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Greater Number (greater + number)
Selected AbstractsHow to be Consistent without Saving the Greater NumberPHILOSOPHY AND PUBLIC AFFAIRS, Issue 2 2006KIRSTEN MEYER First page of article [source] Spatial scale of GIS-derived categorical variables affects their ability to separate sites by community compositionAPPLIED VEGETATION SCIENCE, Issue 3 2008Emily A. Holt Abstract. Questions: How well do GIS-derived categorical variables (e.g., vegetation, soils, geology, elevation, geography, and physiography) separate plots based on community composition? How does the ability to distinguish plots by community composition vary with spatial scale, specifically number of patch types, patch size and spatial correlation? Both these questions bear on the effective use of stratifying variables in landscape ecology. Location: Arctic tundra; Bering Land Bridge National Preserve, northwestern Alaska, USA. Methods: We evaluated the strength of numerous alternative stratifying variables using the multi-response permutation procedure (MRPP). We also created groups based on lichen community composition, using cluster analyses, and evaluated the relationship between these groups and groupings within categorical variables using Mantel tests. Each test represents different measures of community separation, which were then evaluated with respect to each variable's spatial characteristics. Results: We found each categorical variable derived from GIS separated lichen communities to some degree. Separation success ranged from strong (Alaska Subsections) to weak (Watersheds and Reindeer Ownership). Lichen community groups derived from cluster analysis demonstrated statistically significant relationships with 13 of the 17 categorical variables. Partialling out effects of spatial distance had little effect on these relationships. Conclusions: Greater number of patch types and larger average patch sizes contribute to optimal success in separating lichen communities; geographic distance did not appear to significantly alter separation success. Group distinctiveness or strength increased with more patch types or groups. Alternatively, congruence between lichen community types derived from cluster analysis and the 17 categorical variables was inversely related to patch size and spatial correlation. [source] The effects of green tree retention and subsequent prescribed burning on ground beetles (Coleoptera: Carabidae) in boreal pine-dominated forestsECOGRAPHY, Issue 5 2006Petri Martikainen We studied how two methods to promote biodiversity in managed forests, i.e. green tree retention and prescribed fire, affect the assemblages of carabid beetles. Our experiment consisted of 24 study sites, each 3,5 ha in size, which had been prepared according to factorial design. Each of the eight treatment combinations determined by the two factors explored , tree retention level (0, 10, 50 m3/ha,1 and uncut controls) and prescribed use of fire (yes/no) , was replicated three times. We sampled carabids using pitfall traps one year after the treatments. Significantly more individuals were caught in most of the burned sites, but this difference was partially reflective of the trap-catches of Pterostichus adstrictus. The fire did not increase no. of P. adstrictus in the uncut sites as much as in the other sites. Species richness was significantly affected by both factors, being higher in the burned than in the unburned sites and in the harvested than in the unharvested sites. Many species were concentrated in the groups of retention trees in the burned sites, but only a few were in the unburned sites. The species turnover was greater in the burned than in the unburned sites, as indicated by the NMDS ordinations. Greater numbers of smaller sized species and proportion of brachypterous species were present in the burned sites. Fire-favored species, and also the majority of other species that prefer open habitats were more abundantly caught in the burned sites than in the unburned sites. Dead wood or logging waste around the traps did not correlate with the occurrence of species. We conclude that carabids are well adapted to disturbances, and that frequent use of prescribed fire is essential for the maintenance of natural assemblages of carabid beetles in the boreal forest. Small retention tree groups can not maintain assemblages of uncut forest, but they can be important by providing food, shelter and breeding sites for many species, particularly in the burned sites. [source] The impact of later trading hours for hotels on levels of impaired driver road crashes and driver breath alcohol levelsADDICTION, Issue 9 2006Tanya Chikritzhs ABSTRACT Aim To examine the impact of later trading hours for licensed hotels in Perth, Western Australia on levels of associated impaired driver road crashes and driver breath alcohol levels (BALs). Design Police data on the ,last place of drinking' for impaired drivers involved in road crashes and their corresponding BALs were examined to identify those associated with Perth hotels between 1 July 1990 and 30 June 1997. During this period, 43 (23%) of the 186 hotels meeting study criteria were granted an Extended Trading Permit for 1 a.m. closing (ETP hotels), while the rest continued to close at midnight (non-ETP hotels). Time-series analyses employing multiple linear regressions were applied to determine whether an association existed between the introduction of extended trading and (i) monthly levels of impaired driver road crashes associated with ETP hotels and (ii) driver BALs associated with ETP hotels. Trends associated with non-ETP hotels were included as controls and possible confounders were considered. Findings After controlling for the trend in crash rates associated with non-ETP hotels and the introduction of mobile police breath testing stations to Perth freeways, a significant increase in monthly crash rates for ETP hotels was found. This relationship was largely accounted for by higher volumes of high-alcohol