319 research outputs found
The effect of temperature and habitat quality on abundance of the Glanville fritillary on the Isle of Wight: implications for conservation management in a warming climate
Creating variation in microclimates through habitat management is often advocated as a way of ameliorating the impact of climate warming, although the effectiveness of microclimate management has rarely been studied. We compared temporal variation in habitat quality (the availability of suitably warm microclimates) and ambient air temperature on the abundance of a highly thermophilous species of butterfly, the Glanville fritillary Melitaea cinxia, at one site on the south coast of the Isle of Wight, UK, from 1997 to 2010. Ground temperatures beneath the various habitat successional stages were measured and compared, and the relationship between butterfly abundance and hostplant and weather variables was examined. Temporal variation in habitat quality was almost twice as strong as a predictor of butterfly abundance as ambient air temperature. We found no relationship between abundance and rainfall. Comparisons of ground temperatures beneath habitats showed that earlier successional stages were considerably warmer than later successional stages, and the distribution of Glanville fritillary larval âwebsâ within plots was restricted to these warmer habitats. Hostplants selected for oviposition by gravid females were also considerably warmer than ambient temperature. The importance of habitat quality reinforces the notion that thermophilous insects would benefit from site management practices that create thermally diverse environments. Heterogeneous habitats provide refugia for species intolerant of climate change, as well as opportunities for range expansion
Gens sans maßtres: les communes des Antilles et la production du commerce sous le régime colonial
Questo articolo presenta la storia del periodo coloniale nei Caraibi adottando il punto di vista dei masterless people («persone senza padrone»). Sebbene il testo rappresenti unâindagine preliminare piuttosto che unâanalisi conclusiva, mette in evidenza alcuni dei potenziali punti di forza del paradigma dei cosiddetti âattori informaliâ, oggetto di questo numero. Allo stesso tempo, propone uno studio sintetico della transizione al capitalismo nel contesto caraibico. Analizzando questa evoluzione con una prospettiva che si concentri sul passato piuttosto che sul presente che di esso Ăš ereditĂ , tale transizione apparirĂ sotto una nuova luce: primo, perchĂ© questo approccio ci permette di prendere in considerazione le «straordinarie opportunitĂ perdute» (citando le parole di AimĂ© CĂ©saire) come il risultato dello sviluppo di capitalismo e colonialismo; secondo, perchĂ© lâarticolo si basa su studi dedicati alle enclosures, in altri spazi e tempi; terzo, perchĂ© lo studio considera lâarruolamento di persone senza padrone nel âprogetto colonialeâ e le implicazioni che questo ebbe per la loro libertĂ . Infine, analizzando quella che ho definito la production of exchange, questo articolo intende deviare il dibattito sulla transizione dallâattuale analisi dicotomica produzione/scambio: infatti, ritengo che lo scambio fosse parte di un processo di produzione intrinsecamente violento e sfruttatore, che formĂČ e fu plasmato dallâemergente classe operaia.Cet article tente de prĂ©senter lâhistoire des Antilles coloniales du point de vue des gens sans maĂźtres. La narration qui suit est provisoire mais a lâavantage de montrer les mĂ©rites dâune telle dĂ©marche pour lâĂ©tude que les âacteurs informelsâ ont jouĂ© dans lâhistoire plus gĂ©nĂ©ralement. En mĂȘme temps, il prĂ©sente un compte rendu de la transition au capitalisme dans le contexte antillais. Ătudier le capitalisme par rapport aux circonstances qui ont prĂ©cĂ©dĂ© son avĂšnement plutĂŽt que du point de vue de ses consĂ©quences permet dâanalyser cette transition avec un Ćil neuf. Tout dâabord, cela permet de considĂ©rer les «extraordinaires possibilitĂ©s manquĂ©es», dâaprĂšs CĂ©saire, en raison du dĂ©veloppement du capitalisme et du colonialisme. DeuxiĂšmement, cet article Ă©tablit un lien avec dâautres Ă©tudes qui Ă©tudient dâautres enclosures qui pourraient profiter dâune perspective historique sur ces dĂ©veloppements. TroisiĂšmement, en traitant la conscription des gens sans maĂźtres comme intimement liĂ©e au projet colonialiste, ce travail soulĂšve des questions quant Ă la mesure, Ă©videmment variable, de la libertĂ© dont ils jouirent. Finalement, en considĂ©rant que le commerce est en effet un rapport de production, cet article souligne que le commerce fait partie de la production matĂ©rielle