Humoral regulation of somatic and hematopoietic cell growth has been intensely investigated during the past decade. Growth hormone is unique because it regulates the size of the person within the constraints of the genetic program. The somatomedins and insulin growth factors are low molecular weight polypeptides believed to mediate some functions of growth hormone. Epithelial growth factor and nerve growth factor are well-characterized polypeptides that influence the growth and differentiation of epithelial and neural tissues and interact with specific cell surface receptors. The hematopoietins are a family of polypeptide hormones that specifically regulate the proliferation and differentiation of stem cells giving rise to erythrocytes, granulocytes, monocytes, megakaryocytes, and B and T lymphocytes. Platelet-derived growth factor modulates the proliferation of fibroblasts in vitro and may have a role in the development of atherosclerosis and myelofibrosis. New knowledge on the biochemistry and physiology of growth factors will probably have a substantial impact on our understanding of human diseases involving abnormal cell growth.

This study focuses on factors driving insurance demand measured as insurance density and growth rate of premiums in emerging markets during the years 1998?2008. Findings indicate that demographic factors explain a greater variance relative to economic and institutional variables for insurance density, while economic factors explain the greatest amount of variance in terms of insurance growth rates. We find that growth rate of the country, GNI per capita, interest rate, merchandise trade, and business freedom influence insurance density. The influence of growth rate of the country was in opposing directions in the case of non-life and life density.

Angiogenesis is a complex process controlled by the balance of a large number of regulating factors, the pro- and anti-angiogenic factors. Dysregulation of angiogenesis occurs in various pathologies and is one of the hallmarks for cancer. Recent emphasis on the microenvironment's influence in chronic lymphocytic leukemia (CLL) progression and drug resistance nurtures the interest in angiogenesis. Researchers have already identified a variety of angiogenic factors involved in the CLL, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), angiopoietin-2(Ang-2), thrombospondin-1 (TSP-1), as well as extracellular proteinases such as matrix metalloproteinase-9 (MMP-9). Besides modulating neovascularization, angiogenic ...

This selected bibliography includes 250 articles on cassava as a potential energy source. Factors included are things which influence cassava growth; such as weeding, fertilizer, diseases and genetic selection, as well as the conversion of cassava to ethanol. (DP)

Opinions on the world market for wind power are presented in this paper. The paper is divided into three sections: the market, the technology, and general conclusions. The market section compares European and US wind energy growth and contributing factors and barriers to growth. A technology overview discusses wind turbine concepts, mass reduction, blade structural flexibility, and growth in machine size. Political decisions, economic aspects, public acceptance, and technology limitations are assessed for their influence on the growth of wind energy. 11 figs.

We have recently demonstrated the formation of interconnecting canalicular cell processes in bone cells upon contact with basement membrane components. Here we have determined whether growth factors in the reconstituted basement membrane (Matrigel) were active in influencing the cellular network formation. Various growth factors including transforming growth factor beta (TGF-beta), epidermal growth factor (EGF), insulin-like growth factor 1, bovine fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF) were identified in Matrigel. Exogenous TGF-beta blocked the cellular network formation. Conversely, addition of TGF-beta 1 neutralizing antibodies to Matrigel stimulated the cellular network formation. bFGF, EGF, and PDGF all promoted cellular migration and organization on Matrigel. Addition of bFGF to MC3T3-E1 cells grown on Matrigel overcame the inhibitory effect of TGF-beta. Some TGF-beta remained bound to type IV collagen purified from the Engelbreth-Holm-Swarm tumor matrix. These data demonstrate that reconstituted basement membrane contains growth factors which influence cellular behavior, suggesting caution in the interpretation of experiments on cellular activity related to Matrigel, collagen type IV, and possibly other extracellular matrix components. PMID:1511725

In several species of teleost, the pituitary hormones prolactin (PRL), growth hormone (GH) and somatolactin (SL) show different secretory patterns based on gender and development and can also be influenced by abiotic factors (e.g., salinity, photoperiod & temperature). Plasma insulin-like growth fa...

Time is central to our understanding of entrepreneurship. However, while prior research has shown a general link between decision speed and venture performance, little is known about what factors influence the speed of venture creation. Equally, little research has been conducted on how venture creation speed impacts on venture growth. This paper examines the determinants and growth implications of venture creation speed from a social constructionist perspective, which sees that time both shapes and is shaped by individuals, social contexts and spatial structures. We, therefore, investigate the influence of entrepreneurial characteristics, external support, institutional influences and the regional context in which venture creation speed occurs and subsequently impacts on growth in new ven...

Tyrosine kinase growth factor receptor signaling influences proliferation, survival, and apoptosis. Hair follicles undergo cycles of proliferation and apoptotic regression, offering an excellent paradigm to study how this transition is governed. Several factors are known to affect the hair cycle, bu...

This lesson discusses population growth, both in the United States and in the world. Topics include factors that influence population growth, such as government policy, religion, education or economic levels, energy use per capita, and whether a country is agrarian or industrial. The lesson includes an activity in which students research an online resource on population growth and answer questions as they navigate through its presentation.

We have investigated nerve growth factor-dependent neurite growth from adult sensory neurons using the compartmented culture system. The requirement of both TrkA and the p75 neurotrophin receptors in neurite growth was examined using several experimental interventions. Inhibition of TrkA activation using K252a resulted in a total block of distal neurite extension into nerve growth factor-containing compartments. Brain-derived neurotrophic factor and the anti-p75 monoclonal antibody MC192 have been shown to interfere with the binding of nerve growth factor to p75. Brain-derived neurotrophic factor, which binds p75 but not TrkA, competes with nerve growth factorforp75, while the anti-p75 antibody MC192 has been shown to decrease the interaction of nerve growth factor with TrkA. The addition of brain-derived neurotophic factor to nerve growth factor-containing distal compartments inhibited, but did not totally block, distal neurite extension. MC192, on the other hand, totally inhibited nerve growth factor-dependent neurite growth. To test whether MC192 and brain-derived neurotrophic factor might be influencing Trk activation, TrkA phosphorylation was examined biochemically. Both compounds were found to attenuate nerve growth factor-induced Trk phosphorylation, although neither inhibited the activation completely. The possibility that MC192 or brain-derived neurotrophic factor might activate p75 signaling directly (and potentially antagonize TrkA signaling) was also investigated. This was assessed by quantitating the activation and nuclear translocation of the transcription factor NFkB using immunocytochemistry. Only treatment with the anti-p75 antibody MC192 resulted in prolonged and significant increase in the number of neurons displaying nuclear staining for NFkB. Our results demonstrate that both TrkA and p75 play a role in neurite growth response to nerve growth factor, and further suggest that any alteration in optimal TrkA-p75 interactions, or direct activation of p75 at the expense of TrkA, results in an inhibition of nerve growth factor-dependent neurite growth in adult sensory neurons. PMID:10430489

Problem of crystal growth process simulation for the cadmium-mercury-tellurium alloy from tellurium solution by the Travelling heater method under microgravity conditions is considered. The main attention is drawn to the formulation of boundary conditions at the interfaces and calculation of the growth rate. Limitation of the local thermodynamic equilibrium approximation and uncertainty in determination of growth parameters in this case is shown. Non-equilibrium model of HgCdTe crystal growth from solution is considered. It includes one matching parameter, the kinetic factor, which should be determined from experiment. Comparison of the calculation results obtained by the equilibrium and by the non-equilibrium model shows, that the kinetic factor does not influence the crystal growth rate since a certain value. Results of the calculation of HgCdTe crystal growth process at the seed from cadmium telluride are given as well.

Abstract Aim To deepen understanding of the factors that influenced the formation of oak savanna in central Kentucky, USA. Particular attention was focused on the link between historical disturbance and the formation of savanna ecosystem structure. Location Central Kentucky, USA. Methods We used dendrochronological analysis of tree-ring samples to understand the historical growth environment of remnant savanna stems. We used release detection and branch-establishment dates to evaluate changes in tree growth and the establishment of savanna physiognomy. We contrasted our growth chronology with reference chronologies for regional tree growth, climate and human population dynamics. Results Trees growing in Kentucky Inner Bluegrass Region (IBR) savanna remnants exhibited a period of suppressio...

Lactic acid bacteria play an important role in the fermentation of different food products. During the fermentation processes, lactobacilli are confronted with many inhibitor factors. These factors by themselves or in combination can influence the growth of lactic acid bacteria and their acidification capacity. The subject of our study was to monitor with a newly developed biosensing technique how the different chemical stress factors influence the survival of lactic acid bacteria. Electrochemical optical waveguide lightmode spectroscopy combines evanescent-field optical sensing with electrochemical control of surface adsorption processes. For optical sensing, a layer of indium tin oxide served as a high refractive index waveguide and as a conductive electrode, as well.Lactobacillus planta...

Determination of permissible dimensions of cracklike defects with a finite fillet radius of its tips is based on the diagram of crack-growth resistance introducing a safety factor into a criterion equation. Calculation formulas are suggested to estimate the safety factors and permissible dimensions of plane cracklike defects. The influence of a theoretical stress concentration factor and safety factor of yield strength on the safety factor was also investigated. An analysis of permissible dimensions of a cracklike defect demonstrated on an example of a tensile plane with a through cracklike defect allows one to permit larger (in comparison with crack) dimensions of the safe cracklike defect.

A complex interaction involving temporal as well as spatial factors influences plant growth and development. To optimally control the environment for plant growth, an important first step is to develop crop growth models that can predict daily plant growth based on weather data, management practices, and plant genetic information. When this is accomplished, sensing data can contribute to enhanced accuracy of the plant growth model. Recent efforts to integrate plant growth models with sensing methods have provided an opportunity to optimize future plant production systems. In other words, good results require feedback from plants. The general concept is coined the ‘speaking plant’ concept. Consequently, sensors are an essential part of control systems. Machine vision can provide information about current crop status, including growth, nutrient stress and pest infestation. In this paper, current technologies are introduced and sensing system using artificial intelligence are described.   

Little being known of the effect of artificial conditions on Biomphalaria snails maintained in laboratory aquaria, experiments were conducted to determine some of the basic requirements of these snails, expressed in terms of the influence of various factors on their growth, fecundity and mortality. ...

Physiological and growth responses of trees to elevated atmospheric CO[sub 2] are influenced by soil nutrient availability. Interactive effects of these factors on tree chemical composition, however, are largely unknown. We used a split-plot experimental design to assess the impact of CO[sub 2] (whole plots; 355 and 650 ppm) and soil NO[sub 3][sup [minus

Pancreatic ductal adenocarcinoma is an aggressive and highly lethal disease frequently characterized by a dense stromal or desmoplastic response. Accumulating evidence exists that tumor desmoplasia plays a central role in disease progression and that e.g. activated pancreatic stellate cells (PSCs) are responsible for the excess matrix production. The mechanisms underlying the tumor versus stroma interplay are complex. Pancreatic cancer cells release mitogenic and fibrogenic stimulants, such as transforming growth factor ?(1), platelet-derived growth factor (PDGF), sonic hedgehog, galectin 3, endothelin 1 and serine protease inhibitor nexin 2, all of which may promote the activated PSC phenotype. Stellate cells in turn secrete various factors, including PDGF, stromal-derived factor 1, epidermal growth factor, insulin-like growth factor 1, fibroblast growth factor, secreted protein acidic and rich in cysteine, matrix metalloproteinases, small leucine-rich proteoglycans, periostin and collagen type I that mediate effects on tumor growth, invasion, metastasis and resistance to chemotherapy. This review intends to shed light on the mechanisms by which PSCs in the stroma influence pancreatic cancer development. The increased understanding of this interaction will be of potential value in designing new modalities of targeted therapy. and IAP. PMID:21242706

The deer population activity allows students to experiment with the factors which influence population dynamics. In their exploration, they encounter both exponential and logistic growth curves. Students should be familiar with the concepts of birth and death rates, emigration and immigration, predation, limiting factors such as food supply and habitat size, and carrying capacity. The activity is self-paced with extensions provided for those who have extra time.

It is not fully understood how much growth stresses affect the final quality of solid timber products in terms of e.g. shape stability. It is for example difficult to predict the internal growth stress field within the tree stem. Growth stresses are progressively generated during the tree growth and they are highly influenced by climate, biologic and material related factors. To increase the knowledge of the stress formation a finite element model was created to study how the growth stresses develop during the tree growth. The model is an axisymmetric general plane strain model where material for all new annual rings is progressively added to the tree during the analysis. The material model used is based on the theory of small strains (where strains refer to the undeformed configuration which is good approximation for strains less than 4%) where so-called biological maturation strains (growth-related strains that form in the wood fibres during their maturation) are used as a driver for the stress generation. It is formulated as an incremental material model that takes into account elastic strain, maturation strain, viscoelastic strain and progressive stiffening of the wood material. The results clearly show how the growth stresses are progressively generated during the tree growth. The inner core becomes more and more compressed whereas the outer sapwood is subjected to slightly increased tension. The parametric study shows that the growth stresses are highly influenced by the creep behaviour and evolution of parameters such as modulus of elasticity, micro fibril angle and maturation strain.

Voltage-dependent Ca/sup 2 +/ channels were studied by the binding of the potent Ca/sup 2 +/ channel antagonist PN200-110 and by the K/sup +/-induced /sup 45/Ca/sup 2 +/ uptake in human muscle cultured aneurally in the presence of insulin, fibroblast growth factor, and epidermal growth factor, added in combination or individually. Compared to the muscle grown in medium without growth factors, 14-15 days of treatment with insulin (10 micrograms/ml) alone or in combination with two other growth factors caused a 3.4- and 3.8-fold increase per culture dish in the number of PN200-110 binding sites, respectively. There was no change in the affinity of the ligand-receptor complex. Under the same conditions, there was also fourfold increase of the K/sup +/-induced /sup 45/Ca/sup 2 +/ uptake in cultured human muscle. Neither fibroblast growth factor nor epidermal growth factor alone influenced PN200-110 binding sites. Our study demonstrates that insulin enhances the development of functional voltage-dependent Ca/sup 2 +/ channels in cultured human muscle.

Bacterial and fungal growth rate measurements are sensitive variables to detect changes in environmental conditions. However, while considerable progress has been made in methods to assess the species composition and biomass of fungi and bacteria, information about growth rates remains surprisingly rudimentary. We review the recent history of approaches to assess bacterial and fungal growth rates, leading up to current methods, especially focusing on leucine/thymidine incorporation to estimate bacterial growth and acetate incorporation into ergosterol to estimate fungal growth. We present the underlying assumptions for these methods, compare estimates of turnover times for fungi and bacteria based on them, and discuss issues, including for example elusive conversion factors. We review what the application of fungal and bacterial growth rate methods has revealed regarding the influence of the environmental factors of temperature, moisture (including drying/rewetting), pH, as well as the influence of substrate additions, the presence of plants and toxins. We highlight experiments exploring the competitive and facilitative interaction between bacteria and fungi enabled using growth rate methods. Finally, we predict that growth methods will be an important complement to molecular approaches to elucidate fungal and bacterial ecology, and we identify methodological concerns and how they should be addressed. PMID:21470255

The aims of this study were to investigate the level of adversarial growth among telephone counsellors, and to examine the influence of psychological and environmental factors on growth. In particular, the effect of compassion fatigue, empathy, environmental support and calls per shift on posttraumatic growth was assessed. Sixty-four telephone counsellors completed five self-report measures: a demographic questionnaire, the Posttraumatic Growth Inventory, the Professional Quality of Life Scale, the Jefferson Scale of Physician Empathy, and the Crisis Support Scale. Although relatively low, levels of posttraumatic growth were in evidence. As predicted, compassion fatigue was significantly related to posttraumatic growth. In addition, calls per shift were associated with growth, although this was a negative relationship whereby the more calls that were taken, the lower the level of growth. Contrary to expectation, neither empathy nor crisis support were significant predictors of growth. In conclusion, adversarial growth was observed in the current sample of telephone counsellors. However, there appears to be a threshold of adversity, beyond which there is less likelihood of continued growth. This was evident in those telephone counsellors who, having taken a relatively high number of calls in a shift, were less likely to experience growth. (Contains 4 tables.)

The influence of NaCl (salinity; 0-5%%) and higher temperature (heat stress; 32^oC) on yield of turion formation has been tested in the duckweed Spirodela polyrhiza for the first time. Turion formation was more sensitive to both stressors than the growth of the vegetative fronds: (1) the concentration of NaCl which produces half-maximal inhibition was lower for turion formation than for growth by the factor of five. (2) At 32^oC turion formation was completely blocked whereas growth rates decreased by only 20% as compared with 28^oC.

