Energy production in the United States is in transition as the demand for clean and domestic power increases. Wind energy offers the benefit of reduced emissions, yet, like oil and natural gas, it ...also contributes to energy sprawl. We used a diverse set of indicators to quantify the ecological impacts of oil, natural gas, and wind energy development in Colorado and Wyoming. Aerial imagery was supplemented with empirical data to estimate habitat loss, fragmentation, potential for wildlife mortality, susceptibility to invasion, biomass carbon lost, and water resources. To quantify these impacts we digitized the land-use footprint within 375 plots, stratified by energy type. We quantified the change in impacts per unit area and per unit energy produced, compared wind energy to oil and gas, and compared landscapes with and without energy development. We found substantial differences in impacts between energy types for most indicators, although the magnitude and direction of the differences varied. Oil and gas generally resulted in greater impacts per unit area but fewer impacts per unit energy compared with wind. Biologically important and policy-relevant outcomes of this study include: 1) regardless of energy type, underlying land-use matters and development in already disturbed areas resulted in fewer total impacts; 2) the number and source of potential mortality varied between energy types, however, the lack of robust mortality data limits our ability to use this information to estimate and mitigate impacts; and 3) per unit energy produced, oil and gas extraction was less impactful on an annual basis but is likely to have a much larger cumulative footprint than wind energy over time. This rapid evaluation of landscape-scale energy development impacts could be replicated in other regions, and our specific findings can help meet the challenge of balancing land conservation with society's demand for energy.
Using a multidimensional large sieve inequality, we obtain a bound for the mean-square error in the Chebotarev theorem for division fields of elliptic curves that is as strong as what is implied by ...the Generalized Riemann Hypothesis. As an application we prove that, according to height, almost all elliptic curves are Serre curves, where a Serre curve is an elliptic curve whose torsion subgroup, roughly speaking, has as much Galois symmetry as possible.
The Energy Footprint JONES, NATHAN F.; PEJCHAR, LIBA; KIESECKER, JOSEPH M.
Bioscience,
03/2015, Letnik:
65, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Society’s growing demand for clean and abundant energy has repercussions for biodiversity and human well-being. Directives for renewable energy, energy security, and technological advancements such ...as horizontal drilling in conjunction with hydraulic fracturing have spurred a rapid increase in alternative and unconventional energy production over the last decade. Given the projected increases in oil, gas, and wind energy development, we synthesize and compare known impacts on wildlife mortality, habitat loss, fragmentation, noise and light pollution, invasive species, and changes in carbon stock and water resources. The literature on these impacts is unevenly distributed among energy types, geographic regions, and taxonomic groups. Therefore, we suggest priorities for research and practice, including using a landscape approach to predict and plan for the cumulative effects of development. Understanding the full consequences of energy production is necessary for meeting demand while also safeguarding the ecological systems on which we depend.
This article posits a competitive bacterial ecology as a framework for Mexican drug trafficking with a novel focus on bacterial conjugation (one type of horizontal gene transmission) to explain ...tactical homogenization. Individual drug traffickers consciously switch between Mexican organized crime groups sometimes three and four times, much like individual bacteria exchange their DNA in a horizontal genetic transfer that allows rapid evolution and resilience. Bacterial conjugation is a useful amplifying variable for understanding the homogenization of violence and this article probes its plausibility by providing examples of traffickers switching groups and taking tactics with them. Drawing on examples of traffickers and cells from the Arellano Felix Organization, the Sinaloa Cartel, Cartel de Jalisco Nueva Generacion, the Viagras, Zetas, and the Gulf Cartels, this article traces the genealogy of violent tactics, techniques, and procedures such as dissolving bodies in acid, asphyxiation, and infantry tactics, through individual traffickers into new groups drawn generally in the direction of more powerful, proximate, and similar trafficking groups.
Surveying Clinicians by Web Dykema, Jennifer; Jones, Nathan R.; Piché, Tara ...
Evaluation & the health professions,
09/2013, Letnik:
36, Številka:
3
Journal Article
Recenzirano
The versatility, speed, and reduced costs with which web surveys can be conducted with clinicians are often offset by low response rates. Drawing on best practices and general recommendations in the ...literature, we provide an evidence-based overview of methods for conducting online surveys with providers. We highlight important advantages and disadvantages of conducting provider surveys online and include a review of differences in response rates between web and mail surveys of clinicians. When administered online, design-based features affect rates of survey participation and data quality. We examine features likely to have an impact including sample frames, incentives, contacts (type, timing, and content), mixed-mode approaches, and questionnaire length. We make several recommendations regarding optimal web-based designs, but more empirical research is needed, particularly with regard to identifying which combinations of incentive and contact approaches yield the highest response rates and are the most cost-effective.
