bluuebunny/crossref_metadata_2025_split huggingface dataset:
Could the CARE–SHAKTI intervention for injecting drug users be maintaining the low HIV prevalence in Dhaka, Bangladesh?
Authors: Foss Anna M. , Watts Charlotte H. , Vickerman Peter , Azim Tasnim , Guinness Lorna , Ahmed Munir , Rodericks Andrea , Jana Smarajit 
Published: October 2006

ABSTRACTAims  To explore whether the low HIV prevalence observed in Bangladesh results from prevention activities, this study uses mathematical modelling to estimate the impact of a needle/syringe exchange intervention for injecting drug users (IDUs) in Dhaka, Bangladesh.Design  Epidemiological, behavioural and intervention monitoring data were used to parameterize a dynamic mathematical model, and fit it to National HIV Sero‐surveillance data among IDUs (2000–02). The model was used to estimate the impact of the intervention on HIV transmission among IDUs and their sexual partners.Setting  Dhaka, Bangladesh, where the HIV prevalence has remained low despite high‐risk sexual and injecting behaviours, and growing HIV epidemics in neighbouring countries.Findings  The model predicts that the intervention may have reduced the incidence of HIV among IDUs by 90% (95% CI 74–94%), resulting in an IDU HIV prevalence of 10% (95% CI 4–19%) after 8 years of intervention activity instead of 42% (95% CI 30–47%) if the intervention had not occurred.Conclusions  The analysis highlights the potential for rapid HIV spread among IDUs in Dhaka, and suggests that the intervention may have substantially reduced IDU HIV transmission. However, there is no room for complacency. Sustained and expanded funding for interventions in Dhaka and other regions of Bangladesh are crucial to maintaining the low HIV prevalence.
t(8;21) acute myeloid leukaemia cells are dependent on vascular endothelial growth factor (VEGF)/VEGF receptor type2 pathway and phosphorylation of Akt
Authors: Imai Norikazu , Shikami Masato , Miwa Hiroshi , Suganuma Kazuto , Hiramatsu Akihito , Watarai Masaya , Satoh Atsushi , Itoh Masato , Imamura Akira , Mihara Hidetsugu , Nitta Masakazu 
Published: October 2006

SummarySeveral anti‐angiogenic drugs have recently been clinically tested for haematological malignancies. To improve the efficacy of molecular target therapy against angiogenic molecules in acute myeloid leukaemia (AML), we examined the dependency of AML cells on the vascular endothelial growth factor (VEGF)/VEGF receptor type2 (VEGFR2) system by using VEGFR2 kinase inhibitor. Nineteen patient AML samples were cultured with or without VEGFR2 kinase inhibitor. All four t(8;21) viable AML cells showed significant reductions when treated with VEGFR2 kinase inhibitor, although VEGFR2 kinase inhibitor did not affect the cell proliferation of five t(15;17) AML samples. Other AML cases showed variable responses. VEGFR2 kinase inhibitor greatly suppressed the growth of Kasumi‐1, a t(8;21) cell line in a dose‐dependent manner through induction of apoptosis, but did not show any significant influence on NB4, a t(15;17) cell line. In addition, VEGFR2 kinase inhibitor potentiated the growth inhibitory effect of cytarabine in Kasumi‐1. Finally, it was shown that the Akt phosphorylation was augmented by VEGF165 in Kasumi‐1, which was abrogated by VEGFR2 kinase inhibitor. NB4 showed undetectable Akt phosphorylation even with VEGF165. These data demonstrated that t(8;21) AML cells are dependent on VEGF through VEGFR2, resulting in the phosphorylation of Akt.
Modelling potential spawning habitat of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Bay of Biscay
Authors: PLANQUE BENJAMIN , BELLIER EDWIGE , LAZURE PASCAL 
Published: October 2006

