915 resultados para Intra- and inter-specific polymorphism


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Large areas of tropical sub- and inter-tidal seagrass beds occur in highly turbid environments and cannot be mapped through the water column. The purpose of this project was to determine if and how airborne and satellite imaging systems could be used to map inter-tidal seagrass properties along the wet-tropics coast in north Queensland, Australia. The work aimed to: (1) identify the minimum level of seagrass foliage cover that could be detected from airborne and satellite imagery; and (2) define the minimum detectable differences in seagrass foliage cover in exposed intertidal seagrass beds. High resolution spectral-reflectance data (2040 bands, 350 – 2500nm) were collected over 40cm diameter plots from 240 sites on Magnetic Island, Pallarenda Beach and Green Island in North Queensland at spring low tides in April 2006. The seagrass species sampled were: Thalassia hemprechii, Halophila ovalis, Halodule uninerivs; Syringodium isoetifolium, Cymodocea serrulata, and Cymodoea rotundata. Digital photos were captured for each plot and used to derive estimates of seagrass species cover, epiphytic growth, micro- and macro-algal cover, and substrate colour. Sediment samples were also collected and analysed to measure the concentration of Chlorophyll-a associated with benthic micro-algae. The field reflectance spectra were analysed in combination with their corresponding seagrass species foliage cover levels to establish the minimum foliage projective cover required for each seagrass to be significantly different from bare substrate and substrate with algal cover. This analysis was repeated with reflectance spectra resampled to the bandpass functions of Quickbird, Ikonos, SPOT 5 and Landsat 7 ETM. Preliminary results indicate that conservative minimum detectable seagrass cover levels across most the species sampled were between 30%- 35% on dark substrates. Further analysis of these results will be conducted to determine their separability and satellite images and to assess the effects epiphytes and algal cover.

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Goal orientation, a mental framework for understanding how individuals approach learning and achievement situations, has emerged as an important topic in organisational psychology. This study investigated the effects of task practice, personality (openness to experience and neuroticism), and global goal orientation (predisposition to adopt a certain response pattern across all domains) on participants’ task-specific goal orientation (response pattern adopted for a specific task). One hundred and three participants performed an air traffic control task and their task-specific goal orientation was measured prior to each of a total of thirty trials. Results revealed an effect of task practice such that individuals’ task-specific learning orientation decreased over time while their task-specific prove orientation increased over time. The results also showed that individuals’ personality can influence their task-specific goal orientation and further, that this relationship can be mediated by global goal orientation. Specifically, the positive relationship between openness to experience and task-specific prove orientation was mediated by global prove orientation. Similarly, the positive relationship between neuroticism and task-specific avoid orientation was mediated by global avoid orientation. Theoretical and practical implications of these findings are considered.

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Concanavalin A, a T cell mitogen enhanced DNA synthesis in murine splenocytes. Amongst the early signals prior to this event was an increase in cytosolic calcium derived from both intra- and extracellular sources. The requirements for extracellular calcium persisted for four hours after the lectin administration which itself was needed for six hours. Putative calcium channel antagonists and calmodulin inhibitors blocked ihe increase in DNA synthesis. The calcium signal was mimicked by application of the ionophore, A23187, although no increase in DNA synthesis occurred. An activator of protein kinase C, 12-0- tetradecanoylphorbol 13-acetate, had little effect in isolation but the combined application of these two agents greatly enhanced DNA synthesis. The natural mediators of these events are presumed to be inositol trisphosphate and diacylglycerol derived from phosphatidylinositol bisphosphate hydrolysis. Lectin application and protein kinase C activation both increased intracellular pH possibly as a result of Na'l'/H"'' exchange since amiloride an inhibitor of this antiporter inhibited lectin induced DNA synthesis. The calcium and hydrogen ionic changes occur within minutes of lectin application; the protracted requirement for this mitogen suggests further signalling mechanisms occur to elicit maximum DNA synthesis in these cells. Gonadectomy caused an increase in thymic and splenic weight. Spleno-cytes derived from castrated mice showed no change in mitogen response whereas those from ovariectomised mice demonstrated a reduced lectin sensitivity. Testosterone, 5 a dihydrotestosterone, a and 0 oestradiol all inhibited lectin induced DNA synthesis but only at pharmacological concentrations. Testosterone glucuronide and cholesterol were without effect Studies with mouse serum fractions of differing steroidal status were unable to confirm the presence or absence of serum factors which might mediate the effects of steroid on lymphoid cells, all fractions tested inhibited lymphocyte transformation. Both interleukin-2 and lipopolysaccharide induced splenocyte mitogene-sis was also impaired by high steroid concentrations in vitro, suggesting that steroids mediate their effect by a non-specific, non-receptor-mediated event.

