1,058 research outputs found
Recommended from our members
Testing for a unit root in a process exhibiting a structural break in the presence of GARCH errors
This paper considers the effect of GARCH errors on the tests proposed byPerron (1997) for a unit root in the presence of a structural break. We assessthe impact of degeneracy and integratedness of the conditional varianceindividually and find that, apart from in the limit, the testing procedure isinsensitive to the degree of degeneracy but does exhibit an increasingover-sizing as the process becomes more integrated. When we consider the GARCHspecifications that we are likely to encounter in empirical research, we findthat the Perron tests are reasonably robust to the presence of GARCH and donot suffer from severe over-or under-rejection of a correct null hypothesis
Host defence peptides: antimicrobial and immunomodulatory activity and potential applications for tackling antibiotic-resistant infections
The rapidly increasing incidence of multidrug-resistant infections and the alarmingly low rate of discovery of conventional antibiotics create an urgent need for alternative strategies to treat bacterial infections. Host defence peptides are short cationic molecules produced by the immune systems of most multicellular organisms; they are a class of compounds being actively researched. In this review, we provide an overview of the antimicrobial and immunomodulatory activities of natural host defence peptides, and discuss strategies for creating artificial derivatives with improved biological and pharmacological properties, issues of microbial resistance, and challenges associated with their adaptation for clinical use
Recommended from our members
Testing for non-stationarity and cointegration allowing for the possibility of a structural break: an application to EuroSterling interest rates
In this paper we examine the order of integration of EuroSterling interest rates by employing techniques that can allow for a structural break under the null and/or alternative hypothesis of the unit-root tests. In light of these results, we investigate the cointegrating relationship implied by the single, linear expectations hypothesis of the term structure of interest rates employing two techniques, one of which allows for the possibility of a break in the mean of the cointegrating relationship. The aim of the paper is to investigate whether or not the interest rate series can be viewed as I(1) processes and furthermore, to consider whether there has been a structural break in the series. We also determine whether, if we allow for a break in the cointegration analysis, the results are consistent with those obtained when a break is not allowed for. The main results reported in this paper support the conjecture that the âshortâ Euro-currency rates are characterised as I(1) series that exhibit a structural break on or near Black Wednesday, 16 September 1992, whereas the âlongâ rates are I(1) series that do not support the presence of a structural break. The evidence from the cointegration analysis suggests that tests of the expectations hypothesis based on data sets that include the ERM crisis period, or a period that includes a structural break, might be problematic if the structural break is not explicitly taken into account in the testing framework
Researching âbogusâ asylum seekers, âillegalâ migrants and âcrimmigrantsâ
Both immigration and criminal laws are, at their core, systems of inclusion and exclusion. They are designed to determine whether and how to include individuals as members of society or exclude them from it, thereby, creating insiders and outsiders (Stumpf 2006). Both are designed to create distinct categories of people â innocent versus guilty, admitted versus excluded or, as majority would say, âlegalâ versus âillegalâ (Stumpf 2006). Viewed in that light, perhaps it is not surprising that these two areas of law have become inextrica- bly connected in the official discourses. When politicians and policy makers (and also law enforcement authorities and tabloid press) seek to raise the barriers for non-citizens to attain membership in society, it is unremarkable that they turn their attention to an area of the law that similarly func- tions to exclude the âotherâ â transforming immigrants into âcrimmigrantsâ.1 As a criminological researcher one then has to rise up to the challenges of disentangling these so-called officially constructed (pseudo) realities, and breaking free from a continued dominance of authoritative discourses, and developing an alternative understanding of âcrimmigrationâ by connecting the processes of criminal is ation and âother ingâ with poverty, xe no-racism and other forms of social exclusion (see Institute of Race Relations 1987; Richmond 1994; Fekete 2001; Bowling and Phillips 2002; Sivanandan 2002; Weber and Bowling 2004)
A review of clinical decision-making: Models and current research
Aims and objectives: The aim of this paper was to review the current literature with respect to clinical decision-making models and the educational application of models to clinical practice. This was achieved by exploring the function and related research of the three available models of clinical decision making: information processing model, the intuitive-humanist model and the clinical decision making model.
Background: Clinical decision-making is a unique process that involves the interplay between knowledge of pre-existing pathological conditions, explicit patient information, nursing care and experiential learning. Historically, two models of clinical decision making are recognised from the literature; the information processing model and the intuitive-humanist model. The usefulness and application of both models has been examined in relation the provision of nursing care and care related outcomes. More recently a third model of clinical decision making has been proposed. This new multidimensional model contains elements of the information processing model but also examines patient specific elements that are necessary for cue and pattern recognition.
Design: Literature review
Methods: Evaluation of the literature generated from MEDLINE, CINAHL, OVID, PUBMED and EBESCO systems and the Internet from 1980 â November 2005
Population Selection and Sequencing of Caenorhabditis elegans Wild Isolates Identifies a Region on Chromosome III Affecting Starvation Resistance
To understand the genetic basis of complex traits, it is important to be able to efficiently
phenotype many genetically distinct individuals. In the nematode Caenorhabditis elegans, individuals have
been isolated from diverse populations around the globe and whole-genome sequenced. As a result,
hundreds of wild strains with known genome sequences can be used for genome-wide association studies
(GWAS). However, phenotypic analysis of these strains can be laborious, particularly for quantitative traits
requiring multiple measurements per strain. Starvation resistance is likely a fitness-proximal trait for nematodes, and it is related to metabolic disease risk in humans. However, natural variation in C. elegans
starvation resistance has not been systematically characterized, and precise measurement of the trait is
time-intensive. Here, we developed a population-selection-and-sequencing-based approach to phenotype
starvation resistance in a pool of 96 wild strains. We used restriction site-associated DNA sequencing
(RAD-seq) to infer the frequency of each strain among survivors in a mixed culture over time during
starvation. We used manual starvation survival assays to validate the trait data, confirming that strains that
increased in frequency over time are starvation-resistant relative to strains that decreased in frequency.