AbstractLarge amplitude variations in recruitment of small pelagic fish result from interactions between a fluctuating environment and population dynamics processes such as spawning. The spatial extent and location of spawning, which is critical to the fate of eggs and larvae, can vary strongly from year to year, as a result of changing population structure and environmental conditions. Spawning habitat can be divided into ‘potential spawning habitat’, defined as habitat where the hydrographic conditions are suitable for spawning, ‘realized spawning habitat’, defined as habitat where spawning actually occurs, and ‘successful spawning habitat’, defined as habitat from where successful recruitment has resulted. Using biological data collected during the period 2000–2004, as well as hydrographic data, we investigate the role of environmental parameters in controlling the potential spawning habitat of anchovy and sardine in the Bay of Biscay. Anchovy potential spawning habitat appears to be primarily related to bottom temperature followed by surface temperature and mixed‐layer depth, whilst surface and bottom salinity appear to play a lesser role. The possible influence of hydrographic factors on the spawning habitat of sardine seems less clear than for anchovy. Modelled relationships between anchovy and sardine spawning are used to predict potential spawning habitat from hydrodynamical simulations. The results show that the seasonal patterns in spawning are well reproduced by the model, indicating that hydrographic changes may explain a large fraction of spawning spatial dynamics. Such models may prove useful in the context of forecasting potential impacts of future environmental changes on sardine and anchovy reproductive strategy in the north‐east Atlantic.
Predicting the vertical profiles of anchovy (Engraulis mordax) and sardine (Sardinops sagax) eggs in the California Current System
Authors: ALEXANDRA CURTIS K. , CHECKLEY DAVID M. , PEPIN PIERRE 
Published: October 2006

AbstractSeveral published models exist for simulating vertical profiles of pelagic fish eggs, but no one has rigorously assessed their capacity to explain observed variability. In this study, we applied a steady‐state model, with four different formulations for vertical diffusivity, to northern anchovy (Engraulis mordax) and Pacific sardine (Sardinops sagax) eggs in the California Current region. Vertical mixing profiles, based on wind speed and hydrography, were combined with estimated terminal ascent velocities of the eggs based on measurements of egg buoyancy and size, to simulate the vertical profiles of the eggs. We evaluated model performance with two data sets: (1) vertically stratified tows for both species and (2) paired samples for sardine eggs from 3‐m depth and in vertically integrated tows. We used two criteria: whether the model predicted individual observed vertical profiles (1) as well as the observed mean and (2) better than the observed mean. Model predictions made with the formulation producing the most gradual profile of vertical diffusivity provided the best match to observations from both data sets and for both species. Addition of a random error term to the terminal ascent velocity further improved prediction for anchovy eggs, but not sardine. For the paired data, model prediction of integrated abundance from abundance at 3‐m depth had significantly lower mean square error than prediction based on a linear regression of 3 m on integrated abundance. Our results support the feasibility of using data from the Continuous Underway Fish Egg Sampler quantitatively as well as qualitatively in stock assessments.
Potential carbon release from permafrost soils of Northeastern Siberia
Authors: DUTTA KOUSHIK , SCHUUR E. A. G. , NEFF J. C. , ZIMOV S. A. 
Published: October 2006