In this study we determined the base temperature and Heat units for leaf flushing initiation and growth of RRIM-600 and GT1 Hevea clones. The minimum base temperature was found to be approximately 16° C for leaf flushing emission and 19° C for shoot growth in terms of height. Approximately 420 degree days at 16° C as base temperature is required for successive leaf flushing initiation. Linear equations with correlation coefficients above 0.95 allow an estimation of the height increase from the accumulated degree days, corrected or otherwise for photoperiod. The highest correlation coefficients demonstrated a positive effect of the photoperiod among the factors influencing the shoot growth.

The adrenal gland is composed of two separate endocrine tissues that control a multitude of bodily functions in their adaptation to external and internal stressors through hormone secretion. The functions of the adrenal gland are regulated by circulating, neural and local factors that ensure proper cell growth and hormone production. Activins and inhibins are among the locally expressed growth factors affecting adrenal cell function. They have been found to influence several aspects of adrenal cell development, adrenocortical steroidogenesis, adrenocortical tumor formation and adrenomedullary cell differentiation. Especially the finding that inhibin @a-subunit knockout mice develop adrenocortical carcinomas after gonadectomy has prompted research on the physiological and pathophysiological...

Genetic diversity within plant populations can influence plant community structure along environmental gradients. In wetland habitats, salinity and soil type are factors that can vary along gradients and therefore affect plant growth. To test for intraspecific growth variation in response to these factors, a greenhouse study was conducted using common plants that occur in northern Gulf of Mexico brackish and salt marshes. Individual plants of Distichlis spicata, Phragmites australis, Schoenoplectus californicus, and Schoenoplectus robustus were collected from several locations along the coast in Louisiana, USA. Plant identity, based on collection location, was used as a measure of intraspecific variability. Prepared soil mixtures were organic, silt, or clay, and salinity treatments were 0 ...

Productivity of seagrasses can be controlled by physiological processes, as well as various biotic and abiotic factors that influence plant metabolism. Light, temperature, and inorganic nutrients affect biochemical processes of organisms, and are considered as major factors controlling seagrass growth. Minimum light requirements for seagrass growth vary among species due to unique physiological and morphological adaptations of each species, and within species due to photo-acclimation to local light regimes. Seagrasses can enhance light harvesting efficiencies through photo-acclimation during low light conditions, and thus plants growing near their depth limit may have higher photosynthetic efficiencies. Annual temperatures, which are highly predictable in aquatic systems, play an important...

The bibliometric measure impact factor is a leading indicator of journal influence, and impact factors are routinely used in making decisions ranging from selecting journal subscriptions to allocating research funding to deciding tenure cases. Yet journal impact factors have increased gradually over time, and moreover impact factors vary widely across academic disciplines. Here we quantify inflation over time and differences across fields in impact factor scores and determine the sources of these differences. We find that the average number of citations in reference lists has increased gradually, and this is the predominant factor responsible for the inflation of impact factor scores over time. Field-specific variation in the fraction of citations to literature indexed by Thomson Scientific's Journal Citation Reports is the single greatest contributor to differences among the impact factors of journals in different fields. The growth rate of the scientific literature as a whole, and cross-field differences in...

ObjectivesTo describe growth patterns in infants with single ventricle physiology and determine factors influencing growth. Study designData from 230 subjects enrolled in the Pediatric Heart Network Infant Single Ventricle Enalapril Trial were used to assess factors influencing change in weight-for-age z-score (?z) from study enrollment (0.7 +- 0.4 months) to pre-superior cavopulmonary connection (SCPC; 5.1 +- 1.8 months, period 1) and pre-SCPC to final study visit (14.1 +- 0.9 months, period 2). Predictor variables included patient characteristics, feeding regimen, clinical center, and medical factors during neonatal (period 1) and SCPC hospitalizations (period 2). Univariate regression analysis was performed, followed by backward stepwise regression and bootstrapping reliability t...

Human adult mesenchymal stem cells (MSCs) support the engineering of functional tissue constructs by secreting angiogenic and cytoprotective factors, which act in a paracrine fashion to influence cell survival and vascularization. MSCs have been isolated from many different tissue sources, but little is known about how paracrine factor secretion varies between different MSC populations. We evaluated paracrine factor expression patterns in MSCs isolated from adipose tissue (ASCs), bone marrow (BMSCs), and dermal tissues [dermal sheath cells (DSCs) and dermal papilla cells (DPCs)]. Specifically, mRNA expression analysis identified insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor-D (VEGF-D), and interleukin-8 (IL-8) to be expressed at higher levels in ASCs compared wit...

Growth factor(s) present in a spent liquid medium after culture of the yeast form of Histoplasma capsulatum enhanced both yeast and mycelial growth of nine isolates tested. Hydroxamic acid extracted from the culture fluid displayed growth factor activity.

Progressive massive fibrosis (PMF) is a chronic interstitial lung disease with a complex aetiology that can occur after cumulative dust exposure. A case-control study was conducted to test the hypothesis that single nucleotide polymorphisms (SNPs) within genes involved in inflammatory and fibrotic processes modulate the risk of PMF development. The study population consisted of 648 underground coal miners participating in the National Coal Workers Autopsy Study, of which 304 were diagnosed with PMF SNPs that influence the regulation of interleukin (IL)-1, IL-6, tumour necrosis factor-alpha, transforming growth factor-beta 1, vascular endothelial growth factor (VEGF), epidermal growth factor intercellular cell adhesion molecule (ICAM)-1 and matrix metalloproteinase-2 genes were determined using a 5'-nuclease real-time PCR assay. There were no significant differences in the distribution of any individual SNP or haplotype between the PMF and control groups. However, the polygenotype of VEGF +405/ICAM-1 +241/IL-6 -174 (C-A-G) conferred an increased risk for PMF (odds ratio 3.4, 95% confidence interval 1.3-8.8). The present study suggests that the examined genetic variations that help regulate inflammatory and fibrotic processes are unlikely to strongly influence susceptibility to this interstitial lung disease, although the role of vascular endothelial growth factor, intercellular cell adhesion molecule-1 and interleukin-6 polymorphisms in the development of progressive massive fibrosis may require further investigation.

3-factor experiment was used to study the combined effects of temperature, irradiance and salinity on the growth of an HAB species diatom Skeletonema costatum (Grev.) Cleve. The results showed that temperature (12, 19, 25, 32 °C), irradiance (0.02, 0.08, 0.3, 1.6)×1016 quanta/(s·cm2)) and salinity (10, 18, 25, 30, 35) significantly influenced the growth of this species. There were interactive effects between any two of and among all three physical factors on the growth. In the experiment, the most optimal growth condition for S. costatum was temperature of 25°C, salinity of 18 35 and irradiance of 1.6×1016 quanta/(s·cm2). The results indicated S. costatum could divide at higher rate and were more likely to bloom under high temperature and high illumination from spring to fall. It was able to distribute widely in ocean and estuary due to its adaptation to a wide range of salinities.

We propose an environmental framework for simulation and visualization of woody plant forests. A complex application software system develops and animates a spontaneous afforestation process within this environment. The system considers several environmental properties and combines computer animation with artificial life. The main goal of the presented software system is to use it in computer animation for synthesis of natural environments and visual analysis of their natural look credibility. The afforestation process is modeled as an ecosystem simulation, where trees struggle for survival based on several growth factors. A detailed description of the procedures for simulating tree growth and the factors that might influence tree growth is provided. All the tree growth simulation procedur...

Thyroid status is known to influence growth in mammals. The aim of this study is to investigate the possible relationship between autoimmune subclinical hypothyroidism and growth hormone (GH), insulin-like growth factor-1(IGF-1) and insulin-like growth factor binding protein-3(IGFBP-3) levels. Thirty-five women with autoimmune subclinical hypothyroidism, 33 years of age, were used as controls and enrolled in the study. Free triiodothyronin (FT3), free thyroxin(FT4), thyrotropin(TSH), anti-thyroid peroxidase(Anti-TPO), anti-thyroglobuline(Anti-Tg), GH, IGF-1 and IGFBP-3 levels were measured in blood samples and correlations among these parameters were evaluated. We found no significant differences in GH, IGF-1 or IGFBP-3 between patients and controls. In patients and controls, there were no...

Abstract Natural glycosaminoglycans (GAGs) and chemically modified GAG derivatives are known to support osteogenic differentiation of mesenchymal stromal cells (MSC). This effect has mainly been described to be mediated by increasing the effectiveness of bone anabolic growth factors such as bone morphogenetic proteins (BMPs) due to the binding and presentation of the growth factor or by modulating its signal transduction pathway. In the present study, the influence of chondroitin sulfate (CS) and two chemically over-sulfated CS derivatives on osteogenic differentiation of human mesenchymal stromal cells (hMSC) and on BMP-2 and transforming growth factor 1 (TGF-1) signalling was investigated. Over-sulfated CS derivatives induced an increase of tissue non-specific alkaline phosphatase (TNAP)...

In bone tissue engineering, growth factors are widely used. Bone morphogenetic proteins (BMPs) and vascular endothelial growth factor (VEGF) are the most well-known regulators of osteogenesis and angiogenesis. We investigated whether the timing of dual release of VEGF and BMP-2 influences the amount of bone formation in a large-animal model. Poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) were loaded with BMP-2 or VEGF to create sustained-release profiles, and rapidly degrading gelatin was loaded with either growth factor for fast-release profiles. To study in vivo osteogenicity, the two delivery vehicles were combined with biphasic calcium phosphate (BCP) scaffolds and implanted in 10 Beagle dogs for 9 weeks, at both ectopic (paraspinal muscles) and orthotopic sites (critical-si...

The higher steam temperatures and pressures in advanced supercritical steam turbines require the use of steels with improved creep rupture strength. The tempered martensitic steel P92 is a creep resistant material used for the production of components for live steam with operating temperature 550-630 C. For the application of these steels is essentially necessary to know the impact of different test atmospheres and temperatures on the crack growth rate. In the present work, the influence of atmosphere (air, vacuum, simulated live steam), proof-temperature, hold time, thermal exposure on the crack growth has been studied at temperatures between 500 and 600 C. The influence of proof-temperature and atmosphere has been reflected on micrographs of fracture surface. SEM-micrographs of the principal crack and also optical micrographs coming from the cross sections perpendicular to the plane of a crack propagation (secondary cracks) show changes in the character of a crack propagation dependent of the loading cycle and temperature. By fatigue crack growth tests has been enhancement of crack growth due to the aggressive atmosphere (air) noted. The fatigue crack growth rates in air are at least one order of magnitude faster than those in vacuum (inert atmosphere). The effects of air, vacuum, simulated live steam on creep crack growth of P92 was also studied. A hold time leads to a higher crack growth rate compared with pure creep crack growth tests. The results from crack growth tests demonstrated, that steam oxidation plays a important role among the three factor, creep crack growth, fatigue crack growth and oxidation, in crack growth of these steel in superheated steam. In this work was also effect of side-grooves on the local stress and crack growth rate experimentally examined. (orig.)

Platelet concentrates for surgical use are tools of regenerative medicine designed for the local release of platelet growth factors into a surgical or wounded site, in order to stimulate tissue healing or regeneration. Leukocyte content and fibrin architecture are 2 key characteristics of all platelet concentrates and allow to classify these technologies in 4 families, but very little is known about the impact of these 2 parameters on the intrinsic biology of these products. In this demonstration, we highlight some outstanding differences in the growth factor and matrix protein release between 2 families of platelet concentrate: Pure Platelet-Rich Plasma (P-PRP, here the Anitua's PRGF - Preparation Rich in Growth Factors - technique) and Leukocyte- and Platelet-Rich Fibrin (L-PRF, here the Choukroun's method). These 2 families are the extreme opposites in terms of fibrin architecture and leukocyte content. The slow release of 3 key growth factors (Transforming Growth Factor ?1 (TGF?1), Platelet-Derived Growth Factor AB (PDGF-AB) and Vascular Endothelial Growth Factor (VEGF)) and matrix proteins (fibronectin, vitronectin and thrombospondin-1) from the L-PRF and P-PRP gel membranes in culture medium is described and discussed. During 7 days, the L-PRF membranes slowly release significantly larger amounts of all these molecules than the P-PRP gel membranes, and the 2 products display different release patterns. In both platelet concentrates, vitronectin is the sole molecule to be released almost completely after only 4 hours, suggesting that this molecule is not trapped in the fibrin matrix and not produced by the leukocytes. Moreover the P-PRP gel membranes completely dissolve in the culture medium after less than 5 days only, while the L-PRF membranes are still intact after 7 days. This simple demonstration shows that the polymerization and final architecture of the fibrin matrix considerably influence the strength and the growth factor trapping/release potential of the membrane. It also suggests that the leukocyte populations have a strong influence on the release of some growth factors, particularly TGF?1. Finally, the various platelet concentrates present very different biological characteristics, and an accurate definition and characterization of the different families of product is a key issue for a better understanding and comparison of the reported clinical effects of these surgical adjuvants. PMID:21740377

Colorectal cancer arises in individuals with acquired or inherited genetic predisposition who are exposed to a range of risk factors. Many of these risk factors are associated with affluent Western societies. More than 95% of colorectal cancers are sporadic, arising in individuals without a significant hereditary risk. Geographic variation in the incidence of colorectal cancer is considerable with a higher incidence observed in the West. Environmental factors contribute substantially to this variation. A number of these risk factors are associated with a Western lifestyle and could be considered a product of 'civilization'. Recently, smoking has been recognized as a risk factor. Energy consumption also influences colorectal cancer risk, with obesity increasing risk and exercise reducing risk. However, the strongest contribution to environmental risk for colorectal cancer is dietary. Consumption of fat, alcohol and red meat is associated with an increased risk. Fresh fruit and vegetables and dietary fibre may be protective. Much has been learnt recently about the molecular pathogenesis of colorectal cancer. Colorectal cancer always arises in the context of genomic instability. There is inactivation of the tumour suppressor genes adenomatous polyposis coli, p53, transforming growth factor-?, activation of oncogene pathways including K-ras, and activation of the cyclooxygenase-2, epidermal growth factor receptor and vascular endothelial growth factor pathways. The mechanisms by which some environmental factors modify the mutation risk in these pathways have been described. PMID:21734388

Angiogenesis is controlled by a balance between stimulators and inhibitors. We propose that the balance, as well as the general sensitivity of the endothelium to these factors, varies from individual to individual. Indeed, we have found that individual mouse strains have dramatically different responses to growth factor-induced neovascularization. Quantitative trait loci (QTLs), which influence the extent of corneal angiogenesis induced by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF2), were previously identified by our laboratory. To investigate the genetic contribution to choroidal neovascularization (CNV), a leading cause of blindness, we have undertaken a similar mapping approach to identify QTLs that influence laser-induced CNV in the BXD series of recombinant inbred mouse strains. Composite interval mapping identified new angiogenic QTLs on chromosomes 2 and 19, in addition to confirming our previous corneal neovascularization QTLs of AngVq1 and AngFq2. The new QTLs are named AngCNVq1 and AngCNVq2. The newly mapped regions contain several candidate genes involved in the angiogenic process, including thrombospondin 1, delta-like 4, BclII modifying factor, phospholipase C, beta 2, adrenergic receptor, beta 1, actin-binding LIM protein 1 and colony stimulating factor 2 receptor, alpha. Differences in these regions may control individual susceptibility to CNV. PMID:19237505

Measuring the concentration of growth hormone (GH) in blood samples taken during dynamic tests represents the basis for diagnosis of growth hormone related disorders, namely growth hormone deficiency and growth hormone excess. Today, a wide spectrum of immunoassays are in use, enabling rapid and sensitive determination of growth hormone concentrations in routine diagnostics. From a clinical point of view several difficulties exist with the use and interpretation of GH assay results in the assessment of GH related disorders: Many physiological factors such as fat mass, age and gender influence the outcome of dynamic tests, overall leading to significant inter-individual differences in GH responses. However, in addition to the physiological variability, considerable variability exists in GH ...

The topical application of recombinant growth factors such as epidermal growth factor, platelet-derived growth factor-BB homodimer (rPDGF-BB), keratinocyte growth factor (rKGF), and neu differentiation factor has resulted in significant acceleration of healing in several animal models of wound repai...

Recent research using model organisms such as the nematode Caenorhabditis elegans has highlighted a crucial role for several conserved signaling pathways in longevity determination. Here, we review three major endocrine- and nutrient-sensing signaling pathways with influence on lifespan, the insulin/insulin-like growth factor (IGF), target of rapamycin (TOR), and germline signaling pathways. Although these pathways engage distinct sets of transcription factors, the three pathways appear to modulate aging in C. elegans through partially overlapping effector mechanisms, including lipid metabolism and autophagy. This review highlights the latest advances in our understanding of how the insulin/IGF-1, TOR, and germline signaling pathways utilize different transcription factors to modulate agin...

