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Ramifications
Kinds of Ramifications Selected AbstractsEffects of Perceived Emotional Intensity on Mock Jurors' Murder/Manslaughter DistinctionsJOURNAL OF APPLIED BIOBEHAVIORAL RESEARCH, Issue 2 2002Matthew P. Spackman Anglo-American law instructs jurors that defendants' emotions might constitute mitigating circumstances in murder/manslaughter cases. The present study examined which aspects of defendants' emotions mock jurors take into consideration when determining their murder/manslaughter verdicts. Four factors found to be predictive of perceptions of emotional intensity in previous research were shown to be predictive of murder/manslaughter convictions. These factors included whether the defendant had a history of violence with the victim, the particular emotion experienced, whether the defendant dwelt upon the feelings associated with his or her emotion, and whether the defendant intended the actions associated with his or her emotion. These findings are compared with two approaches that the law has taken to evaluate defendants' emotions: objective standards and subjective standards. Ramifications of these findings for jury instructions as well as for the law's conception of emotion are discussed. [source] Together we are heard: Effectiveness of daily ,language' groups in a community preschoolNURSING & HEALTH SCIENCES, Issue 2 2004Telêri Hodge BSc Abstract Strong oral language skills are a prerequisite for successful literacy and there is a strong interdependence between oral language acquisition and emergent literacy development. Ramifications of this are that children with language impairments are at great risk for difficulties in learning to read and write, with problems often persisting throughout the school years into adulthood. The Together we are heard program involved improving each child's oral language skills through group sessions facilitated by a speech pathologist on a daily basis at preschool. The aim of the present research was to determine the effectiveness of the program to identify the best way to assist children to develop appropriate language skills. The study showed that the children improved significantly in all four levels of the Preschool Language Assessment Inventory (PLAI). Importantly, the program was effective for both genders and there was no difference in the success of Indigenous children when compared to their European counterparts. There is a strong recommendation for further research and to expand such programs, particularly in areas that target children from impoverished and deprived environmental backgrounds. [source] Ramifications of North Korean Leader Kim Jong Il ,s Declaration of Independence from the International CommunityPACIFIC FOCUS, Issue 2 2006C. Kenneth Quinones The United States and Japanese governments' reactions to North Korea's launching of several ballistic missiles in early July 2006 was either completely misunderstood by North Korea watchers in Washington and Tokyo, are they simply preferred to ignore yongyang's underlying motives. Actually, North Korea has been relatively transparent about its intentions regarding not just its ballistic missile but also nuclear programs. Since February 2005, ranking North Korean officials and Foreign Ministry spokesmen have made it North Korea's intentions clear. It aspires to strengthen its "deterrence capability." In other words, North Korea is striving to counter the US-Japan alliance by matching its military capability not just with conventional but also nuclear weapons. The United States and Japan need to recognize this. Otherwise, their efforts to compel North Korea's submission using economic pressure will back fire. Pyongyang's priority is national defense through deterrence. Economic revitalization is a secondary goal. As the United States concentrates on the Middle East and gradually withdraws from Northeast Asia, Japan would do well to assess its relations with its neighbors China and the two Koreas. If Japan's new prime minister perpetuates Japan's commitment to the US-Japan alliance, it could find itself increasingly estranged from its neighbors. This became evident when Japan clashed with China over the UN resolution that censured North Korea's missile launchings. Japan's stance regarding issues rooted in history, such as prime ministerial visits to Yasukuni Shrine, if unaltered, will intensify Japan's isolation in Northeast Asia. This will work to North Korea's benefit. [source] The Expanded Criteria Donor Policy: An Evaluation of Program Objectives and Indirect RamificationsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2006J. D. Schold The expanded criteria donor (ECD) policy was formalized in 2002, which defined higher-risk deceased donor kidneys recovered for transplantation. There has not been a comprehensive examination of the impact of policy on the allocation of ECD kidneys, waiting times for transplant, center listing patterns or human leukocyte antigen (HLA) matching. We examined transplant candidates from 1998 to 2004 utilizing a national database. We constructed models to assess alterations in recipient characteristics of ECD kidneys and trends in waiting time and cold ischemia time (CIT) associated with policy. We also evaluated the impact of the proportion of center candidate listings for ECD kidneys on waiting times. Elderly recipients were more likely to receive ECDs following policy (odds ratio = 1.36, p < 0.01). There was no association of decreased CIT or pretransplant dialysis time while increasing HLA mismatching with policy inception. Over one quarter of centers listed <20% of candidates for ECDs, while an additional quarter of centers listed >90%. Only centers with selective listing for ECDs offered reduced waiting times to ECD recipients. The ECD policy demonstrates potential to achieve certain ascribed goals; however, the full impact of the program, reaching all transplant candidates, may only be achieved once ECD listing patterns are recommended and adopted accordingly. [source] The effect of anthropogenic habitat usage on the social behaviour of a vulnerable species, Cyclura nubilaANIMAL CONSERVATION, Issue 1 2003Kathryn E. Lacy With the increasing human population