AbstractPermafrost soils are an important reservoir of carbon (C) in boreal and arctic ecosystems. Rising global temperature is expected to enhance decomposition of organic matter frozen in permafrost, and may cause positive feedback to warming as CO2 is released to the atmosphere. Significant amounts of organic matter remain frozen in thick mineral soil (loess) deposits in northeastern Siberia, but the quantity and lability of this deep organic C is poorly known. Soils from four tundra and boreal forest locations in northeastern Siberia that have been continuously frozen since the Pleistocene were incubated at controlled temperatures (5, 10 and 15°C) to determine their potential to release C to the atmosphere when thawed. Across all sites, CO2 with radiocarbon (14C) ages ranging between∼21 and 24 ka bp was respired when these permafrost soils were thawed. The amount of C released in the first several months was strongly correlated to C concentration in the bulk soil in the different sites, and this correlation remained the same for fluxes up to 1 year later. Fluxes were initially strongly related to temperature with a mean Q10 value of 1.9±0.3 across all sites, and later were unrelated to temperature but still correlated with bulk soil C concentration. Modeled inversions of Δ14CO2 values in respiration CO2 and soil C components revealed mean contribution of 70% and 26% from dissolved organic C to respiration CO2 in case of two permafrost soils, while organic matter fragments dominated respiration (mean 68%) from a surface mineral soil that served as modern reference sample. Our results suggest that if 10% of the total Siberian permafrost C pool was thawed to a temperature of 5°C, about 1 Pg C will be initially released from labile C pools, followed by respiration of∼40 Pg C to the atmosphere over a period of four decades.
Fifteen years of climate change manipulations alter soil microbial communities in a subarctic heath ecosystem
Authors: RINNAN RIIKKA , MICHELSEN ANDERS , BÅÅTH ERLAND , JONASSON SVEN 
Published: October 2006

AbstractSoil microbial biomass in arctic heaths has been shown to be largely unaffected by treatments simulating climate change with temperature, nutrient and light manipulations. Here, we demonstrate that more than 10 years is needed for development of significant responses, and that changes in microbial biomass are accompanied with strong alterations in microbial community composition. In contrast to slight or nonsignificant responses after 5, 6 and 10 treatment years, 15 years of inorganic NPK fertilizer addition to a subarctic heath had strong effects on the microbial community and, as observed for the first time, warming and shading also led to significant responses, often in opposite direction to the fertilization responses. The effects were clearer in the top 5 cm soil than at the 5–10 cm depth. Fertilization increased microbial biomass C and more than doubled microbial biomass P compared to the non‐fertilized plots. However, it only increased microbial biomass N at the 5–10 cm depth. Fertilization increased fungal biomass and the relative abundance of phospholipid fatty acid (PLFA) markers of gram‐positive bacteria. Warming and shading decreased the relative abundance of fungal PLFAs, and shading also altered the composition of the bacterial community. The long time lag in responses may be associated with indirect effects of the gradual changes in the plant biomass and community composition. The contrasting responses to warming and fertilization treatments show that results from fertilizer addition may not be similar to the effects of increased nutrient mineralization and availability following climatic warming.
Establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) in disturbed soil as a function of an urban–rural macro‐environment
Authors: ZISKA L. H. , GEORGE K. , FRENZ D. A. 
Published: October 2006

AbstractNo data are available on whether rising carbon dioxide concentration [CO2] or increased air temperature can alter the establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) within a plant community following soil disturbance. To determine ragweed longevity, we exposed disturbed soil with a common seed bank population to an in situ temperature and [CO2] gradient along an urban–rural transect beginning in early 2002. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented over the course of the study (2002–2005). Above‐ground measurements of biomass over this period demonstrated that ragweed along the transect responded to urban induced increases in [CO2]/temperature with peak biomass being observed at this location by the end of 2003. However, by the Fall of 2004, and continuing through 2005, urban ragweed populations had dwindled to a few plants. The temporal decline in ragweed populations was not associated with increased disease, herbivory or auto‐allelopathy, but was part of a demographic reduction in the total number of annual plant species observed for the urban location. In a separate experiment, we showed that such a demographic shift is consistent with CO2/temperature induced increases in biomass and litter accumulation, with a subsequent reduction in germination/survival of annual plant species. Overall, these data indicate that [CO2]/temperature differences associated with urbanization may increase initial ragweed productivity and pollen production, but suggest that long‐term, multi‐year persistence of ragweed in the urban macro‐environment may be dependent on other factors.
Lagged effects of North Atlantic Oscillation on spittlebug Philaenus spumarius (Homoptera) abundance and survival
Authors: HALKKA ANTTI , HALKKA LIISA , HALKKA OLLI , ROUKKA KAISA , POKKI JUSSI 
Published: October 2006

