461 research outputs found

    Evaluation of the Yard Gard Ultrasonic Yard Protector for Repelling White-Tailed Deer

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    Ultrasonic devices are marketed for pest control because some manufacturers believe they possess properties aversive to animals. However, there is little evidence that ultrasound is more aversive to animals than is audible sound. In this study, we examined the efficacy of the Yard Gard ultrasonic device for deterring deer (Odocoileus virginianus) from feeding on apples. Four deer feeding stations were established at private residential properties with a history of deer damage to ornamental plants, so that control (A1 and B1) and experimental (A2 and B2) stations existed at each site. Apples were placed at each feeding station and restocked daily from mid-February to mid-March 1995. Yard Gard devices were set up at one station at each site, and we monitored daily deer activity by counting: (1) apples remaining, (2) deer tracks, and (3) deer fecal pellet groups at all feeding stations. Of the 360 total apples offered at site A while the devices were on, 175.0 (97.2%) and 179.5 (99.7%) apples were consumed at control (A1) and experimental (A2) stations, respectively. Of the 400 total apples offered at site B while the devices were on, 188 (94.0%) and 196.5 (98.3%) apples were consumed at control (B1) and experimental (B2) stations, respectively. Apple consumption at feeding stations proved to be the only quantitative data which provided a consistent measure of deer activity. Behavioral observations made at each site revealed that several deer visited the control and experimental feeding stations while Yard Gard devices were on. Apparently, the deer were alerted by the ultrasonic emissions but were not deterred from consuming apples. In conclusion, this study produced no evidence that the Yard Gard ultrasonic device protected the area from deer activity, or preferred foods from deer damage

    Implementation of a Dose Response to Wood Smoke PM: A Potential Method to Further Explain CVD in Wildland Firefighters.

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    The presentation of cardiovascular disease (CVD) and comorbidities in aging and retired wildland firefighters (WLFF) continues to be one of the top health priorities to address by The United States Forest Service. In the past 20 years, experts at multiple meetings and conferences have confronted this growing concern as a formal call to action to investigation the individual components related to working in the wildland fire setting. The inhalation of wood smoke particulate matter (PM) shows evidence of altering homeostasis in WLLF’s in the areas of oxidative stress, inflammation, and arterial stiffness, all of which contribute to the development of (CVD). To date, comprehensive investigation into the dose response of wood smoke PM and subsequent cardiovascular outcomes remains under studied. Emphasis on a wood smoke PM dose response is based on the inclusion of key variables measuring the size, concentration, sources, and inhalation rate of PM. The literature investigating wood smoke PM induced phycological changes is significantly lack in comparison to the reach studying anthropogenic PM and pollution. Recently, published studies in both field experiments and laboratory simulations provide new insight on how the PM dose of acute exposures alters normative cardiovascular function. There is a growing consensus within the scientific community of wood smoke PM inducing oxidative stress, upregulating inflammatory markers, and elevating pulmonary and systemic inflammation. At this time, fluctuations in autonomic nervous system control of heart rate and vascular tone do not warrant the same strength of confidence as the direct influence of wood smoke PM inhalation. Furthermore, the concentrations, volumes, PM size, and ventilation rates are contextual to each individual dose. What is true in one scenario cannot be extrapolated all wood smoke PM exposures and settings. Based on the findings of this academic exercise, we recommend that future scientific investigations in this area implement directed dose-response methodology, in combination with clinically relevant outcome measures, in order to determine the effects from multiple PM smoke exposures on the development of CVD aging and pathology

    Distribution of the Number of Encryptions in Revocation Schemes for Stateless Receivers

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    We study the number of encryptions necessary to revoke a set of users in the complete subtree scheme (CST) and the subset-difference scheme (SD). These are well-known tree based broadcast encryption schemes. Park and Blake in: Journal of Discrete Algorithms, vol. 4, 2006, pp. 215--238, give the mean number of encryptions for these schemes. We continue their analysis and show that the limiting distribution of the number of encryptions for these schemes is normal. This implies that the mean numbers of Park and Blake are good estimates for the number of necessary encryptions used by these schemes

    Scenario Planning for Building Coastal Resilience in the Face of Sea Level Rise: The Case of Jacobs Avenue, Eureka, CA

