Showing papers by "University of Amsterdam published in 2005"
TL;DR: In response to stress, the brain activates several neuropeptide-secreting systems, which eventually leads to the release of adrenal corticosteroid hormones, which subsequently feed back on the brain and bind to two types of nuclear receptor that act as transcriptional regulators as mentioned in this paper.
Abstract: In response to stress, the brain activates several neuropeptide-secreting systems. This eventually leads to the release of adrenal corticosteroid hormones, which subsequently feed back on the brain and bind to two types of nuclear receptor that act as transcriptional regulators. By targeting many genes, corticosteroids function in a binary fashion, and serve as a master switch in the control of neuronal and network responses that underlie behavioural adaptation. In genetically predisposed individuals, an imbalance in this binary control mechanism can introduce a bias towards stress-related brain disease after adverse experiences. New candidate susceptibility genes that serve as markers for the prediction of vulnerable phenotypes are now being identified.
3,727 citations
TL;DR: In this article, the period prevalence of acute renal failure (ARF) requiring renal replacement therapy (RRT) was found to be between 5% and 6% and was associated with a high hospital mortality rate.
Abstract: ContextAlthough acute renal failure (ARF) is believed to be common in the setting
of critical illness and is associated with a high risk of death, little is
known about its epidemiology and outcome or how these vary in different regions
of the world.ObjectivesTo determine the period prevalence of ARF in intensive care unit (ICU)
patients in multiple countries; to characterize differences in etiology, illness
severity, and clinical practice; and to determine the impact of these differences
on patient outcomes.Design, Setting, and PatientsProspective observational study of ICU patients who either were treated
with renal replacement therapy (RRT) or fulfilled at least 1 of the predefined
criteria for ARF from September 2000 to December 2001 at 54 hospitals in 23
countries.Main Outcome MeasuresOccurrence of ARF, factors contributing to etiology, illness severity,
treatment, need for renal support after hospital discharge, and hospital mortality.ResultsOf 29 269 critically ill patients admitted during the study period,
1738 (5.7%; 95% confidence interval [CI], 5.5%-6.0%) had ARF during their
ICU stay, including 1260 who were treated with RRT. The most common contributing
factor to ARF was septic shock (47.5%; 95% CI, 45.2%-49.5%). Approximately
30% of patients had preadmission renal dysfunction. Overall hospital mortality
was 60.3% (95% CI, 58.0%-62.6%). Dialysis dependence at hospital discharge
was 13.8% (95% CI, 11.2%-16.3%) for survivors. Independent risk factors for
hospital mortality included use of vasopressors (odds ratio [OR], 1.95; 95%
CI, 1.50-2.55; P<.001), mechanical ventilation
(OR, 2.11; 95% CI, 1.58-2.82; P<.001), septic
shock (OR, 1.36; 95% CI, 1.03-1.79; P = .03),
cardiogenic shock (OR, 1.41; 95% CI, 1.05-1.90; P = .02),
and hepatorenal syndrome (OR, 1.87; 95% CI, 1.07-3.28; P = .03).ConclusionIn this multinational study, the period prevalence of ARF requiring
RRT in the ICU was between 5% and 6% and was associated with a high hospital
mortality rate.
3,706 citations
TL;DR: Intensive lipid-lowering therapy with 80 mg of atorvastatin per day in patients with stable CHD provides significant clinical benefit beyond that afforded by treatment with 10 mg of least-in- LDL cholesterol levels per day, with a greater incidence of elevated aminotransferase levels.
