bluuebunny/crossref_metadata_2025_split huggingface dataset:
Which drugs cause preventable admissions to hospital? A systematic review
Authors: Howard R. L. , Avery A. J. , Slavenburg S. , Royal S. , Pipe G. , Lucassen P. , Pirmohamed M. 
Published: June 2006

AimsPrevious systematic reviews have found that drug‐related morbidity accounts for 4.3% of preventable hospital admissions. None, however, has identified the drugs most commonly responsible for preventable hospital admissions. The aims of this study were to estimate the percentage of preventable drug‐related hospital admissions, the most common drug causes of preventable hospital admissions and the most common underlying causes of preventable drug‐related admissions.MethodsBibliographic databases and reference lists from eligible articles and study authors were the sources for data. Seventeen prospective observational studies reporting the proportion of preventable drug‐related hospital admissions, causative drugs and/or the underlying causes of hospital admissions were selected. Included studies used multiple reviewers and/or explicit criteria to assess causality and preventability of hospital admissions. Two investigators abstracted data from all included studies using a purpose‐made data extraction form.ResultsFrom 13 papers the median percentage of preventable drug‐related admissions to hospital was 3.7% (range 1.4–15.4). From nine papers the majority (51%) of preventable drug‐related admissions involved either antiplatelets (16%), diuretics (16%), nonsteroidal anti‐inflammatory drugs (11%) or anticoagulants (8%). From five studies the median proportion of preventable drug‐related admissions associated with prescribing problems was 30.6% (range 11.1–41.8), with adherence problems 33.3% (range 20.9–41.7) and with monitoring problems 22.2% (range 0–31.3).ConclusionsFour groups of drugs account for more than 50% of the drug groups associated with preventable drug‐related hospital admissions. Concentrating interventions on these drug groups could reduce appreciably the number of preventable drug‐related admissions to hospital from primary care.
Fetal hepatic haematopoiesis is modulated by arterial blood flow to the liver
Authors: Kunisaki Shaun M. , Azpurua Humberto , Fuchs Julie R. , Graves Sara C. , Zurakowski David , Fauza Dario O. 
Published: June 2006

SummaryWe describe an as yet unrecognised relationship between fetal hepatic haematopoiesis and arterial blood flow to the liver. To increase hepatic arterial flow, the common bile duct (CBD) was ligated in fetal lambs. Reduction of hepatic arterial flow was accomplished in age‐matched animals by hepatic artery (HA) ligation. Multiple analyses performed before term showed a significant increase in haematopoietic cell density in CBD animals when compared with sham controls and HA animals. In contrast, HA animals demonstrated a decrease in liver haematopoietic activity. Fetal hepatic haematopoiesis is dependent upon arterial blood flow to the liver.
Age changes the diagnostic accuracy of mean profile and nadir growth hormone levels after oral glucose in postoperative patients with acromegaly
Authors: Colao Annamaria , Pivonello Rosario , Cavallo Luigi M. , Gaccione Maria , Auriemma Renata S. , Esposito Felice , Cappabianca Paolo , Lombardi Gaetano 
Published: June 2006

SummaryBackground  This analytical, retrospective study was designed to select cut‐off thresholds of mean GH levels during a diurnal profile and nadir GH levels after oral glucose tolerance test (OGTT) according to age to diagnose surgical remission of acromegaly.Methods   One hundred forty‐one patients (76 women, aged 44 ± 15 years and 65 men, aged 43 ± 13 years) were included in this study. For the purpose of this study, remission was based on insulin‐like growth factor‐I (IGF‐I) levels in the normal range for age. Diagnostic accuracy was analysed by receiving‐operator characteristics (ROC) curves in the entire series, and in young (20–40 years), middle‐aged (41–60 years) and older patients (> 60 years), separately.Results   Sixty patients (42·6%) had normal IGF‐I levels after surgery. In the entire series, in young and in middle‐aged patients, the ROC analysis showed that optimum cut‐off for mean GH levels was 2·3 µg/l (diagnostic accuracy range, 94–97%) whereas that for nadir GH after OGTT were, respectively, 0·85, 0·9 and 0·8 µg/l (diagnostic accuracy range, 90–95%). In the older patients, the optimum cut‐off selected for mean GH levels was 1·4 µg/l and that for nadir GH after OGTT was 0·5 µg/l (diagnostic accuracy, 100% for both). The comparative analysis of the ROC curves did not show any significant difference between mean GH and nadir GH after OGTT (P = 0·21).Conclusions   The criteria currently accepted for diagnosing post‐surgical remission of acromegaly have high diagnostic accuracy only in the patients aged below 60 years. In older patients, lower cut‐offs (i.e. = 1·4 µg/l for fasting GH and = 0·5 µg/l for nadir GH after OGTT) predict normal IGF‐I levels. Mean GH levels during a diurnal profile have similar diagnostic accuracy of nadir GH levels after OGTT. This suggests that OGTT is not necessary to establish surgical cure.
Effects of plant species diversity, atmospheric [CO2], and N addition on gross rates of inorganic N release from soil organic matter
Authors: WEST JASON B. , HOBBIE SARAH E. , REICH PETER B. 
Published: June 2006

