica serovar Typhimurium are recognized by pathogen recognition receptors on cells in the lamina propria. A review of the current literature reveals that, while pathogen recognition receptors are clearly involved in eliciting neutrophil influx during S. enterica serovar Typhimurium infection, a direct contribution of effectors in triggering proinflammatory host cell responses cannot currently be ruled out. [source] Cells migrating from the neural crest contribute to the innervation of the venous pole of the heartJOURNAL OF ANATOMY, Issue 1 2008Victoria Hildreth Abstract Cells migrating from the neural crest are known to septate the outflow tract of the developing heart, and to contribute to the formation of the arterial valves, their supporting sinuses, the coronary arteries and cardiac neural ganglia. Neural crest cells have also been suggested to contribute to development of the venous pole of the heart, but the extent and fate of such cells remains unclear. In this study, in the mouse, it is shown that cells from the neural crest contribute to the parasympathetic and, to a lesser extent, the sympathetic innervation of the venous pole of the heart. Nerves within the venous pole of the heart are shown to be of mixed origin, with some being derived from the neural crest, while others have an alternative origin, presumably placodal. The neurons innervating the nodal tissue, which can exert chronotropic effects on cardiac conduction, are shown not to be derived from the neural crest. In particular, no evidence was found to support previous suggestions that cells from the neural crest make a direct contribution to the myocardial atrioventricular conduction axis, although a small subset of these cells do co-localize with the developing left bundle branch. We have therefore confirmed that cells from the neural crest migrate to the venous pole of the heart, and that their major role is in the development of the parasympathetic innervation. In addition, in some embryos, a population of cells derived from the neural crest persist in the leaflets of the atrioventricular valves, but their role in subsequent development remains unknown. [source] Dendritic Cells at the Osteo-Immune Interface: Implications for Inflammation-Induced Bone Loss,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2007Mawadda Alnaeeli Abstract Within the past decade, the critical roles of T cells and T cell,mediated immunity in inflammation-induced osteoclastogenesis and subsequent bone loss have been extensively studied, thereby establishing the new paradigm of osteoimmunology. Therefore, dendritic cells (DCs), the most potent antigen-presenting cells, responsible for activation of naïve T cells and orchestration of the immune response, became critically situated at the osteo-immune interface. Today, emerging new evidence suggests that DC may be directly involved in inflammation-induced osteoclastogenesis and bone loss, by acting as osteoclast (OC) precursors that can further develop into DC-derived OCs (DDOC) under inflammatory conditions. These findings have tremendous implications, because in addition to DC's important roles in regulating innate and adaptive immunity, a direct contribution by these cells to inflammation-induced bone loss may provide a promising therapeutic target not only for controlling inflammation but also for modulating bone destruction. [source] The Bcl-2 Antagonist HA14-1 Forms a Fluorescent Albumin Complex that Can Be Mistaken for Several Oxidized ROS ProbesPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2008David Kessel The proapoptotic effects of the Bcl-2 antagonist HA14-1 are believed to derive from its affinity for the hydrophobic groove on Bcl-2 and Bcl-xL, thereby displacing proapoptotic factors, e.g. Bax and Bak. We have reported that HA14-1 promotes the efficacy of low-dose photodynamic therapy (PDT). A recent report proposed that the proapoptotic activity of HA14-1 reflects its ability to generate reactive oxygen species (ROS) when incubated in an aqueous environment. This later study, like several other HA14-1 investigations, relied on the use of fluorescent probes for ROS detection. We found that HA14-1 reacts with the albumin in serum to yield a fluorescent product. After correcting for this effect, the putative formation of ROS by HA14-1 could not be demonstrated with the fluorescent probes H2DCFDA, dihydroethidium or dihydrorhodamine. Indeed, the fluorescence excitation/emission spectra of HA14-1 encompassed the excitation/emission wavelengths used to detect these ROS probes. Cells cultured in a medium supplemented with ovalbumin, instead of serum, underwent apoptosis following HA14-1 addition, but did not exhibit fluorescence. Hence, HA14-1 fluorescence was unrelated to its proapoptotic activity. We conclude that the enhancement of PDT by HA14-1 reflects a pharmacologic effect, rather than its direct contribution of ROS. [source] Tumor volume of colon carcinoma is related to the invasive pattern but not to the expression of cell adhesion proteinsAPMIS, Issue 3 2009VICTORIA HAHN-STRÖMBERG Tumor volume increases during growth and due to tumor progression various mutations appear that may cause phenotypic changes. The invasive pattern may thus be affected resulting