WorldWideScience

Sample records for hunter safety predator

  1. 76 FR 46149 - Financial Assistance: Wildlife Restoration, Sport Fish Restoration, Hunter Education and Safety

    Science.gov (United States)

    2011-08-01

    ... Assistance: Wildlife Restoration, Sport Fish Restoration, Hunter Education and Safety; Final Rule #0;#0... Restoration, Hunter Education and Safety AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule... Restoration, Sport Fish Restoration, and Hunter Education and Safety (Enhanced Hunter Education and...

  2. Response of moose hunters to predation following wolf return in Sweden.

    Directory of Open Access Journals (Sweden)

    Camilla Wikenros

    Full Text Available Predation and hunter harvest constitute the main mortality factors affecting the size and dynamics of many exploited populations. The re-colonization by wolves (Canis lupus of the Scandinavian Peninsula may therefore substantially reduce hunter harvest of moose (Alces alces, the main prey of wolves.We examined possible effects of wolf presence on hunter harvest in areas where we had data before and after wolf establishment (n = 25, and in additional areas that had been continuously exposed to wolf predation during at least ten years (n = 43. There was a general reduction in the total number of moose harvested (n = 31,827 during the ten year study period in all areas irrespective of presence of wolves or not. However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves. The reduction in harvest was larger in small (500-800 km2 compared to large (1,200-1,800 km2 wolf territories. In areas with newly established wolf territories moose management appeared to be adaptive with regard to both managers (hunting quotas and to hunters (actual harvest. In these areas an instant reduction in moose harvest over-compensated the estimated number of moose killed annually by wolves and the composition of the hunted animals changed towards a lower proportion of adult females.We show that the re-colonization of wolves may result in an almost instant functional response by another large predator-humans-that reduced the potential for a direct numerical effect on the density of wolves' main prey, the moose. Because most of the worlds' habitat that will be available for future colonization by large predators are likely to be strongly influenced by humans, human behavioural responses may constitute a key trait that govern the impact of large predators on their prey.

  3. A Guide to Instruction in the Shooting Sports-Rifles; Air Rifles; Shotguns; Pistols; Hunter Safety.

    Science.gov (United States)

    Niemeyer, Roy K.; And Others

    Prepared for instruction in the use of rifles, air guns, shotguns, pistols, and hunter safety, this guide supplements other materials which are available from the National Rifle Association of America, the National Shooting Sports Foundation, the American Association for Health, Physical Education, and Recreation, industry, and other sources. The…

  4. Vulnerable Hunter

    Directory of Open Access Journals (Sweden)

    Md.Asha Begum

    2016-05-01

    Full Text Available This project "VULNERABLE HUNTER" application main aim is to detect risk in our mobile applications. This application contains modules like Fetch Application, Generate Score, Uninstall and Display Graph. Through this application it detects risk so that this application is very useful to smart phone users Now-a-days so many people are using smart phones and people are crazy about new apps. But by installing all the applications into our mobile may reduce its performance. Some apps contain more risk. But user may not know the effects that are caused by the app which is installed until the performance of mobile is reduced. With the prosperity of the Android app economy, many apps have been published and sold in various markets. However, short development applications and insufficient security development apps have led to many vulnerable apps. So to reduce these type of problems Vulnerable Hunter is proposed. Through the proposed application user can see which application is risky and then the user may uninstall that application. The main advantage of designing this app is without internet also the users will use this application. Users also feel more convenient to work with mobile apps.

  5. A Trial of an All-Terrain Vehicle Safety Education Video in a Community-Based Hunter Education Program

    Science.gov (United States)

    Williams, Robert S.; Graham, James; Helmkamp, James C.; Dick, Rhonda; Thompson, Tonya; Aitken, Mary E.

    2011-01-01

    Purpose: All-terrain vehicle (ATV) injury is an increasingly serious problem, particularly among rural youth. There have been repeated calls for ATV safety education, but little study regarding optimal methods or content for such education. The purpose of this study was to determine if an ATV safety video was effective in increasing ATV safety…

  6. Hunters' motivations and values:

    DEFF Research Database (Denmark)

    Radder, Laetitia; Bech-Larsen, Tino

    2008-01-01

    This article examines the values and motivations of South African biltong hunters. A hierarchical value map of associations between attributes, consequences and values resulted from laddering interviews with 34 hunters. The Means-End Chain approach proved useful in identifying: (a) personal values......, (b) wildlife value orientations, and (c) motivations associated with desired benefits and satisfactions. Values reflected socialization, achievement, stimulation, hedonism, universalism, and conformity. Materialism, attraction/interest, respect, environmentalism, and rational/scientific were...... the predominant wildlife value orientations. Motivations included male identity, escape, appreciation of nature, and bonding with family and friends. The study refuted perceptions that biltong hunters primarily hunt for the meat or for the sake of killing an animal....

  7. Hunters' motivations and values:

    DEFF Research Database (Denmark)

    Radder, Laetitia; Bech-Larsen, Tino

    2008-01-01

    This article examines the values and motivations of South African biltong hunters. A hierarchical value map of associations between attributes, consequences and values resulted from laddering interviews with 34 hunters. The Means-End Chain approach proved useful in identifying: (a) personal values......, (b) wildlife value orientations, and (c) motivations associated with desired benefits and satisfactions. Values reflected socialization, achievement, stimulation, hedonism, universalism, and conformity. Materialism, attraction/interest, respect, environmentalism, and rational/scientific were...... the predominant wildlife value orientations. Motivations included male identity, escape, appreciation of nature, and bonding with family and friends. The study refuted perceptions that biltong hunters primarily hunt for the meat or for the sake of killing an animal....

  8. The Higgs hunter's guide

    CERN Document Server

    Gunion, John F; Haber, Howard E; Kane, Gordon L

    1989-01-01

    The Higgs Hunter's Guide is a definitive and comprehensive guide to the physics of Higgs bosons. In particular, it discusses the extended Higgs sectors required by those recent theoretical approaches that go beyond the Standard Model, including supersymmetry and superstring-inspired models.

  9. Neurogenic bladder in Hunter's syndrome.

    Science.gov (United States)

    Koyama, K; Moda, Y; Sone, A; Tanaka, H; Hino, Y

    1994-01-01

    We encountered a rare patient with Hunter's syndrome who exhibited urinary retention as a result of a neurogenic bladder, uninhibited detrusor contractions, and detrusor-sphincter dyssynergia. Neurological findings were consistent with cervical myelopathy and cervical MR imaging showed very narrow segments at the cord level C2-4. We speculate that this Hunter's syndrome patient has cervical myelopathy and that this neurological dysfunction causes the neurogenic bladder. PMID:8014981

  10. The Infrared Hunter

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2 This image composite compares infrared and visible views of the famous Orion nebula and its surrounding cloud, an industrious star-making region located near the hunter constellation's sword. The infrared picture is from NASA's Spitzer Space Telescope, and the visible image is from the National Optical Astronomy Observatory, headquartered in Tucson, Ariz. In addition to Orion, two other nebulas can be seen in both pictures. The Orion nebula, or M42, is the largest and takes up the lower half of the images; the small nebula to the upper left of Orion is called M43; and the medium-sized nebula at the top is NGC 1977. Each nebula is marked by a ring of dust that stands out in the infrared view. These rings make up the walls of cavities that are being excavated by radiation and winds from massive stars. The visible view of the nebulas shows gas heated by ultraviolet radiation from the massive stars. Above the Orion nebula, where the massive stars have not yet ejected much of the obscuring dust, the visible image appears dark with only a faint glow. In contrast, the infrared view penetrates the dark lanes of dust, revealing bright swirling clouds and numerous developing stars that have shot out jets of gas (green). This is because infrared light can travel through dust, whereas visible light is stopped short by it. The infrared image shows light captured by Spitzer's infrared array camera. Light with wavelengths of 8 and 5.8 microns (red and orange) comes mainly from dust that has been heated by starlight. Light of 4.5 microns (green) shows hot gas and dust; and light of 3.6 microns (blue) is from starlight.

  11. Planet Hunters: A Status Report

    Science.gov (United States)

    Schwamb, Megan E.; Orosz, J. A.; Carter, J. A.; Fischer, D. A.; Howard, A. W.; Crepp, J. R.; Welsh, W. F.; Kaib, N. A.; Lintott, C. J.; Terrell, D.; Jek, K. J.; Gagliano, R.; Parrish, M.; Smith, A. M.; Lynn, S.; Brewer, J. M.; Giguere, M. J.; Schawinski, K.; Simpson, R. J.

    2012-10-01

    The Planet Hunters (http://www.planethunters.org) citizen science project uses the power of human pattern recognition via the World Wide Web to identify transits in the Kepler public data. Planet Hunters uses the Zooniverse (http://www.zooniverse.org) platform to present visitors to the Planet Hunters website with a randomly selected 30-day light curve segment from one of Kepler's 160,000 target stars. Volunteers are asked to draw boxes to mark the locations of visible transits with multiple independent classifiers reviewing each 30-day light curve segment. Since December 2010, more than 170,000 members of the general public have participated in Planet Hunters contributing over 12.5 million classifications searching the 1 1/2 years of publicly released Kepler observations. Planet Hunters is a novel and complementary technique to the automated transit detection algorithms, providing an independent assessment of the completeness of the Kepler exoplanet inventory. We report the latest results from Planet Hunters, highlighting in particular our latest efforts to search for circumbinary planets (planets orbiting a binary star) and single transit events in the first 1.5 years of public Kepler data. We will present a status report of our search of the first 6 Quarters of Kepler data, introducing our new planet candidates and sharing the results of our observational follow-up campaign to characterize these planetary systems. Acknowledgements: MES is supported by a NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1003258. This is research is supported in part by an American Philosophical Society Franklin Grant.

  12. Identification and specialization as a waterfowl hunter

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.; Lawrence, Jeffrey S.; Cordts, Steven D.

    2013-01-01

    Like specialization, identity offers a way for differentiating and understanding recreationists and for gaining insight into the question of participant progression in an activity. We examined how identity related to measures of specialization among lapsed and current waterfowl hunters. Lapsed hunters included those who had purchased a Minnesota waterfowl stamp between 2000 and 2004, but not since this time. Current hunters had purchased a 2010 stamp. Results suggested that some waterfowl hunters specialize and progress toward a waterfowl-hunter identity. Others, however, either hunt for years but never specialize and identify as waterfowl hunters, or move toward but do not attain a waterfowl hunter identity. Individuals who achieve a waterfowl hunter identity may also later relinquish this identity. Identification was associated with increased specialization and resistance to change from a preference for waterfowl hunting. Individuals who had relinquished their identity retained social and knowledge-based commitment to waterfowl hunting, whereas attraction and centrality declined.

  13. Fencing predators: Hunters and prey on South African game farms

    NARCIS (Netherlands)

    Spierenburg, M.J.; Wels, H.

    2016-01-01

    The wildlife industry in South Africa is thriving, with increasing numbers of game farms. Large parts of the South African countryside are enclosed with fences. Fences have always been strategically important in wildlife production and conservation, both to protect wildlife, but also to keep local p

  14. Travels with the Fossil Hunters

    Science.gov (United States)

    Whybrow, Peter J.

    2000-04-01

    Whether dodging bullets in West Africa, or rabid dogs in Pakistan, surviving yak-butter tea in Tibet, or eating raw fish in China, the life of a globe-trotting fossil hunter is often hazardous and always filled with surprises. Travels with the Fossil Hunters lets readers share the wonder, joys of discovery, and excitement of these intrepid scientists. Packed with more than 100 beautiful, full-color photographs, the volume takes readers on twelve expeditions to remote parts of the world in search of diverse fossil remains, from those of dinosaurs to human ancestors. Each expedition by paleontologists from London's Natural History Museum reveals the problems and challenges of working in extreme conditions, from the deserts of the Sahara and Yemen to the frozen wastes of Antarctica, from the mountains of India to the forests of Latvia. Along the way they also describe the paleontology and geology of the countries they visit and the scientific reasons for their expeditions. With a foreword from Sir David Attenborough and an introduction from Richard Fortey, this fascinating book will appeal to amateur and professional fossil hunters alike and to readers interested in accounts of exotic locales. Peter Whybrow is a research scientist at the Natural History Museum, London. His research interests include Arabian Miocene vertebrates, paleoclimates, paleogeography, and biotic diversity. He is senior editor with A. Hill of Fossil Vertebrates of Arabia (Yale University Press, New Haven, 1999).

  15. Hunter Valley的诚信%Hunter Valley's Honesty

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 去年圣诞节假期,我和小T曾和大连狮子一家三口,到悉尼附近知名旅游地Hunter Valley(猎人谷)度过了快乐充实的三天. 我们一行五人在圣诞节那天乘坐提前预订好的马车,大约走访了八、九个大大小小的葡萄洒园.

  16. Hunters in the new millennium”

    DEFF Research Database (Denmark)

    Hansen, Hans Peter

    of the modern world continue to practice hunting? What are the preferences of the modern hunter? How are the preferences and conduct of hunters related to the social and demographic factors? What are the social, political and economical impacts of hunting? What motivates people to hunt? - In spite of the fact...... that hunting is a common source of conflict between different interests, only very few studies has been made to produce knowledge about people hunting for leisure. The survey “Hunters in the new millennium” is an attempt to contribute to a better understanding of hunters and hunting in an increasing urbanized...

  17. Danes - The keen bargain hunters

    DEFF Research Database (Denmark)

    Jensen, Birger Boutrup

    2008-01-01

    New research proves that Danes are keen bargain hunters, and that they do specific price checks before selecting a product.......New research proves that Danes are keen bargain hunters, and that they do specific price checks before selecting a product....

  18. Predation risk and elk-aspen foraging patterns

    Science.gov (United States)

    Clifford A. White; Michael C. Feller

    2001-01-01

    Elk-aspen foraging patterns may be influenced by cover type, distance from roads or trails, the type of user on road or trail (park visitor, human hunter, or predator), and two general states of aspen condition (open-grown or thicket). Pellet group and browse utilization transects in the Canadian Rockies showed that elk were attracted to roads used by park visitors and...

  19. The hunter a scientific novel

    CERN Document Server

    Genta, Giancarlo

    2013-01-01

    The 24th century: humankind has become a spacefaring civilization, colonizing the solar system and beyond. While no alien forms of life have yet been encountered in this expansion into space, colonists suddenly encounter machines of alien origin - huge robots able to reproduce themselves.  Called replicators by the colonists, they seem to have but a single goal: to destroy all organic life they come in contact with. Since the colonial governments have no means to fight this menace directly, they instead promise huge rewards to whoever destroys a replicator. As a result, the frontier attracts a new kind of adventurers, the Hunters, who work to find and destroy the replicators. Mike Edwards, a skilled young maintenance technician and robotics expert at a faraway outpost, will not only become one of them - but be the very first one to unlock the secret behind the replicators’ origin and mission.   The scientific and technical aspects underlying the plot - in particular space travel, robotics and self-replica...

  20. Hydrology of Hunters Lake, Hernando County, Florida

    Science.gov (United States)

    Henderson, S.E.

    1986-01-01

    The size and shape of Hunters Lake, Florida has been significantly altered by development of the surrounding Spring Hill residential community. The lake is the largest in Hernando County, enlarged by lakeshore excavation and connection to nearby ponds to an area of 360 acres at an average stage of 17.2 ft above sea level. Hunters Lake is naturally a closed lake, but development of Spring Hill has resulted in a surface water outflow from the lake in its southwest corner. Inflow to the lake could occur on the east side during extreme high-water periods. The karst terrain of the Hunters Lake area is internally drained through permeable soils, depressions, and sinkholes, and natural surface drainage is absent. The underlying Floridan aquifer system is unconfined except locally near coastal springs. Flow in the groundwater system is to the west regionally and to the southwest in the immediate area of Hunters Lake. Water level gradients in the groundwater system increase from 1.4 ft/mi east of the lake to about 8 ft/mi southwest of the lake. Hunters Lake is hydraulically connected to the groundwater system, receiving groundwater on the northeast side and losing water to the groundwater system on the southwest side. This close relationship with the groundwater system is demonstrated by graphical and numerical comparison of Hunters Lake stage with water levels in nearby groundwater sites. During 1965-84, the stage of Hunters Lake fluctuated between 12.48 and 20.7 ft above sea level. Because area lakes are all directly affected by groundwater levels, they also show a close relationship with water levels in Hunters Lake. Analysis of water quality data for Hunters Lake indicates that the water of the lake is a soft calcium bicarbonate type with ionic concentrations higher than in water from nearby shallow wells and lower than in water from the Upper Floridan aquifer. Samples collected in 1981-1983 indicate slightly higher levels of ionic concentration than in 1965

  1. Motivations of female Black Hills deer hunters

    Science.gov (United States)

    Gigliotti, Larry M.; Covelli Metcalf, Elizabeth

    2016-01-01

    State fish and wildlife agencies are particularly interested in attracting female participation because of the potential to offset declining participation in hunting. Understanding female hunters’ motivations will be critical for designing effective recruitment and retention programs for women hunters. Although female participation in hunting is increasing, males still outnumber females by about tenfold. Gender differences in deer hunters were explored by comparing ratings of eight motivations (social, nature, excitement, meat, challenge, trophy, extra hunting opportunity, and solitude). Hunter types were defined by hunters’ selection of the most important motivation for why they like Black Hills deer hunting. Overall, females and males were relatively similar in their ratings of the eight motivations, and we found 85% gender similarity in the selection of the most important motivation. Women were slightly more motivated by the food aspect of the hunt while men placed slightly more value on the hunt as a sporting activity.

  2. The Hunter pulmonary angiography catheter for a brachiocephalic vein approach.

    Science.gov (United States)

    Rosen, Galia; Kowalik, Karen J; Ganguli, Suverano; Hunter, David W

    2006-01-01

    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a "C-shaped" curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk.

  3. Pasta Predation.

    Science.gov (United States)

    Waugh, Michael L.

    1986-01-01

    Presents a predator-prey simulation which involves students in collecting data, solving problems, and making predictions on the evolution of prey populations. Provides directives on how to perform the chi-square test and also includes an Applesoft BASK program that performs the calculations. (ML)

  4. Promoting Interest in Plant Biology with Biographies of Plant Hunters.

    Science.gov (United States)

    Daisey, Peggy

    1996-01-01

    Describes the use of biographical stories to promote student interest in plant biology. Discusses plant hunters of various time periods, including ancient, middle ages, renaissance, colonial Americas, and 18th and 19th centuries; women plant hunters of the 1800s and early 1900s; and modern plant hunters. Discusses classroom strategies for the…

  5. 32 CFR 636.10 - Hunter Army Airfield vehicle registration.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Hunter Army Airfield vehicle registration. 636.10... Stewart, Georgia § 636.10 Hunter Army Airfield vehicle registration. Personnel assigned or employed at Hunter Army Airfield are required to register their privately owned vehicles within five days...

  6. Native grasses for rehabilitating Hunter Valley minesites

    Energy Technology Data Exchange (ETDEWEB)

    Huxtable, C. [NSW Department of Land and Water Conservation, NSW (Australia)

    1998-04-01

    Introduced plant species, particularly grasses, have long been used to rehabilitate mined land in Australia. Interest in using native species spawned a research project in the Hunter Valley which has demonstrated the suitability of certain native species for rehabilitation and put forward guidelines to enhance the chance of their successful establishment. 4 photos., 1 tab.

  7. Hunter College Dance Therapy Masters Program.

    Science.gov (United States)

    Schmais, Claire; White, Elissa Q.

    Described is development of the Hunter College dance therapy 18-month 30-credit masters program involving 33 adult students, (in two classes beginning in 1971 and 1972), an educational model, internship in psychiatric institutions, and preparation of instructional materials. The dance therapist is said to incorporate the psychiatric patient's…

  8. Hunters Try to Capture Their Past

    Institute of Scientific and Technical Information of China (English)

    China Daily

    2012-01-01

    Mo Guizhen was 5 when she saw a real bed for the first time.She refused to sleep on it,accustomed as she was to deer furs laid on the ground of hunters' huts in the depths of the Greater Hinggan Mountains in northeastern China.

  9. Hunters syndrom og hørenedsaettelse

    DEFF Research Database (Denmark)

    Kiaer, Eva Kirkegaard; Møller, Troels Reinholdt; Wetke, Randi

    2010-01-01

    functions and language were delayed, and he made audible respiratory sounds and was obviously nasally congested. The boy was referred for further investigations at the Department of Paediatrics. The tests showed that the boy suffered from Hunter Syndrome (MPSII) and he underwent relevant treatment....

  10. The effects of harvest regulations on behaviors of duck hunters

    Science.gov (United States)

    Haugen, Matthew T.; Powell, Larkin A.; Vrtiska, Mark P.; Pope, Kevin L.

    2015-01-01

    Uncertainty exists as to how duck harvest regulations influence waterfowl hunter behavior. We used the U.S. Fish and Wildlife Service’s Parts Collection Survey to examine how harvest regulations affected behaviors of Central Flyway duck hunters. We stratified hunters into ranked groups based on seasonal harvest and identified three periods (1975–1984, 1988–1993, 2002–2011) that represented different harvest regulations (moderate, restrictive, and liberal, respectively; season length and daily bag limits smallest in restrictive seasons and largest in liberal seasons). We examined variability of seven measures of duck hunter behaviors across the periods: days harvesting ducks, daily harvest, hunter mobility, mallard (Anas platyrhynchos) selectivity, gender selectivity, daily female mallard harvest, and timing of harvest. Hunters reported harvesting ducks on more days, at a higher efficiency, and in slightly more counties during liberal seasons relative to restrictive and moderate seasons. We provide evidence to suggest that future regulation change will affect hunter behaviors.

  11. Wildlife value orientations among hunters, landowners and the general public

    DEFF Research Database (Denmark)

    Gamborg, Christian; Jensen, Frank Søndergaard

    2016-01-01

    . Significant differences in wildlife value orientations were found. Mutualists and distanced dominated in the public; most landowners and hunters were utilitarian followed by pluralist. Male hunters were more utilitarian than female. More active hunters were more utilitarian; hunters belonging to a hunting...... association were more utilitarian than those who did not belong to associations. Full-time farmers were more utilitarian than part-time farmers, and conventional farmers were more utilitarian than organic farmers. No significant difference with regard to residence for all three groups was found. Future...

  12. Orthopedic manifestations in patients with muco­polysaccharidosis type II (Hunter syndrome enrolled in the Hunter Outcome Survey

    Directory of Open Access Journals (Sweden)

    Bianca Link

    2010-07-01

    Full Text Available Mucopolysaccharidosis type II (MPS II or Hunter syndrome is a rare, inherited disorder caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase. As a result of this deficiency, glycosaminoglycans accumulate in lysosomes in many tissues, leading to progressive multisystemic disease. The cardiopulmonary and neurological problems associated with MPS II have received considerable attention. Orthopedic manifestations are common but not as well characterized. This study aimed to characterize the prevalence and severity of orthopedic manifestations of MPS II and to determine the relationship of these signs and symptoms with cardiovascular, pulmonary and central nervous system involvement. Orthopedic manifestations of MPS II were studied using cross-sectional data from the Hunter Outcome Survey (HOS. The HOS is a global, physician-led, multicenter observational database that collects information on the natural history of MPS II and the long-term safety and effectiveness of enzyme replacement therapy. As of January 2009, the HOS contained baseline data on joint range of motion in 124 males with MPS II. In total, 79% of patients had skeletal manifestations (median onset, 3.5 years and 25% had abnormal gait (median onset, 5.4 years. Joint range of motion was restricted for all joints assessed (elbow, shoulder, hip, knee and ankle. Extension was the most severely affected movement: the exception to this was the shoulder. Surgery for orthopedic problems was rare. The presence of orthopedic manifestations was associated with the presence of central nervous system and pulmonary involvement, but not so clearly with cardiovascular involvement. Orthopedic interventions should be considered on an individual-patient basis. Although some orthopedic manifestations associated with MPS II may be managed routinely, a good knowledge of other concurrent organ system involvement is essential. A multidisciplinary approach is required.

  13. Radioactive caesium in hunters and their families

    Energy Technology Data Exchange (ETDEWEB)

    Aagren, G.; Bergman, R. [Natonal Defence Research Establishment, Umeaa (Sweden); Drottz-Sjoeberg, B.M. [Center for Risk Research, Stockholm (Sweden); Enander, A. [National Defence Research Establishment, Karlstad (Sweden); Johansson, K.J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

    1995-12-01

    We have measured the whole-body content of radiocesium in men and women in households, where at least one member is a hunter. Hunter families live to a great extent on forest products, such as mushrooms, berries and meat from game. Measurements were performed in two areas in northern Sweden and in three areas in the middle part of Sweden with deposition levels between 7 to 80 kBq/m{sup 2}. The average whole body content of {sup 137}Cs varied between 0.3 to 1.9 kBq for women and 0.6 to 4.7 kBq for men, depending on the deposition level. Each individual in the measured group was also asked to fill in questionnaire and a food diary to provide complementary information of, e.g., food intake and other life conditions. The single dietary factor most clearly related to whole-body content in these groups is the intake of meat from moose. The best regression model with variables from the questionnaire explained 60% of the variance in the whole-body content of {sup 137}Cs in the measurement group. Some of the variables in this model were deposition level, sex, rate of intake and estimated consumption of moose meat and estimated amount of bilberries in the fridge. 6 refs, 5 figs, 14 tabs.

  14. Duck hunters' perceptions of risk for avian influenza, Georgia, USA.

    Science.gov (United States)

    Dishman, Hope; Stallknecht, David; Cole, Dana

    2010-08-01

    To determine duck hunters'risk for highly pathogenic avian influenza, we surveyed duck hunters in Georgia, USA, during 2007-2008, about their knowledge, attitudes, and practices. We found they engage in several practices that could expose them to the virus. Exposures and awareness were highest for those who had hunted >10 years.

  15. Play as a Foundation for Hunter-Gatherer Social Existence

    Science.gov (United States)

    Gray, Peter

    2009-01-01

    The author offers the thesis that hunter-gatherers promoted, through cultural means, the playful side of their human nature and this made possible their egalitarian, nonautocratic, intensely cooperative ways of living. Hunter-gatherer bands, with their fluid membership, are likened to social-play groups, which people could freely join or leave.…

  16. Attribute-based analysis of hunters' lease preferences.

    Science.gov (United States)

    Hussain, Anwar; Munn, Ian A; Hudson, Darren; West, Ben

    2010-12-01

    Understanding of hunter preferences for hunting lease attributes is important to landowners because such knowledge provides key information for managing and marketing fee-hunting in order to maximize revenues. Premised on this insight, we used attribute based modeling to investigate how hunter preferences for potential leases were influenced by lease and hunter-specific attributes. A mail survey of Mississippi licensed hunters provided the necessary data. Estimation results based on McFadden conditional logit regression suggested that lease attributes including game diversity, lease location relative to hunter residence, lease size, lease duration and lease rate influenced willingness to pay for additional units of lease attributes. Depending on the specific levels of these attributes, WTP could vary as much as $5.70 per acre. Of the hunter-specific attributes, age and income significantly influenced hunter decision to buy a lease or opt for status quo. Results of this study should assist landowners in increasing financial returns from fee-hunting endeavors through appropriate changes to their hunting access policies and wildlife management activities in response to hunter preferences regarding lease attributes.

  17. Wild boar hunters profile in Shimane prefecture, western Japan

    Directory of Open Access Journals (Sweden)

    Ueda, G.

    2005-12-01

    Full Text Available Wild boars have been expanding their range and seriously damage agricultural crops all over Japan. Such situation is obvious in Shimane Prefecture, western end of Honshu Island, where most of its territory is mountainous. Populaton control is strongly expected by farmers and administration. However, the number of hunters has been drastically decreasing since the 1970’s. To maintain and increase hunters, we must investigate their activities and attitudes to clarify the problems. Questionnaires were conducted in 2001 on 310 hunters who renewed their hunting license at local office. The response rate was 80.0%. Wild boar hunters accounted for 61.6%, and the others were mostly bird hunters (32.5%. The objective of wild boar hunting was predominantly nuisance control, and very few hunted for money despite of its high commercial value. Most of them were farmers (35.8% and/or farm village dwellers (53.6%, and used the leg snare (61.4%. Despite the stable number of hunters, the number of hunters using guns is decreasing. Hunters do not to appear to be interested in maintaining the local hunting society. Leisure is the most pursued objective rather nuisance control. Therefore, actions should be taken to stimulate hunting as a leisure activity thus maintaining an important tool for wild boar management.

  18. 78 FR 77113 - Bakken Hunter, LLC; Notice of Application

    Science.gov (United States)

    2013-12-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Bakken Hunter, LLC; Notice of Application Take notice that on December 2, 2013 Bakken Hunter, LLC (Bakken), 410 17th Street, Denver, Colorado 80202, filed in Docket No....

  19. Why do good hunters have higher reproductive success?

    Science.gov (United States)

    Smith, Eric Alden

    2004-12-01

    Anecdotal evidence from many hunter-gatherer societies suggests that successful hunters experience higher prestige and greater reproductive success. Detailed quantitative data on these patterns are now available for five widely dispersed cases (Ache, Hadza, !Kung, Lamalera, and Meriam) and indicate that better hunters exhibit higher age-corrected reproductive success than other men in their social group. Leading explanations to account for this pattern are: (1) direct provisioning of hunters' wives and offspring, (2) dyadic reciprocity, (3) indirect reciprocity, (4) costly signaling, and (5) phenotypic correlation. I examine the qualitative and quantitative evidence bearing on these explanations and conclude that although none can be definitively rejected, extensive and apparently unconditional sharing of large game somewhat weakens the first three explanations. The costly signaling explanation has support in some cases, although the exact nature of the benefits gained from mating or allying with or deferring to better hunters needs further study.

  20. Predation and caribou populations

    Directory of Open Access Journals (Sweden)

    Dale R. Seip

    1991-10-01

    Full Text Available Predation, especially wolf (Canis lupus predation, limits many North American caribou (Rangifer tarandus populations below the density that food resources could sustain. The impact of predation depends on the parameters for the functional and numerical response of the wolves, relative to the potential annual increment of the caribou population. Differences in predator-avoidance strategies largely explain the major differences in caribou densities that occur naturally in North America. Caribou migrations that spatially separate caribou from wolves allow relatively high densities of caribou to survive. Non-migratory caribou that live in areas where wolf populations are sustained by alternate prey can be eliminated by wolf predation.

  1. SAFETY

    CERN Document Server

    Niels Dupont

    2013-01-01

    CERN Safety rules and Radiation Protection at CMS The CERN Safety rules are defined by the Occupational Health & Safety and Environmental Protection Unit (HSE Unit), CERN’s institutional authority and central Safety organ attached to the Director General. In particular the Radiation Protection group (DGS-RP1) ensures that personnel on the CERN sites and the public are protected from potentially harmful effects of ionising radiation linked to CERN activities. The RP Group fulfils its mandate in collaboration with the CERN departments owning or operating sources of ionising radiation and having the responsibility for Radiation Safety of these sources. The specific responsibilities concerning "Radiation Safety" and "Radiation Protection" are delegated as follows: Radiation Safety is the responsibility of every CERN Department owning radiation sources or using radiation sources put at its disposition. These Departments are in charge of implementing the requi...

  2. Channel centerline for Hunter Creek, Oregon in 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold...

  3. The Hunter Drain Stillwater National Wildlife Refuge Fallon, Nevada

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document outlines water quality concerns related to the operation of the Hunter Drain located in the vicinity of the Stillwater National Wildlife Refuge. This...

  4. Channel centerline for Hunter Creek, Oregon in 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  5. Channel centerline for Hunter Creek, Oregon in 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  6. perceptions and adaptations of beekeepers and honey hunters to ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    honey sector (i.e. honey hunters) to climate change are, however, not adequately explored. The objective ... resort, beekeepers that are severely affected by climate change had no other choice than abandoned beekeeping for .... Trees, shrub.

  7. Morality and Gender: A Commentary on Pratt, Golding, and Hunter.

    Science.gov (United States)

    Smetana, Judith G.

    1984-01-01

    Discusses problems in Pratt, Golding, and Hunter's investigation (in this issue) of two propositions central to Gilligan's (1982) thesis on the mismeasurement of women's moral orientation and development. Describes research addressing the problems and indicates directions for further research. (RH)

  8. Channel centerline for Hunter Creek, Oregon in 1965

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  9. Aerial photo mosaic of Hunter Creek, Oregon in 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  10. Aerial photo mosaic of Hunter Creek, Oregon in 1965

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  11. Do predators influence the behaviour of bats?

    Science.gov (United States)

    Lima, Steven L; O'Keefe, Joy M

    2013-08-01

    Many aspects of animal behaviour are affected by real-time changes in the risk of predation. This conclusion holds for virtually all taxa and ecological systems studied, but does it hold for bats? Bats are poorly represented in the literature on anti-predator behaviour, which may reflect a lack of nocturnal predators specialized on bats. If bats actually experience a world with minimal anti-predator concerns, then they will provide a unique contrast within the realm of vertebrate ecology. Alternatively, such predator-driven behaviour in bats may not yet be fully understood, given the difficulties in working with these highly mobile and nocturnal animals. We provide a wide-ranging exploration of these issues in bat behaviour. We first cover the basic predator-prey information available on bats, both on potential predators and the ways in which bats might perceive predators and respond to attacks. We then cover work relevant to key aspects of bat behaviour, such as choice of daytime roosts, the nature of sleep and torpor, evening roost departures, moonlight avoidance, landscape-related movement patterns, and habitat selection. Overall, the evidence in favour of a strong influence of predators on bat behaviour is equivocal, with the picture clouded by contradictory results and a lack of information on potential predators and the perception of risk by bats. It seems clear that day-active bats run a considerable risk of being killed by diurnal raptors, which are able to capture bats with relative ease. Thus, bats taking advantage of a pulse of insects just prior to sunset are likely taking risks to gain much-needed energy. Further, the choice of daytime roosts by bats is probably strongly influenced by roost safety. Few studies, however, have directly addressed either of these topics. As a group, insectivorous temperate-zone bats show no clear tendency to avoid apparently risky situations, such as activity on moonlit nights. However, some observations are consistent

  12. [A case of tularemia in a Danish hunter].

    Science.gov (United States)

    Edfors, Robert; Smith, Birgitte; Lillebaek, Troels

    2010-02-01

    "Rabbit fever" (Francisella Tularensis) is a rare infection in Denmark. It was first described in Denmark in 1987. It is most likely to affect people who come into close contact with infected animals or ticks, such as hunters, butchers and veterinarians. The diagnosis should be suspected in such persons presenting with fever, headache, lethargy, lymphadenitis and bite wounds. We present a Danish case describing the diagnosis and treatment of a hunter infected with T. tularensis.

  13. Hunter perceptions and acceptance of alternative deer management regulations

    Science.gov (United States)

    Cornicelli, L.; Fulton, D.C.; Grund, M.D.; Fieberg, J.

    2011-01-01

    Wildlife managers are often confronted with a policy paradox where a majority of the public supports an outcome, but there is no agreement on specific management strategies to achieve this outcome. Previous research has also reported a link between regulatory acceptance, hunter satisfaction, and hunter participation rates. Thus, human dimensions research aimed at understanding hunter motivations and behavior is needed for effective management. In 2005, we surveyed Minnesota (USA) deer hunters (n = 6,000; 59% response) to evaluate attitudes regarding alternative deer (Odocoileus virginianus) harvest regulations. We also conducted a series of forced choice experiments in which respondents were asked to select an option from a list of representative regulations that might be adopted to achieve a particular deer management goal. Specifically, we modeled 5 deer population scenarios ranging from low populations with high buck-harvest rates to populations 50% over goal density. Our results indicate that hunters preferred different regulations depending on the population scenario, but generally preferred antler-point restrictions and disliked limiting buck licenses through a lottery. We also found consistency among scenarios, in that a small percentage of respondents indicated they would not hunt if regulations were changed. The results from this study should help wildlife managers design deer harvest regulations that are both acceptable to hunters and achieve management objectives. ?? 2011 The Wildlife Society.

  14. 'Impact hunters' catalyse cooperative hunting in two wild chimpanzee communities.

    Science.gov (United States)

    Gilby, Ian C; Machanda, Zarin P; Mjungu, Deus C; Rosen, Jeremiah; Muller, Martin N; Pusey, Anne E; Wrangham, Richard W

    2015-12-05

    Even when hunting in groups is mutually beneficial, it is unclear how communal hunts are initiated. If it is costly to be the only hunter, individuals should be reluctant to hunt unless others already are. We used 70 years of data from three communities to examine how male chimpanzees 'solve' this apparent collective action problem. The 'impact hunter' hypothesis proposes that group hunts are sometimes catalysed by certain individuals that hunt more readily than others. In two communities (Kasekela and Kanyawara), we identified a total of five males that exhibited high hunt participation rates for their age, and whose presence at an encounter with red colobus monkeys increased group hunting probability. Critically, these impact hunters were observed to hunt first more often than expected by chance. We argue that by hunting first, these males dilute prey defences and create opportunities for previously reluctant participants. This by-product mutualism can explain variation in group hunting rates within and between social groups. Hunting rates declined after the death of impact hunter FG in Kasekela and after impact hunter MS stopped hunting frequently in Kanyawara. There were no impact hunters in the third, smaller community (Mitumba), where, unlike the others, hunting probability increased with the number of females present at an encounter with prey.

  15. Improvements to the Hunter Dose tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Whiteside, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Aucott, T. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brand, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-01

    Since 1965, the Savannah River Site (SRS) has conducted deer hunts which are open to the general public. SRS performs field monitoring for cesium-137 (Cs-137) of each harvested animal to determine whether the animal may be released to the hunter. A new field system for measuring Cs-137 in the harvested animals has been developed. The system incorporates numerous enhancements compared to the original system. The original system was composed of two Ludlum Measurements scalar-driven 2 inch x 2 inch sodium iodide counters, while the new system is based on a single Ametek Ortec Digibase-driven 2 inch x 4 inch x 16 inch sodium iodide gamma spectrometer. The new system includes a series of easy-to-assemble stainless steel encapsulated lead shields. The combination of the larger detector size and lead shielding improved the detection limit of the new system by a factor of approximately three compared to the original system. This lower detection limit allows for a larger number of measurements to be directly compared to the laboratory results, in cases where animal portions have been sampled. The results from developing and using this system are presented as well as recommendations on improvements to the overall field monitoring of the SRS hunts.

  16. Safety

    CERN Multimedia

    2003-01-01

    Please note that the safety codes A9, A10 AND A11 (ex annexes of SAPOCO/42) entitled respectively "Safety responsibilities in the divisions" "The safety policy committee (SAPOCO) and safety officers' committees" and "Administrative procedure following a serious accident or incident" are available on the web at the following URLs: Code A9: http://edms.cern.ch/document/337016/LAST_RELEASED Code A10: http://edms.cern.ch/document/337019/LAST_RELEASED Code A11: http://edms.cern.ch/document/337026/LAST_RELEASED Paper copies can also be obtained from the TIS divisional secretariat, e-mail: tis.secretariat@cern.ch. TIS Secretariat

  17. Bioinsecticide-predator interactions: azadirachtin behavioral and reproductive impairment of the coconut mite predator Neoseiulus baraki.

    Science.gov (United States)

    Lima, Debora B; Melo, José Wagner S; Guedes, Nelsa Maria P; Gontijo, Lessando M; Guedes, Raul Narciso C; Gondim, Manoel Guedes C

    2015-01-01

    Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.

  18. Bioinsecticide-predator interactions: azadirachtin behavioral and reproductive impairment of the coconut mite predator Neoseiulus baraki.

    Directory of Open Access Journals (Sweden)

    Debora B Lima

    Full Text Available Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae. The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot (Acari: Phytoseiidae. Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.

  19. On a periodic two-component Hunter-Saxton equation

    CERN Document Server

    Kohlmann, Martin

    2011-01-01

    We determine the solution of the geodesic equation associated with a periodic two-component Hunter-Saxton system on a semidirect product obtained from the diffeomorphism group of the circle, modulo rigid rotations, and a space of scalar functions. In particular, we compute the time of breakdown of the geodesic flow. As a further goal, we establish a local well-posedness result for the two-component Hunter-Saxton system in the smooth category. The paper gets in line with some recent results for the generalized Hunter-Saxton equation provided by Escher, Wu and Wunsch in [J. Escher, Preprint 2010] and [H. Wu, M. Wunsch, arXiv:1009.1688v1 [math.AP

  20. Hunter-gatherer plant use in southwest Asia

    DEFF Research Database (Denmark)

    Otaegui, Amaia Arranz; Ibañez, Juan José; Zapata, Lydia

    2016-01-01

    This paper focuses on plant use by the last hunter-gatherers in the Levant, from the Last Glacial Maximum (LGM) to the first experiments with plant cultivation at the beginning of the Holocene. This review of Epipaleolithic and Early Neolithic plant use summarises available archaeobotanical and t...

  1. Planet Hunters 2 in the K2 Era

    Science.gov (United States)

    Schwamb, Megan E.; Fischer, Debra; Boyajian, Tabetha S.; Giguere, Matthew J.; Ishikawa, Sascha; Lintott, Chris; Lynn, Stuart; Schmitt, Joseph; Snyder, Chris; Wang, Ji; Barclay, Thomas

    2015-01-01

    Planet Hunters (http://www.planethunters.org) is an online citizen science project enlisting hundreds of thousands of people to search for planet transits in the publicly released Kepler data. Volunteers mark the locations of visible transits in a web interface, with multiple independent classifiers reviewing a randomly selected ~30-day light curve segment. In September 2014, Planet Hunters entered a new phase. The project was relaunched with a brand new online classification interface and discussion tool built using the Zooniverse's (http://www.zooniverse.org) latest technology and web platform. The website has been optimized for the rapid discovery and identification of planet candidates in the light curves from K2, the two-wheeled ecliptic plane Kepler mission. We will give an overview of the new Planet Hunters classification interface and Round 2 review system in context of the K2 data. We will present the first results from the Planet Hunters 2 search of K2 Campaigns 0 and 1 including a summary of new planet candidates.

  2. Planet Hunters: Assessing the Kepler Inventory of Short Period Planets

    CERN Document Server

    Schwamb, Megan E; Fischer, Debra A; Giguere, Matthew J; Lynn, Stuart; Smith, Arfon M; Brewer, John M; Parrish, Michael; Schawinski, Kevin; Simpson, Robert J

    2012-01-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of \\geq 2 R\\oplus planets on short period (< 15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, \\geq 4 R\\oplus Planet Hunters \\geq 85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Ke...

  3. Honey, Hadza, hunter-gatherers, and human evolution.

    Science.gov (United States)

    Marlowe, Frank W; Berbesque, J Colette; Wood, Brian; Crittenden, Alyssa; Porter, Claire; Mabulla, Audax

    2014-06-01

    Honey is the most energy dense food in nature. It is therefore not surprising that, where it exists, honey is an important food for almost all hunter-gatherers. Here we describe and analyze widespread honey collecting among foragers and show that where it is absent, in arctic and subarctic habitats, honey bees are also rare to absent. Second, we focus on one hunter-gatherer society, the Hadza of Tanzania. Hadza men and women both rank honey as their favorite food. Hadza acquire seven types of honey. Hadza women usually acquire honey that is close to the ground while men often climb tall baobab trees to raid the largest bee hives with stinging bees. Honey accounts for a substantial proportion of the kilocalories in the Hadza diet, especially that of Hadza men. Cross-cultural forager data reveal that in most hunter-gatherers, men acquire more honey than women but often, as with the Hadza, women do acquire some. Virtually all warm-climate foragers consume honey. Our closest living relatives, the great apes, take honey when they can. We suggest that honey has been part of the diet of our ancestors dating back to at least the earliest hominins. The earliest hominins, however, would have surely been less capable of acquiring as much honey as more recent, fully modern human hunter-gatherers. We discuss reasons for thinking our early ancestors would have acquired less honey than foragers ethnographically described, yet still significantly more than our great ape relatives.

  4. Medicinal and ethnoveterinary remedies of hunters in Trinidad

    OpenAIRE

    Georges Karla; Harper Tisha; Lans Cheryl; Bridgewater Elmo

    2001-01-01

    Abstract Background Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. Results Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Pe...

  5. Sources of nonresponse to the Federal Waterfowl Hunter Questionnaire Survey

    Science.gov (United States)

    Barker, R.J.; Geissler, P.H.; Hoover, B.A.

    1992-01-01

    Response rates to the Federal Waterfowl Hunter Questionnaire Survey (WHQS) have declined since the 1950's, suggesting that harvest estimates may be biased. Consequently, we investigated reasons for WHQS nonresponse using surveys of waterfowl hunters in Arkansas, California, Louisiana, Minnesota, New Jersey, and Texas [USA]. Sampling frames were constructed using lists of buyers of state hunting licenses or state duck stamps. We mailed questionnaires to 16,452 randomly selected hunters, with 2 follow-up mailings at 3-week intervals. Questionnaires were completed by 8,812 respondents, and a further 587 interviews were conducted by telephone. Post offices accounted for between 53.7% (Minn.) and 92.8% (N.J.) of federal waterfowl duck stamp sales, and stores accounted for most other sales. Of hunters who bought a federal waterfowl stamp from sample post offices, between 16.7% (Minn.) and 40.0% (Ark.) reported receiving a WHQS contact card. Of those receiving contact cards, between 30.0% (N.J.) and 64.3% (La. and Tex.) reported returning them. Because survey coverage of the target population is poor, we recommend that a new sampling frame be developed for the WHQS.

  6. Hot subduction: Magmatism along the Hunter Ridge, SW Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, A.J.; Verbeeten, A.; Danyushevsky, L.V.; Sigurdsson, I.A. [SRC for Ore Deposit Research, Hobart, TAS (Australia); Maillet, P. [Australian National University, Canberra, ACT (Australia). Department of Geology; Maillet, P. [ORSTOM Centre de Brest, France, (France); Monzier, M. [ORSTOM Centre, Ecuador, (Ecuador)

    1997-12-31

    The Hunter `fracture zone` is generally regarded as a transform plate boundary linking the oppositely dipping Tongan and Vanuatu subduction systems. Dredging along the Hunter Ridge and sampling of its northernmost extent, exposed as the island of Kadavu in Fiji, has yielded a diversity of magmatic suites, including arc tholeiites and high-Ca boninites, high-Mg lavas with some affinities to boninites and some affinities to adakites, and true adakitic lavas associated with remarkable low-Fe, high-Na basalts with 8-16 ppm Nb (herein high-Nb basalts). Lavas which show clear evidence of slab melt involvement in their petrogenesis occur at either end of the Hunter Ridge, whereas the arc tholeiites and high-Ca boninites appear to be restricted to the south central part of the ridge. Mineralogical and whole rock geochemical data for each of these suites are summarized, and a tectono-magmatic model for their genesis and distribution is suggested. Trace element features and radiogenic isotope data for the Hunter Ridge lavas indicate compositions analogue to Pacific MORB-like mantle. Extended abstract. 6 refs., 2 figs.

  7. The Enchanted Hunters in Nabokov’s Lolita

    National Research Council Canada - National Science Library

    Justine Shu- Ting Kao

    2017-01-01

    In Nabokov’s Lolita, Humbert Humbert’s The Enchanted Hunters, as a quest for love, aims to reconstruct a felicitous world or integrate various fragmentary details into an organic unity that revives a lost love, experiencing it on the...

  8. Camp stability predicts patterns of hunter-gatherer cooperation.

    Science.gov (United States)

    Smith, Daniel; Dyble, Mark; Thompson, James; Major, Katie; Page, Abigail E; Chaudhary, Nikhil; Salali, Gul Deniz; Vinicius, Lucio; Migliano, Andrea Bamberg; Mace, Ruth

    2016-07-01

    Humans regularly cooperate with non-kin, which has been theorized to require reciprocity between repeatedly interacting and trusting individuals. However, the role of repeated interactions has not previously been demonstrated in explaining real-world patterns of hunter-gatherer cooperation. Here we explore cooperation among the Agta, a population of Filipino hunter-gatherers, using data from both actual resource transfers and two experimental games across multiple camps. Patterns of cooperation vary greatly between camps and depend on socio-ecological context. Stable camps (with fewer changes in membership over time) were associated with greater reciprocal sharing, indicating that an increased likelihood of future interactions facilitates reciprocity. This is the first study reporting an association between reciprocal cooperation and hunter-gatherer band stability. Under conditions of low camp stability individuals still acquire resources from others, but do so via demand sharing (taking from others), rather than based on reciprocal considerations. Hunter-gatherer cooperation may either be characterized as reciprocity or demand sharing depending on socio-ecological conditions.

  9. Librarians as Hunter-Gatherers: Lessons Learned from an Excursion

    Science.gov (United States)

    Cooper, Mindy M.

    2013-01-01

    Fueled by the pressing need for electronic resource usage statistics, librarians are finding themselves being thrust into the role of hunter-gatherer. This article discusses the work done at University Library at Indiana University-Purdue University Indianapolis to provide usage statistics for all its paid subscriptions for a 3-year period. The…

  10. Hunter syndrome: Case report and review of literature

    African Journals Online (AJOL)

    There are about thirteen different clinical syndromes of. MPS.2 We report a case of Hunter syndrome, as far as we know this is the .... egaly and cardiovascular complications after the transplant in children. ' .... Bone marrow trans- plantation in ...

  11. SAFETY

    CERN Multimedia

    M. Plagge, C. Schaefer and N. Dupont

    2013-01-01

    Fire Safety – Essential for a particle detector The CMS detector is a marvel of high technology, one of the most precise particle measurement devices we have built until now. Of course it has to be protected from external and internal incidents like the ones that can occur from fires. Due to the fire load, the permanent availability of oxygen and the presence of various ignition sources mostly based on electricity this has to be addressed. Starting from the beam pipe towards the magnet coil, the detector is protected by flooding it with pure gaseous nitrogen during operation. The outer shell of CMS, namely the yoke and the muon chambers are then covered by an emergency inertion system also based on nitrogen. To ensure maximum fire safety, all materials used comply with the CERN regulations IS 23 and IS 41 with only a few exceptions. Every piece of the 30-tonne polyethylene shielding is high-density material, borated, boxed within steel and coated with intumescent (a paint that creates a thick co...

  12. SAFETY

    CERN Multimedia

    C. Schaefer and N. Dupont

    2013-01-01

      “Safety is the highest priority”: this statement from CERN is endorsed by the CMS management. An interpretation of this statement may bring you to the conclusion that you should stop working in order to avoid risks. If the safety is the priority, work is not! This would be a misunderstanding and misinterpretation. One should understand that “working safely” or “operating safely” is the priority at CERN. CERN personnel are exposed to different hazards on many levels on a daily basis. However, risk analyses and assessments are done in order to limit the number and the gravity of accidents. For example, this process takes place each time you cross the road. The hazard is the moving vehicle, the stake is you and the risk might be the risk of collision between both. The same principle has to be applied during our daily work. In particular, keeping in mind the general principles of prevention defined in the late 1980s. These principles wer...

  13. Stress triangle: do introduced predators exert indirect costs on native predators and prey?

    Directory of Open Access Journals (Sweden)

    Jennifer R Anson

    Full Text Available Non-consumptive effects of predators on each other and on prey populations often exceed the effects of direct predation. These effects can arise from fear responses elevating glucocorticoid (GC hormone levels (predator stress hypothesis or from increased vigilance that reduces foraging efficiency and body condition (predator sensitive foraging hypothesis; both responses can lead to immunosuppression and increased parasite loads. Non-consumptive effects of invasive predators have been little studied, even though their direct impacts on local species are usually greater than those of their native counterparts. To address this issue, we explored the non-consumptive effects of the invasive red fox Vulpes vulpes on two native species in eastern Australia: a reptilian predator, the lace monitor Varanus varius and a marsupial, the ringtail possum Pseudocheirus peregrinus. In particular, we tested predictions derived from the above two hypotheses by comparing the basal glucocorticoid levels, foraging behaviour, body condition and haemoparasite loads of both native species in areas with and without fox suppression. Lace monitors showed no GC response or differences in haemoparasite loads but were more likely to trade safety for higher food rewards, and had higher body condition, in areas of fox suppression than in areas where foxes remained abundant. In contrast, ringtails showed no physiological or behavioural differences between fox-suppressed and control areas. Predator sensitive foraging is a non-consumptive cost for lace monitors in the presence of the fox and most likely represents a response to competition. The ringtail's lack of response to the fox potentially represents complete naiveté or strong and rapid selection to the invasive predator. We suggest evolutionary responses are often overlooked in interactions between native and introduced species, but must be incorporated if we are to understand the suite of forces that shape community

  14. Predator interference and stability of predator-prey dynamics.

    Science.gov (United States)

    Přibylová, Lenka; Berec, Luděk

    2015-08-01

    Predator interference, that is, a decline in the per predator consumption rate as predator density increases, is generally thought to promote predator-prey stability. Indeed, this has been demonstrated in many theoretical studies on predator-prey dynamics. In virtually all of these studies, the stabilization role is demonstrated as a weakening of the paradox of enrichment. With predator interference, stable limit cycles that appear as a result of environmental enrichment occur for higher values of the environmental carrying capacity of prey, and even a complete absence of the limit cycles can happen. Here we study predator-prey dynamics using the Rosenzweig-MacArthur-like model in which the Holling type II functional response has been replaced by a predator-dependent family which generalizes many of the commonly used descriptions of predator interference. By means of a bifurcation analysis we show that sufficiently strong predator interference may bring about another stabilizing mechanism. In particular, hysteresis combined with (dis)appearance of stable limit cycles imply abrupt increases in both the prey and predator densities and enhanced persistence and resilience of the predator-prey system. We encourage refitting the previously collected data on predator consumption rates as well as for conducting further predation experiments to see what functional response from the explored family is the most appropriate.

  15. Cape Fur Seal Arctocephalus pusillus predation on Cape Cormorants Phalacrocorax capensis and other birds at Dyer Island, South Africa

    OpenAIRE

    Marks, M.M.; Brooke, R.K.; Gildenhuys, A.M.

    1997-01-01

    Predation on seabirds by fur seals and sea lions (Otariidae) has been widely reported (Glegg 1945, Hamilton 1946, Spellerberg 1975, Bonner 1981, Bonner & Hunter 1982, Lucas & McLaren 1988, Gjertz 1990, Riedman 1990). The incidents were, however, at low levels of intensity and the predatory behaviour appeared to have been restricted to small subgroups. Penguins (Spheniscidae) and auks (Alcidae) are the families most commonly preyed upon, whereas petrels (Procellariidae), d...

  16. A bivalent scale for measuring crowding among deer hunters

    Science.gov (United States)

    Gigliotti, Larry M.; Chase, Loren

    2014-01-01

    One factor that may influence satisfaction in outdoor recreation is crowding, which historically has been defined as a negative evaluation of the density of other participants. While this definition is suitable for most scenarios, there are circumstances where encounters with others in the area are evaluated positively and thus contribute to the satisfaction of the participant. To adequately describe this phenomenon we suggest a more inclusive measurement of crowding that allows for both positive and negative evaluations of participant density to more accurately explore the relationship between crowding and satisfaction. We identified a sub-group of deer hunters who negatively evaluated the low density of other hunters, which reduced their satisfaction with their overall hunting experience. The methodology for measuring crowding in recreation research may have an important effect in identifying the relationship crowding has with other relevant variables as well as management implications.

  17. Mobility of moose-comparing the effects of wolf predation risk, reproductive status, and seasonality.

    Science.gov (United States)

    Wikenros, Camilla; Balogh, Gyöngyvér; Sand, Håkan; Nicholson, Kerry L; Månsson, Johan

    2016-12-01

    In a predator-prey system, prey species may adapt to the presence of predators with behavioral changes such as increased vigilance, shifting habitats, or changes in their mobility. In North America, moose (Alces alces) have shown behavioral adaptations to presence of predators, but such antipredator behavioral responses have not yet been found in Scandinavian moose in response to the recolonization of wolves (Canis lupus). We studied travel speed and direction of movement of GPS-collared female moose (n = 26) in relation to spatiotemporal differences in wolf predation risk, reproductive status, and time of year. Travel speed was highest during the calving (May-July) and postcalving (August-October) seasons and was lower for females with calves than females without calves. Similarly, time of year and reproductive status affected the direction of movement, as more concentrated movement was observed for females with calves at heel, during the calving season. We did not find support for that wolf predation risk was an important factor affecting moose travel speed or direction of movement. Likely causal factors for the weak effect of wolf predation risk on mobility of moose include high moose-to-wolf ratio and intensive hunter harvest of the moose population during the past century.

  18. HiggsHunters - a citizen science project for ATLAS

    CERN Document Server

    Haas, Andrew; The ATLAS collaboration

    2017-01-01

    Since the launch of HiggsHunters.org in November 2014, citizen science volunteers have classified more than a million points of interest in images from the ATLAS experiment at the LHC. Volunteers have been looking for displaced vertices and unusual features in images recorded during LHC Run-1. We discuss the design of the project, its impact on the public, and the surprising results of how the human volunteers performed relative to the computer algorithms in identifying displaced secondary vertices.

  19. Sacrificing Steve: How I Killed the Crocodile Hunter

    Directory of Open Access Journals (Sweden)

    Luke Carman

    2010-09-01

    Full Text Available Bob Hodge and Vijay Mishra argue that the complex issues of illegitimacy at the core of Australian identity are repressed through a continual process of cyclical silencing, where traces of a shameful past are exorcised by a focus on images of a mythologised ‘legend’, embodied in characters such as 'The Man from Snowy River'. This article explores such a 'schizophrenic' cycle in relation to the life, death and resurrection of Steve 'Crocodile Hunter' Irwin.

  20. HiggsHunters - a citizen science project for ATLAS

    CERN Document Server

    Haas, Andrew; The ATLAS collaboration

    2016-01-01

    Since the launch of HiggsHunters.org in November 2014, citizen science volunteers have classified more than a million points of interest in images from the ATLAS experiment at the LHC. Volunteers have been looking for displaced vertices and unusual features in images recorded during LHC Run-1. We discuss the design of the project, its impact on the public, and the surprising results of how the human volunteers performed relative to the computer algorithms in identifying displaced secondary vertices.

  1. Sacrificing Steve : how I killed the Crocodile Hunter

    Directory of Open Access Journals (Sweden)

    Carman, Luke

    2010-01-01

    Full Text Available Bob Hodge and Vijay Mishra argue that the complex issues of illegitimacy at the core of Australian identity are repressed through a continual process of cyclical silencing, where traces of a shameful past are exorcised by a focus on images of a mythologised ‘legend’, embodied in characters such as 'The Man from Snowy River'. This article explores such a 'schizophrenic' cycle in relation to the life, death and resurrection of Steve 'Crocodile Hunter' Irwin.