Induction is designed to support teachers’ effectiveness, improve their students’ learning, and foster their retention. We consider how high-leverage practices (HLPs) might provide an instructional ...framework for special education teacher (SET) induction. With sensemaking theory as a conceptual foundation, we posit that, by structuring induction experiences and instructional conditions around HLPs, schools and districts can send more coherent messages about effective instruction, thereby easing new SETs’ efforts to make sense of their roles. We first provide a brief review of research on new SETs’ experiences. Next, we consider how specific induction components (i.e., professional development and mentoring, teacher evaluation, and collaboration) and instructional conditions (i.e., collaboration, instructional curricula and resources, and schedules) might be structured to support SETs’ learning of and use of these HLPs. We conclude with considerations for researchers and practitioners.
Review(s) of: 'COVID-19, Gangs, and Conflict', Edited by John P. Sullivan and Robert J. Bunker. A Small Wars Journal-El Centro Reader. Bloomington: Xlibris. 2020. Photos. Endnotes. Contributor ...biographies. Prologue. Foreword. Postscript. Afterword. Selected References. pp. 153. Paperback $12.17. Kindle $3.99. 'Criminal Contagion: How Mafias, Gangsters and Scammers Profit from a Pandemic'. By Tuesday Reitano and Mark Shaw. London: Hurst and Company, 2021. ISBN 9781787384460. Notes. Index. pp. 320. Hardcover $26.95.
Abstract
Methane emissions from small freshwater ecosystems represent one of the largest components of uncertainty in the global methane budget. While these systems are known to produce large amounts ...of methane relative to their size, quantifying the timing, magnitude, and spatial extent of their emissions remains challenging. We begin to address this challenge in seasonally inundated forested mineral soil wetlands by (1) measuring wetland methane fluxes and hydrologic regime across both inundated and non-inundated soils, (2) characterizing how wetland hydrologic regime impacts the spatial extent of methane emission source areas, and (3) modeling average daily wetland-scale flux rates using four different upscaling techniques. Our results show that inundation extent and duration, but not frequency or depth, were major drivers of wetland methane emissions. Moreover, we found that methane fluxes were best described by the direction of water level change (i.e. rising or falling), where emissions were generally higher when water levels were falling. Once soils were inundated, subsequent changes in water level did not explain observed variability of methane concentrations in standing water. Finally, our spatial modeling suggests that representing inundation and associated methane source areas is a critical step in estimating local to regional scale methane emissions. Intermittently inundated soils alternated between being sources and sinks of methane depending on water level, soil moisture, and the direction of water level change. These results demonstrate that quantifying the hydrologic regime of seasonally inundated forested freshwater wetlands enables a more accurate estimation of methane emissions.
Floodplain inundation poses both risks and benefits to society. In this study, we characterize floodplain inundation across the United States using 5800 stream gages. We find that between 4% and ...12.6% of a river's annual flow moves through its floodplains. Flood duration and magnitude is greater in large rivers, whereas the frequency of events is greater in small streams. However, the relative exchange of floodwater between the channel and floodplain is similar across small streams and large rivers, with the exception of the water-limited arid river basins. When summed up across the entire river network, 90% of that exchange occurs in small streams on an annual basis. Our detailed characterization of inundation hydrology provides a unique perspective that the regulatory, management, and research communities can use to help balance both the risks and benefits associated with flooding.
One third of people newly living with HIV/AIDS are adolescents. Research on adolescent HIV prevention is critical owing to differences between adolescents and adults. Parental permission requirements ...are often considered a barrier to adolescent enrollment in research, but whether adolescents view this barrier as the most important one is unclear.
Adolescents were approached in schools in KwaZulu-Natal, South Africa, and at a sexually transmitted infection clinic at the Children’s Hospital of Aurora, Colorado. Surveys with a hypothetical vignette about participation in a pre-exposure prophylaxis trial were conducted on smartphones or tablets with 75 adolescents at each site. We calculated descriptive statistics for all variables, using 2-sample tests for equality of proportions with continuity correction. Statistical significance was calculated at p < 0.05. Multivariate analyses were also conducted.
Most adolescents thought side effects (77%) and parental consent requirements (69%) were very important barriers to research participation. When asked to rank barriers, adolescents did not agree on a single barrier as most important, but the largest group of adolescents ranked parental consent requirements as most important (29.5%). Parental consent was seen as more of a barrier for adolescents in South Africa than in the United States. Concerns about being experimented on or researchers’ mandatory reporting to authorities were ranked much lower. Finally, most (71%, n = 106) adolescents said they would want to extra support from another adult if parental permission was not required.
Adolescents consider both parental permission requirements and side effects important barriers to their enrollment in HIV prevention research. Legal reform and better communication strategies may help address these barriers.
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