Abstract: background Previous trials have demonstrated that lowering low-density lipoprotein (LDL) cholesterol levels below currently recommended levels is beneficial in patients with acute coronary syndromes. We prospectively assessed the efficacy and safety of lowering LDL cholesterol levels below 100 mg per deciliter (2.6 mmol per liter) in patients with stable coronary heart disease (CHD). methods A total of 10,001 patients with clinically evident CHD and LDL cholesterol levels of less than 130 mg per deciliter (3.4 mmol per liter) were randomly assigned to double-blind therapy and received either 10 mg or 80 mg of atorvastatin per day. Patients were followed for a median of 4.9 years. The primary end point was the occurrence of a first major cardiovascular event, defined as death from CHD, nonfatal non–procedure-related myocardial infarction, resuscitation after cardiac arrest, or fatal or nonfatal stroke. results The mean LDL cholesterol levels were 77 mg per deciliter (2.0 mmol per liter) during treatment with 80 mg of atorvastatin and 101 mg per deciliter (2.6 mmol per liter) during treatment with 10 mg of atorvastatin. The incidence of persistent elevations in liver aminotransferase levels was 0.2 percent in the group given 10 mg of atorvastatin and 1.2 percent in the group given 80 mg of atorvastatin (P<0.001). A primary event occurred in 434 patients (8.7 percent) receiving 80 mg of atorvastatin, as compared with 548 patients (10.9 percent) receiving 10 mg of atorvastatin, representing an absolute reduction in the rate of major cardiovascular events of 2.2 percent and a 22 percent relative reduction in risk (hazard ratio, 0.78; 95 percent confidence interval, 0.69 to 0.89; P<0.001). There was no difference between the two treatment groups in overall mortality. conclusions Intensive lipid-lowering therapy with 80 mg of atorvastatin per day in patients with stable CHD provides significant clinical benefit beyond that afforded by treatment with 10 mg of atorvastatin per day. This occurred with a greater incidence of elevated aminotransferase levels.
3,141 citations
TL;DR: The bivariate model can be seen as an improvement and extension of the traditional sROC approach by reanalyzing the data of a published meta-analysis of diagnostic studies reporting pairs of sensitivity and specificity.
2,582 citations
Book•
01 Jan 2005TL;DR: The second edition of Pajek as discussed by the authors is an extensively revised and expanded second edition on social network analysis integrating theory, applications, and network analysis using pajek, which includes a new chapter on random network models, such as scale-free and small-world networks and Monte Carlo simulation.
Abstract: This is an extensively revised and expanded second edition of the successful textbook on social network analysis integrating theory, applications, and network analysis using Pajek. The main structural concepts and their applications in social research are introduced with exercises. Pajek software and data sets are available so readers can learn network analysis through application and case studies. Readers will have the knowledge, skill, and tools to apply social network analysis across the social sciences, from anthropology and sociology to business administration and history. This second edition has a new chapter on random network models, for example, scale-free and small-world networks and Monte Carlo simulation; discussion of multiple relations, islands, and matrix multiplication; new structural indices such as eigenvector centrality, degree distribution, and clustering coefficients; new visualization options that include circular layout for partitions and drawing a network geographically as a 3D surface; and using Unicode labels. This new edition also includes instructions on exporting data from Pajek to R software. It offers updated descriptions and screen shots for working with Pajek (version 2.03).
2,389 citations
TL;DR: The capability approach is a broad normative framework for the evaluation and assessment of individual well-being and social arrangements, the design of policies, and proposals about social change in society.
Abstract: This paper aims to present a theoretical survey of the capability approach in an interdisciplinary and accessible way. It focuses on the main conceptual and theoretical aspects of the capability approach, as developed by Amartya Sen, Martha Nussbaum, and others. The capability approach is a broad normative framework for the evaluation and assessment of individual well‐being and social arrangements, the design of policies, and proposals about social change in society. Its main characteristics are its highly interdisciplinary character, and the focus on the plural or multidimensional aspects of well‐being. The approach highlights the difference between means and ends, and between substantive freedoms (capabilities) and outcomes (achieved functionings).
2,221 citations
TL;DR: It is shown that sustained BRAFV600E expression in human melanocytes induces cell cycle arrest, which is accompanied by the induction of both p16INK4a and senescence-associated acidic β-galactosidase (SA-β-Gal) activity, a commonly usedsenescence marker.
