3,681 research outputs found
Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome
Objective: To investigate the potential value of uterine artery Doppler at 30 34 weeks’ gestation in the prediction of adverse perinatal outcome.
Methods: Screening study in 30,780 singleton pregnancies at 30 34 weeks. Uterine artery pulsatility index (PI) was measured and the values were converted to multiples of the median (MoM) after adjustment from variables in maternal characteristics and medical history that affect the measurements. Multivariable logistic regression analysis was used to determine if uterine artery PI had a significant additional contribution to maternal characteristics, medical history and obstetric factors in predicting adverse outcome. The detection rate (DR) and false positive rate (FPR) of screening by uterine artery PI were estimated for stillbirth, cesarean section for fetal distress, umbilical arter ial cord blood pH <7.0 or umbilical venous pH <7.1 and Apgar score <7 at 5 minutes.
Results: The incidence of adverse perinatal outcome was higher in small for gestational age (SGA) than in non SGA fetuses, but the majority of cases for each adverse outcome were in the non SGA group, including about 70% of stillbirths and more than 80% of cases of cesarean section for fetal distress, low cord blood pH and low Apgar score. The performance of uterine artery PI >95 th percentile in screening for each adverse outcome was poor with DR of 6 16% and FPR of 5 6%. T he DR of high uterine artery PI for adverse outcome was higher in the SGA than non SGA groups, including 24% vs. 13% for stillbirth , 15% vs. 5% for cesarean section for fetal distress, 22% vs. 9% for low cord blood pH and 20% vs. 3% for low Apgar score.
Conclusion: High uterine artery PI at 30 34 weeks’ gestation may be useful in the prediction of adverse perinatal outcome in pregnancies with SGA fetuses, but not in those with non SGA fetuses
Novel performance-based technique for predicting maintenance strategy of bitumen stabilised ballast
Despite being the most used worldwide, railway ballasted tracks presents high maintenance cost related to ballast settlement and particle degradation. With the aim of reducing life cycle costs, bitumen stabilised ballast (BSB) has been recently proposed as a relatively cheap alternative maintenance solution to be applied to existing tracks. This study aims at assessing the potential advantages of this technology, defining a novel maintenance strategy of traditional ballasted track- beds. A protocol for the application of the BSB technology and its associated maintenance strategy is defined. To estimate minor and major maintenance operations of BSB scenario in comparison to traditional ballasted track-bed, an integrated model, based on laboratory tests, combining the evolution of track irregularities and ballast contamination with traffic, was used. Results together with a sensitivity analysis related to main parameters adopted revealed that the application of BSB is expected to provide a significant increase of intervals between both minor and major maintenance activities
A comparative life-cycle assessment of asphalt mixtures for railway sub-ballast containing alternative materials
Effects of Bark Beetle Attacks on Forest Snowpack and Avalanche Formation – Implications for Protection Forest Management
Healthy, dense forests growing in avalanche terrain reduce the likelihood of slab avalanche release by inhibiting the formation of continuous snow layers and weaknesses in the snowpack. Driven by climate change, trends towards more frequent and severe bark beetle disturbances have already resulted in the death of millions of hectares of forest in North America and central Europe, affecting snowpack in mountain forests and potentially reducing their protective capacity against avalanches. We examined the spatial variability in snow stratigraphy, i.e., the characteristic layering of the snowpack, by repeatedly measuring vertical profiles of snow penetration resistance with a digital snow micro penetrometer (SMP) along 10- and 20-m transects in a spruce beetle-infested Engelmann spruce forest in Utah, USA. Three study plots were selected characterizing different stages within a spruce beetle outbreak cycle: non-infested/green, infested \u3e 3 years ago/gray stage, and salvage-logged. A fourth plot was installed in a non-forested meadow as the control. Based on our SMP measurements and a layer matching algorithm, we quantified the spatial variability in snow stratigraphy, and tested which forest, snow and/or meteorological conditions influenced differences between our plots using linear mixed effects models. Our results showed that spatial variability in snow stratigraphy was best explained by the percentage of canopy covering a transect (R2 = 0.71, p \u3c 0.001), and that only 14% of the variance was explained by the stage within the outbreak cycle. That is, differences between green and gray stage stands did not depend much on the reduction in needle mass, but spatial variability