AbstractA significant challenge in predicting terrestrial ecosystem response to global changes comes from the relatively poor understanding of the processes that control pools and fluxes of plant nutrients in soil. In addition, individual global changes are often studied in isolation, despite the potential for interactive effects among them on ecosystem processes. We studied the response of gross N mineralization and microbial respiration after 6 years of application of three global change factors in a grassland field experiment in central Minnesota (the BioCON experiment). BioCON is a factorial manipulation of plant species diversity (1, 4, 9 and 16 prairie species), atmospheric [CO2] (ambient and elevated: 560 μmol mol−1), and N inputs (ambient and ambient +4 g N m−2 yr−1). We hypothesized that gross N mineralization would increase with increasing levels of all factors because of stimulated plant productivity and thus greater organic inputs to soils. However, we also hypothesized that N addition would enhance, while elevated [CO2] and greater diversity would temper, gross N mineralization responses because of increased and reduced plant tissue N concentrations, respectively. In partial support of our hypothesis, gross N mineralization increased with greater diversity and N addition, but not with elevated [CO2]. The ratio of gross N mineralization to microbial respiration (i.e. the ‘yield’ of inorganic N mineralized per unit C respired) declined with greater diversity and [CO2] suggesting increasing limitation of microbial processes by N relative to C in these treatments. Based on these results, we conclude that the plant supply of organic matter primarily controls gross N mineralization and microbial respiration, but that the concentration of N in organic matter input secondarily influences these processes. Thus, in systems where N limits plant productivity these global change factors could cause different long‐term ecosystem trajectories because of divergent effects on soil N and C cycling.
Points, patches, and regions: scaling soil biogeochemical patterns in an urbanized arid ecosystem
Authors: JENERETTE G. DARREL , WU JIANGUO , GRIMM NANCY B. , HOPE DIANE 
Published: June 2006

AbstractCities are rapidly growing throughout the world and are altering biologic processes in many regions, with global consequences. Urbanization in the Phoenix, USA metropolitan region has dramatically altered regional ecosystem patterns, but little is known about how these changes have influenced soil organic matter, total nitrogen, and the distribution of nitrogen stable isotopes. Because urban development is a phenomenon occurring at multiple scales, ecological consequences of urbanization will likely differ between individual patches and the entire metropolitan region. To investigate such changes we conducted spatially explicit surveys including three dominant land‐use types in this region: native desert, agriculture, and mesic residential. These data were combined for analysis with previously collected samples from a synoptic regional survey. A landscape scaling approach was implemented to compare the dependence of soil variability on the sampled extent and the uncertainty associated with scaling from points to patches, land‐use types, and the Phoenix metropolitan region. The multiple‐scale analysis of soil properties showed that variation in total soil nitrogen, soil organic matter, andδ5N content of soils differed between patch and regional scales. The majority of variation in the urbanized patch types was exhibited between patches while for the native desert the majority of variation was observed within individual patches. These differences show the impact of urbanization on the scaling relations of ecosystem components. Overall, urbanization in this region appears to have increased soil organic matter by 44%, total nitrogen by 48%, and has elevatedδ15N by 21%.
Ecosystem CO2 production during winter in a Swedish subarctic region: the relative importance of climate and vegetation type
Authors: GROGAN PAUL , JONASSON SVEN 
Published: June 2006