Abstract: Cellular senescence, a growth-arrest program that limits the lifespan of mammalian cells and prevents unlimited cell proliferation, is attracting considerable interest because of its links to tumour suppression. Using a mouse model in which the oncogene Ras is activated in the haematopoietic compartment of bone marrow, Braig et al. show that cellular senescence can block lymphoma development. Genetic inactivation of the histone methyltransferase Suv39h1 that controls senescence by ‘epigenetic’ modification of DNA-associated proteins, or a pharmacological approach that mimics loss of this enzyme, allow the formation of malignant lymphomas in response to oncogenic Ras. This work has important implications for both tumour development and tumour therapy. Michaloglou et al. report that oncogene-induced senescence may be a physiologically important process in humans, keeping moles in a benign state for many years: unchecked they develop into malignant melanomas. Chen et al. also find that cellular senescence blocks tumorigenesis in vivo: they show that acting together, the p53 tumour suppressor and the cellular senescence system can prevent prostate cancer induction in mice by the PTEN mutation. Collado et al. show that cellular senescence is a defining feature of Ras-initiated premalignant tumours; this could prove valuable in the diagnosis and prognosis of cancer. See the web focus
. Most normal mammalian cells have a finite lifespan1, thought to constitute a protective mechanism against unlimited proliferation2,3,4. This phenomenon, called senescence, is driven by telomere attrition, which triggers the induction of tumour suppressors including p16INK4a (ref. 5). In cultured cells, senescence can be elicited prematurely by oncogenes6; however, whether such oncogene-induced senescence represents a physiological process has long been debated. Human naevi (moles) are benign tumours of melanocytes that frequently harbour oncogenic mutations (predominantly V600E, where valine is substituted for glutamic acid) in BRAF7, a protein kinase and downstream effector of Ras. Nonetheless, naevi typically remain in a growth-arrested state for decades and only rarely progress into malignancy (melanoma)8,9,10. This raises the question of whether naevi undergo BRAFV600E-induced senescence. Here we show that sustained BRAFV600E expression in human melanocytes induces cell cycle arrest, which is accompanied by the induction of both p16INK4a and senescence-associated acidic β-galactosidase (SA-β-Gal) activity, a commonly used senescence marker. Validating these results in vivo, congenital naevi are invariably positive for SA-β-Gal, demonstrating the presence of this classical senescence-associated marker in a largely growth-arrested, neoplastic human lesion. In growth-arrested melanocytes, both in vitro and in situ, we observed a marked mosaic induction of p16INK4a, suggesting that factors other than p16INK4a contribute to protection against BRAFV600E-driven proliferation. Naevi do not appear to suffer from telomere attrition, arguing in favour of an active oncogene-driven senescence process, rather than a loss of replicative potential. Thus, both in vitro and in vivo, BRAFV600E-expressing melanocytes display classical hallmarks of senescence, suggesting that oncogene-induced senescence represents a genuine protective physiological process.
2,074 citations
TL;DR: In this paper, an empirical analysis of the importance of comparison income for individual well-being or happiness is presented, where the authors use a self-reported measure of satisfaction with life as a measure of individual wellbeing.
1,760 citations
TL;DR: In this paper, the authors described the clinical presentations of the disorder such as those that occur after a head injury or lumbar puncture, and suggested anticoagulation, thrombolysis, and measures to control intracranial hypertension.
Abstract: Thrombosis of the cerebral veins and sinuses affects mainly young adults and children This potentially disabling or fatal condition is usually not diagnosed until a week after the onset of symptoms This review article describes the clinical presentations of the disorder such as those that occur after a head injury or lumbar puncture Therapeutic options include anticoagulation, thrombolysis, and measures to control intracranial hypertension
1,217 citations
Duke University1, University of Barcelona2, Drexel University3, Tel Aviv University4, Alfred Hospital5, University of Michigan6, University of Zagreb7, Medical University of South Carolina8, Federal University of Rio de Janeiro9, Autonomous University of Barcelona10, Geelong Hospital11, University of Amsterdam12, Wayne State University13, University of California, Los Angeles14
TL;DR: Characteristics of patients with S aureus IE vary significantly by region, and further studies are required to determine the causes of regional variation.
Abstract: ContextThe global significance of infective endocarditis (IE) caused by Staphylococcus aureus is unknown.ObjectivesTo document the international emergence of health care–associated S aureus IE and methicillin-resistant S aureus (MRSA) IE and to evaluate regional variation in patients with S aureus IE.Design, Setting, and ParticipantsProspective observational cohort study set in 39 medical centers in
16 countries. Participants were a population of 1779 patients with definite
IE as defined by Duke criteria who were enrolled in the International Collaboration
on Endocarditis-Prospective Cohort Study from June 2000 to December 2003.Main Outcome MeasureIn-hospital mortality.ResultsS aureus was the most common pathogen among
the 1779 cases of definite IE in the International Collaboration on Endocarditis
Prospective-Cohort Study (558 patients, 31.4%). Health care−associated
infection was the most common form of S aureus IE
(218 patients, 39.1%), accounting for 25.9% (Australia/New Zealand) to 54.2%
(Brazil) of cases. Most patients with health care−associated S aureus IE (131 patients, 60.1%) acquired the infection outside of
the hospital. MRSA IE was more common in the United States (37.2%) and Brazil
(37.5%) than in Europe/Middle East (23.7%) and Australia/New Zealand (15.5%, P<.001). Persistent bacteremia was independently associated
with MRSA IE (odds ratio, 6.2; 95% confidence interval, 2.9-13.2). Patients
in the United States were most likely to be hemodialysis dependent, to have
diabetes, to have a presumed intravascular device source, to receive vancomycin,
to be infected with MRSA, and to have persistent bacteremia (P<.001 for all comparisons).ConclusionsS aureus is the leading cause of IE in many
regions of the world. Characteristics of patients with S aureus IE vary significantly by region. Further studies are required
to determine the causes of regional variation.
