WorldWideScience

Sample records for achieve high foraging

  1. Effect of forage quality in faeces from different ruminant species fed high and low quality forage

    DEFF Research Database (Denmark)

    Jalali, A R; Nørgaard, P; Nielsen, M O;

    2010-01-01

    Effect of forage quality in faeces from different ruminant species fed high and low quality forage......Effect of forage quality in faeces from different ruminant species fed high and low quality forage...

  2. Bust economics: foragers choose high quality habitats in lean times

    Science.gov (United States)

    Dickman, Christopher R.

    2016-01-01

    In environments where food resources are spatially variable and temporarily impoverished, consumers that encounter habitat patches with different food density should focus their foraging initially where food density is highest before they move to patches where food density is lower. Increasing missed opportunity costs should drive individuals progressively to patches with lower food density as resources in the initially high food density patches deplete. To test these expectations, we assessed the foraging decisions of two species of dasyurid marsupials (dunnarts: Sminthopsis hirtipes and S. youngsoni) during a deep drought, or bust period, in the Simpson Desert of central Australia. Dunnarts were allowed access to three patches containing different food densities using an interview chamber experiment. Both species exhibited clear preference for the high density over the lower food density patches as measured in total harvested resources. Similarly, when measuring the proportion of resources harvested within the patches, we observed a marginal preference for patches with initially high densities. Models analyzing behavioral choices at the population level found no differences in behavior between the two species, but models analyzing choices at the individual level uncovered some variation. We conclude that dunnarts can distinguish between habitat patches with different densities of food and preferentially exploit the most valuable. As our observations were made during bust conditions, experiments should be repeated during boom times to assess the foraging economics of dunnarts when environmental resources are high. PMID:26839751

  3. Model of high-productive varieties in forage pea

    Directory of Open Access Journals (Sweden)

    Valentin Kosev

    2015-06-01

    Full Text Available A linear equation of regression was used for establishment of the influence of quantitative characteristics on the grain productivity in forage pea and for development of a model for breeding work. The model for pea plant with high productivity was characterized by average height of 60–70 cm, 8–10 formed pods, 30–40 seeds per plant and 160–260 g in regard to 1000-seed weight. The obtained results showed that the greatest effect on grain productivity had the seed number per plant, first pod height and 1000-seed weight. Kristal variety had high ecological plasticity and could be considered as close to an ideal type, suitable for growing under wide range of environments. Pleven 4 and Rezonator were determined as high-productive varieties and with low stability, Kerpo and Pikardi - as low-productive but stable varieties. Druzba was identified as unstable and low-productive variety.

  4. Management and assessment of ensiled forages and high-moisture grain.

    Science.gov (United States)

    Seglar, William J; Shaver, Randy D

    2014-11-01

    Various forage and grain crops are grown, harvested, and fed to dairy cattle as ensiled forages or high-moisture grains. Although the nutritional value of hybrids and varieties is influenced by genetic inheritability, the crop growing environment dictates the outcome of forage quality, affecting nutrient digestibility. How the crop is managed based on its stage of harvest maturity and dry matter, along with key ensiling management factors, also determine the nutritional quality of fermented forages and grains. Veterinary practitioners can implement silage quality evaluations as part of a nutritional consultation service to help dairy clients maximize dairy performance and efficiencies. PMID:25245612

  5. Improved forage strategies for high-yielding dairy cows in Vietnam : report of a workshop

    NARCIS (Netherlands)

    Wouters, A.P.; Lee, van der J.

    2013-01-01

    This report presents results of the workshop "Improved forage strategies for high-yielding dairy cows in Vietnam" which was held with Vietnamese stakeholders on January 17-18, 2013 in Ho Chi Minh City as part of the project "Forage and Grass Production for Dairy Development in Vietnam" funded by the

  6. Mathematics Achievement in High- and Low-Achieving Secondary Schools

    Science.gov (United States)

    Mohammadpour, Ebrahim; Shekarchizadeh, Ahmadreza

    2015-01-01

    This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the…

  7. Climatic and management factors affecting the forage yield and quality of a high density mulberry forage bank established under low input tropical farming conditions

    OpenAIRE

    Martin-Martin, Giraldo

    2015-01-01

    Effects of year season (SEAS), organic fertilization (N) and harvest frequency (FREQ) on forage yield and composition were evaluated in a high density mulberry forage bank, established under low input tropical farming conditions. The experiment, replicated 2 consecutive years, was arranged in 18 treatments resulting from a 3 × 3 × 2 factorial design combining 3 FREQ (60, 90 and 120 d), 3 N rates (100, 300 and 500 kg N/ha/year) and the 2 seasons (RAIN and DRY). Forage yield, leaf to stem ratio...

  8. Catholic High Schools and Rural Academic Achievement.

    Science.gov (United States)

    Sander, William

    1997-01-01

    A study of national longitudinal data examined effects of rural Catholic high schools on mathematics achievement, high school graduation rates, and the likelihood that high school graduates attend college. Findings indicate that rural Catholic high schools had a positive effect on mathematics test scores and no effect on graduation rates or rates…

  9. Low and high achievers in math

    DEFF Research Database (Denmark)

    Overgaard, Steffen; Tonnesen, Pia Beck; Weng, Peter;

    2015-01-01

    In this session we will present the results of the preliminary analysis of the qualitative and quantitative data, which can be used to enhance the teaching of low and high mathematics achievers so as to increase their mathematical knowledge and confidence.......In this session we will present the results of the preliminary analysis of the qualitative and quantitative data, which can be used to enhance the teaching of low and high mathematics achievers so as to increase their mathematical knowledge and confidence....

  10. Identifying learning techniques among high achievers

    Directory of Open Access Journals (Sweden)

    Shanmukananda P

    2013-04-01

    Full Text Available Background: In every college, it is noticed that in spite of being exposed to the same teaching modalities and adopting seemingly similar strategies, some students perform much better than their peers. This can be evaluated in the form of better academic performance in the internal assessments they undertake. This project is an endeavor to identify the learning techniques among high achievers which they employ to outperform others. We can also suggest the same to the medium and low achievers so that they can improve their academic performance. This study was conducted to identify different learning techniques adopted by high achievers and suggesting the same to medium and low achievers. Methods: After obtaining clearance from the institutional ethics committee, the high achievers were identified by selecting the upper third of the students in the ascending order of marks obtained in the consecutive three internal assessments in three consecutive batches. The identity of the students was not revealed. They were then administered an open ended questionnaire which addressed relevant issues. The most common and feasible techniques will be suggested to the medium and low achievers. Results: The respondents’ (n=101 replies were analyzed by calculating the percentages of responses, and assessing based on that, which were the most frequently adapted techniques by these high achievers Conclusions: High-achievers have a diligent study pattern; they not only study regularly, but also involve in group discussions and approach their teachers when in doubt. Additionally, they refer to other sources of information like the internet, demonstrating a proactive attitude towards studies. [Int J Basic Clin Pharmacol 2013; 2(2.000: 203-207

  11. Identifying learning techniques among high achievers

    OpenAIRE

    Shanmukananda P; L. Padma

    2013-01-01

    Background: In every college, it is noticed that in spite of being exposed to the same teaching modalities and adopting seemingly similar strategies, some students perform much better than their peers. This can be evaluated in the form of better academic performance in the internal assessments they undertake. This project is an endeavor to identify the learning techniques among high achievers which they employ to outperform others. We can also suggest the same to the medium and low achievers ...

  12. Student Perceptions of High-Achieving Classmates

    Science.gov (United States)

    Händel, Marion; Vialle, Wilma; Ziegler, Albert

    2013-01-01

    The reported study investigated students' perceptions of their high-performing classmates in terms of intelligence, social skills, and conscientiousness in different school subjects. The school subjects for study were examined with regard to cognitive, physical, and gender-specific issues. The results show that high academic achievements in…

  13. Ultra-High Foraging Rates of Harbor Porpoises Make Them Vulnerable to Anthropogenic Disturbance.

    Science.gov (United States)

    Wisniewska, Danuta Maria; Johnson, Mark; Teilmann, Jonas; Rojano-Doñate, Laia; Shearer, Jeanne; Sveegaard, Signe; Miller, Lee A; Siebert, Ursula; Madsen, Peter Teglberg

    2016-06-01

    The question of how individuals acquire and allocate resources to maximize fitness is central in evolutionary ecology. Basic information on prey selection, search effort, and capture rates are critical for understanding a predator's role in its ecosystem and for predicting its response to natural and anthropogenic disturbance. Yet, for most marine species, foraging interactions cannot be observed directly. The high costs of thermoregulation in water require that small marine mammals have elevated energy intakes compared to similar-sized terrestrial mammals [1]. The combination of high food requirements and their position at the apex of most marine food webs may make small marine mammals particularly vulnerable to changes within the ecosystem [2-4], but the lack of detailed information about their foraging behavior often precludes an informed conservation effort. Here, we use high-resolution movement and prey echo recording tags on five wild harbor porpoises to examine foraging interactions in one of the most metabolically challenged cetacean species. We report that porpoises forage nearly continuously day and night, attempting to capture up to 550 small (3-10 cm) fish prey per hour with a remarkable prey capture success rate of >90%. Porpoises therefore target fish that are smaller than those of commercial interest, but must forage almost continually to meet their metabolic demands with such small prey, leaving little margin for compensation. Thus, for these "aquatic shrews," even a moderate level of anthropogenic disturbance in the busy shallow waters they share with humans may have severe fitness consequences at individual and population levels. PMID:27238281

  14. What Characterises High Achieving Students’ Mathematical Reasoning?

    OpenAIRE

    Haavold, Per Øystein

    2011-01-01

    This study investigates high achieving students’ mathematical reasoning when given an unfamiliar trigonometric equation. The findings indicate that the students’ way of thinking is strongly linked with imitative reasoning and only when they received some form of guidance, were they able to display flexible and creative mathematical reasoning.

  15. Paternal kin recognition in the high frequency / ultrasonic range in a solitary foraging mammal

    OpenAIRE

    Kessler Sharon E; Scheumann Marina; Nash Leanne T; Zimmermann Elke

    2012-01-01

    Abstract Background Kin selection is a driving force in the evolution of mammalian social complexity. Recognition of paternal kin using vocalizations occurs in taxa with cohesive, complex social groups. This is the first investigation of paternal kin recognition via vocalizations in a small-brained, solitary foraging mammal, the grey mouse lemur (Microcebus murinus), a frequent model for ancestral primates. We analyzed the high frequency/ultrasonic male advertisement (courtship) call and alar...

  16. Devclopment of the Forage Riees WithHigh Protein Gontent in Hunan

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The meaning of the high protein forage rices Rices may be classified by itsuses as human'sfood.animal's on poultry's feed,or the raw materials of various industries.For ricesused as people's food.its breeding objectives are focused on the varietal characters such as medium amylose content .high rale of head rice.hyaline smoothmilled grains and delicious taste:for those used in making rice meal.beer,gourmet powder,etc.specially on high amylose content:while in wine making,it should be focused on big white belly and white beart,but low protein content in particular.As for the rices used as feed,the most important is its high rate of pre -protein in the brown rice ,leaving its grain appearance out of consideration.Thcrefore,the so called forage rice (FR)sgiykd be a kind of paddy rice with high pre-protein content of brown rice(≥8.25%)and high grain yicld (≥8.25t/ha),to be used as the composition of the animal feed by applying cultivation management oplimized under the suitable growth duration and strong pest resistance.

  17. Paternal kin recognition in the high frequency / ultrasonic range in a solitary foraging mammal

    Directory of Open Access Journals (Sweden)

    Kessler Sharon E

    2012-11-01

    Full Text Available Abstract Background Kin selection is a driving force in the evolution of mammalian social complexity. Recognition of paternal kin using vocalizations occurs in taxa with cohesive, complex social groups. This is the first investigation of paternal kin recognition via vocalizations in a small-brained, solitary foraging mammal, the grey mouse lemur (Microcebus murinus, a frequent model for ancestral primates. We analyzed the high frequency/ultrasonic male advertisement (courtship call and alarm call. Results Multi-parametric analyses of the calls’ acoustic parameters and discriminant function analyses showed that advertisement calls, but not alarm calls, contain patrilineal signatures. Playback experiments controlling for familiarity showed that females paid more attention to advertisement calls from unrelated males than from their fathers. Reactions to alarm calls from unrelated males and fathers did not differ. Conclusions 1 Findings provide the first evidence of paternal kin recognition via vocalizations in a small-brained, solitarily foraging mammal. 2 High predation, small body size, and dispersed social systems may select for acoustic paternal kin recognition in the high frequency/ultrasonic ranges, thus limiting risks of inbreeding and eavesdropping by predators or conspecific competitors. 3 Paternal kin recognition via vocalizations in mammals is not dependent upon a large brain and high social complexity, but may already have been an integral part of the dispersed social networks from which more complex, kin-based sociality emerged.

  18. Academic Attitudes of High Achieving and Low Achieving Academically Able Black Male Adolescents.

    Science.gov (United States)

    Trotter, John Rhodes

    1981-01-01

    In order to identify the relationships between the attitudes and perceptions of peer pressure and the academic achievement of academically able male adolescents, this study compares the school attitudes of high achieving and low achieving Black male youth. (EF)

  19. Attitudes and Opinions from the Nation's High Achieving Teens: 26th Annual Survey of High Achievers.

    Science.gov (United States)

    Who's Who among American High School Students, Lake Forest, IL.

    A national survey of 3,351 high achieving high school students (junior and senior level) was conducted. All students had A or B averages. Topics covered include lifestyles, political beliefs, violence and entertainment, education, cheating, school violence, sexual violence and date rape, peer pressure, popularity, suicide, drugs and alcohol,…

  20. Achieving High Data Throughput in Research Networks

    Institute of Scientific and Technical Information of China (English)

    WarrenMatthews; LesCottrell

    2001-01-01

    After less than a year of operation ,the BaBar experiment at SLAC has collected almost 100 million particle collision events in a database approaching 165TB.Around 20 TB of data has been exported via the Internet to the BaBar regional center at IN2P3 in Lyon,France,and around 40TB of simulated data has been imported from the Lawrence Livermore National Laboratory(LLNL),BaBar Collaborators plan to double data collection each year and export a third of the data to IN2P3.So within a few years the SLAC OC3 (155Mbps) connection will be fully utilized by file transfer to France alone.Upgrades to infrastructure is essential and detailed understanding of performance issues and the requirements for reliable high throughput transfers is critical.In this talk results from active and passive monitoring and direct measurements of throughput will be reviewed.Methods for achieving the ambitious requirements will be discussed.

  1. Bed disturbance via foraging fish increases bedload transport during subsequent high flows and is controlled by fish size and species

    Science.gov (United States)

    Pledger, A. G.; Rice, S. P.; Millett, J.

    2016-01-01

    Benthic foraging by fish can modify the nature and rates of fine sediment accrual and the structure and topography of coarse-grained fluvial substrates, with the potential to alter bed material characteristics, particle entrainment thresholds, and bedload transport fluxes. However, knowledge of what controls the nature, extent, and intensity of benthic foraging and the consequent influence of these controls on geomorphic impact remain rudimentary. An ex-situ experiment utilising Barbel Barbus barbus and Chub Leuciscus cephalus extended previous work by considering the role of fish size and species as controls of sediment disturbance by foraging and the implications for bed material characteristics and bedload transport. In a laboratory flume, changes in bed microtopography and structure were measured when a water-worked bed of 5.6-22.6 mm gravels was exposed to four size classes of Barbel (4-5″, 5-6″, 6-8″, 8-10″ in length) and a single size class of Chub (8-10″). In line with other studies that have investigated animal size as a control of zoogeomorphic agency, increasing the size of Barbel had a significant effect on measured disturbance and transport metrics. Specifically, the area of disturbed substrate, foraging depth, and the fish's impact on microtopographic roughness and imbrication all increased as a function of fish size. In a comparison of the foraging effects of like-sized Barbel and Chub, 8-10″ in length, Barbel foraged a larger area of the test bed and had a greater impact on microtopographic roughness and sediment structure. Relative to water-worked beds that were not foraged, bed conditioning by both species was associated with increased bedload transport during the subsequent application of high flows. However, the bedload flux after foraging by Barbel, which is a specialist benthivore, was 150% higher than that following foraging by Chub, which feed opportunistically from the bed, and the total transported mass of sediment was 98

  2. High Involvement Mothers of High Achieving Children: Potential Theoretical Explanations

    Science.gov (United States)

    Hunsaker, Scott L.

    2013-01-01

    In American society, parents who have high aspirations for the achievements of their children are often viewed by others in a negative light. Various pejoratives such as "pushy parent," "helicopter parent," "stage mother," and "soccer mom" are used in the common vernacular to describe these parents. Multiple…

  3. Ultra-high foraging rates of harbour porpoises make them vulnerable to anthropogenic disturbance

    DEFF Research Database (Denmark)

    Wisniewska, Danuta; Johnson, Mark; Teilmann, Jonas;

    2016-01-01

    and prey echo recording tags on five wild harbour porpoises to examine foraging interactions in one of the most metabolically challenged cetacean species. We report that porpoises forage nearly continuously day and night, attempting to capture up to 550 small (3-10 cm) fish prey per hour with a...

  4. Does High School Homework Increase Academic Achievement?

    OpenAIRE

    Kalenkoski, Charlene Marie; Wulff Pabilonia, Sabrina

    2014-01-01

    Although previous research has shown that homework improves students' academic achievement, the majority of these studies use data on students' homework time from retrospective questionnaires, which are less accurate than time-diary data. However, most time-diary data sets do not contain outcome measures, and thus are limited in the questions they can answer. One data set that does have both time-diary and outcome information is the combined Child Development Supplement (CDS) and the Transiti...

  5. Shallow food for deep divers: Dynamic foraging behavior of male sperm whales in a high latitude habitat

    DEFF Research Database (Denmark)

    Teloni, Valeria; Johnson, M.P.; Miller, P.J.O.;

    2008-01-01

    Groups of female and immature sperm whales live at low latitudes and show a stereotypical diving and foraging behavior with dives lasting about 45 min to depths of between 400 and 1200 m. In comparison, physically mature male sperm whales migrate to high latitudes where little is known about...

  6. Factors affecting forage stand establishment

    OpenAIRE

    Sulc R.M.

    1998-01-01

    Significant advances have been made in our knowledge of forage seed physiology, technology, and stand establishment practices; however, stand establishment continues to be one of the most common production problems affecting forage crops in the USA. There is a need for research on stand establishment of forage crops under abiotic and biotic stress. Although the forage seed industry produces and markets seed of high quality, new methods of assessing seed vigor are needed and their use should b...

  7. Early Predictors of High School Mathematics Achievement

    Science.gov (United States)

    Siegler, Robert S.; Duncan, Greg J.; Davis-Kean, Pamela E.; Duckworth, Kathryn; Claessens, Amy; Engel, Mimi; Susperreguy, Maria Ines; Meichu, Chen

    2012-01-01

    Identifying the types of mathematics content knowledge that are most predictive of students' long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students' knowledge of algebra and overall mathematics…

  8. Achieving High-Temperature Ferromagnetic Topological Insulator

    Science.gov (United States)

    Katmis, Ferhat

    Topological insulators (TIs) are insulating materials that display conducting surface states protected by time-reversal symmetry, wherein electron spins are locked to their momentum. This unique property opens new opportunities for creating next-generation electronic and spintronic devices, including TI-based quantum computation. Introducing ferromagnetic order into a TI system without compromising its distinctive quantum coherent features could lead to a realization of several predicted novel physical phenomena. In particular, achieving robust long-range magnetic order at the TI surface at specific locations without introducing spin scattering centers could open up new possibilities for devices. Here, we demonstrate topologically enhanced interface magnetism by coupling a ferromagnetic insulator (FMI) to a TI (Bi2Se3); this interfacial ferromagnetism persists up to room temperature, even though the FMI (EuS) is known to order ferromagnetically only at low temperatures (FMI bilayer system. Due to the short range nature of the ferromagnetic exchange interaction, the time-reversal symmetry is broken only near the surface of a TI, while leaving its bulk states unaffected. The topological magneto-electric response originating in such an engineered TI could allow for an efficient manipulation of the magnetization dynamics by an electric field, providing an energy efficient topological control mechanism for future spin-based technologies. Work supported by MIT MRSEC through the MRSEC Program of NSF under award number DMR-0819762, NSF Grant DMR-1207469, the ONR Grant N00014-13-1-0301, and the STC Center for Integrated Quantum Materials under NSF grant DMR-1231319.

  9. Achievement Goals, Learning Strategies and Language Achievement among Peruvian High School Students

    Directory of Open Access Journals (Sweden)

    Lennia Matos

    2007-05-01

    Full Text Available We used an achievement goal framework to study the role of motivation in the academic context of a Peruvian sample of 8th to 10th grade high school students (N = 1505. The purpose of this cross-sectional study was to examine the relationship between students' achievement goals, their use of learning strategies and their academic achievement. Multiple Hierarchical Regressions Analyses identified, as predicted, positive effects of mastery goals, including more use of learning strategies and higher academic achievement, and negative effects of performance avoidance goals, including lower academic achievement. Mixed results were found for pursuing performance approach goals, which predicted a greater use of learning strategies, but were unrelated to academic achievement. The present findings support the external validity of achievement goal theory in a sample of students from a culture that is understudied in the achievement goal literature in particular and the motivational literature in general.

  10. High sea surface temperatures driven by a strengthening current reduce foraging success by penguins.

    Science.gov (United States)

    Carroll, Gemma; Everett, Jason D; Harcourt, Robert; Slip, David; Jonsen, Ian

    2016-01-01

    The world's oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming "hotspots", we use a novel prey capture signature derived from accelerometry to understand how the warm East Australian Current shapes foraging success by a meso-predator, the little penguin. This seabird feeds on low trophic level species that are sensitive to environmental change. We found that in 2012, prey capture success by penguins was high when SST was low relative to the long-term mean. In 2013 prey capture success was low, coincident with an unusually strong penetration of warm water. Overall there was an optimal temperature range for prey capture around 19-21 °C, with lower success at both lower and higher temperatures, mirroring published relationships between commercial sardine catch and SST. Spatially, higher SSTs corresponded to a lower probability of penguins using an area, and lower prey capture success. These links between high SST and reduced prey capture success by penguins suggest negative implications for future resource availability in a system dominated by a strengthening western boundary current. PMID:26923901

  11. Achievement Goals, Learning Strategies and Language Achievement among Peruvian High School Students

    OpenAIRE

    Lennia Matos; Willy Lens; Maarten Vansteenkiste

    2007-01-01

    We used an achievement goal framework to study the role of motivation in the academic context of a Peruvian sample of 8th to 10th grade high school students (N = 1505). The purpose of this cross-sectional study was to examine the relationship between students' achievement goals, their use of learning strategies and their academic achievement. Multiple Hierarchical Regressions Analyses identified, as predicted, positive effects of mastery goals, including more use of learning strategies and hi...

  12. Evaluation of barley (hordeum vulgare l.) germplasm for high forage production under salt stress

    International Nuclear Information System (INIS)

    To explore high biomass producing salt tolerant cultivars of a potential forage crop barley (Hordeum vulgare L.), 30-day old plants of 105 different accessions from different origin were subjected to saline and non-saline (control) conditions for 45 days. Salinity stress (150 mM NaCl) markedly suppressed plant growth (shoot and/or root fresh and dry weights), chlorophyll pigments (a and b), internal CO/sub 2/ concentration, stomatal conductance, rate of transpiration and photosynthesis, while a considerable salt-induced increase was observed in all fluorescence related attributes including efficiency of photosystem-II (Fv/Fm), co-efficient of non-photochemical quenching (QN), photochemical quenching (QP), and non-photochemical quenching (NPQ) in all 105 accessions of barley. The response of all 105 barley accessions to salt stress varied significantly for all the morpho-physiological attributes determined in the present study. Overall, on the basis of shoot and root dry weights, accessions, 4050, 4053, 4056, 4163, 4228, 4229, 4244, 4245, 4290, 4414, 4415, 4427, 4452, Mahali, Jesto, 4165, 4229, 4249, 4405, 4409, 4426, 4456, and Giza 123 were found superior while accessions, 4245, 4158, 4166, 4246, 4406, 4423, 4441, 4442 4447, 4453 and 4458 inferior under saline conditions. (author)

  13. Differences in foraging ecology align with genetically divergent ecotypes of a highly mobile marine top predator.

    Science.gov (United States)

    Jeglinski, Jana W E; Wolf, Jochen B W; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz

    2015-12-01

    Foraging differentiation within a species can contribute to restricted gene flow between ecologically different groups, promoting ecological speciation. Galapagos sea lions (Zalophus wollebaeki) show genetic and morphological divergence between the western and central archipelago, possibly as a result of an ecologically mediated contrast in the marine habitat. We use global positioning system (GPS) data, time-depth recordings (TDR), stable isotope and scat data to compare foraging habitat characteristics, diving behaviour and diet composition of Galapagos sea lions from a western and a central colony. We consider both juvenile and adult life stages to assess the potential role of ontogenetic shifts that can be crucial in shaping foraging behaviour and habitat choice for life. We found differences in foraging habitat use, foraging style and diet composition that aligned with genetic differentiation. These differences were consistent between juvenile and adult sea lions from the same colony, overriding age-specific behavioural differences. Our study contributes to an understanding of the complex interaction of ecological condition, plastic behavioural response and genetic make-up of interconnected populations.

  14. Differences in foraging ecology align with genetically divergent ecotypes of a highly mobile marine top predator.

    Science.gov (United States)

    Jeglinski, Jana W E; Wolf, Jochen B W; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz

    2015-12-01

    Foraging differentiation within a species can contribute to restricted gene flow between ecologically different groups, promoting ecological speciation. Galapagos sea lions (Zalophus wollebaeki) show genetic and morphological divergence between the western and central archipelago, possibly as a result of an ecologically mediated contrast in the marine habitat. We use global positioning system (GPS) data, time-depth recordings (TDR), stable isotope and scat data to compare foraging habitat characteristics, diving behaviour and diet composition of Galapagos sea lions from a western and a central colony. We consider both juvenile and adult life stages to assess the potential role of ontogenetic shifts that can be crucial in shaping foraging behaviour and habitat choice for life. We found differences in foraging habitat use, foraging style and diet composition that aligned with genetic differentiation. These differences were consistent between juvenile and adult sea lions from the same colony, overriding age-specific behavioural differences. Our study contributes to an understanding of the complex interaction of ecological condition, plastic behavioural response and genetic make-up of interconnected populations. PMID:26307593

  15. Nutrient Utilization, Lactational Performance, and Profitability of Dairy Cows by Feeding Protein Supplements in High-Forage Lactation Diets

    OpenAIRE

    Neal, Kathryn

    2014-01-01

    Due to the increasing cost of soybean meal and concerns of excess N being excreted into the environment, new protein supplements have been developed. Two products that have shown potential in increasing N utilization efficiency are slow release urea (SRU; Optigen) and ruminal escape protein derived from yeast (YMP; DEMP). The objective of this study was to assess the effects of feeding these 2 supplements in high-forage [(54% of total dietary dry matter (DM)] dairy diets on nutrient utilizati...

  16. Foraging segregation and genetic divergence between geographically proximate colonies of a highly mobile seabird

    Science.gov (United States)

    Wiley, Anne E.; Welch, Andreanna J.; Ostrom, P.H.; James, Helen F.; Stricker, C.A.; Fleischer, R.C.; Gandhi, H.; Adams, J.; Ainley, D.G.; Duvall, F.; Holmes, N.; Hu, D.; Judge, S.; Penniman, J.; Swindle, K.A.

    2012-01-01

    Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (?? 13C, ?? 15N and ??D, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with ?? ST = 0. 50 (p focus of conservation strategies. ?? 2011 Springer-Verlag (outside the USA).

  17. Daily torpor in mice : high foraging costs trigger energy-saving hypothermia

    NARCIS (Netherlands)

    Schubert, Kristin A.; Boerema, Ate S.; Vaanholt, Lobke M.; de Boer, Sietse F.; Strijkstra, Arjen M.; Daan, Serge

    2010-01-01

    Many animal species employ natural hypothermia in seasonal (hibernation) and daily (torpor) strategies to save energy. Facultative daily torpor is a typical response to fluctuations in food availability, but the relationship between environmental quality, foraging behaviour and torpor responses is p

  18. Mobility and Student Achievement in High Poverty Schools

    Science.gov (United States)

    Dalton, Janet Denise

    2013-01-01

    Student mobility is an issue for high poverty schools in the shadow of increased rigor and accountability for student performance. Whereas mobility is not a sole cause for poor achievement, it is a contributing factor for students in poverty who are already considered to be at risk of low achievement. Student mobility creates a hardship for…

  19. High sea surface temperatures driven by a strengthening current reduce foraging success by penguins

    OpenAIRE

    Gemma Carroll; Everett, Jason D.; Robert Harcourt; David Slip; Ian Jonsen

    2016-01-01

    The world’s oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming “hotspots”, we use a novel prey capture signature derived from accelerometry to understand how the warm East Australian Current shapes foraging success by a meso-predator, th...

  20. Utilization of complete rumen modifier on sheep fed high fibrous forages.

    Directory of Open Access Journals (Sweden)

    Amlius Thalib

    2010-06-01

    Full Text Available A research to improve livestock productivity and lower enteric methane production on ruminant was conducted by manipulation approach on rumen system using a complete rumen modifier (CRM. An in vivo experiment was carried out using twenty four sheep ( mean weight 18 kg which were distributed into 3 treatment groups of feed additive: I. control ( without treatment: K; II: K + CRM-LG; III: K + CRM-EL. Diet given consisted of fermented rice straw (ad libitum + concentrate containing 16 % protein (400 g/head/day, and drinking water was given ad libitum. The experiment was conducted for 14 weeks based on completely randomized design. By the end of the experiment, animals were placed in the metabolism cages for 2 weeks (ie. 1 week for adaptation and 1 week for data collection. Rumen liquid of each treated animal was taken for the measurement of rumen characteristics. Parameter measuremed were: total gas production; gas composition of CO2 and CH4; in vitro DMD; NH3 and VFA contents; pH; bacterial and protozoal counts; consumption/ DMI; in vivo DMD; ADG and FCR. The results showed that productivity of sheep was improved by CRM treatments followed by lowered enteric methane production. The ADG values of CRM treatments (71.4 to 73.5 g were significantly higher (P < 0.05 than that of control (50 g. The improvement of average daily gain was followed by a better feed conversion (P < 0.05 (ie. 10.6 vs. 12.8. The CRM treatments lowered the percentage of CH4 by 24% compared to Control (P < 0.05. The total and composition of VFA of CRM-treated rumen liquor were significantly different (P<0.05 compared to that of rumen liquor of Control (ie. the total VFA: 85.3 vs 73.5 mM and the percentage of acetic acid: 67.8 vs 60.3%. It is concluded that CRM treatment resulted in positive effects on growth of ruminant fed high fibrous forages such as rice straw and could lower enteric methane production.

  1. The "Renaissance Child": High Achievement and Gender in Late Modernity

    Science.gov (United States)

    Skelton, Christine; Francis, Becky

    2012-01-01

    This paper draws on the concept of the "Renaissance Child" to illustrate the ways in which gender influences the opportunities and possibilities of high-achieving pupils. Using data from a study of 12-13-year high-achieving boys and girls based in schools in England, the paper considers the ways in which a group of popular boys was able to show an…

  2. A review on studies in forage in China

    Institute of Scientific and Technical Information of China (English)

    LONG Wenxing; YANG Xiaobo; QI Meiying

    2007-01-01

    A review is made of the achievements in the collection,conservation,and genetic diversity of forage germplasm resources;methods and goals for forage breeding;and development and utilization of forage in China.The current problems based on the researches in forage are analyzed,and some suggestions are put forward.

  3. High School Employment and Academic Achievement: A Note for Educators

    Science.gov (United States)

    Keister, Mary; Hall, Joshua

    2010-01-01

    Educators are often in a position to affect student decisions to work during the school term. This study reviews and summarizes the literature on the effect that employment during high school has on academic achievement. The available evidence suggests that part-time jobs for high school students are beneficial as long as the number of hours…

  4. Exploring High-Achieving Students' Images of Mathematicians

    Science.gov (United States)

    Aguilar, Mario Sánchez; Rosas, Alejandro; Zavaleta, Juan Gabriel Molina; Romo-Vázquez, Avenilde

    2016-01-01

    The aim of this study is to describe the images that a group of high-achieving Mexican students hold of mathematicians. For this investigation, we used a research method based on the Draw-A-Scientist Test (DAST) with a sample of 63 Mexican high school students. The group of students' pictorial and written descriptions of mathematicians assisted us…

  5. An Analysis of High School Mathematics Achievement and English Language Arts Achievement as Predictors of Science Achievement

    Science.gov (United States)

    Edwards, Anthony C.

    2012-01-01

    Science assessments require students to read and comprehend questions and to solve mathematical problems. The purpose of this study is to determine whether the following variables can be used to predict science achievement: English language arts achievement, mathematics achievement, socioeconomic status (SES), limited English proficiency (LEP)…

  6. Best Practices for Achieving High, Rapid Reading Gains

    Science.gov (United States)

    Carbo, Marie

    2008-01-01

    The percentage of students who read at the proficient level on the National Assessment of Educational Progress (NAEP) has not improved, and is appallingly low. In order for students to achieve high reading gains and become life-long readers, reading comprehension and reading enjoyment must be the top two goals. This article presents several…

  7. Relationship between High School Leadership Team Practices and Student Achievement

    Science.gov (United States)

    McInnis, Timothy M.

    2009-01-01

    This study investigated if a relationship existed between student achievement in 10th grade Missouri Assessment Program mathematics and 11th grade communication arts scores in 2007 and high school leadership team perceptions of the extent to which they demonstrated leadership practices. The secondary purpose was to compare perceptional…

  8. Self-Esteem and Academic Achievement of High School Students

    Science.gov (United States)

    Moradi Sheykhjan, Tohid; Jabari, Kamran; Rajeswari, K.

    2014-01-01

    The primary purpose of this study was to determine the influence of self-esteem on academic achievement among high school students in Miandoab City of Iran. The methodology of the research is descriptive and correlation that descriptive and inferential statistics were used to analyze the data. Statistical Society includes male and female high…

  9. Database - Student's Achievements in High School and Thereafter

    OpenAIRE

    Branislav Oreskovic; Ana Hajdic; Marko Baotic

    2005-01-01

    Computer infrastructure represented in the Croatian educational system is rather developed nowadays. It would be necessary to develop an integral information system (IIS) within the competent Ministry (Ministry of Science, Education and Sports) for the purpose of more efficient and high-quality management of the educational process itself as well as process control. In this paper by the proposed database “Students’ achievements in high school and thereafter” we describe a possible model of da...

  10. Academic achievement of junior high school students with sleep disorders

    Directory of Open Access Journals (Sweden)

    Fijri Auliyanti

    2015-01-01

    Full Text Available Background Sleep disorders are prevalent in adolescents and may influence their academic achievement. To date, no study has been done in Indonesia on academic achievement in students with sleep disorders and its related factors. Objective To assess for relationships between academic achievement and related factors, including gender, motivation and learning strategies, IQ level, maternal educational level, socioeconomic status, family structure, after-hours education program, presence of TV/computer in the bedroom, sleep duration during school days, as well as bedtime and wakeup time difference in junior high school students with sleep disorders. Methods This cross-sectional study was performed from January to March 2013. Subjects were students from five junior high schools in Jakarta who fulfilled the criteria for sleep disorders based on the Sleep Disturbance Scale for Children questionnaire. Results There were 111 study subjects. The prevalence of sleep disorders was 39.7%, mostly in difficulties initiating and maintaining sleep (70.2%. Below-average academic achievement was seen in 47.6% of subjects. Factors significantly related to below-average academic achievement were after-hours education program (prevalence ratio 5.6; 95%CI 1.36 to 23.18; P = 0.017, average IQ level (prevalence ratio 3.26; 95%CI 1.38 to 7.71; P = 0.007, and male gender (prevalence ratio 2.68; 95%CI 1.06 to 6.78; P = 0.037. Conclusion Among junior high school students with sleep disorders, factors related to below-average academic achievement are after-hours education program (more than 2 types, the average IQ level, and male gender. [Paediatr Indones. 2015;55:50-8.].

  11. Academic achievement of junior high school students with sleep disorders

    Directory of Open Access Journals (Sweden)

    Fijri Auliyanti

    2016-07-01

    Full Text Available Background Sleep disorders are prevalent in adolescents and may influence their academic achievement. To date, no study has been done in Indonesia on academic achievement in students with sleep disorders and its related factors. Objective To assess for relationships between academic achievement and related factors, including gender, motivation and learning strategies, IQ level, maternal educational level, socioeconomic status, family structure, after-hours education program, presence of TV/computer in the bedroom, sleep duration during school days, as well as bedtime and wakeup time difference in junior high school students with sleep disorders. Methods This cross-sectional study was performed from January to March 2013. Subjects were students from five junior high schools in Jakarta who fulfilled the criteria for sleep disorders based on the Sleep Disturbance Scale for Children questionnaire. Results There were 111 study subjects. The prevalence of sleep disorders was 39.7%, mostly in difficulties initiating and maintaining sleep (70.2%. Below-average academic achievement was seen in 47.6% of subjects. Factors significantly related to below-average academic achievement were after-hours education program (prevalence ratio 5.6; 95%CI 1.36 to 23.18; P = 0.017, average IQ level (prevalence ratio 3.26; 95%CI 1.38 to 7.71; P = 0.007, and male gender (prevalence ratio 2.68; 95%CI 1.06 to 6.78; P = 0.037. Conclusion Among junior high school students with sleep disorders, factors related to below-average academic achievement are afterhours education program (more than 2 types, the average IQ level, and male gender.

  12. Learning environment, motivation, and achievement in high school science

    Science.gov (United States)

    Bobbitt Nolen, Susan

    2003-04-01

    In a study of the relationship between high school students' perceptions of their science learning environments and their motivation, learning strategies, and achievement, 377 students in 22 introductory science classrooms completed surveys in the fall and spring of their ninth-grade year. Hierarchical linear regression was used to model the effects of variables at both the classroom and individual level simultaneously. High intraclass agreement (indicated by high parameter reliability) on all classroom environment measures indicated that students shared perceptions of the classroom learning environment. Controlling for other factors, shared perceptions that only the most able could succeed in science classrooms and that instruction was fast-paced and focused on correct answers negatively predicted science achievement, as measured on a districtwide curriculum-linked test. Shared perceptions that classrooms focused on understanding and independent thinking positively predicted students' self-reported satisfaction with learning. Implications of these results for both teaching and research into classroom environments are discussed.

  13. A SELF PROCESS IMPROVEMENT FOR ACHIEVING HIGH SOFTWARE QUALITY

    Directory of Open Access Journals (Sweden)

    DR. SHASHANK.D.JOSHI

    2011-05-01

    Full Text Available Quality has been one of the most important factors in judging any product. Quality means “a degree or grade of excellence or worth”. Quality is a term that is usually described using adjectives. Quality has several attributes to it, some of which can be quantified using metrics. These attributes such as usability, portability, security, performance, reliability etc have different importance in different projects. Different software quality assurance methods & practices have been used in different software projects to attain the true value. Quality is an attribute which is a distinct feature and it differs with people’s perception. Achieving high software quality involves measurement of software metrics and optimization based on estimated values. As the software systems grow larger, complexity ofdesign and implementation increases, and this in turn is more prone to defects and hence directly affect the quality of the systems. However, in any software project, high quality is always desirable, and many projects have specific quality requirements. Achieving high software quality involves measurement of software metrics and optimization based on estimated values. Developing high quality software is governed by factors such as people, process, technology and cost. This paper attempts to present a novel approach towards achieving high software quality in various kinds of projects under given constraints.

  14. Parent Involvement Practices of High-Achieving Elementary Science Students

    Science.gov (United States)

    Waller, Samara Susan

    This study addressed a prevalence of low achievement in science courses in an urban school district in Georgia. National leaders and educators have identified the improvement of science proficiency as critical to the future of American industry. The purpose of this study was to examine parent involvement in this school district and its contribution to the academic achievement of successful science students. Social capital theory guided this study by suggesting that students achieve best when investments are made into their academic and social development. A collective case study qualitative research design was used to interview 9 parent participants at 2 elementary schools whose children scored in the exceeds category on the Science CRCT. The research questions focused on what these parents did at home to support their children's academic achievement. Data were collected using a semi-structured interview protocol and analyzed through the categorical aggregation of transcribed interviews. Key findings revealed that the parents invested time and resources in 3 practices: communicating high expectations, supporting and developing key skills, and communicating with teachers. These findings contribute to social change at both the local and community level by creating a starting point for teachers, principals, and district leaders to reexamine the value of parent input in the educational process, and by providing data to support the revision of current parent involvement policies. Possibilities for further study building upon the findings of this study may focus on student perceptions of their parents' parenting as it relates to their science achievement.

  15. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings.

  16. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. PMID:26479907

  17. Achieving High Performance on the i860 Microprocessor

    Science.gov (United States)

    Lee, King; Kutler, Paul (Technical Monitor)

    1998-01-01

    The i860 is a high performance microprocessor used in the Intel Touchstone project. This paper proposes a paradigm for programming the i860 that is modelled on the vector instructions of the Cray computers. Fortran callable assembler subroutines were written that mimic the concurrent vector instructions of the Cray. Cache takes the place of vector registers. Using this paradigm we have achieved twice the performance of compiled code on a traditional solve.

  18. Forage density effect on sound insulation properties

    DEFF Research Database (Denmark)

    Green, Ole; Tortajada, Vicent Gassó; Gislum, René;

    2010-01-01

    One of the main parameters affecting forage management and quality is density. Existing methods used for measuring physical properties of forage involve costly destructive analysis. A frequent and appropriate control of the forage density is required for optimizing the management of silage, hay and...... forage density. The method has been used to analyse the correlation of the density with the sound insulation spectra produced by small-scale models of hay, silage and straw. Results show that the sound insulation spectra of forage have a high correlation with the density and a significant congruence with...

  19. Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but increase milk iodine output in early lactation dairy cows fed high-forage diets

    Science.gov (United States)

    The objective of this study was to investigate the effects of incremental amounts of Ascophyllum nodosum meal (ANOD) on milk production, milk composition including fatty acids and I, blood metabolites, and nutrient intake and digestibility in early lactation dairy cows fed high-forage diets. Twelve ...

  20. Unlocking Emergent Talent: Supporting High Achievement of Low-Income, High Ability Students

    Science.gov (United States)

    Olszewski-Kubilius, Paula; Clarenbach, Jane

    2012-01-01

    This report takes a comprehensive look at achievement for low-income promising learners--past, present, and future. At its core, it challenges the nation to move beyond its near-singular focus of achieving minimum performance for all students, to identifying and developing the talent of all students who are capable of high achievement, including…

  1. Mindmapping: Its effects on student achievement in high school biology

    Science.gov (United States)

    Cunningham, Glennis Edge

    The primary goal of schools is to promote the highest degree of learning possible. Yet teachers spend the majority of their time engaged in lecturing while students spend the majority of their time passively present (Cawelti, 1997, Grinder, 1991; Jackson & Davis, 2000; Jenkins, 1996). Helping students develop proficiency in learning, which translates into using that expertise to construct knowledge in subject domains, is a crucial goal of education. Students need exposure to teaching and learning practices that prepare them for both the classroom and their places in the future workforce (Ettinger, 1998; Longley, Goodchild, Maguire, & Rhind, 2001; NRC, 1996; Texley & Wild, 1996). The purpose of this study was to determine if achievement in high school science courses could be enhanced utilizing mindmapping. The subjects were primarily 9th and 10th graders (n = 147) at a suburban South Texas high school. A pretest-posttest control group design was selected to determine the effects of mindmapping on student achievement as measured by a teacher-developed, panel-validated instrument. Follow-up interviews were conducted with the teacher and a purposive sample of students (n = 7) to determine their perceptions of mindmapping and its effects on teaching and learning. Mindmapping is a strategy for visually displaying large amounts of conceptual, hierarchical information in a concise, organized, and accessible format. Mindmaps arrange information similar to that found on the traditional topic outline into colorful spatial displays that offer the user a view of the "forest" as well as the "trees" (Hyerle, 1996; Wandersee, 1990b). An independent samples t-test and a one-way analysis of covariance (ANCOVA) determined no significant difference in achievement between the groups. The experimental group improved in achievement at least as much as the control group. Several factors may have played a role in the lack of statistically significant results. These factors include the

  2. Computer Security: SAHARA - Security As High As Reasonably Achievable

    CERN Multimedia

    Stefan Lueders, Computer Security Team

    2015-01-01

    History has shown us time and again that our computer systems, computing services and control systems have digital security deficiencies. Too often we deploy stop-gap solutions and improvised hacks, or we just accept that it is too late to change things.    In my opinion, this blatantly contradicts the professionalism we show in our daily work. Other priorities and time pressure force us to ignore security or to consider it too late to do anything… but we can do better. Just look at how “safety” is dealt with at CERN! “ALARA” (As Low As Reasonably Achievable) is the objective set by the CERN HSE group when considering our individual radiological exposure. Following this paradigm, and shifting it from CERN safety to CERN computer security, would give us “SAHARA”: “Security As High As Reasonably Achievable”. In other words, all possible computer security measures must be applied, so long as ...

  3. Achieving High Resolution Timer Events in Virtualized Environment.

    Directory of Open Access Journals (Sweden)

    Blazej Adamczyk

    Full Text Available Virtual Machine Monitors (VMM have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service. Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events.

  4. Achieving High Resolution Timer Events in Virtualized Environment.

    Science.gov (United States)

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  5. Achieving ultra-high temperatures with a resistive emitter array

    Science.gov (United States)

    Danielson, Tom; Franks, Greg; Holmes, Nicholas; LaVeigne, Joe; Matis, Greg; McHugh, Steve; Norton, Dennis; Vengel, Tony; Lannon, John; Goodwin, Scott

    2016-05-01

    The rapid development of very-large format infrared detector arrays has challenged the IR scene projector community to also develop larger-format infrared emitter arrays to support the testing of systems incorporating these detectors. In addition to larger formats, many scene projector users require much higher simulated temperatures than can be generated with current technology in order to fully evaluate the performance of their systems and associated processing algorithms. Under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) is developing a new infrared scene projector architecture capable of producing both very large format (>1024 x 1024) resistive emitter arrays and improved emitter pixel technology capable of simulating very high apparent temperatures. During earlier phases of the program, SBIR demonstrated materials with MWIR apparent temperatures in excess of 1400 K. New emitter materials have subsequently been selected to produce pixels that achieve even higher apparent temperatures. Test results from pixels fabricated using the new material set will be presented and discussed. A 'scalable' Read In Integrated Circuit (RIIC) is also being developed under the same UHT program to drive the high temperature pixels. This RIIC will utilize through-silicon via (TSV) and Quilt Packaging (QP) technologies to allow seamless tiling of multiple chips to fabricate very large arrays, and thus overcome the yield limitations inherent in large-scale integrated circuits. Results of design verification testing of the completed RIIC will be presented and discussed.

  6. Learning Styles and High School Students' Chemistry Achievement

    Science.gov (United States)

    Uzuntiryaki, Esen

    2007-01-01

    The aim of the present study was to investigate the effects of students' learning styles on their chemistry achievement, and whether matching between teaching and learning styles also affects students' chemistry achievement. Two hundred and sixty-five tenth-grade students enrolled in a chemistry course and seven chemistry teachers participated in…

  7. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    Science.gov (United States)

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  8. Fishing amplifies forage fish population collapses

    OpenAIRE

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish provide substantial benefits to both humans and ocean food webs, but these benefits may be in conflict unless there are effective policies governing human activities, such as fishing. Collapses of forage fish induce widespread ecological effects on dependent predators, but attributing collapses to fishing has been difficult because of natural fluctuations of these stocks. We implicate fishing in forage fish stock collapses by showing that high fishing rates are maintained when sto...

  9. Nutritional Evaluation of Non Forage High Fibrous Tropical Feeds for Ruminant Using In Vitro Gas Production Technique

    Directory of Open Access Journals (Sweden)

    Songsak CHUMPAWADEE

    2005-06-01

    Full Text Available Six non forage high fibrous tropical feedstuffs were used to evaluate their nutritive value using an in vitro gas production technique. The rumen mixed microbe inoculums were taken from 2fistulated Brahman-Thai native crossbred steers. The treatments were 1 palm meal (mech-extd, 2 palm meal (solv-extd, 3 leucaena meal (leaf and stem, 4 coconut meal (mech-extd, 5 mung bean meal and 6 dried brewers grain. The treatments were assigned to a completely randomized design. The results indicated that the soluble gas fraction (a; -7.91, -24.06, -2.11, -28.96, -10.31 and -4.35 ml, respectively, fermentation of the insoluble fraction (b; 99.33, 124.06, 70.90, 128.96, 110.31 and 99.33 ml, respectively, rate of gas production (c; 0.054, 0.071, 0.047, 0.122, 0.050 and 0.045 %/h, respectively and potential extent of gas production (a+b; 107.26, 148.13, 73.02, 157.93, 120.62 and 103.82 ml, respectively were significantly different (P < 0.01 among treatments. The cumulative gas volume at 24, 48 and 96 h after incubation were significantly different (P < 0.01. These results suggested that coconut meal (mech-extd, palm meal (solv-extd, mung bean meal, palm meal (mech-extd and dried brewer grain exhibit high fermentability in the rumen while luecaena meal has the lowest value.

  10. Preferences of High Achieving High School Students in Their Career Development

    Science.gov (United States)

    Kim, Mihyeon

    2010-01-01

    The intent of this study was to identify the needs and preference of high-achieving high school students. In terms of career related programs in high school, students listed AP courses and mentoring as their preferred career-related programs. Also, students stated that career guidance by counselors, workshops or sessions, and tech prep were the…

  11. Threatened and Placed at Risk: High Achieving African American Males in Urban High Schools

    Science.gov (United States)

    McGee, Ebony O.

    2013-01-01

    This study investigated the risk and protective factors of 11 high-achieving African American males attending 4 urban charter high schools in a Midwestern city to determine what factors account for their resilience and success in mathematics courses, and in high school more generally. This research was guided by a Phenomenological Variant of…

  12. Honeybee economics: optimisation of foraging in a variable world.

    Science.gov (United States)

    Stabentheiner, Anton; Kovac, Helmut

    2016-01-01

    In honeybees fast and efficient exploitation of nectar and pollen sources is achieved by persistent endothermy throughout the foraging cycle, which means extremely high energy costs. The need for food promotes maximisation of the intake rate, and the high costs call for energetic optimisation. Experiments on how honeybees resolve this conflict have to consider that foraging takes place in a variable environment concerning microclimate and food quality and availability. Here we report, in simultaneous measurements of energy costs, gains, and intake rate and efficiency, how honeybee foragers manage this challenge in their highly variable environment. If possible, during unlimited sucrose flow, they follow an 'investment-guided' ('time is honey') economic strategy promising increased returns. They maximise net intake rate by investing both own heat production and solar heat to increase body temperature to a level which guarantees a high suction velocity. They switch to an 'economizing' ('save the honey') optimisation of energetic efficiency if the intake rate is restricted by the food source when an increased body temperature would not guarantee a high intake rate. With this flexible and graded change between economic strategies honeybees can do both maximise colony intake rate and optimise foraging efficiency in reaction to environmental variation. PMID:27320240

  13. Honeybee economics: optimisation of foraging in a variable world.

    Science.gov (United States)

    Stabentheiner, Anton; Kovac, Helmut

    2016-06-20

    In honeybees fast and efficient exploitation of nectar and pollen sources is achieved by persistent endothermy throughout the foraging cycle, which means extremely high energy costs. The need for food promotes maximisation of the intake rate, and the high costs call for energetic optimisation. Experiments on how honeybees resolve this conflict have to consider that foraging takes place in a variable environment concerning microclimate and food quality and availability. Here we report, in simultaneous measurements of energy costs, gains, and intake rate and efficiency, how honeybee foragers manage this challenge in their highly variable environment. If possible, during unlimited sucrose flow, they follow an 'investment-guided' ('time is honey') economic strategy promising increased returns. They maximise net intake rate by investing both own heat production and solar heat to increase body temperature to a level which guarantees a high suction velocity. They switch to an 'economizing' ('save the honey') optimisation of energetic efficiency if the intake rate is restricted by the food source when an increased body temperature would not guarantee a high intake rate. With this flexible and graded change between economic strategies honeybees can do both maximise colony intake rate and optimise foraging efficiency in reaction to environmental variation.

  14. Assessing the Effects of Grassland Management on Forage Production and Environmental Quality to Identify Paths to Ecological Intensification in Mountain Grasslands.

    Science.gov (United States)

    Loucougaray, Grégory; Dobremez, Laurent; Gos, Pierre; Pauthenet, Yves; Nettier, Baptiste; Lavorel, Sandra

    2015-11-01

    Ecological intensification in grasslands can be regarded as a process for increasing forage production while maintaining high levels of ecosystem functions and biodiversity. In the mountain Vercors massif, where dairy cattle farming is the main component of agriculture, how to achieve forage autonomy at farm level while sustaining environmental quality for tourism and local dairy products has recently stimulated local debate. As specific management is one of the main drivers of ecosystem functioning, we assessed the response of forage production and environmental quality at grassland scale across a wide range of management practices. We aimed to determine which components of management can be harnessed to better match forage production and environmental quality. We sampled the vegetation of 51 grasslands stratified across 13 grassland types. We assessed each grassland for agronomic and environmental properties, measuring forage production, forage quality, and indices based on the abundance of particular plant species such as timing flexibility, apiarian potential, and aromatic plants. Our results revealed an expected trade-off between forage production and environmental quality, notably by stressing the contrasts between sown and permanent grasslands. However, strong within-type variability in both production and environmental quality as well as in flexibility of timing of use suggests possible ways to improve this trade-off at grassland and farm scales. As achieving forage autonomy relies on increasing both forage production and grassland resilience, our results highlight the critical role of the ratio between sown and permanent grasslands as a major path for ecological intensification in mountain grasslands.

