Showing papers by "Dalhousie University published in 2005"

A global clinical measure of fitness and frailty in elderly people

Abstract: Background: There is no single generally accepted clinical definition of frailty. Previously developed tools to assess frailty that have been shown to be predictive of death or need for entry into an institutional facility have not gained acceptance among practising clinicians. We aimed to develop a tool that would be both predictive and easy to use. Methods: We developed the 7-point Clinical Frailty Scale and applied it and other established tools that measure frailty to 2305 elderly patients who participated in the second stage of the Canadian Study of Health and Aging (CSHA). We followed this cohort prospectively; after 5 years, we determined the ability of the Clinical Frailty Scale to predict death or need for institutional care, and correlated the results with those obtained from other established tools. Results: The CSHA Clinical Frailty Scale was highly correlated ( r = 0.80) with the Frailty Index. Each 1-category increment of our scale significantly increased the medium-term risks of death (21.2% within about 70 mo, 95% confidence interval [CI] 12.5%–30.6%) and entry into an institution (23.9%, 95% CI 8.8%–41.2%) in multivariable models that adjusted for age, sex and education. Analyses of receiver operating characteristic curves showed that our Clinical Frailty Scale performed better than measures of cognition, function or comorbidity in assessing risk for death (area under the curve 0.77 for 18-month and 0.70 for 70-month mortality). Interpretation: Frailty is a valid and clinically important construct that is recognizable by physicians. Clinical judgments about frailty can yield useful predictive information.

The new higher level classification of eukaryotes with emphasis on the taxonomy of protists

Abstract: This revision of the classification of unicellular eukaryotes updates that of Levine et al. (1980) for the protozoa and expands it to include other protists. Whereas the previous revision was primarily to incorporate the results of ultrastructural studies, this revision incorporates results from both ultrastructural research since 1980 and molecular phylogenetic studies. We propose a scheme that is based on nameless ranked systematics. The vocabulary of the taxonomy is updated, particularly to clarify the naming of groups that have been repositioned. We recognize six clusters of eukaryotes that may represent the basic groupings similar to traditional ''kingdoms.'' The multicellular lineages emerged from within monophyletic protist lineages: animals and fungi from Opisthokonta, plants from Archaeplastida, and brown algae from Stramenopiles.