in snow stratigraphy increased significantly with increasing forest canopy cover. At both study plots, a more heterogeneous snow stratigraphy developed, which translates to disrupted and discontinuous snow layers and, therefore, reduced avalanche formation. We attribute this to the effect that small fine branches and twigs still present in the canopy of gray stage trees have on snow interception and unloading, and especially on canopy drip. In contrast, salvage logging that reduced the canopy cover to ∼25%, led to a spatially less variable and similar snow stratigraphy as observed in the meadow. At these two study plots, a homogeneous snow stratigraphy consisting of distinct vertical and continuous slope-parallel soft and hard snow layers including weak layers had formed, a condition which is generally more prone to avalanche release. Our findings therefore emphasize advantages of leaving dead trees in place, especially in protection forests where bark beetle populations have reached epidemic levels
Provinciality and the Art World: The Midland Group 1961- 1977
This paper takes as its focus the Midland Group Gallery in order to first, make a case for the consideration of the geographies of art galleries. Second, highlight the importance of galleries in the context of cultural geographies of the sixties. Third, discuss the role of provinciality in the operation of art worlds. In so doing it explicates one set of geographies surrounding the gallery
– those of the local, regional and international networks that connected to produce art works and art space. It reveals how the interactions between places and practices outside of metropolitan and regional hierarchies provides a more nuanced insight into how art worlds operated during the
sixties, a period of growing internationalism of art, and how contested definitions of the provincial played an integral role in this. The paper charts the operations of the Midland Group Gallery and the spaces that it occupied to demonstrate how it was representative of a post-war
discourse of provincialism and a corresponding re-evaluation of regional cultural activity
Ultra wide band receiver based on turbo-equalization
La technologie de l'Ultra-Large-bande (UWB) est actuellement étudiée comme une solution utile pour les systèmes de communications sans fil de grande capacité. Le rapport élevé de la largeur de bande du signal à la largeur de bande de l'information rend la technologie d'UWB attrayante pour des applications d'accès multiple. La synchronisation et l'égalization du canal sont les questions cruciales dans le développement de la technologie d'UWB, dû à la courte durée des signaux transmises. Dans cette contribution, nous proposons un turbo-égaliseur pour des récepteurs d'UWB, afin d'améliorer l'exécution de l'approche conventionnelle (récepteur RAKE). En particulier, les résultats obtenus ont démontré un perfectionnement d'exécution, en termes de taux d'erreurs sur les bits, avec une complexité computationelle menable
Central nervous system manganese induced lesions and clinical consequences in patients with hereditary hemorrhagic telangiectasia
Abstract Background Around 47–74% of patients with hereditary hemorrhagic telangiectasia (HHT) have hepatic vascular malformations (HVMs); magnetic resonance images (MRI) of the central nervous system (CNS) might show in T1 sequences a hyper-intensity signal in different areas, mainly in the basal ganglia (BG) as consequence of manganese (Mn) deposits as observed in cirrhotic patients. These patients might suffer from different neuropsychiatric disorders (hepatic encephalopathy). In HHT patients, even in the presence of hepatic shunts, hepatocellular function is usually preserved. Additionally, Mn shares iron absorption mechanisms, transferrin and CNS transferrin receptors. In iron deficiency conditions, the Mn may harbor transferrin and access BG. The objectives were to describe frequency of BG Mn deposit-induced lesions (BGMnIL) in HHT patients, its relationship with iron deficiency anemia (IDA) and HVMs. Finally, explore the association between neuropsychological and motor consequences. We performed a cross-sectional study. We determined HHT patients with or without BG-MnIL by the MRI screening of the CNS. We included all patients with lesions and a random sample of those without lesions. All patients underwent standardized and validated neuropsychological assessment to evaluate BG actions. Results were analyzed with multiple logistic regression, adjusting for potential confounders. Results Among 307 participants from a cohort included in the Institutional HHT Registry, 179 patients had MRI performed and Curaçao Criteria ≥3. The prevalence of BG-MnIL was 34.6% (95%CI 27.69-42.09). While neuropsychological symptoms were present in all patients, BG-MnIL patients performed poorly in three of the neuropsychological tests (serial dotting, line tracing time, number connection test A). HVMs frequency in BG-MnIL was 95.1%, versus 71.4% in those without lesions (p < 0.001). IDA frequency was 90.3% versus 54% (p < 0.001). When IDA is present, estimated risk for BG-MnIL is remarkably high (OR 7.73, 95%CI 2.23–26.73). After adjustment for possible confounders (gender, age, presence of HVMs), IDA was still associated with increased risk of BG-MnIL (adjusted OR 6.32, 95% CI 2.32–17.20; p < 0.001). Conclusions Physicians should assess BG-MnIL in HHT patients in CNS-MRI. IDA and HVMs present increased risk of lesions. Patients with BG-MnIL have neuropsychological impairment, and they might benefit from sparing IDA, or undergoing future therapeutic options. Trial registration NCT01761981 . Registered January 3rd 2013
