4,457 research outputs found
High impact activities in parks: best management practice and future research
Off-road driving, horseriding, rock climbing and similar activities can be lucrative for tour operators and important for local recreational groups, but contentious for management of national parks and protected areas, both because of safety and liability and because of potentially high environmental impacts. These include spreading weeds and pathogens, starting fires and crushing bird nests on beaches, amongst many others. In Australia as elsewhere, off-road vehicles and horses are allowed only in some places in some parks, and often only under permit. We have very little reliable scientific information to-date on just how serious these impacts may be, and on how well they might be managed through minimal-impact practices such as vehicle washdowns, stockfeed processing and seasonal closures. Such information can only be obtained through site specific ecological studies of the plants, animals and watercourses likely to be affected, differentiating tourism impacts from natural causes and fluctuations. This report examines management strategies for these activities worldwide and in Australia. Suggestions for best management practice and future research agendas are set
Genome-Wide Association Study and Subsequent Exclusion of ATCAY as a Candidate Gene Involved in Equine Neuroaxonal Dystrophy Using Two Animal Models.
Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disorder of unknown etiology. Clinical signs of neurological deficits develop within the first year of life in vitamin E (vitE) deficient horses. A genome-wide association study (GWAS) was carried out using 670,000 SNP markers in 27 case and 42 control Quarter Horses. Two markers, encompassing a 2.5 Mb region on ECA7, were associated with the phenotype (p = 2.05 × 10-7 and 4.72 × 10-6). Within this region, caytaxin (ATCAY) was identified as a candidate gene due to its known role in Cayman Ataxia and ataxic/dystonic phenotypes in mouse models. Whole-genome sequence data in four eNAD/EDM and five unaffected horses identified 199 associated variants within the ECA7 region. MassARRAY® genotyping was performed on these variants within the GWAS population. The three variants within ATCAY were not concordant with the disease phenotype. No difference in expression or alternative splicing was identified using qRT-PCR in brainstem across the ATCAY transcript. Atcayji-hes mice were then used to conduct functional analysis in a second animal model. Histologic lesions were not identified in the central nervous system of Atcayji-hes mice. Additionally, supplementation of homozygous Atcayji-hes mice with 600 IU/day of dl-α-tocopheryl acetate (vitE) during gestation, lactation, and adulthood did not improve the phenotype. ATCAY has therefore been excluded as a candidate gene for eNAD/EDM
Helical Tubes in Crowded Environments
When placed in a crowded environment, a semi-flexible tube is forced to fold
so as to make a more compact shape. One compact shape that often arises in
nature is the tight helix, especially when the tube thickness is of comparable
size to the tube length. In this paper we use an excluded volume effect to
model the effects of crowding. This gives us a measure of compactness for
configurations of the tube, which we use to look at structures of the
semi-flexible tube that minimize the excluded volume. We focus most of our
attention on the helix and which helical geometries are most compact. We found
that helices of specific pitch to radius ratio 2.512 to be optimally compact.
This is the same geometry that minimizes the global curvature of the curve
defining the tube. We further investigate the effects of adding a bending
energy or multiple tubes to begin to explore the more complete space of
possible geometries a tube could form.Comment: 10 page
When Silence is Not Golden: Why Acknowledgement Matters Even When Being Excluded
Following ostracism, individuals are highly sensitive to social cues. Here we investigate whether and when minimal acknowledgment can improve need satisfaction following an ostracism experience. In four studies, participants were either ostracized during Cyberball (Studies 1 and 2) or through a novel apartment-application paradigm (Studies 3 and 4). To signal acknowledgement following ostracism, participants were either thrown a ball a few times at the end of the Cyberball game, or received a message that was either friendly, neutral, or hostile in the apartment-application paradigm. Both forms of acknowledgment increased need satisfaction, even when the acknowledgment was hostile (Study 4), emphasizing the beneficial effect of any kind of acknowledgment following ostracism. Reinclusion buffered threat immediately, whereas acknowledgment without reinclusion primarily aided recovery. Our results suggest that minimal acknowledgment such as a few ball throws or even an unfriendly message can reduce the sting of ostracism
Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
The \hi 21 cm transition line is expected to be an important probe into the
cosmic dark ages and epoch of reionization. Foreground source removal is one of
the principal challenges for the detection of this signal. This paper
investigates the extragalactic point source contamination and how accurately
bright sources ( ~Jy) must be removed in order to detect 21 cm
emission with upcoming radio telescopes such as the Murchison Widefield Array
(MWA). We consider the residual contamination in 21 cm maps and power spectra
due to position errors in the sky-model for bright sources, as well as
frequency independent calibration errors. We find that a source position
accuracy of 0.1 arcsec will suffice for detection of the \hi power spectrum.