The Health and Well-Being of Caregivers of Children With Cerebral Palsy

Abstract: Objective. Most children enjoy healthy childhoods with little need for specialized health care services. However, some children experience difficulties in early childhood and require access to and utilization of considerable health care resources over time. Although impaired motor function is the hallmark of the cerebral palsy (CP) syndromes, many children with this development disorder also experience sensory, communicative, and intellectual impairments and may have complex limitations in self-care functions. Although caregiving is a normal part of being the parent of a young child, this role takes on an entirely different significance when a child experiences functional limitations and possible long-term dependence. One of the main challenges for parents is to manage their child9s chronic health problems effectively and juggle this role with the requirements of everyday living. Consequently, the task of caring for a child with complex disabilities at home might be somewhat daunting for caregivers. The provision of such care may prove detrimental to both the physical health and the psychological well-being of parents of children with chronic disabilities. It is not fully understood why some caregivers cope well and others do not. The approach of estimating the “independent” or “direct” effects of the care recipient9s disability on the caregiver9s health is of limited value because (1) single-factor changes are rare outside the context of constrained experimental situations; (2) assumptions of additive relationships and perfect measurements rarely hold; and (3) such approaches do not provide a complete perspective, because they fail to examine indirect pathways that occur between predictor variables and health outcomes. A more detailed analytical approach is needed to understand both direct and indirect effects simultaneously. The primary objective of the current study was to examine, within a single theory-based multidimensional model, the determinants of physical and psychological health of adult caregivers of children with CP. Methods. We developed a stress process model and applied structural equation modeling with data from a large cohort of caregivers of children with CP. This design allowed the examination of the direct and indirect relationships between a child9s health, behavior and functional status, caregiver characteristics, social supports, and family functioning and the outcomes of caregivers9 physical and psychological health. Families ( n = 468) of children with CP were recruited from 19 regional children9s rehabilitation centers that provide outpatient disability management and supports in Ontario, Canada. The current study drew on a population available to the investigators from a previous study, the Ontario Motor Growth study, which explored patterns of gross motor development in children with CP. Data on demographic variables and caregivers9 physical and psychological health were assessed using standardized, self-completed parent questionnaires as well as a face-to-face home interview. Structural equation modeling was used to test specific hypotheses outlined in our conceptual model. This analytic approach involved a 2-step process. In the first step, observed variables that were hypothesized to measure the underlying constructs were tested using confirmatory factor analysis; this step led to the so-called measurement model. The second step tested hypotheses about relationships among the variables in the structural model. All of the hypothesized paths in the conceptual model were tested and included in the structural model. However, only paths that were significant were shown in the final results. The direct, indirect, and total effects of theoretical constructs on physical and psychological health were calculated using the structural model. Results. The most important predictors of caregivers9 well-being were child behavior, caregiving demands, and family function. A higher level of behavior problems was associated with lower levels of both psychological (β = −.22) and physical health (β = −.18) of the caregivers, whereas fewer child behavior problems were associated with higher self-perception (β = −.37) and a greater ability to manage stress (β = −.18). Less caregiving demands were associated with better physical (β = .23) and psychological (β = .12) well-being of caregivers, respectively. Similarly, higher reported family functioning was associated with better psychological health (β = .33) and physical health (β = .33). Self-perception and stress management were significant direct predictors of caregivers9 psychological health but did not directly influence their physical well-being. Caregivers9 higher self-esteem and sense of mastery over the caregiving situation predicted better psychological health (β = .23). The use of more stress management strategies was also associated with better psychological health of caregivers (β = .11). Gross income (β = .08) and social support (β = .06) had indirect overall effects only on psychological health outcome, whereas self-perception (β = .22), stress management (β = .09), gross income (β = .07), and social support (β = .06) had indirect total effects only on physical health outcomes. Conclusions. The psychological and physical health of caregivers, who in this study were primarily mothers, was strongly influenced by child behavior and caregiving demands. Child behavior problems were an important predictor of caregiver psychological well-being, both directly and indirectly, through their effect on self-perception and family function. Caregiving demands contributed directly to both the psychological and the physical health of the caregivers. The practical day-to-day needs of the child created challenges for parents. The influence of social support provided by extended family, friends, and neighbors on health outcomes was secondary to that of the immediate family working closely together. Family function affected health directly and also mediated the effects of self-perception, social support, and stress management. In families of children with CP, strategies for optimizing caregiver physical and psychological health include supports for behavioral management and daily functional activities as well as stress management and self-efficacy techniques. These data support clinical pathways that require biopsychosocial frameworks that are family centered, not simply technical and short-term rehabilitation interventions that are focused primarily on the child. In terms of prevention, providing parents with cognitive and behavioral strategies to manage their child9s behaviors may have the potential to change caregiver health outcomes. This model also needs to be examined with caregivers of children with other disabilities.

Pollen Limitation of Plant Reproduction: Pattern and Process

Abstract: ▪ Abstract Quantifying the extent to which seed production is limited by the availability of pollen has been an area of intensive empirical study over the past few decades. Whereas theory predicts that pollen augmentation should not increase seed production, numerous empirical studies report significant and strong pollen limitation. Here, we use a variety of approaches to examine the correlates of pollen limitation in an effort to understand its occurrence and importance in plant evolutionary ecology. In particular, we examine the role of recent ecological perturbations in influencing pollen limitation and discuss the relation between pollen limitation and plant traits. We find that the magnitude of pollen limitation observed in natural populations depends on both historical constraints and contemporary ecological factors.

Psoriasis: epidemiology, clinical features, and quality of life

Abstract: Psoriasis is a common chronic, recurrent, immune mediated disease of the skin and joints. It can have a significant negative impact on the physical, emotional, and, psychosocial wellbeing of affected patients. Psoriasis is found worldwide but the prevalence varies among different ethnic groups. It has a strong genetic component but environmental factors such as infections can play an important role in the presentation of disease. There are several clinical cutaneous manifestations of psoriasis but most commonly the disease presents as chronic, symmetrical, erythematous, scaling papules and plaques. The epidemiology, clinical features, and impact on quality of life of psoriasis are reviewed.

Robust state-space modeling of animal movement data

Abstract: Remotely sensed tracking data collected on animal movement is vastly un- derutilized due to a lack of statistical tools for appropriate analysis. Features of such data that make analysis particularly challenging include the presence of estimation errors that are non-Gaussian and vary in time, observations that occur irregularly in time, and com- plexity in the underlying behavioral processes. We develop a state-space framework that simultaneously deals with these features and demonstrate our method by analyzing three seal pathway data sets. We show how known information regarding error distributions can be used to improve inference of the underlying process(es) and demonstrate that our frame- work provides a powerful and flexible method for fitting different behavioral models to tracking data.

