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Sample records for climbing perch anabas

  1. Starvation induced cholesterogenesis in hepatic and extra hepatic tissues of climbing Perch, Anabas testudineus (Bloch)

    PubMed Central

    Godavarthy, Padmavathi; Sunila Kumari, Y.; Bikshapathy, E.

    2012-01-01

    Cholesterol is a structural lipid, which may be differentially utilized or synthesized in response to stress or during insulin deficient states such as starvation. In the present investigation we estimated the levels of cholesterol in Anabas testudineus, which was subjected to brief (15 days) and prolonged fasting (60 days). Tissues such as liver, kidney, brain, accessory respiratory organ, pectoral and lateral line muscle were selected for the study. Cholesterol content was estimated by the Crawford method (1958). Both the starvation regimes showed a significant increase in cholesterol levels in almost all the tissues, but for liver, which strangely showed an insignificant decline during the short-term starvation. This overall upsurge in cholesterol levels observed in all extra hepatic tissues may be attributed to the synthesis of stress hormones such as glucocorticoids, which may promote gluconeogenesis and adrenocorticoids, which may help the animal to combat the stressful condition of starvation. Anabas adapted well to starvation stress and survived all throughout the experimental period. PMID:23961210

  2. Autochthonous Gut Bacteria in Two Indian Air-breathing Fish, Climbing Perch (Anabas testudineus) and Walking Catfish (Clarias batrachus): Mode of Association, Identification and Enzyme Producing Ability.

    PubMed

    Banerjee, Goutam; Dan, Suhas K; Nandi, Ankita; Ghosh, Pinki; Ray, Arun K

    2015-01-01

    Scanning electron microscopy (SEM) was used to define the location of epithelium-associated bacteria in the gastrointestinal (GI) tract of two Indian air-breathing fish, the climbing perch (Anabas testudineus) and walking catfish (Clarias batrachus). The SEM examination revealed substantial numbers of rod shaped bacterial cells associated with the microvillus brush borders of enterocytes in proximal (PI) and distal regions (DI) of the GI tract of both the fish species. Ten (two each from the PI and DI of climbing perch and three each from the PI and DI of walking catfish) isolated bacterial strains were evaluated for extracellular protease, amylase and cellulase production quantitatively. All the bacterial strains exhibited high cellulolytic activity compared to amylolytic and proteolytic activites. Only two strains, CBH6 and CBH7, isolated from the DI of walking catfish exhibited high proteolytic activity. Maximum cellulase activity was exhibited by the strain, CBF2, isolated from the PI of climbing perch. Six most promising enzyme-producing adherent bacterial strains were identified by 16S rDNA gene sequence analysis. The strain ATH1 (isolated from climbing perch) showed high similarity fo Bacillus amyloliquefaciens whereas, the remaining five strains (isolated from walking catfish) were most closely related to Bacillus licheniformis.

  3. Increases in apoptosis, caspase activity and expression of p53 and bax, and the transition between two types of mitochondrion-rich cells, in the gills of the climbing perch, Anabas testudineus, during a progressive acclimation from freshwater to seawater

    PubMed Central

    Ching, Biyun; Chen, Xiu L.; Yong, Jing H. A.; Wilson, Jonathan M.; Hiong, Kum C.; Sim, Eugene W. L.; Wong, Wai P.; Lam, Siew H.; Chew, Shit F.; Ip, Yuen K.

    2013-01-01

    This study aimed to test the hypothesis that branchial osmoregulatory acclimation involved increased apoptosis and replacement of mitochdonrion-rich cells (MRCs) in the climbing perch, Anabas testudineus, during a progressive acclimation from freshwater to seawater. A significant increase in branchial caspase-3/-7 activity was observed on day 4 (salinity 20), and an extensive TUNEL-positive apoptosis was detected on day 5 (salinity 25), indicating salinity-induced apoptosis had occurred. This was further supported by an up-regulation of branchial mRNA expression of p53, a key regulator of cell cycle arrest and apoptosis, between day 2 (salinity 10) and day 6 (seawater), and an increase in branchial p53 protein abundance on day 6. Seawater acclimation apparently activated both the extrinsic and intrinsic pathways, as reflected by significant increases in branchial caspase-8 and caspase-9 activities. The involvement of the intrinsic pathway was confirmed by the significant increase in branchial mRNA expression of bax between day 4 (salinity 20) and day 6 (seawater). Western blotting results revealed the presence of a freshwater Na+/K+-ATPase (Nka) α-isoform, Nka α1a, and a seawater isoform, Nka α1b, the protein abundance of which decreased and increased, respectively, during seawater acclimation. Immunofluorescence microscopy revealed the presence of two types of MRCs distinctly different in sizes, and confirmed that the reduction in Nka α1a expression, and the prominent increases in expression of Nka α1b, Na+:K+:2Cl− cotransporter 1, and cystic fibrosis transmembrane conductance regulator Cl− channel coincided with the salinity-induced apoptotic event. Since modulation of existing MRCs alone could not have led to extensive salinity-induced apoptosis, it is probable that some, if not all, freshwater-type MRCs could have been removed through increased apoptosis and subsequently replaced by seawater-type MRCs in the gills of A. testudineus during seawater

  4. Physiologic implications of inter-hormonal interference in fish: lessons from the interaction of adrenaline with cortisol and thyroid hormones in climbing perch (Anabas testudineus Bloch).

    PubMed

    George, Nimta; Peter, Valsa S; Peter, M C Subhash

    2013-01-15

    Adrenaline and cortisol, the major stress hormones, are known for its direct control on stress response in fish. Likewise, as an important stress modifier hormone, thyroid hormone has also been implicated in stress response of fish. We tested whether the hypothesis on the phenomenon of inter-hormonal interference, a process that explains the hormonal interactions, operates in fish particularly between adrenaline, cortisol and thyroid hormones. To achieve this goal, indices of acid-base, osmotic and metabolic regulations were quantified after adrenaline challenge in propranolol pre-treated air-breathing fish (Anabas testudineus). Short-term adrenaline (10 ng g(-1)) injection for 30 min produced a rise in plasma cortisol without affecting plasma T(3) and T(4). On the contrary, blocking of adrenaline action with a non-selective blocker, propranolol (25 ng g(-1)) for 90 min reduced plasma cortisol along with plasma T(4) and that indicate a possible interference of these hormones in the absence of adrenaline challenge. Similarly, a reduction in plasma T(3) was found after adrenaline challenge in propranolol pre-treated fish and that suggests a functional synergistic interference of adrenaline with T(3). Adrenaline challenge in these fish, however, failed to abolish this propranolol effect. The remarkable systemic hypercapnia and acidosis by propranolol pre-treatment were reversed by adrenaline challenge, pointing to a direct action of adrenaline on acid-base indices probably by a mechanism which may not require β-adrenergic receptor systems. Interestingly, the prominent adrenaline-induced hyperglycemia, hyperlactemia and hyperuremea were not altered by propranolol treatment. Similarly, adrenaline challenge promoted and propranolol reduced the osmotic competencies of the gills, kidneys and liver of this fish as evident in the sodium and proton pump activities. The modified physiologic actions of adrenaline and its modified interaction with THs and cortisol in blocked

  5. Effects of Sequential Applications of Bassa 50EC (Fenobucarb) and Vitashield 40EC (Chlorpyrifos ethyl) on Acetylcholinesterase Activity in Climbing Perch (Anabas testudineus) Cultured in Rice Fields in the Mekong Delta, Vietnam.

    PubMed

    Tam, Nguyen Thanh; Berg, Håkan; Laureus, Jenny; Cong, Nguyen Van; Tedengren, Michael

    2016-07-01

    This study assesses the effects of sequential applications of the insecticides Bassa 50EC (fenobucarb-F) and Vitashield 40EC (chlorpyrifos ethyl-CPF), sprayed at concentrations used by rice farmers in the Mekong Delta, on the brain acetylcholinesterase (AChE) in climbing perch fingerlings. After spraying the pesticides on the rice fields, the water concentrations of both insecticides decreased below the detection levels within 3 days. The sequential applications caused significant inhibition on the brain AChE activity in the exposed fish. The inhibition by F was quicker, but less prolonged, than for CPF. The inhibition levels caused by the sequential applications were lower than those caused by only CPF and by a mixture of CPF and F. The results indicate that sequential applications of pesticides could have a negative impact on aquatic organisms and fish yields, with implication for the aquatic biodiversity, local people's livelihood and the aquaculture industry in the Mekong Delta.