AbstractThe North Atlantic Oscillation (NAO) is a large‐scale pattern of climate variability that has been shown to have important ecological effects on a wide spectrum of taxa. Studies on terrestrial invertebrates are, however, lacking. We studied climate‐connected causes of changes in population sizes in island populations of the spittlebug Philaenus spumarius (L.) (Homoptera). Three populations living in meadows on small Baltic Sea islands were investigated during the years 1970–2005 in Tvärminne archipelago, southern Finland. A separate analysis was done on the effects of NAO and local climate variables on spittlebug survival in 1969–1978, for which survival data existed for two islands. We studied survival at two stages of the life cycle: growth rate from females to next year's instars (probably mostly related to overwintering egg survival), and survival from third instar stage to adult. The latter is connected to mortality caused by desiccation of plants and spittle masses.Higher winter NAO values were consistently associated with smaller population sizes on all three islands. Local climate variables entering the most parsimonious autoregressive models of population abundance were April and May mean temperature, May precipitation, an index of May humidity, and mean temperature of the coldest month of the previous winter. High winter NAO values had a clear negative effect on late instar survival in 1969–1978. Even May–June humidity and mean temperature of the coldest month were associated with late instar survival. The climate variables studied (including NAO) had no effect on the growth rate from females to next year's instars.NAO probably affected the populations primarily in late spring. Cold and snowy winters contribute to later snow melt and greater spring humidity in the meadows. We show that winter NAO has a considerable lagged effect on April and May temperature; even this second lagged effect contributes to differences in humidity. The lagged effect of the winter NAO to spring temperatures covers a large area in northern Europe and has been relatively stationary for 100 years at least in the Baltic area.
Complete spontaneous regression of congenital epulis in a baby by 8 months of age
Authors: SAKAI VIVIEN T. , OLIVEIRA THAIS M. , SILVA THIAGO C. , MORETTI ANA BEATRIZ S. , SANTOS CARLOS F. , MACHADO MARIA APARECIDA A. M. 
Published: October 2006

Background.  This paper describes the case of a 7‐day‐old girl who was referred to a paediatric dentistry clinic because of the presence of a pedunculated mass protruding from the front of her mouth.Case report.  The mass was attached to the maxillary alveolus to the right of the midline, and was clinically diagnosed as a congenital epulis. The baby had no airway obstruction and was able to feed well. A conservative treatment was proposed, with monthly follow‐up appointments to monitor the lesion.Conclusion.  After 8 months, the lesion had completely regressed, meaning that the girl did not have to be exposed to unnecessary surgical procedures in her first few days of life. The eruption of the upper anterior teeth was not affected.
A tale of two flatties: different responses of two terrestrial flatworms to past environmental climatic fluctuations at Tallaganda in montane southeastern Australia
Authors: SUNNUCKS PAUL , BLACKET MARK J. , TAYLOR JODY M. , SANDS CHESTER J. , CIAVAGLIA SHERRYN A. , GARRICK RYAN C. , TAIT NOEL N. , ROWELL DAVID M. , PAVLOVA ALEXANDRA 
Published: October 2006