AbstractGeneral circulation models consistently predict that regional warming will be most rapid in the Arctic, that this warming will be predominantly in the winter season, and that it will often be accompanied by increasing snowfall. Paradoxically, despite the strong cold season emphasis in these predictions, we know relatively little about the plot and landscape‐level controls on tundra biogeochemical cycling in wintertime as compared to summertime.We investigated the relative influence of vegetation type and climate on CO2 production rates and total wintertime CO2 release in the Scandinavian subarctic. Ecosystem respiration rates and a wide range of associated environmental and substrate pool size variables were measured in the two most common vegetation types of the region (birch understorey and heath tundra) at four paired sites along a 50 km transect through a strong snow depth gradient in northern Sweden.Both climate and vegetation type were strong interactive controls on ecosystem CO2 production rates during winter. Of all variables tested, soil temperature explained by far the largest amount of variation in respiration rates (41–75%). Our results indicate that vegetation type only exerted an influence on respiration when snow depth was below a certain threshold (∼1 m). Thus, tall vegetation that enhanced snow accumulation within that threshold resulted in more effective thermal insulation from severe air temperatures, thereby significantly increasing respiratory activity. At the end of winter, within several days of snowmelt, gross ecosystem photosynthesis rates were of a similar magnitude to ecosystem respiration, resulting in significant net carbon gain in some instances. Finally, climate and vegetation type were also strong interactive controls on total wintertime respiration, suggesting that spatial variations in maximum snowdepth may be a primary determinant of regional patterns of wintertime CO2 release. Together, our results have important implications for predictions of how the distribution of tundra vegetation types and the carbon balances of arctic ecosystems will respond to climate change during winter because they indicate a threshold (∼1 m) above which there would be little effect of increased snow accumulation on wintertime biogeochemical cycling.
Advanced snowmelt causes shift towards positive neighbour interactions in a subarctic tundra community
Authors: WIPF SONJA , RIXEN CHRISTIAN , MULDER CHRISTA P. H. 
Published: June 2006

AbstractPositive and negative species interactions are important factors in structuring vegetation communities. Studies in many ecosystems have focussed on competition; however, facilitation has often been found to outweigh competition under harsh environmental conditions. The balance between positive and negative species interactions is known to shift along spatial, temporal and environmental gradients and thus is likely to be affected by climate change.Winter temperature and precipitation patterns in Interior Alaska are rapidly changing and could lead to warmer winters with a shallow, early melting snow cover in the near future. We conducted snow manipulation and neighbour removal experiments to test whether the relative importance of positive and negative species interactions differs between three winter climate scenarios in a subarctic tundra community. In plots with ambient, manually advanced or delayed snowmelt, we assessed the relative importance of neighbours for survival, phenology, growth and reproduction of two dwarf shrub species. Under ambient conditions and after delayed snowmelt, positive and negative neighbour effects were generally balanced, but when snowmelt was advanced we found overall facilitative neighbour effects on survival, phenology, growth and reproduction of Empetrum nigrum, the earlier developing of the two target species. As earlier snowmelt was correlated with colder spring temperatures and a higher number of frosts, we conclude that plants experienced harsher environmental conditions after early snowmelt and that neighbours could have played an important role in ameliorating the physical environment at the beginning of the growing season.
The relative importance of climatic effects, wildfires and management for future forest landscape dynamics in the Swiss Alps
Authors: SCHUMACHER SABINE , BUGMANN HARALD 
Published: June 2006