  6. Uptake and elimination of 137Cs by climbing perch (Anabus testudineus).

    PubMed

    Malek, M A

    1999-12-01

    This work describes the uptake and retention/biological elimination of 137Cs by climbing perch (Anabus testudineus) under laboratory conditions. The accumulated 137Cs concentration in the whole body of the fish was measured at certain intervals up to 38 d. A significant accumulation of 137Cs was found, but a steady state accumulation of 137Cs was not achieved by the end of the experiment. The bioaccumulation factors and the distribution of the radionuclide in edible parts of the fish were determined. The effective half-life of 137Cs in the fish species was found to be approximately 147 d (average) for elderly and adult fishes and approximately 300 d for younger fishes. Accumulation of 137Cs in the edible parts of the fish was found to be approximately 77% of whole body accumulation.

  7. Effects of chlorpyrifos ethyl on acetylcholinesterase activity in climbing perch cultured in rice fields in the Mekong Delta, Vietnam.

    PubMed

    Nguyen, Tam Thanh; Berg, Håkan; Nguyen, Hang Thi Thuy; Nguyen, Cong Van

    2015-07-01

    Climbing perch is commonly harvested in rice fields and associated wetlands in the Mekong Delta. Despite its importance in providing food and income to local households, there is little information how this fish species is affected by the high use of pesticides in rice farming. Organophosphate insecticides, such as chlorpyrifos ethyl, which are highly toxic to aquatic organisms, are commonly used in the Mekong Delta. This study shows that the brain acetylcholinesterase (AChE) activity in climbing perch fingerlings cultured in rice fields, was significantly inhibited by a single application of chlorpyrifos ethyl, at doses commonly applied by rice farmers (0.32-0.64 kg/ha). The water concentration of chlorpyrifos ethyl decreased below the detection level within 3 days, but the inhibition of brain AChE activity remained for more than 12 days. In addition, the chlorpyrifos ethyl treatments had a significant impact on the survival and growth rates of climbing perch fingerlings, which were proportional to the exposure levels. The results indicate that the high use of pesticides among rice farmers in the Mekong Delta could have a negative impact on aquatic organisms and fish yields, with implications for the aquatic biodiversity, local people's livelihoods and the aquaculture industry in the Mekong Delta.

  8. Climbing.

    ERIC Educational Resources Information Center

    Vignola, H. George

    Goals and objectives, student activities, and a detailed course evaluation are provided in this guide for an English unit in which a rock climb serves as the basis for learning about different forms of literature and improving written and oral communication skills. The unit, designed to give below-average students an opportunity for success in…

  9. The complete mitochondrial genome of the Anabas testudineus (Perciformes, Anabantidae) and its comparison with other related fish species.

    PubMed

    Behera, Bijay Kumar; Baisvar, Vishwamitra Singh; Kumari, Kavita; Rout, Ajaya Kumar; Pakrashi, Sudip; Paria, Prasenjet; Rao, A R; Rai, Anil

    2017-03-01

    In the present study, the complete mitochondrial genome sequence of Anabas testudineusis reported using PGM sequencer (Ion Torrent, Life Technologies, La Jolla, CA). The complete mitogenome of climbing perch, A. testudineusis obtained by the de novo sequences assembly of genomic reads using the Torrent Mapping Alignment Program (TMAP), which is 16 603 bp in length. The mitogenome of A. testudineus composed of 13 protein- coding genes, two rRNA, and 22 tRNAs. Here, 20 tRNAs genes showed typical clover leaf model, and D-Loop as the control region along with gene order and organization, being closely similar to Osphronemidae and most of other Perciformes fish mitogenomes of NCBI databases. The mitogenome in the present study has 99% similarity to the complete mitogenome sequence of earlier reported A. testudineus. The phylogenetic analysis of Anabantidae depicted that their mitogenomes are closely related to each other. The complete mitogenome sequence of A. testudineus would be helpful in understanding the population genetics, phylogenetics, and evolution of Anabantidae.

  10. Roles of three branchial Na(+)-K(+)-ATPase α-subunit isoforms in freshwater adaptation, seawater acclimation, and active ammonia excretion in Anabas testudineus.

    PubMed

    Ip, Yuen K; Loong, Ai M; Kuah, Jie S; Sim, Eugene W L; Chen, Xiu L; Wong, Wai P; Lam, Siew H; Delgado, Inês L S; Wilson, Jonathan M; Chew, Shit F

    2012-07-01

    Three Na(+)-K(+)-ATPase (nka) α-subunit isoforms, nka α1a, nka α1b, and nka α1c, were identified from gills of the freshwater climbing perch Anabas testudineus. The cDNA sequences of nka α1a and nka α1b consisted of 3,069 bp, coding for 1,023 amino acids, whereas nka α1c was shorter by 22 nucleotides at the 5' end. In freshwater, the quantity of nka α1c mRNA transcripts present in the gills was the highest followed by nka α1a and nka α1b that was almost undetectable. The mRNA expression of nka α1a was downregulated in the gills of fish acclimated to seawater, indicating that it could be involved in branchial Na(+) absorption in a hypoosmotic environment. By contrast, seawater acclimation led to an upregulation of the mRNA expression of nka α1b and to a lesser extent nka α1c, indicating that they could be essential for ion secretion in a hyperosmotic environment. More importantly, ammonia exposure led to a significant upregulation of the mRNA expression of nka α1c, which might be involved in active ammonia excretion. Both seawater acclimation and ammonia exposure led to significant increases in the protein abundance and changes in the kinetic properties of branchial Na(+)-K(+)-ATPase (Nka), but they involved two different types of Nka-immunoreactive cells. Since there was a decrease in the effectiveness of NH(4)(+) to substitute for K(+) to activate branchial Nka from fish exposed to ammonia, Nka probably functioned to remove excess Na(+) and to transport K(+) instead of NH(4)(+) into the cell to maintain intracellular Na(+) and K(+) homeostasis during active ammonia excretion.

  11. Technical Tree Climbing.

    ERIC Educational Resources Information Center

    Jenkins, Peter

    Tree climbing offers a safe, inexpensive adventure sport that can be performed almost anywhere. Using standard procedures practiced in tree surgery or rock climbing, almost any tree can be climbed. Tree climbing provides challenge and adventure as well as a vigorous upper-body workout. Tree Climbers International classifies trees using a system…

  12. Reducing Rock Climbing Risks.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1998-01-01

    Provides checklists that can be used as risk-management tools to evaluate rock-climbing programs: developing goals, policies, and procedures; inspecting the climbing environment; maintaining and inspecting equipment; protecting participants; and managing staff (hiring, training, retraining, and evaluating) and campers (experience level, needs, and…

  13. Lifting as You Climb

    ERIC Educational Resources Information Center

    Sullivan, Debra R.

    2009-01-01

    This article addresses leadership themes and answers leadership questions presented to "Exchange" by the Panel members who attended the "Exchange" Panel of 300 Reception in Dallas, Texas, last November. There is an old proverb that encourages people to lift as they climb: "While you climb a mountain, you must not forget others along the way." With…

  14. The Rock Climbing Teaching Guide.

    ERIC Educational Resources Information Center

    Kudlas, John

    The product of 10 years of rock climbing instruction, this guide provides material from which an instructor can teach basic climbing concepts and safety skills as well as conduct a safe, enjoyable rock climbing class in a high school setting. It is designed for an instructor with limited experience in climbing; however, the need for teacher…

  15. The Social Climbing Game

    NASA Astrophysics Data System (ADS)

    Bardoscia, Marco; De Luca, Giancarlo; Livan, Giacomo; Marsili, Matteo; Tessone, Claudio J.