The progression of melanoma toward the metastatic phenotype occurs in a defined stepwise manner. While many molecular changes take place early in melanoma development, progression toward the malignant phenotype, most notably during the transition from the radial growth phase (RGP) to the vertical growth phase (VGP) involves deregulated expression of several transcription factors. For example, the switch from RGP to VGP is associated with the loss of the transcription factor AP2? and gain of transcriptional activity of cAMP-responsive element binding protein. Together with the upregulation of microphthalmia-associated transcription factor, activating transcription factor 2, nuclear factor kappa B, and other transcription factors, these changes lead to dysregulated expression or function of important cellular adhesion molecules, matrix degrading enzymes, survival factors, as well as other factors leading to metastatic melanoma. Additionally, recent evidence suggests that microRNAs and RNA editing machinery influence the expression of transcription factors or are regulated themselves by transcription factors. Many of the downstream signaling molecules regulated by transcription factors, such as protease activated receptor-1, interleukin-8, and MCAM/MUC18 represent new treatment prospects. PMID:22684365

The growth of three tree species (Alnus glutinosa, Betula spp. and Quercus spp.) was related to soil factors on two restored opencast coal sites in South Wales, UK. The main factors favouring tree growth were greater soil depth and organic content. Factors limiting growth included poor site drainage and high magnesium levels. Whilst all species were related to most of the above factors, soil depth was of particular importance for Alnus glutinosa and Betula spp., whilst site drainage had the greatest influence for Betula spp. Soil-tree associations tended to be closer on the older of the two sites. Combinations of soil depth, percentage clay and percentage organic content in a multiple regression predicted around 40% of the growth variation in Alnus glutinosa, between 6.9 and 32% of that for Betula spp. and between 14.5 and 32.6% of that for Quercus spp. Growth prediction for Betula spp. improved to 40.9 and 34.8% when a site drainage factor was included in the regression. The development of such predictive relationships might contribute to the planning of site reinstatement for tree planting after opencast mining, and to a better `matching` of tree species to site characteristics.

Angiogenesis is a complex process controlled by the balance of a large number of regulating factors, the pro- and anti-angiogenic factors. Dysregulation of angiogenesis occurs in various pathologies and is one of the hallmarks for cancer. Recent emphasis on the microenvironment's influence in chronic lymphocytic leukemia (CLL) progression and drug resistance nurtures the interest in angiogenesis. Researchers have already identified a variety of angiogenic factors involved in the CLL, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), angiopoietin-2(Ang-2), thrombospondin-1 (TSP-1), as well as extracellular proteinases such as matrix metalloproteinase-9 (MMP-9). Besides modulating neovascularization, angiogenic factors also participate in the regulation of pro-survival effects of CLL cells. However, the precise mechanism involved still needs to be elucidated further. At present, the levels of some angiogenic factors are regarded as prognostic markers of the progression of CLL, although it is not widely used. Several anti-VEGF agents are currently under clinical trial. Advances in the understanding of the bases of angiogenesis regulators will be benefit for the comprehension of CLL pathogenesis and help to conquer the disease. PMID:22727510

The two-dimensional intergranular stress corrosion cracking (IGSCC) growth model has been developed to simulate branching cracks of IGSCC. In the model, the IGSCC is grown using the "grain-scaled" factors such as the length and strength of grain boundary and so on. Especially, the corrosion of grain boundary and the influence of shear stress acting on the grain boundary are introduced in the model. Using the model, computer simulation of crack growth was carried out under several load conditions with changing the ratio of axial to shear stress against the grain boundary. As a result of the simulations, we found out that the cause of crack branching was the influence of shear stress against the grain boundary, and that the synergistic effect of shear stress and corrosion of grain boundary leads to the oblique crack growth.   

CaCO3 crystals' physical properties, such as polymorphism and hence the reflectivity and stability, are critical factors of their qualities in industrial applications. Factors such as additives and substrates that influence CaCO3 polymorphism have been intensively studied. However, the effects of ionic strength created by varying additives are seldom paid attention to. This study is analyzing how ionic strength of the growth solution influences the crystalline structure of CaCO3, by applying growth solutions containing different types of cations of varying concentrations, K+, Na+, and NH4+. This study reveals that the ionic strength plays a significant role in polymorph selection in the way that the percentage of vaterite among the precipitates increases with the concentration of ionic strength.

In the present study, the abattoir digestate was used as a culture medium for Spongiochloris sp. growth with added mineral components under optimized conditions in batch culture. Firstly, an Hadamard matrix was used to investigate the impact of certain influencing factors on the Spongiochloris sp. growth. Then, a fractional factorial design 2(7-4) was successfully employed to optimize the concentration of different added components to abattoir digestate for increased Spongiochloris sp. biomass production. The major influencing factors were NaHCO(3) and FeSO(4) at a level of 2000 mg/L and 5mg/L, respectively. A high biomass production of 5.29 × 10(6) cell/mL and an important content of chlorophyll a of 65.32 mg/L were obtained after 42 days of culture of Spongiochloris sp. on the defined abattoir medium at static conditions. PMID:21177100

In global climate change, the most important ecological factors influencing agricultural production and agro-ecosystem are elevated atmospheric CO2 concentration, enhanced air temperature, and changed precipitation, which mainly exert on crop output, crop growth, diseases and pests, agricultural water resources, and structure and function of agro-ecosystem. In past decades, global climate change already made great influences on our agriculture and agro-ecosystem, especially the agricultural production in arid regions of North China, and many of the influences were negative or adverse. This paper summarized the impact of global climate change on agricultural water resources, soil nutrients, crop growth and development, diseases and pests, weeds, food safety, and structure and function of agro-ecosystem. Aiming at the challenges brought about by the global climate change to the agricultural production and agro-ecosystem in China in 21st century, the key points and difficulties in future research were put forward. PMID:17974260

Human adult mesenchymal stem cells (MSCs) support the engineering of functional tissue constructs by secreting angiogenic and cytoprotective factors, which act in a paracrine fashion to influence cell survival and vascularization. MSCs have been isolated from many different tissue sources, but little is known about how paracrine factor secretion varies between different MSC populations. We evaluated paracrine factor expression patterns in MSCs isolated from adipose tissue (ASCs), bone marrow (BMSCs), and dermal tissues [dermal sheath cells (DSCs) and dermal papilla cells (DPCs)]. Specifically, mRNA expression analysis identified insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor-D (VEGF-D), and interleukin-8 (IL-8) to be expressed at higher levels in ASCs compared with other MSC populations whereas VEGF-A, angiogenin, basic fibroblast growth factor (bFGF), and nerve growth factor (NGF) were expressed at comparable levels among the MSC populations examined. Analysis of conditioned media (CM) protein confirmed the comparable level of angiogenin and VEGF-A secretion in all MSC populations and showed that DSCs and DPCs produced significantly higher concentrations of leptin. Functional assays examining in vitro angiogenic paracrine activity showed that incubation of endothelial cells in ASC(CM) resulted in increased tubulogenic efficiency compared with that observed in DPC(CM). Using neutralizing antibodies we concluded that VEGF-A and VEGF-D were 2 of the major growth factors secreted by ASCs that supported endothelial tubulogenesis. The variation in paracrine factors of different MSC populations contributes to different levels of angiogenic activity and ASCs maybe preferred over other MSC populations for augmenting therapeutic approaches dependent upon angiogenesis. PMID:22188562

A study has been undertaken to identify the microbiological and environmental factors which influence the formation of hydrogen sulfide in oily-water wastes in ships of the Royal Australian Navy (RAN). In particular, methods were developed for isolation and enumeration of sulfate-reducing bacteria which produce the hydrogen sulfide in the waste. These methods were then used to find the important environmental features which contribute to the growth and metabolism of these bacteria.

Transforming growth factor-? (TGF-?) influences the development of myocardiopathy in Chagas disease through regulation of (i) parasite invasion of heart cells, (ii) an intracellular parasite cycle, (iii) inflammation and immune response, (iv) heart fibrosis and remodeling, and (v) gap junction modulation and heart conduction. In this review, we discuss the rationale for developing TGF-? signaling–interfering therapies as adjuvant approaches for the management of the cardiac alterations of Chagas disease-affected patients.

This article analyzes the influences of family background and institutional factors on the acquisition of education (1940-2001) and demonstrates that the increase or decrease in the inequality of educational opportunity allocations are closely linked to the government's relevant policies. The rapid growth of the inequality in educational opportunities in the recent ten or so years is, to a large extent, the outcome of government policies. Therefore, the inequality in the distribution of educational opportunities may be increasing. (Contains 1 note.)

Fresh waters rich in nutrients often show mass development of cyanobacteria. The kind of cyanobacteria to be found depends on the properties of the lake. In non-stratified shallow lakes, the most common species Oscillatoria agardhii. In stratified lakes, cyanobacteria can be found in restricted zones of the deeper part of the lakes, and always possess cells with very active gas vacuoles. The most common species are Microcystis aeruginosa, Oscillatoria agardhii var isothrix, Oscillatoria "var red" and different Anabaena species. In lakes with prolonged nitrogen limitation, genera such as Anabaena and Aphanizomenon are common. Two important factors determine the distribution of these organisms: the light climate and the availability of nutrients. We have limited our discussion in this paper to the influence of the light climate. This influence of the light climate on growth can be determined in different ways. The influence of light intensity on the growth rate of Oscillatoria agardhii can be described using a Monod-like relation with light inhibition at light intensities above 40 W m-2. Studies with other species of cyanobacteria like Microcystis aeruginosa and Aphanizomenon flos-aquae support the assumption that most cyanobacteria living in fresh water are extremely sensitive to high light intensities. The energy balance of phototrophic growth can be described by the equation mu = qE . c - mue where mu is the specific growth rate, mue the specific maintenance energy rate and qE the specific light energy uptake rate; c represents the growth efficiency factor with which light energy is converted into cell material. In this equation, there are two factors which determine the growth of the organisms: ue and c. It was found that the value of mue of Oscillatoria was extremely low (mue approximately 0.001 h-1) compared with a eukaryotic organism (Scenedesmus: mue 0.008 h-1). The value of c was found to be dependent on the growth rate, but did not greatly differ from values found in eukaryotic algal cells. Data obtained from cultures of Oscillatoria grown under light-dark cycles, so that total energy input over 24 h was growth-limiting, showed good regulation of both the carbohydrate synthesis rate and the growth rate. In comparing the data of light-limited growth of cyanobacteria, the conclusion can be drawn that these organisms are favoured at low light intensities by their low specific maintenance energy rate and their pigment composition. A number of competition experiments support the conclusion that the light climate is the most important steering factor for the distribution of cyanobacteria in fresh waters. PMID:6416128

We have examined the effects of in vitro aging on the growth capacity of human umbilical vein endothelial cells (HUVECs) under the influence of tumor necrosis factor (TNF) with or without interferon-gamma (IFN-gamma). The growth and colony-forming abilities of control cells were impaired with advancing age in vitro, especially at later stages (more than 70-80% of life span completed). It was found that treatment with TNF inhibited growth and colony-forming efficiency at any in vitro age. The effects of TNF were shown to increase with increasing in vitro age, as reflected by a more pronounced increase in doubling times, a decrease in saturation density, and a reduction in colony-forming efficiency. However, the characteristics of TNF receptors, including the dissociation constant, and the number of TNF-binding sites per cell-surface area remained rather constant. The effect of TNF was augmented by IFN-gamma at a dose that alone affected growth and colony formation only slightly. The augmentation by IFN-gamma was also found to depend on in vitro age; the synergy with TNF in the deterioration of colony-forming ability was observed only in aged cells. These results suggest that the intrinsic responsiveness of HUVECs to growth-inhibiting factors, as well as to growth-stimulating factors, changes during aging in vitro.

Abstract In order to study the effects of soil factors and bacterial inoculation on alfalfa (Medicago sativa), plants were inoculated with Ensifer meliloti L33 and Azospirillum brasilense Sp7 in pot experiments using two different soils separately as well as in a mixture. One soil was contaminated with chemical waste products; the other was an arable soil. Soil factors, including the availability of macro- and micronutrients as well as carbon and nitrogen contents, were found to exhibit a much greater influence on the growth of alfalfa than any of the inoculations. In contaminated soil, the shoot and root growth of alfalfa was decreased and nodules were diminished and ineffective. Bacterial inoculations did not significantly improve this hostile growth environment. However, in a mixture (4...

Tree ring analysis investigates growth processes at time horizons of several weeks to millennia, but lacks the detail of short-term fluctuation in cambial activity. This study used electronic high-precision dendrometry for analyzing the environmental factors controlling stem diameter variation and radial growth in daily resolution in five co-existing temperate broad-leaved tree species (genera Fraxinus, Acer, Carpinus, Tilia and Fagus) with different growth and survival strategies. Daily stem radius change (SRCd) was primarily influenced by the atmospheric demand for water vapor (expressed either as vapor pressure deficit (D) or relative air humidity (RH)) while rainfall, soil matrix potential, temperature and radiation were only secondary factors. SRCd increased linearly with increasing R...

Climate change could alter the biogeography of many tree species. However, there have been few studies of tree growth across climatic gradients at a continental scale. Callitris columellaris is a widespread conifer that spans many climates and landscape positions across Australia. Our aim was to determine how stem radial growth of C. columellaris varies with tree size and with the biogeographic factors of rainfall, temperature, soil fertility and inter-tree competition. We sampled cores from trees at 85 sites in biomes ranging from tropical savanna to arid desert and temperate forest, and measured widths of the 100 outermost growth rings. We analysed ring width in relation to changes in tree age and diameter, and also evaluated the influence of the biogeographic factors on the width of the...

Abnormal grain growth in austenite is a well known but relatively poorly understood phenomenon. It often takes place quite erratically, its quantification is difficult and it can cause significant losses in ductility and toughness in the final product. Since 1987 a series of studies have been carried out regarding the influence of several factors upon abnormal grain growth as well as its rigorous characterization. The main results obtained so far are presented and discussed, and also relating to other works in the field. (author). 30 refs., 4 figs., 1 tab.

A study of two beech stands of fairly similar soil formations is presented, revealing that distribution patterns of living and dead fine roots follow acidification variables in soil solution. An evaluation of the data collected shows a fairly close relationship between leaf cover and the amount of living fine roots. The assimilate supply of roots turned out to be no limiting factor for undisturbed root growth. It seems that the actual chemical state of the soil has evident influence not only on root growth but also on the stability of the whole forest ecosystem.

We provide a test of the thesis that Protestantism influenced the development of modern capitalism by using quantitative data from 1500 through 1870. Results show that during this period the percentage of a country's population that is Protestant is unrelated to both its level of per capita GDP and the average rate of its annual growth in per capita GDP. We conclude that the thesis that the Protestant ethic has been an important factor in the growth of modern capitalism is not supported. (Contains 1 figure, 2 tables, and 1 note.)

Abstract in spanish Se presentan las características del crecimiento normal del niño y del adolescente, precisando los factores que influyen en él, las características del fenómeno de sobre aceleración del crecimiento con especial referencia al que se produce después que actúa una noxa que frena el crecimiento y a la tendencia secular del crecimiento tanto en Chile como en otras partes del mundo. Se explica la importancia de las mediciones antropométricas para la evaluación del cre (more) cimiento y desarrollo. Se define el retraso de crecimiento, las técnicas para diagnosticarlo y las múltiples etiologías que lo pueden producir Abstract in english Characteristics of growth in children and adolescents are described. Factors that influence growth, characteristics of catch up growth fenomena, specially the one produced after a noxa that decrease growth velocity, and secular trend of growth in Chile and other countries are presented. The importance of anthropometric measurements for the evaluation of growth and development is described, as well as the definition of growth failure, the tools for their diagnosis and the multiple etiologies of it, are described

During bone growth, development, and remodeling, angiogenesis as well as osteogenesis are closely associated processes, sharing some essential mediators. Vascular endothelial growth factor (VEGF) was initially recognized as the best-characterized endothelial-specific growth factor, which increased v...