content beer, wine and spirits purchased by ETP hotels. No relation was found between driver BALs and the introduction of ETPs. Conclusions Late trading was associated with increased levels of impaired driver road crashes and alcohol consumption, particularly high-risk alcoholic beverages. Greater numbers of patrons and characteristics specific to clientele of hotels which applied for late trading hours (i.e. younger age, greater propensity to drunk-drive, preference for high-risk beverages) were suggested as having contributed to this increase. [source] Diversity of Cicadellidae in agricultural production areas in the Ovens Valley, north-east Victoria, AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2010Piotr Tr, bicki Abstract There is a paucity of data on the distribution of Cicadellidae (leafhoppers) in Australia. This study quantifies the relative abundance, seasonal activity and diversity of leafhoppers in the Ovens Valley region of north-east Victoria, Australia. Species diversity and abundance was assessed at four field sites in and around the field borders of commercially grown tobacco crops using three sampling techniques (pan trap, sticky trap and sweep net). Over 51 000 leafhopper samples were collected, with 57 species from 11 subfamilies and 19 tribes identified. Greater numbers and diversity of leafhoppers were collected in yellow pan traps. The predominant leafhopper collected was Orosius orientalis (Matsumura). Twenty-three leafhopper species were recorded for the first time in Victoria and eight economically important pest species were recorded. Seasonal activity of selected leafhopper species, covering two sampling seasons, is presented. [source] Emergency Department Crowding and Decreased Quality of Pain CareACADEMIC EMERGENCY MEDICINE, Issue 12 2008Ula Hwang MD Abstract Objectives:, The objective of this study was to evaluate the association of emergency department (ED) crowding factors with the quality of pain care. Methods:, This was a retrospective observational study of all adult patients (,18 years) with conditions warranting pain care seen at an academic, urban, tertiary care ED from July 1 to July 31, 2005, and December 1 to December 31, 2005. Patients were included if they presented with a chief complaint of pain and a final ED diagnosis of a painful condition. Predictor ED crowding variables studied were 1) census, 2) number of admitted patients waiting for inpatient beds (boarders), and 3) number of boarders divided by ED census (boarding burden). The outcomes of interest were process of pain care measures: documentation of clinician pain assessment, medications ordered, and times of activities (e.g., arrival, assessment, ordering of medications). Results:, A total of 1,068 patient visits were reviewed. Fewer patients received analgesic medication during periods of high census (>50th percentile; parameter estimate = ,0.47; 95% confidence interval [CI] = ,0.80 to ,0.07). There was a direct correlation with total ED census and increased time to pain assessment (Spearman r = 0.33, p < 0.0001), time to analgesic medication ordering (r = 0.22, p < 0.0001), and time to analgesic medication administration (r = 0.25, p < 0.0001). There were significant delays (>1 hour) for pain assessment and the ordering and administration of analgesic medication during periods of high ED census and number of boarders, but not with boarding burden. Conclusions:, ED crowding as measured by patient volume negatively impacts patient care. Greater numbers of patients in the ED, whether as total census or number of boarders, were associated with worse pain care. [source] Comparison of bone marrow and peripheral blood ZAP-70 status examined by flow cytometric immunophenotyping in patients with chronic lymphocytic leukemiaCYTOMETRY, Issue 4 2006Rachel Sheridan Abstract Background: The mutational status of the immunoglobulin heavy chain variable gene in patients with chronic lymphocytic leukemia correlates with prognosis. Patients with mutated IgVH genes fare better than those with unmutated genes. Gene expression profiling studies identified the tyrosine kinase ZAP-70 to be expressed in unmutated CLL samples. Flow cytometric examination of ZAP-70 expression in tumor cells has been proposed to be a convenient surrogate marker for IgVH mutational status. However, a few studies have shown a small number of discordant results between ZAP-70 positivity, IgVH mutational status, and clinical outcome. There have been no reported studies comparing bone marrow samples with peripheral blood for ZAP-70 expression in CLL patients. Methods: We searched our flow cytometry files from October 2004 through April 2006 and identified CLL in 311 bone marrow and peripheral blood specimens from 256 patients. We defined ZAP-70 positivity as greater than 30% of the CD19+ B-cells above the isotype control value that coexpress ZAP-70. Statistical analyses were performed using the Fisher exact test and student t -test. Results: A significantly greater number of bone marrow specimens were positive for ZAP-70 when compared with the number of peripheral blood specimens. Of all the ZAP-70 negative specimens, CLL cells from bone marrow had a greater mean percentage of ZAP-70 positive cells when compared with the CLL cells from peripheral blood. Finally, six patients were identified who were ZAP-70 positive in the bone marrow but ZAP-70 negative in the peripheral blood. Conclusions: These results may be due to either an increase in the false positive rate in bone marrow specimens or to an intrinsic feature of CLL cells in the compartment that is biologically distinct from peripheral tumor cells. As prognosis and treatment decisions may be based on ZAP-70 results from either specimen type, it is prudent to further examine this observation. © 2006 International Society for Analytical Cytology [source] Early adversity in chronic depression: clinical correlates and response to pharmacotherapy,,DEPRESSION AND ANXIETY, Issue 8 2009Daniel N. Klein Ph.D. Abstract Background: There