960 research outputs found
Target localization of 3D versus 4D cone beam computed tomography in lipiodol-guided stereotactic radiotherapy of hepatocellular carcinomas
published_or_final_versio
The generality of changes in the trait composition of fish and invertebrate communities after flow restoration in a large river (French Rhône)
1. A multiple-trait-based approach can provide predictions and interpretations of the responses of freshwater communities to river restoration that apply in different taxonomic contexts. We compared the observed and predicted effects of restoration on sets of traits in fish and invertebrate communities in four reaches of the Rhône River. Restoration included minimum flow increases in three bypassed main channels and the reconnection of eight floodplain channels. 2. Predictions (described in detail in three other articles in this Special Issue) were based on habitat models that related the density of modelled taxa to their physical habitats. We used trait information extracted from the literature to translate predicted taxonomic changes into predicted changes in traits. Observed changes in traits calculated for modelled taxa and for all taxa in the community were both compared to predictions. 3. In 10 of 12 cases, observed changes in traits correlated with predicted ones. With few exceptions, the agreement was higher for fish and invertebrates in the main channels than for invertebrates in floodplain channels. Predictions translated to the trait category level improved those at the taxonomic level in 5/6 and 4/6 cases for modelled taxa and all taxa, respectively. However, the improvement was statistically significant according to a null model for 1/6 and 3/6 cases for modelled taxa and all taxa, respectively. 4. The validation of trait predictions suggested that traits related to locomotion and attachment, as well as general biology and physiology, were particularly suited to predicting and understanding the effects of physical restoration. For example, after restoration, clingers and passive filter feeders dominated invertebrate communities in the main channels, whereas invertebrate communities in the floodplain underwent a selection of traits frequent in running water (clingers, flattened shape and gill respiration). Within fish communities, the periodic life-history strategy that characterises fish species in downstream reaches (long life span, large body, late sexual maturity) increased with restoration, whereas the opportunistic strategy decreased. 5. Our results suggest that a better understanding of how hydraulics shapes traits in riverine systems is critically needed for assessing the effects of restoration measures impacting flow. In addition, existing trait databases (especially for fish) should be expanded to better reflect the energetic trade-offs that organisms must make in various flow contexts
Global distribution of two fungal pathogens threatening endangered sea turtles
This work was supported by grants of Ministerio de Ciencia e Innovación, Spain (CGL2009-10032, CGL2012-32934). J.M.S.R was supported by PhD fellowship of the CSIC (JAEPre 0901804). The Natural Environment Research Council and the Biotechnology and Biological Sciences Research Council supported P.V.W. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Thanks Machalilla National Park in Ecuador, Pacuare Nature Reserve in Costa Rica, Foundations Natura 2000 in Cape Verde and Equilibrio Azul in Ecuador, Dr. Jesus Muñoz, Dr. Ian Bell, Dr. Juan Patiño for help and technical support during samplingPeer reviewedPublisher PD
Pre-crisis mouse cells show strain-specific covariation in the amount of 54-kilodalton phosphoprotein and in susceptibility to transformation by simian virus 40.