AbstractForest landscape dynamics result from the complex interaction of driving forces and ecological processes operating on various scales. Projected climate change for the 21st century will alter climate‐sensitive processes, causing shifts in species composition and also bringing about changes in disturbance regimes, particularly regarding wildfires. Previous studies of the impact of climate change on forests have focused mainly on the direct effects of climate. In the present study, we assessed the interactions among forest dynamics, climate change and large‐scale disturbances such as fire, wind and forest management. We used the LandClimmodel to investigate the influence, interactions and the relative importance of these different drivers of landscape dynamics in two case study areas of the European Alps. The simulations revealed that projected future climate change would cause extensive forest cover changes, beginning in the coming decades. Fire is likely to become almost as important for shaping the landscape as the direct effects of climate change, even in areas where major wildfires do not occur under current climatic conditions. The effects of variable wind disturbances and harvesting regimes, however, are less likely to have a considerable impact on forest development compared with the direct effects of climate change coupled with the indirect effects of increased fire activity. We conclude that the joint direct and indirect effects of climate change are likely to have major consequences for mountain forests in the European Alps, including their ability to provide protection against natural hazards.
Using metabolic fingerprinting of plants for evaluating nitrogen deposition impacts on the landscape level
Authors: GIDMAN ELEANOR A. , STEVENS CARLY J. , GOODACRE ROYSTON , BROADHURST DAVID , EMMETT BRIDGET , GWYNN‐JONES DYLAN 
Published: June 2006

AbstractNitrogen emissions and atmospheric deposition are globally significant with the potential to alter ecosystem nutrient balance, provoking changes in vegetation composition. Shifts in plant biochemistry are good indicators of nitrogen pollution and have been used to monitor vegetation health. Fourier transform‐infrared (FT‐IR) spectroscopy has previously been shown to be a rapid and relatively inexpensive method for evaluating leaf biochemistry. In the present study, FT‐IR spectra were collected from Galium saxatile samples taken from sites across the United Kingdom. Spectral changes in the tissue samples were correlated with a gradient of N deposition using partial least squares regression analysis. We show that FT‐IR analysis of G. saxatile leaf tissue is an effective way to evaluate nitrogen deposition across the entire UK landscape.
Predicting climate‐induced range shifts: model differences and model reliability
Authors: LAWLER JOSHUA J. , WHITE DENIS , NEILSON RONALD P. , BLAUSTEIN ANDREW R. 
Published: June 2006

AbstractPredicted changes in the global climate are likely to cause large shifts in the geographic ranges of many plant and animal species. To date, predictions of future range shifts have relied on a variety of modeling approaches with different levels of model accuracy. Using a common data set, we investigated the potential implications of alternative modeling approaches for conclusions about future range shifts and extinctions. Our common data set entailed the current ranges of 100 randomly selected mammal species found in the western hemisphere. Using these range maps, we compared six methods for modeling predicted future ranges. Predicted future distributions differed markedly across the alternative modeling approaches, which in turn resulted in estimates of extinction rates that ranged between 0% and 7%, depending on which model was used. Random forest predictors, a model‐averaging approach, consistently outperformed the other techniques (correctly predicting >99% of current absences and 86% of current presences). We conclude that the types of models used in a study can have dramatic effects on predicted range shifts and extinction rates; and that model‐averaging approaches appear to have the greatest potential for predicting range shifts in the face of climate change.
Lactoferrin decreases pollen antigen‐induced allergic airway inflammation in a murine model of asthma
Authors: Kruzel Marian L. , Bacsi Attila , Choudhury Barun , Sur Sanjiv , Boldogh Istvan 
Published: June 2006

SummaryPollen grains contain reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidases and in contact with mucosal surfaces generate superoxide anion (O2•–). In the presence of iron, O2•– may be converted to more reactive oxygen radicals, such as to H2O2 and/or •OH, which may augment antigen‐induced airway inflammation. The aim of the study was to examine the impact of lactoferrin (LF), an iron‐binding protein, on ragweed (Ambrosia artemisiifolia) pollen extract (RWE)‐induced cellular oxidative stress levels in cultured bronchial epithelial cells and accumulation of inflammatory and mucin‐producing cells in airways in a mouse model of allergic airway inflammation. Results show that LF lowered RWE‐induced increase in cellular reactive oxygen species (ROS) levels in bronchial epithelial cells. Most importantly, LF significantly decreased accumulation of eosinophils into airways and subepithelium of intranasally challenged, sensitized mice. LF also prevented development of mucin‐producing cells. Amb a 1, the major allergenic ragweed pollen antigen lacking NAD(P)H oxidase activity, induced low‐grade airway inflammation. When administered along with glucose oxidase (G‐ox), a superoxide‐generating enzyme, Amb a 1 induced robust airway inflammation, which was significantly lowered by LF. Surprisingly, LF decreased also inflammation caused by Amb a 1 alone. Iron‐saturated hololactoferrin had only a marginal effect on RWE‐induced cellular ROS levels and RWE‐ or Amb a 1 plus G‐ox‐induced inflammation. We postulate that free iron in the airways chemically reduces O2•– to more reactive species which augment antigen‐induced inflammation in a mouse model of asthma. Our results suggest the utility of LF in human allergic inflammatory disorders.
Deep genealogies and the mid‐peninsular seaway of Baja California
Authors: Lindell Johan , Ngo Andre , Murphy Robert W. 
Published: June 2006