  2. Hunter Fleming与Access合作开发oligotropin

    Institute of Scientific and Technical Information of China (English)

    陆义(摘)

    2005-01-01

    英国Hunter Fleming公司已与美国的药物输送公司Access Pharmaceuticals签署合作协议,采用Access公司的维生素B12口服药物输送技术,开发治疗亨廷顿氏阿尔茨海默氏病的口服制剂oligotropin(HF0420)。

  3. Hunter-Gatherers and the Origins of Religion.

    Science.gov (United States)

    Peoples, Hervey C; Duda, Pavel; Marlowe, Frank W

    2016-09-01

    Recent studies of the evolution of religion have revealed the cognitive underpinnings of belief in supernatural agents, the role of ritual in promoting cooperation, and the contribution of morally punishing high gods to the growth and stabilization of human society. The universality of religion across human society points to a deep evolutionary past. However, specific traits of nascent religiosity, and the sequence in which they emerged, have remained unknown. Here we reconstruct the evolution of religious beliefs and behaviors in early modern humans using a global sample of hunter-gatherers and seven traits describing hunter-gatherer religiosity: animism, belief in an afterlife, shamanism, ancestor worship, high gods, and worship of ancestors or high gods who are active in human affairs. We reconstruct ancestral character states using a time-calibrated supertree based on published phylogenetic trees and linguistic classification and then test for correlated evolution between the characters and for the direction of cultural change. Results indicate that the oldest trait of religion, present in the most recent common ancestor of present-day hunter-gatherers, was animism, in agreement with long-standing beliefs about the fundamental role of this trait. Belief in an afterlife emerged, followed by shamanism and ancestor worship. Ancestor spirits or high gods who are active in human affairs were absent in early humans, suggesting a deep history for the egalitarian nature of hunter-gatherer societies. There is a significant positive relationship between most characters investigated, but the trait "high gods" stands apart, suggesting that belief in a single creator deity can emerge in a society regardless of other aspects of its religion.

  4. Evolutionary history of hunter-gatherer marriage practices.

    Directory of Open Access Journals (Sweden)

    Robert S Walker

    Full Text Available BACKGROUND: The universality of marriage in human societies around the world suggests a deep evolutionary history of institutionalized pair-bonding that stems back at least to early modern humans. However, marriage practices vary considerably from culture to culture, ranging from strict prescriptions and arranged marriages in some societies to mostly unregulated courtship in others, presence to absence of brideservice and brideprice, and polyandrous to polygynous unions. The ancestral state of early human marriage is not well known given the lack of conclusive archaeological evidence. METHODOLOGY: Comparative phylogenetic analyses using data from contemporary hunter-gatherers around the world may allow for the reconstruction of ancestral human cultural traits. We attempt to reconstruct ancestral marriage practices using hunter-gatherer phylogenies based on mitochondrial DNA sequences. RESULTS: Arranged marriages are inferred to go back at least to first modern human migrations out of Africa. Reconstructions are equivocal on whether or not earlier human marriages were arranged because several African hunter-gatherers have courtship marriages. Phylogenetic reconstructions suggest that marriages in early ancestral human societies probably had low levels of polygyny (low reproductive skew and reciprocal exchanges between the families of marital partners (i.e., brideservice or brideprice. DISCUSSION: Phylogenetic results suggest a deep history of regulated exchange of mates and resources among lineages that enhanced the complexity of human meta-group social structure with coalitions and alliances spanning across multiple residential communities.

  5. PhosphoHunter: An Efficient Software Tool for Phosphopeptide Identification

    Directory of Open Access Journals (Sweden)

    Alessandra Tiengo

    2015-01-01

    Full Text Available Phosphorylation is a protein posttranslational modification. It is responsible of the activation/inactivation of disease-related pathways, thanks to its role of “molecular switch.” The study of phosphorylated proteins becomes a key point for the proteomic analyses focused on the identification of diagnostic/therapeutic targets. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS is the most widely used analytical approach. Although unmodified peptides are automatically identified by consolidated algorithms, phosphopeptides still require automated tools to avoid time-consuming manual interpretation. To improve phosphopeptide identification efficiency, a novel procedure was developed and implemented in a Perl/C tool called PhosphoHunter, here proposed and evaluated. It includes a preliminary heuristic step for filtering out the MS/MS spectra produced by nonphosphorylated peptides before sequence identification. A method to assess the statistical significance of identified phosphopeptides was also formulated. PhosphoHunter performance was tested on a dataset of 1500 MS/MS spectra and it was compared with two other tools: Mascot and Inspect. Comparisons demonstrated that a strong point of PhosphoHunter is sensitivity, suggesting that it is able to identify real phosphopeptides with superior performance. Performance indexes depend on a single parameter (intensity threshold that users can tune according to the study aim. All the three tools localized >90% of phosphosites.

  6. Does lateral transmission obscure inheritance in hunter-gatherer languages?

    Science.gov (United States)

    Bowern, Claire; Epps, Patience; Gray, Russell; Hill, Jane; Hunley, Keith; McConvell, Patrick; Zentz, Jason

    2011-01-01

    In recent years, linguists have begun to increasingly rely on quantitative phylogenetic approaches to examine language evolution. Some linguists have questioned the suitability of phylogenetic approaches on the grounds that linguistic evolution is largely reticulate due to extensive lateral transmission, or borrowing, among languages. The problem may be particularly pronounced in hunter-gatherer languages, where the conventional wisdom among many linguists is that lexical borrowing rates are so high that tree building approaches cannot provide meaningful insights into evolutionary processes. However, this claim has never been systematically evaluated, in large part because suitable data were unavailable. In addition, little is known about the subsistence, demographic, ecological, and social factors that might mediate variation in rates of borrowing among languages. Here, we evaluate these claims with a large sample of hunter-gatherer languages from three regions around the world. In this study, a list of 204 basic vocabulary items was collected for 122 hunter-gatherer and small-scale cultivator languages from three ecologically diverse case study areas: northern Australia, northwest Amazonia, and California and the Great Basin. Words were rigorously coded for etymological (inheritance) status, and loan rates were calculated. Loan rate variability was examined with respect to language area, subsistence mode, and population size, density, and mobility; these results were then compared to the sample of 41 primarily agriculturalist languages. Though loan levels varied both within and among regions, they were generally low in all regions (mean 5.06%, median 2.49%, and SD 7.56), despite substantial demographic, ecological, and social variation. Amazonian levels were uniformly very low, with no language exhibiting more than 4%. Rates were low but more variable in the other two study regions, in part because of several outlier languages where rates of borrowing were

  7. Does lateral transmission obscure inheritance in hunter-gatherer languages?

    Directory of Open Access Journals (Sweden)

    Claire Bowern

    Full Text Available In recent years, linguists have begun to increasingly rely on quantitative phylogenetic approaches to examine language evolution. Some linguists have questioned the suitability of phylogenetic approaches on the grounds that linguistic evolution is largely reticulate due to extensive lateral transmission, or borrowing, among languages. The problem may be particularly pronounced in hunter-gatherer languages, where the conventional wisdom among many linguists is that lexical borrowing rates are so high that tree building approaches cannot provide meaningful insights into evolutionary processes. However, this claim has never been systematically evaluated, in large part because suitable data were unavailable. In addition, little is known about the subsistence, demographic, ecological, and social factors that might mediate variation in rates of borrowing among languages. Here, we evaluate these claims with a large sample of hunter-gatherer languages from three regions around the world. In this study, a list of 204 basic vocabulary items was collected for 122 hunter-gatherer and small-scale cultivator languages from three ecologically diverse case study areas: northern Australia, northwest Amazonia, and California and the Great Basin. Words were rigorously coded for etymological (inheritance status, and loan rates were calculated. Loan rate variability was examined with respect to language area, subsistence mode, and population size, density, and mobility; these results were then compared to the sample of 41 primarily agriculturalist languages. Though loan levels varied both within and among regions, they were generally low in all regions (mean 5.06%, median 2.49%, and SD 7.56, despite substantial demographic, ecological, and social variation. Amazonian levels were uniformly very low, with no language exhibiting more than 4%. Rates were low but more variable in the other two study regions, in part because of several outlier languages where rates of

  8. The Enchanted Hunters in Nabokov’s Lolita

    Directory of Open Access Journals (Sweden)

    Justine Shu- Ting Kao

    2017-06-01

    Full Text Available In Nabokov’s Lolita, Humbert Humbert’s The Enchanted Hunters, as a quest for love, aims to reconstruct a felicitous world or integrate various fragmentary details into an organic unity that revives a lost love, experiencing it on the basis of irony, and revealing a simulation of the desire, violence, and despondency which have been expressed in myths of nymphs and Persephone. The protagonist never reaches this unity, but his narrative of erotic and romantic love reveals him as a pathetic addict engaged in mechanical reproduction related to the phenomena of desire, seduction, violence, and sex. His The Enchanted Hunters does not simulate what he expects of his childhood love with Annabel; rather, it simulates the erotic imagination suggested in Mary D. Sheriff’s term “nymphomania,” in which artists fall degenerately to a model of tragedy. Keywords: simulation, nymph, nymphomania, The Enchanted Hunters The Enchanted Hunters in Nabokov’s Lolita refers to the name of a hotel and the title of a play. This seeming coincidence is actually not coincidental: Nabokov weaves a story concerning a pedophile’s seduction of a prepubescent child into a “story within a story,” in which the girl is imagined as a seducer who bewitches a number of hunters. Just as the girl in the play is a figment of a poet’s imagination, so Lolita in the novel Lolita is an imaginary production of a middle-aged pedophile. Yet Lolita is not so much a novel revealing guilt and mental disorder, but a mélange of art and reality, or more specifically, it is about a coinage in which the author fabricates art and myth in real life. Parallel to the protagonist who simulates what he expects of his childhood love, Annabel, in the form of the nymphet, Lolita, Nabokov replicates the beauty of butterflies in the pursuit of beauty and immortality, and develops the world of art with a pathetic tone whereby we gradually perceive a simulation of the desire, violence, and

  9. The ecological and evolutionary energetics of hunter-gatherer residential mobility

    CERN Document Server

    Hamilton, Marcus J; Rupley, Eric; Youn, Hyejin; West, Geoffrey B

    2016-01-01

    Residential mobility is deeply entangled with all aspects of hunter-gatherer life ways, and is therefore an issue of central importance in hunter-gatherer studies. Hunter-gatherers vary widely in annual rates of residential mobility, and understanding the sources of this variation has long been of interest to anthropologists and archaeologists. Since mobility is, to a large extent, driven by the need for a continuous supply of food, a natural framework for addressing this question is provided by the metabolic theory of ecology. This provides a powerful framework for formulating formal testable hypotheses concerning evolutionary and ecological constraints on the scale and variation of hunter-gatherer residential mobility. We evaluate these predictions using extant data and show strong support for the hypotheses. We show that the overall scale of hunter-gatherer residential mobility is predicted by average human body size, and the limited capacity of mobile hunter-gatherers to store energy internally. We then s...

  10. Social deprivation affects cooperative predator inspection in a cichlid fish.

    Science.gov (United States)

    Hesse, Saskia; Anaya-Rojas, Jaime M; Frommen, Joachim G; Thünken, Timo

    2015-03-01

    The social environment individuals are exposed to during ontogeny shapes social skills and social competence in group-living animals. Consequently, social deprivation has serious effects on behaviour and development in animals but little is known about its impact on cooperation. In this study, we examined the effect of social environment on cooperative predator inspection. Predator inspection behaviour is a complex behaviour, which is present in a variety of shoaling fish species. Often, two fish leave the safety of the group and inspect a potentially dangerous predator in order to gather information about the current predation risk. As predator inspection is highly risky, it is prone to conflicts and cheating. However, cooperation among individuals may reduce the individual predation risk. We investigated this complex social behaviour in juveniles of the cichlid fish Pelvicachromis taeniatus that were reared in two different social environments throughout development. Fish reared in a group inspected more often than isolation-reared fish and were more likely to cooperate, i.e. they conducted conjoint inspection of a predator. By contrast, isolation-reared fish were more likely to perform a single inspection without a companion. These results suggest an impairment of cooperative behaviour in isolation-reared fish most probably due to lack of social experience and resulting in lowered social skills needed in coordinated behaviour.

  11. The Fugue Pattern in The Heart is a Lonely Hunter

    Institute of Scientific and Technical Information of China (English)

    郭主美

    2013-01-01

    Carson McCullers The Heart is a Lonely Hunter is her representative work. McCullers deploys the skill of fugue pattern through the multi-voices reflected in the characters, tactfully unite the form and content into a whole. By adopting Bakhtin ’s theory of polyphony, this paper aims to analyze the fugue pattern together with its multi-voices in the three parts, namely, the exposition, the development and the return reflected in the novel, which highlights its theme of universal loneliness so impressive-ly.

  12. Solar Energy Development Assistance for Fort Hunter Liggett

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Bryan J.; Hoffman, Michael G.; Chvala, William D.

    2011-03-30

    Pacific Northwest National Laboratory provided assistance to Fort Hunter Liggett to determine the opportunities for solar energy development on the site. Increasing use of renewable energy is mandated by several executive orders and legislation. Fort Hunter Liggett has many attributes that enhance its suitability for renewable energy development. First, the site is located south of San Francisco in a remote portion of the costal foothills. Brush and forest fires are frequent and often result in power outages, which subsequently impacts the site’s training mission. In addition, the site’s blended electric rate during fiscal year (FY) 2010 was high at 12 ¢/kWh. Lastly, the solar resource is moderately high; the site receives nearly 5.7 kWh/m2/day on a south facing, latitude-tilted surface. In light of these factors, the site is a clear candidate for a solar photovoltaic array. Prior to Pacific Northwest National Laboratory’s (PNNL) involvement, the site secured funding for a 1 megawatt (MW) photovoltaic (PV) array that will also provide shading for site vehicles. To best implement this project, PNNL conducted a site visit and was tasked with providing the site technical guidance and support regarding module selection, array siting, and other ancillary issues.

  13. Medicinal and ethnoveterinary remedies of hunters in Trinidad

    Directory of Open Access Journals (Sweden)

    Georges Karla

    2001-11-01

    Full Text Available Abstract Background Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. Results Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Petiveria alliacea, Renealmia alpinia, Justicia secunda, Phyllanthus urinaria,Phyllanthus niruri,Momordica charantia, Xiphidium caeruleum, Ottonia ovata, Lepianthes peltata, Capsicum frutescens, Costus scaber, Dendropanax arboreus, Siparuma guianensis, Syngonium podophyllum, Monstera dubia, Solanum species, Eclipta prostrata, Spiranthes acaulis, Croton gossypifolius, Barleria lupulina, Cola nitida, Acrocomia ierensis (tentative ID. Conclusion Plant use is based on odour, and plant morphological characteristics and is embedded in a complex cultural context based on indigenous Amerindian beliefs. It is suggested that the medicinal plants exerted a physiological action on the hunter or his dog. Some of the plants mentioned contain chemicals that may explain the ethnomedicinal and ethnoveterinary use. For instance some of the plants influence the immune system or are effective against internal and external parasites. Plant baths may contribute to the health and well being of the hunting dogs.

  14. Metagenome Sequencing of the Hadza Hunter-Gatherer Gut Microbiota.

    Science.gov (United States)

    Rampelli, Simone; Schnorr, Stephanie L; Consolandi, Clarissa; Turroni, Silvia; Severgnini, Marco; Peano, Clelia; Brigidi, Patrizia; Crittenden, Alyssa N; Henry, Amanda G; Candela, Marco

    2015-06-29

    Through human microbiome sequencing, we can better understand how host evolutionary and ontogenetic history is reflected in the microbial function. However, there has been no information on the gut metagenome configuration in hunter-gatherer populations, posing a gap in our knowledge of gut microbiota (GM)-host mutualism arising from a lifestyle that describes over 90% of human evolutionary history. Here, we present the first metagenomic analysis of GM from Hadza hunter-gatherers of Tanzania, showing a unique enrichment in metabolic pathways that aligns with the dietary and environmental factors characteristic of their foraging lifestyle. We found that the Hadza GM is adapted for broad-spectrum carbohydrate metabolism, reflecting the complex polysaccharides in their diet. Furthermore, the Hadza GM is equipped for branched-chain amino acid degradation and aromatic amino acid biosynthesis. Resistome functionality demonstrates the existence of antibiotic resistance genes in a population with little antibiotic exposure, indicating the ubiquitous presence of environmentally derived resistances. Our results demonstrate how the functional specificity of the GM correlates with certain environment and lifestyle factors and how complexity from the exogenous environment can be balanced by endogenous homeostasis. The Hadza gut metagenome structure allows us to appreciate the co-adaptive functional role of the GM in complementing the human physiology, providing a better understanding of the versatility of human life and subsistence. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Medicinal and ethnoveterinary remedies of hunters in Trinidad.

    Science.gov (United States)

    Lans, C; Harper, T; Georges, K; Bridgewater, E

    2001-01-01

    Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Petiveria alliacea, Renealmia alpinia, Justicia secunda, Phyllanthus urinaria,Phyllanthus niruri,Momordica charantia, Xiphidium caeruleum, Ottonia ovata, Lepianthes peltata, Capsicum frutescens, Costus scaber, Dendropanax arboreus, Siparuma guianensis, Syngonium podophyllum, Monstera dubia, Solanum species, Eclipta prostrata, Spiranthes acaulis, Croton gossypifolius, Barleria lupulina, Cola nitida, Acrocomia ierensis (tentative ID). Plant use is based on odour, and plant morphological characteristics and is embedded in a complex cultural context based on indigenous Amerindian beliefs. It is suggested that the medicinal plants exerted a physiological action on the hunter or his dog. Some of the plants mentioned contain chemicals that may explain the ethnomedicinal and ethnoveterinary use. For instance some of the plants influence the immune system or are effective against internal and external parasites. Plant baths may contribute to the health and well being of the hunting dogs.

  16. Modern day relevance of William Hunter's approach to teaching "The organ of hearing".

    Science.gov (United States)

    Roth, Helena; Smith, Robert A; Mackay, Sarah

    2013-07-01

    William Hunter, a pioneering teacher of Anatomy in the the eighteenth century, championed the use of dissected specimens as aids in the teaching of anatomy. Although Hunter promoted the Paris method of learning Anatomy, by student dissection, he also used prosected material as an adjunct to his lectures. We are fortunate that Hunter bequeathed his extensive collection of over 3,000 museum specimens to the University of Glasgow, many of which are housed in the Laboratory of Human Anatomy in the Thomson Building. Regions such as the temporal bone are frequently difficult for students, and indeed postgraduate trainees in ear nose and throat surgery, to visualize and understand. Hunter overcame this difficulty by producing elegant specimens highlighting the three-dimensional complexity of the area. The current vignette stresses the importance of Hunter in his contemporary setting, but also demonstrates the potential of his approach for current and future teaching programmes in this age of the Internet.

  17. Analysis of heat pumps installed in family housing at Hunter Army Air Field

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S.A.

    1994-08-01

    The US Army Forces Command (FORSCOM) tasked Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) Federal Energy Management Program (FEMP) to conduct a postconstruction evaluation of the air-source heat pumps installed in family housing at Hunter Army Air Field (AAF). The objective of this project was to investigate and resolve concerns about an increase in energy costs at Hunter AAF following the installation of heat pumps in November 1992. After completing several analyses and a field inspection of the heat pumps in family housing at Hunter AAF, the following conclusions were made: the installation of air-source heat pumps reduced the annual energy cost in family housing by $46,672 in 1993; the heat pump thermostat controls in Hunter AAF family housing appear to be incorrectly installed; and the Hunter AAF electric utility bill increased 10% during the first 6 months of 1993 compared to the first 6 months of 1992.

  18. Legitimization of regulatory norms: Waterfowl hunter acceptance of changing duck bag limits

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.; Lawrence, Jeffrey S.; Cordts, Steven D.

    2014-01-01

    Few studies have examined response to regulatory change over time, or addressed hunter attitudes about changes in hunting bag limits. This article explores Minnesota waterfowl hunters’ attitudes about duck bag limits, examining attitudes about two state duck bag limits that were initially more restrictive than the maximum set by the U.S. Fish and Wildlife Service (USFWS), but then increased to match federal limits. Results are from four mail surveys that examined attitudes about bag limits over time. Following two bag limit increases, a greater proportion of hunters rated the new bag limit “too high” and a smaller proportion rated it “too low.” Several years following the first bag limit increase, the proportion of hunters who indicated that the limit was “too high” had declined, suggesting hunter acceptance of the new regulation. Results suggest that waterfowl bag limits may represent legal norms that influence hunter attitudes and gain legitimacy over time.

  19. Density-dependent prey mortality is determined by the spatial scale of predator foraging.

    Science.gov (United States)

    McCarthy, Erin K; White, J Wilson

    2016-02-01

    Foraging theory predicts which prey patches predators should target. However, in most habitats, what constitutes a 'patch' and how prey density is calculated are subjective concepts and depend on the spatial scale at which the predator (or scientist) is observing. Moreover, the predator's 'foraging scale' affects prey population dynamics: predators should produce directly density-dependent (DDD) prey mortality at the foraging scale, but inversely density-dependent (IDD) mortality (safety-in-numbers) at smaller scales. We performed the first experimental test of these predictions using behavioral assays with guppies (Poecilia reticulata) feeding on bloodworm 'prey' patches. The guppy's foraging scale had already been estimated in a prior study. Our experimental results confirmed theoretical predictions: predation was IDD when prey were aggregated at a scale smaller than the foraging scale, but not when prey were aggregated at larger scales. These results could be used to predict outcomes of predator-prey interactions in continuous, non-discrete habitats in the field.

  20. Bat predation by spiders.

    Directory of Open Access Journals (Sweden)

    Martin Nyffeler

    Full Text Available In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (≈ 90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S. Most reports refer to the Neotropics (42% of observed incidences, Asia (28.8%, and Australia-Papua New Guinea (13.5%. Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae. In addition to this, an attack attempt by a large araneomorph hunting spider of the family Pisauridae on an immature bat was witnessed. Eighty-eight percent of the reported incidences of bat catches were attributable to web-building spiders and 12% to hunting spiders. Large tropical orb-weavers of the genera Nephila and Eriophora in particular have been observed catching bats in their huge, strong orb-webs (of up to 1.5 m diameter. The majority of identifiable captured bats were small aerial insectivorous bats, belonging to the families Vespertilionidae (64% and Emballonuridae (22% and usually being among the most common bat species in their respective geographic area. While in some instances bats entangled in spider webs may have died of exhaustion, starvation, dehydration, and/or hyperthermia (i.e., non-predation death, there were numerous other instances where spiders were seen actively attacking, killing, and eating the captured bats (i.e., predation. This evidence suggests that spider predation on flying vertebrates is more widespread than previously assumed.

  1. Bat predation by spiders.

    Science.gov (United States)

    Nyffeler, Martin; Knörnschild, Mirjam

    2013-01-01

    In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (≈ 90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S). Most reports refer to the Neotropics (42% of observed incidences), Asia (28.8%), and Australia-Papua New Guinea (13.5%). Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae. In addition to this, an attack attempt by a large araneomorph hunting spider of the family Pisauridae on an immature bat was witnessed. Eighty-eight percent of the reported incidences of bat catches were attributable to web-building spiders and 12% to hunting spiders. Large tropical orb-weavers of the genera Nephila and Eriophora in particular have been observed catching bats in their huge, strong orb-webs (of up to 1.5 m diameter). The majority of identifiable captured bats were small aerial insectivorous bats, belonging to the families Vespertilionidae (64%) and Emballonuridae (22%) and usually being among the most common bat species in their respective geographic area. While in some instances bats entangled in spider webs may have died of exhaustion, starvation, dehydration, and/or hyperthermia (i.e., non-predation death), there were numerous other instances where spiders were seen actively attacking, killing, and eating the captured bats (i.e., predation). This evidence suggests that spider predation on flying vertebrates is more widespread than previously assumed.

  2. Predation risk drives social complexity in cooperative breeders.

    Science.gov (United States)

    Groenewoud, Frank; Frommen, Joachim Gerhard; Josi, Dario; Tanaka, Hirokazu; Jungwirth, Arne; Taborsky, Michael

    2016-04-12

    Predation risk is a major ecological factor selecting for group living. It is largely ignored, however, as an evolutionary driver of social complexity and cooperative breeding, which is attributed mainly to a combination of habitat saturation and enhanced relatedness levels. Social cichlids neither suffer from habitat saturation, nor are their groups composed primarily of relatives. This demands alternative ecological explanations for the evolution of advanced social organization. To address this question, we compared the ecology of eight populations of Neolamprologus pulcher, a cichlid fish arguably representing the pinnacle of social evolution in poikilothermic vertebrates. Results show that variation in social organization and behavior of these fish is primarily explained by predation risk and related ecological factors. Remarkably, ecology affects group structure more strongly than group size, with predation inversely affecting small and large group members. High predation and shelter limitation leads to groups containing few small but many large members, which is an effect enhanced at low population densities. Apparently, enhanced safety from predators by cooperative defense and shelter construction are the primary benefits of sociality. This finding suggests that predation risk can be fundamental for the transition toward complex social organization, which is generally undervalued.

  3. 75 FR 21663 - Maysteel, LLC Including On-Site Leased Workers From Staff One, Badger Tech, Boyd Hunter, Seek...

    Science.gov (United States)

    2010-04-26

    ... Tech, Boyd Hunter, Seek, QPS, and Service First, Menomonee Falls, WI; Amended Certification Regarding..., including on-site leased workers from Staff One, Badger Tech, Boyd Hunter, Seek, and QPS, Menomonee Falls... Maysteel, LLC, including on-site leased workers from Staff One, Badger Tech, Boyd Hunter, Seek, QPS,...

  4. Hunter standoff killer team (HSKT) ground and flight test results

    Science.gov (United States)

    Moreland, Balinda; Ennis, Mark; Yeates, Robert; Condon, Timothy

    2007-04-01

    Since the inception of powered flight, manned aerial vehicles have been a force multiplier on the battlefield. With the emergence of new technology, the structure of the military battlefield is changing. One such technology, the Unmanned Aerial Vehicle (UAV) has emerged as a valuable asset for today's war fighter. UAVs have traditionally been operated by ground control stations, yet minimum research has been targeted towards UAV connectivity. Airborne Manned Unmanned System Technology Baseline (AMUST-Baseline) was a concept that demonstrated the battlefield synergy gained by Manned and Unmanned Vehicle teaming. AMUST-Baseline allowed an Apache Longbow's (AH-64D) co-pilot gunner (CPG) to have Level IV control of a Hunter fixed wing UAV. Level IV control of a UAV includes payload control, flight control and direct data receipt. With the success of AMUST-Baseline, AATD, Lockheed Martin, Northrop Grumman, and the Boeing Company worked towards enhanced Manned and Unmanned connectivity through a technology investment agreement. This effort named Airborne Manned Unmanned System Technology Demonstration (AMUST-D) focused on the connectivity between two manned platforms, Apache Longbow (AH-64D) and Command and Control (C2) Blackhawk, and Hunter UAV. It allows robust communication from the UAV to each platform through the Tactical Common Data Link (TCDL). AMUST-D used decision aiding technology developed under the Rotorcraft Pilots Associate (RPA) Advanced Technology Demonstration (ATD) as to assist in control of the Hunter UAV, as well as assist the pilot in regularly performed duties. Through the use of decision aiding and UAV control, the pilot and commander were better informed of potential threats and targets, thus increasing his situational awareness. The potential benefits of improved situational awareness are increased pilot survivability, increased lethality, and increased operational effectiveness. Two products were developed under the AMUST-D program, the

  5. Food Sharing among Hadza Hunter-Gatherer Children.

    Science.gov (United States)

    Crittenden, Alyssa N; Zes, David A

    2015-01-01

    Human prosociality is one of the defining characteristics of our species, yet the ontogeny of altruistic behavior remains poorly understood. The evolution of widespread food sharing in humans helped shape cooperation, family formation, life history, language, and the development of economies of scale. While the behavioral and ecological correlates of food sharing among adults are widely studied, very little is known about food sharing among children. Here, in the first study to analyze the food sharing patterns of hunter-gatherer children, we show that while sharing may be biased towards kin, reciprocity characterizes the majority of all sharing dyads, both related and unrelated. These data lend support to the recent claim that discrimination among kin might be linked with reciprocal altruism theory. Furthermore, we show that age positively correlates with an increase in sharing, both in frequency and amount, supporting recent suggestions that prosocial behaviors and egalitarianism develop strongly in middle childhood when children acquire the normative rules of their society.

  6. Representation of Self among Chinese College Job-hunters

    Institute of Scientific and Technical Information of China (English)

    徐嗣群

    2010-01-01

    @@ Introduction: Some of their researches (Booher, 1988; Smith and Bernhardt, 1996; Munter, 2006) have been concentrated on teaching students writing skills.On the other hand, some of their researches (Lakoff, 1975; Labov, 1990; Coates, 1998) have been carried on about identifying and instantiating possible differences in linguistic styles between males and females.However, little work has been undertaken on investigating gender differences reflected in business letters writing, especially job-application letter, by analyzing the genre components and politeness strategies.In this project, by providing a content analysis of 20 job application letters written by Chinese college job applicants, I try to explore the differences between Chinese male and female college job hunters presented in their job application letters.

  7. Visual Analysis of Biological Activity Data with Scaffold Hunter.

    Science.gov (United States)

    Klein, Karsten; Koch, Oliver; Kriege, Nils; Mutzel, Petra; Schäfer, Till

    2013-12-01

    The growing interest in chemogenomics approaches over the last years has led to an increasing amount of data regarding chemical and the corresponding biological activity space. The resulting data, collected in either in-house or public databases, need to be analyzed efficiently to speed-up the increasingly difficult task of drug discovery. Unfortunately, the discovery of new chemical entities or new targets for known drugs ('drug repurposing') is not suitable to a fully automated analysis or a simple drill down process. Visual interactive interfaces that allow to explore chemical space in a systematic manner and facilitate analytical reasoning can help to overcome these problems. Scaffold Hunter is a tool for the visual analysis of chemical compound databases that provides integrated visualization and analysis of biological activity data and fosters the interactive exploration of data imported from a variety of sources. We describe the features and illustrate the use by means of an exemplary analysis workflow.

  8. Costs and benefits in hunter-gatherer punishment.

    Science.gov (United States)

    Boehm, Christopher

    2012-02-01

    Hunter-gatherer punishment involves costs and benefits to individuals and groups, but the costs do not necessarily fit with the assumptions made in models that consider punishment to be altruistic--which brings in the free-rider problem and the problem of second-order free-riders. In this commentary, I present foragers' capital punishment patterns ethnographically, in the interest of establishing whether such punishment is likely to be costly; and I suggest that in many cases abstentions from punishment that might be taken as defections by free-riders are actually caused by social-structural considerations rather than being an effect of free-rider genes. This presentation of data supplements the ethnographic analysis provided by Guala.

  9. Decoys in Predation and Parasitism

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    2003-01-01

    Predator-prey or host-parasite dynamics can be altered by the presence of other species through several mechanisms. One such mechanism is the ‘‘decoy effect,’’ which itself can take a variety of forms. In its simplest form, the third species, which is inedible to the predator, nonetheless interferes

  10. Decoys in Predation and Parasitism

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    2003-01-01

    Predator-prey or host-parasite dynamics can be altered by the presence of other species through several mechanisms. One such mechanism is the ‘‘decoy effect,’’ which itself can take a variety of forms. In its simplest form, the third species, which is inedible to the predator, nonetheless interferes

  11. The Truth About the Internet and Online Predators

    CERN Document Server

    Dingwell, Heath; Peterson, Fred L

    2011-01-01

    To help readers avoid and recognize risky behaviors, The Truth About the Internet and Online Predators explains many of the dangers associated with the Internet. The A-to-Z entries detail the social, legal, and personal risks of Internet use, while personal testimonies and question-and-answer sections provide readers with an inside look at common issues online. Entries include:. Bullies and cyberbullying. Characteristics of online predators. Chat rooms and instant messaging. Internet safety. Parental control. Peers and peer pressure. Phishing and pharming. Privacy issues. Social networking Web

  12. The Bayesian image retrieval system, PicHunter: theory, implementation, and psychophysical experiments.

    Science.gov (United States)

    Cox, I J; Miller, M L; Minka, T P; Papathomas, T V; Yianilos, P N

    2000-01-01

    This paper presents the theory, design principles, implementation and performance results of PicHunter, a prototype content-based image retrieval (CBIR) system. In addition, this document presents the rationale, design and results of psychophysical experiments that were conducted to address some key issues that arose during PicHunter's development. The PicHunter project makes four primary contributions to research on CBIR. First, PicHunter represents a simple instance of a general Bayesian framework which we describe for using relevance feedback to direct a search. With an explicit model of what users would do, given the target image they want, PicHunter uses Bayes's rule to predict the target they want, given their actions. This is done via a probability distribution over possible image targets, rather than by refining a query. Second, an entropy-minimizing display algorithm is described that attempts to maximize the information obtained from a user at each iteration of the search. Third, PicHunter makes use of hidden annotation rather than a possibly inaccurate/inconsistent annotation structure that the user must learn and make queries in. Finally, PicHunter introduces two experimental paradigms to quantitatively evaluate the performance of the system, and psychophysical experiments are presented that support the theoretical claims.

  13. Influence of Age and Educational Level on the Behavior of Hunters in Vojvodina Province (Serbia

    Directory of Open Access Journals (Sweden)

    Vladimir Marković

    2011-07-01

    Full Text Available Education as an important factor in the development of economy has a major impact on the development of hunting and hunting tourism. In this research, it has conducted a survey of hunters from the territory of Vojvodina Province regarding their attitude and motives for hunting, importance of education, importance of GIS in hunting, poaching as well as their level of hunting ethics. Using SPSS program, it was cross-referenced the individual responses in relation to age category and level of education. The results show that the youngest hunters (18 to 35 years compared to middle age hunters (35-59 years and old hunters (over 60 visit hunting events more, they are the most informed about GIS and they are most willing to learn about these technologies. The number of hunters that took part in the poaching is proportional with their level of education, so that most hunters that participate in poaching hold a university degree. However, hunters holding a university degree in the highest percentage believe that GIS can contribute to the development of hunting largely, and are willing to participate in training.

  14. Stability of an intraguild predation system with mutual predation

    Science.gov (United States)

    Wang, Yuanshi; DeAngelis, Donald L.

    2016-04-01

    We examine intraguild predation (IGP), in which species both compete for resources or space and prey on each other. The IGP system is modeled here by a lattice gas model of the mean-field theory. First, we consider the IGP system of one species in which individuals of the same species cannibalize each other. The dynamical behavior of the model demonstrates a mechanism by which the intraspecific predation promotes persistence of the species. Then we consider the IGP system of two species with mutual predation. Global dynamics of the model exhibit basic properties of IGP: (i) When both species' efficiencies in converting the consumptions into fitness are large, the outcome of their interaction is mutualistic in form and the IGP promotes persistence of both species. (ii) When one species' efficiency is large but the other's is small, the interaction outcomes become parasitic in nature, in which an obligate species can survive through the mutual predation with a facultative one. (iii) When both species' efficiencies are small, the interaction outcomes are competitive in nature and the IGP leads to extinction of one of the species. A novel result of this work is that varying one parameter or population density of the species can lead to transition of interaction outcomes between mutualism, parasitism and competition. On the other hand, dynamics of the models demonstrate that over-predation or under-predation will result in extinction of one/both species, while intermediate predation is favorable under certain parameter ranges.

  15. Fungal-mediated multitrophic interactions--do grass endophytes in diet protect voles from predators?

    Directory of Open Access Journals (Sweden)

    Susanna Saari

    Full Text Available Plant-associated micro-organisms such as mycotoxin-producing endophytes commonly have direct negative effects on herbivores. These effects may be carried over to natural enemies of the herbivores, but this has been rarely explored. We examined how feeding on Neotyphodium endophyte infected (E+ and endophyte free (E- meadow ryegrass (Scherodonus pratensis affects body mass, population size and mobility of sibling voles (Microtus levis, and whether the diet mediates the vulnerability of voles to least weasel (Mustela nivalis nivalis predation. Because least weasels are known to be olfactory hunters, we also examined whether they are able to distinguish olfactory cues of voles fed on E+ and E- diets. Neither body mass of voles nor population size differed between diets. However, contrary to our prediction, least weasels preyed more often on voles fed with E- grass than on voles fed with E+ grass. The mobility of voles fed on E+ grass was reduced compared to voles fed on E- grass, but this effect was unrelated to risk of predation. Least weasels appeared unable to distinguish between excrement odours of voles between the two treatments. Our results suggest that consumption of endophytic grass is not directly deleterious to sibling voles. What's more, consumption of endophytes appears to be advantageous to voles by reducing risk of mammalian predation. Our study is thus the first to demonstrate an effect of plant-associated microbial symbionts on herbivore-predator interactions in vertebrate communities.

  16. Fungal-mediated multitrophic interactions--do grass endophytes in diet protect voles from predators?

    Science.gov (United States)

    Saari, Susanna; Sundell, Janne; Huitu, Otso; Helander, Marjo; Ketoja, Elise; Ylönen, Hannu; Saikkonen, Kari

    2010-03-24

    Plant-associated micro-organisms such as mycotoxin-producing endophytes commonly have direct negative effects on herbivores. These effects may be carried over to natural enemies of the herbivores, but this has been rarely explored. We examined how feeding on Neotyphodium endophyte infected (E+) and endophyte free (E-) meadow ryegrass (Scherodonus pratensis) affects body mass, population size and mobility of sibling voles (Microtus levis), and whether the diet mediates the vulnerability of voles to least weasel (Mustela nivalis nivalis) predation. Because least weasels are known to be olfactory hunters, we also examined whether they are able to distinguish olfactory cues of voles fed on E+ and E- diets. Neither body mass of voles nor population size differed between diets. However, contrary to our prediction, least weasels preyed more often on voles fed with E- grass than on voles fed with E+ grass. The mobility of voles fed on E+ grass was reduced compared to voles fed on E- grass, but this effect was unrelated to risk of predation. Least weasels appeared unable to distinguish between excrement odours of voles between the two treatments. Our results suggest that consumption of endophytic grass is not directly deleterious to sibling voles. What's more, consumption of endophytes appears to be advantageous to voles by reducing risk of mammalian predation. Our study is thus the first to demonstrate an effect of plant-associated microbial symbionts on herbivore-predator interactions in vertebrate communities.

  17. Estimated lifetime effective dose to hunters and their families in the three most contaminated counties in Sweden after the Chernobyl nuclear power plant accident in 1986 - A pilot study.

    Science.gov (United States)

    Tondel, Martin; Rääf, Christopher; Wålinder, Robert; Mamour, Afrah; Isaksson, Mats

    2017-10-01

    Hunters and their families were one of the most exposed subpopulations in Sweden after the Chernobyl nuclear power plant accident in 1986. In this pilot study we used existing registries and whole-body measurements to develop algorithms to calculate lifetime effective doses and collective doses to some hunters in Sweden. Ten hunters and their family members were randomly selected from each of the three most contaminated counties in Sweden (Västernorrland, Uppsala, Gävleborg) using the register for hunting weapons from the Police Authority in 1985. Hence, this design can be regarded as a closed cohort only including hunters and their family members living in these three counties at the time of the accident. Statistics Sweden matched these individuals (n = 85) with their dwelling coordinates onto the digital map produced by the Swedish Radiation Safety Authority after aerial measurements of (137)Cs (kBq m(-2)). Internal effective doses were estimated using aggregated transfer factors from ground deposition to in-vivo body concentration for (134)Cs and (137)Cs in hunters (Bq kg(-1)). External effective doses were also calculated on the dwelling coordinate for (134)Cs, (137)Cs and short-lived nuclides in these three counties. Annual effective doses for external and internal doses were then cumulated up to a life expectancy of 80 years for men and 84 years for women, respectively. The total lifetime effective doses to the members of the hunter families in this cohort were on average 8.3 mSv in Västernorrland, 4.7 mSv in Uppsala and 4.1 mSv in Gävleborg. The effective dose to men were about 40% higher than in women. In all counties the internal dose was about 75% of the total lifetime effective dose. The collective dose for all hunters with family members, in total about 44,000 individuals, in these three counties could be approximated at about 256 manSv. This study shows it is possible to use register data to develop algorithms for calculating lifetime effective

  18. Intraguild predation in pioneer predator communities of alpine glacier forelands.

    Science.gov (United States)

    Raso, Lorna; Sint, Daniela; Mayer, Rebecca; Plangg, Simon; Recheis, Thomas; Brunner, Silvia; Kaufmann, Rüdiger; Traugott, Michael

    2014-08-01

    Pioneer communities establishing themselves in the barren terrain in front of glacier forelands consist principally of predator species such as carabid beetles and lycosid spiders. The fact that so many different predators can co-inhabit an area with no apparent primary production was initially explained by allochthonous material deposited in these forelands. However, whether these populations can be sustained on allochthonous material alone is questionable and recent studies point towards this assumption to be flawed. Intraguild predation (IGP) might play an important role in these pioneer predator assemblages, especially in the very early successional stages where other prey is scarce. Here, we investigated IGP between the main predator species and their consumption of Collembola, an important autochthonous alternative prey, within a glacier foreland in the Ötztal (Austrian Alps). Multiplex PCR and stable isotope analysis were used to characterize the trophic niches in an early and late pioneer stage over 2 years. Results showed that intraguild prey was consumed by all invertebrate predators, particularly the larger carabid species. Contrary to our initial hypothesis, the DNA detection frequency of IGP prey was not significantly higher in early than in late pioneer stage, which was corroborated by the stable isotope analysis. Collembola were the most frequently detected prey in all of the predators, and the overall prey DNA detection patterns were consistent between years. Our findings show that IGP appears as a constant in these pioneer predator communities and that it remains unaffected by successional changes. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  19. Symmetry Reduction and Group Invariant Solutions of Hunter-Saxton Equations%Hunter-Saxton方程的对称约化与群不变解

    Institute of Scientific and Technical Information of China (English)

    檀美英; 胡恒春

    2016-01-01

    借助符号计算软件Maple,根据微分方程单参数不变群和群不变解的概念,利用李群对称的待定系数法,得到Hunter-Saxton方程的包含5个任意常数和一个任意函数的一般形式的对称.通过该对称中任意的函数和常数的不同选取,将Hunter-Saxton方程约化为不同形式的常微分方程.最后对约化后的常微分方程进行变换求解,进一步得出Hunter-Saxton方程的一些群不变解和精确解.

  20. Ocean acidification alters predator behaviour and reduces predation rate.

    Science.gov (United States)

    Watson, Sue-Ann; Fields, Jennifer B; Munday, Philip L

    2017-02-01

    Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO2) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus Projected near-future seawater CO2 levels (975 µatm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min(-1)) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 µatm). Despite increasing activity, elevated CO2 reduced predation rate during predator-prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO2 predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator-prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator-prey relationship are altered by elevated CO2 suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades. © 2017 The Author(s).

  1. Assessing the Main-Belt Comet Population with Comet Hunters

    Science.gov (United States)

    Schwamb, Megan E.; Hsieh, Henry H.; Zhang, Zhi-Wei; Chen, Ying-Tung; Lintott, Chris; Wang, Shiang-Yu; Mishra, Ishan

    2017-01-01

    Cometary activity in the asteroid belt is a recent discovery. Evidence suggests recent collisions play a role excavating subsurface water ice in these Main Belt Comets (MBCs). MBCs may be an alternative source of Earth’s water. The properties and origins of the MBCs remain elusive. To date ~15 MBCs are known, but only with many tens to 100s of MBCs can we fully explore this new reservoir and its implications for the early Earth.Automated routines identify cometary objects by comparing the point spread functions (PSFs) of moving objects to background stars. This approach may miss cometary activity with low-level dust comae or trails that are too weak or extended to affect an object's near-nucleus PSF profile. Direct visual inspection of moving objects by survey team members can often catch such unusual objects, but such an approach is impractical for the largest surveys to date, and will only become more intractable with the next generation wide-field surveys.With the Internet, tens of thousands of people can be engaged in the scientific process. With this citizen science approach, the combined assessment of many non-experts often equals or rivals that of a trained expert and in many cases outperforms automated algorithms. The Comet Hunters (http://www.comethunters.org) project enlists the public to search for MBCs in data from the Hyper Suprime-Cam (HSC) wide survey. HSC is to date the largest field-of-view camera (covering a 1.5 degree diameter circle on sky) on a 8-10-m class telescope. The HSC wide survey provides the sensitivity to detect cometary activity at lower levels than have been possible for previous surveys.We will give an overview of the Comet Hunters project. We will present the results from the first ~10,000 HSC asteroids searched and provide an estimate on the frequency of cometary activity in the Main Asteroid beltAcknowledgements: This work uses data generated via the Zooniverse.org platform, development of which was supported by a Global

  2. Kinship reinforces cooperative predator inspection in a cichlid fish.

    Science.gov (United States)

    Hesse, Saskia; Anaya-Rojas, Jaime M; Frommen, Joachim G; Thünken, Timo

    2015-11-01

    Kin selection theory predicts that cooperation is facilitated between genetic relatives, as by cooperating with kin an individual might increase its inclusive fitness. Although numerous theoretical papers support Hamilton's inclusive fitness theory, experimental evidence is still underrepresented, in particular in noncooperative breeders. Cooperative predator inspection is one of the most intriguing antipredator strategies, as it implies high costs on inspectors. During an inspection event, one or more individuals leave the safety of a group and approach a potential predator to gather information about the current predation risk. We investigated the effect of genetic relatedness on cooperative predator inspection in juveniles of the cichlid fish Pelvicachromis taeniatus, a species in which juveniles live in shoals under natural conditions. We show that relatedness significantly influenced predator inspection behaviour with kin dyads being significantly more cooperative. Thus, our results indicate a higher disposition for cooperative antipredator behaviour among kin as predicted by kin selection theory. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  3. Integrability and Solutions of the (2 + 1)-dimensional Hunter-Saxton Equation

    Science.gov (United States)

    Cai, Hong-Liu; Qu, Chang-Zheng

    2016-04-01

    In this paper, the (2 + 1)-dimensional Hunter-Saxton equation is proposed and studied. It is shown that the (2 + 1)-dimensional Hunter-Saxton equation can be transformed to the Calogero-Bogoyavlenskii-Schiff equation by reciprocal transformations. Based on the Lax-pair of the Calogero-Bogoyavlenskii-Schiff equation, a non-isospectral Lax-pair of the (2 + 1)-dimensional Hunter-Saxton equation is derived. In addition, exact singular solutions with a finite number of corners are obtained. Furthermore, the (2 + 1)-dimensional μ-Hunter-Saxton equation is presented, and its exact peaked traveling wave solutions are derived. Supported by National Natural Science Foundation of China under Grant No. 11471174 and NSF of Ningbo under Grant No. 2014A610018

  4. Wetted channel and bar features for Hunter Creek, Oregon in 1965

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  5. Wetted channel and bar features for Hunter Creek, Oregon in 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  6. Hunter Harvest and Effort North Mississippi Refuges Complex 2001-2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Reports contains summarized yearly harvest of game species on Coldwater River, Dahomey, and Tallahatchie NWRs and the total hunter effort based on daily use cards...

  7. Wetted channel and bar features for Hunter Creek, Oregon in 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  8. Wetted channel and bar features for Hunter Creek, Oregon in 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach,...

  9. Predator control problems in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One of the important wildlife management activities in Alaska is that of predator control. This simple statement requires some explanation. In the course of these...

  10. Waterfowl experts support predator work

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This article is on the need for predator management and trapping to increase waterfowl production in the wake on Conservation Reserve Program land being converted to...

  11. 弱耗散μ-Hunter-Saxton 方程的爆破%Blow-up of a weakly dissipative μ-Hunter-Saxton equation

    Institute of Scientific and Technical Information of China (English)

    吕红杰; 刘静静; 齐静; 刘硕

    2015-01-01

    研究了弱耗散μ-Hunter-Saxton 方程 Caucly 问题的爆破现象。给出了一个新的爆破结果,推导出爆破强解精确的爆破率。%We study the Cauchy problem of the weakly dissipative μ-Hunter-Saxton equation.The present work is main-ly concerned with blow-up phenomena of the equation.We first present a new blow-up result for strong solutions to the equation.Then,we drive the precise blow-up rate for strong solutions to the equation.

  12. Evaluating cost-efficiency and accuracy of hunter harvest survey designs

    Science.gov (United States)

    Lukacs, P.M.; Gude, J.A.; Russell, R.E.; Ackerman, B.B.

    2011-01-01

    Effective management of harvested wildlife often requires accurate estimates of the number of animals harvested annually by hunters. A variety of techniques exist to obtain harvest data, such as hunter surveys, check stations, mandatory reporting requirements, and voluntary reporting of harvest. Agencies responsible for managing harvested wildlife such as deer (Odocoileus spp.), elk (Cervus elaphus), and pronghorn (Antilocapra americana) are challenged with balancing the cost of data collection versus the value of the information obtained. We compared precision, bias, and relative cost of several common strategies, including hunter self-reporting and random sampling, for estimating hunter harvest using a realistic set of simulations. Self-reporting with a follow-up survey of hunters who did not report produces the best estimate of harvest in terms of precision and bias, but it is also, by far, the most expensive technique. Self-reporting with no followup survey risks very large bias in harvest estimates, and the cost increases with increased response rate. Probability-based sampling provides a substantial cost savings, though accuracy can be affected by nonresponse bias. We recommend stratified random sampling with a calibration estimator used to reweight the sample based on the proportions of hunters responding in each covariate category as the best option for balancing cost and accuracy. ?? 2011 The Wildlife Society.

  13. Predators of the Whitetail

    Science.gov (United States)

    Fagre, Daniel B.

    1994-01-01

    white-tailed deer have long been important prey for large predators. Before Europeans colonized North America, deer roaming the forested region east of the Great Plains and areas along the Gulf of Mexico were hunted by wolves and mountain lions, and by Native Americans for food and clothing materials. Today, wolves and mountain lions are largely gone from the white-tailed deer range of the eastern United States. Deer still face the threat of wolves in northern Minnesota, Michigan, and Wisconsin, and of mountain lions, to a limited extent, in Texas and south Florida. Relatively small populations of whitetails have expanded westward, showing up in the Great Plains and several areas west of the Continental Divide such as northwestern Montana, northern Idaho, and eastern Washington. More than half the prey killed by recolonizing wolves in northwestern Montana are white-tailed deer. Although it has not been well documented, these western whitetails undoubtedly also are preyed on by mountain lions. Wolves and mountain lions have evolved as effective killers of deer but with very different physical characteristics and hunting behaviors. Of course, for their part, whitetails have found ways to protect themselves.

  14. Portrait of a Geothermal Spring, Hunter's Hot Springs, Oregon.

    Science.gov (United States)

    Castenholz, Richard W

    2015-01-27

    Although alkaline Hunter's Hot Springs in southeastern Oregon has been studied extensively for over 40 years, most of these studies and the subsequent publications were before the advent of molecular methods. However, there are many field observations and laboratory experiments that reveal the major aspects of the phototrophic species composition within various physical and chemical gradients of these springs. Relatively constant temperature boundaries demark the upper boundary of the unicellular cyanobacterium, Synechococcus at 73-74 °C (the world-wide upper limit for photosynthesis), and 68-70 °C the upper limit for Chloroflexus. The upper limit for the cover of the filamentous cyanobacterium, Geitlerinema (Oscillatoria) is at 54-55 °C, and the in situ lower limit at 47-48 °C for all three of these phototrophs due to the upper temperature limit for the grazing ostracod, Thermopsis. The in situ upper limit for the cyanobacteria Pleurocapsa and Calothrix is at ~47-48 °C, which are more grazer-resistant and grazer dependent. All of these demarcations are easily visible in the field. In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology. Most of the temperature and chemical limits have been explained by field and laboratory experiments.

  15. Food Sharing among Hadza Hunter-Gatherer Children.

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    Alyssa N Crittenden

    Full Text Available Human prosociality is one of the defining characteristics of our species, yet the ontogeny of altruistic behavior remains poorly understood. The evolution of widespread food sharing in humans helped shape cooperation, family formation, life history, language, and the development of economies of scale. While the behavioral and ecological correlates of food sharing among adults are widely studied, very little is known about food sharing among children. Here, in the first study to analyze the food sharing patterns of hunter-gatherer children, we show that while sharing may be biased towards kin, reciprocity characterizes the majority of all sharing dyads, both related and unrelated. These data lend support to the recent claim that discrimination among kin might be linked with reciprocal altruism theory. Furthermore, we show that age positively correlates with an increase in sharing, both in frequency and amount, supporting recent suggestions that prosocial behaviors and egalitarianism develop strongly in middle childhood when children acquire the normative rules of their society.

  16. Genetic and cultural kinship among the Lamaleran whale hunters.

    Science.gov (United States)

    Alvard, Michael

    2011-07-01

    The human ability to form large, coordinated groups is among our most impressive social adaptations. Larger groups facilitate synergistic economies of scale for cooperative breeding, such economic tasks as group hunting, and success in conflict with other groups. In many organisms, genetic relationships provide the structure for sociality to evolve via the process of kin selection, and this is the case, to a certain extent, for humans. But assortment by genetic affiliation is not the only mechanism that can bring people together. Affinity based on symbolically mediated and socially constructed identity, or cultural kinship, structures much of human ultrasociality. This paper examines how genetic kinship and two kinds of cultural kinship--affinal kinship and descent--structure the network of cooperating whale hunters in the village of Lamalera, Indonesia. Social network analyses show that each mechanism of assortment produces characteristic networks of different sizes, each more or less conducive to the task of hunting whales. Assortment via close genetic kin relationships (r = 0.5) produces a smaller, denser network. Assortment via less-close kin relations (r = 0.125) produces a larger but less dense network. Affinal networks are small and diffuse; lineage networks are larger, discrete, and very dense. The roles that genetic and cultural kinship play for structuring human sociality is discussed in the context of these results.

  17. Adaptive memory: fitness relevance and the hunter-gatherer mind.

    Science.gov (United States)

    Nairne, James S; Pandeirada, Josefa N S; Gregory, Karie J; Van Arsdall, Joshua E

    2009-06-01

    Recent studies suggest that human memory systems are "tuned" to remember information that is processed in terms of its fitness value. When people are asked to rate the relevance of words to a survival scenario, performance on subsequent surprise memory tests exceeds that obtained after most other known encoding techniques. The present experiments explored this effect using survival scenarios designed to mimic the division of labor thought to characterize early hunter-gatherer societies. It has been suggested that males and females have different cognitive specializations due to the unique survival tasks (hunting and gathering, respectively) they typically performed during periods of human evolution; the present experiments tested whether such specializations might be apparent in memory for words rated for relevance to these activities. Males and females were asked to rate the relevance of random words to prototypical hunting and gathering scenarios or to matched, non-fitness-relevant control scenarios (gathering food on a scavenger hunt or in a hunting contest). Surprise retention tests revealed superior memory for the words when they were rated for relevance to hunting and gathering scenarios, compared with when they were rated for relevance to the control scenarios, but no sex differences were found in memory performance.

  18. Conservation laws and symmetries of Hunter-Saxton equation: revisited

    Science.gov (United States)

    Tian, Kai; Liu, Q. P.

    2016-03-01

    Through a reciprocal transformation {{T}0} induced by the conservation law {{\\partial}t}≤ft(ux2\\right)={{\\partial}x}≤ft(2uux2\\right) , the Hunter-Saxton (HS) equation {{u}xt}=2u{{u}2x}+ux2 is shown to possess conserved densities involving arbitrary smooth functions, which have their roots in infinitesimal symmetries of {{w}t}={{w}2} , the counterpart of the HS equation under {{T}0} . Hierarchies of commuting symmetries of the HS equation are studied under appropriate changes of variables initiated by {{T}0} , and two of these are linearized while the other is identical to the hierarchy of commuting symmetries admitted by the potential modified Korteweg-de Vries equation. A fifth order symmetry of the HS equation is endowed with a sixth order hereditary recursion operator, which is proved to have a bi-Hamiltonian factorization, by its connection with the Fordy-Gibbons equation. These results reveal the origin for the rich and remarkable structures of the HS equation and partially answer the questions raised by Wang (2010 Nonlinearity 23 2009).

  19. Rabbit hunter uveitis: case report of tularemia uveitis.

    Science.gov (United States)

    Terrada, Céline; Azza, Said; Bodaghi, Bahram; Le Hoang, Phuc; Drancourt, Michel

    2016-09-01

    Literature reports on ophthalmological manifestations related to tularemia, a zoonose caused by the bacterium Francisella tularensis, largely refer to Parinaud's oculoglandular syndrome, which consists of the association of conjunctivitis with preauricular lymphadenitis. In this paper, we report a case of intraocular inflammation during tularemia infection. A 52-year-old Caucasian man was diagnosed with unilateral uveitis. The uveitis was posterior, with a 2+ vitritis and a large yellowish lesion involving the macula with an overlying sub-retinal detachment, extending inferiorly, and subretinal hemorrhages. Fluorescein angiography showed a late hyperfluorescence with focal vascular leakage. Ultrasound biomicroscopy confirmed the presence of a 3.8 mm parietal granuloma with a few calcifications in the left eye. While extensive work-up eliminated any other infectious and non-infectious etiology, tularemia was diagnosed by advanced serology consisting of two-dimensional Western-immunoblotting. The patient, a hunter, recalled having killed rabbits in the days before the symptoms appeared. Uveitis was rapidly controlled following treatment with doxycycline, yet three years after initiation of the treatment, the patient still complained of loss of vision in the left eye with a central scotoma. Posterior uveitis may be an infrequent manifestation of tularemia infection, and therefore this infection should be considered in the differential diagnosis of intraocular inflammation in areas where F. tularensis is endemic.

