33 resultados para Points and lines
Resumo:
Defining the degree of host specificity in host-parasite studies can greatly inform cophylogenetic history. In a recent paper, Guiller and Deunff (2010) cast doubt on some points and conclusions drawn from a cophylogenetic study between European bats and Spinturnicid mites (Bruyndonckx et al., 2009a). Here we answer their criticisms and discuss the notion of specificity in Spinturnicid mites.
Resumo:
Forensic intelligence is a distinct dimension of forensic science. Forensic intelligence processes have mostly been developed to address either a specific type of trace or a specific problem. Even though these empirical developments have led to successes, they are trace-specific in nature and contribute to the generation of silos which hamper the establishment of a more general and transversal model. Forensic intelligence has shown some important perspectives but more general developments are required to address persistent challenges. This will ensure the progress of the discipline as well as its widespread implementation in the future. This paper demonstrates that the description of forensic intelligence processes, their architectures, and the methods for building them can, at a certain level, be abstracted from the type of traces considered. A comparative analysis is made between two forensic intelligence approaches developed independently in Australia and in Europe regarding the monitoring of apparently very different kind of problems: illicit drugs and false identity documents. An inductive effort is pursued to identify similarities and to outline a general model. Besides breaking barriers between apparently separate fields of study in forensic science and intelligence, this transversal model would assist in defining forensic intelligence, its role and place in policing, and in identifying its contributions and limitations. The model will facilitate the paradigm shift from the current case-by-case reactive attitude towards a proactive approach by serving as a guideline for the use of forensic case data in an intelligence-led perspective. A follow-up article will specifically address issues related to comparison processes, decision points and organisational issues regarding forensic intelligence (part II).
Resumo:
AIMS: We aimed to assess the prevalence and management of clinical familial hypercholesterolaemia (FH) among patients with acute coronary syndrome (ACS). METHODS AND RESULTS: We studied 4778 patients with ACS from a multi-centre cohort study in Switzerland. Based on personal and familial history of premature cardiovascular disease and LDL-cholesterol levels, two validated algorithms for diagnosis of clinical FH were used: the Dutch Lipid Clinic Network algorithm to assess possible (score 3-5 points) or probable/definite FH (>5 points), and the Simon Broome Register algorithm to assess possible FH. At the time of hospitalization for ACS, 1.6% had probable/definite FH [95% confidence interval (CI) 1.3-2.0%, n = 78] and 17.8% possible FH (95% CI 16.8-18.9%, n = 852), respectively, according to the Dutch Lipid Clinic algorithm. The Simon Broome algorithm identified 5.4% (95% CI 4.8-6.1%, n = 259) patients with possible FH. Among 1451 young patients with premature ACS, the Dutch Lipid Clinic algorithm identified 70 (4.8%, 95% CI 3.8-6.1%) patients with probable/definite FH, and 684 (47.1%, 95% CI 44.6-49.7%) patients had possible FH. Excluding patients with secondary causes of dyslipidaemia such as alcohol consumption, acute renal failure, or hyperglycaemia did not change prevalence. One year after ACS, among 69 survivors with probable/definite FH and available follow-up information, 64.7% were using high-dose statins, 69.0% had decreased LDL-cholesterol from at least 50, and 4.6% had LDL-cholesterol ≤1.8 mmol/L. CONCLUSION: A phenotypic diagnosis of possible FH is common in patients hospitalized with ACS, particularly among those with premature ACS. Optimizing long-term lipid treatment of patients with FH after ACS is required.
Resumo:
Demonstration of survival and outcome of progressive multifocal leukoencephalopathy (PML) in a 56-year-old patient with common variable immunodeficiency, consisting of severe hypogammaglobulinemia and CD4+ T lymphocytopenia, during continuous treatment with mirtazapine (30 mg/day) and mefloquine (250 mg/week) over 23 months. Regular clinical examinations including Rankin scale and Barthel index, nine-hole peg and box and block tests, Berg balance, 10-m walking tests, and Montreal Cognitive Assessment (MoCA) were done. Laboratory diagnostics included complete blood count and JC virus (JCV) concentration in cerebrospinal fluid (CSF). The noncoding control region (NCCR) of JCV, important for neurotropism and neurovirulence, was sequenced. Repetitive MRI investigated the course of brain lesions. JCV was detected in increasing concentrations (peak 2568 copies/ml CSF), and its NCCR was genetically rearranged. Under treatment, the rearrangement changed toward the archetype sequence, and later JCV DNA became undetectable. Total brain lesion volume decreased (8.54 to 3.97 cm(3)) and atrophy increased. Barthel (60 to 100 to 80 points) and Rankin (4 to 2 to 3) scores, gait stability, and box and block (7, 35, 25 pieces) and nine-hole peg (300, 50, 300 s) test performances first improved but subsequently worsened. Cognition and walking speed remained stable. Despite initial rapid deterioration, the patient survived under continuous treatment with mirtazapine and mefloquine even though he belongs to a PML subgroup that is usually fatal within a few months. This course was paralleled by JCV clones with presumably lower replication capability before JCV became undetectable. Neurological deficits were due to PML lesions and progressive brain atrophy.