  15. Assessing the Effects of Grassland Management on Forage Production and Environmental Quality to Identify Paths to Ecological Intensification in Mountain Grasslands

    Science.gov (United States)

    Loucougaray, Grégory; Dobremez, Laurent; Gos, Pierre; Pauthenet, Yves; Nettier, Baptiste; Lavorel, Sandra

    2015-11-01

    Ecological intensification in grasslands can be regarded as a process for increasing forage production while maintaining high levels of ecosystem functions and biodiversity. In the mountain Vercors massif, where dairy cattle farming is the main component of agriculture, how to achieve forage autonomy at farm level while sustaining environmental quality for tourism and local dairy products has recently stimulated local debate. As specific management is one of the main drivers of ecosystem functioning, we assessed the response of forage production and environmental quality at grassland scale across a wide range of management practices. We aimed to determine which components of management can be harnessed to better match forage production and environmental quality. We sampled the vegetation of 51 grasslands stratified across 13 grassland types. We assessed each grassland for agronomic and environmental properties, measuring forage production, forage quality, and indices based on the abundance of particular plant species such as timing flexibility, apiarian potential, and aromatic plants. Our results revealed an expected trade-off between forage production and environmental quality, notably by stressing the contrasts between sown and permanent grasslands. However, strong within-type variability in both production and environmental quality as well as in flexibility of timing of use suggests possible ways to improve this trade-off at grassland and farm scales. As achieving forage autonomy relies on increasing both forage production and grassland resilience, our results highlight the critical role of the ratio between sown and permanent grasslands as a major path for ecological intensification in mountain grasslands.

  16. The Effect of Music Participation on Mathematical Achievement and Overall Academic Achievement of High School Students

    Science.gov (United States)

    Cox, H. A.; Stephens, L. J.

    2006-01-01

    A study was conducted on high school students, comparing those with some music credits to those with none. No statistically significant difference was found in their mean math grade point averages (GPA) or their mean cumulative GPAs. Students were then separated into two groups based on the number of music credits. Students who had earned at least…

  17. Heat Damaged Forages: Effects on Forage Quality

    Science.gov (United States)

    Traditionally, heat damage in forages has been associated with alterations in forage protein quality as a result of Maillard reactions, and most producers and nutritionists are familiar with this concept. However, this is not necessarily the most important negative consequence of spontaneous heating...

  18. Winter distribution and use of high elevation caves as foraging sites by the endangered Hawaiian hoary bat, Lasiurus cinereus semotus

    Science.gov (United States)

    Bonaccorso, Frank; Montoya-Aiona, Kristina; Pinzari, Corinna A.; Todd, Christopher M.

    2016-01-01

    We examine altitudinal movements involving unusual use of caves by Hawaiian hoary bats, Lasiurus cinereus semotus, during winter and spring in the Mauna Loa Forest Reserve (MLFR), Hawai‘i Island. Acoustic detection of hoary bat vocalizations, were recorded with regularity outside 13 lava tube cave entrances situated between 2,200 to 3,600 m asl from November 2012 to April 2013. Vocalizations were most numerous in November and December with the number of call events and echolocation pulses decreasing through the following months. Bat activity was positively correlated with air temperature and negatively correlated with wind speed. Visual searches found no evidence of hibernacula nor do Hawaiian hoary bats appear to shelter by day in these caves. Nevertheless, bats fly deep into caves as evidenced by numerous carcasses found in cave interiors. The occurrence of feeding buzzes around cave entrances and visual observations of bats flying in acrobatic fashion in cave interiors point to the use of these spaces as foraging sites. Peridroma moth species (Noctuidae), the only abundant nocturnal, flying insect sheltering in large numbers in rock rubble and on cave walls in the MLFR, apparently serve as the principal prey attracting hoary bats during winter to lava tube caves in the upper MLFR. Caves above 3,000 m on Mauna Loa harbor temperatures suitable for Pseudogymnoascus destructansfungi, the causative agent of White-nose Syndrome that is highly lethal to some species of North American cave-dwelling bats. We discuss the potential for White-nose Syndrome to establish and affect Hawaiian hoary bats.

  19. Academic attainment and the high school science experiences among high-achieving African American males

    Science.gov (United States)

    Trice, Rodney Nathaniel

    This study examines the educational experiences of high achieving African American males. More specifically, it analyzes the influences on their successful navigation through high school science. Through a series of interviews, observations, questionnaires, science portfolios, and review of existing data the researcher attempted to obtain a deeper understanding of high achieving African American males and their limitations to academic attainment and high school science experiences. The investigation is limited to ten high achieving African American male science students at Woodcrest High School. Woodcrest is situated at the cross section of a suburban and rural community located in the southeastern section of the United States. Although this investigation involves African American males, all of whom are successful in school, its findings should not be generalized to this nor any other group of students. The research question that guided this study is: What are the limitations to academic attainment and the high school science experiences of high achieving African American males? The student participants expose how suspension and expulsion, special education placement, academic tracking, science instruction, and teacher expectation influence academic achievement. The role parents play, student self-concept, peer relationships, and student learning styles are also analyzed. The anthology of data rendered three overarching themes: (1) unequal access to education, (2) maintenance of unfair educational structures, and (3) authentic characterizations of African American males. Often the policies and practices set in place by school officials aid in creating hurdles to academic achievement. These policies and practices are often formed without meaningful consideration of the unintended consequences that may affect different student populations, particularly the most vulnerable. The findings from this study expose that high achieving African American males face major

  20. Effects of artificial illumination on the nocturnal foraging of waders

    Science.gov (United States)

    Santos, Carlos D.; Miranda, Ana C.; Granadeiro, José P.; Lourenço, Pedro M.; Saraiva, Sara; Palmeirim, Jorge M.

    2010-03-01

    Large areas of natural and semi-natural habitats are exposed to artificial illumination from adjacent urban areas and roads. Estuarine and coastal wetlands are particularly exposed to such illumination because shorelines often are heavily utilized by man. However, the impact of artificial illumination on the waders that forage in these highly productive habitats is virtually unknown. We evaluated the effects of artificial illumination on the nocturnal habitat selection and foraging behaviour of six wader species with different feeding strategies: three visual foragers, two species that alternate visual and tactile strategies (mixed foragers), and one tactile forager. We quantified the number of birds and their foraging behaviour at sites affected and not affected by streetlights, and also before and after illuminating experimental sites. Areas illuminated by streetlights were used more during the night by visual foragers, and to a lesser extent by mixed foragers, than non-illuminated areas. Visual foragers increased their foraging effort in illuminated areas, and mixed foragers changed to more efficient visual foraging strategies. These behavioural shifts improved prey intake rate by an average of 83% in visual and mixed foragers. We have showed that artificial illumination has a positive effect on the nocturnal foraging of waders, but on the other hand may draw them to degraded areas close to urban centres, and potentially raises their exposure to predators. Our findings suggest that artificial illumination is worth investigation as a tool in the management of intertidal habitats for waders.

  1. Dominant Achievement Goals across Tracks in High School

    Science.gov (United States)

    Scheltinga, Peter A. M.; Kuyper, Hans; Timmermans, Anneke C.; van der Werf, Greetje P. C.

    2016-01-01

    The dominant achievement goals (DAGs) of 7,008 students in the third grade of Dutch secondary education (US grade 9) were investigated, based on Elliot & McGregors' 2 × 2 framework (2001), in relation to track-level and motivational variables. We found the mastery-approach goal and the performance-approach goal, generally considered adaptive,…

  2. "Brains before "Beauty"?" High Achieving Girls, School and Gender Identities

    Science.gov (United States)

    Skelton, Christine; Francis, Becky; Read, Barbara

    2010-01-01

    In recent years educational policy on gender and achievement has concentrated on boys' underachievement, frequently comparing it with the academic success of girls. This has encouraged a perception of girls as the "winners" of the educational stakes and assumes that they no longer experience the kinds of gender inequalities identified in earlier…

  3. Cooperative Learning: A Standard for High Achievement. The Nutshell Series.

    Science.gov (United States)

    Williams, R. Bruce

    2007-01-01

    This book reveals some of the structural complexities involved in implementing authentic cooperative learning in the classroom. It also suggests that when full cooperative learning structures are implemented, the benefits in student achievement often can be astounding. Descriptions, decisions, designs, and developments, a simple four-part scheme,…

  4. Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults

    Science.gov (United States)

    Miller, Angie L.; Lambert, Amber D.; Speirs Neumeister, Kristie L.

    2012-01-01

    The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and…

  5. Precision-feeding dairy heifers a high rumen-degradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios.

    Science.gov (United States)

    Lascano, G J; Koch, L E; Heinrichs, A J

    2016-09-01

    The objective of this experiment was to determine the effects of feeding a high-rumen-degradable protein (RDP) diet when dietary fiber content is manipulated within differing forage-to-concentrate ratio (F:C) on nutrient utilization of precision-fed dairy heifers. Six cannulated Holstein heifers (486.98±15.07kg of body weight) were randomly assigned to 2 F:C, low- (45% forage; LF) and high-forage (90% forage; HF) diets and to a fiber proportion sequence [33% grass hay and wheat straw (HS), 67% corn silage (CS; low fiber); 50% HS, 50% CS (medium fiber); and 67% HS, 33% CS (high fiber)] within forage proportion administered according to a split-plot, 3×3 Latin square design (16-d periods). Heifers fed LF had greater apparent total-tract organic matter digestibility coefficients (dC), neutral detergent fiber, and cellulose than those fed LC diets. Substituting CS with HS resulted in a linear reduction in dry matter, organic matter, and cellulose dC. Nitrogen dC was not different between F:C or with increasing proportions of HS in diets, but N retention tended to decrease linearly as HS was increased in the diets. Predicted microbial protein flow to the duodenum decreased linearly with HS addition and protozoa numbers HS interacted linearly, exhibiting a decrease as HS increased for LF, whereas no effects were observed for HF. Blood urea N increased linearly as HS was incorporated. The LF-fed heifers had a greater ruminal volatile fatty acids concentration. We noted a tendency for a greater dry matter, and a significantly higher liquid fraction turnover rate for HF diets. There was a linear numerical increase in the liquid and solid fraction turnover rate as fiber was added to the diets. Rumen fermentation parameters and fractional passages (solid and liquid) rates support the reduction in dC, N retention, and microbial protein synthesis observed as more dietary fiber is added to the rations of dairy heifers precision-fed a constant proportion of rumen

  6. Examination of high resolution rainfall products and satellite greenness indices for estimating patch and landscape forage biomass

    Science.gov (United States)

    Angerer, Jay Peter

    Assessment of vegetation productivity on rangelands is needed to assist in timely decision making with regard to management of the livestock enterprise as well as to protect the natural resource. Characterization of the vegetation resource over large landscapes can be time consuming, expensive and almost impossible to do on a near real-time basis. The overarching goal of this study was to examine available technologies for implementing near real-time systems to monitor forage biomass available to livestock on a given landscape. The primary objectives were to examine the ability of the Climate Prediction Center Morphing Product (CMORPH) and Next Generation Weather Radar (NEXRAD) rainfall products to detect and estimate rainfall at semi-arid sites in West Texas, to verify the ability of a simulation model (PHYGROW) to predict herbaceous biomass at selected sites (patches) in a semi-arid landscape using NEXRAD rainfall, and to examine the feasibility of using cokriging for integrating simulation model output and satellite greenness imagery (NDVI) for producing landscape maps of forage biomass in Mongolia's Gobi region. The comparison of the NEXRAD and CMORPH rainfall products to gage collected rainfall revealed that NEXRAD outperformed the CMORPH rainfall with lower estimation bias, lower variability, and higher estimation efficiency. When NEXRAD was used as a driving variable in PHYGROW simulations that were calibrated using gage measured rainfall, model performance for estimating forage biomass was generally poor when compared to biomass measurements at the sites. However, when model simulations were calibrated using NEXRAD rainfall, performance in estimating biomass was substantially better. A suggested reason for the improved performance was that calibration with NEXRAD adjusted the model for the general over or underestimation of rainfall by the NEXRAD product. In the Gobi region of Mongolia, the PHYGROW model performed well in predicting forage biomass except

  7. Achieving Timeliness and High Throughput Metrics in Dissemination Systems

    Directory of Open Access Journals (Sweden)

    MANNE ANUSHA

    2012-09-01

    Full Text Available Existing systems for information dissemination is inadequate and typically results in information gaps. The lack of a clear concise system for information dissemination makes it difficult to determine the most efficient and effective way to pass information especially in the fields of ecommerce and security alerting systems to the appropriate parties. These systems usually require that the desired information be matched between numerous sources and sinks based on established subscriptions. Timeliness and Throughput are performance metrics used for evaluation. And these existing systems fail to achieve a balance between the two. So a much better system termed INFOD (INFOrmation Dissemination was proposed earlier that achieves a balance between performance metrics. We observed that an Integrated Control Loop used by admission control scheme of INFOD employs PL/SQL stored procedures that are huge computation overhead. We propose to replace them with Java stored procedures that can tremendously increase the performance.

  8. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman;

    2016-01-01

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t aboveground dry matter ha− 1 year− 1 saving around 325 kg mineral N fertilizer ha− 1 compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3 t DM more than red clover...... lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total...

  9. The Information Search Process of High-, Middle-, and Low-Achieving High School Seniors.

    Science.gov (United States)

    Kuhlthau, Carol C.

    1989-01-01

    Presents a model of the information search process as a complex series of stages involving thoughts and feelings as well as actions. A study that sought to verify the model using high school seniors from three different achievement levels is described, and the implications for library instruction are discussed. (five references) (CLB)

  10. Practically Perfect in Every Way: Can Reframing Perfectionism for High-Achieving Undergraduates Impact Academic Resilience?

    Science.gov (United States)

    Dickinson, Mary J.; Dickinson, David A. G.

    2015-01-01

    This study focuses on a pan-disciplinary scheme that targeted high-achieving undergraduate students. Earlier research from the scheme argued that high achievers have discernibly different learning and personal development support needs. One of the most frequent self-reported challenges within this high-achieving group is perfectionism. This…

  11. Achieving Mixtures of Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Mircea POPA

    2013-07-01

    Full Text Available Ultra-High Performance Concrete (UHPC is a relatively new concrete. According to [11] UHPC is that concrete which features compressive strength over C100/115 class. Up to this point standards for this type of concrete were not adopted, although its characteristic strength exceeds those specified in [33]. Its main property is high compressive strength. This provides the possibility of reducing the section of elements (beams or columns made of this type of concrete, while the load capacity remains high. The study consists in blending mixtures of UHPC made of varying proportions of materials. The authors have obtained strengths of up to 160 MPa. The materials used are: Portland cement, silica fume, quartz powder, steel fibers, superplasticiser, sand and crushed aggregate for concrete - andesite.

  12. Testing Theories of Learning: Effects on High School Achievement.

    Science.gov (United States)

    Keith, Timothy Z.; Cool, Valerie A.

    Theories of school learning consistently point to variables such as ability, time (e.g., homework), quality of instruction, motivation, and academic coursework as important influences on learning. In this study, path analysis was used to test the direct and indirect effects of these variables on high school learning, with learning measured by both…

  13. Impact of learning orientation on African American children's attitudes toward high-achieving peers.

    Science.gov (United States)

    Marryshow, Derrick; Hurley, Eric A; Allen, Brenda A; Tyler, Kenneth M; Boykin, A Wade

    2005-01-01

    This study examined Ogbu's widely accepted thesis that African American students reject high academic achievement because they perceive its limited utility in a world where their upward mobility is constrained by racial discrimination. Boykin's psychosocial integrity model contends that Black students value high achievement but that discrepancies between their formative cultural experiences and those imposed in school lead them to reject the modes of achievement available in classrooms. Ninety Black children completed a measure of attitudes toward students who achieve via mainstream or African American cultural values. Participants rejected the mainstream achievers and embraced the African American cultural achievers. Moreover, they expected their teachers to embrace the mainstream achievers and reject those who achieved through high-verve behavior. Results suggest that Boykin's thesis is a needed refinement to Ogbu's ideas. They indicate that Black children may reject not high achievement but some of the mainstream cultural values and behaviors on which success in mainstream classrooms is made contingent.

  14. Achieving High Reliability Operations Through Multi-Program Integration

    Energy Technology Data Exchange (ETDEWEB)

    Holly M. Ashley; Ronald K. Farris; Robert E. Richards

    2009-04-01

    Over the last 20 years the Idaho National Laboratory (INL) has adopted a number of operations and safety-related programs which has each periodically taken its turn in the limelight. As new programs have come along there has been natural competition for resources, focus and commitment. In the last few years, the INL has made real progress in integrating all these programs and are starting to realize important synergies. Contributing to this integration are both collaborative individuals and an emerging shared vision and goal of the INL fully maturing in its high reliability operations. This goal is so powerful because the concept of high reliability operations (and the resulting organizations) is a masterful amalgam and orchestrator of the best of all the participating programs (i.e. conduct of operations, behavior based safety, human performance, voluntary protection, quality assurance, and integrated safety management). This paper is a brief recounting of the lessons learned, thus far, at the INL in bringing previously competing programs into harmony under the goal (umbrella) of seeking to perform regularly as a high reliability organization. In addition to a brief diagram-illustrated historical review, the authors will share the INL’s primary successes (things already effectively stopped or started) and the gaps yet to be bridged.

  15. Telescoping Solar Array Concept for Achieving High Packaging Efficiency

    Science.gov (United States)

    Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

    2015-01-01

    Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

  16. Maize forage aptitude: Combining ability of inbred lines and stability of hybrids

    Institute of Scientific and Technical Information of China (English)

    Luis; Máximo; Bertoia; Mónica; Beatriz; Aulicino

    2014-01-01

    Breeding of forage maize should combine improvement achieved for grain with the specific needs of forage hybrids. Production stability is important when maize is used for silage if the planting area is not in the ideal agronomic environment. The objectives of the present research were:(i) to quantify environmental and genetic and their interaction effects on maize silage traits;(ii) to identify possible heterotic groups for forage aptitude and suggest the formation of potential heterotic patterns, and(iii) to identify suitable inbred line combinations for producing hybrids with forage aptitude. Forty-five hybrids derived from diallelic crosses(without reciprocals) among ten inbred lines of maize were evaluated in this study. Combined ANOVA over environments showed differences between genotypes(G), environments(E), and their interactions(GEI). Heritability(H2), and genotypic and phenotypic correlations were estimated to evaluate the variation in and relationships between forage traits. Postdictive and predictive AMMI models were fitted to determine the importance of each source of variation, G, E, and GEI, and to select genotypes simultaneously on yield, quality and stability. A predominance of additive effects was found in the evaluated traits. The heterotic pattern Reid-BSSS × Argentine flint was confirmed for ear yield(EY) and harvest index(HI). High and broad genetic variation was found for stover and whole plant traits. Some inbred lines had genes with differential breeding aptitude for ear and stover. Stover and ear yield should be the main breeding objectives in maize forage breeding.

  17. Self-learning Multiscale Simulation for Achieving High Accuracy and High Efficiency Simultaneously

    CERN Document Server

    Li, Wenfei

    2009-01-01

    We propose a new multi-scale molecular dynamics simulation method which can achieve high accuracy and high sampling efficiency simultaneously without aforehand knowledge of the coarse grained (CG) potential and test it for a biomolecular system. Based on the resolution exchange simulations between atomistic and CG replicas, a self-learning strategy is introduced to progressively improve the CG potential by an iterative way. Two tests show that, the new method can rapidly improve the CG potential and achieve efficient sampling even starting from an unrealistic CG potential. The resulting free energy agreed well with exact result and the convergence by the method was much faster than that by the replica exchange method. The method is generic and can be applied to many biological as well as non-biological problems.

  18. Utilisation of Intensive Foraging Zones by Female Australian Fur Seals

    Science.gov (United States)

    Hoskins, Andrew J.; Costa, Daniel P.; Arnould, John P. Y.

    2015-01-01

    Within a heterogeneous environment, animals must efficiently locate and utilise foraging patches. One way animals can achieve this is by increasing residency times in areas where foraging success is highest (area-restricted search). For air-breathing diving predators, increased patch residency times can be achieved by altering both surface movements and diving patterns. The current study aimed to spatially identify the areas where female Australian fur seals allocated the most foraging effort, while simultaneously determining the behavioural changes that occur when they increase their foraging intensity. To achieve this, foraging behaviour was successfully recorded with a FastLoc GPS logger and dive behaviour recorder from 29 individual females provisioning pups. Females travelled an average of 118 ± 50 km from their colony during foraging trips that lasted 7.3 ± 3.4 days. Comparison of two methods for calculating foraging intensity (first-passage time and first-passage time modified to include diving behaviour) determined that, due to extended surface intervals where individuals did not travel, inclusion of diving behaviour into foraging analyses was important for this species. Foraging intensity ‘hot spots’ were found to exist in a mosaic of patches within the Bass Basin, primarily to the south-west of the colony. However, the composition of benthic habitat being targeted remains unclear. When increasing their foraging intensity, individuals tended to perform dives around 148 s or greater, with descent/ascent rates of approximately 1.9 m•s-1 or greater and reduced postdive durations. This suggests individuals were maximising their time within the benthic foraging zone. Furthermore, individuals increased tortuosity and decreased travel speeds while at the surface to maximise their time within a foraging location. These results suggest Australian fur seals will modify both surface movements and diving behaviour to maximise their time within a foraging patch

  19. Utilisation of intensive foraging zones by female Australian fur seals.

    Directory of Open Access Journals (Sweden)

    Andrew J Hoskins

    Full Text Available Within a heterogeneous environment, animals must efficiently locate and utilise foraging patches. One way animals can achieve this is by increasing residency times in areas where foraging success is highest (area-restricted search. For air-breathing diving predators, increased patch residency times can be achieved by altering both surface movements and diving patterns. The current study aimed to spatially identify the areas where female Australian fur seals allocated the most foraging effort, while simultaneously determining the behavioural changes that occur when they increase their foraging intensity. To achieve this, foraging behaviour was successfully recorded with a FastLoc GPS logger and dive behaviour recorder from 29 individual females provisioning pups. Females travelled an average of 118 ± 50 km from their colony during foraging trips that lasted 7.3 ± 3.4 days. Comparison of two methods for calculating foraging intensity (first-passage time and first-passage time modified to include diving behaviour determined that, due to extended surface intervals where individuals did not travel, inclusion of diving behaviour into foraging analyses was important for this species. Foraging intensity 'hot spots' were found to exist in a mosaic of patches within the Bass Basin, primarily to the south-west of the colony. However, the composition of benthic habitat being targeted remains unclear. When increasing their foraging intensity, individuals tended to perform dives around 148 s or greater, with descent/ascent rates of approximately 1.9 m•s-1 or greater and reduced postdive durations. This suggests individuals were maximising their time within the benthic foraging zone. Furthermore, individuals increased tortuosity and decreased travel speeds while at the surface to maximise their time within a foraging location. These results suggest Australian fur seals will modify both surface movements and diving behaviour to maximise their time within a

  20. High Achievement in Mathematics Education in India: A Report from Mumbai

    Science.gov (United States)

    Raman, Manya

    2010-01-01

    This paper reports a study aimed at characterizing the conditions that lead to high achievement in mathematics in India. The study involved eight schools in the greater Mumbai region. The main result of the study is that the notion of high achievement itself is problematic, as reflected in the reports about mathematics achievement within and…

  1. Achieving High-Frequency Optical Control of Synaptic Transmission

    Science.gov (United States)

    Jackman, Skyler L.; Beneduce, Brandon M.; Drew, Iain R.

    2014-01-01

    The optogenetic tool channelrhodopsin-2 (ChR2) is widely used to excite neurons to study neural circuits. Previous optogenetic studies of synapses suggest that light-evoked synaptic responses often exhibit artificial synaptic depression, which has been attributed to either the inability of ChR2 to reliably fire presynaptic axons or to ChR2 elevating the probability of release by depolarizing presynaptic boutons. Here, we compare light-evoked and electrically evoked synaptic responses for high-frequency stimulation at three synapses in the mouse brain. At synapses from Purkinje cells to deep cerebellar nuclei neurons (PC→DCN), light- and electrically evoked synaptic currents were remarkably similar for ChR2 expressed transgenically or with adeno-associated virus (AAV) expression vectors. For hippocampal CA3→CA1 synapses, AAV expression vectors of serotype 1, 5, and 8 led to light-evoked synaptic currents that depressed much more than electrically evoked currents, even though ChR2 could fire axons reliably at up to 50 Hz. The disparity between optical and electrical stimulation was eliminated when ChR2 was expressed transgenically or with AAV9. For cerebellar granule cell to stellate cell (grc→SC) synapses, AAV1 also led to artificial synaptic depression and AAV9 provided superior performance. Artificial synaptic depression also occurred when stimulating over presynaptic boutons, rather than axons, at CA3→CA1 synapses, but not at PC→DCN synapses. These findings indicate that ChR2 expression methods and light stimulation techniques influence synaptic responses in a neuron-specific manner. They also identify pitfalls associated with using ChR2 to study synapses and suggest an approach that allows optogenetics to be applied in a manner that helps to avoid potential complications. PMID:24872574

  2. Ruminal fermentation of Anti-methanogenic Nitrate- and Nitro-Containing Forages In Vitro

    Directory of Open Access Journals (Sweden)

    Robin C. Anderson

    2016-08-01

    Full Text Available Nitrate, 3-nitro-1-propionic acid (NPA and 3-nitro-1-propanol (NPOH can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA- or NPOH-containing forages effectively decreased methane production, by 35 to 87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH but was dramatically higher, exceeding 40 µmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 µmol added formate per mL to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA- and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA- and NPOH-containing forages to achieve efficacious mitigation in

  3. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro

    Science.gov (United States)

    Anderson, Robin C.; Ripley, Laura H.; Bowman, Jan G. P.; Callaway, Todd R.; Genovese, Kenneth J.; Beier, Ross C.; Harvey, Roger B.; Nisbet, David J.

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35–87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation

  4. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro.

    Science.gov (United States)

    Anderson, Robin C; Ripley, Laura H; Bowman, Jan G P; Callaway, Todd R; Genovese, Kenneth J; Beier, Ross C; Harvey, Roger B; Nisbet, David J

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35-87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation in

  5. EFFECTS OF FORAGE SPECIES ON RIB COMPOSITION, COLOR, AND PALATABILITY IN FORAGE-FINISHED BEEF

    Science.gov (United States)

    Forty-seven Angus-crossbred steers were used to evaluate the effects of forage species grazed in the last 41 d of the finishing period on rib composition, color, and palatability in forage-finished beef and compared to traditional high concentrate finished. Steers grazed naturalized pastures (bluegr...

  6. COMPARATIVE PERSPECTIVES OF STUDY STRATEGIES AMONG HIGH AND LOW ACHIEVERS DISTANCE LEARNING STUDENTS

    Directory of Open Access Journals (Sweden)

    Muhammad Imran YOUSUF

    2009-07-01

    Full Text Available The main aim of this research is to better understand and draw perceptions of low and high achiever distance learners about their study patterns. The study indicates the areas where significant difference is found among low and high achievers of Allama Iqbal Open University, Pakistan through a self developed questionnaire covering their preferred study location, study times, number of hours spent on study, the difficulties affecting their study patterns and the organization of study strategies in comparative perspective. Greater difficulties were being faced by low achievers in their study. Increased difficulties were encountered by low achievers with study material, volume of study, self-motivation and other factors. There was no significant difference between low and high achievers for their study strategies of studying materials without taking notes and reading aloud. Greater low achievers attempted easy portions of their study material first and took notes simultaneously as compared to high achievers.

  7. The Chinese High School Student's Stress in the School and Academic Achievement

    Science.gov (United States)

    Liu, Yangyang; Lu, Zuhong

    2011-01-01

    In a sample of 466 Chinese high school students, we examined the relationships between Chinese high school students' stress in the school and their academic achievements. Regression mixture modelling identified two different classes of the effects of Chinese high school students' stress on their academic achievements. One class contained 87% of…

  8. English and Mathematics: Determinants of Physics Achievement among Public High School Seniors in Naga City

    OpenAIRE

    DR. EDGAR M. BAYLON, JR.

    2014-01-01

    This evaluative and relational study determined the influence of English and Mathematics on the Physics achievement of public high school senior students in Naga City, Philippines. Results showed that the students had an average achievement level in Speaking, Reading, Literature and Grammar. The overall achievement level in Advanced Algebra, Trigonometry and Statistics was average. The overall achievement level in Optics and Waves, Nuclear Physics and Mechanics was average. There was a signif...

  9. Scavenger: Transparent Development of Efficient Cyber Foraging Applications

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø

    2010-01-01

    Cyber foraging is a pervasive computing technique where small mobile devices offload resource intensive tasks to stronger computing machinery in the vicinity. This paper presents Scavenger-a new cyber foraging system supporting easy development of mobile cyber foraging applications, while still...... delivering efficient, mobile use of remote computing resources through the use of a custom built mobile code execution environment and a new dual-profiling scheduler. One of the main difficulties within cyber foraging is that it is very challenging for application programmers to develop cyber foraging...... enabled applications. An application using cyber foraging is working with mobile, distributed and, possibly, parallel computing; fields within computer science known to be hard for programmers to grasp. In this paper it is shown by example, how a highly distributed, parallel, cyber foraging enabled...

  10. Zebrafish learn to forage in the dark.

    Science.gov (United States)

    Carrillo, Andres; McHenry, Matthew J

    2016-02-01

    A large diversity of fishes struggle early in life to forage on zooplankton while under the threat of predation. Some species, such as zebrafish (Danio rerio), acquire an ability to forage in the dark during growth as larvae, but it is unclear how this is achieved. We investigated the functional basis of this foraging by video-recording larval and juvenile zebrafish as they preyed on zooplankton (Artemia sp.) under infrared illumination. We found that foraging improved with age, to the extent that 1-month-old juveniles exhibited a capture rate that was an order of magnitude greater than that of hatchlings. At all ages, the ability to forage in the dark was diminished when we used a chemical treatment to compromise the cranial superficial neuromasts, which facilitate flow sensing. However, a morphological analysis showed no developmental changes in these receptors that could enhance sensitivity. We tested whether the improvement in foraging with age could instead be a consequence of learning by raising fish that were naïve to the flow of prey. After 1 month of growth, both groups foraged with a capture rate that was significantly less than that of fish that had the opportunity to learn and indistinguishable from that of fish with no ability to sense flow. This suggests that larval fish learn to use water flow to forage in the dark. This ability could enhance resource acquisition under reduced competition and predation. Furthermore, our findings offer an example of learning in a model system that offers promise for understanding its neurophysiological basis.

  11. Ant Foraging As an Indicator of Tropical Dry Forest Restoration.

    Science.gov (United States)

    Hernández-Flores, J; Osorio-Beristain, M; Martínez-Garza, C

    2016-08-01

    Variation in foraging behavior may indicate differences in food availability and allow assessment of restoration actions. Ants are prominent bioindicators used in assessing ecological responses to disturbance. However, behavioral data have been poorly incorporated as an index. The foraging performance of red harvester ants was quantified in order to evaluate the success of a restoration ecology experiment in the tropical dry forest of Sierra de Huautla, Morelos, in central Mexico. Foraging performance by granivorous, Pogonomyrmex barbatus, ants was diminished after 6 and 8 years of cattle grazing and wood harvest were excluded as part of a restoration experiment in a highly degraded biome. Despite investing more time in foraging, ant colonies in exclusion plots showed lower foraging success and acquired less seed biomass than colonies in control plots. In line with the predictions of optimal foraging theory, in restored plots where ant foraging performance was poor, ants harvested a higher diversity of seeds. Reduced foraging success and increased harvest of non-preferred foods in exclusion plots were likely due to the growth of herbaceous vegetation, which impedes travel by foragers. Moreover, by 8 years of exclusion, 37% of nests in exclusion plots had disappeared compared to 0% of nests in control plots. Ants' foraging success and behavior were sensitive to changes in habitat quality due to the plant successional process triggered by a restoration intervention. This study spotlights on the utility of animal foraging behavior in the evaluation of habitat restoration programs.

  12. An Analysis of Java Programming Behaviors, Affect, Perceptions, and Syntax Errors among Low-Achieving, Average, and High-Achieving Novice Programmers

    Science.gov (United States)

    Rodrigo, Ma. Mercedes T.; Andallaza, Thor Collin S.; Castro, Francisco Enrique Vicente G.; Armenta, Marc Lester V.; Dy, Thomas T.; Jadud, Matthew C.

    2013-01-01

    In this article we quantitatively and qualitatively analyze a sample of novice programmer compilation log data, exploring whether (or how) low-achieving, average, and high-achieving students vary in their grasp of these introductory concepts. High-achieving students self-reported having the easiest time learning the introductory programming…

  13. Aggressive and foraging behavioral interactions among ruffe

    Science.gov (United States)

    Savino, Jacqueline F.; Kostich, Melissa J.

    2000-01-01

    The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100 cm in diameter, 15 cm water depth) were conducted to determine whether fish density (low = 2, medium = 4, high = 6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated a hierarchy based on aggressive interactions, but ruffe were most aggressive at low and high fish densities. Time spent in foraging was lowest at the low fish density. The best forager at the low fish density was the most aggressive individual, but the second most aggressive fish at the medium and high fish density was the best forager and also the one chased most frequently. A medium fish density offered the best energetic benefits to ruffe by providing the lowest ratio of time spent in aggression to that spent foraging. Based on our results, ruffe should grow best at an intermediate density. With high ruffe densities, we would also expect disparity in size as the more aggressive fish are able to garner a disproportionate amount of the resources. Alternatively, as the Great Lakes are a fairly open system, ruffe could migrate out of one area to colonize another as populations exceed optimal densities.

  14. Co-evolution of learning complexity and social foraging strategies.

    Science.gov (United States)

    Arbilly, Michal; Motro, Uzi; Feldman, Marcus W; Lotem, Arnon

    2010-12-21

    Variation in learning abilities within populations suggests that complex learning may not necessarily be more adaptive than simple learning. Yet, the high cost of complex learning cannot fully explain this variation without some understanding of why complex learning is too costly for some individuals but not for others. Here we propose that different social foraging strategies can favor different learning strategies (that learn the environment with high or low resolution), thereby maintaining variable learning abilities within populations. Using a genetic algorithm in an agent-based evolutionary simulation of a social foraging game (the producer-scrounger game) we demonstrate how an association evolves between a strategy based on independent search for food (playing a producer) and a complex (high resolution) learning rule, while a strategy that combines independent search and following others (playing a scrounger) evolves an association with a simple (low resolution) learning rule. The reason for these associations is that for complex learning to have an advantage, a large number of learning steps, normally not achieved by scroungers, are necessary. These results offer a general explanation for persistent variation in cognitive abilities that is based on co-evolution of learning rules and social foraging strategies.

  15. Feeding of wheat bran and sugar beet pulp as sole supplements in high-forage diets emphasizes the potential of dairy cattle for human food supply.

    Science.gov (United States)

    Ertl, P; Zebeli, Q; Zollitsch, W; Knaus, W

    2016-02-01

    Besides the widely discussed negative environmental effects of dairy production, such as greenhouse gas emissions, the feeding of large amounts of potentially human-edible feedstuffs to dairy cows is another important sustainability concern. The aim of this study was therefore to investigate the effects of a complete substitution of common cereal grains and pulses with a mixture of wheat bran and sugar beet pulp in a high-forage diet on cow performance, production efficiency, feed intake, and ruminating behavior, as well as on net food production potential. Thirteen multiparous and 7 primiparous mid-lactation Holstein dairy cows were randomly assigned to 1 of 2 treatments in a change-over design with 7-wk periods. Cows were fed a high-forage diet (grass silage and hay accounted for 75% of the dry matter intake), supplemented with either a cereal grain-based concentrate mixture (CON), or a mixture of wheat bran and dried sugar beet pulp (WBBP). Human-edible inputs were calculated for 2 different scenarios based on minimum and maximum potential recovery rates of human-edible energy and protein from the respective feedstuffs. Dietary starch and neutral detergent fiber contents were 3.0 and 44.1% for WBBP, compared with 10.8 and 38.2% in CON, respectively. Dietary treatment did not affect milk production, milk composition, feed intake, or total chewing activity. However, chewing index expressed in minutes per kilogram of neutral detergent fiber ingested was 12% lower in WBBP compared with CON. In comparison to CON, the human-edible feed conversion efficiencies for energy and protein, defined as human-edible output per human-edible input, were 6.8 and 5.3 times higher, respectively, in WBBP under the maximum scenario. For the maximum scenario, the daily net food production (human-edible output minus human-edible input) increased from 5.4 MJ and 250 g of crude protein per cow in CON to 61.5 MJ and 630 g of crude protein in the WBBP diet. In conclusion, our data suggest

  16. Feeding of wheat bran and sugar beet pulp as sole supplements in high-forage diets emphasizes the potential of dairy cattle for human food supply.

    Science.gov (United States)

    Ertl, P; Zebeli, Q; Zollitsch, W; Knaus, W

    2016-02-01

    Besides the widely discussed negative environmental effects of dairy production, such as greenhouse gas emissions, the feeding of large amounts of potentially human-edible feedstuffs to dairy cows is another important sustainability concern. The aim of this study was therefore to investigate the effects of a complete substitution of common cereal grains and pulses with a mixture of wheat bran and sugar beet pulp in a high-forage diet on cow performance, production efficiency, feed intake, and ruminating behavior, as well as on net food production potential. Thirteen multiparous and 7 primiparous mid-lactation Holstein dairy cows were randomly assigned to 1 of 2 treatments in a change-over design with 7-wk periods. Cows were fed a high-forage diet (grass silage and hay accounted for 75% of the dry matter intake), supplemented with either a cereal grain-based concentrate mixture (CON), or a mixture of wheat bran and dried sugar beet pulp (WBBP). Human-edible inputs were calculated for 2 different scenarios based on minimum and maximum potential recovery rates of human-edible energy and protein from the respective feedstuffs. Dietary starch and neutral detergent fiber contents were 3.0 and 44.1% for WBBP, compared with 10.8 and 38.2% in CON, respectively. Dietary treatment did not affect milk production, milk composition, feed intake, or total chewing activity. However, chewing index expressed in minutes per kilogram of neutral detergent fiber ingested was 12% lower in WBBP compared with CON. In comparison to CON, the human-edible feed conversion efficiencies for energy and protein, defined as human-edible output per human-edible input, were 6.8 and 5.3 times higher, respectively, in WBBP under the maximum scenario. For the maximum scenario, the daily net food production (human-edible output minus human-edible input) increased from 5.4 MJ and 250 g of crude protein per cow in CON to 61.5 MJ and 630 g of crude protein in the WBBP diet. In conclusion, our data suggest

  17. Approaches to achieve high grain yield and high resource use efficiency in rice

    Directory of Open Access Journals (Sweden)

    Jianchang YANG

    2015-06-01

    Full Text Available This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

  18. Achieving combined high strength and high conductivity in re-processed Cu-Cr alloy

    Directory of Open Access Journals (Sweden)

    A.O. Olofinjanaa

    2009-07-01

    Full Text Available Purpose: Precipitation hardening by nano-sized precipitates had proven to be the most adequate way to achieve the optimum combination for strength and conductivity in copper based alloys. However, precipitation strengthened Cu- alloys are limited to very dilute concentration thereby limiting the volume proportion hardening precipitates. In this work, we report the investigation of the reprocessing of higher Cr concentration Cu- based alloys via rapid solidification.Design/methodology/approach: The ingot alloys with Cr content up to 10 wt.% were prepared via semi-chilling of small rods before been cast into ribbon using chill block melt spinner. Thermal aging studies followed by conductivity and microhardness tests were performed to follow the HSHC properties.Findings: It is found that the rapid solidification in the as-cast ribbon imposed combined solution extension and ultra-refinement of Cr rich phases. X-ray diffraction evidences suggest that the solid solution extension was up to 6wt%Cr. Lattice parameters determined confirmed the many folds extension of solid solution of Cr in Cu. Thermal aging studies of the cast ribbons indicated that peak aging treatments occurred in about twenty minutes. Peak aged hardness ranged from about 200 to well over 300Hv. The maximum peak aged hardness of 380Hv was obtained for alloy containing 6wt.%Cr but with conductivity of about 50%IACS. The best combined strength/conductivity was obtained for 4wt.%Cr alloy with hardness of 350HV and conductivity of 80% IACS. The high strengths observed are attributed to the increased volume proportion of semi-coherent Cr rich nano-sized precipitates that evolved from the supersaturated solid solution of Cu-Cr that was achieved from the high cooling rates imposed by the ribbon casting processResearch limitations/implications: The rapid overaging of the high Cr concentration Cu-Cr alloy is still a cause for concern in optimising the process for reaching peak HSHC properties

  19. Achieving high strength and high ductility in magnesium alloy using hard-plate rolling (HPR) process.

    Science.gov (United States)

    Wang, Hui-Yuan; Yu, Zhao-Peng; Zhang, Lei; Liu, Chun-Guo; Zha, Min; Wang, Cheng; Jiang, Qi-Chuan

    2015-11-25

    Magnesium alloys are highly desirable for a wide range of lightweight structural components. However, rolling Mg alloys can be difficult due to their poor plasticity, and the strong texture yielded from rolling often results in poor plate forming ability, which limits their further engineering applications. Here we report a new hard-plate rolling (HPR) route which achieves a large reduction during a single rolling pass. The Mg-9Al-1Zn (AZ91) plates processed by HPR consist of coarse grains of 30-60 μm, exhibiting a typical basal texture, fine grains of 1-5 μm and ultrafine (sub) grains of 200-500 nm, both of the latter two having a weakened texture. More importantly, the HPR was efficient in gaining a simultaneous high strength and uniform ductility, i.e., ~371 MPa and ~23%, respectively. The superior properties should be mainly attributed to the cooperation effect of the multimodal grain structure and weakened texture, where the former facilitates a strong work hardening while the latter promotes the basal slip. The HPR methodology is facile and effective, and can avoid plate cracking that is prone to occur during conventional rolling processes. This strategy is applicable to hard-to-deform materials like Mg alloys, and thus has a promising prospect for industrial application.

  20. English and Mathematics: Determinants of Physics Achievement among Public High School Seniors in Naga City

    Directory of Open Access Journals (Sweden)

    DR. EDGAR M. BAYLON, JR.

    2014-02-01

    Full Text Available This evaluative and relational study determined the influence of English and Mathematics on the Physics achievement of public high school senior students in Naga City, Philippines. Results showed that the students had an average achievement level in Speaking, Reading, Literature and Grammar. The overall achievement level in Advanced Algebra, Trigonometry and Statistics was average. The overall achievement level in Optics and Waves, Nuclear Physics and Mechanics was average. There was a significant positive relationship between English and Physics achievement, and between Mathematics and Physics Achievement. Reading, Literature and Grammar were the areas in English that significantly influenced Physics achievement. In Mathematics, Advanced Algebra and Trigonometry significantly influenced Physics achievement. The students’ achievement between English and Physics had no significant difference at 1% level but significantly different at 5% level. Mathematics and Physics achievement had no significant difference at 1% and 5% levels. There was no significant difference between schools C and D; A and C; and schools B and C at 5% and 1% levels. However, the achievement level between schools A and B, B and D, and schools A and D were significantly different at 1% level.

  1. Decreased latent inhibition is associated with increased creative achievement in high-functioning individuals.

    Science.gov (United States)

    Carson, Shelley H; Peterson, Jordan B; Higgins, Daniel M

    2003-09-01

    Reductions in latent inhibition (LI), the capacity to screen from conscious awareness stimuli previously experienced as irrelevant, have been generally associated with the tendency towards psychosis. However, "failure" to screen out previously irrelevant stimuli might also hypothetically contribute to original thinking, particularly in combination with high IQ. Meta-analysis of two studies, conducted on youthful high-IQ samples. demonstrated that high lifetime creative achievers had significantly lower LI scores than low creative achievers (r(effect size) = .31, p = .0003, one-tailed). Eminent creative achievers (participants under 21 years who reported unusually high scores in a single domain of creative achievement) were 7 times more likely to have low rather than high LI scores, chi2 (1, N = 25) = 10.69, phi = .47. p = .003.

  2. Intergenerational Closure and Academic Achievement in High School: A New Evaluation of Coleman's Conjecture

    Science.gov (United States)

    Morgan, Stephen L.; Todd, Jennifer J.

    2009-01-01

    This article reexamines the conjecture of James S. Coleman that intergenerational social closure promotes student achievement in high schools, analyzing the best national data on academic achievement and social networks: the 2002 and 2004 waves of the Education Longitudinal Study. The results show that within the Catholic school sector, schools…

  3. Early Reading Skills and Academic Achievement Trajectories of Students Facing Poverty, Homelessness, and High Residential Mobility

    Science.gov (United States)

    Herbers, Janette E.; Cutuli, J. J.; Supkoff, Laura M.; Heistad, David; Chan, Chi-Keung; Hinz, Elizabeth; Masten, Ann S.

    2012-01-01

    This investigation tested the importance of early academic achievement for later achievement trajectories among 18,011 students grouped by level of socioeconomic risk. Students considered to be at highest risk were those who experienced homelessness or high residential mobility (HHM). HHM students were compared with students eligible for free…

  4. Unforgiving Confucian Culture: A Breeding Ground for High Academic Achievement, Test Anxiety and Self-Doubt?

    Science.gov (United States)

    Stankov, Lazar

    2010-01-01

    This paper reviews findings from several studies that contribute to our understanding of cross-cultural differences in academic achievement, anxiety and self-doubt. The focus is on comparisons between Confucian Asian and European regions. Recent studies indicate that high academic achievement of students from Confucian Asian countries is…

  5. Cohort versus Non-Cohort High School Students' Math Performance: Achievement Test Scores and Coursework

    Science.gov (United States)

    Parke, Carol S.; Keener, Dana

    2011-01-01

    The purpose of this study is to compare multiple measures of mathematics achievement for 1,378 cohort students who attended the same high school in a district from 9th to 12th grade with non-cohort students in each grade level. Results show that mobility had an impact on math achievement. After accounting for gender, ethnicity, and SES, adjusted…

  6. Gender and High School Chemistry: Student Perceptions on Achievement in a Selective Setting

    Science.gov (United States)

    Cousins, Andrew; Mills, Martin

    2015-01-01

    This paper reports on research undertaken in a middle-class Australian school. The focus of the research was on the relationship between gender and students' engagement with high school chemistry. Achievement data from many OECD [Organisation for Economic Co-operation and Development] countries suggest that middle-class girls are achieving equally…

  7. Parental Involvement, Homework, and TV Time: Direct and Indirect Effects on High School Achievement.

    Science.gov (United States)

    Keith, Timothy Z.; And Others

    1986-01-01

    A set of High School and Beyond data was used to study the effect of three variables on academic achievement. Homework had a positive effect, TV a negative, and parental involvement no direct effect on seniors' achievement scores, but influenced the amount of time students spent on homework. (Author/JAZ)

  8. Achievement Motivation in High School: Contrasting Theoretical Models in the Classroom.

    Science.gov (United States)

    Garcia-Celay, I. Montero; Tapia, J. Alonso

    1992-01-01

    Three models of achievement motivation in the classroom are contrasted. Results with 155 high school students suggest that the model of C. S. Dweck and E. S. Elliott offers a better explanation of the relationships among achievement motivation, attributions, emotional reactions, expectancies, and performance than do the other models. (SLD)

  9. Fishing amplifies forage fish population collapses

    Science.gov (United States)

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  10. Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

    Science.gov (United States)

    Lyons, J.E.

    2005-01-01

    Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

  11. Impacts of comprehensive reading instruction on diverse outcomes of low- and high-achieving readers.

    Science.gov (United States)

    Guthrie, John T; McRae, Angela; Coddington, Cassandra S; Lutz Klauda, Susan; Wigfield, Allan; Barbosa, Pedro

    2009-01-01

    Low-achieving readers in Grade 5 often lack comprehension strategies, domain knowledge, word recognition skills, fluency, and motivation to read. Students with such multiple reading needs seem likely to benefit from instruction that supports each of these reading processes. The authors tested this expectation experimentally by comparing the effects of Concept-Oriented Reading Instruction (CORI) with traditional instruction (TI) on several outcomes in a 12-week intervention for low achievers and high achievers. Low achievers in the CORI group were afforded explicit instruction, leveled texts, and motivation support. Compared with TI students, CORI students scored higher on posttest measures of word recognition speed, reading comprehension on the Gates-MacGinitie Reading Test, and ecological knowledge. CORI was equally effective for lower achievers and higher achievers. Explicitly supporting multiple aspects of reading simultaneously appeared to benefit diverse learners on a range of reading outcomes.

  12. Energetic Optimisation of Foraging Honeybees: Flexible Change of Strategies in Response to Environmental Challenges

    OpenAIRE

    Anton Stabentheiner; Helmut Kovac

    2014-01-01

    Heterothermic insects like honeybees, foraging in a variable environment, face the challenge of keeping their body temperature high to enable immediate flight and to promote fast exploitation of resources. Because of their small size they have to cope with an enormous heat loss and, therefore, high costs of thermoregulation. This calls for energetic optimisation which may be achieved by different strategies. An 'economizing' strategy would be to reduce energetic investment whenever possible, ...

  13. Seasonal Changes in Forage Nutrients and Mineral Contents in Water Resources,Forage and Yak Blood

    Institute of Scientific and Technical Information of China (English)

    阎萍

    2005-01-01

    This paper reports results of a study conducted to investigate the concentrations of seven mineral elements in yak blood, forage and water resources around the Qinghai Lake in Qinghai Province in different seasons. Meanwhile, the nutritional compositions of the forage were also surveyed. The results suggest that the mineral elements and the forage nutrients change in a seasonal pattern. In yak blood,the sodium(Na)concentration varies from 0.291 to 0.034 mg/mL,and this is lower than the normal value. In the forage,the ratio calcium(Ca)to phosphorus(P)is 4.06~7.47:1 and potassium(K)to Na 30~27:1. These results indicate that the nutrition of the yak in the area is deficient in Na but high in K. For the withered forage sampled in February,the protein content is only 31.14% of the total protein in the forage growing at puerile stage in June. The severe loss of protein by 68. 9% and decrease of effective nutrients in the wintered forage are considered to be the reasons resulting in the poor condition of yak in winter and spring seasons.

  14. Postweaning substitution of grazed forage with a high-energy concentrate has variable long-term effects on subcutaneous fat and marbling in Bos taurus genotypes.

    Science.gov (United States)

    Greenwood, P L; Siddell, J P; Walmsley, B J; Geesink, G H; Pethick, D W; McPhee, M J

    2015-08-01

    The objective of this study was to quantify the effects and interactions of stage of growth and genotype on commercial carcass traits and intramuscular fat (IMF) content in 5 muscles of steers ( = 165) and to test the hypothesis that substituting pasture with a high-energy concentrate during the immediate postweaning period increases IMF. Cattle of 3 genotypes (Angus, Hereford, and Wagyu × Angus; = 55/genotype) were selected at weaning from commercial herds, targeting genotypic differences in marbling and subcutaneous fatness. Following weaning, steers were fed for 168 d within 2 different improved, temperate pasture-based nutritional systems: a forage-only system (FS) and forage with high-energy supplemented system (SS), with 2 replicates per system. The supplement was fed at a level of 1% of average BW adjusted every 2 wk to provide an estimated 50% of energy requirements for 168 d from weaning. Pasture on offer in both systems was managed to match the BW of the FS and SS steers during the postweaning treatment period to avoid confounding due to differences in growth rate during this period. Steers were then regrouped into 2 replicates and backgrounded on improved, temperate pasture for 158 d and then grain fed within 1 group for 105 d (short fed) or 259 d (long fed). Groups were slaughtered at commencement (d 0) and end of postweaning nutritional treatments (d 168), end of backgrounding (d 326), and after short (d 431) or long feedlotting (d 585). Serial slaughter stage had an effect on all traits assessed ( < 0.01). The FS steers had more rib fat ( < 0.01) and higher Meat Standards Australia marbling score ( < 0.05) and a tendency ( < 0.10) to have greater eye muscle area than the SS steers throughout the study. Genotypic differences were evident ( < 0.05) for all traits assessed except HCW, dressing percentage, rib fat depth, ossification score, ultimate pH, and IMF in the semitendinosus muscle. The results for marbling and IMF do not support the use of a

  15. Redesigning forages with condensed tannins

    Science.gov (United States)

    Maximizing protein content in forages and minimizing protein loss during silage fermentation and rumen digestion are concerns for livestock and dairy producers. Substantial amounts of forage protein undergo proteolysis (breakdown) during the ensiling process and during rumen fermentation, transforme...

  16. Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but do increase milk iodine output in early lactation dairy cows fed high-forage diets.

