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Potential Consequences (potential + consequence)
Selected AbstractsProbing ligand-induced conformational changes of human CD38FEBS JOURNAL, Issue 10 2000Valérie Berthelier The lymphoid surface antigen CD38 is basically a NAD+glycohydrolase, which is also involved in the metabolism of cyclic ADP-ribose. Besides, this ecto-enzyme has potential signalling roles in T- and B-cells. Such multiple functions prompted us to study the molecular dynamics of the CD38 protein and especially the relationship between its ecto-enzymatic active site and its epitope, i.e. the binding site of most known anti-CD38 monoclonal antibodies. Both epitopic and enzymatic sites were shown to be degraded by proteases, such as trypsin or chymotrypsin. This sensitivity was almost entirely suppressed in the presence of substrates or inhibitors. Both sites were also degraded in the presence of reducing agents, as dithiothreitol. Inhibitory ligands induced the same resistance of both sites against reducing attack. The binding of CD38 ligands to the active site triggers therefore conformational changes that shield some backbone bonds and disulfide bridges against, respectively, proteolytic cleavage or reduction. This transconformation was found moreover to irreversibly take place after incubation with substrates such as NAD+ in the presence of dithiothreitol. The epitope remained preserved, while the enzymatic activity was lost. This inactivation probably resulted from the covalent trapping of the catalytically reactive intermediate in the active site (i.e. paracatalytic inactivation). These data have major implications in the knowledge of the CD38 structure, especially with regard to the location of disulfide bridges and their accessibility. Potential consequences of the conformational plasticity of CD38 should also be considered in its physiological functions such as signalling. [source] Applying climatically associated species pools to the modelling of compositional change in tropical montane forestsGLOBAL ECOLOGY, Issue 2 2008Duncan J. Golicher ABSTRACT Aim, Predictive species distribution modelling is a useful tool for extracting the maximum amount of information from biological collections and floristic inventories. However, in many tropical regions records are only available from a small number of sites. This can limit the application of predictive modelling, particularly in the case of rare and endangered species. We aim to address this problem by developing a methodology for defining and mapping species pools associated with climatic variables in order to investigate potential species turnover and regional species loss under climate change scenarios combined with anthropogenic disturbance. Location, The study covered an area of 6800 km2 in the highlands of Chiapas, southern Mexico. Methods, We derived climatically associated species pools from floristic inventory data using multivariate analysis combined with spatially explicit discriminant analysis. We then produced predictive maps of the distribution of tree species pools using data derived from 451 inventory plots. After validating the predictive power of potential distributions against an independent historical data set consisting of 3105 botanical collections, we investigated potential changes in the distribution of tree species resulting from forest disturbance and climate change. Results, Two species pools, associated with moist and cool climatic conditions, were identified as being particularly threatened by both climate change and ongoing anthropogenic disturbance. A change in climate consistent with low-emission scenarios of general circulation models was shown to be sufficient to cause major changes in equilibrium forest composition within 50 years. The same species pools were also found to be suffering the fastest current rates of deforestation and internal forest disturbance. Disturbance and deforestation, in combination with climate change, threaten the regional distributions of five tree species listed as endangered by the IUCN. These include the endemic species Magnolia sharpii Miranda and Wimmeria montana Lundell. Eleven vulnerable species and 34 species requiring late successional conditions for their regeneration could also be threatened. Main conclusions, Climatically associated species pools can be derived from floristic inventory data available for tropical regions using methods based on multivariate analysis even when data limitations prevent effective application of individual species modelling. Potential consequences of climate change and anthropogenic disturbance on the species diversity of montane tropical forests in our study region are clearly demonstrated by the method. [source] The aging male , diagnosis and therapy of late-onset hypogonadismJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2008Gerhard Schreiber Summary Managing the clinical features of hormone insufficiency in aging men is an important field of activity for dermatologists and in particular for dermatologists specialized in andrology. Potential consequences of age-associated decrease in plasma testosterone levels include long-term changes in diverse organ systems including changes of bone architecture, body composition, muscular strength, cognitive functions, and mood as well as negative effects on skin and hair. Indications and contraindications for a hormone replacement therapy as well as therapy monitoring are well-defined. Replacement of testosterone in the case of late-onset hypogonadism is not a standardized therapy. Previous studies suggest that testosterone replacement therapy has positive clinical effects. Dermatologic effects of testosterone replacement therapy have not yet been investigated. Further research is required to identify potential benefits and risks of hormone replacement therapy