  20. Hand in Hand: Media Literacy and Internet Safety

    Science.gov (United States)

    Gallagher, Frank

    2011-01-01

    Internet safety cannot be effectively taught without also teaching media literacy. The two go hand in hand, and both are necessary, but neither is sufficient. To understand why, it is important to first appreciate what the real risks to children are. Many of the early Internet safety programs were based on a fear of predators. Predators turned out…

  1. Hand in Hand: Media Literacy and Internet Safety

    Science.gov (United States)

    Gallagher, Frank

    2011-01-01

    Internet safety cannot be effectively taught without also teaching media literacy. The two go hand in hand, and both are necessary, but neither is sufficient. To understand why, it is important to first appreciate what the real risks to children are. Many of the early Internet safety programs were based on a fear of predators. Predators turned out…

  2. ESPRESSO: the ultimate rocky exoplanets hunter for the VLT

    Science.gov (United States)

    Mégevand, Denis; Zerbi, Filippo M.; Cabral, Alexandre; Di Marcantonio, Paolo; Amate, Manuel; Pepe, Francesco; Cristiani, Stefano; Rebolo, Rafael; Santos, Nuno C.; Dekker, Hans; Abreu, Manuel; Affolter, Michael; Avila, Gerardo; Baldini, Veronica; Bristow, Paul; Broeg, Christopher; Carvas, Pedro; Cirami, Roberto; Coelho, João.; Comari, Maurizio; Conconi, Paolo; Coretti, Igor; Cupani, Guido; D'Odorico, Valentina; De Caprio, Vincenzo; Delabre, Bernard; Figueira, Pedro; Fleury, Michel; Fragoso, Ana; Genolet, Ludovic; Gomes, Ricardo; Gonzalez Hernandez, Jonay; Hughes, Ian; Iwert, Olaf; Kerber, Florian; Landoni, Marco; Lima, Jorge; Lizon, Jean-Louis; Lovis, Christophe; Maire, Charles; Mannetta, Marco; Martins, Carlos; Moitinho, André; Molaro, Paolo; Monteiro, Manuel; Rasilla, José Luis; Riva, Marco; Santana Tschudi, Samuel; Santin, Paolo; Sosnowska, Danuta; Sousa, Sergio; Spanò, Paolo; Tenegi, Fabio; Toso, Giorgio; Vanzella, Eros; Viel, Matteo; Zapatero Osorio, Maria Rosa

    2012-09-01

    ESPRESSO, the VLT rocky exoplanets hunter, will combine the efficiency of modern echelle spectrograph with extreme radial-velocity precision. It will be installed at Paranal on ESO's VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radial-velocity precision will be improved to reach 10 cm/s level. We have constituted a Consortium of astronomical research institutes to fund, design and build ESPRESSO on behalf of and in collaboration with ESO, the European Southern Observatory. The project has passed the preliminary design review in November 2011. The spectrograph will be installed at the so-called "Combined Coudé Laboratory" of the VLT, it will be linked to the four 8.2 meters Unit Telescopes (UT) through four optical "Coudé trains" and will be operated either with a single telescope or with up to four UTs. In exchange of the major financial and human effort the building Consortium will be awarded with guaranteed observing time (GTO), which will be invested in a common scientific program. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in many fields of astronomy. Our main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of quiet, near-by G to M-dwarfs, and the analysis of the variability of fundamental physical constants. In this paper, we present the ambitious scientific objectives, the capabilities of ESPRESSO, the technical solutions for the system and its subsystems, enlightening the main differences between ESPRESSO and its predecessors. The project aspects of this facility are also described, from the consortium and partnership structure to the planning phases and milestones.

  3. Transsulfuration pathway thiols and methylated arginines: the Hunter Community Study.

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    Arduino A Mangoni

    Full Text Available BACKGROUND: Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH activity] and with symmetric dimethylarginine (SDMA. We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level. METHODS: Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS, and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR = 64 (60-70 years]. RESULTS: REGRESSION ANALYSIS SHOWED THAT: a age (P = 0.001, gender (P = 0.03, lower estimated glomerular filtration rate (eGFR, P = 0.08, body mass index (P = 0.008, treatment with beta-blockers (P = 0.03, homocysteine (P = 0.02, and glutamylcysteine (P = 0.003 were independently associated with higher ADMA concentrations; and b age (P = 0.001, absence of diabetes (P = 0.001, lower body mass index (P = 0.01, lower eGFR (P<0.001, cysteine (P = 0.007, and glutamylcysteine (P < 0.001 were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations. CONCLUSIONS: After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA and/or cationic amino acid transport requires further investigations.

  4. The night of the hunter: children & adults in the secret

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    Terry caesar

    2010-04-01

    Full Text Available Night of the Hunter is  the 1956 Charles Laughton’s film considered  one of the best discussions about childhood. In this film, the story revolves around the fate of John and Pearl, two orphaned siblings whose father was hanged for stealing. The father had given the children the money, and they hid the money inside the girl’s doll. When the Preacher Powell enters their lives , both John and Pearl are in danger. The siblings have to keep a secret which is both where they put the money, and the fact that, for children, money is simply paper.

  5. The Effects of Changing Sea Ice on Marine Mammals and Their Hunters in Northern Alaska

    Science.gov (United States)

    Huntington, H.; Quakenbush, L.; Nelson, M.

    2015-12-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information and insight relevant to ecological understanding, conservation action, and the regulation of human activity. We interviewed hunters in villages from northern Bering Sea to the Beaufort Sea, focusing on bowhead whales, walrus, and ice seals. Hunters reported extensive changes in sea ice, with resulting effects on the timing of marine mammal migrations, the distribution and behavior of the animals, and the efficacy of certain hunting methods, for example the difficulty of finding ice thick enough to support a bowhead whale for butchering. At the same time, hunters acknowledged impacts and potential impacts from changing technology such as more powerful outboard engines and from industrial activity such as shipping and oil and gas development. Hunters have been able to adapt to some changes, for example by hunting bowhead whales in fall as well as spring on St. Lawrence Island, or by focusing their hunt in a shorter period in Nuiqsut to accommodate work schedules and worse weather. Other changes, such as reduced availability of ice seals due to rapid retreat of pack ice after spring break-up, continue to defy easy responses. Continued environmental changes, increased disturbance from human activity, and the introduction of new regulations for hunting may further challenge the ability of hunters to provide food as they have done to date, though innovation and flexibility may also provide new sources of adaptation.

  6. Targeting hunter distribution based on host resource selection and kill sites to manage disease risk.

    Science.gov (United States)

    Dugal, Cherie J; van Beest, Floris M; Vander Wal, Eric; Brook, Ryan K

    2013-10-01

    Endemic and emerging diseases are rarely uniform in their spatial distribution or prevalence among cohorts of wildlife. Spatial models that quantify risk-driven differences in resource selection and hunter mortality of animals at fine spatial scales can assist disease management by identifying high-risk areas and individuals. We used resource selection functions (RSFs) and selection ratios (SRs) to quantify sex- and age-specific resource selection patterns of collared (n = 67) and hunter-killed (n = 796) nonmigratory elk (Cervus canadensis manitobensis) during the hunting season between 2002 and 2012, in southwestern Manitoba, Canada. Distance to protected area was the most important covariate influencing resource selection and hunter-kill sites of elk (AICw = 1.00). Collared adult males (which are most likely to be infected with bovine tuberculosis (Mycobacterium bovis) and chronic wasting disease) rarely selected for sites outside of parks during the hunting season in contrast to adult females and juvenile males. The RSFs showed selection by adult females and juvenile males to be negatively associated with landscape-level forest cover, high road density, and water cover, whereas hunter-kill sites of these cohorts were positively associated with landscape-level forest cover and increasing distance to streams and negatively associated with high road density. Local-level forest was positively associated with collared animal locations and hunter-kill sites; however, selection was stronger for collared juvenile males and hunter-killed adult females. In instances where disease infects a metapopulation and eradication is infeasible, a principle goal of management is to limit the spread of disease among infected animals. We map high-risk areas that are regularly used by potentially infectious hosts but currently underrepresented in the distribution of kill sites. We present a novel application of widely available data to target hunter distribution based on host resource

  7. Predator-dependent functional response in wolves: from food limitation to surplus killing.

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    Zimmermann, Barbara; Sand, Håkan; Wabakken, Petter; Liberg, Olof; Andreassen, Harry Peter

    2015-01-01

    The functional response of a predator describes the change in per capita kill rate to changes in prey density. This response can be influenced by predator densities, giving a predator-dependent functional response. In social carnivores which defend a territory, kill rates also depend on the individual energetic requirements of group members and their contribution to the kill rate. This study aims to provide empirical data for the functional response of wolves Canis lupus to the highly managed moose Alces alces population in Scandinavia. We explored prey and predator dependence, and how the functional response relates to the energetic requirements of wolf packs. Winter kill rates of GPS-collared wolves and densities of cervids were estimated for a total of 22 study periods in 15 wolf territories. The adult wolves were identified as the individuals responsible for providing kills to the wolf pack, while pups could be described as inept hunters. The predator-dependent, asymptotic functional response models (i.e. Hassell-Varley type II and Crowley-Martin) performed best among a set of 23 competing linear, asymptotic and sigmoid models. Small wolf packs acquired >3 times as much moose biomass as required to sustain their field metabolic rate (FMR), even at relatively low moose abundances. Large packs (6-9 wolves) acquired less biomass than required in territories with low moose abundance. We suggest the surplus killing by small packs is a result of an optimal foraging strategy to consume only the most nutritious parts of easy accessible prey while avoiding the risk of being detected by humans. Food limitation may have a stabilizing effect on pack size in wolves, as supported by the observed negative relationship between body weight of pups and pack size. © 2014 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  8. Open-cut coal mining in Australia's Hunter Valley: Sustainability and the industry's economic, ecological and social implications

    Directory of Open Access Journals (Sweden)

    Drew Cottle

    2014-09-01

    Full Text Available This article questions the sustainability of open-cut coal mining in the Hunter Valley region of Australia. The issue of sustainability is examined in relation to the economic, ecological and social implications of the Hunter Valley’s open-cut coal mining industry. The article demonstrates that critical social and ecological ramifications have been overshadowed by the open-cut coal mining industry’s importance to the economy of the Hunter region and of New South Wales.

  9. Medicine and music: a note on John Hunter (1728-93) and Joseph Haydn (1732-1809).

    Science.gov (United States)

    Fu, Louis

    2010-05-01

    Joseph Haydn was a central figure in the development and growth of the European classical musical tradition in its transition from the Baroque period. John Hunter as the Founder of Scientific Surgery was a dominant figure in 18th-century British medical science. Anne Hunter née Home (1742-1821) was in her own right a figure of some eminence in the literary circles of 18th-century London. Attracted to the burgeoning medical and musical scenes of London, John Hunter married Anne Home and became a famous surgeon; Haydn became acquainted with the Hunters. The people, the opportunities and the circumstances had coincided.

  10. Anterior Hypopituitarism and Treatment Response in Hunter Syndrome: A Comparison of Two Patients

    Science.gov (United States)

    Luca, Paola; Wei, Xing-Chang; Khan, Aneal

    2016-01-01

    Hypopituitarism is a clinically important diagnosis and has not previously been reported in Hunter syndrome. We contrast two cases with anatomic pituitary anomalies: one with anterior panhypopituitarism and the other with intact pituitary function. Patient 1, a 10-year-old boy with Hunter syndrome, was evaluated for poor growth and an ectopic posterior pituitary gland. Endocrine testing revealed growth hormone (GH) deficiency, secondary adrenal insufficiency, and tertiary hypothyroidism. An improvement in growth velocity with hormone replacement (GH, thyroxine, and corticosteroid) was seen; however, final adult height remained compromised. Patient 2, a 13-year-old male with Hunter syndrome, was evaluated for growth failure. He had a large empty sella turcica with posteriorly displaced pituitary. Functional endocrine testing was normal and a trial of GH-treatment yielded no significant effect. Panhypopituitarism associated with pituitary anomalies has not been previously reported in Hunter syndrome and was an incidental finding of significant clinical importance. In the setting of documented anterior hypopituitarism, while hormone replacement improved growth velocity, final height remained impaired. In patient 2 with equivocal GH-testing results, treatment had no effect on linear growth. These cases highlight the importance of careful clinical assessment in Hunter syndrome and that judicious hormone replacement may be indicated in individual cases. PMID:28018694

  11. Applications of resilience theory in management of a moose-hunter system in Alaska

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    Casey L. Brown

    2015-03-01

    Full Text Available We investigated wildfire-related effects on a slow ecological variable, i.e., forage production, and fast social-ecological variables, i.e., seasonal harvest rates, hunter access, and forage offtake, in a moose-hunter system in interior Alaska. In a 1994 burn, average forage production increased slightly (5% between 2007 and 2013; however, the proportional removal across all sites declined significantly (10%. This suggests that moose are not utilizing the burn as much as they have in the past and that, as the burn has aged, the apparent habitat quality has declined. Areas with a greater proportion of accessible burned area supported both high numbers of hunters and harvested moose. Our results suggest that evaluating ecological variables in conjunction with social variables can provide managers with information to forecast management scenarios. We recommend that wildlife managers monitor fast variables frequently, e.g., annually, to adapt and keep their management responsive as resources fluctuate; whereas slower variables, which require less frequent monitoring, should be actively incorporated into long-term management strategies. Climate-driven increases in wildfire extent and severity and economically driven demographic changes are likely to increase both moose density and hunting pressure. However, the future resilience of this moose-hunter system will depend on integrated management of wildfire, hunter access, and harvest opportunities.

  12. DBD-Hunter: a knowledge-based method for the prediction of DNA-protein interactions.

    Science.gov (United States)

    Gao, Mu; Skolnick, Jeffrey

    2008-07-01

    The structures of DNA-protein complexes have illuminated the diversity of DNA-protein binding mechanisms shown by different protein families. This lack of generality could pose a great challenge for predicting DNA-protein interactions. To address this issue, we have developed a knowledge-based method, DNA-binding Domain Hunter (DBD-Hunter), for identifying DNA-binding proteins and associated binding sites. The method combines structural comparison and the evaluation of a statistical potential, which we derive to describe interactions between DNA base pairs and protein residues. We demonstrate that DBD-Hunter is an accurate method for predicting DNA-binding function of proteins, and that DNA-binding protein residues can be reliably inferred from the corresponding templates if identified. In benchmark tests on approximately 4000 proteins, our method achieved an accuracy of 98% and a precision of 84%, which significantly outperforms three previous methods. We further validate the method on DNA-binding protein structures determined in DNA-free (apo) state. We show that the accuracy of our method is only slightly affected on apo-structures compared to the performance on holo-structures cocrystallized with DNA. Finally, we apply the method to approximately 1700 structural genomics targets and predict that 37 targets with previously unknown function are likely to be DNA-binding proteins. DBD-Hunter is freely available at http://cssb.biology.gatech.edu/skolnick/webservice/DBD-Hunter/.

  13. Future Discounting in Congo Basin Hunter-Gatherers Declines with Socio-Economic Transitions.

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    Gul Deniz Salali

    Full Text Available Humans have a tendency to discount the future; that is we value small, short-term rewards over larger, long-term rewards. The degree of future discounting, however, changes in response to socio-ecological factors. Here, we study Mbendjele BaYaka hunter-gatherers of northern Congo and their farmer neighbours to investigate adaptations in inter-temporal preferences in humans. We argue that in immediate-return systems, where food storage is absent and egalitarianism is enforced through levelling mechanisms, future discounting is an adaptive strategy to prevent wealth accumulation and the emergence of hierarchies. This ensures food sharing and allows for survival in unpredictable environments where there is risk of an energy shortfall. On the other hand, when food storage is made possible by the emergence of agriculture or as seen in some delayed-return hunter-gatherer populations, wealth accumulation, hierarchies and lower discount rates become the adaptive strategy. Therefore, individuals in immediate-return, egalitarian societies will discount the future more than those in non-egalitarian, delayed-return societies. Consistent with the predictions we found that market integration and socio-economic transitions decrease the future discounting in Mbendjele hunter-gatherers. Our measures of socio-economic differences marked this transition in hunter-gatherers living in a logging town. The degree of future-discounting was the same between more market-integrated hunter-gatherers and their farmer neighbours.

  14. Comparing Road-Kill Datasets from Hunters and Citizen Scientists in a Landscape Context

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    Florian Heigl

    2016-10-01

    Full Text Available Road traffic has severe effects on animals, especially when road-kills are involved. In many countries, official road-kill data are provided by hunters or police; there are also road-kill observations reported by citizen scientists. The aim of the current study was to test whether road-kill reports by hunters stem from similar landscapes than those reported by citizen scientists. We analysed the surrounding landscapes of 712 road-kill reportings of European hares in the province of Lower Austria. Our data showed that road-killed hares reported both by hunters and citizens are predominantly surrounded by arable land. No difference of hedges and solitary trees could be found between the two datasets. However, significant differences in landcover classes and surrounding road networks indicate that hunters’ and citizen scientists’ data are different. Hunters reported hares from landscapes with significantly higher percentages of arable land, and greater lengths of secondary roads. In contrast, citizens reported hares from landscapes with significantly higher percentages of urban or industrial areas and greater lengths of motorways, primary roads, and residential roads. From this we argue that hunters tend to report data mainly from their hunting areas, whereas citizens report data during their daily routine on the way to/from work. We conclude that a citizen science approach is an important source for road-kill data when used in addition to official data with the aim of obtaining an overview of road-kill events on a landscape scale.

  15. Reducing Lead on the Landscape: Anticipating Hunter Behavior in Absence of a Free Nonlead Ammunition Program.

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    Loren Chase

    Full Text Available Lead is a neurotoxin that has been documented to affect many forms of wildlife, and has been identified as a limiting factor in a population of California Condors in Northern Arizona. The Arizona Game and Fish Department provides vouchers for free nonlead ammunition to hunters selected to hunt within the distribution of California Condors, with the intention of having fewer lead-laden offal piles available to California Condors. Although wildlife agencies may reasonably assume voucher programs motivate hunters into choosing nonlead ammunition, the lead reduction efforts attributable to the voucher program has not been empirically quantified. Our intention was to compare a control group of hunters to a treatment group of hunters within California Condor occupied areas. Both groups received educational materials regarding the deleterious effects of lead, but the treatment group also received a voucher for a free initial box of ammunition. About half of the control group used nonlead ammunition, compared to about three-fourths of the treatment group. Prominent barriers to adoption of nonlead ammunition included a general difficulty of obtaining it, obtaining it in the desired caliber, and its costliness. Frequently mentioned motivations for using nonlead was the exhortation to use it by the Department, and the desire to aid California Condor recovery by hunters. The disparate compliance rates found herein confirm and quantify the success of nonlead ammunition voucher programs, but underscore the importance of working to increase the supply of nonlead ammunition with the end of facilitating its procurement and reducing its cost.

  16. Anterior Hypopituitarism and Treatment Response in Hunter Syndrome: A Comparison of Two Patients

    Directory of Open Access Journals (Sweden)

    Munier A. Nour

    2016-01-01

    Full Text Available Hypopituitarism is a clinically important diagnosis and has not previously been reported in Hunter syndrome. We contrast two cases with anatomic pituitary anomalies: one with anterior panhypopituitarism and the other with intact pituitary function. Patient 1, a 10-year-old boy with Hunter syndrome, was evaluated for poor growth and an ectopic posterior pituitary gland. Endocrine testing revealed growth hormone (GH deficiency, secondary adrenal insufficiency, and tertiary hypothyroidism. An improvement in growth velocity with hormone replacement (GH, thyroxine, and corticosteroid was seen; however, final adult height remained compromised. Patient 2, a 13-year-old male with Hunter syndrome, was evaluated for growth failure. He had a large empty sella turcica with posteriorly displaced pituitary. Functional endocrine testing was normal and a trial of GH-treatment yielded no significant effect. Panhypopituitarism associated with pituitary anomalies has not been previously reported in Hunter syndrome and was an incidental finding of significant clinical importance. In the setting of documented anterior hypopituitarism, while hormone replacement improved growth velocity, final height remained impaired. In patient 2 with equivocal GH-testing results, treatment had no effect on linear growth. These cases highlight the importance of careful clinical assessment in Hunter syndrome and that judicious hormone replacement may be indicated in individual cases.

  17. Predators and the public trust.

    Science.gov (United States)

    Treves, Adrian; Chapron, Guillaume; López-Bao, Jose V; Shoemaker, Chase; Goeckner, Apollonia R; Bruskotter, Jeremy T

    2017-02-01

    Many democratic governments recognize a duty to conserve environmental resources, including wild animals, as a public trust for current and future citizens. These public trust principles have informed two centuries of U.S.A. Supreme Court decisions and environmental laws worldwide. Nevertheless numerous populations of large-bodied, mammalian carnivores (predators) were eradicated in the 20th century. Environmental movements and strict legal protections have fostered predator recoveries across the U.S.A. and Europe since the 1970s. Now subnational jurisdictions are regaining management authority from central governments for their predator subpopulations. Will the history of local eradication repeat or will these jurisdictions adopt public trust thinking and their obligation to broad public interests over narrower ones? We review the role of public trust principles in the restoration and preservation of controversial species. In so doing we argue for the essential roles of scientists from many disciplines concerned with biological diversity and its conservation. We look beyond species endangerment to future generations' interests in sustainability, particularly non-consumptive uses. Although our conclusions apply to all wild organisms, we focus on predators because of the particular challenges they pose for government trustees, trust managers, and society. Gray wolves Canis lupus L. deserve particular attention, because detailed information and abundant policy debates across regions have exposed four important challenges for preserving predators in the face of interest group hostility. One challenge is uncertainty and varied interpretations about public trustees' responsibilities for wildlife, which have created a mosaic of policies across jurisdictions. We explore how such mosaics have merits and drawbacks for biodiversity. The other three challenges to conserving wildlife as public trust assets are illuminated by the biology of predators and the interacting

  18. Intraguild predation and native lady beetle decline.

    Directory of Open Access Journals (Sweden)

    Mary M Gardiner

    Full Text Available Coccinellid communities across North America have experienced significant changes in recent decades, with declines in several native species reported. One potential mechanism for these declines is interference competition via intraguild predation; specifically, increased predation of native coccinellid eggs and larvae following the introduction of exotic coccinellids. Our previous studies have shown that agricultural fields in Michigan support a higher diversity and abundance of exotic coccinellids than similar fields in Iowa, and that the landscape surrounding agricultural fields across the north central U.S. influences the abundance and activity of coccinellid species. The goal of this study was to quantify the amount of egg predation experienced by a native coccinellid within Michigan and Iowa soybean fields and explore the influence of local and large-scale landscape structure. Using the native lady beetle Coleomegilla maculata as a model, we found that sentinel egg masses were subject to intense predation within both Michigan and Iowa soybean fields, with 60.7% of egg masses attacked and 43.0% of available eggs consumed within 48 h. In Michigan, the exotic coccinellids Coccinella septempunctata and Harmonia axyridis were the most abundant predators found in soybean fields whereas in Iowa, native species including C. maculata, Hippodamia parenthesis and the soft-winged flower beetle Collops nigriceps dominated the predator community. Predator abundance was greater in soybean fields within diverse landscapes, yet variation in predator numbers did not influence the intensity of egg predation observed. In contrast, the strongest predictor of native coccinellid egg predation was the composition of edge habitats bordering specific fields. Field sites surrounded by semi-natural habitats including forests, restored prairies, old fields, and pasturelands experienced greater egg predation than fields surrounded by other croplands. This study shows

  19. 75 FR 32877 - Financial Assistance: Wildlife Restoration, Sport Fish Restoration, Hunter Education and Safety

    Science.gov (United States)

    2010-06-10

    ... Wildlife and Sport Fish Restoration Programs Improvement Act of 2000. Section 80.61 What requirements apply... the Dingell-Johnson Sport Fish Restoration Act, but the current regulations apply the requirement to... Dingell-Johnson Sport Fish Restoration Act. This would help agencies comply with statutory requirements...

  20. Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco.

    Science.gov (United States)

    Humphrey, Louise T; De Groote, Isabelle; Morales, Jacob; Barton, Nick; Collcutt, Simon; Bronk Ramsey, Christopher; Bouzouggar, Abdeljalil

    2014-01-21

    Dental caries is an infectious disease that causes tooth decay. The high prevalence of dental caries in recent humans is attributed to more frequent consumption of plant foods rich in fermentable carbohydrates in food-producing societies. The transition from hunting and gathering to food production is associated with a change in the composition of the oral microbiota and broadly coincides with the estimated timing of a demographic expansion in Streptococcus mutans, a causative agent of human dental caries. Here we present evidence linking a high prevalence of caries to reliance on highly cariogenic wild plant foods in Pleistocene hunter-gatherers from North Africa, predating other high caries populations and the first signs of food production by several thousand years. Archaeological deposits at Grotte des Pigeons in Morocco document extensive evidence for human occupation during the Middle Stone Age and Later Stone Age (Iberomaurusian), and incorporate numerous human burials representing the earliest known cemetery in the Maghreb. Macrobotanical remains from occupational deposits dated between 15,000 and 13,700 cal B.P. provide evidence for systematic harvesting and processing of edible wild plants, including acorns and pine nuts. Analysis of oral pathology reveals an exceptionally high prevalence of caries (51.2% of teeth in adult dentitions), comparable to modern industrialized populations with a diet high in refined sugars and processed cereals. We infer that increased reliance on wild plants rich in fermentable carbohydrates and changes in food processing caused an early shift toward a disease-associated oral microbiota in this population.

  1. Planet Hunters: Assessing the Kepler Inventory of Short-period Planets

    Science.gov (United States)

    Schwamb, Megan E.; Lintott, Chris J.; Fischer, Debra A.; Giguere, Matthew J.; Lynn, Stuart; Smith, Arfon M.; Brewer, John M.; Parrish, Michael; Schawinski, Kevin; Simpson, Robert J.

    2012-08-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of >=2 R ⊕ planets on short-period (=4 R ⊕ Planet Hunters >=85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler >=4 R ⊕ planets suggests that the Kepler inventory of >=4 R ⊕ short-period planets is nearly complete.

  2. Ancient DNA reveals lack of continuity between neolithic hunter-gatherers and contemporary Scandinavians

    DEFF Research Database (Denmark)

    Malmström, Helena; Gilbert, M Thomas P; Thomas, Mark G

    2009-01-01

    The driving force behind the transition from a foraging to a farming lifestyle in prehistoric Europe (Neolithization) has been debated for more than a century [1-3]. Of particular interest is whether population replacement or cultural exchange was responsible [3-5]. Scandinavia holds a unique pla......]. Furthermore, our data are consistent with the view that the eastern Baltic represents a genetic refugia for some of the European hunter-gatherer populations....... in this debate, for it maintained one of the last major hunter-gatherer complexes in Neolithic Europe, the Pitted Ware culture [6]. Intriguingly, these late hunter-gatherers existed in parallel to early farmers for more than a millennium before they vanished some 4,000 years ago [7, 8]. The prolonged coexistence...

  3. Zoonotic disease risk and the bushmeat trade: assessing awareness among hunters and traders in Sierra Leone.

    Science.gov (United States)

    Subramanian, Melanie

    2012-12-01

    The bushmeat industry has been a topic of increasing importance among both conservationists and public health officials for its influence on zoonotic disease transmission and animal conservation. While the association between infectious diseases and the bushmeat trade is well established in the research community, risk perception among bushmeat hunters and traders has not been well characterized. I conducted surveys of 123 bushmeat hunters and traders in rural Sierra Leone to investigate hunting practices and awareness of zoonotic disease risk associated with the bushmeat trade. Twenty-four percent of bushmeat hunters and traders reported knowledge of disease transmission from animals to humans. Formal education did not significantly affect awareness of zoonotic disease transmission. Individuals who engaged exclusively in preparation and trading of bushmeat were more likely to accidentally cut themselves compared to those who primarily engaged in bushmeat hunting (P zoonotic pathogens through accidental self-cutting compared to men (P zoonotic disease transmission risk among vulnerable communities.

  4. Clarifying beliefs underlying hunter intentions to support a ban on lead shot

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.; Doncarlos, Kathy

    2016-01-01

    Shot from hunting adds toxic lead to environments worldwide. Existing lead shot regulations have been instituted with little understanding of hunter beliefs and attitudes. This study applied the Theory of Reasoned Action, using a multilevel, multivariate approach, to clarify how positive and negative beliefs relate to attitudes about a ban on lead shot. Structure coefficients and commonality analysis were employed to further examine relationships between beliefs and attitudes. Results suggest that while both positive and negative outcomes influence attitudes, positive outcomes were more influential for supporters and negative beliefs for opposers. Management may need to focus on the results from hunters who indicated that they would be unlikely to support a ban, as these hunters include those who may actively oppose additional efforts to regulate lead.

  5. Ethical acceptability of recreational hunting - does the motive of the hunter matter?

    DEFF Research Database (Denmark)

    Gamborg, Christian; Jensen, Frank Søndergaard; Sandøe, Peter

    2016-01-01

    ,001) and hunters (n=1,130) in Denmark. In this survey just under half of the general public indicated that the hunters’ motives affected their attitude to the acceptability of hunting. A significant difference in wildlife value orientations was found between the two groups. Motives relating to nature, the social...... is to assess the extent to which the perceived motive for recreational hunting plays a role in its public acceptance. We also compare public perceptions of the importance of motive with those of hunters. We conducted a nationally representative survey (web-based questionnaires) of the general public (n=1......’, ‘the sport’, ‘the excitement’, and ‘to kill’ to recreational hunting to a much greater degree than the hunters themselves; and these motives were associated with lower assessments of the acceptability of recreational hunting among the public. The mismatch between presumed and professed motives among...

  6. Herbivory, Predation, and Biological Control.

    Science.gov (United States)

    Murphy, Terence M.; And Others

    1992-01-01

    Authors describe a set of controlled ecosystems that can be used to demonstrate the effects of herbivory on the health and growth of a plant population and of predation on the growth of a primary consumer population. The system also shows the effectiveness of biological pest control measures in a dramatic way. The construction of the ecosystems is…

  7. Power lines, roads, and avian nest survival: effects on predator identity and predation intensity.

    Science.gov (United States)

    DeGregorio, Brett A; Weatherhead, Patrick J; Sperry, Jinelle H

    2014-05-01

    1 Anthropogenic alteration of landscapes can affect avian nest success by influencing the abundance, distribution, and behavior of predators. Understanding avian nest predation risk necessitates understanding how landscapes affect predator distribution and behavior. 2 From a sample of 463 nests of 17 songbird species, we evaluated how landscape features (distance to forest edge, unpaved roads, and power lines) influenced daily nest survival. We also used video cameras to identify nest predators at 137 nest predation events and evaluated how landscape features influenced predator identity. Finally, we determined the abundance and distribution of several of the principal predators using surveys and radiotelemetry. 3 Distance to power lines was the best predictor of predator identity: predation by brown-headed cowbirds (Molothrus ater), corvids (Corvus sp. and Cyanocitta cristata), racers (Coluber constrictor), and coachwhips (Masticophis flagellum) increased with proximity to power lines, whereas predation by rat snakes (Elaphe obsoleta) and raptors decreased. In some cases, predator density may reliably indicate nest predation risk because racers, corvids, and cowbirds frequently used power line right-of-ways. 4 Of five bird species with enough nests to analyze individually, daily nest survival of only indigo buntings (Passerina cyanea) decreased with proximity to power lines, despite predation by most predators at our site being positively associated with power lines. For all nesting species combined, distance to unpaved road was the model that most influenced daily nest survival. This pattern is likely a consequence of rat snakes, the locally dominant nest predator (28% of predation events), rarely using power lines and associated areas. Instead, rat snakes were frequently associated with road edges, indicating that not all edges are functionally similar. 5 Our results suggest that interactions between predators and landscape features are likely to be specific to

  8. Radioiodination and biodistribution of quantum dots using Bolton-Hunter reagent

    Energy Technology Data Exchange (ETDEWEB)

    Jun Park, Jae [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), 215-4 Gongneung-Dong, Nowon-Gu, Seoul 139-706 (Korea, Republic of); Sup Lee, Tae, E-mail: nobelcow@kirams.re.k [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), 215-4 Gongneung-Dong, Nowon-Gu, Seoul 139-706 (Korea, Republic of); Hyun Kang, Joo [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), 215-4 Gongneung-Dong, Nowon-Gu, Seoul 139-706 (Korea, Republic of); Song, Rita [Nano/Bio Chemistry Group, Institut Pasteur Korea (IP-Korea), Seongnam 463-400 (Korea, Republic of); Jeong Cheon, Gi, E-mail: larry@kirams.re.k [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), 215-4 Gongneung-Dong, Nowon-Gu, Seoul 139-706 (Korea, Republic of); Department of Nuclear medicine, Korea Institute of Radiological and Medical Sciences (KIRAMS), 215-4 Gongneung-Dong, Nowon-Gu, Seoul 139-706 (Korea, Republic of)

    2011-01-15

    In this study, the radioiodination and biodistribution of quantum dots (QDs) using Bolton-Hunter reagent were investigated. Radioiodination yield was 33.4{+-}2.0%. Fluorescent intensity of radioiodinated QDs decreased to 75.4% of the maximum prior to radioiodination. In biodistribution and ex vivo fluorescence imaging, radioiodinated QDs were highly accumulated in reticuloendothelial system (liver and spleen) and had low level bone uptakes and slow clearance from body. These results suggest that the radioiodination method of nanoparticles using Bolton-Hunter reagent could be easily used in the biodistribution and quantification of nanoparticles in vivo.

  9. 利用Hunter-Lab色差仪测量彩涂板的色差

    Institute of Scientific and Technical Information of China (English)

    李红军; 陈剑; 王文杰; 曹彦婷

    2006-01-01

    介绍了利用Hunter-Lab色差仪对彩涂板进行色差测量的方法和原理,并对该方法的准确度和精密度进行了分析.结果表明,利用Hunter-Lab色差仪可快速准确的测量彩涂板色差,对彩涂板的生产具有极强的指导意义.

  10. Generic regularity and Lipschitz metric for the Hunter-Saxton type equations

    Science.gov (United States)

    Cai, Hong; Chen, Geng; Shen, Yannan; Tan, Zhong

    2017-01-01

    The Hunter-Saxton equation determines a flow of conservative solutions taking values in the space H1 (R+). However, the solution typically includes finite time gradient blowups, which make the solution flow not continuous w.r.t. the natural H1 distance. The aim of this paper is to first study the generic properties of conservative solutions of some initial boundary value problems to the Hunter-Saxton type equations. Then using these properties, we give a new way to construct a Finsler type metric which renders the flow uniformly Lipschitz continuous on bounded subsets of H1 (R+).

  11. Molecular characterization of Histoplasma capsulatum isolated from an outbreak in treasure hunters Histoplasma capsulatum in treasure hunters

    Directory of Open Access Journals (Sweden)

    Muñoz Bertha

    2010-09-01

    Full Text Available Abstract Background In Mexico, primary pulmonary histoplasmosis is the most relevant clinical form of the disease. The geographical distribution of specific strains of Histoplasma capsulatum circulating in Mexico has not been fully established. Outbreaks must be reported in order to have current, updated information on this disease, identifying new endemic areas, manner of exposure to the fungi, and molecular characterization of the causative agents. We report a recent outbreak of histoplasmosis in treasure hunters and the molecular characterization of two isolates obtained from these patients. Methods Six patients admitted to the National Institute of Respiratory Diseases (INER in Mexico City presented severe respiratory symptoms suggestive of histoplasmosis. They acquired the infection in the Veracruz (VZ endemic zone. Diagnosis was made by X-ray and Computed tomography (CT, liver function, immunological techniques, and culture. Identification of H. capsulatum isolates was confirmed by using Polymerase chain reaction (PCR was conducted with a probe from the M antigen, and the isolates were characterized by means of Random amplification of polymorphic DNA (RAPD-PCR employed the 1253 oligonucleotide and a mixture of oligonucleotides 1281 and 1283. These were compared to eight reference strain isolates from neighboring areas. Results X-ray and CT revealed disseminated micronodular images throughout lung parenchyma, as well as bilateral retrocaval, prevascular, subcarinal, and hilar adenopathies, hepatosplenomegaly, and altered liver function tests. Five of the six patients developed disseminated histoplasmosis. Two H. capsulatum strains were isolated. The same band profile was detected in both strains, indicating that both isolates corresponded to the sole H. capsulatum strain. Molecular characterization of the isolates was similar in 100% with the EH-53 Hidalgo human (HG strain (reference strain integrated into the LAm A clade described for

  12. Hunter-Schmidt Meta-Analysis Paradigm: Its Properties and Applications%Hunter-Schmidt元分析范式:特征和应用

    Institute of Scientific and Technical Information of China (English)

    王拥军; 俞国良

    2010-01-01

    Hunter-Schmidt元分析范式是一种以随机效应模型为基础的比较完备的元分析技术,可以校正效应值的抽样误差、测量误差和全距误差.Hunter-Schmidt元分析范式是应用心理学领域30年来最重要的进展之一,它拓展了心理学的研究方法,开创了校正各种测验误差的方法论研究,激励了心理学家对预测因子的效度概化研究,确认了预测因子和效标之间的水平关系特征和结构关系特征.

  13. Sunday Schools and English Teaching: Re-Reading Ian Hunter and the Emergence of "English" in the United States

    Science.gov (United States)

    Brass, Jory

    2011-01-01

    This article represents an "overdue encounter" with the ideas of Ian Hunter to reconsider the historical emergence and descent of English teaching in the United States. Influenced by Hunter's account of the "pastoral" and "bureaucratic" genealogy of English teaching in England, my historical study documented…

  14. Flyway Habitat Management Unit Project report no. 11: The extent that waterfowl hunting space met the needs of waterfowl hunters in 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To determine the adequacy of waterfowl hunting space, it is necessary to compare the number of hunters that space available can support with the number of hunters...

  15. Escape by the Balearic Lizard (Podarcis lilfordi is affected by elevation of an approaching predator, but not by some other potential predation risk factors

    Directory of Open Access Journals (Sweden)

    William E. Cooper

    2011-12-01

    Full Text Available Many predation risk factors to affect escape behavior by lizards, but effects of some potential risk factors are unknown or are variable among species. We studied effects of several risk factors on escape responses by the Balearic lizard (Podarcis lilfordi, Lacertidae on escape responses. Escape was elicited by an approaching experimenter who recorded flight initiation distance (predator-prey distance when escape begins and distance fled. When an experimenter approached from above (upslope, flight initiation distance and distance fled were longer than when the experimenter approached from below. This novel effect suggests that lizards exposed to aerial predation might have been naturally selected to respond rapidly to predators approaching from above or that effects of path inclination of escape ability may differ between predators and prey in a manner requiring a larger margin of safety during approaches from above than below. Although sex differences in aspects of escape occur in some lizards, including lacertids, no sex difference was observed in P. lilfordi. Because vigilance and some other aspects of antipredatory behavior exhibit cortical lateralization, we tested effects of approach from the left and right sides of lizards. As predicted by optimal escape theory, side of approach did not affect flight initiation distance. Because many lizards have color vision and respond to pigmentation of conspecifics in social settings, researchers have often worn only drably colored clothing when simulating predators. This precaution may be unnecessary because flight initiation distance did not differ among investigator shirt colors (red, orange, olive.

  16. Cannibalism and intraguild predation of eggs within a diverse predator assemblage.

    Science.gov (United States)

    Takizawa, Tadashi; Snyder, William E

    2011-02-01

    Greater biodiversity among aphid predators sometimes leads to greater predator reproductive success. This could occur if cannibalism of predator eggs is consistently stronger than intraguild predation, such that diversity dilutes cannibalism risk when total predator densities remain constant across diversity levels. We compared the frequency of cannibalism versus intraguild predation by adult predators of four species [the lady beetles Coccinella septempunctata L. and Hippodamia convergens Guerin-Meneville, and the predatory bugs Geocoris bullatus (Say) and Nabis alternatus Parshley] on the eggs of three predator species (all of these predators but Nabis). For both coccinellid species, egg predation averaged across all intraguild predators was less frequent than cannibalism. In contrast, Geocoris eggs were generally more likely to be consumed by intraguild predators than by conspecifics. Closer inspection of the data revealed that Geocoris consistently consumed fewer eggs than the other species, regardless of egg species. Indeed, for lady beetle eggs it was relatively infrequent egg predation by Geocoris that brought down the average across all heterospecific predators, masking the fact that adults of the two lady beetles were no more likely to act as egg cannibals than as intraguild predators. Nabis ate eggs of the two beetles at approximately equal rates, but rarely ate Geocoris eggs. Female predators generally consumed more eggs than did males, but this did not alter any of the patterns described above. Altogether, our results suggest that species-specific differences in egg predation rates determined the relative intensity of egg intraguild-predation versus cannibalism, rather than any more general trend for egg cannibalism to always exceed intraguild predation.

  17. Landscape heterogeneity shapes predation in a newly restored predator-prey system.

    Science.gov (United States)

    Kauffman, Matthew J; Varley, Nathan; Smith, Douglas W; Stahler, Daniel R; MacNulty, Daniel R; Boyce, Mark S

    2007-08-01

    Because some native ungulates have lived without top predators for generations, it has been uncertain whether runaway predation would occur when predators are newly restored to these systems. We show that landscape features and vegetation, which influence predator detection and capture of prey, shape large-scale patterns of predation in a newly restored predator-prey system. We analysed the spatial distribution of wolf (Canis lupus) predation on elk (Cervus elaphus) on the Northern Range of Yellowstone National Park over 10 consecutive winters. The influence of wolf distribution on kill sites diminished over the course of this study, a result that was likely caused by territorial constraints on wolf distribution. In contrast, landscape factors strongly influenced kill sites, creating distinct hunting grounds and prey refugia. Elk in this newly restored predator-prey system should be able to mediate their risk of predation by movement and habitat selection across a heterogeneous risk landscape.

  18. Costs of predator-induced phenotypic plasticity: a graphical model for predicting the contribution of nonconsumptive and consumptive effects of predators on prey.

    Science.gov (United States)

    Peacor, Scott D; Peckarsky, Barbara L; Trussell, Geoffrey C; Vonesh, James R

    2013-01-01

    Defensive modifications in prey traits that reduce predation risk can also have negative effects on prey fitness. Such nonconsumptive effects (NCEs) of predators are common, often quite strong, and can even dominate the net effect of predators. We develop an intuitive graphical model to identify and explore the conditions promoting strong NCEs. The model illustrates two conditions necessary and sufficient for large NCEs: (1) trait change has a large cost, and (2) the benefit of reduced predation outweighs the costs, such as reduced growth rate. A corollary condition is that potential predation in the absence of trait change must be large. In fact, the sum total of the consumptive effects (CEs) and NCEs may be any value bounded by the magnitude of the predation rate in the absence of the trait change. The model further illustrates how, depending on the effect of increased trait change on resulting costs and benefits, any combination of strong and weak NCEs and CEs is possible. The model can also be used to examine how changes in environmental factors (e.g., refuge safety) or variation among predator-prey systems (e.g., different benefits of a prey trait change) affect NCEs. Results indicate that simple rules of thumb may not apply; factors that increase the cost of trait change or that increase the degree to which an animal changes a trait, can actually cause smaller (rather than larger) NCEs. We provide examples of how this graphical model can provide important insights for empirical studies from two natural systems. Implementation of this approach will improve our understanding of how and when NCEs are expected to dominate the total effect of predators. Further, application of the models will likely promote a better linkage between experimental and theoretical studies of NCEs, and foster synthesis across systems.

  19. Effects of Behavioral Tactics of Predators on Dynamics of a Predator-Prey System

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2014-01-01

    Full Text Available A predator-prey model incorporating individual behavior is presented, where the predator-prey interaction is described by a classical Lotka-Volterra model with self-limiting prey; predators can use the behavioral tactics of rock-paper-scissors to dispute a prey when they meet. The predator behavioral change is described by replicator equations, a game dynamic model at the fast time scale, whereas predator-prey interactions are assumed acting at a relatively slow time scale. Aggregation approach is applied to combine the two time scales into a single one. The analytical results show that predators have an equal probability to adopt three strategies at the stable state of the predator-prey interaction system. The diversification tactics taking by predator population benefits the survival of the predator population itself, more importantly, it also maintains the stability of the predator-prey system. Explicitly, immediate contest behavior of predators can promote density of the predator population and keep the preys at a lower density. However, a large cost of fighting will cause not only the density of predators to be lower but also preys to be higher, which may even lead to extinction of the predator populations.

  20. Non-viral transfer approaches for the gene therapy of mucopolysaccharidosis type II (Hunter syndrome).

    Science.gov (United States)

    Tomanin, R; Friso, A; Alba, S; Piller Puicher, E; Mennuni, C; La Monica, N; Hortelano, G; Zacchello, F; Scarpa, M

    2002-01-01

    Hunter syndrome is a rare X-linked lysosomal storage disorder caused by the deficiency of the housekeeping enzyme iduronate-2-sulphatase (IDS). Deficiency of IDS causes accumulation of undegraded dermatan and heparan-sulphate in various tissues and organs. Approaches have been proposed for the symptomatic therapy of the disease, including bone marrow transplantation and, very recently, enzyme replacement. To date, gene therapy strategies have considered mainly retroviral and adenoviral transduction of the correct cDNA. In this paper, two non-viral somatic gene therapy approaches are proposed: encapsulated heterologous cells and muscle electro-gene transfer (EGT). Hunter primary fibroblasts were co-cultured with either cell clones over-expressing the lacking enzyme or with the same incorporated in alginate microcapsules. For EGT, plasmid vector was injected into mouse quadriceps muscle, which was then immediately electro-stimulated. Co-culturing Hunter primary fibroblasts with cells over-expressing IDS resulted in a three- to fourfold increase in fibroblast enzyme activity with respect to control cells. Fibroblast IDS activity was also increased after co-culture with encapsulated cells. EGT was able to transduce genes in mouse muscle, resulting in at least a tenfold increase in IDS activity 1-5 weeks after treatment. Although preliminary, results from encapsulated heterologous cell clones and muscle EGT encourage further evaluations for possible application to gene therapy for Hunter syndrome.

  1. PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Schwamb, Megan E. [Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J. [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Parrish, Michael [Adler Planetarium, 1300 S. Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: megan.schwamb@yale.edu [Department of Physics, Yale University, New Haven, CT 06511 (United States)

    2012-08-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of {>=}2 R{sub Circled-Plus} planets on short-period (<15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, {>=}4 R{sub Circled-Plus} Planet Hunters {>=}85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler {>=}4 R{sub Circled-Plus} planets suggests that the Kepler inventory of {>=}4 R{sub Circled-Plus} short-period planets is nearly complete.

  2. Teaching Experientially with the Madeline Hunter Method: An Application in a Marketing Research Course

    Science.gov (United States)

    Burns, Alvin C.

    2006-01-01

    Due to concerns about the disparity of learning and the high nonresponse rates encountered by student marketing research teams working with sponsors, the author adopted the Hunter Method to restructure his course. This method requires the use of a model onto which students can map their learning via guided practice as well as independent practice.…

  3. Teaching Experientially with the Madeline Hunter Method: An Application in a Marketing Research Course

    Science.gov (United States)

    Burns, Alvin C.

    2006-01-01

    Due to concerns about the disparity of learning and the high nonresponse rates encountered by student marketing research teams working with sponsors, the author adopted the Hunter Method to restructure his course. This method requires the use of a model onto which students can map their learning via guided practice as well as independent practice.…

  4. Indice de Indices en la Biblioteca de Hunter College para el Estudiante Hispano.

    Science.gov (United States)

    Talero Bielsa, Alberto; And Others

    Designed for Spanish-speaking students of Hunter College of the City University of New York, this guide explains the use of 70 English-language indexes found in the college library. The explanations are given in Spanish in order to simplify the process of library research for students who are not completely comfortable with English. Each index is…

  5. The seed hunter in het spoor van Vavilov (interview met C. Kik)

    NARCIS (Netherlands)

    Zanderink, R.; Kik, C.

    2013-01-01

    Er moet voor een veredelaar een grote variatie aan plantmateriaal aanwezig zijn om uit te kunnen putten zodat onze gewassen, die vaak bestaan uit monoculturen, voor de toekomst veiliggesteld worden. Het vinden van die variatie is het werk van seed hunters of zadenverzamelaars. Eén van die seed

  6. The Oxford Handbook of the Archaeology and Anthropology of Hunter-Gatherers

    NARCIS (Netherlands)

    Cummings, Vicky; Jordan, Peter; Zvelebil, Marek

    2014-01-01

    For more than a century, the study of hunting and gathering societies has been central to the development of both archaeology and anthropology as academic disciplines, and has also generated widespread public interest and debate. The Oxford Handbook of the Archaeology and Anthropology of Hunter-Gath

  7. Big game hunting practices, meanings, motivations and constraints: a survey of Oregon big game hunters

    Science.gov (United States)

    Suresh K. Shrestha; Robert C. Burns

    2012-01-01

    We conducted a self-administered mail survey in September 2009 with randomly selected Oregon hunters who had purchased big game hunting licenses/tags for the 2008 hunting season. Survey questions explored hunting practices, the meanings of and motivations for big game hunting, the constraints to big game hunting participation, and the effects of age, years of hunting...

  8. Recent origin and cultural reversion of a hunter-gatherer group.

    Directory of Open Access Journals (Sweden)

    Hiroki Oota

    2005-03-01

    Full Text Available Contemporary hunter-gatherer groups are often thought to serve as models of an ancient lifestyle that was typical of human populations prior to the development of agriculture. Patterns of genetic variation in hunter-gatherer groups such as the Kung and African Pygmies are consistent with this view, as they exhibit low genetic diversity coupled with high frequencies of divergent mtDNA types not found in surrounding agricultural groups, suggesting long-term isolation and small population sizes. We report here genetic evidence concerning the origins of the Mlabri, an enigmatic hunter-gatherer group from northern Thailand. The Mlabri have no mtDNA diversity, and the genetic diversity at Y-chromosome and autosomal loci are also extraordinarily reduced in the Mlabri. Genetic, linguistic, and cultural data all suggest that the Mlabri were recently founded, 500-800 y ago, from a very small number of individuals. Moreover, the Mlabri appear to have originated from an agricultural group and then adopted a hunting-gathering subsistence mode. This example of cultural reversion from agriculture to a hunting-gathering lifestyle indicates that contemporary hunter-gatherer groups do not necessarily reflect a pre-agricultural lifestyle.

  9. Period Determination of Binary Asteroid Targets Observed at Hunters Hill Observatory: May-September 2009

    Science.gov (United States)

    Higgins, David; Oey, Julian; Pravec, Petr

    2011-01-01

    Lightcurves for seven confirmed or possible binary asteroids were obtained at the Hunters Hill Observatory (HHO) and Leura Observatory from 2009 May through 2010 September: 1453 Fennia, 2501 Lohja, 3076 Garbor, 4029 Bridges, 5325 Silver, 6244 Okamoto, and (6265) 1985 TW3.

  10. Using the Madeline Hunter Direct Instruction Model to Improve Outcomes Assessments in Marketing Programs

    Science.gov (United States)

    Steward, Michelle D.; Martin, Gregory S.; Burns, Alvin C.; Bush, Ronald F.

    2010-01-01

    This study introduces marketing educators to the Madeline Hunter Direct Instruction Model (HDIM) as an approach to significantly and substantially improve student learning through course-embedded assessment. The effectiveness of the method is illustrated in three different marketing courses taught by three different marketing professors. The…

  11. Adaptation of Hunter Cynism Scale to Turkish: Validity and Reliability Study

    Science.gov (United States)

    Kiraz, Zafer; Bakioglu, Fuad

    2016-01-01

    The aim of this study is to carry out the adaptation of Hunter Cynicism Scale to Turkish. For this purpose, this study consists of two stages. 311 university students participated in for the first stage and 313 university students participated in for the second stage of this study. In the first stage, translation, exploratory factor analysis,…

  12. 76 FR 9345 - Brian Hunter; Third Supplemental Notice of Designation of Commission Staff

    Science.gov (United States)

    2011-02-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Brian Hunter; Third Supplemental Notice of Designation of Commission Staff On February 1, 2008, the Commission issued an order that, inter alia, designated the staff of...

  13. History and Development of the Schmidt-Hunter Meta-Analysis Methods

    Science.gov (United States)

    Schmidt, Frank L.

    2015-01-01

    In this article, I provide answers to the questions posed by Will Shadish about the history and development of the Schmidt-Hunter methods of meta-analysis. In the 1970s, I headed a research program on personnel selection at the US Office of Personnel Management (OPM). After our research showed that validity studies have low statistical power, OPM…

  14. Geometric Integrability of Two-Component Camassa-Holm and Hunter-Saxton Systems

    Institute of Scientific and Technical Information of China (English)

    SONG Juu-Feng; QU Chang-Zheng

    2011-01-01

    It is shown that the two-component Camassa-Holm and Hunter-Saxton systems are geometrically integrable, namely they describe pseudo-spherical surfaces. As a consequence, their infinite number o, conservation laws are directly constructed. In addition, a class of nonlocal symmetries depending on the pseudo-potentials are obtained.

  15. Targeting hunter distribution based on host resource selection and kill sites to manage disease risk

    DEFF Research Database (Denmark)

    Dugal, Cherie; van Beest, Floris; Vander Wal, Eric

    2013-01-01

    Endemic and emerging diseases are rarely uniform in their spatial distribution or prevalence among cohorts of wildlife. Spatial models that quantify risk-driven differences in resource selection and hunter mortality of animals at fine spatial scales can assist disease management by identifying hi...

  16. Coevolution can reverse predator-prey cycles.

    Science.gov (United States)

    Cortez, Michael H; Weitz, Joshua S

    2014-05-20

    A hallmark of Lotka-Volterra models, and other ecological models of predator-prey interactions, is that in predator-prey cycles, peaks in prey abundance precede peaks in predator abundance. Such models typically assume that species life history traits are fixed over ecologically relevant time scales. However, the coevolution of predator and prey traits has been shown to alter the community dynamics of natural systems, leading to novel dynamics including antiphase and cryptic cycles. Here, using an eco-coevolutionary model, we show that predator-prey coevolution can also drive population cycles where the opposite of canonical Lotka-Volterra oscillations occurs: predator peaks precede prey peaks. These reversed cycles arise when selection favors extreme phenotypes, predator offense is costly, and prey defense is effective against low-offense predators. We present multiple datasets from phage-cholera, mink-muskrat, and gyrfalcon-rock ptarmigan systems that exhibit reversed-peak ordering. Our results suggest that such cycles are a potential signature of predator-prey coevolution and reveal unique ways in which predator-prey coevolution can shape, and possibly reverse, community dynamics.

  17. Serological surveillance of vector-borne and zoonotic diseases among hunters in eastern Poland

    Directory of Open Access Journals (Sweden)

    Małgorzata Tokarska-Rodak

    2016-01-01

    Full Text Available Background & objectives: Many etiological agents of zoonoses are considered as significant biological hazard to people visiting forested areas frequently, for instance, hunters. They may be exposed to ticks, rodents, and birds as well as excreta/secretions of wild animals or contaminated water and soil. Hence, this population is at risk of contracting infection with pathogens such as Borrelia burgdorferi sensu lato (s.l., Anaplasma phagocytophilum, Babesia spp., tick-borne encephalitis virus, Bartonella spp., Francisella tularensis, Echinococcus spp., or hantaviruses. The aim of the study was to assess the seroprevalence of zoonotic agents, viz. A. phagocytophilum, hantaviruses, and Echinococcus spp., with special regard to B. burgdorferi s.l., among hunters in Lubelskie Voivodeship (eastern Poland. Methods: Serum samples collected from 134 hunters from Lubelskie Voivodeship were analyzed with the use of immunological techniques (enzyme-linked immunosorbent assay, line immunoblot test, and indirect fluorescence assay for the presence of antibodies against the agents. Results: Specific antibodies were detected in 66% of the tested individuals. Antibodies against B. burgdorferi s.l. (39%, A. phagocytophilum (30%, hantaviruses (9%, and Echinococcus spp. (8% were detected individually or as mixed results. Interpretation & conclusion: The results confirm that there is a risk of exposure to different pathogens in the forested areas in eastern Poland and that hunters are highly vulnerable to infection with the examined zoonotic agents. A significant proportion of co-occurring antibodies against different pathogens was noticed. Thus, hunters have to take special care of their health status evaluation and mitigate the exposure risk by using adequate prophylaxis measures.

  18. Predator-prey interactions mediated by prey personality and predator hunting mode.

    Science.gov (United States)

    Belgrad, Benjamin A; Griffen, Blaine D

    2016-04-13

    Predator-prey interactions are important drivers in structuring ecological communities. However, despite widespread acknowledgement that individual behaviours and predator species regulate ecological processes, studies have yet to incorporate individual behavioural variations in a multipredator system. We quantified a prevalent predator avoidance behaviour to examine the simultaneous roles of prey personality and predator hunting mode in governing predator-prey interactions. Mud crabs, Panopeus herbstii, reduce their activity levels and increase their refuge use in the presence of predator cues. We measured mud crab mortality and consistent individual variations in the strength of this predator avoidance behaviour in the presence of predatory blue crabs, Callinectes sapidus, and toadfish, Opsanus tau We found that prey personality and predator species significantly interacted to affect mortality with blue crabs primarily consuming bold mud crabs and toadfish preferentially selecting shy crabs. Additionally, the strength of the predator avoidance behaviour depended upon the predation risk from the predator species. Consequently, the personality composition of populations and predator hunting mode may be valuable predictors of both direct and indirect predator-prey interaction strength. These findings support theories postulating mechanisms for maintaining intraspecies diversity and have broad implications for community dynamics.

  19. Dynamics of a intraguild predation model with generalist or specialist predator.

    Science.gov (United States)

    Kang, Yun; Wedekin, Lauren

    2013-11-01

    Intraguild predation (IGP) is a combination of competition and predation which is the most basic system in food webs that contains three species where two species that are involved in a predator/prey relationship are also competing for a shared resource or prey. We formulate two intraguild predation (IGP: resource, IG prey and IG predator) models: one has generalist predator while the other one has specialist predator. Both models have Holling-Type I functional response between resource-IG prey and resource-IG predator; Holling-Type III functional response between IG prey and IG predator. We provide sufficient conditions of the persistence and extinction of all possible scenarios for these two models, which give us a complete picture on their global dynamics. In addition, we show that both IGP models can have multiple interior equilibria under certain parameters range. These analytical results indicate that IGP model with generalist predator has "top down" regulation by comparing to IGP model with specialist predator. Our analysis and numerical simulations suggest that: (1) Both IGP models can have multiple attractors with complicated dynamical patterns; (2) Only IGP model with specialist predator can have both boundary attractor and interior attractor, i.e., whether the system has the extinction of one species or the coexistence of three species depending on initial conditions; (3) IGP model with generalist predator is prone to have coexistence of three species.

  20. Adult predation risk drives shifts in parental care strategies: a long-term study.

    Science.gov (United States)

    Jaatinen, Kim; Ost, Markus; Lehikoinen, Aleksi

    2011-01-01

    1. Grouping provides antipredatory benefits, and therefore aggregation tendencies increase under heightened predation risk. In socially breeding groups, however, conflicts over reproductive shares or safety tend to disintegrate groups. Group formation thereby involves a balance between the antipredatory benefits of aggregation and the destabilizing effect of reproductive conflict. 2. We study the grouping behaviour of a facultatively social precocial sea duck with uniparental female care, the eider (Somateria mollissima Linnaeus). Females tend their young solitarily or in groups of 2-5 females. Here, we focus on the effect predation on adults has on group-formation decisions of brood-caring females. 3. By modifying an existing bidding game over care, we model the effects of predation risk on the width of the window of selfishness, which delimits the reproductive sharing allowing cooperation within brood-rearing coalitions, and generate predictions about the relative frequencies of solitary versus cooperative parental care modes. Furthermore, we model the dilution effect as a function of female group size and predation risk. 4. The window of selfishness widens with increasing predation risk, and the dilution of predation risk increases with both female group size and increasing predation risk, yielding the following predictions: (i) cooperative brood care becomes more prevalent and, conversely, solitary brood care less prevalent under heightened predation risk and (ii) group sizes increase concomitantly. 5. We tested these predictions using 13 years of data on female grouping decisions and annual predation rates, while controlling for the potentially confounding effect of female body condition. 6. Our data supported both predictions, where heightened predation risk of nesting females, but not changes in their condition, increased the relative frequency of cooperative brood care. Increased female nesting mortality also resulted in larger groups of cooperative females

  1. Does the association of young fishes with jellyfishes protect from predation?A report on a failure case due to damage to the jellyfish

    Directory of Open Access Journals (Sweden)

    Roberta Martini Bonaldo

    Full Text Available The fish-jellyfish association is regarded as a temporary symbiosis believed to protect the fishes from predators. Here we report on juvenile scads (Trachurus lathami associated with the jellyfish Chrysaora lactea, opportunistically preyed on by the grouper Mycteroperca acutirostris while the medusa was being damaged. The predation instances occurred when a couple of the filefish Stephanolepis hispidus approached the jellyfish to nibble on its umbrella. The feeding of the filefish caused a momentary disturbance of the defensive association, perceived and capitalised on by the watchful grouper, an opportunistic and versatile hunter. Before and after the disturbance, the protection offered to the young fish by the jellyfish showed to be effective, which strengthens the hypothesis of defensive function of this association.