    Science.gov (United States)

    Antaya, N T; Soder, K J; Kraft, J; Whitehouse, N L; Guindon, N E; Erickson, P S; Conroy, A B; Brito, A F

    2015-03-01

    The objective of this study was to investigate the effects of incremental amounts of Ascophyllum nodosum meal (ANOD) on milk production, milk composition including fatty acids and I, blood metabolites, and nutrient intake and digestibility in early lactation dairy cows fed high-forage diets. Twelve multiparous Jersey cows averaging (mean±standard deviation) 40±21 d in milk and 464±35 kg of body weight and 4 primiparous Jersey cows averaging 75±37 d in milk and 384±17kg of body weight were randomly assigned to treatment sequences in a replicated 4×4 Latin square design. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Cows were fed a total mixed ration (64:36 forage-to-concentrate ratio) supplemented (as fed) with 0, 57, 113, or 170 g/d of ANOD. Milk yield as well as concentrations and yields of milk components (fat, protein, lactose, milk urea N) were not affected by increasing dietary amounts of ANOD. Concentration (from 178 to 1,370 µg/L) and yield (from 2.8 to 20.6 mg/d) of milk I increased linearly in cows fed incremental amounts of ANOD as a result of the high concentration of I (820 mg/kg of dry matter) in ANOD. Overall, only minor changes were observed in the proportion of milk fatty acids with ANOD supplementation. Quadratic trends were observed for dry matter intake and total-tract digestibilities of organic matter and neutral detergent fiber, whereas negative linear trends were observed for serum concentration of cortisol and crude protein digestibility with ANOD supplementation. Serum concentrations of triiodothyronine and thyroxine were not affected by ANOD supplementation and averaged 1.1 and 48.4 ng/mL, respectively. However, feeding increasing amounts of ANOD linearly reduced the plasma concentration of nonesterified fatty acids (from 164 to 132 mEq/L). Quadratic effects were found for the total-tract digestibility of ADF and urinary output of purine derivatives, suggesting that ANOD supplementation

  17. Adaptive collective foraging in groups with conflicting nutritional needs.

    Science.gov (United States)

    Senior, Alistair M; Lihoreau, Mathieu; Charleston, Michael A; Buhl, Jerome; Raubenheimer, David; Simpson, Stephen J

    2016-04-01

    Collective foraging, based on positive feedback and quorum responses, is believed to improve the foraging efficiency of animals. Nutritional models suggest that social information transfer increases the ability of foragers with closely aligned nutritional needs to find nutrients and maintain a balanced diet. However, whether or not collective foraging is adaptive in a heterogeneous group composed of individuals with differing nutritional needs is virtually unexplored. Here we develop an evolutionary agent-based model using concepts of nutritional ecology to address this knowledge gap. Our aim was to evaluate how collective foraging, mediated by social retention on foods, can improve nutrient balancing in individuals with different requirements. The model suggests that in groups where inter-individual nutritional needs are unimodally distributed, high levels of collective foraging yield optimal individual fitness by reducing search times that result from moving between nutritionally imbalanced foods. However, where nutritional needs are highly bimodal (e.g. where the requirements of males and females differ) collective foraging is selected against, leading to group fission. In this case, additional mechanisms such as assortative interactions can coevolve to allow collective foraging by subgroups of individuals with aligned requirements. Our findings indicate that collective foraging is an efficient strategy for nutrient regulation in animals inhabiting complex nutritional environments and exhibiting a range of social forms. PMID:27152206

  18. Adaptive collective foraging in groups with conflicting nutritional needs.

    Science.gov (United States)

    Senior, Alistair M; Lihoreau, Mathieu; Charleston, Michael A; Buhl, Jerome; Raubenheimer, David; Simpson, Stephen J

    2016-04-01

    Collective foraging, based on positive feedback and quorum responses, is believed to improve the foraging efficiency of animals. Nutritional models suggest that social information transfer increases the ability of foragers with closely aligned nutritional needs to find nutrients and maintain a balanced diet. However, whether or not collective foraging is adaptive in a heterogeneous group composed of individuals with differing nutritional needs is virtually unexplored. Here we develop an evolutionary agent-based model using concepts of nutritional ecology to address this knowledge gap. Our aim was to evaluate how collective foraging, mediated by social retention on foods, can improve nutrient balancing in individuals with different requirements. The model suggests that in groups where inter-individual nutritional needs are unimodally distributed, high levels of collective foraging yield optimal individual fitness by reducing search times that result from moving between nutritionally imbalanced foods. However, where nutritional needs are highly bimodal (e.g. where the requirements of males and females differ) collective foraging is selected against, leading to group fission. In this case, additional mechanisms such as assortative interactions can coevolve to allow collective foraging by subgroups of individuals with aligned requirements. Our findings indicate that collective foraging is an efficient strategy for nutrient regulation in animals inhabiting complex nutritional environments and exhibiting a range of social forms.

  19. Application of genomics to forage crop breeding for quality traits

    DEFF Research Database (Denmark)

    Lübberstedt, Thomas

    2007-01-01

    studied in detail and sequence motifs with likely effect on forage quality have been identified by association studies. Moreover, transgenic approaches substantiated the effect of several of these genes on forage quality. Perspectives and limitations of these findings for forage crop breeding...... selection ultimately without need of field trials, and being environment independent. In addition, once identified relevant genes controlling forage quality are targets for transgenic approaches. Substantial progress has recently been achieved in the development and application of genomic tools both...... programs. Therefore, several indirect methods including near-infrared reflectance spectroscopy (NIRS) have been established to overcome this limitation. However, the ideal indirect system for the prediction of forage performance would be based on gene-derived "functional" DNA markers, allowing early...

  20. Evaluation of English Achievement Test: A Comparison between High and Low Achievers amongst Selected Elementary School Students of Pakistan

    Science.gov (United States)

    Haider, Zubair; Latif, Farah; Akhtar, Samina; Mushtaq, Maria

    2012-01-01

    Validity, reliability and item analysis are critical to the process of evaluating the quality of an educational measurement. The present study evaluates the quality of an assessment constructed to measure elementary school student's achievement in English. In this study, the survey model of descriptive research was used as a research method.…

  1. The Relationship between Cognitive and Emotional Intelligence and High School Academic Achievement.

    Science.gov (United States)

    Matešić, Krunoslav

    2015-06-01

    The study investigated the relationship between intelligence, emotional intelligence and academic achievement in high school. The study was conducted within the standardization of two instruments for Croatian samples. A total of 369 high school students from the Republic of Croatia participated in the study. They completed the Naglieri Nonverbal Ability Test (NNAT)--a test of cognitive intelligence and the BarOn Emotional Quotient Inventory: Youth Version (EQ-i:YV). Academic achievement criteria were general school achievement, Croatian language and mathematics. Several regression analyses were conducted on the results. The results show that cognitive intelligence and the adaptability scale to be consistent predictors of academic achievement. Emotional intelligence was not shown to be a significant predictor of school success. PMID:26753453

  2. Resilience influence, goals and social context in the academic achievement of high school students

    Directory of Open Access Journals (Sweden)

    José Concepción Gaxiola Romero

    2012-05-01

    Full Text Available The academic achievement in high school students of Mexico, according to national and international evaluations has been insufficient. In spite of this situation, is possible to find excellent students, even in the context of sharing negative contextual and physical conditions. There are few investigations that describe the variables associated to resilient students. The alumni that are beyond the risks are called resilient (Rutter, 2007. The aim of this research was to explore and identify the internal variables: goals and resilience, and the external variables: risky neighborhood and risky friends that predicted the scholar achievement of high school students. To measure those variables, was used a compilation of scales validated in the region. The data were analyzed using structural equation modeling, and show that resilience predicted indirectly the scholar achievement trough the academic goals. The results could be used in programs to improve the academic achievement of this group of students.

  3. Optimal Foraging in Semantic Memory

    Science.gov (United States)

    Hills, Thomas T.; Jones, Michael N.; Todd, Peter M.

    2012-01-01

    Do humans search in memory using dynamic local-to-global search strategies similar to those that animals use to forage between patches in space? If so, do their dynamic memory search policies correspond to optimal foraging strategies seen for spatial foraging? Results from a number of fields suggest these possibilities, including the shared…

  4. An Evaluation of the English Achievement Test for Junior High School Graduation 2012

    Institute of Scientific and Technical Information of China (English)

    叶译

    2013-01-01

    This paper evaluates the Achievement Test for Junior High School Graduation in reliability, validity and practicality, which is aimed to help junior English teachers to understand how to identify a useful test and develop their test writing skills as well as improve their teaching. The result suggests that the Achievement Test is a reasonably reliable and valid test though some of the listening items need to be improved. It is the ideal frame of evaluating language learning through language testing.

  5. Emotional Intelligence as a Predictor of Leadership of Kuwaiti High and Low Achieving 11th Graders

    Science.gov (United States)

    Alnabhan, Mousa

    2010-01-01

    The current study examined the association between emotional intelligence (EI) and the Leadership components (L) of high school students in the state of Kuwait. The possibility of predicting each leadership component via emotional intelligence components was investigated for high and low achievers. A sample of 11th grade students from Kuwaiti…

  6. Causes of Nonattendance and Its Effect on Student Achievement at the High School Level

    Science.gov (United States)

    Bracht, Kelly D.

    2010-01-01

    Many high schools in America have issues with student nonattendance. The researcher designed this mixed methods study to determine the affect of nonattendance on student achievement and to ascertain whether home-related factors or school-related factors were more significant causes of nonattendance. Both the high school in this study and other…

  7. Mathematics Achievement with Digital Game-Based Learning in High School Algebra 1 Classes

    Science.gov (United States)

    Ferguson, Terri Lynn Kurley

    2014-01-01

    This study examined the impact of digital game-based learning (DGBL) on mathematics achievement in a rural high school setting in North Carolina. A causal comparative research design was used in this study to collect data to determine the effectiveness of DGBL in high school Algebra 1 classes. Data were collected from the North Carolina…

  8. The Effects of Modeling Instruction on High School Physics Academic Achievement

    Science.gov (United States)

    Wright, Tiffanie L.

    2012-01-01

    The purpose of this study was to explore whether Modeling Instruction, compared to traditional lecturing, is an effective instructional method to promote academic achievement in selected high school physics classes at a rural middle Tennessee high school. This study used an "ex post facto," quasi-experimental research methodology. The…

  9. School Context, Precollege Educational Opportunities, and College Degree Attainment among High-Achieving Black Males

    Science.gov (United States)

    Rose, Valija C.

    2013-01-01

    Access to high-quality educational opportunities is central to growing postsecondary degree attainment. This study employs secondary data analysis of the public-use National Education Longitudinal Study (NELS:88/00) to examine how school context and precollege educational opportunities influence college degree attainment among high-achieving Black…

  10. Incremental amounts of ground flaxseed decrease milk yield but increase n-3 fatty acids and conjugated linoleic acids in dairy cows fed high-forage diets(1).

    Science.gov (United States)

    Resende, T L; Kraft, J; Soder, K J; Pereira, A B D; Woitschach, D E; Reis, R B; Brito, A F

    2015-07-01

    The objective of this study was to investigate the effect of incremental amounts of ground flaxseed (GFX) on milk yield and concentrations and yields of milk components, milk fatty acids (FA) profile, ruminal metabolism, and nutrient digestibility in dairy cows fed high-forage diets. Twelve multiparous Jersey cows averaging (mean ± SD) 112±68d in milk and 441±21kg of body weight and 8 primiparous Jersey cows averaging 98±43d in milk and 401±43kg of body weight were randomly assigned to treatment sequences in a replicated 4×4 Latin square design. Each period lasted 21d with 14d for diet adaptation and 7d for data and sample collection. Treatments were fed as a total mixed ration (63:37 forage-to-concentrate ratio) with corn meal and soybean meal replaced by incremental levels (i.e., 0, 5, 10, or 15% diet dry matter) of GFX. The ruminal molar proportions of acetate and butyrate decreased linearly with GFX supplementation, whereas the ruminal molar proportion of propionate increased linearly resulting in decreased acetate-to-propionate ratio. Apparent total-tract digestibilities of nutrients either decreased (dry matter) or tended to decrease (organic matter, neutral detergent fiber, acid detergent fiber) linearly in cows fed GFX. Milk yield decreased linearly in cows fed increasing amounts of GFX, which is explained by the linear reduction in dry matter intake. Except for the concentrations of milk protein and urea N, which decreased linearly with GFX supplementation, no other changes in the concentration of milk components were observed. However, yields of milk protein and fat decreased linearly with GFX supplementation. The linear decrease in the yields of milk fat and protein are explained by reduced milk yield, whereas that in milk urea N is explained by decreased crude protein intake. No treatment effects were observed for plasma urea N and nonesterified fatty acids, serum cortisol, and body weight change. Milk odd- and branched-chain FA and saturated FA

  11. Arboreal forage lichen response to partial cutting of high elevation mountain caribou range in the Quesnel Higland of east-central British Columbia

    Directory of Open Access Journals (Sweden)

    Michaela J. Waterhouse

    2007-04-01

    Full Text Available Group selection silvicultural systems have been recommended for managing mountain caribou (Rangifer tarandus caribou habitat in high elevation Engelmann spruce – subalpine fir forests in east-central British Columbia. We measured the response of arboreal lichen (a key winter forage to harvesting of 30% of the forested area using three partial cutting treatments, which created small (0.03 ha, medium (0.13 ha, and large (1.0 ha openings, and a no-harvest treatment. Treatments were replicated on four sites, and monitored over a ten year post-harvest period. The short-term loss of lichen associated with removal of approximately one third of the trees was partially offset by a significant (P=0.01 increase in lichen abundance on trees in the caribou feeding zone (up to 4.5 m in the three partial cutting treatments relative to trees in the uncut forest. Differences among treatments in the change in lichen composition, as measured by the percentage of Alectoria sarmentosa and Bryoria spp., were marginally significant (P=0.10. The partial cutting treatments showing a greater likelihood of shifting towards more Bryoria spp. than no-harvest treatment (P=0.04. In the year of harvest (1993, larger trees were found to hold more lichen than smaller trees (P=0.04, and live trees supported more lichen than dead trees (P=0.01, but lichen loading was similar among tree species (P=0.51. Tree fall rates were similar among treatments, based on the ten year average (0.6–0.8% of sample trees per year. The results indicate that caribou foraging habitat is maintained in the residual forest when group selection systems that remove only 30% of the trees are applied. Information on the distribution of lichen is useful for developing stand level prescriptions. Providing lichen bearing habitat meets just one of the needs of caribou. A comprehensive approach that considers all factors and their interactions is essential to maintain and recover the threatened mountain

  12. Effect of Propionibacterium spp. on ruminal fermentation, nutrient digestibility, and methane emissions in beef heifers fed a high-forage diet.

    Science.gov (United States)

    Vyas, D; McGeough, E J; McGinn, S M; McAllister, T A; Beauchemin, K A

    2014-05-01

    The objective of this study was to test the efficacy of different Propionibacterium strains in mitigating methane (CH4) emissions in beef heifers fed a high-forage diet. Twenty ruminally cannulated beef heifers were used in a randomized block design with 28-d periods. Treatments included 1) Control, 2) Propionibacterium acidipropionici strain P169, 3) Propionibacterium acidipropionici strain P5, and 4) Propionibacterium jensenii strain P54. Strains (5 × 10(9) CFU) were administered daily directly into the rumen in 10 g of a maltodextrin carrier in a gel capsule. Control heifers received the carrier only. All heifers were fed a basal diet (70:30 forage to concentrate, DM basis) based on barley silage and corn grain. No treatment effects were observed for overall DMI (P = 0.78) or DMI in chambers (P = 0.29). Dry matter intake was 12 to 29% less in the chambers, with intake depression numerically lower in heifers receiving Propionibacterium than Control. Mean ruminal pH averaged 6.47 and was not affected by treatments (P = 0.34). Likewise, no treatment differences were observed for ruminal concentrations of total VFA (P = 0.24) and ammonia-N (P = 0.49) or for molar proportion of individual VFA. Total daily enteric CH4 production was not affected by Propionibacterium strains as compared to Control and averaged 178 g/d (P = 0.69). However, enteric CH4 emission intensity (g CH4/kg of DMI) was reduced by 12, 8, and 13% with P169, P5, and P54 as compared to Control, respectively (P = 0.03). No treatment effects were observed for total tract digestibility of nutrients. Likewise, total universal bacterial (P = 0.22) and methanogen (P = 0.64) counts were similar among treatments. However, the relative abundance of total Propionibacteria tended to increase with inoculation as compared to Control (P = 0.06). The relative abundance of Propionibacterium P169 tended to be greater at 3 h postdosing, but returned to pretreatment (0 h) levels within 9 h, suggesting it failed to

  13. Habitat-specific foraging strategies in Australasian gannets.

    Science.gov (United States)

    Wells, Melanie R; Angel, Lauren P; Arnould, John P Y

    2016-07-15

    Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator) typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26), in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change.

  14. Habitat-specific foraging strategies in Australasian gannets

    Directory of Open Access Journals (Sweden)

    Melanie R. Wells

    2016-07-01

    Full Text Available Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26, in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change.

  15. Habitat-specific foraging strategies in Australasian gannets

    Science.gov (United States)

    Wells, Melanie R.; Arnould, John P. Y.

    2016-01-01

    ABSTRACT Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator) typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26), in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change. PMID:27305927

  16. Habitat-specific foraging strategies in Australasian gannets.

    Science.gov (United States)

    Wells, Melanie R; Angel, Lauren P; Arnould, John P Y

    2016-01-01

    Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator) typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26), in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change. PMID:27305927

  17. Field application of mycorrhizal bio-inoculants affects the mineral uptake of a forage legume (Hedysarum coronarium L.) on a highly calcareous soil.

    Science.gov (United States)

    Labidi, S; Jeddi, F Ben; Tisserant, B; Yousfi, M; Sanaa, M; Dalpé, Y; Sahraoui, A Lounès-Hadj

    2015-05-01

    The efficiency of two mycorrhizal bio-inoculants on the mineral uptake during the growth stages of a Mediterranean forage legume sulla (Hedysarum coronarium L.) was studied in the field on a highly calcareous soil. The first inoculum (Mm) was made up of a mixture of native arbuscular mycorrhizal fungi (AMF) isolated from calcareous soils: Septoglomus constrictum, Funneliformis geosporum, Glomus fuegianum, Rhizophagus irregularis and Glomus sp. The second was a commercial inoculum (Mi) containing one AMF species: R. irregularis. Both mycorrhizal inoculants increased total and arbuscular colonization of sulla roots. Inoculation with Mm showed a positive effect on sulla shoot dry weight (SDW) when compared to Mi and non-inoculated plants (control). Mineral contents (P, Mg, Mn, Fe) were higher in the shoots of sulla plants cultivated on mycorrhiza-inoculated plots compared to non-inoculated ones. This enhancement was observed during the flowering stage for P, Mg and Mn and during the rosette stage for Fe. An increase in P content of 50 % in plants inoculated with Mm compared to non-inoculated ones may be explained by the induction of root alkaline and acid phosphatase activities. Higher efficiency of native AMF species adapted to calcareous soils opens the way towards the development of mycorrhiza bio-fertilizers targeted to improve sustainable fertilization management in such soils. PMID:25323044

  18. High frequency wide-band transformer uses coax to achieve high turn ratio and flat response

    Science.gov (United States)

    De Parry, T.

    1966-01-01

    Center-tap push-pull transformer with toroidal core helically wound with a single coaxial cable creates a high frequency wideband transformer. This transformer has a high-turn ratio, a high coupling coefficient, and a flat broadband response.

  19. School factors affecting postsecondary career pursuits of high-achieving girls in mathematics and science

    Science.gov (United States)

    Yoo, Hyunsil

    This study examined the influences of secondary school experiences of high-achieving girls in math and science on their postsecondary career pursuits in science fields. Specifically, using the National Education Longitudinal Study of 1988 (NELS:88), the study investigated how science class experiences in high school affect science career persistence of high-achieving girls over and above personal and family factors. Selecting the top 10% on the 8 th grade math and science achievement tests from two panel samples of 1988--1994 and 1988--2000, this study examined which science instructional experiences (i.e., lecture-oriented, experiment-oriented, and student-oriented) best predicted college major choices and postsecondary degree attainments in the fields of science after controlling for personal and family factors. A two-stage test was employed for the analysis of each panel sample. The first test examined the dichotomous career pursuits between science careers and non-science careers and the second test examined the dichotomous pursuits within science careers: "hard" science and "soft" science. Logistic regression procedures were used with consideration of panel weights and design effects. This study identified that experiment-oriented and student-oriented instructional practices seem to positively affect science career pursuits of high-achieving females, while lecture-oriented instruction negatively affected their science career pursuits, and that the longitudinal effects of the two positive instructional contributors to science career pursuits appear to be differential between major choice and degree attainment. This study also found that the influences of instructional practices seem to be slight for general females, while those for high-achieving females were highly considerable, regardless of whether negative or positive. Another result of the study found that only student-oriented instruction seemed to have positive effects for high-achieving males. In

  20. Achieving Both High Power and Energy Density in Electrochemical Supercapacitors with Nanoporous Graphene Materials

    OpenAIRE

    Yang, Hao; Kannappan, Santhakumar; Pandian, Amaresh S.; Jang, Jae-Hyung; Lee, Yun Sung; Lu, Wu

    2013-01-01

    Supercapacitors, based on the fast ion transportation, are specialized to provide high power, long stability, and efficient energy storage with highly porous electrode materials. However, their low energy density and specific capacitance prevent them from many applications that require long duration. Using a scalable nanoporous graphene synthesis method involving a simple annealing process in hydrogen, here we show graphene supercapacitors capable of achieving a high energy density comparable...

  1. What leadership behaviors were demonstrated by the principal in a high poverty, high achieving elementary school?

    Directory of Open Access Journals (Sweden)

    E. Hayet J. Woods

    2016-12-01

    Full Text Available Examined through the lens of leadership, were the behaviors of a principal as perceived by stakeholders. The following themes emerged: (1 Educating the Whole Child, with the subthemes: (a providing basic needs; (b academic interventions based on achievement data; (c an emphasis on reading; (d extended academic time; and (e relationships; and (2 Synergy of Expectations, with the subthemes: (a consistent student expectations; (b increased staff accountability; and (c community involvement. The researchers found that the principal by demonstrating behaviors as a change agent, a creator of vision, and a provider of necessary support and strategies, rather than adopting numerous programs, the school personnel were able to increase and sustain academic achievement of the students of poverty as well as their peers. Implications for principal practices, along with leadership preparatory programs are significant.

  2. Fatty acid profile, meat quality, and carcass traits of Nellore young bulls fed different sources of forage in high-concentrate diets with crude glycerin

    Directory of Open Access Journals (Sweden)

    Andressa Ferreira Ribeiro

    2016-04-01

    Full Text Available ABSTRACT The objectives of this study were to evaluate the effect of forages with different nutritional values - specifically, corn silage (CS, sugar cane (SC, and sugar cane bagasse (SB - in diets with crude glycerin, on carcass traits, meat quality, and fatty acid profile, using young Nellore bulls finished in the feedlot. Thirty young Nellore bulls with an initial average body weight of 416.70±24.74 kg were randomly assigned to three treatments containing different sources of forage. The carcass traits and variables related to meat quality of the Nellore young bulls were not significantly influenced by different sources of forage in diets with crude glycerin. The yellow color index was significantly greater in the fat of animals fed corn silage. Heptadecenoic fatty acid was significantly lower in the meat of animals fed sugar cane bagasse. The sources of forage in diets with crude glycerin did not influence the profile of saturated, monounsaturated, or polyunsaturated fatty acids in the longissimus muscle. Overall, our results indicate that none of the treatments changed the carcass and meat quality traits of Nellore young bulls finished in the feedlot. Thus, sugar cane and sugar cane bagasse could be used in feedlot as a viable forage alternative to corn silage.

  3. EFFECTS OF FORAGE SPECIES ON FATTY ACID COMPOSITION OF BEEF LONGISSIMUS MUSCLE FROM FORAGE-FINISHED BEEF

    Science.gov (United States)

    Forty-seven Angus-crossbred steers were used to evaluate the effects of forage species grazed in the last 41 d of the finishing period on rib composition, color, and palatability in forage-finished beef and compared to traditional high concentrate finished. Steers grazed naturalized pastures (bluegr...

  4. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman;

    2016-01-01

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest...... reducing crop yields and thereby farmers earnings....

  5. High IQ Is Sufficient to Explain the High Achievements in Math and Science of the East Asian Peoples

    Science.gov (United States)

    Lynn, Richard

    2010-01-01

    It is argued that it is unnecessary to propose that Confucian values explain the high achievements in math and science of the North East Asian peoples, and that these can be satisfactorily and more parsimoniously be explained by their high IQs.

  6. Pronounced Seasonal Changes in the Movement Ecology of a Highly Gregarious Central-Place Forager, the African Straw-Coloured Fruit Bat (Eidolon helvum.

    Directory of Open Access Journals (Sweden)

    Jakob Fahr

    Full Text Available Straw-coloured fruit bats (Eidolon helvum migrate over vast distances across the African continent, probably following seasonal bursts of resource availability. This causes enormous fluctuations in population size, which in turn may influence the bats' impact on local ecosystems. We studied the movement ecology of this central-place forager with state-of-the-art GPS/acceleration loggers and concurrently monitored the seasonal fluctuation of the colony in Accra, Ghana. Habitat use on the landscape scale was assessed with remote sensing data as well as ground-truthing of foraging areas.During the wet season population low (~ 4000 individuals, bats foraged locally (3.5-36.7 km in urban areas with low tree cover. Major food sources during this period were fruits of introduced trees. Foraging distances almost tripled (24.1-87.9 km during the dry season population peak (~ 150,000 individuals, but this was not compensated for by reduced resting periods. Dry season foraging areas were random with regard to urban footprint and tree cover, and food consisted almost exclusively of nectar and pollen of native trees.Our study suggests that straw-coloured fruit bats disperse seeds in the range of hundreds of meters up to dozens of kilometres, and pollinate trees for up to 88 km. Straw-coloured fruit bats forage over much larger distances compared to most other Old World fruit bats, thus providing vital ecosystem services across extensive landscapes. We recommend increased efforts aimed at maintaining E. helvum populations throughout Africa since their keystone role in various ecosystems is likely to increase due to the escalating loss of other seed dispersers as well as continued urbanization and habitat fragmentation.

  7. Experiencing More Mathematics Anxiety than Expected? Contrasting Trait and State Anxiety in High Achieving Students

    Science.gov (United States)

    Roos, A.-L.; Bieg, M.; Goetz, T.; Frenzel, A. C.; Taxer, J.; Zeidner, M.

    2015-01-01

    This study examined mathematics anxiety among high and low achieving students (N = 237, grades 9 and 10) by contrasting trait (habitual) and state (momentary) assessments of anxiety. Previous studies have found that trait anxiety measures are typically rated higher than state measures. Furthermore, the academic self-concept has been identified to…

  8. The Influence of Social Capital Factors on African-American and Hispanic High School Student Achievement

    Science.gov (United States)

    Davis, Jacqueline L.

    2009-01-01

    The underachievement of African American and Hispanic students has been an ongoing problem for schools in the United States. The purpose of this investigation was to add to the existing body of knowledge concerning social capital of African American and Hispanic high school students' academic achievement. Using a nationally representative sample…

  9. The Effects of Alcohol Use on Academic Achievement in High School

    Science.gov (United States)

    Balsa, Ana I.; Giuliano, Laura M.; French, Michael T.

    2011-01-01

    This paper examines the effects of alcohol use on high school students' quality of learning. We estimate fixed-effects models using data from the National Longitudinal Study of Adolescent Health. Our primary measure of academic achievement is the student's grade point average (GPA) abstracted from official school transcripts. We find that…

  10. One-to-One Computing and Student Achievement in Ohio High Schools

    Science.gov (United States)

    Williams, Nancy L.; Larwin, Karen H.

    2016-01-01

    This study explores the impact of one-to-one computing on student achievement in Ohio high schools as measured by performance on the Ohio Graduation Test (OGT). The sample included 24 treatment schools that were individually paired with a similar control school. An interrupted time series methodology was deployed to examine OGT data over a period…

  11. Social Media Use, Loneliness, and Academic Achievement: A Correlational Study with Urban High School Students

    Science.gov (United States)

    Neto, Roque; Golz, Nancy; Polega, Meaghan

    2015-01-01

    This study explored the association between social media use, loneliness, and academic achievement in high school students and identified the demographic characteristics associated with these three elements. This study also aimed to identify the percentage of variance in loneliness accounted for by social media use and GPA. Participants were 345…

  12. The Relationship between Illinois School District Superintendent Longevity and High School Student Achievement

    Science.gov (United States)

    Libka, Robert J.

    2012-01-01

    Frequent changes in school district superintendents may be having a detrimental impact on student achievement. Rapid changes in leadership today parallel the present (NCLB) era of high stakes state assessments. The goal of the study was to provide correlation research that would have a positive effect on school district management, superintendent…

  13. Organizational Practices of High-Achieving Rural School Districts in California's San Joaquin Valley

    Science.gov (United States)

    Doerksen, Amanda López; Wise, Donald

    2016-01-01

    For over 25 years, researchers have identified "best practices" used by high-achieving school districts. However, little research exists regarding rural school systems, making it difficult to determine whether the best practices identified are relevant within this context. This study filled a void in research by focusing on the…

  14. Actively Closing the Gap? Social Class, Organized Activities, and Academic Achievement in High School

    Science.gov (United States)

    Morris, David S.

    2015-01-01

    Participation in Organized Activities (OA) is associated with positive behavioral and developmental outcomes in children. However, less is known about how particular aspects of participation affect the academic achievement of high school students from different social class positions. Using the Education Longitudinal Study of 2002, this study…

  15. Comparing Computer Game and Traditional Lecture Using Experience Ratings from High and Low Achieving Students

    Science.gov (United States)

    Grimley, Michael; Green, Richard; Nilsen, Trond; Thompson, David

    2012-01-01

    Computer games are purported to be effective instructional tools that enhance motivation and improve engagement. The aim of this study was to investigate how tertiary student experiences change when instruction was computer game based compared to lecture based, and whether experiences differed between high and low achieving students. Participants…

  16. Emotional Intelligence and Academic Achievement of High School Students in Kanyakumari District

    Science.gov (United States)

    Lawrence, A. S. Arul; Deepa, T.

    2013-01-01

    The objective of the study is to find the significant relationship between emotional intelligence and academic achievement of high school students with reference to the background variables. Survey method was employed. Two tools are used in this study namely self-made Trait Emotional Intelligence Questionnaire Short Form (TEIQue SF) and the…

  17. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    Science.gov (United States)

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey…

  18. An Analysis of the Academic Achievement of Indian High School Students in Federal and Public Schools.

    Science.gov (United States)

    Bass, Willard P.

    A longitudinal study was designed to determine whether there were significant differences in academic achievement between senior high American Indian students in Federal on-reservation, Federal off-reservation, public on-reservation, and public off-reservation schools. The purpose of the study was to gather a variety of data on psychological and…

  19. Honeybee foraging in differentially structured landscapes.

    Science.gov (United States)

    Steffan-Dewenter, Ingolf; Kuhn, Arno

    2003-03-22

    Honeybees communicate the distance and location of resource patches by bee dances, but this spatial information has rarely been used to study their foraging ecology. We analysed, for the first time to the best of the authors' knowledge, foraging distances and dance activities of honeybees in relation to landscape structure, season and colony using a replicated experimental approach on a landscape scale. We compared three structurally simple landscapes characterized by a high proportion of arable land and large patches, with three complex landscapes with a high proportion of semi-natural perennial habitats and low mean patch size. Four observation hives were placed in the centre of the landscapes and switched at regular intervals between the six landscapes from the beginning of May to the end of July. A total of 1137 bee dances were observed and decoded. Overall mean foraging distance was 1526.1 +/- 37.2 m, the median 1181.5 m and range 62.1-10037.1 m. Mean foraging distances of all bees and foraging distances of nectar-collecting bees did not significantly differ between simple and complex landscapes, but varied between month and colonies. Foraging distances of pollen-collecting bees were significantly larger in simple (1743 +/- 95.6 m) than in complex landscapes (1543.4 +/- 71 m) and highest in June when resources were scarce. Dancing activity, i.e. the number of observed bee dances per unit time, was significantly higher in complex than in simple landscapes, presumably because of larger spatial and temporal variability of resource patches in complex landscapes. The results facilitate an understanding of how human landscape modification may change the evolutionary significance of bee dances and ecological interactions, such as pollination and competition between honeybees and other bee species. PMID:12769455

  20. Factors affecting forage stand establishment Fatores que afetam o estabelecimento do estande em plantas forrageiras

    OpenAIRE

    Sulc, R.M.

    1998-01-01

    Significant advances have been made in our knowledge of forage seed physiology, technology, and stand establishment practices; however, stand establishment continues to be one of the most common production problems affecting forage crops in the USA. There is a need for research on stand establishment of forage crops under abiotic and biotic stress. Although the forage seed industry produces and markets seed of high quality, new methods of assessing seed vigor are needed and their use should b...

  1. Breeding Better Forages to Help Feed Man and Preserve and Enhance the Environment

    Science.gov (United States)

    Burton, Glenn W.

    1973-01-01

    Discusses the importance of forages in agriculture, and expresses the need for the same high level of technology that is used in the production of corn, wheat, and rice to be applied to forage production. Describes promising forage species, breeding objectives, and breeding procedures used in research. (JR)

  2. The Information Search Process of High, Middle, and Low Achieving High School Seniors.

    Science.gov (United States)

    Kuhlthau, Carol C.

    Traditionally, library instruction has been based on the sources in the library and not on the process of seeking information. A new approach to library skills may be needed to enable students to become effective information users. This study investigated the information search process of 140 high school seniors in six high schools. Subjects were…

  3. High-quality forage can replace concentrate when cows enter the deposition phase without negative consequences for milk production

    DEFF Research Database (Denmark)

    Hymøller, Lone; Alstrup, Lene; Larsen, Mette Krogh;

    2014-01-01

    Mobilization and deposition in cows are different strategies of metabolism; hence, the aim was to study the possibility of reducing the crude protein (CP) supply during deposition to limit the use of protein supplements and minimize the environmental impact. A total of 61 Jersey and 107 Holstein...... calving. Subsequently, cows either remained on HCFR-RP or changed to one of the other mixed rations. Comparing strategies during wk 9 to 30 of lactation showed higher dry matter intake (DMI) of mixed ration on HCFR compared with LCFR and on RP compared with LP. The DMI of the concentrate was higher...... persistency after the ration change. Milk composition did not differ among strategies but the protein to fat ratio was higher on HCFR than on LCFR and tended to be lower on RP than on LP. Differences in fatty acid composition were small, and de novo synthesis was high (>60%). Energy efficiency was higher...

  4. Energetic optimisation of foraging honeybees: flexible change of strategies in response to environmental challenges.

    Science.gov (United States)

    Stabentheiner, Anton; Kovac, Helmut

    2014-01-01

    Heterothermic insects like honeybees, foraging in a variable environment, face the challenge of keeping their body temperature high to enable immediate flight and to promote fast exploitation of resources. Because of their small size they have to cope with an enormous heat loss and, therefore, high costs of thermoregulation. This calls for energetic optimisation which may be achieved by different strategies. An 'economizing' strategy would be to reduce energetic investment whenever possible, for example by using external heat from the sun for thermoregulation. An 'investment-guided' strategy, by contrast, would be to invest additional heat production or external heat gain to optimize physiological parameters like body temperature which promise increased energetic returns. Here we show how honeybees balance these strategies in response to changes of their local microclimate. In a novel approach of simultaneous measurement of respiration and body temperature foragers displayed a flexible strategy of thermoregulatory and energetic management. While foraging in shade on an artificial flower they did not save energy with increasing ambient temperature as expected but acted according to an 'investment-guided' strategy, keeping the energy turnover at a high level (∼56-69 mW). This increased thorax temperature and speeded up foraging as ambient temperature increased. Solar heat was invested to increase thorax temperature at low ambient temperature ('investment-guided' strategy) but to save energy at high temperature ('economizing' strategy), leading to energy savings per stay of ∼18-76% in sunshine. This flexible economic strategy minimized costs of foraging, and optimized energetic efficiency in response to broad variation of environmental conditions.

  5. Implementation and control of electrolysers to achieve high penetrations of renewable power

    Energy Technology Data Exchange (ETDEWEB)

    Troncoso, E.; Newborough, M. [ITM Power plc, Orkney House, Great Chesterford Court, Great Chesterford, Saffron Walden CB10 1PF (United Kingdom)

    2007-09-15

    The mass deployment of electrolysers, within a power system serving a region of high wind resource, as the enabling mechanism for achieving five key objectives is assessed (that is: a very high installed capacity of wind power plant (WPP); zero wind curtailment during times of low demand; a very high load factor for thermal power plant; an electricity supply of low-carbon intensity; and a hydrogen supply of low-carbon intensity). Three electrolyser implementation cases were simulated for three days characterised mainly by wind availability and emphasis was placed on maximizing the smoothness of the load profile (LF) applied to thermal power plant. If zero-carbon hydrogen is to be produced a daily load factor for thermal power plant of 90% is the upper limit, but load factors of up to 100% are achievable if a carbon intensity of 3kgCO{sub 2}/kgH{sub 2} is permitted. For wind penetrations exceeding approximately 30% of system maximum demand, the electrolyser stock must include implementations close to WPP if curtailment is to be avoided. To achieve very high wind penetrations and very high load factors for thermal power plant requires a large stock of electrolysers - for the system investigated approximately 1.1 MW of electrolyser capacity is required per installed MW of wind power. (author)

  6. Relationship of constructivist learning environment to student attitudes and achievement in high school mathematics and science

    Science.gov (United States)

    Dethlefs, Theresa Marie

    This study investigated the relationship of constructivist learning environment and standards-based teaching practices to student achievement and attitudes (self-efficacy, intrinsic value, and learning strategies) in Algebra and Biology. Further, these relationships were examined as a function of student gender and prior achievement. A purposive sample of 804 high school students enrolled in Biology I, Algebra I, or Advanced Algebra was selected for inclusion in this study. Although the dimensions of constructivist learning environment that contributed to predicting student achievement and attitudes varied by content area and criterion, the results of the present study generally provide strong support for a positive relationship between constructivist learning environment and student attitudes, but little support for a direct relationship to student achievement. Teacher reports of overall constructivist learning environment were not correlated with achievement or attitudes. Observer reports of constructivist learning environment were correlated with student intrinsic value and learning strategies. Student reports of constructivist learning environment were correlated with all three attitude measures. Multiple regression findings showed that neither overall constructivist learning environment nor standards-based teaching practices predicted achievement in any of the content areas. Overall constructivist learning environment and standards-based teaching practices were significant positive predictors of student intrinsic value and learning strategies in all three content areas, after controlling for student and classroom demographic variables. Overall constructivist learning environment and standards-based teaching practices were also significant positive predictors of self-efficacy in Algebra 1. In addition, standards-based teaching practices was a significant positive predictor of student self-efficacy in Biology. No specific dimensions of constructivist learning

  7. The role of chronotype, gender, test anxiety, and conscientiousness in academic achievement of high school students.

    Science.gov (United States)

    Rahafar, Arash; Maghsudloo, Mahdis; Farhangnia, Sajedeh; Vollmer, Christian; Randler, Christoph

    2016-01-01

    Previous findings have demonstrated that chronotype (morningness/intermediate/eveningness) is correlated with cognitive functions, that is, people show higher mental performance when they do a test at their preferred time of day. Empirical studies found a relationship between morningness and higher learning achievement at school and university. However, only a few of them controlled for other moderating and mediating variables. In this study, we included chronotype, gender, conscientiousness and test anxiety in a structural equation model (SEM) with grade point average (GPA) as academic achievement outcome. Participants were 158 high school students and results revealed that boys and girls differed in GPA and test anxiety significantly, with girls reporting better grades and higher test anxiety. Moreover, there was a positive correlation between conscientiousness and GPA (r = 0.17) and morningness (r = 0.29), respectively, and a negative correlation between conscientiousness and test anxiety (r = -0.22). The SEM demonstrated that gender was the strongest predictor of academic achievement. Lower test anxiety predicted higher GPA in girls but not in boys. Additionally, chronotype as moderator revealed a significant association between gender and GPA for evening types and intermediate types, while intermediate types showed a significant relationship between test anxiety and GPA. Our results suggest that gender is an essential predictor of academic achievement even stronger than low or absent test anxiety. Future studies are needed to explore how gender and chronotype act together in a longitudinal panel design and how chronotype is mediated by conscientiousness in the prediction of academic achievement.

  8. High fat diet promotes achievement of peak bone mass in young rats

    Energy Technology Data Exchange (ETDEWEB)

    Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Mittal, Monika; Chattopadhyay, Naibedya [Division of Endocrinology and Center for Research in Anabolic Skeletal Targets in Health and Illness (ASTHI), CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226 031 (India); Wani, Mohan R. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Bhat, Manoj Kumar, E-mail: manojkbhat@nccs.res.in [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India)

    2014-12-05

    Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

  9. High fat diet promotes achievement of peak bone mass in young rats

    International Nuclear Information System (INIS)

    Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet

  10. Achievement Motivation of the High School Students: A Case Study among Different Communities of Goalpara District of Assam

    Science.gov (United States)

    Sarangi, C.

    2015-01-01

    Achievement motivation is a consistent striving force of an individual to achieve success to a certain standard of excellence in competing situation. In this study an attempt was made to study the effect of achievement motivation on the academic achievement of the high school students of tribal and non tribal communities in relation to their sex…

  11. Niche dynamics of shorebirds in Delaware Bay: Foraging behavior, habitat choice and migration timing

    Science.gov (United States)

    Novcic, Ivana

    2016-08-01

    Niche differentiation through resource partitioning is seen as one of the most important mechanisms of diversity maintenance contributing to stable coexistence of different species within communities. In this study, I examined whether four species of migrating shorebirds, dunlins (Calidris alpina), semipalmated sandpipers (Calidris pusilla), least sandpipers (Calidris minutilla) and short-billed dowitchers (Limnodromus griseus), segregate by time of passage, habitat use and foraging behavior at their major stopover in Delaware Bay during spring migration. I tested the prediction that most of the separation between morphologically similar species will be achieved by differential migration timing. Despite the high level of overlap along observed niche dimensions, this study demonstrates a certain level of ecological separation between migrating shorebirds. The results of analyses suggest that differential timing of spring migration might be the most important dimension along which shorebird species segregate while at stopover in Delaware Bay. Besides differences in time of passage, species exhibited differences in habitat use, particularly least sandpipers that foraged in vegetated areas of tidal marshes more frequently than other species, as well as short-billed dowitchers that foraged in deeper water more often than small sandpipers did. Partitioning along foraging techniques was less prominent than segregation along temporal or microhabitat dimensions. Such ranking of niche dimensions emphasizes significance of temporal segregation of migratory species - separation of species by time of passage may reduce the opportunity for interspecific aggressive encounters, which in turn can have positive effects on birds' time and energy budget during stopover period.

  12. Disruption of foraging by a dominant invasive species to decrease its competitive ability.

    Directory of Open Access Journals (Sweden)

    Fabian Ludwig Westermann

    Full Text Available Invasive species are a major threat to biodiversity when dominant within their newly established habitat. The globally distributed Argentine ant Linepithema humile has been reported to break the trade-off between interference and exploitative competition, achieve high population densities, and overpower nests of many endemic ant species. We have used the sensitivity of the Argentine ant to the synthetic trail pheromone (Z-9-hexadecanal to investigate species interactions for the first time. We predicted that disrupting Argentine ant trail following behaviour would reduce their competitive ability and create an opportunity for three other resident species to increase their foraging success. Argentine ant success in the control was reduced with increasing pheromone concentration, as predicted, but interactions varied among competing resident species. These behavioural variations provide an explanation for observed differences in foraging success of the competing resident species and how much each of these individual competitors can increase their foraging if the competitive ability of the dominant invader is decreased. The mechanism for the observed increase in resource acquisition of resident species appears to be a decrease in aggressive behaviour displayed by the Argentine ant, which may create an opportunity for other resident species to forage more successfully. Our demonstration of species interactions with trail pheromone disruption is the first known case of reduced dominance under a pheromone treatment in ants.

  13. Disruption of foraging by a dominant invasive species to decrease its competitive ability.

    Science.gov (United States)

    Westermann, Fabian Ludwig; Suckling, David Maxwell; Lester, Philip John

    2014-01-01

    Invasive species are a major threat to biodiversity when dominant within their newly established habitat. The globally distributed Argentine ant Linepithema humile has been reported to break the trade-off between interference and exploitative competition, achieve high population densities, and overpower nests of many endemic ant species. We have used the sensitivity of the Argentine ant to the synthetic trail pheromone (Z)-9-hexadecanal to investigate species interactions for the first time. We predicted that disrupting Argentine ant trail following behaviour would reduce their competitive ability and create an opportunity for three other resident species to increase their foraging success. Argentine ant success in the control was reduced with increasing pheromone concentration, as predicted, but interactions varied among competing resident species. These behavioural variations provide an explanation for observed differences in foraging success of the competing resident species and how much each of these individual competitors can increase their foraging if the competitive ability of the dominant invader is decreased. The mechanism for the observed increase in resource acquisition of resident species appears to be a decrease in aggressive behaviour displayed by the Argentine ant, which may create an opportunity for other resident species to forage more successfully. Our demonstration of species interactions with trail pheromone disruption is the first known case of reduced dominance under a pheromone treatment in ants.

  14. Intercropping of Cereals and Legumes for Forage Production

    OpenAIRE

    Hamdollah ESKANDARI; Ghanbari, Ahmad; Abdollah JAVANMARD

    2009-01-01

    Cereals are high important in feeding ruminant animals for their high dry matter production and low cost. However, cereals forage is poor in protein content which shows their low quality and nutritive value. Regarding to high feed costs of protein supplementations, legumes can be used in livestock nutrition for their high protein content and, thus, providing cost saving. Since legumes have low dry matter yield, acceptable forage yield and quality can obtained from intercropping of cereals and...

  15. A general strategy to achieve ultra-high gene transfection efficiency using lipid-nanoparticle composites.

    Science.gov (United States)

    Vankayala, Raviraj; Chiang, Chi-Shiun; Chao, Jui-I; Yuan, Chiun-Jye; Lin, Shyr-Yeu; Hwang, Kuo Chu

    2014-09-01

    Gene therapy provides a new hope for previously "incurable" diseases. Low gene transfection efficiency, however, is the bottle-neck to the success of gene therapy. It is very challenging to develop non-viral nanocarriers to achieve ultra-high gene transfection efficiencies. Herein, we report a novel design of "tight binding-but-detachable" lipid-nanoparticle composite to achieve ultrahigh gene transfection efficiencies of 60∼82%, approaching the best value (∼90%) obtained using viral vectors. We show that Fe@CNPs nanoparticles coated with LP-2000 lipid molecules can be used as gene carriers to achieve ultra-high (60-80%) gene transfection efficiencies in HeLa, U-87MG, and TRAMP-C1 cells. In contrast, Fe@CNPs having surface-covalently bound N,N,N-trimethyl-N-2-methacryloxyethyl ammonium chloride (TMAEA) oligomers can only achieve low (23-28%) gene transfection efficiencies. Similarly ultrahigh gene transfection/expression was also observed in zebrafish model using lipid-coated Fe@CNPs as gene carriers. Evidences for tight binding and detachability of DNA from lipid-nanoparticle nanocarriers will be presented. PMID:24973297

  16. Relative contribution of ruminal buffering systems to pH regulation in feedlot cattle fed either low- or high-forage diets.

    Science.gov (United States)

    Chibisa, G E; Beauchemin, K A; Penner, G B

    2016-07-01

    The relative contribution of ruminal short-chain fatty acid (SCFA) absorption and salivary buffering to pH regulation could potentially change under different dietary conditions. Therefore, the objective of this study was to investigate the effects of altering the ruminal supply of rapidly fermentable carbohydrate (CHO) on absorptive function and salivation in beef cattle. Eight heifers (mean BW±SD=410±14 kg) were randomly allocated to two treatments in a crossover design with 37-day periods. Dietary treatments were barley silage at 30% low forage (LF) or 70% high forage (HF) of dietary dry matter (DM), with the remainder of the diet consisting of barley grain (65% or 25% on a DM basis) and a constant level (5%) of supplement. The LF and HF diets contained 45.3% and 30.9% starch, and 4.1% and 14.0% physically effective fiber (DM basis), respectively. Ruminal pH was continuously measured from day 17 to day 23, whereas ruminal fluid was collected on day 23 to determine SCFA concentration. Ruminal liquid passage rate was determined on day 23 using Cr-ethylenediaminetetraacetic acid. Eating or resting salivation was measured by collecting masticate (days 28 and 29) or saliva samples (days 30 and 31) at the cardia, respectively. On days 30 and 31, the temporarily isolated and washed reticulo-rumen technique was used to measure total, and Cl--competitive (an indirect measure of protein-mediated transport) absorption of acetate, propionate and butyrate. As a result of the higher dietary starch content and DM intake, the ruminal supply of rapidly fermentable CHO, total ruminal SCFA concentration (118 v. 95 mM; P<0.001) and osmolality (330 v. 306 mOsm/kg; P=0.018) were greater in cattle fed LF compared with HF. In addition, feeding LF resulted in a longer duration (2.50 v. 0.09 h/day; P=0.02) and a larger area (0.44 v. 0.01 (pH×h)/day; P=0.050) that pH was below 5.5. There was no diet effect on total and Cl--competitive absorption (mmol/h and %/h) of acetate, propionate

  17. Collective foraging in heterogeneous landscapes

    CERN Document Server

    Bhattacharya, Kunal

    2013-01-01

    Animals foraging alone are hypothesized to optimize the encounter rates with resources through L\\'evy walks. However, the issue of how the interactions between multiple foragers influence their search efficiency is still not completely understood. To address this, we consider a model to study the optimal strategy for a group of foragers searching for targets distributed heterogeneously. In our model foragers move on a square lattice containing immobile but regenerative targets. At any instant a forager is able to detect only those targets that happen to be in the same site. However, we allow the foragers to have information about the state of other foragers. A forager who has not detected any target walks towards the nearest location, where another forager has detected a target, with probability $\\exp{\\left(-\\alpha d\\right)}$, where $d$ is the distance and $\\alpha$ is a parameter. The model reveals that neither overcrowding ($\\alpha\\to 0$) nor independent searching ($\\alpha\\to\\infty$) is beneficial for the gr...

  18. AN ENERGY MODEL FOR ACHIEVING HIGH PERFORMANCE BURST TRANSMISSION IN OBCS NETWORKS

    OpenAIRE

    Renuka, R.; Kavitha, V.

    2013-01-01

    Optical burst switching is a promising solution for all optical WDM networks. It combines the benefits of optical circuit switching and optical packet switching. In OBS, the user data is collected at the edge of the network, sorted based on the destination address and grouped into variable size bursts. The OBS framework has been widely used in past years, for recent work use Optical Burst Chain switching (OBCS) to achieve high performance. Here switching unit is burst chain it consist of non-...

  19. What Makes a Good Program? A Case Study of a School Admitting High Academic Achievers

    OpenAIRE

    Ching Man Lam

    2008-01-01

    This paper reports the results of a qualitative study that explored the administration and implementation of the Tier 1 Program (Secondary 1 Curriculum) of the Project P.A.T.H.S. The case study method was used to explore perceptions of the teachers and the project coordinator of program effectiveness, and to identify various factors for program success. A school admitting high academic achievers was selected, and site visits, as well as individual and focus group interviews, were conducted wi...

  20. Design Guidelines to Achieve a Very High ESD Robustness in a Self-Biased NPN

    OpenAIRE

    Trémouilles, David; Bertrand, Géraldine; Bafleur, Marise; Nolhier, Nicolas; Lescouzères, Lionel

    2002-01-01

    International audience; In this paper, using extensive TCAD simulations and measurement results, we analyze the basic mechanisms involved during an ESD stress in a self-biased NPN bipolar transistor used as an ESD protection. From the deep understanding of these mechanisms, we define design guidelines to achieve a very high ESD robustness (=10kV) in this type of device. These guidelines are validated on several CMOS technologies.

  1. RELATIONSHIP BETWEEN PARENTAL RESTRAINTS, EMOTIONAL INTELLIGENCE AND ACADEMIC ACHIEVEMENT AMONG RURAL HIGH SCHOOL GIRLS

    OpenAIRE

    Sushma H.B; Surekha Ksheerasagar

    2014-01-01

    This study investigated the relationship among parental restraints on emotional intelligence and academic achievement of 60 high school going pre-adolescent girls (30 Kannada Medium and 30 English Medium) of rural areas of Gulbarga district. The participants ranged in age between 11 to 17years. Two hypotheses were tested for significance at 0.05 margin in error. The main objective of the study is to find the relationship between parental restraints on emotional intelligence an...

  2. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.

    Science.gov (United States)

    Krapohl, Eva; Rimfeld, Kaili; Shakeshaft, Nicholas G; Trzaskowski, Maciej; McMillan, Andrew; Pingault, Jean-Baptiste; Asbury, Kathryn; Harlaar, Nicole; Kovas, Yulia; Dale, Philip S; Plomin, Robert

    2014-10-21

    Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35-58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.

  3. High-fidelity simulation: Assessment of student nurses' team achievements of clinical judgment.

    Science.gov (United States)

    Hallin, Karin; Bäckström, Britt; Häggström, Marie; Kristiansen, Lisbeth

    2016-07-01

    Nursing educators have the challenge of preparing nursing students to handle complex patient care situations in real life, but much remains unknown about the ability to make clinical judgments. In this study, high-fidelity simulation (HFS) was used at a Swedish university to find answers about pre-licensure nursing students' success in clinical judgment in terms of team ability and relationships with theoretical achievements, and personal and scenario circumstances. The matrix Lasater Clinical Judgment Rubric (LCJR) was used to analyze and score the students' ability in teams to notice, interpret and respond to complex care situations. Overall, the results showed the student teams in their first meeting with HFS in a complex care situation achieved low clinical judgment points; most teams were in the stages of Beginning and Developing. For attaining high team achievements the majority of the students in the team should theoretically be "high performance". Being observers and having HFS experience before nursing education was significant too. However, age, health care experience, and assistant nurse degrees were of secondary importance. Further research at universities regionally, nationally, and internationally is needed. PMID:27428686

  4. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    Science.gov (United States)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  5. Breeding tropical forages

    Directory of Open Access Journals (Sweden)

    L Jank

    2011-01-01

    Full Text Available Brazil has the largest commercial beef cattle herd and is the main beef exporter in the world. Cultivated pastures arethe basis for the Brazilian beef production, and occupy an area of 101.4 million hectares. However, very few forage cultivars arecommercially available, and the majority of these are of apomictic reproduction, thus genetically homogeneous. Tropical foragebreeding is at its infancy, but much investment and efforts have been applied in the last three decades and some new cultivars havebeen released. In this paper, origin of different species, modes of reproduction, breeding programs and targets are discussed andthe resulting new cultivars released are presented.

  6. 7 CFR 1437.401 - Forage.

    Science.gov (United States)

    2010-01-01

    ... Coverage of Forage Intended for Animal Consumption § 1437.401 Forage. (a) Forage eligible for benefits... the minimum period in order to preserve vegetation and prevent erosion, or otherwise mitigate...

  7. The Effect of English Learning Anxiety on Iranian High-School Students’ English Language Achievement

    Directory of Open Access Journals (Sweden)

    Sara Atef-Vahid

    2011-10-01

    Full Text Available The present study explored English language learning anxiety among 38 third-year high school students in English classrooms and its relationship with overall English achievement. Students’ foreign language anxiety was surveyed and analyzed using the Foreign Language Classroom Anxiety Scale (Horwitz, Horwitz, & Cope, 1986 [14] and their English achievement was measured through their final standardized English exam administered by the school. The results showed that although some students felt extremely confident and relaxed, however, one-third of the
    students experienced moderate to high-anxiety levels while learning the English language in class. Correlational analysis revealed that the total FLCAS scores had a significantly moderate negative correlation (r=-.0586, p<.01 with the total final English exams scores of the participants. Anxiety was also analyzed according to the four different variables of anxiety (communication anxiety, test anxiety, fear of negative evaluation, English classroom anxiety which were measured by the FLCAS. The results of the Pearson correlational analysis indicated that English achievement was modestly correlated with all four anxiety variables (p<0.01. Of the four types of anxiety, English Classroom anxiety had the highest correlational value. Finally, possible anxiety provoking factors
    leading to these findings are examined and discussed, and some pedagogical implications are proposed.