Ecosystem dynamics based on plankton functional types for global ocean biogeochemistry models

Abstract: Ecosystem processes are important determinants of the biogeochemistry of the ocean, and they can be profoundly affected by changes in climate. Ocean models currently express ecosystem processes through empirically derived parameterizations that tightly link key geochemical tracers to ocean physics. The explicit inclusion of ecosystem processes in models will permit ecological changes to be taken into account, and will allow us to address several important questions, including the causes of observed glacial-interglacial changes in atmospheric trace gases and aerosols, and how the oceanic uptake of CO2 is likely to change in the future. There is an urgent need to assess our mechanistic understanding of the environmental factors that exert control over marine ecosystems, and to represent their natural complexity based on theoretical understanding. We present a prototype design for a Dynamic Green Ocean Model (DGOM) based on the identification of (a) key plankton functional types that need to be simulated explicitly to capture important biogeochemical processes in the ocean; (b) key processes controlling the growth and mortality of these functional types and hence their interactions; and (c) sources of information necessary to parameterize each of these processes within a modeling framework. We also develop a strategy for model evaluation, based on simulation of both past and present mean state and variability, and identify potential sources of validation data for each. Finally, we present a DGOM-based strategy for addressing key questions in ocean biogeochemistry. This paper thus presents ongoing work in ocean biogeochemical modeling, which, it is hoped will motivate international collaborations to improve our understanding of the role of the ocean in the climate system.

Electronic tagging and population structure of Atlantic bluefin tuna

Abstract: The Atlantic bluefin tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin tuna fishery collapsed and some conservationists say it will not recover unless the International Commission for Conservation of Atlantic Tunas adopts a tougher regime. Results from an electronic tagging programme on bluefin tuna are presented this week, and they make alarming reading. Western tagged bluefin tuna are shown to migrate freely across the international stock boundary into the eastern Atlantic, where they are vulnerable to European fisheries; and both known spawning grounds, in the Gulf of Mexico and the Mediterranean Sea, are shown to be linked to the endangered western Atlantic fishery. Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems1,2,3,4,5,6. Here we report on the electronic tagging of 772 Atlantic bluefin tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data7,8,9 that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.

An AeroCom Initial Assessment - Optical Properties in Aerosol Component Modules of Global Models

Abstract: The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment simulated global distributions for mass and mid-visible aerosol optical thickness (aot) were compared among 20 different modules. Model diversity was also explored in the context of previous comparisons. For the component combined aot general agreement has improved for the annual global mean. At 0.11 to 0.14, simulated aot values are at the lower end of global averages suggested by remote sensing from ground (AERONET ca. 0.135) and space (satellite composite ca. 0.15). More detailed comparisons, however, reveal that larger differences in regional distribution and significant differences in compositional mixture remain. Of particular concern are large model diversities for contributions by dust and carbonaceous aerosol, because they lead to significant uncertainty in aerosol absorption (aab). Since aot and aab, both, influence the aerosol impact on the radiative energy-balance, the aerosol (direct) forcing uncertainty in modeling is larger than differences in aot might suggest. New diagnostic approaches are proposed to trace model differences in terms of aerosol processing and transport: These include the prescription of common input (e.g. amount, size and injection of aerosol component emissions) and the use of observational capabilities from ground (e.g. measurements networks) or space (e.g. correlations between aerosol and clouds).

The tree of eukaryotes

Abstract: Recent advances in resolving the tree of eukaryotes are converging on a model composed of a few large hypothetical 'supergroups', each comprising a diversity of primarily microbial eukaryotes (protists, or protozoa and algae). The process of resolving the tree involves the synthesis of many kinds of data, including single-gene trees, multigene analyses, and other kinds of molecular and structural characters. Here, we review the recent progress in assembling the tree of eukaryotes, describing the major evidence for each supergroup, and where gaps in our knowledge remain. We also consider other factors emerging from phylogenetic analyses and comparative genomics, in particular lateral gene transfer, and whether such factors confound our understanding of the eukaryotic tree.