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The supply chain management (SCM) concept has become embedded in the thinking of many organisations in recent years. Originally introduced by management consultants in the early 1980s, SCM has a strong focus on integration of processes across functions within firms, as well as between the organisations that comprise the wider extended enterprise. There is a significant body of research to support the notion that the consistent delivery of value to customers is predicated on higher levels of intra-firm and inter-firm integration. Putting the supply chain integration (SCI) concept into practice is critically dependent on the ability of firms to manage material, money and information flows in a holistic manner. It also depends on the way in which relationships between key supply chain actors are managed. This article explores the “mega-trends” that are evident across most sectors and which have a potentially significant impact on the ability of organisations to put SCM theory into practice. The late Don Bowersox and his colleagues from Michigan State University introduced the idea of supply chain “mega-trends” over a decade ago in their widely cited article in the Journal of Business Logistics (Bowersox et al., 2000). This article explores the current status of these “mega-trends” in an Irish context based on research being undertaken at the National Institute for Transport and Logistics (NITL). It also identifies some key factors that are likely to impact upon progress in these key areas in the medium term.

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Suboptimal maternal nutrition during gestation results in the establishment of long-term phenotypic changes and an increased disease risk in the offspring. To elucidate how such environmental sensitivity results in physiological outcomes, the molecular characterisation of these offspring has become the focus of many studies. However, the likely modification of key cellular processes such as metabolism in response to maternal undernutrition raises the question of whether the genes typically used as reference constants in gene expression studies are suitable controls. Using a mouse model of maternal protein undernutrition, we have investigated the stability of seven commonly used reference genes (18s, Hprt1, Pgk1, Ppib, Sdha, Tbp and Tuba1) in a variety of offspring tissues including liver, kidney, heart, retro-peritoneal and inter-scapular fat, extra-embryonic placenta and yolk sac, as well as in the preimplantation blastocyst and blastocyst-derived embryonic stem cells. We find that although the selected reference genes are all highly stable within this system, they show tissue, treatment and sex-specific variation. Furthermore, software-based selection approaches rank reference genes differently and do not always identify genes which differ between conditions. Therefore, we recommend that reference gene selection for gene expression studies should be thoroughly validated for each tissue of interest. © 2011 Elsevier Inc.

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Background aims: The cost-effective production of human mesenchymal stromal cells (hMSCs) for off-the-shelf and patient specific therapies will require an increasing focus on improving product yield and driving manufacturing consistency. Methods: Bone marrow-derived hMSCs (BM-hMSCs) from two donors were expanded for 36 days in monolayer with medium supplemented with either fetal bovine serum (FBS) or PRIME-XV serum-free medium (SFM). Cells were assessed throughout culture for proliferation, mean cell diameter, colony-forming potential, osteogenic potential, gene expression and metabolites. Results: Expansion of BM-hMSCs in PRIME-XV SFM resulted in a significantly higher growth rate (P < 0.001) and increased consistency between donors compared with FBS-based culture. FBS-based culture showed an inter-batch production range of 0.9 and 5 days per dose compared with 0.5 and 0.6 days in SFM for each BM-hMSC donor line. The consistency between donors was also improved by the use of PRIME-XV SFM, with a production range of 0.9 days compared with 19.4 days in FBS-based culture. Mean cell diameter has also been demonstrated as a process metric for BM-hMSC growth rate and senescence through a correlation (R2 = 0.8705) across all conditions. PRIME-XV SFM has also shown increased consistency in BM-hMSC characteristics such as per cell metabolite utilization, in vitro colony-forming potential and osteogenic potential despite the higher number of population doublings. Conclusions: We have increased the yield and consistency of BM-hMSC expansion between donors, demonstrating a level of control over the product, which has the potential to increase the cost-effectiveness and reduce the risk in these manufacturing processes.