  8. Foraging strategy quick response to temperature of Messor barbarus (Hymenoptera: Formicidae) in Mediterranean environments.

    Science.gov (United States)

    Doblas-Miranda, Enrique; Reyes-López, Joaquín

    2008-08-01

    Animals principally forage to try to maximize energy intake per unit of feeding time, developing different foraging strategies. Temperature effects on foraging have been observed in diverse ant species; these effects are limited to the duration of foraging or the number of foragers involved. The harvester ant Messor barbarus L. 1767 has a specialized foraging strategy that consists in the formation of worker trails. Because of the high permeability of their body integument, we presume that the length, shape, and type of foraging trails of M. barbarus must be affected by temperature conditions. From mid-June to mid-August 1999, we tested the effect on these trail characteristics in a Mediterranean forest. We found that thermal stress force ants to use a foraging pattern based on the variation of the workers trail structure. Ants exploit earlier well-known sources using long physical trails, but as temperatures increases throughout the morning, foragers reduce the length of the foraging column gradually, looking for alternative food sources in nonphysical trails. This study shows that animal forage can be highly adaptable and versatile in environments with high daily variations.

  9. Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

    Science.gov (United States)

    Belen-Ferrer, Bellasanta

    2009-12-01

    This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

  10. Achieving High Performance Distributed System: Using Grid, Cluster and Cloud Computing

    Directory of Open Access Journals (Sweden)

    Sunil Kr Singh

    2015-02-01

    Full Text Available To increase the efficiency of any task, we require a system that would provide high performance along with flexibilities and cost efficiencies for user. Distributed computing, as we are all aware, has become very popular over the past decade. Distributed computing has three major types, namely, cluster, grid and cloud. In order to develop a high performance distributed system, we need to utilize all the above mentioned three types of computing. In this paper, we shall first have an introduction of all the three types of distributed computing. Subsequently examining them we shall explore trends in computing and green sustainable computing to enhance the performance of a distributed system. Finally presenting the future scope, we conclude the paper suggesting a path to achieve a Green high performance distributed system using cluster, grid and cloud computing

  11. Movement patterns for a critically endangered species, the leatherback turtle (Dermochelys coriacea, linked to foraging success and population status.

    Directory of Open Access Journals (Sweden)

    Helen Bailey

    Full Text Available Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (<15 km d(-1 and transit at high speeds (20-45 km d(-1. Only a single mode was evident in the Pacific, which occurred at speeds of 21 km d(-1 indicative of transit. The mean dive depth was more variable in relation to latitude but closer to the mean annual depth of the thermocline and nutricline for North Atlantic than Eastern Pacific turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic.

  12. Achieving High Performance in AC-Field Driven Organic Light Sources.

    Science.gov (United States)

    Xu, Junwei; Carroll, David L; Smith, Gregory M; Dun, Chaochao; Cui, Yue

    2016-04-11

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m(2) with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today's OLEDs in performance.

  13. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Science.gov (United States)

    Yang, Ding-Xin; Gu, Feng-Shou; Feng, Guo-Jin; Yang, Yong-Min; Ball, Andrew

    2015-11-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. Project supported by the National Natural Science Foundation of China (Grant No. 51379526).

  14. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Institute of Scientific and Technical Information of China (English)

    杨定新; 谷丰收; 冯国金; 杨拥民

    2015-01-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications.

  15. Achieving High Performance in AC-Field Driven Organic Light Sources

    Science.gov (United States)

    Xu, Junwei; Carroll, David L.; Smith, Gregory M.; Dun, Chaochao; Cui, Yue

    2016-04-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m2 with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today’s OLEDs in performance.

  16. Race and Academic Achievement in Racially Diverse High Schools: Opportunity and Stratification.

    Science.gov (United States)

    Muller, Chandra; Riegle-Crumb, Catherine; Schiller, Kathryn S; Wilkinson, Lindsey; Frank, Kenneth A

    2010-04-01

    BACKGROUND/CONTEXT: Brown v Board of Education fundamentally changed our nation's schools, yet we know surprisingly little about how and whether they provide equality of educational opportunity. Although substantial evidence suggests that African American and Latino students who attend these schools face fewer learning opportunities than their White counterparts, until now, it has been impossible to examine this using a representative sample because of lack of data. PURPOSE/OBJECTIVE/RESEARCH QUESTION/FOCUS OF STUDY: This study uses newly available data to investigate whether racially diverse high schools offer equality of educational opportunity to students from different racial and ethnic groups. This is examined by measuring the relative representation of minority students in advanced math classes at the beginning of high school and estimating whether and how this opportunity structure limits the level of achievement attained by African American and Latino students by the end of high school. SETTING: This study uses data from the Adolescent Health and Academic Achievement Study (AHAA) and its partner study, the National Longitudinal Study of Adolescent Health (Add Health), a stratified, nationally representative study of students in U.S. high schools first surveyed in 1994-1995. POPULATION/PARTICIPANTS/SUBJECTS: Two samples of racially diverse high schools were used in the analysis: one with African Americans, Whites, and Asians (26 schools with 3,149 students), and the other with Latinos, Whites, and Asians (22 schools with 2,775 students). RESEARCH DESIGN: Quantitative analyses first assess how high schools vary in the extent to which minority students are underrepresented in advanced sophomore math classes. Hierarchical multilevel modeling is then used to estimate whether racial-ethnic differences in representation in advanced math have an impact on African American and Latino students' achievement by the end of high school, relative to the Whites and Asians

  17. AN ENERGY MODEL FOR ACHIEVING HIGH PERFORMANCE BURST TRANSMISSION IN OBCS NETWORKS

    Directory of Open Access Journals (Sweden)

    R.RENUKA

    2013-04-01

    Full Text Available Optical burst switching is a promising solution for all optical WDM networks. It combines the benefits of optical circuit switching and optical packet switching. In OBS, the user data is collected at the edge of the network, sorted based on the destination address and grouped into variable size bursts. The OBS framework has been widely used in past years, for recent work use Optical Burst Chain switching (OBCS to achieve high performance. Here switching unit is burst chain it consist of non-periodic bursts in one wavelength. We present extensive simulation result for throughput, delay and energy to demonstrate its superior performance over OBS networks.

  18. Students High Achievement on Learning Style Preferences in Chinese Department, Binus University

    Directory of Open Access Journals (Sweden)

    Yetty Go

    2015-02-01

    every student has her/his own individual way to resolve their problems in learning. In learning process, students individual differences exist. These differences lead to different learning speed and learning style of the student. The purpose of this study was to investigate the high achievement students learning styles. This study was based on Reids learning styles theory and also uses Reids Perceptual Learning Style Preference Questionnaire (PLSPQ to investigate students learning styles. The main finding of this study is that students learning style preference is group style. According to student learning style preferences results, students prefer to learn together with others or in group and learn in a more interactive way.

  19. Number Sense-Based Strategies Used by High-Achieving Sixth Grade Students Who Experienced Reform Textbooks

    Science.gov (United States)

    Alsawaie, Othman N.

    2012-01-01

    The purpose of this study was to explore strategies used by high-achieving 6th grade students in the United Arab Emirates (UAE) to solve basic arithmetic problems involving number sense. The sample for the study consisted of 15 high-achieving boys and 15 high-achieving girls in grade 6 from 2 schools in the Emirate of Abu Dhabi, UAE. Data for the…

  20. Achieving high mass-throughput of therapeutic proteins through parvovirus retentive filters.

    Science.gov (United States)

    Bolton, Glen R; Basha, Jonida; Lacasse, Daniel P

    2010-01-01

    Parvovirus retentive filters that assure removal of viruses and virus-like particles during the production of therapeutic proteins significantly contribute to total manufacturing costs. Operational approaches that can increase throughput and reduce filtration area would result in a significant cost savings. A combination of methods was used to achieve high throughputs of an antibody or therapeutic protein solution through three parvovirus retentive filters. These methods included evaluation of diatomaceous earth or size-based prefilters, the addition of additives, and the optimization of protein concentration, temperature, buffer composition, and solution pH. An optimum temperature of 35°C was found for maximizing throughput through the Virosart CPV and Viresolve Pro filters. Mass-throughput values of 7.3, 26.4, and 76.2 kg/m(2) were achieved through the Asahi Planova 20N, Virosart CPV, and Viresolve Pro filters, respectively, in 4 h of processing. Mass-throughput values of 73, 137, and 192 kg/m(2) were achieved through a Millipore Viresolve Pro filter in 4.0, 8.8, and 22.1 h of processing, respectively, during a single experiment. However, large-scale parvovirus filtration operations are typically controlled to limit volumetric throughput to below the level achieved during small-scale virus spiking experiments. The virus spike may cause significant filter plugging, limiting throughput. Therefore newer parvovirus filter spiking strategies should be adopted that may lead to more representative viral clearance data and higher utilization of large-scale filter capacity.

  1. High Titer and Yields Achieved with Novel, Low-Severity Pretreatment Strategy

    Energy Technology Data Exchange (ETDEWEB)

    2016-03-01

    NREL researchers obtained high concentration sugar syrups in enzymatic hydrolysis that are fermentable to ethanol and other advanced biofuels and intermediate products at high yields. The novel DMR process is simpler and bypasses all severe pretreatment methods, thus reducing the environmental impact. The results are unprecedented. Researchers achieved a high concentration of sugars (230g/L of monomeric sugar and 270 g/L total sugar) and this low toxicity, highly fermentable syrup yielded 86 g/L ethanol (> 90 percent conversion). In addition, the lignin streams from this process can readily be converted to jet or renewable diesel blendstocks through a hydrodeoxygenation step. The NREL-developed, low severity DMR process may potentially replace higher severity chemical pretreatments and associated expensive reactors constructed of exotic alloys with a simpler process, using commercial-scale equipment commonly associated with the pulp and paper industry, to produce high concentration, low toxicity sugar streams and highly reactive lignin streams from non-food renewable biomass for biological and catalytic upgrading to advanced biofuels and chemicals. The simpler DMR process with black liquor recycling could reduce environmental and life-cycle impacts, and repurpose shuttered pulp and paper mills to help revitalize rural economies.

  2. Personality, foraging and fitness consequences in a long lived seabird.

    Directory of Open Access Journals (Sweden)

    Samantha C Patrick

    Full Text Available While personality differences in animals are defined as consistent behavioural variation between individuals, the widely studied field of foraging specialisation in marine vertebrates has rarely been addressed within this framework. However there is much overlap between the two fields, both aiming to measure the causes and consequences of consistent individual behaviour. Here for the first time we use both a classic measure of personality, the response to a novel object, and an estimate of foraging strategy, derived from GPS data, to examine individual personality differences in black browed albatross and their consequences for fitness. First, we examine the repeatability of personality scores and link these to variation in foraging habitat. Bolder individuals forage nearer the colony, in shallower regions, whereas shyer birds travel further from the colony, and fed in deeper oceanic waters. Interestingly, neither personality score predicted a bird's overlap with fisheries. Second, we show that both personality scores are correlated with fitness consequences, dependent on sex and year quality. Our data suggest that shyer males and bolder females have higher fitness, but the strength of this relationship depends on year quality. Females who forage further from the colony have higher breeding success in poor quality years, whereas males foraging close to the colony always have higher fitness. Together these results highlight the potential importance of personality variation in seabirds and that the fitness consequences of boldness and foraging strategy may be highly sex dependent.

  3. Attention in Urban Foraging

    Directory of Open Access Journals (Sweden)

    Malcolm McCullough

    2013-05-01

    Full Text Available This position paper argues how there has to be much more to smart city learning than just wayshowing, and something better as augmented reality than covering the world with instructions. Attention has become something for many people to know better in an age of information superabundance. Embodied cognition explains how the work-ings of attention are not solely a foreground task, as if attention is something to pay. As digital media appear in ever more formats and contexts, their hybrids with physical form increasing influence how habitual engagement with persistent situations creates learning. Ambient information can just add to the distraction by multitasking, or it can support more favorable processes of shifting among different kinds of information with a particular intent. As one word for this latter process, foraging deserves more consideration in smart city learning

  4. The Pentagon-S process: A systematic approach for achieving high confidence in high-consequence products

    Energy Technology Data Exchange (ETDEWEB)

    D`Antonio, P.E.; Covan, J.M.; Ekman, M.E.

    1997-10-01

    Sandia National Laboratories has developed a systematic approach for achieving high confidence in major products requiring high reliability for use in high-consequence applications. A high-consequence application is one in which product failure could result in significant loss of life, damage to major systems or to the environment, financial loss, or political repercussions. The application of this process has proven to be of significant benefit in the early identification, verification, and correction of potential product design and manufacturing process failure modes. Early identification and correction of these failures modes and the corresponding controls placed on safety-critical features, ensures product adherence to safety-critical design requirements, and enhances product quality, reliability, and the cost effectiveness of delivered products. Safety-critical features include design features such as materials and dimensions, as well as manufacturing features such as assembly processes, inspections, and testing.

  5. Forage yield and nitrogen nutrition dynamics of warm-season native forage genotypes under two shading levels and in full sunlight

    Directory of Open Access Journals (Sweden)

    Raquel Santiago Barro

    2012-07-01

    Full Text Available The successful achievement of a highly productive understorey pasture in silvopastoral systems depends on the use of well-adapted forage genotypes, showing good agronomic performance and persistence under shading and grazing. In this study, the herbage dry matter yield (DMY and nitrogen nutrition dynamics were determined in three native warm-season grasses (Paspalum regnellii, Paspalum dilatatum and Paspalum notatum and a forage legume (Arachis pintoi under two shading levels compared with full sun. The experiment was conducted in the Campanha region, Bagé, state of Rio Grande do Sul, Brazil, during two evaluation cycles (2008/2009 and 2009/2010. Three shade cloth levels (0%, 50% and 80% of light restriction were applied to the forage genotypes in a split plot design, in which shading levels were the main plot and forage genotypes were the subplots, with three replications. P. regnellii showed the highest accumulated DMY (1500 and 1700 g m-2, respectively, for the first and second evaluation cycles at all shading levels and showed no DMY decreased under the heavy shade (80%. Average DMY over the four genotypes under the 50% shade level was higher or equal compared with full sun. Influence of rainfall was observed on the DMY performance of all genotypes: the positive effect of moderate shading (50% on P. dilatatum and P. notatum DMY was associated to a low soil water availability status. Increased shading level resulted in high nitrogen nutrition index values on grasses, in comparison with full sun. All genotypes performed well under the moderate shading level, but the DMY of both P. regnellii and P. dilatatum and the herbage N content in P. notatum and A. pintoi of all genotypes stood out, showing that those main genotypes are promising to grow in silvopastoral systems at the Campanha region in southern Brazil.

  6. Anaerobic co-digestion of forage radish and dairy manure in complete mix digesters

    Science.gov (United States)

    Farmers are increasingly using forage radish as a winter cover crop to achieve multiple soil and environmental benefits. In this study, pilot-scale mixed digesters were used to quantify methane (CH4) and hydrogen sulfide (H2S) production when using forage radish, a sulfur-rich cover crop, as a co-d...

  7. Biological conversion of forage sorghum biomass to ethanol by steam explosion pretreatment and simultaneous hydrolysis and fermentation at high solid content

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares, Paloma; Ballesteros, Ignacio; Negro, Maria Jose; Oliva, Jose Miguel; Gonzalez, Alberto; Ballesteros, Mercedes [Renewable Energy Department-CIEMAT, Biofuels Unit, Madrid (Spain)

    2012-06-15

    In this work, forage sorghum biomass was studied as feedstock for ethanol production by a biological conversion process comprising the steps of hydrothermal steam explosion pretreatment, enzymatic hydrolysis with commercial enzymes, and fermentation with the yeast Saccharomyces cerevisiae. Steam explosion conditions were optimized using a response surface methodology considering temperature (180-230 C) and time (2-10 min). Sugar recovery in the pretreatment and the enzymatic digestibility of the pretreated solid were used to determine the optimum conditions, i.e., 220 C and 7 min. At these conditions, saccharification efficiency attained 89 % of the theoretical and the recovery of xylose in the prehydrolyzate accounted for 35 % of the amount of xylose present in raw material. Then, a simultaneous hydrolysis and fermentation (SSF) process was tested at laboratory scale on the solid fraction of forage sorghum pretreated at optimum condition, in order to evaluate ethanol production. The effect of the enzyme dose and the supplementation with xylanase enzyme of the cellulolytic enzyme cocktail was studied at increasing solid concentration up to 18 % (w/w) in SSF media. Results show good performance of SSF in all consistencies tested with a significant effect of increasing enzyme load in SSF yield and final ethanol concentration. Xylanase supplementation allows increasing solid concentration up to 18 % (w/w) with good SSF performance and final ethanol content of 55 g/l after 4-5 days. Based on this result, about 190 l of ethanol could be obtained from 1 t of untreated forage sorghum, which means a transformation yield of 85 % of the glucose contained in the feedstock. (orig.)

  8. Depletion of selenium in whole blood, liver and muscle tissue of beef heifers that had previously grazed forages containing high amounts of selenium

    International Nuclear Information System (INIS)

    time after grazing (P < 0.01), but the rates of Se mobilization from blood, liver and muscle differed. Even though the concentration of Se in liver was 25% higher in TWG heifers at the end of grazing, after 20 d of being fed a diet with lower levels of Se, both groups had similar concentrations of Se in liver (i.e., 0.92 vs. 0.85 mg/kg), demonstrating that mobilization of Se that had accumulated in liver occurred quickly. The Se concentration in blood decreased at a much slower rate than in liver, possibly because Se mobilized from liver and muscle continuously entered the blood pool. At 81 d of post-grazing feeding, concentrations of Se were reduced by 77% in liver, 49% in blood, but only 31% in muscle. Overall, muscle tissue had the slowest rate of Se mobilization after grazing high Se pastures, but it is the largest pool of Se in the body. The differences in the muscle Se content for CWR and TWG grazed heifers also demonstrate that the content of Se in forage is critical to maximizing Se levels in muscle. Beef production systems that target marketing of Se enriched beef may have to rely on feeding strategies that allow finishing of cattle in no more than 60 d after Se loading, but ideally in as short a time as possible

  9. Colony variation in the collective regulation of foraging by harvester ants.

    Science.gov (United States)

    Gordon, Deborah M; Guetz, Adam; Greene, Michael J; Holmes, Susan

    2011-03-01

    This study investigates variation in collective behavior in a natural population of colonies of the harvester ant, Pogonomyrmex barbatus. Harvester ant colonies regulate foraging activity to adjust to current food availability; the rate at which inactive foragers leave the nest on the next trip depends on the rate at which successful foragers return with food. This study investigates differences among colonies in foraging activity and how these differences are associated with variation among colonies in the regulation of foraging. Colonies differ in the baseline rate at which patrollers leave the nest, without stimulation from returning ants. This baseline rate predicts a colony's foraging activity, suggesting there is a colony-specific activity level that influences how quickly any ant leaves the nest. When a colony's foraging activity is high, the colony is more likely to regulate foraging. Moreover, colonies differ in the propensity to adjust the rate of outgoing foragers to the rate of forager return. Naturally occurring variation in the regulation of foraging may lead to variation in colony survival and reproductive success.

  10. High school students' perceptions of EFL teacher control orientations and their English academic achievement.

    Science.gov (United States)

    Kiany, Gholam Reza; Shayestefar, Parvaneh

    2011-09-01

    BACKGROUND. Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between strong, shared, or loose teacher control during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. AIM. The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). SAMPLE. The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. METHOD. To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok et al. (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. RESULTS AND CONCLUSION. Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students

  11. High school students' perceptions of EFL teacher control orientations and their English academic achievement.

    Science.gov (United States)

    Kiany, Gholam Reza; Shayestefar, Parvaneh

    2011-09-01

    BACKGROUND. Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between strong, shared, or loose teacher control during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. AIM. The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). SAMPLE. The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. METHOD. To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok et al. (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. RESULTS AND CONCLUSION. Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students

  12. Science literacy in high school students: A comparison of achievement in two curriculum approaches

    Science.gov (United States)

    McAlister, Diane C.

    2009-12-01

    Academic achievement as measured by the Florida Comprehensive Assessment Test (FCAT) in science for 367 students in two science curriculum options, integrated science and the traditional subject-specific courses, in one central Florida high school were compared. A multivariate analysis of covariance (MANCOVA) of science curriculum choice was analyzed for three variables, total FCAT score, earth science subscore, and scientific thinking subscore. Covariate of academic ability as defined by grade point average (GPA) and academic focus as defined by post secondary plans were considered for use. Analysis of statistically significant results was completed through analysis of covariance (ANCOVA). While statistically significant results were found in favor of the traditional curriculum group, additional statistical analysis of the curriculum groups for differences in socioeconomic status (SES), gender, and instructional level led to a logistic regression to explore the ability of these variables, GPA, and total FCAT score to predict curriculum group membership. GPA, level of instruction and FCAT score were found to be statistically significant predictors. Final conclusions to the study indicated a significant difference in scientific literacy for the two groups in favor of the traditional curriculum. However, logistic regression results indicated that due to significant differences in SES, gender, GPA, and level of instruction for the groups, the differences in academic achievement were probably due to factors other than curriculum design. Limitations of the study and suggestions for further research were presented.

  13. Is Early Ability Grouping Good for High-Achieving Students' Psychosocial Development? Effects of the Transition into Academically Selective Schools

    Science.gov (United States)

    Becker, Michael; Neumann, Marko; Tetzner, Julia; Böse, Susanne; Knoppick, Henrike; Maaz, Kai; Baumert, Jürgen; Lehmann, Rainer

    2014-01-01

    The present study investigates school context effects on psychosocial characteristics (academic self-concept, peer relations, school satisfaction, and school anxiety) of high-achieving and gifted students. Students who did or did not make an early transition from elementary to secondary schools for high-achieving and gifted students in 5th grade…

  14. A Comparison of Strategic Development for Multiplication Problem Solving in Low-, Average-, and High-Achieving Students

    Science.gov (United States)

    Zhang, Dake; Ding, Yi; Barrett, Dave E.; Xin, Yan Ping; Liu, Ru-de

    2014-01-01

    The present study investigated the differences of strategy use between low-, average-, and high-achieving students when solving different multiplication problems. Nineteen high-, 48 average-, and 17 low-achieving students participated in this study. All participants were asked to complete three different multiplication tests and to explain how…

  15. Robust and Fragile Mathematical Identities: A Framework for Exploring Racialized Experiences and High Achievement among Black College Students

    Science.gov (United States)

    McGee, Ebony O.

    2015-01-01

    I introduce the construct of fragile and robust identities for the purpose of exploring the experiences that influenced the mathematical and racial identities of high-achieving Black college students in mathematics and engineering. These students maintained high levels of academic achievement in these fields while enduring marginalization,…

  16. Held Back: The Impact of Curricular and Pedagogical Factors on Tested Achievement in High School Mathematics

    Science.gov (United States)

    Agvanian, Zara

    2013-01-01

    This study examined the impact of curricular factors and teaching practices on students' tested achievement in mathematics, explored the best predictors of the tested achievement, and examined differences in the tested achievement among student subgroups. The study utilized qualitative and quantitative methods and triangulated findings from…

  17. Alfalfa (Medicago Sativa L As A Promising Forage In Indonesia

    Directory of Open Access Journals (Sweden)

    Sajimin

    2011-06-01

    Full Text Available Alfalfa (Medicago sativa L or Lucerne is a perennial herbaceous legume with superior forage quality. It is the most important forage crop in the world and it was the first domesticated forage crop. Alfalfa is able to fix nitrogen from the air through a symbiotic relationship with Rhizobium bacteria with N production 7.85 – 10.37 g/m2. Its rooting system can reach 4.5 m that allows it to escape drought. Forage production can reach 15.48 tons of dry matter per ha/year and containing 18.0 – 29.1 % crude protein. Plants can live 3 to 12 years depending on climatic conditions and crop varieties. However, alfalfa is not a tropical plant, thus it has not been widely cultivated in Indonesia. The problem of alfalfa cultivation are high pest attacks and competition with weeds. Therefore, alfalfa cultivation requires attention and good management to obtain optimum yield.

  18. Corn in consortium with forages

    OpenAIRE

    Cássia Maria de Paula Garcia; Marcelo Andreotti; Marcelo Carvalho Minhoto Teixeira Filho; Keny Samejima Mascarenha Lopes; Ciniro Costa; Erikelly Aline Ribeiro de Santana

    2013-01-01

    The basic premises for sustainable agricultural development with focus on rural producers are reducing the costs of production and aggregation of values through the use crop-livestock system (CLS) throughout the year. The CLS is based on the consortium of grain crops, especially corn with tropical forages, mainly of the genus Panicum and Urochloa. The study aimed to evaluate the grain yield of irrigated corn crop intercropped with forage of the genus Panicum and Urochloa. The experiment was c...

  19. Achieving a high-reliability organization through implementation of the ARCC model for systemwide sustainability of evidence-based practice.

    Science.gov (United States)

    Melnyk, Bernadette Mazurek

    2012-01-01

    High-reliability health care organizations are those that provide care that is safe and one that minimizes errors while achieving exceptional performance in quality and safety. This article presents major concepts and characteristics of a patient safety culture and a high-reliability health care organization and explains how building a culture of evidence-based practice can assist organizations in achieving high reliability. The ARCC (Advancing Research and Clinical practice through close Collaboration) model for systemwide implementation and sustainability of evidence-based practice is highlighted as a key strategy in achieving high reliability in health care organizations.

  20. Important aspects for consideration in minimizing plant outage times. Swiss experience in achieving high availability

    International Nuclear Information System (INIS)

    Operation of Swiss nuclear power plants has not been entirely free of trouble. They have experienced defective fuel elements, steam generator tube damage, excessive vibration of the core components, leakages in the recirculation pump seals and excessive corrosion and erosion in the steam-feedwater plant. Despite these technical problems in the early life of the plants, on overall balance the plants can be considered to have performed exceedingly well. The safety records from more than 40 reactor-years of operation are excellent and, individually and collectively, the capacity factors obtained are among the highest in the world. The problems mentioned have been solved and the plants continue operation with high availabilities. This success can be attributed to the good practices of the utilities with regard to the choice of special design criteria, plant organization, plant operation and plant maintenance, and also to the pragmatic approach of the licensing authorities and their consultants to quality assurance and quality control. The early technical problems encountered, the corresponding solutions adopted and the factors that contributed towards achieving high availabilities in Swiss nuclear power plants are briefly described. (author)

  1. Achieving Energy Savings with Highly-Controlled Lighting in an Open-Plan Office

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, Francis; Enscoe, Abby

    2010-04-19

    An installation in a Federal building tested the effectiveness of a highly-controlled, workstation-specific lighting retrofit. The study took place in an open-office area with 86 cubicles and low levels of daylight. Each cubicle was illuminated by a direct/indirectpendant luminaire with three 32 watt lamps, two dimmable DALI ballasts, and an occupancy sensor. A centralized control system programmed all three lamps to turn on and off according to occupancy on a workstation-by-workstation basis. Field measurements taken over the course of several monthsdemonstrated 40% lighting energy savings compared to a baseline without advanced controls that conforms to GSA's current retrofit standard. A photometric analysis found that the installation provided higher desktop light levels than the baseline, while an occupant survey found that occupants in general preferred the lighting system to thebaseline.Simple payback is fairly high; projects that can achieve lower installation costs and/or higher energy savings and those in which greenhouse gas reduction and occupant satisfaction are significant priorities provide the ideal setting for workstation-specific lighting retrofits.

  2. Combination of Engineering Physics and Modern Scientific Management in High Technology Achievements

    Directory of Open Access Journals (Sweden)

    Arezu Jahanshir

    2015-02-01

    Full Text Available Studying and contemplating the current managerial structure of developed countries show that management and its strategic results have lost their own traditional and usual concept. In these countries, modern management has been developed depending on the knowledge-based infrastructures. In other words, long-term and short-term modern management in all fields is founded upon the predetermined ordered scientific principles and structures that has entered different scientific concepts, wishes and objectives into this field and affects both  and non-organizational managerial procedure observed widely in each field of sciences. For this reason, the results and achievements of knowledge-based management of developed countries indicate the significant development of a kind of modern management in the basic and human sciences. While it is doubtlessly true that developed countries are better endowed more than others to compete in the global knowledge high technologies and new equipment management, the problem is rarely that the fewer successful countries lack sufficient scientific high technologies management.

  3. The relationship between family atmosphere and motivation for achievement in year 12 high school students in Yazd 2006-2007

    Directory of Open Access Journals (Sweden)

    G.A Heidary

    2012-02-01

    Results: Six factors were analyzed as predictors of achievement motivation including (rational, cultural based, ethical, religious circuit, control and organization. None of them were significant predictors. The relationship between gender and achievement motivation were significant. A correlation between gender, family atmosphere and achievement motivation was not observed in this study. Conclusion: The family atmosphere with various aspects of motivation may effect on development of students and educational success in Yazd high school students.

  4. Qualitative research study of high-achieving females' life experiences impacting success

    Science.gov (United States)

    Butcher, Ann Patrice

    2003-07-01

    This qualitative study investigated the life experiences of five academically gifted female students in math and science in reflection of their elementary learning prior to enrollment at a prestigious science and mathematics high school. The elite high school limits admission to the state of Illinois' top students. The purpose of this study is to unfold the story of five academically gifted females in attendance at the elite high school reflecting on their life experiences in elementary school that contributed to their current academic success. Twelve female students, who at the time of this study were currently in their senior year (12th grade) of high school, were solicited from the top academic groups who are regarded by their teachers as highly successful in class. Students were selected as part of the study based on academic status, survey completion and interest in study, Caucasian and Asian ethnicity, locale of elementary school with preference given to the variety of school demographics---urban, suburban, and rural---further defined the group to the core group of five. All female participants were personally interviewed and communicated via Internet with the researcher. Parents and teachers completing surveys as well met the methodological requirements of triangulation. An emergent theme of paternal influence came from the research. Implications supported in the research drawn from this study to increase achievement of academically gifted females include: (a) proper early identification of learner strengths plays a role; (b) learning with appropriate intellectual peers is more important than learning with their age group; (c) teachers are the greatest force for excellent instruction; (d) effective teaching strategies include cooperative learning, multi-sensory learning, problem-based learning, and hands-on science; (e) rigor in math is important; (f) gender and stereotypes need not be barriers; (g) outside interests and activities are important for self

  5. Intellectual and non-intellectual determinants of high academic achievement – the contribution of personality traits to the assessment of high performance potential

    OpenAIRE

    Silvia Schubhart; Stefana Holocher-Ertl; Georg Wilflinger

    2013-01-01

    In this paper a study is presented which tries to explain and predict high academic achievement in children or adolescents on the basis of intellectual and non-intellectual determinants – in this case, performance relevant personality traits as well as the social environment of stimulation. The prognosis of high academic achievement is based on a new diagnostic model, the Viennese Diagnostic Model of High Achievement Potential, which undergoes its first empirical validation here. The resu...

  6. Optimal microelectromechanical systems (MEMS) device for achieving high pyroelectric response of AlN

    Science.gov (United States)

    Kebede, Bemnnet; Coutu, Ronald A.; Starman, LaVern

    2014-03-01

    This paper discusses research being conducted on aluminum nitride (AlN) as a pyroelectric material for use in detecting applications. AlN is being investigated because of its high pyroelectric coefficient, thermal stability, and high Curie temperature. In order to determine suitability of the pyroelectric properties of AlN for use as a detector, testing of several devices was conducted. These devices were fabricated using microelectromechanical systems (MEMS) fabrication processes; the devices were also designed to allow for voltage and current measurements. The deposited AlN films used were 150 nm - 300 nm in thickness. Thin-films were used to rapidly increase the temperature response after the thermal stimulus was applied to the pyroelectric material. This is important because the pyroelectric effect is directly proportional to the rate of temperature change. The design used was a face-electrode bridge that provides thermal isolation which minimizes heat loss to the substrate, thereby increasing operation frequency of the pyroelectric device. A thermal stimulus was applied to the pyroelectric material and the response was measured across the electrodes. A thermal imaging camera was used to monitor the changes in temperature. Throughout the testing process, the annealing temperatures, type of layers, and thicknesses were also varied. These changes resulted in improved MEMS designs, which were fabricated to obtain an optimal design configuration for achieving a high pyroelectric response. A pyroelectric voltage response of 38.9 mVp-p was measured without filtering, 12.45 mVp-p was measured in the infrared (IR) region using a Si filter, and 6.38 mVp-p was measured in the short wavelength IR region using a long pass filter. The results showed that AlN's pyroelectric properties can be used in detecting applications.

  7. Intellectual and non-intellectual determinants of high academic achievement – the contribution of personality traits to the assessment of high performance potential

    Directory of Open Access Journals (Sweden)

    Silvia Schubhart

    2013-09-01

    Full Text Available In this paper a study is presented which tries to explain and predict high academic achievement in children or adolescents on the basis of intellectual and non-intellectual determinants – in this case, performance relevant personality traits as well as the social environment of stimulation. The prognosis of high academic achievement is based on a new diagnostic model, the Viennese Diagnostic Model of High Achievement Potential, which undergoes its first empirical validation here. The results show impressive evidence that performance-relevant personality traits and categories of social environment of stimulation contribute to high academic achievement in children and adolescents of above-average intelligence.

  8. Relationships between high-stakes testing policies and student achievement after controlling for demographic factors in aggregated data.

    Directory of Open Access Journals (Sweden)

    Gregory J. Marchant

    2006-11-01

    Full Text Available With the mandate of No Child Left Behind, high-stakes achievement testing is firmly in place in every state. The few studies that have explored the effectiveness of high-stakes testing using NAEP scores have yielded mixed results. This study considered state demographic characteristics for each NAEP testing period in reading, writing, mathematics, and science from 1992 through 2002, in an effort to examine the relation of high-stakes testing policies to achievement and changes in achievement between testing periods. As expected, demographic characteristics and their changes were related significantly to most achievement outcomes, but high-stakes testing policies demonstrated few relationships with achievement. The few relationships between high-stakes testing and achievement or improvement in reading, writing, or science tended to appear only when demographic data were missing; and the minimal relationships with math achievement were consistent with findings in previous research. Considering the cost and potential unintended negative consequences, high-stakes testing policies seem to provide a questionable means of improving student learning.

  9. Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

    Science.gov (United States)

    Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

    2016-02-01

    A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively. PMID:26820247

  10. Extrinsic Motivation for Large-Scale Assessments: A Case Study of a Student Achievement Program at One Urban High School

    Science.gov (United States)

    Emmett, Joshua; McGee, Dean

    2013-01-01

    The purpose of this case study was to discover the critical attributes of a student achievement program, known as "Think Gold," implemented at one urban comprehensive high school as part of the improvement process. Student achievement on state assessments improved during the period under study. The study draws upon perspectives on motivation as a…

  11. Teacher Credentials and Student Achievement in High School: A Cross-Subject Analysis with Student Fixed Effects

    Science.gov (United States)

    Clotfelter, Charles T.; Ladd, Helen F.; Vigdor, Jacob L.

    2010-01-01

    We use data on statewide end-of-course tests in North Carolina to examine the relationship between teacher credentials and student achievement at the high school level. We find compelling evidence that teacher credentials, particularly licensure and certification, affects student achievement in systematic ways and that the magnitudes are large…

  12. Performance Assessment of High and Low Income Families through "Online RAW Achievement Battery Test" of Primary Grade Students

    Science.gov (United States)

    Ahmed, Tamim; Hanif, Maria

    2016-01-01

    This study is intended to investigate student's achievement capability among two families i.e. Low and High income families and designed for primary level learners. A Reading, Arithmetic and Writing (RAW) Achievement test that was developed as a part of another research study (Tamim Ahmed Khan, 2015) was adopted for this study. Both English medium…

  13. The Impact of Principal Perception on Student Academic Climate and Achievement in High School: How Does It Measure Up?

    Science.gov (United States)

    Urick, Angela; Bowers, Alex J.

    2014-01-01

    The purpose of this study is to examine the independent direct effects of student and principal perceptions of academic climate on student achievement in high school. To date, few studies have considered the influence of principal perceptions of academic climate on student achievement. In the present study, we test a set of two-level hierarchical…

  14. A Multi-Institutional Study of the Relationship between High School Mathematics Achievement and Performance in Introductory College Statistics

    Science.gov (United States)

    Dupuis, Danielle N.; Medhanie, Amanuel; Harwell, Michael; LeBeau, Brandon; Monson, Debra; Post, Thomas R.

    2012-01-01

    In this study we examined the effects of prior mathematics achievement and completion of a commercially developed, National Science Foundation-funded, or University of Chicago School Mathematics Project high school mathematics curriculum on achievement in students' first college statistics course. Specifically, we examined the relationship between…

  15. (Re)Defining the Narrative: High-Achieving Nontraditional Black Male Undergraduates at a Historically Black College and University

    Science.gov (United States)

    Goings, Ramon B.

    2016-01-01

    Using Harper's anti-deficit achievement framework as a theoretical guide, the purpose of this phenomenological study was to investigate the academic and social experiences of four nontraditional, high-achieving, Black male undergraduates attending one historically Black university. Findings show that the participants were intrinsically motivated…

  16. American High School Students from Different Ethnic Backgrounds: The Role of Parents and the Classroom in Achievement Motivation

    Science.gov (United States)

    Kim, Jung-In

    2015-01-01

    The purpose of this study was to investigate the relationships between ethnically diverse US high school students' (N = 331) perceptions of their parents' or classroom's motivating factors and their achievement motivation in their math class, connecting achievement goal orientation and self-determination theories. Two hypothesized path models were…

  17. Forage based animal production systems and sustainability, an invited keynote

    Directory of Open Access Journals (Sweden)

    Abdul Shakoor Chaudhry

    2008-07-01

    Full Text Available Forages are essential for the successful operation of animal production systems. This is more relevant to ruminants which are heavily dependant upon forages for their health and production in a cost-effective and sustainable manner. While forages are an economical source of nutrients for animal production, they also help conserve the soil integrity, water supply and air quality. Although the role of these forages for animal production could vary depending upon the regional preferences for the animal and forage species, climate and resources, their importance in the success of ruminant production is acknowledged. However with the increasing global human population and urbanisation, the sustainability of forage based animal production systems is sometimes questioned due to the interrelationship between animal production and the environment. It is therefore vital to examine the suitability of these systems for their place in the future to supply quality food which is safe for human consumption and available at a competitive price to the growing human population. Grassland and forage crops are recognised for their contribution to the environment, recreation and efficiency of meat and milk production,. To maintain sustainability, it is crucial that such farming systems remain profitable and environmentally friendly while producing nutritious foods of high economical value. Thus, it is pertinent to improve the nutritive value of grasses and other forage plants in order to enhance animal production to obtain quality food. It is also vital to develop new forages which are efficiently utilised and wasted less by involving efficient animals. A combination of forage legumes, fresh or conserved grasses, crop residues and other feeds could help develop an animal production system which is economically efficient, beneficial and viable. Also, it is crucial to use efficient animals, improved forage conservation methods, better manure handling, and minimum

  18. Evidence for ship noise impacts on humpback whale foraging behaviour.

    Science.gov (United States)

    Blair, Hannah B; Merchant, Nathan D; Friedlaender, Ari S; Wiley, David N; Parks, Susan E

    2016-08-01

    Noise from shipping activity in North Atlantic coastal waters has been steadily increasing and is an area of growing conservation concern, as it has the potential to disrupt the behaviour of marine organisms. This study examines the impacts of ship noise on bottom foraging humpback whales (Megaptera novaeangliae) in the western North Atlantic. Data were collected from 10 foraging whales using non-invasive archival tags that simultaneously recorded underwater movements and the acoustic environment at the whale. Using mixed models, we assess the effects of ship noise on seven parameters of their feeding behaviours. Independent variables included the presence or absence of ship noise and the received level of ship noise at the whale. We found significant effects on foraging, including slower descent rates and fewer side-roll feeding events per dive with increasing ship noise. During 5 of 18 ship passages, dives without side-rolls were observed. These findings indicate that humpback whales on Stellwagen Bank, an area with chronically elevated levels of shipping traffic, significantly change foraging activity when exposed to high levels of ship noise. This measureable reduction in within-dive foraging effort of individual whales could potentially lead to population-level impacts of shipping noise on baleen whale foraging success. PMID:27512131

  19. Nutritional Characteristics of Forage Grown in South of Benin.

    Science.gov (United States)

    Musco, Nadia; Koura, Ivan B; Tudisco, Raffaella; Awadjihè, Ghislain; Adjolohoun, Sebastien; Cutrignelli, Monica I; Mollica, Maria Pina; Houinato, Marcel; Infascelli, Federico; Calabrò, Serena

    2016-01-01

    In order to provide recommendations on the most useful forage species to smallholder farmers, eleven grass and eleven legume forages grown in Abomey-Calavi in Republic of Benin were investigated for nutritive value (i.e. chemical composition and energy content) and fermentation characteristics (i.e. gas and volatile fatty acid production, organic matter degradability). The in vitro gas production technique was used, incubating the forages for 120 h under anaerobic condition with buffalo rumen fluid. Compared to legume, tropical grass forages showed lower energy (8.07 vs 10.57 MJ/kg dry matter [DM]) and crude protein level (16.10% vs 19.91% DM) and higher cell wall content (neutral detergent fiber: 63.8% vs 40.45% DM), respectively. In grass forages, the chemical composition showed a quite high crude protein content; the in vitro degradability was slightly lower than the range of tropical pasture. The woody legumes were richer in protein and energy and lower in structural carbohydrates than herbaceous plants, however, their in vitro results are influenced by the presence of complex compounds (i.e. tannins). Significant correlations were found between chemical composition and in vitro fermentation characteristics. The in vitro gas production method appears to be a suitable technique for the evaluation of the nutritive value of forages in developing countries. PMID:26732328

  20. A comparison of rural high school students in Germany with rural Tennessee high school students' mathematics and science achievement

    Science.gov (United States)

    Harding, R. Fredrick

    This descriptive study compared the science and mathematics aptitudes and achievement test scores for the final school year students in rural White County and Van Buren County, Tennessee with rural county students in Germany. In accordance with the previous research literature (Stevenson, 2002), German students outperformed U.S. students on The International Trends in Math and Science test (TIMSS). As reform in the U.S. education system has been underway, this study intended to compare German county student final school year performance with White County and Van Buren County (Grade 12) performance in science and mathematics. The entire populations of 176 White and Van Buren Counties senior high final school year students were compared with 120 school final year students from two rural German county high schools. The student responses to identical test and questionnaire items were compared using the t-test statistical analysis. In conclusion after t-test analyses, there was no significant difference (p>.05 level) in student attitudes on the 27 problem achievement and the 35 TIMSS questionnaire items between the sampled population of 120 German students compared with the population of 176 White and Van Buren students. Also, there was no statistically significant difference (p>.05 level) between the German, White, and Van Buren County rural science and math achievement in the TIMSS problem section of the final year test. Based on the research, recommendations to improve U.S. student scores to number one in the world include making changes in teaching methodology in mathematics and science; incorporating pamphlet lessons rather than heavily reliance on textbooks; focusing on problem solving; establishing an online clearinghouse for effective lessons; creating national standards in mathematics and science; matching students' course choices to job aspirations; tracking misbehaving students rather than mainstreaming them into the regular classroom; and designing

  1. Effect of bead and illustrations models on high school students' achievement in molecular genetics

    Science.gov (United States)

    Rotbain, Yosi; Marbach-Ad, Gili; Stavy, Ruth

    2006-05-01

    Our main goal in this study was to explore whether the use of models in molecular genetics instruction in high school can contribute to students' understanding of concepts and processes in genetics. Three comparable groups of 11th and 12th graders participated: The control group (116 students) was taught in the traditional lecture format, while the others received instructions which integrated a bead model (71 students), or an illustration model (71 students). Similar instructions and the same guiding questions accompanied the two models. We used three instruments: a multiple-choice and an open-ended written questionnaire, as well as personal interviews. Five of the multiple-choice questions were also given to students before receiving their genetics instruction (pretest). We found that students who used one of the two types of models improved their knowledge in molecular genetics compared to the control group. However, the open-ended questions revealed that bead model activity was significantly more effective than illustration activity. On the basis of these findings we conclude that, though it is advisable to use a three-dimensional model, such as the bead model, engaging students in activities with illustrations can still improve their achievement in comparison to traditional instruction.

  2. Untangling the debate surrounding strategies for achieving sustainable high coverage of insecticide-treated nets.

    Science.gov (United States)

    Stevens, Warren

    2005-01-01

    On the question of how to achieve the goal of long-term high utilisation of insecticide-treated nets (ITNs), most protagonists fall into one of two camps: free distribution or market development. The 'free distribution' camp argue that given the health benefit to be gained and lives saved, not to mention the relative cost effectiveness of ITNs, such an intervention should be provided free and paid for by governments or donors. In addition, they argue that it is unrealistic to ask the poorest of the population, who are often the ones at most risk, to pay for an ITN, and this risks producing greater inequalities in health. The market advocates counter that free distribution compromises sustainability, both in terms of demand and supply. Firstly they argue that, without a price, people will be less inclined to value ITNs. In turn this could mean lower utilisation, and a lower inclination to replace such an asset at the end of its useful life. In addition, on the supply side, without a price there is little chance of a local market developing for ITNs, although this would be the surest way to ensure a sustainable supply. It is hard to argue with either viewpoint, as both have merit. This article considers three major issues in the debate, and attempts to draw policy conclusions.

  3. Safety management systems and their role in achieving high standards of operational safety

    International Nuclear Information System (INIS)

    Achieving high standards of operational safety requires a robust management framework that is visible to all personnel with responsibility for its implementation. The structure of the management framework must ensure that all processes used to manage safety interlink in a logical and coherent manner, that is, they form a management system that leads to continuous improvement in safety performance. This Paper describes BNFL's safety management system (SMS). The SMS has management processes grouped within 5 main elements: 1. Policy, 2. Organisation, 3. Planning and Implementation, 4. Measuring and Reviewing Performance, 5. Audit. These elements reflect the overall process of setting safety objective (from Policy), measuring success and reviewing the performance. Effective implementation of the SMS requires senior managers to demonstrate leadership through their commitment and accountability. However, the SMS as a whole reflects that every employee at every level within BNFL is responsible for safety of operations under their control. The SMS therefore promotes a proactive safety culture and safe operations. The system is formally documented in the Company's Environmental, Health and Safety (EHS) Manual. Within in BNFL Group, the Company structures enables the Manual to provide overall SMS guidance and co-ordination to its range of nuclear businesses. Each business develops the SMS to be appropriate at all levels of its organisation, but ensuring that each level is consistent with the higher level. The Paper concludes with a summary of BNFL's safety performance. (author)

  4. New Powder Metallurgical Approach to Achieve High Fatigue Strength in Ti-6Al-4V Alloy

    Science.gov (United States)

    Cao, Fei; Ravi Chandran, K. S.; Kumar, Pankaj; Sun, Pei; Zak Fang, Z.; Koopman, Mark

    2016-05-01

    Recently, manufacturing of titanium by sintering and dehydrogenation of hydride powders has generated a great deal of interest. An overarching concern regarding powder metallurgy (PM) titanium is that critical mechanical properties, especially the high-cycle fatigue strength, are lower than those of wrought titanium alloys. It is demonstrated here that PM Ti-6Al-4V alloy with mechanical properties comparable (in fatigue strength) and exceeding (in tensile properties) those of wrought Ti-6Al-4V can be produced from titanium hydride powder, through the hydrogen sintering and phase transformation process. Tensile and fatigue behavior, as well as fatigue fracture mechanisms, have been investigated under three processing conditions. It is shown that a reduction in the size of extreme-sized pores by changing the hydride particle size distribution can lead to improved fatigue strength. Further densification by pneumatic isostatic forging leads to a fatigue strength of ~550 MPa, comparable to the best of PM Ti-6Al-4V alloys prepared by other methods and approaching the fatigue strengths of wrought Ti-6Al-4V alloys. The microstructural factors that limit fatigue strength in PM titanium have been investigated, and pathways to achieve greater fatigue strengths in PM Ti-6Al-4V alloys have been identified.

  5. Achieving numerical accuracy and high performance using recursive tile LU factorization with partial pivoting

    KAUST Repository

    Dongarra, Jack

    2013-09-18

    The LU factorization is an important numerical algorithm for solving systems of linear equations in science and engineering and is a characteristic of many dense linear algebra computations. For example, it has become the de facto numerical algorithm implemented within the LINPACK benchmark to rank the most powerful supercomputers in the world, collected by the TOP500 website. Multicore processors continue to present challenges to the development of fast and robust numerical software due to the increasing levels of hardware parallelism and widening gap between core and memory speeds. In this context, the difficulty in developing new algorithms for the scientific community resides in the combination of two goals: achieving high performance while maintaining the accuracy of the numerical algorithm. This paper proposes a new approach for computing the LU factorization in parallel on multicore architectures, which not only improves the overall performance but also sustains the numerical quality of the standard LU factorization algorithm with partial pivoting. While the update of the trailing submatrix is computationally intensive and highly parallel, the inherently problematic portion of the LU factorization is the panel factorization due to its memory-bound characteristic as well as the atomicity of selecting the appropriate pivots. Our approach uses a parallel fine-grained recursive formulation of the panel factorization step and implements the update of the trailing submatrix with the tile algorithm. Based on conflict-free partitioning of the data and lockless synchronization mechanisms, our implementation lets the overall computation flow naturally without contention. The dynamic runtime system called QUARK is then able to schedule tasks with heterogeneous granularities and to transparently introduce algorithmic lookahead. The performance results of our implementation are competitive compared to the currently available software packages and libraries. For example

  6. Achieving accurate simulations of urban impacts on ozone at high resolution

    International Nuclear Information System (INIS)

    The effects of urbanization on ozone levels have been widely investigated over cities primarily located in temperate and/or humid regions. In this study, nested WRF-Chem simulations with a finest grid resolution of 1 km are conducted to investigate ozone concentrations [O3] due to urbanization within cities in arid/semi-arid environments. First, a method based on a shape preserving Monotonic Cubic Interpolation (MCI) is developed and used to downscale anthropogenic emissions from the 4 km resolution 2005 National Emissions Inventory (NEI05) to the finest model resolution of 1 km. Using the rapidly expanding Phoenix metropolitan region as the area of focus, we demonstrate the proposed MCI method achieves ozone simulation results with appreciably improved correspondence to observations relative to the default interpolation method of the WRF-Chem system. Next, two additional sets of experiments are conducted, with the recommended MCI approach, to examine impacts of urbanization on ozone production: (1) the urban land cover is included (i.e., urbanization experiments) and, (2) the urban land cover is replaced with the region’s native shrubland. Impacts due to the presence of the built environment on [O3] are highly heterogeneous across the metropolitan area. Increased near surface [O3] due to urbanization of 10–20 ppb is predominantly a nighttime phenomenon while simulated impacts during daytime are negligible. Urbanization narrows the daily [O3] range (by virtue of increasing nighttime minima), an impact largely due to the region’s urban heat island. Our results demonstrate the importance of the MCI method for accurate representation of the diurnal profile of ozone, and highlight its utility for high-resolution air quality simulations for urban areas. (letter)

  7. Social Adaptation and Its Relationship to Achievement Motivation among High School Students in Jordan

    Science.gov (United States)

    AlZboon, Saleem Odeh

    2013-01-01

    The study amid at exploring and detecting the level of social adaptation and its relationship with the achievement motivation of the secondary school students in Jordan, the study sample consisted of 495 secondary school students in the province of Jerash, and to achieve the objective of this study comes the development of two tools: the first one…

  8. Motivational Factors Contributing to Turkish High School Students' Achievement in Gases and Chemical Reactions

    Science.gov (United States)

    Kadioglu, Cansel; Uzuntiryaki, Esen

    2008-01-01

    This study aimed to investigate the contribution of motivational factors to 10th grade students' achievement in gases and chemical reactions in chemistry. Three hundred fifty nine 10th grade students participated in the study. The Gases and Chemical Reactions Achievement Test and the Motivated Strategies for Learning Questionnaire were…

  9. Longitudinal Analysis of Chinese High School Student's Stress in School and Academic Achievement

    Science.gov (United States)

    Liu, Yangyang; Lu, Zuhong

    2011-01-01

    In previous research, few studies have examined the effects of adolescents' stress in school on the change rates of their academic achievement. In the present study, we seek to examine the longitudinal relationships between adolescents' stress in school and the change rates of their academic achievement. The results indicated that for those whose…

  10. Relationships of cognitive and metacognitive learning strategies to mathematics achievement in four high-performing East Asian education systems.

    Science.gov (United States)

    Areepattamannil, Shaljan; Caleon, Imelda S

    2013-01-01

    The authors examined the relationships of cognitive (i.e., memorization and elaboration) and metacognitive learning strategies (i.e., control strategies) to mathematics achievement among 15-year-old students in 4 high-performing East Asian education systems: Shanghai-China, Hong Kong-China, Korea, and Singapore. In all 4 East Asian education systems, memorization strategies were negatively associated with mathematics achievement, whereas control strategies were positively associated with mathematics achievement. However, the association between elaboration strategies and mathematics achievement was a mixed bag. In Shanghai-China and Korea, elaboration strategies were not associated with mathematics achievement. In Hong Kong-China and Singapore, on the other hand, elaboration strategies were negatively associated with mathematics achievement. Implications of these findings are briefly discussed.

  11. Effects of forage type, forage to concentrate ratio, and crushed linseed supplementation on milk fatty acid profile in lactating dairy cows

    NARCIS (Netherlands)

    Sterk, A.R.; Johansson, B.E.O.; Taweel, H.Z.H.; Murphy, M.; Vuuren, van A.M.; Hendriks, W.H.; Dijkstra, J.

    2011-01-01

    The effects of an increasing proportion of crushed linseed (CL) in combination with varying forage type (grass or corn silage) and forage to concentrate ratio (F:C), and their interactions on milk fatty acid (FA) profile of high-producing dairy cows was studied using a 3-factor Box-Behnken design. S

  12. Do crabeater seals forage cooperatively?

    Science.gov (United States)

    Gales, Nicholas J.; Fraser, William R.; Costa, Daniel P.; Southwell, Colin

    2004-08-01

    Crabeater seals are abundant pack-ice predators that feed almost exclusively on krill. They have a circumpolar distribution and are generally sighted hauled out on ice floes alone or in pairs. Here we report our observations of a sighting of 150-200 crabeater seals, which were synchronised in their diving and surfacing behaviour, along with a summary of similar observations from western Antarctica of large groups of crabeater seals in synchronous dive cycles. We report on the low frequency of sightings of such groups during Antarctic pack-ice seal surveys in eastern (Greater) Antarctica. We examine plausible hypotheses to explain these observations, and suggest this behaviour is likely to represent some form of cooperative foraging behaviour, whereby a net advantage in individual energy intake rates is conferred to each seal. Current research on crabeater seal foraging using satellite-linked dive recorders is unlikely to provide sufficiently fine-scale data to examine this hypothesis. Nor will this approach indicate if a seal is foraging with conspecifics. The use of remote or animal-borne camera systems is more likely to provide an insight into fine-scale foraging tactics, as well as the possible, occasional use of cooperative foraging strategies.