We have used several inbred mouse strains to examine the role of the 54-kilodalton (kDa) cellular phosphoprotein in transformation by the papovavirus simian virus 40. We have measured the endogenous 54-kDa phosphoprotein in cells obtained from these inbred mouse strains. To study the effect of passage, cell cultures were measured for amount of the 54-kDa phosphoprotein at the 2nd and 12th passages. In the absence of any transforming agent, the amount of endogenous 54-kDa phosphoprotein in early pre-crisis mouse cells varied in a strain-specific way. Transformation frequency varied coordinately with endogenous 54-kDa expression. Mouse strains whose cells produced a high level of endogenous 54-kDa phosphoprotein on passage did not further increase its expression after simian virus 40 transformation
Anti-müllerian hormone is not associated with cardiometabolic risk factors in adolescent females
<p>Objectives: Epidemiological evidence for associations of Anti-Müllerian hormone (AMH) with cardiometabolic risk factors is lacking. Existing evidence comes from small studies in select adult populations, and findings are conflicting. We aimed to assess whether AMH is associated with cardiometabolic risk factors in a general population of adolescent females.</p>
<p>Methods: AMH, fasting insulin, glucose, HDLc, LDLc, triglycerides and C-reactive protein (CRP) were measured at a mean age 15.5 years in 1,308 female participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Multivariable linear regression was used to examine associations of AMH with these cardiometabolic outcomes.</p>
<p>Results: AMH values ranged from 0.16–35.84 ng/ml and median AMH was 3.57 ng/ml (IQR: 2.41, 5.49). For females classified as post-pubertal (n = 848) at the time of assessment median (IQR) AMH was 3.81 ng/ml (2.55, 5.82) compared with 3.25 ng/ml (2.23, 5.05) in those classed as early pubertal (n = 460, P≤0.001). After adjusting for birth weight, gestational age, pubertal stage, age, ethnicity, socioeconomic position, adiposity and use of hormonal contraceptives, there were no associations with any of the cardiometabolic outcomes. For example fasting insulin changed by 0% per doubling of AMH (95%CI: −3%,+2%) p = 0.70, with identical results if HOMA-IR was used. Results were similar after additional adjustment for smoking, physical activity and age at menarche, after exclusion of 3% of females with the highest AMH values, after excluding those that had not started menarche and after excluding those using hormonal contraceptives.</p>
<p>Conclusion: Our results suggest that in healthy adolescent females, AMH is not associated with cardiometabolic risk factors.</p>
Titulaciones con alta frecuencia : Significado de las lecturas obtenidas con un oscilador de placa sintonizada y grilla sintonizada
Desde el año 1945 hasta la actualidad se ha evidenciado en la bibliografíaquímica un creciente interés por los métodos llamados "Titulaciones con radiofrecuencia". Se incluye bajo esta denominación el estudio a frecuencias elevadas desoluciones de electrolitos o líquidos orgánicos sin contacto directo con electrodos metálicos. Dos tipos de celdas se han utilizado: consisten en un recipiente aislante, a) rodeado por una espiral metálica y b) con láminas metálicas aplicadas exteriormente. Varios son los tipos de instrumentos utilizados: a) Los osciladores con uno o dos circuitos sintonizados en que la celda, utilizada como "carga", provoca variaciones de corriente de placa y grilla, que sonmedidas. b) El método llamado "de radiofrecuencia rectificada", que consiste en ungenerador de radiofrecuencia cuya salida pasa a través de la celda, midiéndosela intensidad de la corriente de radiofrecuencia que circula, previa rectificación. c) Instrumentos en que la variable medida es la variación de frecuencia deun oscilador por efecto dc la celda. d) Puentes del tipo "doble T" que pueden medir por separado las componentesde la admitancia de la celda, Y: la conductancia equivalente en paralelo Gp y lasusceptancia B. (') Se han desarrollado numerosas aplicaciones analíticas de estos métodos; porejemplo titulaciones ácido base y de precipitación, titulaciones en medios orgárnicos, resolución de sistemas orgánicos de dos y tres componentes, determinaciónde velocidades de reacción, detección de zonas cromatográficas, etc. (') La admitancia de la celda Y (inversa de la impedancia Z) es igual a: Y = l/Z = Gp + j Bsiendo Gp la parte real o conductiva de la admitancia y B la parte imaginariao capacitiva. j es el operador imaginario (j^(2) = -l) Con algún retraso se ha desarrollado la parte teórica