in a more disorganized growth. This phenomenon might be due to mutations in the genome of the adhesion proteins, which are responsible for the structural integrity of epithelial tissue. Tumor volume was assessed in whole mount sections of 33 colon carcinomas using Cavalieri's principle. Images from the entire invasive border were captured and used for calculating the irregularity of the border (Complexity Index). The expression of the adhesion proteins E-cadherin, ,-catenin, Claudin 2 and Occludin was assessed after immunohistochemical staining of two randomly selected areas of the invasive front of the tumor. Statistical significance for differences in volume was obtained for tumor Complexity Index, tumor stage (pT) and lymph node status (pN). Expression of adhesion proteins was significantly perturbed in the tumors compared with normal mucosa but only infrequently correlated to tumor differentiation or invasive pattern. The results show that when tumor volume increases the invasive pattern becomes more irregular which is compatible with tumor progression. A direct contribution of adhesion protein derangement to this process appears to be insignificant. [source] Mature antigen-experienced T helper cells synthesize and secrete the B cell chemoattractant CXCL13 in the inflammatory environment of the rheumatoid jointARTHRITIS & RHEUMATISM, Issue 11 2008Antonio Manzo Objective Synovial B cells play a critical role in rheumatoid arthritis (RA), being involved in autoantibody synthesis, T cell activation, and cytokine production. CXCL13 is a B cell chemoattractant that is instrumental in synovial B cell organization; the regulatory determinants of CXCL13 in inflammation are poorly characterized. This study was undertaken to investigate the functional involvement of synovial T cells in the ectopic expression of CXCL13 in RA. Methods CXCL13 production and regulation were addressed using immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, multicolor flow cytometry, and enzyme-linked immunosorbent assay, by in situ,ex vivo analysis and in vitro functional assays with rheumatoid synovial tissue and primary cells. Results CXCL13 messenger RNA and protein expression and spontaneous CXCL13 secretion were detected in RA synovial fluid T cells but were not detected (or were detected only occasionally) in peripheral blood T cells. Analysis of tissue expression confirmed cytoplasm localization of CXCL13 in T lymphocytes infiltrating B cell follicles and small perivascular aggregates. Multicolor characterizations in synovial fluid demonstrated CXCL13 expression in antigen-experienced T helper cells, frequently characterized by terminal differentiation and the lack of the follicular helper T cell markers CXCR5 and BCL6 protein. In vitro functional assays revealed the enhancing effect of T cell receptor,CD28 engagement on CXCL13 production and secretion in primary cells. Conclusion Our findings define a new functional property of synovial T cells, demonstrating their active involvement in the local production of B cell chemoattractants, and support a direct contribution of the adaptive immune system and antigen-dependent signals in the mechanisms of B cell localization in RA. [source] Ted White's Legacy to Gibbsite Precipitation ResearchASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5-6 2002D. Ilievski Professor E.T. (Ted) White's direct contribution to the understanding of gibbsite precipitation and to the modelling of this process has been enormous. In addition, he has had, and will continue to have, a profound indirect influence on developments in this area through former students, their students, and others following upon work that he has pioneered. The outcomes have been both academically and commercially important. The precipitation of gibbsite (aluminium trihydroxide) is a critical step in the production of alumina from bauxite, and Australia produces over 25% of the world's smelter grade alumina, earning about $3.5bn in revenue. This paper traces some of the recent developments in this area that have built upon the foundations laid by the seminal studies of Ted and his students. [source] The Role of Frugivorous Bats in Tropical Forest SuccessionBIOLOGICAL REVIEWS, Issue 4 2007Robert Muscarella Abstract Discussion of successional change has traditionally focused on plants. The role of animals in producing and responding to successional change has received far less attention. Dispersal of plant propagules by animals is a fundamental part of successional change in the tropics. Here we review the role played by frugivorous bats in successional change in tropical forests. We explore the similarities and differences of this ecological service provided by New and Old World seed-dispersing bats and conclude with a discussion of their current economic and conservation implications. Our review suggests that frugivorous New World phyllostomid bats play a more important role in early plant succession than their Old World pteropodid counterparts. We propose that phyllostomid bats have shared a long evolutionary history with small-seeded early successional shrubs and treelets while pteropodid bats are principally dispersers of the seeds of later successional canopy fruits. When