  13. Needs-Satisfaction, Motivation, and Achievement in High School Students: Testing Predictive Models by Gender and Ethnicity

    OpenAIRE

    Bialis-White, Lionel Henry

    2013-01-01

    Student motivation is one proposed contributing factor to disparate rates of high school achievement. Guided by self-determination theory (SDT; Ryan & Deci, 2000a), the purpose of the present study is to investigate whether a process model of the relationship between motivation and achievement varied by gender and racial subsamples of students within one large high school (see Figure 1). First, I examined the reliability and structural validity of the measures within the model. Second, I e...

  14. Closing the Academic Achievement Gap on the California High School Exit Exam (CAHSEE) through Professional Learning Communities (PLC) Characteristics

    Science.gov (United States)

    Buenrostro, Samuel

    2012-01-01

    Purpose: The purpose of this study was to determine the degree of importance that DuFour's nine characteristics of highly effective schools have on closing the academic achievement gap on the California High School Exit Exam, as perceived by high school principals. The study also examined the strategies believed to be most important in…

  15. Achievement and Social Ascription: A Comparison of Public and Private High Schools.

    Science.gov (United States)

    Bickel, Robert

    1986-01-01

    Public and private schooling have a roughly uniform effect on achievement, but variability among students' home and neighborhood environments mask the leveling effect. Includes an historical discussion of egalitarianism and stratification in American education. (PS)

  16. What’s Past is Prologue: Relations Between Early Mathematics Knowledge and High School Achievement

    OpenAIRE

    Watts, TW; Duncan, GJ; Siegler, RS; Davis-Kean, PE

    2014-01-01

    © 2014 AERA. Although previous research has established the association between early-grade mathematics knowledge and later mathematics achievement, few studies have measured mathematical skills prior to school entry, and few have investigated the predictive power of early gains in mathematics ability. The current paper relates mathematical skills measured at 54 months to adolescent mathematics achievement using multisite longitudinal data. We find that preschool mathematics ability predicts ...

  17. Family socioeconomic status, family health, and changes in students' math achievement across high school: A mediational model.

    Science.gov (United States)

    Barr, Ashley Brooke

    2015-09-01

    In response to recent calls to integrate understandings of socioeconomic disparities in health with understandings of socioeconomic disparities in academic achievement, this study tested a mediational model whereby family socioeconomic status predicted gains in academic achievement across high school through its impact on both student and parent health. Data on over 8000 high school students in the U.S. were obtained from wave 1 (2009-2010) and wave 2 (2012) of the High School Longitudinal Study of 2009 (HSLS:09), and structural equation modeling with latent difference scores was used to determine the role of family health problems in mediating the well-established link between family SES and gains in academic achievement. Using both static and dynamic indicators of family SES, support was found for this mediational model. Higher family SES in 9th grade reduced the probability of students and their parents experiencing a serious health problem in high school, thereby promoting growth in academic achievement. In addition, parent and student health problems mediated the effect of changes in family SES across high school on math achievement gains. Results emphasize the importance of considering the dynamic nature of SES and that both student and parent health should be considered in understanding SES-related disparities in academic achievement. This relational process provides new mechanisms for understanding the intergenerational transmission of socioeconomic status and the status attainment process more broadly. PMID:26189011

  18. Family socioeconomic status, family health, and changes in students' math achievement across high school: A mediational model.

    Science.gov (United States)

    Barr, Ashley Brooke

    2015-09-01

    In response to recent calls to integrate understandings of socioeconomic disparities in health with understandings of socioeconomic disparities in academic achievement, this study tested a mediational model whereby family socioeconomic status predicted gains in academic achievement across high school through its impact on both student and parent health. Data on over 8000 high school students in the U.S. were obtained from wave 1 (2009-2010) and wave 2 (2012) of the High School Longitudinal Study of 2009 (HSLS:09), and structural equation modeling with latent difference scores was used to determine the role of family health problems in mediating the well-established link between family SES and gains in academic achievement. Using both static and dynamic indicators of family SES, support was found for this mediational model. Higher family SES in 9th grade reduced the probability of students and their parents experiencing a serious health problem in high school, thereby promoting growth in academic achievement. In addition, parent and student health problems mediated the effect of changes in family SES across high school on math achievement gains. Results emphasize the importance of considering the dynamic nature of SES and that both student and parent health should be considered in understanding SES-related disparities in academic achievement. This relational process provides new mechanisms for understanding the intergenerational transmission of socioeconomic status and the status attainment process more broadly.

  19. Are seabirds foraging for unpredictable resources?

    Science.gov (United States)

    Weimerskirch, Henri

    2007-02-01

    It is generally assumed that the extreme life history traits of pelagic seabirds, such as low fecundity or slow growth of chicks, result from the difficulties obtaining energy at sea from unpredictable and patchily distributed resources. However, little information on seabird prey distribution and availability exists to sustain this widely accepted hypothesis. Using tracking studies of 68 sub-populations of flying seabirds, I examine whether it is possible to gain information on the predictability of their marine resources. Because prey are clustered from fine to large scale in nested unities, from swarms to patches and concentrations of patches, it is important to take into account spatial scale. In temperate and polar regions, at large and meso-scales, seabirds appear to have a good knowledge of the location and concentrations of patches and generally use a commuting type of trip to reach foraging zones. Predictability appears to be high at large and meso-scales, with individuals from each sub-population heading in a particular direction from the colony to reach favoured habitats of known enhanced productivity such as shelf edges, frontal zones, upwellings. Within these mesoscale features, the animals use an area-restricted search behaviour to search for patches and swarms at finer scales. Using information on foraging site fidelity of individual birds, I show that differences in predictability at coarse scales are related to the distance and time spent foraging, and in particular to the specific types of foraging habitat. Some habitats appear to be more predictable than others: birds return consistently to the same coarse-scale sectors on shelf edges, whereas predictability is low in oceanic waters, even in frontal zones. Preliminary results on tropical species suggest that the environment here is less predictable in tropic than in temperate or polar zones. This review highlights that patchiness and predictability of marine resources are complex notions

  20. Forage characteristics affecting meat goat preferences for forage chicory cultivars

    Science.gov (United States)

    Concentration of bitter sesquiterpene lactones (SL), lactucin, lactucopicrin, and 8-deoxylactucin, has been associated with low soil phosphorus fertility and reduced livestock preference for forage chicory (Cichorium intybus L.). We evaluated the effect of cultivar and available soil P (ASP) on mea...

  1. Markets, voucher subsidies and free nets combine to achieve high bed net coverage in rural Tanzania

    Directory of Open Access Journals (Sweden)

    Gerrets Rene PM

    2008-06-01

    Full Text Available Abstract Background Tanzania has a well-developed network of commercial ITN retailers. In 2004, the government introduced a voucher subsidy for pregnant women and, in mid 2005, helped distribute free nets to under-fives in small number of districts, including Rufiji on the southern coast, during a child health campaign. Contributions of these multiple insecticide-treated net delivery strategies existing at the same time and place to coverage in a poor rural community were assessed. Methods Cross-sectional household survey in 6,331 members of randomly selected 1,752 households of 31 rural villages of Demographic Surveillance System in Rufiji district, Southern Tanzania was conducted in 2006. A questionnaire was administered to every consenting respondent about net use, treatment status and delivery mechanism. Findings Net use was 62.7% overall, 87.2% amongst infants (0 to1 year, 81.8% amongst young children (>1 to 5 years, 54.5% amongst older children (6 to 15 years and 59.6% amongst adults (>15 years. 30.2% of all nets had been treated six months prior to interview. The biggest source of nets used by infants was purchase from the private sector with a voucher subsidy (41.8%. Half of nets used by young children (50.0% and over a third of those used by older children (37.2% were obtained free of charge through the vaccination campaign. The largest source of nets amongst the population overall was commercial purchase (45.1% use and was the primary means for protecting adults (60.2% use. All delivery mechanisms, especially sale of nets at full market price, under-served the poorest but no difference in equity was observed between voucher-subsidized and freely distributed nets. Conclusion All three delivery strategies enabled a poor rural community to achieve net coverage high enough to yield both personal and community level protection for the entire population. Each of them reached their relevant target group and free nets only temporarily

  2. Investigate Factor Effecting Of Students’ Achievement on High School Entrance Exam-(SBS Respect to the Different Variables

    Directory of Open Access Journals (Sweden)

    Mustafa METİN

    2013-04-01

    Full Text Available The aim of study is to investigate factor affecting of secondary school students’ achievement on high school entrance exam (SBS respect to the different variables. The study was carried out at fall semester of 2012 with 991 students educating primary schools in Artvin. In this study survey method was used and data gathered with questionnaire consists of 40 items. As a result of study, it was determinate that effects of family, educational facilities, teachers and personal characters on students’ achievement are at high level. There is no different between gender and students achievement (p>0.05, although there are different between grade level, family incomes, graduation types of mother and father and students achievement (p<0.05.

  3. Seasonal variations in the diet and foraging behaviour of dunlins Calidris alpina in a south European estuary: improved feeding conditions for northward migrants.

    Directory of Open Access Journals (Sweden)

    Ricardo C Martins

    Full Text Available During the annual cycle, migratory waders may face strikingly different feeding conditions as they move between breeding areas and wintering grounds. Thus, it is of crucial importance that they rapidly adjust their behaviour and diet to benefit from peaks of prey abundance, in particular during migration, when they need to accumulate energy at a fast pace. In this study, we compared foraging behaviour and diet of wintering and northward migrating dunlins in the Tagus estuary, Portugal, by video-recording foraging birds and analysing their droppings. We also estimated energy intake rates and analysed variations in prey availability, including those that were active at the sediment surface. Wintering and northward migrating dunlins showed clearly different foraging behaviour and diet. In winter, birds predominantly adopted a tactile foraging technique (probing, mainly used to search for small buried bivalves, with some visual surface pecking to collect gastropods and crop bivalve siphons. Contrastingly, in spring dunlins generally used a visual foraging strategy, mostly to consume worms, but also bivalve siphons and shrimps. From winter to spring, we found a marked increase both in the biomass of invertebrate prey in the sediment and in the surface activity of worms and siphons. The combination of these two factors, together with the availability of shrimps in spring, most likely explains the changes in the diet and foraging behaviour of dunlins. Northward migrating birds took advantage from the improved feeding conditions in spring, achieving 65% higher energy intake rates as compared with wintering birds. Building on these results and on known daily activity budgets for this species, our results suggest that Tagus estuary provides high-quality feeding conditions for birds during their stopovers, enabling high fattening rates. These findings show that this large wetland plays a key role as a stopover site for migratory waders within the East

  4. Seasonal variations in the diet and foraging behaviour of dunlins Calidris alpina in a south European estuary: improved feeding conditions for northward migrants.

    Science.gov (United States)

    Martins, Ricardo C; Catry, Teresa; Santos, Carlos D; Palmeirim, Jorge M; Granadeiro, José P

    2013-01-01

    During the annual cycle, migratory waders may face strikingly different feeding conditions as they move between breeding areas and wintering grounds. Thus, it is of crucial importance that they rapidly adjust their behaviour and diet to benefit from peaks of prey abundance, in particular during migration, when they need to accumulate energy at a fast pace. In this study, we compared foraging behaviour and diet of wintering and northward migrating dunlins in the Tagus estuary, Portugal, by video-recording foraging birds and analysing their droppings. We also estimated energy intake rates and analysed variations in prey availability, including those that were active at the sediment surface. Wintering and northward migrating dunlins showed clearly different foraging behaviour and diet. In winter, birds predominantly adopted a tactile foraging technique (probing), mainly used to search for small buried bivalves, with some visual surface pecking to collect gastropods and crop bivalve siphons. Contrastingly, in spring dunlins generally used a visual foraging strategy, mostly to consume worms, but also bivalve siphons and shrimps. From winter to spring, we found a marked increase both in the biomass of invertebrate prey in the sediment and in the surface activity of worms and siphons. The combination of these two factors, together with the availability of shrimps in spring, most likely explains the changes in the diet and foraging behaviour of dunlins. Northward migrating birds took advantage from the improved feeding conditions in spring, achieving 65% higher energy intake rates as compared with wintering birds. Building on these results and on known daily activity budgets for this species, our results suggest that Tagus estuary provides high-quality feeding conditions for birds during their stopovers, enabling high fattening rates. These findings show that this large wetland plays a key role as a stopover site for migratory waders within the East Atlantic Flyway. PMID

  5. Improving Pervasive Positioning through Three-tier Cyber Foraging

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Kjærgaard, Mikkel Baun; Toftkjær, Thomas;

    2011-01-01

    Cyber foraging is a pervasive computing technique where small, mobile devices offload resource intensive work to stronger, nearby surrogate computers in order to preserve energy and achieve better performance. The problem with relying only on local resources is, that the availability of such reso......Cyber foraging is a pervasive computing technique where small, mobile devices offload resource intensive work to stronger, nearby surrogate computers in order to preserve energy and achieve better performance. The problem with relying only on local resources is, that the availability...... of such resources may be scarce in many environments. In this paper we therefore argue that a third tier should be added when considering cyber foraging; namely cloud computing. By considering the local device, nearby surrogates, and the cloud when scheduling, the mobile device may be able to continue using remote...... the possible accuracy in many cases. In this paper we describe how a three tier cyber foraging approach can help improve the positioning capabilities of mobile devices. We demonstrate initial results for how such an approach applies to particle filtering-based GSM positioning....

  6. Students' attitude to homework: how is homework perceived by high-achieving students and those with learning disabilities

    OpenAIRE

    Trobec, Nika

    2013-01-01

    Homework assignments have many positive educational effects, which are achieved only when they are regularly performed and completed. While doing homework, students are under the influence of various external and internal factors that affect its utility. Many of them experience homework-related problems in one or more areas which are described in theoretical part. Aim of the empirical survey was to do a research on homework practices of students with learning disabilities and high achieving s...

  7. Gender Differences in Korean High School Students' Science Achievements and Attitudes towards Science in Three Different School Settings

    Science.gov (United States)

    Bang, EunJin; Baker, Dale R.

    2013-01-01

    This study analysed the effect of high schools' gender organization on Korean tenth-grade students' science achievements, and their attitudes towards science. The high schools involved included an all-male institution, an all-female institution, and a co-educational institution. Three schools, three principals, three science teachers, and 302…

  8. The Effect of Community Linguistic Isolation on Language-Minority Student Achievement in High School

    Science.gov (United States)

    Drake, Timothy Arthur

    2014-01-01

    Research on language-minority student outcomes has revealed sizeable and persistent achievement gaps. The reasons for these gaps are often closely linked with other factors related to underperformance, including generational status, race/ethnicity, and socioeconomic status. Using sociocultural second-language acquisition theories and community…

  9. Effect of Blended Learning Environment Model on High School Students' Academic Achievement

    Science.gov (United States)

    Kazu, Ibrahim Yasar; Demirkol, Mehmet

    2014-01-01

    This study analyzes the students' academic performance by comparing the blended learning environment and traditional learning environment. It has been observed whether there is a significant difference between the academic achievement grade dispersions and the male-female students' grades. The study has been carried out in Diyarbakir…

  10. Low-Achieving Readers, High Expectations: Image Theatre Encourages Critical Literacy

    Science.gov (United States)

    Rozansky, Carol Lloyd; Aagesen, Colleen

    2010-01-01

    Students in an eighth-grade, urban, low-achieving reading class were introduced to critical literacy through engagement in Image Theatre. Developed by liberatory dramatist Augusto Boal, Image Theatre gives participants the opportunity to examine texts in the triple role of interpreter, artist, and sculptor (i.e., image creator). The researchers…

  11. What's Past Is Prologue: Relations between Early Mathematics Knowledge and High School Achievement

    Science.gov (United States)

    Watts, Tyler W.; Duncan, Greg J.; Siegler, Robert S.; Davis-Kean, Pamela E.

    2014-01-01

    Although previous research has established the association between early-grade mathematics knowledge and later mathematics achievement, few studies have measured mathematical skills prior to school entry, and few have investigated the predictive power of early gains in mathematics ability. The current paper relates mathematical skills measured at…

  12. Factors Affecting the Achievement of High School Students in Beginning Computer Science Courses.

    Science.gov (United States)

    Guinan, Tricia; Stephens, Larry

    1988-01-01

    Considers three questions regarding computer science courses: (1) Can performance be predicted?; (2) Does a solid mathematical background provide the student with an advantage?; and (3) Is gender a factor in performance or aptitude? Reports a strong math background was related to achievement in a beginning course while gender was not related. (MVL)

  13. Impacts of Comprehensive Reading Instruction on Diverse Outcomes of Low- and High-Achieving Readers

    Science.gov (United States)

    Guthrie, John T.; McRae, Angela; Coddington, Cassandra S.; Klauda, Susan Lutz; Wigfield, Allan; Barbosa, Pedro

    2009-01-01

    Low-achieving readers in Grade 5 often lack comprehension strategies, domain knowledge, word recognition skills, fluency, and motivation to read. Students with such multiple reading needs seem likely to benefit from instruction that supports each of these reading processes. The authors tested this expectation experimentally by comparing the…

  14. Three Dopaminergic Polymorphisms Are Associated with Academic Achievement in Middle and High School

    Science.gov (United States)

    Beaver, Kevin M.; Vaughn, Michael G.; Wright, John Paul; DeLisi, Matt; Howard, Matthew O.

    2010-01-01

    Although academic achievement is a heritable construct, to date research has yet to explore its molecular genetic underpinnings. Drawing on data from the National Longitudinal Study of Adolescent Health, the current longitudinal study investigated the associations between polymorphisms in three dopaminergic genes (DAT1, DRD2, and DRD4) and…

  15. The Influence of Mathematics Anxiety in Middle and High School Students Math Achievement

    Science.gov (United States)

    Al Mutawah, Masooma Ali

    2015-01-01

    Math anxiety has been the focus of much psychological and educational research in the past few years, there are many international studies showing that mathematics anxiety is an influence on student's achievements in school, but little research has been done about this issue in Bahrain. Bahrain is a country in the Arabian Gulf region, its economic…

  16. Squirrel Foraging Preferences: Gone Nuts?

    Science.gov (United States)

    Darling, Randi A.

    2007-01-01

    This field exercise examines the feeding preferences of Gray Squirrels ("Sciurus carolinensis"). Students present squirrels with a variety of food types in a cafeteria-style arrangement in order to test hypotheses about foraging preferences. This exercise, which is appropriate for introductory biology, ecology, and animal behavior classes, is…

  17. Food limitation of sea lion pups and the decline of forage off central and southern California.

    Science.gov (United States)

    McClatchie, Sam; Field, John; Thompson, Andrew R; Gerrodette, Tim; Lowry, Mark; Fiedler, Paul C; Watson, William; Nieto, Karen M; Vetter, Russell D

    2016-03-01

    California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish and market squid forage. In the last decade off central California, where breeding female sea lions from San Miguel rookery feed, sardine and anchovy greatly decreased in biomass, whereas market squid and rockfish abundance increased. Pup weights fell as forage food quality declined associated with changes in the relative abundances of forage species. A model explained 67% of the variance in pup weights using forage from central and southern California and 81% of the variance in pup weights using forage from the female sea lion foraging range. A shift from high to poor quality forage for breeding females results in food limitation of the pups, ultimately flooding animal rescue centres with starving sea lion pups. Our study is unusual in using a long-term, fishery-independent dataset to directly address an important consequence of forage decline on the productivity of a large marine predator. Whether forage declines are environmentally driven, are due to a combination of environmental drivers and fishing removals, or are due to density-dependent interactions between forage and sea lions is uncertain. However, declining forage abundance and quality was coherent over a large area (32.5-38° N) for a decade, suggesting that trends in forage are environmentally driven.

  18. Multiple-stage decisions in a marine central-place forager.

    Science.gov (United States)

    Friedlaender, Ari S; Johnston, David W; Tyson, Reny B; Kaltenberg, Amanda; Goldbogen, Jeremy A; Stimpert, Alison K; Curtice, Corrie; Hazen, Elliott L; Halpin, Patrick N; Read, Andrew J; Nowacek, Douglas P

    2016-05-01

    Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator-prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager

  19. The energetic importance of night foraging for waders wintering in a temperate estuary

    Science.gov (United States)

    Lourenço, Pedro M.; Silva, Andreia; Santos, Carlos D.; Miranda, Ana C.; Granadeiro, José P.; Palmeirim, Jorge M.

    2008-07-01

    Many species of waders forage extensively at night, but there is very little information on the relevance of this behaviour for the energy budget of waders wintering in estuarine wetlands. Quantitative data on diurnal and nocturnal intake rates can indicate the extent to which birds need to forage at night to supplement their diurnal energetic intake, or rather show a preference for nocturnal foraging. We compared day and night foraging behaviour, diet, and energy consumption of several wader species in the Tejo estuary, Portugal. There were significant differences between diurnal and nocturnal foraging behaviour. In general, birds moved less at night and scolopacid waders tended to use more tactile foraging methods. Although birds consumed the same type of prey in the two periods, the relative importance of each type changed. Overall, energy consumption was higher during the day except in grey plover, which achieved higher crude intake rates at night. Our results support the assertion that night foraging is an important part of the energy balance of waders during late winter, but that in most species it is less profitable than diurnal foraging.

  20. Diet Overlap and Foraging Activity between Feral Pigs and Native Peccaries in the Pantanal.

    Directory of Open Access Journals (Sweden)

    Mauro Galetti

    Full Text Available Inter-specific competition is considered one of the main selective pressures affecting species distribution and coexistence. Different species vary in the way they forage in order to minimize encounters with their competitors and with their predators. However, it is still poorly known whether and how native species change their foraging behavior in the presence of exotic species, particularly in South America. Here we compare diet overlap of fruits and foraging activity period of two sympatric native ungulates (the white-lipped peccary, Tayassu pecari, and the collared peccary, Pecari tajacu with the invasive feral pig (Sus scrofa in the Brazilian Pantanal. We found high diet overlap between white-lipped peccaries and feral pigs, but low overlap between collared peccaries and feral pigs. Furthermore, we found that feral pigs may influence the foraging period of both native peccaries, but in different ways. In the absence of feral pigs, collared peccary activity peaks in the early evening, possibly allowing them to avoid white-lipped peccary activity peaks, which occur in the morning. In the presence of feral pigs, collared peccaries forage mostly in early morning, while white-lipped peccaries forage throughout the day. Our results indicate that collared peccaries may avoid foraging at the same time as white-lipped peccaries. However, they forage during the same periods as feral pigs, with whom they have lower diet overlap. Our study highlights how an exotic species may alter interactions between native species by interfering in their foraging periods.

  1. Diet Overlap and Foraging Activity between Feral Pigs and Native Peccaries in the Pantanal.

    Science.gov (United States)

    Galetti, Mauro; Camargo, Hiléia; Siqueira, Tadeu; Keuroghlian, Alexine; Donatti, Camila I; Jorge, Maria Luisa S P; Pedrosa, Felipe; Kanda, Claudia Z; Ribeiro, Milton C

    2015-01-01

    Inter-specific competition is considered one of the main selective pressures affecting species distribution and coexistence. Different species vary in the way they forage in order to minimize encounters with their competitors and with their predators. However, it is still poorly known whether and how native species change their foraging behavior in the presence of exotic species, particularly in South America. Here we compare diet overlap of fruits and foraging activity period of two sympatric native ungulates (the white-lipped peccary, Tayassu pecari, and the collared peccary, Pecari tajacu) with the invasive feral pig (Sus scrofa) in the Brazilian Pantanal. We found high diet overlap between white-lipped peccaries and feral pigs, but low overlap between collared peccaries and feral pigs. Furthermore, we found that feral pigs may influence the foraging period of both native peccaries, but in different ways. In the absence of feral pigs, collared peccary activity peaks in the early evening, possibly allowing them to avoid white-lipped peccary activity peaks, which occur in the morning. In the presence of feral pigs, collared peccaries forage mostly in early morning, while white-lipped peccaries forage throughout the day. Our results indicate that collared peccaries may avoid foraging at the same time as white-lipped peccaries. However, they forage during the same periods as feral pigs, with whom they have lower diet overlap. Our study highlights how an exotic species may alter interactions between native species by interfering in their foraging periods.

  2. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals

    Science.gov (United States)

    Peterson, Sarah H.; Ackerman, Joshua T.; Costa, Daniel P.

    2015-01-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ13C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation.

  3. Junior High School Students’ Perception of Classroom Environment and Their English Achievement

    OpenAIRE

    Rahmedia Alfi Rahmi; Chuzaimah Dahlan Diem

    2014-01-01

    Classroom environment is different from one school to another. This may lead to students’ achievement. This study was aimed at finding out whether the two variables were correlated positively by involving 378 students selected randomly from 55 schools in different sub-districts. The ‘What Is Happening In this Class (WIHIC) questionnaire’ and an English test were used to collect the data. The findings showed that: (1) there was a positive correlation between classroom environment and students’...

  4. Foraging Activity Pattern Is Shaped by Water Loss Rates in a Diurnal Desert Rodent.

    Science.gov (United States)

    Levy, Ofir; Dayan, Tamar; Porter, Warren P; Kronfeld-Schor, Noga

    2016-08-01

    Although animals fine-tune their activity to avoid excess heat, we still lack a mechanistic understanding of such behaviors. As the global climate changes, such understanding is particularly important for projecting shifts in the activity patterns of populations and communities. We studied how foraging decisions vary with biotic and abiotic pressures. By tracking the foraging behavior of diurnal desert spiny mice in their natural habitat and estimating the energy and water costs and benefits of foraging, we asked how risk management and thermoregulatory requirements affect foraging decisions. We found that water requirements had the strongest effect on the observed foraging decisions. In their arid environment, mice often lose water while foraging for seeds and cease foraging even at high energetic returns when water loss is high. Mice also foraged more often when energy expenditure was high and for longer times under high seed densities and low predation risks. Gaining insight into both energy and water balance will be crucial to understanding the forces exerted by changing climatic conditions on animal energetics, behavior, and ecology. PMID:27420785

  5. Intelligence, classroom behavior, and academic achievement in children at high and low risk for psychopathology: a structural equation analysis.

    Science.gov (United States)

    Worland, J; Weeks, D G; Janes, C L; Strock, B D

    1984-09-01

    The intelligence, academic achievement, and classroom behavior of 158 children were assessed in a sample that is being followed longitudinally. The sample included children at high risk for mental disorder by virtue of having a parent with a psychiatric diagnosis of schizophrenia or affective disorder, children at moderate risk, and children at low risk. A series of path analyses indicated that in this sample (1) classroom behavior was more likely an affect that a cause of academic achievement, and (2) the influence of parental psychopathology on classroom behavior was mediated by a child's intelligence and academic achievement. We were unable to substantiate an unmediated causal link between parental psychopathology and children's academic achievement or classroom behavior.

  6. Genotypic Differences of Forage Crop Tolerance to Acid Soils

    Institute of Scientific and Technical Information of China (English)

    YANGYUAI; CHUXIANGYUN; 等

    1998-01-01

    Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay(pH4.16) and red sandstone(pH4.55) to study genotypic differences of the forage crops in tolerance to acid soils as affected by liming,phosporus and potassium fertilizer application.Eight forage species,Lolium nultiflorum L., Brachiaria decumbens,Digitaria sumtisii,Melinis minutiflora,Paspalum dilatatum,Paspalum wettsteinii,Sataria viridis Beanv and Shcep's Festuca,were highly toleran to acid soils,and grew relatively well in the tested soils without lime application,whereas most of the other 20 tested forage species such as Lolium perenne L., Meadow Festuca and Trifolium praense L. were intolerant to acid soil ,showing retarded growth when the soil pH was below 5.5 and significant increase in dry matter yields by phosphrus fertilizer application at soil pH 6.0 Results showed that large differences in tolerance to acid soils existed among the forage species,and tolerance of the froage species to acid soils might be closely associated with their tolerance to Al and P efficiency.

  7. Potency Of Clitoria Ternatea As Forage For Livestock

    Directory of Open Access Journals (Sweden)

    Endang Sutedi

    2013-06-01

    Full Text Available Availability of forage is one of the factors determining the success of ruminant livestock production, especially during drought that resulting in poor livestock condition. Forage legume is an important group of forage plants, containing high nutritive value. One of the legume plants which potential as ruminant feed is Clitoria ternatea. This plant can grow well in all types of soil and dry conditions, also produces seed continously. The production of forage was 25-29 ton DM/ha with seed production was 2.2 ton DM/ha per harvest (42 day cutting interval. The crude protein and crude fiber contents of C. ternatea leaf were 21.5 and 29%, respectively. Meanwhile, the crude protein, crude fat and sugar contents of C. ternatea seed were 25-38,10 and 5%, respectively. This plant can be fed to ruminant as fresh forage or hay with no negative effect on growth performance of animal. The average daily gain of cattle grazing on mixture of Brachiaria mutica grass and C. ternatea was 680 g/day. The value of DM and OM digestibilities of C. ternatea in cattle were 50.15 and 53.47%, respectively. Feeding C. ternatea to dairy cow impoved the content of fat and total solid of milk, meanwhile feeding it to male sheep improved quality of semen.

  8. Inquiry-Based Laboratory Activities in Electrochemistry: High School Students' Achievements and Attitudes

    Science.gov (United States)

    Sesen, Burcin Acar; Tarhan, Leman

    2013-01-01

    This study aimed to investigate the effects of inquiry-based laboratory activities on high school students' understanding of electrochemistry and attitudes towards chemistry and laboratory work. The participants were 62 high school students (average age 17 years) in an urban public high school in Turkey. Students were assigned to experimental (N =…

  9. Safety as high and as harmonized as reasonably achievable: Nuclear regulators facing globalization

    International Nuclear Information System (INIS)

    The use of nuclear energy and ionizing radiation is being extensively scrutinized once again in light of the present debate on its role in sustainable development and on global security problems. Nuclear power is an important feature of today's energy supply. Commercial nuclear generation is a mature, established technology, having accumulated over 40 years of successful operation. Yet nuclear power raises passions as do few other energy issues. Within countries and among them, both support and opposition are strong. Loyola de Palacio, the European Union Commissioner responsible for energy and transport, summed up the dilemma very succinctly: Either we shut down the nuclear sector and give up on Kyoto, or we do not shut down the nuclear sector and we respect Kyoto. It is as simple as that: sometimes you have to put it crudely so that people understand. What is the role of nuclear regulators in this environment? The primary objective of government intervention into nuclear business is to allow humankind to maximize the benefits and minimize the risks emanating from nuclear sciences and their applications. Because both the nuclear power industry and the societal context within which it is regulated are dynamic, regulators must continuously assess their approaches to regulation to best achieve their regulatory mandate. This includes adjusting the boundaries of activity between the plant and the regulator. That is, working out the practical approaches that allow the power reactor operator/owner to achieve and maintain safety while allowing the regulatory body to assure itself and the public that appropriate levels of safety are achieved and maintained

  10. IDENTITY AND TEMPORAL PERSPECTIVE OF ADOLESCENTS WITH HIGH ACHIEVEMENTS IN SCHOOL

    Directory of Open Access Journals (Sweden)

    Denitsa Alipieva

    2015-12-01

    Full Text Available The current article is an empirical approach reviewing the theories for the factors for formation of identity and self-conception in the adolescent. Under the theories for internal attribution and temporal perspective the study was conducted with teenagers between 11 and 18 years with different achievements. The aim is to show the relevance between the subjective affective involving and success in academic activity and realistic self-esteem that could enhance the abilities of students to create adequate plans and goals for future and mature self-conception

  11. Multimodal floral signals and moth foraging decisions.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Riffell

    Full Text Available BACKGROUND: Combinations of floral traits - which operate as attractive signals to pollinators - act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition - a contrast to many studies that have used artificial stimuli (essential oils, single odorants that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers - a species that is not very attractive to hawkmoths - showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however - a flower that is highly attractive to naïve hawkmoths - did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays. CONCLUSIONS/SIGNIFICANCE: These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as

  12. Forage Polyphenol Oxidase and Ruminant Livestock Nutrition

    Directory of Open Access Journals (Sweden)

    Michael Richard F. Lee

    2014-12-01

    Full Text Available Polyphenol oxidase (PPO is associated with the detrimental effect of browning fruit and vegetables, however interest within PPO containing forage crops has grown since the brownng reaction was associated with reduced nitrogen (N losses in silo and the rumen. The reduction in protein breakdown in silo of red clover (high PPO forage increased the quality of protein, improving N-use efficiency (NUE when fed to ruminants. A further benefit of red clover silage feeding is a significant reduction in lipolysis in silo and an increase in the deposition of beneficial C18 polyunsaturated fatty acid (PUFA in animal products, which has also been linked to PPO activity. PPOs protection of plant protein and glycerol based-PUFA in silo is related to the deactivation of plant proteases and lipases. This deactivation occurs through PPO catalysing the conversion of diphenols to quinones which bind with cellular nucleophiles such as protein reforming a protein-bound phenol (PBP. If the protein is an enzyme the complexing denatures the enzyme. However, PPO is inactive in the anaerobic rumen and therefore any subsequent protection of plant protein and glycerol based-PUFA in the rumen must be as a result of events that occurred to the forage pre-ingestion. Reduced activity of plant proteases and lipases would have little effect on NUE and glycerol based-PUFA in the rumen due to the greater concentration of rumen microbial proteases and lipases. The mechanism for PPOs protection of plant protein in the rumen is a consequence of complexing plant protein, rather than protease deactivation per se. These complexed proteins reduce protein digestibility in the rumen and subsequently increase un-degraded dietary protein flow to the small intestine. The mechanism for protecting glycerol-based PUFA has yet to be fully elucidated but may be associated with entrapment within PBP reducing access to microbial lipases or differences in rumen digestion kinetics of red clover.

  13. Corn in consortium with forages

    Directory of Open Access Journals (Sweden)

    Cássia Maria de Paula Garcia

    2013-12-01

    Full Text Available The basic premises for sustainable agricultural development with focus on rural producers are reducing the costs of production and aggregation of values through the use crop-livestock system (CLS throughout the year. The CLS is based on the consortium of grain crops, especially corn with tropical forages, mainly of the genus Panicum and Urochloa. The study aimed to evaluate the grain yield of irrigated corn crop intercropped with forage of the genus Panicum and Urochloa. The experiment was conducted at the Fazenda de Ensino, Pesquisa e Extensão – FEPE  of the Faculdade de Engenharia - UNESP, Ilha Solteira in an Oxisol in savannah conditions and in the autumn winter of 2009. The experimental area was irrigated by a center pivot and had a history of no-tillage system for 8 years. The corn hybrid used was simple DKB 390 YG at distances of 0.90 m. The seeds of grasses were sown in 0.34 m spacing in the amount of 5 kg ha-1, they were mixed with fertilizer minutes before sowing  and placed in a compartment fertilizer seeder and fertilizers were mechanically deposited in the soil at a depth of 0.03 m. The experimental design used was a randomized block with four replications and five treatments: Panicum maximum cv. Tanzania sown during the nitrogen fertilization (CTD of the corn; Panicum maximum cv. Mombaça sown during the nitrogen fertilization (CMD of the corn; Urochloa brizantha cv. Xaraés sown during the occasion of nitrogen fertilization (CBD of the corn; Urochloa ruziziensis cv. Comumsown during the nitrogen fertilization (CRD of the corn and single corn (control. The production components of corn: plant population per hectare (PlPo, number of ears per hectare (NE ha-1, number of rows per ear (NRE, number of kernels per row on the cob (NKR, number of grain in the ear (NGE and mass of 100 grains (M100G were not influenced by consortium with forage. Comparing grain yield (GY single corn and maize intercropped with forage of the genus Panicum

  14. The effects of a science intervention program on the attitudes and achievement of high school girls in science

    Science.gov (United States)

    Steakley, Carrie Capers

    This study investigated the effects of a high school science intervention program that included hands-on activities, science-related career information and exposure, and real-world experiences on girls' attitudes and achievement in science. Eighty-four girls, 44 ninth-graders and 40 tenth-graders, and 105 parents participated in the study. Survey data was collected to assess the girls' attitudes toward science in seven distinct areas: social implications of science, normality of scientists, attitude toward scientific inquiry, adoption of scientific attitudes, enjoyment of science lessons, leisure interest in science, and career interest in science. Additional questionnaires were used to determine the extent of the girls' participation in sports and the attitudes of their parents toward science. The girls' cumulative science semester grade point averages since the seventh grade were used to assess academic science achievement. This study found no evidence that participation in the program improved the girls' attitudes or achievement in science. Parent attitudes and years of participation in sports were not accurate predictors of science achievement. Additionally, no significant relationship was detected between the girls' and their parents' perceptions of science. However, the study did suggest that extended participation in sports may positively affect science achievement for girls. This study holds implications for educational stakeholders who seek to implement intervention methods and programs that may improve student attitudes and achievement in science and attract more youth to future science-related careers.

  15. Self-Regulated Learning and a Sense of Achievement in MOOCs among High School Science and Technology Students

    Science.gov (United States)

    Cohen, Lizi; Magen-Nagar, Noga

    2016-01-01

    This study, conducted in Israel, examined how learning strategies and motivational orientations contributed to high school students' sense of achievement in a massive open online course. The objective was to integrate an innovative teaching-learning strategy into the educational system that is based on online learning for students in subjects that…

  16. The Perceptions of Principals and Teachers Regarding Mental Health Providers' Impact on Student Achievement in High Poverty Schools

    Science.gov (United States)

    Perry, Teresa

    2012-01-01

    This study examined the perceptions of principals and teachers regarding mental health provider's impact on student achievement and behavior in high poverty schools using descriptive statistics, t-test, and two-way ANOVA. Respondents in this study shared similar views concerning principal and teacher satisfaction and levels of support for the…

  17. Practice Brief: Assessing Compensatory Strategies and Motivational Factors in High-Achieving Postsecondary Students with Attention Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Schaffer, Gary

    2013-01-01

    Research speculates that high-achieving college students with attention deficit/hyperactivity disorder (ADHD) may demonstrate a set of compensatory strategies and experience areas of difficulty and motivational factors that differ from the general ADHD populace. This Practice Brief used informal surveys with seven undergraduates with ADHD who had…

  18. The Effect of Blended Learning Model on High School Students' Biology Achievement and on Their Attitudes towards the Internet

    Science.gov (United States)

    Yapici, I.Umit; Akbayin, Hasan

    2012-01-01

    The present study aims to determine the effect of the blended learning model on high school students' biology achievement and on their attitudes towards the Internet. Among the experimental models, the pretest-posttest control group model was used in the study. The study was carried out with 107 students (47 of whom were in the experimental group,…

  19. Mathematics: Self-Efficacy, Identity, and Achievement among African American Males from the High School Longitudinal Study

    Science.gov (United States)

    Briggs, Calvin

    2014-01-01

    The purpose of this study was to determine if a relationship existed between mathematics self-efficacy and mathematics identity to mathematics achievement among African American males from High School Longitudinal Study of 2009 (HSLS:09). Subsequently, the extent to which mathematics self-efficacy and mathematics identity accounted for low and…

  20. An Exploration of the Psychosocial Characteristics of High Achieving Students and Identified Gifted Students: Implications for Practice

    Science.gov (United States)

    Ritchotte, Jennifer A.; Suhr, Diana; Alfurayh, Naif F.; Graefe, Amy K.

    2016-01-01

    High achieving students or "bright children" are often denied access to gifted services because they do not meet "gifted" criteria. Although psychosocial factors play an integral role in academic success, and can be useful in providing a clearer picture of student need, they are seldom considered in the decision to identify a…

  1. Differences between High and Low Academic Achieving University Students in Learning and Study Strategies: A Further Investigation

    Science.gov (United States)

    Yip, Michael C. W.

    2009-01-01

    Following up on the general framework of the research study of Yip (2007), this article sets out a similar research question, investigating the differences between high and low academic achieving Hong Kong university students based on their different learning and study strategies. In this study, we recruited 100 university students who pursued…

  2. Public, Catholic Single-Sex, and Catholic Coeducational High Schools: Their Effects on Achievement, Affect, and Behaviors.

    Science.gov (United States)

    Marsh, Herbert W.

    1991-01-01

    Using data from the High School and Beyond survey, compares junior and senior year performance and other variables in Catholic single sex, Catholic coed, and public schools. Finds Catholic school students are urged to take more academically demanding courses; this accounts for public/Catholic differences in achievement and university attendance.…

  3. High-School Students' Need for Cognition, Self-Control Capacity, and School Achievement: Testing a Mediation Hypothesis

    Science.gov (United States)

    Bertrams, Alex; Dickhauser, Oliver

    2009-01-01

    In the present article, we examine the hypothesis that high-school students' motivation to engage in cognitive endeavors (i.e., their need for cognition; NFC) is positively related to their dispositional self-control capacity. Furthermore, we test the prediction that the relation between NFC and school achievement is mediated by self-control…

  4. Unpacking High and Low Efficacy Teachers' Task Analysis and Competence Assessment in Teaching Low-Achieving Students in Secondary Schools

    Science.gov (United States)

    Wang, Li-Yi; Jen-Yi, Li; Tan, Liang-See; Tan, Irene; Lim, Xue-Fang; Wu, Bing Sheng

    2016-01-01

    This study adopted a pragmatic qualitative research design to unpack high and low efficacy teachers' task analysis and competence assessment in the context of teaching low-achieving students. Nine secondary school English and Science teachers were recruited and interviewed. Results of thematic analysis show that helping students perform well in…

  5. Relationships of Cognitive and Metacognitive Learning Strategies to Mathematics Achievement in Four High-Performing East Asian Education Systems

    Science.gov (United States)

    Areepattamannil, Shaljan; Caleon, Imelda S.

    2013-01-01

    The authors examined the relationships of cognitive (i.e., memorization and elaboration) and metacognitive learning strategies (i.e., control strategies) to mathematics achievement among 15-year-old students in 4 high-performing East Asian education systems: Shanghai-China, Hong Kong-China, Korea, and Singapore. In all 4 East Asian education…

  6. The Effect of Poverty on the Achievement of Urban African American Male Students Successfully Completing High School

    Science.gov (United States)

    Welch, Amy L.

    2013-01-01

    The purpose of this study was to determine the impact of poverty on the achievement of African American male high school students attending the same large Midwest urban school district. Cumulative grade point average (GPA) at the tenth grade level were compared to the level of poverty provided through census data of African American male tenth…

  7. High-Achieving Black Students, Biculturalism, and Out-of-School STEM Learning Experiences: Exploring Some Unintended Consequences

    Science.gov (United States)

    McGee, Ebony O.

    2013-01-01

    In this article, the author discusses the complex challenges of high-achieving Black students who are successful in becoming immersed in predominately White STEM (science, technology, engineering, and mathematics) spaces and how such immersion can exacerbate their experiences of racial stereotyping and other forms of racial bias. The author…

  8. A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Schiess, Adrian B.; Howell, Jamie; Baca, Michael J.; Partridge, L. Donald; Finnegan, Patrick Sean; Wolfley, Steven L.; Dagel, Daryl James; Spahn, Olga Blum; Harper, Jason C.; Pohl, Kenneth Roy; Mickel, Patrick R.; Lohn, Andrew; Marinella, Matthew

    2013-10-01

    The human brain (volume=1200cm3) consumes 20W and is capable of performing > 10^16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m^3 and 3MW, giving the brain a 10^12 advantage in operations/s/W/cm^3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

  9. Need for Closure, Achievement Goals, and Cognitive Engagement in High School Students

    Science.gov (United States)

    Harlow, Lea; DeBacker, Teresa; Crowson, H. Michael

    2011-01-01

    The authors extend their understanding of learner motivation by addressing questions around the construct of classroom need for closure in a high school sample. First, they established that their classroom need for closure measure demonstrated adequate psychometric properties when used with high school students. Subsequently, they explored…

  10. Teachers' Awareness of Cultural Diversity and Academic Achievement in Ninth Grade Academies and Senior High Schools

    Science.gov (United States)

    Whipps-Johnson, Jamellah Renee

    2016-01-01

    High school graduation rates are higher than they have ever been in 40 years, but disparities continue to exist for students of color and students from poverty when compared to their counterparts. High school reform efforts like creating small learning communities are promising, but small schools alone do not improve student outcomes.…

  11. Effective Leadership Practices of Catholic High School Principals That Support Student Achievement

    Science.gov (United States)

    Valadez, Denise

    2013-01-01

    The purpose of this study was to determine what effective leadership practices are employed by Catholic high school principals to cultivate a culture of academic success and foster Catholic identity. This study addressed and identified the following: 1) the effective leadership skills Catholic high school principals need to embody to be successful…

  12. The Effects of Two Scheduling Formats on Student Achievement in a Suburban High School Setting

    Science.gov (United States)

    Jackson, Kenyada Morton

    2013-01-01

    Limited studies have been conducted on the relationship between scheduling formats and academic performance of high school students. At the target high school, students underperform on standardized tests in English language arts (ELA) and math. The purpose of this causal comparative quantitative study was to compare the means of ELA and math test…

  13. Gender differences in Korean high school students’ science achievements and attitudes towards science in three different school settings

    OpenAIRE

    EunJin Bang; Dale R. Baker

    2013-01-01

    This study analysed the effect of high schools' gender organization on Korean tenth-grade students’ science achievements, and their attitudes towards science. The high schools involved included an all-male institution, an all-female institution, and a co-educational institution. Three schools, three principals, three science teachers, and 302 tenthgrade students from their respective school types responded to an initial survey, and eleven academically outstanding students were subsequently in...

  14. In situ Rumen Degradation Kinetics of High-Protein Forage Crops in Temperate Climates Cinética de Degradación Ruminal in situ en Forrajes de Alto Contenido Proteico en Clima Templado

    Directory of Open Access Journals (Sweden)

    Ximena Valderrama L.

    2011-12-01

    Full Text Available The present study was conducted to evaluate the nutritional value and in situ degradation kinetics of eight high protein forage crops: alfalfa (Medicago sativa L., forage oat (Avena sativa L., mixed pasture, and ryegrass (Lolium multiflorum Lam. pasture in early vegetative stages, two forage lupins (Lupinus albus L. in early bloom stages, sugar beet (Beta vulgaris L. and kale (Brassica napus var. pabularia (DC. Rchb. leaves at root maturity. Dry matter (DM and crude protein (CP degradation kinetics were evaluated by the nylon bag technique through the in situ procedure described by 0rskov and MacDonald (1979 using three ruminally cannulated sheep. Chemical composition of the forage crops showed on average 13.7% DM; 21.4% CP; 31.5% neutral detergent fiber (NDF; 17.7% crude fiber (CF, 80.6% digestibility of organic matter (DOMD and 12.13 MJ kg-1 metabolizable energy (ME. The high total degradability of forage crops reported here (> 87% DM; > 93% CP can be associated with the presence of large quantities of fraction a (> 34% DMa; > 29% CPa and high degradability of fraction b, resulting in low amounts of undegradable fraction (U (7.02% DM and 3.55% CP. Correlations between CPb and DMb degradability (r = 0.79 and CPc and DMc degradation rates (r = 0.78 were high, however differences in c were not explained by differences in CP or NDF contents, nor by the amounts of a or b fractions. Degradation for DM and CP during the first 6 h of incubation was strongly and inversely correlated to b (36 h (r = 0.93 (P El presente estudio se desarrolló con el objetivo de evaluar el valor nutricional y la cinética de degradación in situ de ocho forrajes de alto valor proteico: alfalfa (Medicago sativa L., avena (Avena sativa L., pastos mixtos y pastos de ballica (Lolium multiflorum Lam., en las primeras etapas vegetativas, dos lupinos forrajeros (Lupinus albus L. en etapas inicio de la floración, hojas de remolacha azucarera (Beta vulgaris L. y de col (Brassica

  15. Foraging decisions in wild versus domestic Mus musculus: What does life in the lab select for?

    Science.gov (United States)

    Troxell-Smith, Sandra M; Tutka, Michal J; Albergo, Jessica M; Balu, Deebika; Brown, Joel S; Leonard, John P

    2016-01-01

    What does domestication select for in terms of foraging and anti-predator behaviors? We applied principles of patch use and foraging theory to test foraging strategies and fear responses of three strains of Mus musculus: wild-caught, control laboratory, and genetically modified strains. Foraging choices were quantified using giving-up densities (GUDs) under three foraging scenarios: (1) patches varying in microhabitat (covered versus open), and initial resource density (low versus high); (2) daily variation in auditory cues (aerial predators and control calls); (3) patches with varying seed aggregations. Overall, both domestic strains harvested significantly more food than wild mice. Each strain revealed a significant preference for foraging under cover compared to the open, and predator calls had no detectable effects on foraging. Both domestic strains biased their harvest toward high quality patches; wild mice did not. In terms of exploiting favorable and avoiding unfavorable distributions of seeds within patches, the lab strain performed best, the wild strain worst, and the mutant strain in between. Our study provides support for hypothesis that domestic animals have more energy-efficient foraging strategies than their wild counterparts, but retain residual fear responses. Furthermore, patch-use studies can reveal the aptitudes and priorities of both domestic and wild animals. PMID:26548716

  16. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera).

    Science.gov (United States)

    Chang, Lun-Hsien; Barron, Andrew B; Cheng, Ken

    2015-06-01

    Worker honey bees change roles as they age as part of a hormonally regulated process of behavioural development that ends with a specialised foraging phase. The rate of behavioural development is highly plastic and responsive to changes in colony condition such that forager losses, disease or nutritional stresses accelerate behavioural development and cause an early onset of foraging in workers. It is not clear to what degree the behavioural development of workers can be accelerated without there being a cost in terms of reduced foraging performance. Here, we compared the foraging performance of bees induced to accelerate their behavioural development by treatment with the juvenile hormone analogue methoprene with that of controls that developed at a normal rate. Methoprene treatment accelerated the onset of both flight and foraging behaviour in workers, but it also reduced foraging span, the total time spent foraging and the number of completed foraging trips. Methoprene treatment did not alter performance in a short-range navigation task, however. These data indicate a limitation to the physiological plasticity of bees, and a trade off between forager performance and the speed at which bees begin foraging. Chronic stressors will be expected to reduce the mean age of the foraging force, and therefore also reduce the efficiency of the foraging force. This interaction may explain why honey bee colonies react to sustained stressors with non-linear population decline. PMID:25883376

  17. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera).

    Science.gov (United States)

    Chang, Lun-Hsien; Barron, Andrew B; Cheng, Ken

    2015-06-01

    Worker honey bees change roles as they age as part of a hormonally regulated process of behavioural development that ends with a specialised foraging phase. The rate of behavioural development is highly plastic and responsive to changes in colony condition such that forager losses, disease or nutritional stresses accelerate behavioural development and cause an early onset of foraging in workers. It is not clear to what degree the behavioural development of workers can be accelerated without there being a cost in terms of reduced foraging performance. Here, we compared the foraging performance of bees induced to accelerate their behavioural development by treatment with the juvenile hormone analogue methoprene with that of controls that developed at a normal rate. Methoprene treatment accelerated the onset of both flight and foraging behaviour in workers, but it also reduced foraging span, the total time spent foraging and the number of completed foraging trips. Methoprene treatment did not alter performance in a short-range navigation task, however. These data indicate a limitation to the physiological plasticity of bees, and a trade off between forager performance and the speed at which bees begin foraging. Chronic stressors will be expected to reduce the mean age of the foraging force, and therefore also reduce the efficiency of the foraging force. This interaction may explain why honey bee colonies react to sustained stressors with non-linear population decline.

  18. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

    Science.gov (United States)

    Geib, Jennifer C; Strange, James P; Galenj, Candace

    2015-04-01

    Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured

  19. Geographic profiling and animal foraging.

    Science.gov (United States)

    Le Comber, Steven C; Nicholls, Barry; Rossmo, D Kim; Racey, Paul A

    2006-05-21

    Geographic profiling was originally developed as a statistical tool for use in criminal cases, particularly those involving serial killers and rapists. It is designed to help police forces prioritize lists of suspects by using the location of crime scenes to identify the areas in which the criminal is most likely to live. Two important concepts are the buffer zone (criminals are less likely to commit crimes in the immediate vicinity of their home) and distance decay (criminals commit fewer crimes as the distance from their home increases). In this study, we show how the techniques of geographic profiling may be applied to animal data, using as an example foraging patterns in two sympatric colonies of pipistrelle bats, Pipistrellus pipistrellus and P. pygmaeus, in the northeast of Scotland. We show that if model variables are fitted to known roost locations, these variables may be used as numerical descriptors of foraging patterns. We go on to show that these variables can be used to differentiate patterns of foraging in these two species.

  20. An examination of the saturation microstructures achieved in ultrafine-grained metals processed by high-pressure torsion

    Directory of Open Access Journals (Sweden)

    Shima Sabbaghianrad

    2014-10-01

    Full Text Available Experiments were conducted on two commercial alloys, a Cu–0.1%Zr alloy and an Al-7075 aluminum alloy, to investigate the significance of the saturation microstructure which is achieved after processing by high-pressure torsion (HPT. Samples were processed by HPT and also by a combination of equal-channel angular pressing (ECAP followed by HPT. The results show that the saturation conditions are dependent upon the grain size in the material immediately prior to the HPT processing. Additional grain refinement may be achieved in HPT by initially processing the material to produce an ultrafine-grain size before conducting the processing by HPT.

  1. Effects of Visible and Invisible Hyperlinks on Vocabulary Acquisition and Reading Comprehension for High- and Average-Foreign Language Achievers

    Directory of Open Access Journals (Sweden)

    Ofelia R. Nikolova

    2004-12-01

    Full Text Available This study investigated the effects of visible and invisible links for annotated words in a computer module for learning French on the vocabulary acquisition and reading comprehension of two types of students – high – and average-achievers. Two hundred and sixty four second-semester students of French were identified as high- or average-achievers. Each type of students was then randomly assigned to two groups – with visible or invisible hyperlinks. All students were instructed to read a short passage in French (181 words for general comprehension and allowed to consult the annotated words (made visible by bold face for the visible links group as much as they needed. The students took a vocabulary pretest and an immediate and delayed (two weeks vocabulary and reading comprehension posttest. The results of the study showed that average- achievers benefited more from the visible links for vocabulary acquisition and reading comprehension than high-achievers. The results are discussed in light of second language acquisition and gifted-student theories and suggestions for future research are made.

