884 resultados para UNIT-ROOT HYPOTHESIS
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Rapport de synthèse :Le céfépime a été associé à un taux de mortalité supérieur à celui des autres bêta-lactamines chez les patients traités pour un sepsis sévère. Une des hypothèses avancées pour expliquer ces échecs thérapeutiques sont de possibles effets secondaires cachés (par ex. neurologiques) ou des paramètres pharmacocinétiques/pharmacodynamiques (PK/PD) inadaptés. Le présent travail a étudié cette problématique en mesurant prospectivement la pharmacocinétique du céfépime chez 21 patients consécutifs hospitalisés aux soins intensifs adultes (SIAD) pour une pneumonie nosocomiale. La population étudiée avec un âge médian 55,1 ans, a reçu par voie intraveineuse du céfépime à raison de 2 g toutes les 12 heures pour une clairance de la créatinine (Clcr)>50 mI/ min, et 2 g toutes les 24 heures ou 36 heures pour une Clcr<50 ml /min. Les taux plasmatiques de céfépime ont été mesurés à plusieurs reprises avant et après administration du médicament après la lèoe dose et à l'état d'équilibre par chromatographie en phase liquide à haute pression. Les taux plasmatiques ont considérablement varié entre les patients. Cent pour cent (21/21) des patients ont eu une durée appropriée d'antibiothérapie avec des taux plasmatiques supérieures à la CMI du céfépime (T>CMI>50%) pour les agents pathogènes retrouvés dans cette étude (CMI<4 mg/I), mais seulement 45-65% d'entre eux ont eu une couverture appropriée pour les agents pathogènes potentiels présentant une CMI> 8 mg/I pour le céfépime. Deux patients avec une insuffisance rénale (Clcr<30 ml/min) ont présenté des symptômes compatibles avec une épilepsie non-convulsive (état confusionnel et myoclonies) attribuée dans un 2ème temps à une toxicité du céfépime après que les taux plasmatiques aient été communiqués aux soignants qui ont suspendu l'antibiothérapie avec disparition des symptômes. Les résultats de cette étude empirique confirment l'existence d'effets secondaires cachés et de paramètres PK/PD inappropriés (pour les agents pathogènes ayant des CMI de limite supérieure) dans notre population de SIAD. En outre, ils mettent en évidence une fenêtre thérapeutique efficace pour une posologie de céfépime de 2 g toutes les 12 heures chez les patients ayant une Clcr>50 ml/min infectés par des pathogènes avec des CMI pour le céfépime <4 mg/I. Les échecs thérapeutiques constatés dans cette étude sont probablement liés à des taux sériques inadaptés, résultant de la difficulté de prescription dans les situations cliniques complexes. Dans ce contexte, un prompt dosage plasmatique du céfépime doit être considéré en cas de diminution de la Clcr ou en présence de CMI élevées.
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Maize root growth is negatively affected by compacted layers in the surface (e.g. agricultural traffic) and subsoil layers (e.g. claypans). Both kinds of soil mechanical impedances often coexist in maize fields, but the combined effects on root growth have seldom been studied. Soil physical properties and maize root abundance were determined in three different soils of the Rolling Pampa of Argentina, in conventionally-tilled (CT) and zero-tilled (ZT) fields cultivated with maize. In the soil with a light Bt horizon (loamy Typic Argiudoll, Chivilcoy site), induced plough pans were detected in CT plots at a depth of 0-0.12 m through significant increases in bulk density (1.15 to 1.27 Mg m-3) and cone (tip angle of 60 º) penetrometer resistance (7.18 to 9.37 MPa in summer from ZT to CT, respectively). This caused a reduction in maize root abundance of 40-80 % in CT compared to ZT plots below the induced pans. Two of the studied soils had hard-structured Bt horizons (clay pans), but in only one of them (silty clay loam Abruptic Argiudoll, Villa Lía site) the expected penetrometer resistance increases (up to 9 MPa) were observed with depth. In the other clay pan soil (silty clay loam Vertic Argiudoll, Pérez Millán site), penetrometer resistance did not increase with depth but reached 14.5 MPa at 0.075 and 0.2 m depth in CT and ZT plots, respectively. However, maize root abundance was stratified in the first 0.2 m at the Villa Lía and Pérez Millán sites. There, the hard Bt horizons did not represent an absolute but a relative mechanical impedance to maize roots, by the observed root clumping through desiccation cracks.