Resumo:
Fractal geometry is a fundamental approach for describing the complex irregularities of the spatial structure of point patterns. The present research characterizes the spatial structure of the Swiss population distribution in the three Swiss geographical regions (Alps, Plateau and Jura) and at the entire country level. These analyses were carried out using fractal and multifractal measures for point patterns, which enabled the estimation of the spatial degree of clustering of a distribution at different scales. The Swiss population dataset is presented on a grid of points and thus it can be modelled as a "point process" where each point is characterized by its spatial location (geometrical support) and a number of inhabitants (measured variable). The fractal characterization was performed by means of the box-counting dimension and the multifractal analysis was conducted through the Renyi's generalized dimensions and the multifractal spectrum. Results showed that the four population patterns are all multifractals and present different clustering behaviours. Applying multifractal and fractal methods at different geographical regions and at different scales allowed us to quantify and describe the dissimilarities between the four structures and their underlying processes. This paper is the first Swiss geodemographic study applying multifractal methods using high resolution data.
Resumo:
Background: While quality of life (QoL) is a well-recognised outcome measure of Crohn disease (CD) activity, its influence on other outcome measures, including exacerbation of CD is poorly understood. If QoL measures were to be associated with intestinal inflammatory activity, they might be useful for early detection of subclinical flares. Aims: We hypothesised that low QoL might be associated with subsequent CD flares. Methods: A cohort of 318 adult CD patients was observed for 1 year after assessment of baseline characteristics. Data were collected in Swiss university hospitals, regional hospitals and private practices. At inclusion, patients completed the Inflammatory Bowel Disease QoL Questionnaire (gastrointestinal QoL; range: 32 to 224 points) and the Short Form-36 Health Survey (general QoL; range: 35 to 145 points). During follow up, flares were recorded. Binary logistic regression was performed to estimate the relation between QoL and the odds of subsequent flares. Results: A twofold decrease in the odds of flares (99% CI: 1.1; 4.0) per standard deviation of gastrointestinal QoL and a threefold decrease (99% CI: 1.5; 6.2) per standard deviation of general QoL were observed. Conclusions: The close association between QoL and subsequent flares suggests that QoL measures might be useful in detecting upcoming flares before they become clinically apparent.
Resumo:
Forest fire sequences can be modelled as a stochastic point process where events are characterized by their spatial locations and occurrence in time. Cluster analysis permits the detection of the space/time pattern distribution of forest fires. These analyses are useful to assist fire-managers in identifying risk areas, implementing preventive measures and conducting strategies for an efficient distribution of the firefighting resources. This paper aims to identify hot spots in forest fire sequences by means of the space-time scan statistics permutation model (STSSP) and a geographical information system (GIS) for data and results visualization. The scan statistical methodology uses a scanning window, which moves across space and time, detecting local excesses of events in specific areas over a certain period of time. Finally, the statistical significance of each cluster is evaluated through Monte Carlo hypothesis testing. The case study is the forest fires registered by the Forest Service in Canton Ticino (Switzerland) from 1969 to 2008. This dataset consists of geo-referenced single events including the location of the ignition points and additional information. The data were aggregated into three sub-periods (considering important preventive legal dispositions) and two main ignition-causes (lightning and anthropogenic causes). Results revealed that forest fire events in Ticino are mainly clustered in the southern region where most of the population is settled. Our analysis uncovered local hot spots arising from extemporaneous arson activities. Results regarding the naturally-caused fires (lightning fires) disclosed two clusters detected in the northern mountainous area.