During liver regeneration, quiescent hepatocytes re-enter the cell cycle to proliferate and compensate for lost tissue. Multiple signals including hepatocyte growth factor, epidermal growth factor, tumor necrosis factor ?, interleukin-6, insulin and transforming growth factor ? orchestrate these responses and are integrated during the G(1) phase of the cell cycle. To investigate how these inputs influence DNA synthesis as a measure for proliferation, we established a large-scale integrated logical model connecting multiple signaling pathways and the cell cycle. We constructed our model based upon established literature knowledge, and successively improved and validated its structure using hepatocyte-specific literature as well as experimental DNA synthesis data. Model analyses showed that activation of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways was sufficient and necessary for triggering DNA synthesis. In addition, we identified key species in these pathways that mediate DNA replication. Our model predicted oncogenic mutations that were compared with the COSMIC database, and proposed intervention targets to block hepatocyte growth factor-induced DNA synthesis, which we validated experimentally. Our integrative approach demonstrates that, despite the complexity and size of the underlying interlaced network, logical modeling enables an integrative understanding of signaling-controlled proliferation at the cellular level, and thus can provide intervention strategies for distinct perturbation scenarios at various regulatory levels. PMID:22443451

Abstract Background Human nail clippings are increasingly used in epidemiological studies as biomarkers for assessing diet and environmental exposure to trace elements or other chemical compounds. However, little is known about the growth rate of human nails. Objective To estimate the average growth rate of fingernails and toenails and examine factors that may influence nail growth rate. Methods Twenty-two healthy American young adults marked their nails close to the proximal nail fold with a provided nail file following a standardized protocol, and recorded the date and the distance from the proximal nail fold to the mark. One to three months later, participants recorded the date and distance from the proximal nail fold to the mark again. Nail growth rate was calculated based on recorded ...

Some of the factors influencing the propagation of caper (Capparis spinosa L.) plants in vitro and germination of the seed were studied. The number of adventitious shoots emerging from caper stems cultured in vitro increased from 2.2 shoots per explant when the growth medium contained 2mg/L of gibberellic acid (GA3) to 5.5 when the growth medium contained 2mg/L zeatin riboside (ZR) and 1mg/L naphthalene acetic acid (NAA). The best medium for callus formation from leaf and stem parts contained the growth regulators 1mg/L 6-benzylaminopurine (BAP) and 0.1mg/L NAA and the best medium for plant regeneration contained 1mg/L kinetin and 0.1mg/L indole-3-acetic acid (IAA). The effect of gamma irradiation on the growth of caper shoots in vitro was also studied. A 10Gy dose of gamma irradiation sti...

Understanding the factors that influence the growth and final shape of noble metal nanostructures is important for controlling their properties. However, relative to their single-crystalline counterparts, the growth of nanoparticles that contain twin defects can be difficult to control because multiple competitive growth pathways can yield such structures. We used spherical, cubic, and octahedral single-crystalline gold nanoparticles as dual electron microscopy labels and plasmonic seeds to track the growth of multiply twinned silver nanostructures. As the bimetallic nanostructures grew, they successively developed twin planes to ultimately form multiply twinned nanoparticles from single-crystalline seeds. Collectively, these data demonstrate how a series of nanoparticles of different shapes and internal crystal structures are interrelated and develop from one another.

The literature contains a substantial amount of information about factors that adversely influence the linear growth in up to 85% of patients undergoing haematopoietic SCT (HSCT) with TBI and/or cranial irradiation (CI) for acute leukaemia (AL). By contrast, only a few studies have evaluated the impact of growth hormone (GH) therapy on growth rate and final height (FH) in these children. We evaluated growth rates during the pre- and post-transplant periods to FH in a group of 25 children treated with HSCT (n=22), TBI (n=21) or/and CI (n=8) for AL and receiving GH therapy. At the start of GH treatment, the median height Z-score was ?2.19 (?3.95 to 0.02), significantly lower than at AL diagnosis (P<0.001). Overall height gain from start of GH treatment to FH was 0.59Z (?2.7...

There is a lack of information on plant response to multifactor environmental variability including the interactive response to temperature and atmospheric humidity. These two factors are almost always confounded because saturated vapor pressure increases exponentially with temperature, and vapor pressure deficit (VPD) could have a large impact on plant growth. In this study using climate controlled mini-greenhouses, we examined the interacting influence of temperature and VPD on long-term growth of tall fescue (Festuca arundinacea Schreb), a cool season grass. From past studies it was expected that growth of tall fescue would decline with warmer temperatures over the range of 18.5?27?C, but growth actually increased markedly with increasing temperature when VPD was held constant. In contr...

Samples of uterine myometrium and leiomyoma from 11 women were analyzed for the presence of epidermal growth factor receptors and insulin-like growth factor I receptors. In addition, the content of soluble insulin-like growth factor binding protein (IGF-BP/PP12) was measured in the tissue cytosols. Cell membrane preparations of myoma tissue bound significantly more insulin-like growth factor I than did those of adjacent normal myometrium, whereas myoma tissue bound less epidermal growth factor than did the normal myometrium. The differences in both insulin-like growth factor I and epidermal growth factor binding were due to changes in receptor concentration rather than to alterations in receptor affinity. Neither myoma nor myometrial tissue contained detectable levels of insulin-like growth factor binding protein. The changes in epidermal growth factor and insulin-like growth factor I binding to the myometrium may play a role in the pathogenesis of uterine leiomyomata.

The features of Korean higher education development are related to sociocultural tradition (Confucian tradition), the model university ideas, and economic development in Korea. The modern university ideas adopted in Korean are based on the German model which was established by the Japanese colonial government and drawing on the US university model after the World War II. However, the modern university ideas are intertwined with socio-cultural factors and have been embedded in current Korean universities. As well as the western ideas and the Confucian tradition, the growth of Korean higher education has relied upon the rapid growth of the Korean economy. Education development is well aligned with economic development in Korea thanks to government policy initiatives. This framework can be applied in the analysis of higher education development in other countries. Higher education development cannot be solely explained by individual cultural, historical or economic factor. These three factors are interlinked and influence the development of Korean higher education.

Early in the work on this grant the authors established that the growth factor-dependence of radiation-induced thymic leukemia cells was dependent on the autocrine/paracrine growth factor IL-4. Localized, thymic leukemias always grew by virtue of an IL-4-driven autocrine/paracrine pathway. They continued and investigated the mechanism of progression of the thymic leukemias to the later, disseminate disease. Linking the generation of disseminated leukemias to their growth factor-dependent status [10,11], they found that the development of growth factor-independence was associated with the dissemination of the leukemia from the thymus to other sites, e.g. spleen, lymphnodes, liver and kidney [9,8]. Indeed, all disseminated leukemias were composed of growth factor-independent cells. The generation of disseminated radiation-induced leukemia is associated with the loss of specific differentiation antigens and the mutation of the p53 tumor suppressor gene. The thymic, growth factor-independent leukemia carried non-mutated, wild type p53 [4]. These results suggested that it might be possible to influence the dissemination [6,7] of leukemia cell propagation in vivo by the re-introduction of wild type p53 into the leukemias cells. They could show that the transduction of genes encoding specific mutant p53 proteins enhanced their dissemination potential and, in addition, the transduction of constructs encoding wild type p53 reversed the disseminated phenotype--and the leukemic phenotype--of murine and human acute leukemia cells. As a result of the DOE grant, and to further study the gene-transduction approach for the inhibition of leukemia and other cancer cells, they developed an acute retroviral gene transfer system that was capable of the rapid generation of high-titer retroviral virions that were non-mutated and non-deleted [12]. This system has been supplied to dozens of laboratories in the country and is widely used in many research laboratories.

The factors influencing somatic embryo maturation, high frequency somatic embryo germination, and plantlet formation were studied in Terminalia chebula Retz. Maturation of somatic embryo were influenced by a number of factors such as in vitro culture passage, concentrations of sucrose, levels of abscisic acid (ABA), basal media and media additive combinations. Maximum frequency of somatic embryo maturation (57.22???2.02), was obtained on MS medium supplemented with 50?g/l sucrose. Different factors such as strengths of MS nutrients, plant growth regulators, media additives and their combinations controlling somatic embryo germination and plantlet formation were studied. High frequency of germination and plantlet formation (58.80???1.47) were achieved by subsequent subculture of mature soma...

This paper reports the use of a GIS based Probabilistic Certainty Factor method to assess the geo-environmental factors that contribute to landslide susceptibility in Tevankarai Ar sub-watershed, Kodaikkanal. Landslide occurrences are a common phenomenon in the Tevankarai Ar sub-watershed, Kodaikkanal owing to rugged terrain at high altitude, high frequency of intense rainfall and rapidly expanding urban growth. The spatial database of the factors influencing landslides are compiled primarily from topographical maps, aerial photographs and satellite images. They are relief, slope, aspect, curvature, weathering, soil, land use, proximity to road and proximity to drainage. Certainty Factor Approach is used to study the interaction between the factors and the landslide, highlighting the impor...

Responses of Douglas-fir seedlings were studied for 3 yr following eight vegetation-control treatments in three western Oregon clearcuts. The objectives were to determine seedling growth response to different areas of spot vegetation control and to determine the relative influence of early woody and herbaceous competition on seedling growth. Herbicide treatment areas varied in size from those receiving no control to full control. Controlled areas were maintained free of herbaceous vegetation for 2 yr and all woody vegetation was controlled for 3 yr. Two additional treatments, complete control of woody vegetation only and complete control of herbaceous vegetation only, were also examined. On two sites (Summit and Marcola), seedling growth parameters were maximized at or near full vegetation control with a tree spacing of 3 m x 3 m. On the third site (Pedee), maximum growth response occurred between 5 and 6 m[sup 2] of control. Herbaceous vegetation control resulted in increased seedling growth at all sites while woody vegetation control yielded increased seedling growth only at the Pedee site. Cumulative 3 yr herbaceous cover accounted for 68% and 41% of the variability in stem volume at Summit and Marcola, respectively. Adding cumulative 3 yr woody cover to the model accounted for an additional 18% and 48% of the variability in stem volume at Summit and Marcola, respectively. At Pedee, neither herbaceous nor woody cover significantly influenced 3 yr stem volume, suggesting that factors other than vegetation cover were responsible for differences measured.

Based on research results on the impacts of solar light, seawater temperature, and nutrient available to phytoplankton growth and changes in phytoplankton physiology and assemblage, we discussed the order of influence of these factors. By clarifying the mechanisms and processes of the impacts by these factors, we have determined the rising order of the importance as solar light, seawater temperature, and nutrient silicon (Si). Therefore, for human interests in sustaining economic development, the first thing to be considered is the input of nutrient Si into the ocean, followed by seawater temperature change.

The protocols for clinical evaluation and management of children with complex craniosynostoses are significantly different from those used in single suture forms. The time at which the various anatomical and functional anomalies observed in the affected subjects become clinically relevant varies from patient to patient, consequently requiring a tailored approach. The clinical course is variable and influenced by multiple factors, acting at different steps of the children growth. Intracranial hypertension is a major concern already in the first months of life; active cerebrospinal fluid (CSF) dynamics disorders, venous hypertension, and progressive craniocerebral disproportion are considered the main pathogenetic factors. Cranial vault and skull base sutures synostoses account for the frequ...

The importance of SMEs for economic growth and employment has long been recognised, although the entrepreneurial activity in SMEs has not been understood all that well. In the light of this, a better understanding of entrepreneurs and their local environment might be helpful, since these are usually key factors in the discovery and exploitation of new opportunities. In order to research this situation into more details, a framework taking into account aspects of social, human and financial capita has been developed. Therefore, the purpose of this paper is to address the influence of these factors on the entrepreneurial process in technology based new ventures.

Formerly regarded purely as passive energy storage, adipose tissue is now recognized as a vital endocrine organ. Adipocytes secrete diverse peptide hormones named adipokines, which act in a autocrine, paracrine or endocrine way to influence several biological functions. Adipokines comprise diverse bioactive substances, including cytokines, growth, and complement factors, which perform essential regulatory functions related to energy balance, satiety and immunity. Presently adipokines have been widely implicated in obesity, diabetes, hypertension and cardiovascular diseases. In this article we aim to present a brief description of the roles and potential therapeutic modulation of adipokines, such as leptin, resistin, adiponectin, apelin, visfatin, FABP-4, tumor necrosis factor-a (TNF-a), in...

BACKGROUND: Anti-mullerian hormone (AMH) is a glycoprotein of the transforming growth factor-? superfamily secreted by male Sertoli cells and female ovarian granulosa cells. This study determined squirrel monkey AMH levels as influenced by gender and seasonality. METHODS: Squirrel monkey sera AMH were measured by an enzymatically amplified two-site immunoassay. RESULTS: A significant difference (P squirrel monkeys (mean = 22.12 ng/ml). A significant difference (P squirrel monkeys are the highest in any primate species reported, whereas in the male, levels are within reported ranges. The AMH assay may allow us soon to assess the squirrel monkey fertility potential as a function of various factors. PMID:23082826

Strontium to calcium ratios (Sr/Ca) are reported for a massive brain coral Diploria labyrinthiformis collected from the south shore of Bermuda and are strongly correlated with both sea surface temperature (SST) and mean annual skeletal growth rate. High Sr/Ca ratios correspond with cold SSTs and slow skeletal growth rate and vice versa. We provide a quantitative calibration of Sr/Ca to extension rate and SST along the axis of maximum growth and derive a growth-dependent Sr/Ca-SST calibration equation to reconstruct western subtropical North Atlantic SSTs for the past 223 years. When the influence of growth rate is excluded from the calibration, Sr/Ca ratios yield SSTs that are too cold during cool anomalies and too warm during warm anomalies. Toward the end of the Little Ice Age (~1850), SST changes derived using a calibration that is not growth-dependent are exaggerated by a factor of 2 relative to those from the growth-corrected model that yields SSTs ~1.5°C cooler than today. Our results indicate that incorporation of growth rate effects into coral Sr/Ca calibrations may improve the accuracy of SSTs derived from living and fossil corals.

... Also some issues about possibly other factors: insulin growth factors. We see that women with polycystic ovary ... they have more insulin and it is a growth factor that causes problems with them. So the ...

Is bacterial growth always exponential? Do bacteria with the fastest rate of growth always have the largest populations? Biota models offer extended opportunities to observe population growth over time. What are the factors that affect growth? Explore continuous, chaotic, and cyclic growth models. * examine the dynamics of growth for populations of virtual bacteria with differing growth rates and carrying capacities

Marine calcifiers, such as planktonic foraminifera, form a major component of the global carbon cycle, acting as both a source and sink of CO2. Understanding factors that affect calcification in these organisms is therefore critical in predicting how the oceans will respond to increased CO2 concentrations in the atmosphere. Here, size-normalised weights (SNWs) of the planktonic foraminifera Globigerina bulloides, collected from the surface waters of the North Atlantic Ocean, are compared with in situ carbonate ion concentrations ([CO32-]), sea-surface temperature, optimum growth conditions and nutrient concentrations. Changes in phosphate concentrations ([PO43-], range: 0.04-0.39 ?M) explained the majority of G. bulloides SNW variation, with reduced test masses at higher concentrations. Two factors already known to influence calcification in foraminifers, [CO32-] and temperature, were also positively correlated over the range of values examined (148-181 ?M kg-1 and 10.3-12.7 °C respectively). No evidence was found for increased SNWs under apparent optimum growth conditions, indicated by G. bulloides abundances. However, "growth potentials" (?), derived from modelled growth rates (d-1), were positively correlated with SNWs, suggesting that this may be a better proxy for optimum growth conditions. These findings point to the potential importance of [PO43-] in determining calcification intensities in foraminifera, a factor which has been overlooked by previous studies on these organisms. The confirmation of this via carefully controlled culture studies is recommended in the future.