world-wide, animals and humans are sharing more habitat. In this study, we consider the consequences of this habitat usage overlap on the behaviour patterns and social structure of a threatened species. Specifically, we used focal animal samples to collect data on the Cuban rock iguana, Cyclura nubila, in six field sites. Three of these sites are subject to considerable anthropogenic habitat usage, whereas three are in relatively low anthropogenic usage areas. Individuals in high anthropogenic usage sites were more closely assembled, with more males and females sharing a smaller amount of space. These animals exhibited even more aggressive behaviour and social interactions than expected when taking into account the larger number of possible interactants. High anthropogenic usage sites also had more male,male interactions and fewer males interacting with females. We suggest that social and mating system changes have occurred. Ramifications of these recent changes in the behavioural repertoires on the long-term survival of the species are discussed. [source] Cell organization of barb ridges in regenerating feathers of the quail: implications of the elongation of barb ridges for the evolution and diversification of feathersACTA ZOOLOGICA, Issue 2 2007L. Alibardi Abstract This ultrastructural study on the regenerating feathers of quail describes the cellular organization of the barb ridges responsible for the ramification of adult feathers. Bilateral symmetry of the barb ridges determines the organization of feather cells into feather branching. The length of the barb ridges, derived from the number of cells associated to form the barbule plates, determines the length of the barbule branching. Long chains of barb cells form long barbs that branch from the rachis with an increase of feather size. Supportive cells function as spacers between the barbule cells. New cells derive from stem cells localized in the collar region of the feather follicle, as indicated from the re-organization of collar cells into barb ridges (a morphogenetic process inherited from that of embryonic feathers), production of an embryonic type of keratin (feather keratin), permanence of periderm granules (typical embryonic organelles) in barb vane ridge cells. Variations in the process of barb ridge morphogenesis allow the fusion of ridges into a rachis. The differentiation of hooklets contributes to the origin of planar feathers. Separation between rachis and merging barb ridges is by supportive cells, derived from the marginal plates of the barb ridges. Speculations on the evolution and diversification of feathers are presented. [source] The application of perfluorooctanoate to investigate trimerization of the human immunodeficiency virus-1 gp41 ectodomain by electrophoresisELECTROPHORESIS, Issue 15 2008Chi-Hui Lin Abstract The transmembrane glycoprotein gp41 of human immunodeficiency virus has been proposed to form trimer-of-hairpin during virus-cell membrane fusion. To investigate its oligomerization propensity under soluble and membrane-mimic conditions, sodium salt of perfluorooctanoate (PFO) was applied. A recombinant gp41 ectodomain devoid of disulfide linkage was overexpressed in Escherichia coli and characterized by MS and circular dichroism spectropolarimetry in PFO solution in comparison to SDS. The helical content of this ectodomain in PFO is higher than that in SDS. Notably, PFO employed in PAGE clearly conduced to the formation of trimer under the optimized condition as visualized in the gel. In addition, the proteins expressed from the two mutants in the heptad repeat (HR) domains of gp41, I62P, and N126K, were also examined by the PFO-PAGE analysis for functional ramification of molecular organization. Remarkably, the I62P mutation completely abolished the gp41 trimer formation, whereas the N126K mutation resulted in a more stable trimer. The data suggested that PFO-PAGE analysis is appropriate for evaluating the effect of mutations on the trimerization of gp41 and other fusion proteins which may be implicated in the alteration of their fusogenicity. [source] Astrocytic factors protect neuronal integrity and reduce microglial activation in an in vitro model of N -methyl- d -aspartate-induced excitotoxic injury in organotypic hippocampal slice culturesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2001Nils P. Hailer Abstract Acute CNS lesions lead to neuronal injury and a parallel glial activation that is accompanied by the release of neurotoxic substances. The extent of the original neuronal damage can therefore be potentiated in a process called secondary damage. As astrocytes are known to secrete immunomodulatory and neuroprotective substances, we investigated whether astrocytic factors can attenuate the amount of neuronal injury as well as the degree of microglial activation in a model of excitotoxic neurodegeneration. Treatment of organotypic hippocampal slice cultures with N-methyl- d -aspartate (NMDA) resulted in a reproducible loss of viable granule cells, partial destruction of the regular hippocampal cytoarchitecture and a concomitant accumulation of amoeboid microglial cells at sites of neuronal damage. Astrocyte-conditioned media reduced the amount of NMDA-induced neuronal injury by 45.3%, diminished the degree of microglial activation and resulted in an improved preservation of the hippocampal cytoarchitecture. Transforming growth factor (TGF)-, failed to act as a neuroprotectant and even enhanced the amount of neuronal injury by 52.5%. Direct effects of astrocytic factors on isolated microglial cells consisted of increased microglial ramification and down-regulated expression of intercellular adhesion molecule-1, whereas incubation with TGF-, had no such effects. In summary, our findings show that hitherto unidentified astrocyte-derived factors that are probably not identical with TGF-, can substantially enhance neuronal survival, either by eliciting direct neuroprotective effects or by modulating the microglial response to neuronal injury. [source] Perceiving Rogue States: The Use of the "Rogue State" Concept by U.S. Foreign Policy ElitesFOREIGN POLICY ANALYSIS, Issue 4 2007K. P. O'Reilly In the aftermath of the Cold War, U.S. foreign policy dialogue has shifted from