Further, we found that variation in starvation resistance is significantly associated with variation at a region
on chromosome III. Using a near-isogenic line (NIL), we showed the importance of this genomic interval for
starvation resistance. This study demonstrates the feasibility of using population selection and sequencing
in an animal model for phenotypic analysis of quantitative traits, documents natural variation of starvation
resistance in C. elegans, and identifies a genomic region that contributes to such variation
Modelling chemotherapy resistance in palliation and failed cure
The goal of palliative cancer chemotherapy treatment is to prolong survival and improve quality of life when tumour eradication is not feasible. Chemotherapy protocol design is considered in this context using a simple, robust, model of advanced tumour growth with Gompertzian dynamics, taking into account the effects of drug resistance. It is predicted that reduced chemotherapy protocols can readily lead to improved survival times due to the effects of competition between resistant and sensitive tumour cells. Very early palliation is also predicted to quickly yield near total tumour resistance and thus decrease survival duration. Finally, our simulations indicate that failed curative attempts using dose densification, a common protocol escalation strategy, can reduce survival times
Specification of an extensible and portable file format for electronic structure and crystallographic data
In order to allow different software applications, in constant evolution, to
interact and exchange data, flexible file formats are needed. A file format
specification for different types of content has been elaborated to allow
communication of data for the software developed within the European Network of
Excellence "NANOQUANTA", focusing on first-principles calculations of materials
and nanosystems. It might be used by other software as well, and is described
here in detail. The format relies on the NetCDF binary input/output library,
already used in many different scientific communities, that provides
flexibility as well as portability accross languages and platforms. Thanks to
NetCDF, the content can be accessed by keywords, ensuring the file format is
extensible and backward compatible
Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients
Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented.EEA BarilocheFil: Haider, Sylvia. German Centre for Integrative Biodiversity Research; AlemaniaFil: Haider, Sylvia. Martin Luther University. Institute of Biology. Geobotany and Botanical Garden; AlemaniaFil: Lembrechts, Jonas Johan. University of Antwerp. Centre of Excellence Plants and Ecosystems (PLECO); BĂ©lgicaFil: McDougall, Keith. Department of Planning, Industry and Environment; AustraliaFil: Pauchard, AnĂbal. Universidad de ConcepciĂłn. Facultad de Ciencias Forestales. Laboratorio de Invasiones BiolĂłgicas; ChileFil: Pauchard, AnĂbal. Institute of Ecology and Biodiversity (IEB); ChileFil: Alexander, Jake M. Institute of Integrative Biology; SuizaFil: Barros, Agustina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico. Instituto Argentino de NivologĂa y GlaciologĂa y Ciencias Ambientales (IANIGLA); ArgentinaFil: Cavieres, Lohengrin A. Universidad de ConcepciĂłn. Facultad de Ciencias Naturales y OceanogrĂĄficas. Departamento de BotĂĄnica; ChileFil: Cavieres, Lohengrin A. Institute of Ecology and Biodiversity (IEB); ChileFil: Rashid, Irfan. University of Kashmir. Department of Botany; IndiaFil: Rew, Lisa J. Montana State University. Department of Land Resource and Environmental Sciences; Estados UnidosFil: Aleksanyan, Alla. Institute of Botany aft. A.L. Takhtajyan NAS RA. Department of Geobotany and Plant Ecophysiology; ArmeniaFil: Aleksanyan, Alla. Armenian National Agrarian University. Chair of Biology and Biotechnologies; ArmeniaFil: Dimarco, Romina Daniela. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. Grupo de EcologĂa de Poblaciones de Insectos; ArgentinaFil: Dimarco, Romina Daniela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. Grupo de EcologĂa de Poblaciones de Insectos; ArgentinaFil: Dimarco, Romina Daniela. University of Houston. Department of Biology and Biochemistry; Estados UnidosFil: Seipel, Tim. Montana State University. Department of Land Resource and Environmental Sciences; Estados Unido
Compassion Stress and the Qualitative Researcher
Human subjects are carefully protected in the research process. However, the same consideration is not currently being given to the qualitative researcher, even those investigating topics that are likely to elicit powerful emotions. The role of researcherâs emotional responses and the self-care strategies that, in some circumstances, are appropriate for the researcher and other research support personnel have not received the attention they deserve in qualitative research literature. Based on experience in conducting research on the topic of self-directed learning and breast cancer, and on the limited literature available, the author makes the case for the use of strategies such as counseling, peer debriefing, and journal writing as means of dealing with the potential for âcompassion stressâ as experienced by the researcher and other research support personnel. She also suggests that the preparation of social science researchers should include information on appropriate self-care strategies.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
- âŠ