    2013-05-01

    The structure of societies depends, to some extent, on the incentives of the individuals they are composed of. We study a stylized model of this interplay, that suggests that the more individuals aim at climbing the social hierarchy, the more society's hierarchy gets strong. Such a dependence is sharp, in the sense that a persistent hierarchical order emerges abruptly when the preference for social status gets larger than a threshold. This phase transition has its origin in the fact that the presence of a well defined hierarchy allows agents to climb it, thus reinforcing it, whereas in a "disordered" society it is harder for agents to find out whom they should connect to in order to become more central. Interestingly, a social order emerges when agents strive harder to climb society and it results in a state of reduced social mobility, as a consequence of ergodicity breaking, where climbing is more difficult.

  16. Minimalistic Dynamic Climbing

    DTIC Science & Technology

    2010-11-01

    The motion of these dynamic robots resembles the motion of an athlete jumping and climbing inside a chute. Whereas this environment might be an...namic robots resembles the motion of an athlete jumping and climbing inside a chute. Whereas this environment might be an unnavigable obstacle for a slow...122 5.10 Mean Jumps To Failure (MJTF) vs. leg retraction ζ̂0. . . . . . . . . . . . . . . . 123 5.11

  17. Escape tactics and effects of perch height and habituation on flight initiation distance in two Jamaican anoles (Squamata: polychrotidae).

    PubMed

    Cooper, William E

    2010-12-01

    Escape by Anolis lizards is influenced by microhabitats and fight initiation distance increases with predation risk. Differences in microhabitat use among ecomorphs affect escape behavior, but only two studies have reported ecomorphological differences in flight initiation distance among Greater Antillean species. I studied effects of predation risk and microhabitats on escape behavior by conducting field experiments using two species of anoles, Anolis lineatopus and A. grahami, on the campus of the University of the West Indies at Mona, Jamaica. Because ecomorphological variation of anoles has evolved independently within each island of the Greater Antilles, but relationships between ecomorphs and escape behaviors are poorly known, I characterized microhabitat use and escape tactics, and determined relationships between flight initiation distance and two risk factors, habituation to human presence and perch height, in Anolis lineatopus, a trunk-ground anole and A. grahami, a trunk-crown anole. Sample sizes for A. lineatopus and A. grahami were 214 and 93, for microhabitat use and escape destinations, 74 and 34 for human presence and 125 and 34 for perch height. The two species occurred in similar microhabitats and exhibited similar escape tactics, but exhibited key differences expected for their ecomorphs. Both species were sighted frequently on the ground and on trees, but A. lineatopus were more frequently on ground and were perched lower than A. grahami. Both species escaped from ground to trees and when on trees hid on far sides and escaped without changing climbing direction with equal frequency. The frequency of fleeing upward was greater for A. grahami than A. lineatopus. Both species exhibited habituation by having shorter flight initiation distances in areas with more frequent exposure to people. In both species flight initiation distance increased as perch height decreased because, lizards had to climb farther to be out of reach when perched lower. The

  18. Perching aerodynamics and trajectory optimization

    NASA Astrophysics Data System (ADS)

    Wickenheiser, Adam; Garcia, Ephrahim

    2007-04-01

    Advances in smart materials, actuators, and control architecture have enabled new flight capabilities for aircraft. Perching is one such capability, described as a vertical landing maneuver using in-flight shape reconfiguration in lieu of high thrust generation. A morphing, perching aircraft design is presented that is capable of post stall flight and very slow landing on a vertical platform. A comprehensive model of the aircraft's aerodynamics, with special regard to nonlinear affects such as flow separation and dynamic stall, is discussed. Trajectory optimization using nonlinear programming techniques is employed to show the effects that morphing and nonlinear aerodynamics have on the maneuver. These effects are shown to decrease the initial height and distance required to initiate the maneuver, reduce the bounds on the trajectory, and decrease the required thrust for the maneuver. Perching trajectories comparing morphing versus fixed-configuration and stalled versus un-stalled aircraft are presented. It is demonstrated that a vertical landing is possible in the absence of high thrust if post-stall flight capabilities and vehicle reconfiguration are utilized.

  19. Accreditation for Indoor Climbing Facilities.

    ERIC Educational Resources Information Center

    Mayfield, Peter

    To ensure that the rapidly growing climbing gym industry maintains the excellent safety record established so far, the Climbing Gym Association (CGA) has developed the Peer Review and Accreditation Program, a process of review between qualified and experienced CGA reviewers and a climbing facility operator to assess the facility's risk management…

  20. Multiscale Theory of Dislocation Climb.

    PubMed

    Geslin, Pierre-Antoine; Appolaire, Benoît; Finel, Alphonse

    2015-12-31

    Dislocation climb is a ubiquitous mechanism playing a major role in the plastic deformation of crystals at high temperature. We propose a multiscale approach to model quantitatively this mechanism at mesoscopic length and time scales. First, we analyze climb at a nanoscopic scale and derive an analytical expression of the climb rate of a jogged dislocation. Next, we deduce from this expression the activation energy of the process, bringing valuable insights to experimental studies. Finally, we show how to rigorously upscale the climb rate to a mesoscopic phase-field model of dislocation climb. This upscaling procedure opens the way to large scale simulations where climb processes are quantitatively reproduced even though the mesoscopic length scale of the simulation is orders of magnitude larger than the atomic one.

  1. Influence of perched groundwater on base flow

    USGS Publications Warehouse

    Niswonger, R.G.; Fogg, G.E.

    2008-01-01

    Analysis with a three-dimensional variably saturated groundwater flow model provides a basic understanding of the interplay between streams and perched groundwater. A simplified, layered model of heterogeneity was used to explore these relationships. Base flow contribution from perched groundwater was evaluated with regard to varying hydrogeologic conditions, including the size and location of the fine-sediment unit and the hydraulic conductivity of the fine-sediment unit and surrounding coarser sediment. Simulated base flow was sustained by perched groundwater with a maximum monthly discharge in excess of 15 L/s (0.6 feet3/s) over the length of the 2000-m stream reach. Generally, the rate of perched-groundwater discharge to the stream was proportional to the hydraulic conductivity of sediment surrounding the stream, whereas the duration of discharge was proportional to the hydraulic conductivity of the fine-sediment unit. Other aspects of the perched aquifer affected base flow, such as the depth of stream penetration and the size of the fine-sediment unit. Greater stream penetration decreased the maximum base flow contribution but increased the duration of contribution. Perched groundwater provided water for riparian vegetation at the demand rate but reduced the duration of perched-groundwater discharge nearly 75%. Copyright 2008 by the American Geophysical Union.

  2. Tri-iodothyronine alters superoxide dismutase expression in a teleost Anabas testudineus.

    PubMed

    Sreejith, P; Oommen, O V

    2008-12-01

    The effect of tri-iodothyronine (T3) on superoxide dismutase (SOD) expression was evaluated in a teleost Anabas testudineus (cuthyroid fish) by native gel eletrophoresis and Western blot analysis. SOD is an essential enzyme for the survival of oxygen-utilizing organisms. Its expression is altered by the stress, presumably due to the increase in concentration of superoxide radical in cells. Variations of thyroid honnone levels are the major physiological modulators of cellular oxidative stress. T3 administration generates an oxidative stress, which to some extent is neutralized by the changed activity of enzymes like SOD. T3 treatment decreased CuZn SOD density in liver and brain of A. testudineus. The activity of CuZn SOD in liver and brain was confirmed by native gel analysis. The different physiological states of thyroid influenced the CuZn SOD activity. Western blot analysis further confirmed that liver and brain CuZn SOD decreased after T3 treatment. From these findings, it was clear that T3 treatment in euthyroid fish created an oxidative stress condition and thyroid hormone effectively maintained antioxidant status to overcome this situation in teleosts.

  3. Triiodothyronine and melatonin influence antioxidant defense mechanism in a teleost Anabas testudineus (Bloch): in vitro study.