Cluster-head election using fuzzy logic for wireless sensor networks

Abstract: Wireless sensor networks (WSNs) present a new generation of real-time embedded systems with limited computation, energy and memory resources that are being used in a wide variety of applications where traditional networking infrastructure is practically infeasible. Appropriate cluster-head node election can drastically reduce the energy consumption and enhance the lifetime of the network. In this paper, a fuzzy logic approach to cluster-head election is proposed based on three descriptors-energy, concentration and centrality. Simulation shows that depending upon network configuration, a substantial increase in network lifetime can be accomplished as compared to probabilistically selecting the nodes as cluster-heads using only local information.

Pathways Between Social Support, Family Well Being, Quality of Parenting, and Child Resilience: What We Know

Abstract: We contribute to the theoretical and research knowledge base regarding the pathways between parental social support, family well being, quality of parenting, and the development of child resilience in families with a child with serious emotional problems. Little conceptual development has been done that provides a theoretical framework for studying the relationships among these variables. We identify key findings from social support theory and research, including the impact of social support on family well being and the parents’ capacity to parent, and the experience of parental social support in families with a child with a disability. We review the constructs of family well being, quality of parenting, and child resilience. Further, we explain the pathways between parental social support, family well being, quality of parenting, and child resilience in families with a child with serious emotional problems. Key variables of the model and the nature of their inter-relationships are described. Social support is constructed as a protective mechanism with main and buffering effects that can impact family well being, quality of parenting, and child resilience at a number of junctures. The conceptual model’s implications for future theory development and research are discussed.

Small heat shock proteins: molecular structure and chaperone function

Abstract: Small heat shock proteins (sHSPs) associate with nuclei, cytoskeleton and membranes, and as molecular chaperones they bind partially denatured proteins, thereby preventing irreversible protein aggregation during stress. sHSP monomers consist of a conserved alpha-crystallin domain of approximately 90 amino acid residues, bordered by variable amino- and carboxy-terminal extensions. The sHSPs undergo dynamic assembly into mono- and poly-disperse oligomers where the rate of disassembly affects chaperoning. The alpha-crystallin domain contains several beta-strands organized into two beta-sheets responsible for dimer formation, the basic building block of most sHSPS. The amino-terminal extension modulates oligomerization, subunit dynamics and substrate binding, whereas the flexible carboxy-terminal extension promotes solubility, chaperoning and oligomerization, the latter by inter-subunit linkage. Crystallization studies have revealed sHSP structure and function. Additionally, site-directed mutagenesis, biophysical investigations, functional studies and the discovery of relationships between mutated sHSPs and diseases have illuminated the role of sHSP within cells.

Environmental correlates of population differentiation in Atlantic herring.

Abstract: The marine environment is characterized by few physical barriers, and pelagic fishes commonly show high migratory potential and low, albeit in some cases statistically significant, levels of genetic divergence in neutral genetic marker analyses. However, it is not clear whether low levels of differentiation reflect spatially separated populations experiencing gene flow or shallow population histories coupled with limited random genetic drift in large, demo- graphically isolated populations undergoing independent evolutionary processes. Using information for nine micro- satellite loci in a total of 1951 fish, we analyzed genetic differentiation among Atlantic herring from eleven spawning locations distributed along a longitudinal gradient from the North Sea to the Western Baltic. Overall genetic differ- entiation was low ( u5 0.008) but statistically significant. The area is characterized by a dramatic shift in hydrography from the highly saline and temperature stable North Sea to the brackish Baltic Sea, where temperatures show high annual variation. We used two different methods, a novel computational geometric approach and partial Mantel correlation analysis coupled with detailed environmental information from spawning locations to show that patterns of reproductive isolation covaried with salinity differences among spawning locations, independent of their geograph- ical distance. We show that reproductive isolation can be maintained in marine fish populations exhibiting substantial mixing during larval and adult life stages. Analyses incorporating genetic, spatial, and environmental parameters indicated that isolating mechanisms are associated with the specific salinity conditions on spawning locations.

Extinction, survival or recovery of large predatory fishes.