species of figs (Ficus) are involved in the early stages of primary succession (e.g. in the river meander system in Amazonia and on Krakatau, Indonesia), both groups of bats are important contributors of propagules. Because they disperse and sometimes pollinate canopy trees, pteropodid bats have a considerable impact on the economic value of Old World tropical forests; phyllostomid bats appear to make a more modest direct contribution to the economic value of New World tropical forests. Nonetheless, because they critically influence forest regeneration, phyllostomid bats make an important indirect contribution to the economic value of these forests. Overall, fruit-eating bats play important roles in forest regeneration throughout the tropics, making their conservation highly desirable. [source] Maternal, paternal and environmental tobacco smoking and breast feedingPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2002Gabriel M. Leung Summary The effects of environmental tobacco smoke (ETS) on breast-feeding patterns are poorly understood, while those of parental smoking on breast-feeding initiation vs. duration have not been clearly delineated. We conducted a prospective, population-based birth cohort study to examine the independent effects of maternal, paternal and ETS on breast-feeding initiation and duration. A total of 6747 Hong Kong Chinese infants were recruited and followed up in 1997,8. We obtained detailed household smoking history and recorded breast-feeding patterns in three follow-up interviews over 9 months. We found that both maternal and paternal smoking were associated with not initiating breast feeding (odds ratio [OR] for ever maternal smoking = 2.51, 95% confidence interval [CI] = 1.63, 3.86; OR for ever paternal smoking = 1.22, 95% CI = 1.08, 1.39). Exposure to ETS in utero and post partum were also related to not starting breast feeding (ORETS in utero = 1.10, 95% CI = 0.99,1.24; ORETS post partum = 1.21, 95% CI = 1.08, 1.36). These effects, however, did not persist for breast-feeding duration of , 4 months. Cox proportional hazards modelling confirmed the lack of association between any form of smoking and breast-feeding duration. Our findings suggest that smoking of any kind, during or after pregnancy, is a strong risk indicator for not initiating breast feeding. Smoking as a risk indicator for underlying socio-economic, demographic and psychosocial factors is probably responsible for most of the observed adverse effects, although we cannot rule out direct contributions from pathophysiological mechanisms. Public health strategies directed at these underlying factors should be vigorously pursued to reduce the adverse effects of tobacco on breast feeding and infant health in general. [source] Technological Innovativeness as a Moderator of New Product Design Integration and Top Management SupportTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 3 2000Morgan Swink Many war stories, as well as a number of empirical research studies, point to the value of design integration and top management support in new product development (NPD) efforts, where design integration is conceptualized as the coordination of product and process design activities performed by various organizational groups. However, some emerging evidence suggests that these aspects of program management are not equally valuable in all NPD contexts. Furthermore, the benefits of these approaches may not extend to all dimensions of NPD performance. This article addresses these issues as they relate to technological innovativeness. The author reports the results of a research study designed to (1) assess the direct contributions of design integration and top management support to several dimensions of NPD performance, and (2) identify potential moderating influences of technological innovativeness on these direct effects. A survey of 136 NPD projects drawn from firms representing most of the major U.S. manufacturing industries provides data for the study. The overall goals of the study were to amplify our understanding of management's role in NPD and to further the development of contingency theory explaining new product success. The results indicate that design integration is positively associated with higher design quality in NPD, but it is not significantly linked with better financial performance. In addition, design integration appears to be an important influence on achieving NPD time goals, but only in cases of high technological innovativeness. This result suggests that increased design integration produces its greatest impacts when development processes are full of uncertainty. Top management support is positively associated with better time-based performance, design quality, and financial performance on the whole. However, a significant interaction effect suggests that high levels of top management support are ineffective in securing good financial performance in high technologically innovative environments. Other forces appear to be at work in these circumstances, making top management support less important. The article discusses the implications of these findings for management practice, a contingency-oriented view of NPD processes, and future research. [source] | |||||||||||||