4,014 research outputs found
Emergency Messaging to General Public via Public Wireless Networks
Warnings to the broad population in an emergency situation, irrespective of location and condition, is a public policy responsibility. Public wireless networks offer now the opportunity to deliver emergency warnings in this way with explanations, because in many countries the mobile penetration rates are higher than any other access form .The paper summarizes the analysis of the selection process between Short messaging services (SMS) and Cell Broadcast messaging in the context of Denmark based on end user requirements and stakeholder roles. It demonstrates the many technical, cost-benefit and other trade-offs needed in supporting the population now with a dependable and wide-spread technology.SMS;cell broadcast (CB);emergency warnings;public wireless networks
Examining Patterns in Nest Predation using Artificial Nests
The use of artificial nests to study the predation of avian nests has faced disregard by ecologists due to inconsistencies found between the survival rates of real and artificial nests across studies and reviews. The negative perception of artificial nests providing an inconsistent assessment of survival has thus fostered the perception that artificial nests are a secondary option to be used to overcome logistical hurdles associated with achieving sufficient sample sizes in systems where study species are rare or elusive, or as merely a preliminary method to study predation across gradients. We argue that the greatest mistake ecologists have made with artificial nests is not the flaws within poorly designed studies, but rather the failure to look for patterns in inconsistencies between properly designed studies. Therefore, we conducted a case study to demonstrated the utility of artificial nests as a tool to consistently measure inherent nest predation risk across a set of manipulated experimental treatments. We also conducted a meta-analysis to examine the patterns of real and artificial nest survival across several gradients theorized to influence nest survival (e.g., absolute latitude). We used only data from peer-reviewed journal articles where researchers recorded the survival of both real and artificial nests, to demonstrate that when extraneous variation is reduced inconsistencies give way to prominent patterns in survival.
Advisor: Joseph J. Fontain
Substrate influence on the plasmonic response of clusters of spherical nanoparticles
The plasmonic response of nanoparticles is exploited in many subfields of
science and engineering to enhance optical signals associated with probes of
nanoscale and subnanoscale entities. We develop a numerical algorithm based on
previous theoretical work that addresses the influence of a substrate on the
plasmonic response of collections of nanoparticles of spherical shape. Our
method is a real space approach within the quasi-static limit that can be
applied to a wide range of structures. We illustrate the role of the substrate
through numerical calculations that explore single nanospheres and nanosphere
dimers fabricated from either a Drude model metal or from silver on dielectric
substrates, and from dielectric spheres on silver substrates.Comment: 12 pages, 13 figure
Distinguishing fractional and white noise in one and two dimensions
We discuss the link between uncorrelated noise and Hurst exponent for one and
two-dimensional interfaces. We show that long range correlations cannot be
observed using one-dimensional cuts through two-dimensional self-affine
surfaces whose height distributions are characterized by a Hurst exponent lower
than -1/2. In this domain, fractional and white noise are not distinguishable.
A method analysing the correlations in two dimensions is necessary. For Hurst
exponents larger than -1/2, a crossover regime leads to a systematic over
estimate of the Hurst exponent.Comment: 3 pages RevTeX, 4 Postscript figure
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What Women With Disabilities Write in Personal Blogs About Pregnancy and Early Motherhood: Qualitative Analysis of Blogs.