et de la formation de la classe ouvriĂšre, et fut, par consĂ©quent, un processus violent et qui relevait fondamentalement de lâexploitation.This article presents the history of the colonial Caribbean from the perspective of masterless people. Though the narrative presents a preliminary account rather than a conclusive analysis, it shows some of the potential strengths of the so-called âinformal actorsâ paradigm on display in this issue. At the same time, it presents a summary of the transition to capitalism in the Caribbean context. By approaching this transition from the perspective of the past that preceded it rather than the present that is its legacy, this transition emerges in a new light. First of all, this approach allows us to consider the «extraordinary opportunities lost», in the words of AimĂ© CĂ©saire, as a result of the development of capitalism and colonialism. Secondly, it builds on studies of âenclosuresâ in other places and times. Thirdly, it considers the conscription of masterless people to the colonial project and the implications for their liberty. Finally, in analyzing what I call âthe production of exchangeâ, this article intends to redirect the transition debate away from an either-or analysis of production and exchange. Instead, I argue that exchange was part of an inherently violent and exploitative material production process that shaped and was shaped by the emerging working class
The rise and demise of the Glanville fritillary on the Isle of Wight
The Glanville fritillary is one of Britainâs rarest breeding butterflies, and is predominantly restricted to the south coast of the Isle of Wight. Populations have been monitored annually at a high proportion of known sites by counting the number of larval âwebsâ during spring since 1996. In this paper, we present population time series for eight core sites. Populations have been observed to fluctuate considerably over the last 18 years, with a high degree of synchrony between sites. Recently, numbers of larval webs have shown a severe decline, with simultaneous extinctions occurring across many former strongholds. We combine our web count data with counts of adult butterflies from five sites of the UK Butterfly Monitoring Scheme. Together, these data suggest that the Glanville fritillary is threatened by extinction on the Isle of Wight, and that the total area used for breeding is likely no more than a few km2. The results flag up the need for a national census of remaining populations and further research to understand causes of decline, so that a conservation recovery plan can be developed
Welfare Reform and Unitended Consequences: Its Impact on a Local Child Protection Program
On August 22, 1996, President Clinton signed into law the Personal Responsibility and Work Opportunity Reconciliation Act. The Act represents a fundamental shift in the relationship between the federal government, the fifty states, and persons living in poverty. A shift of this magnitude cannot be analyzed properly without considering the significant impact of unintended consequences that may result from the new policy. Often, unintended consequences occur when two different policies, in this case, public welfare and child protective services, collide. One such possible unintended consequence of this policy shift may be to reduce the effectiveness of a successful child protection program in Walton County, Georgia. The kinship care program in Walton County has considerably reduced the number of children in foster care, altered foster roles, and resulted in savings of hundreds of thousands of dollars. However, without careful planning, the current welfare reform effort will limit the ability of extended family members to offer care for abused and neglected children via the kinship care program. This paper explores the complexity of such a major shift in federal welfare policy by analyzing its impact on a successful county-based child protection program
Butterfly abundance is determined by food availability and is mediated by species traits
1. Understanding the drivers of population abundance across species and sites is crucial for effective conservation management. At present, we lack a framework for predicting which sites are likely to support abundant butterfly communities.
2. We address this problem by exploring the determinants of abundance among 1111 populations of butterflies in the UK, spanning 27 species on 54 sites. Our general hypothesis is that the availability of food resources is a strong predictor of population abundance both within and between species, but that the relationship varies systematically with speciesâ traits.