We evaluated the relationship between TN:TP ratio and Microcystis growth via a database that includes worldwide lakes based on four types of lake origin (dammed, tectonic, coastal, and volcanic lakes). We used microcosm and mesocosm for the nutrient elution tests with lake water and four kinds of sediment (nontreated, MgO sprinkling treated, dissolved air flotation [DAF] treated, and combined treated sediment) in order to control TN:TP ratio and to suppress Microcystis growth. Microcystis growth was related to TN:TP ratio, with the maximum value at an optimum TN:TP ratio and the minimum values when the TN:TP ratios reached to 0 or "V. The kurtosis of the distribution curve varied with the type of lake origin; the lowest kurtosis was found in dammed lakes, while the highest was found in volcanic lakes. The lake trophic state could affect the change in the kurtosis, providing much lower kurtosis at eutrophic lakes (dammed lakes) than that at oligotrophic lakes (volcanic lakes). The relationship between TN:TP ratio and Microcystis growth could be explained by the nutrient elution tests under controlled TN:TP ratios through the various sediment treatments. A significant suppression of Microcystis growth of 70% could be achieved when the TN:TP ratios exceeded 21. Lake origin could be regarded as an index including morphological and geographical factors, and controlling the trophic state in lakes. The origin rather than trophic state for lakes could be considered as an important factor of TN:TP influences on Microcystis growth. PMID:18604439

Tumor necrosis factor-{alpha}, interleukin-1{Beta}, interleukin-6, and transforming growth factor-{Beta} are cytokines synthesized by alveolar macrophages. We investigated the effect of sulfur dioxide, a major air pollutant, on the production of these cytokines by alveolar macrophages. The cells were layered on a polycarbonate membrane and exposed for 30 min to 0.0, 1.0, 2.5, and 5.0 ppm sulfur dioxide at 37 {degrees}C and 100% air humidity. The cells were incubated for 24 h after exposure, thus allowing cytokine release. Cytotoxic effects of sulfur dioxide were evaluated by trypan flue exclusion. Cytokine release. Cytotoxic effects of sulfur dioxide were evaluated by trypan blue exclusion. Cytokines were measured with enzyme-linked immunosorbent assays (i.e., tumor necrosis factor-{alpha}, interleukin-1{Beta}, and interleukin-6) or by use of a specific bioassay (i.e., transforming growth factor-{Beta}). The toxicity of sulfur dioxide for alveolar macrophages ranged from 3.1% to 9.5%. A 30-min exposure to sulfur dioxide induced a significant decrease in spontaneous and lipopolysaccharide-stimulated tumor necrosis factor-{alpha} (p < .001) and lipopolysaccharide-stimulated interleukin-1{Beta} release (p < .05). The release of interleukin-6 and transforming growth factor-{Beta} was not affected significantly by sulfur dioxide exposure. Our results demonstrated a functional impairment of alveolar macrophages after sulfur dioxide exposure (i.e., release of tumor necrosis factor-{alpha} and interleukin-1{Beta}). Neither spontaneous nor stimulated release of interleukin-6 and transforming growth factor-{Beta} were influenced by exposure to sulfur dioxide. 31 refs., 3 figs.

The main function of tests in Larger Benthic Foraminifera (LBF) is to provide their endosymbiotic algae with enough light to obtain net photosynthetic rates and to create sufficient accommodation space. To study the relation between these two factors and to understand how the cell reacts to growth and to the environment, the newly developed technique of X-ray micro-Computer-Tomography (microCT) allows measurement of all characters of complex tests without destruction. Growth studies on 48 specimens of living and fossil species have been performed. The volumes of the lumina have been calculated as well as further 2-dimensional parameters related to volumes as chamber height, chamber width and septal distance. The volumes of chamber lumina represent cell growth in their sequence, thus demonstrating interruptions, increase/decrease or oscillations in growth rates caused by external factors affecting growth during life time (e.g. seasons). Correlations between volumes and the one-dimensional parameters have been calculated to check the form of relationship. According to our results, some parameters seem to oscillate exactly as the volume (therefore accommodating it), while others seem to oscillate constantly around a given growth function. Concerning the palaeobiology, beside the study of specimens with 'normal' growth, thus not drastically affected by external factors, some interesting morphologies have been investigated. Pluriembryonal apparati as well as secondary equatorial layers have been segmented, extracted and quantified in almost 15 specimens of Cycloclypeus carpenteri, 8 twin specimens of nummulitids tests have been also investigated to show where and how the fusion starts and volumetric quantifications of each single spiral in multispiral grown test of some large Eocene Nummulitids has also been calculated to show in which way and when (ontogenetically) a new spiral starts. The combination of all measurements allows interpretation of different biological and environmental dependencies of LBF. Varying growth rates determines environmental abiotic (e.g. seasons, instantaneous events) and biotic influence (e.g. predation), leading to life time estimation for the fossil forms by comparison with their living relatives.

Common chronic diseases of Western societies, such as coronary heart disease, diabetes mellitus, cancer, hypertension, obesity, dementia, and allergic diseases are significantly influenced by dietary habits. Cow's milk and dairy products are nutritional staples in most Western societies. Milk and dairy product consumption is recommended by most nutritional societies because of their beneficial effects for calcium uptake and bone mineralization and as a source of valuable protein. However, the adverse long-term effects of milk and milk protein consumption on human health have been neglected. A hypothesis is presented, showing for the first time that milk protein consumption is an essential adverse environmental factor promoting most chronic diseases of Western societies. Milk protein consumption induces postprandial hyperinsulinaemia and shifts the growth hormone/insulin-like growth factor-1 (IGF-1) axis to permanently increased IGF-1 serum levels. Insulin/IGF-1 signalling is involved in the regulation of fetal growth, T-cell maturation in the thymus, linear growth, pathogenesis of acne, atherosclerosis, diabetes mellitus, obesity, cancer and neurodegenerative diseases, thus affecting most chronic diseases of Western societies. Of special concern is the possibility that milk intake during pregnancy adversely affects the early fetal programming of the IGF-1 axis which will influence health risks later in life. An accumulated body of evidence for the adverse effects of cow's milk consumption from fetal life to childhood, adolescence, adulthood and senescence will be provided which strengthens the presented hypothesis. PMID:19232475

  In order to understand systematically the influence of an environmental factor on the intergranular stress corrosion cracking (IGSCC) susceptibility of cold-worked 316 stainless steel, constant extension rate tensile tests were carried out under simulated pressurized water reactor (PWR) primary water conditions while varying the boric acid, lithium hydroxide, and dissolved hydrogen concentrations and temperature. It was found that IGSCC susceptibility increased for a low boric acid concentration and high lithium hydroxide and dissolved hydrogen concentrations, and a high temperature. The influences of the water chemistry changes were recognized as the changes in pH and magnetite solubility in a manner that IGSCC was promoted for higher pH and magnetite solubility. On the other hand, IGSCC crack growth rates measured using compact-tension-type specimens revealed that boric acid, lithium hydroxide, and dissolved hydrogen did not affect IGSCC crack growth rate significantly.   

The purpose of this article was to investigate the influence of loading asymmetry on the tendency of construction materials toward hydrogen embrittlement in corrosion fatigue. The influence of cathodic polarization on the kinetics of crack growth in corrosion fatigue of SP-33oh high-speed steel (32Kh3NMFA) and VMD 10 magnesium alloy was investigated. The tests were made at room temperature in corrosive solutions of CrO/sub 3/ and Na/sub 2/B/sub 4/O/sub 7/ for the SP-33oh steel and of Cr/sub 3/ and NaOH for the VMD 10 alloy. Relationships were determined for the critical range of stress intensity factors to loading asymmetry. It was established that the leading role of hydrogen embrittlement in the development of corrosion fatigue cracks does not eliminate the possibility of other mechanisms of crack growth.

Genetic and environmental factors influence insulin sensitivity (IS) during one's lifetime. Actually, uterine environment may affect IS at birth and later in life. In particular, various exogenous toxic substances, coupled to a genetic predisposition, may remarkably influence the regulation of the hypothalamus?hypophysis?adrenal gland axis, and the production or the activity of insulin, cerebral incretins, pro-inflammatory cytokines, and placental hormones. Owing to this reaction against environmental injuries, fetal growth and endocrine system development may be impaired, leading to low or large birth weight, or prematurity. Reduced growth in early life has been related to insulin resistance, which can be silent for years and evident in predisposed adults. The incidence of type 2 diabetes...

The aim of this study was to identify novel angiogenic mechanisms underlying the regenerative process. To that end, interactions between adipose tissue-derived stromal cells(ASCs) and bone marrow cells (BMCs) were initially investigated using real-time fluorescence optical imaging. To monitor cell behavior in mice, we infused green fluorescent protein (GFP)-positive (?) BMCs into the tail vein and injected PKH26-labeled ASCs behind the ears. Angiogenesis and inflammation were observed at these sites via an optical imaging probe. Infused GFP? BMCs migrated from the blood vessels into the tissues surrounding the ASC injection sites. Many of the migrating GFP? BMCs discovered at the ASC injection sites were inflammatory cells, including Gr-1?, CD11b?, and F4/80? cells. ASCs cocultured with inflammatory cells secreted increased levels of chemokines such as macrophage inflammatory protein (MIP)-1?, MIP-1?, keratinocyte-derived chemokines, and monocyte chemotactic protein 1. Similarly, these ASCs secreted increased levels of angiogenic growth factors such as hepatocyte growth factor and vascular endothelial growth factor. However, when anti-CXC chemokine receptor type 4 antibody was infused at regular intervals, the migration of GFP? BMCs (especially Gr-1? and CD11b? cells) to ASC injection sites was inhibited, as was angiogenesis. The collective influence of the injected ASCs and BMC-derived inflammatory cells promoted acute inflammation and angiogenesis. Together, the results suggest that the outcome of cell-based angiogenic therapy is influenced not only by the injected cells but also by the effect of intrinsic inflammatory cells. PMID:23146336

Since inhaled and intranasal corticosteroids may be systemically bioavailable, risk of growth suppression cannot be ruled out in children treated with these compounds. The mechanisms by which exogenous corticosteroids can cause growth suppression may be multifactorial, involving influences on growth hormone secretory profiles and insulin-like growth factor-I activity, direct effects on the epiphyseal growth plate, and effects on bone and collagen turnover. When studies on growth in children treated with inhaled and intranasal corticosteroids are interpreted, it is important to discriminate between data on the final outcome of growth (adult height) and data on growth rate. No firm conclusions can be drawn on adult height from the available data. While the data on children treated with inhaled corticosteroids appear reassuring, there are no peer-reviewed studies on the final height of children treated with intranasal corticosteroids. The possibility of additive effects on the final height or growth rate of children receiving intranasal plus inhaled corticosteroids has also not been studied. When assessing the risk of growth rate suppression, specific corticosteroids, doses and inhaler systems must be evaluated separately. Standard paediatric doses of inhaled corticosteroids (budesonide 200 to 400 microg/day delivered from a metered dose inhaler with a spacer, dry powder budesonide 200 microg/day, or dry powder fluticasone propionate 200 microg/day) do not affect growth rate when a twice daily administration regimen is used. The risk of growth rate suppression in children treated with inhaled budesonide depends on the dosage and may become significant with 800 microg/day administered with a spacer, or with 400 microg/day administered with a dry powder device. When high doses of inhaled corticosteroids are used, the risk of adverse effects on growth rate can be reduced by once daily dosage in the morning. In fact, intranasal mometasone furoate 100 and 200microg from an aqueous pump spray and dry powder budesonide 200 and 400microg once daily in the morning have been found not to affect growth rate. Sensitivity to adverse effects on growth rate may vary between individuals. If growth suppression is detected, 'catch-up growth' may be expected when the dose of the inhaled or intranasal corticosteroid is reduced or other treatment modalities are introduced. Inhaled or intranasal corticosteroids should not be withheld from children with asthma or rhinitis. Topical corticosteroids should be given in doses that control disease symptoms; however, height measurements should be performed regularly in children receiving corticosteroids. PMID:18034541

A 3D finite element study of creep crack growth in cross-weld CT specimens with material properties of 2.25Cr1Mo at 550 deg C is carried out, where large strain and displacement theory is used. The creep crack growth rate is calculated using a creep ductility based damage model, in which the creep strain rate perpendicular to the crack plane ahead of the crack tip is integrated, considering the multiaxial stress state. The influence of specimen size on creep crack growth rate under constant load is given special attention, but the possibility to transfer results from cross-weld CT specimens to welded high temperature components is also investigated. The creep crack growth rate of a crack in a circumferentially welded pipe is compared with the creep crack growth rate of cross-weld CT specimens of three different sizes, cut out from the pipe. Although the constraint ahead of the crack tip is higher for a larger CT specimen, the creep crack growth rate is higher for a smaller specimen than for a larger one if they are loaded to attain the same stress intensity factor. If the specimens are loaded to the same C* value, however, a more complicated pattern occurs; depending on the material properties of the weldment constituents, the CT specimen with the intermediate size will either yield the highest or the lowest creep crack growth rate 11 refs, 6 figs

There is a lack of information on plant response to multifactor environmental variability including the interactive response to temperature and atmospheric humidity. These two factors are almost always confounded because saturated vapor pressure increases exponentially with temperature, and vapor pressure deficit (VPD) could have a large impact on plant growth. In this study using climate controlled mini-greenhouses, we examined the interacting influence of temperature and VPD on long-term growth of tall fescue (Festuca arundinacea Schreb), a cool season grass. From past studies it was expected that growth of tall fescue would decline with warmer temperatures over the range of 18.5-27 degrees C, but growth actually increased markedly with increasing temperature when VPD was held constant. In contrast, growth declined in experiments where tall fescue was exposed to increasing VPD and temperature was held constant at 21 degrees C. The inhibited growth appears to be in response to a maximum transpiration rate that can be supported by the tall fescue plants. The sensitivity to VPD indicates that if VPD remains stable in future climates as it has in the past, growth of tall fescue could well be stimulated rather than decreased by global warming in temperate climate zones. PMID:17955259

Abstract in spanish El crecimiento del cuerpo humano se entiende como cambios estructurales del cuerpo, mientras que su desarrollo significa cambios funcionales. El propósito de este trabajo fue estudiar la influencia de los diferentes deportes en el crecimiento corporal de los atletas jóvenes. Con el fin de analizar la influencia del perfil de los diferentes deportes en el crecimiento físico humano, se analizaron 3011 jugadores de fútbol y 393 jugadores de baloncesto. Dos grupos de depo (more) rtistas, de acuerdo a su edad fueron separados en cuatro grupos (13, 14, 15 y 16 años de edad). La evaluación del crecimiento físico de los deportistas jóvenes se ha probado en base a los cambios de nueve variables morfométricas. Los datos obtenidos fueron analizados en términos de parámetros estadísticos básicos, mientras que las diferencias entre los grupos independientes se analizaron mediante T-test y análisis discriminante canónico. Las diferencias estadísticamente significativas, que fueron probadas entre las medidas de los grupos de deportistas nos hacen concluir que en esta fase de la vida de los deportistas, cuando su organismo está en una fase intensa de pubertad cambiante, los factores externos, como elementos de baloncesto (saltar y correr), tienen más influencia en los factores de crecimiento morfométricos de los jóvenes jugadores de baloncesto en comparación con la influencia de elementos de fútbol en jóvenes futbolistas (principalmente correr). A pesar de que, la dimensión longitudinal es cerca del 98% controlada por el genotipo, mientras que la dimensión transversal es de alrededor del 93%. Es interesante que en nuestro estudio la dimensión longitudinal ha sido muy influenciada por elementos de baloncesto, en comparación con la dimensión transversal. Como conclusión, podría ser un hecho que aunque el crecimiento del cuerpo humano está por encima del 90% controlado por el factor genético, factores como actos externos en la fase sensible e intensiva de crecimiento corporal, pueden tener un efecto muy importante. Abstract in english Human body growth means structural changes of human body, whereas development means its functional changes. The purpose of this study was to study the influence of different sports in bodily growth of the young athletes. In order to analyze the influence of different sports profiles on human physical growth, in this study, 3011 footballers and 393 basketball players were tested. Two groups of athletes, according to their ages have been separated in four groups (ages 13,14 (more) ,15 and 16 years old). The evaluation of bodily growth of young athletes has been tested based on changes of nine morphometrical variables. The data obtained were analyzed in terms of basic statistical parameters, whilst the differences between independent groups were analyzed by T-test and Discriminant Canonical Analysis. Statistically significant differences that have been proved, between sportsmen's measured groups, lead us to conclude that in this phase of the sportsmen's life, when their organism is in the intensive changeable puberty phase, the external factors, such as basketball elements (jumping and running), have more influence on morphometrical growth factors of young basketball players, compared with the influence of football elements on young footballers (mainly running elements). Even though, longitudinal dimension is controlled about 98% by genotype, whereas transversal dimensions account for about 93%, it is interesting that in our study longitudinal dimension has been most influenced by basketball elements, compared with transversal dimension. As a conclusion of this study, a fact could be, that even though human bodily growth is controlled over 90% by genetic factor, if external factors such as external acts occur during the sensitive and intensive phase of bodily growth, their effect may be very important.

Canopy gap recruitment in beech (Fagus sylvatica L.) old-growth forests is influenced by the interplay of the canopy gap disturbance regime, site factors, and stand history. Persistent seedling and sapling banks of beech and other shade tolerant species often play a major role in canopy gap closure. To gain more insight into interactions between medium-sized gaps and pre-gap ground vegetation patterns, we studied beech regeneration over a 10-year period on a site rich in wild garlic (Allium ursinum L.) in a Dinaric beech old-growth forest. In 1999 we selected the five largest newly created gaps (200m2) and systematically established 13 permanent plots (1x2m) in each gap. In 1999, 2004, and 2009, we sampled tree species regeneration (density, cover, and growth), ground vegetation (compositi...

