3,086 research outputs found
A Survey on Metamorphic Testing
A test oracle determines whether a test execution reveals a fault, often by comparing the observed program output to the expected output. This is not always practical, for example when a program's input-output relation is complex and difficult to capture formally. Metamorphic testing provides an alternative, where correctness is not determined by checking an individual concrete output, but by applying a transformation to a test input and observing how the program output “morphs” into a different one as a result. Since the introduction of such metamorphic relations in 1998, many contributions on metamorphic testing have been made, and the technique has seen successful applications in a variety of domains, ranging from web services to computer graphics. This article provides a comprehensive survey on metamorphic testing: It summarises the research results and application areas, and analyses common practice in empirical studies of metamorphic testing as well as the main open challenges
Moving on up: Second-Line Agents as Initial Treatment for Newly-Diagnosed Patients with Chronic Phase CML
The treatment of chronic myelogenous leukemia (CML) was revolutionized by the development of imatinib mesylate, a small molecule inhibitor of several protein tyrosine kinases, including the ABL1 protein tyrosine kinase. The current second generation of FDA-approved ABL tyrosine kinase inhibitors, dasatinib and nilotinib, are more potent inhibitors of BCR-ABL1 kinase in vitro. Originally approved for the treatment of patients who were refractory to or intolerant of imatinib, dasatinib and nilotinib are now also FDA approved in the first-line setting. The choice of tyrosine kinase inhibitor (ie, standard or high dose imatinib, dasatinib, nilotinib) to use for initial therapy in chronic-phase CML (CML-CP) will not always be obvious. Therapy selection will depend on both clinical and molecular factors, which we will discuss in this review
Sensitivity analysis in optimized parametric curve fitting
Purpose – Curve fitting from unordered noisy point samples is needed for surface reconstruction in many applications -- In the literature, several approaches have been proposed to solve this problem -- However, previous works lack formal characterization of the curve fitting problem and assessment on the effect of several parameters (i.e. scalars that remain constant in the optimization problem), such as control points number (m), curve degree (b), knot vector composition (U), norm degree (k), and point sample size (r) on the optimized curve reconstruction measured by a penalty function (f) -- The paper aims to discuss these issues -- Design/methodology/approach - A numerical sensitivity analysis of the effect of m, b, k and r on f and a characterization of the fitting procedure from the mathematical viewpoint are performed -- Also, the spectral (frequency) analysis of the derivative of the angle of the fitted curve with respect to u as a means to detect spurious curls and peaks is explored -- Findings - It is more effective to find optimum values for m than k or b in order to obtain good results because the topological faithfulness of the resulting curve strongly depends on m -- Furthermore, when an exaggerate number of control points is used the resulting curve presents spurious curls and peaks -- The authors were able to detect the presence of such spurious features with spectral analysis -- Also, the authors found that the method for curve fitting is robust to significant decimation of the point sample -- Research limitations/implications - The authors have addressed important voids of previous works in this field -- The authors determined, among the curve fitting parameters m, b and k, which of them influenced the most the results and how -- Also, the authors performed a characterization of the curve fitting problem from the optimization perspective -- And finally, the authors devised a method to detect spurious features in the fitting curve -- Practical implications – This paper provides a methodology to select the important tuning parameters in a formal manner -- Originality/value - Up to the best of the knowledge, no previous work has been conducted in the formal mathematical evaluation of the sensitivity of the goodness of the curve fit with respect to different possible tuning parameters (curve degree, number of control points, norm degree, etc.