    PubMed

    Sreejith, P; Beyo, R S; Divya, L; Vijayasree, A S; Manju, M; Oommen, O V

    2007-06-01

    The effect of the hormones triiodothyronine (T3) and melatonin on antioxidant defense system was studied in 6-propyl thiouracil (6-PTU)-treated or photoperiod-exposed teleost Anabas testudineus. 6-PTU (2 microg/g) treatment or photoperiod exposure (24 h) increased malondialdehyde (MDA) and conjugated dienes (CD) concentrations, indicating increased lipid peroxidation (LPO) in the experimental conditions. T3 or melatonin (10(-6) M) treatment for 15 min in vitro in PTU-treated fish reversed the activity of superoxide dismutase (SOD), catalase and glutathione content. T3-treated group showed no change in glutathione peroxidase (GPx) activity, whereas melatonin treatment decreased its activity. T3 inhibited glutathione reductase (GR) activity. Photoperiod exposure (physiological pinealotomy) induced a stressful situation in this teleost, as evidenced by LPO products and antioxidant enzyme activities. Melatonin and T3 treatment for 15 min in vitro also reversed the effect of photoperiod on peroxidation products and the SOD and catalase activities. GR activity decreased in photoperiod-exposed group and melatonin and T3 treatment reversed the activities. The antioxidant enzymes responded to the stress situation after 6-PTU treatment and photoperiod exposure by altering their activities. The study suggested an independent effect of T3 and melatonin on antioxidant defence mechanism in different physiological situations in fish.

  4. Preparticipation Evaluation for Climbing Sports.

    PubMed

    Campbell, Aaron D; Davis, Christopher; Paterson, Ryan; Cushing, Tracy A; Ng, Pearlly; Peterson, Charles S; Sedgwick, Peter E; McIntosh, Scott E

    2015-12-01

    Climbing is a popular wilderness sport among a wide variety of professional athletes and amateur enthusiasts, and many styles are performed across many environments. Potential risks confront climbers, including personal health or exacerbation of a chronic condition, in addition to climbing-specific risks or injuries. Although it is not common to perform a preparticipation evaluation (PPE) for climbing, a climber or a guide agency may request such an evaluation before participation. Formats from traditional sports PPEs can be drawn upon, but often do not directly apply. The purpose of this article was to incorporate findings from expert opinion from professional societies in wilderness medicine and in sports medicine, with findings from the literature of both climbing epidemiology and traditional sports PPEs, into a general PPE that would be sufficient for the broad sport of climbing. The emphasis is on low altitude climbing, and an overview of different climbing styles is included. Knowledge of climbing morbidity and mortality, and a standardized approach to the PPE that involves adequate history taking and counseling have the potential for achieving risk reduction and will facilitate further study on the evaluation of the efficacy of PPEs.

  5. Preparticipation Evaluation for Climbing Sports.

    PubMed

    Campbell, Aaron D; Davis, Christopher; Paterson, Ryan; Cushing, Tracy A; Ng, Pearlly; Peterson, Charles S; Sedgwick, Peter E; McIntosh, Scott E

    2015-09-01

    Climbing is a popular wilderness sport among a wide variety of professional athletes and amateur enthusiasts, and many styles are performed across many environments. Potential risks confront climbers, including personal health or exacerbation of a chronic condition, in addition to climbing-specific risks or injuries. Although it is not common to perform a preparticipation evaluation (PPE) for climbing, a climber or a guide agency may request such an evaluation before participation. Formats from traditional sports PPEs can be drawn upon, but often do not directly apply. The purpose of this article was to incorporate findings from expert opinion from professional societies in wilderness medicine and in sports medicine, with findings from the literature of both climbing epidemiology and traditional sports PPEs, into a general PPE that would be sufficient for the broad sport of climbing. The emphasis is on low altitude climbing, and an overview of different climbing styles is included. Knowledge of climbing morbidity and mortality, and a standardized approach to the PPE that involves adequate history taking and counseling have the potential for achieving risk reduction and will facilitate further study on the evaluation of the efficacy of PPEs.

  6. Tree climbing and human evolution

    PubMed Central

    Venkataraman, Vivek V.; Kraft, Thomas S.; Dominy, Nathaniel J.

    2013-01-01

    Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion in museum specimens of climbing hunter–gatherers from the Ituri forest, we did find that climbing by the Twa is associated with longer fibers in the gastrocnemius muscle relative to those of neighboring, nonclimbing agriculturalists. This result suggests that a more excursive calf muscle facilitates climbing with a bipedally adapted ankle and foot by positioning the climber closer to the tree, and it might be among the mechanisms that allow hunter–gatherers to access the canopy safely. Given that we did not find a skeletal correlate for this observed behavior, our results imply that derived aspects of the hominin ankle associated with bipedalism remain compatible with vertical climbing and arboreal resource acquisition. Our findings challenge the persistent arboreal–terrestrial dichotomy that has informed behavioral reconstructions of fossil hominins and highlight the value of using modern humans as models for inferring the limits of hominin arboreality. PMID:23277565

  7. The physiology of rock climbing.

    PubMed

    Giles, Luisa V; Rhodes, Edward C; Taunton, Jack E

    2006-01-01

    In general, elite climbers have been characterised as small in stature, with low percentage body fat and body mass. Currently, there are mixed conclusions surrounding body mass and composition, potentially because of variable subject ability, method of assessment and calculation. Muscular strength and endurance in rock climbers have been primarily measured on the forearm, hand and fingers via dynamometry. When absolute hand strength was assessed, there was little difference between climbers and the general population. When expressed in relation to body mass, elite-level climbers scored significantly higher, highlighting the potential importance of low body mass. Rock climbing is characterised by repeated bouts of isometric contractions. Hand grip endurance has been measured by both repeated isometric contractions and sustained contractions, at a percentage of maximum voluntary contraction. Exercise times to fatigue during repeated isometric contractions have been found to be significantly better in climbers when compared with sedentary individuals. However, during sustained contractions until exhaustion, climbers did not differ from the normal population, emphasising the importance of the ability to perform repeated isometric forearm contractions without fatigue becoming detrimental to performance. A decrease in handgrip strength and endurance has been related to an increase in blood lactate, with lactate levels increasing with the angle of climbing. Active recovery has been shown to provide a better rate of recovery and allows the body to return to its pre-exercised state quicker. It could be suggested that an increased ability to tolerate and remove lactic acid during climbing may be beneficial. Because of increased demand placed upon the upper body during climbing of increased difficulty, possessing greater strength and endurance in the arms and shoulders could be advantageous. Flexibility has not been identified as a necessary determinant of climbing success

  8. Imaging of rock climbing injuries.

    PubMed

    Martinoli, Carlo; Bianchi, Stefano; Cotten, Anne

    2005-12-01

    Competition climbing has grown increasingly in popularity, and many people are being drawn to this sport with a parallel increase in the occurrence of sport-related injuries. One of the most common and unique lesions occurring in the rock climbing population is the closed rupture of the flexor pulley system of the fingers. This lesion is strictly related to some climbing techniques in which the entire body weight is placed on fingerholds, which causes bowstringing of the flexor tendons with subsequent loss of strength across the full range of motion of the finger. This article summarizes the current literature regarding the application of imaging modalities in the diagnosis of rock climbing injuries with a specific focus on ultrasound and magnetic resonance imaging. Biomechanics of the sporting activity and resultant pathophysiologic and clinical considerations concerning flexor pulley system injuries are also discussed.

  9. The effect of predation on stunted and nonstunted white perch

    USGS Publications Warehouse

    Gosch, N.J.C.; Pierce, L.L.; Pope, K.L.

    2010-01-01

    Predation is widely regarded as a means to prevent or minimise the establishment of a stunted (high density of slow growing individuals) population. We investigated the effect of predation on two different white perch Morone americana populations (stunted and nonstunted) by examining the stomach contents of piscivorous fishes. White perch and gizzard shad dominated piscivore diets in Branched Oak Lake, whereas white perch dominated piscivore diets in Pawnee Lake. White perch consumed in the stunted population (Branched Oak Lake) were larger and older than white perch consumed in the nonstunted population (Pawnee Lake). Many of the consumed white perch in the stunted population were sexually mature and had the opportunity to spawn at least once. In contrast, all of the consumed white perch in the nonstunted population were sexually immature. Predation may have reinforced the stunting of white perch in Branched Oak Lake through removal of the largest, oldest individuals. ?? 2010 John Wiley & Sons A/S.

  10. Habitat Suitability Index Models: Yellow perch

    USGS Publications Warehouse

    Krieger, Douglas A.; Terrell, James W.; Nelson, Patrick C.

    1983-01-01

    A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for yellow perch (Perca flavescens). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for riverine, lacustrine, and palustrine habitat in the 48 contiguous United States. Habitat Suitability Indexes (HSI's) are designed for use with the Habitat Evaluation Procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of yellow perch habitat.