Resumo:
Among pollutants released into the environment by human activities, residues of pharmaceuticals are an increasing matter of concern because of their potential impact on ecosystems. The aim of this study was to analyze differences of protein expression resulting from acute (2 days) and middle-term (7 days) exposure of aquatic microcrustacean Daphnia pulex to the anticancer drug tamoxifen. Using a liquid chromatography-mass spectrometry shotgun approach, about 4000 proteins could be identified, providing the largest proteomics data set of D. pulex published up to now. Considering both time points and tested concentrations, 189 proteins showed a significant fold change. The identity of regulated proteins suggested a decrease in translation, an increase in protein degradation and changes in carbohydrate and lipid metabolism as the major effects of the drug. Besides these impacted processes, which reflect a general stress response of the organism, some other regulated proteins play a role in Daphnia reproduction. These latter results are in accordance with our previous observations of the impact of tamoxifen on D. pulex reproduction and illustrate the potential of ecotoxicoproteomics to unravel links between xenobiotic effects at the biochemical and organismal levels. Data are available via ProteomeXchange with identifier PXD001257.
Resumo:
SummaryDiscrete data arise in various research fields, typically when the observations are count data.I propose a robust and efficient parametric procedure for estimation of discrete distributions. The estimation is done in two phases. First, a very robust, but possibly inefficient, estimate of the model parameters is computed and used to indentify outliers. Then the outliers are either removed from the sample or given low weights, and a weighted maximum likelihood estimate (WML) is computed.The weights are determined via an adaptive process such that if the data follow the model, then asymptotically no observation is downweighted.I prove that the final estimator inherits the breakdown point of the initial one, and that its influence function at the model is the same as the influence function of the maximum likelihood estimator, which strongly suggests that it is asymptotically fully efficient.The initial estimator is a minimum disparity estimator (MDE). MDEs can be shown to have full asymptotic efficiency, and some MDEs have very high breakdown points and very low bias under contamination. Several initial estimators are considered, and the performances of the WMLs based on each of them are studied.It results that in a great variety of situations the WML substantially improves the initial estimator, both in terms of finite sample mean square error and in terms of bias under contamination. Besides, the performances of the WML are rather stable under a change of the MDE even if the MDEs have very different behaviors.Two examples of application of the WML to real data are considered. In both of them, the necessity for a robust estimator is clear: the maximum likelihood estimator is badly corrupted by the presence of a few outliers.This procedure is particularly natural in the discrete distribution setting, but could be extended to the continuous case, for which a possible procedure is sketched.RésuméLes données discrètes sont présentes dans différents domaines de recherche, en particulier lorsque les observations sont des comptages.Je propose une méthode paramétrique robuste et efficace pour l'estimation de distributions discrètes. L'estimation est faite en deux phases. Tout d'abord, un estimateur très robuste des paramètres du modèle est calculé, et utilisé pour la détection des données aberrantes (outliers). Cet estimateur n'est pas nécessairement efficace. Ensuite, soit les outliers sont retirés de l'échantillon, soit des faibles poids leur sont attribués, et un estimateur du maximum de vraisemblance pondéré (WML) est calculé.Les poids sont déterminés via un processus adaptif, tel qu'asymptotiquement, si les données suivent le modèle, aucune observation n'est dépondérée.Je prouve que le point de rupture de l'estimateur final est au moins aussi élevé que celui de l'estimateur initial, et que sa fonction d'influence au modèle est la même que celle du maximum de vraisemblance, ce qui suggère que cet estimateur est pleinement efficace asymptotiquement.L'estimateur initial est un estimateur de disparité minimale (MDE). Les MDE sont asymptotiquement pleinement efficaces, et certains d'entre eux ont un point de rupture très élevé et un très faible biais sous contamination. J'étudie les performances du WML basé sur différents MDEs.Le résultat est que dans une grande variété de situations le WML améliore largement les performances de l'estimateur initial, autant en terme du carré moyen de l'erreur que du biais sous contamination. De plus, les performances du WML restent assez stables lorsqu'on change l'estimateur initial, même si les différents MDEs ont des comportements très différents.Je considère deux exemples d'application du WML à des données réelles, où la nécessité d'un estimateur robuste est manifeste : l'estimateur du maximum de vraisemblance est fortement corrompu par la présence de quelques outliers.La méthode proposée est particulièrement naturelle dans le cadre des distributions discrètes, mais pourrait être étendue au cas continu.
