Agent-based Simulation of Open Source Software Evolution

We present an agent-based simulation model of open source software (OSS). To our knowledge, this is the first model of OSS evolution that includes four significant factors: productivity limited by the complexity of software modules, the software's fitness for purpose, the motivation of developers, and the role of users in defining requirements. The model was evaluated by comparing the simulated results against four measures of software evolution (system size, proportion of highly complex modules, level of complexity control work, and distribution of changes) for four large OSS systems. The simulated results resembled all the observed data, including alternating periods of growth and stagnation. The fidelity of the model suggests that the factors included here have significant effects on the evolution of OSS systems

Issue Brief: Women and Voting Behavior

This issue brief aims to look at women and their emergence as a cohesive voting block. It tries too look at what issues have traditionally united women and what issues interest women today

Explaining the Early Exit of Eta Carinae from its 2009 X-Ray Minimum with the Accretion Model

We use the accretion model to explain the early exit of Eta Carinae from its 2009 X-ray minimum. In the accretion model the secondary star accretes mass from the primary wind near periastron passage, a process that suppresses the secondary wind. As the shocked secondary wind is responsible for most of the X-ray emission, the accretion process accounts for the X-ray minimum. The early exit from the 2009 X-ray minimum after four weeks, instead of ten weeks as in the two previous minima, is attributed to the primary wind that during the last minimum was somewhat faster and of lower mass loss rate than during the two previous X-ray minima. This results in a much lower mass accretion rate during the X-ray minimum. We show that using fluctuations in these quantities that are within the range deduced from fluctuations in the X-ray flux outside the minimum, can account for the short duration of the last X-ray minimum. The shorter X-ray minimum may have further implications on the recovery of the system from the spectroscopic event.Comment: ApJ Letters, 5 pages, 1 figur

The impact of mental health services at outreach clinics and non-clinic sites on the attendance of Deaf children and young people and families

Deaf children show high rates of mental health disorders, with difficulties getting access to appropriate health care. The National Deaf Child and Adolescent Mental Health Service (ND-CAMHS) was set up to provide specialist mental health care to Deaf young people and hearing children of Deaf adults in the UK. This study retrospectively examined the impact of the introduction of ND-CAMHS at outreach clinics and non-clinic sites on attendance rates at clients and carers’ first and follow-up appointments over a three-and-a-half-year period. In all, 4177 appointments, 372 first and 3805 follow-up, associated with 369 clients were considered for analyses. First appointments were much more likely to be clinic-based than follow-up appointments (78.2% versus 34.3%, p < 0.001), which were administered in a variety of sites, most frequently at the client’s school or home. The overall attendance rates for first and follow-up appointments were 68.5% and 79.2%, respectively. There was no significant effect of appointment location on attendance rates for first appointments. However, multivariate analyses indicated that clients at follow-up appointments were more likely to attend when appointments occurred at non-clinic sites compared with clinic-based appointments (81.9% versus 74.1%; odds ratio (OR) = 1.39, 95% confidence interval (CI) 1.17, 1.65). Improved attendance rates were a function of significant decreases in ‘did not attends’ (DNA) and client/carer cancellations at non-clinic sites. There was also an increased attendance rate for follow-up appointments held in outreach clinics relative to hospital-based sites (79.0% versus 72.2%), although this failed to achieve significance after adjusting for other relevant factors (OR = 1.27, 95% CI 0.93, 1.73). The findings indicate that providing specialised mental health services for Deaf children and young people into schools and other locations that are easier to access can improve service accessibility and continuity of care

The Price of Beauty: An Economic Approach to Aesthetic Nuisance

This Article advocates a wider judicial recognition of nuisance actions based on aesthetic considerations. Contrary to the majority of legal opinion to the contrary, it is argued that a right to enjoy property should include a right to be free from non-invasive aesthetic or visual nuisances. With modern real estate appraisal methods making it possible to express community aesthetic preferences in monetary terms, courts are now no longer prevented from using these tools in assessing injuries to real estate. Thus, determinations of aesthetic nuisance actions are not any more subjective than the current task of courts in the context of aural and olfactory nuisance disputes. Indeed, the judiciary should resolve conflicts emanating from the unaesthetic uses of land through the Restatement of Torts “objective” balancing test in order to determine what, according to prevailing community standards, is reasonable under the circumstances.The expanded popularity of aesthetic zoning in many municipalities demonstrates anew the social value of aesthetics and thereby illustrates with clarity a very conscious relationship which exists between economic development and American nuisance law. Judicial recognition of police powers to enforce zoning regulations of this order contradicts - clearly - the heretofore seen reluctance of the Common Law to confront aesthetics in the realm of nuisance and thus invites a more contemporary and enlightened judicial response to this legal issue

TEMPORAL AND SPATIAL DISTRIBUTION OF POACEAE POLLEN IN AREAS OF SOUTHERN UNITED KINGDOM, SPAIN AND PORTUGAL

Overall, longer Poaceae pollen seasons coincided with earlier pollen season start dates. Winter rainfall noticeably affects the intensity of Poaceae pollen seasons in Mediterranean areas, but this was not as important in Worcester. Weekly data from Worcester followed a similar pattern to that of Badajoz and Évora but at a distance of more than 1500 km and 4-5 weeks later

Research and in situ conservation of owl monkeys enhances environmental law enforcement at the Colombian-Peruvian border

This study reports on impacts of illegal trade in owl monkeys (Aotus nancymaae, A. vociferans) for the biomedical research market in the Colombian-Peruvian Amazonian border. Through freedom of information requests and interviews with hunters we found that 912 owl monkeys, including A. nancymaae captured in Peru, were trapped over a 3-month period in 2012 to supply a malaria research facility based in Leticia, Colombia, which had trapping permits for the use of only 800 A. vociferans annually yet experimentation took place using A. nancymaae. High levels of extraction in Peru have had population-level impacts with significantly lower densities of Aotus spp. (3-24individuals/km2) compared to Colombian sites with low hunting pressure (26-44individuals/km2). Post-experimental release of this species in Colombian territory has created a new distribution whose status and impacts on resident populations of A. vociferans remain unknown. The trapping method has also had environmental impact, with loss of over 65,000 trees (including sleeping sites), annually. As Aotus species are registered under the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II, international trade requires official permission and evidence that extraction does not impact wild populations. However, no official records exist and CITES legislation has failed, due principally to a lack of appropriate monitoring by national authorities responsible for compliance. Of further concern is that we had previously documented and reported the illegal trade to the appropriate governmental authorities yet still no action was taken-as demonstrated by the continuing trade in 2013. Enforcement eventually occurred when a non-governmental organization initiated legal action against organizations responsible. A successful second instance ruling by the Colombian State's Council in 2013 revoked trapping permits. Using the trade in owl monkeys as a case study we consider implementation, compliance, and enforcement of CITES in the border area to identify mechanisms to improve enforcement of environmental legislation. Am. J. Primatol. 76:658-669, 2014. © 2014 Wiley Periodicals, Inc

Explaining the transient fast blue absorption lines in the massive binary system Eta Carinae

We use recent observations of the He I $\lambda10830 \AA$ absorption line and 3D hydrodynamical numerical simulations of the winds collision, to strengthen the case for an orientation of the semimajor axis of the massive binary system Eta Carinae where the secondary star is toward us at periastron passage. Those observations show that the fast blue absorption component exists for only several weeks prior to the periastron passage. We show that the transient nature of the fast blue absorption component supports a geometry where the fast secondary wind, both pre and post-shock material, passes in front of the primary star near periastron passage.Comment: 8 pages, 5 figures, accepted by MNRAS, includes astro-ph only appendice