  11. Physiology of difficult rock climbing.

    PubMed

    Watts, Phillip B

    2004-04-01

    The purpose of this review is to explore existing research on the physiological aspects of difficult rock climbing. Findings will be categorized into the areas of an athlete profile and an activity model. An objective here is to describe high-level climbing performance; thus the focus will primarily be on studies that involve performances at the 5.11/6c (YDS/French) level of difficulty or higher. Studies have found climbers to be small in stature with low body mass and low body fat. Although absolute strength values are not unusual, strength to body mass ratio is high in accomplished climbers. There is evidence that muscular endurance and high upper body power are important. Climbers do not typically possess extremely high aerobic power, typically averaging between 52-55 ml.kg(-1).min(-1) for maximum oxygen uptake. Performance time for a typical ascent ranges from 2 to 7 min and oxygen uptake (VO2) averages around 20-25 ml.kg(-1).min(-1) over this period. Peaks of over 30 ml.kg(-1).min(-1) for VO2 have been reported. VO2 tends to plateau during sustained climbing yet remains elevated into the post-climb recovery period. Blood lactate accumulates during ascent and remains elevated for over 20 min post-climbing. Handgrip endurance decreases to a greater degree than handgrip strength with severe climbing. On the basis of this review, it appears that a specific training program for high-level climbing would include components for developing high, though not elite-level, aerobic power; specific muscular strength and endurance; ATP-PC and anaerobic glycolysis system power and capacity; and some minimum range of motion for leg and arm movements.

  12. Biomechanics of climbing palms and how they climb.

    PubMed

    Rowe, Nick; Isnard, Sandrine

    2009-09-01

    Climbing plants have fascinated botanists since the pioneering works of Darwin and his contemporaries in the 19(th) century. Diverse plants have evolved different ways of climbing and a wide range of attachment devices and stem biomechanics to cope with the particular physical demands of life as a climber. We investigated the biomechanics of attachment in a range of climbing palms, including true rattans from Southeast Asia and the genus Desmoncus from South America. We found that hook strength and orientation is coordinated with rachis geometry and rigidity. These findings support the notion of a ratchet-type attachment mechanism and partly explain why these spiny plants are so catchy and efficient at attaching to supports.

  13. Nile perch: the great lake experiment.

    PubMed

    Ogutu-ohwayo, R

    1998-01-01

    In order to improve the fishery of Lake Victoria, a large predatory fish, the Nile perch (Lates niloticus), was introduced into the lake to feed on the smaller but abundant haplochromines, thereby producing a larger fish for food consumption. Originally the lake had a very high fish species diversity, dominated by more than 300 species of haplochromine cichlids; however, they were too small to be exploited for food. It took about 20 years for the population of the Nile perch in the lake to increase significantly. Although increased fish production has benefited riparian communities by providing revenue, employment, and food, the introduction of the Nile perch has also resulted in extinction and has transformed the lake ecosystem. In response to the concern caused by the introduction of the Nile perch, the deteriorating water quality, and the need to sustain the lucrative fishery, the governments of Uganda, Kenya, and Tanzania have initiated the multisectoral Lake Victoria Environment Management Programme. Its goals are to control the loading of nutrients and contaminants into the lake, manage land use in the catchment area, manage the introduced fish species, conserve biodiversity, and control the spread of water hyacinths.

  14. Climbing techniques for bridge inspection

    NASA Astrophysics Data System (ADS)

    Kaslan, Erol C.

    1998-03-01

    California has about 24,000 publicly owned bridges that require routine structural evaluations to comply with National Bridge Inspection Standard (NBIS) mandates. Of these, about 800 are identified as possessing fatigue prone or fracture critical details requiring thorough tactile investigations. Gaining access to bridge elements to perform these investigations has become increasingly difficult and costly. The traditional uses of under bridge inspection trucks, lift equipment and rigging are economically and practically limited by bridge size, structure type, traffic demands and support costs. In some cases, bridges that have become damaged by earthquakes cannot safely support the loads of heavy personnel lift equipment. The California Department of Transportation (Caltrans)'s Office of Structural Materials and Office of Structure Maintenance and Investigations evaluated the use of rock climbing and mountaineering techniques as an alternative means of gaining access for bridge inspections. Under a small research grant, a bridge climbing training course was developed through a local University of California outdoor recreation group and 7 engineers and technicians were initially trained. A comprehensive Code of Safe Practices was created and standards of training, procedures and equipment required for bridge inspections were established. A successful climb investigation on a large, previously inaccessible arch bridge was completed at the end of the training that proved the techniques safe, economical and effective. Within one year, 20 bridge maintenance engineers were trained, and a formal program was established to organize, schedule, equip and certify engineers and technicians for bridge climbing. Several other offices within Caltrans as well as the California Department of Water Resources have since adopted these techniques for specialized structural inspection tasks. Climbing techniques are now used routinely in California as an alterative means of gaining access

  15. Climbing Walls and Climbing Tuitions. A Delta Perspective

    ERIC Educational Resources Information Center

    Kirshstein, Rita J.; Kadamus, James A.

    2012-01-01

    High-end amenities like rock climbing walls on college campuses have become an easy target for those attempting to explain rising tuitions. This Delta Perspective looks beyond the media attention surrounding these "frills" to examine more serious questions about spending on campus facilities, college spending in general, and the real drivers of…

  16. Re-Establishing a Clean Climbing Ethic.

    ERIC Educational Resources Information Center

    Attarian, Aram

    This paper addresses environmental impact issues associated with rock climbing and stresses the importance of reestablishing a clean climbing ethic through climber education and ethical considerations. The adventure sport of rock climbing has grown considerably over the last decade: it is estimated that there are currently over 200,000 rock…

  17. 14 CFR 23.63 - Climb: General.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Climb: General. 23.63 Section 23.63... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.63 Climb... revised text is set forth as follows: § 23.63 Climb: General. (c) For reciprocating...

  18. Ben-Hur Staircase Climbs

    ERIC Educational Resources Information Center

    Dodge, John; Simoson, Andrew

    2012-01-01

    How many ways may one climb an even number of stairs so that left and right legs are exercised equally, that is, both legs take the same number of strides, take the same number of total stairs, and take strides of either 1 or 2 stairs at a time? We characterize the solution with a difference equation and find its generating function.

  19. Acoustic Climb to Cruise Test

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Flight test film footage of three different aircraft testing the acoustical noise levels during take-off, climb, maneuvers, and touch and go landings are described. These sound tests were conducted on two fighter aircraft and one cargo aircraft. Results from mobile test vehicle are shown.

  20. The physiological effect of a 'climb assist' device on vertical ladder climbing.

    PubMed

    Barron, Peter James; Burgess, Katherine; Cooper, Kay; Stewart, Arthur D

    2016-10-15

    'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O2 and rate of perceived exertion (RPE). All three variables decreased significantly (p < 0.05) with climb assist with [Formula: see text]O2 decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O2 decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O2, HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O2, HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

  1. Longitudinal dynamics of a perching aircraft concept

    NASA Astrophysics Data System (ADS)

    Wickenheiser, Adam; Garcia, Ephrahim; Waszak, Martin

    2005-05-01

    This paper introduces a morphing aircraft concept whose purpose is to demonstrate a new bio-inspired flight capability: perching. Perching is a maneuver that utilizes primarily aerodynamics -- as opposed to thrust generation -- to achieve a vertical or short landing. The flight vehicle that will accomplish this is described herein with particular emphasis on its addition levels of actuation beyond the traditional aircraft control surfaces. A computer model of the aircraft is developed in order to predict the changes in applied aerodynamic loads as it morphs and transitions through different flight regimes. The analysis of this model is outlined, including a lifting-line-based analytical technique and a trim and stability analysis. These analytical methods -- compared to panel or computational fluid dynamics (CFD) methods -- are considered desirable for the analysis of a large number of vehicle configurations and flight conditions. The longitudinal dynamics of this aircraft are studied, and several interesting results are presented. Of special interest are the changes in vehicle dynamics as the aircraft morphs from a cruise configuration to initiate the perching maneuver. Changes in trim conditions and stability are examined as functions of vehicle geometry. The time response to changes in vehicle configuration is also presented.