is growing evidence suggesting that early adversity may be a marker for a distinct pathway to major depressive disorder (MDD). We examined associations between childhood adversity and a broad variety of clinical characteristics and response to pharmacotherapy in a large sample of patients with chronic forms of MDD. Methods: Subjects included 808 patients with chronic forms of MDD (chronic MDD, double depression, or recurrent MDD with incomplete recovery between episodes and a total continuous duration of >2 years) who were enrolled in a 12-week open-label trial of algorithm-guided pharmacotherapy. Baseline assessments included a semi-structured diagnostic interview, and clinician- and self-rated measures of depressive symptoms, social functioning, depressotypic cognitions, and personality traits, and childhood adversity. Patients were re-evaluated every 2 weeks. Results: A longer duration of illness; earlier onset; greater number of episodes, symptom severity, self-rated functional impairment, suicidality, and comorbid anxiety disorder; and higher levels of dysfunctional attitudes and self-criticism were each associated with multiple forms of childhood adversity. A history of maternal overcontrol, paternal abuse, paternal indifference, sexual abuse, and an index of clinically significant abuse each predicted a lower probability of remission. Among patients completing the 12-week trial, 32% with a history of clinically significant abuse, compared to 44% without such a history, achieved remission. Conclusions: These findings indicate that a history of childhood adversity is associated with an especially chronic form of MDD that is less responsive to antidepressant pharmacotherapy. Depression and Anxiety, 2009. Published 2009 Wiley-Liss, Inc. [source] Recent Changes in the Workforce and Practice of Dermatologic SurgeryDERMATOLOGIC SURGERY, Issue 3 2009EMILY P. TIERNEY MD BACKGROUND The increasing number of American College of Mohs Surgery (ACMS) fellowship positions over the last decade has resulted in a greater number of fellowship-trained surgeons in dermatologic surgery. METHODS Mohs micrographic fellowship-trained surgeons (MMFTSs) and non-Mohs fellowship-trained surgeons performing Mohs micrographic surgery (NMMFTSs) were compared using the American Academy of Dermatology Practice Profile Survey (2002/05). An analysis of recent Mohs fellowship classes was also performed. RESULTS In 2005, there was an equivalent proportion of MMFTSs and NMMFTSs in the workforce (ratio MMFTS:NMMFTS=0.9) but, in 2005, there was a shift in the youngest age cohort (29,39) to a greater proportion of MMFTSs (MMFTS:NMMFTS=1.55). In 2005, the youngest MMFTSs (29,39) were more likely to be female (47.1%) than of MMFTSs overall (24%). MMFTSs were 5 times as likely to be in full-time academic positions and performed 2 to 3 times as many Mohs cases per week as NMMFTSs. CONCLUSIONS Consistent with demographic shifts in dermatology, differences have emerged in the demographics, surgical volumes, and settings of MMFTSs and NMMFTSs. Recent increases in the ACMS fellowship positions have resulted in a greater proportion of MMFTSs among younger dermatologic surgeons. It will be important to follow how this increase in fellowship trainees affects the dermatologic surgery workforce. [source] Psychotic-like experiences are associated with suicidal feelings and deliberate self-harm behaviors in adolescents aged 12,15 yearsACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010A. Nishida Nishida A, Sasaki T, Nishimura Y, Tanii H, Hara N, Inoue K, Yamada T, Takami T, Shimodera S, Itokawa M, Asukai N, Okazaki Y. Psychotic-like experiences are associated with suicidal feelings and deliberate self-harm behaviors in adolescents aged 12,15 years. Objective:, Psychotic disorders are a significant risk factor for suicide, especially among young people. Psychotic-like experiences (PLEs) in the general population may share an etiological background with psychotic disorders. Therefore, the present study examined the association between PLEs and risk of suicide in a community sample of adolescents. Method:, Psychotic-like experiences, suicidal feelings, and self-harm behaviors were studied using a self-report questionnaire administered to 5073 Japanese adolescents. Depression and anxiety were evaluated using the 12-item General Health Questionnaire (GHQ). Results:, The presence of PLEs was significantly associated with suicidal feelings (OR = 3.1, 95% CI = 2.2,4.5) and deliberate self-harm behaviors (OR = 3.1, 95% CI = 2.0,4.8) after controlling for the effects of age, gender, GHQ-12 score, victimization, and substance use. Suicidal feelings and behaviors were more prevalent in subjects with a greater number of PLEs. Conclusion:, Psychotic-like experiences may increase the risk of suicidal problems among adolescents. [source] Somatic H1 histone accumulation and germ layer determination in amphibian embryosDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2006Reed A. Flickinger The induction of mesoderm and/or endoderm from prospective ectoderm and dorsalization of the marginal zone mesoderm may be linked to inhibition of cell cycling and DNA synthesis in early amphibian embryos. In turn, this may lead to reduction of somatic H1 histone accumulation. A greater number of cell cycles and rounds of DNA synthesis characterizes the induction of neural tissue. This is correlated with an increase of somatic H1 histone accumulation. The number of rounds of DNA replication may regulate the level of H1 histone accumulation and this may have a role in germ layer determination. [source] Association between familial suicidal behavior and frequency of attempts among depressed suicide attemptersACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2009D. Lizardi Objective:, Only a few studies have examined whether a family history of suicide influences the severity of suicidal acts and the results have been inconsistent. The current study aimed to examine whether a family history of suicidal acts predicts