its half century focus dominated by the superpower struggle with the Soviet Union to the challenges presented by so-called "rogue states." For many observers, however, the term "rogue state" is viewed as problematic failing to providing either a clear picture of who and what constitutes a rogues state, or, perhaps more importantly, the ramification of this term on U.S. policy action. In examining the public statements of key U.S. foreign policy decision makers over the course of 1993 to 2004, this paper offers insights as to the perceptions which manifest the "rogue" stereotype as exhibited by statements on the policies and behaviors associated with rogue states. What is revealed is a relatively fixed and stable image over time as held by key decisions-makers with similar unity expressed as to policy prescriptions. Combining perceptions of power capabilities and cultural judgments unique to this rogue stereotype, the rogue image presents a challenge to U.S. strategy demanding attention to the future threat posed by these states while also constraining policy options. [source] Rhizomorph growth habit, saprophytic ability and virulence of 15 Armillaria speciesFOREST PATHOLOGY, Issue 1 2004D. J. Morrison Summary The rhizomorph branching habit in soil, competitive saprophytic ability and virulence were determined for 15 species of Armillaria from Europe, North America and Australia and New Zealand. In soil, rhizomorphs of northern hemisphere species branched either monopodially or dichotomously, whereas all five species from Australia and New Zealand branched dichotomously. The dry weight of rhizomorphs produced in soil by isolates of a species and by species was very variable. Species with monopodially branched rhizomorphs had significantly higher saprophytic colonization scores than dichotomously branched species and scores were significantly higher in Garry oak than Douglas-fir segments and in fresh than autoclaved segments. The damage to Douglas-fir seedlings caused by isolates of most dichotomously branched species was significantly greater than that caused by monopodially branched species. Species producing dichotomously branched rhizomorphs were more aggressive than monopodially branched species, killing 80% (vs. 17%) of seedlings that died during the first year of the 2-year experiment. Résumé Le type de ramification des rhizomorphes dans le sol, la compétitivité saprophytique et la virulence ont étéétudiés chez 15 espèces d'Armillaria d'Europe, Amérique du Nord, Australie et Nouvelle-Zélande. Dans le sol, les rhizomorphes des espèces de l'hémisphère nord ont une ramification soit monopodiale soit dichotomique, alors que les 5 espèces d'Australie et de Nouvelle-Zélande ont une ramification dichotomique. Le poids sec de rhizomorphes produit dans le sol varie beaucoup entre isolats d'une espèce et entre espèces. Les espèces avec rhizomorphes à ramification monopodiale ont présenté des notes de colonisation saprophytique supérieures à celles des espèces à ramification dichotomique. Les notes ont été significativement supérieures sur des baguettes de chêne de Garry par rapport à des baguettes de Douglas et sur baguettes fraîches par rapport à des baguettes autoclavées. Les dégâts observés sur semis de Douglas ont été significativement supérieurs avec les isolats de la plupart des espèces à ramification dichotomique par rapport aux espèces à ramification monopodiale. Les espèces produisant des rhizomorphes à ramification dichotomique se sont montrées plus agressives que les espèces à ramification monopodiale, 80% (contre 17%) de la mortalité totale, après 2 années d'expérimentation, étant observée dès la première année. Zusammenfassung Bei 15 Armillaria -Arten aus Europa, Nord-Amerika sowie Australien und Neuseeland wurden die Verzweigungsmuster der Rhizomorphen im Boden, das Ausmass der saprophytischen Besiedelung und die Virulenz bestimmt. Im Boden verzweigten sich die Rhizomorphen der Arten der Nordhemisphäre monopodial oder dichotom, alle 5 Arten aus Australien und Neuseeland verzweigten sich dichotom. Das Trockengewicht der im Boden produzierten Rhizomorphen variierte sowohl bei den Isolaten einer Art als auch zwischen den Arten sehr stark. Arten mit monopodial verzweigten Rhizomorphen hatten signifikant höhere saprophytische Besiedelungsgrade als dichotom verzweigte Arten. Der Besiedelungsgrad war auf Triebsegmenten von Quercus garryana höher als auf Pseudotsuga menziesii -Segmenten, sowie höher auf frischen Segmenten als auf autoklavierten. Der an Douglasiensämlingen verursachte Schaden lag bei den Isolaten der meisten dichotom verzweigten Arten signifikant höher als derjenige der monopodial verzweigten Arten. Arten mit dichotom verzweigten Rhizomorphen waren aggressiver als monopodial verzweigte Arten, sie töteten 80% (vs. 17%) aller absterbenden Pflanzen bereits im ersten Jahr der zweijährigen Untersuchungsperiode. [source] Activation and deactivation of periventricular white matter phagocytes during postnatal mouse developmentGLIA, Issue 1 2010Mariya Hristova Abstract Brain microglia are related to peripheral macrophages but undergo a highly specific process of regional maturation and differentiation inside the brain. Here, we examined this deactivation and morphological differentiation in cerebral cortex and periventricular subcortical white matter, the main "fountain of microglia" site, during postnatal mouse development, 0,28 days after birth (P0,P28). Only macrophages in subcortical white matter but not cortical microglia exhibited strong expression of typical activation markers alpha5, alpha6, alphaM, alphaX, and beta2 integrin subunits and B7.2 at any postnatal time point studied. White matter phagocyte activation was maximal at P0, decreased linearly over P3 and P7 and disappeared at P10. P7 white matter phagocytes also expressed high levels of IGF1 and MCSF, but not TNFalpha mRNA; this expression disappeared at P14. This process of deactivation followed the presence of ingested phagocytic material but correlated only moderately with ramification, and not with the extent of TUNEL+ death in neighboring cells, their ingestion or microglial proliferation. Intravenous fluosphere labeling revealed postnatal recruitment and transformation of circulating