  2. Predator diversity and density affect levels of predation upon strongly interactive species in temperate rocky reefs.

    Science.gov (United States)

    Guidetti, Paolo

    2007-12-01

    Indirect effects of predators in the classic trophic cascade theory involve the effects of basal species (e.g. primary producers) mediated by predation upon strongly interactive consumers (e.g. grazers). The diversity and density of predators, and the way in which they interact, determine whether and how the effects of different predators on prey combine. Intraguild predation, for instance, was observed to dampen the effects of predators on prey in many ecosystems. In marine systems, species at high trophic levels are particularly susceptible to extinction (at least functionally). The loss of such species, which is mainly attributed to human activities (mostly fishing), is presently decreasing the diversity of marine predators in many areas of the world. Experimental studies that manipulate predator diversity and investigate the effects of this on strongly interactive consumers (i.e. those potentially capable of causing community-wide effects) in marine systems are scant, especially in the rocky sublittoral. I established an experiment that utilised cage enclosures to test whether the diversity and density of fish predators (two sea breams and two wrasses) would affect predation upon juvenile and adult sea urchins, the most important grazers in Mediterranean sublittoral rocky reefs. Changes in species identity (with sea breams producing major effects) and density of predators affected predation upon sea urchins more than changes in species richness per se. Predation upon adult sea urchins decreased in the presence of multiple predators, probably due to interference competition between sea breams and wrasses. This study suggests that factors that influence both fish predator diversity and density in Mediterranean rocky reefs (e.g. fishing and climate change) may have the potential to affect the predators' ability to control sea urchin population density, with possible repercussions for the whole benthic community structure.

  3. Species Diversity Enhances Predator Growth Rates

    Directory of Open Access Journals (Sweden)

    Mark H. Olson

    2007-01-01

    Full Text Available Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index and growth rates of largemouth bass (Micropterus salmoides. This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

  4. Predator Bounties in Western Canada Cause Animal Suffering and CompromiseWildlife Conservation Efforts

    Directory of Open Access Journals (Sweden)

    Gilbert Proulx

    2015-10-01

    Full Text Available Although predation bounty programs (rewards offered for capturing or killing an animal ended more than 40 years ago in Canada, they were reintroduced in Alberta in 2007 by hunting, trapping, and farming organizations, municipalities and counties, and in 2009 in Saskatchewan, by municipal and provincial governments and the Saskatchewan Cattlemen’s Association. Bounty hunters use inhumane and non-selective killing methods such as shooting animals in non-vital regions, and killing neck snares and strychnine poisoning, which cause suffering and delayed deaths. They are unselective, and kill many non-target species, some of them at risk. Predator bounty programs have been found to be ineffective by wildlife professionals, and they use killing methods that cause needless suffering and jeopardize wildlife conservation programs. Our analysis therefore indicates that government agencies should not permit the implementation of bounty programs. Accordingly, they must develop conservation programs that will minimize wildlife-human conflicts, prevent the unnecessary and inhumane killing of animals, and ensure the persistence of all wildlife species.

  5. Human predators outpace other agents of trait change in the wild.

    Science.gov (United States)

    Darimont, Chris T; Carlson, Stephanie M; Kinnison, Michael T; Paquet, Paul C; Reimchen, Thomas E; Wilmers, Christopher C

    2009-01-20

    The observable traits of wild populations are continually shaped and reshaped by the environment and numerous agents of natural selection, including predators. In stark contrast with most predators, humans now typically exploit high proportions of prey populations and target large, reproductive-aged adults. Consequently, organisms subject to consistent and strong 'harvest selection' by fishers, hunters, and plant harvesters may be expected to show particularly rapid and dramatic changes in phenotype. However, a comparison of the rate at which phenotypic changes in exploited taxa occurs relative to other systems has never been undertaken. Here, we show that average phenotypic changes in 40 human-harvested systems are much more rapid than changes reported in studies examining not only natural (n = 20 systems) but also other human-driven (n = 25 systems) perturbations in the wild, outpacing them by >300% and 50%, respectively. Accordingly, harvested organisms show some of the most abrupt trait changes ever observed in wild populations, providing a new appreciation for how fast phenotypes are capable of changing. These changes, which include average declines of almost 20% in size-related traits and shifts in life history traits of nearly 25%, are most rapid in commercially exploited systems and, thus, have profound conservation and economic implications. Specifically, the widespread potential for transitively rapid and large effects on size- or life history-mediated ecological dynamics might imperil populations, industries, and ecosystems.

  6. Linking Hunter Knowledge with Forest Change to Understand Changing Deer Harvest Opportunities in Intensively Logged Landscapes

    Directory of Open Access Journals (Sweden)

    Todd J. Brinkman

    2009-06-01

    Full Text Available The effects of landscape changes caused by intensive logging on the availability of wild game are important when the harvest of wild game is a critical cultural practice, food source, and recreational activity. We assessed the influence of extensive industrial logging on the availability of wild game by drawing on local knowledge and ecological science to evaluate the relationship between forest change and opportunities to harvest Sitka black-tailed deer (Odocoileus hemionus sitkensis on Prince of Wales Island, Alaska. We used data collected through interviews with local deer hunters and GIS analysis of land cover to determine relationships among landscape change, hunter access, and habitat for deer hunting over the last 50 yr. We then used these relationships to predict how harvest opportunities may change in the future. Intensive logging from 1950 into the 1990s provided better access to deer and habitat that facilitated deer hunting. However, successional changes in intensively logged forests in combination with a decline in current logging activity have reduced access to deer and increased undesirable habitat for deer hunting. In this new landscape, harvest opportunities in previously logged landscapes have declined, and hunters identify second-growth forest as one of the least popular habitats for hunting. Given the current state of the logging industry in Alaska, it is unlikely that the logging of the remaining old-growth forests or intensive management of second-growth forests will cause hunter opportunities to rebound to historic levels. Instead, hunter opportunities may continue to decline for at least another human generation, even if the long-term impacts of logging activity and deer harvest on deer numbers are minimal. Adapting hunting strategies to focus on naturally open habitats such as alpine and muskeg that are less influenced by external market forces may require considerably more hunting effort but provide the best option for

  7. Higher nest predation risk in association with a top predator: mesopredator attraction?

    Science.gov (United States)

    Morosinotto, Chiara; Thomson, Robert L; Hänninen, Mikko; Korpimäki, Erkki

    2012-10-01

    Breeding close to top predators is a widespread reproductive strategy. Breeding animals may gain indirect benefits if proximity to top predators results in a reduction of predation due to suppression of mesopredators. We tested if passerine birds gain protection from mesopredators by nesting within territories of a top predator, the Ural owl (Strix uralensis). We placed nest boxes for pied flycatchers (Ficedula hypoleuca) in Ural owl nest sites and in control sites (currently unoccupied by owls). The nest boxes were designed so that nest predation risk could be altered (experimentally increased) after flycatcher settlement; we considered predation rate as a proxy of mesopredator abundance. Overall, we found higher nest predation rates in treatment than in control sites. Flycatcher laying date did not differ between sites, but smaller clutches were laid in treatment sites compared to controls, suggesting a response to perceived predation risk. Relative nest predation rate varied between years, being higher in owl nest sites in 2 years but similar in another; this variation might be indirectly influenced by vole abundance. Proximity to Ural owl nests might represent a risky habitat for passerines. High predation rates within owl territories could be because small mesopredators that do not directly threaten owl nests are attracted to owl nest sites. This could be explained if some mesopredators use owl territories to gain protection from their own predators, or if top predators and mesopredators independently seek similar habitats.

  8. Maternal intraguild predation risk affects offspring anti-predator behavior and learning in mites.

    Science.gov (United States)

    Seiter, Michael; Schausberger, Peter

    2015-10-09

    Predation risk is a strong selective force shaping prey morphology, life history and behavior. Anti-predator behaviors may be innate, learned or both but little is known about the transgenerational behavioral effects of maternally experienced predation risk. We examined intraguild predation (IGP) risk-induced maternal effects on offspring anti-predator behavior, including learning, in the predatory mite Phytoseiulus persimilis. We exposed predatory mite mothers during egg production to presence or absence of the IG predator Amblyseius andersoni and assessed whether maternal stress affects the anti-predator behavior, including larval learning ability, of their offspring as protonymphs. Protonymphs emerging from stressed or unstressed mothers, and having experienced IGP risk as larvae or not, were subjected to choice situations with and without IG predator traces. Predator-experienced protonymphs from stressed mothers were the least active and acted the boldest in site choice towards predator cues. We argue that the attenuated response of the protonymphs to predator traces alone represents optimized risk management because no immediate risk existed. Such behavioral adjustment could reduce the inherent fitness costs of anti-predator behaviors. Overall, our study suggests that P. persimilis mothers experiencing IGP risk may prime their offspring to behave more optimally in IGP environments.

  9. Effects of a disease affecting a predator on the dynamics of a predator-prey system.

    Science.gov (United States)

    Auger, Pierre; McHich, Rachid; Chowdhury, Tanmay; Sallet, Gauthier; Tchuente, Maurice; Chattopadhyay, Joydev

    2009-06-07

    We study the effects of a disease affecting a predator on the dynamics of a predator-prey system. We couple an SIRS model applied to the predator population, to a Lotka-Volterra model. The SIRS model describes the spread of the disease in a predator population subdivided into susceptible, infected and removed individuals. The Lotka-Volterra model describes the predator-prey interactions. We consider two time scales, a fast one for the disease and a comparatively slow one for predator-prey interactions and for predator mortality. We use the classical "aggregation method" in order to obtain a reduced equivalent model. We show that there are two possible asymptotic behaviors: either the predator population dies out and the prey tends to its carrying capacity, or the predator and prey coexist. In this latter case, the predator population tends either to a "disease-free" or to a "disease-endemic" state. Moreover, the total predator density in the disease-endemic state is greater than the predator density in the "disease-free" equilibrium (DFE).

  10. Landscape forest cover and edge effects on songbird nest predation vary by nest predator

    Science.gov (United States)

    W. Andrew Cox; Frank R. III Thompson; John. Faaborg

    2012-01-01

    Rates of nest predation for birds vary between and within species across multiple spatial scales, but we have a poor understanding of which predators drive such patterns. We video-monitored nests and identified predators at 120 nests of the Acadian Flycatcher (Empidonax virescens) and the Indigo Bunting (Passerina cyanea) at eight...

  11. Resource Selection by an Endangered Ungulate: A Test of Predator-Induced Range Abandonment

    Directory of Open Access Journals (Sweden)

    Jeffrey T. Villepique

    2015-01-01

    Full Text Available We investigated influences of risk of predation by mountain lions (Puma concolor, topographic metrics at multiple scales, and vegetation, land, and snow cover on resource selection by Sierra Nevada bighorn sheep (Ovis canadensis sierrae, an endangered taxon, during winters 2002–2007, in the Sierra Nevada, California, USA. We hypothesized that those mountain ungulates would trade off rewards accrued from using critical low-elevation habitat in winter for the safety of areas with reduced risk of predation. Sierra Nevada bighorn sheep did not trade off benefits of forage for reduced risk of predation but selected areas of high solar radiation, a correlate of vegetation productivity, where risk of predation by mountain lions was greatest, while mitigating indirect risk of predation by selecting for steep, rugged terrain. Bighorn sheep selected more strongly for areas where mountain lions were active, than for low-elevation habitat in winter, likely because mountain lions were most active in those areas of bighorn sheep winter ranges overlapping ranges of mule deer (Odocoileus hemionus, where both ungulates accrued forage benefits. We demonstrated reduced benefit of migration to low elevation during drought years, providing an alternative explanation to the predator-induced abandonment hypothesis for the disuse of low-elevation winter range observed during drought years.

  12. Predation efficiency of Anopheles gambiae larvae by aquatic predators in western Kenya highlands

    Directory of Open Access Journals (Sweden)

    Nyindo Mramba

    2011-07-01

    Full Text Available Abstract Background The current status of insecticide resistance in mosquitoes and the effects of insecticides on non-target insect species have raised the need for alternative control methods for malaria vectors. Predation has been suggested as one of the important regulation mechanisms for malaria vectors in long-lasting aquatic habitats, but the predation efficiency of the potential predators is largely unknown in the highlands of western Kenya. In the current study, we examined the predation efficiency of five predators on Anopheles gambiae s.s larvae in 24 hour and semi- field evaluations. Methods Predators were collected from natural habitats and starved for 12 hours prior to starting experiments. Preliminary experiments were conducted to ascertain the larval stage most predated by each predator species. When each larval instar was subjected to predation, third instar larvae were predated at the highest rate. Third instar larvae of An. gambiae were introduced into artificial habitats with and without refugia at various larval densities. The numbers of surviving larvae were counted after 24 hours in 24. In semi-field experiments, the larvae were counted daily until they were all either consumed or had developed to the pupal stage. Polymerase chain reaction was used to confirm the presence of An. gambiae DNA in predator guts. Results Experiments found that habitat type (P P P P An. gambiae DNA was found in at least three out of ten midguts for all predator species. Gambusia affins was the most efficient, being three times more efficient than tadpoles. Conclusion These experiments provide insight into the efficiency of specific natural predators against mosquito larvae. These naturally occurring predators may be useful in biocontrol strategies for aquatic stage An. gambiae mosquitoes. Further investigations should be done in complex natural habitats for these predators.

  13. Does sex-selective predation stabilize or destabilize predator-prey dynamics?

    Directory of Open Access Journals (Sweden)

    David S Boukal

    Full Text Available BACKGROUND: Little is known about the impact of prey sexual dimorphism on predator-prey dynamics and the impact of sex-selective harvesting and trophy hunting on long-term stability of exploited populations. METHODOLOGY AND PRINCIPAL FINDINGS: We review the quantitative evidence for sex-selective predation and study its long-term consequences using several simple predator-prey models. These models can be also interpreted in terms of feedback between harvesting effort and population size of the harvested species under open-access exploitation. Among the 81 predator-prey pairs found in the literature, male bias in predation is 2.3 times as common as female bias. We show that long-term effects of sex-selective predation depend on the interplay of predation bias and prey mating system. Predation on the 'less limiting' prey sex can yield a stable predator-prey equilibrium, while predation on the other sex usually destabilizes the dynamics and promotes population collapses. For prey mating systems that we consider, males are less limiting except for polyandry and polyandrogyny, and male-biased predation alone on such prey can stabilize otherwise unstable dynamics. On the contrary, our results suggest that female-biased predation on polygynous, polygynandrous or monogamous prey requires other stabilizing mechanisms to persist. CONCLUSIONS AND SIGNIFICANCE: Our modelling results suggest that the observed skew towards male-biased predation might reflect, in addition to sexual selection, the evolutionary history of predator-prey interactions. More focus on these phenomena can yield additional and interesting insights as to which mechanisms maintain the persistence of predator-prey pairs over ecological and evolutionary timescales. Our results can also have implications for long-term sustainability of harvesting and trophy hunting of sexually dimorphic species.

  14. Nest Predation Deviates from Nest Predator Abundance in an Ecologically Trapped Bird.

    Science.gov (United States)

    Hollander, Franck A; Van Dyck, Hans; San Martin, Gilles; Titeux, Nicolas

    2015-01-01

    In human-modified environments, ecological traps may result from a preference for low-quality habitat where survival or reproductive success is lower than in high-quality habitat. It has often been shown that low reproductive success for birds in preferred habitat types was due to higher nest predator abundance. However, between-habitat differences in nest predation may only weakly correlate with differences in nest predator abundance. An ecological trap is at work in a farmland bird (Lanius collurio) that recently expanded its breeding habitat into open areas in plantation forests. This passerine bird shows a strong preference for forest habitat, but it has a higher nest success in farmland. We tested whether higher abundance of nest predators in the preferred habitat or, alternatively, a decoupling of nest predator abundance and nest predation explained this observed pattern of maladaptive habitat selection. More than 90% of brood failures were attributed to nest predation. Nest predator abundance was more than 50% higher in farmland, but nest predation was 17% higher in forest. Differences between nest predation on actual shrike nests and on artificial nests suggested that parent shrikes may facilitate nest disclosure for predators in forest more than they do in farmland. The level of caution by parent shrikes when visiting their nest during a simulated nest predator intrusion was the same in the two habitats, but nest concealment was considerably lower in forest, which contributes to explaining the higher nest predation in this habitat. We conclude that a decoupling of nest predator abundance and nest predation may create ecological traps in human-modified environments.

  15. Fish species and other data from DERWENT HUNTER from 31 August 1959 to 16 June 1960 (NODC Accession 7300634)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In September 1959 the cruise programme for F.R.V. DERWENT HUNTER was changed and cruises were planned to investigate tuna in South-East Australian waters in a much...

  16. Human behavior. Sex equality can explain the unique social structure of hunter-gatherer bands.

    Science.gov (United States)

    Dyble, M; Salali, G D; Chaudhary, N; Page, A; Smith, D; Thompson, J; Vinicius, L; Mace, R; Migliano, A B

    2015-05-15

    The social organization of mobile hunter-gatherers has several derived features, including low within-camp relatedness and fluid meta-groups. Although these features have been proposed to have provided the selective context for the evolution of human hypercooperation and cumulative culture, how such a distinctive social system may have emerged remains unclear. We present an agent-based model suggesting that, even if all individuals in a community seek to live with as many kin as possible, within-camp relatedness is reduced if men and women have equal influence in selecting camp members. Our model closely approximates observed patterns of co-residence among Agta and Mbendjele BaYaka hunter-gatherers. Our results suggest that pair-bonding and increased sex egalitarianism in human evolutionary history may have had a transformative effect on human social organization. Copyright © 2015, American Association for the Advancement of Science.

  17. The influence of generalist predators in spatially extended predator-prey systems

    DEFF Research Database (Denmark)

    Chakraborty, Subhendu

    2015-01-01

    dynamics of a predator-prey system is investigated by considering two different types of generalist predators. In one case, it is considered that the predator population has an additional food source and can survive in the absence of the prey population. In the other case, the predator population...... the cases. In the presence of generalist predators, the system shows different pattern formations and spatiotemporal chaos which has important implications for ecosystem functioning not only in terms of their predictability, but also in influencing species persistence and ecosystem stability in response...

  18. Influence of predator mutual interference and prey refuge on Lotka-Volterra predator-prey dynamics

    Science.gov (United States)

    Chen, Liujuan; Chen, Fengde; Wang, Yiqin

    2013-11-01

    A Lotka-Volterra predator-prey model incorporating a constant number of prey using refuges and mutual interference for predator species is presented. By applying the divergency criterion and theories on exceptional directions and normal sectors, we show that the interior equilibrium is always globally asymptotically stable and two boundary equilibria are both saddle points. Our results indicate that prey refuge has no influence on the coexistence of predator and prey species of the considered model under the effects of mutual interference for predator species, which differently from the conclusion without predator mutual interference, thus improving some known ones. Numerical simulations are performed to illustrate the validity of our results.

  19. Beyond the Cut Hunter: A Historical Epidemiology of HIV Beginnings in Central Africa.

    Science.gov (United States)

    Rupp, Stephanie; Ambata, Philippe; Narat, Victor; Giles-Vernick, Tamara

    2016-12-01

    In the absence of direct evidence, an imagined "cut hunter" stands in for the index patient of pandemic HIV/AIDS. During the early years of colonial rule, this explanation goes, a hunter was cut or injured from hunting or butchering a chimpanzee infected with simian immunodeficiency virus, resulting in the first sustained human infection with the virus that would emerge as HIV-1M. We argue here that the "cut hunter" relies on a historical misunderstanding and ecological oversimplification of human-chimpanzee (Pan Troglodytes troglodytes) interactions that facilitated pathogenic transmission. This initial host shift cannot explain the beginnings of the HIV/AIDS pandemic. Instead, we must understand the processes by which the virus became transmissible, possibly between Sangha basin inhabitants and ultimately reached Kinshasa. A historical epidemiology of the late nineteenth and twentieth centuries, provides a much-needed corrective to the major shortcomings of the cut hunter. Based on 62 oral historical interviews conducted in southeastern Cameroon and archival research, we show that HIV emerged from ecological, economic, and socio-political transformations of the late nineteenth and twentieth centuries. The gradual imposition of colonial rule built on and reoriented ecologies and economies, and altered older patterns of mobility and sociality. Certain changes may have contributed to the initial viral host shift, but more importantly, facilitated the adaptation of HIV-1M to human-to-human transmission. Our evidence suggests that the most critical changes occurred after 1920. This argument has important implications for public health policy, underscoring recent work emphasizing alternative pathways for zoonotic spillovers into human beings.

  20. A Philatelic Excursion with Jeff Hunter in Probability and Matrix Theory

    Directory of Open Access Journals (Sweden)

    George P. H. Styan

    2007-01-01

    Full Text Available We present an excursion with Jeff Hunter, visiting some of his research topics. Specifically, we will present some facts about certain people whose work seems to have influenced Jeff in his scientific career; we illustrate our presentation with postage stamps that have been issued in honour of these people. Our main guide is Hunter’s two-volume book entitled Mathematical Techniques of Applied Probability (Academic Press, 1983.

  1. Newborn screening for hunter disease: a small-scale feasibility study.

    Science.gov (United States)

    Ruijter, G J G; Goudriaan, D A; Boer, A M; Van den Bosch, J; Van der Ploeg, A T; Elvers, L H; Weinreich, S S; Reuser, A J

    2014-01-01

    Hunter disease (Mucopolysaccharidosis type II, MPS II) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). Two main therapies have been reported for MPS II patients: enzyme-replacement therapy (ERT) and hematopoietic stem-cell transplantation (HSCT). Both treatment modalities have been shown to improve some symptoms, but the results with regard to cognitive functioning have been poor. Early initiation of therapy, i.e., before neurological symptoms have manifested, may alter cognitive outcome. The need for early identification makes Hunter disease a candidate for newborn screening (NBS). Our objective was to explore the use of a fluorometric assay that could be applicable for high-throughput analysis of IDS activity in dried blood spots (DBS). The median IDS activity in DBS samples from 1,426 newborns was 377 pmol/punch/17 h (range 78-1111). The IDS activity in one sample was repeatedly under the cutoff value (set at 20% of the median value), which would imply a recall rate of 0.07%. A sample from a clinically diagnosed MPS II individual, included in each 96-well test plate, had IDS activities well below the 20% cutoff value. Coefficients of variation in quality control samples with low, medium, and high IDS activities (190, 304, and 430 pmol/punch/17 h, respectively) were 12% to 16%. This small-scale pilot study shows that newborn screening for Hunter disease using a fluorometric assay in DBS is technically feasible with a fairly low recall rate. NBS may allow for identification of infants with Hunter disease before clinical symptoms become evident enabling early intervention.

  2. Shell beads of the Last Hunter-Gatherers and Earliest Farmers in South-Western Europe

    Directory of Open Access Journals (Sweden)

    Álvarez-Fernández, E.

    2010-01-01

    Full Text Available This paper analyses the suspended objects of adornment made from marine mollusc shells that have been recorded at Mesolithic and Neolithic sites in southwest Europe. Particular attention will be given to taxonomic determination, technological aspects and the strategies utilised to obtain the raw materials for these objects. The distribution of certain species and the types of ornamentation used by the last hunter-gatherers and first farming communities will also be discussed.

  3. 演奏八弦吉他的怪才Charlie Hunter

    Institute of Scientific and Technical Information of China (English)

    石岩

    2002-01-01

      一看到这把怪琴,少见的8弦配置加上扇形的弦品指板,你就会知道使用这把吉他的吉他手一定是个怪才.他就是Charlie Hunter,一个富于创新的年轻爵士吉他手.……

  4. Modeling predator habitat to enhance reintroduction planning

    Science.gov (United States)

    Shiloh M. Halsey; William J. Zielinski; Robert M. Scheller

    2015-01-01

    Context The success of species reintroduction often depends on predation risk and spatial estimates of predator habitat. The fisher (Pekania pennanti) is a species of conservation concern and populations in the western United States have declined substantially in the last century. Reintroduction plans are underway, but the ability...

  5. Predator-induced neophobia in juvenile cichlids.

    Science.gov (United States)

    Meuthen, Denis; Baldauf, Sebastian A; Bakker, Theo C M; Thünken, Timo

    2016-08-01

    Predation is an important but often fluctuating selection factor for prey animals. Accordingly, individuals plastically adopt antipredator strategies in response to current predation risk. Recently, it was proposed that predation risk also plastically induces neophobia (an antipredator response towards novel cues). Previous studies, however, do not allow a differentiation between general neophobia and sensory channel-specific neophobic responses. Therefore, we tested the neophobia hypothesis focusing on adjustment in shoaling behavior in response to a novel cue addressing a different sensory channel than the one from which predation risk was initially perceived. From hatching onwards, juveniles of the cichlid Pelvicachromis taeniatus were exposed to different chemical cues in a split-clutch design: conspecific alarm cues which signal predation risk and heterospecific alarm cues or distilled water as controls. At 2 months of age, their shoaling behavior was examined prior and subsequent to a tactical disturbance cue. We found that fish previously exposed to predation risk formed more compact shoals relative to the control groups in response to the novel disturbance cue. Moreover, the relationship between shoal density and shoal homogeneity was also affected by experienced predation risk. Our findings indicate predator-induced, increased cross-sensory sensitivity towards novel cues making neophobia an effective antipredator mechanism.

  6. Coexistence of predator and prey in intraguild predation systems with ontogenetic niche shifts.

    Science.gov (United States)

    Hin, Vincent; Schellekens, Tim; Persson, Lennart; de Roos, André M

    2011-12-01

    In basic intraguild predation (IGP) systems, predators and prey also compete for a shared resource. Theory predicts that persistence of these systems is possible when intraguild prey is superior in competition and productivity is not too high. IGP often results from ontogenetic niche shifts, in which the diet of intraguild predators changes as a result of growth in body size (life-history omnivory). As a juvenile, a life-history omnivore competes with the species that becomes its prey later in life. Competition can hence limit growth of young predators, while adult predators can suppress consumers and therewith neutralize negative effects of competition. We formulate and analyze a stage-structured model that captures both basic IGP and life-history omnivory. The model predicts increasing coexistence of predators and consumers when resource use of stage-structured predators becomes more stage specific. This coexistence depends on adult predators requiring consumer biomass for reproduction and is less likely when consumers outcompete juvenile predators, in contrast to basic IGP. Therefore, coexistence occurs when predation structures the community and competition is negligible. Consequently, equilibrium patterns over productivity resemble those of three-species food chains. Life-history omnivory thus provides a mechanism that allows intraguild predators and prey to coexist over a wide range of resource productivity.

  7. The Behavioral Type of a Top Predator Drives the Short-Term Dynamic of Intraguild Predation.

    Science.gov (United States)

    Michalko, Radek; Pekár, Stano

    2017-03-01

    Variation in behavior among individual top predators (i.e., the behavioral type) can strongly shape pest suppression in intraguild predation (IGP). However, the effect of a top predator's behavioral type-namely, foraging aggressiveness (number of killed divided by prey time) and prey choosiness (preference degree for certain prey type)-on the dynamic of IGP may interact with the relative abundances of top predator, mesopredator, and pest. We investigated the influence of the top predator's behavioral type on the dynamic of IGP in a three-species system with a top predator spider, a mesopredator spider, and a psyllid pest using a simulation model. The model parameters were estimated from laboratory experiments and field observations. The top predator's behavioral type altered the food-web dynamics in a context-dependent manner. The system with an aggressive/nonchoosy top predator, without prey preferences between pest and mesopredator, suppressed the pest more when the top predator to mesopredator abundance ratio was high. In contrast, the system with a timid/choosy top predator that preferred the pest to the mesopredator was more effective when the ratio was low. Our results show that the behavioral types and abundances of interacting species need to be considered together when studying food-web dynamics, because they evidently interact. To improve biocontrol efficiency of predators, research on the alteration of their behavioral types is needed.

  8. Guidelines for diagnosis and treatment of Hunter Syndrome for clinicians in Latin America

    Science.gov (United States)

    Giugliani, Roberto; Villarreal, Martha Luz Solano; Valdez, C. Araceli Arellano; Hawilou, Antonieta Mahfoud; Guelbert, Norberto; Garzón, Luz Norela Correa; Martins, Ana Maria; Acosta, Angelina; Cabello, Juan Francisco; Lemes, Aída; Santos, Mara Lucia Schmitz Ferreira; Amartino, Hernán

    2014-01-01

    This review aims to provide clinicians in Latin America with the most current information on the clinical aspects, diagnosis, and management of Hunter syndrome, a serious and progressive disease for which specific treatment is available. Hunter syndrome is a genetic disorder where iduronate-2-sulfatase (I2S), an enzyme that degrades glycosaminoglycans, is absent or deficient. Clinical manifestations vary widely in severity and involve multiple organs and tissues. An attenuated and a severe phenotype are recognized depending on the degree of cognitive impairment. Early diagnosis is vital for disease management. Clinical signs common to children with Hunter syndrome include inguinal hernia, frequent ear and respiratory infections, facial dysmorphisms, macrocephaly, bone dysplasia, short stature, sleep apnea, and behavior problems. Diagnosis is based on screening urinary glycosaminoglycans and confirmation by measuring I2S activity and analyzing I2S gene mutations. Idursulfase (recombinant I2S) (Elaprase®, Shire) enzyme replacement therapy (ERT), designed to address the underlying enzyme deficiency, is approved treatment and improves walking capacity and respiratory function, and reduces spleen and liver size and urinary glycosaminoglycan levels. Additional measures, responding to the multi-organ manifestations, such as abdominal/inguinal hernia repair, carpal tunnel surgery, and cardiac valve replacement, should also be considered. Investigational treatment options such as intrathecal ERT are active areas of research, and bone marrow transplantation is in clinical practice. Communication among care providers, social workers, patients and families is essential to inform and guide their decisions, establish realistic expectations, and assess patients’ responses. PMID:25071396

  9. Guidelines for diagnosis and treatment of Hunter Syndrome for clinicians in Latin America

    Directory of Open Access Journals (Sweden)

    Roberto Giugliani

    2014-06-01

    Full Text Available This review aims to provide clinicians in Latin America with the most current information on the clinical aspects, diagnosis, and management of Hunter syndrome, a serious and progressive disease for which specific treatment is available. Hunter syndrome is a genetic disorder where iduronate-2-sulfatase (I2S, an enzyme that degrades glycosaminoglycans, is absent or deficient. Clinical manifestations vary widely in severity and involve multiple organs and tissues. An attenuated and a severe phenotype are recognized depending on the degree of cognitive impairment. Early diagnosis is vital for disease management. Clinical signs common to children with Hunter syndrome include inguinal hernia, frequent ear and respiratory infections, facial dysmorphisms, macrocephaly, bone dysplasia, short stature, sleep apnea, and behavior problems. Diagnosis is based on screening urinary glycosaminoglycans and confirmation by measuring I2S activity and analyzing I2S gene mutations. Idursulfase (recombinant I2S (Elaprase®, Shire enzyme replacement therapy (ERT, designed to address the underlying enzyme deficiency, is approved treatment and improves walking capacity and respiratory function, and reduces spleen and liver size and urinary glycosaminoglycan levels. Additional measures, responding to the multi-organ manifestations, such as abdominal/inguinal hernia repair, carpal tunnel surgery, and cardiac valve replacement, should also be considered. Investigational treatment options such as intrathecal ERT are active areas of research, and bone marrow transplantation is in clinical practice. Communication among care providers, social workers, patients and families is essential to inform and guide their decisions, establish realistic expectations, and assess patients' responses.

  10. Indigenous knowledge of medicinal plants among Dozo hunters: an ethnobotanical survey in Niamberla village, Burkina Faso.

    Science.gov (United States)

    Tibiri, André; Sawadogo, Wamtinga Richard; Dao, Abou; Elkington, Bethany G; Ouedraogo, Noufou; Guissou, Innocent Pierre

    2015-05-01

    This investigation aims to provide a database of Dozo traditional knowledge of medicinal plants used for the treatment of common diseases. The study was conducted through individual interviews using a survey form. Data were recorded in a database allowing statistical analysis. Each plant was recorded and documented with a herbarium specimen. Settings/Location & Subjects: The term Dozo refers to great hunters from Burkina Faso, highly renowned for their knowledge of medicinal plants. Niamberla village was founded by Dozo hunters and is currently the residence of many traditional healers. Unfortunately, their indigenous knowledge is not well recorded and may be lost between two generations. A total of 16 traditional healers were interviewed, giving 89 recipes for the treatment of 37 diseases. The most common diseases are malaria (13%), psychological/spiritual issues (12%), gastric disorders (11%), sexually transmitted diseases (10%), and wounds (8%). A total of 56 medicinal plants have been identified, consisting mostly of trees (44%), shrubs (34%), and herbs (16%). The results of this research provide a basis for pharmacological and toxicological investigations and are necessary to preserve the indigenous knowledge of traditional medicine among Dozo hunters.

  11. Looking at the Camp: Paleolithic Depiction of a Hunter-Gatherer Campsite.

    Directory of Open Access Journals (Sweden)

    Marcos García-Diez

    Full Text Available Landscapes and features of the everyday world were scarcely represented in Paleolithic art, especially those features associated with the human landscape (huts and campsites. On the contrary, other figurative motifs (especially animals and signs, traditionally linked to the magic or religious conceptions of these hunter-gatherer societies, are the predominant themes of Upper Paleolithic art. This paper seeks to present an engraved schist slab recently found in the Molí del Salt site (North-eastern Iberia and dated at the end of the Upper Paleolithic, ca. 13,800 years ago. This slab displays seven semicircular motifs that may be interpreted as the representation of dome-shaped huts. The analysis of individual motifs and the composition, as well as the ethnographic and archeological contextualization, suggests that this engraving is a naturalistic depiction of a hunter-gatherer campsite. Campsites can be considered the first human landscape, the first area of land whose visible features were entirely constructed by humans. Given the social meaning of campsites in hunter-gatherer life-styles, this engraving may be considered one of the first representations of the domestic and social space of a human group.

  12. Looking at the Camp: Paleolithic Depiction of a Hunter-Gatherer Campsite.

    Science.gov (United States)

    García-Diez, Marcos; Vaquero, Manuel

    2015-01-01

    Landscapes and features of the everyday world were scarcely represented in Paleolithic art, especially those features associated with the human landscape (huts and campsites). On the contrary, other figurative motifs (especially animals) and signs, traditionally linked to the magic or religious conceptions of these hunter-gatherer societies, are the predominant themes of Upper Paleolithic art. This paper seeks to present an engraved schist slab recently found in the Molí del Salt site (North-eastern Iberia) and dated at the end of the Upper Paleolithic, ca. 13,800 years ago. This slab displays seven semicircular motifs that may be interpreted as the representation of dome-shaped huts. The analysis of individual motifs and the composition, as well as the ethnographic and archeological contextualization, suggests that this engraving is a naturalistic depiction of a hunter-gatherer campsite. Campsites can be considered the first human landscape, the first area of land whose visible features were entirely constructed by humans. Given the social meaning of campsites in hunter-gatherer life-styles, this engraving may be considered one of the first representations of the domestic and social space of a human group.

  13. Estimating occupancy and predicting numbers of gray wolf packs in Montana using hunter surveys

    Science.gov (United States)

    Rich, Lindsey N.; Russell, Robin E.; Glenn, Elizabeth M.; Mitchell, Michael S.; Gude, Justin A.; Podruzny, Kevin M.; Sime, Carolyn A.; Laudon, Kent; Ausband, David E.; Nichols, James D.

    2013-01-01

    Reliable knowledge of the status and trend of carnivore populations is critical to their conservation and management. Methods for monitoring carnivores, however, are challenging to conduct across large spatial scales. In the Northern Rocky Mountains, wildlife managers need a time- and cost-efficient method for monitoring gray wolf (Canis lupus) populations. Montana Fish, Wildlife and Parks (MFWP) conducts annual telephone surveys of >50,000 deer and elk hunters. We explored how survey data on hunters' sightings of wolves could be used to estimate the occupancy and distribution of wolf packs and predict their abundance in Montana for 2007–2009. We assessed model utility by comparing our predictions to MFWP minimum known number of wolf packs. We minimized false positive detections by identifying a patch as occupied if 2–25 wolves were detected by ≥3 hunters. Overall, estimates of the occupancy and distribution of wolf packs were generally consistent with known distributions. Our predictions of the total area occupied increased from 2007 to 2009 and predicted numbers of wolf packs were approximately 1.34–1.46 times the MFWP minimum counts for each year of the survey. Our results indicate that multi-season occupancy models based on public sightings can be used to monitor populations and changes in the spatial distribution of territorial carnivores across large areas where alternative methods may be limited by personnel, time, accessibility, and budget constraints.

  14. Migratory bird hunter opinions regarding potential management strategies for controlling light goose populations

    Science.gov (United States)

    Dinges, Andrew J.; Webb, Elisabeth B.; Vrtiska, Mark P.; Nilon, Charles H.; Wilhelm Stanis, Sonja A.

    2014-01-01

    We expanded the Nebraska Light Goose Conservation Order (LGCO) harvest survey (NE, USA) in spring 2012 to assess migratory bird hunter opinions regarding future management strategies for controlling light goose populations. Although hunters strongly agreed that population control of light geese was an important wildlife management issue, they were generally unsupportive of wildlife officials using forms of direct control methods to control light goose populations. Respondents who indicated participation in the 2012 LGCO were also less supportive of any form of direct control compared with migratory bird hunters who did not participate in the LGCO. When presented with alternative methods by wildlife officials for future light goose population control, respondents were most supportive of wildlife agencies selectively shooting light geese on migration and wintering areas and least supportive of wildlife officials using bait with approved chemicals to euthanize light geese. A clear understanding of public perception of various potential direct-control options will likely assist wildlife biologists in making informed decisions on how to proceed with population control of light geese.

  15. Neuraminidase subtyping of avian influenza viruses with PrimerHunter-designed primers and quadruplicate primer pools.

    Science.gov (United States)

    Huang, Yanyan; Khan, Mazhar I; Khan, Mazhar; Măndoiu, Ion; Măndoiu, Ion I

    2013-01-01

    We have previously developed a software package called PrimerHunter to design primers for PCR-based virus subtyping. In this study, 9 pairs of primers were designed with PrimerHunter and successfully used to differentiate the 9 neuraminidase (NA) genes of avian influenza viruses (AIVs) in multiple PCR-based assays. Furthermore, primer pools were designed and successfully used to decrease the number of reactions needed for NA subtyping from 9 to 4. The quadruplicate primer-pool method is cost-saving, and was shown to be suitable for the NA subtyping of both cultured AIVs and uncultured AIV swab samples. The primers selected for this study showed excellent sensitivity and specificity in NA subtyping by RT-PCR, SYBR green-based Real-time PCR and Real-time RT-PCR methods. AIV RNA of 2 to 200 copies (varied by NA subtypes) could be detected by these reactions. No unspecific amplification was displayed when detecting RNAs of other avian infectious viruses such as Infectious bronchitis virus, Infectious bursal disease virus and Newcastle disease virus. In summary, this study introduced several sensitive and specific PCR-based assays for NA subtyping of AIVs and also validated again the effectiveness of the PrimerHunter tool for the design of subtyping primers.

  16. Multimodal image analysis of the retina in Hunter syndrome (mucopolysaccharidosis type II): Case report.

    Science.gov (United States)

    Salvucci, Isadora Darriba Macedo; Finzi, Simone; Oyamada, Maria Kiyoko; Kim, Chong Ae; Pimentel, Sérgio Luis Gianotti

    2017-08-18

    We report a case of retinal and posterior ocular findings in a 33-year-old man diagnosed with Hunter syndrome (Mucopolysaccharidosis type II) in a multimodal imaging way. Our patient was complaining of blurred night vision for the past 3 years. He had not received any systemic treatment for Hunter syndrome. Vision acuity was 20/20 in both eyes and corneas were clear. Fundus examination revealed bilateral crowded and hyperemic optic nerve heads (elevated in the ocular ultrasound) and areas of subretinal hypopigmentation. There was hyperautofluorescence at the central fovea and perifovea, and a diffuse bilateral choroidal fluorescence in angiography. Macular SD-OCT showed a thinning of the external retina at the perifovea in both eyes. Visual field testing showed a bilateral ring scotoma. The full field ERG was subnormal, with a negative response in the scotopic phase. Visual Evoked Potencial test and cranial MRI were normal. Our multimodal analysis reported here attempted to contribute to the knowledge of the natural history of GAG deposition in the eye, focusing on the retina and retinal pigment epithelium. Defining this natural history is essential for a proper comparison with Hunter patients receiving systemic treatment, thus determining if it can or cannot improve retinal function in humans with this disorder.

  17. Permanence of Periodic Predator-Prey System with General Nonlinear Functional Response and Stage Structure for Both Predator and Prey

    Directory of Open Access Journals (Sweden)

    Xuming Huang

    2009-01-01

    Full Text Available We study the permanence of periodic predator-prey system with general nonlinear functional responses and stage structure for both predator and prey and obtain that the predator and the prey species are permanent.

  18. Effects of changing sea ice on marine mammals and subsistence hunters in northern Alaska from traditional knowledge interviews.

    Science.gov (United States)

    Huntington, Henry P; Quakenbush, Lori T; Nelson, Mark

    2016-08-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access to them by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information relevant to understanding the ecosystem to which humans belong. We interviewed hunters in 11 coastal villages from the northern Bering Sea to the Beaufort Sea. Hunters reported extensive changes in sea ice and weather that have affected the timing of marine mammal migrations, their distribution and behaviour and the efficacy of certain hunting methods. Amidst these changes, however, hunters cited offsetting technological benefits, such as more powerful and fuel-efficient outboard engines. Other concerns included potential impacts to subsistence hunting from industrial activity such as shipping and oil and gas development. While hunters have been able to adjust to some changes, continued environmental changes and increased disturbance from human activity may further challenge their ability to acquire food in the future. There are indications, however, that innovation and flexibility provide sources of resilience.

  19. Nonlocal Symmetries and Geometric Integrability of Multi-Component Camassa-Holm and Hunter-Saxton Systems

    Institute of Scientific and Technical Information of China (English)

    YAN Lu; SONG Jun-Feng; QU Chang-Zheng

    2011-01-01

    We present the multi-component Hunter-Saxton and μ-Camassa-Holm systems. It is shown that the multicomponent Camassa-Holm, Hunter-Saxton and μ-Camassa-Holm systems are geometrically integrable, namely they describe pseudo-spherical surfaces. As a consequence, their infinite number of conservation laws can be directly constructed. For the three-component Camo ssa-Holm and Hunter-Saxton systems, their nonlocal symmetries depending on the pseudo-potentials are obtained.%@@ We present the multi-component Hunter-Saxton and μ-Camassa-Holm systems.It is shown that the multicomponent Camassa-Holm,Hunter-Saxton and μ-Camassa-Holm systems are geometrically integrable,namely they describe pseudo-spherical surfaces.As a consequence,their infinite number of conservation laws can be directly constructed.For the three-component Camassa-Holm and Hunter-Saxton systems,their nonlocal symmetries depending on the pseudo-potentials are obtained.

  20. Evolution in predator-prey systems

    CERN Document Server

    Durrett, Rick

    2009-01-01

    We study the adaptive dynamics of predator prey systems modeled by a dynamical system in which the characteristics are allowed to evolve by small mutations. When only the prey are allowed to evolve, and the size of the mutational change tends to 0, the system does not exhibit long term prey coexistence and the parameters of the resident prey type converges to the solution of an ODE. When only the predators are allowed to evolve, coexistence of predators occurs. In this case, depending on the parameters being varied we see (i) the number of coexisting predators remains tight and the differences of the parameters from a reference species converge in distribution to a limit, or (ii) the number of coexisting predators tends to infinity, and we conjecture that the differences converge to a deterministic limit.

  1. The relationship between direct predation and antipredator responses: a test with multiple predators and multiple prey.

    Science.gov (United States)

    Creel, Scott; Dröge, Egil; M'soka, Jassiel; Smit, Daan; Becker, Matt; Christianson, Dave; Schuette, Paul

    2017-08-01

    Most species adjust their behavior to reduce the likelihood of predation. Many experiments have shown that antipredator responses carry energetic costs that can affect growth, survival, and reproduction, so that the total cost of predation depends on a trade-off between direct predation and risk effects. Despite these patterns, few field studies have examined the relationship between direct predation and the strength of antipredator responses, particularly for complete guilds of predators and prey. We used scan sampling in 344 observation periods over a four-year field study to examine behavioral responses to the immediate presence of predators for a complete antelope guild (dominated by wildebeest, zebra, and oribi) in Liuwa Plains National Park, Zambia, testing for differences in response to all large carnivores in the ecosystem (lions, spotted hyenas, cheetahs, and African wild dogs). We quantified the proportion that each prey species contributed to the kills made by each predator (516 total kills), used distance sampling on systematic line transects to determine the abundance of each prey species, and combined these data to quantify the per-capita risk of direct predation for each predator-prey pair. On average, antelopes increased their vigilance by a factor of 2.4 when predators were present. Vigilance varied strongly among prey species, but weakly in response to different predators. Increased vigilance was correlated with reduced foraging in a similar manner for all prey species. The strength of antipredator response was not detectably related to patterns of direct predation (n = 15 predator-prey combinations with sufficient data). This lack of correlation has implications for our understanding of the role of risk effects as part of the limiting effect of predators on prey. © 2017 by the Ecological Society of America.

  2. Predation on dormice in Italy

    Directory of Open Access Journals (Sweden)

    Dino Scaravelli

    1995-05-01

    Full Text Available Abstract The authors analyse available data on the impact of predators on Dormouse populations in Italy. Dormice are found in the diet of 2 snakes (Vipera berus and V. aspis, 2 diurnal birds of prey (Buteo buteo and Aquila chrysaetos, 6 owls (Tyto alba, Strix aluco, Asio otus, Athene noctua, Bubo bubo and Glaucidium passerinum and 9 mammals (Rattus rattus, Ursus arctos, Canis lupus, Vulpes vulpes, Martes martes, M. foina, Meles meles, Felis silvestris and Sus scrofa in a variable percentage of the prey taken. Only Dryomys nitedula was never encountered as a prey item. The most common prey is Muscardinus avellanarius. There are significative regional differences in predation between bioclimatic areas of the Italian peninsula. The contribution of studies on predation to knowledge of Myoxid distribution is discussed. Riassunto Predazione di Mioxidi in Italia - Sono analizzati i dati pubblicati sull'impatto dei predatori sulle popolazioni di Myoxidae in Italia. Myoxidae sono stati riscontrati nelle diete di 2 serpenti (Vipera berus e V. aspis, 2 rapaci diurni (Buteo buteo e Aquila chrysaetos, 6 notturni (Tyto alba, Strix aluco, Asio otus, Athene noctua, Bubo bubo e Glaucidium passerinum e 9 mammiferi (Rattus rattus, Ursus arctos, Canis lupus, Vulpes vulpes, Martes martes, M foina, Meles meles, Felis silvestris e Sus scrofa in percentuale variabile nella comunità di prede. Solo Dryomys nitedula non è mai stato incontrato come preda. La specie piu comunemente predata risulta Muscardinus avellanarius. Sono discusse le

  3. Low-Reynolds-number predator

    Science.gov (United States)

    Ebrahimian, Mehran; Yekehzare, Mohammad; Ejtehadi, Mohammad Reza

    2015-12-01

    To generalize simple bead-linker model of swimmers to higher dimensions and to demonstrate the chemotaxis ability of such swimmers, here we introduce a low-Reynolds predator, using a two-dimensional triangular bead-spring model. Two-state linkers as mechanochemical enzymes expand as a result of interaction with particular activator substances in the environment, causing the whole body to translate and rotate. The concentration of the chemical stimulator controls expansion versus the contraction rate of each arm and so affects the ability of the body for diffusive movements; also the variation of activator substance's concentration in the environment breaks the symmetry of linkers' preferred state, resulting in the drift of the random walker along the gradient of the density of activators. External food or danger sources may attract or repel the body by producing or consuming the chemical activators of the organism's enzymes, inducing chemotaxis behavior. Generalization of the model to three dimensions is straightforward.

  4. Predation on rose galls: parasitoids and predators determine gall size through directional selection.

    Directory of Open Access Journals (Sweden)

    Zoltán László

    Full Text Available Both predators and parasitoids can have significant effects on species' life history traits, such as longevity or clutch size. In the case of gall inducers, sporadically there is evidence to suggest that both vertebrate predation and insect parasitoid attack may shape the optimal gall size. While the effects of parasitoids have been studied in detail, the influence of vertebrate predation is less well-investigated. To better understand this aspect of gall size evolution, we studied vertebrate predation on galls of Diplolepis rosae on rose (Rosa canina shrubs. We measured predation frequency, predation incidence, and predation rate in a large-scale observational field study, as well as an experimental field study. Our combined results suggest that, similarly to parasitoids, vertebrate predation makes a considerable contribution to mortality of gall inducer larvae. On the other hand, its influence on gall size is in direct contrast to the effect of parasitoids, as frequency of vertebrate predation increases with gall size. This suggests that the balance between predation and parasitoid attack shapes the optimal size of D. rosae galls.

  5. The Lotka-Volterra predator-prey model with foraging-predation risk trade-offs.

    Science.gov (United States)

    Krivan, Vlastimil

    2007-11-01

    This article studies the effects of adaptive changes in predator and/or prey activities on the Lotka-Volterra predator-prey population dynamics. The model assumes the classical foraging-predation risk trade-offs: increased activity increases population growth rate, but it also increases mortality rate. The model considers three scenarios: prey only are adaptive, predators only are adaptive, and both species are adaptive. Under all these scenarios, the neutral stability of the classical Lotka-Volterra model is partially lost because the amplitude of maximum oscillation in species numbers is bounded, and the bound is independent of the initial population numbers. Moreover, if both prey and predators behave adaptively, the neutral stability can be completely lost, and a globally stable equilibrium would appear. This is because prey and/or predator switching leads to a piecewise constant prey (predator) isocline with a vertical (horizontal) part that limits the amplitude of oscillations in prey and predator numbers, exactly as suggested by Rosenzweig and MacArthur in their seminal work on graphical stability analysis of predator-prey systems. Prey and predator activities in a long-term run are calculated explicitly. This article shows that predictions based on short-term behavioral experiments may not correspond to long-term predictions when population dynamics are considered.

  6. Bald eagle predation on common loon egg

    Science.gov (United States)

    DeStefano, Stephen; McCarthy, Kyle P.; Laskowski, Tom

    2010-01-01

    The Common Loon (Gavia immer) must defend against many potential egg predators during incubation, including corvids, Herring Gulls (Larus argentatus), raccoons (Procyon lotor), striped skunk (Mephitis mephitis), fisher (Martes pennanti), and mink (Neovison vison) (McIntyre 1988, Evers 2004, McCann et al. 2005). Bald Eagles (Haliaeetus leucocephalus) have been documented as predators of both adult Common Loons and their chicks (Vliestra and Paruk 1997, Paruk et al. 1999, Erlandson et al. 2007, Piper et al. 2008). In Wisconsin, where nesting Bald Eagles are abundant (>1200 nesting pairs, >1 young/pair/year), field biologists observed four instances of eagle predation of eggs in loon nests during the period 2002–2004 (M. Meyer pers. comm.). In addition, four cases of eagle predation of incubating adult loons were inferred from evidence found at the loon nest (dozens of plucked adult loon feathers, no carcass remains) and/or loon leg, neck, and skull bones beneath two active eagle nests, including leg bones containing the bands of the nearby (<25 m) incubating adult loon. However, although loon egg predation has been associated with Bald Eagles, predation events have yet to be described in peer-reviewed literature. Here we describe a photographic observation of predation on a Common Loon egg by an immature Bald Eagle as captured by a nest surveillance video camera on Lake Umbagog, a large lake (32 km2) at Umbagog National Wildlife Refuge (UNWR) in Maine.

  7. Management of Large Predators in Alaska

    Directory of Open Access Journals (Sweden)

    Boertje, R.D.

    2005-06-01

    Full Text Available Populations of wolves (Canis lupus, brown bears (Ursus arctos, and black bears (Ursus americanus in Alaska are abundant and highly productive. Their long-term future is secure due to abundant habitat and good wildlife management practices. In many areas of Alaska hunting and trapping regulates wolf numbers and keep them "in balance" with moose populations. However, high predation rates by wolves can severely depress prey populations and then hold them at a very low density many years. This is often referred to as a predator pit. Several moose populations in interior Alaska are in predator pits. In some of these areas, high densities of black and brown bears complicate the situation. Bears generally prey on moose calves for only a few weeks after they are born, but in some areas they kill up to 65% of the calves produced. Moose populations faced with high levels of predation by both wolves and bears will not recover without special management actions to reduce the predation rate. Efforts to regulate predator populations outside of normal hunting and trapping seasons are highly controversial. Many people are very strongly opposed to reducing wolf or bear populations to increase moose populations and provide for a higher harvest by humans. Other people that depend on the moose for food and/or recreation strongly support predator management. It is a clash of values that is generates great controversy in Alaska. We provide a brief history of the controversy over predator management in Alaska and make recommendations on how to manage large predators in Alaska.

  8. Birds as predators in tropical agroforestry systems.

    Science.gov (United States)

    Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell; Bichier, Peter; Barber, Nicholas A; Mooney, Kailen A; Gruner, Daniel S

    2008-04-01

    Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory.

  9. Site Formation Processes and Hunter-Gatherers Use of Space in a Tropical Environment: A Geo-Ethnoarchaeological Approach from South India

    OpenAIRE

    Friesem, David E.; Lavi, Noa; Madella, Marco; Ajithprasad, P; French, C

    2016-01-01

    Hunter-gatherer societies have distinct social perceptions and practices which are expressed in unique use of space and material deposition patterns. However, the identification of archaeological evidence associated with hunter-gatherer activity is often challenging, especially in tropical environments such as rainforests. We present an integrated study combining ethnoarchaeology and geoarchaeology in order to study archaeological site formation processes related to hunter-gatherers’ ways of ...

  10. Acute and subchronic toxicity study of the water extract from the fruits of Piper chaba Hunter in rats

    Directory of Open Access Journals (Sweden)

    K Jaijoy

    2010-12-01

    Full Text Available Summary: The water extract from the fruits of Piper chaba Hunter was evaluated for acute and subchronic toxicity in both male and female rats. For the study of acute toxicity, a single oral dose of 5,000 mg/kg body weight was administered in rats (five females, five males. The results showed no signs of toxicity such as general behavior change, mortality, or change in gross appearance of internal organs. Subchronic toxicity was studied by daily oral doses (ten females, ten males of 300, 600 and 1,200 mg/kg body weight for consecutive 90 days. The satellite group was treated with the extract at the dose of 1,200 mg/kg/day for 90 days and kept for other 28 days after treatment. The results showed no abnormalities in treated groups as compared to the controls. Although significantly different, all of the values were within normal limits. Neither gross abnormalities nor histopathological changes were observed. The results suggest that P. chaba extract does not produce acute or subchronic toxicity in either female or male rats. Industrial relevance: Herbal medicines are popular and extensively used in the developing world. In many places, they offer a more wide available and more affordable alternative to pharmaceutical drugs and natural food supplements. The data of the acute and subchronic toxicity studies on medicinal plants or preparations derived from them should be obtained in order to increase the confidence in its safety to human, particularly for use in the development of pharmaceutical.

  11. Vertebrate predator-prey interactions in a seasonal environment

    DEFF Research Database (Denmark)

    Schmidt, Niels Martin; Berg, Thomas B; Forchhammer, Mads

    2008-01-01

    winters, predation by the only remaining predator, the stoat, is insufficient to regulate the lemming population. In the predator-lemming model, seasonality plays an important role in determining the. growth rate of the lemming population as well as the density of the various lemming predators. We...

  12. Coupled predator-prey oscillations in a chaotic food web

    NARCIS (Netherlands)

    Beninca, E.; Jöhnk, K.; Heerkloss, R.; Huisman, J.

    2009-01-01

    Coupling of several predator-prey oscillations can generate intriguing patterns of synchronization and chaos. Theory predicts that prey species will fluctuate in phase if predator-prey cycles are coupled through generalist predators, whereas they will fluctuate in anti-phase if predator-prey cycles

  13. Coupled predator-prey oscillations in a chaotic food web

    NARCIS (Netherlands)

    Benincà, E.; Johnk, K.D.; Heerkloss, R.; Huisman, J.

    2009-01-01

    Coupling of several predator-prey oscillations can generate intriguing patterns of synchronization and chaos. Theory predicts that prey species will fluctuate in phase if predator-prey cycles are coupled through generalist predators, whereas they will fluctuate in anti-phase if predator-prey cycles

  14. Dynamics of additional food provided predator-prey system with mutually interfering predators.

    Science.gov (United States)

    Prasad, B S R V; Banerjee, Malay; Srinivasu, P D N

    2013-11-01

    Use of additional/alternative food source to predators is one of the widely recognised practices in the field of biological control. Both theoretical and experimental works point out that quality and quantity of additional food play a vital role in the controllability of the pest. Theoretical studies carried out previously in this direction indicate that incorporating mutual interference between predators can stabilise the system. Experimental evidence also point out that mutual interference between predators can affect the outcome of the biological control programs. In this article dynamics of additional food provided predator-prey system in the presence of mutual interference between predators has been studied. The mutual interference between predators is modelled using Beddington-DeAngelis type functional response. The system analysis highlights the role of mutual interference on the success of biological control programs when predators are provided with additional food. The model results indicate the possibility of stable coexistence of predators with low prey population levels. This is in contrast to classical predator-prey models wherein this stable co-existence at low prey population levels is not possible. This study classifies the characteristics of biological control agents and additional food (of suitable quality and quantity), permitting the eco-managers to enhance the success rate of biological control programs.

  15. 2012 Fish Springs NWR predator report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report on a 2012 study to determine a relative index of predator populations, primarily coyote, on fish Springs National Wildlife refuge. Scat deposition transects...

  16. Apex Predators Program Age and Growth Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Apex Predators Program staff have collected vertebral centra from sportfishing tournaments, cruises, commercial fishermen and strandings in the Northeast US since...

