1,299 research outputs found
General procedure to initialize the cyclic soil water balance by the Thornthwaite and Mather method
The original Thornthwaite and Mather method, proposed in 1955 to calculate a climatic monthly cyclic soil water balance, is frequently used as an iterative procedure due to its low input requirements and coherent estimates of water balance components. Using long term data sets to establish a characteristic water balance of a location, the initial soil water storage is generally assumed to be at field capacity at the end of the last month of the wet season, unless the climate is (semi-) arid when the soil water storage is lower than the soil water holding capacity. To close the water balance, several iterations might be necessary, which can be troublesome in many situations. For (semi-) arid climates with one dry season, Mendon a derived in 1958 an equation to quantify the soil water storage monthly at the end of the last month of the wet season, which avoids iteration procedures and closes the balance in one calculation. The cyclic daily water balance application is needed to obtain more accurate water balance output estimates. In this note, an equation to express the water storage for the case of the occurrence of more than one dry season per year is presented as a generalization of Mendon a's equation, also avoiding iteration procedures
Anaerobic Biodegradation, Activity and Inhibition (ABAI) Task Group Meeting 9th to 10th October 2006, in Prague
Language motivation in a reconfigured Europe: access, identity, autonomy
In this paper, I propose that we need to develop an appropriate set of conceptual tools for examining motivational issues pertaining to linguistic diversity, mobility and social integration in a rapidly changing and expanding Europe. I begin by drawing on research that has begun to reframe the concept of integrative motivation in the context of theories of self and identity. Expanding the notion of identity, I discuss the contribution of the Council of Europe's European Language Portfolio in promoting a view of motivation as the development of a plurilingual European identity and the enabling of access and mobility across a multilingual Europe. Next, I critically examine the assumption that the individual pursuit of a plurilingual identity is unproblematic, by highlighting the social context in which motivation and identity are constructed and embedded. To illuminate the role of this social context, I explore three inter-related theoretical frameworks: poststructuralist perspectives on language motivation as 'investment'; sociocultural theory; and theories of autonomy in language education. I conclude with the key message that, as with autonomy, language motivation today has an inescapably political dimension of which we need to take greater account in our research and pedagogical practice
A software tool for estimation of burden of infectious diseases in Europe using incidence-based disability adjusted life years
The burden of disease framework facilitates the assessment of the health impact of diseases through the use of summary measures of population health such as Disability- Adjusted Life Years (DALYs). However, calculating, interpreting and communicating the results of studies using this methodology poses a challenge. The aim of the Burden of Commu
Structure-Sensitive Mechanism of Nanographene Failure
The response of a nanographene sheet to external stresses is considered in
terms of a mechanochemical reaction. The quantum chemical realization of the
approach is based on a coordinate-of-reaction concept for the purpose of
introducing a mechanochemical internal coordinate (MIC) that specifies a
deformational mode. The related force of response is calculated as the energy
gradient along the MIC, while the atomic configuration is optimized over all of
the other coordinates under the MIC constant-pitch elongation. The approach is
applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy
in the microscopic behavior of both objects under elongation along a MIC has
been observed when the MIC is oriented either along or normally to the C-C
bonds chain. Both the anisotropy and high stiffness of the nanographene
originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl
Nanomechanical Properties and Phase Transitions in a Double-Walled (5,5)@(10,10) Carbon Nanotube: ab initio Calculations
The structure and elastic properties of (5,5) and (10,10) nanotubes, as well
as barriers for relative rotation of the walls and their relative sliding along
the axis in a double-walled (5,5)@(10,10) carbon nanotube, are calculated using
the density functional method. The results of these calculations are the basis
for estimating the following physical quantities: shear strengths and diffusion
coefficients for relative sliding along the axis and rotation of the walls, as
well as frequencies of relative rotational and translational oscillations of
the walls. The commensurability-incommensurability phase transition is
analyzed. The length of the incommensurability defect is estimated on the basis
of ab initio calculations. It is proposed that (5,5)@(10,10) double-walled
carbon nanotube be used as a plain bearing. The possibility of experimental
verification of the results is discussed.Comment: 14 page
Gender differences in developmental links between antisocial behavior, friends' antisocial behavior and peer rejection in childhood: Results in two cultures
This study addressed gender differences in the developmental links among antisocial behavior, friends' anti-social behavior, and peer rejection. High and increasing, moderate, and low antisocial developmental trajectories were identified among 289 Dutch children, ages 7 to 10, and 445 French-Canadian children, ages 9 to 12. Only boys followed the high trajectory. These boys had more deviant friends and were more often rejected than other children. A minority of girls followed the moderate antisocial behavior trajectory. These girls had fewer deviant friends than moderate antisocial boys, but moderate antisocial boys and girls were equally likely to be rejected. The influence of friends and poor peer relations plays a crucial but different role in the development of antisocial behavior among boys and girls. © 2005 by the Society for Research in Child Development, Inc. All rights reserved
Atomistic Simulations of Nanotube Fracture
The fracture of carbon nanotubes is studied by atomistic simulations. The
fracture behavior is found to be almost independent of the separation energy
and to depend primarily on the inflection point in the interatomic potential.