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Objective.- The Patient-Rated Wrist Evaluation is a specific questionnaire for the wrist [1]. It consists of 15 questions with a total score of 100. It was recently translated into French [2]. However, its validity has not been tested in this language. The Disabilities Arm Shoulder and Hand (DASH), with well-established psychometric properties, is considered as the reference questionnaire for the evaluation of upper extremities. The objective of this study is to measure the construct validity of the PRWE-F with the DASH-F in patients with wrist pathology.Patients and methods.- Fifty-one patients (40 m, 11 w, mean age 42 years), 25 fractures of the radius and 26 lesions of the carpus.Questionnaires PRWE-F and DASH-F at entry and at discharge (0 to 100). Calculation of the construct validity of the PRWE-F comparing with the DASH-F with Pearson correlation coefficients (r) at entry and at discharge. Level of significance (alpha) was set at 5%.Results.- Correlation DASH/PRWE at entry: r = 0.799 (95% CI 0.671 to 0.881), P < 0.0001. Correlation DASH/PRWE at discharge: r = 0.847 (95% CI: 0.745 to 0.910), P < 0.0001.Discussion.- The construct validity of the two instruments indicates that they measure the same concept. Our correlation between DASH-F and PRWE-F, going from 0.799 to 0.847, are comparable to those published in different languages (0.71 to 0.84) [3,4]. The questionnaires PRWE-F can thus be used in rehabilitation patients presenting with wrist pathologies; it is comparable to the DASH but described by MacDermid [1] to be more specific. Compared to the DASH it has the advantage of consisting of two dimensions. Its construct validity is excellent. This questionnaire should be evaluated in other populations, and it should be compared with hand questionnaires more specific than the DASH.
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Empirical studies have shown little evidence to support the presence of all unit roots present in the $^{\Delta_4}$ filter in quarterly seasonal time series. This paper analyses the performance of the Hylleberg, Engle, Granger and Yoo (1990) (HEGY) procedure when the roots under the null are not all present. We exploit the Vector of Quarters representation and cointegration relationship between the quarters when factors $(1-L),(1+L),\bigg(1+L^2\bigg),\bigg(1-L^2\bigg) y \bigg(1+L+L^2+L^3\bigg)$ are a source of nonstationarity in a process in order to obtain the distribution of tests of the HEGY procedure when the underlying processes have a root at the zero, Nyquist frequency, two complex conjugates of frequency $^{\pi/2}$ and two combinations of the previous cases. We show both theoretically and through a Monte-Carlo analysis that the t-ratios $^{t_{{\hat\pi}_1}}$ and $^{t_{{\hat\pi}_2}}$ and the F-type tests used in the HEGY procedure have the same distribution as under the null of a seasonal random walk when the root(s) is/are present, although this is not the case for the t-ratio tests associated with unit roots at frequency $^{\pi/2}$.