3. We found strong positive correlations between butterfly abundance and the availability of food resources. Our indices of host plant and nectar are both significant predictors of butterfly population density, but the relationship is strongest for host plants, which explain up to 36% of the inter-site variance in abundance for some species.
4. Among species, the host plantâabundance relationship is mediated by butterfly species traits. It is strongest among those species with narrow diet breadths, low mobility and habitat specialists. Abundance for species with generalist diet and habitat associations is uncorrelated with our host plant index.
5. The host plantâabundance relationship is more pronounced on sites with predominantly north-facing slopes, suggesting a role for microclimate in mediating resource availability.
6. Synthesis and applications. We have shown that simple measures can be used to help understand patterns in abundance at large spatial scales. For some butterfly species, population carrying capacity on occupied sites is predictable from information about the vegetation composition. These results suggest that targeted management to increase host plant availability will translate into higher carrying capacity. Among UK butterflies, the species that would benefit most from such intervention have recently experienced steep declines in both abundance and distribution. The host plantâabundance relationship we have identified is likely to be transferrable to other systems characterized by strong interspecific interactions across trophic levels. This raises the possibility that the quality of habitat patches for specialist species is estimable from rapid assessment of the host plant resource
Performance of two handheld NIR spectrometers to quantify crude protein of composite animal forage and feedstuff
Two handheld near infrared (NIR) spectrometers were used to quantify crude protein (CP) content of mixed forage and feedstuff composed of Sweet Bran, distillerâs grains, corn silage, and corn stalk. First was a transportable spectrometer, which measured in the visible and NIR ranges (320â2500 nm) with a spectral interval of 1 nm (H1). Second was a smartphone spectrometer, which measured from 900â1700 nm with a spectral interval of 4 nm (H2). Spectral data of 147 forage and feed samples were collected by both handheld instruments and split into calibration (n= 120) and validation (n= 27) sets. For H1, only absorbances in the NIR region (780â2500 nm) were used in the multivariate analyses, while for H2, absorbances in the second and third overtone regions (940â1660 nm) were used. Principal component analysis (PCA) and partial least squares (PLS) regression models were developed using mean-centered data that had been preprocessed using standard normal variate (SNV) or Savitzky-Golay first derivative (SG1) or second derivative (SG2) algorithm. PCA models showed two major groupsâone with Sweet Bran and distillers grains, and the other with corn silage and corn stalk. Using H1 spectra, the PLS regression model that best predicted CP followed SG1 preprocessing. This model had low root mean square error of prediction (RMSEP= 2.22%) and high ratio of prediction to deviation (RPD= 5.24). With H2 spectra, the model best predicting CP was based on SG2 preprocessing, returning RMSEP= 2.05% and RPD= 5.74. These values were not practically different than those of H1, indicating similar performance of the two devices despite having absorbance measurements only in the second and third overtone regions with H2. The result of this study showed that both handheld NIR instruments can accurately measure forage and feed CP during screening, quality, and process control applications
Knowledge of HIV/AIDS among older adults (50 years and above) in a peri-urban setting: A descriptive cross-sectional study
Background: In the absence of vaccine or cure, public knowledge about Human Immune Virus (HIV) is a central tool for curbing HIV epidemic. This study sought to assess the knowledge of HIV among older adults (50 years and above) at the Methodist Faith Healing hospital, Ankaase, Ghana. Methods: Using a descriptive study design, older adults (50 years and above) who visited the Ankaase Methodist Faith Healing hospital were randomly sampled for the study. A structured questionnaire was administered to collect data which was analyzed quantitatively using Statistical Package for Social Sciences (SPSS version 16.0). Results: A total of 100 respondents who were aged 50 to 68 (54 ± 2.3) were recruited. Most of the respondents had average knowledge of the mode of HIV transmission (62%) as well as HIV prevention (58%) and signs and symptoms of HIV (60%). HIV status was significantly associated with HIV knowledge among older adults as HIV positive respondents were 2.25 times more knowledgeable in terms of signs and symptoms, mode of transmission and prevention of HIV [AOR (95% CI) 2.25(1.02-8.68)]. Conclusion: Most older adults (50 years and above) have average knowledge of the mode of transmission, prevention as well as signs and symptoms of HIV. The National Commission for Civic Education should collaborate with various key stakeholders to educate older adults on issues related to HIV/AIDS