This paper evaluates results of investigations carried out at a spoil bank of the Opatovice coal-fired power plant in Bukovina. Factors which influenced spoil bank reclamation were analyzed: chemical composition of fly ash and slags, physical properties (grain size distribution, density, capillary capacity etc.), atmospheric precipitations. Effects of using a soil cover on fly ash on revegetation and plant growth were analyzed. Four reclamation schemes were used: fly ash without a soil cover, fly ash with a soil cover 10, 30 and 50 cm thick. Effects of soil cover on plant growth and crops were investigated (cereals, grass, potatoes). Effects of atmospheric precipitations and physical ash properties on plant growth on a soil cover were comparatively evaluated. On the basis of these evaluations recommendations for the optimum soil cover type, thickness, fertilizers and manures are made. Use of a 50 cm soil cover is recommended. 8 refs.

This study used the dilution method to examine growth and grazing rates of heterotrophic bacteria and an autotrophic picoplankton, Synechococcus spp., from 1 to 11 July 2007 in the East China Sea. The main influence of oceanographic conditions in this aquatic system was the introduction of fresh, high-nutrient water from Changjiang River and the extremely nutrient-poor, high-salinity waters of Kuroshio Water. In these experiments, deviation from linearity in the relationship between dilution factor and net growth rate was significant in a large number of cases. Growth rates for heterotrophic bacteria ranged from 0.024 to 0.24, and for Synechococcus spp. from 0.03 to 0.21?h?1. Grazing rates ranged from 0.02 to 0.19 and 0.01 to 0.13?h?1, respectively. The spatial variations of Synechococcus ...

Undaria pinnatifida is an edible brown seaweed, and its cultivation is being considered in Northwest Spain. Water motion is considered to be a key factor in growth and production of macroalgae; however, little is known about their influence on the farming of commercial seaweeds. In this study we investigated water motion effects on the cultivation of U. pinnatifida in a coastal bay of Galicia (Northwest Spain). Growth and morphological features of fronds and biomass yield were compared between two locations with different degrees of water motion (moderately exposed site vs. sheltered site). Growth rate, which was measured either as length and weight changes of fronds, was significantly higher for the moderately exposed site compared to the sheltered site. Fronds in the moderately exposed s...

Abstract Axonal outgrowth is of paramount significance for establishing the intricate neuronal network both during embryogenesis and nerve regeneration. Vascular endothelial growth factor (VEGF), which is known for its essential role in vascular sprouting and its involvement in cancer, has recently been found to exert a trophic activity on neurons leading to an increased axonal outgrowth. Although two receptors, VEGFR-2 and neuropilin-1, were identified on neurons, the signaling pathways associated with them are not well understood. The aim of this study was to analyze the influence of VEGF on the growth cone morphology and motility of dorsal root ganglia (DRG) neurons. Moreover, we aimed for a deeper understanding of VEGFR-2 on growth cones that potentially mediates the stimulating and at...

This review describes environmental factors that influence severity of crop disease epidemics, especially in the UK and north-west Europe, in order to assess the effects of climate change on crop growth and yield and severity of disease epidemics. While work on some diseases, such as phoma stem canker of oilseed rape and fusarium ear blight of wheat, that combine crop growth, disease development and climate change models is described in detail, climate-change projections and predictions of the resulting biotic responses to them are complex to predict and detailed models linking climate, crop growth and disease development are not available for many crop-pathogen systems. This review uses a novel approach of comparing pathogen biology according to ?ecotype? (a categorization based on aspect...

We have proposed the mechanism of the directional growth of microcrystalline silicon (mc-Si) thin films deposited by PECVD (plasma enhanced chemical vapor deposition) from SiH4 and H2 gas mixture, where dimeric radicals act a key role to form bridge nuclei for the ledge formation on the (110) facet. In order to look further into details of the mechanism, we investigated other important factors that influence the growth of mc-Si in direction in terms of their impact on crystallinity with varying deposition temperature. The enhancement of surface diffusion length of radicals is inferred from the enlargement of the crystalline grain size accompanied with the increase of the deposition temperature. The growth in direction is also promoted as the deposition temperature increas...

Abstract The influence of stocking density (1, 2, 4, 6 and 8 kg m-2) was investigated on haematological parameters, growth and fin erosion of great sturgeon (Huso huso) juveniles for a period of 8 weeks. The mean weight of fish at the start of trial was 93.13+-1.04 g. After 8 weeks of rearing, the mean weight was 362.4, 319.7, 267, 242.1 and 211.1 in densities 1-8 kg m-2 respectively. The results of this study showed that growth parameters, including condition factor, weight, weight gain, feed conversion ratio, specific growth rate and body weight increase, had a statistically significant difference among treatments (P<0.05). A significant difference (P<0.05) was observed in haematocrit, but the other haematological parameters, including red blood cells, white blood cells (WBC), haemoglobi...

The roles of "top-down" and "bottom-up" factors were investigated in terms of their influence on the diatom and dinoflagellate abundances in the microtidal, salt wedge Huon Estuary, Tasmania, Australia. Long-term (1996-2005) changes in Chl a, the peridinin:Chl a ratio and the abundance of autotrophic dinoflagellates were observed to coincide with the warming of regional surface waters. There were significant seasonal differences in pigment-specific net growth rates for Chl a, peridinin and fucoxanthin. Diatoms dominated the spring bloom when species such as Skeletonema costatum had the highest net growth rates and fucoxanthin-specific gross growth rates were 0.9 day-1. During late summer, the peridinin-specific grazing mortality was significantly less than the fucoxanthin-specific grazing ...

A specific net present value (SNPV) approach is introduced as a criterion in economic engineering decisions. The SNPV expresses average costs, including the growth rate and plant utilisation over the planning horizon, factors that are excluded from a standard net present value approach. The use of SNPV favours alternatives that are cheaper per service unit and are therefore closer to the costs that a user has to cover. It also shows that demand growth has a similar influence on average costs as an economy of scale. In a high growth scenario, solutions providing less idle capacity can have higher present value costs and still be economically favourable. The SNPV approach is applied in two examples to calculate acceptable additional costs for modularisation and comparable costs for on-site t...

Shockwave shape can influence dynamic damage evolution. Features such as rise time, pulse duration, peak shock pressure, pull back, and release rate are influenced as wave shape changes. However, their individual influence on dynamic damage evolution is not well understood. Specifically, changing from a square to triangular or Taylor wave loading profile can alter the release kinetics from peak shock pressure and the volume of material sampled during release. This creates a spatial influence. In high purity metals, because damage is often linked to boundaries within the microstructure (grain or twin), changing the volume of material sampled during release, can have a drastic influence on dynamic damage evolution as the number of boundaries or defects sampled is altered. In this study, model-driven dynamic experiments have been conducted on eu with four different grain sizes to examine, for a given shockwave shape, how the spatial effect of boundary distribution influences dynamic damage evolution. Both two and three dimensional damage characterization techniques have been utilized. This study shows the critical influence of spatial effects, in this case boundary density, on dynamic damage evolution. As the boundary density decreases, the damage evolution transitions from nucleation controlled to growth controlled. It also shows that specific boundaries, those with high Schmid factor orientations on either side, maybe a necessary condition for void formation.

@b-Tricalcium phosphate (@b-TCP) is an attractive ceramic for bone tissue repair because of its similar composition to bone mineral and its osteoconductivity. However, compared with other ceramics @b-TCP has a rapid and uncontrolled rate of degradation. In the current study @b-TCP granules were mineral coated with the aim of influencing the dissolution rate of @b-TCP, and also to use the coating as a carrier for controlled release of the growth factors recombinant human vascular endothelial growth factor (rhVEGF), modular VEGF peptide (mVEGF), and modular bone morphogenetic protein 2 peptide (mBMP2). The biomineral coatings were formed by heterogeneous nucleation in aqueous solution using simulated body fluid solutions with varying concentrations of bicarbonate (HCO"3). Our results demonst...

Mesangial cell (MC) proliferation, mediated by platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-?1, and cyclin-dependent kinases (CDK), is the common feature of glomerulosclerosis. Magnolia officinalis, stem bark of Machilus thunbergii S., has multiple pharmacological effects. In this study, we investigated the influence of aqueous extract of Magnolia officinalis on MC proliferation, DNA synthesis, and expression of PDGF-BB, TGF-?1, CDK1, CDK2, and CDK4 in fetal bovine serum (FBS)-activated human MC. Magnolia officinalis inhibited the MC proliferation, DNA synthesis, and the expression of PDGF-BB, CDK1, and CDK2 gene and CDK1, CDK2, and TGF-?1 protein. These results suggest that the inhibitory effect of Magnolia officinalis on MC proliferation may be mediated by regulation of PDGF-BB and TGF-?1expressions and by modulation of CDK1 and CDK2 expression.   

The decay rate of mRNA varied in a wide range within a species and the special sequence features were considered as important factor determining this variation. In order to investigate the effect of ORF length on mRNA degradation in Escherichia coli genome, the correlation between ORF length and mRNA half-life was calculated in different cultures for mRNA growing. Although the effect of ORF length on mRNA degradation is strongly dependent of the growth medium, a significant negative correlation between ORF length and mRNA half-life is observed in the mRNAs less affected by the growth medium. In particular, some important genes, such as essential genes, show significant inverse correlation between ORF length and mRNA degradation. Our results indicate that ORF length is an important factor influencing mRNA degradation and the increasing length tends to decrease the mRNA longevity.

This article analyses current attempts to identify the factors underlying long-term economic growth. The author criticises some of the arguments and historical evidence on which the two main explanations that dominate recent literature are based: the institutional approach and the approach focusing on the importance of geographical factors. Using an approach which is deliberately eclectic, the author considers the role of geography, international trade, human capital and institutional quality in explaining development. A new estimation is carried out through Two Stages Least Squares (TSLS) with instrumental variables. The results of the empirical model confirm the central role of institutions in long-term economic growth. However, certain geographical conditions also seem to have influence...

Gastric cancer shows intratumoral heterogeneity for human epidermal growth factor receptor 2 expression. We evaluated whether the number of tissue blocks analyzed or the antibodies used may influence the immunohistochemical results in gastrectomy specimens. Clinicopathologic data from 148 patients receiving gastric surgery for cancer were collected. One tissue block for each of 88 primary tumors and 60 paired primary tumors and metastases was examined for human epidermal growth factor receptor 2 status by immunohistochemistry using 3 different antibodies (HercepTest, CB11, and 4B5) and by fluorescent in situ hybridization. Two additional tissue blocks of the primary tumor were tested by immunohistochemistry if the results were negative on the first tissue block. The concordance among the 3...

Objective. Insulin-like growth factor-1 (IGF-1) is essential for the pubertal growth spurt and for normal mammary gland development. IGF-1 increases premenopausal breast cancer risk. Oral contraceptives (OCs) decrease IGF-1 in most women. The endogenous estrogens and their metabolites also influence IGF-1 levels. Glutathione S-transferases (GSTs) are involved in estrogen metabolism. We aimed to study IGF-1 levels and body size in relation to GSTM1 and GSTT1 deletions, and GSTP1*1B and current oral contraceptive (OC) status.Design. Questionnaires on reproductive factors and OC use were completed and blood samples were obtained during menstrual cycle day 18?23 in healthy women (? 40 years) from breast cancer high-risk families. IGF-1 was analyzed with radioimmunoassay. Genetic analyses were ...

Background:Brain tumour stem cells (BTSCs) are a small population of cancer cells that exhibit self-renewal, multi-drug resistance, and recurrence properties. We have shown earlier that peroxisome proliferator-activated receptor gamma (PPAR?) agonists inhibit the expansion of BTSCs in T98G and U87MG glioma. In this study, we analysed the influence of PPAR? agonists on the expression of stemness and differentiation genes in BTSCs.Methods:The BTSCs were isolated from T98G and DB29 glioma cells, and cultured in neurobasal medium with epidermal growth factor+basic fibroblast growth factor. Proliferation was measured by WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2?H-5-tetrazolio]-1,3-benz ene disulphonate) and 3H thymidine uptake assays, and gene expression was analysed by qua...

Most of the PWR Steam generators with tubes in Alloy 600 alloy are affected by Stress Corrosion Cracking, such as PWSCC(Primary Water Stress Corrosion Cracking) and ODSCC(Outside Diameter Stress Corrosion Cracking). This study was undertaken to establish the background for remedial technology development to prevent SCC. in the report are included the following topics: (1) General: (i) water chemistry related factors, (ii) Pourbaix(Potential-pH) Diagram, (iii) polarization plot, (iv) corrosion mode of Alloy 600, 690, and 800, (v) IGA/SCC growth rate, (vi) material suspetibility of IGA/SCC, (vii) carbon solubility of Alloy 600 (2) Microstructures of Alloy 600 MA, Alloy 600 TT, Alloy 600 SEN Alloy 690 TT(Optical, SEM, and TEM) (3) Influencing factors for PWSCC initiation rate of Alloy 600: (i) microstructure, (ii) water chemistry(B, Li), (iii) temperature, (iv) plastic deformation, (v) stress relief annealing (4) Influencing factors for PWSCC growth rate of Alloy 600: (i) water chemistry(B, Li), (ii) Scott Model, (iii) intergranular carbide, (iv) temperature, (v) hold time (5) Laboratory conditions for ODSCC initiation rate: 1% NaOH, 316 deg C; 1% NaOH, 343 deg C; 50% NaOH, 288 deg C; 10% NaOH, 302 deg C; 10% NaOH, 316 deg C; 50% NaOH, 343 deg C (6) Sludge effects for ODSCC initiation rate: CuO, Cr{sub 2}O{sub 3}, Fe{sub 3}O{sub 4} (7) Influencing factors for PWSCC growth rate of Alloy 600: (i) Caustic concentration effect, (ii) carbonate addition effect (8) Sulfate corrosion: (i) sulfate ratio and pH effect, (ii) wastage rate of Alloy 600 and Alloy 690 (9) Crevice corrosion: (i) experimental setup for crevice corrosion, (ii) organic effect, (iii) (Na{sub 2}SO{sub 4} + NaOH) effect (10) Remedial measures for SCC: (i) Inhibitors, (ii) ZnO effect. (author). 30 refs., 174 figs., 51 tabs.

There are many factors that influence nurse faculty job satisfaction including professional achievement and growth, interpersonal relations, leadership, recognition, responsibility, salary, and working conditions. However, much of the research in this area is limited to the clinical nurse setting. There are few studies that focus on nurse faculty job satisfaction in the community college setting. One of the primary drivers for the current nursing shortage in the United States is a shortage of faculty. Better understanding of the factors influencing job satisfaction among faculty may be helpful in addressing the faculty shortage. The purpose of this study was to explore the constructs of job satisfaction and intent to stay. Community college nursing faculty was chosen given that all of the ...

An understanding of influencing factors and genetic principles affecting the growth traits is needed to implement optimal breeding and selection programs. In this study, heritabilities (direct additive and maternal) of body weights at birth (BW0), 90?days (BW90) and 300?days (BW300) of age and average daily gains from birth to 90?days (ADG0-90), birth to 300?days (ADG0-300) and 90?days to 300?days (ADG90?300) of age in Boer goats were estimated on the basis of 1520 Boer goats at Boer Goat Breeding Station in Yidu, China, during 2002?2007. The parameters were estimated using a DFREML procedure by excluding or including maternal genetic or permanent maternal environmental effects, four analysis models were fitted in order to optimize the model for each trait. Influencing factors such as pari...

A reliable prediction of mould risk in buildings is important to ensure a healthy environment and to avoid social and economical damage. Whereas previously the temperature ratio was often used to minimize the mould risk, nowadays- more advanced - mould prediction models can be found (e.g. isopleth systems, biohygrothermal model, ESP-r mould prediction model, empirical VTT model). These models include the main influencing factors for mould growth: the surface temperature and relative humidity. However, they are based on either experiments or assumptions and some of them neglect a third important influencing factor: the exposure time. The current paper gives an overview of the different existing models and analyses the impact of the mould prediction model on the mould risk evaluation. To do ...