severity of suicide attempts. Method:, 190 suicide attempters aged 18,75 years with a lifetime history of major depression were assessed for first-degree family history of suicidality and severity of suicide attempts (number and lethality of prior suicide attempts and age at first attempt). Results:, Regression analyses indicate that a positive family history of suicidal behaviors predicts a greater number of suicide attempts. Reasons for living predict number and lethality of prior attempts. Conclusion:, It is critical to assess for family history of suicidal behavior when treating depressed suicide attempters as it may serve as an indicator of the risk of repeat suicide attempt and as a guide for treatment. [source] Subcellular compartmentalization of aromatase is sexually dimorphic in the adult zebra finch brainDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2007Kevin N. Rohmann Abstract The vertebrate brain is a source of estrogen (E) via the expression of aromatase (E-synthase). In the zebra finch (Taeniopygia guttata), despite documented dimorphisms in E-action, no differences are detectable in circulating E, or the neural levels of aromatase transcription, activity, or somal protein expression. Studies of aromatase expression at the light- and electron-microscope levels reveal greater numbers of fibers and presynaptic boutons in adult males relative to females. We assayed aromatase activity and content in synaptosomes and microsomes from the anterior [containing lMAN and Area X (males)] and posterior telencephalon (containing HVC and RA) of adult birds. In contrast to non-song birds and mammals, both cell fractions contain abundant aromatase measurable in terms of activity (enzyme assays) and content (Western blots) with minimal enrichment in microsomes. From brain homogenates of identical concentration, aromatase activity was higher in the synaptosomal relative to the microsomal fraction, in males relative to females, and in the posterior compared to anterior telencephalon. These effects were driven by high levels of synaptosomal aromatase in the male posterior telencephalon. These data suggest that males possess more aromatase per presynaptic bouton, or a greater number of aromatase-containing presynaptic boutons than females in the posterior telencephalon. Further, the present report reveals synaptic aromatization as a considerable source of E in the zebra finch brain, and supports the idea that telencephalic synapses in and around the adult male song production nuclei may be exposed to higher levels of E compared to the female brain. © 2006 Wiley Periodicals, Inc. J Neurobiol 67: 1,9, 2007 [source] Human papillomavirus prevalence and cytopathology correlation in young Ugandan women using a low-cost liquid-based pap preparationDIAGNOSTIC CYTOPATHOLOGY, Issue 8 2010Janis M. Taube M.D. Abstract Screening for HPV-driven cervical dysplasia and neoplasia is a significant public health concern in the developing world. The purpose of this study was to use a manual, low-cost liquid-based Pap preparation to determine HPV prevalence in HIV-positive and HIV-negative young women in Kampala, Uganda and to correlate cervical cytopathology with HPV-DNA genotype. About 196 post-partum women aged 18,30 years underwent rapid HIV testing and pelvic examination. Liquid-based cervical cytology samples were processed using a low-cost manual technique. A DNA collection device was used to collect specimens for HPV genotyping. HIV and HPV prevalence was 18 and 64%, respectively. Overall, 49% of women were infected with a high-risk HPV genotype. The most common high-risk HPV genotypes were 16 (8.2%), 33 (7.7%), 35 (6.6%), 45 (5.1%), and 58 (5.1%). The prevalence of HPV 18 was 3.6%. HIV-positive women had an HPV prevalence of 86% compared to 59% in HIV-negative women (P = 0.003). The prevalence of HPV 16/18 did not differ by HIV status. HIV-positive women were infected with a significantly greater number of HPV genotypes compared to HIV-negative women. By multivariate analysis, the main risk factor for HPV infection was coinfection with HIV. HIV-positive women were four times more likely to have abnormal cytology than HIV-negative women (43% vs. 11.6%, P < 0.001). These data highlight that HIV infection is a strong risk factor for HPV infection and resultant abnormal cervical cytology. Notably, the manual low-cost liquid-based Pap preparation is practical in this setting and offers an alternate method for local studies of HPV vaccine efficacy. Diagn. Cytopathol. 2010;38:555,563. 2009 Wiley-Liss, Inc. [source] Nuclear morphometry and texture analysis of B-cell non-Hodgkin lymphoma: Utility in subclassification on cytosmearsDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2010Shilpa Gupta M.D. Abstract Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid neoplasms and accurate subclassification is an essential prerequisite for proper management of patients. This study was aimed at evaluating the utility of nuclear morphometry and textural features on cytology smears to classify the cases of NHL on aspiration cytology. Fine needle aspiration smears of 50 cases of B-cell NHL were included. Various morphometric and texture parameters were obtained by manually tracing the nuclei on digitized images in each case and discriminant analysis performed using various features taken individually as well as all together. The percentage of cells correctly classified to a particular NHL subtype using the discriminant functions so obtained was noted. Our results show that discriminant analysis done on size parameters could correctly classify a greater number of cells than on shape parameters (36.4% vs. 21.2%, respectively). Texture parameters based on single pixel values (first order texture) were inferior (42.8%) to those based on pair of pixels (58.7%) in subtyping of cells. Discriminant analysis based on color parameters was more effective (61.9%) as compared to rest of the morphometric and textural parameters. Using all the morphometric and textural parameters together, 83.3% of cells could be correctly classified to a particular NHL subtype. The present study, perhaps the first study of detailed morphometric analysis on cytosmears, shows that satisfactory classification of NHL on aspiration cytology is possible using nuclear morphometry and textural parameters considered together. These results are promising for further studies on this subject and development of automated cytodiagnosis. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source] Dynamic performance of twin curved cable-stayed bridgesEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 1 2004C. Gentile Abstract The dynamic behaviour of two curved cable-stayed bridges, recently constructed in northern Italy, has been investigated by full-scale testing and theoretical models. Two different excitation techniques were employed in the dynamic tests: traffic-induced ambient vibrations and free vibrations. Since the modal behaviour identified from the two types of test are very well correlated and a greater number of normal modes was detected during ambient vibration tests, the validity of the ambient vibration survey is assessed in view of future monitoring. For both bridges, 11 vibration modes were identified in the frequency range of 0ndash;10Hz, being a one-to-one correspondence between the observed modes of the two bridges. Successively, the information obtained from the field tests was used to validate and improve 3D finite elements so that the dynamic performance of the two systems were assessed and compared based on both the experimental results and the updated theoretical models. Copyright © 2003 John Wiley & Sons, Ltd. [source] Do competitive intraguild interactions affect space and habitat use by small carnivores in a forested landscape?ECOGRAPHY, Issue 4 2006Caroline St-Pierre Complex interactions such as interference competition and predation, including intraguild predation, are now recognized as important components in animal community structure. At the lower end of a guild, weasels may be highly affected by other guild members due to small body size in relation to other predators. In 2000 and 2001, we radio-collared 24 ermines Mustela erminea and 25 long-tailed weasels M. frenata in 2 areas that differed in abundance of guild members. We tested the hypothesis that when faced with an increased density of other guild members, weasels would modify space and habitat use to reduce the risk of predation associated with encounters involving guild members. We predicted that weasels would increase use of specific habitats (such as refuges) to reduce encounter rates in the presence of a greater number of guild members. Because M. erminea is smaller than M. frenata and thus better able to take advantage of small rodent burrows as refuges from predators and as feeding grounds, we also predicted that M. frenata would show a stronger response to a higher abundance of guild members than M. erminea. Results were consistent with our predictions. Faced with an increased abundance of guild members, M. frenata showed increased habitat selectivity and reduced activity levels, which resulted in increased daily travel distances and increased home ranges. Mustela erminea responded to an increased abundance of guild members through reduced use of preferred habitat which M. frenata already occupied. The contrasting pattern of habitat selection observed between the 2 mustelid species suggested cascading effects, whereby large-predator pressure on M. frenata relaxed pressure of M. frenata on M. erminea. Our results draw attention to the likelihood that competitive intraguild interactions play a facilitating role in M. erminea,M. frenata coexistence. [source] Species,energy relationships and habitat complexity in bird communitiesECOLOGY LETTERS, Issue 8 2004Allen H. Hurlbert Abstract Species,energy theory is a commonly invoked theory predicting a positive relationship between species richness and available energy. The More Individuals Hypothesis (MIH) attempts to explain this pattern, and assumes that areas with greater food resources support more individuals, and that communities with more individuals include more species. Using a large dataset for North American birds, I tested these predictions of the MIH, and also examined the effect of habitat complexity on community structure. I found qualitative support for the relationships predicted by the MIH, however, the MIH alone was inadequate for fully explaining richness patterns. Communities in more productive sites had more individuals, but they also had more even relative abundance distributions such that a given number of individuals yielded a greater number of species. Richness and evenness were also higher in structurally complex forests compared to structurally more simple grasslands when controlling for available energy. [source] Body size and invasion success in marine bivalvesECOLOGY LETTERS, Issue 2 2002Kaustuv Roy The role of body size in marine bivalve invasions has been the subject of debate. Roy et al. found that large-bodied species of marine bivalves were more likely to be successful invaders, consistent with patterns seen during Pleistocene climatic change, but Miller et al. argued that such selectivity was largely driven by the inclusion of mariculture species in the analysis and that size-selectivity was absent outside of mariculture introductions. Here we use data on non-mariculture species from the north-eastern Pacific coast and from a global species pool to test the original hypothesis of Roy et al. that range limits of larger bivalves are more fluid than those of smaller species. First, we test the hypothesis that larger bivalve species are more successful than small species in expanding their geographical ranges following introduction into new regions. Second, we compare body sizes of indigenous and non-indigenous species for 299 of the 303 known intertidal and shelf species within the marine bivalve clade that contains the greater number of non-mariculture invaders, the Mytilidae. The