que permita aclarar cuales la propiedad responsable de las lecturas obtenidas. Actualmente, para algunosinstrumentos están bien aclaradas y para otros faltan aún verificaciones cuantitativas. Mediante el estudio del circuito equivalente de la celda se determinaron lasecuaciones de Gp y B, explicando cuantitativamente la respuesta de los puentes "doble T" y de los instrumentos que miden frecuencia. El método de radiofrecuencia rectificada permite lecturas de intensidad proporcionales a la admitancia de la celda. En cuanto a los instrumentos que miden intensidad de corriente de placa teniendoun circuito sintonizado o dos circuitos en resonancia, se supone que las variaciones de corriente de placa son aproximadamente proporcionales a Gp de la celdaconectada, aunque no conocemos ninguna comprobación cuantitativa. Parte experimental: Se desarrolló con el objeto de verificar si, en un oscilador de grilla sintonizada y placa sintonizada trabajando en resonancia, las variaciones de intensidad de placa que se producen al conectar una celda con electrodos exteriores conteniendo soluciones acuosas de electrolitos, dependen únicamentede la conductancia equivalente en paralelo Gp de la celda, siendo esa dependenciaaproximadamente lineal. Se utilizó un oscilador de grilla sintonizada placa sintonizada trabajando al megaciclo/segundo alimentado por una fuente de tensión anódica regulada. Se emplearon dos celdas tipo condensador, una de las cuales era de caras planas y paralelas, lo que permitió el cálculo geométrico de sus constantes. Estasceldas se conectaron exteriormsnte al oscilador. Para calibrar las lecturas de intensidad de placa en función de la conductancia de la celda se emplearon celdas de conductividad de electrodos sumergidos deplatino platinado, cuya conductancia se midió a baja frecuencia por los métodos ordinarios. El valor de la conductancia en paralelo de la celda es: Gp = (k.A.w^2.Cl^2)/(k^2.A^2 + w^2.((Cl + p.A)^2))donde k= conductividad del líquido contenido en la celda, A= constante geométrica de la celda,w= 2π frecuencia, Cl= Capacidad a través de las paredes de la celda,p= 0,08842 x 10^(-2) x constante dieléctrica del contenido. Para calcular Gp necesitamos conocer Cl y A. Para ello se determinaron losvalores Ca= Capacidad de la celda llena de aire, Cb= Capacidad de la celda llena de agua de conductividad, Cc= Capacidad de la celda llena de mercurio,deduciéndose que A= (Cb-Ca)x(Cc-Ca)x(Cc-Cb)x(78,8-1)/[78,8x(Cc-Cb)-(Cc-Ca)]^2x0,08842 Cl= (Cc-Ca)x(Cc-Cb)x(78,8-1)/78,8x(Cc-Cb)-(Cc-Ca) Con estos datos se calcula Gp = f(k) y se compara con los valores de Gp medidos colocando en las celdas soluciones de conductividad conocida, leyendo laintensidad de corriente de placa y hallando su equivalencia en unidades de conductancia. Por los métodos habituales se calculó que los errores más probables entrelos valores medidos y los calculados, eran en general para las celdas usadas, inferiores a 2.10^(-6) mho. Se realizaron con una de las celdas 283 determinaciones comprendidas en unrango de conductividades de 2.10^(-6) a 10^(-3) ohm^(-1) cm^(-1) obteniéndose 40 por ciento de discrepancias superiores a la más probable; con la otra celda se realizaron 237 determinaciones comprendidas entre conductividades de 2.10^(-6) y 4.10^(-3) ohm^(-1)cm^(-1), resultando 53 por ciento de discrepancias superiores a la más probable. Este resultado constituye la prueba de la corrección de la hipótesis enunciada como objeto de la parte experimental.Fil: Blanck, Emilce R.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
The SBRT database initiative of the German Society for Radiation Oncology (DEGRO): patterns of care and outcome analysis of stereotactic body radiotherapy (SBRT) for liver oligometastases in 474 patients with 623 metastases
Background: The intent of this pooled analysis as part of the German society for radiation oncology (DEGRO)stereotactic body radiotherapy (SBRT) initiative was to analyze the patterns of care of SBRT for liver oligometastases and to derive factors influencing treated metastases control and overall survival in a large patient cohort.
Methods: From 17 German and Swiss centers, data on all patients treated for liver oligometastases with SBRT since its introduction in 1997 has been collected and entered into a centralized database. In addition to patient and tumor characteristics, data on immobilization, image guidance and motion management as well as dose prescription and fractionation has been gathered. Besides dose response and survival statistics, time trends of the aforementioned variables have been investigated.
