Tests of Landscape Influence: Nest Predation and Brood Parasitism in Fragmented Ecosystems

The effects of landscape fragmentation oil nest predation and brood parasitism, the two primary Causes of avian reproductive failure, have been difficult to generalize across landscapes, yet few Studies have clearly considered the context and spatial scale of: fragmentation. Working in two river systems fragmented by agricultural and rural-housing development, we tracked nesting Success and brood parasitism in \u3e 2500 bird nests in 38 patches of deciduous riparian woodland. Patches oil both river Systems were embedded in one of two local contexts (buffered from agriculture by coniferous forest, or adjacent to agriculture), but the abundance of agriculture and human habitation within 1 km of each patch was highly variable. We examined evidence for three models of landscape effects oil nest predation based on (1) the relative importance of generalist agricultural nest predators, (2) predators associated with the natural habitats typically removed by agricultural development, or (3) an additive combination of: these two predator communities. We found strong support for all additive predation model in which landscape features affect nest predation differently at different spatial scales. Riparian habitat with forest buffers had higher nest predation rates than sites adjacent to agriculture, but nest predation also increased with increasing agriculture in the larger landscape Surrounding each site. These results suggest that predators living in remnant woodland buffers, as well as generalist nest predators associated with agriculture, affect nest predation rates, but they appear to respond at different spatial scales. Brood parasitism, in Contrast, Was unrelated to agricultural abundance oil the landscape, but showed a strong nonlinear relationship with farm and house density, indicating a critical point at which increased human habitat Causes increased brood parasitism. Accurate predictions regarding landscape effects oil nest predation and brood parasitism will require an increased appreciation of the multiple scales at which landscape components influence predator and parasite behavior

Incorporating collisions and resistance into the transition from field emission to the space charge regime

Advancements in microelectromechanical systems (MEMS) and microplasmas, particularly with respect to applications in combustion and biotechnology, motivate studies into microscale gas breakdown to enable safe system design and implementation. Breakdown at microscale deviates from that predicted by Paschen’s law due to field emission—the stripping of electrons from the cathode in the presence of strong surface field—and follows the Fowler-Nordheim (FN) law. As injected current increases at this length scale, electrons accumulate in the gap and FN electron emission becomes space charge limited, leading to the Child-Langmuir (CL) law at vacuum and the Mott-Gurney (MG) law at high pressure. While theoretical studies link CL to FN and CL to MG, none links all three to simultaneously assess the importance of pressure and external resistance (perturbation) on electron emission. This study extends existing theory to elucidate the transition between these regimes as a function of applied voltage, gap distance, electron mobility, and external resistance, and in particular, derives asymptotic equations illustrating the transitions between the three. It also demonstrates the presence of a triple point, where one theoretically encounters FN, CL, and MG at once, and characterizes the importance of gap pressure and distance on these regimes, especially when MG dominates at non-vacuum pressures. The sensitivity of the triple point to external resistance, representative of the effects of perturbations in system parameters on electron emission, receives special attention

Optimizing Neutron Yield for Active Interrogation

Neutrons are commonly used for many applications, including active interrogation and cancer therapy. One critical aspect for active interrogation efficiency is neutron yield, which is more important for successful resolution than the energy spectrum. The typical approach for improving neutron yield entails producing more neutrons, which has motivated multiple studies using the interaction of increasingly more powerful tabletop lasers with plastic targets to generate protons or deuterons that are absorbed by another target to create neutrons [1]. Alternatively, one may use lenses to focus the neutrons to increase yield rather than simply generating more neutrons with more powerful lasers [2]. Assessing either approach requires a comprehensive model simulating neutron generation and transport to optimize the target material, system geometry, and neutron yield. A complete model from laser source to neutron generation is beyond the scope of the current study, so this project focuses on simulating the interaction of deuterons with typical target materials, such as lithium or beryllium. We use the neutron transport code Monte Carlo N-Particles (MCNP), which applies the Monte Carlo method to track particles [3]. The simulations accurately reflected experimental results from several groups [4]. Future analyses will assess improvements in neutron yield and directionality through strategically incorporating neutron lenses

Can false memories prime alternative solutions to ambiguous problems?

Research has demonstrated that false memories are capable of priming and facilitating insight-based problem-solving tasks by increasing solution rates and decreasing solution times. The present research extended this finding by investigating whether false memories could be used to bias ambiguous insight-based problem-solving tasks in a similar manner. Compound remote associate task (CRAT) problems with two possible correct answers, a dominant and a non-dominant solution, were created and normed (Experiment 1). In Experiment 2, participants were asked to solve these CRAT problems after they were given Deese/Roediger-McDermott lists whose critical lures were also the non-dominant solution to half of the corresponding CRATs. As predicted, when false memories served as primes, solution rates were higher and solution times were faster for non-dominant than dominant CRAT solutions. This biasing effect was only found when participants falsely recalled the critical lure, and was not found when participants did not falsely recall the critical lure, or when they were not primed. Results are discussed with regard to spreading activation models of solution competition in problem-solving tasks and current theories of false memory priming effects

The Impact Of A Collegiate Course In Bargaining And Negotiation On Students Perceptions Of Their Own And Others Attitudes And Behaviors: An Exploratory Study

This article presents a discussion of the importance of a course in bargaining and negotiation to university-level students in an accredited business school environment. In addition to discussing recommended content, pedagogy, and assessment methods, the results of a study that examines the impact of the course on students perceptions of skills, attitudes, and behaviors associated with effective negotiation is presented. The results of the study clearly demonstrate significant shifts in students perceptions regarding power, constructive dialogue, and the appropriate role and definition of winning in such bargaining and negotiation encounters

Strength in diversity: enhancing learning in vocationally-orientated, master's level courses

Postgraduate education in geography, especially at the Master’s level, is undergoing significant changes in the developed world. There is an expansion of vocationally-oriented degree programmes, increasing recruitment of international students, integration of work place skills, and the engagement of non-traditional postgraduate students as departments respond to policies for a more ‘inclusive’ higher education. This paper sets the context by outlining some programmatic changes in selected countries (Australia, the UK, and the USA). We briefly reflect on how postgraduate ‘bars’ or ‘levels’ are defined and explore in detail what ‘diversity’ or ‘heterogeneity’ means in these new postgraduate settings. The paper then explores some examples of practice drawn from our own experiences, whilst recognising that relevance will vary in other contexts. Finally we consider how diversity can be harnessed as a strength that has potential to enhance taught elements of contemporary postgraduate education in and beyond the discipline

Academic Achievement and School Resources

This chapter examines the national and local trends in educational policy, focusing in particular on Nevada’s academic achievement, standardized test performance, available school resources, and unmet needs. The discussion begins with the concept of academic achievement and the ways it is measured. After that, we analyze the policies impacting academic achievement, most notably the No Child Left Behind (NCLB) Act. Next, we suggest the strategies to improve academic performance in the Nevada K12 System and make recommendations to increase parental involvement in education and encourage culturally competent policies of bringing together children, families, and schools. Finally, we discuss the resources needed to raise academic performances in Nevada schools