  2. Perch use by laying hens in a commercial aviary1

    PubMed Central

    Campbell, D. L. M.; Makagon, M. M.; Swanson, J. C.; Siegford, J. M.

    2016-01-01

    Non-cage housing systems, such as the aviary, are being implemented by the laying hen industry, including in North America, in an attempt to improve the welfare of hens. Perches are a resource that is consistently included in aviaries. Hens are strongly motivated to perch, and perching can improve leg bone strength. However, hens may prefer elevated perches, particularly at night, and thus simply providing perches is not enough to improve welfare; they must be provided in a way that allows all hens to access them. Observations of laying hens using perches and ledges (flat, solid metal shelves to assist hens’ movement between tiers) in a commercial aviary revealed variation in where hens roosted within the tiered aviary enclosure across the flock cycle (peak, mid and end of lay; P < 0.001 for all age points). Hens most often preferred roosting in the highest enclosure levels, leading to crowding on upper perches and ledges while perch space remained available on lower levels. Restricted access to preferable perches may cause frustration in hens, leading to welfare issues. Hens roosted more on perches at peak lay than mid and end lay (P < 0.001) but roosted less on ledges at peak lay than mid and end lay (P < 0.001). Additionally, more hens roosted on both perches and ledges in the ‘dark’ observation period compared with the number of hens roosting during the ‘light’ observation period (P < 0.001). Further research should look at all structural elements within the system that are used by hens for roosting, such as edges of tiers and upper wire floors, to evaluate how changes in perching preferences across the lay cycle may correlate with system design and bird-based parameters. PMID:26994206

  3. Altitude transitions in energy climbs

    NASA Technical Reports Server (NTRS)

    Weston, A. R.; Cliff, E. M.; Kelley, H. J.

    1982-01-01

    The aircraft energy-climb trajectory for configurations with a sharp transonic drag rise is well known to possess two branches in the altitude/Mach-number plane. Transition in altitude between the two branches occurs instantaneously, a 'corner' in the minimum-time solution obtained with the energy-state model. If the initial and final values of altitude do not lie on the energy-climb trajectory, then additional jumps (crude approximations to dives and zooms) are required at the initial and terminal points. With a singular-perturbation approach, a 'boundary-layer' correction is obtained for each altitude jump, the transonic jump being a so-called 'internal' boundary layer, different in character from the initial and terminal layers. The determination of this internal boundary layer is examined and some computational results for an example presented.

  4. Multiple-Segment Climbing Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James; May, Edward; Eklund, Wayne

    1994-01-01

    Multiple-segment climbing robots developed to perform such tasks as inspection, sandblasting, welding, and painting on towers and other structures. Look and move like caterpillars. Video camera mounted on one of segments rotated to desired viewing angle. Used in remote inspection of structure, to view motion of robot and/or provides video feedback for control of motion, and/or to guide operation of head mounted on foremost segment with motorized actuators.

  5. The role of vision in perching and grasping for MAVs

    NASA Astrophysics Data System (ADS)

    Thomas, Justin; Loianno, Giuseppe; Daniilidis, Kostas; Kumar, Vijay

    2016-05-01

    In this work, we provide an overview of vision-based control for perching and grasping for Micro Aerial Vehicles. We investigate perching on at, inclined, or vertical surfaces as well as visual servoing techniques for quadrotors to enable autonomous perching by hanging from cylindrical structures using only a monocular camera and an appropriate gripper. The challenges of visual servoing are discussed, and we focus on the problems of relative pose estimation, control, and trajectory planning for maneuvering a robot with respect to an object of interest. Finally, we discuss future challenges to achieve fully autonomous perching and grasping in more realistic scenarios.

  6. Field Verification of Stable Perched Groundwater in Layered Bedrock Uplands

    USGS Publications Warehouse

    Carter, J.T.; Gotkowitz, M.B.; Anderson, M.P.

    2011-01-01

    Data substantiating perched conditions in layered bedrock uplands are rare and have not been widely reported. Field observations in layered sedimentary bedrock in southwestern Wisconsin, USA, provide evidence of a stable, laterally extensive perched aquifer. Data from a densely instrumented field site show a perched aquifer in shallow dolomite, underlain by a shale-and-dolomite aquitard approximately 25 m thick, which is in turn underlain by sandstone containing a 30-m-thick unsaturated zone above a regional aquifer. Heads in water supply wells indicate that perched conditions extend at least several kilometers into hillsides, which is consistent with published modeling studies. Observations of unsaturated conditions in the sandstone over a 4-year period, historical development of the perched aquifer, and perennial flow from upland springs emanating from the shallow dolomite suggest that perched groundwater is a stable hydrogeologic feature under current climate conditions. Water-table hydrographs exhibit apparent differences in the amount and timing of recharge to the perched and regional flow systems; steep hydraulic gradients and tritium and chloride concentrations suggest there is limited hydraulic connection between the two. Recognition and characterization of perched flow systems have practical importance because their groundwater flow and transport pathways may differ significantly from those in underlying flow systems. Construction of multi-aquifer wells and groundwater withdrawal in perched systems can further alter such pathways. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  7. Field verification of stable perched groundwater in layered bedrock uplands.

    PubMed

    Carter, Jonathon T V; Gotkowitz, Madeline B; Anderson, Mary P

    2011-01-01

    Data substantiating perched conditions in layered bedrock uplands are rare and have not been widely reported. Field observations in layered sedimentary bedrock in southwestern Wisconsin, USA, provide evidence of a stable, laterally extensive perched aquifer. Data from a densely instrumented field site show a perched aquifer in shallow dolomite, underlain by a shale-and-dolomite aquitard approximately 25 m thick, which is in turn underlain by sandstone containing a 30-m-thick unsaturated zone above a regional aquifer. Heads in water supply wells indicate that perched conditions extend at least several kilometers into hillsides, which is consistent with published modeling studies. Observations of unsaturated conditions in the sandstone over a 4-year period, historical development of the perched aquifer, and perennial flow from upland springs emanating from the shallow dolomite suggest that perched groundwater is a stable hydrogeologic feature under current climate conditions. Water-table hydrographs exhibit apparent differences in the amount and timing of recharge to the perched and regional flow systems; steep hydraulic gradients and tritium and chloride concentrations suggest there is limited hydraulic connection between the two. Recognition and characterization of perched flow systems have practical importance because their groundwater flow and transport pathways may differ significantly from those in underlying flow systems. Construction of multi-aquifer wells and groundwater withdrawal in perched systems can further alter such pathways.

  8. Injury risk evaluation in sport climbing.

    PubMed

    Neuhof, A; Hennig, F F; Schöffl, I; Schöffl, V

    2011-10-01

    The aim of this study was to quantify and rate acute sport climbing injuries. Acute sport climbing injuries occurring from 2002 to 2006 were retrospectively assessed with a standardized web based questionnaire. A total number of 1962 climbers reported 699 injuries, which is equivalent to 0.2 injuries per 1 000 h of sport participation. Most (74.4%) of the injuries were of minor severity rated NACA I or NACA II. Injury distribution between the upper (42.6%) and lower extremities (41.3%) was similar, with ligament injuries, contusions and fractures being the most common injury types. Years of climbing experience (p<0.01), difficulty level (p<0.01), climbing time per week during summer (p<0.01) and winter (p<0.01) months were correlated with the injury rate. Age (p<0.05 (p=0.034)), years of climbing experience (p<0.01) and average climbing level (p<0.01) were correlated to the injury severity rated through NACA scores. The risk of acute injuries per 1 000 h of sport participation in sport climbing was lower than in previous studies on general rock climbing and higher than in studies on indoor climbing. In order to perform inter-study comparisons of future studies on climbing injuries, the use of a systematic and standardized scoring system (UIAA score) is essential.