in aging men. [source] Loss of Ammine from Platinum(II) Complexes: Implications for Cisplatin Inactivation, Storage, and Resistance,CHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2005Justin Kai-Chi Lau Abstract Potential consequences of the binding of the anticancer drug cisplatin to various biomolecules in the cell have been investigated by using a combined density functional theory and continuum dielectric model approach. Since the ammine ligands remain coordinated at the metal upon formation of the most frequent DNA adducts, whereas they were found to be displaced from the metal upon formation of drug metabolites, we have analyzed the factors governing ammine loss from platinum(II) complexes as a possible pathway of cisplatin inactivation. The calculations systematically show the effect of 1) the trans ligand, 2) the charge of complex, 3) the nucleophile, and 4) the environment on the thermodynamic instability and kinetic lability of the platinum,ammine bonds. After initial binding of cisplatin hydrolysis products to thioethers or thiols, loss of the ammine trans to this sulfur ligand rather than replacement of the sulfur ligand itself by other nucleophiles like guanine-N7 is predicted to be the predominant reaction. The results of this study contribute to an understanding of the modes of cisplatin inactivation prior to DNA binding, for example, by elevated glutathione levels in cisplatin-resistant cancer cells. [source] SEXUAL CONFLICT AND PROTEIN POLYMORPHISMEVOLUTION, Issue 7 2004Ralph Haygood Abstract Sexual conflict, where male and female reproductive interests differ, is probably widespread and often mediated by male or sperm proteins and female or egg proteins that bind to each other during mating or fertilization. One potential consequence is maintenance of polymorphism in these proteins, which might result in reproductive isolation between sympatric subpopulations. I investigate the conditions for polymorphism maintenance in a series of mathematical models of sexual conflict over mating or fertilization frequency. The models represent a male or sperm ligand and a female or egg receptor, and they differ in whether expression of either protein is haploid or diploid. For diploid expression, the conditions imply that patterns of dominance, which involve neither overdominance nor un-derdominance, can determine whether polymorphism is maintained. For example, suppose ligand expression is diploid, and consider ligand alleles L1 and L2 in interactions with a given receptor genotype; if L1/L1 males are fitter than L2/L2 males in these interactions, then polymorphism is more likely to be maintained when L1/L2 males more closely resemble L1/L1 males in these interactions. Such fitter-allele dominance might be typical of a ligand or its receptor due to their biochemistry, in which case polymorphism might be typical of the pair. [source] The price of natural gasOPEC ENERGY REVIEW, Issue 4 2001A.M. Samsam Bakhtiari Natural gas used to be a relatively Cheap primary energy source, always at a discount to crude oil (on a comparative British thermal unit basis). It gradually evolved into a major resource during the 20th century , reaching a 24 per cent share of global primary energy in 1999. In the year 2000, natural gas prices in the USA rose to unheard-of highs of $10/million Btu, ushering in a new era, with natural gas at a 120 per cent premium to crude oil. This clearly was a watershed for gas, somehow similar to the 1973-74 watershed for oil prices. And similarly, any return to the status quo-ante looks rather improbable, although a number of experts (alongside the International Energy Agency) still believe the 2000 price ,spike' to have been "only transitory" The consequences of higher gas prices (at a level equal to crude oil prices on a Btu basis) will be multifaceted and momentous, altering habits and uses in downstream industries and economic sectors, as well as providing added income for major gas-exporters, such as Russia, Canada and Algeria. Another potential consequence of the 2000 watershed might be to propel US standard prices (such as the ,Henry Hub' spot) to international status and gas price-setter, as the ,WTI spot' became an "international benchmark" for crude oils in the post-1993 era. For the time being, the equality of gas and oil prices has become the new norm; but, in the longer term, a discount of crude oil relative to natural gas might be envisaged, as the latter is a cleaner fuel and emits less carbon dioxide when used. [source] Reduced Cold Pain Tolerance in Chronic Pain Patients Following Opioid DetoxificationPAIN MEDICINE, Issue 8 2008Jarred Younger PhD ABSTRACT Objective., One potential consequence of chronic opioid analgesic administration is a paradoxical increase of pain sensitivity over time. Little scientific attention has been given to how cessation of opioid medication affects the hyperalgesic state. In this study, we examined the effects of opioid tapering on pain sensitivity in chronic pain patients. Design., Twelve chronic pain patients on long-term opioid analgesic treatment were observed in a 7- to 14-day inpatient pain rehabilitation program, with cold pain tolerance assessed at admission and discharge. The majority of participants were completely withdrawn from their opioids during their stay. Outcome Measures., We hypothesized that those patients with the greatest reduction in daily opioid use would show the greatest increases in pain tolerance, as assessed by a cold pressor task. Results., A linear regression revealed that the amount of opioid medication withdrawn was a significant predictor of pain tolerance changes, but not in the direction hypothesized. Greater opioid reduction was associated with decreased pain tolerance. This reduction of pain tolerance was not associated with opioid withdrawal symptoms or changes in general