The rangle of fracture strians compares well with experimental results, but
predicted range of fracture stresses is marketly higher than observed. Various
plausible small-scale defects do not suffice to bring the failure stresses into
agreement with available experimental results. As in the experiments, the
fracture of carbon nanotubes is predicted to be brittle. The results show
moderate dependence of fracture strength on chirality.Comment: 12 pages, PDF, submitted to Phy. Rev.
Preoperative image-guided identification of response to neoadjuvant chemoradiotherapy in esophageal cancer (PRIDE):a multicenter observational study
BACKGROUND: Nearly one third of patients undergoing neoadjuvant chemoradiotherapy (nCRT) for locally advanced esophageal cancer have a pathologic complete response (pCR) of the primary tumor upon histopathological evaluation of the resection specimen. The primary aim of this study is to develop a model that predicts the probability of pCR to nCRT in esophageal cancer, based on diffusion-weighted magnetic resonance imaging (DW-MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and (18)F-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG PET-CT). Accurate response prediction could lead to a patient-tailored approach with omission of surgery in the future in case of predicted pCR or additional neoadjuvant treatment in case of non-pCR. METHODS: The PRIDE study is a prospective, single arm, observational multicenter study designed to develop a multimodal prediction model for histopathological response to nCRT for esophageal cancer. A total of 200 patients with locally advanced esophageal cancer - of which at least 130 patients with adenocarcinoma and at least 61 patients with squamous cell carcinoma - scheduled to receive nCRT followed by esophagectomy will be included. The primary modalities to be incorporated in the prediction model are quantitative parameters derived from MRI and (18)F-FDG PET-CT scans, which will be acquired at fixed intervals before, during and after nCRT. Secondary modalities include blood samples for analysis of the presence of circulating tumor DNA (ctDNA) at 3 time-points (before, during and after nCRT), and an endoscopy with (random) bite-on-bite biopsies of the primary tumor site and other suspected lesions in the esophagus as well as an endoscopic ultrasonography (EUS) with fine needle aspiration of suspected lymph nodes after finishing nCRT. The main study endpoint is the performance of the model for pCR prediction. Secondary endpoints include progression-free and overall survival. DISCUSSION: If the multimodal PRIDE concept provides high predictive performance for pCR, the results of this study will play an important role in accurate identification of esophageal cancer patients with a pCR to nCRT. These patients might benefit from a patient-tailored approach with omission of surgery in the future. Vice versa, patients with non-pCR might benefit from additional neoadjuvant treatment, or ineffective therapy could be stopped. TRIAL REGISTRATION: The article reports on a health care intervention on human participants and was prospectively registered on March 22, 2018 under ClinicalTrials.gov Identifier: NCT03474341
Combinatorial nuclear level density by a Monte Carlo method
We present a new combinatorial method for the calculation of the nuclear
level density. It is based on a Monte Carlo technique, in order to avoid a
direct counting procedure which is generally impracticable for high-A nuclei.
The Monte Carlo simulation, making use of the Metropolis sampling scheme,
allows a computationally fast estimate of the level density for many fermion
systems in large shell model spaces. We emphasize the advantages of this Monte
Carlo approach, particularly concerning the prediction of the spin and parity
distributions of the excited states, and compare our results with those derived
from a traditional combinatorial or a statistical method. Such a Monte Carlo
technique seems very promising to determine accurate level densities in a large
energy range for nuclear reaction calculations.Comment: 30 pages, LaTex, 7 figures (6 Postscript figures included). Fig. 6
upon request to the autho
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