  9. Perching Experiment at Low Reynolds Number: Force and PIV Measurements of Rectangular Flat Wing Models in Perching Motion

    DTIC Science & Technology

    2010-11-10

    In this context, the perching motion is modeled according to the wing motions of birds to rapidly reduce velocity when landing on a small spot i.e...is modelled according to the wing motions of birds to rapidly reduce velocity when landing on a small spot i.e. a perch. The here discussed perching...called virtual cams) are exported into the . csv file format. Here, a resolution of 4096 coordinate points is used, which is the maximum capacity of

  10. Controller design for a morphing, perching aircraft

    NASA Astrophysics Data System (ADS)

    Hurst, Allen; Garcia, Ephrahim

    2011-03-01

    This article compares two feedback compensator strategies for the task of guiding a morphing aircraft along a perching trajectory. The aircraft model includes novel, actuated degrees of freedom that allow for bulk movement of some airframe structures. This morphing ability allows the aircraft to perform maneuvers in a manner similar to some birds. The control methods compared in this article are a multi-stage compensator and a linear quadratic regulator. Simulations test the effectiveness of the compensators for initial state error and a trajectory disturbance. In these simulations the linear quadratic regulator outperforms the multi-stage compensator by repeatedly producing smaller state errors and by having lower error standard deviations.

  11. New technology turns wastes into revenue at Indiana perch farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bell Aquaculture is vertically integrated and has closed the perch lifecycle within environmentally friendly land-based closed-containment systems. This means that Bell Aquaculture controls the broodstock, spawning, fry culture, grow-out, and 52 week per year harvest of the perch, plus the fish proc...

  12. Robot Would Climb Steep Terrain

    NASA Technical Reports Server (NTRS)

    Kennedy, Brett; Ganino, Anthony; Aghazarian, Hrand; Hogg, Robert; McHerny, Michael; Garrett, Michael

    2007-01-01

    This brief describes the steep terrain access robot (STAR) -- a walking robot that has been proposed for exploring steep terrain on remote planets. The STAR would be able to climb up or down on slopes as steep as vertical, and even beyond vertical to overhangs. Its system of walking mechanisms and controls would be to react forces and maintain stability. To enable the STAR to anchor itself in the terrain on steep slopes to maintain stability and react forces, it would be necessary to equip the tips of the walking legs with new ultrasonic/ sonic drill corers (USDCs) and to develop sensors and control algorithms to enable robust utilization of the USDCs.

  13. Fibrillar Adhesive for Climbing Robots

    NASA Technical Reports Server (NTRS)

    Pamess, Aaron; White, Victor E.

    2013-01-01

    A climbing robot needs to use its adhesive patches over and over again as it scales a slope. Replacing the adhesive at each step is generally impractical. If the adhesive or attachment mechanism cannot be used repeatedly, then the robot must carry an extra load of this adhesive to apply a fresh layer with each move. Common failure modes include tearing, contamination by dirt, plastic deformation of fibers, and damage from loading/ unloading. A gecko-like fibrillar adhesive has been developed that has been shown useful for climbing robots, and may later prove useful for grasping, anchoring, and medical applications. The material consists of a hierarchical fibrillar structure that currently contains two levels, but may be extended to three or four levels in continuing work. The contacting level has tens of thousands of microscopic fibers made from a rubberlike material that bend over and create intimate contact with a surface to achieve maximum van der Waals forces. By maximizing the real area of contact that these fibers make and minimizing the bending energy necessary to achieve that contact, the net amount of adhesion has been improved dramatically.

  14. Mountaineering and Climbing on Mars

    NASA Astrophysics Data System (ADS)

    Cowing, K. L.

    Initial human missions to Mars will be a precious commodity wherein a maximum amount of information is gathered by each crew. As was the case during innumerable terrestrial missions of exploration, the Martian terrain that visiting crews must traverse in order to gain an understanding will often be difficult. This is accentuated by the fact that Mars is a world of geology - one whose surface area is equal to dry surface on Earth. Human crews will be called upon to use a variety of skills and tools to traverse the Martian surface - including those often associated with hiking, mountaineering and technical climbing. While rovers and other mechanical devices will be employed, it should be assumed that skills commonly associated with rock climbing, caving, and mountaineering on Earth will also be required. This paper looks at the human factors associated with such activity on Mars: space suit design requirements, life support, tools and procedures, traverse planning, logistics issues and navigation. Implications for adaptation of terrestrial gear will be examined as will implications raised by planetary protection. Lessons learned during sorties conducted on the lunar surface during the Apollo program are discussed.

  15. 14 CFR 31.17 - Performance: Climb.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Performance: Climb. 31.17 Section 31.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.17 Performance: Climb. (a) Each balloon must...

  16. 14 CFR 31.17 - Performance: Climb.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Performance: Climb. 31.17 Section 31.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.17 Performance: Climb. (a) Each balloon must...

  17. Three-dimensional formulation of dislocation climb

    NASA Astrophysics Data System (ADS)

    Gu, Yejun; Xiang, Yang; Quek, Siu Sin; Srolovitz, David J.

    2015-10-01

    We derive a Green's function formulation for the climb of curved dislocations and multiple dislocations in three-dimensions. In this new dislocation climb formulation, the dislocation climb velocity is determined from the Peach-Koehler force on dislocations through vacancy diffusion in a non-local manner. The long-range contribution to the dislocation climb velocity is associated with vacancy diffusion rather than from the climb component of the well-known, long-range elastic effects captured in the Peach-Koehler force. Both long-range effects are important in determining the climb velocity of dislocations. Analytical and numerical examples show that the widely used local climb formula, based on straight infinite dislocations, is not generally applicable, except for a small set of special cases. We also present a numerical discretization method of this Green's function formulation appropriate for implementation in discrete dislocation dynamics (DDD) simulations. In DDD implementations, the long-range Peach-Koehler force is calculated as is commonly done, then a linear system is solved for the climb velocity using these forces. This is also done within the same order of computational cost as existing discrete dislocation dynamics methods.

  18. Indoor rock climbing: who gets injured?

    PubMed Central

    Wright, D; Royle, T; Marshall, T

    2001-01-01

    Objectives—To determine the frequency of overuse injury in indoor climbers, the common sites of such injury, and the factors that influence the probability that a climber will have sustained an overuse injury while climbing indoors. Method—A semisupervised questionnaire was used to survey overuse injury in 295 spectators and competitors at the Entre-Prises World Climbing Championships held in Birmingham 3–5 December 1999. Statistical analysis included simple cross tabulations, calculation of odds ratios, and multiple logistic regression to explore the effect of several factors simultaneously. Results—Some 44% of respondents had sustained an overuse injury, 19% at more than one site. The most common site of injury was the fingers. Univariate analysis showed that the probability of having sustained a climbing injury is higher in men (p = 0.009), those who have climbed for more than 10 years (p = 0.006), those who climb harder routes (p<0.0005), and those who boulder or lead more than they top rope (p<0.0005). The relation between lead grade and climbing injury is linear. Multivariate analysis removed the effect of sex as an independent predictor. Conclusions—Many climbers sustain overuse injury. The most at risk are those with the most ability and dedication to climbing. Climbers should be aware of the risk factors that influence injury and be able to spot the signs and symptoms of injury once they occur. Key Words: rock climbing; overuse injury; pulley tendon PMID:11375878

  19. 14 CFR 29.64 - Climb: General.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Climb: General. 29.64 Section 29.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.64 Climb: General. Compliance with...

  20. 14 CFR 29.64 - Climb: General.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Climb: General. 29.64 Section 29.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.64 Climb: General. Compliance with...

  1. 14 CFR 29.64 - Climb: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: General. 29.64 Section 29.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.64 Climb: General. Compliance with...

  2. 14 CFR 29.64 - Climb: General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Climb: General. 29.64 Section 29.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.64 Climb: General. Compliance with...

  3. 14 CFR 29.64 - Climb: General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: General. 29.64 Section 29.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.64 Climb: General. Compliance with...

  4. 14 CFR 31.17 - Performance: Climb.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Performance: Climb. 31.17 Section 31.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.17 Performance: Climb. (a) Each balloon must...

  5. 14 CFR 31.17 - Performance: Climb.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Performance: Climb. 31.17 Section 31.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.17 Performance: Climb. (a) Each balloon must...

  6. 14 CFR 31.17 - Performance: Climb.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Performance: Climb. 31.17 Section 31.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.17 Performance: Climb. (a) Each balloon must...