BackgroundMore than 1 in 10 women of reproductive age identify as having some type of disability. Most of these women are able to become pregnant and have similar desires for motherhood as women without disability. Women with disability, however, face greater stigma and stereotyping, additional risk factors, and may be less likely to receive adequate reproductive health care compared with their peers without disability. More and more individuals, including those with disability, are utilizing the internet to seek information and peer support. Blogs are one source of peer-to-peer social media engagement that may provide a forum for women with disability to both share and obtain peer-to-peer information and support. Nevertheless, it is not clear what content about reproductive health and pregnancy and/or motherhood is featured in personal blogs authored by women with spinal cord injury (SCI), traumatic brain injury (TBI), spina bifida, and autism.ObjectiveThe objective of this study was twofold: (1) to examine the information being shared in blogs by women with 4 types of disabilities, namely, SCI, TBI, spina bifida, and autism, about reproductive health, disability, health care, pregnancy, and motherhood; and (2) to classify the content of reproductive health experiences addressed by bloggers to better understand what they viewed as important.MethodsPersonal blogs were identified by searching Google with keywords related to disabilities, SCI, TBI, spina bifida, and autism, and a variety of keywords related to reproductive health. The first 10 pages of each database search in Google, based on the relevance of the search terms, were reviewed and all blogs in these pages were included. Blog inclusion criteria were as follows: (1) written by a woman or care partner (ie, parent or spouse) of a woman with a self-identified diagnosis of SCI, TBI, spina bifida, or autism; (2) focused on the personal experience of health and health care during the prepregnancy, prenatal, antepartum, intrapartum, and/or postpartum periods; (3) written in English; and (4) published between 2013 and 2017. A descriptive and thematic qualitative analysis of blogs and corresponding comments was facilitated with NVivo software and matrix analysis.ResultsOur search strategy identified 125 blogs that met all the inclusion criteria; no blogs written by women with spina bifida were identified. We identified 4 reproductive health themes featured in the blog of women with disabilities: (1) (in)accessible motherhood, (2) (un)supportive others, (3) different, but not different, and (4) society questioning motherhood.ConclusionsThis analysis of personal blogs about pregnancy and health care written by women with SCI, TBI, and autism provides a glimpse into their experiences. The challenges faced by these women and the adaptations they made to successfully navigate pregnancy and early motherhood provide insights that can be used to shape future research
Patch Size and Nest Density Influence Nest Survival
Nest predation is the primary cause of avian nest failure and therefore an important driver of avian population growth. Studies indicate that landscape context plays an important role in nest success, and although this is widely attributed to changes in nest predator communities, landscape context also influences nest density which affects predator search area and effort. Much debate remains as to whether specifically the size of a habitat patch or the density of nests has the greatest effect on nest predation rates. We explored the interactions between landscape context, predator efficiency, and nest survival. Northern bobwhite quail (Colinus virginianus) possess specific habitat requirements within a small home range and are a short-lived species that relies upon high reproductive performance, which make them the ideal system to test the extent to which landscape context affects nest predation rates. We investigated the extent to which the size of a grassland patch versus nest density affects nest survival by studying the predation rates of 617 artificial nests during two 23 day trials on 12 study sites in south central Nebraska. To examine the effects of patch size, we selected 6 study sites that were small patches of grassland (including pastures and Conservation Reserve Program fields) ranging in size from 40-60 ha and 6 study sites that were approximately 50 ha sections of larger contiguous grasslands. A high density of artificial nests were placed on half of the small and large patch study sites with the remaining sites having a low density of nests, for the second trial the nest density treatments were switched for each site
Landscape Context Influences Nest Survival in a Midwest Grassland
Although the management and restoration of habitat is the key method to conserve species of interest, local habitat management often fails to elicit desired responses in populations. Landscape features beyond the local habitat scale affect the population dynamics of ring-necked pheasants (Phasianus colchicus), but the mechanism behind this response is unknown. One possibility is that nest survival, which is primarily reduced by nest predation, is regulating pheasant responses to the landscape. We investigated the extent to which land use affected nest survival by studying 202 artificial nests on 12 Conservation Reserve Program (CRP) fields in Nebraska, USA with varying surrounding land-use practices. After running a hierarchical analysis of competing models, we found that predicted nest survival increased as the amount of CRP, winter wheat, and pastureland surrounding a CRP field increased, whereas increasing fallow fields was correlated with decreased nest success. Our findings support theoretical and empirical evidence that nest predation rates are shaped by predator search efficacy. Changing the relative availability of nesting habitat that potentially holds alternative prey sources in our study affected nest survival rates, possibly by altering the search area of opportunistic nest predators. The similarities between the landscape relationships that predict nest survival and landscape predictors of pheasant abundance indicate that nest survival may potentially act as the mechanism shaping population dynamics within an ever changing farmland ecosystem. We recommend that managers consider the land use surrounding areas under consideration for habitat improvement to enhance conservation investments
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