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Introduction: Delirium is frequent in hospitalized older people, with incidence rate up to 40% in acute care. Delirium is associated with several adverse consequences, including increased mortality and institutionalization. This study aims to investigate the prevalence, incidence, and consequences of delirium in patients hospitalized in an acute care unit for elderly (ACE unit). Methods: Over a 3 months period, every patient (N = 93, mean age 84.1 ± 7.8 years, 66/93(71%) women) admitted to a 28-bed ACE unit were systematically assessed for delirium. Trained nurses used the Confusion Assessment Method (CAM) instrument to determine the presence of delirium at admission and on each subsequent day over patients' stay. Delirium prevalence rate was defined as the proportion of patients with a positive CAM within 24 hours of admission to the ACE unit. Delirium incidence rate was defined as the proportion of patients with a negative CAM at admission whose CAM became positive at least once during their stay. This evaluation was part of a functional assessment, including Basic Activities of Daily Life (Katz BADL, from 0 to 6, higher score indicating better function). Delirium prevention interventions and specific treatment was provided if needed. Results: Overall,25/93(27%)patients had delirium during their stay. Prevalence of delirium at admission was 10/93 (11%), with an incidence of 15/83(18%). Compared with non-delirious patients, those with delirium were more frequently men (10/25(40%) vs 17/68(25%), p <.001) and had reduced functional status at admission(BADL 2.0 ± 1.9 vs 3.6 ± 2.1, p = .004). They tended to be older (86.0 ± 6.7 vs 83.3 ± 8.1 years, p = .110). At discharge, delirium was associated with reduced functional status (BADL 2.0 ± 2.1 vs 4.3 ± 1.9, p <.001), lower rate of home discharge (6/20(30%) vs 28/65 (43%), p = .009) and increased mortality (5/25 (20%) vs 3/68 (5%), p <.001). On average, patients with delirium stayed 5.7 days longer (17.0 ± 9.8 vs 11.31 ± 6.3, p = .011). Conclusion: Delirium occurred in almost a third of these older patients, even though its incidence was relatively low in this frail population. Despite specific management, delirium remained associated with higher risk for adverse outcomes at discharge. These results suggest that early preventive interventions, implemented as soon as possible after hospital admission, might be needed in similar population to achieve better outcomes. Effectiveness of such interventions will be evaluated in future studies.
Effect of soil-spraying time on root-colonization ability of antagonistic Streptomyces griseoviridis
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Selostus: Kasvualustan käsittelyajan vaikutus Streptomyces griseoviridis -antagonistin juurten asutuskykyyn
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The deleterious effects of both Mn deficiency and excess on the development of plants have been evaluated with regard to aspects of shoot anatomy, ultrastructure and biochemistry, focusing mainly on the manifestation of visual symptoms. However, there is little information in the literature on changes in the root system in response to Mn supply. The objective of this study was to evaluate the effects of Mn doses (0.5, 2.0 and 200.0 μmol L-1) in a nutrient solution on the anatomy of leaves and roots of the Glycine max (L.) cultivars Santa Rosa, IAC-15 and IAC-Foscarin 31. Visual deficiency symptoms were first observed in Santa Rosa and IAC-15, which were also the only cultivars where Mn-toxicity symptoms were observed. Only in IAC-15, a high Mn supply led to root diameter thickening, but without alteration in cells of the bark, epidermis, exodermis and endodermis. The degree of disorganization of the xylem vessels, in particular the metaxylem, differed in the cultivars. Quantity and shape of the palisade parenchyma cells were influenced by both Mn deficiency and toxicity. A reduction in the number of chloroplasts was observed in the three Mn-deficient genotypes. The anatomical alterations in IAC-15 due to nutritional stress were greater, as expressed in extensive root cell cytoplasm disorganization and increased vacuolation at high Mn doses. The degree of changes in the anatomical and ultrastructural organization of roots and leaves of the soybean genotypes studied differed, suggesting the existence of tolerance mechanisms to different intensities of Mn deficiency or excess.
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Neuronal hyperexcitability following peripheral nerve lesions may stem from altered activity of voltage-gated sodium channels (VGSCs), which gives rise to allodynia or hyperalgesia. In vitro, the ubiquitin ligase Nedd4-2 is a negative regulator of VGSC α-subunits (Na(v)), in particular Na(v)1.7, a key actor in nociceptor excitability. We therefore studied Nedd4-2 in rat nociceptors, its co-expression with Na(v)1.7 and Na(v)1.8, and its regulation in pathology. Adult rats were submitted to the spared nerve injury (SNI) model of neuropathic pain or injected with complete Freund's adjuvant (CFA), a model of inflammatory pain. L4 dorsal root ganglia (DRG) were analyzed in sham-operated animals, seven days after SNI and 48h after CFA with immunofluorescence and Western blot. We observed Nedd4-2 expression in almost 50% of DRG neurons, mostly small and medium-sized. A preponderant localization is found in the non-peptidergic sub-population. Additionally, 55.7±2.7% and 55.0±3.6% of Nedd4-2-positive cells are co-labeled with Na(v)1.7 and Na(v)1.8 respectively. SNI significantly decreases the proportion of Nedd4-2-positive neurons from 45.9±1.9% to 33.5±0.7% (p<0.01) and the total Nedd4-2 protein to 44%±0.13% of its basal level (p<0.01, n=4 animals in each group, mean±SEM). In contrast, no change in Nedd4-2 was found after peripheral inflammation induced by CFA. These results indicate that Nedd4-2 is present in nociceptive neurons, is downregulated after peripheral nerve injury, and might therefore contribute to the dysregulation of Na(v)s involved in the hyperexcitability associated with peripheral nerve injuries.