  2. Differential regulation of the foraging gene associated with task behaviors in harvester ants

    Directory of Open Access Journals (Sweden)

    Kleeman Lindsay

    2011-08-01

    Full Text Available Abstract Background The division of labor in social insect colonies involves transitions by workers from one task to another and is critical to the organization and ecological success of colonies. The differential regulation of genetic pathways is likely to be a key mechanism involved in plasticity of social insect task behavior. One of the few pathways implicated in social organization involves the cGMP-activated protein kinase gene, foraging, a gene associated with foraging behavior in social insect species. The association of the foraging gene with behavior is conserved across diverse species, but the observed expression patterns and proposed functions of this gene vary across taxa. We compared the protein sequence of foraging across social insects and explored whether the differential regulation of this gene is associated with task behaviors in the harvester ant, Pogonomyrmex occidentalis. Results Phylogenetic analysis of the coding region of the foraging gene reveals considerable conservation in protein sequence across insects, particularly among hymenopteran species. The absence of amino acid variation in key active and binding sites suggests that differences in behaviors associated with this gene among species may be the result of changes in gene expression rather than gene divergence. Using real time qPCR analyses with a harvester ant ortholog to foraging (Pofor, we found that the brains of harvester ant foragers have a daily fluctuation in expression of foraging with mRNA levels peaking at midday. In contrast, young workers inside the nest have low levels of Pofor mRNA with no evidence of daily fluctuations in expression. As a result, the association of foraging expression with task behavior within a species changes depending on the time of day the individuals are sampled. Conclusions The amino acid protein sequence of foraging is highly conserved across social insects. Differences in foraging behaviors associated with this gene among

  3. The Effect of Forage Level and Oil Supplement on Butyrivibrio fibrisolvens and Anaerovibrio lipolytica in Continuous Culture Fermenters.

    Science.gov (United States)

    Gudla, P; Ishlak, A; AbuGhazaleh, A A

    2012-02-01

    The objective of this study was to evaluate the effects of forage level and oil supplement on selected strains of rumen bacteria believed to be involved in biohydrogenation (BH). A continuous culture system consisting of four fermenters was used in a 4×4 Latin square design with a factorial arrangement of treatments, with four 10 d consecutive periods. Treatment diets were: i) high forage diet (70:30 forage to concentrate (dry matter basis); HFC), ii) high forage plus oil supplement (HFO), iii) low forage diet (30:70 forage to concentrate; LFC), and iv) low forage plus oil supplement (LFO). The oil supplement was a blend of fish oil and soybean oil added at 1 and 2 g/100 g dry matter, respectively. Treatment diets were fed for 10 days and samples were collected from each fermenter on the last day of each period 3 h post morning feeding. The concentrations of vaccenic acid (t11C18:1; VA) and c9t11 conjugated linoleic acid (CLA) were greater with the high forage diet while the concentrations of t10 C18:1 and t10c12 CLA were greater with the low forage diet and addition of oil supplement increased their concentrations at both forage levels. The DNA abundance of Anaerovibrio lipolytica, and Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) were lower with the low forage diets but not affected by oil supplement. The DNA abundance of Butyrivibrio fibrisolvens stearic acid producer subgroup (Butyrivibrio SA) was not affected by forage level or oil supplement. In conclusion, oil supplement had no effects on the tested rumen bacteria and forage level affected Anaerovibrio lipolytica and Butyrivibrio VA. PMID:25049556

  4. A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Schiess, Adrian B.; Howell, Jamie; Baca, Micheal J.; Partridge, L. Donald [University of New Mexico, Albuquerque, NM; Finnegan, Patrick Sean; Wolfley, Steven L.; Dagel, Daryl James; Spahn, Olga Blum; Harper, Jason C.; Pohl, Kenneth Roy; Mickel, Patrick R.; Lohn, Andrew; Marinella, Matthew

    2013-10-01

    The human brain (volume=1200cm3) consumes 20W and is capable of performing>10%5E16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m%5E3 and 3MW, giving the brain a 10%5E12 advantage in operations/s/W/cm%5E3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

  5. Yield and persistence response of forage chicory to phosphorus fertility

    Science.gov (United States)

    Forage chicory (Cichorium intybus) is a productive plant that appears particularly well suited to improving summer yield of pastures in the USA. Poor palatability of some chicory cultivars in locations with low soil phosphorus fertility has been linked to high levels of sesquiterpene lactone, a bit...

  6. Nutritive value response of forage chicory cultivars to phosphorus fertility

    Science.gov (United States)

    Forage chicory (Cichorium intybus L.) is a productive plant that appears particularly well suited to improving summer yield of pastures in the USA. Poor palatability of some chicory cultivars in locations with low soil phosphorus fertility has been linked to high levels of sesquiterpene lactones, b...

  7. Achieving a long-lived high-beta plasma state by energetic beam injection.

    Science.gov (United States)

    Guo, H Y; Binderbauer, M W; Tajima, T; Milroy, R D; Steinhauer, L C; Yang, X; Garate, E G; Gota, H; Korepanov, S; Necas, A; Roche, T; Smirnov, A; Trask, E

    2015-04-23

    Developing a stable plasma state with high-beta (ratio of plasma to magnetic pressures) is of critical importance for an economic magnetic fusion reactor. At the forefront of this endeavour is the field-reversed configuration. Here we demonstrate the kinetic stabilizing effect of fast ions on a disruptive magneto-hydrodynamic instability, known as a tilt mode, which poses a central obstacle to further field-reversed configuration development, by energetic beam injection. This technique, combined with the synergistic effect of active plasma boundary control, enables a fully stable ultra-high-beta (approaching 100%) plasma with a long lifetime.

  8. Achieving and Sustaining New Knowledge Development in High-Expectation Start-Ups

    Science.gov (United States)

    Matricano, Diego

    2010-01-01

    In markets characterized by strong competition, new knowledge and new knowledge development are generally recognized as the key means for an enterprise to gain competitive advantage. This knowledge-based competitive advantage is critical for all commercial ventures, but is especially so for high-expectation start-ups (technology-based ventures…

  9. World first in high level waste vitrification - A review of French vitrification industrial achievements

    Energy Technology Data Exchange (ETDEWEB)

    Brueziere, J.; Chauvin, E. [AREVA, 1 place Jean Millier, 92084 Paris La Defense (France); Piroux, J.C. [Joint Vitrification Laboratory - LCV, Marcoule, BP171, 30207 Bagnols sur Ceze (France)

    2013-07-01

    AREVA has more than 30 years experience in operating industrial HLW (High Level radioactive Waste) vitrification facilities (AVM - Marcoule Vitrification Facility, R7 and T7 facilities). This vitrification technology was based on borosilicate glasses and induction-heating. AVM was the world's first industrial HLW vitrification facility to operate in-line with a reprocessing plant. The glass formulation was adapted to commercial Light Water Reactor fission products solutions, including alkaline liquid waste concentrates as well as platinoid-rich clarification fines. The R7 and T7 facilities were designed on the basis of the industrial experience acquired in the AVM facility. The AVM vitrification process was implemented at a larger scale in order to operate the R7 and T7 facilities in-line with the UP2 and UP3 reprocessing plants. After more than 30 years of operation, outstanding record of operation has been established by the R7 and T7 facilities. The industrial startup of the CCIM (Cold Crucible Induction Melter) technology with enhanced glass formulation was possible thanks to the close cooperation between CEA and AREVA. CCIM is a water-cooled induction melter in which the glass frit and the waste are melted by direct high frequency induction. This technology allows the handling of highly corrosive solutions and high operating temperatures which permits new glass compositions and a higher glass production capacity. The CCIM technology has been implemented successfully at La Hague plant.

  10. The Influence of Momentary Classroom Goal Structures on Student Engagement and Achievement in High School Science

    Science.gov (United States)

    Zaleski, Diana Janet

    2012-01-01

    Teachers' instructional practices fundamentally shape students' classroom experiences. However, it is still unclear what patterns of instructional practice are related to specific classroom goal structures, and how momentary changes in classroom goal structures affect students' momentary cognitive engagement in high school science.…

  11. How to simultaneously achieve low emissions and high efficiency in a hybrid powertrain

    NARCIS (Netherlands)

    Mourad, S.; Eijnden, E. van den; Foster, D.L.; Helden, M. van; Rondel, M.; Schmal, P.

    2001-01-01

    In order to investigate the possibilities of hybrid driveline architecture and to provide a platform for further technical developments, TNO has designed and prototyped a test platform for a series hybrid powertrain, including a compact, highly advanced generator set. This powertrain is subjected to

  12. School-Wide Positive Behavior Support: Effects on Pennsylvania High School Achievement, Discipline, and Climate

    Science.gov (United States)

    Fox, Jon David

    2013-01-01

    Teachers and administrators are faced with managing the behaviors of students while preparing for the high stakes testing associated with the No Child Left Behind Act. One program that has demonstrated positive results at the elementary and middle school level is the school-wide positive behavior support model (SWPBS). Limited research is…

  13. The Contributions of Vocational Education to Career Aspirations, Work Attitudes, and Academic Achievement in High School.

    Science.gov (United States)

    Stone, James R., III

    1988-01-01

    The goal of the study was to determine the relationship between participation in marketing education, a vocational program, and the development of skills and attitudes with lifelong relevance. The conclusion was that high school vocational experience did not influence occupational aspirations for marketing education students. (JOW)

  14. Preparation for High School Chemistry: The Effects of a Summer School Course on Student Achievement

    Science.gov (United States)

    Garland, Eva R.; Garland, Harry T.

    2006-01-01

    A summer course was developed with the goal of preparing girls to succeed in secondary school chemistry. Group work and mathematical, logical, and laboratory skills were stressed in the course, with minimal emphasis on memorization. Students who took the summer course ranked statistically higher during their first semester of high school chemistry…

  15. Self-Directed Activity-Based Learning and Achievement in High School Chemistry

    Science.gov (United States)

    Bassett, Meighan M.; Martinez, James; Martin, Ellice P.

    2014-01-01

    The effects of student-directed activity-based learning (SDABL) were examined in two high school chemistry classes. Students in the SDABL class were given pretest results, a list of standards to be mastered, and a chart of learning activities categorized by difficulty level. They selected activities to meet their needs and preferences.…

  16. Achieving reversibility of ultra-high mechanical stress by hydrogen loading of thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, M.; Burlaka, V.; Wagner, S.; Pundt, A., E-mail: apundt@ump.gwdg.de [Institut of Materials Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany)

    2015-06-15

    Nano-materials are commonly stabilized by supports to maintain their desired shape and size. When these nano-materials take up interstitial atoms, this attachment to the support induces mechanical stresses. These stresses can be high when the support is rigid. High stress in the nano-material is typically released by delamination from the support or by the generation of defects, e.g., dislocations. As high mechanical stress can be beneficial for tuning the nano-materials properties, it is of general interest to deduce how real high mechanical stress can be gained. Here, we show that below a threshold nano-material size, dislocation formation can be completely suppressed and, when delamination is inhibited, even the ultrahigh stress values of the linear elastic limit can be reached. Specifically, for hydrogen solved in epitaxial niobium films on sapphire substrate supports a threshold film thickness of 6 nm was found and mechanical stress of up to (−10 ± 1) GPa was reached. This finding is of basic interest for hydrogen energy applications, as the hydride stability in metals itself is affected by mechanical stress. Thus, tuning of the mechanical stress-state in nano-materials may lead to improved storage properties of nano-sized materials.

  17. A Study of Organizational Justice, Organizational Citizenship Behavior, and Student Achievement in High Schools

    Science.gov (United States)

    Burns, W. R. Travis; DiPaola, Michael F.

    2013-01-01

    Emerging research suggests that teachers' perceptions of fairness with respect to interactions with school administrators, decision-making processes, and decision outcomes can contribute greatly to understanding effective schools. This study of Virginia public high schools used correlational analysis to measure the strength of the…

  18. The Effects of Learning Styles on High School Students' Achievement on a Mathematics Course

    Science.gov (United States)

    Orhun, Nevin

    2013-01-01

    This study examined the relationship between learning styles of students and their success on a mathematics course. In this study, the categorization of high school students' learning style scores was defined. The given method for calculating the learning style scores was developed by the author. The purpose of this study was to raise the…

  19. Achieving reversibility of ultra-high mechanical stress by hydrogen loading of thin films

    International Nuclear Information System (INIS)

    Nano-materials are commonly stabilized by supports to maintain their desired shape and size. When these nano-materials take up interstitial atoms, this attachment to the support induces mechanical stresses. These stresses can be high when the support is rigid. High stress in the nano-material is typically released by delamination from the support or by the generation of defects, e.g., dislocations. As high mechanical stress can be beneficial for tuning the nano-materials properties, it is of general interest to deduce how real high mechanical stress can be gained. Here, we show that below a threshold nano-material size, dislocation formation can be completely suppressed and, when delamination is inhibited, even the ultrahigh stress values of the linear elastic limit can be reached. Specifically, for hydrogen solved in epitaxial niobium films on sapphire substrate supports a threshold film thickness of 6 nm was found and mechanical stress of up to (−10 ± 1) GPa was reached. This finding is of basic interest for hydrogen energy applications, as the hydride stability in metals itself is affected by mechanical stress. Thus, tuning of the mechanical stress-state in nano-materials may lead to improved storage properties of nano-sized materials

  20. Recent Achievements in Developing Low Temperature and High Strain Rate Superplastic Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper is to briefly outline our recent activities in developing low temperature or high strain rate superplastic materials, including aircraft-used and general-purpose Al- and Mg-base alloys or composites, as well as Ti3Al base intermetallic alloys. The processing routes applied included the thermomechanical treatment, equal channel angular pressing and other extrusion or forging methods.

  1. The Impact of High-Speed Internet Connectivity at Home on Eighth-Grade Student Achievement

    Science.gov (United States)

    Kingston, Kent J.

    2013-01-01

    In the fall of 2008 Westside Community Schools - District 66, in Omaha, Nebraska implemented a one-to-one notebook computer take home model for all eighth-grade students. The purpose of this study was to determine the effect of a required yearlong one-to-one notebook computer program supported by high-speed Internet connectivity at school on (a)…

  2. Bridging the High School and College Achievement Gap for Hispanics--It All Begins at Home

    Science.gov (United States)

    Cooper, Mary Ann

    2011-01-01

    According to a Pew Hispanic Center study, "Between Two Worlds: How Young Latinos Come of Age in America, Educational Expectations and Attainment," that surveyed Hispanics 16 years old and older, the high school dropout rate among Latino youths is nearly three times higher than that among white youths and nearly double the rate among blacks. Nearly…

  3. The challenges of achieving high training coverage for IMCI: case studies from Kenya and Tanzania.

    Science.gov (United States)

    Mushi, Hildegalda P; Mullei, Kethi; Macha, Janet; Wafula, Frank; Borghi, Josephine; Goodman, Catherine; Gilson, Lucy

    2011-09-01

    Health worker training is a key component of the integrated management of childhood illness (IMCI). However, training coverage remains low in many countries. We conducted in-depth case studies in two East African countries to examine the factors underlying low training coverage 10 years after IMCI had been adopted as policy. A document review and in-depth semi-structured interviews with stakeholders at facility, district, regional/provincial and national levels in two districts in Kenya (Homa Bay and Malindi) and Tanzania (Bunda and Tarime) were carried out in 2007-08. Bunda and Malindi achieved higher levels of training coverage (44% and 25%) compared with Tarime and Homa Bay (5% and 13%). Key factors allowing the first two districts to perform better were: strong district leadership and personal commitment to IMCI, which facilitated access to external funding and encouraged local-level policy adaptation; sensitization and training of district health managers; and lower staff turnover. However, IMCI training coverage remained well below target levels across all sites. The main barrier to expanding coverage was the cost of training due to its duration, the number of facilitators and its residential nature. Mechanisms for financing IMCI also restricted district capacity to raise funds. In Tanzania, districts could not spend more than 10% of their budgets on training. In Kenya, limited financial decentralization meant that district managers had to rely on donors for financial support. Critically, the low priority given to IMCI at national and international levels also limited the expansion of training. Levels of domestic and donor support for IMCI have diminished over time in favour of vertical programmes, partly due to the difficulty in monitoring and measuring the impact of an integrated intervention like IMCI. Alternative, lower cost methods of IMCI training need to be promoted, and greater advocacy for IMCI is needed both nationally and internationally.

  4. Achieving highly-enhanced UV photoluminescence and its origin in ZnO nanocrystalline films

    Science.gov (United States)

    Thapa, Dinesh; Huso, Jesse; Morrison, John L.; Corolewski, Caleb D.; McCluskey, Matthew D.; Bergman, Leah

    2016-08-01

    ZnO is an efficient luminescent material in the UV-range ∼3.4 eV with a wide range of applications in optical technologies. Sputtering is a cost-effective and relatively straightforward growth technique for ZnO films; however, most as-grown films are observed to contain intrinsic defects which can significantly diminish the desirable UV-emission. In this research the defect dynamics and optical properties of ZnO sputtered films were studied via post-growth annealing in Ar or O2 ambient, with X-ray diffraction (XRD), imaging, transmission and Urbach analysis, Raman scattering, and photoluminescence (PL). The imaging, XRD, Raman and Urbach analyses indicate significant improvement in crystal morphology and band-edge characteristics upon annealing, which is nearly independent of the annealing environment. The native defects specific to the as-grown films, which were analyzed via PL, are assigned to Zni related centers that luminesce at 2.8 eV. Their presence is attributed to the nature of the sputtering growth technique, which supports Zn-rich growth conditions. After annealing, in either environment the 2.8 eV center diminished accompanied by morphology improvement, and the desirable UV-PL significantly increased. The O2 ambient was found to introduce nominal Oi centers while the Ar ambient was found to be the ideal environment for the enhancement of the UV-light emission: an enhancement of ∼40 times was achieved. The increase in the UV-PL is attributed to the reduction of Zni-related defects, the presence of which in ZnO provides a competing route to the UV emission. Also, the effect of the annealing was to decrease the compressive stress in the films. Finally, the dominant UV-PL at the cold temperature regime is attributed to luminescent centers not associated with the usual excitons of ZnO, but rather to structural defects.

  5. Achievement of Runaway Electron Energy Dissipation by High-Z Gas Injection in DIII-D

    Science.gov (United States)

    Hollmann, E. M.

    2014-10-01

    Disruption runaway electron (RE) formation followed by RE beam-wall strikes is a concern for future tokamaks, motivating the study of mitigation techniques to reduce the RE beam energy in a controlled manner. A promising approach for doing this is the injection of high-Z gas into the RE beam. Massive (100 torr-l) injection of high-Z gas into RE beams in DIII-D is shown to significantly dissipate both RE magnetic and kinetic energy. For example, injection of argon into a typical 300 kA current RE beam is observed to cause a drop in kinetic energy from 50 kJ to 10 kJ in 10 ms, thus rapidly reducing the damage-causing capability of the RE beam. Both the RE kinetic energy and pitch angle are important for determining the resulting wall damage, with high energy, high pitch angle electrons typically considered most dangerous. The RE energy distribution is found to be more skewed toward low energies than predicted by avalanche theory. The pitch angle is not found to be constant, as is frequently assumed, but is shown to drop from sin(θ) ~ 1 for energies less than 1 MeV to sin(θ) ~ 0 . 2 for energies greater than 10 MeV. Injection of high-Z impurities does not appear to change the overall shape of the energy or pitch angle distributions dramatically. The enhanced RE energy dissipation appears to be caused primarily via collisions with the cold plasma leading to line radiation. Synchrotron power loss only becomes significant in the absence of high-Z impurities, while radial transport loss of REs is seen to become dominant if the RE beam moves sufficiently close to the vessel walls. The experiments demonstrate that avalanche theory somewhat underestimates collisional dissipation of REs in the presence of high-Z atoms, even in the absence of radial transport losses, meaning that reducing RE wall damage in large tokamaks should be easier than previously expected. Supported by the US Department of Energy under DE-FG02-07ER54917 and DE-FC02-04ER54698.

  6. Development of a 14-inch ID High-Pressure Hybrid Riser for SBOP Drilling Développement d’un riser hybride 14”ID haute pression pour le forage SBOP

    Directory of Open Access Journals (Sweden)

    Persent E.

    2009-11-01

    Full Text Available This paper discusses the development of a 14-inch ID high-pressure hybrid riser (10 000 psi for surface BOP drilling in ultra-deep water (10 000 ft. The high-pressure hybrid riser system is obtained by adapting and combining two existing technologies, previously developed by the IFP for other applications: – the Clip connector, a double breech-block type connector to provide a quick and safe connection for riser joints; – hybrid pipe technology, a steel pipe hoop-wound with tapes of carbon fibers impregnated with polyamide thermoplastic resin. IFP has developed a new 14-inch ID HP Clip connector for the hybrid riser application. The connector is capable of withstanding a 2.8 million pound tension and a 10 000 psi operating pressure. In addition, a 16-inch nominal OD hybrid riser pipe has been designed to replace the steel riser pipe with a thinnerwalled hoop-wound steel pipe. The significant weight savings that can be achieved with the hybrid riser pipe make it possible to design an effective riser architecture to withstand the high pressure and deep water requirements. Pursuant to design studies, a 14-inch ID prototype assembly consisting of two hybrid riser pipe sections with a high-pressure Clip connector was manufactured. A test program, including burst and collapse tests as well as cyclic fatigue testing, was formulated and carried out to qualify the performance of the Clip connector and hybrid riser pipe system. Completion of hybrid pipe additional fatigue testing and realization of a scale-one field testing of the hybrid riser are considered as the next steps of the project. To date, the main test results (burst, collapse, fatigue resistance confirm that the Clip connector and the hybrid pipe technologies are well suited for ultra-deep sea drilling with a surface BOP. However, the fatigue resistance of hybrid riser pipes still needs to be better characterized. Cet article présente le développement d’un riser hybride 14”ID haute

  7. The effects of using diagramming as a representational technique on high school students' achievement in solving math word problems

    Science.gov (United States)

    Banerjee, Banmali

    Methods and procedures for successfully solving math word problems have been, and continue to be a mystery to many U.S. high school students. Previous studies suggest that the contextual and mathematical understanding of a word problem, along with the development of schemas and their related external representations, positively contribute to students' accomplishments when solving word problems. Some studies have examined the effects of diagramming on students' abilities to solve word problems that only involved basic arithmetic operations. Other studies have investigated how instructional models that used technology influenced students' problem solving achievements. Still other studies have used schema-based instruction involving students with learning disabilities. No study has evaluated regular high school students' achievements in solving standard math word problems using a diagramming technique without technological aid. This study evaluated students' achievement in solving math word problems using a diagramming technique. Using a quasi-experimental experimental pretest-posttest research design, quantitative data were collected from 172 grade 11 Hispanic English language learners (ELLS) and African American learners whose first language is English (EFLLs) in 18 classes at an inner city high school in Northern New Jersey. There were 88 control and 84 experimental students. The pretest and posttest of each participating student and samples of the experimental students' class assignments provided the qualitative data for the study. The data from this study exhibited that the diagramming method of solving math word problems significantly improved student achievement in the experimental group (pattention to the creation and labeling of diagrams to represent the mathematics involved in standard word problems. Although Learnertype (ELL, EFLL), Classtype (Bilingual and Mixed), and Gender (Female, Male) were not significant indicators of student achievement, there was

  8. Different Gender Students' Participation in the High- and Low-achieving Middle School Questioning-orientated Biology Classrooms in Taiwan

    Science.gov (United States)

    She, Hsiao-Ching

    2001-02-01

    This case study investigated gender-based differences in classroom participation through examining teacher-student interactions between a female biology teacher and two groups of middle school students, namely high achievers and low achievers. The female teacher used a questioning-orientated instructional strategy as her major teaching style which creates greater opportunities for student participation in biology learning. Classroom sessions were videotaped for one school year, then analysed for gender differences in question-and-answer patterns. The results showed that more teacher-initiated questions, teacher-directed interactions, and teacher feedback were given to males than females in both groups, but a large difference was found between the two groups of students. Girls in the low-achieving biology class (LABC) were more likely to participate at a rate comparable with their male classmates; girls answered more procedure questions and an equal percentage of process questions, called out approximately the same percentage of answers to undirected teacher-initiated questions, and received more instances of praise and follow-up questions. Contrary to what was observed in the high-achieving biology class (HABC), LABC girls initiated more questions than LABC boys.

  9. The rewards of restraint in the collective regulation of foraging by harvester ant colonies.

    Science.gov (United States)

    Gordon, Deborah M

    2013-06-01

    Collective behaviour, arising from local interactions, allows groups to respond to changing conditions. Long-term studies have shown that the traits of individual mammals and birds are associated with their reproductive success, but little is known about the evolutionary ecology of collective behaviour in natural populations. An ant colony operates without central control, regulating its activity through a network of local interactions. This work shows that variation among harvester ant (Pogonomyrmex barbatus) colonies in collective response to changing conditions is related to variation in colony lifetime reproductive success in the production of offspring colonies. Desiccation costs are high for harvester ants foraging in the desert. More successful colonies tend to forage less when conditions are dry, and show relatively stable foraging activity when conditions are more humid. Restraint from foraging does not compromise a colony's long-term survival; colonies that fail to forage at all on many days survive as long, over the colony's 20-30-year lifespan, as those that forage more regularly. Sensitivity to conditions in which to reduce foraging activity may be transmissible from parent to offspring colony. These results indicate that natural selection is shaping the collective behaviour that regulates foraging activity, and that the selection pressure, related to climate, may grow stronger if the current drought in their habitat persists.

  10. Evidence of trapline foraging in honeybees.

    Science.gov (United States)

    Buatois, Alexis; Lihoreau, Mathieu

    2016-08-15

    Central-place foragers exploiting floral resources often use multi-destination routes (traplines) to maximise their foraging efficiency. Recent studies on bumblebees have showed how solitary foragers can learn traplines, minimising travel costs between multiple replenishing feeding locations. Here we demonstrate a similar routing strategy in the honeybee (Apis mellifera), a major pollinator known to recruit nestmates to discovered food resources. Individual honeybees trained to collect sucrose solution from four artificial flowers arranged within 10 m of the hive location developed repeatable visitation sequences both in the laboratory and in the field. A 10-fold increase of between-flower distances considerably intensified this routing behaviour, with bees establishing more stable and more efficient routes at larger spatial scales. In these advanced social insects, trapline foraging may complement cooperative foraging for exploiting food resources near the hive (where dance recruitment is not used) or when resources are not large enough to sustain multiple foragers at once. PMID:27307487

  11. Combining Harmonic Generation and Laser Chirping to Achieve High Spectral Density in Compton Sources

    CERN Document Server

    Terzić, Balša; Krafft, Geoffrey A

    2015-01-01

    Recently various laser-chirping schemes have been investigated with the goal of reducing or eliminating ponderomotive line broadening in Compton or Thomson scattering occurring at high laser intensities. As a next level of detail in the spectrum calculations, we have calculated the line smoothing and broadening expected due to incident beam energy spread within a one-dimensional plane wave model for the incident laser pulse, both for compensated (chirped) and unchirped cases. The scattered compensated distributions are treatable analytically within three models for the envelope of the incident laser pulses: Gaussian, Lorentzian, or hyperbolic secant. We use the new results to demonstrate that the laser chirping in Compton sources at high laser intensities: (i) enables the use of higher order harmonics, thereby reducing the required electron beam energies; and (ii) increases the photon yield in a small frequency band beyond that possible with the fundamental without chirping. This combination of chirping and h...

  12. In Search of Variables Distinguishing Low and High Achievers in Music Sight Reading Task

    OpenAIRE

    Ligges, Uwe; Weihs, Claus; Kopiez, Reinhard; Lee, Ji In

    2004-01-01

    The unrehearsed performance of music, called ?sight reading? (SR), is a basic skill for all musicians. Despite the merits of expertise theory, there is no comprehensive model which can classify subjects into high and low performance groups. This study is the first that classifies subjects and is based on an extensive experiment measuring the total SR performance of 52 piano students. Classification methods (cluster analysis, classification tree, linear discriminant analysis) were applied. Res...

  13. The study experiences of the high achievers in a competitive academic environment: A cost of success?

    OpenAIRE

    Nordmo, Ivar; Samara, Akylina

    2009-01-01

    The present paper is a case study that explores the study experiences and possible costs of success for the students accepted into the professional program in psychology at the University of Bergen in Norway. In this highly competitive environment, between 500 and 1000 students compete for 36 places during the introduction year. The study is based on 31 students' written narratives about their studying experiences during the introductory year in psychology. The data were analys...

  14. Self-esteem, personality and achievement in high school: a prospective longitudinal study in Texas.

    Science.gov (United States)

    Hair, Elizabeth C; Graziano, William G

    2003-12-01

    This research explored four empirical questions: (1) Is self-esteem a better predictor of academic success and adjustment than other aspects of personality? (2) How is self-esteem related to Big-Five dimensions of personality during the transition from middle school to high school? (3) Do dispositions like Agreeableness or Openness relate to an adolescent's adaptation and affect reactions to the self? and (4) Do sources of information about adolescents (e.g., self-rating, other rating, objective "life history") converge? We also explored the general hypothesis that personality, self-esteem, and teachers' ratings of adjustment during the middle school years predict later life outcomes during high school. Overall, results indicate Big-Five personality characteristics were more stable than self-esteem across this transition period. Agreeableness and Openness assessed in middle school are related to later scholastic competence and behavioral conduct, academic success, and adjustment in high school. Results were discussed in terms of personality development and self-evaluation.

  15. Rearing and foraging affects bumblebee (Bombus terrestris) gut microbiota.

    Science.gov (United States)

    Newbold, Lindsay K; Oliver, Anna E; Cuthbertson, Leah; Walkington, Sarah E; Gweon, Hyun S; Heard, Matthew S; van der Gast, Christopher J

    2015-08-01

    Bumblebees are ecologically and economically important as pollinators of crop and wild plants, especially in temperate systems. Species, such as the buff-tailed bumblebee (Bombus terrestris), are reared commercially to pollinate high-value crops. Their highly specific gut microbiota, characterized by low diversity, may affect nutrition and immunity and are likely to be important for fitness and colony health. However, little is known about how environmental factors affect bacterial community structure. We analysed the gut microbiota from three groups of worker bumblebees (B. terrestris) from distinct colonies that varied in rearing and foraging characteristics: commercially reared with restricted foraging (RR); commercially reared with outside foraging (RF); and wild-caught workers (W). Contrary to previous studies, which indicate that bacterial communities are highly conserved across workers, we found that RF individuals had an intermediate community structure compared with RR and W types. Further, this was shaped by differences in the abundances of common operational taxonomic units (OTUs) and the diversity of rare OTUs present, which we propose results from an increase in the variety of carbohydrates obtained through foraging. PMID:25994560

  16. Foraging: an ecology model of consumer behaviour?

    OpenAIRE

    Wells, V.K.

    2012-01-01

    Foraging theory is a well established set of models and ideas in ecology, anthropology and behavioural psychology. Two areas of research, the behavioural ecology of consumption and information foraging, have made strides in the application of foraging theories in relation to consumption and related behaviours. These focus on online situations and restrictions in methodologies utilized allows application to only a small range of marketing problems. This paper broadens the application of these ...

  17. Cadmium and chromium concentrations in six forage species irrigated with canal, sewage or mixed canal and sewage water

    International Nuclear Information System (INIS)

    Cadmium (Cd) and chromium (Cr) concentrations were investigated in six different forage species, i.e., Trifolium alexandrium, Cichorium intybus, Avena sativa, Medicago polymorpha, Brassica campestris and Medicago sativa, irrigated with canal, sewage or mixed canal and sewage water. The Cd levels of the forages irrigated with different water treatments in this study were greater than the tolerance level for grazing livestock reported in the literature. Thus, the Cd levels in the six plant species found in the current study showed high potential threat for livestock consuming these forages. Similarly, high levels of Cr in the six forages were observed with sewage water treatment only. However, in the present investigation, Cr concentration of forages was below the toxic level. Therefore, there was no threat of Cr toxicity for animals being reared on these forages. (author)

  18. From cradle to early grave: juvenile mortality in European shags Phalacrocorax aristotelis results from inadequate development of foraging proficiency.

    Science.gov (United States)

    Daunt, F; Afanasyev, V; Adam, A; Croxall, J P; Wanless, S

    2007-08-22

    In most long-lived animal species, juveniles survive less well than adults. A potential mechanism is inferior foraging skills but longitudinal studies that follow the development of juvenile foraging are needed to test this. We used miniaturized activity loggers to record daily foraging times of juvenile and adult European shags Phalacrocorax aristotelis from fledging to the following spring. Juveniles became independent from their parents 40 days post-fledging. They compensated for poor foraging proficiency by foraging for approximately 3 h d(-1) longer than adults until constrained by day length in early November. Thereafter, juvenile foraging time tracked shortening day length up to the winter solstice, when foraging time of the two age classes converged and continued to track day length until early February. Few individuals died until midwinter and mortality peaked in January-February, with juvenile mortality (including some of the study birds) five times that of adults. In their last two weeks of life, juveniles showed a marked decline in foraging time consistent with individuals becoming moribund. Our results provide compelling evidence that juveniles compensate for poor foraging proficiency by increasing foraging time, a strategy that is limited by day length resulting in high winter mortality. PMID:17504733

  19. Doping in the Mixed Layer to Achieve High Brightness and Efficiency Organic Light Emitting Devices

    Institute of Scientific and Technical Information of China (English)

    高文宝; 杨开霞; 刘宏宇; 冯晶; 刘式墉

    2002-01-01

    Doping in the mixed layer was introduced to fabricate high brightness and high efficiency organic light emitting devices. In these devices, a copper phthalocyanine (CuPc) film acts as the buffer layer, a naphthylphenybiphenyl amine (NPB) film as the hole transport layer and a tris(8-hydroxyquinolinolate)aluminium (Alq3) film as the electron transport layer. The luminescent layer consists of the mixture of NPB, Alq3 (to be called the mixed layer), and an emitting dopant 5,6,11,12-petraphenylnaphthacene (rubrene), where the concentration of NPB declined and the concentration of Alq3 was increased gradually in the deposition process. Adopting this doping mixed layer, the device exhibits the maximum emission of 49300cd/m2 at 35 V and the maximum efficiency of 7.96cd/A at 10.5 V, which have been improved by two times in comparison with conventional doped devices. We attribute this improvement to the effective confinement of carriers in the mixed layer, which leads to the increase of the recombination efficiency of carriers.

  20. U.S. Dairy Forage Research Center

    Data.gov (United States)

    Federal Laboratory Consortium — Vision: Leading the world in integrated dairy forage systems research. Mission: Providing dairy industry solutions for food security, environmental sustainability,...

  1. U.S. DAIRY FORAGE RESEARCH CENTER

    Data.gov (United States)

    Federal Laboratory Consortium — Vision: Leading the world in integrated dairy forage systems research. Mission: Providing dairy industry solutions for food security, environmental sustainability,...

  2. Developing Cyber Foraging Applications for Portable Devices

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Bouvin, Niels Olof

    2008-01-01

    This paper presents the Locusts cyber foraging framework. Cyber foraging is the opportunistic use of computing resources available in the nearby environment, and using such resources thus fall into the category of distributed computing. Furthermore, for the resources to be used efficiently......, parallel computing techniques must also be employed. Distributed and parallel computing are two concepts that are both notoriously known for being very hard for developers to grasp. Because of this one might think that techniques such as cyber foraging would have a hard time surviving outside of research...... environments. In this paper a framework is presented that has special focus on making cyber foraging accessible for all developers....

  3. Visual Foraging With Fingers and Eye Gaze.

    Science.gov (United States)

    Jóhannesson, Ómar I; Thornton, Ian M; Smith, Irene J; Chetverikov, Andrey; Kristjánsson, Árni

    2016-03-01

    A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a) The fact that a sizeable number of observers (in particular during gaze foraging) had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b) While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints. PMID:27433323

  4. An examination of the saturation microstructures achieved in ultrafine-grained metals processed by high-pressure torsion

    OpenAIRE

    Shima Sabbaghianrad; Jittraporn Wongsa-Ngam; Megumi Kawasaki; Terence G. Langdon

    2014-01-01

    Experiments were conducted on two commercial alloys, a Cu–0.1%Zr alloy and an Al-7075 aluminum alloy, to investigate the significance of the saturation microstructure which is achieved after processing by high-pressure torsion (HPT). Samples were processed by HPT and also by a combination of equal-channel angular pressing (ECAP) followed by HPT. The results show that the saturation conditions are dependent upon the grain size in the material immediately prior to the HPT processing. Additional...

  5. Exploring the Dimensions of Problem-solving Ability on High-achieving Secondary Students: A Mixed Methods Study

    OpenAIRE

    Hamm, Jolene Diane

    2010-01-01

    This mixed-methods study investigated the relationship between self-concept and problem-solving style and how these two constructs compared and contrasted in regards to a participantâ s perception of his or her problem-solving ability. The 86 study participants were high-achieving rising 11th and 12th grade students attending a summer enrichment program for agriculture. This study used a concurrent triangulation mixed methods design. The quantitative aspect of the study employed two instrum...

  6. NEMO5: Achieving High-end Internode Communication for Performance Projection Beyond Moore's Law

    CERN Document Server

    Andrawis, Robert; Charles, James; Fang, Jianbin; Fonseca, Jim; He, Yu; Klimeck, Gerhard; Jiang, Zhengping; Kubis, Tillmann; Mejia, Daniel; Lemus, Daniel; Povolotskyi, Michael; Rubiano, Santiago Alonso Perez; Sarangapani, Prasad; Zeng, Lang

    2015-01-01

    Electronic performance predictions of modern nanotransistors require nonequilibrium Green's functions including incoherent scattering on phonons as well as inclusion of random alloy disorder and surface roughness effects. The solution of all these effects is numerically extremely expensive and has to be done on the world's largest supercomputers due to the large memory requirement and the high performance demands on the communication network between the compute nodes. In this work, it is shown that NEMO5 covers all required physical effects and their combination. Furthermore, it is also shown that NEMO5's implementation of the algorithm scales very well up to about 178176CPUs with a sustained performance of about 857 TFLOPS. Therefore, NEMO5 is ready to simulate future nanotransistors.

  7. Focal plane actuation to achieve ultra-high resolution on suborbital balloon payloads

    Science.gov (United States)

    Scowen, Paul A.; Miller, Alex; Challa, Priya; Veach, Todd; Groppi, Chris; Mauskopf, Phil

    2014-07-01

    Over the past few years there has been remarkable success flying imaging telescope systems suspended from suborbital balloon payload systems. These imaging systems have covered optical, ultraviolet, sub-­-millimeter and infrared passbands (i.e. BLAST, STO, SBI, Fireball and others). In recognition of these advances NASA is now considering ambitious programs to promote planetary imaging from high altitude at a fraction of the cost of similar fully orbital systems. The challenge with imaging from a balloon payload is delivering the full diffraction-­-limited resolution of the system from a moving payload. Good progress has been made with damping mechanisms and oscillation control to remove most macroscopic movement in the departures of the imaging focal plane from a static configuration, however a jitter component remains that is difficult to remove using external corrections. This paper reports on work to demonstrate in the laboratory the utility and performance of actuating a detector focal plane (of whatever type) to remove the final jitter terms using an agile hexapod design. The input to this demonstration is the jitter signal generated by the pointing system of a previously flown balloon mission (the Stratospheric Terahertz Observatory, STO). Our group has a mature jitter compensation system that thermally isolates the control head from the focal plane itself. This allows the hexapod to remain at ambient temperature in a vacuum environment with the focal plane cooled to cryogenic temperatures. Our lab design mounts the focal plane on the hexapod in a custom cryostat and delivers an active optical stimulus together with the corresponding jitter signal, using the actuation of the hexapod to correct for the departures from a static, stable configuration. We believe this demonstration will make the case for inclusion of this technological solution in future balloon-­-borne imaging systems requiring ultra-­-high resolution.

  8. Individual honey bee (Apis cerana) foragers adjust their fuel load to match variability in forage reward

    Science.gov (United States)

    Tan, Ken; Latty, Tanya; Dong, Shihao; Liu, Xiwen; Wang, Chao; Oldroyd, Benjamin P.

    2015-01-01

    Animals may adjust their behavior according to their perception of risk. Here we show that free-flying honey bee (Apis cerana) foragers mitigate the risk of starvation in the field when foraging on a food source that offers variable rewards by carrying more ‘fuel’ food on their outward journey. We trained foragers to a feeder located 1.2 km from each of four colonies. On average foragers carried 12.7% greater volume of fuel, equivalent to 30.2% more glucose when foraging on a variable source (a random sequence of 0.5, 1.5 and 2.5 M sucrose solution, average sucrose content 1.5 M) than when forging on a consistent source (constant 1.5 M sucrose solution). Our findings complement an earlier study that showed that foragers decrease their fuel load as they become more familiar with a foraging place. We suggest that honey bee foragers are risk sensitive, and carry more fuel to minimize the risk of starvation in the field when a foraging trip is perceived as being risky, either because the forager is unfamiliar with the foraging site, or because the forage available at a familiar site offers variable rewards. PMID:26549746

  9. A study of the relationships between "highly qualified" status, instructional practices, and students' science achievement in three high poverty Louisiana school systems

    Science.gov (United States)

    Clayton, Michelle

    Using a mixed methods research design, the author examined the relationships between "highly qualified" status, instructional practices, and students' science achievement for six third grade teachers in three high poverty Louisiana school systems. The study analyzed qualitative and quantitative data for three science classes taught by "highly qualified" teachers and three science classes taught by "non-highly qualified" teachers. The qualitative portion of the study was conducted through classroom observations, teacher interviews, and lesson plan reviews. The qualitative data was coded and triangulated to determine whether the instructional practices of each teacher were more "teacher-centered" or "student-centered." The qualitative data analysis indicated various patterns and consistencies in the instructional practices used by the "highly qualified" and "non-highly qualified" teachers selected for this study. The quantitative portion of the study involved analysis of the students' science achievement data for the six third grade science teachers selected for the study. Science achievement was measured by the third grade Integrated Louisiana Education Assessment Program (iLEAP) scores. A two-way ANOVA indicated that there were statistically significant differences in the mean scores of the three high poverty Louisiana school systems as well as the students taught by "highly qualified" and "non-highly qualified" teachers and the interactions between the two: F(2, 123) = 46.99, p teachers in the study: F (5, 123) = 20.386, p teachers' scores significantly differed from each other.

  10. 黑龙江省垦区西北部高寒地区优质牧草引种试验%Introduction Test of Forages of High Quality in Cold Area in Northwest Part of Heilongjiang Reclamation Area

    Institute of Scientific and Technical Information of China (English)

    范圣华; 孙伯臣; 邱继兰; 阚文亮; 荣占华

    2009-01-01

    对来源不同的22份优质牧草材料通过4年(2004~2007年)的试验进行筛选,结果表明:草原2号苜蓿、肇东苜蓿、龙牧801苜蓿、农菁1号苜蓿、草原1.号苜蓿、敖汉苜蓿、公农1号苜蓿、羊草、鹅观草、冰草等牧草能够在黑龙江垦区西北部高寒地区安全越冬,产量性状、抗病性等都优于其它品种.%22 high-quality forage materials from different parts were screened for four years (2004~ 2007), the results showed that: alfalfa "Caoyuan No. 2",alfalfa "Zhaodong", alfalfa "Longmu 801", alfal- fa "Nongjing No. 1", alfalfa "Caoyuan No. 1", alfalfa "Aohan", alfalfa "Gongnong No. 1", Leymus chinesis, Roegneria kamogi and wheatgrass can over winter safely, they were superior to other varieties in yield and diseases resistance.

  11. Effect of cattle age, forage level, and corn processing on diet digestibility and feedlot performance.

    Science.gov (United States)

    Gorocica-Buenfil, M A; Loerch, S C

    2005-03-01

    Three experiments were conducted to determine the effects of cattle age and dietary forage level on the utilization of corn fed whole or ground to feedlot cattle. In Exp. 1, 16 steers were used to investigate the effects of cattle age and corn processing on diet digestibility. Two cattle age categories were evaluated (weanling [254 +/- 20 kg BW] and yearling [477 +/- 29 kg BW]; eight steers per group), and corn was fed either ground or whole to each cattle age category. Cattle age and corn processing did not affect (P > 0.10) diet digestibility of DM, OM, starch, CP, NDF or ADF, and no interactions (P > 0.10) between these two factors were detected. In Exp. 2, the effects of forage level and corn processing on feedlot performance and carcass characteristics were evaluated. One hundred eighty steers (310 +/- 40 kg BW) were allotted to 24 pens, and were fed one of the following diets: high-forage (18.2% corn silage) cracked corn (HFCC); high-forage shifting corn (whole corn for the first half of the trial, then cracked corn until harvest; HFSC); high-forage whole corn (HFWC); low-forage (5.2% corn silage) cracked corn (LFCC); low-forage shifting corn (LFSC); and low-forage whole corn (LFWC). For the high-forage diets, steers fed cracked corn had 7% greater DMI than those fed whole corn, whereas for the low-forage diets, grain processing did not affect DMI (interaction; P = 0.02). No interactions (P > 0.10) between forage level and corn processing were found for ADG and G:F. Total trial ADG and G:F, and percentage of carcasses grading USDA Choice, and carcass yield grade were not affected (P > 0.10) by corn processing. Cattle with fewer days on feed grew faster and more efficiently when cracked corn was fed, whereas cattle with longer days on feed had greater ADG and G:F when corn was fed whole (interaction; P 0.10) between forage level and corn processing were detected for starch digestibility. Forage level and corn processing (grinding) did not affect (P > 0

  12. Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

    Science.gov (United States)

    Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

    2016-04-01

    Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest

  13. Geographic structure of adelie penguin populations: overlap in colony-specific foraging areas

    Science.gov (United States)

    Ainley, D.G.; Ribic, C.A.; Ballard, G.; Heath, S.; Gaffney, I.; Karl, B.J.; Barton, K.J.; Wilson, P.R.; Webb, S.

    2004-01-01

    the study, when foraging trips of the large colony were very long, parents lost mass, and chick meals were smaller. In light of existing data on prey abundance in neritic waters in Antarctica suggesting that krill are relatively evenly distributed and in high abundance in the Southern Ross Sea, we conclude that penguins depleted or changed the availability of their prey, that the degree of alteration was a function of colony size, and that the large colony affected the location (and perhaps ultimately the size) of foraging areas for the smaller colonies. It appears, therefore, that foraging dynamics play a role in the geographic structuring of colonies in this species. ?? 2004 by the Ecological Society of America.

  14. Achieving a high coverage – the challenge of controlling HIV spread in heroin users

    Directory of Open Access Journals (Sweden)

    Meng Jin-Huai

    2007-02-01

    Full Text Available Abstract In China, the national plan to open 1000 methadone clinics over a five-year period provides a unique opportunity to assess the impacts of harm reduction in a country with concentrated HIV epidemic amongst heroin users. To track the progress of this public health response, data were collected from the first methadone clinic in Liuzhou, Guangxi, a province with a high HIV prevalence. In the first 15 months of its operation, a cumulative total of 488 heroin users, 86% of which male, had joined the programme. The first dose of methadone was given efficiently at a median of 2 days after registration. Of the 240 heroin users attending the clinic in August 2006, 61% took methadone for four days or more each week. The number of active methadone users, however, leveled off at around 170 after the first two months, despite the availability of capacity to deliver more services. The reasons for this observation are: firstly, the provision of one single service that may not be convenient to all heroin users; and secondly, concerns of heroin users who may feel insecure to come forward. As broad coverage is essential in ultimately reducing HIV risk, a low threshold approach is crucial, which should be supported by the removal of social obstacles and a refinement of the administrative procedures.

  15. Achievement of a high-mobility FET with a cloud-aligned composite oxide semiconductor

    Science.gov (United States)

    Yamazaki, Shunpei; Shima, Yukinori; Hosaka, Yasuharu; Okazaki, Kenichi; Koezuka, Junichi

    2016-11-01

    We have recently discovered that films of a widely used In–Ga–Zn oxide (IGZO) with \\text{In}:\\text{Ga}:\\text{Zn} = 1:1:1 have different material composition states when sputter-deposited under different conditions using the same polycrystalline IGZO target. Significant improvements in on-state current and mobility (as high as 40 cm2·V‑1·s‑1) are obtained. The results of local composition analysis indicate that the deposited film is not composed of any known homogeneous IGZO compound and that the components of this film are separated into two types of nanoparticle regions: one type is composed mainly of GaO x and GaZnO x , which contribute to on/off (switching) characteristics, and the other is composed mainly of InO x and InZnO x , which contribute to on-state characteristics. These regions constitute a new type of oxide semiconductor (OS) film. The nanoparticles with a blurry boundary extend like a cloud, probably complementing one another. We consider that this OS film has a novel composition, which can be described as a “cloud-aligned composite OS” (CAC-OS).

  16. A luciferin analogue generating near-infrared bioluminescence achieves highly sensitive deep-tissue imaging.

    Science.gov (United States)

    Kuchimaru, Takahiro; Iwano, Satoshi; Kiyama, Masahiro; Mitsumata, Shun; Kadonosono, Tetsuya; Niwa, Haruki; Maki, Shojiro; Kizaka-Kondoh, Shinae

    2016-06-14

    In preclinical cancer research, bioluminescence imaging with firefly luciferase and D-luciferin has become a standard to monitor biological processes both in vitro and in vivo. However, the emission maximum (λmax) of bioluminescence produced by D-luciferin is 562 nm where light is not highly penetrable in biological tissues. This emphasizes a need for developing a red-shifted bioluminescence imaging system to improve detection sensitivity of targets in deep tissue. Here we characterize the bioluminescent properties of the newly synthesized luciferin analogue, AkaLumine-HCl. The bioluminescence produced by AkaLumine-HCl in reactions with native firefly luciferase is in the near-infrared wavelength ranges (λmax=677 nm), and yields significantly increased target-detection sensitivity from deep tissues with maximal signals attained at very low concentrations, as compared with D-luciferin and emerging synthetic luciferin CycLuc1. These characteristics offer a more sensitive and accurate method for non-invasive bioluminescence imaging with native firefly luciferase in various animal models.

  17. How to Achieve High-Quality Oocytes? The Key Role of Myo-Inositol and Melatonin

    Science.gov (United States)

    Rossetti, Paola; Corrado, Francesco; Rapisarda, Agnese Maria Chiara; Condorelli, Rosita Angela; Valenti, Gaetano; Sapia, Fabrizio; Buscema, Massimo

    2016-01-01

    Assisted reproductive technologies (ART) have experienced growing interest from infertile patients seeking to become pregnant. The quality of oocytes plays a pivotal role in determining ART outcomes. Although many authors have studied how supplementation therapy may affect this important parameter for both in vivo and in vitro models, data are not yet robust enough to support firm conclusions. Regarding this last point, in this review our objective has been to evaluate the state of the art regarding supplementation with melatonin and myo-inositol in order to improve oocyte quality during ART. On the one hand, the antioxidant effect of melatonin is well known as being useful during ovulation and oocyte incubation, two occasions with a high level of oxidative stress. On the other hand, myo-inositol is important in cellular structure and in cellular signaling pathways. Our analysis suggests that the use of these two molecules may significantly improve the quality of oocytes and the quality of embryos: melatonin seems to raise the fertilization rate, and myo-inositol improves the pregnancy rate, although all published studies do not fully agree with these conclusions. However, previous studies have demonstrated that cotreatment improves these results compared with melatonin alone or myo-inositol alone. We recommend that further studies be performed in order to confirm these positive outcomes in routine ART treatment. PMID:27651794

  18. Integrated Operating Scenario to Achieve 100-Second, High Electron Temperature Discharge on EAST

    Science.gov (United States)

    Qian, Jinping; Gong, Xianzu; Wan, Baonian; Liu, Fukun; Wang, Mao; Xu, Handong; Hu, Chundong; Wang, Liang; Li, Erzhong; Zeng, Long; Ti, Ang; Shen, Biao; Lin, Shiyao; Shao, Linming; Zang, Qing; Liu, Haiqing; Zhang, Bin; Sun, Youwen; Xu, Guosheng; Liang, Yunfeng; Xiao, Bingjia; Hu, Liqun; Li, Jiangang; EAST Team

    2016-05-01

    Stationary long pulse plasma of high electron temperature was produced on EAST for the first time through an integrated control of plasma shape, divertor heat flux, particle exhaust, wall conditioning, impurity management, and the coupling of multiple heating and current drive power. A discharge with a lower single null divertor configuration was maintained for 103 s at a plasma current of 0.4 MA, q95 ≈7.0, a peak electron temperature of >4.5 keV, and a central density ne(0)˜2.5×1019 m-3. The plasma current was nearly non-inductive (Vloop heating at 140 GHz, and 0.4 MW modulated neutral deuterium beam injected at 60 kV. This progress demonstrated strong synergy of electron cyclotron and lower hybrid electron heating, current drive, and energy confinement of stationary plasma on EAST. It further introduced an example of integrated “hybrid” operating scenario of interest to ITER and CFETR. supported by the National Magnetic Confinement Fusion Science Foundation of China (Nos. 2015GB102000 and 2014GB103000)

  19. A luciferin analogue generating near-infrared bioluminescence achieves highly sensitive deep-tissue imaging.

    Science.gov (United States)

    Kuchimaru, Takahiro; Iwano, Satoshi; Kiyama, Masahiro; Mitsumata, Shun; Kadonosono, Tetsuya; Niwa, Haruki; Maki, Shojiro; Kizaka-Kondoh, Shinae

    2016-01-01

    In preclinical cancer research, bioluminescence imaging with firefly luciferase and D-luciferin has become a standard to monitor biological processes both in vitro and in vivo. However, the emission maximum (λmax) of bioluminescence produced by D-luciferin is 562 nm where light is not highly penetrable in biological tissues. This emphasizes a need for developing a red-shifted bioluminescence imaging system to improve detection sensitivity of targets in deep tissue. Here we characterize the bioluminescent properties of the newly synthesized luciferin analogue, AkaLumine-HCl. The bioluminescence produced by AkaLumine-HCl in reactions with native firefly luciferase is in the near-infrared wavelength ranges (λmax=677 nm), and yields significantly increased target-detection sensitivity from deep tissues with maximal signals attained at very low concentrations, as compared with D-luciferin and emerging synthetic luciferin CycLuc1. These characteristics offer a more sensitive and accurate method for non-invasive bioluminescence imaging with native firefly luciferase in various animal models. PMID:27297211

  20. Integrated Operating Scenario to Achieve 100-Second, High Electron Temperature Discharge on EAST

    Institute of Scientific and Technical Information of China (English)

    QIAN Jinping; GONG Xianzu; WAN Baonian; LIU Fukun; WANG Mao; XU Handong; HU Chundong

    2016-01-01

    Stationary long pulse plasma of high electron temperature was produced on EAST for the first time through an integrated control of plasma shape,divertor heat flux,particle exhaust,wall conditioning,impurity management,and the coupling of multiple heating and current drive power.A discharge with a lower single null divertor configuration was maintained for 103 s at a plasma current of 0.4 MA,q95 ≈7.0,a peak electron temperature of >4.5 keV,and a central density ne(0)~ 2.5×1019 m-3.The plasma current was nearly non-inductive (Vloop <0.05 V,poloidal beta ~ 0.9) driven by a combination of 0.6 MW lower hybrid wave at 2.45 GHz,1.4 MW lower hybrid wave at 4.6 GHz,0.5 MW electron cyclotron heating at 140 GHz,and 0.4 MW modulated neutral deuterium beam injected at 60 kV.This progress demonstrated strong synergy of electron cyclotron and lower hybrid electron heating,current drive,and energy confinement of stationary plasma on EAST.It further introduced an example of integrated “hybrid” operating scenario of interest to ITER and CFETR.