1,101 citations
TL;DR: This first multicentre study assessing the long-term efficacy of either STN or GPi stimulation shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.
Abstract: Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n = 49) or globus pallidus internus (GPi, n = 20) included in a multicentre study. Patients were assessed preoperatively and at 1 year and 3-4 years after surgery. The primary outcome measure was the change in the 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) at 3-4 years. Stimulation of the STN or GPi induced a significant improvement (50 and 39%; P < 0.0001) of the 'off' medication UPDRS-III score at 3-4 years with respect to baseline. Stimulation improved cardinal features and activities of daily living (ADL) (P < 0.0001 and P < 0.02 for STN and GPi, respectively) and prolonged the 'on' time spent with good mobility without dyskinesias (P < 0.00001). Daily dosage of levodopa was significantly reduced (35%) in the STN-treated group only (P < 0.001). Comparison of the improvement induced by stimulation at 1 year with 3-4 years showed a significant worsening in the 'on' medication motor states of the UPDRS-III, ADL and gait in both STN and GPi groups, and speech and postural stability in the STN-treated group. Adverse events (AEs) included cognitive decline, speech difficulty, instability, gait disorders and depression. These were more common in patients treated with DBS of the STN. No patient abandoned treatment as a result of these side effects. This experience, which represents the first multicentre study assessing the long-term efficacy of either STN or GPi stimulation, shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.
TL;DR: The authors assesses the contribution of discourse analysis to the study of environmental politics over the period of the past decade and highlight the role of language in politics, its capacity to reveal the embeddedness of language and its ability to answer "how" questions and to illuminate mechanisms.
Abstract: This article assesses the contribution of discourse analysis to the study of environmental politics over the period of the past decade. Defining discourse as a particular linguistic regularity that can be found in conversations distinguishes it from ‘deliberation’ and ‘discussion’. Discourse analysis is seen as focused on situational logics studying ‘language-in-use’. Three strengths of discourse analysis are highlighted: its capacity to reveal the role of language in politics, its capacity to reveal the embeddedness of language in practices and its capacity to answer ‘how’ questions and to illuminate mechanisms. The article concludes by sketching some of the challenges lying ahead of discourse analysis. Given the changing nature of policy making, discourse analysts are supposed to have a task in identifying the new sites of politics and analysing the political dynamics therein.
TL;DR: In this paper, the frequency and pattern of cognitive dysfunction in patients with newly diagnosed Parkinson disease (PD) and to identify its demographic and clinical correlates were identified with multiple logistic regression analysis.
Abstract: Objective: To determine the frequency and pattern of cognitive dysfunction in patients with newly diagnosed Parkinson disease (PD) and to identify its demographic and clinical correlates. Methods: A cohort of 115 consecutive patients with newly diagnosed PD and 70 healthy controls underwent a comprehensive neuropsychological assessment including tests of psychomotor speed, attention, language, memory, executive and visuospatial functions, as well as measures of affective status. Patients also received quantitative ratings of motor symptom severity and functional status. Neuropsychological performance of PD patients was compared with that of healthy controls and with available normative data. Independent demographic and clinical predictors of cognitive impairment were identified with multiple logistic regression analysis. Results: Relative to controls, PD patients performed significantly worse on most cognitive measures. However, further analysis revealed that group differences in cognitive performance could mainly be explained by measures of immediate memory and executive function. Comparison with normative data showed that impairments were most frequent on measures of executive function, memory and psychomotor speed. In all, 24% of PD patients (4% of controls) displayed defective performance on at least three neuropsychological tests and were classified as cognitively impaired. Late onset of disease was an independent predictor of cognitive dysfunction in PD. Conclusion: Cognitive impairments are common even in newly diagnosed Parkinson disease patients, with deficits being most prominent in the domains of memory and executive functions. Older age at disease onset is likely to be an important determinant of cognitive dysfunction in Parkinson disease.
TL;DR: In order to capture the sensory variation in object recordings, this work systematically varied viewing angle, illumination angle, and illumination color for each object, and additionally captured wide-baseline stereo images.