leukocytes into meningeal and perivascular macrophages as well as into ramified cortical microglia, but bypassing the white matter areas. In conclusion, this study describes strong and selective activation of postnatally resident phagocytes in the P0,P7 subcortical white matter, roughly equivalent to mid 3rd trimester human fetal development. This presence of highly active and IGF1- and MCSF-expressing phagocytes in the neighborhood of vulnerable white matter could play an important role in the genesis of or protection against axonal damage in the fetus and premature neonate. © 2009 Wiley-Liss, Inc. [source] Radial migration of developing microglial cells in quail retina: A confocal microscopy studyGLIA, Issue 3 2004Ana Sánchez-López Abstract Microglial cells spread within the nervous system by tangential and radial migration. The cellular mechanism of tangential migration of microglia has been described in the quail retina but the mechanism of their radial migration has not been studied. In this work, we clarify some aspects of this mechanism by analyzing morphological features of microglial cells at different steps of their radial migration in the quail retina. Microglial cells migrate in the vitreal half of the retina by successive jumps from the vitreal border to progressively more scleral levels located at the vitreal border, intermediate regions, and scleral border of the inner plexiform layer (IPL). The cellular mechanism used for each jump consists of the emission of a leading thin radial process that ramifies at a more scleral level before retraction of the rear of the cell. Hence, radial migration and ramification of microglial cells are simultaneous events. Once at the scleral border of the IPL, microglial cells migrate through the inner nuclear layer to the outer plexiform layer by another mechanism: they retract cell processes, become round, and squeeze through neuronal bodies. Microglial cells use radial processes of s-laminin-expressing Müller cells as substratum for radial migration. Levels where microglial cells stop and ramify at each jump are always interfaces between retinal strata with strong tenascin immunostaining and strata showing weak or no tenascin immunoreactivity. When microglial cell radial migration ends, tenascin immunostaining is no longer present in the retina. These findings suggest that tenascin plays a role in the stopping and ramification of radially migrating microglial cells. © 2004 Wiley-Liss, Inc. [source] A closed-loop proposal for hydrogen generation using steel waste and a prototype solar concentratorINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2009Abdul-Majeed Azad Abstract An economically viable and environmental-friendly method of generating PEM grade hydrogen has been proposed and is by the reaction of certain metals with steam, appropriately called ,metal,steam reforming',MSR. The drawbacks of conventional processes (hydrogen and carbothermic reduction schemes) are overcome by resorting to solution-based reduction schemes and are made economically feasible using iron oxides from steel industry's mill-scale waste. A novel aqueous-based room temperature technique using sodium borohydride (NaBH4) as the reducing agent has been developed that produces highly active nanoscale iron particles (,40,nm). By using hydrazine as an inexpensive and, compared with NaBH4, more stable reductant, body centered cubic iron particles with ,5,nm edges were obtained via solvothermal process under mild conditions from acid digested mill-scale waste. The nanoscale zerovalent iron (nZVI) powder showed improved kinetics and greater propensity for hydrogen generation than the coarser microscale iron. The rate constants for the MSR were obtained for all the reduction schemes employed in this work and are given by khydrogen=0.0158,min,1kcarbon=0.0248,min,1ksodiumborohydride=0.0521,min,1 and khydrazine=0.1454,min,1, assuming first order kinetics. Another innovative effort converted the magnetite waste directly into nZVI under solvothermal conditions, thus obviating the sluggish and time-consuming acid dissolution step. This particular aspect has significant ramification in terms of time and cost of making the iron precursor. To initiate and sustain the somewhat endothermic MSR process, a solar concentrator consisting of a convex polyacrylic bowl with reflective aluminum coating was fabricated and evaluated. This unique combination of mill-scale waste as iron source, hydrazine as reductant, mild process conditions and solar energy as the MSR actuator obviates several drawbacks plaguing the grand scheme of producing and delivering pure and humidified H2 to a PEMFC stack. Copyright © 2008 John Wiley & Sons, Ltd. [source] Ultrastructure and embryonic development of a syconoid calcareous spongeINVERTEBRATE BIOLOGY, Issue 3 2006Dafne I. Eerkes-Medrano Abstract. Recent molecular data suggest that the Porifera is paraphyletic (Calcarea+Silicea) and that the Calcarea is more closely related to the Metazoa than to other sponge groups, thereby implying that a sponge-like animal gave rise to other metazoans. One ramification of these data is that calcareous sponges could provide clues as to what features are shared among this ancestral metazoan and higher animals. Recent studies describing detailed morphology in the Calcarea are lacking. We have used a combination of microscopy techniques to study the fine structure of Syconcoactum Urban 1905, a cosmopolitan calcareous sponge. The sponge has a distinct polarity, consisting of a single tube with an apically opening osculum. Finger-like chambers, several hundred micrometers in length, form the sides of the tube. The inner and outer layers of the chamber wall are formed by epithelia characterized by apical,basal polarity and occluding junctions between cells. The outer layer,the pinacoderm,and atrial cavity are lined by plate-like cells (pinacocytes), and the inner choanoderm is lined by a continuous sheet of choanocytes. Incurrent openings of the sponge are formed by porocytes, tubular cells that join the pinacoderm to the choanoderm. Between these two layers lies a collagenous mesohyl that houses sclerocytes, spicules, amoeboid cells, and a progression of embryonic stages. The morphology of