pain. Conclusions., These findings suggest that the withdrawal of opioids in a chronic pain sample leads to an acute increase in pain sensitivity. [source] An overview of inherently safer design,PROCESS SAFETY PROGRESS, Issue 2 2006Dennis C. Hendershot Inherently safer product and process design represents a fundamentally different approach to safety in the manufacture and use of chemicals. The designer is challenged to identify ways to eliminate or significantly reduce hazards, rather than to develop add-on protective systems and procedures. In the chemical process industries, risk management layers of protection are classified as inherent, passive, active, and procedural. Inherently safer design focuses on eliminating hazards, or minimizing them significantly, to reduce the potential consequence to people, the environment, property, and business. Inherently safer design is considered to be the most robust way of dealing with process risk and can be considered to be a subset of green chemistry and green engineering. It focuses on safety hazards,the immediate impacts of single events such as fires, explosions, and short-term toxic impacts. Many of the strategies of inherently safer design are not specific to the chemical industry, but apply to a broad range of technologies. Strategies for identifying inherently safer options are discussed, with examples. However, for most facilities, a complete risk management program will include features from all categories of layers of protection. Also, the designer must be aware that all processes and materials have multiple hazards and that there can be conflicts among the risks associated with different alternatives. Design alternatives that reduce or eliminate one hazard may create or increase the magnitude of others. Recognition and understanding of these conflicts will enable the designer to make intelligent decisions to optimize the design. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source] Serum Iron and Matrix Metalloproteinase-9 Variations in Limbs Affected by Chronic Venous Disease and Venous Leg UlcersDERMATOLOGIC SURGERY, Issue 6 2005Paolo Zamboni MD Background. Severe chronic venous disease (CVD) is characterized by both dermal hemosiderin accumulation and matrix metalloproteinase (MMP) hyperactivation. The iron-driven pathway is one of the recognized mechanisms of MMP hyperactivation. Objective. To investigate the potential consequences of leg hemosiderin deposits on both iron metabolism and activation of MMPs. Methods. We contemporaneously assessed the following in the serum of the arm and ankle veins of 30 patients (C4,6) with CVD and 14 normal subjects: ferritin, transferrin, iron, percentage of transferrin iron binding capacity (%TIBC), and MMP-9. Optical microscopy examinations with Perls' staining of chronic wounds were also performed. Results. Histology consistently revealed iron deposits. Serum ferritin, iron, and %TIBC were significantly increased in the legs affected by severe CVD compared with the arm of the same subjects or the controls. In addition, iron and %TIBC were significantly elevated in the legs of ulcer patients. The rate of activation of MMP-9 was significantly elevated in CVD. Conclusions. The increased iron deposition in legs affected by CVD seems to be more instable in ulcer patients, leading to iron release in the serum of the affected leg. Our data suggest the iron-driven pathway as a further mechanism for MMP hyperexpression leading to tissue lesion. [source] Global Trade Models and Economic Policy Analyses: Relevance, Risks and Repercussions for AfricaDEVELOPMENT POLICY REVIEW, Issue 2 2008Hakim Ben Hammouda Computable general equilibrium models are widely used for trade policy analyses and recommendations. There is, however, increasing discomfort with the use of these models, especially in Africa. This article demonstrates that the results of several such studies of the impact of trade reforms in Africa differ drastically in terms of both magnitude and direction, failing to take account of key features of African economies. It also outlines potential consequences of the misuse of CGE models for policy evaluation and suggests pitfalls to be avoided. [source] Spontaneous kicking in full-term and preterm infants with and without white matter disorderDEVELOPMENTAL PSYCHOBIOLOGY, Issue 6 2010Linda Fetters Abstract Early damage to white matter of the brain may have developmental consequences for prematurely born infants including the coordination of leg movements. Our perspective is that white matter damage initiates an ontogenetic course that may lead to movement dysfunction leading to disability. In this study, spontaneous kicking in the human infant is a "window" for evaluating the potential consequences of perinatal brain damage for sensori-motor coordination. We compare the intra-limb coordination patterns of 5-month-old premature infants with white matter damage (PTWMD) to a group of prematurely born infants without WMD (PT) and a group of full-term (FT) infants. The PT group demonstrates advanced kicking patterns in comparison to both the PTWMD and FT groups. The PTWMD group has less mature patterns than the FT group on some, but not all measures. The movement challenge for PTWMD infants may be in the transition from spontaneous kicking to movements with the legs that require decoupling of intralimb joints. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 524,536, 2010. [source] The rise of methamphetamine in Southeast and East AsiaDRUG AND ALCOHOL REVIEW, Issue 3 2008REBECCA McKETIN Abstract Introduction and Aims. Southeast and East Asia has become a global hub for methamphetamine production and trafficking over the past decade. This paper describes the rise of methamphetamine supply and to what extent use of the drug is occurring in the region. Method and Design. The current review uses data collected through the Drug Abuse Information Network for Asia and the Pacific (DAINAP) and other available sources to analyse retrospectively methamphetamine trends within Southeast and East Asia. Results. Southeast and East Asia has experienced a methamphetamine epidemic in the past decade which began around 1997 and peaked in 2000,2001. While the situation has since stabilised in many countries, methamphetamine trafficking and use are still increasing in parts of the Mekong region and there is evidence of large-scale manufacture in Cambodia, Indonesia, Malaysia and the Philippines. Methamphetamine is typically smoked or ingested, but injection of the drug is apparent. Conclusion. While the peak of the methamphetamine epidemic has passed in parts of Southeast and East Asia, attention is needed to minimise the potential consequences of spreading methamphetamine production, trafficking and use in the Mekong region and in the peninsular and archipelago of Southeast Asia. [source] Stem galls affect oak foliage with potential consequences for herbivoryECOLOGICAL ENTOMOLOGY, Issue 3 2004L. K. Foss Abstract., ,1. On two dates, foliar characteristics of pin oak, Quercus palustris, infested with stem galls caused by the horned oak gall, Callirhytis cornigera, were investigated, and the consequences for subsequent herbivory assessed. 2. Second-instar caterpillars of the gypsy moth, Lymantria dispar, preferred foliage from ungalled trees. 3. Ungalled trees broke bud earlier than their galled counterparts. 4. Galled trees produced denser leaves with higher nitrogen and tannin concentrations, but foliar carbohydrates did not differ among galled and ungalled trees. 5. Concentrations of foliar carbohydrates in both galled and ungalled trees increased uniformly between the two assay dates. Nitrogen concentrations were greater in leaves from galled trees, and decreased uniformly in galled and ungalled trees over time. Foliar tannins were also greater in foliage from galled trees early in the season; however, foliar tannins declined seasonally in galled tissue so that by the second assay date there was no difference in tannin concentrations between galled and ungalled foliage. 6. In spite of differences in foliar characteristics, performance of older, fourth instar gypsy moth caterpillars did not differ between galled and ungalled trees. [source] The promise and the potential consequences of the global transport of mycorrhizal fungal inoculumECOLOGY LETTERS, Issue 5 2006Mark W. Schwartz Abstract Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species' introductions. Moreover, recent studies of mycorrhizal symbionts have led to an increased knowledge of the potential utility of fungal inoculations in agricultural, horticultural and ecological management. The intentional movement of mycorrhizal fungal species is growing, but the concomitant potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. We assess the degree to which introductions of mycorrhizal fungi may lead to unintended negative, and potentially costly, consequences. Our purpose is to make recommendations regarding appropriate management guidelines and highlight top priority research needs. Given the difficulty in discerning invasive species problems associated with mycorrhizal inoculations, we recommend the following. First, careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Second, invasive species problems are costly and often impossible to control by the time they are recognized. We recommend using local inoculum sources whenever possible. Third, non-sterile cultures of inoculum can result in the movement of saprobes and pathogens as well as mutualists. We recommend using material that has been produced through sterile culture when local inoculum is not available. Finally, life-history characteristics of inoculated fungi may provide general guidelines relative to the likelihood of establishment and spread. We recommend that, when using non-local fungi, managers choose fungal taxa that carry life-history traits that may minimize the likelihood of deleterious invasive species problems. Additional research is needed on the potential of mycorrhizal fungi to spread to non-target areas and cause ecological damage. [source] Effects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studiesECOLOGY OF FRESHWATER FISH, Issue 3 2004M. A. Sotiropoulos Abstract,,, We examined whether solvent-based lipid extractions, commonly used for stable isotope analysis (SIA) of biota, alters ,15N or ,13C values of fish muscle tissue or whole juvenile fish. Lipid extraction from muscle tissue led to only small (<1,) isotope shifts in ,13C and ,15N values. By contrast, ecologically significant shifts (+3.4, for ,13C and +2.8, for ,15N) were observed for whole juvenile fish. Sample variance was not affected by lipid extraction. For tissue-specific SIA, two sample aliquots may be required: a lipid-extracted aliquot for stable carbon isotope analysis when differing lipid content among tissues is a concern, and a nonextracted aliquot for ,15N determination. Whole organism SIA is not recommended because of the mix of tissues having different turnover times; for very small fish, we recommend that fish be eviscerated, decapitated, and skinned to minimise differences with samples of muscle tissue. Resumen 1. Cada vez con mayor frecuencia, los ecólogos de peces utilizan análisis de isótopos estables. Por ello, se hace cada vez más importante comprender las fuentes de variación, - debido a diferencias inherentes entre muestreos biológicos o como resultado de técnicas de procesamiento de muestreo - tanto como identificar estrategias para tratar tales fuentes. Examinamos si la extracción de lípidos basada en disolventes, comúnmente utilizada en análisis de isótopos de carbono estable, altera negativamente los valores de ,15N y ,13C de tejido muscular de tres peces de tamaño pequeño y de peces juveniles completos. 