  17. Apex Predators Program Sportfishing Tournament Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Apex Predators Program staff have collected shark sportfishing tournamant data from the Northeast US since the 1960's. These tournaments offer a unique opportunity...

  18. Dynamics of a Stochastic Intraguild Predation Model

    Directory of Open Access Journals (Sweden)

    Zejing Xing

    2016-04-01

    Full Text Available Intraguild predation (IGP is a widespread ecological phenomenon which occurs when one predator species attacks another predator species with which it competes for a shared prey species. The objective of this paper is to study the dynamical properties of a stochastic intraguild predation model. We analyze stochastic persistence and extinction of the stochastic IGP model containing five cases and establish the sufficient criteria for global asymptotic stability of the positive solutions. This study shows that it is possible for the coexistence of three species under the influence of environmental noise, and that the noise may have a positive effect for IGP species. A stationary distribution of the stochastic IGP model is established and it has the ergodic property, suggesting that the time average of population size with the development of time is equal to the stationary distribution in space. Finally, we show that our results may be extended to two well-known biological systems: food chains and exploitative competition.

  19. Predator trapping on Monte Vista NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This letter is summarizing the status of predator trapping on Monte Vista National Wildlife refuge in light of the referendum passes in the State of Colorado banning...

  20. Biodiversity effects of the predation gauntlet

    Science.gov (United States)

    Stier, Adrian C.; Stallings, Christopher D.; Samhouri, Jameal F.; Albins, Mark A.; Almany, Glenn R.

    2017-06-01

    The ubiquity of trophic downgrading has led to interest in the consequences of mesopredator release on prey communities and ecosystems. This issue is of particular concern for reef-fish communities, where predation is a key process driving ecological and evolutionary dynamics. Here, we synthesize existing experiments that have isolated the effects of mesopredators to quantify the role of predation in driving changes in the abundance and biodiversity of recently settled reef fishes. On average, predators reduced prey abundance through generalist foraging behavior, which, through a statistical sampling artifact, caused a reduction in alpha diversity and an increase in beta diversity. Thus, the synthesized experiments provide evidence that predation reduces overall abundance within prey communities, but—after accounting for sampling effects—does not cause disproportionate effects on biodiversity.

  1. Bat predation on nocturnally migrating birds

    OpenAIRE

    Ibáñez, Carlos; Juste, Javier; García-Mudarra, Juan L.; Agirre-Mendi, Pablo T.

    2001-01-01

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concen- trate and cross over the world’s temperate regions during migra- tion, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures a...

  2. Using obsidian transfer distances to explore social network maintenance in late Pleistocene hunter-gatherers.

    Science.gov (United States)

    Pearce, Eiluned; Moutsiou, Theodora

    2014-12-01

    Social behaviour is notoriously difficult to study archaeologically and it is unclear how large the networks of prehistoric humans were, or how they remained connected. Maintaining social cohesion was crucial for early humans because social networks facilitate cooperation and are imperative for survival and reproduction. Recent hunter-gatherer social organisation typically comprises a number of nested layers, ranging from the nuclear family through to the ~1500-strong ethnolinguistic tribe. Here we compare maximum obsidian transfer distances from the late Pleistocene with ethnographic data on the size of the geographic areas associated with each of these social grouping layers in recent hunter-gatherers. The closest match between the two is taken to indicate the maximum social layer within which contact could be sustained by Pleistocene hominins. Within both the (sub)tropical African and Subarctic biomes, the maximum obsidian transfer distances for Pleistocene modern humans (~200km and ~400km respectively) correspond to the geographic ranges of the outermost tribal layer in recent hunter-gatherers. This suggests that modern humans could potentially sustain the cohesion of their entire tribe at all latitudes, even though networks are more dispersed nearer the poles. Neanderthal obsidian transfer distances (300km) indicate that although Neanderthal home ranges are larger than those of low latitude hominins, Neanderthals travelled shorter distances than modern humans living at the same high latitudes. We argue that, like modern humans, Neanderthals could have maintained tribal cohesion, but that their tribes were substantially smaller than those of contemporary modern humans living in similar environments. The greater time taken to traverse the larger modern human tribal ranges may have limited the frequency of their face-to-face interactions and thus necessitated additional mechanisms to ensure network connectivity, such as the exchange of symbolic artefacts

  3. Settlement-Size Scaling among Prehistoric Hunter-Gatherer Settlement Systems in the New World.

    Science.gov (United States)

    Haas, W Randall; Klink, Cynthia J; Maggard, Greg J; Aldenderfer, Mark S

    2015-01-01

    Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare-behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation.

  4. Bartonella henselae infection in a family experiencing neurological and neurocognitive abnormalities after woodlouse hunter spider bites

    Science.gov (United States)

    2013-01-01

    Background Bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches. Methods PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region was used in conjunction with BAPGM (Bartonella alpha Proteobacteria growth medium) enrichment blood culture to determine the infection status of the family members and to amplify DNA from spiders and woodlice. Antibody titers to B. vinsonii subsp. berkhoffii (Bvb) genotypes I-III, B. henselae (Bh) and B. koehlerae (Bk) were determined using an IFA test. Management of the medical problems reported by these patients was provided by their respective physicians. Results In this investigation, immediately prior to the onset of symptoms two children in a family experienced puncture-like skin lesions after exposure to and presumptive bites from woodlouse hunter spiders. Shortly thereafter, the mother and both children developed hive-like lesions. Over the ensuing months, the youngest son was diagnosed with Guillain-Barre (GBS) syndrome followed by Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The older son developed intermittent disorientation and irritability, and the mother experienced fatigue, headaches, joint pain and memory loss. When tested approximately three years after the woodlouse hunter spider infestation, all three family members were Bartonella henselae seroreactive and B. henselae DNA was amplified and sequenced from blood, serum or Bartonella alpha-proteobacteria (BAPGM) enrichment blood cultures from the mother and oldest son. Also, B. henselae DNA was PCR amplified and sequenced from a woodlouse and from woodlouse hunter spiders collected adjacent to the family’s home. Conclusions Although it was not possible to determine whether the family’s B. henselae infections were acquired by spider bites or whether the spiders and woodlice were merely accidental hosts, physicians should consider the possibility that B

  5. Thoracolumbar kyphoscoliosis with unilateral subluxation of the spine and postoperative lumbar spondylolisthesis in Hunter syndrome.

    Science.gov (United States)

    Roberts, Simon B; Tsirikos, Athanasios I

    2016-03-01

    Surgical correction for kyphoscoliosis is increasingly being performed for patients with mucopolysaccharidosis (MPS). Reported case series have predominantly included patients with Type I (Hurler) and Type IV (Morquio) MPS. To their knowledge, the authors describe the first case report of surgical management of thoracolumbar kyphoscoliosis in Hunter syndrome (MPS Type II) and the rare occurrence of lumbar spondylolisthesis following surgical stabilization. A 12-year-old boy with Hunter syndrome presented with severe thoracolumbar kyphoscoliosis and no associated symptoms. Spinal radiographs demonstrated kyphosis of 48° (T11-L3) and scoliosis of 22° (T11-L3) with an anteriorly hypoplastic L-1 vertebra. The deformity progressed to kyphosis of 60° and scoliosis of 42° prior to surgical intervention. Spinal CT scans identified left T12-L1 facet subluxation, causing anterior rotatory displacement of the spine proximal to L-1 and bilateral L-5 isthmic spondylolysis with no spondylolisthesis. A combined single-stage anterior and posterior instrumented spinal arthrodesis from T-9 to L-4 was performed. Kyphosis and scoliosis were corrected to 4° and 0°, respectively. Prolonged ventilator support and nasogastric feedings were required for 3 months postoperatively. At 2.5 years following surgery, the patient was asymptomatic, mobilizing independently, and had achieved a solid spinal fusion. However, he had also developed a Grade II spondylolisthesis at L4-5; this was managed nonoperatively in the absence of symptoms or further deterioration of the spondylolisthesis to the 3.5-year postoperative follow-up visit. Satisfactory correction of thoracolumbar kyphoscoliosis in Hunter syndrome can be achieved by combined anterior/posterior instrumented arthrodesis. The risk of developing deformity or instability in motion segments adjacent to an instrumented fusion may be greater in patients with MPS related to the underlying connective tissue disorder.

  6. Settlement-Size Scaling among Prehistoric Hunter-Gatherer Settlement Systems in the New World.

    Directory of Open Access Journals (Sweden)

    W Randall Haas

    Full Text Available Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare-behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation.

  7. Effect of Piper chaba Hunter, Piper sarmentosum Roxb. and Piper interruptum Opiz. on natural killer cell activity and lymphocyte proliferation.

    Science.gov (United States)

    Panthong, Sumalee; Itharat, Arunporn

    2014-08-01

    Immune system is the most important system ofhuman body. Thaifolk doctors have used some medicinal plants as an adaptogenic drug or immunomodulatory agent. Piper chaba Hunter, Piper sarmentosum Roxb. and Piper interruptum Opiz. are used by folk doctors to activate immune response in cancer patients. To investigate the effect on natural killer cell activity and on lymphocyte proliferation activity of water extract of P chaba Hunter P. sarmentosum Roxb. and P interruptum Opiz. MATERIAL ANDMETHOD: Plant materials were extracted by decoction method. All extracts were testedfor an immunomodulatory effect using PBMCs from twelve healthy donors by chromium release assay. Lymphocyte proliferation was also determined by 3H-thymidine uptake assay. The degree of activation was expressed as the stimulation index. The water extract of P chaba Hunter significantly increased lymphocyte proliferation at concentrations ofl ng/ml, 10 ng/ml, 1 μg/ml, 5 μg/ml, 10 μg/ml and 100 μg/ml. P sarmentosum Roxb., and P interruptum Opiz. extracts at those concentrations significantly stimulated lymphocyteproliferation. P sarmentosum Roxb. extractsignificantly increased natural killer (NK) cell activity at a concentration of 100 μg/ml but P chaba Hunter and P interruptum Opiz. extracts did not significantly stimulate natural killer cell activity. P chaba Hunter, P interruptum Opiz. andP sarmentosum Roxb. have an immunomodulatory effect especially for P sarmentosum Roxb. extract which can activate both lymphocyte proliferation and NK cell activity.

  8. Predator-prey molecular ecosystems.

    Science.gov (United States)

    Fujii, Teruo; Rondelez, Yannick

    2013-01-22

    Biological organisms use intricate networks of chemical reactions to control molecular processes and spatiotemporal organization. In turn, these living systems are embedded in self-organized structures of larger scales, for example, ecosystems. Synthetic in vitro efforts have reproduced the architectures and behaviors of simple cellular circuits. However, because all these systems share the same dynamic foundations, a generalized molecular programming strategy should also support complex collective behaviors, as seen, for example, in animal populations. We report here the bottom-up assembly of chemical systems that reproduce in vitro the specific dynamics of ecological communities. We experimentally observed unprecedented molecular behaviors, including predator-prey oscillations, competition-induced chaos, and symbiotic synchronization. These synthetic systems are tailored through a novel, compact, and versatile design strategy, leveraging the programmability of DNA interactions under the precise control of enzymatic catalysis. Such self-organizing assemblies will foster a better appreciation of the molecular origins of biological complexity and may also serve to orchestrate complex collective operations of molecular agents in technological applications.

  9. Increased incidence of neonatal respiratory distress in infants with mucopolysaccharidosis type II (MPS II, Hunter syndrome).

    Science.gov (United States)

    Dodsworth, Charlotte; Burton, Barbara K

    2014-02-01

    Records were reviewed on all patients with mucopolysaccharidosis type II (Hunter syndrome) seen at a single institution from 1999 to 2013 to identify those with a history of neonatal intensive care. Eleven of 34 patients were in a neonatal intensive care unit and all had respiratory distress with 8 diagnoses of respiratory distress syndrome and 3 of transient tachypnea of the newborn. None of the infants were premature; four were delivered by cesarean section. These findings suggest that respiratory distress is more commonly observed in neonates with MPS II than in the general population. This may reflect airway disease already present in this disorder at the time of birth.

  10. Environmental injustice and air pollution in coal affected communities, Hunter Valley, Australia.

    Science.gov (United States)

    Higginbotham, Nick; Freeman, Sonia; Connor, Linda; Albrecht, Glenn

    2010-03-01

    The authors describe environmental injustice from air pollution in the Upper Hunter, Australia, and analyse the inaction of state authorities in addressing residents' health concerns. Obstacles blocking a public-requested health study and air monitoring include: the interdependence of state government and corporations in reaping the economic benefits of coal production; lack of political will, regulatory inertia and procedural injustice; and study design and measurement issues. We analyse mining- and coal-related air pollution in a contested socio-political arena, where residents, civil society and local government groups struggle with corporations and state government over the burden of imposed health risk caused by air pollution.

  11. Period Determination of Asteroid Targets Observed at Hunters Hill Observatory: May 2009 - September 2010

    Science.gov (United States)

    Higgins, David

    2011-01-01

    Lightcurves for 27 asteroids were obtained at the Hunters Hill Observatory (HHO) from 2009 May through 2010 September: 308 Polyxo, 326 Tamara, 369 Aeria, 504 Cora, 822 Lalage, 1164 Kobolda, 1619 Ueta, 1625 The NORC, 1685 Toro, 2189 Zaragoza, 2287 Kalmykia, 2639 Planman, 3695 Fiaia, 4786 Tatianina, 5333 Kanaya, (5452) 1937 NN, 6170 Levasseur, 7741 Fedoseev, 14815 Rutberg, 15724 Zille, 16525 Shumarinaiko, (21996) 1993 XP31, (29729) 1999 BY1, (35404) 1997 YV5, (39087) 2000 VN50, (66146) 1998 TU3, and (101769) 1999 FF52.

  12. 王邪斗争新体验之HUNTER THE RECKONING

    Institute of Scientific and Technical Information of China (English)

    暴龙

    2002-01-01

    《猎手(Hunter)》是High Voltage Software公司很早就推出的一款游戏,原作曾经赢得了很多玩者的赞赏,但是它的续作《猎手:测算(Hunter: The Reckoning)》的制作更加精细。在游戏中,当选择了4个“猎手”之一后,你会切身体会到在黑暗的宇宙中同邪恶进行斗争的艰辛。

  13. Consideration on the Survival and Loneliness in the Heart Is a Lonely Hunter

    Institute of Scientific and Technical Information of China (English)

    Li LI

    2015-01-01

    "Loneliness" is the main melody in almost all the works of Carson McCullers, and it is particularly prominent in novel the Heart Is a Lonely Hunter. All characters in the works were confined by loneliness and could not extricate themselves. Why do human beings feel so lonely?In this paper, the root of the loneliness reflected by human survival itself is discussed, namely, the relationship between the inherent conflict and loneliness of human survival, so as to think about loneliness deeply.

  14. Environmental injustice and air pollution in coal affected communities, Hunter Valley, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Higginbotham, N.; Freeman, S.; Connor, L.; Albrecht, G. [University of Newcastle, Callaghan, NSW (Australia). School of Medicine & Public Health

    2010-03-15

    The authors describe environmental injustice from air pollution in the Upper Hunter, Australia, and analyse the inaction of state authorities in addressing residents' health concerns. Obstacles blocking a public-requested health study and air monitoring include: the interdependence of state government and corporations in reaping the economic benefits of coal production; lack of political will, regulatory inertia and procedural injustice; and study design and measurement issues. We analyse mining- and coal-related air pollution in a contested socio-political arena, where residents, civil society and local government groups struggle with corporations and state government over the burden of imposed health risk caused by air pollution.

  15. From Head-hunter to Organ-thief: Verisimilitude, Doubt and Plausible Worlds in Indonesia and Beyond

    DEFF Research Database (Denmark)

    Bubandt, Nils Ole

    2017-01-01

    In the last couple of years, so people in Indonesia claim, head-hunters – figures of dread and fascination that have haunted societies, politics, and the public imagination in Indonesia at least since colonial times – have begun to adopt a novel and troubling tactic. Instead of decapitating...... their victims and using the human heads in construction rituals as they used to do, head-hunters are now allegedly harvesting the victims’ organs for sale on the international organ market. Based on a comparison of ethnographic material from North Maluku, a province in the eastern part of Indonesia, and news...... reports I trace the shift from head-hunting to organ theft and suggest that this plasticity is not merely a symbolic representation of changing political and economic realities. Rather, I argue, the organ-stealing head-hunters are part of a global travelling package that includes and entangles organ...

  16. Diagnosis of Hunter's syndrome carriers; radioactive sulphate incorporation into fibroblasts in the presence of fructose 1-phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Toennesen, T.; Lykkelund, C.; Guettler, F.

    1982-01-01

    Mutual correction of co-cultivated fibroblasts from patients with Hunter's and Hurler's syndrome could be inhibited by either fructose 1-phosphate or mannose 6-phosphate. In the presence of fructose 1-phosphate a 50% mixture of fibroblasts from a patient with Hunter's syndrome and a normal homozygous individual showed an increased /sup 35/S-sulphate incorporation into acid mucopolysaccharides. When fibroblast cultures from one obligate and two possible carriers of Hunter's syndrome were tested for /sup 35/S-sulphate incorporation, the cultures showed either twice the normal /sup 35/S-sulphate incorporation into acid mucopolysaccharides in the presence of fructose 1-phosphate or an abnormally high incorporation in the presence as well as in the absence of the sugar phosphate.

  17. Hunter syndrome

    Science.gov (United States)

    ... Diagnosis and Treatment . 5th ed. New York, NY: Springer; 2012:chap 40. Read More Breathing difficulty Chromosome ... medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- ...

  18. MetaboHunter: an automatic approach for identification of metabolites from 1H-NMR spectra of complex mixtures

    Directory of Open Access Journals (Sweden)

    Culf Adrian

    2011-10-01

    Full Text Available Abstract Background One-dimensional 1H-NMR spectroscopy is widely used for high-throughput characterization of metabolites in complex biological mixtures. However, the accurate identification of individual compounds is still a challenging task, particularly in spectral regions with higher peak densities. The need for automatic tools to facilitate and further improve the accuracy of such tasks, while using increasingly larger reference spectral libraries becomes a priority of current metabolomics research. Results We introduce a web server application, called MetaboHunter, which can be used for automatic assignment of 1H-NMR spectra of metabolites. MetaboHunter provides methods for automatic metabolite identification based on spectra or peak lists with three different search methods and with possibility for peak drift in a user defined spectral range. The assignment is performed using as reference libraries manually curated data from two major publicly available databases of NMR metabolite standard measurements (HMDB and MMCD. Tests using a variety of synthetic and experimental spectra of single and multi metabolite mixtures show that MetaboHunter is able to identify, in average, more than 80% of detectable metabolites from spectra of synthetic mixtures and more than 50% from spectra corresponding to experimental mixtures. This work also suggests that better scoring functions improve by more than 30% the performance of MetaboHunter's metabolite identification methods. Conclusions MetaboHunter is a freely accessible, easy to use and user friendly 1H-NMR-based web server application that provides efficient data input and pre-processing, flexible parameter settings, fast and automatic metabolite fingerprinting and results visualization via intuitive plotting and compound peak hit maps. Compared to other published and freely accessible metabolomics tools, MetaboHunter implements three efficient methods to search for metabolites in manually curated

  19. Olfactory response of the predator Zetzellia mali to a prey patch occupied by a conspecific predator

    NARCIS (Netherlands)

    Zahedi-Golpayegani, A.; Saboori, A.; Sabelis, M.W.

    2007-01-01

    While searching for food, predators may use volatiles associated with their prey, but also with their competitors for prey. This was tested for the case of Zetzellia mali (Ewing) (Acari: Stigmaeidae), an important predator of the hawthorn spider mite, Amphitetranychus viennensis (Zacher) (Acari: Tet

  20. Coexistence of Predator and Prey in Intraguild Predation systems with Ontogenetic Niche Shifts

    NARCIS (Netherlands)

    Hin, V.; Schellekens, T.; Persson, L.; Roos, A.M.

    2011-01-01

    In basic intraguild predation (IGP) systems, predators and prey also compete for a shared resource. Theory predicts that persistence of these systems is possible when intraguild prey is superior in competition and productivity is not too high. IGP often results from ontogenetic niche shifts, in

  1. Global Stability of a Predator-Prey System with Stage Structure for the Predator

    Institute of Scientific and Technical Information of China (English)

    Yan Ni XIAO; Lan Sun CHEN

    2004-01-01

    In this paper, some feasibly sufficient conditions are obtained for the global asymptotic stability of a positive steady state of a predator-prey system with stage structure for the predator by using the theory of competitive systems, compound matrices and stability of periodic orbits, and then the work of Wang [4] is improved.

  2. Predator interference effects on biological control: The "paradox" of the generalist predator revisited

    Science.gov (United States)

    Parshad, Rana D.; Bhowmick, Suman; Quansah, Emmanuel; Basheer, Aladeen; Upadhyay, Ranjit Kumar

    2016-10-01

    An interesting conundrum in biological control questions the efficiency of generalist predators as biological control agents. Theory suggests, generalist predators are poor agents for biological control, primarily due to mutual interference. However field evidence shows they are actually quite effective in regulating pest densities. In this work we provide a plausible answer to this paradox. We analyze a three species model, where a generalist top predator is introduced into an ecosystem as a biological control, to check the population of a middle predator, that in turn is depredating on a prey species. We show that the inclusion of predator interference alone, can cause the solution of the top predator equation to blow-up in finite time, while there is global existence in the no interference case. This result shows that interference could actually cause a population explosion of the top predator, enabling it to control the target species, thus corroborating recent field evidence. Our results might also partially explain the population explosion of certain species, introduced originally for biological control purposes, such as the cane toad (Bufo marinus) in Australia, which now functions as a generalist top predator. We also show both Turing instability and spatio-temporal chaos in the model. Lastly we investigate time delay effects.

  3. Predator-induced changes in metabolism cannot explain the growth/predation risk tradeoff

    DEFF Research Database (Denmark)

    Steiner, Uli; Van Buskirk, Josh

    2009-01-01

    allocation to defensive structures under predation risk. Here, we tested for a physiological origin of defence costs by measuring oxygen consumption in tadpoles (Rana temporaria) exposed to predation risk over short and long periods of time. The short term reaction was an increase in oxygen consumption...

  4. A predator-2 prey fast-slow dynamical system for rapid predator evolution

    DEFF Research Database (Denmark)

    Piltz, Sofia Helena; Veerman, Frits; Maini, Philip K.

    2017-01-01

    We consider adaptive change of diet of a predator population that switches its feeding between two prey populations. We develop a novel 1 fast-3 slow dynamical system to describe the dynamics of the three populations amidst continuous but rapid evolution of the predator's diet choice. The two ext...

  5. Preliminary assessment of channel stability and bed-material transport along Hunter Creek, southwestern Oregon

    Science.gov (United States)

    Jones, Krista L.; Wallick, J. Rose; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Risley, John C.

    2011-01-01

    This preliminary assessment of (1) bed-material transport in the Hunter Creek basin, (2) historical changes in channel condition, and (3) supplementary data needed to inform permitting decisions regarding instream gravel extraction revealed the following: Along the lower 12.4 km (kilometers) of Hunter Creek from its confluence with the Little South Fork Hunter Creek to its mouth, the river has confined and unconfined segments and is predominately alluvial in its lowermost 11 km. This 12.4-km stretch of river can be divided into two geomorphically distinct study reaches based primarily on valley physiography. In the Upper Study Reach (river kilometer [RKM] 12.4-6), the active channel comprises a mixed bed of bedrock, boulders, and smaller grains. The stream is confined in the upper 1.4 km of the reach by a bedrock canyon and in the lower 2.4 km by its valley. In the Lower Study Reach (RKM 6-0), where the area of gravel bars historically was largest, the stream flows over bed material that is predominately alluvial sediments. The channel alternates between confined and unconfined segments. The primary human activities that likely have affected bed-material transport and the extent and area of gravel bars are (1) historical and ongoing aggregate extraction from gravel bars in the study area and (2) timber harvest and associated road construction throughout the basin. These anthropogenic activities likely have varying effects on sediment transport and deposition throughout the study area and over time. Although assessing the relative effects of these anthropogenic activities on sediment dynamics would be challenging, the Hunter Creek basin may serve as a case study for such an assessment because it is mostly free of other alterations to hydrologic and geomorphic processes such as flow regulation, dredging, and other navigation improvements that are common in many Oregon coastal basins. Several datasets are available that may support a more detailed physical assessment

  6. High frequency of lactose intolerance in a prehistoric hunter-gatherer population in northern Europe

    Directory of Open Access Journals (Sweden)

    Holmlund Gunilla

    2010-03-01

    Full Text Available Abstract Background Genes and culture are believed to interact, but it has been difficult to find direct evidence for the process. One candidate example that has been put forward is lactase persistence in adulthood, i.e. the ability to continue digesting the milk sugar lactose after childhood, facilitating the consumption of raw milk. This genetic trait is believed to have evolved within a short time period and to be related with the emergence of sedentary agriculture. Results Here we investigate the frequency of an allele (-13910*T associated with lactase persistence in a Neolithic Scandinavian population. From the 14 individuals originally examined, 10 yielded reliable results. We find that the T allele frequency was very low (5% in this Middle Neolithic hunter-gatherer population, and that the frequency is dramatically different from the extant Swedish population (74%. Conclusions We conclude that this difference in frequency could not have arisen by genetic drift and is either due to selection or, more likely, replacement of hunter-gatherer populations by sedentary agriculturalists.

  7. The coexistence of Baird's tapir (Tapirus bairdii) and indigenous hunters in northeastern Honduras.

    Science.gov (United States)

    Dunn, Marc; Estrada, Nereyda; Smith, Derek A

    2012-12-01

    The Baird's tapir (Tapirus bairdii) is a popular game species throughout Central America, particularly among indigenous populations, and is currently endangered. Research on Miskitu hunting was conducted over 4 months in a remote region in northeastern Honduras that overlaps with the Río Plátano Biosphere Reserve. The hunting zone was mapped together with hunters and interviews were conducted with elders and other community members about tapir hunting. Results show that tapir harvesting is targeted toward specific habitats at specific times of year. Harvest rates for one year suggest that tapir hunting in the area exceeds estimates of maximum sustainable production. Nevertheless, field surveys reveal the presence of tapir within 1 km of the community, and its harvest tends to be nearby, in both forested and agricultural landscapes, suggesting that the animal has not been depleted in the area. It appears that the existence of forest areas adjacent to the hunting zone that do not experience hunting, together with the anthropogenic habitats created through shifting cultivation, are factors that help explain the presence of tapirs in the area. The article concludes with a discussion regarding the potential positive role of indigenous hunters in tapir conservation throughout its distribution range.

  8. Síndrome de Hunter Mucopolisacaridosis (II:reporte de un caso

    Directory of Open Access Journals (Sweden)

    Ghunter Paz

    2011-06-01

    Full Text Available El síndrome de Hunter, es una alteración genética que afecta principalmente a los varones, debido a la deficiencia o ausencia de la enzima iduronato-2-sulfatasa, que interfiere con lacapacidad del cuerpo de descomponer y reciclar los mucopolisacáridos. La incidencia es de 1:10.000 a 1:25.000 de recién nacidos vivos. Las manifestaciones físicas, incluyen rasgos faciales distintivos, cabeza grande, abdomen aumentado, engrosamiento de válvulas cardíacas, enfermedad respiratoria obstructiva, retraso del desarrollo mental y aumento de tamaño del hígado y del bazo.Presentamos el caso clínico de un paciente de sexo masculino de 7 años de edad, con diagnostico de síndrome de Hunter hace seis años, con antecedentes de crisis convulsivas en dos oportunidades y cuadros de bronconeumonía.Al examen físico presenta fascie tosca, contractura en musculo bíceps braquial, se logra la extensión de las manos, camina con la punta de los pies y presenta hepato y esplenomegalia. Al cual se le trató la sintomatología respiratoria con el uso de antibióticos.

  9. Current views on hunter-gatherer nutrition and the evolution of the human diet.

    Science.gov (United States)

    Crittenden, Alyssa N; Schnorr, Stephanie L

    2017-01-01

    Diet composition and food choice are not only central to the daily lives of all living people, but are consistently linked with turning points in human evolutionary history. As such, scholars from a wide range of fields have taken great interest in the role that subsistence has played in both human cultural and biological evolution. Central to this discussion is the diet composition and nutrition of contemporary hunters and gatherers, who are frequently conscripted as model populations for ancestral human nutrition. Research among the world's few remaining foraging populations is experiencing a resurgence, as they are making the final transition away from diets composed of wild foods, to those dominated by domesticated cultigens and/or processed foods. In an effort to glean as much information as possible, before such populations are no longer hunting and gathering, researchers interested in the evolution of human nutrition are rapidly collecting and accessing new and more data. Methods of scientific inquiry are in the midst of rapid change and scholars are able to revisit long-standing questions using state of the art analyses. Here, using the most relevant findings from studies in ethnography, nutrition, human physiology, and microbiomes, we provide a brief summary of the study of the evolution of human nutrition as it has specifically pertained to data coming from living hunter-gatherers. In doing so, we hope to bridge the disciplines that are currently invested in research on nutrition and health among foraging populations. © 2017 American Association of Physical Anthropologists.

  10. Dietary resilience among hunter-gatherers of Tierra del Fuego: Isotopic evidence in a diachronic perspective.

    Science.gov (United States)

    Tafuri, Mary Anne; Zangrando, Atilio Francisco Javier; Tessone, Augusto; Kochi, Sayuri; Moggi Cecchi, Jacopo; Di Vincenzo, Fabio; Profico, Antonio; Manzi, Giorgio

    2017-01-01

    The native groups of Patagonia have relied on a hunter-gatherer economy well after the first Europeans and North Americans reached this part of the world. The large exploitation of marine mammals (i.e., seals) by such allochthonous groups has had a strong impact on the local ecology in a way that might have forced the natives to adjust their subsistence strategies. Similarly, the introduction of new foods might have changed local diet. These are the premises of our isotopic-based analysis. There is a large set of paleonutritional investigations through isotopic analysis on Fuegians groups, however a systematic exploration of food practices across time in relation to possible pre- and post-contact changes is still lacking. In this paper we investigate dietary variation in hunter-gatherer groups of Tierra del Fuego in a diachronic perspective, through measuring the isotopic ratio of carbon (∂13C) and nitrogen (∂15N) in the bone collagen of human and a selection of terrestrial and marine animal samples. The data obtained reveal an unexpected isotopic uniformity across prehistoric and recent groups, with little variation in both carbon and nitrogen mean values, which we interpret as the possible evidence of resilience among these groups and persistence of subsistence strategies, allowing inferences on the dramatic contraction (and extinction) of Fuegian populations.

  11. Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

    Science.gov (United States)

    Lombardo, Umberto; Szabo, Katherine; Capriles, José M.; May, Jan-Hendrik; Amelung, Wulf; Hutterer, Rainer; Lehndorff, Eva; Plotzki, Anna; Veit, Heinz

    2013-01-01

    We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region’s past and offers a new context within which the late Holocene “Earthmovers” of the Llanos de Moxos could have emerged. PMID:24013964

  12. Early and middle holocene hunter-gatherer occupations in western Amazonia: the hidden shell middens.

    Science.gov (United States)

    Lombardo, Umberto; Szabo, Katherine; Capriles, José M; May, Jan-Hendrik; Amelung, Wulf; Hutterer, Rainer; Lehndorff, Eva; Plotzki, Anna; Veit, Heinz

    2013-01-01

    We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged.

  13. Resource Selection by an Endangered Ungulate: A Test of Predator-Induced Range Abandonment

    OpenAIRE

    2015-01-01

    We investigated influences of risk of predation by mountain lions (Puma concolor), topographic metrics at multiple scales, and vegetation, land, and snow cover on resource selection by Sierra Nevada bighorn sheep (Ovis canadensis sierrae), an endangered taxon, during winters 2002–2007, in the Sierra Nevada, California, USA. We hypothesized that those mountain ungulates would trade off rewards accrued from using critical low-elevation habitat in winter for the safety of areas with reduced risk...

  14. Inducible defenses in prey intensify predator cannibalism.

    Science.gov (United States)

    Kishida, Osamu; Trussell, Geoffrey C; Nishimura, Kinya; Ohgushi, Takayuki

    2009-11-01

    Trophic cascades are often a potent force in ecological communities, but abiotic and biotic heterogeneity can diffuse their influence. For example, inducible defenses in many species create variation in prey edibility, and size-structured interactions, such as cannibalism, can shift predator diets away from heterospecific prey. Although both factors diffuse cascade strength by adding heterogeneity to trophic interactions, the consequences of their interactioh remain poorly understood. We show that inducible defenses in tadpole prey greatly intensify cannibalism in predatory larval salamanders. The likelihood of cannibalism was also strongly influenced by asymmetries in salamander size that appear to be most important in the presence of defended prey. Hence, variation in prey edibility and the size structure of the predator may synergistically affect predator-prey population dynamics by reducing prey mortality and increasing predator mortality via cannibalism. We also suggest that the indirect effects of prey defenses may shape the evolution of predator traits that determine diet breadth and how trophic dynamics unfold in natural systems.

  15. Resetting predator baselines in coral reef ecosystems

    Science.gov (United States)

    Bradley, Darcy; Conklin, Eric; Papastamatiou, Yannis P.; McCauley, Douglas J.; Pollock, Kydd; Pollock, Amanda; Kendall, Bruce E.; Gaines, Steven D.; Caselle, Jennifer E.

    2017-01-01

    What did coral reef ecosystems look like before human impacts became pervasive? Early efforts to reconstruct baselines resulted in the controversial suggestion that pristine coral reefs have inverted trophic pyramids, with disproportionally large top predator biomass. The validity of the coral reef inverted trophic pyramid has been questioned, but until now, was not resolved empirically. We use data from an eight-year tag-recapture program with spatially explicit, capture-recapture models to re-examine the population size and density of a key top predator at Palmyra atoll, the same location that inspired the idea of inverted trophic biomass pyramids in coral reef ecosystems. Given that animal movement is suspected to have significantly biased early biomass estimates of highly mobile top predators, we focused our reassessment on the most mobile and most abundant predator at Palmyra, the grey reef shark (Carcharhinus amblyrhynchos). We estimated a density of 21.3 (95% CI 17.8, 24.7) grey reef sharks/km2, which is an order of magnitude lower than the estimates that suggested an inverted trophic pyramid. Our results indicate that the trophic structure of an unexploited reef fish community is not inverted, and that even healthy top predator populations may be considerably smaller, and more precarious, than previously thought. PMID:28220895

  16. Invasion and predation in aquatic ecosystems

    Institute of Scientific and Technical Information of China (English)

    Judith S. WEIS

    2011-01-01

    This article reviews biological invasions in which predation (or its absence) plays a major role in the success of the invader.Examples are described in which the invader out-competes native species for the same food,and cases in which the invader consumes valued native species.In many instances,better predator avoidance by the invasive species or the absence of predators in the new habitat contributes to the success of the invaders; in other cases native or introduced predators appear to be able to keep the invasive species in check.A relatively new management approach in the US is the idea of adding another trophic level-to have humans act as the predators and consume the invasive species.This approach is being utilized in Florida and throughout the Caribbean against the lionfish,but could be extended to other fishes,as well as to various invasive crustaceans and mollusks.This idea is controversial,and current regulations prohibiting the possession of individuals of the invasive species (e.g.,mitten crabs or snakefish) would preclude the development of a fishery for them [Current Zoology 57 (5):613-624,2011].

  17. Local predation pressure predicts the strength of mobbing responses in tropical birds

    Institute of Scientific and Technical Information of China (English)

    Luis SANDOVAL; David R.WILSON

    2012-01-01

    Many birds join cooperative mobbing aggregations and collectively harass predators.Individuals participating in these ephemeral associations benefit by deterring the predator,but also incur energetic costs and increased risk of predation.Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob.An important step in understanding the evolution of mobbing is to identify factors affecting its expression.The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions,such as when local predation pressure is high.We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator,the ferruginous pygmy-owl Glaucidium brasilianum.We used acoustic playback to elicit mobbing responses in environments where owls were common,uncommon,or rare.Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl's common prey species.During each playback,we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker,as well as the closest approach by any bird.Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common,intermediate where owls were uncommon,and weak where they were rare.This pattern persisted even after controlling for differences in species richness and composition among the three environments.Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds.

  18. Local predation pressure predicts the strength of mobbing responses in tropical birds

    Directory of Open Access Journals (Sweden)

    Luis SANDOVAL, David R. WILSON

    2012-10-01

    Full Text Available Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl’s common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds [Current Zoology 58 (5: 781-790, 2012].

  19. Vaccine Safety

    Science.gov (United States)

    ... Vaccine Safety Shingles (Herpes Zoster) Vaccine Safety Smallpox Vaccine Safety Common Concerns Adjuvants Autism CDC Statement: 2004 Pediatrics Paper on MMR and Autism Fainting (Syncope) Febrile ...

  20. Predation on Daphnia pulex by Lepidurus arcticus

    DEFF Research Database (Denmark)

    Christoffersen, Kirsten Seestern

    2001-01-01

    concentrations and the saturation levels were far above natural prey densities. Small-sized Daphnia (1.6 mm) were removed at significant faster rates (t-test, pLepidurus when offered in combination but not when offered separately. Although the recorded...... predation rates were biased due to the manipulated conditions (e.g. increased encounter rates), Lepidurus appears to be an active and efficient predator on planktonic prey, and its presence in arctic lakes and ponds may consequently have a significant impact on the structure of the planktonic food web...

  1. Predator-prey encounters in turbulent waters

    DEFF Research Database (Denmark)

    Mann, J.; Ott, Søren; Pécseli, H.L.;

    2002-01-01

    With reference to studies of predator-prey encounters in turbulent waters, we demonstrate the feasibility of an experimental method for investigations of particle fluxes to an absorbing surface in turbulent flows. A laboratory experiment is carried out, where an approximately homogeneous and isot......With reference to studies of predator-prey encounters in turbulent waters, we demonstrate the feasibility of an experimental method for investigations of particle fluxes to an absorbing surface in turbulent flows. A laboratory experiment is carried out, where an approximately homogeneous...

  2. Under What Conditions Do Children Thrive in the Madeline Hunter Model? A Report of Project Follow Through, Napa, California.

    Science.gov (United States)

    Stallings, Jane; And Others

    This study evaluated the effect of a comprehensive training program for teachers based on Madeline Hunter's Instructional Theory Into Practice (ITIP). To examine the question of implementation, teachers in the first through fourth grades in Napa Valley elementary schools were observed teaching two reading and two mathematics classes before and…

  3. Arrowheads as indicators of interpersonal violence and group identity among the Neolithic Pitted Ware hunters of southwestern Scandinavia

    DEFF Research Database (Denmark)

    Iversen, Rune

    2016-01-01

    The three main types of tanged flint arrowheads (A, B, and C) characteristic of the Neolithic Pitted Ware hunter, fisher and gatherers of southwestern Scandinavia are traditionally viewed as chronological conditioned. However, recent studies have shown their simultaneity during the early 3rd mill...

  4. Quest for water in coastal Georgia: assessment of alternative water sources at Hunter Army Airfield, Chatham County, Georgia

    Science.gov (United States)

    Clarke, John S.

    2011-01-01

    To meet growing demands for water in the coastal Georgia area, the U.S. Geological Survey, in cooperation with the U.S. Department of the Army, conducted detailed site investigations and modeling studies at Hunter Army Airfield to assess the water-bearing potential of ponds and wells completed in the Lower Floridan aquifer.

  5. The Catalyst Scholarship Program at Hunter College. A Partnership among Earth Science, Physics, Computer Science and Mathematics

    Science.gov (United States)

    Salmun, Haydee; Buonaiuto, Frank

    2016-01-01

    The Catalyst Scholarship Program at Hunter College of The City University of New York (CUNY) was established with a four-year award from the National Science Foundation (NSF) to fund scholarships to 40 academically talented but financially disadvantaged students majoring in four disciplines of science, technology, engineering and mathematics…

  6. Effect of hunter selectivity on harvest rates of radio-collared white-tailed deer in Pennsylvania

    Science.gov (United States)

    Buderman, Frances E.; Diefenbach, Duane R.; Rosenberry, C.S.; Wallingford, Bret D.; Long, Eric S.

    2014-01-01

    Radio transmitters are a commonly used tool for monitoring the fates of harvested species, although little research has been devoted to whether a visible radio transmitter changes a hunters' willingness to harvest that animal. We initially surveyed deer hunters to assess their willingness to harvest radio-collared deer and predicted radio collars were unlikely to affect the harvest of antlerless deer, but hunters may be less willing to harvest small-antlered males with radio collars compared to large-antlered males. We fitted white-tailed deer (Odocoileus virginianus) with radio collars that were visible to hunters or with ear-tag transmitters or ear-tags that were difficult to detect visually and estimated if harvest rates differed among marking methods. For females, the best model failed to detect an effect of radio collars on harvest rates. Also, we failed to detect a difference between male deer fitted with radio collars and ear-tag transmitters. When we compared males fitted with radio collars versus ear tags, we found harvest rate patterns were opposite to our predictions, with lower harvest rates for adult males fitted with radio collars and higher harvest rates for yearling males fitted with radio collars. Our study suggests that harvest rate estimates generated from a sample of deer fitted with visible radio collars can be representative of the population of inference. 

  7. From Head-hunter to Organ-thief: Verisimilitude, Doubt and Plausible Worlds in Indonesia and Beyond

    DEFF Research Database (Denmark)

    Bubandt, Nils Ole

    2017-01-01

    In the last couple of years, so people in Indonesia claim, head-hunters – figures of dread and fascination that have haunted societies, politics, and the public imagination in Indonesia at least since colonial times – have begun to adopt a novel and troubling tactic. Instead of decapitating...

  8. Seasonally perturbed prey-predator system with predator-dependent functional response

    Energy Technology Data Exchange (ETDEWEB)

    Gakkhar, Sunita E-mail: sungkfma@iitr.ernet.in; Naji, Raid Kamel E-mail: naj66dma@iitr.ernet.in

    2003-12-01

    The effect of seasonality on the prey-predator model with predator-dependent trophic function is investigated analytically as well as numerically. The effect of periodic variations is considered on two different parameters of the system: the growth rate of prey and the death rate of the predators. The two parameters may not be in the same phase. The behavior of the system is simulated and bifurcation diagrams are obtained for different parameters. The results show that seasonality in two different parameters with or without phase difference can give rise to multiple attractors, including chaos, with variations in critical parameters.

  9. Predation vulnerability of planktonic copepods: consequences of predator foraging strategies and prey sensory abilities

    DEFF Research Database (Denmark)

    Viitasalo, M; Kiørboe, T; Flinkman, J.;

    1998-01-01

    We investigated the vulnerability of 2 copepod species (Eurytemora affinis and Temora longicornis) to predation by predators with different foraging modes, three-spined stickleback Gasterosteus aculeatus juveniles and mysid shrimps Neomysis integer. Copepods were videofilmed escaping from predators...... of the sticklebacks was higher than that of mysids. In the case of sticklebacks foraging on E. affinis, copepod reaction distance was significantly correlated with stickleback approaching speed; sticklebacks captured a copepod only if they were able to slowly approach to within a strike distance of...

  10. Core Hunter II: fast core subset selection based on multiple genetic diversity measures using Mixed Replica search

    Directory of Open Access Journals (Sweden)

    Beukelaer Herman De

    2012-11-01

    Full Text Available Abstract Background Sampling core subsets from genetic resources while maintaining as much as possible the genetic diversity of the original collection is an important but computationally complex task for gene bank managers. The Core Hunter computer program was developed as a tool to generate such subsets based on multiple genetic measures, including both distance measures and allelic diversity indices. At first we investigate the effect of minimum (instead of the default mean distance measures on the performance of Core Hunter. Secondly, we try to gain more insight into the performance of the original Core Hunter search algorithm through comparison with several other heuristics working with several realistic datasets of varying size and allelic composition. Finally, we propose a new algorithm (Mixed Replica search for Core Hunter II with the aim of improving the diversity of the constructed core sets and their corresponding generation times. Results Our results show that the introduction of minimum distance measures leads to core sets in which all accessions are sufficiently distant from each other, which was not always obtained when optimizing mean distance alone. Comparison of the original Core Hunter algorithm, Replica Exchange Monte Carlo (REMC, with simpler heuristics shows that the simpler algorithms often give very good results but with lower runtimes than REMC. However, the performance of the simpler algorithms is slightly worse than REMC under lower sampling intensities and some heuristics clearly struggle with minimum distance measures. In comparison the new advanced Mixed Replica search algorithm (MixRep, which uses heterogeneous replicas, was able to sample core sets with equal or higher diversity scores than REMC and the simpler heuristics, often using less computation time than REMC. Conclusion The REMC search algorithm used in the original Core Hunter computer program performs well, sometimes leading to slightly better results

  11. Patterns of Lynx Predation at the Interface between Protected Areas and Multi-Use Landscapes in Central Europe.

    Directory of Open Access Journals (Sweden)

    Elisa Belotti

    Full Text Available In Central Europe, protected areas are too small to ensure survival of populations of large carnivores. In the surrounding areas, these species are often persecuted due to competition with game hunters. Therefore, understanding how predation intensity varies spatio-temporally across areas with different levels of protection is fundamental. We investigated the predation patterns of Eurasian lynx (Lynx lynx on roe deer (Capreolus capreolus and red deer (Cervus elaphus in both protected areas and multi-use landscapes of the Bohemian Forest Ecosystem. Based on 359 roe and red deer killed by 10 GPS-collared lynx, we calculated the species-specific annual kill rates and tested for effects of season and lynx age, sex and reproductive status. Because roe and red deer in the study area concentrate in unprotected lowlands during winter, we modeled spatial distribution of kills separately for summer and winter and calculated-the probability of a deer killed by lynx and-the expected number of kills for areas with different levels of protection. Significantly more roe deer (46.05-74.71/year/individual lynx were killed than red deer (1.57-9.63/year/individual lynx, more deer were killed in winter than in summer, and lynx family groups had higher annual kill rates than adult male, single adult female and subadult female lynx. In winter the probability of a deer killed and the expected number of kills were higher outside the most protected part of the study area than inside; in summer, this probability did not differ between areas, and the expected number of kills was slightly larger inside than outside the most protected part of the study area. This indicates that the intensity of lynx predation in the unprotected part of the Bohemian Forest Ecosystem increases in winter, thus mitigation of conflicts in these areas should be included as a priority in the lynx conservation strategy.

  12. 2005 nest success data : Klettke WPA predator exclosure

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report summarizing nest success at Klettke Waterfowl Production Area predator exclosure on Kulm wetland Management District in 2005. In 2005, the Klettke predator...

  13. Experimental Evidence That Predation Promotes Divergence in Adaptive Radiation

    National Research Council Canada - National Science Library

    Patrik Nosil; Bernard J. Crespi

    2006-01-01

    .... The role and importance of other processes, such as predation, remains controversial. Here we use Timema stick insects to show that adaptive radiation can be driven by divergent selection from visual predators...

  14. Effects Of Predator Exclosures On Nesting Success Of Killdeer

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Nests of shorebirds are often destroyed by predators and in some instances predation may cause severe local declines in breeding success and in size of a breeding...

  15. Una valigia caduta in mare: Jaume Serra Hunter e la "Scuola di Barcellona"

    Directory of Open Access Journals (Sweden)

    Nazzareno Fioraso

    2014-12-01

    Full Text Available Nella storiografia filosofica spagnola non esiste, probabilmente, una definizione ambigua e problematica come quella che riguarda la cosiddetta "Scuola di Barcellona". La tesi principale di questo articolo è che tale scuola non giunse mai a nascere, ma ne esistette soltanto una forma embrionale che non poté maturare perché, in conseguenza della situazione politica venutasi a creare con la guerra civile (1936-1939, i suoi componenti si dispersero nell'esilio. Ciò nonostante, è possibile riconoscere alcuni tratti comuni, seppur labili e (forse non sostanziali, nella diaspora degli intellettuali catalani che rendono possibile definirla, con le dovute cautele, "Scuola di Barcellona". Tali caratteristiche comuni si possono far risalire a colui che, in un certo senso, fu il fondatore della scuola, essendo il principale maestro delle nuove leve filosofiche della Catalogna all'inizio del XX secolo: Jaume Serra Hunter.

  16. The curvature of semidirect product groups associated with two-component Hunter-Saxton systems

    Science.gov (United States)

    Kohlmann, Martin

    2011-06-01

    In this paper, we study two-component versions of the periodic Hunter-Saxton equation and its μ-variant. Considering both equations as a geodesic flow on the semidirect product of the circle diffeomorphism group Diff( S) with a space of scalar functions on S we show that both equations are locally well posed. The main result of this paper is that the sectional curvature associated with the 2HS is constant and positive and that 2µHS allows for a large subspace of positive sectional curvature. The issues of this paper are related to some of the results for 2CH and 2DP presented in Escher et al (2011 J. Geom. Phys. 61 436-52).

  17. Evolutionary or fragmented environmental policy making? coal, power, and agriculture in the Hunter Valley, Australia

    Science.gov (United States)

    Day, Diana G.

    1988-05-01

    Intensified surface mining, power generation, and smelting operations in the Hunter River lowlands, NSW, Australia have posed numerous new environmental management problems. Legislative controls over water, soils, and land use management have been clearly insufficient and remain so. The complex range of environmental changes is challenging government agencies as well as coal developers. While water demands are increasing in the region the proportionally greatest competitors are power generation and irrigation. Comprehensive regional water quality assessment is inadequate and divided between a number of agencies with fragmentary interests. Coal development inquiries signal further controversy over appropriate management solutions and are an ongoing phenomenon in the region. The early 1980s resource boom has been followed by lower rates of economic growth, which have resulted in disparate agency responses to major ongoing environmental questions. While issue attention cycles are often remarkably short in environmental management, matters of water, land, and air quality require intensive and ongoing monitoring and policy development.

  18. Symmetry Analysis and Conservation Laws for the Hunter-Saxton Equation

    Institute of Scientific and Technical Information of China (English)

    Mehdi Nadjafikhah; Fatemeh Ahangari

    2013-01-01

    In this paper,the problem of determining the most generalLie point symmetries group and conservation laws of a well known nonlinear hyperbolic PDE in mathematical physics called the Hunter-Saxton equation (HSE) is analyzed.By applying the basic Lie symmetry method for the HSE,the classical Lie point symmetry operators are obtained.Also,the algebraic structure of the Lie algebra of symmetries is discussed and an optimal system of one-dimensional subalgebras of the HSE symmetry algebra which creates the preliminary classification of group invariant solutions is constructed.Particularly,the Lie invariants as well as similarity reduced equations corresponding to infinitesimal symmetries are obtained.Mainly,the conservation laws of the HSE are computed via three different methods including Boyer's generalization of Noether's theorem,first homotopy method and second homotopy method.

  19. Maximum likelihood methods for investigating reporting rates of rings on hunter-shot birds

    Science.gov (United States)

    Conroy, M.J.; Morgan, B.J.T.; North, P.M.

    1985-01-01

    It is well known that hunters do not report 100% of the rings that they find on shot birds. Reward studies can be used to estimate what this reporting rate is, by comparison of recoveries of rings offering a monetary reward, to ordinary rings. A reward study of American Black Ducks (Anas rubripes) is used to illustrate the design, and to motivate the development of statistical models for estimation and for testing hypotheses of temporal and geographic variation in reporting rates. The method involves indexing the data (recoveries) and parameters (reporting, harvest, and solicitation rates) by geographic and temporal strata. Estimates are obtained under unconstrained (e.g., allowing temporal variability in reporting rates) and constrained (e.g., constant reporting rates) models, and hypotheses are tested by likelihood ratio. A FORTRAN program, available from the author, is used to perform the computations.

  20. Planet Hunters: New Kepler planet candidates from analysis of quarter 2

    CERN Document Server

    Lintott, Chris; Sharzer, Charlie; Fisher, Debra A; Barclay, Thomas; Parrish, Michael; Batalha, Natalie; Bryson, Steve; Jenkins, Jon; Ragozzine, Darin; Rowe, Jason F; Schawinski, Kevin; Gagliano, Rovert; Gilardi, Joe; Jek, Kian J; Pääkkönen, Jari-Pekka; Smits, Tjapko

    2012-01-01

    We present new planet candidates identified in NASA Kepler quarter two public release data by volunteers engaged in the Planet Hunters citizen science project. The two candidates presented here survive checks for false-positives, including examination of the pixel offset to constrain the possibility of a background eclipsing binary. The orbital periods of the planet candidates are 97.46 days (KIC 4552729) and 284.03 (KIC 10005758) days and the modeled planet radii are 5.3 and 3.790 R_Earth. The latter star has an additional known planet candidate with a radius of 5.05 R_Earth and a period of 134.49 which was detected by the Kepler pipeline. The discovery of these candidates illustrates the value of massively distributed volunteer review of the Kepler database to recover candidates which were otherwise uncatalogued.

  1. Emergence of social complexity among coastal hunter-gatherers in the Atacama Desert of northern Chile.

    Science.gov (United States)

    Marquet, Pablo A; Santoro, Calogero M; Latorre, Claudio; Standen, Vivien G; Abades, Sebastián R; Rivadeneira, Marcelo M; Arriaza, Bernardo; Hochberg, Michael E

    2012-09-11

    The emergence of complex cultural practices in simple hunter-gatherer groups poses interesting questions on what drives social complexity and what causes the emergence and disappearance of cultural innovations. Here we analyze the conditions that underlie the emergence of artificial mummification in the Chinchorro culture in the coastal Atacama Desert in northern Chile and southern Peru. We provide empirical and theoretical evidence that artificial mummification appeared during a period of increased coastal freshwater availability and marine productivity, which caused an increase in human population size and accelerated the emergence of cultural innovations, as predicted by recent models of cultural and technological evolution. Under a scenario of increasing population size and extreme aridity (with little or no decomposition of corpses) a simple demographic model shows that dead individuals may have become a significant part of the landscape, creating the conditions for the manipulation of the dead that led to the emergence of complex mortuary practices.

  2. The curvature of semidirect product groups associated with two-component Hunter-Saxton systems

    Energy Technology Data Exchange (ETDEWEB)

    Kohlmann, Martin, E-mail: kohlmann@ifam.uni-hannover.de [Institute for Applied Mathematics, University of Hannover, D-30167 Hannover (Germany)

    2011-06-03

    In this paper, we study two-component versions of the periodic Hunter-Saxton equation and its {mu}-variant. Considering both equations as a geodesic flow on the semidirect product of the circle diffeomorphism group Diff(S) with a space of scalar functions on S we show that both equations are locally well posed. The main result of this paper is that the sectional curvature associated with the 2HS is constant and positive and that 2{mu}HS allows for a large subspace of positive sectional curvature. The issues of this paper are related to some of the results for 2CH and 2DP presented in Escher et al (2011 J. Geom. Phys. 61 436-52).

  3. General medicine advanced training: lessons from the John Hunter training programme.

    Science.gov (United States)

    Jackel, D; Attia, J; Pickles, R

    2014-03-01

    Recent years have seen a rapid growth in the number of advanced trainees pursuing general medicine as a specialty. This reflects an awareness of the need for broader training experiences to equip future consultant physicians with the skills to manage the healthcare challenges arising from the demographic trends of ageing and increasing comorbidity. The John Hunter Hospital training programme in general medicine has several characteristics that have led to the success in producing general physicians prepared for these challenges. These include support from a core group of committed general physicians, an appropriate and sustainable funding model, flexibility with a focus on genuine training and developing awareness of a systems approach, and strong links with rural practice.

  4. Bounty Hunter x Alpha Industries 暗黑军事结合

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    日本里原系品牌找来正宗军服品牌Alpha Industries合作已不算新鲜事,早在1999年里原文化的黄金时期,差不多每到冬季总见不同类型的合作军褛款式,直到今年也不例外,而且一直延伸到春夏季。向来以朋克摇滚作设计方针的Bounty Hunter,在最新单品中再次找来Alpha Industries合作,推出以MA-1作蓝本的暗黑款式,并在细节上经过特别加工。

  5. Hurricane Safety

    Science.gov (United States)

    ... English Hurricane Safety Checklist - Arabic Hurricane Safety Checklist - Chinese Hurricane Safety Checklist - French Hurricane Safety Checklist - Haitian ... Cross serves in the US, its territories and military installations around the world. Please try again. Your ...

  6. Hepatitis E Virus in Domestic Pigs, Wild Boars, Pig Farm Workers, and Hunters in Estonia.

    Science.gov (United States)

    Ivanova, Anna; Tefanova, Valentina; Reshetnjak, Irina; Kuznetsova, Tatiana; Geller, Julia; Lundkvist, Åke; Janson, Marilin; Neare, Kädi; Velström, Kaisa; Jokelainen, Pikka; Lassen, Brian; Hütt, Pirje; Saar, Tiiu; Viltrop, Arvo; Golovljova, Irina

    2015-12-01

    While hepatitis E is a growing health concern in Europe, epidemiological data on hepatitis E virus (HEV) in Estonia are scarce. Along with imported HEV infections, autochthonous cases are reported from European countries. Both domestic and wild animals can be a source of human cases of this zoonosis. Here, we investigated the presence of anti-HEV antibodies and HEV RNA in domestic pigs and wild boars, as well as in pig farm workers and hunters in Estonia. Anti-HEV antibodies were detected in 234/380 (61.6%) of sera from domestic pigs and in all investigated herds, and in 81/471 (17.2%) of meat juice samples from wild boars. HEV RNA was detected by real-time PCR in 103/449 (22.9%) of fecal samples from younger domestic pigs and 13/81 (16.0%) of anti-HEV-positive wild boar samples. Analysis of sera from 67 pig farm workers and 144 hunters revealed the presence of HEV-specific IgG in 13.4 and 4.2% of the samples, respectively. No HEV RNA was detected in the human serum samples. Phylogenetic analyses of HEV sequences from domestic pigs and wild boars, based on a 245 bp fragment from the open reading frame 2 showed that all of them belonged to genotype 3. The present study demonstrates the presence of HEV in Estonian domestic pig and wild boar populations, as well as in humans who have direct regular contact with these animals. Our results suggest that HEV infections are present in Estonia and require attention.