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Few studies on sugar cane have evaluated the root system of the crop, in spite of its importance. This is mainly due to the difficulty of evaluation and high variability of results. The objective of this study was to develop an evaluation method of the cane root system by means of probes so as to evaluate the mass, distribution and metabolically active roots related to N fertilization at planting. For this purpose, an experiment was conducted in an Arenic Kandiustults with medium texture in Jaboticabal/SP, in a randomized block design with four replications and four treatments: control (without N) and 40, 80 and 120 kg ha-1 of N applied in the form of urea in the planting furrow of the cane variety SP81 3250. One week before harvest, a urea-15N solution was applied at the cane stalk base to detect active metabolism in the root system. Trenches of 1.5 m length and 0.6 m depth were opened between two sugar cane rows for root sampling by two methods: monoliths (0.3, 0.2 and 0.15 m wide, deep and long respectively) taken from the trench wall and by probe (internal diameter 0.055 m). For each method, 15 samples per plot were collected. The roots were separated from the soil in a sieve (2 mm mesh), oven-dried (at 65 ºC) and the dry matter was measured. Root sampling by probes resulted in root mass that did not differ from the evaluation in monoliths, indicating that this evaluation method may be used for sugar cane root mass, although neither the root distribution in the soil profile nor the rhizome mass were efficiently evaluated, due to the small sample volume. Nitrogen fertilization at planting did not result in a greater root accumulation in the sugar cane plant, but caused changes in the distribution of the root system in the soil. The absence of N fertilization led to a better root distribution in the soil profile, with 50, 34 and 16 % in the 0-0.2, 0.2-0.4 and 0.4-0.6 m layers, respectively; in the fertilized treatments the roots were concentrated in the surface layer, with on average 70, 17 and 13 % for the same layers. The metabolically active roots were concentrated in the center of the cane stool, amounting to 40 % of the total root mass, regardless of N fertilization (application of 120 kg ha-1 N or without N).
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Soil and fertilizer management during cultivation can affect crop productivity and profitability. Long-term experiments are therefore necessary to determine the dynamics of nutrient and root distribution as related to soil profile, as well as the effects on nutrient uptake and crop growth. An 18-year experiment was conducted at the Federal University of Rio Grande do Sul State (UFRGS), in Eldorado do Sul, Brazil, on Rhodic Paleudult soil. Black oat and vetch were planted in the winter and corn in the summer. The soil management methods were conventional, involving no-tillage and strip tillage techniques and broadcast, row-and strip-applied fertilizer placement (triple superphosphate). Available P (Mehlich-1) and root distribution were determined in soil monoliths during the corn grain filling period. Corn shoot dry matter production and P accumulation during the 2006/2007 growing season were determined and the efficiency of P utilization calculated. Regardless of the degree of soil mobilization, P and roots were accumulated in the fertilized zone with time, mainly in the surface layer (0-10 cm). Root distribution followed P distribution for all tillage systems and fertilizer treatments. Under no-tillage, independent of the fertilizer placement, the corn plants developed more roots than in the other tillage systems. Although soil tillage systems and fertilizer treatments affected P and root distribution throughout the soil profile, as well as P absorption and corn growth, the efficiency of P utilization was not affected.
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Empirical studies have shown little evidence to support the presence of all unit roots present in the $^{\Delta_4}$ filter in quarterly seasonal time series. This paper analyses the performance of the Hylleberg, Engle, Granger and Yoo (1990) (HEGY) procedure when the roots under the null are not all present. We exploit the Vector of Quarters representation and cointegration relationship between the quarters when factors $(1-L),(1+L),\bigg(1+L^2\bigg),\bigg(1-L^2\bigg) y \bigg(1+L+L^2+L^3\bigg)$ are a source of nonstationarity in a process in order to obtain the distribution of tests of the HEGY procedure when the underlying processes have a root at the zero, Nyquist frequency, two complex conjugates of frequency $^{\pi/2}$ and two combinations of the previous cases. We show both theoretically and through a Monte-Carlo analysis that the t-ratios $^{t_{{\hat\pi}_1}}$ and $^{t_{{\hat\pi}_2}}$ and the F-type tests used in the HEGY procedure have the same distribution as under the null of a seasonal random walk when the root(s) is/are present, although this is not the case for the t-ratio tests associated with unit roots at frequency $^{\pi/2}$.