AbstractGeological forces and long‐term climate changes can have profound effects on species. Such effects may be manifested in the pattern and magnitude of genealogical diversity, as revealed by mitochondrial DNA (mtDNA) lineages. The relative importance of the different forces on a regional biota must be evaluated along with a good understanding of geological and climatological history. The peninsula of Baja California of north‐western Mexico is one area where both geology and climate have affected the historical biogeography of the regional biota. Molecular studies based on the genealogical relationships among mtDNA lineages have contributed greatly towards elucidating the historical biogeography of Baja California. Perhaps most noticeably, numerous concordant breaks in mtDNA genealogies half‐way along the peninsula suggest a vicariant history in which the mid‐peninsula was temporarily submerged. This vicariant explanation has recently been criticized, as no conclusive geological evidence exists for a continuous submergence of the mid‐peninsula. As an alternative, a scenario based on climatological factors has been suggested. Here we discuss the validity of the hypothesized mid‐peninsular vicariance event and the climate‐based alternative in explaining the concordant genealogical breaks. We argue that, despite the significant changes in climate brought about by the glacial cycles throughout the Quaternary, a vicariant history involving a mid‐peninsular seaway remains the most parsimonious explanation of the observed patterns in mtDNA genealogies.
Modelling the influence of change in fire regime on the local distribution of a Mediterranean pyrophytic plant species (Cistus salviifolius) at its northern range limit
Authors: Moretti Marco , Conedera Marco , Moresi Ruben , Guisan Antoine 
Published: June 2006

AbstractAims  To assess the potential distribution of an obligate seeder and active pyrophyte, Cistus salviifolius, a vulnerable species in the Swiss Red List; to derive scenarios by changing the fire return interval; and to discuss the results from a conservation perspective. A more general aim is to assess the impact of fire as a natural factor influencing the vegetation of the southern slopes of the Alps.Location  Alps, southern Switzerland.Methods  Presence–absence data to fit the model were obtained from the most recent field mapping of C. salviifolius. The quantitative environmental predictors used in this study include topographic, climatic and disturbance (fire) predictors. Models were fitted by logistic regression and evaluated by jackknife and bootstrap approaches. Changes in fire regime were simulated by increasing the time‐return interval of fire (simulating longer periods without fire). Two scenarios were considered: no fire in the past 15 years; or in the past 35 years.Results  Rock cover, slope, topographic position, potential evapotranspiration and time elapsed since the last fire were selected in the final model. The Nagelkerke R2 of the model for C. salviifolius was 0.57 and the Jackknife area under the curve evaluation was 0.89. The bootstrap evaluation revealed model robustness. By increasing the return interval of fire by either up to 15 years, or 35 years, the modelled C. salviifolius population declined by 30–40%, respectively.Main conclusions  Although fire plays a significant role, topography and rock cover appear to be the most important predictors, suggesting that the distribution of C. salviifolius in the southern Swiss Alps is closely related to the availability of supposedly competition‐free sites, such as emerging bedrock, ridge locations or steep slopes. Fire is more likely to play a secondary role in allowing C. salviifolius to extend its occurrence temporarily, by increasing germination rates and reducing the competition from surrounding vegetation. To maintain a viable dormant seed bank for C. salviifolius, conservation managers should consider carrying out vegetation clearing and managing wild fire propagation to reduce competition and ensure sufficient recruitment for this species.