Abstract: We present the ALOI collection of 1,000 objects recorded under various imaging circumstances. In order to capture the sensory variation in object recordings, we systematically varied viewing angle, illumination angle, and illumination color for each object, and additionally captured wide-baseline stereo images. We recorded over a hundred images of each object, yielding a total of 110,250 images for the collection. These images are made publicly available for scientific research purposes.
TL;DR: The aim is to examine patient‐ and provider‐reported psychosocial problems and barriers to effective self‐care and resources for dealing with those barriers.
Abstract: Aims To examine patient- and provider-reported psychosocial problems and barriers to effective self-care and resources for dealing with those barriers. Methods Cross-sectional study using face-to-face or telephone interviews with diabetic patients and health-care providers in 13 countries in Asia, Australia, Europe and North America. Participants were randomly selected adults ( n = 5104) with Type 1 or Type 2 diabetes, and providers ( n = 3827), including primary care physicians, diabetes specialist physicians and nurses. Results Regimen adherence was poor, especially for diet and exercise; provider estimates of patient self-care were lower than patient reports for all behaviours. Diabetes-related worries were common among patients, and providers generally recognized these worries. Many patients (41%) had poor psychological wellbeing. Providers reported that most patients had psychological problems that affected diabetes self-care, yet providers often reported they did not have the resources to manage these problems, and few patients (10%) reported receiving psychological treatment. Conclusions Psychosocial problems appear to be common among diabetic patients worldwide. Addressing these problems may improve diabetes outcomes, but providers often lack critical resources for doing so, particularly skill, time and adequate referral sources.
Mayo Clinic1, Lille University of Science and Technology2, University of British Columbia3, University of Western Ontario4, University of Chicago5, University of Western Australia6, University of Calgary7, University of Kiel8, Cedars-Sinai Medical Center9, University of Amsterdam10, Élan11, Katholieke Universiteit Leuven12
TL;DR: Induction therapy with natalizumab for Crohn's disease resulted in small, nonsignificant improvements in response and remission rates, which will need to be weighed against the risk of serious adverse events.
Abstract: BackgroundNatalizumab, a humanized monoclonal antibody against α4 integrin, inhibits leukocyte adhesion and migration into inflamed tissue. MethodsWe conducted two controlled trials to evaluate natalizumab as induction and maintenance therapy in patients with active Crohn's disease. In the first trial, 905 patients were randomly assigned to receive 300 mg of natalizumab or placebo at weeks 0, 4, and 8. The primary outcome was response, defined by a decrease in the Crohn's Disease Activity Index (CDAI) score of at least 70 points, at week 10. In the second trial, 339 patients who had a response to natalizumab in the first trial were randomly reassigned to receive 300 mg of natalizumab or placebo every four weeks through week 56. The primary outcome was a sustained response through week 36. A secondary outcome in both trials was disease remission (a CDAI score of less than 150). ResultsIn the first trial, the natalizumab and placebo groups had similar rates of response (56 percent and 49 percent, respective...
TL;DR: It is hypothesized that particularly a subgroup of CRH neurons that projects into the brain is activated in depression and induces the symptoms of this disorder, which is a basis for the higher prevalence of mood disorders in women as compared to men.
TL;DR: Early radiotherapy after surgery lengthens the period without progression but does not affect overall survival, and Radiotherapy could be deferred for patients with low-grade glioma who are in a good condition, provided they are carefully monitored.
TL;DR: In this article, a review of magnetic refrigerant-materials for room-temperature applications is presented, considering both scientific aspects and industrial applicability, and some theoretical considerations.
Abstract: Modern society relies on readily available refrigeration. Magnetic refrigeration has three prominent advantages compared with compressor-based refrigeration. First, there are no harmful gases involved; second, it may be built more compactly as the working material is a solid; and third, magnetic refrigerators generate much less noise. Recently a new class of magnetic refrigerant-materials for room-temperature applications was discovered. These new materials have important advantages over existing magnetic coolants: they exhibit a large magnetocaloric effect (MCE) in conjunction with a magnetic phase-transition of first order. This MCE is larger than that of Gd metal, which is used in the demonstration refrigerators built to explore the potential of this evolving technology. In the present review we compare the different materials considering both scientific aspects and industrial applicability. Because fundamental aspects of MCE are not so widely discussed, we also give some theoretical considerations.