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Introduction Pediatric intensive care patient represent a population athigh risk for drug-related problems. Our objective is to describe drugrelated problems and intervention of four decentralized pharmacists inpediatric and cardiac intensive care unit.Materials & Methods Multicentric, descriptive and prospectivestudy over a six-month period (August 1st 2009-January 31st 2010).Drug-related problems and clinical interventions were compiled infour pediatric centers using a tool developed by the Socie´te´ Franc¸aisede Pharmacie Clinique. Data concerning patients, drugs, intervention,documentation, approval (if needed), and estimated impact werecompiled. The four pharmacists participating were from Belgium (B),France (F), Quebec (Q) and Switzerland (S).Results A total of 996 interventions were collected: 129 (13%) in B,238 (24%) in F, 278 (28%) in Q and 351 (35%) in S. These interventionstargeted 269 patients (median 22 month-old, 52% male): 69(26%) in B, 88 (33%) in F, 56 (21%) in Q and in S. These data werecollected during 28 non consecutive days in the clinical unit in B, 59days in F, 42 days in Q and 63 days in S. The main drug-relatedproblems were inappropriate administration technique (293, 29%),untreated indication (254, 25%) and supra therapeutic dosage (106,11%). The pharmacist's interventions concerned mainly administrationmode optimization (223, 22%), dose adjustment (200, 20%) andtherapeutic monitoring (164, 16%). The three major drug classesleading to interventions were anti-infectives for systemic use (233,23%) and alimentary tract and metabolism drugs (218, 22%). Interventionsconcerned mainly residents and all clinical staff (209, 21%).Among the 879 (88%) interventions requiring a physician's approval,731 (83%) were accepted. Interventions were considered as having amoderate (51%) or major (17%) clinical impact. Among the interventionsprovided, 10% were considered to have an economicalpositive impact. Differences and similarities between countries willbe presented at the poster session.Discussion & Conclusion Decentralized pharmacist at patient bedsideis a pre-requisite for pharmaceutical care. There are limitedstudies comparing the activity of clinical pharmacists betweencountries. This descriptive study illustrates the ability of clinicalpharmacist to identify and solve drug-related problems in pediatricintensive care unit in four different francophone countries.
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Although silicon is not recognized as a nutrient, it may benefit rice plants and may alleviate the Mn toxicity in some plant species. The dry matter yield (root, leaf, sheaths and leaf blade) and plant architecture (angle of leaf insertion and leaf arc) were evaluated in rice plants grown in nutrient solutions with three Mn doses, with and without Si addition. The treatments were arranged in a 2 x 3 factorial [with and without (2 mmol L-1) Si; three Mn doses (0.5; 2.5 and 10 µmol L-1)], in a randomized block design with 4 replications. The experimental unit was a 4 L plastic vase with 4 rice (Metica-1 cultivar) plants. Thirty nine days after keeping the seedlings in the nutrient solution the plant dry matter yield was determined; the angle of leaf insertion in the sheath and the leaf arc were measured; and the Si and Mn concentrations in roots, sheaths and leaves were determined. The analysis of variance (F test at 5 and 1 % levels) and the regression analysis (for testing plant response to Mn with the Si treatments) were performed. The Si added to the nutrient solution increased the dry matter yield of roots, sheaths and leaf blades and also decreased the angle of leaf blade insertion into the sheath and the foliar arc in the rice plant. Additionally, it ameliorated the rice plant architecture which allowed an increase in the dry matter yield. Similarly, the addition of Mn to the solution improved the architecture of the rice plants with gain in dry matter yield. As Si was added to the nutrient solution, the concentration of Mn in leaves decreased and in roots increased thus alleviating the toxic effects of Mn on the plants.