  1. Achieving the Benefits of a High-Potassium, Paleolithic Diet, Without the Toxicity.

    Science.gov (United States)

    Palmer, Biff F; Clegg, Deborah J

    2016-04-01

    The average US dietary intake of K(+) is well below the current recommended nutritional requirements. This deficiency is even more striking when comparing our current intake with that of our ancestors, who consumed large amounts of dietary K(+). K(+) deficiency has been implicated in many diseases including cardiovascular disease, kidney stones, and osteoporosis. Importantly, dietary supplementation of K(+) has favorable effects on reducing blood pressure, decreasing the risk of stroke, improving bone health, and reducing the risk of nephrolithiasis. For this comprehensive review, we scanned the literature using PubMed and MEDLINE using the following search terms: potassium intake, renal potassium excretion, and prevention of hyperkalemia. Articles were selected for inclusion if they represented primary data or review articles published between 1980 and 2015 in high-impact journals. The normal kidney has the capacity to tightly regulate K(+) homoeostasis. We discuss new findings with respect to sensing mechanisms by which the kidney maintains K(+) homeostasis in the gastrointestinal tract and distal tubule. There are widely prescribed hypertensive medications that cause hyperkalemia and thus require dietary K(+) restriction. We conclude by discussing newly approved drugs capable of binding K(+) in the gastrointestinal tract and speculate that this new pharmacology might allow diet liberalization in patients at risk for hyperkalemia, affording them the numerous benefits of a K(+)-rich diet. PMID:26948054

  2. How to Achieve High-Quality Oocytes? The Key Role of Myo-Inositol and Melatonin.

    Science.gov (United States)

    Vitale, Salvatore Giovanni; Rossetti, Paola; Corrado, Francesco; Rapisarda, Agnese Maria Chiara; La Vignera, Sandro; Condorelli, Rosita Angela; Valenti, Gaetano; Sapia, Fabrizio; Laganà, Antonio Simone; Buscema, Massimo

    2016-01-01

    Assisted reproductive technologies (ART) have experienced growing interest from infertile patients seeking to become pregnant. The quality of oocytes plays a pivotal role in determining ART outcomes. Although many authors have studied how supplementation therapy may affect this important parameter for both in vivo and in vitro models, data are not yet robust enough to support firm conclusions. Regarding this last point, in this review our objective has been to evaluate the state of the art regarding supplementation with melatonin and myo-inositol in order to improve oocyte quality during ART. On the one hand, the antioxidant effect of melatonin is well known as being useful during ovulation and oocyte incubation, two occasions with a high level of oxidative stress. On the other hand, myo-inositol is important in cellular structure and in cellular signaling pathways. Our analysis suggests that the use of these two molecules may significantly improve the quality of oocytes and the quality of embryos: melatonin seems to raise the fertilization rate, and myo-inositol improves the pregnancy rate, although all published studies do not fully agree with these conclusions. However, previous studies have demonstrated that cotreatment improves these results compared with melatonin alone or myo-inositol alone. We recommend that further studies be performed in order to confirm these positive outcomes in routine ART treatment. PMID:27651794

  3. A luciferin analogue generating near-infrared bioluminescence achieves highly sensitive deep-tissue imaging

    Science.gov (United States)

    Kuchimaru, Takahiro; Iwano, Satoshi; Kiyama, Masahiro; Mitsumata, Shun; Kadonosono, Tetsuya; Niwa, Haruki; Maki, Shojiro; Kizaka-Kondoh, Shinae

    2016-01-01

    In preclinical cancer research, bioluminescence imaging with firefly luciferase and D-luciferin has become a standard to monitor biological processes both in vitro and in vivo. However, the emission maximum (λmax) of bioluminescence produced by D-luciferin is 562 nm where light is not highly penetrable in biological tissues. This emphasizes a need for developing a red-shifted bioluminescence imaging system to improve detection sensitivity of targets in deep tissue. Here we characterize the bioluminescent properties of the newly synthesized luciferin analogue, AkaLumine-HCl. The bioluminescence produced by AkaLumine-HCl in reactions with native firefly luciferase is in the near-infrared wavelength ranges (λmax=677 nm), and yields significantly increased target-detection sensitivity from deep tissues with maximal signals attained at very low concentrations, as compared with D-luciferin and emerging synthetic luciferin CycLuc1. These characteristics offer a more sensitive and accurate method for non-invasive bioluminescence imaging with native firefly luciferase in various animal models. PMID:27297211

  4. High resolution anoscopy may be useful in achieving reductions in anal cancer local disease failure rates.

    Science.gov (United States)

    Goon, P; Morrison, V; Fearnhead, N; Davies, J; Wilson, C; Jephcott, C; Sterling, J; Crawford, R

    2015-05-01

    Anal cancer is uncommon, with an incidence rate of 0.5-1.0 per 100,000 of the population but incidence rates have been steadily increasing over the last 3 decades. Biological and epidemiological evidence have been mounting and demonstrate that anal cancer has many similarities to cervical cancer, especially in regard to its aetiology. High-resolution anoscopy (HRA) of the anal region – analogous to colposcopy of the cervix, is a technique that is not well-known in the medical and surgical fraternity. Evidence to support the use of HRA for detection and treatment in the surveillance of AIN exists and strongly suggests that it is beneficial, resulting in reduced rates of cancer progression. Pilot data from our study showed a local disease failure rate of 1.73 per 1000 patient-months compared with a published rate of 9.89 per 1000 patient-months. This demonstrates a 5.72-fold reduction in local disease failure rates of patients with T1-T3 tumours; the data therefore suggests that use of HRA for detection and treatment in surveillance of anal cancer patients will help prevent local regional relapse at the anal site. There is an urgent need for a large, randomised controlled clinical trial to definitively test this hypothesis. PMID:24373061

  5. The Impact of Attending a School with High-Achieving Peers: Evidence from the New York City Exam Schools

    OpenAIRE

    Will Dobbie; Roland G. Fryer Jr.

    2014-01-01

    This paper uses data from three prominent exam high schools in New York City to estimate the impact of attending a school with high-achieving peers on college enrollment and graduation. Our identification strategy exploits sharp discontinuities in the admissions process. Applicants just eligible for an exam school have peers that score 0.17 to 0.36 standard deviations higher on eighth grade state tests and that are 6.4 to 9.5 percentage points less likely to be black or Hispanic. However, exp...

  6. Context-dependent expression of the foraging gene in field colonies of ants: the interacting roles of age, environment and task

    Science.gov (United States)

    Gordon, Deborah M.; Greene, Michael; Kahler, John; Peteru, Swetha

    2016-01-01

    Task allocation among social insect workers is an ideal framework for studying the molecular mechanisms underlying behavioural plasticity because workers of similar genotype adopt different behavioural phenotypes. Elegant laboratory studies have pioneered this effort, but field studies involving the genetic regulation of task allocation are rare. Here, we investigate the expression of the foraging gene in harvester ant workers from five age- and task-related groups in a natural population, and we experimentally test how exposure to light affects foraging expression in brood workers and foragers. Results from our field study show that the regulation of the foraging gene in harvester ants occurs at two time scales: levels of foraging mRNA are associated with ontogenetic changes over weeks in worker age, location and task, and there are significant daily oscillations in foraging expression in foragers. The temporal dissection of foraging expression reveals that gene expression changes in foragers occur across a scale of hours and the level of expression is predicted by activity rhythms: foragers have high levels of foraging mRNA during daylight hours when they are most active outside the nests. In the experimental study, we find complex interactions in foraging expression between task behaviour and light exposure. Oscillations occur in foragers following experimental exposure to 13 L : 11 D (LD) conditions, but not in brood workers under similar conditions. No significant differences were seen in foraging expression over time in either task in 24 h dark (DD) conditions. Interestingly, the expression of foraging in both undisturbed field and experimentally treated foragers is also significantly correlated with the expression of the circadian clock gene, cycle. Our results provide evidence that the regulation of this gene is context-dependent and associated with both ontogenetic and daily behavioural plasticity in field colonies of harvester ants. Our results underscore

  7. Thirty Years of Social Science Research on High-Level Nuclear Waste: Achievements and Future Challenges

    International Nuclear Information System (INIS)

    Research on high-level nuclear waste management has focused on technical and scientific issues since the U.S. National Academy of Sciences first studied the problem in the mid 1950s and recommended long-term disposal in deep salt formations. In this review, we trace the development of the problem's definition and its associated research since socioeconomic, political and policy issues were first given consideration and nuclear waste management became recognized as more than a technical issue. Three time periods are identified. First, from the mid 1970s to early 1980s, initial research explored institutional dimensions of nuclear waste, including ethics. The second period began in the early 1980s with a concerted effort to solve the problem and site nuclear waste repositories, and ended in the mid 1990s with minimal progress in the U.S. and general stalemate in Asia and Europe (with the notable exception of Sweden). This phase accelerated research on risk perception and stigma of nuclear waste, and elevated a focus on public trust. Great attention was given to repository siting conflicts, while minimal attention was placed on ethics, equity, political systems, and public participation. The last period, since the mid 1990s, has been characterized by continuing political stalemate and increased attention to public participation, political systems and international solutions. Questions of ethics have been given renewed attention, while research on risk perceptions and siting conflicts continues. We frame these periods in a broader context of the shifting role of applied social scientists. The paper concludes with a general discussion of this research area and prospects for future research

  8. Volumetric modulated arc therapy for lung stereotactic radiation therapy can achieve high local control rates

    International Nuclear Information System (INIS)

    The aim of this study was to report the outcome of primary or metastatic lung cancer patients undergoing volumetric modulated arc therapy for stereotactic body radiation therapy (VMAT-SBRT). From October 2010 to December 2013, consecutive 67 lung cancer patients received single-arc VMAT-SBRT using an Elekta-synergy system. All patients were treated with an abdominal compressor. The gross tumor volumes were contoured on 10 respiratory phases computed tomography (CT) datasets from 4-dimensional (4D) CT and merged into internal target volumes (ITVs). The planning target volume (PTV) margin was isotropically taken as 5 mm. Treatment was performed with a D95 prescription of 50 Gy (43 cases) or 55 Gy (12 cases) in 4 fractions for peripheral tumor or 56 Gy in 7 fractions (12 cases) for central tumor. Among the 67 patients, the median age was 73 years (range, 59–95 years). Of the patients, male was 72% and female 28%. The median Karnofsky performance status was 90-100% in 39 cases (58%) and 80-90% in 20 cases (30%). The median follow-up was 267 days (range, 40–1162 days). Tissue diagnosis was performed in 41 patients (61%). There were T1 primary lung tumor in 42 patients (T1a in 28 patients, T1b in 14 patients), T2 in 6 patients, three T3 in 3 patients, and metastatic lung tumor in 16 patients. The median mean lung dose was 6.87 Gy (range, 2.5-15 Gy). Six patients (9%) developed radiation pneumonitis required by steroid administration. Actuarial local control rate were 100% and 100% at 1 year, 92% and 75% at 2 years, and 92% and 75% at 3 years in primary and metastatic lung cancer, respectively (p = 0.59). Overall survival rate was 83% and 84% at 1 year, 76% and 53% at 2 years, and 46% and 20% at 3 years in primary and metastatic lung cancer, respectively (p = 0.12). Use of VMAT-based delivery of SBRT in primary in metastatic lung tumors demonstrates high local control rates and low risk of normal tissue complications

  9. Contrasting Foraging Patterns: Testing Resource-Concentration and Dilution Effects with Pollinators and Seed Predators

    Directory of Open Access Journals (Sweden)

    Alexandria Wenninger

    2016-06-01

    Full Text Available Resource concentration effects occur when high resource density patches attract and support more foragers than low density patches. In contrast, resource dilution effects can occur if high density patches support fewer consumers. In this study, we examined the foraging rates of pollinators and seed predators on two perennial plant species (Rudbeckia triloba and Verbena stricta as functions of resource density. Specifically, we examined whether resource-dense patches (densities of flower and seeds on individual plants resulted in greater visitation and seed removal rates, respectively. We also examined whether foraging rates were context-dependent by conducting the study in two sites that varied in resource densities. For pollinators, we found negative relationships between the density of flowers per plant and visitation rates, suggesting dilution effects. For seed predators, we found positive relationships consistent with concentration effects. Saturation effects and differences in foraging behaviors might explain the opposite relationships; most of the seed predators were ants (recruitment-based foragers, and pollinators were mostly solitary foragers. We also found that foraging rates were site-dependent, possibly due to site-level differences in resource abundance and consumer densities. These results suggest that these two plant species may benefit from producing as many flowers as possible, given high levels of pollination and low seed predation.

  10. Contrasting Foraging Patterns: Testing Resource-Concentration and Dilution Effects with Pollinators and Seed Predators.

    Science.gov (United States)

    Wenninger, Alexandria; Kim, Tania N; Spiesman, Brian J; Gratton, Claudio

    2016-01-01

    Resource concentration effects occur when high resource density patches attract and support more foragers than low density patches. In contrast, resource dilution effects can occur if high density patches support fewer consumers. In this study, we examined the foraging rates of pollinators and seed predators on two perennial plant species (Rudbeckia triloba and Verbena stricta) as functions of resource density. Specifically, we examined whether resource-dense patches (densities of flower and seeds on individual plants) resulted in greater visitation and seed removal rates, respectively. We also examined whether foraging rates were context-dependent by conducting the study in two sites that varied in resource densities. For pollinators, we found negative relationships between the density of flowers per plant and visitation rates, suggesting dilution effects. For seed predators, we found positive relationships consistent with concentration effects. Saturation effects and differences in foraging behaviors might explain the opposite relationships; most of the seed predators were ants (recruitment-based foragers), and pollinators were mostly solitary foragers. We also found that foraging rates were site-dependent, possibly due to site-level differences in resource abundance and consumer densities. These results suggest that these two plant species may benefit from producing as many flowers as possible, given high levels of pollination and low seed predation. PMID:27271673

  11. Experimental evidence for cryptic interference among socially foraging shorebirds

    NARCIS (Netherlands)

    Bijleveld, A.I.; Folmer, E.O.; Piersma, T.

    2012-01-01

    Foraging rate and the distribution of foragers depend on prey distribution in conjunction with interindividual interactions. Generalized functional response models predict intake rates and spatial distributions of foragers on the basis of resource distribution and interference competition. The adequ

  12. The effect of an integrated high school science curriculum on student achievement, knowledge retention, and science attitudes

    Science.gov (United States)

    Smith, Kimberly A.

    The research study investigates the effectiveness of an integrated high school science curriculum on student achievement, knowledge retention and science attitudes using quantitative and qualitative research. Data was collected from tenth grade students, in a small urban high school in Kansas City, Missouri, who were enrolled in a traditional Biology course or an integrated Environmental Science course. Quantitative data was collected in Phase 1 of the study. Data collected for academic achievement included pretest and posttest scores on the CTBS MATN exam. Data collected for knowledge retention included post-posttest scores on the CTBS MATN exam. Data collected for science attitudes were scores on a pretest and posttest using the TOSRA. SPSS was used to analyze the data using independent samples t-tests, one-way ANCOVA's and paired samples statistics. Qualitative data was collected in Phase 2 of the study. Data included responses to open-ended interview questions using three focus groups. Data was analyzed for common themes. Data analysis revealed the integrated Environmental Science course had a statistically significant impact on academic achievement, knowledge retention and positive science attitudes. Gender and socioeconomic status did not influence results. The study also determined that the CTBS MATN exam was not an accurate predictor of scores on state testing as was previously thought.

  13. Impact of Mindfulness-based Stress Reduction Training on Third Grade High School Female Students' Mental Health and Educational Achievement

    Directory of Open Access Journals (Sweden)

    Gholamreza Sharifiniya

    2014-01-01

    Full Text Available This study is conducted with the title of "Impact of Mindfulness-Based Stress Reduction training on third grade high school female students' mental health and educational achievement in Asadabad city during the school year 2011-2012. This study aims at investigating the impact of Mindfulness-Based Stress Reduction (MBSR training on students' mental health and educational achievement. This research is conducted based on clinical trial with the empirical study (pretest-posttest method with the control group. Statistical population of this survey includes all third grade high school female students (780 students, who were educating in Asadabad city and the sample group contains 40 students ¬who were selected according to the randomized cluster method (20 subjects in the empirical group and 20 subjects in the control group. Data collection tool for mental health structure includes the components of interpersonal sensitivity, obsessive thoughts, depression, anxiety and somatization which are selected from the General Health Questionnaire (SCL-90. Results indicated that the Mindfulness-based stress reduction training has affected the components of obsessive thoughts, interpersonal sensitivity, depression and anxiety after 8 sessions, but it has no effect on the somatization. Furthermore, the mindfulness training also has a positive effect on the educational achievement.

  14. Relationships Among Student-body Composition, School Process, and Mathematics Achievement in Argentina’s High Schools

    Directory of Open Access Journals (Sweden)

    Rubén Alberto Cervini Iturre

    2003-05-01

    Full Text Available This is a study of the relationships between the student-body composition of the school, some characteristics of the scholastic process—culture and school climate—according to learners’ perceptions, and the mathematics achievement of students in the last year of high school in Argentina. The data used came from the 1998 National Census of High School Completion, carried out by the nation’s Ministry of Culture and Education. The file contains data for 135,000 students of 2,708 schools in 25 states. Multilevel linear modeling with three levels (student, school and state was applied. A strong relationship was detected between mathematics achievement and the variables student-body composition and school process. When both variables acted together, the effect of other variables experienced a pronounced descent. Although reduced, the variables of the process influenced the student’s achievement. There was identified for future works a reference model which would evaluate other institutional learning factors.

  15. Following a foraging fish-finder: diel habitat use of Blainville's beaked whales revealed by echolocation.

    Directory of Open Access Journals (Sweden)

    Patricia Arranz

    Full Text Available Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9 hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL or near the sea-floor with little diel change. At least 43% (420/974 of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean.

  16. The roles of sex, mass and individual specialisation in partitioning foraging-depth niches of a pursuit-diving predator.

    Science.gov (United States)

    Ratcliffe, Norman; Takahashi, Akinori; O'Sullivan, Claire; Adlard, Stacey; Trathan, Philip N; Harris, Michael P; Wanless, Sarah

    2013-01-01

    Intra-specific foraging niche partitioning can arise due to gender differences or individual specialisation in behaviour or prey selection. These may in turn be related to sexual size dimorphism or individual variation in body size through allometry. These variables are often inter-related and challenging to separate statistically. We present a case study in which the effects of sex, body mass and individual specialisation on the dive depths of the South Georgia shag on Bird Island, South Georgia are investigated simultaneously using a linear mixed model. The nested random effects of trip within individual explained a highly significant amount of the variance. The effects of sex and body mass were both significant independently but could not be separated statistically owing to them being strongly interrelated. Variance components analysis revealed that 45.5% of the variation occurred among individuals, 22.6% among trips and 31.8% among Dives, while R(2) approximations showed gender explained 31.4% and body mass 55.9% of the variation among individuals. Male dive depths were more variable than those of females at the levels of individual, trip and dive. The effect of body mass on individual dive depths was only marginally significant within sexes. The percentage of individual variation in dive depths explained by mass was trivial in males (0.8%) but substantial in females (24.1%), suggesting that differences in dive depths among males was largely due to them adopting different behavioural strategies whereas in females allometry played an additional role. Niche partitioning in the study population therefore appears to be achieved through the interactive effects of individual specialisation and gender upon vertical foraging patch selection, and has the potential to interact in complex ways with other axes of the niche hypervolume such as foraging locations, timing of foraging and diet. PMID:24205368

  17. The roles of sex, mass and individual specialisation in partitioning foraging-depth niches of a pursuit-diving predator.

    Directory of Open Access Journals (Sweden)

    Norman Ratcliffe

    Full Text Available Intra-specific foraging niche partitioning can arise due to gender differences or individual specialisation in behaviour or prey selection. These may in turn be related to sexual size dimorphism or individual variation in body size through allometry. These variables are often inter-related and challenging to separate statistically. We present a case study in which the effects of sex, body mass and individual specialisation on the dive depths of the South Georgia shag on Bird Island, South Georgia are investigated simultaneously using a linear mixed model. The nested random effects of trip within individual explained a highly significant amount of the variance. The effects of sex and body mass were both significant independently but could not be separated statistically owing to them being strongly interrelated. Variance components analysis revealed that 45.5% of the variation occurred among individuals, 22.6% among trips and 31.8% among Dives, while R(2 approximations showed gender explained 31.4% and body mass 55.9% of the variation among individuals. Male dive depths were more variable than those of females at the levels of individual, trip and dive. The effect of body mass on individual dive depths was only marginally significant within sexes. The percentage of individual variation in dive depths explained by mass was trivial in males (0.8% but substantial in females (24.1%, suggesting that differences in dive depths among males was largely due to them adopting different behavioural strategies whereas in females allometry played an additional role. Niche partitioning in the study population therefore appears to be achieved through the interactive effects of individual specialisation and gender upon vertical foraging patch selection, and has the potential to interact in complex ways with other axes of the niche hypervolume such as foraging locations, timing of foraging and diet.

  18. The relationship between service-learning participation and high school students' achievement in math and science education

    Science.gov (United States)

    Elliott, Eddie Brown

    This study examined a causal relationship between service-learning participation and academic achievement of 9th grade students in math and science courses. The central purpose of the study was to examine the impact of service-learning participation on students' academic outcomes, and to determine if this impact was consistent after controlling for the socioeconomic status (SES) of the student. The participants in this study were from the base year data of the High School Longitudinal Study of 2009 (HSLS:09). For this study, 15,058 students identified as being enrolled in mathematics and science classes were selected. Quantitative methods were used to analyze cross-sectional data from the HSLS:09 study. The initial findings from this study suggest that service-learning participation was consistent in student's academic achievement of all students regardless of socioeconomic status.

  19. Individual honey bee (Apis cerana) foragers adjust their fuel load to match variability in forage reward

    OpenAIRE

    Ken Tan; Tanya Latty; Shihao Dong; Xiwen Liu; Chao Wang; Oldroyd, Benjamin P.

    2015-01-01

    Animals may adjust their behavior according to their perception of risk. Here we show that free-flying honey bee (Apis cerana) foragers mitigate the risk of starvation in the field when foraging on a food source that offers variable rewards by carrying more ‘fuel’ food on their outward journey. We trained foragers to a feeder located 1.2 km from each of four colonies. On average foragers carried 12.7% greater volume of fuel, equivalent to 30.2% more glucose when foraging on a variable source ...

  20. High Performing Schools in High Risk Environments: A Study on Leadership, School Safety, and Student Achievement at Two Urban Middle Schools in Los Angeles County

    Science.gov (United States)

    Frias, Gus

    2010-01-01

    In the United States of America, all students and staff have a constitutional right to attend schools that are safe, secure, and successful. Despite this right, at many public schools, education leaders have failed to ensure the safety and high academic achievement of all students. The purpose of this research study is to expand knowledge about…

  1. Environmental conditions and intraspecific interference: unexpected effects of turbidity on pike (Esox lucius) foraging

    DEFF Research Database (Denmark)

    Nilsson, P.A.; Jacobsen, Lene; Berg, Søren;

    2009-01-01

    on pike foraging alone or among conspecifics in different levels of water turbidity, we expected high turbidity to decrease the perceived risk of intraspecific interactions among pike, and thereby decrease the strength of interference, as turbidity would decrease the visual contact between...... individuals and act as a refuge from behavioural interactions. The results show that this is not the case, but suggest that interference is induced instead of reduced in high turbidity. Per capita foraging rates do not differ between pike foraging alone or in groups in our clear and moderately turbid...... treatments, indicating no effect of interference. As high turbidity enhances prey consumption for pike individuals foraging alone, but does not have this effect for pike in groups, high turbidity induces the relative interference effect. We suggest that future evaluations of the stabilizing effects of...

  2. Palatability of Forage Chicory Cultivars for Goats

    Science.gov (United States)

    Sesquiterpene lactones (SL) in forage chicory (Cichorium intybus L.) may have anthelmintic activity against gastrointestinal parasites in sheep and goats, but have been implicated in poor palatability of forage. We used three levels of soil P fertilization to influence SL concentrations in three cu...

  3. The dilemma of foraging herbivores: dealing with food and fear.

    Science.gov (United States)

    McArthur, Clare; Banks, Peter B; Boonstra, Rudy; Forbey, Jennifer Sorensen

    2014-11-01

    For foraging herbivores, both food quality and predation risk vary across the landscape. Animals should avoid low-quality food patches in favour of high-quality ones, and seek safe patches while avoiding risky ones. Herbivores often face the foraging dilemma, however, of choosing between high-quality food in risky places or low-quality food in safe places. Here, we explore how and why the interaction between food quality and predation risk affects foraging decisions of mammalian herbivores, focusing on browsers confronting plant toxins in a landscape of fear. We draw together themes of plant-herbivore and predator-prey interactions, and the roles of animal ecophysiology, behaviour and personality. The response of herbivores to the dual costs of food and fear depends on the interplay of physiology and behaviour. We discuss detoxification physiology in dealing with plant toxins, and stress physiology associated with perceived predation risk. We argue that behaviour is the interface enabling herbivores to stay or quit food patches in response to their physiological tolerance to these risks. We hypothesise that generalist and specialist herbivores perceive the relative costs of plant defence and predation risk differently and intra-specifically, individuals with different personalities and physiologies should do so too, creating individualised landscapes of food and fear. We explore the ecological significance and emergent impacts of these individual-based foraging outcomes on populations and communities, and offer predictions that can be clearly tested. In doing so, we provide an integrated platform advancing herbivore foraging theory with food quality and predation risk at its core.

  4. A collimated focused ultrasound beam of high acoustic transmission and minimum diffraction achieved by using a lens with subwavelength structures

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhou; Tu, Juan; Cheng, Jianchun [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); Guo, Xiasheng, E-mail: guoxs@nju.edu.cn, E-mail: dzhang@nju.edu.cn [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Wu, Junru [Department of Physics, University of Vermont, Burlington, Vermont 05405 (United States); Huang, Pingtong [Department of Ultrasound, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009 (China); Zhang, Dong, E-mail: guoxs@nju.edu.cn, E-mail: dzhang@nju.edu.cn [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); The State Key Laboratory of Acoustics, Chinese Academy of Science, Beijing 10080 (China)

    2015-09-14

    An acoustic focusing lens incorporated with periodically aligned subwavelength grooves corrugated on its spherical surface has been developed. It is demonstrated theoretically and experimentally that acoustic focusing achieved by using the lens can suppress the relative side-lobe amplitudes, enhance the focal gain, and minimize the shifting of the focus. Use of the lens coupled with a planar ultrasound transducer can generate an ultrasound beam with enhanced acoustic transmission and collimation effect, which offers the capability of improving the safety, efficiency, and accuracy of targeted surgery implemented by high intensity focused ultrasound.

  5. Sex-related differences in the trade-off between foraging and vigilance in a granivorous forager.

    Directory of Open Access Journals (Sweden)

    Thibaut Powolny

    Full Text Available The relationship between intake rate and food density can provide the foundation for models that predict the spatiotemporal distribution of organisms across a range of resource densities. The functional response, describing the relationship between resource density and intake rate is often interpreted mechanistically as the relationships between times spend searching and handling. While several functional response models incorporate anti-predator vigilance (defined here as an interruption of feeding or some other activity to visually scan the environment, directed mainly towards detecting potential predators, the impacts of environmental factors influencing directly anti-predator vigilance remains unclear. We examined the combined effects of different scenarios of predation risk and food density on time allocation between foraging and anti-predator vigilance in a granivorous species. We experimentally exposed Skylarks to various cover heights and seed densities, and measured individual time budget and pecking and intake rates. Our results indicated that time devoted to different activities varied as a function of both seed density and cover height. Foraging time increased with seed density for all cover heights. Conversely, an increased cover height resulted in a decreased foraging time. Contrary to males, the decreased proportion of time spent foraging did not translate into a foraging disadvantage for females. When vegetation height was higher, females maintained similar pecking and intake rates compared to intermediate levels, while males consistently decreased their energy gain. This difference in anti-predator responses suggests a sexually mediated strategy in the food-safety trade-off: when resource density is high a females would adopt a camouflage strategy while an escape strategy would be adopted by males. In other words, males would leave risky-areas, whereas females would stay when resource density is high. Our results suggest that

  6. Fearful foragers: honey bees tune colony and individual foraging to multi-predator presence and food quality.

    Directory of Open Access Journals (Sweden)

    Ken Tan

    Full Text Available Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller and V. tropica (bigger preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w, colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55-79% and residence times by 17-33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose, colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger, colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees.

  7. Fearful foragers: honey bees tune colony and individual foraging to multi-predator presence and food quality.

    Science.gov (United States)

    Tan, Ken; Hu, Zongwen; Chen, Weiwen; Wang, Zhengwei; Wang, Yuchong; Nieh, James C

    2013-01-01

    Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller) and V. tropica (bigger) preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive) as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w), colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55-79% and residence times by 17-33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose), colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger), colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees.

  8. Achieving High Efficiency and Eliminating Degradation in Solid Oxide Electrochemical Cells Using High Oxygen-Capacity Perovskite.

    Science.gov (United States)

    Jun, Areum; Kim, Junyoung; Shin, Jeeyoung; Kim, Guntae

    2016-09-26

    Recently, there have been efforts to use clean and renewable energy because of finite fossil fuels and environmental problems. Owing to the site-specific and weather-dependent characteristics of the renewable energy supply, solid oxide electrolysis cells (SOECs) have received considerable attention to store energy as hydrogen. Conventional SOECs use Ni-YSZ (yttria-stabilized zirconia) and LSM (strontium-doped lanthanum manganites)-YSZ as electrodes. These electrodes, however, suffer from redox-instability and coarsening of the Ni electrode along with delamination of the LSM electrode during steam electrolysis. In this study, we successfully design and fabricate highly efficient SOECs using layered perovskites, PrBaMn2 O5+δ (PBM) and PrBa0.5 Sr0.5 Co1.5 Fe0.5 O5+δ (PBSCF50), as both electrodes for the first time. The SOEC with layered perovskites as both-side electrodes shows outstanding performance, reversible cycling, and remarkable stability over 600 hours. PMID:27604172

  9. Amygdala Signaling during Foraging in a Hazardous Environment.

    Science.gov (United States)

    Amir, Alon; Lee, Seung-Chan; Headley, Drew B; Herzallah, Mohammad M; Pare, Denis

    2015-09-23

    conditioning studies bear little resemblance to normal life. In natural conditions, subjects are simultaneously presented with potential threats and rewards, forcing them to engage in a form of risk assessment. We examined this process using a seminaturalistic foraging task. In constant conditions of threats and rewards, amygdala activity could be high or low, depending on the rats' decisions on a given trial. Therefore, amygdala activity does not only encode threats or rewards but is also closely related to behavioral output. PMID:26400931

  10. Flexible foraging shapes the topology of plant-pollinator interaction networks.

    Science.gov (United States)

    Spiesman, Brian J; Gratton, Claudio

    2016-06-01

    In plant-pollinator networks, foraging choices by pollinators help form the connecting links between species. Flexible foraging should therefore play an important role in defining network topology. Factors such as morphological trait complementarity limit a pollinator's pool of potential floral resources, but which potential resource species are actually utilized at a location depends on local environmental and ecological context. Pollinators can be highly flexible foragers, but the effect of this flexibility on network topology remains unclear. To understand how flexible foraging affects network topology, we examined differences between sets of locally realized interactions and corresponding sets of potential interactions within 25 weighted plant-pollinator networks in two different regions of the United States. We examined two possible mechanisms for flexible foraging effects on realized networks: (1) preferential targeting of higher-density plant resources, which should increase network nestedness, and (2) context-dependent resource partitioning driven by interspecific competition, which should increase modularity and complementary specialization. We found that flexible foraging has strong effects on realized network topology. Realized connectance was much lower than connectance based on potential interactions, indicating a local narrowing of diet breadth. Moreover, the foraging choices pollinators made, which particular plant species to visit and at what rates, resulted in networks that were significantly less nested and significantly more modular and specialized than their corresponding networks of potential interactions. Preferentially foraging on locally abundant resources was not a strong driver of the realization of potential interactions. However, the degree of modularity and complementary specialization both increased with the number of competing pollinator species and with niche availability. We therefore conclude that flexible foraging affects realized

  11. Flexible foraging shapes the topology of plant-pollinator interaction networks.

    Science.gov (United States)

    Spiesman, Brian J; Gratton, Claudio

    2016-06-01

    In plant-pollinator networks, foraging choices by pollinators help form the connecting links between species. Flexible foraging should therefore play an important role in defining network topology. Factors such as morphological trait complementarity limit a pollinator's pool of potential floral resources, but which potential resource species are actually utilized at a location depends on local environmental and ecological context. Pollinators can be highly flexible foragers, but the effect of this flexibility on network topology remains unclear. To understand how flexible foraging affects network topology, we examined differences between sets of locally realized interactions and corresponding sets of potential interactions within 25 weighted plant-pollinator networks in two different regions of the United States. We examined two possible mechanisms for flexible foraging effects on realized networks: (1) preferential targeting of higher-density plant resources, which should increase network nestedness, and (2) context-dependent resource partitioning driven by interspecific competition, which should increase modularity and complementary specialization. We found that flexible foraging has strong effects on realized network topology. Realized connectance was much lower than connectance based on potential interactions, indicating a local narrowing of diet breadth. Moreover, the foraging choices pollinators made, which particular plant species to visit and at what rates, resulted in networks that were significantly less nested and significantly more modular and specialized than their corresponding networks of potential interactions. Preferentially foraging on locally abundant resources was not a strong driver of the realization of potential interactions. However, the degree of modularity and complementary specialization both increased with the number of competing pollinator species and with niche availability. We therefore conclude that flexible foraging affects realized

  12. A simple method for detection of food foraging behavior in the rat: involvement of NMDA and dopamine receptors in the behavior.

    Science.gov (United States)

    Li, F; Cao, W Y; Li, M B; Xu, Y; Zhang, J W; Zhang, J Y; Luo, X G; Dai, R P; Zhou, X F; Li, C Q

    2012-03-15

    Food foraging behavior involves food removing, hoarding, and competitive preying upon other animals. It is also associated with high cognitive functions such as investing effort into decision making, but no established laboratory model is available to detect the behaviors. In the present study, we have developed a novel laboratory rodent model to detect competitive, non-competitive, and no-hurdle foraging conditions that can mimic the corresponding environment in nature. We found that normal rats consistently foraged the food from a food container to the field and spread food into piles in the open field. There was no difference between male and female rats in the amount of foraged food in the competitive, non-competitive, and no-hurdle food foraging tests. The amount of foraged food was consistent each day for five consecutive days with a slight increase in following days. There was no significant difference in the amount of food foraged in the presence or absence of bedding materials. A dramatic decrease of foraged food was found in the rats after administration of haloperidol (dopamine D2 receptor antagonist) in the competitive, non-competitive, and no-hurdle food foraging tests. Treatment with MK-801 (non-competitive N-methy-D-aspartate receptor antagonist) reduced the foraged food in the competitive food foraging test, but did not affect the foraged food in the non-competitive and no-hurdle food foraging tests. Our study provides a simple but consistent analogue of natural food foraging behavior. Our study also suggests that dopaminergic and glutaminergic systems are differentially involved in the food foraging behaviors.

  13. A simple method for detection of food foraging behavior in the rat: involvement of NMDA and dopamine receptors in the behavior.

    Science.gov (United States)

    Li, F; Cao, W Y; Li, M B; Xu, Y; Zhang, J W; Zhang, J Y; Luo, X G; Dai, R P; Zhou, X F; Li, C Q

    2012-03-15

    Food foraging behavior involves food removing, hoarding, and competitive preying upon other animals. It is also associated with high cognitive functions such as investing effort into decision making, but no established laboratory model is available to detect the behaviors. In the present study, we have developed a novel laboratory rodent model to detect competitive, non-competitive, and no-hurdle foraging conditions that can mimic the corresponding environment in nature. We found that normal rats consistently foraged the food from a food container to the field and spread food into piles in the open field. There was no difference between male and female rats in the amount of foraged food in the competitive, non-competitive, and no-hurdle food foraging tests. The amount of foraged food was consistent each day for five consecutive days with a slight increase in following days. There was no significant difference in the amount of food foraged in the presence or absence of bedding materials. A dramatic decrease of foraged food was found in the rats after administration of haloperidol (dopamine D2 receptor antagonist) in the competitive, non-competitive, and no-hurdle food foraging tests. Treatment with MK-801 (non-competitive N-methy-D-aspartate receptor antagonist) reduced the foraged food in the competitive food foraging test, but did not affect the foraged food in the non-competitive and no-hurdle food foraging tests. Our study provides a simple but consistent analogue of natural food foraging behavior. Our study also suggests that dopaminergic and glutaminergic systems are differentially involved in the food foraging behaviors. PMID:22244978

  14. Relationships between area-specific measures of self-concept, self-esteem and academic achievement for junior high school students.

    Science.gov (United States)

    Muller, D; Chambliss, J; Wood, M

    1977-12-01

    Physical maturity, peer relations, academic success and school adaptiveness self-concept and self-esteem measures were correlated with reading, language, mathematics, and composite achievement scores for 26 male and 48 female junior high school students. Academic success self-concept was significantly correlated with each of the achievement measures. Peer relations self-concept and self-esteem correlated with language, math, and composite achievement. Academic success self-esteem measures did not correlate with any of the measures of achievement.

  15. Harvest-related edge effects on prey availability and foraging of hooded warblers in a bottomland hardwood forest.

    Energy Technology Data Exchange (ETDEWEB)

    John Kilgo

    2005-04-20

    The effects of harvest-created canopy gaps in bottomland hardwood forests on arthropod abundance and, hence, the foraging ecology of birds are poorly understood. I predicted that arthropod abundance would be high near edges of group-selection harvest gaps and lower in the surrounding forest, and that male Hooded Warblers (Wilsonia citrina) foraging near gaps would find more prey per unit time than those foraging in the surrounding forest. In fact, arthropod abundance was greater >100 m from a gap edge than at 0-30 m or 30-100 m from an edge, due to their abundance on switchcane (Arundinaria gigantea); arthropods did not differ in abundance among distances from gaps on oaks (Quercus spp.) or red maple (Acer rubrum). Similarly, Hooded Warbler foraging attack rates were not higher near gap edges: when foraging for fledglings, attack rate did not differ among distances from gaps, but when foraging for themselves, attack rates actually were lower 0-30 m from gap edges than 30-100 m or >100 m from a gap edge. Foraging attack rate was positively associated with arthropod abundance. Hooded Warblers apparently encountered fewer prey and presumably foraged less efficiently where arthropods were least abundant, i.e., near gaps. That attack rates among birds foraging for fledglings were not affected by distance from gap (and hence arthropod abundance) suggests that prey availability may not be limiting at any location across the forest, despite the depressing effects of gaps on arthropod abundance.

  16. Teaching image-processing concepts in junior high school: boys' and girls' achievements and attitudes towards technology

    Science.gov (United States)

    Barak, Moshe; Asad, Khaled

    2012-04-01

    Background : This research focused on the development, implementation and evaluation of a course on image-processing principles aimed at middle-school students. Purpose : The overarching purpose of the study was that of integrating the learning of subjects in science, technology, engineering and mathematics (STEM), and linking the learning of these subjects to the children's world and to the digital culture characterizing society today. Sample : The participants were 60 junior high-school students (9th grade). Design and method : Data collection included observations in the classes, administering an attitude questionnaire before and after the course, giving an achievement exam and analyzing the students' final projects. Results and conclusions : The findings indicated that boys' and girls' achievements were similar throughout the course, and all managed to handle the mathematical knowledge without any particular difficulties. Learners' motivation to engage in the subject was high in the project-based learning part of the course in which they dealt, for instance, with editing their own pictures and experimenting with a facial recognition method. However, the students were less interested in learning the theory at the beginning of the course. The course increased the girls', more than the boys', interest in learning scientific-technological subjects in school, and the gender gap in this regard was bridged.

  17. Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A.; Westlake, Karl R.; Cross, Karen Charlene; Allerman, Andrew Alan; Lee, Stephen Roger

    2011-12-01

    We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical spectroscopy to AlGaN epilayers to quantify deep level energies and densities and further correlate defect properties with AlGaN luminescence efficiency. We further review our development of p-type short period superlattice structures as an approach to mitigate the high acceptor activation energies in AlGaN alloys. Finally, we describe our laser diode fabrication process, highlighting the development of highly vertical and smooth etched laser facets, as well as characterization of resulting laser heterostructures.

  18. Gender differences in Korean high school students’ science achievements and attitudes towards science in three different school settings

    Directory of Open Access Journals (Sweden)

    EunJin Bang

    2013-08-01

    Full Text Available This study analysed the effect of high schools' gender organization on Korean tenth-grade students’ science achievements, and their attitudes towards science. The high schools involved included an all-male institution, an all-female institution, and a co-educational institution. Three schools, three principals, three science teachers, and 302 tenthgrade students from their respective school types responded to an initial survey, and eleven academically outstanding students were subsequently interviewed. Also, the students’ pencil and paper tests—which included second semester midterms, and final exams containing their general science test scoreswere collected from each school. The questionnaire responses and the transcribed interview sections were analysed using One-Way ANOVA, followed by Post Hoc analysis, constant comparison, and content analysis. Results indicated that the male and female students from the co-ed school had significantly higher science achievement and positive attitudes towards science. Interview transcripts of the selected students from the all-male, the all-female, and the co-ed schools confirmed the findings. Later discussion addresses the improvement of the Korean science curriculum, of learning environments, of the teachers’ and students' roles in the classroom, and of education policies.

  19. Influence of milk production potential on forage dry matter intake by multiparous and primiparous Brangus females.

    Science.gov (United States)

    Johnson, C R; Lalman, D L; Brown, M A; Appeddu, L A; Buchanan, D S; Wettemann, R P

    2003-07-01

    Brangus cows (n = 29) were used in three experiments to evaluate the effects of parity (multiparous vs. primiparous) and potential genetic merit for milk production (high vs. low) on forage intake during late gestation, early lactation, and late lactation. Cows were selected for milk production based on their sire's EPD for milk production (MEPD). Cows had ad libitum access to (130% of previous 2-d average intake) low-quality hay (5.3% CP and 76% NDF), and cottonseed meal was supplemented to ensure adequate degradable intake protein. All females were adapted to diets for at least 7 d, and individual intake data were collected for 9 d. During the lactation trials, actual milk production was determined using a portable milking machine following a 12-h separation from calves. During late gestation, multiparous cows consumed 24% more (P = 0.01) forage DM (kg/d) than primiparous cows; however, parity class did not influence forage intake when intake was expressed relative to BW. Furthermore, MEPD did not influence forage intake during late gestation. During early lactation, multiparous cows produced 66% more (P < 0.001) milk than primiparous cows, and high MEPD tended (P = 0.10) to produce more milk than low MEPD. Multiparous cows consumed 19% more (P < 0.0001) forage DM than did primiparous cows when expressed on an absolute basis, but not when expressed on a BW basis. High-MEPD cows consumed 8% more (P < 0.05) forage DM than did low-MEPD cows. During late lactation, multiparous cows produced 84% more milk than primiparous cows, although MEPD did not influence (P = 0.40) milk yield. In addition, multiparous cows consumed 17% more (P < 0.01) forage DM per day than primiparous cows, but when intake was expressed relative to BW, neither parity nor MEPD influenced forage DMI during late lactation. Milk yield and BW explained significant proportions of the variation in forage DMI during early and late lactation. Each kilogram increase in milk yield was associated with a 0

  20. Similar Comparative Low and High Doses of Deltamethrin and Acetamiprid Differently Impair the Retrieval of the Proboscis Extension Reflex in the Forager Honey Bee (Apis mellifera)

    Science.gov (United States)

    Thany, Steeve H.; Bourdin, Céline M.; Graton, Jérôme; Laurent, Adèle D.; Mathé-Allainmat, Monique; Lebreton, Jacques; Le Questel, Jean-Yves

    2015-01-01

    In the present study, the effects of low (10 ng/bee) and high (100 ng/bee) doses of acetamiprid and deltamethrin insecticides on multi-trial learning and retrieval were evaluated in the honey bee Apis mellifera. After oral application, acetamiprid and deltamethrin at the concentrations used were not able to impair learning sessions. When the retention tests were performed 1 h, 6 h, and 24 h after learning, we found a significant difference between bees after learning sessions when drugs were applied 24 h before learning. Deltamethrin-treated bees were found to be more sensitive at 10 ng/bee and 100 ng/bee doses compared to acetamiprid-treated bees, only with amounts of 100 ng/bee and at 6 h and 24 h delays. When insecticides were applied during learning sessions, none of the tested insecticides was able to impair learning performance at 10 ng/bee or 100 ng/bee but retention performance was altered 24 h after learning sessions. Acetamiprid was the only one to impair retrieval at 10 ng/bee, whereas at 100 ng/bee an impairment of retrieval was found with both insecticides. The present results therefore suggest that acetamiprid and deltamethrin are able to impair retrieval performance in the honey bee Apis mellifera. PMID:26466901

  1. A study on cultural practices for high forage yield in stylosanthes guianensis cv. Reyan No. 2%柱花草高产栽培综合农艺措施的研究

    Institute of Scientific and Technical Information of China (English)

    戚春林; 胡耀华; 林日健

    2000-01-01

    试验采用5因素二次正交旋转组合回归设计,对柱花草高产栽培的综合农艺措施进行研究,并建立了干物质产量与种植密度、收割次数、施过磷酸钙量、施复合肥量、喷施钼酸铵浓度等5项农艺措施之间的数学模型,通过模型解析和寻优,得出在试验条件下,5项农艺措施对热研2号柱花草产量影响的程度依次为:收割次数>种植密度>施复合肥量>施过磷酸钙量>喷施钼酸铵浓度,并得出高产栽培组合方案.%Field test was conducted by quadratic orthogonal regression design. A regressive mode! Between the dry matter yield of Stylosanthes guianensis cv. Reyan No. 2 and cultural variables included plant density, cutting frequency, superphosphate application rates, compound fertilizer application rates and spraying concentration of ammonium molybdate was built. After analysis and optimization, it was concluded from the model that based on the extent of the effects of the variables on forae yields their order as follows: cutting frequency>plant density> compound fertilizer application rates>superphosphate application rates spraying concentration of ammonium molybdate. Cultural pratcices for high forage yield in S. Guianensis cv. Reyan No. 2 was recommended.

  2. 无意识成就目标对高低成就动机个体的激励%Effects of Unconscious Achievement Goals:When Individuals Are in High or Low Achievement Motivation

    Institute of Scientific and Technical Information of China (English)

    陈瑞涵; 杨文静; 李海江; 张庆林

    2013-01-01

    The 2X2 mixed paradigm was used to investigate the effects of unconscious achievement goals on the outcome expectation and task performance of priming and non-priming in high and low achievement motivation individuals. The results showed that the priming effects of unconscious achievement goals were regulated by the level of the individuals' achievement motivation. Priming of unconscious achievement goals had no significant effects on the outcome expectation when the individuals were high on achievement motivation, but produced expectation of high outcome prior to working on the task when the individuals were low on achievement motivation. Priming of unconscious achievement goals had no significant effects on the task performance of the individuals with either high or low achievement motivation, and the individuals who scored high on achievement motivation got higher task performance whether the unconscious a-chievement goals were primed or not.%采用2×2混合实验设计探讨了在个体无意识状态下启动的成就目标,对高、低成就动机个体结果预期及任务表现的影响.研究结果表明无意识成就目标启动效应是否出现,受个体成就动机水平的调节:①无意识成就目标的启动,对高成就动机个体的结果预期没有显著影响,但是能显著提高低成就动机个体的结果预期;②无意识成就目标的启动,对高、低成就动机个体的任务表现均没有显著影响,但是高成就动机个体的任务表现显著好于低成就动机个体.

  3. COMMUNICATION: Stochastic resonance and the evolution of Daphnia foraging strategy

    Science.gov (United States)

    Dees, Nathan D.; Bahar, Sonya; Moss, Frank

    2008-12-01

    Search strategies are currently of great interest, with reports on foraging ranging from albatrosses and spider monkeys to microzooplankton. Here, we investigate the role of noise in optimizing search strategies. We focus on the zooplankton Daphnia, which move in successive sequences consisting of a hop, a pause and a turn through an angle. Recent experiments have shown that their turning angle distributions (TADs) and underlying noise intensities are similar across species and age groups, suggesting an evolutionary origin of this internal noise. We explore this hypothesis further with a digital simulation (EVO) based solely on the three central Darwinian themes: inheritability, variability and survivability. Separate simulations utilizing stochastic resonance (SR) indicate that foraging success, and hence fitness, is maximized at an optimum TAD noise intensity, which is represented by the distribution's characteristic width, σ. In both the EVO and SR simulations, foraging success is the criterion, and the results are the predicted characteristic widths of the TADs that maximize success. Our results are twofold: (1) the evolving characteristic widths achieve stasis after many generations; (2) as a hop length parameter is changed, variations in the evolved widths generated by EVO parallel those predicted by SR. These findings provide support for the hypotheses that (1) σ is an evolved quantity and that (2) SR plays a role in evolution.

  4. Multimedia OC12 parallel interface using VCSEL array to achieve high-performance cost-effective optical interconnections

    Science.gov (United States)

    Chang, Edward S.

    1996-09-01

    ribbon cable, and MT connectors to achieve a high-performance, low-cost parallel link. A logical model of a multimedia server with parallel connections to an ATM switch, and to clients is presented. The design of the parallel optical link is analyzed. Furthermore, the link configured for testing, the test method, and test results are presented to confirm the analysis and to assure reliable link performance.

  5. Emerging technologies advancing forage and turf grass genomics.

    Science.gov (United States)

    Kopecký, David; Studer, Bruno

    2014-01-01

    Grassland is of major importance for agricultural production and provides valuable ecosystem services. Its impact is likely to rise in changing socio-economic and climatic environments. High yielding forage grass species are major components of sustainable grassland production. Understanding the genome structure and function of grassland species provides opportunities to accelerate crop improvement and thus to mitigate the future challenges of increased feed and food demand, scarcity of natural resources such as water and nutrients, and high product qualities. In this review, we will discuss a selection of technological developments that served as main drivers to generate new insights into the structure and function of nuclear genomes. Many of these technologies were originally developed in human or animal science and are now increasingly applied in plant genomics. Our main goal is to highlight the benefits of using these technologies for forage and turf grass genome research, to discuss their potentials and limitations as well as their relevance for future applications. PMID:24309540

  6. Harvester ants use interactions to regulate forager activation and availability.

    Science.gov (United States)

    Pinter-Wollman, Noa; Bala, Ashwin; Merrell, Andrew; Queirolo, Jovel; Stumpe, Martin C; Holmes, Susan; Gordon, Deborah M

    2013-07-01

    Social groups balance flexibility and robustness in their collective response to environmental changes using feedback between behavioural processes that operate at different timescales. Here we examine how behavioural processes operating at two timescales regulate the foraging activity of colonies of the harvester ant, Pogonomyrmex barbatus, allowing them to balance their response to food availability and predation. Previous work showed that the rate at which foragers return to the nest with food influences the rate at which foragers leave the nest. To investigate how interactions inside the nest link the rates of returning and outgoing foragers, we observed outgoing foragers inside the nest in field colonies using a novel observation method. We found that the interaction rate experienced by outgoing foragers inside the nest corresponded to forager return rate, and that the interactions of outgoing foragers were spatially clustered. Activation of a forager occurred on the timescale of seconds: a forager left the nest 3-8 s after a substantial increase in interactions with returning foragers. The availability of outgoing foragers to become activated was adjusted on the timescale of minutes: when forager return was interrupted for more than 4-5 min, available foragers waiting near the nest entrance went deeper into the nest. Thus, forager activation and forager availability both increased with the rate at which foragers returned to the nest. This process was checked by negative feedback between forager activation and forager availability. Regulation of foraging activation on the timescale of seconds provides flexibility in response to fluctuations in food abundance, whereas regulation of forager availability on the timescale of minutes provides robustness in response to sustained disturbance such as predation.

  7. Experimental Wing Damage Affects Foraging Effort and Foraging Distance in Honeybees Apis mellifera

    Directory of Open Access Journals (Sweden)

    Andrew D. Higginson

    2011-01-01

    Full Text Available Bees acquire wing damage as they age, and loss of wing area affects longevity and behaviour. This may influence colony performance via effects on worker behaviour. The effects of experimental wing damage were studied in worker honeybees in observation hives by recording survivorship, how often and for how long bees foraged, and by decoding waggle dances. Mortality rate increased with both age and wing damage. Damaged bees carried out shorter and/or less frequent foraging trips, foraged closer to the hive, and reported the profitability of flower patches to be lower than did controls. These results suggest that wing damage caused a reduction in foraging ability, and that damaged bees adjusted their foraging behaviour accordingly. Furthermore, the results suggest that wing damage affects the profitability of nectar sources. These results have implications for the colony dynamics and foraging efficiency in honeybees.