TL;DR: In this article, the authors test the hypothesis that international collaboration is a self-organizing network and show that the growth of international co-authorships can be explained based on the organizing principle of preferential attachment, although the attachment mechanism deviates from an ideal power-law.
TL;DR: Findings suggest that people can indeed predict upcoming words in fluent discourse and, moreover, that these predicted words can immediately begin to participate in incremental parsing operations.
Abstract: The authors examined whether people can use their knowledge of the wider discourse rapidly enough to anticipate specific upcoming words as a sentence is unfolding. In an event-related brain potential (ERP) experiment, subjects heard Dutch stories that supported the prediction of a specific noun. To probe whether this noun was anticipated at a preceding indefinite article, stories were continued with a gender-marked adjective whose suffix mismatched the upcoming noun's syntactic gender. Prediction-inconsistent adjectives elicited a differential ERP effect, which disappeared in a no-discourse control experiment. Furthermore, in self-paced reading, prediction-inconsistent adjectives slowed readers down before the noun. These findings suggest that people can indeed predict upcoming words in fluent discourse and, moreover, that these predicted words can immediately begin to participate in incremental parsing operations.
TL;DR: In this paper, the trigger-transfer-reserve-pulse framework was used to evaluate how strongly four eco-hydrological interactions apply across other patchy semi-arid vegetations, and how these interactions are affected by disturbances.
Abstract: Ecological and hydrological processes can interact strongly in landscapes, yet these processes are often studied separately. One particularly important interaction between these processes in patchy semiarid lands is how vegetation patches serve to obstruct runoff and then how this retained water increases patch growth that, in turn, provides feedbacks to the system. Such ecohydrological interactions have been mostly demonstrated for semiarid landscapes with distinctly banded vegetation patterns. In this paper, we use data from our studies and from the literature to evaluate how strongly four ecohydrological interactions apply across other patchy semiarid vegetations, and how these interactions are affected by disturbances. We specifically address four questions concerning ecohydrological interactions: (1) if vegetation patches obstruct runoff flows during rainfall events, how much more soil water is stored in these patches compared to open interpatch areas; (2) if inputs of water are higher in patches, how much stronger is the pulse of plant growth compared to interpatches; (3) if more soil water in patches promotes greater biological activity by organisms such as earthworms that create macropores, how much does this improve soil infiltrability; and (4) if vegetation patches are damaged on a hillslope, how much does this increase runoff and erosion and decrease biomass production? We used the trigger-transfer-reserve-pulse framework developed for Australian semiarid woodlands to put these four questions into a landscape context. For a variety of patchy semiarid vegetation types in Australia, Europe, and North America, we found that patches significantly stored more soil water, produced more growth and had better infiltrability than interpatches, and that runoff and erosion can markedly increase on disturbed hillslopes. However, these differences varied greatly and appeared to depend on factors such as the intensity and amount of input events (rainstorms) and type of topography, soils, and vegetation. Exper- imental and modeling studies are needed to better quantify how these factors specifically affect ecohydrological interactions. Our current findings do support the conclusion that vegetation patches and runoff-erosion processes do strongly interact in many semiarid landscapes across the globe, not just banded landscapes.
06 Nov 2005
TL;DR: It is shown by experiment on 184 hours of broadcast video data and for 20 semantic concepts, that late fusion tends to give slightly better performance for most concepts, however, for those concepts where early fusion performs better the difference is more significant.
Abstract: Semantic analysis of multimodal video aims to index segments of interest at a conceptual level. In reaching this goal, it requires an analysis of several information streams. At some point in the analysis these streams need to be fused. In this paper, we consider two classes of fusion schemes, namely early fusion and late fusion. The former fuses modalities in feature space, the latter fuses modalities in semantic space. We show by experiment on 184 hours of broadcast video data and for 20 semantic concepts, that late fusion tends to give slightly better performance for most concepts. However, for those concepts where early fusion performs better the difference is more significant.
TL;DR: The targeting of DC-SIGN by certain probiotic bacteria might explain their beneficial effect in the treatment of a number of inflammatory diseases, including atopic dermatitis and Crohn's disease.