Abstract: Large predatory fishes have long played an important role in marine ecosystems and fisheries. Overexploitation, however, is gradually diminishing this role. Recent estimates indicate that exploitation has depleted large predatory fish communities worldwide by at least 90% over the past 50-100 years. We demonstrate that these declines are general, independent of methodology, and even higher for sensitive species such as sharks. We also attempt to predict the future prospects of large predatory fishes. (i) An analysis of maximum reproductive rates predicts the collapse and extinction of sensitive species under current levels of fishing mortality. Sensitive species occur in marine habitats worldwide and have to be considered in most management situations. (ii) We show that to ensure the survival of sensitive species in the northwest Atlantic fishing mortality has to be reduced by 40-80%. (iii) We show that rapid recovery of community biomass and diversity usually occurs when fishing mortality is reduced. However, recovery is more variable for single species, often because of the influence of species interactions. We conclude that management of multi-species fisheries needs to be tailored to the most sensitive, rather than the more robust species. This requires reductions in fishing effort, reduction in bycatch mortality and protection of key areas to initiate recovery of severely depleted communities.

Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines for the management of patients with bipolar disorder: consensus and controversies.

Abstract: Since the previous publication of Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines in 1997, there has been a substantial increase in evidence-based treatment options for bipolar disorder. The present guidelines review the new evidence and use criteria to rate strength of evidence and incorporate effectiveness, safety, and tolerability data to determine global clinical recommendations for treatment of various phases of bipolar disorder. The guidelines suggest that although pharmacotherapy forms the cornerstone of management, utilization of adjunctive psychosocial treatments and incorporation of chronic disease management model involving a healthcare team are required in providing optimal management for patients with bipolar disorder. Lithium, valproate and several atypical antipsychotics are first-line treatments for acute mania. Bipolar depression and mixed states are frequently associated with suicidal acts; therefore assessment for suicide should always be an integral part of managing any bipolar patient. Lithium, lamotrigine or various combinations of antidepressant and mood-stabilizing agents are first-line treatments for bipolar depression. First-line options in the maintenance treatment of bipolar disorder are lithium, lamotrigine, valproate and olanzapine. Historical and symptom profiles help with treatment selection. With the growing recognition of bipolar II disorders, it is anticipated that a larger body of evidence will become available to guide treatment of this common and disabling condition. These guidelines also discuss issues related to bipolar disorder in women and those with comorbidity and include a section on safety and monitoring.

Cell type analysis of functional fetal dopamine cell suspension transplants in the striatum and substantia nigra of patients with Parkinson's disease

Abstract: We report the first post-mortem analysis of two patients with Parkinson's disease who received fetal midbrain transplants as a cell suspension in the striatum, and in one case also in the substantia nigra. These patients had a favourable clinical evolution and positive 18F-fluorodopa PET scans and did not develop motor complications. The surviving transplanted dopamine neurons were positively identified with phenotypic markers of normal control human substantia nigra (n = 3), such as tyrosine hydroxylase, G-protein-coupled inward rectifying current potassium channel type 2 (Girk2) and calbindin. The grafts restored the cell type that provides specific dopaminergic innervation to the most affected striatal regions in the parkinsonian brain. Such transplants were able to densely reinnervate the host putamen with new dopamine fibres. The patients received only 6 months of standard immune suppression, yet by post-mortem analysis 3-4 years after surgery the transplants appeared only mildly immunogenic to the host brain, by analysis of microglial CD45 and CD68 markers. This study demonstrates that, using these methods, dopamine neuronal replacement cell therapy can be beneficial for patients with advanced disease, and that changing technical approaches could have a favourable impact on efficacy and adverse events following neural transplantation.

Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurements

Abstract: [1] To assess the current status of climate models in simulating clouds, basic cloud climatologies from ten atmospheric general circulation models are compared with satellite measurements from the International Satellite Cloud Climatology Project (ISCCP) and the Clouds and Earth's Radiant Energy System (CERES) program. An ISCCP simulator is employed in all models to facilitate the comparison. Models simulated a four-fold difference in high-top clouds. There are also, however, large uncertainties in satellite high thin clouds to effectively constrain the models. The majority of models only simulated 30–40% of middle-top clouds in the ISCCP and CERES data sets. Half of the models underestimated low clouds, while none overestimated them at a statistically significant level. When stratified in the optical thickness ranges, the majority of the models simulated optically thick clouds more than twice the satellite observations. Most models, however, underestimated optically intermediate and thin clouds. Compensations of these clouds biases are used to explain the simulated longwave and shortwave cloud radiative forcing at the top of the atmosphere. Seasonal sensitivities of clouds are also analyzed to compare with observations. Models are shown to simulate seasonal variations better for high clouds than for low clouds. Latitudinal distribution of the seasonal variations correlate with satellite measurements at >0.9, 0.6–0.9, and −0.2–0.7 levels for high, middle, and low clouds, respectively. The seasonal sensitivities of cloud types are found to strongly depend on the basic cloud climatology in the models. Models that systematically underestimate middle clouds also underestimate seasonal variations, while those that overestimate optically thick clouds also overestimate their seasonal sensitivities. Possible causes of the systematic cloud biases in the models are discussed.