  7. Trophy hunters' willingness to pay for wildlife conservation and community benefits.

    Science.gov (United States)

    Fischer, Anke; Tibebe Weldesemaet, Yitbarek; Czajkowski, Mikołaj; Tadie, Degu; Hanley, Nick

    2015-08-01

    In the face of fundamental land-use changes, the potential for trophy hunting to contribute to conservation is increasingly recognized. Trophy hunting can, for example, provide economic incentives to protect wildlife populations and their habitat, but empirical studies on these relationships are few and tend to focus on the effects of benefit-sharing schemes from an ex post perspective. We investigated the conditions under which trophy hunting could facilitate wildlife conservation in Ethiopia ex ante. We used a choice experiment approach to survey international trophy hunters' (n = 224) preferences for trips to Ethiopia, here operationalized as trade-offs between different attributes of a hunting package, as expressed through choices with an associated willingness to pay. Participants expressed strong preferences and, consequently, were willing to pay substantial premiums for hunting trips to areas with abundant nontarget wildlife where domestic livestock was absent and for arrangements that offered benefit sharing with local communities. For example, within the range of percentages considered in the survey, respondents were on average willing to pay an additional $3900 for every 10 percentage points of the revenue being given to local communities. By contrast, respondents were less supportive of hunting revenue being retained by governmental bodies: Willingness to pay decreased by $1900 for every 10 percentage points of the revenue given to government. Hunters' preferences for such attributes of hunting trips differed depending on the degree to which they declared an interest in Ethiopian culture, nature conservation, or believed Ethiopia to be politically unstable. Overall, respondents thus expressly valued the outcomes of nature conservation activities--the presence of wildlife in hunting areas--and they were willing to pay for them. Our findings highlight the usefulness of insights from choice modeling for the design of wildlife management and conservation

  8. Predicting hunter behavior of indigenous communities in the Ecuadorian Amazon: insights from a household production model

    Directory of Open Access Journals (Sweden)

    Enrique de la Montaña

    2015-12-01

    Full Text Available Many indigenous communities living in the Amazon rely on hunting and fishing to meet the majority of their protein needs. Despite the importance of these practices, few studies from the region have analyzed the socioeconomic drivers of hunting and fishing at the household level. We propose a household production model to assess the effect of key economic parameters on hunting and fishing in small indigenous communities located in the Ecuadorian Amazon, whose principal source of protein is derived from hunting and fishing. The model was validated using empirical data from two communities that reflect different levels of market integration and forest conservation. Demand and supply functions were generated from household data gathered over 19 months. Elasticities were derived to determine the sensitivity of the decision to engage in hunting to exogenous parameters such as off-farm wages, hunting costs, bushmeat price, penalties for the illegal sale of bushmeat, and biological characteristics of the game species. After calibrating the model, we simulated changes in the key economic parameters. The parameter that most directly affected hunting activity in both communities was off-farm wages. Simulating a 10% wage increase resulted in a 16-20% reduction in harvested biomass, while a 50% increase diminished harvested biomass by > 50%. Model simulations revealed that bushmeat price and penalties for illegal trade also had important effects on hunter behavior in terms of amount of bushmeat sold, but not in terms of total harvest. As a tool for understanding hunters' economic decision-making, the model provides a basis for developing strategies that promote sustainable hunting and wildlife conservation while protecting indigenous livelihoods.

  9. Measured elemental transfer factors for boreal hunter/gatherer scenarios: fish, game and berries.

    Science.gov (United States)

    Sheppard, S C; Long, J M; Sanipelli, B

    2010-11-01

    The environmental assessment of long-term nuclear waste management requires data to estimate food chain transfers for radionuclides in various environmental settings. For key elements such as iodine (I) and chlorine (Cl), there is a paucity of transfer factor data, particularly outside of agricultural food chains. This study dealt with transfers of I, Cl and 28 other elements to foods that would be typical of boreal hunter/gatherer lifestyles, as well as being common foods for modern recreational and subsistence hunters. Food/substrate concentration ratios (CRs) and related transfer factors for eight species of widely distributed fish, whitetail deer (Odocoileus virginianus), Canada geese (Branta canadensis) and wild blueberries (Vaccinium myrtilloides) were measured and compared to the literature. Limited data were obtained for caribou (Rangifer tarandus), elk (Cervus elaphus) and moose (Alces americanus). Freshwater sediment Kd values and CRs for a ubiquitous freshwater macrophyte were also obtained. The CRs for I in fish were 29Lkg(-1) in edible muscle (fillets) of large-bodied species and 85Lkg(-1) for whole, small-bodied fish. The logCRs for fish and macrophytes were correlated across elements. For several elements, the Kds for sediments in deep water were approximately 4-fold higher than for littoral samples. The elemental transfers to wild animals for some elements were notably different than the literature indicates for domestic animals. It is argued that the transfer data obtained using indigenous elements from real environmental settings, as opposed to contaminant elements in experimental or impacted environments, are especially relevant to assessment of long-term impacts.

  10. Enzymatic replacement therapy for Hunter disease: Up to 9 years experience with 17 patients

    Directory of Open Access Journals (Sweden)

    Rossella Parini

    2015-06-01

    Full Text Available Hunter disease is an X-linked lysosomal storage disorder characterized by progressive storage of glycosaminoglycans (GAGs and multi-organ impairment. The central nervous system (CNS is involved in at least 50% of cases. Since 2006, the enzymatic replacement therapy (ERT is available but with no effect on the cognitive impairment, as the present formulation does not cross the blood–brain barrier. Here we report the outcome of 17 Hunter patients treated in a single center. Most of them (11 started ERT in 2006, 3 had started it earlier in 2004, enrolled in the phase III trial, and 3 after 2006, as soon as the diagnosis was made. The liver and spleen sizes and urinary GAGs significantly decreased and normalized throughout the treatment. Heart parameters improved, in particular the left ventricular mass index/m2 decreased significantly. Amelioration of hearing was seen in many patients. Joint range of motion improved in all patients. However, no improvement on respiratory function, eye, skeletal and CNS disease was found. The developmental quotient of patients with a CNS involvement showed a fast decline. These patients were no more testable after 6 years of age and, albeit the benefits drawn from ERT, their quality of life worsened throughout the years. The whole group of patients showed a consistent residual disease burden mainly represented by persistent skeletal disease and frequent need of surgery. This study suggests that early diagnosis and treatment and other different therapies which are able to cross the blood–brain barrier, might in the future improve the MPS II outcome.

  11. Brood surveys and hunter observations used to predict gobbling activity wild turkeys in Mississippi

    Science.gov (United States)

    Palumbo, Matthew D.; Vilella, Francisco; Strickland, Bronson K.; Wang, Guiming; Godwin, Dave

    2014-01-01

    The Mississippi Department of Wildlife, Fisheries, and Parks utilize data from turkey hunter observations and brood surveys from across the state to manage wild turkey Meleagris gallopavo populations. Since 1995, hunters have collected gobbling and jake observation data, while the Mississippi Department of Wildlife, Fisheries, and Parks' personnel and cooperating wildlife managers of several natural resource agencies throughout the state have collected brood survey data. Both sources of data serve to forecast poult recruitment and gobbling activity. The objective of this study was to evaluate if these data can serve as a viable predictor of gobbling activity. We used three mixed models to investigate the relationship between the number of jakes observed per hour of hunting 1 y prior and the total number of poults per hens 2 y prior (model 1), number of gobblers heard per hour of hunting and the number of jakes observed per hour of hunting 1 y prior (model 2), the number of gobblers heard per hour of hunting and the total number poults per total hens observed 2 y prior (model 3) using data from 1995 to 2008 among five wild turkey management regions encompassing the state. We incorporated region as a random effect to account for spatial variation. We found the number of jakes observed per hour of hunting 1 y prior correlated with the total number of poults per total hens observed 2 y prior. We also found the number of gobblers heard per hour of hunting correlated with the number of jakes observed per hour of hunting 1 y prior. Additionally, we found that the total poults per total hens observed 2 y prior was correlated to the number of gobblers heard per hour of hunting. Our results show promise for using indices of gobbling activity, jake observations, and brood surveys to estimate gobbling activity.

  12. Predator personality and prey behavioural predictability jointly determine foraging performance

    Science.gov (United States)

    Chang, Chia-chen; Teo, Huey Yee; Norma-Rashid, Y.; Li, Daiqin

    2017-01-01

    Predator-prey interactions play important roles in ecological communities. Personality, consistent inter-individual differences in behaviour, of predators, prey or both are known to influence inter-specific interactions. An individual may also behave differently under the same situation and the level of such variability may differ between individuals. Such intra-individual variability (IIV) or predictability may be a trait on which selection can also act. A few studies have revealed the joint effect of personality types of both predators and prey on predator foraging performance. However, how personality type and IIV of both predators and prey jointly influence predator foraging performance remains untested empirically. Here, we addressed this using a specialized spider-eating jumping spider, Portia labiata (Salticidae), as the predator, and a jumping spider, Cosmophasis umbratica, as the prey. We examined personality types and IIVs of both P. labiata and C. umbratica and used their inter- and intra-individual behavioural variation as predictors of foraging performance (i.e., number of attempts to capture prey). Personality type and predictability had a joint effect on predator foraging performance. Aggressive predators performed better in capturing unpredictable (high IIV) prey than predictable (low IIV) prey, while docile predators demonstrated better performance when encountering predictable prey. This study highlights the importance of the joint effect of both predator and prey personality types and IIVs on predator-prey interactions. PMID:28094288

  13. A minimal model of predator-swarm interactions.

    Science.gov (United States)

    Chen, Yuxin; Kolokolnikov, Theodore

    2014-05-06

    We propose a minimal model of predator-swarm interactions which captures many of the essential dynamics observed in nature. Different outcomes are observed depending on the predator strength. For a 'weak' predator, the swarm is able to escape the predator completely. As the strength is increased, the predator is able to catch up with the swarm as a whole, but the individual prey is able to escape by 'confusing' the predator: the prey forms a ring with the predator at the centre. For higher predator strength, complex chasing dynamics are observed which can become chaotic. For even higher strength, the predator is able to successfully capture the prey. Our model is simple enough to be amenable to a full mathematical analysis, which is used to predict the shape of the swarm as well as the resulting predator-prey dynamics as a function of model parameters. We show that, as the predator strength is increased, there is a transition (owing to a Hopf bifurcation) from confusion state to chasing dynamics, and we compute the threshold analytically. Our analysis indicates that the swarming behaviour is not helpful in avoiding the predator, suggesting that there are other reasons why the species may swarm. The complex shape of the swarm in our model during the chasing dynamics is similar to the shape of a flock of sheep avoiding a shepherd.

  14. Evolutionary dynamics of prey exploitation in a metapopulation of predators

    NARCIS (Netherlands)

    Pels, S.H.; de Roos, A.M.; Sabelis, M.W.

    2002-01-01

    In well-mixed populations of predators and prey, natural selection favors predators with high rates of prey consumption and population growth. When spatial structure prevents the populations from being well mixed, such predators may have a selective disadvantage because they do not make full use of

  15. Weed seed predation in organic and conventional fields

    DEFF Research Database (Denmark)

    Navntoft, S; Wratten, S D; Kristensen, K;

    2009-01-01

    Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation was st...

  16. Harvesting and Conversation in a Predator-Prey System

    NARCIS (Netherlands)

    Hoekstra, Jeljer; Bergh, van den Jeroen C.J.M.

    2001-01-01

    Optimal harvesting of prey in a predator-prey ecosystem is studiedunder the condition that the existence of the predator has value. Predators (birds) and humans (fishers) compete for prey (shellfish). The behavior of the system is studied and conditions for optimal control are deduced. Various optim

  17. Spider mite web mediates anti-predator behaviour

    NARCIS (Netherlands)

    Lemos, F.; de Almeida Sarmento, R.; Pallini, A.; Rosa Dias, C.; Sabelis, M.W.; Janssen, A.

    2010-01-01

    Herbivores suffer significant mortality from predation and are therefore subject to natural selection on traits promoting predator avoidance and resistance. They can employ an array of strategies to reduce predation, for example through changes in behaviour, morphology and life history. So far, the

  18. Levy Walks Suboptimal under Predation Risk.

    Directory of Open Access Journals (Sweden)

    Masato S Abe

    2015-11-01

    Full Text Available A key challenge in movement ecology is to understand how animals move in nature. Previous studies have predicted that animals should perform a special class of random walks, called Lévy walk, to obtain more targets. However, some empirical studies did not support this hypothesis, and the relationship between search strategy and ecological factors is still unclear. We focused on ecological factors, such as predation risk, and analyzed whether Lévy walk may not be favored. It was remarkable that the ecological factors often altered an optimal search strategy from Lévy walk to Brownian walk, depending on the speed of the predator's movement, density of predators, etc. This occurred because higher target encounter rates simultaneously led searchers to higher predation risks. Our findings indicate that animals may not perform Lévy walks often, and we suggest that it is crucial to consider the ecological context for evaluating the search strategy performed by animals in the field.

  19. Some exclusion cages do not exclude predators

    Directory of Open Access Journals (Sweden)

    Olga M. C. C. Ameixa

    2011-12-01

    Full Text Available Exclusion techniques, such as cages, are the most frequently used means of evaluating the efficiency of natural enemies in suppressing the abundance of their prey. The growth rates and peak densities of aphid populations within cages are usually larger than those in uncaged populations. However, cages change the microenvironment and prevent aphids from emigrating. Attempts were made to avoid the change in the microenvironment by using cages with a large (8 mm mesh. Here we test the hypothesis that because of the large mesh size, predators can easily penetrate into such cages during an experiment. Our results have shown that cages with a large (8 mm mesh size do not prevent predators from entering the cages and therefore cannot be used as “exclusion cages” for measuring the effect of predators on aphid numbers. Other methods of assessing the effectiveness of natural enemies in reducing the abundance of their prey, like removing the predators or direct observations, should be used instead.

  20. Functional responses modified by predator density

    NARCIS (Netherlands)

    Kratina, P.; Vos, M.; Bateman, A.W.; Anholt, B.R.

    2009-01-01

    Realistic functional responses are required for accurate model predictions at the community level. However, controversy remains regarding which types of dependencies need to be included in functional response models. Several studies have shown an effect of very high predator densities on per capita

  1. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...

  2. Predator diversity hotspots in the blue ocean.

    Science.gov (United States)

    Worm, Boris; Lotze, Heike K; Myers, Ransom A

    2003-08-19

    Concentrations of biodiversity, or hotspots, represent conservation priorities in terrestrial ecosystems but remain largely unexplored in marine habitats. In the open ocean, many large predators such as tunas, sharks, billfishes, and sea turtles are of current conservation concern because of their vulnerability to overfishing and ecosystem role. Here we use scientific-observer records from pelagic longline fisheries in the Atlantic and Pacific Oceans to show that oceanic predators concentrate in distinct diversity hotspots. Predator diversity consistently peaks at intermediate latitudes (20-30 degrees N and S), where tropical and temperate species ranges overlap. Individual hotspots are found close to prominent habitat features such as reefs, shelf breaks, or seamounts and often coincide with zooplankton and coral reef hotspots. Closed-area models in the northwest Atlantic predict that protection of hotspots outperforms other area closures in safeguarding threatened pelagic predators from ecological extinction. We conclude that the seemingly monotonous landscape of the open ocean shows rich structure in species diversity and that these features should be used to focus future conservation efforts.

  3. Ants, rodents and seed predation in Proteaceae

    African Journals Online (AJOL)

    Ants may reduce seed predation by rapidly transporting and burying seeds in their .... the size and shape of inverted waste paper baskets or b) by securing a lid 5 ... Mimetes experiment was dry for only 3 h before rain set in. Ant activity ceased ...

  4. Predators, prey, and natural disasters attract ecologists.

    Science.gov (United States)

    Mlot, C

    1993-08-27

    Some 2200 ecologists turned out for the 78th annual meeting of the Ecological Society of America (ESA), held in Madison, Wisconsin, 31 July to 4 August. Among the offerings: reports on the effect of dams and levees on large river ecology, predator-prey interactions, how parasites might control evolution, and the impact of clearcutting on soil organisms.

  5. Carbon fluxes to Antarctic top predators

    NARCIS (Netherlands)

    Franeker, van J.A.; Bathmann, U.V.; Mathot, S.

    1997-01-01

    The role of birds, seals and whales in the overall biological carbon fluxes of the Southern Ocean has been estimated based on census counts of top predator individuals in the region. Using standard routines for conversion to food consumption and respiration rates we demonstrate that at most 0.3-0.6%

  6. Climate change and marine top predators

    DEFF Research Database (Denmark)

    Climate change affects all components of marine ecosystems. For endothermic top predators, i.e. seabirds and marine mammals, these impacts are often complex and mediated through trophic relationships. In this Research Topic, leading researchers attempt to identify patterns of change among seabirds...

  7. Sexually Violent Predators and Civil Commitment Laws

    Science.gov (United States)

    Beyer Kendall, Wanda D.; Cheung, Monit

    2004-01-01

    This article analyzes the civil commitment models for treating sexually violent predators (SVPs) and analyzes recent civil commitment laws. SVPs are commonly defined as sex offenders who are particularly predatory and repetitive in their sexually violent behavior. Data from policy literature, a survey to all states, and a review of law review…

  8. Attitudes and Beliefs of Pig Farmers and Wild Boar Hunters Towards Reporting of African Swine Fever in Bulgaria, Germany and the Western Part of the Russian Federation.

    Science.gov (United States)

    Vergne, T; Guinat, C; Petkova, P; Gogin, A; Kolbasov, D; Blome, S; Molia, S; Pinto Ferreira, J; Wieland, B; Nathues, H; Pfeiffer, D U

    2016-04-01

    This study investigated the attitudes and beliefs of pig farmers and hunters in Germany, Bulgaria and the western part of the Russian Federation towards reporting suspected cases of African swine fever (ASF). Data were collected using a web-based questionnaire survey targeting pig farmers and hunters in these three study areas. Separate multivariable logistic regression models identified key variables associated with each of the three binary outcome variables whether or not farmers would immediately report suspected cases of ASF, whether or not hunters would submit samples from hunted wild boar for diagnostic testing and whether or not hunters would report wild boar carcasses. The results showed that farmers who would not immediately report suspected cases of ASF are more likely to believe that their reputation in the local community would be adversely affected if they were to report it, that they can control the outbreak themselves without the involvement of veterinary services and that laboratory confirmation would take too long. The modelling also indicated that hunters who did not usually submit samples of their harvested wild boar for ASF diagnosis, and hunters who did not report wild boar carcasses are more likely to justify their behaviour through a lack of awareness of the possibility of reporting. These findings emphasize the need to develop more effective communication strategies targeted at pig farmers and hunters about the disease, its epidemiology, consequences and control methods, to increase the likelihood of early reporting, especially in the Russian Federation where the virus circulates.

  9. Perceived predation risk as a function of predator dietary cues in terrestrial salamanders.

    Science.gov (United States)

    Murray; Jenkins

    1999-01-01

    Prey often avoid predator chemical cues, and in aquatic systems, prey may even appraise predation risk via cues associated with the predator's diet. However, this relationship has not been shown for terrestrial predator-prey systems, where the proximity of predators and prey, and the intensity of predator chemical cues in the environment, may be less than in aquatic systems. In the laboratory, we tested behavioural responses (avoidance, habituation and activity) of terrestrial red-backed salamanders, Plethodon cinereus, to chemical cues from garter snakes, Thamnophis sirtalis, fed either red-backed salamanders or earthworms (Lumbricus spp.). We placed salamanders in arenas lined with paper towels pretreated with snake chemicals, and monitored salamander movements during 120 min. Salamanders avoided substrates preconditioned by earthworm-fed (avoidanceX+/-SE=91.1+/-2.5%, N=25) and salamander-fed (95.2+/-2.5%, N=25) snakes, when tested against untreated substrate (control). Salamanders avoided cues from salamander-fed snakes more strongly (75.2+/-5.5%, N=25) than earthworm-fed snakes when subjected to both treatments simultaneously, implying that salamanders were sensitive to predator diet. Salamanders tended to avoid snake substrate more strongly during the last 60 min of a trial, but activity patterns were similar between salamanders exposed exclusively to control substrate versus those subject to snake cues. In another experiment, salamanders failed to avoid cues from dead conspecifics, suggesting that the stronger avoidance of salamander-fed snakes in the previous experiment was not directly due to chemical cues emitted by predator-killed salamanders. Salamanders also did not discriminate between cues from a salamander-fed snake versus a salamander-fed snake that was recently switched (i.e. <14 days) to an earthworm diet. Our results imply that terrestrial salamanders are sensitive to perceived predation risk via by-products of predator diet, and that snake

  10. Interclonal proteomic responses to predator exposure in Daphnia magna may depend on predator composition of habitats.

    Science.gov (United States)

    Otte, Kathrin A; Schrank, Isabella; Fröhlich, Thomas; Arnold, Georg J; Laforsch, Christian

    2015-08-01

    Phenotypic plasticity, the ability of one genotype to express different phenotypes in response to changing environmental conditions, is one of the most common phenomena characterizing the living world and is not only relevant for the ecology but also for the evolution of species. Daphnia, the water flea, is a textbook example for predator-induced phenotypic plastic defences; however, the analysis of molecular mechanisms underlying these inducible defences is still in its early stages. We exposed Daphnia magna to chemical cues of the predator Triops cancriformis to identify key processes underlying plastic defensive trait formation. To get a more comprehensive idea of this phenomenon, we studied four genotypes with five biological replicates each, originating from habitats characterized by different predator composition, ranging from predator-free habitats to habitats containing T. cancriformis. We analysed the morphologies as well as proteomes of predator-exposed and control animals. Three genotypes showed morphological changes when the predator was present. Using a high-throughput proteomics approach, we found 294 proteins which were significantly altered in their abundance after predator exposure in a general or genotype-dependent manner. Proteins connected to genotype-dependent responses were related to the cuticle, protein synthesis and calcium binding, whereas the yolk protein vitellogenin increased in abundance in all genotypes, indicating their involvement in a more general response. Furthermore, genotype-dependent responses at the proteome level were most distinct for the only genotype that shares its habitat with Triops. Altogether, our study provides new insights concerning genotype-dependent and general molecular processes involved in predator-induced phenotypic plasticity in D. magna. © 2015 John Wiley & Sons Ltd.

  11. Global Stability for a Delayed Predator-Prey System with Stage Structure for the Predator

    Directory of Open Access Journals (Sweden)

    Xiao Zhang

    2009-01-01

    Full Text Available A delayed predator-prey system with stage structure for the predator is investigated. By analyzing the corresponding characteristic equations, the local stability of equilibria of the system is discussed. The existence of Hopf bifurcation at the positive equilibrium is established. By using an iteration technique and comparison argument, respectively, sufficient conditions are derived for the global stability of the positive equilibrium and two boundary equilibria of the system. Numerical simulations are carried out to illustrate the theoretical results.

  12. Undercover predators: Vegetation mediates foraging, trophic cascades, and biological control by omnivorous weed seed predators

    OpenAIRE

    Blubaugh, Carmen K

    2015-01-01

    Weed pressure is the most costly challenge that vegetable growers face, requiring more labor investment than other production inputs. Vertebrate and invertebrate seed predators destroy a large percentage of weed propagules on the soil surface, and their ecosystem services may ease labor requirements for farmers in herbicide-free systems. Cover provided by living vegetation is an important predictor of seed predator activity, and my dissertation takes a comprehensive approach to understanding ...

  13. Cascading effects of predation risk determine how marine predators become terrestrial prey on an oceanic island.

    Science.gov (United States)

    Thomsen, Sarah K; Green, David J

    2016-12-01

    Apex predators can suppress the foraging activity of mesopredators, which may then result in cascading benefits for the prey of those mesopredators. We studied the interactions between a top predator, the Barn Owl (Tyto alba), and their primary prey, an island endemic deer mouse (Peromyscus maniculatus elusus), which in turn consumes the eggs of seabirds nesting on Santa Barbara Island in California. Scripps's Murrelets (Synthliboramphus scrippsi), a threatened nocturnal seabird, arrive annually to breed on this island, and whose first egg is particularly vulnerable to predation by mice. We took advantage of naturally occurring extreme variations in the density of mice and owls on the island over 3 years and predicted that (1) mouse foraging would decrease with increasing predation risk from owls and moonlight and (2) these decreases in foraging would reduce predation on murrelet eggs. We measured the giving up densities of mice with experimental foraging stations and found that mice were sensitive to predation risk and foraged less when owls were more abundant and less during the full moon compared to the new moon. We also monitored the fates of 151 murrelet eggs, and found that murrelet egg predation declined as owl abundance increased, and was lower during the full moon compared to the new moon. Moreover, high owl abundance suppressed egg predation even when mice were extremely abundant. We conclude that there is a behaviorally mediated cascade such that owls on the island had a positive indirect effect on murrelet egg survival. Our study adds to the wider recognition of the strength of risk effects to structure food webs, as well as highlighting the complex ways that marine and terrestrial food webs can intersect. © 2016 by the Ecological Society of America.

  14. Adaptive and variable intraguild predators facilitate local coexistence in an intraguild predation module.

    Science.gov (United States)

    Wu, San-He; Okuyama, Toshinori

    2012-05-24

    Intraguild predation (IGP) is common in nature, but its ecological role is still illusive. A number of studies have investigated a three species IGP module that consists of an intraguild predator, intraguild prey, and resource species in which the intraguild predator and the intraguild prey exploitatively compete for the resource while the intraguild predator also consumes the intraguild prey. A common prediction of models of the IGP module is that the coexistence of the species is difficult, which is considered inconsistent to the ubiquity of IGP in nature. This study revisits the IGP module and provides an alternative coexistence mechanism by focusing on a commonly used analysis method (i.e., invasion analysis) in light of individual variation in adaptive behavior. Invasion analysis underestimates the possibility of coexistence regardless of the presence or absence of adaptive behavior. Coexistence is possible even when invasion analysis predicts otherwise. The underestimation by invasion analysis is pronounced when the intraguild predator forages adaptively, which is even further pronounced when the expression of foraging behavior is variable among intraguild predators. The possibility of coexistence in the IGP module is greater than previously thought, which may have been partly due to how models were analyzed. Inconsistent conclusions may result from the same model depending on how the model is analyzed. Individual variation in adaptive behavior can be an important factor promoting the coexistence of species in IGP modules.

  15. Predation of Five Generalist Predators on Brown Planthopper (Nilaparvata lugens Stål

    Directory of Open Access Journals (Sweden)

    Sri Karindah

    2015-09-01

    Full Text Available Two generalist predators of brown planthopper,Metioche vittaticollis and Anaxipha longipennis (Gryllidae have not been much studied in Indonesia. This research was conducted to study and compare the predatory ability of M. vittaticollis, A. longipennis (Gryllidae and three coleopterans, Paederus fuscipes (Staphylinidae, Ophionea sp. (Carabidae,and Micraspis sp. (Coccinellidae against brown planthopper (fourth and fifth instars under laboratory condition. In total, 20 nymphs of N. lugens were exposed for 2 hour to each predator for 5 consecutive days. Prey consumptions by the predatory crickets, M. vittaticollis and A. longipennis were greater than the other predators and followed by A. longipennis, Micraspis sp., P. fuscipes, and Ophionea sp. respectively. Consumption rates of M. vittaticolis and A. longipenis were also higher than other predators. Micraspis sp was more active on predation in the morning,while M. vittaticollis, A. longipennis, P. fuscipes, and Ophionea sp. were more active both in the morning and the night but not in the afternoon. However, all five species of predators were not so active in preying during the afternoon. In conclusion, a major effort should be extended to conserve these predatory crickets especially M. vittaticollis and A. longipennis.

  16. PERMANENCE OF A NONLINEAR PERIODIC PREDATOR-PREY SYSTEM WITH PREY DISPERSAL AND PREDATOR DENSITY-INDEPENDENCE

    Institute of Scientific and Technical Information of China (English)

    Lijuan Chen; Junyan Xu

    2009-01-01

    In this paper,a set of sufficient conditions which ensure the permanence of a nonlinear periodic predator-prey system with prey dispersal and predator density-independence are obtained,where the prey species can disperse among n patches,while the density-independent predator is confined to one of the patches and cannot disperse. Our results generalize some known results.

  17. PERMANENCE OF A NONLINEAR PERIODIC PREDATOR-PREY SYSTEM WITH PREY DISPERSAL AND PREDATOR DENSITY-INDEPENDENCE

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,a set of suffcient conditions which ensure the permanence of a nonlinear periodic predator-prey system with prey dispersal and predator density-independence are obtained,where the prey species can disperse among n patches,while the density-independent predator is confined to one of the patches and cannot disperse. Our results generalize some known results.

  18. Hide Tanning and Its Use in Taiga: The Case of the Orochen-Evenki Reindeer Herders and Hunters of Zabaikalye (East Siberia

    Directory of Open Access Journals (Sweden)

    Donatas Brandišauskas

    2010-12-01

    Full Text Available This article documents the way in which the Orochen-Evenki hunters and herders in northern part of Zabaikalye tan hides and produce gear in the post-Soviet era. Here, I wish to present the argument that it is difficult to understand the reviving of hide tanning in remote villages and the taiga without understanding how hunters and herders in this region adapt to the unstable post-Soviet environment. I suggest that hunters and herders aim to maintain their autonomy from goods and resources imported from cities, and, in spending little effort connecting with state powers in this way, securing their lives from socio-economic constraints.

  19. A non-autonomous stochastic predator-prey model.

    Science.gov (United States)

    Buonocore, Aniello; Caputo, Luigia; Pirozzi, Enrica; Nobile, Amelia G

    2014-04-01

    The aim of this paper is to consider a non-autonomous predator-prey-like system, with a Gompertz growth law for the prey. By introducing random variations in both prey birth and predator death rates, a stochastic model for the predator-prey-like system in a random environment is proposed and investigated. The corresponding Fokker-Planck equation is solved to obtain the joint probability density for the prey and predator populations and the marginal probability densities. The asymptotic behavior of the predator-prey stochastic model is also analyzed.

  20. Effects of uniform rotational flow on predator-prey system

    Science.gov (United States)

    Lee, Sang-Hee

    2012-12-01

    Rotational flow is often observed in lotic ecosystems, such as streams and rivers. For example, when an obstacle interrupts water flowing in a stream, energy dissipation and momentum transfer can result in the formation of rotational flow, or a vortex. In this study, I examined how rotational flow affects a predator-prey system by constructing a spatially explicit lattice model consisting of predators, prey, and plants. A predation relationship existed between the species. The species densities in the model were given as S (for predator), P (for prey), and G (for plant). A predator (prey) had a probability of giving birth to an offspring when it ate prey (plant). When a predator or prey was first introduced, or born, its health state was assigned an initial value of 20 that subsequently decreased by one with every time step. The predator (prey) was removed from the system when the health state decreased to less than zero. The degree of flow rotation was characterized by the variable, R. A higher R indicates a higher tendency that predators and prey move along circular paths. Plants were not affected by the flow because they were assumed to be attached to the streambed. Results showed that R positively affected both predator and prey survival, while its effect on plants was negligible. Flow rotation facilitated disturbances in individuals’ movements, which consequently strengthens the predator and prey relationship and prevents death from starvation. An increase in S accelerated the extinction of predators and prey.

  1. A minimal model of predator-swarm interactions

    CERN Document Server

    Chen, Yuxin

    2014-01-01

    We propose a minimal model of predator-swarm interactions which captures many of the essential dynamics observed in nature. Different outcomes are observed depending on the predator strength. For a "weak" predator, the swarm is able to escape the predator completely. As the strength is increased, the predator is able to catch up with the swarm as a whole, but the individual prey are able to escape by "confusing" the predator: the prey forms a ring with the predator at the center. For higher predator strength, complex chasing dynamics are observed which can become chaotic. For even higher strength, the predator is able to successfully capture the prey. Our model is simple enough to be amenable to a full mathematical analysis which is used to predict the shape of the swarm as well as the resulting predator-prey dynamics as a function of model parameters. We show that as the predator strength is increased, there is a transition (due to a Hopf bifurcation) from confusion state to chasing dynamics, and we compute ...

  2. Alcohol impairs predation risk response and communication in zebrafish.

    Directory of Open Access Journals (Sweden)

    Thiago Acosta Oliveira

    Full Text Available The effects of ethanol exposure on Danio rerio have been studied from the perspectives of developmental biology and behavior. However, little is known about the effects of ethanol on the prey-predator relationship and chemical communication of predation risk. Here, we showed that visual contact with a predator triggers stress axis activation in zebrafish. We also observed a typical stress response in zebrafish receiving water from these conspecifics, indicating that these fish chemically communicate predation risk. Our work is the first to demonstrate how alcohol effects this prey-predator interaction. We showed for the first time that alcohol exposure completely blocks stress axis activation in both fish seeing the predator and in fish that come in indirect contact with a predator by receiving water from these conspecifics. Together with other research results and with the translational relevance of this fish species, our data points to zebrafish as a promising animal model to study human alcoholism.

  3. Food and predators affect egg production in song sparrows.

    Science.gov (United States)

    Zanette, Liana; Clinchy, Michael; Smith, James N M

    2006-10-01

    Although the possibility that food and predators may interact in limiting avian populations has long been recognized, there have been few attempts to test this experimentally in the field. We conducted a manipulative food addition experiment on the demography of Song Sparrows (Melospiza melodia) across sites that varied in predator abundance, near Victoria, British Columbia, Canada, over three consecutive breeding seasons. We previously showed that food and predators had interactive effects on annual reproductive success (young fledged per female). Here, we report the effects on egg production. Our results show that food limits the total number of eggs laid over the breeding season ("total egg production") and that interactive food and predator effects, including food effects on nest predation, determine how those eggs are "parceled out" into different nests. Food addition alone significantly affected total egg production, and there was no significant interannual variability in this result. At the same time, both food and predators affected the two determinants of total egg production: "clutch number" (total number of clutches laid) and average clutch size. Both clutch number and size were affected by a food x predator x year interaction. Clutch number was lower at low-predator locations because there was less nest predation and thus less renesting. Food addition also significantly reduced nest predation, but there was significant interannual variation in this effect. This interannual variation was responsible for the food x predator x year interactions because the larger the effect of food on nest predation in a given year, the smaller was the effect of food on clutch number; and the smaller the effect of food on clutch number, the larger was the effect of food on clutch size. Potential predator and year effects on total egg production were thus cancelled out by an inverse relationship between clutch number and clutch size. We suggest that combined food and

  4. Beyond Predation: The Zoophytophagous Predator Macrolophus pygmaeus Induces Tomato Resistance against Spider Mites.

    Science.gov (United States)

    Pappas, Maria L; Steppuhn, Anke; Geuss, Daniel; Topalidou, Nikoleta; Zografou, Aliki; Sabelis, Maurice W; Broufas, George D

    2015-01-01

    Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur) on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI), may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood). The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators.

  5. Beyond Predation: The Zoophytophagous Predator Macrolophus pygmaeus Induces Tomato Resistance against Spider Mites.

    Directory of Open Access Journals (Sweden)

    Maria L Pappas

    Full Text Available Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI, may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood. The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators.

  6. Revealing the role of predator interference in a predator-prey system with disease in prey population

    DEFF Research Database (Denmark)

    Chakraborty, Subhendu; Kooi, B.W.; Biswas, B.

    2015-01-01

    on infected populations can have both positive and negative influences on disease in prey populations. Here, we present a predator-prey system where the prey population is subjected to an infectious disease to explore the impact of predator on disease dynamics. Specifically, we investigate how...... the interference among predators affects the dynamics and structure of the predator-prey community. We perform a detailed numerical bifurcation analysis and find an unusually large variety of complex dynamics, such as, bistability, torus and chaos, in the presence of predators. We show that, depending...... on the strength of interference among predators, predators enhance or control disease outbreaks and population persistence. Moreover, the presence of multistable regimes makes the system very sensitive to perturbations and facilitates a number of regime shifts. Since, the habitat structure and the choice...

  7. Comet Hunters: A Citizen Science Project to Search for Comets in the Main Asteroid Belt

    Science.gov (United States)

    Hsieh, Henry H.; Schwamb, Megan Elizabeth; Zhang, Zhi-Wei; Chen, Ying-Tung; Wang, Shiang-Yu; Lintott, Chris

    2016-10-01

    Fully automated detection of comets in wide-field surveys remains a challenge, as even highly successful comet-finding surveys like Pan-STARRS rely on a combination of both automated flagging algorithms and vetting by human eyes. To take advantage of the long-noted superiority of the human eye over computer algorithms in certain types of pattern recognition, particularly when dealing with a range of target morphologies of interest, we have created a citizen science website with the aim of allowing the general public to aid in the search for active asteroids, which are objects that occupy dynamically asteroidal orbits yet exhibit comet-like dust emission due to sublimation, impact disruption, rotational destabilization, or other effects. Located at comethunters.org, the Comet Hunters website was built using the Zooniverse Project Builder (https://www.zooniverse.org/lab), and displays images of known asteroids obtained either from archival data obtained between 1999 and 2014 by the Suprime-Cam wide-field imager mounted on the 8-m Subaru telescope on Mauna Kea in Hawaii, or more contemporary data obtained by the Hyper Suprime-Cam (HSC) wide-field imager also on the Subaru Telescope as part of the ongoing HSC Subaru Strategic Program (SSP) survey. By using observations from such a large-aperture telescope, most of which have never been searched for solar system objects, much less cometary ones, we expect that volunteers should be able to make genuinely scientifically significant discoveries, and also provide valuable insights into the potential and challenges of searching for comets in the LSST era. To date, over 13,000 registered volunteers have contributed 350,000 classifications. We will discuss the design and construction of the Comet Hunters website, and also discuss early results from the project.This work uses data generated via the Zooniverse.org platform, development of which was supported by a Global Impact Award from Google, and by the Alfred P. Sloan

  8. Mount Pinatubo, inflammatory cytokines, and the immunological ecology of Aeta hunter-gatherers.

    Science.gov (United States)

    Bernstein, Robin M; Dominy, Nathaniel J

    2013-01-01

    Early growth cessation and reproduction are predicted to maximize fitness under conditions of high adult mortality, factors that could explain the pygmy phenotype of many rainforest hunter-gatherers. This life-history hypothesis is elegant but contentious in part because it lacks a clear biological mechanism. One mechanism stems from the field of human immunological ecology and the concept of inflammation "memory" across the life cycle and into subsequent generations. Maternal exposures to disease can influence immunological cues present in breast milk; because maternal provisioning via lactation occurs during critical periods of development, it is plausible that these cues can also mediate early growth cessation and small body size. Such epigenetic hypotheses are difficult to test, but the concept of developmental programming is attractive because it could explain how the stature of a population can change over time, in terms of both secular increases and rapid intergenerational decreases. Here we explore this concept by focusing on the Aeta, a population of former hunter-gatherers, and the Ilocano, a population of rice farmers. We predicted that Aeta mothers would produce breast milk with higher concentrations of four bioactive factors due to high infectious burdens. Further, we predicted that the concentrations of these factors would be highest in the cohort of women born in the early 1990s, when exposure to infectious disease was acute following the eruption of Mount Pinatubo in June 1991. We analyzed levels of adiponectin, C-reactive protein, and epidermal growth factor in the milk of 24 Aeta and 31 Ilocano women and found no detectable differences, whereas levels of transforming growth factor-?2 were elevated among the Aeta, particularly as a function of maternal age. We found no difference between cohorts divided by the volcanic eruption (n = 43 born before, n = 12 born after). We discuss the implications of our findings for the terminal investment

  9. Macrophysical climate models and Holocene hunter-gatherer subsistence shifts in Central Texas, USA

    Science.gov (United States)

    Mauldin, R. P.; Munoz, C.

    2013-12-01

    We use stable carbon isotopic values from bone collagen, as well as carbon values from carbonate extracted from bone apatite from 69 prehistoric human skeletal samples to investigate past resource use and climate relationships over the Middle and Late Holocene in Central Texas. Bone samples come from seven archaeological sites and samples date from 6,900 BP to the close of the prehistoric sequence at about 350 BP. Carbon isotopes from these samples suggest four broad dietary trends. From 6,900 through about 3,800 BP, carbon isotopes suggest a gradual increase in the consumption of resources that ultimately use a C3 photosynthetic pathway. A decline in δ13C in both collagen and carbonate values follows, suggesting a decrease in C3 resource use through roughly 2,900 BP. A variable, but once again increasing pattern on C3 resource use by prehistoric hunter-gatherers is indicated in bone isotopes through about 1,000 BP. After that date, a decrease in C3 resource dependence, with hints at greater subsistence diversity, is suggested through the close of the sequence at 350 BP. To assess the impact of climate shifts on this isotopic pattern, we developed a series of macrophysical climate models (MCM) for several locations in Central Texas focusing on fall, winter, and early spring precipitation. This fall-spring rainfall should closely determine C3 production. If subsistence shifts are responding to climate-induced changes in resource availability, then the measured hunter-gatherer carbon isotope trends summarized above should pattern with C3 production as monitored by the modeled fall-spring precipitation values. For the Middle Holocene portion of the sequence, the precipitation models suggest increasing C3 production, consistent with increasing C3 dependence shown in the isotopic data. A decline in C3 production between 3,900 and 3,000 BP in the models is also consistent with the isotopic decline at that point. After 3,000 BP, however, the coupling between fall

  10. Neurobiology of acoustically mediated predator detection.

    Science.gov (United States)

    Pollack, Gerald S

    2015-01-01

    Ultrasound-driven avoidance responses have evolved repeatedly throughout the insecta as defenses against predation by echolocating bats. Although the auditory mechanics of ears and the properties of auditory receptor neurons have been studied in a number of groups, central neural processing of ultrasound stimuli has been examined in only a few cases. In this review, I summarize the neuronal basis for ultrasound detection and predator avoidance in crickets, tettigoniids, moths, and mantises, where central circuits have been studied most thoroughly. Several neuronal attributes, including steep intensity-response functions, high firing rates, and rapid spike conduction emerge as common themes of avoidance circuits. I discuss the functional consequences of these attributes, as well as the increasing complexity with which ultrasound stimuli are represented at successive levels of processing.

  11. The Great White Guppy: Top Predator

    Science.gov (United States)

    Michalski, G. M.

    2011-12-01

    Nitrogen isotopes are often used to trace the trophic level of members of an ecosystem. As part of a stable isotope biogeochemistry and forensics course at Purdue University, students are introduced to this concept by analyzing nitrogen isotopes in sea food purchased from local grocery stores. There is a systematic increase in 15N/14N ratios going from kelp to clams/shrimp, to sardines, to tuna and finally to shark. These enrichments demonstrate how nitrogen is enriched in biomass as predators consume prey. Some of the highest nitrogen isotope enrichments observed, however, are in the common guppy. We investigated a number of aquarium fish foods and find they typically have high nitrogen isotope ratios because they are made form fish meal that is produced primarily from the remains of predator fish such as tuna. From, a isotope perspective, the guppy is the top of the food chain, more ferocious than even the Great White shark.

  12. Bat predation on nocturnally migrating birds.

    Science.gov (United States)

    Ibáñez, C; Juste, J; García-Mudarra, J L; Agirre-Mendi, P T

    2001-08-14

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

  13. Moral Bargain Hunters Purchase Moral Righteousness When it is Cheap: Within-Individual Effect of Stake Size in Economic Games.

    Science.gov (United States)

    Yamagishi, Toshio; Li, Yang; Matsumoto, Yoshie; Kiyonari, Toko

    2016-06-14

    Despite the repeatedly raised criticism that findings in economic games are specific to situations involving trivial incentives, most studies that have examined the stake-size effect have failed to find a strong effect. Using three prisoner's dilemma experiments, involving 479 non-student residents of suburban Tokyo and 162 students, we show here that stake size strongly affects a player's cooperation choices in prisoner's dilemma games when stake size is manipulated within each individual such that each player faces different stake sizes. Participants cooperated at a higher rate when stakes were lower than when they were higher, regardless of the absolute stake size. These findings suggest that participants were 'moral bargain hunters' who purchased moral righteousness at a low price when they were provided with a 'price list' of prosocial behaviours. In addition, the moral bargain hunters who cooperated at a lower stake but not at a higher stake did not cooperate in a single-stake one-shot game.

  14. Hydrological disturbance diminishes predator control in wetlands.

    Science.gov (United States)

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  15. Phenotypic plasticity in anti-intraguild predator strategies: mite larvae adjust their behaviours according to vulnerability and predation risk.

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2013-05-01

    Interspecific threat-sensitivity allows prey to maximize the net benefit of antipredator strategies by adjusting the type and intensity of their response to the level of predation risk. This is well documented for classical prey-predator interactions but less so for intraguild predation (IGP). We examined threat-sensitivity in antipredator behaviour of larvae in a predatory mite guild sharing spider mites as prey. The guild consisted of the highly vulnerable intraguild (IG) prey and weak IG predator Phytoseiulus persimilis, the moderately vulnerable IG prey and moderate IG predator Neoseiulus californicus and the little vulnerable IG prey and strong IG predator Amblyseius andersoni. We videotaped the behaviour of the IG prey larvae of the three species in presence of either a low- or a high-risk IG predator female or predator absence and analysed time, distance, path shape and interaction parameters of predators and prey. The least vulnerable IG prey A. andersoni was insensitive to differing IGP risks but the moderately vulnerable IG prey N. californicus and the highly vulnerable IG prey P. persimilis responded in a threat-sensitive manner. Predator presence triggered threat-sensitive behavioural changes in one out of ten measured traits in N. californicus larvae but in four traits in P. persimilis larvae. Low-risk IG predator presence induced a typical escape response in P. persimilis larvae, whereas they reduced their activity in the high-risk IG predator presence. We argue that interspecific threat-sensitivity may promote co-existence of IG predators and IG prey and should be common in predator guilds with long co-evolutionary history.

  16. Seasonally Varying Predation Behavior and Climate Shifts Are Predicted to Affect Predator-Prey Cycles.

    Science.gov (United States)

    Tyson, Rebecca; Lutscher, Frithjof

    2016-11-01

    The functional response of some predator species changes from a pattern characteristic for a generalist to that for a specialist according to seasonally varying prey availability. Current theory does not address the dynamic consequences of this phenomenon. Since season length correlates strongly with altitude and latitude and is predicted to change under future climate scenarios, including this phenomenon in theoretical models seems essential for correct prediction of future ecosystem dynamics. We develop and analyze a two-season model for the great horned owl (Bubo virginialis) and snowshoe hare (Lepus americanus). These species form a predator-prey system in which the generalist to specialist shift in predation pattern has been documented empirically. We study the qualitative behavior of this predator-prey model community as summer season length changes. We find that relatively small changes in summer season length can have a profound impact on the system. In particular, when the predator has sufficient alternative resources available during the summer season, it can drive the prey to extinction, there can be coexisting stable states, and there can be stable large-amplitude limit cycles coexisting with a stable steady state. Our results illustrate that the impacts of global change on local ecosystems can be driven by internal system dynamics and can potentially have catastrophic consequences.

  17. Top marine predators track Lagrangian coherent structures.

    Science.gov (United States)

    Tew Kai, Emilie; Rossi, Vincent; Sudre, Joel; Weimerskirch, Henri; Lopez, Cristobal; Hernandez-Garcia, Emilio; Marsac, Francis; Garçon, Veronique

    2009-05-19

    Meso- and submesoscales (fronts, eddies, filaments) in surface ocean flow have a crucial influence on marine ecosystems. Their dynamics partly control the foraging behavior and the displacement of marine top predators (tuna, birds, turtles, and cetaceans). In this work we focus on the role of submesoscale structures in the Mozambique Channel in the distribution of a marine predator, the Great Frigatebird. Using a newly developed dynamic concept, the finite-size Lyapunov exponent (FSLE), we identified Lagrangian coherent structures (LCSs) present in the surface flow in the channel over a 2-month observation period (August and September 2003). By comparing seabird satellite positions with LCS locations, we demonstrate that frigatebirds track precisely these structures in the Mozambique Channel, providing the first evidence that a top predator is able to track these FSLE ridges to locate food patches. After comparing bird positions during long and short trips and different parts of these trips, we propose several hypotheses to understand how frigatebirds can follow these LCSs. The birds might use visual and/or olfactory cues and/or atmospheric current changes over the structures to move along these biologic corridors. The birds being often associated with tuna schools around foraging areas, a thorough comprehension of their foraging behavior and movement during the breeding season is crucial not only to seabird ecology but also to an appropriate ecosystemic approach to fisheries in the channel.

  18. AllerHunter: a SVM-pairwise system for assessment of allergenicity and allergic cross-reactivity in proteins.

    Science.gov (United States)

    Muh, Hon Cheng; Tong, Joo Chuan; Tammi, Martti T

    2009-06-10

    Allergy is a major health problem in industrialized countries. The number of transgenic food crops is growing rapidly creating the need for allergenicity assessment before they are introduced into human food chain. While existing bioinformatic methods have achieved good accuracies for highly conserved sequences, the discrimination of allergens and non-allergens from allergen-like non-allergen sequences remains difficult. We describe AllerHunter, a web-based computational system for the assessment of potential allergenicity and allergic cross-reactivity in proteins. It combines an iterative pairwise sequence similarity encoding scheme with SVM as the discriminating engine. The pairwise vectorization framework allows the system to model essential features in allergens that are involved in cross-reactivity, but not limited to distinct sets of physicochemical properties. The system was rigorously trained and tested using 1,356 known allergen and 13,449 putative non-allergen sequences. Extensive testing was performed for validation of the prediction models. The system is effective for distinguishing allergens and non-allergens from allergen-like non-allergen sequences. Testing results showed that AllerHunter, with a sensitivity of 83.4% and specificity of 96.4% (accuracy = 95.3%, area under the receiver operating characteristic curve AROC = 0.928+/-0.004 and Matthew's correlation coefficient MCC = 0.738), performs significantly better than a number of existing methods using an independent dataset of 1443 protein sequences. AllerHunter is available at (http://tiger.dbs.nus.edu.sg/AllerHunter).

  19. AllerHunter: a SVM-pairwise system for assessment of allergenicity and allergic cross-reactivity in proteins.

    Directory of Open Access Journals (Sweden)

    Hon Cheng Muh

    Full Text Available Allergy is a major health problem in industrialized countries. The number of transgenic food crops is growing rapidly creating the need for allergenicity assessment before they are introduced into human food chain. While existing bioinformatic methods have achieved good accuracies for highly conserved sequences, the discrimination of allergens and non-allergens from allergen-like non-allergen sequences remains difficult. We describe AllerHunter, a web-based computational system for the assessment of potential allergenicity and allergic cross-reactivity in proteins. It combines an iterative pairwise sequence similarity encoding scheme with SVM as the discriminating engine. The pairwise vectorization framework allows the system to model essential features in allergens that are involved in cross-reactivity, but not limited to distinct sets of physicochemical properties. The system was rigorously trained and tested using 1,356 known allergen and 13,449 putative non-allergen sequences. Extensive testing was performed for validation of the prediction models. The system is effective for distinguishing allergens and non-allergens from allergen-like non-allergen sequences. Testing results showed that AllerHunter, with a sensitivity of 83.4% and specificity of 96.4% (accuracy = 95.3%, area under the receiver operating characteristic curve AROC = 0.928+/-0.004 and Matthew's correlation coefficient MCC = 0.738, performs significantly better than a number of existing methods using an independent dataset of 1443 protein sequences. AllerHunter is available at (http://tiger.dbs.nus.edu.sg/AllerHunter.

  20. Inferring the demographic history of African farmers and pygmy hunter-gatherers using a multilocus resequencing data set.

    Directory of Open Access Journals (Sweden)

    Etienne Patin

    2009-04-01

    Full Text Available The transition from hunting and gathering to farming involved a major cultural innovation that has spread rapidly over most of the globe in the last ten millennia. In sub-Saharan Africa, hunter-gatherers have begun to shift toward an agriculture-based lifestyle over the last 5,000 years. Only a few populations still base their mode of subsistence on hunting and gathering. The Pygmies are considered to be the largest group of mobile hunter-gatherers of Africa. They dwell in equatorial rainforests and are characterized by their short mean stature. However, little is known about the chronology of the demographic events-size changes, population splits, and gene flow--ultimately giving rise to contemporary Pygmy (Western and Eastern groups and neighboring agricultural populations. We studied the branching history of Pygmy hunter-gatherers and agricultural populations from Africa and estimated separation times and gene flow between these populations. We resequenced 24 independent noncoding regions across the genome, corresponding to a total of approximately 33 kb per individual, in 236 samples from seven Pygmy and five agricultural populations dispersed over the African continent. We used simulation-based inference to identify the historical model best fitting our data. The model identified included the early divergence of the ancestors of Pygmy hunter-gatherers and farming populations approximately 60,000 years ago, followed by a split of the Pygmies' ancestors into the Western and Eastern Pygmy groups approximately 20,000 years ago. Our findings increase knowledge of the history of the peopling of the African continent in a region lacking archaeological data. An appreciation of the demographic and adaptive history of African populations with different modes of subsistence should improve our understanding of the influence of human lifestyles on genome diversity.

  1. Murine neural stem cells model Hunter disease in vitro: glial cell-mediated neurodegeneration as a possible mechanism involved.

    Science.gov (United States)

    Fusar Poli, E; Zalfa, C; D'Avanzo, F; Tomanin, R; Carlessi, L; Bossi, M; Nodari, L Rota; Binda, E; Marmiroli, P; Scarpa, M; Delia, D; Vescovi, A L; De Filippis, L

    2013-11-07

    Mucopolysaccharidosis type II (MPSII or Hunter Syndrome) is a lysosomal storage disorder caused by the deficit of iduronate 2-sulfatase (IDS) activity and characterized by progressive systemic and neurological impairment. As the early mechanisms leading to neuronal degeneration remain elusive, we chose to examine the properties of neural stem cells (NSCs) isolated from an animal model of the disease in order to evaluate whether their neurogenic potential could be used to recapitulate the early phases of neurogenesis in the brain of Hunter disease patients. Experiments here reported show that NSCs derived from the subventricular zone (SVZ) of early symptomatic IDS-knockout (IDS-ko) mouse retained self-renewal capacity in vitro, but differentiated earlier than wild-type (wt) cells, displaying an evident lysosomal aggregation in oligodendroglial and astroglial cells. Consistently, the SVZ of IDS-ko mice appeared similar to the wt SVZ, whereas the cortex and striatum presented a disorganized neuronal pattern together with a significant increase of glial apoptotic cells, suggesting that glial degeneration likely precedes neuronal demise. Interestingly, a very similar pattern was observed in the brain cortex of a Hunter patient. These observations both in vitro, in our model, and in vivo suggest that IDS deficit seems to affect the late phases of neurogenesis and/or the survival of mature cells rather than NSC self-renewal. In particular, platelet-derived growth factor receptor-α-positive (PDGFR-α+) glial progenitors appeared reduced in both the IDS-ko NSCs and in the IDS-ko mouse and human Hunter brains, compared with the respective healthy controls. Treatment of mutant NSCs with IDS or PDGF throughout differentiation was able to increase the number of PDGFR-α+ cells and to reduce that of apoptotic cells to levels comparable to wt. This evidence supports IDS-ko NSCs as a reliable in vitro model of the disease, and suggests the rescue of PDGFR-α+ glial cells as a

  2. Origin and diet of the prehistoric hunter-gatherers on the mediterranean island of Favignana (Egadi Islands, Sicily.

    Directory of Open Access Journals (Sweden)

    Marcello A Mannino

    Full Text Available Hunter-gatherers living in Europe during the transition from the late Pleistocene to the Holocene intensified food acquisition by broadening the range of resources exploited to include marine taxa. However, little is known on the nature of this dietary change in the Mediterranean Basin. A key area to investigate this issue is the archipelago of the Ègadi Islands, most of which were connected to Sicily until the early Holocene. The site of Grotta d'Oriente, on the present-day island of Favignana, was occupied by hunter-gatherers when Postglacial environmental changes were taking place (14,000-7,500 cal BP. Here we present the results of AMS radiocarbon dating, palaeogenetic and isotopic analyses undertaken on skeletal remains of the humans buried at Grotta d'Oriente. Analyses of the mitochondrial hypervariable first region of individual Oriente B, which belongs to the HV-1 haplogroup, suggest for the first time on genetic grounds that humans living in Sicily during the early Holocene could have originated from groups that migrated from the Italian Peninsula around the Last Glacial Maximum. Carbon and nitrogen isotope analyses show that the Upper Palaeolithic and Mesolithic hunter-gatherers of Favignana consumed almost exclusively protein from terrestrial game and that there was only a slight increase in marine food consumption from the late Pleistocene to the early Holocene. This dietary change was similar in scale to that at sites on mainland Sicily and in the rest of the Mediterranean, suggesting that the hunter-gatherers of Grotta d'Oriente did not modify their subsistence strategies specifically to adapt to the progressive isolation of Favignana. The limited development of technologies for intensively exploiting marine resources was probably a consequence both of Mediterranean oligotrophy and of the small effective population size of these increasingly isolated human groups, which made innovation less likely and prevented transmission of

  3. Safety culture

    Energy Technology Data Exchange (ETDEWEB)

    Keen, L.J. [Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada)

    2003-07-01

    Safety culture has become a topic of increasing interest for industry and regulators as issues are raised on safety problems around the world. The keys to safety culture are organizational effectiveness, effective communications, organizational learning, and a culture that encourages the identification and resolution of safety issues. The necessity of a strong safety culture places an onus on all of us to continually question whether the safety measures already in place are sufficient, and are being applied. (author)

  4. Fatal attraction? Intraguild facilitation and suppression among predators

    Science.gov (United States)

    Sivy, Kelly J.; Pozzanghera, Casey B.; Grace, James B.; Prugh, Laura R.

    2017-01-01

    Competition and suppression are recognized as dominant forces that structure predator communities. Facilitation via carrion provisioning, however, is a ubiquitous interaction among predators that could offset the strength of suppression. Understanding the relative importance of these positive and negative interactions is necessary to anticipate community-wide responses to apex predator declines and recoveries worldwide. Using state-sponsored wolf (Canis lupus) control in Alaska as a quasi experiment, we conducted snow track surveys of apex, meso-, and small predators to test for evidence of carnivore cascades (e.g., mesopredator release). We analyzed survey data using an integrative occupancy and structural equation modeling framework to quantify the strengths of hypothesized interaction pathways, and we evaluated fine-scale spatiotemporal responses of nonapex predators to wolf activity clusters identified from radio-collar data. Contrary to the carnivore cascade hypothesis, both meso- and small predator occupancy patterns indicated guild-wide, negative responses of nonapex predators to wolf abundance variations at the landscape scale. At the local scale, however, we observed a near guild-wide, positive response of nonapex predators to localized wolf activity. Local-scale association with apex predators due to scavenging could lead to landscape patterns of mesopredator suppression, suggesting a key link between occupancy patterns and the structure of predator communities at different spatial scales.