results from both tests provide additional support for the view that body size plays an important role in mediating invasion success in marine bivalves, in contrast to Miller et al. Thus range expansions in Recent bivalves are consistent with patterns seen in Pleistocene faunas despite the many differences in the mechanisms. [source] Foraging specialisms, prey size and life-history patterns: a test of predictions using sympatric polymorphic Arctic charr (Salvelinus alpinus)ECOLOGY OF FRESHWATER FISH, Issue 1 2008D. Fraser Abstract,,, We use arguments based on optimal foraging theory to predict body size constraints and the consequences of these on a range of life-history traits in three trophic specialist morphs of Arctic charr, Salvelinus alpinus, living in sympatry in Loch Rannoch, Scotland. As predicted, foraging specialists feeding on small prey items with a narrow size range showed evidence of deterministic growth; the ultimate body size of macrobenthos feeders being larger (L, = 238 mm) than that of planktivores (L, = 216 mm). In contrast, the piscivorous morph showed no evidence of reaching a maximal body size. The two size-constrained morphs (benthivores and planktivores) matured earlier and died younger (living for up to 11 and 7 years, respectively, in this study) than did the piscivorous charr which showed continuous growth up to at least 17 years. The pattern of annual reproductive investment in maturing individuals was complex. Planktivores invested in larger eggs than the other two forms, but benthivores produced a greater number of eggs than planktivores, which in turn produced more than piscivores. Planktivorous males had a greater investment in mean testis weight than the other two forms. Lifetime reproductive output was the greatest in the benthivorous charr, intermediate in planktivorous and the lowest in the piscivorous charr when measured either as fecundity or as gonadal weight. We conclude that constraints imposed upon foraging specialists by foraging efficiency is a significant driver of body size and ultimately reproductive investment in gape-limited foraging salmonids. [source] Do California Counties With Lower Socioeconomic Levels Have Less Access to Emergency Department Care?ACADEMIC EMERGENCY MEDICINE, Issue 5 2010Deepa Ravikumar Abstract Objectives:, The study objective was to examine the relationship between number of emergency departments (EDs) per capita in California counties and measures of socioeconomic status, to determine whether individuals living in areas with lower socioeconomic levels have decreased access to emergency care. Methods:, The authors linked 2005 data from the American Hospital Association (AHA) Annual Survey of Hospitals with the Area Resource Files from the United States Department of Health and Human Services and performed Poisson regression analyses of the association between EDs per capita in individual California counties using the Federal Information Processing Standard (FIPS) county codes and three measures of socioeconomic status: median household income, percentage uninsured, and years of education for individuals over 25 years of age. Multivariate analyses using Poisson regression were also performed to determine if any of these measures of socioeconomic status were independently associated with access to EDs. Results:, Median household income is inversely related to the number of EDs per capita (rate ratio = 0.83; 95% confidence interval [CI] = 0.71 to 0.96). Controlling for income in the multivariate analysis demonstrates that there are more EDs per 100,000 population in FIPS codes with more insured residents when compared with areas having less insured residents with the same levels of household income. Similarly, FIPS codes whose residents have more education have more EDs per 100,000 compared with areas with the same income level whose residents have less education. Conclusions:, Counties whose residents are poorer have more EDs per 100,000 residents than those with higher median household incomes. However, for the same income level, counties with more insured and more highly educated residents have a greater number of EDs per capita than those with less insured and less educated residents. These findings warrant in-depth studies on disparities in access to care as they relate to socioeconomic status. ACADEMIC EMERGENCY MEDICINE 2010; 17:508,513 © 2010 by the Society for Academic Emergency Medicine [source] Attachment of Amine- and Maleimide-Containing Ferrocene Derivatives onto Self-Assembled Alkanethiol and Alkanedithiol Monolayers: Voltammetric Evaluation of Cross-Linking Efficiencies and Surface Coverage of Electroactive GroupsELECTROANALYSIS, Issue 21 2004Yunfeng Wang Abstract Ferrocene derivatives containing primary amines and maleimide groups were attached covalently onto N -hydrosuccinimidyl (NHS)-terminated alkanethiol self-assembled monolayers (SAMs) and SAMs of alkanedithiol. The surface coverage and efficiencies of the two cross-linking reactions were evaluated with cyclic voltammetry. All the ferrocene derivatives attached onto the alkanethiol or alkanedithiol SAMs exhibit reversible redox waves. The surface coverage of the aminated ferrocene groups was compared to that of N -hydrosuccinimidyl (NHS)-terminated alkanethiol SAM. The covalent attachment of ,-ferrocenylethylamine onto a 11,11,-dithio-bis(succinimidylundecanoate) SAM yielded an efficiency as high as 63.1%. The cross-linking efficiency of this reaction was found to increase with the nucleophilicity of the amino groups. SAMs of longer alkyl chains favor the attachment of a greater number of ferrocene derivatives. As for the Michael-type electrophilic addition between the sulfhydryl groups of the alkanedithiol SAMs and the ferrocenyl maleimide, the cross-linking efficiencies were found to range from 6.5% to 25.7%, depending on the alkanedithiol chain length. The difference in the efficiencies between the two types of cross-linking reactions might be partially attributable to the steric hindrance imposed by the