Variability in concentrations of potentially toxic elements in urban parks from six European cities
Use of a harmonised sampling regime has allowed comparison of concentrations of copper, chromium, nickel, lead and zinc in six urban parks located in different European cities differing markedly in their climate and industrial history. Wide concentrations ranges were found for copper, lead and zinc at most sites, but for chromium and nickel a wide range was only seen in the Italian park, where levels were also considerably greater than in other soils. As might be expected, the soils from older cities with a legacy of heavy manufacturing industry (Glasgow, Torino) were richest in potentially toxic elements (PTEs); soils from Ljubljana, Sevilla and Uppsala had intermediate metal contents, and soils from the most recently established park, in the least industrialised city (Aveiro), displayed lowest concentrations. When principal component analysis was applied to the data, associations were revealed between pH and organic carbon content; and between all five PTEs. When pH and organic carbon content were excluded from the PCA, a distinction became clear between copper, lead and zinc (the "urban" metals) on the one hand, and chromium and nickel on the other. Similar results were obtained for the surface (0-10 cm depth) and sub-surface (10-20 cm depth) samples. Comparisons with target or limit concentrations were limited by the existence of different legislation in different countries and the fact that few guidelines deal specifically with public-access urban soils intended for recreational use
Birth elicits a conserved neuroendocrine response with implications for perinatal osmoregulation and neuronal cell death
Long-standing clinical findings report a dramatic surge of vasopressin in umbilical cord blood of the human neonate, but the neural underpinnings and function(s) of this phenomenon remain obscure. We studied neural activation in perinatal mice and rats, and found that birth triggers activation of the suprachiasmatic, supraoptic, and paraventricular nuclei of the hypothalamus. This was seen whether mice were born vaginally or via Cesarean section (C-section), and when birth timing was experimentally manipulated. Neuronal phenotyping showed that the activated neurons were predominantly vasopressinergic, and vasopressin mRNA increased fivefold in the hypothalamus during the 2–3 days before birth. Copeptin, a surrogate marker of vasopressin, was elevated 30-to 50-fold in plasma of perinatal mice, with higher levels after a vaginal than a C-section birth. We also found an acute decrease in plasma osmolality after a vaginal, but not C-section birth, suggesting that the difference in vasopressin release between birth modes is functionally meaningful. When vasopressin was administered centrally to newborns, we found an ~ 50% reduction in neuronal cell death in specific brain areas. Collectively, our results identify a conserved neuroendocrine response to birth that is sensitive to birth mode, and influences peripheral physiology and neurodevelopment.Fil: Hoffiz, Yarely C.. Georgia State University; Estados UnidosFil: Castillo Ruiz, Alexandra. Georgia State University; Estados UnidosFil: Hall, Megan A. L.. Georgia State University; Estados UnidosFil: Hite, Taylor A.. Georgia State University; Estados UnidosFil: Gray, Jennifer M.. Georgia State University; Estados UnidosFil: Cisternas, Carla Daniela. Georgia State University; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Cortes, Laura R.. Georgia State University; Estados UnidosFil: Jacobs, Andrew J.. Georgia State University; Estados UnidosFil: Forger, Nancy G.. Georgia State University; Estados Unido
Association between PTPN1 polymorphisms and obesity-related phenotypes in European adolescents: influence of physical activity
Background: To study the associations of Protein Tyrosine Phosphatase-N1 (PTPN1) polymorphisms with obesity-related phenotypes in European adolescents, and the influence of physical activity on these relationships. Methods: Five polymorphisms of PTPN1 were genotyped in 1057 European adolescents (12–18 years old). We measured several phenotypes related to obesity, such as adiposity markers, and biochemical and clinical parameters. Physical activity was objectively measured by accelerometry. Results: The T, A, T, T and G alleles of the rs6067472, rs10485614, rs2143511, rs6020608 and rs968701 polymorphisms, respectively, were associated with lower levels of obesity-related phenotypes (i.e., body mass index, body fat percentage, hip circumference, fat mass index, systolic blood pressure and leptin) in European adolescents. In addition, the TATTG haplotype was associated with lower body fat percentage and fat mass index compared to the AACCA haplotype. Finally, when physical activity levels were considered, alleles of the rs6067472, rs2143511, rs6020608 and rs968701 polymorphisms were only associated with lower adiposity in active adolescents. Conclusions: PTPN1 polymorphisms were associated with adiposity in European adolescents. Specifically, alleles of these polymorphisms were associated with lower adiposity only in physically active adolescents. Therefore, meeting the recommendations of daily physical activity may reduce obesity risk by modulating the genetic predisposition to obesity. Impact:
- Using gene-phenotype and gene*environment analyses, we detected associations between polymorphisms of the Protein Tyrosine Phosphatase-N1 (PTPN1) gene and obesity-related phenotypes, suggesting a mechanism that can be modulated by physical activity.
- This study shows that genetic variability of PTPN1 is associated with adiposity, while physical activity seems to modulate the genetic predisposition.
- This brings insights about the mechanisms by which physical activity positively influences obesity
Estimation of the real population and its impact on the utilisation of healthcare services in Mediterranean resort regions: an ecological study
BACKGROUND: The demographic structure has a significant influence on the use of healthcare services, as does the size of the population denominators. Very few studies have been published on methods for estimating the real population such as tourist resorts. The lack of information about these problems means there is a corresponding lack of information about the behaviour of populational denominators (the floating population or tourist load) and the effect of this on the use of healthcare services. The objectives of the study were: a) To determine the Municipal Solid Waste (MSW) ratio, per person per day, among populations of known size; b) to estimate, by means of this ratio, the real population in an area where tourist numbers are very significant; and c) to determine the impact on the utilisation of hospital emergency healthcare services of the registered population, in comparison to the non-resident population, in two areas where tourist numbers are very significant. METHODS: An ecological study design was employed. We analysed the Healthcare Districts of the Costa del Sol and the island of Menorca. Both are Spanish territories in the Mediterranean region. RESULTS: In the two areas analysed, the correlation coefficient between the MSW ratio and admissions to hospital emergency departments exceeded 0.9, with p < 0.001. On the basis of MSW generation ratios, obtained for a control zone and also measured in neighbouring countries, we estimated the real population. For the summer months, when tourist activity is greatest and demand for emergency healthcare at hospitals is highest, this value was found to be double that of the registered population. CONCLUSION: The MSW indicator, which is both ecological and indirect, can be used to estimate the real population in areas where population levels vary significantly during the year. This parameter is of interest in planning and dimensioning the provision of healthcare services
Deliverable D2:Consolidation of needs of the european wasten management agencies and the regulator of the consortium: Work Package 1, Site-specific and palaeo environmental data. Modelling sequential biosphere systems under climate change for radioactive waste disposal. (BIOCLIM)
The nature of long-lived radioactive wastes is that
they present a radiological hazard over a period
of time that is extremely long compared with the
timescale over which the engineered protection
systems and institutional management of a disposal, or
long-term storage, facility can be guaranteed. Safety
assessments for potential deep repositories need
to be able to provide indicators of safety performance
over time periods of hundreds of thousands of years.