  5. Predator cannibalism can intensify negative impacts on heterospecific prey.

    Science.gov (United States)

    Takatsu, Kunio; Kishida, Osamu

    2015-07-01

    Although natural populations consist of individuals with different traits, and the degree of phenotypic variation varies among populations, the impact of phenotypic variation on ecological interactions has received little attention, because traditional approaches to community ecology assume homogeneity of individuals within a population. Stage structure, which is a common way of generating size and developmental variation within predator populations, can drive cannibalistic interactions, which can affect the strength of predatory effects on the predator's heterospecific prey. Studies have shown that predator cannibalism weakens predatory effects on heterospecific prey by reducing the size of the predator population and by inducing less feeding activity of noncannibal predators. We predict, however, that predator cannibalism, by promoting rapid growth of the cannibals, can also intensify predation pressure on heterospecific prey, because large predators have large resource requirements and may utilize a wider variety of prey species. To test this hypothesis, we conducted an experiment in which we created carnivorous salamander (Hynobius retardatus) populations with different stage structures by manipulating the salamander's hatch timing (i.e., populations with large or small variation in the timing of hatching), and explored the resultant impacts on the abundance, behavior, morphology, and life history of the salamander's large heterospecific prey, Rana pirica frog tadpoles. Cannibalism was rare in salamander populations having small hatch-timing variation, but was frequent in those having large hatch-timing variation. Thus, giant salamander cannibals occurred only in the latter. We clearly showed that salamander giants exerted strong predation pressure on frog tadpoles, which induced large behavioral and morphological defenses in the tadpoles and caused them to metamorphose late at large size. Hence, predator cannibalism arising from large variation in the timing

  6. Olfactory systems and neural circuits that modulate predator odor fear.

    Science.gov (United States)

    Takahashi, Lorey K

    2014-01-01

    When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS) and accessory olfactory systems (AOS) detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray (DPAG), paraventricular nucleus (PVN) of the hypothalamus, and the medial amygdala (MeA) appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal (HPA) stress hormone secretion. The MeA also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus (VHC) appear prominently involved in predator odor fear behavior. The basolateral amygdala (BLA), medial hypothalamic nuclei, and medial prefrontal cortex (mPFC) are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator

  7. Taphonomy for taxonomists: Implications of predation in small mammal studies

    Science.gov (United States)

    Fernández-Jalvo, Yolanda; Andrews, Peter; Denys, Christiane; Sesé, Carmen; Stoetzel, Emmanuelle; Marin-Monfort, Dolores; Pesquero, Dolores

    2016-05-01

    Predation is one of the most recurrent sources of bone accumulations. The influence of predation is widely studied for large mammal sites where humans, acting as predators, produce bone accumulations similar to carnivore accumulations. Similarly, small mammal fossil sites are mainly occupation levels of predators (nests or dens). In both cases, investigations of past events can be compared with present day equivalents or proxies. Chewing marks are sometimes present on large mammal predator accumulations, but digestion traits are the most direct indication of predation, and evidence for this is always present in small mammal (prey) fossil assemblages. Digestion grades and frequency indicates predator type and this is well established since the publication of Andrews (1990). The identification of the predator provides invaluable information for accurate interpretation of the palaeoenvironment. Traditionally, palaeoenvironmental interpretations are obtained from the taxonomic species identified in the site, but rather than providing direct interpretations of the surrounding palaeoenvironment, this procedure actually describes the dietary preferences of the predators and the type of occupation (nests, marking territory, dens, etc). This paper reviews the identification of traits produced by predators on arvicolins, murins and soricids using a method that may be used equally by taxonomists and taphonomists. It aims to provide the "tools" for taxonomists to identify the predator based on their methodology, which is examining the occlusal surfaces of teeth rather than their lateral aspects. This will greatly benefit both the work of taphonomists and taxonomists to recognize signs of predation and the improvement of subsequent palaeoecological interpretations of past organisms and sites by identifying both the prey and the predator.

  8. More than a safety line: jump-stabilizing silk of salticids

    OpenAIRE

    Chen, Yung-Kang; Liao, Chen-Pan; Tsai, Feng-Yueh; Chi, Kai-Jung

    2013-01-01

    Salticids are diurnal hunters known for acute vision, remarkable predatory strategies and jumping ability. Like other jumpers, they strive for stability and smooth landings. Instead of using inertia from swinging appendages or aerodynamic forces by flapping wings as in other organisms, we show that salticids use a different mechanism for in-air stability by using dragline silk, which was previously believed to function solely as a safety line. Analyses from high-speed images of jumps by the s...

  9. Planet Hunters: the first two planet candidates identified by the public using the Kepler public archive data

    Science.gov (United States)

    Fischer, Debra A.; Schwamb, Megan E.; Schawinski, Kevin; Lintott, Chris; Brewer, John; Giguere, Matt; Lynn, Stuart; Parrish, Michael; Sartori, Thibault; Simpson, Robert; Smith, Arfon; Spronck, Julien; Batalha, Natalie; Rowe, Jason; Jenkins, Jon; Bryson, Steve; Prsa, Andrej; Tenenbaum, Peter; Crepp, Justin; Morton, Tim; Howard, Andrew; Beleu, Michele; Kaplan, Zachary; Vannispen, Nick; Sharzer, Charlie; Defouw, Justin; Hajduk, Agnieszka; Neal, Joe P.; Nemec, Adam; Schuepbach, Nadine; Zimmermann, Valerij

    2012-02-01

    Planet Hunters is a new citizen science project designed to engage the public in an exoplanet search using NASA Kepler public release data. In the first month after launch, users identified two new planet candidates which survived our checks for false positives. The follow-up effort included analysis of Keck HIRES spectra of the host stars, analysis of pixel centroid offsets in the Kepler data and adaptive optics imaging at Keck using NIRC2. Spectral synthesis modelling coupled with stellar evolutionary models yields a stellar density distribution, which is used to model the transit orbit. The orbital periods of the planet candidates are 9.8844 ± 0.0087 d (KIC 10905746) and 49.7696 ± 0.000 39 d (KIC 6185331), and the modelled planet radii are 2.65 and 8.05 R⊕. The involvement of citizen scientists as part of Planet Hunters is therefore shown to be a valuable and reliable tool in exoplanet detection. This publication has been made possible by the participation of more than 40 000 volunteers in the Planet Hunters project. Their contributions are individually acknowledged at .

  10. The impact of agricultural emergence on the genetic history of African rainforest hunter-gatherers and agriculturalists.

    Science.gov (United States)

    Patin, Etienne; Siddle, Katherine J; Laval, Guillaume; Quach, Hélène; Harmant, Christine; Becker, Noémie; Froment, Alain; Régnault, Béatrice; Lemée, Laure; Gravel, Simon; Hombert, Jean-Marie; Van der Veen, Lolke; Dominy, Nathaniel J; Perry, George H; Barreiro, Luis B; Verdu, Paul; Heyer, Evelyne; Quintana-Murci, Lluís

    2014-01-01

    The emergence of agriculture in West-Central Africa approximately 5,000 years ago, profoundly modified the cultural landscape and mode of subsistence of most sub-Saharan populations. How this major innovation has had an impact on the genetic history of rainforest hunter-gatherers-historically referred to as 'pygmies'-and agriculturalists, however, remains poorly understood. Here we report genome-wide SNP data from these populations located west-to-east of the equatorial rainforest. We find that hunter-gathering populations present up to 50% of farmer genomic ancestry, and that substantial admixture began only within the last 1,000 years. Furthermore, we show that the historical population sizes characterizing these communities already differed before the introduction of agriculture. Our results suggest that the first socio-economic interactions between rainforest hunter-gatherers and farmers introduced by the spread of farming were not accompanied by immediate, extensive genetic exchanges and occurred on a backdrop of two groups already differentiated by their specialization in two ecotopes with differing carrying capacities.

  11. Assessment of risk to aquatic biota from elevated salinity -- a case study from the Hunter River, Australia.

    Science.gov (United States)

    Muschal, Monika

    2006-05-01

    An ecological risk assessment was performed on salinity levels of the Hunter River and its tributaries to respond to concerns that high salinity may be damaging aquatic ecosystems. Probabilistic techniques were used to assess likelihood and consequence, and hence the risk to aquatic biota from salinity. Continuous electrical conductivity distributions were used to describe the likelihood that high salinity would occur (exposure dataset) and toxicity values were compiled from the limited literature sources available to describe the consequence of high salinity (effects dataset). The assessment was preliminary in the sense that it modelled risk on the basis of existing data and did not undertake site-specific toxicity testing. Some sections of the Hunter River catchment have geologies that are saline because of their marine origins. Catchment development has increased the liberation rates of salts into surface-waters. Such modifying activities include coal-mining, power generation and land clearing. The aquatic biota of tributaries had a greater risk of impairment from high salinity than that of the Hunter River. High salinities in the tributaries were attributed to the combined factors of naturally saline geologies, increased liberation of salts due to modification of the landscape, and reduced dilution by flushing flows. A salinity guideline trigger value of 1100 mg L(-1) was recommended.

  12. Detection of a new mutation (T1140C) in a patient with Hunter syndrome from Guangdong,China

    Institute of Scientific and Technical Information of China (English)

    GUO Yibin; DU Chuanshu; WANG Jingjing

    2007-01-01

    This study identified mutations of the idumate-2-suffatase (IDS) gene in a patient with Hunter syndrome,and established a basis for the diagnosis of the prenatal gene of Hunter syndrome.Urine glyeosaminoglycan (GAG) assay was used to make the preliminary diagnosis of mucopolysaccharidosis type H.Polymerase chain reaction (PCR) from dried blood spots and DNA sequencing were applied to analyze hotspot mutations in exons 9,3 and 8 of the IDS gene in the proband and his parents.A new missense mutation (T1140C) in exon 8 of the IDS gene was found by using DNA sequencing.This mutation caused a substitution of codon 339 from CTA (leucine) to CCA (praline).The patient is a hemizygote,and his mother is a heterozygote.The new missense mutation results in a change in the primary and tertiary structure of the IDS protein.It is possible that this mutation severely impairs enzymatic activity and is the underlying basis for the pathology seen in this patient with Hunter syndrome.

  13. Voice pitch alters mate-choice-relevant perception in hunter-gatherers.

    Science.gov (United States)

    Apicella, Coren L; Feinberg, David R

    2009-03-22

    In humans, voice pitch is thought to be a cue of underlying quality and an important criterion for mate choice, but data from non-Western cultures have not been provided. Here we test attributions to and preferences for voices with raised and lowered pitch in hunter-gatherers. Using a forced-choice playback experiment, we found that both men and women viewed lower pitched voices in the opposite sex as being better at acquiring resources (e.g. hunting and gathering). While men preferred higher pitched women's voices as marriage partners, women showed no overall preference for voice pitch in men. However, women who were currently breastfeeding had stronger preferences for higher pitched male voices whereas women not currently breastfeeding preferred lower pitched voices. As testosterone is considered a costly signal associated with dominance, heritable immunity to infection and low paternal investment, women's preferences potentially reflect a trade-off between securing good genes and paternal investment. Men's preferences for higher pitched female voices are probably due to an evolved preference for markers of fecundity, reflected in voice pitch.

  14. Planet Hunters. VIII. Characterization of 41 Long-Period Exoplanet Candidates from Kepler Archival Data

    CERN Document Server

    Wang, Ji; Barclay, Thomas; Picard, Alyssa; Ma, Bo; Bowler, Brendan P; Schmitt, Joseph R; Boyajian, Tabetha S; Jek, Kian J; LaCourse, Daryll; Baranec, Christoph; Riddle, Reed; Law, Nicholas M; Lintott, Chris; Schawinski, Kevin; Simister, Dean Joseph; Gregoire, Boscher; Babin, Sean P; Poile, Trevor; Jacobs, Thomas Lee; Jebson, Tony; Omohundro, Mark R; Schwengeler, Hans Martin; Sejpka, Johann; Terentev, Ivan A; Gagliano, Robert; Paakkonen, Jari-Pekka; Berge, Hans Kristian Otnes; Winarski, Troy; Green, Gerald R; Schmitt, Allan R

    2015-01-01

    The census of exoplanets is incomplete for orbital distances larger than 1 AU. Here, we present 41 long-period planet candidates in 38 systems identified by Planet Hunters based on Kepler archival data (Q0-Q17). Among them, 17 exhibit only one transit, 14 have two visible transits and 10 have more than three visible transits. For planet candidates with only one visible transit, we estimate their orbital periods based on transit duration and host star properties. The majority of the planet candidates in this work (75%) have orbital periods that correspond to distances of 1-3 AU from their host stars. We conduct follow-up imaging and spectroscopic observations to validate and characterize planet host stars. In total, we obtain adaptive optics images for 33 stars to search for possible blending sources. Six stars have stellar companions within 4". We obtain high-resolution spectra for 6 stars to determine their physical properties. Stellar properties for other stars are obtained from the NASA Exoplanet Archive a...

  15. Securing a Future: Cree Hunters' Resistance and Flexibility to Environmental Changes, Wemindji, James Bay

    Directory of Open Access Journals (Sweden)

    Jesse S. Sayles

    2010-12-01

    Full Text Available Accounts of the adaptive responses of northern aboriginal peoples include examples of purposive modification and management of ecologically favorable areas to increase resource productivity. Practices include clearing of trees, burning of berry patches and construction of fish weirs. This paper examines the adaptive capacity of the northern aboriginal community of Wemindji, east coast James Bay, in relation to long term landscape changes induced by coastal uplift processes. Associated changes are noticeable within a human lifetime and include the infilling of bays, the merger of islands with the mainland, as well as shifts in vegetative and wildlife communities. In response, generations of Cree hunters have actively modified the landscape using a variety of practices that include the construction of mud dykes and the cutting of tuuhiikaan, which are corridors in the coastal forest, to retain and enhance desirable conditions for goose hunting. We provide an account of the history, construction, and design of these features as well as the motivations and social learning that inform them. We reveal a complex and underappreciated dynamic between human resistance and adaptation to environmental change. While landscape modifications are motivated by a desire to increase resource productivity and predictability, they also reflect an intergenerational commitment to the maintenance of established hunting places as important connections with the past. Our findings support a revised perspective on aboriginal human agency in northern landscape modification and an enhanced role for aboriginal communities in adaptive planning for environmental change.

  16. Skills, division of labour and economies of scale among Amazonian hunters and South Indian honey collectors.

    Science.gov (United States)

    Hooper, Paul L; Demps, Kathryn; Gurven, Michael; Gerkey, Drew; Kaplan, Hillard S

    2015-12-01

    In foraging and other productive activities, individuals make choices regarding whether and with whom to cooperate, and in what capacities. The size and composition of cooperative groups can be understood as a self-organized outcome of these choices, which are made under local ecological and social constraints. This article describes a theoretical framework for explaining the size and composition of foraging groups based on three principles: (i) the sexual division of labour; (ii) the intergenerational division of labour; and (iii) economies of scale in production. We test predictions from the theory with data from two field contexts: Tsimane' game hunters of lowland Bolivia, and Jenu Kuruba honey collectors of South India. In each case, we estimate the impacts of group size and individual group members' effort on group success. We characterize differences in the skill requirements of different foraging activities and show that individuals participate more frequently in activities in which they are more efficient. We evaluate returns to scale across different resource types and observe higher returns at larger group sizes in foraging activities (such as hunting large game) that benefit from coordinated and complementary roles. These results inform us that the foraging group size and composition are guided by the motivated choice of individuals on the basis of relative efficiency, benefits of cooperation, opportunity costs and other social considerations.

  17. Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System

    CERN Document Server

    Schwamb, Megan E; Carter, Joshua A; Welsh, William F; Fischer, Debra A; Torres, Guillermo; Howard, Andrew W; Crepp, Justin R; Keel, William C; Lintott, Chris J; Kaib, Nathan A; Terrell, Dirk; Gagliano, Robert; Jek, Kian J; Parrish, Michael; Smith, Arfon M; Lynn, Stuart; Simpson, Robert J; Giguere, Matthew J; Schawinski, Kevin

    2012-01-01

    We report the discovery and confirmation of a transiting circumbinary planet (PH1) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625.The 6.18 $\\pm$ 0.17 Earth radii planet orbits outside the 20-day orbit of an eclipsing binary consisting of an F dwarf (1.734 +/- 0.044 Solar radii, 1.528 +/- 0.087 Solar masses) and M dwarf (0.378 +/0 0.023 Solar radii, 0.408 +/- 0.024 solar masses). For the planet, we find an upper mass limit of 169 Earth masses(0.5...

  18. Competition for Cooperation: variability, benefits and heritability of relational wealth in hunter-gatherers.

    Science.gov (United States)

    Chaudhary, Nikhil; Salali, Gul Deniz; Thompson, James; Rey, Aude; Gerbault, Pascale; Stevenson, Edward Geoffrey Jedediah; Dyble, Mark; E Page, Abigail; Smith, Daniel; Mace, Ruth; Vinicius, Lucio; Migliano, Andrea Bamberg

    2016-07-12

    Many defining human characteristics including theory of mind, culture and language relate to our sociality, and facilitate the formation and maintenance of cooperative relationships. Therefore, deciphering the context in which our sociality evolved is invaluable in understanding what makes us unique as a species. Much work has emphasised group-level competition, such as warfare, in moulding human cooperation and sociality. However, competition and cooperation also occur within groups; and inter-individual differences in sociality have reported fitness implications in numerous non-human taxa. Here we investigate whether differential access to cooperation (relational wealth) is likely to lead to variation in fitness at the individual level among BaYaka hunter-gatherers. Using economic gift games we find that relational wealth: a) displays individual-level variation; b) provides advantages in buffering food risk, and is positively associated with body mass index (BMI) and female fertility; c) is partially heritable. These results highlight that individual-level processes may have been fundamental in the extension of human cooperation beyond small units of related individuals, and in shaping our sociality. Additionally, the findings offer insight in to trends related to human sociality found from research in other fields such as psychology and epidemiology.

  19. Jaguar conservation in southern Belize: Conflicts, perceptions, and prospects among mayan hunters

    Directory of Open Access Journals (Sweden)

    Michael K Steinberg

    2016-01-01

    Full Text Available Belize has emerged as an international leader in jaguar conservation through the creation of numerous protected areas that contain prime cat habitat and by strengthening conservation laws. For example, in 1984, Belize created the Cockscomb Basin Jaguar Preserve, the first special jaguar protection area in the Americas. In 1995, the government expanded Cockscomb by creating the adjacent Chiquibul National Park. In 2010, the government continued this commitment to jaguar conservation by creating the Labouring Creek Jaguar Corridor Wildlife Sanctuary in central Belize. As a result of these protected areas, Belize has been rightfully lauded as a leader in nature-based tourism and protected areas creation in Central America. However, outside national parks and communities that directly benefit from ecotourism, it is less clear how supportive rural residents are of cat conservation. It is also not clear if jaguars persist outside protected areas in locations such as southern Belize, where the environment has been significantly altered by human activities. Through interviews with Mayan hunters, this paper investigates the attitudes towards jaguars, human-jaguar conflicts, and potential community-based jaguar conservation in two Mayan villages in the Toledo District in southern Belize. Also, using indirect methods, the paper documents the presence/absence and other temporal/spatial aspects of jaguars in a heavily altered landscape in southern Belize.

  20. Schooling, Local Knowledge and Working Memory: A Study among Three Contemporary Hunter-Gatherer Societies.

    Science.gov (United States)

    Reyes-García, Victoria; Pyhälä, Aili; Díaz-Reviriego, Isabel; Duda, Romain; Fernández-Llamazares, Álvaro; Gallois, Sandrine; Guèze, Maximilien; Napitupulu, Lucentezza

    2016-01-01

    Researchers have analysed whether school and local knowledge complement or substitute each other, but have paid less attention to whether those two learning models use different cognitive strategies. In this study, we use data collected among three contemporary hunter-gatherer societies with relatively low levels of exposure to schooling yet with high levels of local ecological knowledge to test the association between i) schooling and ii) local ecological knowledge and verbal working memory. Participants include 94 people (24 Baka, 25 Punan, and 45 Tsimane') from whom we collected information on 1) schooling and school related skills (i.e., literacy and numeracy), 2) local knowledge and skills related to hunting and medicinal plants, and 3) working memory. To assess working memory, we applied a multi-trial free recall using words relevant to each cultural setting. People with and without schooling have similar levels of accurate and inaccurate recall, although they differ in their strategies to organize recall: people with schooling have higher results for serial clustering, suggesting better learning with repetition, whereas people without schooling have higher results for semantic clustering, suggesting they organize recall around semantically meaningful categories. Individual levels of local ecological knowledge are not related to accurate recall or organization recall, arguably due to overall high levels of local ecological knowledge. While schooling seems to favour some organization strategies this might come at the expense of some other organization strategies.

  1. Schooling, Local Knowledge and Working Memory: A Study among Three Contemporary Hunter-Gatherer Societies.

    Directory of Open Access Journals (Sweden)

    Victoria Reyes-García

    Full Text Available Researchers have analysed whether school and local knowledge complement or substitute each other, but have paid less attention to whether those two learning models use different cognitive strategies. In this study, we use data collected among three contemporary hunter-gatherer societies with relatively low levels of exposure to schooling yet with high levels of local ecological knowledge to test the association between i schooling and ii local ecological knowledge and verbal working memory. Participants include 94 people (24 Baka, 25 Punan, and 45 Tsimane' from whom we collected information on 1 schooling and school related skills (i.e., literacy and numeracy, 2 local knowledge and skills related to hunting and medicinal plants, and 3 working memory. To assess working memory, we applied a multi-trial free recall using words relevant to each cultural setting. People with and without schooling have similar levels of accurate and inaccurate recall, although they differ in their strategies to organize recall: people with schooling have higher results for serial clustering, suggesting better learning with repetition, whereas people without schooling have higher results for semantic clustering, suggesting they organize recall around semantically meaningful categories. Individual levels of local ecological knowledge are not related to accurate recall or organization recall, arguably due to overall high levels of local ecological knowledge. While schooling seems to favour some organization strategies this might come at the expense of some other organization strategies.

  2. Planet Hunters, Undergraduate Research, and Detection of Extrasolar Planet Kepler-818 b

    Science.gov (United States)

    Baker, David; Crannell, Graham; Duncan, James; Hays, Aryn; Hendrix, Landon

    2017-01-01

    Detection of extrasolar planets provides an excellent research opportunity for undergraduate students. In Spring 2012, we searched for transiting extrasolar planets using Kepler spacecraft data in our Research Experience in Physics course at Austin College. Offered during the regular academic year, these Research Experience courses engage students in the scientific process, including proposal writing, paper submission, peer review, and oral presentations. Since 2004, over 190 undergraduate students have conducted authentic scientific research through Research Experience courses at Austin College.Zooniverse’s citizen science Planet Hunters web site offered an efficient method for rapid analysis of Kepler data. Light curves from over 5000 stars were analyzed, of which 2.3% showed planetary candidates already tagged by the Kepler team. Another 1.5% of the light curves suggested eclipsing binary stars, and 1.6% of the light curves had simulated planets for training purposes.One of the stars with possible planetary transits had not yet been listed as a planetary candidate. We reported possible transits for Kepler ID 4282872, which later was promoted to planetary candidate KOI-1325 in 2012 and confirmed to host extrasolar planet Kepler-818 b in 2016 (Morton et al. 2016). Kepler-818 b is a “hot Neptune” with period 10.04 days, flux decrease during transit ~0.4%, planetary radius 4.69 Earth radii, and semi-major axis 0.089 au.

  3. The neutrino hunters the chase for the ghost particle and the secrets of the universe

    CERN Document Server

    Jayawardhana, Ray

    2014-01-01

    In Neutrino Hunters, the renowned astrophysicist and award-winning writer Ray Jayawardhana takes us on a thrilling journey into the shadowy world of neutrinos and the colorful lives of those who seek them. Demystifying particle science along the way, Jayawardhana tells a detective story with cosmic implications—interweaving tales of the sharp-witted theorist Wolfgang Pauli; the troubled genius Ettore Majorana; the harbinger of the atomic age Enrico Fermi; the notorious Cold War defector Bruno Pontecorvo; and the dynamic dream team of Marie and Pierre Curie. Then there are the scientists of today who have caught the neutrino bug, and whose experimental investigations stretch from a working nickel mine in Ontario to a long tunnel through a mountain in central Italy, from a nuclear waste site in New Mexico to a bay on the South China Sea, and from Olympic-size pools deep underground to a gigantic cube of Antarctic ice—called, naturally, IceCube. As Jayawardhana recounts a captivating saga of scientific disc...

  4. The Implications of Victimhood Identity: The Case of ‘Persecution’ of Swedish Hunters

    Directory of Open Access Journals (Sweden)

    Erica von Essen

    2017-06-01

    Full Text Available This ethnographically based study examines Swedish hunters’ claims to victimhood through appeal to the term ‘persecution’. Perceiving disenfranchisement, injustice and discrimination on the basis of wolf conservation policy, we present hunters’ self-styled predicament as victimhood-claimants of persecution at the hands of a state that has been co-opted by a conservationist, pro-wolf agenda that systematically disenfranchises rural and hunting interests and lifestyles. Through the phenomenological accounts of hunter respondents, our paper takes seriously the hunters’ perception of persecution and, likewise, considers the opposite case made by conservationists: that wolves have been, and continue to be, the real victims of persecution in the conflict. Nonetheless, we show that the persecution language as it is applied from opposing parties in the conflict is problematic inasmuch as it is focused around creating a moral panic and confusion among the Swedish public who are ultimately responsible, as a democratic body-politic, for assessing the legitimacy of claims to moral wrong-doing and legal redress for the wronged. Our case study joins scholarship that explores the pathologies of claims to victimization

  5. Robert Plant (1818–1858: A Victorian plant hunter in Natal, Zululand, Mauritius and the Seychelles

    Directory of Open Access Journals (Sweden)

    Donal P. McCracken

    2011-03-01

    Full Text Available In the 1850s Robert William Plant collected plants and other natural specimens in what is now KwaZulu-Natal. This one-time Englishman compiled a dictionary for gardeners before emigrating to Natal in 1850. There he worked as the agent for Samuel Stevens, the London dealer in ‘curiosities of natural history’. Though Plant collected mainly plants, he also sent consignments of beetles, butterflies, bird skins and shells back to Britain. He published the first scientific paper on Zululand and was requested by the Royal Botanic Gardens at Kew to write the first Flora natalensis. It was while collecting for this never-to-be-completed treatise that Plant contracted malaria in Maputaland. He died in St Lucia in 1858 and in doing so became South Africa’s martyr to botany. What emerges from this study is a picture of the difficulties faced by plant hunters in mid-19th-century South Africa, the sort of plants they collected and the necessity for them sometimes to diversify into other natural history products to survive.

  6. Hunter-gatherer mobility and embedded raw-material procurement strategies in the mediterranean upper paleolithic.

    Science.gov (United States)

    Tomasso, Antonin; Porraz, Guillaume

    2016-05-06

    Since the early 1980s, the sourcing of lithic raw materials has become central to studies of the territorial range and mobility strategies of Pleistocene foraging societies. Results have been fruitful but somehow repetitive. We will discuss the embedded procurement strategy, which presumes that raw material acquisition was part of other subsistence activities rather than an autonomous technological task. We argue that this theoretical assumption, when taken as dogma, restricts the role of technology in human history and also underestimates the way some lithic resources may have affected the organization of past hunter-gatherers. We base our discussion on the Upper Paleolithic (UP) from the Liguro-Provençal arc, with examples from the Proto-Aurignacian and the Epigravettian. Our regional record shows that in this context the movement of rocks over distances greater than 100 km was the norm rather than the exception. We argue that these long-distance procurements mirror technical needs that were oriented toward the selection of high-quality flints. We support the hypothesis that indirect procurement was an important component of regional socio-economic networks.

  7. Atypical clinical presentation of mucopolysaccharidosis type II (Hunter syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Sharma Subodh

    2010-05-01

    Full Text Available Abstract Introduction We present a very rare case of mucopolysaccharidosis with atypical presentation such as mild mental retardation, an acrocephalic head and no corneal clouding. The purpose of presenting this case is to highlight the distinctive manifestation of mucopolysaccharidosis type II (Hunter syndrome. Case presentation A 10-year-old East Asian boy presented with abdominal distension of five years' duration and complained of shortness of breath on and off for the same period. On examination his head was large and his head circumference was 54.5 cm. His neck was short, he had coarse facial features, a depressed nasal bridge and small stubby fingers with flexion of distal interphalangeal joints, and a low arched palate was observed. There was mild mental retardation. Conclusion Based on clinical findings and radiological features it is possible to diagnose a case of mucopolysaccharidosis. Careful and systemic approach is needed to accurately diagnose the exact type as enzymatic studies are not available in most centers.

  8. The Hunters Point cogeneration project: Environmental justice in power plant siting

    Energy Technology Data Exchange (ETDEWEB)

    Kosloff, L.H. [Trexler and Associates, Inc., Portland, OR (United States); Varanini, E.E. III [Marron, Reid and Sheehy, Sacramento, CA (United States)

    1997-12-31

    The recent Hunters Point, San Francisco power plant siting process in California represents the first time that environmental justice has arisen as a major power plant siting issue. Intervenors argued that the siting process was racially and economically biased and were supported by leading environmental justice activists at the Golden Gate Law School`s Environmental Justice Clinic, a leading thinker in this field. The applicant argued that environmental justice charges cannot realistically be made against a modern natural-gas energy facility with state-of-the-art environmental controls. The applicant also argued that environmental justice concerns were fully addressed through the extensive environmental and socioeconomic review carried out by California Energy Commission staff. After extensive testimony and cross-examination, the Commission agreed with the applicant. This case has important lessons for companies that could be charged with environmental justice violations and environmental justice activists who must decide where to most effectively target their efforts. This paper reviews the proceeding and its lessons and makes recommendations regarding future applicability of environmental justice issues to the power generation sector. The authors represented the applicant in the facility siting proceeding.

  9. Trace elements associated with atmospheric particulate matter in the Upper Hunter Valley, NSW, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Farhana, Biswas Karabi [Bangladesh Institute of Research and Rehabilitation in Diabetes, Endcrine and Metabolic Disorders (BIRDEM), Research Division, Dhaka (Bangladesh); Bridgman, Howard [University of Newcastle, Dept. of Geography and Environmental Science (Australia); McOrist, Gordon [Australian Nuclear Science and Technology Organization (ANSTO), Environment Division, Menai (Australia)

    2002-05-01

    Airbone particulate matter, both total suspended particulate (TSP) and PM{sub 10}, and soil samples from four sampling sites were collected in the Upper Hunter Valley in NSW, Australia in early 1999. This study aimed to measure relative amounts of particulates during this period, and identify associated trace elements and their potential sources. Particulates were analyzed for trace elements using Neutron Activation Analysis technique. Total concentrations ({mu}g m{sup -3}) of TSP and PM{sub 10} varied within 7-135 and 4-19, respectively, among sampling sites. Mean concentrations (ng m{sup -3}) of iron, barium, zinc, lanthanum, bromine, chromium, rubidium, neodymium, cobalt, hafnium, cerium, thorium, uranium, scandium and cesium varied within 2042-2867, 529-1500, 28-40, 5.45-11.44, 5.3-20.6, 10.4-12.7, 4.14-11.56, 5.4-8.1, 1.16-1.98, 1.76-2.17, 0.71-3.9, 0.21-0.50, 0.29-0.84, 0.28-1.23, and 0.18-0.30, respectively. Significant correlation between sites for many elements suggested some common source(s) of some elements. The enrichment levels of the trace elements identified some crustal materials as a predominant source of particulate matter. (author)

  10. Hunter-gatherer inter-band interaction rates: implications for cumulative culture.

    Directory of Open Access Journals (Sweden)

    Kim R Hill

    Full Text Available Our species exhibits spectacular success due to cumulative culture. While cognitive evolution of social learning mechanisms may be partially responsible for adaptive human culture, features of early human social structure may also play a role by increasing the number potential models from which to learn innovations. We present interview data on interactions between same-sex adult dyads of Ache and Hadza hunter-gatherers living in multiple distinct residential bands (20 Ache bands; 42 Hadza bands; 1201 dyads throughout a tribal home range. Results show high probabilities (5%-29% per year of cultural and cooperative interactions between randomly chosen adults. Multiple regression suggests that ritual relationships increase interaction rates more than kinship, and that affinal kin interact more often than dyads with no relationship. These may be important features of human sociality. Finally, yearly interaction rates along with survival data allow us to estimate expected lifetime partners for a variety of social activities, and compare those to chimpanzees. Hadza and Ache men are estimated to observe over 300 men making tools in a lifetime, whereas male chimpanzees interact with only about 20 other males in a lifetime. High intergroup interaction rates in ancestral humans may have promoted the evolution of cumulative culture.

  11. Potential Roles of Essential Oil and Extracts of Piper chaba Hunter to Inhibit Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Atiqur Rahman

    2011-01-01

    Full Text Available The in vitro anti-listerial potential of essential oil and various organic extracts of Piper chaba Hunter (Piperaceae were evaluated. The chemical composition of the essential oil was analyzed by the GC-MS. Fifty four compounds representing 95.4% of the total oil w ere identified, of which α-humulene (16.4%, caryophyllene oxide (12.2%, veridiflorol (8.1%, globulol (7.4%, β-selinene (7.1%, spathulenol (6.2%, trans-nerolidol (5.1%, linalool (4.5%, 3-pentanol (3.5%, tricyclene (2.2% and p-cymene (1.6% were the major compounds. The oil and organic extracts revealed a great potential anti-listerial effect against all five strains of Listeriamonocytogenes ATCC 19111, 19116, 19118, 19166 and 15313. Also the essential oil had a strong inhibitory effect on the viable cell count of the tested Listeria spp. Our findings demonstrate that the essential oil and extracts derived from the leaf of P. chaba might be a potential source of natural preservatives used in food industries.

  12. Hunter-gatherer inter-band interaction rates: implications for cumulative culture.

    Science.gov (United States)

    Hill, Kim R; Wood, Brian M; Baggio, Jacopo; Hurtado, A Magdalena; Boyd, Robert T

    2014-01-01

    Our species exhibits spectacular success due to cumulative culture. While cognitive evolution of social learning mechanisms may be partially responsible for adaptive human culture, features of early human social structure may also play a role by increasing the number potential models from which to learn innovations. We present interview data on interactions between same-sex adult dyads of Ache and Hadza hunter-gatherers living in multiple distinct residential bands (20 Ache bands; 42 Hadza bands; 1201 dyads) throughout a tribal home range. Results show high probabilities (5%-29% per year) of cultural and cooperative interactions between randomly chosen adults. Multiple regression suggests that ritual relationships increase interaction rates more than kinship, and that affinal kin interact more often than dyads with no relationship. These may be important features of human sociality. Finally, yearly interaction rates along with survival data allow us to estimate expected lifetime partners for a variety of social activities, and compare those to chimpanzees. Hadza and Ache men are estimated to observe over 300 men making tools in a lifetime, whereas male chimpanzees interact with only about 20 other males in a lifetime. High intergroup interaction rates in ancestral humans may have promoted the evolution of cumulative culture.

  13. Tumour Angiogenesis: A Growth Area—From John Hunter to Judah Folkman and Beyond

    Directory of Open Access Journals (Sweden)

    J. A. Stephenson

    2013-01-01

    Full Text Available Angiogenesis is the growth of new blood vessels in the body. Abnormal angiogenesis is recognised as a “common denominator” in many disease processes, and the development of angiogenesis inhibitors holds great hope in the ongoing battle against cancer. The field of angiogenesis has roots in the Hunterian era of the late eighteenth century but did not begin to blossom until the early 1970s when the then controversial findings and conclusions of Judah Folkman, the “father of angiogenesis,” were first published. There were only 65 publications with angiogenesis in the title in the 10 years after Folkman first proposed the idea of tumour angiogenesis, compared to over 9,000 publications from the year 2000 to 2010. In this review we will explore the voyage of discovery from the first observations of John Hunter in the eighteenth century, via the struggle faced by Folkman to prove the importance of angiogenesis, and finally how his determination has led to modern angiogenesis inhibitors being used in everyday clinical practice.

  14. Global Dynamics of a Predator-Prey Model with Stage Structure and Delayed Predator Response

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2013-01-01

    Full Text Available A Holling type II predator-prey model with time delay and stage structure for the predator is investigated. By analyzing the corresponding characteristic equations, the local stability of each of feasible equilibria of the system is discussed. The existence of Hopf bifurcations at the coexistence equilibrium is established. By means of the persistence theory on infinite dimensional systems, it is proven that the system is permanent if the coexistence equilibrium exists. By using Lyapunov functionals and LaSalle’s invariance principle, it is shown that the predator-extinction equilibrium is globally asymptotically stable when the coexistence equilibrium is not feasible, and the sufficient conditions are obtained for the global stability of the coexistence equilibrium.

  15. Predator-induced morphological changes in an amphibian: predation by dragonflies affects tadpole shape and color.

    Science.gov (United States)

    McCollum, S A; Leimberger, J D

    1997-02-01

    Predator-induced defenses are well studied in plants and invertebrate animals, but have only recently been recognized in vertebrates. Gray treefrog (Hylachrysoscelis) tadpoles reared with predatory dragonfly (Aeshnaumbrosa) larvae differ in shape and color from tadpoles reared in the absence of dragonflies. By exposing tadpoles to tail damage and the non-lethal presence of starved and fed dragonflies, we determined that these phenotypic differences are induced by non-contact cues present when dragonflies prey on Hyla. The induced changes in shape are in the direction that tends to increase swimming speed; thus, the induced morphology may help tadpoles evade predators. Altering morphology in response to predators is likely to influence interactions with other species in the community as well.

  16. Predation on exotic zebra mussels by native fishes: Effects on predator and prey

    Science.gov (United States)

    Magoulick, D.D.; Lewis, L.C.

    2002-01-01

    1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

  17. Dynamics of a Delayed Predator-prey System with Stage Structure for Predator and Prey

    Institute of Scientific and Technical Information of China (English)

    Liu Juan; Zhang Zi-zhen

    2015-01-01

    In this paper, a predator-prey system with two discrete delays and stage structure for both the predator and the prey is investigated. The dynamical be-haviors such as local stability and local Hopf bifurcation are analyzed by regarding the possible combinations of the two delays as bifurcating parameter. Some explicit formulae determining the direction of the Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by using the normal form method and the center manifold theory. Finally, numerical simulations are presented to support the theoretical analysis.

  18. Intraguild predation by the generalist predator Orius majusculus on the parasitoid Encarsia formosa

    DEFF Research Database (Denmark)

    Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz;

    2013-01-01

    by 5th instar nymphs and adults of O. majusculus offered unparasitised 3rd, early 4th or 4th instar B. tabaci nymphs or parasitised nymphs containing 2nd or 3rd larval instar or pupal parasitoids. In addition, prey preference of the two stages of O. majusculus for parasitised or unparasitised whitefly...... instar B. tabaci and 2nd instar parasitoids. Predation of predator stages was lowest on 4th instar B. tabaci and E. formosa pupae. In all prey combinations, both stages of O. majusculus showed a significant preference for parasitised over unparasitised whitefly nymphs except for the combination of 5th...

  19. Small cryptopredators contribute to high predation rates on coral reefs

    Science.gov (United States)

    Goatley, Christopher H. R.; González-Cabello, Alonso; Bellwood, David R.

    2017-03-01

    Small fishes suffer high mortality rates on coral reefs, primarily due to predation. Although studies have identified the predators of early post-settlement fishes, the predators of small cryptobenthic fishes remain largely unknown. We therefore used a series of mesocosm experiments with natural habitat and cryptobenthic fish communities to identify the impacts of a range of small potential predators, including several invertebrates, on prey fish populations. While there was high variability in predation rates, many members of the cryptobenthic fish community act as facultative cryptopredators, being prey when small and piscivores when larger. Surprisingly, we also found that smashing mantis shrimps may be important fish predators. Our results highlight the diversity of the predatory community on coral reefs and identify previously unknown trophic links in these complex ecosystems.

  20. The narrow range of perceived predation: a 19 group study

    Directory of Open Access Journals (Sweden)

    Olivier Mesly

    2013-05-01

    Full Text Available This paper rests largely on the works of Mesly (1999 to 2012. It argues that the phenomenon of perceived predation as a functional behavioural phenomenon is subjected to certain limits, a finding based on studies performed on 19 different groups spread over a four-year span. It also finds a constant of k = 1.3 which reflects the invariant nature of perceived predation. These findings add to the theory of financial predation which stipulates that financial predators operate below the limits of detection pertaining to their customers (and market regulators. They are experts at minimizing the perception that clients could have that they are after their money, causing them financial harm, by surprise (perceived predation. Understanding the narrow range in which financial predators operate is setting the grounds to offer better protection to investors and to implementing better control and punitive measures.

  1. Predator-prey relationships among larval dragonflies, salamanders, and frogs.

    Science.gov (United States)

    Caldwell, J P; Thorp, J H; Jervey, T O

    1980-09-01

    Tadpoles of the barking tree frog, Hyla gratiosa, are abundant in spring and summer in some ponds and Carolina bays on the Savannah River Plant near Aiken, South Carolina. To determine how these tadpoles survive in the presence of predaceous salamander larvae, Ambystoma talpoideum, and larvae of an aeshnid dragonfly, Anax junius, we determined fields densities and sizes of the predators and the prey and conducted predation experiments in the laboratory. Tadpoles rapidly grow to a size not captured by Ambystoma, although Anax larvae can capture slightly larger tadpoles. Differing habitat preferences among the tadpoles and the two predator species probably aid in reducing predation pressure. Preliminary work indicates that the tadpoles may have an immobility response to an attack by a predator. In addition, the smallest, most vulnerable tadpoles have a distinctive color pattern which may function to disrupt the body outline and make them indiscernable to predators.

  2. Nest predation research: Recent findings and future perspectives

    Science.gov (United States)

    Chalfoun, Anna D.; Ibanez-Alamo, J. D.; Magrath, R. D.; Schmidt, Kenneth A.; Thomson, R. L.; Oteyza, Juan C.; Haff, T. M.; Martin, T.E.

    2016-01-01

    Nest predation is a key source of selection for birds that has attracted increasing attention from ornithologists. The inclusion of new concepts applicable to nest predation that stem from social information, eavesdropping or physiology has expanded our knowledge considerably. Recent methodological advancements now allow focus on all three players within nest predation interactions: adults, offspring and predators. Indeed, the study of nest predation now forms a vital part of avian research in several fields, including animal behaviour, population ecology, evolution and conservation biology. However, within nest predation research there are important aspects that require further development, such as the comparison between ecological and evolutionary antipredator responses, and the role of anthropogenic change. We hope this review of recent findings and the presentation of new research avenues will encourage researchers to study this important and interesting selective pressure, and ultimately will help us to better understand the biology of birds.

  3. Behaviour of Robsonella fontaniana in response to a potential predator

    OpenAIRE

    Ruiz, Juan Francisco; Sepúlveda, Roger D.; Ibáñez,Christian M

    2012-01-01

    Cephalopods have two main defence strategies: the first consists on reducing the odds of being detected by a predator, while the second focuses on avoiding capture. The aim of this study was to understand the basic behavioural aspects of the octopus Robsonella fontaniana in response to the potential predator Schroederichthys chilensis (catshark) in central Chile. Experiments were conducted under laboratory conditions in order to determine the effectiveness of camouflage against predators. The...

  4. Behavior is a major determinant of predation risk in zooplankton

    DEFF Research Database (Denmark)

    Almeda, Rodrigo; van Someren Gréve, Hans; Kiørboe, Thomas

    2017-01-01

    Zooplankton exhibit different small-scale motile behaviors related to feeding and mating activities. These different motile behaviors may result in different levels of predation risk, which may partially determine the structure of planktonic communities. Here, we experimentally determined predation...... behavior is a key trait in zooplankton that significantly affects predation risk and therefore is a main determinant of distribution and composition of zooplankton communities in the ocean...

  5. A Storm-by-Storm Analysis of Alpine and Regional Precipitation Dynamics at the Mount Hunter Ice Core Site, Denali National Park, Central Alaska Range

    Science.gov (United States)

    Saylor, P. L.; Osterberg, E. C.; Kreutz, K. J.; Wake, C. P.; Winski, D.

    2014-12-01

    In May-June 2013, an NSF-funded team from Dartmouth College and the Universities of Maine and New Hampshire collected two 1000-year ice cores to bedrock from the summit plateau of Mount Hunter in Denali National Park, Alaska (62.940291, -151.087616, 3912 m). The snow accumulation record from these ice cores will provide key insight into late Holocene precipitation variability in central Alaska, and compliment existing precipitation paleorecords from the Mt. Logan and Eclipse ice cores in coastal SE Alaska. However, correct interpretation of the Mt. Hunter accumulation record requires an understanding of the relationships between regional meteorological events and micrometeorological conditions at the Mt. Hunter ice core collection site. Here we analyze a three-month window of snow accumulation and meteorological conditions recorded by an Automatic Weather Station (AWS) at the Mt. Hunter site during the summer of 2013. Snow accumulation events are identified in the Mt. Hunter AWS dataset, and compared on a storm-by-storm basis to AWS data collected from the adjacent Kahiltna glacier 2000 m lower in elevation, and to regional National Weather Service (NWS) station data. We also evaluate the synoptic conditions associated with each Mt. Hunter accumulation event using NWS surface maps, NCEP-NCAR Reanalysis data, and the NOAA HYSPLIT back trajectory model. We categorize each Mt. Hunter accumulation event as pure snow accumulation, drifting, or blowing snow events based on snow accumulation, wind speed and temperature data using the method of Knuth et al (2009). We analyze the frequency and duration of events within each accumulation regime, in addition to the overall contribution of each event to the snowpack. Preliminary findings indicate that a majority of Mt. Hunter accumulation events are of pure accumulation nature (55.5%) whereas drifting (28.6%) and blowing (15.4%) snow events play a secondary role. Our results will characterize the local accumulation dynamics on

  6. A self-organized system of smart preys and predators

    Energy Technology Data Exchange (ETDEWEB)

    Rozenfeld, Alejandro F. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP, CONICET, Suc. 4, C.C. 16 (1900) La Plata (Argentina); Albano, Ezequiel V. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP, CONICET, Suc. 4, C.C. 16 (1900) La Plata (Argentina)]. E-mail: ealbano@inifta.unlp.edu.ar

    2004-11-22

    Based on the fact that, a standard prey-predator model (SPPM), exhibits irreversible phase transitions, belonging to the universality class of directed percolation (DP), between prey-predator coexistence and predator extinction [Phys. Lett. A 280 (2001) 45], a self-organized prey-predator model (SOPPM) is formulated and studied by means of extensive Monte Carlo simulations. The SOPPM is achieved defining the parameters of the SPPM as functions of the density of species. It is shown that the SOPPM self-organizes into an active state close the absorbing phase of the SPPM, and consequently their avalanche exponents also belong to the universality class of DP.

  7. Invasive prey indirectly increase predation on their native competitors.

    Science.gov (United States)

    Castorani, Max C N; Hovel, Kevin A

    2015-07-01

    Ecological theory predicts that invasive prey can interact with native prey directly by competing for shared resources or indirectly by changing the abundance or behavior of shared native predators. However, both the study and management of invasive prey have historically overlooked indirect effects. In southern California estuaries, introduction of the Asian nest mussel Arcuatula senhousia has been linked to profound changes in native bivalve assemblages, but the mechanisms of these interactions remain unclear. We performed three field experiments to assess the mechanisms of competition between Arcuatula and native bivalves, and evaluated the potential for Arcuatula to indirectly mediate native predator-prey dynamics. We found that Arcuatula reduces the diversity, abundance, and size of native bivalve recruits by preemptively exploiting space in surface sediments. When paired with native shallow-dwelling clams (Chione undatella and Laevicardium substriatum), Arcuatula reduces adult survival through overgrowth competition. However, Arcuatula also attracts native predators, causing apparent competition by indirectly increasing predation of native clams, especially for poorly defended species. Therefore, invasive prey can indirectly increase predation rates on native competitors by changing the behavior of shared native predators, but the magnitude of apparent competition strongly depends on the vulnerability of natives to predation. Interestingly, our results indicate that the vulnerability of invasive prey to predation can greatly exacerbate impacts on their native competitors. Our findings suggest that consideration of both direct and indirect effects of invasive prey, as well as native predator-prey relationships, should lead to more effective invasive species management.

  8. Evolution of Swarming Behavior Is Shaped by How Predators Attack.

    Science.gov (United States)

    Olson, Randal S; Knoester, David B; Adami, Christoph

    2016-01-01

    Animal grouping behaviors have been widely studied due to their implications for understanding social intelligence, collective cognition, and potential applications in engineering, artificial intelligence, and robotics. An important biological aspect of these studies is discerning which selection pressures favor the evolution of grouping behavior. In the past decade, researchers have begun using evolutionary computation to study the evolutionary effects of these selection pressures in predator-prey models. The selfish herd hypothesis states that concentrated groups arise because prey selfishly attempt to place their conspecifics between themselves and the predator, thus causing an endless cycle of movement toward the center of the group. Using an evolutionary model of a predator-prey system, we show that how predators attack is critical to the evolution of the selfish herd. Following this discovery, we show that density-dependent predation provides an abstraction of Hamilton's original formulation of domains of danger. Finally, we verify that density-dependent predation provides a sufficient selective advantage for prey to evolve the selfish herd in response to predation by coevolving predators. Thus, our work corroborates Hamilton's selfish herd hypothesis in a digital evolutionary model, refines the assumptions of the selfish herd hypothesis, and generalizes the domain of danger concept to density-dependent predation.

  9. A predation cost to bold fish in the wild

    DEFF Research Database (Denmark)

    Hulthén, Kaj; Chapman, Ben; Nilsson, Anders P.

    2017-01-01

    in the animal kingdom. Theory predicts that individual behavioural types differ in a cost-benefit trade-off where bolder individuals benefit from greater access to resources while paying higher predation-risk costs. However, explicitly linking predation events to individual behaviour under natural conditions...... evidence of behavioural type-dependent predation vulnerability in the wild, i.e. that there is a predation cost to boldness, which is critical for our understanding of the evolution and maintenance of behavioural diversity in natural populations....

  10. Bat Predation by Cercopithecus Monkeys: Implications for Zoonotic Disease Transmission.

    Science.gov (United States)

    Tapanes, Elizabeth; Detwiler, Kate M; Cords, Marina

    2016-06-01

    The relationship between bats and primates, which may contribute to zoonotic disease transmission, is poorly documented. We provide the first behavioral accounts of predation on bats by Cercopithecus monkeys, both of which are known to harbor zoonotic disease. We witnessed 13 bat predation events over 6.5 years in two forests in Kenya and Tanzania. Monkeys sometimes had prolonged contact with the bat carcass, consuming it entirely. All predation events occurred in forest-edge or plantation habitat. Predator-prey relations between bats and primates are little considered by disease ecologists, but may contribute to transmission of zoonotic disease, including Ebolavirus.

  11. Top predators negate the effect of mesopredators on prey physiology.

    Science.gov (United States)

    Palacios, Maria M; Killen, Shaun S; Nadler, Lauren E; White, James R; McCormick, Mark I

    2016-07-01

    Predation theory and empirical evidence suggest that top predators benefit the survival of resource prey through the suppression of mesopredators. However, whether such behavioural suppression can also affect the physiology of resource prey has yet to be examined. Using a three-tier reef fish food web and intermittent-flow respirometry, our study examined changes in the metabolic rate of resource prey exposed to combinations of mesopredator and top predator cues. Under experimental conditions, the mesopredator (dottyback, Pseudochromis fuscus) continuously foraged and attacked resource prey (juveniles of the damselfish Pomacentrus amboinensis) triggering an increase in prey O2 uptake by 38 ± 12·9% (mean ± SE). The visual stimulus of a top predator (coral trout, Plectropomus leopardus) restricted the foraging activity of the mesopredator, indirectly allowing resource prey to minimize stress and maintain routine O2 uptake. Although not as strong as the effect of the top predator, the sight of a large non-predator species (thicklip wrasse, Hemigymnus melapterus) also reduced the impact of the mesopredator on prey metabolic rate. We conclude that lower trophic-level species can benefit physiologically from the presence of top predators through the behavioural suppression that top predators impose on mesopredators. By minimizing the energy spent on mesopredator avoidance and the associated stress response to mesopredator attacks, prey may be able to invest more energy in foraging and growth, highlighting the importance of the indirect, non-consumptive effects of top predators in marine food webs.

  12. Population dynamics of intraguild predation in a lattice gas system.

    Science.gov (United States)

    Wang, Yuanshi; Wu, Hong

    2015-01-01

    In the system of intraguild predation (IGP) we are concerned with, species that are in a predator-prey relationship, also compete for shared resources (space or food). While several models have been established to characterize IGP, mechanisms by which IG prey and IG predator can coexist in IGP systems with spatial competition, have not been shown. This paper considers an IGP model, which is derived from reactions on lattice and has a form similar to that of Lotka-Volterra equations. Dynamics of the model demonstrate properties of IGP and mechanisms by which the IGP leads to coexistence of species and occurrence of alternative states. Intermediate predation is shown to lead to persistence of the predator, while extremely big predation can lead to extinction of one/both species and extremely small predation can lead to extinction of the predator. Numerical computations confirm and extend our results. While empirical observations typically exhibit coexistence of IG predator and IG prey, theoretical analysis in this work demonstrates exact conditions under which this coexistence can occur. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Escaping peril: perceived predation risk affects migratory propensity

    DEFF Research Database (Denmark)

    Hulthén, Kaj; Chapman, Ben B.; Nilsson, P. Anders;

    2015-01-01

    to record the migration of individual roach (Rutilus rutilus), a partially migratory fish, in the wild following exposure to manipulation of direct (predator presence/absence) and indirect (high/low roach density) perceived predation risk in experimental mesocosms. Following exposure, we released fish......) affected timing but not propensity showing that elevated risk carried over to alter migratory behaviour in the wild. Our key finding demonstrates predator-driven migratory plasticity, highlighting the powerful role of predation risk for migratory decision-making and dynamics....

  14. A solution to the accelerated-predator-satiety Lotka-Volterra predator-prey problem using Boubaker polynomial expansion scheme.

    Science.gov (United States)

    Dubey, B; Zhao, T G; Jonsson, M; Rahmanov, H

    2010-05-07

    In this study, an analytical method is introduced for the identification of predator-prey populations time-dependent evolution in a Lotka-Volterra predator-prey model which takes into account the concept of accelerated-predator-satiety. Oppositely to most of the predator-prey problem models, the actual model does not suppose that the predation is strictly proportional to the prey density. In reference to some recent experimental results and particularly to the conclusions of May (1973) about predators which are 'never not hungry', an accelerated satiety function is matched with the initial conventional equations. Solutions are plotted and compared to some relevant ones. The obtained trends are in good agreement with many standard Lotka-Volterra solutions except for the asymptotic behaviour. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  15. Wave propagation in predator-prey systems

    Science.gov (United States)

    Fu, Sheng-Chen; Tsai, Je-Chiang

    2015-12-01

    In this paper, we study a class of predator-prey systems of reaction-diffusion type. Specifically, we are interested in the dynamical behaviour for the solution with the initial distribution where the prey species is at the level of the carrying capacity, and the density of the predator species has compact support, or exponentially small tails near x=+/- ∞ . Numerical evidence suggests that this will lead to the formation of a pair of diverging waves propagating outwards from the initial zone. Motivated by this phenomenon, we establish the existence of a family of travelling waves with the minimum speed. Unlike the previous studies, we do not use the shooting argument to show this. Instead, we apply an iteration process based on Berestycki et al 2005 (Math Comput. Modelling 50 1385-93) to construct a set of super/sub-solutions. Since the underlying system does not enjoy the comparison principle, such a set of super/sub-solutions is not based on travelling waves, and in fact the super/sub-solutions depend on each other. With the aid of the set of super/sub-solutions, we can construct the solution of the truncated problem on the finite interval, which, via the limiting argument, can in turn generate the wave solution. There are several advantages to this approach. First, it can remove the technical assumptions on the diffusivities of the species in the existing literature. Second, this approach is of PDE type, and hence it can shed some light on the spreading phenomenon indicated by numerical simulation. In fact, we can compute the spreading speed of the predator species for a class of biologically acceptable initial distributions. Third, this approach might be applied to the study of waves in non-cooperative systems (i.e. a system without a comparison principle).

  16. Discriminative predation: Simultaneous and sequential encounter experiments

    Institute of Scientific and Technical Information of China (English)

    C.D.BEATTY; D.W.FRANKS

    2012-01-01

    There are many situations in which the ability of animals to distinguish between two similar looking objects can have significant selective consequences.For example,the objects that require discrimination may be edible versus defended prey,predators versus non-predators,or mates of varying quality.Working from the premise that there are situations in which discrimination may be more or less successful,we hypothesized that individuals find it more difficult to distinguish between stimuli when they encounter them sequentially rather than simultaneously.Our study has wide biological and psychological implications from the perspective of signal perception,signal evolution,and discrimination,and could apply to any system where individuals are making relative judgments or choices between two or more stimuli or signals.While this is a general principle that might seem intuitive,it has not been experimentally tested in this context,and is often not considered in the design of models or experiments,or in the interpretation of a wide range of studies.Our study is different from previous studies in psychology in that a) the level of similarity of stimuli are gradually varied to obtain selection gradients,and b) we discuss the implications of our study for specific areas in ecology,such as the level of perfection of mimicry in predator-prey systems.Our experiments provide evidence that it is indeed more difficult to distinguish between stimuli - and to learn to distinguish between stimuli - when they are encountered sequentially rather than simultaneously,even if the intervening time interval is short.

  17. A predator-prey system with stage-structure for predator and nonlocal delay

    DEFF Research Database (Denmark)

    Lin, Z.G.; Pedersen, Michael; Zhang, Lai

    2010-01-01

    This paper deals with the behavior of solutions to the reaction-diffusion system under homogeneous Neumann boundary condition, which describes a prey-predator model with nonlocal delay. Sufficient conditions for the global stability of each equilibrium are derived by the Lyapunov functional...

  18. Dispersal and predation in alien Acacia.

    Science.gov (United States)

    Holmes, P M

    1990-06-01

    I investigated seed removal in the litter layer of alien Acacia stands at bimonthly intervals throughout one year. Both ants (dispersers) and rodents (predators) removed significant quantities of seeds and may compete for seeds in low density Acacia stands. Seed removal from depots was greatest prior to seed-fall (Sept.-Nov.) and lowest during seed-fall (Jan.-Mar.). As rodents may consume a large proportion of the annual seed production at low Acacia densities, I propose that ants have played a critical role in accumulating Acacia seed banks.