Time series analysis has been used to evaluate the mechanisms regulating population dynamics of mammals and insects, but has been rarely applied to amphibian populations. In this study, the influence of endogenous (density-dependent) and exogenous (density-independent) factors regulating population dynamics of the terrestrial plethodontid salamander Speleomantes strinatii was analysed by means of time series and multiple regression analyses. During the period 1993-2005, S. strinatii population abundance, estimated by a standardised temporary removal method, displayed relatively low fluctuations, and the autocorrelation function (ACF) analysis showed that the time series had a noncyclic structure. The partial rate correlation function (PRCF) indicated that a strong first-order negative feedback dominated the endogenous dynamics. Stepwise multiple regression analysis showed that the only climatic factor influencing population growth rate was the minimum winter temperature. Thus, at least during the study period, endogenous, density-dependent negative feedback was the main factor affecting the growth rate of the salamander population, whereas stochastic environmental variables, such as temperature and rainfall, seemed to play a minor role in regulation. These results stress the importance of considering both exogenous and endogenous factors when analysing amphibian long-term population dynamics. PMID:17216185

Scholars call for greater attention to social contexts that promote and deter risk factors for health. Parenthood transforms social contexts in a myriad of ways that may influence long-term patterns of weight gain. Life course features of parenthood such as age at first birth, parity, and living with a minor child may further influence weight gain. Moreover, the social and biological features of parenthood vary in systematic ways for women and men, raising questions about how social contexts might differentially affect weight patterns by gender. We consider how parenthood influences trajectories of change in body weight over a fifteen year period (from 1986 to 2001) with growth curve analysis of data from the Americans’ Changing Lives Survey, conducted with adults aged 24 and older ...

Nerve growth factor (NGF) and nerve growth factor receptors (NGFRs) play important roles in tissue remodeling during the would healing process of the skin, oral and paranasal mucosa, and cornea. The interactions between NGF and NGFRs are influenced by or interact with a number of molecules in the tissue remodeling process, in which key niche components are varieties of growth factors and their receptors, including NGF and NGFR. In addition to those interactions mentioned above, cell-cell contacts as well as cell-matrix interactions have also been considered to promote wound healing events. The present review focuses on the pathophysiological roles of NGF and NGFR in saliva and salivary glands, and in tear and lacrimal glands under inflammatory and tissue remodeling conditions, as well as their expression profiles in various kinds of cells including mast cells, macrophages, lymphocytes, and those involved in angiogenesis. Finally, we describe how the expression modes of NGF and NGFR regulate the peripheral nerve fiber growth and stimulate wound healing or tissue remodeling in the organs or tissues mentioned above as well as in pressure wounds and diabetic skin lesions. Based on these lines of evidence, we emphasize that NGF and NGFR could represent new and powerful regimens for treatment of tissue injuries.   

In mammals, skeletal muscle mass is negatively regulated by a muscle-derived growth/differentiating factor named myostatin (MSTN) that belongs to the transforming growth factor-beta superfamily. Although putative MSTN homologs have been identified from several vertebrates, nonmammalian orthologs remained poorly defined. Thus, we isolated and characterized MSTN complementary DNA clones from the skeletal muscle of the tilapia Oreochromis mossambicus and the white bass Morone chrysops. The nucleic and amino acid sequences from both fish species are highly homologous to the previously identified mammalian and avian orthologs, and both possess conserved cysteine residues and putative RXXR proteolytic processing sites that are common to all transforming growth factor-beta family members. Western blotting of conditioned medium from human embryonal kidney (HEK293) cells overexpressing a His-tagged tilapia MSTN indicates that the secreted fish protein is processed in a manner similar to mouse MSTN. However, in contrast to mice, MSTN expression in tilapia is not limited to skeletal muscle as it occurs in many tissues. Furthermore, the timing of MSTN expression in developing tilapia larvae coincides with myogenesis. These results suggest that the biological actions of MSTN in the tilapia and possibly in other fishes may not be limited to myocyte growth repression, but may additionally influence different cell types and organ systems. PMID:11250920

Tree-ring chronologies from 16 sugar maple (Acer saccharum) stands showing various degrees of dieback were used to analyze the spatial extent and timing of the recent sugar maple decline. Two chronologies in each damaged stand were used to examine whether healthy trees showed growth trends similar to those of damaged trees. The climatic variables used to evaluate growth-climatic relationships were mean monthly temperature and total monthly precipitation. The moderate relationships between the maple chronologies and weather data indicated that the two climatic parameters chosen were not the most appropriate to explain the tree growth patterns. However, statistical partitioning of anomalous tree rings showing significantly reduced ring width indicated that the abrupt growth decreases recorded regionally were caused by discrete abiotic factors (drought). It was found that several small-scale drought-induced disturbances occurred repetitively over the last 100 years. Factors explaining the large growth depression in the 1980s were associated with synergistic influence of drought and insect defoliators. The recovery of the stands emphasized the positive responsiveness of robust native trees to frequent natural disturbances. 54 refs., 2 tabs., 2 figs.

Classical crystal growth theory relates growth and dissolution rates to the degree of supersaturation. However, the solution composition may also affect the growth rate of carbonate minerals, via the Ca2+ to CO32- concentration ratio (e.g. Perdikouri et al., 2009; Stack and Grantham, 2010), ionic strength (e.g. Ruiz-Agudo et al. 2010) or the presence of organic matter (Hoch et al., 2000). For this reason, the influence of these parameters on the kinetics of mineral growth and dissolution has generated a considerable amount of research in the last decade. In particular, effects of both inorganic and organic impurities on mineral growth and dissolution have been frequently reported in the literature. Commonly, water in contact with rock forming minerals, contains significant and variable amounts of ions in solution. The effect of such ions on dissolution and growth rates has been traditionally ascribed to changes in solubility. However, experimental studies performed on different minerals have shown that the dependence of growth or dissolution rates on ionic strength is complex, and that the effect of ionic strength is not independent of the ionic species producing it. Here, we report investigations aimed at addressing the basic hypothesis that mineral growth and dissolution is governed by complex interactions between solvent structure, surface hydration and the ion solvation environment induced by the presence of electrolytes. It is proposed that any factor affecting ion solvation should alter growth and dissolution rates. These results have opened the possibility of a new understanding of very diverse phenomena in geochemistry and demonstrate the need for the inclusion of this "hydration effect" in the development of predictive models that describe crystal growth and dissolution in complex systems, such as those found in nature. Furthermore, we can hypothesise that ion-assisted dehydration of trace and minor element ions could occur in biological systems, thus affecting their incorporation and isotopic fractionation, providing interesting insights into the possible origin of anomalies found in systems used as environmental proxies and the so-called "vital effects".

Objective: To investigate the longitudinal development of callous-unemotional traits (CU) in middle childhood using developmental trajectory analyses in a large twin dataset and examine the degree to which genetic and environmental influences contributed to the CU trajectory-group membership in children. Method: The study included 9,462 youths from the Twins Early Development Study, a population-based sample of twins from the United Kingdom. Developmental trajectories were described using teachers' ratings of CU at 7, 9, and 12 years old. Results: We identified four trajectories of CU through general growth mixture modeling: stable high, increasing, decreasing, and stable low. In most cases, the trajectory-group membership was largely driven by genetic and to a lesser extent by nonshared environmental influences for boys and girls. The most notable exception was a strong contribution of shared environment for the girls in the stable-high trajectory group. Conclusions: Our findings suggest distinct developmental trajectories of CU from childhood to early adolescence, which are in most cases influenced by genetic factors and, to a lesser degree, by nonshared environmental factors. Highest heritability was observed for boys on a stable-high CU trajectory. Interestingly, the trajectory-group membership for girls on a stable-high CU trajectory appeared to be almost entirely driven by shared environmental influences. These differences in the etiology of stable-high CU in boys and girls have potential implications for clinical practice and studies attempting to identify genetic and environmental risk factors for high CU. (Contains 1 figure and 4 tables.)

The lateral wall stabilities during the growing process of cellular crystal in the melt were studied in this article. The dynamics equation of cylindrical solid-liquid interface morphological stabilities in melt was first derived, and then the expression of criterion for cylindrical solid-liquid interface morphological stabilities was defined. The effect of the shape factor, solid radius, and other relevant factors on the morphological stabilities was analyzed. Also, the critical shape factor and critical growth rate for keeping the stabilities of the interface were determined. The phenomenon during the lateral growth process of ?-phase cellular crystal in carbon steel was observed under a high-temperature confocal scanning laser microscope (HTCSLM), which was used to verify the theoretical analysis and calculated results. The results indicate that the shape factor is beneficial to improving the stabilities of the cellular crystal lateral wall. During the increase process of the cellular crystal radius, however, there is a certain value of the cellular crystal radius, which induces the shape factor to reduce stabilities of the cellular crystal lateral wall rapidly. Even if the other conditions are unchanged, the shape of the cellular crystal may also cause the cellular crystal lateral wall to lose its stabilities. There are two critical growth rates to keep the cellular crystal lateral wall growing stably under the conditions of this research. For the Fe-0.15 pct C-0.8 pct Mn alloy, these two critical growth rates are 10-4 and 10 cm/s orders of magnitude, respectively. The difference between them is more than 105 times, so the slow critical growth rate conforms to the actual critical growth rate. The radius of the cellular crystal is the main influencing factor of lateral wall stabilities. The bigger the radius of the cellular crystal is, the worse the stabilities of the lateral wall are. That is also one of the reasons that the fine cellular crystal can survive during a certain period. The results of the theoretical analysis about stabilities of the cellular crystal lateral wall agree well with the lateral growth phenomena of ? phase cellular crystal in carbon steel observed by a HTCSLM. The theoretically calculated results of the radial critical growth rates are coincident with the experimental results.

Epidermal growth factor receptors are present in many reproductive tissues but have not been demonstrated in the human corpus luteum. To determine the presence of epidermal growth factor receptors and its binding characteristics, we carried out studies on the plasma cell membrane fraction of seven human corpora lutea (days 16 to 25) of the menstrual cycle. Specific epidermal growth factor receptors were present in human corpus luteum. Insulin, nerve growth factor, and human chorionic gonadotropin did not competitively displace epidermal growth factor binding. The optimal conditions for corpus luteum-epidermal growth factor receptor binding were found to be incubation for 2 hours at 4 degrees C with 500 micrograms plasma membrane protein and 140 femtomol /sup 125/I-epidermal growth factor per incubate. The number (mean +/- SEM) of epidermal growth factor binding sites was 12.34 +/- 2.99 X 10(-19) mol/micrograms protein; the dissociation constant was 2.26 +/- 0.56 X 10(-9) mol/L; the association constant was 0.59 +/- 0.12 X 10(9) L/mol. In two regressing corpora lutea obtained on days 2 and 3 of the menstrual cycle, there was no detectable specific epidermal growth factor receptor binding activity. Similarly no epidermal growth factor receptor binding activity could be detected in ovarian stromal tissue. Our findings demonstrate that specific receptors for epidermal growth factor are present in the human corpus luteum. The physiologic significance of epidermal growth factor receptors in human corpus luteum is unknown, but epidermal growth factor may be involved in intragonadal regulation of luteal function.

The specific growth rates of Brochothrix thermosphacta, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Clostridium perfringens at various temperatures were taken from the Food MicroModel database, and the data sets of specific growth rate versus temperature were fitted using the multiplicative model (r = a Td, r = specific growth rate; T = temperature; a, d = regression parameters). The exponential d-value derived from microbial growth at suboptimum temperatures reflected the effectiveness of temperature in enhancing growth. A microorganism with a large d-value exhibited a large increment of growth rate as temperature increased. The d-value of a microorganism was related to the temperature range for growth. The temperature range for the growth of psychrotrophs was usually narrow for B. thermosphacta and Y. enterocolitica; hence the d-values of these two psychrotrophs were close to 1 whereas d-values of mesophiles, such as B. cereus, E. coli O157:H7, Salmonella spp., and S. aureus, were 2.31-2.90, and the d-value of C. perfringens, a thermophile, was 3.29. The values of parameter a of the model were affected by extra salt added into cultures. For all the strains mentioned above, the a-values decreased when the cultures contained higher levels of salt. The lowering of the a-value implied that the influence of temperature on the growth rate in the model was reduced. The change of the d-value was dependent on the capability of the microorganism to overcome the obstacle to growth and was affected by the composition of the nutrients and by inhibitory factors in the culture. The influence of environmental factors on the d-value was also found in Chinese sausages. The d-value of a dominant spoilage strain of Enterococcus sp. derived from sausages was 0.833 whereas the d-value derived from MRS cultures was 2.36. In refrigerated foods which usually contained some preservatives and were stored at low temperature, the d-value of psychrotrophic spoilage bacteria was around 1. In this case, the linear model could be a reasonable choice for predicting the proliferation of spoilage bacteria. PMID:9615472

In 2005, Swiss citizens endorsed a moratorium on gene technology, resulting in the prohibition of the commercial cultivation of genetically modified crops and the growth of genetically modified animals until 2013. However, scientific research was not affected by this moratorium, and in 2008, GMO field experiments were conducted that allowed us to examine the factors that influence their acceptance by the public. In this study, trust and confidence items were analyzed using principal component analysis. The analysis revealed the following three factors: "economy/health and environment" (value similarity based trust), "trust and honesty of industry and scientists" (value similarity based trust), and "competence" (confidence). The results of a regression analysis showed that all the three factors significantly influenced the acceptance of GM field experiments. Furthermore, risk communication scholars have suggested that fairness also plays an important role in the acceptance of environmental hazards. We, therefore, included measures for outcome fairness and procedural fairness in our model. However, the impact of fairness may be moderated by moral conviction. That is, fairness may be significant for people for whom GMO is not an important issue, but not for people for whom GMO is an important issue. The regression analysis showed that, in addition to the trust and confidence factors, moral conviction, outcome fairness, and procedural fairness were significant predictors. The results suggest that the influence of procedural fairness is even stronger for persons having high moral convictions compared with persons having low moral convictions. PMID:22150405

Early nutrition in infancy may influence later child health outcomes including overweight through 'programming'. Systematic reviews suggest that breastfeeding is associated with a modest reduction in the risk of later overweight and obesity. This commentary explores some of these mechanisms behind this association. Generally breastfed infants are leaner than artificially (formula)-fed infants and behavioural and hormonal mechanisms may explain this difference. The theory is that a high nutrient diet in infancy adversely programs the principal components of the metabolic syndrome in the child (body mass index, blood pressure and blood lipids) by promoting growth acceleration, whereas slower growth benefits later cardiovascular disease and its risk factors. Artificial-feeding stimulates a higher postnatal growth velocity with the adiposity rebound occurring earlier in those children who have greater fatness later, whereas breastfeeding has been shown to promote slower growth. The adverse long-term effects of early growth acceleration emerge as fundamental in later overweight and obesity. The higher protein content of artificial baby milk compared to the lower protein content in breastmilk is responsible for the increased growth rate and adiposity during the influential period of infancy of formula-fed infants. Breastfeeding, on the other hand, has a protective effect on child overweight and obesity by inducing lower plasma insulin levels, thereby decreasing fat storage and preventing excessive early adipocyte development. Plausible biological mechanisms underlying the protective effect of breastfeeding against obesity are based on the unique composition of human milk and the metabolic and physiological responses to human milk. PMID:22946146

In the literature, few studies analyze the effect of GH therapy on height, preferring a more indirect approach, where factors influencing the total pubertal and pre-pubertal growth in GH-deficient patients are evaluated and subsequently used to estimate the overall effect at the end of the therapy; unfortunately, this approach does not quantify the real growth gain in treated patients. Using a non-parametric Empirical Bayes approach, our study analyzes the growth response to GH treatment in a homogeneous cohort of 317 patients with pituitary GH deficiency who were enrolled during their pre-pubertal stage in the GH Piedmont Registry (Italy), between January 2000-October 2008, and have at least 2 yr of follow-up. To estimate the growth curve for males and females, a non-parametric regression model was fitted, applying Empirical Bayes techniques. A validation of the model was also performed. Improvement was evident in both genders, since both males and females mean growth curve, which started below the 3rd percentile at the beginning of the therapy, reached the 10th percentile of the Tanner curve at the end of observation (17 yr old for males and 14 yr old for females); the estimation procedure achieved a good precision. The methodological approach allows for fitting a model able to evaluate longitudinally the response to GH treatment, by means of estimating the overall growth curve, even in presence of sparse information about children heights. PMID:22490990

Heart growth is tightly controlled so that the heart reaches a predetermined size. Fetal heart growth occurs through cardiomyocyte proliferation, whereas postnatal heart growth involves primarily physiological cardiomyocyte hypertrophy. The Hippo kinase cascade is an important regulator of organ growth. A major target of this kinase cascade is YAP1, a transcriptional coactivator that is inactivated by Hippo kinase activity. Here, we used both genetic gain and loss of Yap1 function to investigate its role in regulating proliferative and physiologic hypertrophic heart growth. Fetal Yap1 inactivation caused marked, lethal myocardial hypoplasia and decreased cardiomyocyte proliferation, whereas fetal activation of YAP1 stimulated cardiomyocyte proliferation. Enhanced proliferation was particularly dramatic in trabecular cardiomyocytes that normally exit from the cell cycle. Remarkably, YAP1 activation was sufficient to stimulate proliferation of postnatal cardiomyocytes, both in culture and in the intact heart. A dominant negative peptide that blocked YAP1 binding to TEAD transcription factors inhibited YAP1 proliferative activity, indicating that this activity requires YAP1-TEAD interaction. Although Yap1 was a critical regulator of cardiomyocyte proliferation, it did not influence physiological hypertrophic growth of cardiomyocytes, because postnatal Yap1 gain or loss of function did not significantly alter cardiomyocyte size. These studies demonstrate that Yap1 is a crucial regulator of cardiomyocyte proliferation, cardiac morphogenesis, and myocardial trabeculation. Activation of Yap1 in postnatal cardiomyocytes may be a useful strategy to stimulate cardiomyocyte expansion in therapeutic myocardial regeneration. PMID:22308401

The neurofibromatosis-2 (NF2) gene encodes merlin, an ezrin-radixin-moesin-(ERM)-related protein, that functions as a tumor suppressor. I found that merlin plays a critical role in the establishment and maintenance of contact inhibition of growth. At high cell density, merlin is activated and blocks profileration with corresponding changes in cell cycle parameters. Merlin interfered with growth factor receptor or Ras-dependent signal transduction of MAP kinase and the step of interference was located downstream of Ras and Raf and upstream of MEK. Merlins growth inhibiting function depended on interaction with a specific domain of the cytoplasmic tail of CD44. In addition merlin activity and phosphorylation status depended on the extracellular ligand associated with the N-terminus of CD44. At high cell densities, in the presence of the extracellular ligand HA, merlin was dephosphorylated and bound directly to a basic amino acid motif in the cytoplasmic tail of CD44. Ezrin and moesin, which are also known to bind to the same basic amino acid motif in CD44 were absent within this growth inhibitory complex. Alternatively in logarithmically growing cells, merlin was inactive, phosphorylated and in a complex with ezrin and moesin. This growth permissive complex was also associated with the cytoplasmic tail of CD44. My data provide not only significant clues about how merlin functions as a tumor suppressor but revealed the existence of a novel molecular switch that, under the influence of ligands in the microenvironment, controls a cell decision to proliferate or growth arrest. (orig.)