HarvardX and MITx: Two Years of Open Online Courses Fall 2012-Summer 2014
What happens when well-known universities offer online courses, assessments, and certificates of completion for free? Early descriptions of Massive Open Online Courses (MOOCs) have emphasized large enrollments, low certification rates, and highly educated registrants. We use data from two years and 68 open online courses offered by Harvard University (via HarvardX) and MIT (via MITx) to broaden the scope of answers to this question. We describe trends over this two-year span, depict participant intent using comprehensive survey instruments, and chart course participation pathways using network analysis. We find that overall participation in our MOOCs remains substantial and that the average growth has been steady. We explore how diverse audiences â including explorers, teachers-as-learners, and residential students â provide opportunities to advance the principles on which HarvardX and MITx were founded: access, research, and residential education
Preliminary Multiphysics Analyses of HFIR LEU Fuel Conversion using COMSOL
The research documented herein was performed by several individuals across multiple organizations. We have previously acknowledged our funding for the project, but another common thread among the authors of this document, and hence the research performed, is the analysis tool COMSOL. The research has been divided into categories to allow the COMSOL analysis to be performed independently to the extent possible. As will be seen herein, the research has progressed to the point where it is expected that next year (2011) a large fraction of the research will require collaboration of our efforts as we progress almost exclusively into three-dimensional (3D) analysis. To the extent possible, we have tried to segregate the development effort into two-dimensional (2D) analysis in order to arrive at techniques and methodology that can be extended to 3D models in a timely manner. The Research Reactors Division (RRD) of ORNL has contracted with the University of Tennessee, Knoxville (UTK) Mechanical, Aerospace and Biomedical Engineering Department (MABE) to perform a significant fraction of this research. This group has been chosen due to their expertise and long-term commitment in using COMSOL and also because the participating students are able to work onsite on a part-time basis due to the close proximity of UTK with the ORNL campus. The UTK research has been governed by a statement of work (SOW) which clearly defines the specific tasks reported herein on the perspective areas of research. Ph.D. student Isaac T. Bodey has focused on heat transfer, fluid flow, modeling, and meshing issues and has been aided by his major professor Dr. Rao V. Arimilli and is the primary contributor to Section 2 of this report. Ph.D student Franklin G. Curtis has been focusing exclusively on fluid-structure interaction (FSI) due to the mechanical forces acting on the plate caused by the flow and has also been aided by his major professor Dr. Kivanc Ekici and is the primary contributor to Section 4 of this report. The HFIR LEU conversion project has also obtained the services of Dr. Prashant K. Jain of the Reactor & Nuclear Systems Division (RNSD) of ORNL. Prashant has quickly adapted to the COMSOL tools and has been focusing on thermal-structure interaction (TSI) issues and development of alternative 3D model approaches that could yield faster-running solutions. Prashant is the primary contributor to Section 5 of the report. And finally, while incorporating findings from all members of the COMSOL team (i.e., the team) and contributing as the senior COMSOL leader and advocate, Dr. James D. Freels has focused on the 3D model development, cluster deployment, and has contributed primarily to Section 3 and overall integration of this report. The team has migrated to the current release of COMSOL at version 4.1 for all the work described in this report, except where stated otherwise. Just as in the performance of the research, each of the respective sections has been originally authored by the respective authors. Therefore, the reader will observe a contrast in writing style throughout this document
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