  19. Macronutrient contributions of insects to the diets of hunter-gatherers: a geometric analysis.

    Science.gov (United States)

    Raubenheimer, David; Rothman, Jessica M; Pontzer, Herman; Simpson, Stephen J

    2014-06-01

    We present a geometric model for examining the macronutrient contributions of insects in the diets of pre-agricultural humans, and relate the findings to some contemporary societies that regularly eat insects. The model integrates published data on the macronutrient composition of insects and other foods in the diets of humans, recommended human macronutrient intakes, and estimated macronutrient intakes to examine the assumption that insects provided to pre-agricultural humans an invertebrate equivalent of vertebrate-derived meats, serving primarily as a source of protein. Our analysis suggests that insects vary more widely in their macronutrient content than is likely to be the case for most wild vertebrate meats, spanning a broad range of protein, fat and carbohydrate concentrations. Potentially, therefore, in terms of their proportional macronutrient composition, insects could serve as equivalents not only of wild meat, but of a range of other foods including some shellfish, nuts, pulses, vegetables and even fruits. Furthermore, humans might systematically manipulate the composition of edible insects to meet specific needs through pre-ingestive processing, such as cooking and selective removal of body parts. We present data suggesting that in modern societies for which protein is the more limiting macronutrient, pre-ingestive processing of edible insects might serve to concentrate protein. It is likely, however, that the dietary significance of insects was different for Paleolithic hunter-gatherers who were more limited in non-protein energy. Our conclusions are constrained by available data, but highlight the need for further studies, and suggest that our model provides an integrative framework for conceiving these studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. PLANET HUNTERS. VIII. CHARACTERIZATION OF 41 LONG-PERIOD EXOPLANET CANDIDATES FROM KEPLER ARCHIVAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji; Fischer, Debra A.; Picard, Alyssa; Schmitt, Joseph R.; Boyajian, Tabetha S. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Barclay, Thomas [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Ma, Bo [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Bowler, Brendan P.; Riddle, Reed [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91101 (United States); Jek, Kian J.; LaCourse, Daryll; Simister, Dean Joseph; Grégoire, Boscher; Babin, Sean P.; Poile, Trevor; Jacobs, Thomas Lee; Baranec, Christoph [Institute for Astronomy, University of Hawai‘i at Mānoa, Hilo, HI 96720-2700 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Lintott, Chris [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Schawinski, Kevin [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); and others

    2015-12-20

    The census of exoplanets is incomplete for orbital distances larger than 1 AU. Here, we present 41 long-period planet candidates in 38 systems identified by Planet Hunters based on Kepler archival data (Q0–Q17). Among them, 17 exhibit only one transit, 14 have two visible transits, and 10 have more than three visible transits. For planet candidates with only one visible transit, we estimate their orbital periods based on transit duration and host star properties. The majority of the planet candidates in this work (75%) have orbital periods that correspond to distances of 1–3 AU from their host stars. We conduct follow-up imaging and spectroscopic observations to validate and characterize planet host stars. In total, we obtain adaptive optics images for 33 stars to search for possible blending sources. Six stars have stellar companions within 4″. We obtain high-resolution spectra for 6 stars to determine their physical properties. Stellar properties for other stars are obtained from the NASA Exoplanet Archive and the Kepler Stellar Catalog by Huber et al. We validate 7 planet candidates that have planet confidence over 0.997 (3σ level). These validated planets include 3 single-transit planets (KIC-3558849b, KIC-5951458b, and KIC-8540376c), 3 planets with double transits (KIC-8540376b, KIC-9663113b, and KIC-10525077b), and 1 planet with four transits (KIC-5437945b). This work provides assessment regarding the existence of planets at wide separations and the associated false positive rate for transiting observation (17%–33%). More than half of the long-period planets with at least three transits in this paper exhibit transit timing variations up to 41 hr, which suggest additional components that dynamically interact with the transiting planet candidates. The nature of these components can be determined by follow-up radial velocity and transit observations.

  1. Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System

    Science.gov (United States)

    Schwamb, Megan E.; Orosz, Jerome A.; Carter, Joshua A.; Welsh, William F.; Fischer, Debra A.; Torres, Guillermo; Howard, Andrew W.; Crepp, Justin R.; Keel, William C.; Lintott, Chris J.; Kaib, Nathan A.; Terrell, Dirk; Gagliano, Robert; Jek, Kian J.; Parrish, Michael; Smith, Arfon M.; Lynn, Stuart; Simpson, Robert J.; Giguere, Matthew J.; Schawinski, Kevin

    2013-05-01

    We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625. The 6.18 ± 0.17 R ⊕ planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 ± 0.044 R ⊙, 1.528 ± 0.087 M ⊙) and M dwarf (0.378 ± 0.023 R ⊙, 0.408 ± 0.024 M ⊙). For the planet, we find an upper mass limit of 169 M ⊕ (0.531 Jupiter masses) at the 99.7% confidence level. With a radius and mass less than that of Jupiter, PH1b is well within the planetary regime. Outside the planet's orbit, at ~1000 AU, a previously unknown visual binary has been identified that is likely bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

  2. Knowledge-Sharing Networks in Hunter-Gatherers and the Evolution of Cumulative Culture.

    Science.gov (United States)

    Salali, Gul Deniz; Chaudhary, Nikhil; Thompson, James; Grace, Olwen Megan; van der Burgt, Xander M; Dyble, Mark; Page, Abigail E; Smith, Daniel; Lewis, Jerome; Mace, Ruth; Vinicius, Lucio; Migliano, Andrea Bamberg

    2016-09-26

    Humans possess the unique ability for cumulative culture [1, 2]. It has been argued that hunter-gatherer's complex social structure [3-9] has facilitated the evolution of cumulative culture by allowing information exchange among large pools of individuals [10-13]. However, empirical evidence for the interaction between social structure and cultural transmission is scant [14]. Here we examine the reported co-occurrence of plant uses between individuals in dyads (which we define as their "shared knowledge" of plant uses) in BaYaka Pygmies from Congo. We studied reported uses of 33 plants of 219 individuals from four camps. We show that (1) plant uses by BaYaka fall into three main domains: medicinal, foraging, and social norms/beliefs; (2) most medicinal plants have known bioactive properties, and some are positively associated with children's BMI, suggesting that their use is adaptive; (3) knowledge of medicinal plants is mainly shared between spouses and biological and affinal kin; and (4) knowledge of plant uses associated with foraging and social norms is shared more widely among campmates, regardless of relatedness, and is important for camp-wide activities that require cooperation. Our results show the interdependence between social structure and knowledge sharing. We propose that long-term pair bonds, affinal kin recognition, exogamy, and multi-locality create ties between unrelated families, facilitating the transmission of medicinal knowledge and its fitness implications. Additionally, multi-family camps with low inter-relatedness between camp members provide a framework for the exchange of functional information related to cooperative activities beyond the family unit, such as foraging and regulation of social life.

  3. The spatial structure of hunter access determines the local abundance of forest elephants (Loxodonta africana cyclotis).

    Science.gov (United States)

    Yackulic, Charles B; Strindberg, Samantha; Maisels, Fiona; Blake, Stephen

    2011-06-01

    In many previously remote regions in the world, increasing and often unregulated access is leading to dramatic increases in hunting pressure and declines in the densities of prey species, sometimes to the point of local extinction. Not surprisingly, numerous studies have found a correlation between the distance to the closest access point and prey densities. Here we hypothesized that, for many wide-ranging species, local abundances are reduced by hunting associated with multiple access points as opposed to just the closest access points. We also hypothesized that the distribution of hunter access determines both patterns of occupancy and abundance in occupied areas and that these two patterns (occupancy and abundance) respond to access at different spatial scales. Using data on the distribution of abundances of African forest elephant (Loxodonta africana cyclotis) in and around five national parks in Central Africa, we tested these hypotheses using a model comparison framework. We found that models including an index based on the distance to multiple roads outperformed models including other access-based covariates, including a model based on distance to the closest road only. We also found that models that allowed us to model occupancy and abundance separately outperformed simpler models. Occupancy responds to access at the same scale as previous estimates of average maximum displacement in the subspecies, while the scale of the response of abundance is more ambiguous, but appears to be greater. Lastly, we show that incorporating indices based on multiple access points and modeling abundance and occupancy has important practical consequences for our understanding of overall regional abundances and the distribution of abundances within regions.

  4. Predators on private land: broad-scale socioeconomic interactions influence large predator management

    Directory of Open Access Journals (Sweden)

    Hayley S. Clements

    2016-06-01

    Full Text Available The proliferation of private land conservation areas (PLCAs is placing increasing pressure on conservation authorities to effectively regulate their ecological management. Many PLCAs depend on tourism for income, and charismatic large mammal species are considered important for attracting international visitors. Broad-scale socioeconomic factors therefore have the potential to drive fine-scale ecological management, creating a systemic scale mismatch that can reduce long-term sustainability in cases where economic and conservation objectives are not perfectly aligned. We assessed the socioeconomic drivers and outcomes of large predator management on 71 PLCAs in South Africa. Owners of PLCAs that are stocking free-roaming large predators identified revenue generation as influencing most or all of their management decisions, and rated profit generation as a more important objective than did the owners of PLCAs that did not stock large predators. Ecotourism revenue increased with increasing lion (Panthera leo density, which created a potential economic incentive for stocking lion at high densities. Despite this potential mismatch between economic and ecological objectives, lion densities were sustainable relative to available prey. Regional-scale policy guidelines for free-roaming lion management were ecologically sound. By contrast, policy guidelines underestimated the area required to sustain cheetah (Acinonyx jubatus, which occurred at unsustainable densities relative to available prey. Evidence of predator overstocking included predator diet supplementation and frequent reintroduction of game. We conclude that effective facilitation of conservation on private land requires consideration of the strong and not necessarily beneficial multiscale socioeconomic factors that influence private land management.

  5. Prey, predators, parasites: intraguild predation or simpler community modules in disguise?

    Science.gov (United States)

    Sieber, Michael; Hilker, Frank M

    2011-03-01

    1. Competition and predation are at the heart of community ecology. The theoretical concept of intraguild predation (IGP) combines these key interactions in a single community module. Because IGP is believed to be ubiquitous in nature, it has been subject to extensive research, and there exists a well-developed theoretical framework. 2. We show that a general class of IGP models can be transformed to simpler, but equivalent community structures. This rather unexpected simplification depends critically on the property of 'indiscriminate predation', which we define broadly as the top-predator not distinguishing between its two different prey species. 3. In a broader context, the great importance of IGP and of the simplifying transformation we report here is enhanced by the recent insight that the basic IGP structure extends naturally to host-parasitoid and host-pathogen communities. We show that parasites infecting prey (predators) tend to render IGP effectively into exploitative competition (tritrophic food chain, respectively). 4. The equivalence between the original and simplified community module makes it possible to take advantage from already existing insights. We illustrate this by means of an eco-epidemiological IGP model that is strikingly similar to a classical exploitative competition model. 5. The change of perspective on certain community modules may contribute to a better understanding of food web dynamics. In particular, it may help explain the interactions in food webs that include parasites. Given the ubiquity of parasitism, food webs may appear in a different light when they are transformed to their simplified analogue. © 2010 The Authors. Journal of Animal Ecology © 2010 British Ecological Society.

  6. Fish ladders: safe fish passage or hotspot for predation?

    Directory of Open Access Journals (Sweden)

    Angelo Antonio Agostinho

    Full Text Available Fish ladders are a strategy for conserving biodiversity, as they can provide connectivity between fragmented habitats and reduce predation on shoals that accumulate immediately below dams. Although the impact of predation downstream of reservoirs has been investigated, especially in juvenile salmonids during their downstream movements, nothing is known about predation on Neotropical fish in the attraction and containment areas commonly found in translocation facilities. This study analysed predation in a fish passage system at the Lajeado Dam on the Tocantins River in Brazil. The abundance, distribution, and the permanence (time spent of large predatory fish along the ladder, the injuries imposed by piranhas during passage and the presence of other vertebrate predators were investigated. From December 2002 to October 2003, sampling was conducted in four regions (downstream, along the ladder, in the forebay, and upstream of the reservoir using gillnets, cast nets and counts or visual observations. The captured fish were tagged with thread and beads, and any mutilations were registered. Fish, birds and dolphins were the main predator groups observed, with a predominance of the first two groups. The entrance to the ladder, in the downstream region, was the area with the highest number of large predators and was the only region with relevant non-fish vertebrates. The main predatory fish species were Rhaphiodon vulpinus, Hydrolycus armatus, and Serrasalmus rhombeus. Tagged individuals were detected predating along the ladder for up to 90 days. Mutilations caused by Serrasalmus attacks were noted in 36% of species and 4% of individuals at the top of the ladder. Our results suggested that the high density of fish in the restricted ladder environment, which is associated with injuries suffered along the ladder course and the presence of multiple predator groups with different predation strategies, transformed the fish corridor into a hotspot for

  7. Factors influencing predation on juvenile ungulates and natural selection implications

    Directory of Open Access Journals (Sweden)

    S. M. Barber-Meyer

    2008-06-01

    Full Text Available Juvenile ungulates are generally more vulnerable to predation than are adult ungulates other than senescent individuals, not only because of their relative youth, fragility, and inexperience, but also because of congenital factors. Linnell et al.’s (Wildl. Biol. 1: 209-223 extensive review of predation on juvenile ungulates concluded that research was needed to determine the predisposition of these juveniles to predation. Since then, various characteristics that potentially predispose juvenile ungulates have emerged including blood characteristics, morphometric and other condition factors, and other factors such as birth period, the mother’s experience, and spatial and habitat aspects. To the extent that any of the physical or behavioral traits possessed by juvenile ungulates have a genetic or heritable and partly independent epigenetic component that predisposes them to predation, predators may play an important role in their natural selection. We review the possible influence of these characteristics on predisposing juvenile ungulates to predation and discuss natural selection implications and potential selection mechanisms. Although juvenile ungulates as a class are likely more vulnerable to predation than all but senescent adults, our review presents studies indicating that juveniles with certain tendencies or traits are killed more often than others. This finding suggests that successful predation on juveniles is more selective than is often assumed. Because we are unable to control for (or in some cases even measure the myriad of other possible vulnerabilities such as differences in sensory abilities, intelligence, hiding abilities, tendency to travel, etc., finding selective predation based on the relatively few differences we can measure is noteworthy and points to the significant role that predation on juveniles has in the natural selection of ungulates. Future research should compare characteristics, especially those known to

  8. Modelling the fear effect in predator-prey interactions.

    Science.gov (United States)

    Wang, Xiaoying; Zanette, Liana; Zou, Xingfu

    2016-11-01

    A recent field manipulation on a terrestrial vertebrate showed that the fear of predators alone altered anti-predator defences to such an extent that it greatly reduced the reproduction of prey. Because fear can evidently affect the populations of terrestrial vertebrates, we proposed a predator-prey model incorporating the cost of fear into prey reproduction. Our mathematical analyses show that high levels of fear (or equivalently strong anti-predator responses) can stabilize the predator-prey system by excluding the existence of periodic solutions. However, relatively low levels of fear can induce multiple limit cycles via subcritical Hopf bifurcations, leading to a bi-stability phenomenon. Compared to classic predator-prey models which ignore the cost of fear where Hopf bifurcations are typically supercritical, Hopf bifurcations in our model can be both supercritical and subcritical by choosing different sets of parameters. We conducted numerical simulations to explore the relationships between fear effects and other biologically related parameters (e.g. birth/death rate of adult prey), which further demonstrate the impact that fear can have in predator-prey interactions. For example, we found that under the conditions of a Hopf bifurcation, an increase in the level of fear may alter the direction of Hopf bifurcation from supercritical to subcritical when the birth rate of prey increases accordingly. Our simulations also show that the prey is less sensitive in perceiving predation risk with increasing birth rate of prey or increasing death rate of predators, but demonstrate that animals will mount stronger anti-predator defences as the attack rate of predators increases.

  9. Predators and predation rates of skylark Alauda arvensis and woodlark Lullula arborea nests in a semi-natural area in the Netherlands

    NARCIS (Netherlands)

    Praus, Libor; Hegemann, Arne; Tieleman, B. Irene; Weidinger, Karel

    2014-01-01

    Predation is a major cause of breeding failure in bird species with open nests. Although many studies have investigated nest predation rates, direct identification of nest predators is sporadic, especially in (semi-)natural habitats. We quantified nest success and identified nest predators in a popu

  10. Predators and predation rates of skylark Alauda arvensis and woodlark Lullula arborea nests in a semi-natural area in the Netherlands

    NARCIS (Netherlands)

    Praus, Libor; Hegemann, Arne; Tieleman, B. Irene; Weidinger, Karel

    2014-01-01

    Predation is a major cause of breeding failure in bird species with open nests. Although many studies have investigated nest predation rates, direct identification of nest predators is sporadic, especially in (semi-)natural habitats. We quantified nest success and identified nest predators in a popu

  11. Optimal growth strategies under divergent predation pressure.

    Science.gov (United States)

    Aikio, S; Herczeg, G; Kuparinen, A; Merilä, J

    2013-01-01

    The conditions leading to gigantism in nine-spined sticklebacks Pungitius pungitius were analysed by modelling fish growth with the von Bertalanffy model searching for the optimal strategy when the model's growth constant and asymptotic fish size parameters are negatively related to each other. Predator-related mortality was modelled through the increased risk of death during active foraging. The model was parameterized with empirical growth data of fish from four different populations and analysed for optimal growth strategy at different mortality levels. The growth constant and asymptotic fish size were negatively related in most populations. Optimal fish size, fitness and life span decreased with predator-induced mortality. At low mortality, the fitness of pond populations was higher than that of sea populations. The differences disappeared at intermediate mortalities, and sea populations had slightly higher fitness at extremely high mortalities. In the scenario where all populations mature at the same age, the pond populations perform better at low mortalities and the sea populations at high mortalities. It is concluded that a trade-off between growth constant and asymptotic fish size, together with different mortality rates, can explain a significant proportion of body size differentiation between populations. In the present case, it is a sufficient explanation of gigantism in pond P. pungitius. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  12. Drought-Related Changes in Two Hunter-Gatherer California Populations

    Science.gov (United States)

    Weiss, Elizabeth

    2002-11-01

    Skeletal remains from two California cemeteries bracketing a severe drought that began around 1200 yr B.P. are analyzed to determine drought-related quality of life changes in Native Americans. Cemetery 1 predates the drought at 2895±160 yr B.P. to 1845±90 yr B.P. and Cemetery 2 dates it at 1100±90 yr B.P. to 1220±200 yr B.P. Quality of life was assessed through femoral computerized tomography scan measures of cortical thickness, age at adult death, and pathology/trauma frequency. After controlling for age and sex differences, changes from Cemetery 1 to Cemetery 2 showed decreases in cortical thickness and age at death and increases in pathology and trauma frequency.

  13. Assessing predation risk to threatened fauna from their prevalence in predator scats: dingoes and rodents in arid Australia.

    Directory of Open Access Journals (Sweden)

    Benjamin L Allen

    Full Text Available The prevalence of threatened species in predator scats has often been used to gauge the risks that predators pose to threatened species, with the infrequent occurrence of a given species often considered indicative of negligible predation risks. In this study, data from 4087 dingo (Canis lupus dingo and hybrids scats were assessed alongside additional information on predator and prey distribution, dingo control effort and predation rates to evaluate whether or not the observed frequency of threatened species in dingo scats warrants more detailed investigation of dingo predation risks to them. Three small rodents (dusky hopping-mice Notomys fuscus; fawn hopping-mice Notomys cervinus; plains mice Pseudomys australis were the only threatened species detected in <8% of dingo scats from any given site, suggesting that dingoes might not threaten them. However, consideration of dingo control effort revealed that plains mice distribution has largely retracted to the area where dingoes have been most heavily subjected to lethal control. Assessing the hypothetical predation rates of dingoes on dusky hopping-mice revealed that dingo predation alone has the potential to depopulate local hopping-mice populations within a few months. It was concluded that the occurrence of a given prey species in predator scats may be indicative of what the predator ate under the prevailing conditions, but in isolation, such data can have a poor ability to inform predation risk assessments. Some populations of threatened fauna assumed to derive a benefit from the presence of dingoes may instead be susceptible to dingo-induced declines under certain conditions.

  14. Maternally induced intraclutch cannibalism: an adaptive response to predation risk?

    Science.gov (United States)

    Tigreros, Natasha; Norris, Rachel H; Wang, Eugenia H; Thaler, Jennifer S

    2017-04-01

    Theory on condition-dependent risk-taking indicates that when prey are in poor condition, their anti-predator responses should be weak. However, variation in responses resulting from differences in condition is generally considered an incidental by-product of organisms living in a heterogeneous environment. Using Leptinotarsa decemlineata beetles and stinkbug (Podisus maculiventris) predators, we hypothesised that in response to predation risk, parents improve larval nutritional condition and expression of anti-predator responses by promoting intraclutch cannibalism. We showed that mothers experiencing predation risk increase production of unviable trophic eggs, which assures provisioning of an egg meal to the newly hatched offspring. Next, we experimentally demonstrated that egg cannibalism reduces L. decemlineata vulnerability to predation by improving larval nutritional condition and expression of anti-predator responses. Intraclutch cannibalism in herbivorous insects might be a ubiquitous strategy, aimed to overcome the dual challenge of feeding on protein-limited diets while living under constant predation threat. © 2017 John Wiley & Sons Ltd/CNRS.

  15. Influence of stochastic perturbation on prey-predator systems.

    Science.gov (United States)

    Rudnicki, Ryszard; Pichór, Katarzyna

    2007-03-01

    We analyse the influence of various stochastic perturbations on prey-predator systems. The prey-predator model is described by stochastic versions of a deterministic Lotka-Volterra system. We study long-time behaviour of both trajectories and distributions of the solutions. We indicate the differences between the deterministic and stochastic models.

  16. Patch based predation in a southern Appalachian stream

    Science.gov (United States)

    C.A. Gibson; R.E. Ratajezak; G.D. Grossman

    2004-01-01

    Streams are characterized by high degrees of patchiness that could influence the role of predators in these systems. Here we assess the impact of predatory benthic fishes on benthic macroinvertebrate density, biomass, and community structure at the patch scale in a fourth order stream in the southern Appalachians. We tested the role of predation in two different patch...

  17. Predator-induced reduction of freshwater carbon dioxide emissions

    Science.gov (United States)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  18. Analysis of adaptive foraging in an intraguild predation system

    Directory of Open Access Journals (Sweden)

    T. Okuyama

    2003-09-01

    Full Text Available An intraguild predation (IGP system with adaptive foraging behavior was analyzed using a simple mathematical model. The main aim was to explore how the adaptive behavior affects species interactions as well as how such interactions derived from adaptive behavior affect community stability. The focal system contained top predators, intermediate predators, and basal prey. Intermediate predators exhibit antipredator behavior and balance costs (e.g. perceived predation risk and benefits (e.g. resource intake to determine their foraging effort. Density-dependent foraging behavior with the unique connectance of the IGP food web created unusual species interactions. Notably, increased prey density can transmit negative indirect effects to top predators while increased top predator density transmits positive indirect effects to prey population. The nature of these interactions is density-dependent. The results suggest that both IGP (as opposed to linear food chain and adaptive foraging behaviors may strongly influence community dynamics due to emergent interactions among direct effects and indirect effects. Furthermore, the adaptive foraging of intermediate predators may stabilize the community as a whole.

  19. Disentangling mite predator-prey relationships by multiplex PCR.

    Science.gov (United States)

    Pérez-Sayas, Consuelo; Pina, Tatiana; Gómez-Martínez, María A; Camañes, Gemma; Ibáñez-Gual, María V; Jaques, Josep A; Hurtado, Mónica A

    2015-11-01

    Gut content analysis using molecular techniques can help elucidate predator-prey relationships in situations in which other methodologies are not feasible, such as in the case of trophic interactions between minute species such as mites. We designed species-specific primers for a mite community occurring in Spanish citrus orchards comprising two herbivores, the Tetranychidae Tetranychus urticae and Panonychus citri, and six predatory mites belonging to the Phytoseiidae family; these predatory mites are considered to be these herbivores' main biological control agents. These primers were successfully multiplexed in a single PCR to test the range of predators feeding on each of the two prey species. We estimated prey DNA detectability success over time (DS50), which depended on the predator-prey combination and ranged from 0.2 to 18 h. These values were further used to weight prey detection in field samples to disentangle the predatory role played by the most abundant predators (i.e. Euseius stipulatus and Phytoseiulus persimilis). The corrected predation value for E. stipulatus was significantly higher than for P. persimilis. However, because this 1.5-fold difference was less than that observed regarding their sevenfold difference in abundance, we conclude that P. persimilis is the most effective predator in the system; it preyed on tetranychids almost five times more frequently than E. stipulatus did. The present results demonstrate that molecular tools are appropriate to unravel predator-prey interactions in tiny species such as mites, which include important agricultural pests and their predators.

  20. Global stability of predator-prey system with alternative prey.

    Science.gov (United States)

    Sahoo, Banshidhar

    2013-01-01

    A predator-prey model in presence of alternative prey is proposed. Existence and local stability conditions for interior equilibrium points are derived. Global stability conditions for interior equilibrium points are also found. Bifurcation analysis is done with respect to predator's searching rate and handling time. Bifurcation analysis confirms the existence of global stability in presence of alternative prey.

  1. EXTINCTION OF A DISCRETE NONLINEAR PREDATOR-PREY SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, we consider a discrete nonlinear predator-prey model with nonnegative coefficients bounded above and below by positive constants. We show that under some suitable assumptions the predator species is driven to extinction and the prey species x is globally attractive with any positive solution to a discrete Logistic equation.

  2. Coexistence Steady States in a Predator-Prey Model

    CERN Document Server

    Walker, Christoph

    2010-01-01

    An age-structured predator-prey system with diffusion and Holling-Tanner-type nonlinearities is considered. Regarding the intensity of the fertility of the predator as bifurcation parameter, we prove that a branch of positive coexistence steady states bifurcates from the marginal steady state with no prey. A similar result is obtained when the fertility of the prey varies.

  3. Periodic Solutions of a Discrete Time Predator-Prey System

    Institute of Scientific and Technical Information of China (English)

    Yong-li Song; Mao-an Han

    2006-01-01

    In this paper, we discuss a discrete predator-prey system with a non-monotonic functional response,which models the dynamics of the prey and the predator having non-overlapping generations. By using the coincidence degree theory, sufficient conditions are obtained for the existence of positive periodic solutions.

  4. Sleeping birds do not respond to predator odour.

    Directory of Open Access Journals (Sweden)

    Luisa Amo

    Full Text Available BACKGROUND: During sleep animals are relatively unresponsive and unaware of their environment, and therefore, more exposed to predation risk than alert and awake animals. This vulnerability might influence when, where and how animals sleep depending on the risk of predation perceived before going to sleep. Less clear is whether animals remain sensitive to predation cues when already asleep. METHODOLOGY/PRINCIPAL FINDINGS: We experimentally tested whether great tits are able to detect the chemical cues of a common nocturnal predator while sleeping. We predicted that birds exposed to the scent of a mammalian predator (mustelid twice during the night would not go into torpor (which reduces their vigilance and hence would not reduce their body temperature as much as control birds, exposed to the scent of another mammal that does not represent a danger for the birds (rabbit. As a consequence of the higher body temperature birds exposed to the scent of a predator are predicted to have a higher resting metabolic rate (RMR and to lose more body mass. In the experiment, all birds decreased their body temperature during the night, but we did not find any influence of the treatment on body temperature, RMR, or body mass. CONCLUSIONS/SIGNIFICANCE: Our results suggest that birds are not able to detect predator chemical cues while sleeping. As a consequence, antipredatory strategies taken before sleep, such as roosting sites inspection, may be crucial to cope with the vulnerability to predation risk while sleeping.

  5. Simulating predator attacks on schools : Evolving composite tactics

    NARCIS (Netherlands)

    Demsar, Jure; Hemelrijk, Charlotte K.; Hildenbrandt, Hanno; Bajec, Iztok Lebar

    2015-01-01

    One hypothesis about the origins and evolution of coordinated animal movements is that they may serve as a defensive mechanism against predation. Earlier studies of the possible evolution of coordinated movement in prey concentrated on predators with simple attack tactics. Numerous studies, however,

  6. Sleeping Birds Do Not Respond to Predator Odour

    NARCIS (Netherlands)

    Amo, Luisa; Caro, Samuel P.; Visser, Marcel E.

    2011-01-01

    Background: During sleep animals are relatively unresponsive and unaware of their environment, and therefore, more exposed to predation risk than alert and awake animals. This vulnerability might influence when, where and how animals sleep depending on the risk of predation perceived before going to

  7. Sleeping birds do not respond to predator odour

    NARCIS (Netherlands)

    Amo, L.; Caro, S.P.; Visser, M.E.

    2011-01-01

    Background: During sleep animals are relatively unresponsive and unaware of their environment, and therefore, more exposed to predation risk than alert and awake animals. This vulnerability might influence when, where and how animals sleep depending on the risk of predation perceived before going to

  8. Phenotypically plastic neophobia: a response to variable predation risk.

    Science.gov (United States)

    Brown, Grant E; Ferrari, Maud C O; Elvidge, Chris K; Ramnarine, Indar; Chivers, Douglas P

    2013-04-07

    Prey species possess a variety of morphological, life history and behavioural adaptations to evade predators. While specific evolutionary conditions have led to the expression of permanent, non-plastic anti-predator traits, the vast majority of prey species rely on experience to express adaptive anti-predator defences. While ecologists have identified highly sophisticated means through which naive prey can deal with predation threats, the potential for death upon the first encounter with a predator is still a remarkably important unresolved issue. Here, we used both laboratory and field studies to provide the first evidence for risk-induced neophobia in two taxa (fish and amphibians), and argue that phenotypically plastic neophobia acts as an adaptive anti-predator strategy for vulnerable prey dealing with spatial and temporal variation in predation risk. Our study also illustrates how risk-free maintenance conditions used in laboratory studies may blind researchers to adaptive anti-predator strategies that are only expressed in high-risk conditions.

  9. A review: dietary restrictions on hunter-gatherer women and the implications for fertility and infant mortality.

    Science.gov (United States)

    Spielmann, K A

    1989-09-01

    In many hunter gatherer societies, food taboos dictate the diets of females. These taboos often happen during their most critical reproductive times in their life, e.g., pregnancy. Among some subarctic Athapaskan societies, females at menarche cannot eat fresh meat. They, like other hunter gatherer societies, also restrict fresh meat consumption for menstruating women. Young women of the Aranda society in Australia cannot eat protein rich foods, e.g., lizards, until they have a child. Australian aboriginal societies restrict protein and fat foods for pregnant and lactating women. Even though the literature shows that the undernourished are inclined to reach menarche at a later age than those who eat a well balanced diet, it does not clearly establish whether differences in age at menarche significantly affect overall fertility. Research done on many different under or marginally nourished populations indicates that maternal nutritional health influences birth spacing significantly. Specifically, undernutrition causes longer postpartum amenorrhea. Therefore, lower fertility rates follow longer birth intervals. Research shows that poor maternal nutritional health does not prevent the fetus from surviving and growing. Yet mothers who do not consume many calories often have low birth weight infants. These infants are at high risk of dying because they have little to no fat reserves and they consume inadequate amounts of nutrition since the mothers cannot make insufficient amounts of milk. Since contemporary research shows that maternal nutritional health does effect fertility and infant mortality, food taboos do have the ability to influence population size. More research is needed to understand the factors that influenced the reproductive rates of past hunter-gatherer societies, so anthropologists can identify the demographically significant changes which sedentism and agriculture caused 10,000 years ago.

  10. Estimation of the tourism climate in the Hunter Region, Australia, in the early twenty-first century

    Science.gov (United States)

    Shiue, Ivy; Matzarakis, Andreas

    2011-07-01

    Existing tourism-related climate information and evaluation are typically based on mean monthly conditions of air temperature and precipitation and do not include thermal perception and other climate parameters relevant for tourists. Here, we quantify climate based on the climate facets relevant to tourism (thermal, physical, aesthetical), and apply the results to the Climate-Tourism-Information-Scheme (CTIS). This paper presents bioclimatic and tourism climatological conditions in the Hunter Region—one of Australia's most popular tourist destinations. In the Hunter Region, generally, temperatures below 15°C occur from April through October, temperatures less than 25°C are expected throughout the whole year, while humidity sits around 50%. As expected, large differences between air temperature and physiologically equivalent temperature (PET) were clearly identified. The widest differences were seen in summer time rather than in the winter period. In addition, cold stress was observed less than 10% of the time in winter while around 40-60% of heat stress was observed in summer time. This correlates with the highest numbers of international visitors, who usually seek a warmer weather, at the beginning of summer time (November and December) and also to the number of domestic visitors, who tend to seek cooler places for recreation and leisure, in late summer (January-March). It was concluded that thermal bioclimate assessment such as PET and CTIS can be applied in the Hunter region, and that local governments and the tourism industry should take an integrated approach to providing more relevant weather and climate information for both domestic and international tourists in the near future.

  11. Groundwater modeling to evaluate interaquifer leakage in the Floridan aquifer system near Hunter Army Airfield and Fort Stewart

    Science.gov (United States)

    Cherry, Gregory S.

    2011-01-01

    Simulations using a modified regional groundwater- flow model were used to determine the amount of leakage from the Upper Floridan aquifer (UFA) through the Lower Floridan confining unit (LFC) into the Lower Floridan aquifer (LFA) resulting from pumping about 1 million gallons per day at newly constructed LFA production wells at Hunter Army Airfield and Fort Stewart in coastal Georgia. Simulated steadystate drawdown at each of the LFA production wells closely matched observed drawdown during a 72-hour aquifer test with the observed water levels reaching steady-state by the end of the test period. However, simulated drawdown was greater than observed drawdown in the UFA because of the short duration of the aquifer test and the time required for groundwater movement through the LFC into the LFA. Steadystate simulations provide an estimate of leakage based on the long-term continuous operation of each production well. Results of model simulations indicate that interaquifer leakage accounts for 48 percent of the flow to the well at Hunter Army Airfield, and 98 percent of the flow to the well at Fort Stewart. Simulated results near the Hunter Army Airfield production well indicated that 65 percent of the leakage from the UFA to the LFA occurs within a 1-mile radius, whereas simulated results near the Fort Stewart production well indicated 80-percent leakage from the UFA to the LFA within the same radius. The greater amount of leakage to the production well near Fort Stewart can be attributed to the higher transmissivity of the UFA and higher vertical hydraulic conductivity in the LFC near the well.

  12. The formation of fire residues associated with hunter-gatherers in humid tropical environments: A geo-ethnoarchaeological perspective

    Science.gov (United States)

    Friesem, David E.; Lavi, Noa; Madella, Marco; Boaretto, Elisabetta; Ajithparsad, P.; French, Charles

    2017-09-01

    Tropical forests have been an important human habitat and played a significant role in early human dispersal and evolution. Likewise, the use of fire, besides being one of the exceptional characteristics of humans, serves as a marker for human evolution. While the use of fire by prehistoric hunter-gatherers is relatively well documented in arid and temperate environments, the archaeological evidence in humid tropical environment is to date very limited. We first review the archaeological evidence for hunter-gatherer use of fire in humid tropical environments and suggest that better understanding of formation processes is required. We present a geo-ethnoarchaeological study from South India, involving ethnography, excavations and laboratory-based analyses in order to build a new framework to study fire residues in humid tropical forests associated with hunter-gatherer's use of fire. Ethnographic observations point to a dynamic and ephemeral use of hearths. Hearths location were dictated by the social and ever-changing social dynamics of the site. The hearths deposited small amount of residues which were later swept on a daily basis, re-depositing ash and charcoal in waste areas and leaving only a microscopic signal in the original location. Particular acidic conditions and intensive biological activity within tropical sediments result in the complete dissolution of ash and bones while favouring the preservation of charcoal and phytoliths. Consequently, the identification of fire residues in humid tropical forests and the reconstruction of the human use of fire must involve multi-proxy microscopic analysis to detect its micro-signatures.

  13. Hand Safety

    Science.gov (United States)

    ... Gardening Safety Turkey Carving Removing a Ring Español Artritis de la base del pulgar Dedo en gatillo ... Gardening Safety Turkey Carving Removing a Ring Español Artritis de la base del pulgar Dedo en gatillo ...

  14. Water Safety

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Water Safety KidsHealth > For Parents > Water Safety Print A ... best measure of protection. previous continue Making Kids Water Wise It's important to teach your kids proper ...

  15. SAFETY FIRST

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ensuring safety while peacefully utilizing nuclear energy is a top priority for China A fter a recent earthquake in Japan caused radioactive leaks at a nuclear power plant in Tokyo, the safety of nuclear energy has again aroused public attention.

  16. Safety Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Swan Lake National Wildlife Refuge Safety Plan discusses policies for the safety of the station employees, volunteers, and public. This plan seeks to identify...

  17. The Bayview Hunters Point Foundation for Community Improvement: a pioneering multi-ethnic human service organization (1971-2008).

    Science.gov (United States)

    Joe, Ellen; Schwartz, Sara L; Austin, Michael J

    2011-01-01

    The Bayview Hunters Point Foundation for Community Improvement is a nonprofit organization established in 1971 to defend the legal rights of African-Americans living in its community. Over the years, the agency diversified its services to include mental health and substance abuse treatment, violence prevention, youth programming, and HIV services. The organization has overcome multiple challenges during its 37-year history in relation to social, political, and economic changes that have influenced the way the organization has financed and delivered its services. The history of the organization presents a collaborative approach to community problem-solving and exemplifies the important role that external relationships play in relationship to nonprofit growth and survival.

  18. Functional responses of human hunters to their prey - why harvest statistics may not always reflect changes in prey population abundance

    DEFF Research Database (Denmark)

    Kahlert, Johnny Abildgaard; Fox, Anthony David; Heldbjerg, Henning

    functional response to the point count indices, with similar auto-correlative structures in the two variables. Other species showed different functional responses, the result of hunter behaviour, such as voluntary hunting restraint on species of concern and saturation effects from rapidly expanding abundant...... are used as an index for population size. It is essential that detectability/accessibility of a species does not change systematically over time. Such bias may derive from habitat shifts, difference in timing of counts and hunting harvest, changes in migration patterns and annual reproduction and mortality...

  19. Plan de mejoramiento para la gestión del direccionamiento estratégico en Market Hunters Ltda

    OpenAIRE

    2012-01-01

    Para el presente proyecto de grado, se realizó un análisis situacional de Market Hunters Ltda, empresa dedicada a la comercialización de aceites y aditivo que a su vez presta servicios de asistencia automotriz. Basado en el ambiente percibido en el técnicentro, la entrevista con el gerente y los resultados encontrados en la matriz integral, se llego a concluir que dicha información representaría para dicha investigación un punto de partida en la búsqueda de la raíz del problema; las falencias...

  20. OPERATION ODESSA: THE FLIGHT OF NAZI WAR CRIMINALS TO LATIN AMERICA AFTER WORLD WAR II AND THE NAZI HUNTERS

    Directory of Open Access Journals (Sweden)

    Marcos Eduardo Meinerz

    2013-06-01

    Full Text Available This article aims to analyze why Latin America, especially Argentina, was the region of the world that harbored the most Nazi war criminals—for example, Josef Mengele, Adolf Eichmann and Klaus Barbie—after World War II. It also aims to analyze how this fact has set the tone for the appearance of literary works about the fantastic adventures of “Nazi hunters” seeking the whereabouts of those individuals. For this purpose, in the first part of the article we will address Nazis’ escape to Latin America. Next, we analyze some literary works by authors who called themselves Nazi hunters.

  1. Hunter color dimensions, sugar content and volatile compounds in pasteurized yellow passion fruit juice (Passiflora edulis var. flavicarpa during storage

    Directory of Open Access Journals (Sweden)

    Delcio Sandi

    2004-06-01

    Full Text Available Changes in Hunter L, a and b values, glucose, fructose and sucrose contents, concentration of four volatile compounds (ethyl butirate, ethyl caproate, hexyl butirate and hexyl caproate and furfural, were studied in yellow passion fruit juice (Passiflora edulis var. flavicarpa pasteurized at 75ºC/60s, 80ºC/41s or 85ºC/27s, during storage at room temperature (25±5ºC and refrigeration (5±1ºC for 120 days. While the sucrose content decreased, the glucose and fructose contents increased significantly over storage time. The Hunter L and b values behaved similarly, with a tendency to decrease over time, inversely to Hunter a value. Volatile compound concentrations also decreased over time, inversely to the furfural content. Pasteurization at 85ºC/27s resulted minimum changes in the studied passion fruit characteristics, while that at 75ºC/60s was the most harmful. Storage under refrigeration tended to keep the best quality characteristics of the juice.Foi estudada a variação dos valores "L", "a" e "b" do sistema de Hunter, dos teores de glucose, frutose e sacarose, e da concentração de quatro compostos voláteis (butirato de etila, caproato de etila, butirato de hexila e caproato de hexila e furfural, em suco de maracujá-amarelo (Passiflora edulis var. flavicarpa submetido à pasteurização (75ºC/60 s, 80ºC/41 s e 85ºC/27 s, durante o armazenamento a temperatura ambiente (25±5ºC e refrigerada (5±1ºC por 120 dias. Enquanto os teores de sacarose diminuíram, aqueles de glucose e frutose aumentaram significativamente. Os valores "L" e "b" apresentaram comportamento semelhante, com tendência a diminuir ao longo do tempo, inversamente ao valor "a". As concentrações dos compostos voláteis também diminuíram, exceto para o furfural. A pasteurização a 85ºC/27 s proporcionou as menores alterações nas características estudadas, enquanto aquela à 75ºC/60 s foi a mais prejudicial. O armazenamento sob refrigeração apresentou

  2. Environmental versus demographic variability in stochastic predator-prey models

    Science.gov (United States)

    Dobramysl, U.; Täuber, U. C.

    2013-10-01

    In contrast to the neutral population cycles of the deterministic mean-field Lotka-Volterra rate equations, including spatial structure and stochastic noise in models for predator-prey interactions yields complex spatio-temporal structures associated with long-lived erratic population oscillations. Environmental variability in the form of quenched spatial randomness in the predation rates results in more localized activity patches. Our previous study showed that population fluctuations in rare favorable regions in turn cause a remarkable increase in the asymptotic densities of both predators and prey. Very intriguing features are found when variable interaction rates are affixed to individual particles rather than lattice sites. Stochastic dynamics with demographic variability in conjunction with inheritable predation efficiencies generate non-trivial time evolution for the predation rate distributions, yet with overall essentially neutral optimization.

  3. Assessing ant seed predation in threatened plants: a case study

    Science.gov (United States)

    Albert, María José; Escudero, Adrián; Iriondo, José María

    2005-11-01

    Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed production and ant consumption, assessed by counting seed hulls in refuse piles. According to this method, ant seed predation ranged between 18% and 28%. A more detailed and direct assessment conducted in 1997 raised this estimate to 43%. In this assessment spatial and temporal patterns of seed predation by ants were studied by mapping all nest entrances in the studied area and marking the mature fruits of 109 reproductive plants with a specific colour code throughout the seed dispersal period. Intact fruit coats were later recovered from the refuse piles, and their mother plants and time of dispersal were identified. Seeds dispersed at the end of the dispersal period had a greater probability of escaping from ant seed predation. Similarly, in plants with late dispersal a greater percentage of seeds escaped from ant predation. Optimum dispersal time coincided with the maximum activity of granivorous ants because, at this time, ants focused their harvest on other plant species of the community. It was also observed that within-individual seed dispersal asynchrony minimised seed predation. From a conservation perspective, results show that the granivorous ant-plant interaction cannot be assessed in isolation and that the intensity of its effects basically depends on the seed dispersal pattern of the other members of the plant community. Furthermore, this threat must be assessed by considering the overall situation of the target population. Thus, in E. paularense, the strong limitation of safe-sites for seedling establishment reduces the importance of seed predation.

  4. Size-selective predation and predator-induced life-history shifts alter the outcome of competition between planktonic grazers

    NARCIS (Netherlands)

    Hülsmann, S.; Rinke, K.; Mooij, W.M.

    2011-01-01

    1.We studied the effect of size-selective predation on the outcome of competition between two differently sized prey species in a homogenous environment. 2. Using a physiologically structured population model, we calculated equilibrium food concentrations for a range of predation scenarios defined b

  5. Do Predators Always Win? Starfish versus Limpets: A Hands-On Activity Examining Predator-Prey Interactions

    Science.gov (United States)

    Faria, Claudia; Boaventura, Diana; Galvao, Cecilia; Chagas, Isabel

    2011-01-01

    In this article we propose a hands-on experimental activity about predator-prey interactions that can be performed both in a research laboratory and in the classroom. The activity, which engages students in a real scientific experiment, can be explored not only to improve students' understanding about the diversity of anti-predator behaviors but…

  6. Do Predators Always Win? Starfish versus Limpets: A Hands-On Activity Examining Predator-Prey Interactions

    Science.gov (United States)

    Faria, Claudia; Boaventura, Diana; Galvao, Cecilia; Chagas, Isabel

    2011-01-01

    In this article we propose a hands-on experimental activity about predator-prey interactions that can be performed both in a research laboratory and in the classroom. The activity, which engages students in a real scientific experiment, can be explored not only to improve students' understanding about the diversity of anti-predator behaviors but…

  7. Vertebrate predators have minimal cascading effects on plant production or seed predation in an intact grassland ecosystem

    Science.gov (United States)

    John L. Maron; Dean E. Pearson

    2011-01-01

    The strength of trophic cascades in terrestrial habitats has been the subject of considerable interest and debate. We conducted an 8-year experiment to determine how exclusion of vertebrate predators, ungulates alone (to control for ungulate exclusion from predator exclusion plots) or none of these animals influenced how strongly a three-species assemblage of rodent...

  8. Hunters of the Ice Age: The biology of Upper Paleolithic people.

    Science.gov (United States)

    Holt, Brigitte M; Formicola, Vincenzo

    2008-01-01

    The Upper Paleolithic represents both the phase during which anatomically modern humans appeared and the climax of hunter-gatherer cultures. Demographic expansion into new areas that took place during this period and the diffusion of burial practices resulted in an unprecedented number of well-preserved human remains. This skeletal record, dovetailed with archeological, environmental, and chronological contexts, allows testing of hypotheses regarding biological processes at the population level. In this article, we review key studies about the biology of Upper Paleolithic populations based primarily on European samples, but integrating information from other areas of the Old World whenever possible. Data about cranial morphology, skeletal robusticity, stature, body proportions, health status, diet, physical activity, and genetics are evaluated in Late Pleistocene climatic and cultural contexts. Various lines of evidence delineate the Last Glacial Maximum (LGM) as a critical phase in the biological and cultural evolution of Upper Paleolithic populations. The LGM, a long phase of climatic deterioration culminating around 20,000 BP, had a profound impact on the environment, lifestyle, and behavior of human groups. Some of these effects are recorded in aspects of skeletal biology of these populations. Groups living before and after the LGM, Early Upper Paleolithic (EUP) and Late Upper Paleolithic (LUP), respectively, differ significantly in craniofacial dimensions, stature, robusticity, and body proportions. While paleopathological and stable isotope data suggest good health status throughout the Upper Paleolithic, some stress indicators point to a slight decline in quality of life in LUP populations. The intriguing and unexpected incidence of individuals affected by congenital disorders probably indicates selective burial practices for these abnormal individuals. While some of the changes observed can be explained through models of biocultural or environmental

  9. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet.

    Science.gov (United States)

    Frassetto, L A; Schloetter, M; Mietus-Synder, M; Morris, R C; Sebastian, A

    2009-08-01

    The contemporary American diet figures centrally in the pathogenesis of numerous chronic diseases-'diseases of civilization'. We investigated in humans whether a diet similar to that consumed by our preagricultural hunter-gatherer ancestors (that is, a paleolithic type diet) confers health benefits. We performed an outpatient, metabolically controlled study, in nine nonobese sedentary healthy volunteers, ensuring no weight loss by daily weight. We compared the findings when the participants consumed their usual diet with those when they consumed a paleolithic type diet. The participants consumed their usual diet for 3 days, three ramp-up diets of increasing potassium and fiber for 7 days, then a paleolithic type diet comprising lean meat, fruits, vegetables and nuts, and excluding nonpaleolithic type foods, such as cereal grains, dairy or legumes, for 10 days. Outcomes included arterial blood pressure (BP); 24-h urine sodium and potassium excretion; plasma glucose and insulin areas under the curve (AUC) during a 2 h oral glucose tolerance test (OGTT); insulin sensitivity; plasma lipid concentrations; and brachial artery reactivity in response to ischemia. Compared with the baseline (usual) diet, we observed (a) significant reductions in BP associated with improved arterial distensibility (-3.1+/-2.9, P=0.01 and +0.19+/-0.23, P=0.05);(b) significant reduction in plasma insulin vs time AUC, during the OGTT (P=0.006); and (c) large significant reductions in total cholesterol, low-density lipoproteins (LDL) and triglycerides (-0.8+/-0.6 (P=0.007), -0.7+/-0.5 (P=0.003) and -0.3+/-0.3 (P=0.01) mmol/l respectively). In all these measured variables, either eight or all nine participants had identical directional responses when switched to paleolithic type diet, that is, near consistently improved status of circulatory, carbohydrate and lipid metabolism/physiology. Even short-term consumption of a paleolithic type diet improves BP and glucose tolerance, decreases insulin

  10. Stationary distribution and periodic solution for stochastic predator-prey systems with nonlinear predator harvesting

    Science.gov (United States)

    Zuo, Wenjie; Jiang, Daqing

    2016-07-01

    In this paper, we investigate the dynamics of the stochastic autonomous and non-autonomous predator-prey systems with nonlinear predator harvesting respectively. For the autonomous system, we first give the existence of the global positive solution. Then, in the case of persistence, we prove that there exists a unique stationary distribution and it has ergodicity by constructing a suitable Lyapunov function. The result shows that, the relatively weaker white noise will strengthen the stability of the system, but the stronger white noise will result in the extinction of one or two species. Particularly, for the non-autonomous periodic system, we show that there exists at least one nontrivial positive periodic solution according to the theory of Khasminskii. Finally, numerical simulations illustrate our theoretical results.

  11. Sustainability and optimal control of an exploited prey predator system through provision of alternative food to predator.

    Science.gov (United States)

    Kar, T K; Ghosh, Bapan

    2012-08-01

    In the present paper, we develop a simple two species prey-predator model in which the predator is partially coupled with alternative prey. The aim is to study the consequences of providing additional food to the predator as well as the effects of harvesting efforts applied to both the species. It is observed that the provision of alternative food to predator is not always beneficial to the system. A complete picture of the long run dynamics of the system is discussed based on the effort pair as control parameters. Optimal augmentations of prey and predator biomass at final time have been investigated by optimal control theory. Also the short and large time effects of the application of optimal control have been discussed. Finally, some numerical illustrations are given to verify our analytical results with the help of different sets of parameters.

  12. Prey-Predator Three Species Model Using Predator Harvesting Holling Type II Functional

    Science.gov (United States)

    Vijaya, S.; Rekha, E.

    2016-07-01

    This paper presents three species harvesting model in which there is one predator species and two others are prey species. We derive boundedness and equilibrium point for this system. Also we derive the stability of this system analytically. We find bifurcation for this system. We have derived the binomic equilibrium point by using Pontryagin’s maximum principle (PMP). Presented are various suitable analytical and numerical examples with Maple 18 programming.

  13. Novel trophic cascades: apex predators enable coexistence.

    Science.gov (United States)

    Wallach, Arian D; Ripple, William J; Carroll, Scott P

    2015-03-01

    Novel assemblages of native and introduced species characterize a growing proportion of ecosystems worldwide. Some introduced species have contributed to extinctions, even extinction waves, spurring widespread efforts to eradicate or control them. We propose that trophic cascade theory offers insights into why introduced species sometimes become harmful, but in other cases stably coexist with natives and offer net benefits. Large predators commonly limit populations of potentially irruptive prey and mesopredators, both native and introduced. This top-down force influences a wide range of ecosystem processes that often enhance biodiversity. We argue that many species, regardless of their origin or priors, are allies for the retention and restoration of biodiversity in top-down regulated ecosystems.

  14. Predation of Threespine Stickleback by Dragonfly Naiads.

    Science.gov (United States)

    Lescak, Emily A; von Hippel, Frank A; Lohman, Brian K; Sherbick, Mary L

    2012-10-01

    Threespine stickleback (Gasterosteus aculeatus) populations that have evolved pelvic girdle reduction are most commonly found in lakes with low dissolved ion concentration, a lack of piscivorous fishes, and abundant macroinvertebrate predators. Researchers have speculated that macroinvertebrates have a propensity to consume prey with pelvic spines. If this is true, perhaps macroinvertebrates use the stickleback's spines to facilitate capture and manipulation. This study tested whether dragonfly naiads differentially prey upon stickleback possessing either a complete or reduced pelvis and documented naiad hunting and capturing behavior. Results from an arena experiment suggest that naiads do not prey more heavily upon individuals with one pelvic phenotype over the other. However, results from trials where the naiads were presented with one stickleback with pelvic spines and another without suggest that naiads prey more heavily upon small stickleback with pelvic spines and large stickleback without pelvic spines and that they adjust their predatory behavior based upon the pelvic phenotype of the prey.

  15. Active predation by Greenland shark Somniosus microcephalus

    DEFF Research Database (Denmark)

    Nielsen, Julius; hedeholm, Rasmus; Simon, Malene

    2013-01-01

    Dansk Havforskermøde 2013 Julius Nielsen, Rasmus Hedeholm, Malene Simon og John Fleng Steffensen The Greenland shark is ubiquitous in the northern part of the North Atlantic ranging from eastern Canada to northwest Russia . Although knowledge is scarce it is believed to be abundant and potentially...... important part of the ecosystem. Whether Greenland sharks in general should be considered opportunistic scavengers or active predators is therefore important in understanding ecosystem dynamics. Due to its sluggish appearance and a maximum reported swimming speed of 74 cm per second scavenging seems...... the most likely feeding strategy. However, recent studies suggest that Greenland sharks in some areas feed actively upon seals . Feeding ecology is poorly described in Greenland waters. In this study we provide information on feeding habits of 29 sharks caught in Greenland waters in the summer 2012...

  16. Bumblebees (Bombus terrestris) use social information as an indicator of safety in dangerous environments

    Science.gov (United States)

    Dawson, Erika H.; Chittka, Lars

    2014-01-01

    Avoiding predation is one of the most important challenges that an animal faces. Several anti-predation behaviours can be employed, yet simply using the presence of conspecifics can be a good signal of safety in an environment with potential predation hazards. Here, we show, for the first time, that past experience of predation causes bumblebees (Bombus terrestris) to aggregate with conspecifics, facilitating the identification of safe foraging patches. Bees were trained to differentiate between flowers that harboured predators and flowers that were predator free. When test subjects were subsequently presented solely with the previously predator-infested flower species, there was a significant preference to only land on flowers occupied by other feeding conspecifics. Yet, when safe flowers were made available to subjects previously entrained to discriminate safe from predator-occupied flowers, subjects ignored other bees and the social information potentially provided by them, demonstrating that attraction towards conspecifics is confined to dangerous situations. Our findings demonstrate a previously unknown social interaction in pollinators which may have important implications for plant–pollinator interactions. PMID:24789891

  17. Planet Hunters: The First Two Planet Candidates Identified by the Public using the Kepler Public Archive Data

    CERN Document Server

    Fisher, Debra; Schawinski, Kevin; Lintott, Chris; Brewer, John; Giguere, Matt; Lynn, Stuart; Parrish, Michael; Sartori, Thibault; Simpson, Robert; Smith, Arfon; Spronck, Julien; Batalha, Natalie; Rowe, Jason; Jenkins, Jon; Bryson, Steve; Prsa, Andrej; Tenenbaum, Peter; Crepp, Justin; Morton, Tim; Howard, Andrew; Beleu, Michele; Kaplan, Zachary; vanNispen, Nick; Sharzer, Charlie; DeFouw, Justin; Hajduk, Agnieszka; Neal, Joe; Nemec, Adam; Schuepbach, Nadine; Zimmermann, Valerij

    2011-01-01

    Planet Hunters is a new citizen science project, designed to engage the public in an exoplanet search using NASA Kepler public release data. In the first month after launch, users identified two new planet candidates which survived our checks for false- positives. The follow-up effort included analysis of Keck HIRES spectra of the host stars, analysis of pixel centroid offsets in the Kepler data and adaptive optics imaging at Keck using NIRC2. Spectral synthesis modeling coupled with stellar evolutionary models yields a stellar density distribution, which is used to model the transit orbit. The orbital periods of the planet candidates are 9.8844 ±0.0087 days (KIC 10905746) and 49.7696 ±0.00039 (KIC 6185331) days and the modeled planet radii are 2.65 and 8.05 R⊕. The involvement of citizen scientists as part of Planet Hunters is therefore shown to be a valuable and reliable tool in exoplanet detection.

  18. Speculation on the timing and nature of Late Pleistocene hunter-gatherer colonization of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    P. J. Brantingham; MA Haizhou; J. W. Olsen; GAO Xing; D. B. Madsen; D. E. Rhode

    2003-01-01

    Hunter-gatherer populations in greater northeast Asia experienced dramatic range expansions during the early Upper Paleolithic (45-22 ka) and the late Upper Paleolithic (18-10 ka), both of which led to intensive occupations of cold desert environments including the Mongolian Gobi and northwest China. Range contractions under the cold, arid extremes of the Last Glacial Maximum (LGM, 22-18 ka) may have entailed widespread population extirpations. The high elevation Qinghai-Tibetan Plateau is significantly more extreme in both climate and environment than either the Gobi or the Siberian taiga forests, and provides an ideal setting to test fundamental models of human biogeog-raphy in the context of regional population fluctuations. The area is presently occupied primarily by nomadic pastoralists, but it is clear that these complex middle Holocene (<6 ka) economic adaptations were not a necessary prerequisite for successful colonization of the high elevation Plateau. Exploratory field-work in 2000-2001 has established that Upper Paleolithic hunter-gatherers were present on the Qinghai-Tibetan Plateau by at least 12 ka and possibly much earlier. Aspeculative model for the colonization process is developed and preliminary archaeological data in support of the model are presented.

  19. The issue of socioeconomic complexity in the mesolithic hunter-gatherer communities of the middle and upper Ebro valley

    Directory of Open Access Journals (Sweden)

    García-Martínez de Lagrán, Íñigo

    2008-12-01

    Full Text Available In recent decades several hunter-gatherer groups have been defined, from ethnography and archaeology, as complex socioeconomic communities. This article reviews the main definitions of complexity and its principal feature contrasting them with the archaeological record of the Mesolithic in the Ebro valley. The main goal of this paper is to find out if these hunter-gatherer communities show indications of a certain socioeconomic complexity.

    En las últimas décadas se han definido en el ámbito etnográfico y arqueológico diferentes comunidades de cazadores-recolectores que presentan una organización socioeconómica compleja. En el presente trabajo se hace un repaso a las principales definiciones de esta complejidad y a sus rasgos fundamentales aplicándolos al registro actual del Mesolítico en la Alta y Media Cuenca del Ebro. El objetivo principal es determinar si estas comunidades de cazadores-recolectores presentan rasgos definitorios de una cierta complejidad socioeconómica.

  20. Ethnotaxonomy of mastofauna as practised by hunters of the municipality of Paulista, state of Paraíba-Brazil

    Science.gov (United States)

    Mourão, José S; Araujo, Helder FP; Almeida, Fabiana S

    2006-01-01

    It was aimed in the present work to report aspects related to identification, naming and categorization of the mastofauna species of the caatinga biome, according to hunters' knowledge of Northeast Brazil. The methods of free and semi-structured interviews and guided tours were applied here. The data obtained were analyzed under the emic/etic point of view by comparing the local people's knowledge to those reported in the literature. The inland hunters use some classification models of mammals living around them as for example the folk taxonomy, and a categorization based on the animal utility. Some species are preferably hunted for providing food while others are hunted for therapeutic ends. Hunt techniques were made evident by the informers. The retrieval and comprehension of the whole process related to such knowledge is very important to evaluate the human culture and the protection that people exert on local biodiversity, since these aspects have implications for the conservation and management of faunistic resources. PMID:16603080