Detección de indicadores de seguridad de pacientes (PSI-Patient Safety Indicators) en un estudio multi-céntrico de carga de enfermedad y resultados de la atención
La calidad/ seguridad de la atención médica se puede estimar analizando los registros de egresos de hospitales generales de agudos (HGA). Se obtuvieron indicadores de seguridad de los pacientes (PSI), que detectan eventos adversos en la atención médica (EAs). En un estudio multi-céntrico se adecuó un método para obtener los PSI en la Argentina basado en codificaciones diagnosticas primarias (Dx1) y secundarias (Dx2) y codificaciones de procedimientos (Px1 y Px 2). La estandarización de los diagnósticos y de los procedimientos permitió realizar la plataforma del estudio Utilización de Servicios, Costos y Resultados en Argentina (USCR-A). Se obtienen los EAs definidos por los PSI #3, #7 y #13. El objetivo de este trabajo es presentar los resultados cuali y cuantitativos de una aplicación de los PSI en el contexto del trabajo y registro del estudio multi-céntrico en Utilización de Servicios, Costos y Resultados en Argentina (USCR-A).Sociedad Argentina de Informática e Investigación Operativ
Pathological gambling in adolescence: A narrative review
Pathological gambling is an emerging and increasing phenomenon in Western counties. This work is aimed at reviewing the existing literature on this topic, paying special attention to its development, course and outcome in adolescence. We will explore epidemiological data, the instruments for the diagnostic and clinical assessment, the course and the outcome of the disorder, the comorbidity with other psychiatric syndromes and disorders. The main risk factors will be described at individual, social and community level. We provide an overview of the available pharmacological and psychological treatments and we report a clinical vignette in order to describe the psychological and psychopathological features of pathological gambling in adolescence
The Palermo (Sicily) seismic cluster of September 2002 in the seismotectonic framework of the Tyrrhenian Sea-Sicily border area
The northern coast of Sicily and its offshore area represent a hinge zone between a sector of the Tyrrhenian Basin, characterized by the strongest crustal thinning, and the sector of the Sicilian belt which has emerged. This hinge zone is part of a wider W-E trending right-lateral shear zone, which has been affecting the Maghrebian Chain units since the Pliocene. Seismological and structural data have been used to evaluate the seismotectonic behavior of the area investigated here. Seismological analysis was performed on a data set of about 2100 seismic
events which occurred between January 1988 and October 2002 in the Southern Tyrrhenian Sea. This paper focuses in particular on a set of data relating to the period from 6th September 2002, including both the main shock and about 540 aftershocks of the Palermo seismic sequence. The distribution of the hypocenters revealed
the presence of two main seismogenic zones. The events of the easternmost zone may be related to the Ionian lithospheric slab diving beneath the Calabrian Arc. The seismicity associated with the westernmost zone is closely clustered around a sub-horizontal regression plane contained within the thinned Southern Tyrrhenian crust, hence suggesting that this seismogenic zone is strictly connected to the deformation field active within the hinge zone. On the basis of both structural and seismological data, the brittle deformation pattern is characterized by high-angle faults, mainly represented by transcurrent synthetic right-lateral and antithetic left-lateral systems, producing both restraining/uplifting and releasing/subsiding zones which accommodate strains developing in response to the current stress field (characterized by a maximum axis trending NW-SE) which has been active in
the area since the Pliocene. The cluster of the seismic sequence which started with the 6th September 2002's main shock is located within the hinge zone. The distribution of the hypocenters relative to this sequence emphasizes the presence of a high-angle NE-SW-oriented deformation belt within which several shear surfaces are considered to be found sub-parallel to that established for the main shock. The kinematics of all these structures is consistent with a compressive right-lateral focal mechanism
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