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    This article examines issues surrounding flood control measures for the Jacobs Avenue community located in Eureka, California. This area of northern California is experiencing some of the most rapid rates of sea level rise recorded throughout the state. Researchers conducted interviews with stakeholders, developed geospatial analyses, and reviewed policy documents in order to understand the social, environmental, and political context related to sea level rise planning for Jacobs Avenue. From this information we developed a scenario-based set of management options to guide stakeholders in future decision-making regarding the fate of Jacobs Avenue. We explored the potential challenges and benefits of three possible scenarios: no action, levee improvement, and strategic retreat. Our analysis reveals that there are no easy solutions. Lack of funding and lack of a clear political path towards retreat make it extremely difficult for planners to take proactive steps that might ultimately contribute to increased safety, as well as economic and environmental benefits, for flood-vulnerable communities. The scenario framework developed in this paper can be a useful tool for a wide range of coastal communities, in particular those of geographically isolated northern California and southern Oregon

    Scenario Planning for Building Coastal Resilience in the Face of Sea Level Rise: The Case of Jacobs Avenue, Eureka, CA

    Get PDF
    This article examines issues surrounding flood control measures for the Jacobs Avenue community located in Eureka, California. This area of northern California is experiencing some of the most rapid rates of sea level rise recorded throughout the state. Researchers conducted interviews with stakeholders, developed geospatial analyses, and reviewed policy documents in order to understand the social, environmental, and political context related to sea level rise planning for Jacobs Avenue. From this information we developed a scenario-based set of management options to guide stakeholders in future decision-making regarding the fate of Jacobs Avenue. We explored the potential challenges and benefits of three possible scenarios: no action, levee improvement, and strategic retreat. Our analysis reveals that there are no easy solutions. Lack of funding and lack of a clear political path towards retreat make it extremely difficult for planners to take proactive steps that might ultimately contribute to increased safety, as well as economic and environmental benefits, for flood-vulnerable communities. The scenario framework developed in this paper can be a useful tool for a wide range of coastal communities, in particular those of geographically isolated northern California and southern Oregon

    Radio Emission from SN 1994I in NGC 5194 (M 51) - The Best Studied Type Ib/c Radio Supernova

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    We present the results of detailed monitoring of the radio emission from the Type Ic supernova SN 1994I from 3 days after optical discovery on 1994 March 31 until eight years later at age 2927 days on 2002 April 05. The data were mainly obtained using the Very Large Array at the five wavelengths, 1.3, 2.0, 3.6, 6.2, and 21 cm, and from the Cambridge 5 km Ryle Telescope at 2.0 cm. Two additional measurements were obtained at millimeter wavelengths. This data set represents the most complete, multifrequency radio observations ever obtained for a Type Ib/c supernova. The radio emission evolves regularly in both time and frequency and is well described by established SN emission/absorption models. It is the first radio supernova with sufficient data to show that it is clearly dominated by the effects of synchrotron self-absorption at early times.Comment: 43 pages, 5 figure

    Recent origin of low trabecular bone density in modern humans

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    Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations

    Semi-automatic ladderisation : improving code security through rewriting and dependent types

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    Funding: This work was generously supported by the EU Horizon 2020 project, TeamPlay (https://www.teamplay-h2020.eu), grant number 779882, and UK EPSRC, Energise, grant number EP/V006290/1.Cyber attacks become more and more prevalent every day.An arms race is thus engaged between cyber attacks and cyber defences.One type of cyber attack is known as a side channel attack, where attackers exploit information leakage from the physical execution of a program, e.g. timing or power leakage, to uncover secret information, such as encryption keys or other sensitive data. There have been various attempts at addressing the problem of side-channel attacks, often relying on various measures to decrease the discernibility of several code variants or code paths. Most techniques require a high-degree of expertise by the developer, who often employs ad hoc, hand-crafted code-patching in an attempt to make it more secure. In this paper, we take a different approach: building on the idea of ladderisation, inspired by Montgomery Ladders. We present a semi-automatic tool-supported technique, aimed at the non-specialised developer, which refactors (a class of) C programs into functionally (and even algorithmically) equivalent counterparts with improved security properties. Our approach provides refactorings that transform the source code into its ladderised equivalent, driven by an underlying verified rewrite system, based on dependent types. Our rewrite system automatically finds rewritings of selected C expressions, facilitating the production of their equivalent ladderised counterparts for a subset of C. Using our tool-supported technique, we demonstrate our approach on a number of representative examples from the cryptographic domain, showing increased security.Postprin
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