Allogeneic peripheral blood stem-cell compared with bone marrow transplantation in the management of hematologic malignancies: an individual patient data meta-analysis of nine randomized trials

Abstract: PURPOSE: Considerable uncertainty exists regarding relative effects of allogeneic peripheral blood stem cells transplantation (PBSCT) versus bone marrow transplantation (BMT) on outcomes of patients with hematologic malignancies. PATIENTS AND METHODS: To provide the totality of research evidence related to the effects of PBSCT versus BMT, we conducted an individual-patient data meta-analysis using data from nine randomized trials enrolling 1,111 adult patients. RESULTS: Compared with BMT, PBSCT led to faster neutrophil (odds ratio [OR] = 0.31; 95% CI, 0.25 to 0.38; P < .00001) and platelet engraftment (OR = 0.52; 95% CI, 0.44 to 0.61; P < .00001). PBSCT was associated with a significant increase in the development of grade 3-4 acute graft-versus-host disease (GVHD; OR = 1.39; 95% CI, 1.03 to 1.88) and extensive (47% v 31% at 3 years; OR = 1.89; 95% CI, 1.47 to 2.42; P < .000001) and overall chronic GVHD (68% v 52% at 3 years; OR = 1.92; 95% CI, 1.47 to 2.49; P < .000001), but not grade 2-4 acute GVHD (54% v 53%; P = .49). PBSCT was associated with a decrease in relapse (21% v 27% at 3 years; OR = 0.71; 95% CI, 0.54 to 0.93; P = .01) in both late-stage-(33% v 51% at 3 years; OR = 0.59; 95% CI, 0.38 to 0.93; P = .02) and early-stage-disease patients (16% v 20% at 3 years; OR = 0.69; 95% CI, 0.49 to 0.98; P = .04). Nonrelapse mortality was not different between groups. Overall and disease-free survival were only statistically significantly improved in patients with late-stage disease (overall survival: 46% v 31% at 3 years; OR = 0.64; 95% CI, 0.46 to 0.90; P = .01; disease-free survival: 41% v 27% at 3 years; OR = 0.63 95% CI, 0.45 to 0.87; P = .01). CONCLUSION: PBSCT is associated with a decreased relapse rate in hematologic malignancies and improvement in overall and disease-free survival in patients with late-stage disease. PBSCT is also associated with a significant risk of extensive chronic GVHD.

Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions

Abstract: We use space-based observations of NO2 columns from the Global Ozone Monitoring Experiment (GOME) to derive monthly top-down NOx emissions for 2000 via inverse modeling with the GEOS-CHEM chemical transport model. Top-down NOx sources are partitioned among fuel combustion (fossil fuel and biofuel), biomass burning and soils by exploiting the spatio-temporal distribution of remotely sensed fires and a priori information on the location of regions dominated by fuel combustion. The top-down inventory is combined with an a priori inventory to obtain an optimized a posteriori estimate of the relative roles of NOx sources. The resulting a posteriori fuel combustion inventory (25.6 TgN year−1) agrees closely with the a priori (25.4 TgN year−1), and errors are reduced by a factor of 2, from ±80% to ±40%. Regionally, the largest differences are found over Japan and South Africa, where a posteriori estimates are 25% larger than a priori. A posteriori fuel combustion emissions are aseasonal, with the exception of East Asia and Europe where winter emissions are 30–40% larger relative to summer emissions, consistent with increased energy use during winter for heating. Global a posteriori biomass burning emissions in 2000 resulted in 5.8 TgN (compared to 5.9 TgN year−1 in the a priori), with Africa accounting for half of this total. A posteriori biomass burning emissions over Southeast Asia/India are decreased by 46% relative to a priori; but over North equatorial Africa they are increased by 50%. A posteriori estimates of soil emissions (8.9 TgN year−1) are 68% larger than a priori (5.3 TgN year−1). The a posteriori inventory displays the largest soil emissions over tropical savanna/woodland ecosystems (Africa), as well as over agricultural regions in the western U.S. (Great Plains), southern Europe (Spain, Greece, Turkey), and Asia (North China Plain and North India), consistent with field measurements. Emissions over these regions are highest during summer at mid-latitudes and during the rainy season in the Tropics. We estimate that 2.5–4.5 TgN year−1 are emitted from N-fertilized soils, at the upper end of previous estimates. Soil and biomass burning emissions account for 22% and 14% of global surface NOx emissions, respectively. We infer a significant role for soil NOx emissions at northern mid-latitudes during summer, where they account for nearly half that of the fuel combustion source, a doubling relative to the a priori. The contribution of soil emissions to background ozone is thus likely to be underestimated by the current generation of chemical transport models.