choanocytes and porocytes is plastic. Ostia were closed in sponges that were vigorously shaken and in sponges left in still water for over 30 min. Choanocytes, and in particular collar microvilli, varied in size and shape, depending on their location in the choanocyte chamber. Although some of the odd shapes of choanocytes and their collars can be explained by the development of large embryos first beneath and later on top of the choanocytes, the presence of many fused collar microvilli on choanocytes may reflect peculiarities of the hydrodynamics in large syconoid choanocyte chambers. The unusual formation of a hollow blastula larva and its inversion through the choanocyte epithelium are suggestive of epithelial rather than mesenchymal cell movements. These details illustrate that calcareous sponges have characteristics that allow comparison with other metazoans,one of the reasons they have long been the focus of studies of evolution and development. [source] Effects of azadirachtin and of simpler epoxy-alcohols on survival and behaviour of Galleria mellonella (Lepidoptera)JOURNAL OF APPLIED ENTOMOLOGY, Issue 7 2007C. Charbonneau Abstract:, Investigations into the toxicity of three simpler molecules based on the epoxy-alcohol fragment of azadirachtin have revealed insecticidal activity on the greater wax moth Galleria mellonella L. larvae. The simpler epoxy-alcohols doses giving 50% mortalities (LD50) for G. mellonella larvae were in the increasing order from glycidol (0.022 mg/g), 4,5-epoxy-2-pentanol (0.068 mg/g) and finally, glycerol diglycidyl ether (0.147 mg/g). The three epoxy-alcohols exhibited higher insecticidal activity when compared with the commercial neem product for which the dose giving 50% mortalities was 10.6 mg/g and to azadirachtin that killed the larvae only by injection (dose of 0.20 mg/g of larvae body weight). Our results confirm the importance of the epoxy-alcohol junction between the two parts of the azadirachtin molecule for the biological activity. Other effects of the epoxy-alcohols tested were blackening of larvae and morphological deformities of some adults hatching. In future, the molecules should be complexified (degree of ramification, length of chain and presence of bulky ramified substituent) to obtain an insecticide as toxic for insects only and environmentally safe as azadirachtin but more stable, and their physiological activities on insect's tissues and cells should be studied. [source] Melatonin induces neuritogenesis at early stages in N1E-115 cells through actin rearrangements via activation of protein kinase C and Rho-associated kinaseJOURNAL OF PINEAL RESEARCH, Issue 3 2007Alfredo Bellon Abstract:, Melatonin increases neurite formation in N1E-115 cells through microtubule enlargement elicited by calmodulin antagonism and vimentin intermediate filament reorganization caused by protein kinase C (PKC) activation. Microfilament rearrangement is also a necessary process in growth cone formation during neurite outgrowth. In this work, we studied the effect of melatonin on microfilament rearrangements present at early stages of neurite formation and the possible participation of PKC and the Rho-associated kinase (ROCK), which is a downstream kinase in the PKC signaling pathway. The results showed that 1 nm melatonin increased both the number of cells with filopodia and with long neurites. Similar results were obtained with the PKC activator phorbol 12-myristate 13-acetate (PMA). Both melatonin and PMA increased the quantity of filamentous actin. In contrast, the PKC inhibitor bisindolylmaleimide abolished microfilament organization elicited by either melatonin or PMA, while the Rho inhibitor C3, or the ROCK inhibitor Y27632, abolished the bipolar neurite morphology of N1E-115 cells. Instead, these inhibitors prompted neurite ramification. ROCK activity measured in whole cell extracts and in N1E-115 cells was increased in the presence of melatonin and PMA. The results indicate that melatonin increases the number of cells with immature neurites and suggest that these neurites can be susceptible to differentiation by incoming extracellular signals. Data also indicate that PKC and ROCK are involved at initial stages of neurite formation in the mechanism by which melatonin recruits cells for later differentiation. [source] Microglial colonization of the developing mouse brain: the effect of CD11b deletionNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2002J. K. Jeetle Introduction:, Microglia are resident mononuclear phagocytes of the central nervous system, which colonize the brain both prenatally and after birth. It is proposed that they enter the brain initially via the surrounding mesenchyme, via ventricles and later through blood vessels, but the mechanisms of entry and signals used for migration are still to be established. Previous studies have shown that ligands for some integrin adhesion molecules expressed on blood vessels in the developing nervous system (particularly ICAM-1 and ICAM-2 which bind CD11a/LFA-1 and CD11b/Mac-1), may act as potential recruiting signals for microglial precursors. This study addressed whether CD11b is influential on the migration of microglial precursors into the developing CNS. Material and methods:,Ricinus communis agglutinin-1 (RCA-1) lectin histochemistry was employed to anatomically map the distribution of amoeboid and ramified microglia from embryonic day 15 (E15) to birth. Embryonic mouse brains from CD11b knockout (,/,) (n = 42), and heterozygote (+/,) (n = 52) mice generated on a C57/BL6 background (Melo et al. Cell Immunol 2000; 205: 13,23) and wild-type (+/+) (n = 37) litter mates were fixed in Bouin's solution, processed to paraffin wax and serially sectioned at 15,40 µm. To investigate further potential signals for recruiting microglial precursors, brains were immunochemically screened for integrins CD11a, CD11b, CD18, ,X, VLA-4 and the chemokine MCP-1. Results:, Microscopic analysis revealed the morphological transition of microglia from predominantly amoeboid forms at E15,E16 to a flourishing population of ramified cells at E19,E20. RCA-1 histochemistry showed no clear differences in microglial distribution or timing of colonization between CD11b (,/,) and wild-type mice from E15 