Results: In total, 474 patients with 623 liver oligometastases (median 1 lesion/patient; range 1–4) have been collected from 1997 until 2015. Predominant histologies were colorectal cancer (n= 213 pts.; 300 lesions) and breast cancer (n= 57; 81 lesions). All centers employed an SBRT specific setup. Initially, stereotactic coordinates and CT simulation were used for treatment set-up (55%), but eventually were replaced by CBCT guidance (28%) or more
recently robotic tracking (17%). High variance in fraction (fx) number (median 1 fx; range 1–13) and dose per fraction (median: 18.5 Gy; range 3–37.5 Gy) was observed, although median BED remained consistently high after an initial learning curve. Median follow-up time was 15 months; median overall survival after SBRT was 24 months. One- and 2-year treated metastases control rate of treated lesions was 77% and 64%; if maximum isocenter biological equivalent dose (BED) was greater than 150 Gy EQD2Gy, it increased to 83% and 70%, respectively. Besides radiation dose colorectal and breast histology and motion management methods were associated with improved treated metastases control
Bayesian Inference Semantics: A Modelling System and A Test Suite
We present BIS, a Bayesian Inference Seman- tics, for probabilistic reasoning in natural lan- guage. The current system is based on the framework of Bernardy et al. (2018), but de- parts from it in important respects. BIS makes use of Bayesian learning for inferring a hy- pothesis from premises. This involves estimat- ing the probability of the hypothesis, given the data supplied by the premises of an argument. It uses a syntactic parser to generate typed syn- tactic structures that serve as input to a model generation system. Sentences are interpreted compositionally to probabilistic programs, and the corresponding truth values are estimated using sampling methods. BIS successfully deals with various probabilistic semantic phe- nomena, including frequency adverbs, gener- alised quantifiers, generics, and vague predi- cates. It performs well on a number of interest- ing probabilistic reasoning tasks. It also sus- tains most classically valid inferences (instan- tiation, de Morgan’s laws, etc.). To test BIS we have built an experimental test suite with examples of a range of probabilistic and clas- sical inference patterns
Heterostructures for High Performance Devices
Contains an introduction, reports on thirteen research projects and a list of publications.Charles S. Draper Laboratory Contract DL-H-418483DARPA/NCIPT Subcontract 542383Joint Services Electronics Program Contract DAAL03-89-C-0001IBM Corporation FellowshipNational Science Foundation FellowshipVitesse SemiconductorAT&T Bell LaboratoriesHertz Foundation FellowshipNational Science FoundationTRWBelgian American Education Foundation (BAEF) FellowshipNational Science Foundation Grant ECS 90-08485Harvard University. Division of Applied PhysicsAT&T Bell Laboratories FellowshipNational Science Foundation Grant ECS 90-0774
The contrasting role of technology as both supportive and hindering in the everyday lives of people with mild cognitive deficits: a focus group study
Background: It is well known that people with mild cognitive deficits face challenges when performing complex everyday activities, and that the use of technology has become increasingly interwoven with everyday activities. However, less is known of how technology might be involved, either as a support or hindrance, in different areas of everyday life and of the environments where challenges appear. The aim of this study was to investigate the areas of concern where persons with cognitive deficits meet challenges in everyday life, in what environments these challenges appear and how technology might be involved as part of the challenge and/or the solution to the challenge.
Methods: Data were gathered through four focus group interviews with participants that live with cognitive deficits or cohabit with a person with cognitive deficits, plus health professionals and researchers in the field. Data were transcribed, coded and categorized, and finally synthesized to trace out the involvement of technology.
Results: Five areas of concern in everyday life were identified as offering challenges to persons with cognitive deficits: A) Managing personal finances, B) Getting around, C) Meeting family and friends, D) Engaging with culture and media and, E) Doing everyday chores. Findings showed that the involvement of technology in everyday activities was often contrastive. It could be hindering and evoke stress, or it could bring about feelings of control; that is, being a part of the solution. The involvement of technology was especially obvious in challenges linked to Managing personal finances, which is a crucial necessity in many everyday activities. In contrast, technology was least obviously involved in the area Socializing with family and friends.
Conclusions: The findings imply that technology used for orientation and managing finances, often used outside home, would benefit from being further developed in order to be more supportive; i.e. accessible and usable. To make a positive change for many people, the ideas of inclusive design fit well for this purpose and would contribute to an age-friendly society
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