2. La extracción de lípidos de músculo de pez llevó a pequeños cambios isotópicos de + +0.4 a +1.0, y de +0.3 a +0.5, para ,13C y ,15N, respectivamente. Por el contrario, la extracción de lípidos de peces juveniles completos varió marcadamente en +3.4, para ,13C y +2.8, para ,15N - ambos cambios ecológicamente importantes. La varianza de los valores de muestreos de ,13C y de ,15N tanto para tejido muscular como para los peces completos no difirieron entre los muestreos de lípidos extraídos y muestreos sin tratamiento. 3. Nuestros resultados recomiendan el análisis de isótopos estables de tejidos específicos. Cuando ello no es posible o deseable, dos alícuotas de muestreo pueden ser requeridas: una alícuota de lípidos extraídos para el análisis de isótopos de carbono estable cuando la varianza de ,13C, debida a diferencias en el contenido de lípidos de diferentes tejidos, y una alícuota de no-extracción para determinaciones de ,15N. 4. Dada la mezcla de tejidos, el análisis de isótopos de un organismo completo no es recomendable , en el caso de peces muy pequeños, recomendamos que los peces sean eviscerados, decapitados, y despellejados para minimizar las diferencias de muestreos de tejido muscular. [source] Authority through synergism: the roles of climate change linkagesENVIRONMENTAL POLICY AND GOVERNANCE, Issue 5 2006Björn-Ola Linnér Abstract This article examines the conceptual basis of synergies between the United Nations Framework Convention on Climate Change (UNFCCC) and other international organizations and agreements. It discusses why synergies are made, what kinds there are and their potential consequences. Considering actors' divergent goals, synergies do not necessarily imply win,win outcomes. The article distinguishes between positive and negative synergetic effects, which should be explicated at different levels, such as the differing goals of various agreements, institutions, parties and social groups. Efforts of international organizations to increase synergy can be regarded as attempts to build authority. Yet, synergy is also used by countries to influence this process. Current synergetic efforts may profoundly affect the relocation of authority in global environmental governance, not only by streamlining mandates, practices and objectives, but also by leading to more powerful international organizations (e.g. WTO) increasingly taking precedence over climate change agreements. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment. [source] Catastrophic incident prevention and proactive risk management in the new biofuels industry,ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2009Judy A. Perry Abstract This article is directed at assisting bioethanol manufacturers with preventing catastrophic incidents which could impact the entire Biofuels Industry. The biofuels industry has common hazards and potential consequences like other industries, related to the handling of flammables, dust explosion hazards and toxic or corrosive materials handling. This article ensures the reader understands these specific bioethanol manufacturer's process hazards are very real as demonstrated by past incidents and their catastrophic results. Regulatory obligations are discussed, as well as key engineering resources and design practices to ensure adequate safeguards are incorporated into the design of a new bioethanol manufacturing facility. The industry is fairly new, however, the hazards and safeguards to reduce the risk level with the common hazards are not new. Preliminary indications are this industry has yet to establish the proactive risk management efforts that are required to reduce the risks to a tolerable level. This article is to provide the supporting data and direction to the Biofuels Industry to ensure each are headed down a path of preventing a future catastrophe. © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source] Cytotoxic effects induced by hexachlorobenzene in Squilla mantis (L.) (Crustacea, Stomatopoda)ENVIRONMENTAL TOXICOLOGY, Issue 1 2008Antonio Dell'Anno Abstract Contamination of marine environments by hexachlorobenzene (HCB) represents a serious concern for potential consequences on ecosystem and human health. Despite this, information on cytotoxic effects on marine organisms is still largely lacking. In this study, we investigated cytotoxic effects induced by HCB on gonads and muscular tissue of Squilla mantis by analysing Na+/K+ -ATPase activity and plasma membrane fluidity. This crustacean species was selected as a model for its habitat, trophic level, feeding behavior, and commercial exploitation for human consumption. Time course experiments revealed that low concentrations of HCB (i.e. 50 nM) determine an exponentially decrease of Na+/K+ -ATPase activity and a significant modification of cellular membrane fluidity. Significant negative relationships between Na+/K+ -ATPase activity and membrane fluidity were observed, suggesting that changes in the structure and packing of cellular membranes induced by HCB may be the primary factor affecting the activity of essential bilayer-associated enzymes. Overall these findings suggest that even small concentrations of HCB may determine important changes on cell metabolism with potential cascade effects on recruitment of this commercial species. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Developmental aspects of distal limb conformation in the horse: the potential consequences of uneven feet in foalsEQUINE VETERINARY JOURNAL, Issue 7 2006A. M. KROEKENSTOEL Summary Reasons for performing study: Distal limb conformation is generally accepted to be an important item with respect to performance and soundness in mature horses, but little is known about the developmental aspects. Objectives: To gain insight into the development of distal limb conformation and to assess the possible consequences of uneven feet in foals. Methods: Conformation of the distal front limbs of 23 Warmblood foals was scored visually and measured using radiographs, at ages 27 and 55 weeks. At the same ages, pressure measurements were made under both front feet. Results: At both ages the hoof-pastern axis was broken-backwards on radiographs, but only occasionally recognised as such, when scored by eye. Over time, the hoof angle decreased, while both the angles of the dorsal and solar surfaces of the distal phalanx (P3) increased and the parallelism between hoof wall and P3 improved. The foals with uneven feet at age 27 weeks showed a significant difference in distal limb loading that persisted until age 55 weeks. Conclusions: The alignment of the distal limb in the sagittal plane increased in a 6 month period. Visual assessment was not sensitive enough to appreciate this. The growth processes in the distal limb could not compensate for existing unevenness and ensuing asymmetrical limb loading. Potential relevance: Foals have a different conformation of the distal limb from mature horses, which should be taken into account when interpreting radiographs. Unevenness of the feet resulted in asymmetrical loading of the proximal and distal interphalangeal joint, which might lead to increased susceptibility to overload injuries and decreased performance at mature age. [source] "A Child Is a Child": Fostering Experiences in Northwestern CameroonETHOS, Issue 1 2007Heidi Verhoef Past research comparing fostered and nonfostered children's welfare in sub-Saharan Africa has led to inconsistent results. One reason for this disparity might be that children's experiences are shaped more by the circumstances in which they are fostered than by merely being raised away from their parents. This article examines how fostered children in one urban community in northwestern Cameroon spend time relative to their nonfostered peers and, by grouping fostered children according to fostering circumstances, how they spend time relative to one another. Analysis of children's activities suggests little variance between the experiences of fostered and nonfostered children, but significant differences among fostered children. These results are interpreted using children's views of activities, and the potential consequences of children's relative integration in foster households are discussed. [source] VACCINATION, WITHIN-HOST DYNAMICS, AND VIRULENCE EVOLUTIONEVOLUTION, Issue 1 2006Jean-Baptiste André Abstract We explore the potential consequences of vaccination on parasite epidemiology and evolution. Our model combines a microscopic (within-host dynamics) and a macroscopic (epidemiological dynamics) description of the interaction between the parasite and its host. This approach allows relevant epidemiological traits such as parasite transmission, parasite virulence, and host recovery to emerge from a mechanistic model of acute infection describing the interaction between the parasite and the host immune system. We model the effect of a vaccine as an activator of immunity enhancing the replication rate of lymphocytes, their initial density at infection's initiation, their efficacy to kill the parasite, or their activation delay after infection. We analyze the evolution of the replication rate of parasites and show that vaccination may promote the evolution of faster replicating and, consequently, more virulent strains. We also show that intermediate vaccination coverage may lead to the coexistence of two different parasite strategies (a low-virulence strain adapted to naive hosts, and a high-virulence strain, more generalist, adapted to both naive and vaccinated hosts). We discuss the consequences of various vaccination strategies under different epidemiological situations using several distinct measures to evaluate the cost induced by the parasite on individuals and entire host populations. [source] The Y42H mutation in medium-chain acyl-CoA dehydrogenase, which is prevalent in babies identified by MS/MS-based newborn screening, is temperature sensitiveFEBS JOURNAL, Issue 20 2004Linda O'Reilly Medium-chain acyl-CoA dehydrogenase (MCAD) is a homotetrameric flavoprotein which catalyses the initial step of the ,-oxidation of medium-chain fatty acids. Mutations in MCAD may cause disease in humans. A Y42H mutation is frequently found in babies identified by newborn screening with MS/MS, yet there are no reports of patients presenting clinically with this mutation. As a basis for judging its potential consequences we have examined the protein phenotype of the Y42H mutation and the common disease-associated K304E mutation. Our studies of the intracellular biogenesis of the variant proteins at different temperatures in isolated mitochondria after in vitro translation, together with studies of cultured patient cells, indicated that steady-state levels of the Y42H variant in comparison to wild-type were decreased at higher temperature though to a lesser extent than for the K304E variant. To distinguish between effects of temperature on folding/assembly and the stability of the native enzyme, the thermal stability of the variant proteins was studied after expression and purification by dye affinity chromatography. This showed that, compared with the wild-type enzyme, the thermostability of the Y42H variant was decreased, but not to the same degree as that of the K304E variant. Substrate binding, interaction with the natural electron acceptor, and the binding of the prosthetic group, FAD, were only slightly affected by the Y42H mutation. Our study suggests that Y42H is a temperature sensitive mutation, which is mild at low temperatures, but may have deleterious effects at increased temperatures. [source] Potential changes in skipjack tuna (Katsuwonus pelamis) habitat from