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Potent-selective peptidomimetic inhibitors of tissue transglutaminase (TG2) were developed through a combination of protein-ligand docking and molecular dynamic techniques. Derivatives of these inhibitors were made with the aim of specific TG2 targeting to the intra- and extracellular space. A cell-permeable fluorescently labeled derivative enabled detection of in situ cellular TG2 activity in human umbilical cord endothelial cells and TG2-transduced NIH3T3 cells, which could be enhanced by treatment of cells with ionomycin. Reaction of TG2 with this fluorescent inhibitor in NIH3T3 cells resulted in loss of binding of TG2 to cell surface syndecan-4 and inhibition of translocation of the enzyme into the extracellular matrix, with a parallel reduction in fibronectin deposition. In human umbilical cord endothelial cells, this same fluorescent inhibitor also demonstrated a reduction in fibronectin deposition, cell motility, and cord formation in Matrigel. Use of the same inhibitor in a mouse model of hypertensive nephrosclerosis showed over a 40% reduction in collagen deposition.

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A kutatás azt a kérdéskört vizsgálja, hogyan járul hozzá a bizalom a vállalatok piaci teljesítményéhez. A vállalatok azon képessége, hogy felhasználják a rendelkezésükre álló piaci információkat nehezen másolható, tartós versenyelőnyt biztosít. A marketingmenedzserek a piaci információk hitelességét nehezen tudják objektív módon megítélni, mivel azokat jellemzően mások gyűjtik és rendszerezik számukra. A szerző kutatásában a menedzserek vállalaton belüli és vállalaton kívüli piaci informálódást célzó kapcsolatai esetén modellezte és empirikusan tesztelte a bizalom hatásait. Eredményei szerint a bizalom a vállalaton belüli és vállalaton kívüli kapcsolatok esetében is fontos mozgatórugója az információfelhasználásnak, jóllehet közvetlenül nincs hatással arra. Minél jobban bízik a döntéshozó az információ forrásában, annál jobb minőségűnek fogja észlelni a tőle származó információt. Az információ észlelt minősége meghatározza, hogy arra támaszkodnak-e a vezetők a döntések meghozatalánál. Azok a marketingmenedzserek, akik képesek bizalmi kapcsolatok kiépítésére, szélesebb körű, hiteles piaci információkra támaszkodhatnak a döntéshozatal során, amely hozzájárul a vállalat piaci teljesítményéhez. ____ We have limited knowledge on the potential pattern similarities/differences of trust’s role that may exist in information use obtained through intra- and extra-organizational relationships. This study addresses this question by investigating how trust leads to information use. Data from 338 intra-organizational and a sub-ample of 158 inter-organizationaldyadic information exchange relationships showed that trust is an important driver of the utilization of market information in both cases. Trust has no direct relationship to information use, instead has a strong indirect effect through a mediator, perceived quality of information. The effects of trustontheuse of information obtained throughinter- and extra-organizational dyadic relationships proved to be similar.

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Today's young people are progressing from adolescence into adulthood differently than past generations, including taking a longer time to make this transition. Some believe that the developmental markers and tasks of this transitional period are unique enough to merit the designation of a new life stage--"emerging adulthood." Recently, this new life stage of emerging adulthood has received increasing attention in the developmental literature, including attention to the probable causes for its evolution. However, little is known about specific aspects of intra- and interpersonal development that occur during emerging adulthood. The purpose of this study was to empirically assess hypothesized relations between variables associated with the psychological constructs of attachment, psychosocial maturity, and differentiation of self, in a sample of emerging adults. Structural equation modeling (SEM) analyses indicated an association between the variables measuring these constructs (anxiety, avoidance, I-position, reactivity, cutoff, fusion, identity, and intimacy). The results from structural equation modeling (SEM) analyses helped to confirmed and extended previous research by demonstrating significant associations between attachment, psychosocial maturity, and differentiation of self through the variables operationalizing these constructs. Psychosocial maturity predicted differentiation of self (with intimacy predicting emotional cutoff and identity predicting cutoff and I-position). Attachment also predicted differentiation of self (with anxiety predicting all differentiation variables, and avoidance predicting emotional reactivity and cutoff). However, associations between anxiety and cutoff and between avoidance and cutoff were mediated by psychosocial identity and intimacy, and associations between anxiety and I-position were mediated by identity. Thus, these results corroborate and elaborate previous research conducted on these constructs. Specifically, relational tendencies thought to be influenced by attachment security impact interpersonal functioning in emerging adulthood, but this association is influenced by the degree of resolution of key psychosocial tasks.