For calibration errors, 0.05 % accuracy in antenna gain amplitude is required
in order to detect the cosmic signal. Both sources of subtraction error produce
residuals that are localized to small angular scales, \kperp \gtrsim 0.05
Mpc, in the two-dimensional power spectrum.Comment: 12 pages, 19 Figures, submitted to Ap
Radio Foregrounds for the 21cm Tomography of the Neutral Intergalactic Medium at High Redshifts
Absorption or emission against the cosmic microwave background radiation
(CMB) may be observed in the redshifted 21cm line if the spin temperature of
the neutral intergalactic medium prior to reionization differs from the CMB
temperature. This so-called 21cm tomography should reveal important information
on the physical state of the intergalactic medium at high redshifts. The
fluctuations in the redshifted 21 cm, due to gas density inhomogeneities at
early times, should be observed at meter wavelengths by the next generation
radio telescopes such as the proposed {\it Square Kilometer Array (SKA)}. Here
we show that the extra-galactic radio sources provide a serious contamination
to the brightness temperature fluctuations expected in the redshifted 21 cm
emission from the IGM at high redshifts. Unless the radio source population
cuts off at flux levels above the planned sensitivity of SKA, its clustering
noise component will dominate the angular fluctuations in the 21 cm signal. The
integrated foreground signal is smooth in frequency space and it should
nonetheless be possible to identify the sharp spectral feature arising from the
non-uniformities in the neutral hydrogen density during the epoch when the
first UV sources reionize the intergalactic medium.Comment: 5 pages emulateapj with 1 figure, accepted to Ap
Sport Mega-Events and Public Opposition: A Sociological Study of the London 2012 Olympics
This article examines the diverse forms of public opposition, protest, criticism, and complaint in the United Kingdom on the staging of the 2012 Olympic and Paralympic Games in London. Our discussion draws heavily on empirical research, primarily fieldwork and interviews in East London with local residents, opposition groups, business people, politicians, and other stakeholders. The article is separated into three main parts. First, we explore the setting and political?economic context for London 2012. The main Olympic setting?the London Borough of Newham?features very high levels of poverty and ethnic diversity. We argue that London 2012 represented a form of ?festival capitalism? that was part of a broader set of ?New Right two-step? policies in poor urban areas, involving initial Keynesian investment, followed by a deeper and far-reaching array of neo-liberal measures. Second, in the main part of the article, we identify and examine, in turn, six forms of public conflict, criticism, and complaint that centered on the Games, specifically national criticisms (e.g., on distribution of Olympic resources), local criticisms (e.g., on lack of jobs and business benefits), issue-specific campaigns (e.g., on the environment), ?glocal? protests against specific nations and sponsors (e.g., campaigns against BP, Dow, and Rio Tinto), neo-tribal transgressions and situationist spectacles (e.g., mass cycle rides near Olympic venues), and anti-Olympic forums and demonstrations (e.g., critical web sites, multi-group marches). Third, we set out briefly the importance of conducting research into critics and opponents of sport mega-events, and discuss different arguments on how the social impact of protest movements might have been intensified at London 2012. The findings in this article may be extended to examine critical public responses to the hosting of other mega-events in different settings
Area and individual differences in personal crime victimization incidence: The role of individual, lifestyle/routine activities and contextual predictors
This article examines how personal crime differences between areas and between individuals are predicted by area and population heterogeneity and their synergies. It draws on lifestyle/routine activities and social disorganization theories to model the number of personal victimization incidents over individuals including routine activities and area characteristics, respectively, as well as their (cross-cluster) interactions. The methodology employs multilevel or hierarchical negative binomial regression with extra binomial variation using data from the British Crime Survey and the UK Census. Personal crime rates differ substantially across areas, reflecting to a large degree the clustering of individuals with measured vulnerability factors in the same areas. Most factors suggested by theory and previous research are conducive to frequent personal victimization except the following new results. Pensioners living alone in densely populated areas face disproportionally high numbers of personal crimes. Frequent club and pub visits are associated with more personal crimes only for males and adults living with young children, respectively. Ethnic minority individuals experience fewer personal crimes than whites. The findings suggest integrating social disorganization and lifestyle theories and prioritizing resources to the most vulnerable, rather than all, residents of poor and densely populated areas to prevent personal crimes
Alternative job search strategies in remote rural and peri-urban labour markets: the role of social networks
This paper examines the importance of informal methods (especially social networking) to the job search strategies used by unemployed people. It compares three areas: a small rural town; a larger, more sparsely populated, remote rural area; and a centrally-located, peri-urban labour market. The analysis is based first on survey research undertaken with 490 job seekers across the study areas. Emerging issues were then followed up during a series of twelve focus groups. The survey research showed that job seekers in the rural study areas were significantly more likely to use social networks to look for work. However, those who had experienced repeated or long-term periods out of work, the unskilled and young people were significantly less likely to use such networks. Focus groups confirmed the perceived importance of social networking to the job search process in rural areas, in contrast to the more marginal role such methods appear to play in peri-urban settings. For many rural job seekers, formal job search activities conducted through Jobcentres were seen as largely symbolic, lacking the practical value of social networking. These results suggest that service providers seeking to assist unemployed people in rural areas need to address the problems faced by many disadvantaged job seekers who are currently caught between their lack of social network relations and the absence of local public employment service facilities in more remote communities
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