to birth. Although CD11b deletion did not influence the timing of microglial ramification, there appeared to be fewer ramified cells in (,/,) mice within comparative brain regions. This requires further quantitative morphometric analysis. Of the integrins investigated, none were restricted to microglia and only VLA-4 and ,X showed reactivity within the CNS. However, MCP-1 was notably localized to the cortical plate within all genotypes, consistent with previous findings in human foetal CNS (Rezaie & Male. Microsc Res Tech 1999; 45: 359,382). Conclusion:, The results suggest that CD11b has little influence on the timing or regional distribution of microglia in the developing murine CNS. It is more likely that CD11b is only one of several factors that influence the migration and differentiation of these cells. [source] Synthesis and Stability in Biological Media of 1H -Imidazole-1-carboxylates of ROS203, an Antagonist of the Histamine H3 ReceptorCHEMISTRY & BIODIVERSITY, Issue 1 2008Mirko Rivara Abstract A series of carbamate derivatives of the H3 antagonist ROS203 (1) were prepared, and their lipophilicity and steric hindrance were modulated by introducing linear or branched alkyl chains of various lengths. In vitro stability studies were conducted to evaluate how structural modulations affect the intrinsic reactivity of the carbamoyl moiety and its recognition by metabolic enzymes. Linear alkyl carbamates were the most susceptible to enzymatic hydrolysis, with bioconversion rates being higher in rat liver and plasma. Chain ramification significantly enhanced the enzymatic stability of the set, with two derivatives (1g and 1h) being more stable by a factor of 8,40 than the ethyl carbamate 1a. Incubation with bovine serum albumin (BSA) showed a protective role of proteins on chemical and porcine-liver esterase (PLE)-catalyzed hydrolysis. Ex vivo binding data after i.v. administration of 1h revealed prolonged displacement of the labeled ligand [3H]-(R)- , -methylhistamine ([3H]RAMHA) from rat-brain cortical membranes, when compared to 1. However, the high rates of bioconversion in liver, as well as the chemical instability of 1h, suggest that further work is needed to optimize the enzymatic and chemical stability of these compounds. [source] Irritants in combination with a synergistic or additive effect on the skin response: an overview of tandem irritation studiesCONTACT DERMATITIS, Issue 6 2006Francisca Kartono Sodium lauryl sulfate (SLS) has often been chosen as a model for irritant contact dermatitis (ICD) to study the effect of irritants in combination (1,14). Recently ,tandem', or sequential, exposures with SLS have been performed to study the mechanism of skin barrier impairment in ICD (1,6, 15). The assessment of reactions have been documented with visual scoring, transepidermal water loss (TEWL), skin colour reflectance measurements, skin blood flow; among which TEWL has been noted as the most sensitive value (16). The matched control groups were treated with either a single exposure to a single irritant or in tandem with the same irritant repeatedly. Synergistic and additive effects have been reported for various tandem pairs of irritants, however, the mechanism for both remains unclear. The results of tandem irritation studies were evaluated to define and investigate the responses produced and deduce a possible mechanism of action. Clinical ramifications, albeit complex, are discussed. [source] CONSENT, COMMODIFICATION AND BENEFIT-SHARING IN GENETIC RESEARCH1DEVELOPING WORLD BIOETHICS, Issue 2 2004DONNA DICKENSON ABSTRACT The global value of the biotechnology industry is now estimated at 17 billion dollars, with over 1300 firms involved as of the year 2000.2 It has been said that ,What we are witnessing is nothing less than a new kind of gold rush, and the territory is the body.' As in previous gold rushes, prospectors are flooding into unexplored and ,wide open' territories from all over the world, with possible ramifications for exploitation of Third World populations. These territories are also the Wild West of bioethics insofar as the law has very little hold on them: existing medical and patent law, such as the Moore and Chakrabarty cases, exert little control over powerful economic interests in both the United States and Europe. In the absence of a unified and consistent law on property in the body, the focus is increasingly on refining the consent approach to rights in human tissue and the human genome, with sensitive and promising developments from the Human Genetics Commission and the Department for International Development consultation on intellectual property. These developments incorporate the views of vulnerable genetic communities such as Native Americans or some Third World populations, and should be welcomed because they recognise the power imbalance between such groups and First World researchers or firms. However, they also highlight the continued tension about what is really wrong with commodifying human tissue or the human genome. Where's the injustice, and can it be solved by a more sophisticated consent procedure? [source] Twilight Institutions: Public Authority and Local Politics in AfricaDEVELOPMENT AND CHANGE, Issue 4 2006Christian Lund ABSTRACT Public authority does not always fall within the exclusive realm of government institutions; in some contexts, institutional competition is intense and a range of ostensibly a-political situations become actively politicized. Africa has no shortage of institutions which attempt to exercise public authority: not only are multiple layers and branches of government institutions present and active to various degrees, but so-called traditional institutions bolstered by government recognition also vie for public authority, and new emerging institutions and organizations also enter the field. The practices of these institutions make concepts such as public authority, legitimacy, belonging, citizenship and territory highly relevant. This article proposes an analytical strategy for the understanding of public authority in such contexts. It draws on research from anthropologists, geographers, political scientists and social scientists working on Africa, in an attempt to explore a set of questions