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Cetaceans are aquatic mammals that rely primarily on sound for most daily tasks. A compendium of sounds is emitted for orientation, prey detection, and predator avoidance, and to communicate. Communicative sounds are among the most studied Cetacean signals, particularly those referred to as tonal sounds. Because tonal sounds have been studied especially well in social dolphins, it has been assumed these sounds evolved as a social adaptation. However, whistles have been reported in ‘solitary’ species and have been secondarily lost three times in social lineages. Clearly, therefore, it is necessary to examine closely the association, if any, between whistles and sociality instead of merely assuming it. Several hypotheses have been proposed to explain the evolutionary history of Cetacean tonal sounds. The main goal of this dissertation is to cast light on the evolutionary history of tonal sounds by testing these hypotheses by combining comparative phylogenetic and field methods. This dissertation provides the first species-level phylogeny of Cetacea and phylogenetic tests of evolutionary hypotheses of cetacean communicative signals. Tonal sounds evolution is complex in that has likely been shaped by a combination of factors that may influence different aspects of their acoustical structure. At the inter-specific level, these results suggest that only tonal sound minimum frequency is constrained by body size. Group size also influences tonal sound minimum frequency. Species that live in large groups tend to produce higher frequency tonal sounds. The evolutionary history of tonal sounds and sociality may be intertwined, but in a complex manner rejecting simplistic views such as the hypothesis that tonal sounds evolved ‘for’ social communication in dolphins. Levels of social and tonal sound complexity nevertheless correlate indicating the importance of tonal sounds in social communication. At the intraspecific level, tonal sound variation in frequency and temporal parameters may be product of genetic isolation and local levels of underwater noise. This dissertation provides one of the first insights into the evolution of Cetacean tonal sounds in a phylogenetic context, and points out key species where future studies would be valuable to enrich our understanding of other factors also playing a role in tonal sound evolution. ^

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In isolation and characterization studies, expression level U1 and U2 snRNA isoforms were obtained from the 5th instar larval stage silk gland (SG). The DNA content of the SG cells is approximately 200,000-fold higher compared to the usual (2N) somatic cells of B. mori due to endoreduplication. In this study, the existence of U1 and U2 snRNA isoforms in the SG of the organism is investigated. Bombyx mori U1 and U2-specific RT-PCR libraries from the silk gland were generated. Five U1 and eight U2 isoforms were isolated and characterized. Nucleotide differences, structural alterations, as well as protein and RNA interaction sites were analyzed in these variants. For the U1 snRNA variants, they were compared to the previously reported BmN isoforms. In all these U-snRNA variants, polymorphic sites do not predominate at the core of known functional sequences, which were interspecifically conserved. Variant sites and inter-species differences are located in moderately conserved regions. Free energy (ΔG) values for the entire U1 and U2 snRNA secondary structures and for the individual stem/loops domains of the isoforms were generated and compared to determine their structural stability. This will be the first time that U1 and U2 variants are shown specific for a development stage (larval) other than embryonic or adult. ^ Using phylogenetic analysis, evolutionary trees were generated for the U1 and U2 snRNAs using animal, plant, protista and fungal species. The resulting trees were boostrapped for robustness and rooted with the self-splicing RNA group II intron sequence from the cyanobacterium Calothrix. Using phylogenetic analyses, possible structural and functional evolutionary interdependence between the U1 and U2 snRNAs was investigated. ^