a global warming scenario: modelling approach and preliminary resultsFISHERIES OCEANOGRAPHY, Issue 4-5 2003Harilaos Loukos Abstract Recent studies suggest a reduction of primary production in the tropical oceans because of changes in oceanic circulation under global warming conditions caused by increasing atmospheric CO2 concentration. This might affect the productivity of medium and higher trophic levels with potential consequences on marine resources such as tropical tuna. Here we combine the projections of up-to-date climate and ocean biogeochemical models with recent concepts of representation of fish habitat based on prey abundance and ambient temperature to gain some insight into the impact of climate change on skipjack tuna (Katsuwonus pelamis), the species that dominates present-day tuna catch. For a world with doubled atmospheric CO2 concentration, our results suggest significant large-scale changes of skipjack habitat in the equatorial Pacific. East of the date line, conditions could be improved by an extension of the present favourable habitat zones of the western equatorial Pacific, a feature reminiscent of warming conditions associated with El Niño events. Despite its simplicity and the associated underlying hypothesis, this first simulation is used to stress future research directions and key issues for modelling developments associated to global change. [source] Consequences of maternal yolk testosterone for offspring development and survival: experimental test in a lizardFUNCTIONAL ECOLOGY, Issue 3 2007T. ULLER Summary 1Hormone-mediated maternal effects and developmental plasticity are important sources of phenotypic variation, with potential consequences for trait evolution. Yet our understanding of the importance of maternal hormones for offspring fitness in natural populations is very limited, particularly in non-avian species. 2We experimentally elevated yolk testosterone by injection of a physiological dose into eggs of the lizard Ctenophorus fordi Storr, to investigate its roles in offspring development, growth and survival. 3Yolk testosterone did not influence incubation period, basic hatchling morphology or survival under natural conditions. However, there was evidence for increased growth in hatchlings from testosterone-treated eggs, suggesting that maternal hormones have potential fitness consequences in natural populations. 4The positive effect of prenatal testosterone exposure on postnatal growth could represent a taxonomically widespread developmental mechanism that has evolved into an adaptive maternal effect in some taxa, but remains deleterious or selectively neutral in others. 5A broader taxonomic perspective should increase our understanding of the role of physiological constraints in the evolution of endocrine maternal effects. [source] Litter species composition influences the performance of seedlings of grassland herbsFUNCTIONAL ECOLOGY, Issue 3 2006H. QUESTED Summary 1This study examines the impacts of plant litter species identity and the composition of litter mixtures on seedling recruitment in the context of land-use change (abandonment) in conservationally important southern Swedish semi-natural grasslands. 2We found that plant litter had marked positive effects on the seedling recruitment of two common grassland species, and that these effects varied strongly with the species identity of the litter. 3There was no consistent evidence that litters of species typical of earlier succession had a greater positive impact on recruitment than those typical of late succession. 4The impact of mixtures of the five litter types examined was generally as expected based on the impacts of single-species litters and their contribution to the litter mixture, as predicted by the biomass ratio hypothesis. However, this was not the case for all litter and seedling species combinations, and some interactions were evident. 5Species identity of litter is important even in multispecies litter mixtures. Changes in plant species dominance (and hence the proportions of litter of different species), as a result of shifts in land use, are likely to result in changes in seedling performance, with potential consequences for the persistence of plant populations in former semi-natural grasslands. [source] Ecohydrological impacts of woody-plant encroachment: seasonal patterns of water and carbon dioxide exchange within a semiarid riparian environmentGLOBAL CHANGE BIOLOGY, Issue 2 2006RUSSELL L. SCOTT Abstract Across many dryland regions, historically grass-dominated ecosystems have been encroached upon by woody-plant species. In this paper, we compare ecosystem water and carbon dioxide (CO2) fluxes over a grassland, a grassland,shrubland mosaic, and a fully developed woodland to evaluate potential consequences of woody-plant encroachment on important ecosystem processes. All three sites were located in the riparian corridor of a river in the southwest US. As such, plants in these ecosystems may have access to moisture at the capillary fringe of the near-surface water table. Using fluxes measured by eddy covariance in 2003 we found that ecosystem evapotranspiration (ET) and net ecosystem exchange of carbon dioxide (NEE) increased with increasing woody-plant dominance. Growing season ET totals were 407, 450, and 639 mm in the grassland, shrubland, and woodland, respectively, and in excess of precipitation by 227, 265, and 473 mm. This excess was derived from groundwater, especially during the extremely dry premonsoon period when this was the only source of moisture available to plants. Access to groundwater by the deep-rooted woody plants apparently decouples ecosystem ET from gross ecosystem production (GEP) with respect to precipitation. Compared with grasses, the woody plants were better able to use the stable groundwater source and had an increased net CO2 gain during