related to a variety of political practices and their institutional ramifications. [source] Trade Liberalization and the Fiscal Squeeze: Implications for Public InvestmentDEVELOPMENT AND CHANGE, Issue 3 2003Barsha Khattry This article examines the impact of trade liberalization on the level and structure of government expenditures across countries, with particular emphasis on low income countries. It develops the argument that the policies employed during trade liberalization have resulted in a fiscal squeeze as a result of declining tax revenues and rising interest expenditures. To surmount this fiscal hurdle, expenditures on physical capital, which have negligible political ramifications, have been reduced. Other more politically sensitive expenditures, such as spending on social capital, have been financed by incurring additional debt. However, additional debt has exerted upward pressure on interest payments, further exacerbating the fiscal situation. The statistical analysis carried out to examine the evidence uses panel data for eighty developing and industrialized countries over the period 1970,98 and employs a fixed,effects regression framework to account for country,specific characteristics. The results indicate that trade liberalization has indeed resulted in declining revenues and higher interest expenditures and that these factors have contributed to the observed decline in infrastructure spending. [source] Capital Versus the Districts: A Tale of One Multinational Company's Attempt to Disembed ItselfECONOMIC GEOGRAPHY, Issue 2 2004N. A. Phelps Abstract: The process of international economic integration in which multinational enterprises (MNEs) play a significant orchestrating role is a contradictory one of a space of flows, on the one hand, and a space of places, on the other hand. It is this contradiction that produces a variegated landscape of relations within and among MNEs and a whole range of territorially rooted organizations and institutions. As a result, interest in global production networks, as part of a broader relational turn in economic geography, has sought to highlight and uncover these webs of relations within which MNEs are embedded. In reviewing this literature, we emphasize the economic imperatives underlying such relations or, rather, their political-economic nature and the discontinuities in industrial restructuring they can produce. We then present an empirical illustration of these points and some of the key concerns within the literature on global production networks. We consider a recent round of restructuring by Black & Decker Corporation, focusing on the politico-economic ramifications of closing one of two European factories. Our reading of the literature, coupled with our empirical findings, suggests the continuing tendency for international integration as a space of flows to eclipse the coherence of places. Localized points of resistance can moderate the powers exercised by MNEs internally and across a network of organizations, although there are limits to the transferability of such tactics of resistance. [source] Equity Markets & the EconomyECONOMIC OUTLOOK, Issue 2 2001John Muellbauer Media commentary in the New Year has seen the word ,recession' increasingly associated with short-term US prospects, which seemed so positive only half a year ago. In this article, John Muellbauer discusses this ,boom to bust' phenomenon, the role of asset prices and the wider ramifications for global growth, exchange rates and the UK economy. [source] TOWARDS A MARKET ORIENTED APPROACH: EMPLOYER REQUIREMENTS AND IMPLICATIONS FOR UNDERGRADUATE ECONOMICS PROGRAMSECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 3 2004Phillip Hellier The decline in enrolments in economics degrees and majors has been the focus of much concern in recent times. In 2001, two of the current researchers published a paper outlining a framework with which future investigation into the issue could be conducted (Keneley and Hellier 2001). Essentially this paper argued that a market orientated approach, which takes into account the value students and employers place on economics studies may point the way to a solution to the problem. As a first step in developing such an approach it is necessary to determine what employers require of the economics graduates they hire. With the support of the Economics Society of Australia such a survey was conducted in 2002. This paper presents the results of this survey and discusses some of the ramifications for the teaching of undergraduate economics. [source] Whole sediment toxicity identification evaluation tools for pyrethroid insecticides: III.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2009Temperature manipulation Abstract Since the toxicity of pyrethroid insecticides is known to increase at low temperatures, the use of temperature manipulation was explored as a whole-sediment toxicity identification evaluation (TIE) tool to help identify sediment samples in which pyrethroid insecticides are responsible for observed toxicity. The amphipod Hyalella azteca is commonly used for toxicity testing of sediments at a 23°C test temperature. However, a temperature reduction to 18°C doubled the toxicity of pyrethroids, and a further reduction to 13°C tripled their toxicity. A similar response, though less dramatic, was found for 1,1-bis(p -chlorophenyl)-2,2,2-trichloroethane (DDT), and dissimilar temperature responses were seen for cadmium and the insecticide chlorpyrifos. Tests with field-collected sediments containing pyrethroids and/or chlorpyrifos showed the expected thermal dependency in nearly all instances. The inverse relationship between temperature and toxicity provides a simple approach to help establish when pyrethroids are the principal toxicant in a sediment sample that could be used as a supplemental tool in concert with chemical analysis or other TIE manipulations. The phenomenon appears to be, in part, a consequence of a reduced ability to biotransform the toxic parent compound at cooler temperatures. The strong dependence of pyrethroid toxicity on temperature has important ramifications for predicting their environmental effects, and the standard test temperature of 23°C dramatically underestimates risk to