Resumo:
Abstract APO866 is an inhibitor of nicotinamide adenine dinucleotide (NAD) biosynthesis that exhibits potent anti-lymphoma activity. Rituximab (RTX), an anti-CD20 antibody, kills lymphoma cells by direct apoptosis and antibody- and complement-dependent cell-mediated cytotoxicities, and has clinical efficacy in non-Hodgkin cell lymphomas. In the present study, we evaluated whether RTX could potentiate APO866-induced human B-lymphoma cell death and shed light on death-mediated mechanisms associated with this drug combination. We found that RTX significantly increases APO866-induced death in lymphoma cells from patients and lines. Mechanisms include enhancement of autophagy-mediated cell death, activation of caspase 3 and exacerbation of mitochondrial depolarization, but not increase of reactive oxygen species (ROS) production, when compared with those induced by each drug alone. In vivo, combined administration of APO866 with RTX in a laboratory model of human aggressive lymphoma significantly decreased tumor burden and prolonged survival over single-agent treatment. Our study demonstrates that the combination of RTX and APO866 optimizes B-cell lymphoma apoptosis and therapeutic efficacy over both compounds administered separately.
Resumo:
Modeling concentration-response function became extremely popular in ecotoxicology during the last decade. Indeed, modeling allows determining the total response pattern of a given substance. However, reliable modeling is consuming in term of data, which is in contradiction with the current trend in ecotoxicology, which aims to reduce, for cost and ethical reasons, the number of data produced during an experiment. It is therefore crucial to determine experimental design in a cost-effective manner. In this paper, we propose to use the theory of locally D-optimal designs to determine the set of concentrations to be tested so that the parameters of the concentration-response function can be estimated with high precision. We illustrated this approach by determining the locally D-optimal designs to estimate the toxicity of the herbicide dinoseb on daphnids and algae. The results show that the number of concentrations to be tested is often equal to the number of parameters and often related to the their meaning, i.e. they are located close to the parameters. Furthermore, the results show that the locally D-optimal design often has the minimal number of support points and is not much sensitive to small changes in nominal values of the parameters. In order to reduce the experimental cost and the use of test organisms, especially in case of long-term studies, reliable nominal values may therefore be fixed based on prior knowledge and literature research instead of on preliminary experiments
Resumo:
Odorant receptor (OR) genes constitute with 1200 members the largest gene family in the mouse genome. A mature olfactory sensory neuron (OSN) is thought to express just one OR gene, and from one allele. The cell bodies of OSNs that express a given OR gene display a mosaic pattern within a particular region of the main olfactory epithelium. The mechanisms and cis-acting DNA elements that regulate the expression of one OR gene per OSN - OR gene choice - remain poorly understood. Here, we describe a reporter assay to identify minimal promoters for OR genes in transgenic mice, which are produced by the conventional method of pronuclear injection of DNA. The promoter transgenes are devoid of an OR coding sequence, and instead drive expression of the axonal marker tau-β-galactosidase. For four mouse OR genes (M71, M72, MOR23, and P3) and one human OR gene (hM72), a mosaic, OSN-specific pattern of reporter expression can be obtained in transgenic mice with contiguous DNA segments of only ~300 bp that are centered around the transcription start site (TSS). The ~150bp region upstream of the TSS contains three conserved sequence motifs, including homeodomain (HD) binding sites. Such HD binding sites are also present in the H and P elements, DNA sequences that are known to strongly influence OR gene expression. When a 19mer encompassing a HD binding site from the P element is multimerized nine times and added upstream of a MOR23 minigene that contains the MOR23 coding region, we observe a dramatic increase in the number of transgene-expressing founders and lines and in the number of labeled OSNs. By contrast, a nine times multimerized 19mer with a mutant HD binding site does not have these effects. We hypothesize that HD binding sites in the H and P elements and in OR promoters modulate the probability of OR gene choice.