the dry periods. This enhanced plant activity resulted in substantial accumulation of leaf litter on the soil surface that, during rainy periods, may lead to high microbial respiration rates that offset these photosynthetic fluxes. March,December (primary growing season) totals of NEE were ,63, ,212, and ,233 g C m,2 in the grassland, shrubland, and woodland, respectively. Thus, there was a greater disparity between ecosystem water use and the strength of the CO2 sink as woody plants increased across the encroachment gradient. Despite a higher density of woody plants and a greater plant productivity in the woodland than in the shrubland, the woodland produced a larger respiration response to rainfall that largely offset its higher photosynthetic potential. These data suggest that the capacity for woody plants to exploit water resources in riparian areas results in enhanced carbon sequestration at the expense of increased groundwater use under current climate conditions, but the potential does not scale specifically as a function of woody-plant abundance. These results highlight the important roles of water sources and ecosystem structure on the control of water and carbon balances in dryland areas. [source] Review of the Integrated Groundwater and Surface-Water Model (IGSM)GROUND WATER, Issue 2 2003Eric M. LaBolle Development of the finite-element-based Integrated Groundwater and Surface-Water Model (IGSM) began in the 1970s. Its popularity grew in the early 1990s with its application to California's Central Valley Groundwater Surface-Water Model in support of the Central Valley Project Improvement Act. Since that time, IGSM has been applied by federal, state, and local agencies to model a number of major basins in California. Our review of the recently released version 5.0 of IGSM reveals a solution methodology that deviates from established solution techniques, potentially compromising its reliability under many circumstances. One difficulty occurs because of the semi-explicit time discretization used. Combined with the fixed monthly time step of IGSM, this approach can prevent applications from accurately converging when using parameter values typically found in nature. Additionally, IGSM fails to properly couple and simultaneously solve ground water and surface water models with appropriate mass balance and head convergence under the reasonable conditions considered herein. As a result, IGSM-predicted streamflow is error prone, and errors could exceed 100%. IGSM does not inform the user that there may be a convergence problem with the solution, but instead generally reports good mass balance. Although our review touches on only a few aspects of the code, which exceeds 17,000 lines, our experience is that similar problems arise in other parts of IGSM. Review and examples demonstrate the potential consequences of using the solution methods in IGSM for the prediction, planning, and management of water resources, and provide perspective on the roles of standards and code validation in ground water modeling. [source] Influence of source of phospholipids for APTT-based factor IX assays and potential consequences for the diagnosis of mild haemophilia BHAEMOPHILIA, Issue 1 2009C. POUPLARD First page of article [source] Underage alcohol use, delinquency, and criminal activityHEALTH ECONOMICS, Issue 12 2006Michael T. French Abstract Since 1988, the minimum legal drinking age (MLDA) has been 21 years for all 50 US states. The increasing prevalence of teenagers driving under the influence (DUI) of alcohol and the resulting traffic accidents were two main reasons for raising the MLDA to 21 years. Following the passage of this legislation, several published studies have found that the higher MLDA is associated with a significant reduction in both fatal and non-fatal accidents. While the relationship between MLDA and DUI events among young adults has been extensively studied, less information is available on other potential consequences of underage drinking. The present study uses data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a recent nationally representative survey, to investigate the effects of underage drinking on a variety of delinquency and criminal activity consequences. After controlling for the endogeneity of alcohol use where appropriate, we find strong evidence that various measures of alcohol consumption are related both to delinquency and to criminal activity. However, the findings are not uniform across gender as we find striking differences between males and females. These results have interesting policy and public health implications regarding underage drinking. Copyright © 2006 John Wiley & Sons, Ltd. [source] Working to live or living to work?HUMAN RESOURCE MANAGEMENT JOURNAL, Issue 4 2004Work/life balance early in the career This article reports the findings of research that explored relationships between work/life balance, work/non-work conflict, hours worked and organisational commitment among a sample of graduates in the early years of their career. It concludes that, although graduates seek work/life balance, their concern for career success draws them into a situation where they work increasingly long hours and experience an increasingly unsatisfactory relationship between home and work. The article discusses the causes and potential consequences of this predicament and in particular how work/non-work conflict is linked to hours worked, the state of the psychological contract and organisational commitment. It highlights the role of organisations' policy and practice in helping to manage the relationship between work and non-work and the development of organisational commitment through support for younger employees' lives out-of-work and effective management of aspects of the psychological contract. [source] | ||||||||||||||||||||||||||||||||||||||||||||||