On such timescales, it is generally assumed that
radionuclides may be slowly released from the
containment system, migrating via geosphere pathways
until they reach the accessible environment. Hence,
there is a need to study the evolution of the
environment external to the disposal system and the
ways in which this might impact on its long-term
radiological safety performance, for example in terms
of influences on the migration and accumulation of
radionuclides
Deliverable D3: Global climatic features over the next million years and recommendation for specific situations to be considered. Work Package 2, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)
The BIOCLIM project aims at assessing the
possible long-term impacts of climate change
on the safety of waste repositories in deep
formations using climate simulations of the long-term
climate in various European areas. One of the
objectives of the project is to develop two strategies for
representing sequential climatic changes to the
geosphere-biosphere system for different sites over
Europe, addressing the time scale of one million years.
The results of this work will be interpreted in terms of
global or regional changes of climate and of vegetation.
The first strategy (hierarchical strategy) will use the full
hierarchy of existing climate models (a climate model is
a numerical simplified representation of the climate
system behaviour and evolution). Simple models (LLN
2-D NH and threshold models; see the description here
after) will simulate the overall long-term evolution of the
global climate. Their results will then be used as inputs
to more complex models (LMD climate models possibly
coupled with vegetation models, either SECHIBA or
ORCHIDE) and finally climate and vegetation cover will
be determined for specific sites at specific times. A
second strategy (integrated strategy) will consist in
building an integrated climate model, which represents
most of the physical mechanisms for studying long-term
climatic variations. The results will then be interpreted
on a regional scale. This deliverable is the first step of
the hierarchical strategy. The purpose of this deliverable
is to identify and justify some specific climatic
situations amongst different long-term simulations that
are of interest for assessing the safety of radioactive
waste repository sites and that will be further studied
with GCMs (General Circulation Model)
Deliverable D4/5: Global climatic characteristics, including vegetation and seasonal cycles over Europe, for snapshots over the next 200,000 years. Work Package 2, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)
The aim of the BIOCLIM project is to develop and
present techniques that can be used to develop
self-consistent patterns of possible future
climate changes over the next million years (climate
scenarios), and to demonstrate how these climate
scenarios can be used in assessments of the long-term
safety of nuclear waste repository sites.
Within the project, two strategies are implemented to
predict climate change. The first is the hierarchical
strategy, in which a hierarchy of climate models is used
to investigate the evolution of climate over the period of
interest. These models vary from very simple 2-D and
threshold models, which simulate interactions between
only a few aspects of the earth system, through general
circulation models (GCMs) and vegetation models,
which simulate in great detail the dynamics and physics
of the atmosphere, ocean, and biosphere, to regional
models, which focus in particular on the European
region and the specific areas of interest. The second
strategy is the integrated strategy, in which
intermediate complexity climate models are developed,
and used to consecutively simulate the development of
the earth system over many millennia. Although these
models are relatively simple compared to a GCM, they
are more advanced than 2D models, and do include
physical descriptions of the biosphere, cryosphere,
atmosphere and ocean.
This deliverable, D4/5, focuses on the hierarchical
strategy, and in particular the GCM and vegetation
model simulation of possible future climates.
Deliverable D3 documented the first step in this
strategy. The Louvain-la-Neuve 2-D climate model
(LLN-2D) was used to estimate (among other variables)
annual mean temperatures and ice volume in the
Northern Hemisphere over the next 1 million years.
It was driven by the calculated evolution of orbital
parameters, and plausible scenarios of CO2
concentration. From the results, 3 future time periods
within the next 200,000 years were identified as being
extreme, that is either significantly warmer or cooler
than the present. The next stage in the hierarchical
strategy was to use a GCM and biosphere model, to
simulate in more detail these extreme time periods
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