SAMs and the relative sizes of the functional groups. [source] Quantification by real-time PCR of the magnitude and duration of leucocyte-associated viraemia in horses infected with neuropathogenic vs. non-neuropathogenic strains of EHV- 1EQUINE VETERINARY JOURNAL, Issue 3 2006G. P. Allen Summary Reasons for performing study: Neurological disease in horses caused by infection with certain ,paralytic' strains of equine herpesvirus-1 (EHV-1) is a potentially devastating condition the pathogenesis of which is poorly understood. Preliminary observations in both experimentally induced and naturally occurring cases of the central nervous system disease have revealed a more robust cell-associated viraemia in horses infected with paralytic isolates of EHV-1, relative to horses infected with abortigenic isolates. To investigate further this pathogenesis - rdevant question, the present study was performed using a greater number of horses and a more precise method for quantification of EHV-1 DNA present in viraemic leucocytes. Objective: To compare the magnitude and duration of leucocyte-associated viraemia in seronegative, age-matched foals following infection with paralytic vs. abortigenic isolates of EHV-1. Methods: Peripheral blood mononuclear cells (PBMC) were collected from 20 weanling foals at 2, 4, 7, 9, 11, 14 and 21 days after intranasal inoculation with either paralytic or abortigenic isolates of EHV-1. The amount of EHV-1 DNA present in each PBMC sample was measured by real-time quantitative PCR. Results: Foals inoculated with paralytic strains of EHV-1 developed both a greater magnitude and longer duration of PBMC-associated viraemia than foals inoculated with abortigenic strains of the virus. Conclusions: Both the higher magnitude and longer duration of cell-associated viraemia contribute to the risk for development of neurological signs in horses infected with paralytic strains of EHV-1. Potential relevance: Our results provide empirically derived, scientific data that contributes to a better understanding of the pathogenetic basis for the differing abilities of paralytic and abortigenic strains of EHV-1 to cause post infection central nervous system disease in the horse. The findings identify the importance of minimising the quantitative burden of viraemic leucocytes that follows exposure to the virus, by the use of effective therapeutic antiviral drugs and efficacious prophylactic vaccines that stimulate cytotoxic immune responses against EHV-1 infected cells. [source] Adjustment of Parental Investment in the Dung Beetle Onthophagus atripennis (Col., Scarabaeidae)ETHOLOGY, Issue 12 2006Shigeki Kishi If parents can invest resources optimally per offspring, they should adjust the amount of investment in an offspring according to environmental heterogeneity. Many studies have demonstrated changes in egg size or the amount of resource supplied in response to environmental heterogeneity. However, it remains unclear whether parents simply know the resource type a priori or can assess resource quality and adjust the quantity of investment accordingly. We examined the parental capability to adjust the amount of investment per offspring by providing Onthophagus atripennis dung beetle parents with one of three dung types of different quality: monkey dung (high quality), cow dung (low quality), or a mixture of monkey and cow dung (medium quality). The beetle parents cooperatively produce dung brood masses each with one egg under the ground. The size of a brood mass, on which a larva can only feed until adult, represents a large part of the amount of investment. Parents produced a greater number of smaller brood masses given high-quality resource, while they compensated for low quality of the resource by providing a larger amount of the resource, at the cost of offspring number. However, despite this compensation in the amount of food, offspring raised on low-quality food was still smaller than offspring raised on high-quality food. Thus, O. atripennis parents assessed resource quality partly and adjusted the amount of resource provided for their offspring. [source] Lactosamine modulates the rate of migration of GnRH neurons during mouse developmentEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2006Elizabeth Bless Abstract Gonadotropin-releasing hormone (GnRH) neurons are derived from progenitor cells in the olfactory placodes and migrate from the vomeronasal organ (VNO) across the cribriform plate into the forebrain. At embryonic day (E)12 in the mouse most of these neurons are still in the nasal compartment but by E15 most GnRH neurons have migrated into the forebrain. Glycoconjugates with carbohydrate chains containing terminal lactosamine are expressed by neurons in the main olfactory epithelium and in the VNO. One of the key enzymes required to regulate the synthesis and expression of lactosamine, ,1,3-N-acetylglucosaminyltransferase-1 (,3GnT1), is strongly expressed by neurons in the olfactory epithelium and VNO, and on neurons migrating out of the VNO along the GnRH migratory pathway. Immunocytochemical analysis of lactosamine and GnRH in embryonic mice reveals that the percentage of lactosamine+,GnRH+ double-labeled neurons decreases from >,80% at E13, when migration is near its peak, to ,,30% at E18.5, when most neurons have stopped migrating. In ,3GnT1,/, mice, there is a partial loss of lactosamine expression on GnRH neurons. Additionally, a greater number of GnRH neurons were retained in the nasal compartment of null mice at E15 while fewer GnRH neurons were detected later in embryonic development in the ventral forebrain. These results suggest that the loss of lactosamine on a subset of GnRH neurons impeded the rate of migration from the nose to the brain. [source] Anticlastogenic, antitoxic and sorption effects of humic substances on the mutagen maleic hydrazide tested in leguminous plantsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2004G. Ferrara Summary The potential anticlastogenic and antitoxic effects of a soil humic