AbstractComparative phylogeographic studies of animals with low mobility and/or high habitat specificity remain rare, yet such organisms may hold fine‐grained palaeoecological signal. Comparisons of multiple, codistributed species can elucidate major historical events. As part of a multitaxon programme, mitochondrial cytochrome oxidase I (COI) variation was analysed in two species of terrestrial flatworm,Artioposthia lucasiandCaenoplana coerulea. We applied coalescent demographic estimators and nested clade analysis to examine responses to past, landscape‐scale, cooling‐drying events in a model system of montane forest (Tallaganda). Correspondence of haplotype groups in both species to previously proposed microbiogeographic regions indicates at least four refuges from cool, dry conditions. The region predicted to hold the highest quality refuges (the Eastern Slopes Region), is indicated to have been a long‐term refuge in both species, but so are several other regions. Coalescent analyses suggest that populations ofA. lucasiare declining, whileC. coeruleais expanding, although stronger population substructure in the former could yield similar patterns in the data. The differences in spatial and temporal genetic variation in the two species could be explained by differences in ecological attributes:A. lucasiis predicted to have lower dispersal ability but may be better able to withstand cold conditions. Thus, different contemporary population dynamics may reflect different responses to recent (Holocene) climate warming. The two species show highly congruent patterns of catchment‐based local genetic endemism with one another and with previously studied slime‐mould grazing Collembola.
Speciation and rapid phenotypic differentiation in the yellow‐rumped warblerDendroica coronatacomplex
Authors: MILÁ BORJA , SMITH THOMAS B. , WAYNE ROBERT K. 
Published: October 2006

AbstractThe relative importance of the Pleistocene glacial cycles in driving avian speciation remains controversial, partly because species limits in many groups remain poorly understood, and because current taxonomic designations are often based on phenotypic characteristics of uncertain phylogenetic significance. We use mtDNA sequence data to examine patterns of genetic variation, sequence divergence and phylogenetic relationships between phenotypically distinct groups of the yellow‐rumped warbler complex. Currently classified as a single species, the complex is composed of two North American migratory forms (myrtle warblerDendroica coronata coronataand Audubon's warblerDendroica coronata auduboni), and two largely sedentary forms:Dendroica coronata nigrifronsof Mexico, andDendroica coronata goldmaniof Guatemala. The latter are typically considered to be races of the Audubon's warbler based on plumage characteristics. However, mtDNA sequence data reveal that sedentary Mesoamerican forms are reciprocally monophyletic to each other and to migratory forms, from which they show a long history of isolation. In contrast, migratory myrtle and Audubon's warblers form a single cluster due to high levels of shared ancestral polymorphism as evidenced by widespread sharing of mtDNA haplotypes despite marked phenotypic differentiation. Sedentary and migratory forms diverged in the early Pleistocene, whereas phenotypic differentiation between the two migratory forms has occurred in the Holocene and is likely the result of geographical isolation and subsequent range expansion since the last glaciation. Our results underscore the importance of Quaternary climatic events in driving songbird speciation and indicate that plumage traits can evolve remarkably fast, thus rendering them potentially misleading for inferring systematic relationships.
Dynamic localization and interaction with other Bacillus subtilis actin‐like proteins are important for the function of MreB
Authors: Defeu Soufo Hervé Joël , Graumann Peter L. 
Published: October 2006

SummaryBacterial actin‐like proteins play a key role in cell morphology and in chromosome segregation. Many bacteria, like Bacillus subtilis, contain three genes encoding actin‐like proteins, called mreB, mbl and mreBH in B. subtilis. We show that MreB and Mbl colocalize extensively within live cells, and that all three B. subtilis actin paralogues interact with each other underneath the cell membrane. A mutation in the phosphate 2 motif of MreB had a dominant negative effect on cell morphology and on chromosome segregation. Expression of this mutant allele of MreB interfered with the dynamic localization of Mbl. These experiments show that the interaction between MreB and Mbl has physiological significance. An mreB deletion strain can grow under special media conditions, however, depletion of Mbl in this mutant background abolished growth, indicating that actin paralogues can partially complement each other. The membrane protein MreC was found to interact with Mbl, but not with MreB, revealing a clear distinction between the function of the two paralogues. The phosphate 2 mutant MreB protein allowed for filament formation of mutant or wild‐type MreB, but abolished the dynamic reorganization of the filaments. The latter mutation led to a strong reduction, but not complete loss, of function of MreB, both in terms of chromosome segregation and of cell morphology. Our work shows that that the dynamic localization of MreB is essential for the proper activity of the actin‐like protein and that the interactions between MreB paralogues have important physiological significance.