Resumo:
Systemic lupus erythematosus (SLE) is characterized by multisystem immune-mediated injury in the setting of autoimmunity to nuclear antigens. The clinical heterogeneity of SLE, the absence of universally agreed clinical trial end points, and the paucity of validated therapeutic targets have, historically, contributed to a lack of novel treatments for SLE. However, in 2011, a therapeutic monoclonal antibody that neutralizes the cytokine TNF ligand superfamily member 13B (also known as B-cell-activating factor of the TNF family [BAFF]), belimumab, became the first targeted therapy for SLE to have efficacy in a randomized clinical trial. Because of its specificity, the efficacy of belimumab provides an opportunity to increase understanding of SLE pathophysiology. Although belimumab depletes B cells, this effect is not as powerful as that of other B-cell-directed therapies that have not been proven efficacious in randomized clinical trials. In this article, therefore, we review results suggesting that neutralizing BAFF can have effects on the immune system other than depletion of B cells. We also identify aspects of the BAFF system for which data in relation to SLE are still missing, and we suggest studies to investigate the pathogenesis of SLE and ways to refine anti-BAFF therapies. The role of a related cytokine, TNF ligand superfamily member 13 (also known as a proliferation-inducing ligand [APRIL]) in SLE is much less well understood, and hence this review focuses on BAFF.
Resumo:
BACKGROUND: Fish oil (FO) has antiinflammatory effects, which might reduce systemic inflammation induced by a cardiopulmonary bypass (CPB). OBJECTIVE: We tested whether perioperative infusions of FO modify the cell membrane composition, inflammatory responses, and clinical course of patients undergoing elective coronary artery bypass surgery. DESIGN: A prospective randomized controlled trial was conducted in cardiac surgery patients who received 3 infusions of 0.2 g/kg FO emulsion or saline (control) 12 and 2 h before and immediately after surgery. Blood samples (7 time points) and an atrial biopsy (during surgery) were obtained to assess the membrane incorporation of PUFAs. Hemodynamic data, catecholamine requirements, and core temperatures were recorded at 10-min intervals; blood triglycerides, nonesterified fatty acids, glucose, lactate, inflammatory cytokines, and carboxyhemoglobin concentrations were measured at selected time points. RESULTS: Twenty-eight patients, with a mean ± SD age of 65.5 ± 9.9 y, were enrolled with no baseline differences between groups. Significant increases in platelet EPA (+0.86%; P = 0.0001) and DHA (+0.87%; P = 0.019) were observed after FO consumption compared with at baseline. Atrial tissue EPA concentrations were higher after FO than after control treatments (+0.5%; P < 0.0001). FO did not significantly alter core temperature but decreased the postoperative rise in IL-6 (P = 0.018). Plasma triglycerides increased transiently after each FO infusion. Plasma concentrations of glucose, lactate, and blood carboxyhemoglobin were lower in the FO than in the control group on the day after surgery. Arrhythmia incidence was low with no significant difference between groups. No adverse effect of FO was detected. CONCLUSIONS: Perioperative FO infusions significantly increased PUFA concentrations in platelet and atrial tissue membranes within 12 h of the first FO administration and decreased biological and clinical signs of inflammation. These results suggest that perioperative FO may be beneficial in elective cardiac surgery with CPB. This trial was registered at clinicaltrials.gov as NCT00516178.
Resumo:
Hematocrit (Hct) is one of the most critical issues associated with the bioanalytical methods used for dried blood spot (DBS) sample analysis. Because Hct determines the viscosity of blood, it may affect the spreading of blood onto the filter paper. Hence, accurate quantitative data can only be obtained if the size of the paper filter extracted contains a fixed blood volume. We describe for the first time a microfluidic-based sampling procedure to enable accurate blood volume collection on commercially available DBS cards. The system allows the collection of a controlled volume of blood (e.g., 5 or 10 μL) within several seconds. Reproducibility of the sampling volume was examined in vivo on capillary blood by quantifying caffeine and paraxanthine on 5 different extracted DBS spots at two different time points and in vitro with a test compound, Mavoglurant, on 10 different spots at two Hct levels. Entire spots were extracted. In addition, the accuracy and precision (n = 3) data for the Mavoglurant quantitation in blood with Hct levels between 26% and 62% were evaluated. The interspot precision data were below 9.0%, which was equivalent to that of a manually spotted volume with a pipet. No Hct effect was observed in the quantitative results obtained for Hct levels from 26% to 62%. These data indicate that our microfluidic-based sampling procedure is accurate and precise and that the analysis of Mavoglurant is not affected by the Hct values. This provides a simple procedure for DBS sampling with a fixed volume of capillary blood, which could eliminate the recurrent Hct issue linked to DBS sample analysis.