Abstract: Background Lactobacilli are probiotic bacteria that are frequently tested in the management of allergic diseases or gastroenteritis. It is hypothesized that these probiotics have immunoregulatory properties and promote mucosal tolerance, which is in part mediated by regulatory T cells (Treg cells). On the basis of pathogenic or tissue-specific priming, dendritic cells (DC) acquire different T cell–instructive signals and drive the differentiation of naive T H cells into either T H 1, T H 2, or regulatory effector T cells. Objective We studied in what way different species of lactobacilli prime human DCs for their ability to drive Treg cells. Methods Human monocyte-derived DCs were cultured in vitro with lactobacilli of different species. Results Two different species of lactobacilli, Lactobacillus reuteri and Lactobacillus casei , but not Lactobacillus plantarum , prime monocyte-derived DCs to drive the development of Treg cells. These Treg cells produced increased levels of IL-10 and were capable of inhibiting the proliferation of bystander T cells in an IL-10–dependent fashion. Strikingly, both L reuteri and L casei , but not L plantarum , bind the C-type lectin DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN). Blocking antibodies to DC-SIGN inhibited the induction of the Treg cells by these probiotic bacteria, stressing that ligation of DC-SIGN can actively prime DCs to induce Treg cells. Conclusions The targeting of DC-SIGN by certain probiotic bacteria might explain their beneficial effect in the treatment of a number of inflammatory diseases, including atopic dermatitis and Crohn's disease.
TL;DR: It is reported that corticosterone also rapidly and reversibly changes hippocampal signaling, and would allow the brain to change its function within minutes after stress-induced elevations of corticosteroid levels, in addition to responding later through gene-mediated signaling pathways.
Abstract: The adrenal hormone corticosterone transcriptionally regulates responsive genes in the rodent hippocampus through nuclear mineralocorticoid and glucocorticoid receptors. Via this genomic pathway the hormone alters properties of hippocampal cells slowly and for a prolonged period. Here we report that corticosterone also rapidly and reversibly changes hippocampal signaling. Stress levels of the hormone enhance the frequency of miniature excitatory postsynaptic potentials in CA1 pyramidal neurons and reduce paired-pulse facilitation, pointing to a hormone-dependent enhancement of glutamate-release probability. The rapid effect by corticosterone is accomplished through a nongenomic pathway involving membrane-located receptors. Unexpectedly, the rapid effect critically depends on the classical mineralocorticoid receptor, as evidenced by the effectiveness of agonists, antagonists, and brain-specific inactivation of the mineralocorticoid but not the glucocorticoid receptor gene. Rapid actions by corticosterone would allow the brain to change its function within minutes after stress-induced elevations of corticosteroid levels, in addition to responding later through gene-mediated signaling pathways.
Leeds Teaching Hospitals NHS Trust1, Japanese Foundation for Cancer Research2, University of Geneva3, Tufts University4, Showa University5, International Agency for Research on Cancer6, Columbia University7, Teikyo University8, St. Marianna University School of Medicine9, University of Toronto10, University of Tokyo11, University of Amsterdam12, Mayo Clinic13, Niigata University14
TL;DR: The morphology of superficial and nonprotruding neoplastic lesions is relevant to the prognosis and is an important criterion for the necessity of additional surgical resection after endoscopic resection.
Abstract: Background and Study Aims: Neoplastic lesions in the digestive-tract mucosa are termed superficial when the depth of invasion is limited to the mucosa and submucosa. The endoscopic appearance has a predictive value for invasion into the submucosa, which is critical for the risk of nodal metastases. Materials and Methods: The endoscopic morphology of superficial lesions can be assessed with a standard video endoscope after spraying of a dye - an iodine-potassium iodide solution for the stratified squamous epithelium, or an indigo carmine solution for the columnar epithelium. In 2002, a workshop was held in Paris to explore the relevance of the Japanese classification. The conclusions were revised in 2003 in Osaka in relation to the definition of the subtypes used in endoscopy and the evaluation of the depth of invasion into the submucosa. In Japan, the description of advanced cancer in the digestive-tract mucosa using types 1 -4 is supplemented by a type 0 when the endoscopic appearance is that of a superficial lesion. Type 0 is divided into three categories: protruding (0-1), nonprotruding and nonexcavated (0-11), and excavated (0-III). Type 0-II lesions are then subdivided into slightly elevated (IIa), flat (IIb), or depressed (IIc). Nonprotruding depressed lesions are associated with a higher risk of submucosal invasion. After endoscopic resection, invasion into the submucosa is an important criterion for the necessity of additional surgical resection. Micrometer analysis of the depth of invasion in the specimen is more precise, and distinct cut-off limits have been established in the esophagus, stomach, and large bowel. Conclusions: The morphology of superficial and nonprotruding neoplastic lesions is relevant to the prognosis. Following endoscopic detection, the lesions are analyzed using chromoendoscopy and assigned a subtype of the type 0 classification. The choice between endoscopicorsurgical treatment is based on this description.