Biology of extinction risk in marine fishes

Abstract: We review interactions between extrinsic threats to marine fishes and intrinsic aspects of their biology that determine how populations and species respond to those threats. Information is available on the status of less than 5% of the world's approximately 15 500 marine fish species, most of which are of commercial importance. By 2001, based on data from 98 North Atlantic and northeast Pacific populations, marine fishes had declined by a median 65% in breeding biomass from known historic levels; 28 populations had declined by more than 80%. Most of these declines would be sufficient to warrant a status of threatened with extinction under international threat criteria. However, this interpretation is highly controversial, in part because of a perception that marine fishes have a suite of life history characteristics, including high fecundity and large geographical ranges, which might confer greater resilience than that shown by terrestrial vertebrates. We review 15 comparative analyses that have tested for these and other life history correlates of vulnerability in marine fishes. The empirical evidence suggests that large body size and late maturity are the best predictors of vulnerability to fishing, regardless of whether differences among taxa in fishing mortality are controlled; there is no evidence that high fecundity confers increased resilience. The evidence reviewed here is of direct relevance to the diverse criteria used at global and national levels by various bodies to assess threat status of fishes. Simple life history traits can be incorporated directly into quantitative assessment criteria, or used to modify the conclusions of quantitative assessments, or used as preliminary screening criteria for assessment of the ∼95% of marine fish species whose status has yet to be evaluated either by conservationists or fisheries scientists.

Modern antipsychotic drugs: a critical overview

Abstract: CONVENTIONAL ANTIPSYCHOTIC DRUGS, used for a half century to treat a range of major psychiatric disorders, are being replaced in clinical practice by modern “atypical” antipsychotics, including aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone among others. As a class, the newer drugs have been promoted as being broadly clinically superior, but the evidence for this is problematic. In this brief critical overview, we consider the pharmacology, therapeutic effectiveness, tolerability, adverse effects and costs of individual modern agents versus older antipsychotic drugs. Because of typically minor differences between agents in clinical effectiveness and tolerability, and because of growing concerns about potential adverse long-term health consequences of some modern agents, it is reasonable to consider both older and newer drugs for clinical use, and it is important to inform patients of relative benefits, risks and costs of specific choices.

Semantic similarity methods in wordNet and their application to information retrieval on the web

Abstract: Semantic Similarity relates to computing the similarity between concepts which are not lexicographically similar. We investigate approaches to computing semantic similarity by mapping terms (concepts) to an ontology and by examining their relationships in that ontology. Some of the most popular semantic similarity methods are implemented and evaluated using WordNet as the underlying reference ontology. Building upon the idea of semantic similarity, a novel information retrieval method is also proposed. This method is capable of detecting similarities between documents containing semantically similar but not necessarily lexicographically similar terms. The proposed method has been evaluated in retrieval of images and documents on the Web. The experimental results demonstrated very promising performance improvements over state-of-the-art information retrieval methods.

Global patterns of predator diversity in the open oceans

Abstract: The open oceans comprise most of the biosphere, yet patterns and trends of species diversity there are enigmatic. Here, we derive worldwide patterns of tuna and billfish diversity over the past 50 years, revealing distinct subtropical "hotspots" that appeared to hold generally for other predators and zooplankton. Diversity was positively correlated with thermal fronts and dissolved oxygen and a nonlinear function of temperature (~25°C optimum). Diversity declined between 10 and 50% in all oceans, a trend that coincided with increased fishing pressure, superimposed on strong El Nino–Southern Oscillation–driven variability across the Pacific. We conclude that predator diversity shows a predictable yet eroding pattern signaling ecosystem-wide changes linked to climate and fishing.