  8. Space use and resource selection by foraging Indiana bats at the northern edge of their distribution

    Science.gov (United States)

    Jachowski, David S.; Johnson, Joshua B.; Dobony, Christopher A.; Edwards, John W.; Ford, W. Mark

    2014-01-01

    Despite 4 decades of conservation concern, managing endangered Indiana bat (Myotis sodalis) populations remains a difficult wildlife resource issue facing natural resource managers in the eastern United States. After small signs of population recovery, the recent emergence of white-nose syndrome has led to concerns of local and/or regional extirpation of the species. Where Indiana bats persist, retaining high-quality foraging areas will be critical to meet physiological needs and ensure successful recruitment and overwinter survival. However, insight into foraging behavior has been lacking in the Northeast of the USA. We radio-tracked 12 Indiana bats over 2 summers at Fort Drum, New York, to evaluate factors influencing Indiana bat resource selection during night-time foraging. We found that foraging space use decreased 2% for every 100 m increase in distance to water and 6% for every 100 m away from the forest edge. This suggests high use of riparian areas in close proximity to forest and is somewhat consistent with the species’ foraging ecology in the Midwest and upper South. Given the importance of providing access to high-quality foraging areas during the summer maternity season, Indiana bat conservation at the northern extent of the species’ range will be linked to retention of forested habitat in close proximity to riparian zones. 

  9. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature

    Science.gov (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing

    2016-04-01

    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm2/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  10. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature.

    Science.gov (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing

    2016-04-22

    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm(2)/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  11. Attributes and characteristics of the Mathematics, Engineering, Science, Achievement (MESA) high school program for first-generation Latino students

    Science.gov (United States)

    Flores, Ramon

    This study used a web-based survey collected data from 28 first-generation Latino engineers who participated in the Mathematics, Engineering, Science, Achievement (MESA) program during their high school years. From the set of 28 respondents, 5 volunteered to participate in an optional telephone interview. The purpose of this study was to describe the critical attributes and characteristics of the MESA program that lead to success at both the high school and college levels for first-generation Latino students. Success at the high school level was operationally defined as successfully graduating with a high school diploma. Success at the college level was operationally defined here as college graduation with an engineering degree. Using a mixed-methods technique, the researcher attempted to secure consensus of opinion from a sample population of 28 first-generation Latino engineers. The mixed-methods technique was chosen since it allowed the researcher to draw on the strengths of quantitative and qualitative approaches. According to the findings, the typical respondent felt that mentoring was the attribute of the MESA program that most prepared him to graduate from high school. The respondents felt that the following MESA attributes most helped them transition into an undergraduate engineering program: Academic and University Advising; Enrichment Activities; Career Advising; Field Trips; Mentoring; Scholarship Incentive Awards; and Speakers. The respondents viewed study groups as the MESA attribute that best prepared them to graduate college with an engineering degree. This study was purposefully designed as a descriptive study. Future research is required to extend this work into an evaluative study. This would allow for the generalization of the critical attributes to the general student population serviced by the MESA program.

  12. cGMP-dependent protein kinase: linking foraging to energy homeostasis.

    Science.gov (United States)

    Kaun, Karla R; Sokolowski, Marla B

    2009-01-01

    Successful foraging is necessary for procurement of nutritional resources essential for an animal's survival. Maintenance of foraging and food acquisition is dependent on the ability to balance food intake and energy expenditure. This review examines the role of cGMP-dependent protein kinase (PKG) as a regulator of foraging behaviour, food acquisition, and energy balance. The role of PKG in food-related behaviours is highly conserved among worms, flies, bees, ants, and mammals. A growing body of literature suggests that PKG plays an integral role in the component behaviours and physiologies underlying foraging behaviour. These include energy acquisition, nutrient absorption, nutrient allocation, nutrient storage, and energy use. New evidence suggests that PKG mediates both neural and physiological mechanisms underlying these processes. This review illustrates how investigating the role of PKG in energy homeostasis in a diversity of organisms can offer a broad perspective on the mechanisms mediating energy balance.

  13. Interactions Increase Forager Availability and Activity in Harvester Ants.

    Directory of Open Access Journals (Sweden)

    Evlyn Pless

    Full Text Available Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  14. Interactions Increase Forager Availability and Activity in Harvester Ants.

    Science.gov (United States)

    Pless, Evlyn; Queirolo, Jovel; Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B; Gordon, Deborah M

    2015-01-01

    Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  15. Intellectual and personality factors in the achievement of high exam effectiveness in first-year Russian university students

    Directory of Open Access Journals (Sweden)

    Gorchakova, Olesya Yu.

    2016-09-01

    Full Text Available The goals set forth in regulatory documents for the development of Russian education presuppose quantitative evaluation of factors and conditions that ensure students’ achievement of high competence, personality development, and self-realization. Evaluation of intellectual and personality characteristics of first-year university students and study of the relationship among these characteristics thus become important tasks. The research objective was to evaluate relationships among social and abstractlogical types of intelligence, personality characteristics, and exam effectiveness (performance. The study sample was made up of 900 first-year university students (55.2% female and 44.8% male from Tomsk State University who filled in paper-and-pencil forms in Russian: The Evaluation of Choice in Conflict Situations Questionnaire, Raven’s Progressive Matrices, the Self-Organization of Activity, the Reflexivity Type Assessment Test, the Self-Determination Scale, the Satisfaction with Life Scale, and the World Assumptions Scale. Scores on the Unified National Examination in Mathematics (UNE in Mathematics and the first exam results at the university were used to measure academic performance. The data were statistically processed using descriptive analysis, correlation analysis, and factor analysis. The preference for compromising and collaborating strategies indicates a high level of social intelligence and contributes to socio-psychological adaptation of young people to conditions of university education that are new to them, which require greater independence and activity. Social intelligence and abstract-logical intelligence are relatively independent intelligence types. Social intelligence and personality characteristics are not determinants of scores on the UNE in Mathematics. Probably the process of educating students in mathematics in the graduating classes of Russian secondary schools is replaced by training to solve problems on the UNE, so

  16. MACRO NUTRIENTS UPTAKE OF FORAGE GRASSES AT DIFFERENT SALINITY STRESSES

    Directory of Open Access Journals (Sweden)

    F. Kusmiyati

    2014-10-01

    Full Text Available The high concentration of sodium chloride (NaCl in saline soils has negative effects on the growth ofmost plants. The experiment was designed to evaluate macro nutrient uptake (Nitrogen, Phosphorus andPotassium of forage grasses at different NaCl concentrations in growth media. The experiment wasconducted in a greenhouse at Forage Crops Laboratory of Animal Agriculture Faculty, Diponegoro University.Split plot design was used to arrange the experiment. The main plot was forage grasses (Elephant grass(Pennisetum purpureum and King grass (Pennisetum hybrida. The sub plot was NaCl concentrationin growth media (0, 150, and 300 mM. The nitrogen (N, phosphorus (P and potassium (K uptake in shootand root of plant were measured. The result indicated increasing NaCl concentration in growth mediasignificantly decreased the N, P and K uptake in root and shoot of the elephant grass and king grass. Thepercentage reduction percentage of N, P and K uptake at 150 mM and 300 mM were high in elephant grassand king grass. It can be concluded that based on nitrogen, phosphorus and potassium uptake, elephantgrass and king grass are not tolerant to strong and very strong saline soil.

  17. Wild chacma baboons (Papio ursinus) remember single foraging episodes.

    Science.gov (United States)

    Noser, Rahel; Byrne, Richard W

    2015-07-01

    Understanding animal episodic-like memory is important for tracing the evolution of the human mind. However, our knowledge about the existence and nature of episodic-like memory in non-human primates is minimal. We observed the behaviour of a wild male chacma baboon faced with a trade-off between protecting his stationary group from aggressive extra-group males and foraging among five out-of-sight platforms. These contained high-priority food at a time of natural food shortage. In 10 morning and eight evening trials, the male spontaneously visited the platforms in five and four different sequences, respectively. In addition, he interrupted foraging sequences at virtually any point on eight occasions, returning to the group for up to 2 h. He then visited some or all of the remaining platforms and prevented revisits to already depleted ones, apparently based on his memory for the previous foraging episode about food value, location, and time. Efficient use of memory allowed him to keep minimal time absent from his group while keeping food intake high. These findings support the idea that episodic-like memory offers an all-purpose solution to a wide variety of problems that require flexible, quick, yet precise decisions in situations arising from competition for food and mates in wild primates. PMID:25833223

  18. Progress achieved in restricting the marketing of high-fat, sugary and salty food and beverage products to children.

    Science.gov (United States)

    Kraak, Vivica I; Vandevijvere, Stefanie; Sacks, Gary; Brinsden, Hannah; Hawkes, Corinna; Barquera, Simón; Lobstein, Tim; Swinburn, Boyd A

    2016-07-01

    In May 2010, 192 Member States endorsed Resolution WHA63.14 to restrict the marketing of food and non-alcoholic beverage products high in saturated fats, trans fatty acids, free sugars and/or salt to children and adolescents globally. We examined the actions taken between 2010 and early 2016 - by civil society groups, the World Health Organization (WHO) and its regional offices, other United Nations (UN) organizations, philanthropic institutions and transnational industries - to help decrease the prevalence of obesity and diet-related noncommunicable diseases among young people. By providing relevant technical and policy guidance and tools to Member States, WHO and other UN organizations have helped protect young people from the marketing of branded food and beverage products that are high in fat, sugar and/or salt. The progress achieved by the other actors we investigated appears variable and generally less robust. We suggest that the progress being made towards the full implementation of Resolution WHA63.14 would be accelerated by further restrictions on the marketing of unhealthy food and beverage products and by investing in the promotion of nutrient-dense products. This should help young people meet government-recommended dietary targets. Any effective strategies and actions should align with the goal of WHO to reduce premature mortality from noncommunicable diseases by 25% by 2025 and the aim of the UN to ensure healthy lives for all by 2030.

  19. A method for achieving monotonic frequency-temperature response for langasite surface-acoustic-wave high-temperature sensor

    Science.gov (United States)

    Shaoming, Bao; Yabing, Ke; Yanqing, Zheng; Lina, Cheng; Honglang, Li

    2016-02-01

    To achieve the monotonic frequency-temperature response for a high-temperature langasite (LGS) surface-acoustic-wave (SAW) sensor in a wide temperature range, a method utilizing two substrate cuts with different propagation angles on the same substrate plane was proposed. In this method, the theory of effective permittivity is adopted to calculate the temperature coefficients of frequency (TCF), electromechanical coupling coefficients (k2), and power flow angle (PFA) for different propagation angles on the same substrate plane, and then the two substrate cuts were chosen to have large k2 and small PFA, as well as the difference in their TCFs (ΔTCF) to always have the same sign of their values. The Z-cut LGS substrate plane was taken as an example, and the two suitable substrate cuts with propagation angles of 74 and 80° were chosen to derive a monotonic frequency-temperature response for LGS SAW sensors at -50 to 540 °C. Experiments on a LGS SAW sensor using the above two substrate cuts were designed, and its measured frequency-temperature response at -50 to 540 °C agreed well with the theory, demonstrating the high accuracy of the proposed method.

  20. A methodology for achieving high-speed rates for artificial conductance injection in electrically excitable biological cells.

    Science.gov (United States)

    Butera, R J; Wilson, C G; Delnegro, C A; Smith, J C

    2001-12-01

    We present a novel approach to implementing the dynamic-clamp protocol (Sharp et al., 1993), commonly used in neurophysiology and cardiac electrophysiology experiments. Our approach is based on real-time extensions to the Linux operating system. Conventional PC-based approaches have typically utilized single-cycle computational rates of 10 kHz or slower. In thispaper, we demonstrate reliable cycle-to-cycle rates as fast as 50 kHz. Our system, which we call model reference current injection (MRCI); pronounced merci is also capable of episodic logging of internal state variables and interactive manipulation of model parameters. The limiting factor in achieving high speeds was not processor speed or model complexity, but cycle jitter inherent in the CPU/motherboard performance. We demonstrate these high speeds and flexibility with two examples: 1) adding action-potential ionic currents to a mammalian neuron under whole-cell patch-clamp and 2) altering a cell's intrinsic dynamics via MRCI while simultaneously coupling it via artificial synapses to an internal computational model cell. These higher rates greatly extend the applicability of this technique to the study of fast electrophysiological currents such fast a currents and fast excitatory/inhibitory synapses. PMID:11759927

  1. Progress achieved in restricting the marketing of high-fat, sugary and salty food and beverage products to children.

    Science.gov (United States)

    Kraak, Vivica I; Vandevijvere, Stefanie; Sacks, Gary; Brinsden, Hannah; Hawkes, Corinna; Barquera, Simón; Lobstein, Tim; Swinburn, Boyd A

    2016-07-01

    In May 2010, 192 Member States endorsed Resolution WHA63.14 to restrict the marketing of food and non-alcoholic beverage products high in saturated fats, trans fatty acids, free sugars and/or salt to children and adolescents globally. We examined the actions taken between 2010 and early 2016 - by civil society groups, the World Health Organization (WHO) and its regional offices, other United Nations (UN) organizations, philanthropic institutions and transnational industries - to help decrease the prevalence of obesity and diet-related noncommunicable diseases among young people. By providing relevant technical and policy guidance and tools to Member States, WHO and other UN organizations have helped protect young people from the marketing of branded food and beverage products that are high in fat, sugar and/or salt. The progress achieved by the other actors we investigated appears variable and generally less robust. We suggest that the progress being made towards the full implementation of Resolution WHA63.14 would be accelerated by further restrictions on the marketing of unhealthy food and beverage products and by investing in the promotion of nutrient-dense products. This should help young people meet government-recommended dietary targets. Any effective strategies and actions should align with the goal of WHO to reduce premature mortality from noncommunicable diseases by 25% by 2025 and the aim of the UN to ensure healthy lives for all by 2030. PMID:27429493

  2. The preclinical set-up at the ID17 biomedical beamline to achieve high local dose deposition using interlaced microbeams

    Science.gov (United States)

    Bräuer-Krisch, E.; Nemoz, C.; Brochard, Th; Berruyer, G.; Renier, M.; Pouyatos, B.; Serduc, R.

    2013-03-01

    Microbeam Radiation Therapy (MRT) uses spatially a fractionated "white beam" (energies 50-350 keV) irradiation from a Synchrotron Source. The typical microbeams used at ID17 are 25-100μm-thick, spaced by 200-400μm, and carry extremely high dose rates (up to about 16 kGy/s). These microbeams are well tolerated by biological tissue, i.e. up to several hundred of Gy in the peaks. When valley doses, caused by Compton scattering in between two microbeams, remain within a dose regime similar to conventional RT, a superior tumour control can be achieved with MRT than with conventional RT. The normal tissue tolerance of these microscopically small beams is outstanding and well documented in the literature. The hypothesis of a differential effect in particular on the vasculature of normal versus tumoral tissue might best be proven by using large animal models with spontaneous tumors instead of small laboratory animals with transplantable tumors, an ongoing project on ID17. An alternative approach to deposit a high dose, while preserving the feature of the spatial separation of these microbeams outside the target has opened up new applications in preclinical research. The instrumentation of this method to produce such interlaced beams is presented with an outlook on the challenges to build a treatment platform for human patients. Dose measurements using Gafchromic films exposed in interlaced geometries with their steep profiles highlight the potential to deposit radiotoxic doses in the vicinity of radiosensitive tissues.

  3. Low forager fertility: demographic characteristic or methodological artifact?

    Science.gov (United States)

    Early, J D

    1985-09-01

    Anthropological literature has long held that traditional foraging populations have low fertility levels. This research examines the number of live births per woman for 9 non-western forager groups who have been investigated in the last 20 years. Data are derived from 1) birth registration systems, 2) surveys conducted during short stays with the group, and 3) surveys conducted as part of longer ethnographic studies. Fertility rates for the groups are 1) 3.5 for the Kiunga area of Papula, New Guinea, 2) 4.2 for Northern Territory Australian aborigines, 3) 5.0 for Cayapo groups in Brazil, 4) 5.3 for Hiowe people of New Guinea, 5) 5.7 for 3 Xavante groups in Brazil, 6) 6.0 for West Alaskan Eskimos, 7) 6.9 for Nunamiut Eskimos of Alaska, 8) 7.6 for the Bisman-Asmat group of Indonesian New Guinea, and 9) 8.4 for the Winikina Warao of Venezuela. Since fertility rates are highest when ethnographic studies, which allow for question clarification, memory recall, and cross-checking, are used, the author believes that high fertility rates most accurately represent forager societies. Research on the Dobe ]Kung (fertility rate - 4.7), may contradict these findings, but the author believes that the ]Kung fertility rates are higher than reported because of infanticide practices, sexual abstinence during lactation, and disease related fertility problems. In summary, the study finds high fertility (7-9 births) in traditional foraging societies. Although the study examines small populations, correlation strength and overall consistency help verify the results.

  4. Low forager fertility: demographic characteristic or methodological artifact?

    Science.gov (United States)

    Early, J D

    1985-09-01

    Anthropological literature has long held that traditional foraging populations have low fertility levels. This research examines the number of live births per woman for 9 non-western forager groups who have been investigated in the last 20 years. Data are derived from 1) birth registration systems, 2) surveys conducted during short stays with the group, and 3) surveys conducted as part of longer ethnographic studies. Fertility rates for the groups are 1) 3.5 for the Kiunga area of Papula, New Guinea, 2) 4.2 for Northern Territory Australian aborigines, 3) 5.0 for Cayapo groups in Brazil, 4) 5.3 for Hiowe people of New Guinea, 5) 5.7 for 3 Xavante groups in Brazil, 6) 6.0 for West Alaskan Eskimos, 7) 6.9 for Nunamiut Eskimos of Alaska, 8) 7.6 for the Bisman-Asmat group of Indonesian New Guinea, and 9) 8.4 for the Winikina Warao of Venezuela. Since fertility rates are highest when ethnographic studies, which allow for question clarification, memory recall, and cross-checking, are used, the author believes that high fertility rates most accurately represent forager societies. Research on the Dobe ]Kung (fertility rate - 4.7), may contradict these findings, but the author believes that the ]Kung fertility rates are higher than reported because of infanticide practices, sexual abstinence during lactation, and disease related fertility problems. In summary, the study finds high fertility (7-9 births) in traditional foraging societies. Although the study examines small populations, correlation strength and overall consistency help verify the results. PMID:4077041

  5. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O' Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  6. High effective coverage of vector control interventions in children after achieving low malaria transmission in Zanzibar, Tanzania

    Directory of Open Access Journals (Sweden)

    Beer Netta

    2013-01-01

    appreciated the interventions and recognized the value of sustaining their use. Thus, sustaining high effective coverage of vector control interventions, which is crucial for reaching malaria elimination in Zanzibar, can be achieved by maintaining effective delivery of these interventions.

  7. Individual lifetime pollen and nectar foraging preferences in bumble bees

    Science.gov (United States)

    Hagbery, Jessica; Nieh, James C.

    2012-10-01

    Foraging specialization plays an important role in the ability of social insects to efficiently allocate labor. However, relatively little is known about the degree to which individual bumble bees specialize on collecting nectar or pollen, when such preferences manifest, and if individuals can alter their foraging preferences in response to changes in the colony workforce. Using Bombus impatiens, we monitored all foraging visits made by every bee in multiple colonies and showed that individual foragers exhibit consistent lifetime foraging preferences. Based upon the distribution of foraging preferences, we defined three forager types (pollen specialists, nectar specialists, and generalists). In unmanipulated colonies, 16-36 % of individuals specialized (≥90 % of visits) on nectar or pollen only. On its first day of foraging, an individual's foraging choices (nectar only, pollen only, or nectar and pollen) significantly predicted its lifetime foraging preferences. Foragers that only collected pollen on their first day of foraging made 1.61- to 1.67-fold more lifetime pollen foraging visits (as a proportion of total trips) than foragers that only collected nectar on their first foraging day. Foragers were significantly larger than bees that stayed only in the nest. We also determined the effect of removing pollen specialists at early (brood present) or later (brood absent) stages in colony life. These results suggest that generalists can alter their foraging preferences in response to the loss of a small subset of foragers. Thus, bumble bees exhibit individual lifetime foraging preferences that are established early in life, but generalists may be able to adapt to colony needs.

  8. Nectar robbing, forager efficiency and seed set: Bumblebees foraging on the self incompatible plant Linaria vulgaris (Scrophulariaceae)

    Science.gov (United States)

    Stout, Jane C.; Allen, John A.; Goulson, Dave

    2000-07-01

    In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species ( Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones behaved as legitimate pollinators ( B. hortorum and B. pascuorum). Nectar rewards were highly variable; on average there was less nectar in robbed than in unrobbed flowers, but this difference was not statistically significant. The proportion of flowers containing no nectar was significantly higher for robbed flowers compared with unrobbed flowers. Secondary robbers and legitimate pollinators had similar handling times on flowers and, assuming they select flowers at random to forage on, received approximately the same nectar profit per minute, largely because most flowers had been robbed. There was no significant difference in the number of seeds in pods of robbed flowers and in pods of flowers that were artificially protected against robbing. However, more of the robbed flowers set at least some seed than the unrobbed flowers, possibly as a consequence of the experimental manipulation. We suggest that nectar robbing has little effect on plant fecundity because legitimate foragers are present in the population, and that seed predation and seed abortion after fertilization may be more important factors in limiting seed production in this species.

  9. Quitting time: When do honey bee foragers decide to stop foraging on natural resources?

    Directory of Open Access Journals (Sweden)

    Michael eRivera

    2015-05-01

    Full Text Available Honey bee foragers may use both personal and social information when making decisions about when to visit resources. In particular, foragers may stop foraging at resources when their own experience indicates declining resource quality, or when social information, namely the delay to being able to unload nectar to receiver bees, indicates that the colony has little need for the particular resource being collected. Here we test the relative importance of these two factors in a natural setting, where colonies are using many dynamically changing resources. We recorded detailed foraging histories of individually marked bees, and identified when they appeared to abandon any resources (such as flower patches that they had previously been collecting from consistently. As in previous studies, we recorded duration of trophallaxis events (unloading nectar to receiver bees as a proxy for resource quality and the delays before returning foragers started trophallaxis as a proxy for social need for the resource. If these proxy measures accurately reflect changes in resource quality and social need, they should predict whether bees continue foraging or not. However, neither factor predicted when individuals stopped foraging on a particular resource, nor did they explain changes in colony-level foraging activity. This may indicate that other, as yet unstudied processes also affect individual decisions to abandon particular resources.

  10. 2009 Winter Forage Conference to teach horse owners about forage and grazing management

    OpenAIRE

    Sutphin, Michael D.

    2009-01-01

    Virginia Cooperative Extension and the Virginia Forage and Grassland Council will explore how horse owners can best utilize their land for grazing and protect soil and water resources at the same time during this year's equine forage conference on March 2 through 4.

  11. The Impact of Socioeconomic Status on Achievement of High School Students Participating in a One-to-One Laptop Computer Program

    Science.gov (United States)

    Weers, Anthony J.

    2012-01-01

    The purpose of this study was to determine the impact of socioeconomic status on the achievement of high school students participating in a one-to-one laptop computer program. Students living in poverty struggle to achieve in schools across the country, educators must address this issue. The independent variable in this study is socioeconomic…

  12. The Effects of Middle School Bullying and Victimization on Adjustment through High School: Growth Modeling of Achievement, School Attendance, and Disciplinary Trajectories

    Science.gov (United States)

    Feldman, Marissa A.; Ojanen, Tiina; Gesten, Ellis L.; Smith-Schrandt, Heather; Brannick, Michael; Wienke Totura, Christine M.; Alexander, Lizette; Scanga, David; Brown, Ken

    2014-01-01

    The current 5-year longitudinal study examined the effects of middle school bullying and victimization on adolescent academic achievement, disciplinary referrals, and school attendance through high school (N = 2030; 1016 both boys and girls). Greater engagement in bullying behaviors was concurrently associated with lower achievement and school…

  13. Wintering birds avoid warm sunshine: predation and the costs of foraging in sunlight.

    Science.gov (United States)

    Carr, Jennie M; Lima, Steven L

    2014-03-01

    Wintering birds can gain significant thermal benefits by foraging in direct sunlight. However, exposure to bright sunlight might make birds easier to detect by predators and may also cause visual glare that can reduce a bird's ability to monitor the environment. Thus, birds likely experience a trade-off between the thermal benefits and predation-related costs of foraging in direct sunlight. To examine this possible thermoregulation-predation trade-off, we monitored the behavior of mixed-species flocks of wintering emberizid sparrows foraging in alternating strips of sunlight and shade. On average, these sparrows routinely preferred to forage in the shade, despite midday air temperatures as much as 30 °C below their thermoneutral zone. This preference for shade was strongest at relatively high temperatures when the thermal benefits of foraging in sunlight were reduced, suggesting a thermoregulation-predation trade-off. Glare could be reduced if birds faced away from the sun while feeding in direct sunlight, but we found that foraging birds tended to face southward (the direction of the sun). We speculate that other factors, such as the likely direction of predator approach, may explain this southerly orientation, particularly if predators use solar glare to their advantage during an attack. This interpretation is supported by the fact that birds had the weakest southerly orientation on cloudy days. Wintering birds may generally avoid foraging in direct sunlight to minimize their risk of predation. However, given the thermal benefits of sunshine, such birds may benefit from foraging in habitats that provide a mosaic of sunlit and shaded microhabitats.

  14. The effects of food abundance and disturbance on foraging flock patterns of the wintering Hooded Crane (Grus monacha)

    Institute of Scientific and Technical Information of China (English)

    Ling Yang; Lizhi Zhou; and Yunwei Song

    2015-01-01

    Background:Food abundance and availability affect flock patterns of foraging birds. Cost and risk tradeoffs are especially critical for flocks of wintering waterbirds foraging in lake wetlands. Waterbirds losing suitable habitats face insufficient food supplies and high levels of disturbance, affecting their foraging activities. Our objective was to study the effects of food abundance and disturbances on flock size and the structure of Hooded Crane flocks wintering at Shengjin Lake and, as well, to understand the response of wintering waterbirds to habitat degradation for future management decisions and protection of the population. Methods:We investigated food abundance, disturbances and flock foraging activities of the wintering Hooded Crane in several foraging habitats of Shengjin Lake from November 2013 to April 2014. Flock size and structure were observed by scan sampling. Data on food abundance and disturbances were collected by sampling. Flock size and structure were compared among three wintering stages. The relationship between food resources, disturbances and flock size were illustrated using a generalized linear model. Results:In the early and middle wintering periods, the Hooded Crane used paddy fields as its major foraging habitat, where the number of foraging birds and flocks were the highest. During the late period, the cranes took to meadows as their major foraging habitat. The variation among foraging flock was mainly embodied in the size of the flocks, while the age composition of these flocks did not change perceptibly. Family flocks were notably different from flock groups in size and age composition. The results of a generalized linear model showed that the food abundance had a marked effect on foraging flock size and age composition, while disturbances had a significant effect only on flock size. From our analysis, it appeared that the combined effect of the two variables was significant on the size of the foraging flock, but had less impact

  15. Therapeutic Potential of Temperate Forage Legumes: A Review.

    Science.gov (United States)

    Cornara, Laura; Xiao, Jianbo; Burlando, Bruno

    2016-07-29

    The discovery of bioactive molecules from botanical sources is an expanding field, preferentially oriented to plants having a tradition of use in medicine and providing high yields and availability. Temperate forage legumes are Fabaceae species that include worldwide-important crops. These plants possess therapeutic virtues that have not only been used in veterinary and folk medicine, but have also attracted the interest of official medicine. We have examined here Medicago sativa (alfalfa), Trifolium pratense and T. repens (clovers), Melilotus albus and M. officinalis (sweet clovers), Lotus corniculatus (birdsfoot trefoil), Onobrychis viciifolia (sainfoin), Lespedeza capitata (roundhead lespedeza), and Galega officinalis (goat's rue). The phytochemical complexes of these species contain secondary metabolites whose pharmacological potentials deserve investigation. Major classes of compounds include alkaloids and amines, cyanogenic glycosides, flavonoids, coumarins, condensed tannins, and saponins. Some of these phytochemicals have been related to antihypercholesterolemia, antidiabetic, antimenopause, anti-inflammatory, antiedema, anthelmintic, and kidney protective effects. Two widely prescribed drugs have been developed starting from temperate forage legumes, namely, the antithrombotic warfarin, inspired from sweet clover's coumarin, and the antidiabetic metformin, a derivative of sainfoin's guanidine. Available evidence suggests that temperate forage legumes are a potentially important resource for the extraction of active principles to be used as nutraceuticals and pharmaceuticals. PMID:26507574

  16. Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins

    Directory of Open Access Journals (Sweden)

    Jennifer W. MacAdam

    2015-07-01

    Full Text Available The two temperate forage legumes containing condensed tannins (CT that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT and sainfoin (Onobrychis viciifolia Scop.; SF. Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM, while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb. Dumort. forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.

  17. Mating success and body condition not related to foraging specializations in male fur seals.

    Science.gov (United States)

    Kernaléguen, L; Cherel, Y; Guinet, C; Arnould, J P Y

    2016-07-01

    Individual specialization is widespread among wild populations. While its fitness consequences are central in predicting the ecological and evolutionary trajectories of populations, they remain poorly understood. Long-term individual foraging specializations occur in male Antarctic (Arctocephalus gazella) and Australian (A. pusillus doriferus) fur seals. Strong selective pressure is expected in these highly dimorphic and polygynous species, raising the question of the fitness payoffs associated with different foraging strategies. We investigated the relationship between individual isotopic niche (a proxy of foraging specialization), body size and condition, and an index of reproductive success (harem size) in territorial males. Individuals varied greatly in their skin and fur isotopic values reflecting a range of foraging strategies within the two populations. However, in both species, isotopic niche was not correlated to body size, condition or mating success (R (2)/ρ < 0.06). Furthermore, no foraging niche was predominant in either species, which would have indicated a substantial long-term fitness benefit of a particular strategy via a higher survival rate. These results suggest that the fitness consequences of a foraging strategy depend not only on the quality of prey and feeding habitat but also on an individual's hunting efficiency and skills. PMID:27493771

  18. The effects of chlorpyrifos on cholinesterase activity and foraging behavior in the dragonfly, Anax junius (Odonata)

    Science.gov (United States)

    Brewer, S.K.; Atchison, G.J.

    1999-01-01

    We examined head capsule cholinesterase (ChE) and foraging behavior in nymphs of the dragonfly, Anax junius, exposed for 24 h to 0.2, 0.6 and 1.0 ??g l-1 of the organophosphorus (OP) insecticide, chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate]. The invertebrate community is an important component of the structure and function of wetland ecosystems, yet the potential effects of insecticides on wetland ecosystems are largely unknown. Our objectives were to determine if exposure to environmentally realistic concentrations of chlorpyrifos affected foraging behavior and ChE activity in head capsules of dragonfly nymphs. Nymphs were exposed to different concentrations of chlorpyrifos and different prey densities in a factorial design. ChE activities and foraging behaviors of treated nymphs were not statistically different (p ??? 0.05) from control groups. Prey density effects exerted a greater effect on dragonfly foraging than toxicant exposures. Nymphs offered higher prey densities exhibited more foraging behaviors but also missed their prey more often. High variability in ChE activities within the control group and across treated groups precluded determination of relationships between ChE and foraging behaviors. It appears that A. junius is relatively tolerant of chlorpyrifos, although the concentrations we tested have been shown in other work to adversely affect the prey base; therefore the introduction of this insecticide may have indirect adverse affects on top invertebrate predators such as Odonata.

  19. Mating success and body condition not related to foraging specializations in male fur seals.

    Science.gov (United States)

    Kernaléguen, L; Cherel, Y; Guinet, C; Arnould, J P Y

    2016-07-01

    Individual specialization is widespread among wild populations. While its fitness consequences are central in predicting the ecological and evolutionary trajectories of populations, they remain poorly understood. Long-term individual foraging specializations occur in male Antarctic (Arctocephalus gazella) and Australian (A. pusillus doriferus) fur seals. Strong selective pressure is expected in these highly dimorphic and polygynous species, raising the question of the fitness payoffs associated with different foraging strategies. We investigated the relationship between individual isotopic niche (a proxy of foraging specialization), body size and condition, and an index of reproductive success (harem size) in territorial males. Individuals varied greatly in their skin and fur isotopic values reflecting a range of foraging strategies within the two populations. However, in both species, isotopic niche was not correlated to body size, condition or mating success (R (2)/ρ < 0.06). Furthermore, no foraging niche was predominant in either species, which would have indicated a substantial long-term fitness benefit of a particular strategy via a higher survival rate. These results suggest that the fitness consequences of a foraging strategy depend not only on the quality of prey and feeding habitat but also on an individual's hunting efficiency and skills.

  20. Successful foraging zones of southern elephant seals from the Kerguelen Islands in relation to oceanographic conditions.

    Science.gov (United States)

    Bailleul, Frédéric; Charrassin, Jean-Benoît; Monestiez, Pascal; Roquet, Fabien; Biuw, Martin; Guinet, Christophe

    2007-11-29

    Southern elephant seals, Mirounga leonina, undertake large-scale oceanic movements to access favourable foraging areas. Successful foraging areas of elephant seals from the Kerguelen Islands are investigated here in relation to oceanographic parameters. Movements and diving activity of the seals as well as oceanographic data were collected through a new generation of satellite relayed devices measuring and transmitting locations, pressure, temperature and salinity. For the first time, we have associated foraging behaviour, determined by high increased sinuosity in tracks, and dive density (i.e. number of dives performed per kilometre covered), and changes in body condition, determined by variations in drift rate obtained from drift dives, to identify the oceanographic conditions of successful foraging zones for this species. Two main sectors, one close to the Antarctic continent and the other along the Polar Front (PF), where both foraging activity and body condition increase, seem to be of particular interest for the seals. Within these regions, some seals tended to focus their foraging activity on zones with particular temperature signatures. Along the Antarctic continent, some seals targeted colder waters on the sea bottom during benthic dives, while at the PF the favourable zones tended to be warmer. The possible negative effect of colder waters in Antarctic on the swimming performances of potential fish or squid prey could explain the behaviour of elephant seals in these zones, while warmer waters within the PF could correspond to the optimal conditions for potential myctophid prey of elephant seals. PMID:17472917

  1. Availability and toxicity of cadmium to forage grasses grown in contaminated soil.

    Science.gov (United States)

    Silva, Enilson B; Fonseca, Felipe G; Alleoni, Luís R F; Nascimento, Sandra S; Grazziotti, Paulo H; Nardis, Bárbara O

    2016-09-01

    It is important to know the mechanisms for forage development, especially those related to the tolerance of potentially toxic elements, when considering their use in phytoremediation in heavy metal contaminated areas. In this study, we evaluated plant growth, concentration, and the availability of cadmium (Cd) for forage grasses (Panicum maximum Jacq. cv. Aruana and cv. Tanzânia; Brachiaria decumbens cv. Basilisk; Brachiaria brizantha cv. Xaraés and cv. Marandu) cultivated in Cd contaminated soils. The experiments were performed under greenhouse conditions over a 90-day evaluation period, and the Cd rates were 2, 4, and 12 mg/kg of soil. The relative growth rate of the forage grasses decreased as Cd rates increased, and the following descending order of susceptibility was observed: Marandu > Xaraés > Aruana > Tanzânia > Basilisk, with regard to phytotoxicity in these plants. The forage Cd concentration increased in line with increases in the Cd rates. Cd contents extracted by Mehlich-1 and by diethylenetriaminepentaacetic acid presented high positive correlation with forage relative growth. The forage plants did not block Cd entry into the food chain because they were not capable of limiting Cd absorption. PMID:26854007

  2. Parasitic infection leads to decline in hemolymph sugar levels in honeybee foragers.

    Science.gov (United States)

    Mayack, Christopher; Naug, Dhruba

    2010-11-01

    Parasites by drawing nutrition from their hosts can exert an energetic stress on them. Honeybee foragers with their high metabolic demand due to flight are especially prone to such a stress when they are infected. We hypothesized that infection by the microsporidian gut parasite Nosema ceranae can lower the hemolymph sugar level of an individual forager and uncouple its energetic state from its normally tight correlation with the colony energetic state. We support our hypothesis by showing that free-flying foragers that are infected have lower trehalose levels than uninfected ones but the two do not differ in their trehalose levels when fed until satiation. The trehalose level of infected bees was also found to decline at a faster rate while their glucose level is maintained at a quantity comparable to uninfected bees. These results suggest that infected foragers have lower flying ability and the intriguing possibility that the carbohydrate levels of an individual bee can act as a modulator of its foraging behavior, independent of social cues such as colony demand for nectar. We discuss the importance of such pathophysiological changes on foraging behavior in the context of the recently observed colony collapses.

  3. A simple structure of all circular-air-holes photonic crystal fiber for achieving high birefringence and low confinement loss

    International Nuclear Information System (INIS)

    We propose a simple structure of photonic crystal fibers (PCFs) with high birefringence and low confinement loss based on one rectangular centric ring of smaller circular air holes (CAHs) in the fiber core, and three rings of larger CAHs in the fiber cladding. This simple geometry (using all CAHs with two different air hole sizes) is capable of achieving a flexible control of the birefringence, B = 5.501 × 10−3, and ultra-low confinement loss, 7.30 × 10−5 dB/km, at an excitation wavelength of λ = 1550 nm. The birefringence value is ∼5.0 times greater than that obtained for conventional CAH PCF. This simple structure has the added advantage from the view point of easy fabrication, robustness, and cost. A full-vector finite element method combined with anisotropic perfectly matched layers was used to analyze the various fiber structures. We have analyzed four cases of CAH PCFs, focusing on the core asymmetry design as opposed to the conventional approach of CAHs or elliptical air holes on the cladding and core. The robustness against manufacturing inaccuracies of the proposed structure has also been further investigated in this work

  4. A highly efficient surface plasmon polaritons excitation achieved with a metal-coupled metal-insulator-metal waveguide

    Directory of Open Access Journals (Sweden)

    Hongyan Yang

    2014-12-01

    Full Text Available We propose a novel metal-coupled metal-insulator-metal (MC-MIM waveguide which can achieve a highly efficient surface plasmon polaritons (SPPs excitation. The MC-MIM waveguide is formed by inserting a thin metal film in the insulator of an MIM. The introduction of the metal film, functioning as an SPPs coupler, provides a space for the interaction between SPPs and a confined electromagnetic field of the intermediate metal surface, which makes energy change and phase transfer in the metal-dielectric interface, due to the joint action of incomplete electrostatic shielding effect and SPPs coupling. Impacts of the metal film with different materials and various thickness on SPPs excitation are investigated. It is shown that the highest efficient SPPs excitation is obtained when the gold film thickness is 60 nm. The effect of refractive index of upper and lower symmetric dielectric layer on SPPs excitation is also discussed. The result shows that the decay value of refractive index is 0.3. Our results indicate that this proposed MC-MIM waveguide may offer great potential in designing a new SPPs source.

  5. A simple structure of all circular-air-holes photonic crystal fiber for achieving high birefringence and low confinement loss

    Energy Technology Data Exchange (ETDEWEB)

    Chou Chau, Yuan-Fong, E-mail: chou.fong@ubd.edu.bn; Lim, Chee Ming; Yoong, Voo Nyuk; Syafi' ie Idris, Muhammad Nur [Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Tungku Link, Gadong BE1410, Brunei (Brunei Darussalam)

    2015-12-28

    We propose a simple structure of photonic crystal fibers (PCFs) with high birefringence and low confinement loss based on one rectangular centric ring of smaller circular air holes (CAHs) in the fiber core, and three rings of larger CAHs in the fiber cladding. This simple geometry (using all CAHs with two different air hole sizes) is capable of achieving a flexible control of the birefringence, B = 5.501 × 10{sup −3}, and ultra-low confinement loss, 7.30 × 10{sup −5 }dB/km, at an excitation wavelength of λ = 1550 nm. The birefringence value is ∼5.0 times greater than that obtained for conventional CAH PCF. This simple structure has the added advantage from the view point of easy fabrication, robustness, and cost. A full-vector finite element method combined with anisotropic perfectly matched layers was used to analyze the various fiber structures. We have analyzed four cases of CAH PCFs, focusing on the core asymmetry design as opposed to the conventional approach of CAHs or elliptical air holes on the cladding and core. The robustness against manufacturing inaccuracies of the proposed structure has also been further investigated in this work.

  6. High direct drive illumination uniformity achieved by multi-parameter optimization approach: a case study of Shenguang III laser facility.

    Science.gov (United States)

    Tian, Chao; Chen, Jia; Zhang, Bo; Shan, Lianqiang; Zhou, Weimin; Liu, Dongxiao; Bi, Bi; Zhang, Feng; Wang, Weiwu; Zhang, Baohan; Gu, Yuqiu

    2015-05-01

    The uniformity of the compression driver is of fundamental importance for inertial confinement fusion (ICF). In this paper, the illumination uniformity on a spherical capsule during the initial imprinting phase directly driven by laser beams has been considered. We aim to explore methods to achieve high direct drive illumination uniformity on laser facilities designed for indirect drive ICF. There are many parameters that would affect the irradiation uniformity, such as Polar Direct Drive displacement quantity, capsule radius, laser spot size and intensity distribution within a laser beam. A novel approach to reduce the root mean square illumination non-uniformity based on multi-parameter optimizing approach (particle swarm optimization) is proposed, which enables us to obtain a set of optimal parameters over a large parameter space. Finally, this method is applied to improve the direct drive illumination uniformity provided by Shenguang III laser facility and the illumination non-uniformity is reduced from 5.62% to 0.23% for perfectly balanced beams. Moreover, beam errors (power imbalance and pointing error) are taken into account to provide a more practical solution and results show that this multi-parameter optimization approach is effective. PMID:25969321

  7. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm0.20Ce0.80O2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm−2. The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  8. Influence of feed intake, forage physical form, and forage fiber content on particle size of masticated forage, ruminal digesta, and feces of dairy cows.

    Science.gov (United States)

    Shaver, R D; Nytes, A J; Satter, L D; Jorgensen, N A

    1988-06-01

    Two trials were conducted to determine particle size of masticates, ruminal digesta, and feces of dairy cows. In Trial 1, three Holstein cows with ruminal cannulae were fed prebloom alfalfa hay in long, chopped, or pelleted form in a Latin square design (21-d periods) conducted in early lactation (wk 3 to 11) and again during the dry period to attain high (3.75) and low (1.95% of BW) feed consumption. In trial 2, prebloom, midbloom, and full bloom alfalfa hay, mature bromegrass hay, and corn silage were fed to early lactation (wk 5 to 15) Holsteins in a 5 X 5 Latin square design (15-d periods). All diets (Trials 1 and 2) were formulated to 17% CP and contained forage:grain in a 60:40 ratio (DM basis). Similar particle distributions of digesta from long and chopped hay diets suggest little influence of chopping forage on particle size reduction when high quality forage is fed. The large proportion of DM in the small particle (less than .6 mm) pool in the rumen in both trials suggests that rate of escape of small particles from the rumen is an important factor influencing ruminal retention time. Increased proportion of coarse (greater than or equal to 2.36-mm screen) fecal particles at high intake and with fine grinding appears related to a reduction in chewing per unit feed consumed. Soluble DM and particulate matter passing a .063-mm screen made up a significant portion (30 to 50%) of the total DM sieved from all sampling sites in both trials. PMID:2841366

  9. Social foragers adopt a riskier foraging mode in the centre of their groups.

    Science.gov (United States)

    Beauchamp, Guy

    2013-01-01

    Foraging in groups provides many benefits that are not necessarily experienced the same way by all individuals. I explore the possibility that foraging mode, the way individuals exploit resources, varies as a function of spatial position in the group, reflecting commonly occurring spatial differences in predation risk. I show that semipalmated sandpipers (Calidris pusilla), a social foraging avian species, tended to adopt a riskier foraging mode in the central, more protected areas of their groups. Central birds effectively used the more peripheral group members as sentinels, allowing them to exploit a wider range of resources within the same group at the same time. This finding provides a novel benefit of living in groups, which may have a broad relevance given that social foraging species often exploit a large array of resources. PMID:24108674

  10. Greenhouse gas emissions from fen soils used for forage production in northern Germany

    Science.gov (United States)

    Poyda, Arne; Reinsch, Thorsten; Kluß, Christof; Loges, Ralf; Taube, Friedhelm

    2016-09-01

    A large share of peatlands in northwestern Germany is drained for agricultural purposes, thereby emitting high amounts of greenhouse gases (GHGs). In order to quantify the climatic impact of fen soils in dairy farming systems of northern Germany, GHG exchange and forage yield were determined on four experimental sites which differed in terms of management and drainage intensity: (a) rewetted and unutilized grassland (UG), (b) intensive and wet grassland (GW), (c) intensive and moist grassland (GM) and (d) arable forage cropping (AR). Net ecosystem exchange (NEE) of CO2 and fluxes of CH4 and N2O were measured using closed manual chambers. CH4 fluxes were significantly affected by groundwater level (GWL) and soil temperature, whereas N2O fluxes showed a significant relation to the amount of nitrate in top soil. Annual balances of all three gases, as well as the global warming potential (GWP), were significantly correlated to mean annual GWL. A 2-year mean GWP, combined from CO2-C eq. of NEE, CH4 and N2O emissions, as well as C input (slurry) and C output (harvest), was 3.8, 11.7, 17.7 and 17.3 Mg CO2-C eq. ha-1 a-1 for sites UG, GW, GM and AR, respectively (standard error (SE) 2.8, 1.2, 1.8, 2.6). Yield-related emissions for the three agricultural sites were 201, 248 and 269 kg CO2-C eq. (GJ net energy lactation; NEL)-1 for sites GW, GM and AR, respectively (SE 17, 9, 19). The carbon footprint of agricultural commodities grown on fen soils depended on long-term drainage intensity rather than type of management, but management and climate strongly influenced interannual on-site variability. However, arable forage production revealed a high uncertainty of yield and therefore was an unsuitable land use option. Lowest yield-related GHG emissions were achieved by a three-cut system of productive grassland swards in combination with a high GWL (long-term mean ≤ 20 cm below the surface).

  11. Utilisation des polymères organiques durant le forage et la cimentation des puits à haute température Using Organic Polymers During Drilling and Cementing of High Temperature Wells

    Directory of Open Access Journals (Sweden)

    Martin M.

    2006-11-01

    Full Text Available Dans les puits pétroliers, par suite de l'accroissement de la profondeur, des températures statiques de fond voisines de 250 °C seront probablement atteintes dans un très proche avenir. Dans les puits géothermiques à haute énergie, cette limite est déjà largement dépassée avec des températures pouvant aller jusque 400 °C. II est indispensable que les fluides de forage et les matériaux de cimentation alors mis en oeuvre possèdent des stabilités suffisantes. Pour les fluides de forage, à base d'eau et à base d'huile, il convient de prévenir, à l'aide d'additifs, les évolutions réversibles et irréversibles des caractéristiques de viscosité et de filtration durant le cycle ou pendant des arrêts de circulation de quelques heures. Ces additifs sont, pour la plupart, des polymères susceptibles de se disperser dans la phase liquide. Mais actuellement leur stabilité ne permet guère d'envisager l'utilisation des fluides à base d'eau au-delà de 260 °C et celle des fluides à base d'huile au-delà de 285 °C. Pour les cimentations, il peut être souhaitable de remplacer le ciment hydraulique habituellement employé par un matériau de masse volumique plus faible et/ou de durabilité accrue. Pendant toute la vie du puits, prévue pour 20 à 30 ans, ce matériau devra assurer l'étanchéité de l'annulaire et conserver sa résistance mécanique. II devra, de plus, supporter l'environnement parfois agressif des eaux de formation. Des recherches de laboratoire sur de nouveaux matériaux de cimentation ont été orientées vers des résines organiques et des composés à base d'organosiloxanes. Elles conduisent à sélectionner des formules stables jusqu'à 300 °C. Mais les possibilités de mise en oeuvre sur puits restent encore à étudier et le coût élevé des produits de base risque de limiter leur application. Static downhole temperatures of around 250°C will probably be reached in the very near future in oil wells as the

  12. Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini).

    Science.gov (United States)

    Lopes, Juliane F S; Brugger, Mariana S; Menezes, Regys B; Camargo, Roberto S; Forti, Luiz Carlos; Fourcassié, Vincent

    2016-01-01

    Foraging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level. PMID:26752413

  13. Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini.

    Directory of Open Access Journals (Sweden)

    Juliane F S Lopes

    Full Text Available Foraging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level.

  14. Motives Emanating from Personality Associated with Achievement in a Finnish Senior High School: Physical Activity, Curiosity, and Family Motives

    Science.gov (United States)

    Froiland, John Mark; Mayor, Päivi; Herlevi, Marjaana

    2015-01-01

    Numerous studies indicate that intrinsic motivation predicts academic achievement. However, relatively few have examined various subtypes of intrinsic motivation that predict overall achievement, such as motivation for exercise and physical activity. Based upon the 16 basic desires theory of personality, the current study examined the motives of…

  15. An Analysis of the Impact of Demographic, Structural, Student, and Financial Factors on Texas High School Mathematics Achievement

    Science.gov (United States)

    Carter, Alisa

    2013-01-01

    The purpose of this study was to examine the relationships of demographic (indicators describing student characteristics), structural (indicators describing school characteristics), student (indicators of student academic achievement), and financial (indicators of instructional expenditures) factors to student mathematics achievement. A sample (n…

  16. Self-Perceptions of Ability and Achievement across the High School Transition: Investigation of a State-Trait Model

    Science.gov (United States)

    Silverthorn, Naida; DuBois, David L.; Crombie, Gail

    2005-01-01

    The authors investigated the relationship between self-perceptions of ability and achievement in math, science, and English from Grades 8 to 11 (N = 342). A state-trait model that included an association between stable (i.e., trait-like) components of self-perceptions and achievement as well as time-specific (i.e., state-like) effects during the…

  17. Modality-specific attention in foraging bumblebees.

    Science.gov (United States)

    Nityananda, Vivek; Chittka, Lars

    2015-10-01

    Attentional demands can prevent humans and other animals from performing multiple tasks simultaneously. Some studies, however, show that tasks presented in different sensory modalities (e.g. visual and auditory) can be processed simultaneously. This suggests that, at least in these cases, attention might be modality-specific and divided differently between tasks when present in the same modality compared with different modalities. We investigated this possibility in bumblebees (Bombus terrestris) using a biologically relevant experimental set-up where they had to simultaneously choose more rewarding flowers and avoid simulated predatory attacks by robotic 'spiders'. We found that when the tasks had to be performed using visual cues alone, bees failed to perform both tasks simultaneously. However, when highly rewarding flowers were indicated by olfactory cues and predators were indicated by visual cues, bees managed to perform both tasks successfully. Our results thus provide evidence for modality-specific attention in foraging bees and establish a novel framework for future studies of crossmodal attention in ecologically realistic settings. PMID:26587245

  18. An analysis of predictors of enrollment and successful achievement for girls in high school Advanced Placement physics

    Science.gov (United States)

    Depalma, Darlene M.

    A problem within science education in the United States persists. U.S students rank lower in science than most other students from participating countries on international tests of achievement (National Center for Education Statistics, 2003). In addition, U.S. students overall enrollment rate in high school Advanced Placement (AP) physics is still low compared to other academic domains, especially for females. This problem is the background for the purpose of this study. This investigation examined cognitive and motivational variables thought to play a part in the under-representation of females in AP physics. Cognitive variables consisted of mathematics, reading, and science knowledge, as measured by scores on the 10th and 11th grade Florida Comprehensive Assessment Tests (FCAT). The motivational factors of attitude, stereotypical views toward science, self-efficacy, and epistemological beliefs were measured by a questionnaire developed with questions taken from previously proven reliable and valid instruments. A general survey regarding participation in extracurricular activities was also included. The sample included 12th grade students from two high schools located in Seminole County, Florida. Of the 106 participants, 20 girls and 27 boys were enrolled in AP physics, and 39 girls and 20 boys were enrolled in other elective science courses. Differences between males and females enrolled in AP physics were examined, as well as differences between females enrolled in AP physics and females that chose not to participate in AP physics, in order to determine predictors that apply exclusively to female enrollment in high school AP physics and predictors of an anticipated science related college major. Data were first analyzed by Exploratory Factor Analysis, followed by Analysis of Variance (ANOVA), independent t-tests, univariate analysis, and logistic regression analysis. One overall theme that emerged from this research was findings that refute the ideas that

  19. Forage and seed production of Puero (Pueraria javanica in a Different Light intensity level

    Directory of Open Access Journals (Sweden)

    Fanindi A

    2016-06-01

    Full Text Available Puero (Pueraria javanica is forage that can serve as a cover crop in plantations. The limiting factor for plant growth in the plantation is the light intensity, therefore the influence of light intensity on forage and seed production of Puero needs to be examined. Research was conducted at Kaum Pandak Research station of Indonesian Research Institute for Animal Production Bogor and Laboratory of Agrostology Faculty of Animal Husbandry, Bogor Agricultural University, for 16 months. Four levels of light intensity,i.e 100, 80,60 and 40% were applied, leguminosainous species Puero (Pueraria javanica, was used. The treatments were arangged in Randomized Complete Block Design with 3 replications. Data collected were analyzed by ANOVA and Duncan’s Multiple Range Test. Forage production was evaluated in one year. The forage quality and digestibility (invitro were assessed. Seed production was recorded accumulatively from seasonal seed production during one year. Results show that light intensity affected (P 0.05 quality and digestibility of Puero. The highest forage and seed production of Puero were obtained from full light intensity (100%. and seed production of Puero was affected (P < 0.05 by light intensity. The seed quality of Puero was also affected by light intensity. The best seed quality of Puero was achieved by from 80% light intensity.

  20. Scheduling and development support in the Scavenger cyber foraging system

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Bouvin, Niels Olof

    2010-01-01

    Cyber foraging is a pervasive computing technique where small mobile devices offload resource intensive tasks to stronger computing machinery in the vicinity. One of the main challenges within cyber foraging is that it is very difficult to develop cyber foraging enabled applications. An application...... using cyber foraging is working with mobile, distributed and, possibly, parallel computing; fields within computer science notoriously hard for programmers to grasp. This paper presents Scavenger—a cyber foraging system supporting easy development of mobile cyber foraging applications, while still...