acid (HA), a peat HA and a peat fulvic acid (FA) on the mutagen maleic hydrazide (MH) have been investigated in two legume species, Vicia faba and Pisum sativum. Both HAs and FA were tested at two different concentrations, 20 and 200 mg l,1, either alone or after 24-hour interaction with 10 mg l,1 of MH before addition to the legume seeds. Anticlastogenicity, i.e. an antimutagenic action defined as the capacity for minimizing chromosome breakages, was evaluated by counting both micronuclei (MN) and aberrant anatelophases (AAT) in root-tip cells. Length and dry weight of the seedling primary root were measured to test the antitoxic activity of HA and FA on MH. The possible occurrence and extent of adsorption or desorption of MH onto or from HA were also investigated. The two species responded differently to the anticlastogenic tests, with V. faba showing a greater number of MN and AAT anomalies than P. sativum. Peat HA and FA exhibited anticlastogenic and antitoxic activities of similar intensity and greater than those of soil HA. The adsorption capacity of both HAs for MH was small, thus suggesting that adsorption is not a major mechanism responsible for the reduction of clastogenicity and antitoxicity of MH by HA. [source] Nanogold-Loaded Sharp-Edged Carbon Bullets as Plant-Gene CarriersADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Periyasamy S. Vijayakumar Abstract The higher DNA delivery efficiency into plants by gold nanoparticles embedded in sharp carbonaceous carriers is demonstrated. These nanogold-embedded carbon matrices are prepared by heat treatment of biogenic intracellular gold nanoparticles. The DNA-delivery efficiency is tested on a model plant, Nicotiana tabacum, and is further extended to the monocot, Oryza sativa, and a hard dicot tree species, Leucaena leucocephala. These materials reveal good dispersion of the transport material, producing a greater number of GUS foci per unit area. The added advantages of the composite carrier are the lower plasmid and gold requirements. Plant-cell damage with the carbon-supported particles is very minimal and can be gauged from the increased plant regeneration and transformation efficiency compared with that of the commercial micrometer-sized gold particles. This is ascribed to the sharp edges that the carbon supports possess, which lead to better piercing capabilities with minimum damage. [source] Chemotactic response of plant-growth-promoting bacteria towards roots of vesicular-arbuscular mycorrhizal tomato plantsFEMS MICROBIOLOGY ECOLOGY, Issue 3 2003Sushma Gupta Sood Abstract The chemotactic responses of the plant-growth-promoting rhizobacteria Azotobacter chroococcum and Pseudomonas fluorescens to roots of vesicular-arbuscular mycorrhizal (Glomus fasciculatum) tomato plants were determined. A significantly (P=0.05) greater number of bacterial cells of wild strains were attracted towards vesicular-arbuscular mycorrhizal tomato roots compared to non-vesicular-arbuscular mycorrhizal tomato roots. Substances exuded by roots served as chemoattractants for these bacteria. P. fluorescens was strongly attracted towards citric and malic acids, which were predominant constituents in root exudates of tomato plants. A. chroococcum showed a stronger response towards sugars than amino acids, but the response was weakest towards organic acids. The effects of temperature, pH, and soil water matric potential on bacterial chemotaxis towards roots were also investigated. In general, significantly (P=0.05) greater chemotactic responses of bacteria were observed at higher water matric potentials (0, ,1, and ,5 kPa), slightly acidic to neutral pH (6, 6.5 and 7), and at 20,30°C (depending on the bacterium) than in other environmental conditions. It is suggested that chemotaxis of P. fluorescens and A. chroococcum towards roots and their exudates is one of the several steps in the interaction process between bacteria and vesicular-arbuscular mycorrhizal roots. [source] The Impact of Regulation FD on Institutional Investor InformativenessFINANCIAL MANAGEMENT, Issue 3 2010Douglas O. Cook Although there is conflicting evidence and resulting skepticism regarding the value provided by professional investment management, Gibson, Safieddine, and Sonti (2004) document institutional investor informativeness relative to seasoned equity offering (SEO) purchases. We find that Regulation Fair Disclosure's significantly reduces institutional investors' ability to identify mispriced SEO firms. Informativeness is diminished not by investors following analysts who have experienced a reduction in forecasting accuracy, but limiting investors' direct access to private information. This information loss is replaced by reliance on a greater number of public information variables resulting in less consideration for prudence proxies and a liquidity motive and more for higher price momentum. [source] Population estimation methods to quantify temporal variation in fish accumulations downstream of a weirFISHERIES MANAGEMENT & ECOLOGY, Issue 6 2006L. J. BAUMGARTNER Abstract, Temporal changes in the population sizes of seven migratory species were assessed over a 2-year period prior to the construction of a fishway on the Murrumbidgee River, Australia. Mark-recapture (Chapman,Petersen) and Jackknife removal methods were used at 3-month intervals to determine the composition and sizes of migratory fish populations. No difference in population size estimate was detected between the two methods. However, the Jackknife removal estimator generally provided less variable estimates for a greater number of species. Population sizes were greatest during summer and autumn when bony herring, Nematalosa erebi Günther, and common carp, Cyprinus carpio L., dominated the migratory community. Both estimators provided data essential to further the development of an appropriate fish passage facility and could be applied to other sites where the size of migratory fish populations is of interest. [source] | ||||||||||||||||||||||||||||||||||||||||||||||