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Persistence of HIV-1 reservoirs within the Central Nervous System (CNS) remains a significant challenge to the efficacy of potent anti-HIV-1 drugs. The primary human Brain Microvascular Endothelial Cells (HBMVEC) constitutes the Blood Brain Barrier (BBB) which interferes with anti-HIV drug delivery into the CNS. The ATP binding cassette (ABC) transporters expressed on HBMVEC can efflux HIV-1 protease inhibitors (HPI), enabling the persistence of HIV-1 in CNS. Constitutive low level expression of several ABC-transporters, such as MDR1 (a.k.a. P-gp) and MRPs are documented in HBMVEC. Although it is recognized that inflammatory cytokines and exposure to xenobiotic drug substrates (e.g HPI) can augment the expression of these transporters, it is not known whether concomitant exposure to virus and anti-retroviral drugs can increase drug-efflux functions in HBMVEC. Our in vitro studies showed that exposure of HBMVEC to HIV-1 significantly up-regulates both MDR1 gene expression and protein levels; however, no significant increases in either MRP-1 or MRP-2 were observed. Furthermore, calcein-AM dye-efflux assays using HBMVEC showed that, compared to virus exposure alone, the MDR1 mediated drug-efflux function was significantly induced following concomitant exposure to both HIV-1 and saquinavir (SQV). This increase in MDR1 mediated drug-efflux was further substantiated via increased intracellular retention of radiolabeled [3H-] SQV. The crucial role of MDR1 in 3H-SQV efflux from HBMVEC was further confirmed by using both a MDR1 specific blocker (PSC-833) and MDR1 specific siRNAs. Therefore, MDR1 specific drug-efflux function increases in HBMVEC following co-exposure to HIV-1 and SQV which can reduce the penetration of HPIs into the infected brain reservoirs of HIV-1. A targeted suppression of MDR1 in the BBB may thus provide a novel strategy to suppress residual viral replication in the CNS, by augmenting the therapeutic efficacy of HAART drugs.

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In this study, I divided samples from individuals within Afghanistan based upon geography (i.e., north versus south). I determined allelic frequencies and other statistical parameters for 15 STR loci (i.e., D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, Dl3S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA). I conducted pairwise comparisons with 19 neighboring Eurasian populations to assign Gstatistics and p-values. Categorizing the populations into five groups (i.e., Central Asia, East Asia, South Asia, the Middle East, and the Caucasus/Anatolia), I derived values for intra-population, inter-population, and total variance. Admixture analyses determined the highest allelic contributions to be from the Caucasus/ Anatolia, while negligible contributions were made by Central Asia and East Asia. A Correspondence Analysis revealed clustering of both northern and southern Afghanistan with Georgia, Turkey, northern Iran, and southern Iran of the Caucasus/ Anatolia and the Middle East. A Neighbor-Joining phylogenetic tree was constructed to generate bootstrap values over 1, 000 reiterations.

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Cetaceans are aquatic mammals that rely primarily on sound for most daily tasks. A compendium of sounds is emitted for orientation, prey detection, and predator avoidance, and to communicate. Communicative sounds are among the most studied Cetacean signals, particularly those referred to as tonal sounds. Because tonal sounds have been studied especially well in social dolphins, it has been assumed these sounds evolved as a social adaptation. However, whistles have been reported in ‘solitary’ species and have been secondarily lost three times in social lineages. Clearly, therefore, it is necessary to examine closely the association, if any, between whistles and sociality instead of merely assuming it. Several hypotheses have been proposed to explain the evolutionary history of Cetacean tonal sounds. The main goal of this dissertation is to cast light on the evolutionary history of tonal sounds by testing these hypotheses by combining comparative phylogenetic and field methods. This dissertation provides the first species-level phylogeny of Cetacea and phylogenetic tests of evolutionary hypotheses of cetacean communicative signals. Tonal sounds evolution is complex in that has likely been shaped by a combination of factors that may influence different aspects of their acoustical structure. At the inter-specific level, these results suggest that only tonal sound minimum frequency is constrained by body size. Group size also influences tonal sound minimum frequency. Species that live in large groups tend to produce higher frequency tonal sounds. The evolutionary history of tonal sounds and sociality may be intertwined, but in a complex manner rejecting simplistic views such as the hypothesis that tonal sounds evolved ‘for’ social communication in dolphins. Levels of social and tonal sound complexity nevertheless correlate indicating the importance of tonal sounds in social communication. At the intraspecific level, tonal sound variation in frequency and temporal parameters may be product of genetic isolation and local levels of underwater noise. This dissertation provides one of the first insights into the evolution of Cetacean tonal sounds in a phylogenetic context, and points out key species where future studies would be valuable to enrich our understanding of other factors also playing a role in tonal sound evolution.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)