resident fauna during the cooler months. [source] LINKING COEVOLUTIONARY HISTORY TO ECOLOGICAL PROCESS: DOVES AND LICEEVOLUTION, Issue 10 2003Dale H. Clayton Abstract Many host-specific parasites are restricted to a limited range of host species by ecological barriers that impede dispersal and successful establishment. In some cases, microevolutionary differentiation is apparent on top of host specificity, as evidenced by significant parasite population genetic structure among host populations. Ecological barriers responsible for specificity and genetic structure can, in principle, reinforce macroevolutionary processes that generate congruent host-parasite phylogenies. However, few studies have explored both the micro- and macroevolutionary ramifications of close association in a single host-parasite system. Here we compare the macroevolutionary histories of two genera of feather lice (Phthiraptera: Ischnocera) that both parasitize New World pigeons and doves (Aves: Columbiformes). Earlier work has shown that dove body lice (genus Physconelloides) are more host specific and have greater population genetic structure than dove wing lice (Columbicola). We reconstructed phylogenies for representatives of the two genera of lice and their hosts, using nuclear and mitochondrial DNA sequences. The phylogenies were well resolved and generally well supported. We compared the phylogenies of body lice and wing lice to the host phylogeny using reconciliation analyses. We found that dove body lice show strong evidence of cospeciation whereas dove wing lice do not. Although the ecology of body and wing lice is very similar, differences in their dispersal ability may underlie these joint differences in host specificity, population genetic structure, and coevolutionary history. [source] Nutritional ecology and diachronic trends in Paleolithic diet and healthEVOLUTIONARY ANTHROPOLOGY, Issue 5 2003Bryan Hockett Modern nutritional studies have found that diverse diets are linked to lower infant mortality rates and longer life expectancies in humans. This is primarily because humans require more than fifty essential nutrients for growth and cell maintenance and repair; most of these essential nutrients must come from outside food sources rather than being manufactured by the body itself; and a diversity of food types is required to consume the full suite of essential nutrients necessary for optimal human health. These principles and their related affects on human adaptations and demography are the hallmarks of a theoretical paradigm defined as nutritional ecology. This essay applies concepts derived from nutritional ecology to the study of human evolution. Principles of nutritional ecology are applied to the study of the Middle-to-Upper Paleolithic transition in order to broadly illustrate the interpretive ramifications of this approach. At any stage in human evolution, those hominid populations that chose to diversify their subsistence base may have had a selective advantage over competitors who restricted their diet principally to one food type, such as terrestrial mammals. [source] A Comparison of Data Sources for Motor Vehicle Crash Characteristic AccuracyACADEMIC EMERGENCY MEDICINE, Issue 8 2000Robert J. Grant MD Abstract. Objective: To determine the accuracy of police reports (PRs), ambulance reports (ARs), and emergency department records (EDRs) in describing motor vehicle crash (MVC) characteristics when compared with an investigation performed by an experienced crash investigator trained in impact biomechanics. Methods: This was a cross-sectional, observational study. Ninety-one patients transported by ambulance to a university emergency department (ED) directly from the scene of an MVC from August 1997 to April 1998 were enrolled. Potential patients were identified from the ED log and consent was obtained to investigate the crash vehicle. Data describing MVC characteristics were abstracted from the PR, AR, and medical record. Variables of interest included restraint use (RU), air bag deployment (AD), and type of impact (TI). Agreements between the variables and the independent crash investigation were compared using kappa. Interrater reliability was determined using kappa by comparing a random sample of 20 abstracted reports for each data source with the originally abstracted data. Results: Agreement using kappa between the crash investigation and each data source was 0.588 (95% CI = 0.508 to 0.667) for the PR, 0.330 (95% CI = 0.252 to 0.407) for the AR, and 0.492 (95% CI = 0.413 to 0.572) for the EDR. Variable agreement was 0.239 (95% CI = 0.164 to 0.314) for RU, 0.350 (95% CI = 0.268 to 0.432) for AD, and 0.631 (95%= 0.563 to 0.698) for TI. Interrater reliability was excellent (kappa > 0.8) for all data sources. Conclusions: The strength of the agreement between the independent crash investigation and the data sources that were measured by kappa was fair to moderate, indicating inaccuracies. This presents ramifications for researchers and necessitates consideration of the validity and accuracy of crash characteristics contained in these data sources. [source] Realism, Prediction, and Foreign PolicyFOREIGN POLICY ANALYSIS, Issue 3 2009Samuel Barkin Attempts by some contemporary realists to both claim that international politics are objectively predictable and at the same time prescribe particular foreign policies cannot hold together logically, because they are internally contradictory. The core argument of this article is that these attempts not only fail to fulfill their goal, but that the attempt to be scientific, to see the world as predictable, is ontologically incompatible with the core insight of classical realism, that we must see the world as it is, rather than as we want it to be. There are two ramifications of this observation for a realism that is not internally contradictory. The first is that a prescriptive realism must be a theory of foreign policy, not a theory of systems structure. And the second is that a realism that works as a theory of foreign policy prediction needs to be reflexive, needs to examine its own assumptions and biases as an integral part of the process of studying international politics. [source] | |||||||||||||||||||||||||||||||||||||||||||