Students in the United States change schools often, and frequent changes are associated with poor outcomes along numerous dimensions. These moves occur for many reasons, including both promotional transitions between educational levels and nonpromotional moves. Promotional student mobility is less likely than nonpromotional mobility to suffer from confounding due to unobserved factors. Using panel data from students enrolled in grades 3 to 8 in the Metropolitan Nashville Public Schools during the implementation of a major change in school attendance policies, this article investigates the potential influence of four types of school changes--including promotional student mobility--on test score growth in reading and mathematics. All types of changes are associated with lower achievement growth during the year the enrollment change occurred, representing approximately 6 percent of expected annual growth, or 10 days of instruction. This incremental deficit is particularly concerning for disadvantaged students since they change schools more frequently. The results suggest that being new to a school does influence student achievement net of other factors; they also imply that important social ties are ruptured when students change schools. (Contains 10 notes, 2 figures, and 3 tables.)

Abstract in english The precise nature of hormones and growth factors directly responsible for cartilage maturation is still largely unclear. Since longitudinal bone growth occurs through endochondral bone formation, excess or deficiency of most hormones and growth factors strongly influences final adult height. The structure and composition of the cartilaginous extracellular matrix have a critical role in regulating the behavior of growth plate chondrocytes. Therefore, the maintenance of th (more) e three-dimensional cell-matrix interaction is necessary to study the influence of individual signaling molecules on chondrogenesis, cartilage maturation and calcification. To investigate the effects of insulin on both proliferation and induction of hypertrophy in chondrocytes in vitro we used high-density micromass cultures of chick embryonic limb mesenchymal cells. Culture medium was supplemented with 1% FCS + 60 ng/ml (0.01 µM) insulin and cultures were harvested at regular time points for later analysis. Proliferating cell nuclear antigen immunoreactivity was widely detected in insulin-treated cultures and persisted until day 21 and [³H]-thymidine uptake was highest on day 14. While apoptosis increased in control cultures as a function of culture time, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-labeled cells were markedly reduced in the presence of insulin. Type II collagen production, alkaline phosphatase activity and cell size were also lower in insulin-treated cultures. Our results indicate that under the influence of 60 ng/ml insulin, chick chondrocytes maintain their proliferative potential but do not become hypertrophic, suggesting that insulin can affect the regulation of chondrocyte maturation and hypertrophy, possibly through an antiapoptotic effect.

Articular cartilage degeneration in osteoarthritis (OA) involves type II collagen degradation and chondrocyte differentiation (hypertrophy). Because these changes resemble growth plate remodeling, we hypothesized that collagen degradation may be inhibitable by growth factors known to suppress growth...

Responses of mountain birch growth to changed environmental conditions are strongly affected by birch genotype, and nitrogen economy is a key factor influencing the winter survival of first-year seedlings. These are some of the findings of a series of studies, in which growth, nitrogen economy and winter survival were analysed using pot-grown seedlings of mountain birch (Betula pubescens ssp. czerepanovii) exposed to various environmental conditions in northern Sweden. Differences between birch genotypes were studied at the individual, ecotype and provenance levels. The experimental factors included temperature, nutrient availability and ultraviolet radiation. In addition, the influence of neighbouring vegetation on birch nitrogen economy was evaluated. Nutrient availability and temperature were recorded in situ during one year in three mountain birch woodland soils. Environmental effects on nitrogen economy varied between years, during a growing season and between seedling age groups. In many cases differences in growth between birch genotypes were only apparent under certain types of environmental conditions. An interaction between genotype and environment was apparent in the case of elevational ecotypes. Thus, an increase in leaf nitrogen content with altitude was attributed to both a phenotypic adjustment and a genetic adaptation to decreasing temperature. The rate of nitrogen accumulation in mountain birch during the growing season determined the survival rate of first-year seedlings the following winter. The environmental conditions, neighbouring vegetation, and genotype all affected the nitrogen accumulation rate of young seedlings and could influence their survival. Soil temperature was concluded to have a major influence on the survival of young birch seedlings owing to its strong impact on the root nitrogen uptake rate 69 refs, 3 figs, 2 tabs

... the tissue to basically sit and also there's growth factors in this. The humeral head has a ... possibly enrolled this patient is the use of growth factors, where we spin the patient's blood, remove ...

... proteins called transforming growth factor beta receptor 1 (TGFBR1) and transforming growth factor beta receptor 2 (TGFBR2.) ... to determine if there is a mutation in TGFBR1 or TGFBR2 The special tests should include both ...

The ileal Peyer's patch (PP) is the major site of B cell production and immunoglobulin diversification in lambs, but the factors which regulate these processes are poorly understood. As a first step toward identifying possible regulatory mechanisms, stable long-term cultures of ileal PP stromal cells were established at the clonal level. Four distinct cell types were identified by their phenotype and growth requirements. Immunohistochemical staining confirmed that all clones were mesenchymal (vimentin+; cytokeratin-) in origin and were negative for T cell, B cell, and macrophage markers. Three cell lines were negative for major histocompatibility complex (MHC) I and II molecules, but one cell line, SCN, expressed MHC I, MHC II and CD44 molecules, and a subpopulation of SCN cells expressed BAQ44A, a B cell differentiation molecule. The four cell lines produced different types and amounts of extracellular matrix proteins, and their growth was not influenced by exogenous human interleukin 1 (IL-1), IL-2, transforming growth factor beta 1 (TGF beta 1), or bovine fibroblast growth factor (FGF) but was influenced by serum. When tested for their capacity to support lymphocyte growth, all clones produced a soluble factor(s) that was mitogenic for ileal and jejunal PP cells and thymocytes. Similar growth promoting activity was observed with culture supernatants of murine, human and bovine fibroblasts but could not be reproduced using recombinant human cytokines. Furthermore, coculture of stromal cells with ileal PP follicular B cells elicited a proliferative response unique to each stromal cell line. Coculture with increasing numbers of SCN cells inhibited B cell proliferative responses, whereas coculture with SCG2 and SCF32 cells enhanced B cell proliferative response at both low and high stromal cell densities. Ileal PP follicular B cells rapidly bound to the surface of all stromal cell clones, and this interaction was specific when compared with thymocytes or peripheral blood lymphocytes. These results suggest that ileal PP stromal cells are a phenotypically and functionally heterogeneous population that may enhance or inhibit B lymphopoiesis in the ileal PP. PMID:8457786

We present experimental and theoretical investigations of the influence of static electric and magnetic fields on the exciton g-factor (g{sub ex,zz}) of self-assembled InGaAs-GaAs quantum dots. The use of a novel growth procedure allows us to precisely control the dot height (h=2-6 nm) by partially capping the dots with GaAs before introducing a growth interruption and annealing step to remove Indium from the growth surface (''In-flush'' method). By performing single quantum dot photoluminescence and photocurrent absorption measurements with magnetic fields up to 15 T applied parallel to the quantum dot growth axis we show that the g{sub ex,zz} can be tuned from 0.4 to -0.4 by applying static electric fields{<=}70 kV/cm. Microscopically, the effect is caused by pushing the electron and hole components of the exciton wavefunction into different regions of the dot, with differing local In-Ga composition. For the tallest dots (h=6 nm) we find that vertical stroke g{sub ex,zz} vertical stroke is also influenced by the static magnetic field. Our experimental findings are in good qualitative agreement with detailed 3D eight-band k.p calculations that incorporates the magnetic field in a fully gauge invariant manner.

Nanoparticulate metal sulfides such as ZnS can influence the transport and bioavailability of pollutant metals in anaerobic environments. The aim of this work was to investigate how the composition of dissolved natural organic matter (NOM) influences the stability of zinc sulfide nanoparticles as they nucleate and aggregate in water with dissolved NOM. We compared NOM fractions that were isolated from several surface waters and represented a range of characteristics including molecular weight, type of carbon, and ligand density. Dynamic light scattering was employed to monitor the growth and aggregation of Zn-S-NOM nanoparticles in supersaturated solutions containing dissolved aquatic humic substances. The NOM was observed to reduce particle growth rates, depending on solution variables such as type and concentration of NOM, monovalent electrolyte concentration, and pH. The rates of growth increased with increasing ionic strength, indicating that observed growth rates primarily represented aggregation of charged Zn-S-NOM particles. Furthermore, the observed rates decreased with increasing molecular weight and aromatic content of the NOM fractions, while carboxylate and reduced sulfur content had little effect. Differences between NOM were likely due to properties that increased electrosteric hindrances for aggregation. Overall, results of this study suggest that the composition and source of NOM are key factors that contribute to the stabilization and persistence of zinc sulfide nanoparticles in the aquatic environment.

Considering the broad influence that microbial Fe(III) oxide reduction can have on subsurface metal/organic contaminant biogeochemistry, understanding the mechanisms that control this process is critical for predicting the behavior and fate of these contaminants in anaerobic subsurface environments. Knowledge of the factors that influence the rates of growth and activity of Fe(III) oxide-reducing bacteria is critical for predicting (i.e., modeling) the long-term influence of these organisms on the fate of contaminants in the subsurface, and for effectively utilizing Fe(III) oxide reduction and associated geochemical affects for the purpose of subsurface metal/organic contamination bioremediation. This research project will refine existing models for microbiological and geochemical controls on Fe(III) oxide reduction, using laboratory reactor systems that mimic, to varying degrees, the physical and chemical conditions of the subsurface. Novel experimental methods for studying the kinetics of microbial Fe(III) oxide reduction and measuring growth rates of Fe(III) oxide-reducing bacteria will be developed. These new methodologies will be directly applicable to studies on subsurface contaminant transformations directly coupled to or influenced by microbial Fe(III) oxide reduction.

The properties of wave-like helically twisted normal mode structures on steady relativistic jets are summarized. Wave speeds are a function of the wavelength and less than the jet speed. However, normal mode interference can lead to both stationary and superluminal phase effects. A maximum pressure fluctuation criterion suggested by numerical simulations of axisymmetric relativistic jets is used to find the maximum asymmetric jet distortions and velocity fluctuations. Cyclic transverse velocity fluctuation can lead to variation in the flow direction on the order of the relativistic beaming angle. Resulting variation in the Doppler boost factor can lead to significant brightness asymmetries as helical structures twist around the jet beam. Growth of these structures is reduced as the jet density, Lorentz factor or Mach number are increased. Maximum jet distortion is reduced as the Lorentz factor increases and this suggests a reduction in mass entrainment or other non-linear disruptive processes that influence t...

The protein kinase field is a very active research area in the pharmaceutical industry and many activities are ongoing to identify inhibitors of these proteins. The design of new chemical entities with improved pharmacological properties requires a deeper understanding of the factors that modulate inhibitor-kinase interactions. In this report, we studied the effect of two of these factors-the magnesium ion cofactor and the protein substrate-on inhibitors of the type I insulin-like growth factor receptor. Our results show that the concentration of magnesium ion influences the potency of adenosine triphosphate (ATP) competitive inhibitors, suggesting an explanation for the observation that such compounds retain their nanomolar potency in cells despite the presence of millimolar levels of ATP...

An important aspect of studying mixed cultures of microalgae is the artificial ecosystems containing algal culture as a regeneration link and a source of vegetable substances. The peculiarities of studying the stability of microalgae mixed cultures in the laboratory and natural environment have been considered in the work. The role of factors most essentially affecting the species structure of phytoplankton community (temperature factor, light intensity, pH environments, elements of mineral nutrition, algal metabolites, predation and fluctuation of environmental conditions) has been displayed. As a result of experimental and theoretical modelling of the microalgae Chlorella vulgaris and Scenedesmus quadricauda competition under limitation on nitrogen, the impossibility of their co-existence has been revealed. Under these conditions Chl. vulgaris turned out to be less competitive than Sc. quadricauda. The influence of the ratio of biogenic elements concentration in the environment, which should be recognized as an independent regulatory factor limiting growth of populations in the community and, thus affecting its structure, has been analyzed.

The monoclonal HBA-71 antibody recognizes a Ewing's sarcoma associated antigen, which is also highly expressed on the cell surface of human cortical thymocytes and islets of Langerhans among normal tissues. The antibody was found to inhibit partially the growth of ES tumor cell lines and to trigger proliferation in thymocyte cultures. The influence of growth factors and the effect of the HBA-71 antibody was further investigated in the present study. The growth of ES tumor cells was demonstrated to be dependent on the presence of insulin-like growth factor I or insulin. The HBA-71 antibody (25 micrograms/ml) enhanced the growth stimulatory effect of IGF-I under serum-free conditions. The expression of the HBA-71 epitope is modulated positively by IGF-I and insulin and negatively by dexamethasone and human growth hormone in ES/PNET tumor cells and thymocytes. IGF-I either alone or in combination with HBA-71 stimulated the proliferation of thymocytes under serum-free conditions whereas in complete medium, IGF-I stimulated thymidine incorporation and the HBA-71 antibody either alone or in the presence of IGF-I showed inhibitory activity most likely due to down-regulation of the receptor. These data demonstrate the important role of IGF-I in the growth of ES/PNET tumor cells as well in the proliferative activity of HBA-71 positive normal thymocytes. The biological activity of IGF-I in malignant thymocytes, pancreas tumors, fetal muscle, brain, granulosa and Sertoli cells has been documented in the literature.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1656551

Hepatic stellate cells (HSCs) are key cellular components of hepatic wound healing and fibrosis. There is emerging evidence that the fibrogenic function of HSCs may be influenced by neurochemical and neurotrophic factors. This study addresses the potential for the serotonin (5-HT) system to influence HSC biology. Rat and human HSCs express the 5-HT1B, 5-HT1F 5-HT2A 5-HT2B, and 5-HT7 receptors, with expression of 5-HT1B 5-HT2A and 5-HT2B being induced on HSC activation. Induction of 5-HT2A and 5-HT2B was 106+/-39- and 52+/-8.5-fold that of quiescent cells, respectively. 5-HT2B was strongly associated with fibrotic tissue in diseased rat liver. Treatment of HSCs with 5-HT2 antagonists suppressed proliferation and elevated their rate of apoptosis; by contrast 5-HT was protective against nerve growth factor-induced apoptosis. 5-HT synergized with platelet-derived growth factor to stimulate increased HSC proliferation. HSCs were shown to express a functional serotonin transporter and to participate in both active uptake and release of 5-HT. We conclude that HSCs express key regulatory components of the 5-HT system enabling them to store and release 5-HT and to respond to the neurotransmitter in a profibrogenic manner. Antagonists that selectively target the 5-HT class of receptors may be exploited as antifibrotic drugs. PMID:16936262