TL;DR: The findings from a cohort of 2414 people born as term singletons around the time of the 1944-1945 Dutch famine show that maternal undernutrition during gestation has important effects on health in later life, but that the timing of the nutritional insult determines which organ system is affected.
TL;DR: In sepsis, where inflammation-induced autoregulatory dysfunction persists and oxygen need is not matched by supply, the microcirculation can be recruited by reducing pathological shunting, promoting microcirculatory perfusion, supporting pump function, and controlling hemorheology and coagulation.
Abstract: Regional tissue distress caused by microcirculatory dysfunction and mitochondrial depression underlies the condition in sepsis and shock where, despite correction of systemic oxygen delivery variables, regional hypoxia and oxygen extraction deficit persist. We have termed this condition microcirculatory and mitochondrial distress syndrome (MMDS). Orthogonal polarization spectral imaging allowed the first clinical observation of the microcirculation in human internal organs, and has identified the pivotal role of microcirculatory abnormalities in defining the severity of sepsis, a condition not revealed by systemic hemodynamic or oxygen-derived variables. Recently, sublingual sidestream dark-field (SDF) imaging has been introduced, allowing observation of the microcirculation in even greater detail. Microcirculatory recruitment is needed to ensure adequate microcirculatory perfusion and the oxygenation of tissue cells that follows. In sepsis, where inflammation-induced autoregulatory dysfunction persists and oxygen need is not matched by supply, the microcirculation can be recruited by reducing pathological shunting, promoting microcirculatory perfusion, supporting pump function, and controlling hemorheology and coagulation. Resuscitation following MMDS must include focused recruitment of hypoxic-shunted microcirculatory units and/or resuscitation of the mitochondria. A combination of agents is required for successful rescue of the microcirculation. Single compounds such as activated protein C, which acts on multiple pathways, can be expected to be beneficial in rescuing the microcirculation in sepsis.
TL;DR: It is shown that SARS-CoV shares its receptor ACE2 with HCoV-NL63, which suggests that highly pathogenic variants have ample opportunity to evolve, underlining the need for vaccines against HCoVs.
Abstract: Coronavirus (CoV) infection of humans is usually not associated with severe disease. However, discovery of the severe acute respiratory syndrome (SARS) CoV revealed that highly pathogenic human CoVs (HCoVs) can evolve. The identification and characterization of new HCoVs is, therefore, an important task. Recently, a HCoV termed NL63 was discovered in patients with respiratory tract illness. Here, cell tropism and receptor usage of HCoV-NL63 were analyzed. The NL63 spike (S) protein mediated infection of different target cells compared with the closely related 229E-S protein but facilitated entry into cells known to be permissive to SARS-CoV-S-driven infection. An analysis of receptor engagement revealed that NL63-S binds angiotensin-converting enzyme (ACE) 2, the receptor for SARS-CoV, and HCoV-NL63 uses ACE2 as a receptor for infection of target cells. Potent neutralizing activity directed against NL63- but not 229E-S protein was detected in virtually all sera from patients 8 years of age or older, suggesting that HCoV-NL63 infection of humans is common and usually acquired during childhood. Here, we show that SARS-CoV shares its receptor ACE2 with HCoV-NL63. Because the two viruses differ dramatically in their ability to induce disease, analysis of HCoV-NL63 might unravel pathogenicity factors in SARS-CoV. The frequent HCoV-NL63 infection of humans suggests that highly pathogenic variants have ample opportunity to evolve, underlining the need for vaccines against HCoVs.
TL;DR: This work presents a randomized point-based value iteration algorithm called PERSEUS, which backs up only a (randomly selected) subset of points in the belief set, sufficient for improving the value of each belief point in the set.
Abstract: Partially observable Markov decision processes (POMDPs) form an attractive and principled framework for agent planning under uncertainty. Point-based approximate techniques for POMDPs compute a policy based on a finite set of points collected in advance from the agent's belief space. We present a randomized point-based value iteration algorithm called PERSEUS. The algorithm performs approximate value backup stages, ensuring that in each backup stage the value of each point in the belief set is improved; the key observation is that a single backup may improve the value of many belief points. Contrary to other point-based methods, PERSEUS backs up only a (randomly selected) subset of points in the belief set, sufficient for improving the value of each belief point in the set. We show how the same idea can be extended to dealing with continuous action spaces. Experimental results show the potential of PERSEUS in large scale POMDP problems.