  7. A kingfisher perches on a branch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A belted kingfisher perches on a twig in the Merritt Island National Wildlife Refuge, which shares a boundary with the Kennedy Space Center. The pigeon-sized, blue-gray male is identified by the blue-gray breast band; females show a chestnut belly band. The belted kingfisher ranges throughout the United States and Canada, wintering south to Panama and the West Indies. They dive into the water for fish and may also take crabs, crayfish, salamanders, lizards, mice and insects. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  8. Evaporative instabilities in climbing films

    NASA Astrophysics Data System (ADS)

    Hosoi, A. E.; Bush, John W. M.

    2001-09-01

    We consider flow in a thin film generated by partially submerging an inclined rigid plate in a reservoir of ethanol or methanol water solution and wetting its surface. Evaporation leads to concentration and surface tension gradients that drive flow up the plate. An experimental study indicates that the climbing film is subject to two distinct instabilities. The first is a convective instability characterized by flattened convection rolls aligned in the direction of flow and accompanied by free-surface deformations; in the meniscus region, this instability gives rise to pronounced ridge structures aligned with the mean flow. The second instability, evident when the plate is nearly vertical, takes the form of transverse surface waves propagating up the plate.

  9. Fit-climbing test: a field test for indoor rock climbing.

    PubMed

    Bertuzzi, Rômulo; Franchini, Emerson; Tricoli, Valmor; Lima-Silva, Adriano E; Pires, Flávio De Oliveira; Okuno, Nilo M; Kiss, Maria A P D M

    2012-06-01

    The aim of this study was to develop an indoor rock-climbing test on an artificial wall (Fit-climbing test). Thirteen climbers (elite group [EG] = 6; recreational group [RG] = 7) performed the following tests: (a) familiarization in the Fit-climbing test, (b) the Fit-climbing test, and (c) a retest to evaluate the Fit-climbing test's reliability. Gas exchange, blood lactate concentration, handgrip strength, and heart rate were measured during the test. Oxygen uptake during the Fit-climbing test was not different between groups (EG = 8.4 ± 1.1 L; RG = 7.9 ± 1.5 L, p > 0.05). The EG performance (120 ± 7 movements) was statistically higher than the RG climbers' performance (78 ± 13 movements) during the Fit-climbing test. Consequently, the oxygen cost per movement during the Fit-climbing test of the EG was significantly lower than that of the RG (p < 0.05). Handgrip strength was higher in the EG when compared with that in the RG in both pre-Fit- and post-Fit-climbing test (p < 0.05). There were no significant differences in any other variables analyzed during the Fit-climbing test (p > 0.05). Furthermore, the performance in the Fit-climbing test presented high reliability (intraclass correlation coefficient = 0.97). Therefore, the performance during the Fit-climbing test may be an alternative to evaluate rock climbers because of its specificity and relation to oxygen cost per movement during climbing.

  10. Correlates of simulated hill climb cycling performance.

    PubMed

    Davison, R C; Swan, D; Coleman, D; Bird, S

    2000-02-01

    The aim of this study was to assess the relationship between several commonly used aerobic and anaerobic cycle ergometer tests and performance during a treadmill cycling hill climb. Eight competitive cyclists (age 27+/-7 years; body mass 73.2+/-5.2 kg; height 177+/-6 cm; mean +/- s) completed six tests in random order: a lactate minimum test; a Wingate anaerobic power test; and two 6-km climbs at 6% and two 1-km climbs at 12% gradient performed on a motorized treadmill. The mean times and power outputs for the 6-km and 1-km climbs were 16:30+/-1:08 min: s and 330+/-17.8 W, and 4:19+/-0:27 min: s and 411+/-24.4 W, respectively. The best individual predictor of 6-km and 1-km performance times was the time for the corresponding climb at the other distance (r = 0.97). The next strongest predictor of both hill climb performances was the average power produced during the Wingate test divided by body mass. Stepwise regression analysis showed that the two variables contributing most to the prediction equation for both climbs were the Wingate average power per unit of body mass and maximal aerobic power divided by total mass (rider + bike), which together accounted for 92 and 96% of the variability in the 6-km and 1-km climbs. In conclusion, among competitive cyclists, the Wingate average power per unit of body mass was the best single predictor of simulated cycling hill climb performance at the distance and gradient used.

  11. Development and evaluation of a SUAS perching system

    NASA Astrophysics Data System (ADS)

    Reynolds, Ryan

    Perching has been proposed as a possible landing technique for Small Unmanned Aircraft Systems (SUAS). The current research study develops an onboard open loop perching system for a fixed-wing SUAS and examines the impact of initial flight speed and sensor placement on the perching dynamics. A catapult launcher and modified COTS aircraft were used for the experiments, while an ultrasonic sensor on the aircraft was used to detect the perching target. Thirty tests were conducted varying the initial launch speed and ultrasonic sensor placement to see if they affected the time the aircraft reaches its maximum pitch angle, since the maximum pitch angle is the optimum perching point for the aircraft. High-speed video was analyzed to obtain flight data, along with data from an onboard inertial measuring unit. The data were analyzed using a model 1, two-way ANOVA to determine if launch speed and sensor placement affect the optimum perching point where the aircraft reaches its maximum pitch angle during the maneuver. The results show the launch speed does affect the time at which the maximum pitch angle occurs, but sensor placement does not. This means a closed loop system will need to adjust its perching distance based on its initial velocity. The sensor placement not having any noticeable effect means the ultrasonic sensor can be placed on the nose or the wing of the aircraft as needed for the design. There was also no noticeable interaction between the two variables. Aerodynamic parameters such as lift, drag, and moment coefficients were derived from the dynamic equations of motion for use in numerical simulations and dynamic perching models.

  12. 49 CFR 238.407 - Anti-climbing mechanism.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between...

  13. 49 CFR 238.407 - Anti-climbing mechanism.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between...

  14. 49 CFR 238.407 - Anti-climbing mechanism.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between...

  15. 49 CFR 238.407 - Anti-climbing mechanism.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between...

  16. 49 CFR 238.407 - Anti-climbing mechanism.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between...

  17. PSYCHOPHYSICAL BENEFITS OF ROCK-CLIMBING ACTIVITY.

    PubMed

    Gallotta, Maria Chiara; Emerenziani, Gian Pietro; Monteiro, Maria Dolores; Iasevoli, Luigi; Iazzoni, Sara; Baldari, Carlo; Guidetti, Laura

    2015-12-01

    The aim of the study was to compare the psychophysical effects of rock climbing with a supervised fitness training in adults. Thirty-three healthy participants (M age=32 yr., SD=7) participated in rock climbing or in fitness training. The participants' functional fitness, anxiety, and mood states were tested before and after 3 mo. of training. There was significant improvement of physical fitness in both groups after the intervention period. Anxiety significantly decreased after each single training session at the end of both courses. Differential effects in the rock-climbing group, as compared to the fitness group, emerged only on Vigor. Specifically, the rock-climbing group showed a decreasing trend in Vigor while the fitness group showed an increasing trend of Vigor after the intervention.

  18. The behavioural ecology of climbing plants

    PubMed Central

    Gianoli, Ernesto

    2015-01-01

    Climbing plants require an external support to grow vertically and enhance light acquisition. Vines that find a suitable support have greater performance and fitness than those that remain prostrate. Therefore, the location of a suitable support is a key process in the life history of climbing plants. Numerous studies on climbing plant behaviour have elucidated mechanistic details of support searching and attachment. Far fewer studies have addressed the ecological significance of support-finding behaviour and the factors that affect it. Without this knowledge, little progress can be made in the understanding of the evolution of support-finding behaviour in climbers. Here I review studies addressing ecological causes and consequences of support finding and use by climbing plants. I also propose the use of behavioural ecology theoretical frameworks to study climbing plant behaviour. I show how host tree attributes may determine the probability of successful colonization for the different types of climbers, and examine the evidence of environmental and genetic control of circumnutation behaviour and phenotypic responses to support availability. Cases of oriented vine growth towards supports are highlighted. I discuss functional responses of vines to the interplay between herbivory and support availability under different abiotic environments, illustrating with one study case how results comply with a theoretical framework of behavioural ecology originally conceived for animals. I conclude stressing that climbing plants are suitable study subjects for the application of behavioural–ecological theory. Further research under this framework should aim at characterizing the different stages of the support-finding process in terms of their fit with the different climbing modes and environmental settings. In particular, cost–benefit analysis of climbing plant behaviour should be helpful to infer the selective pressures that have operated to shape current climber

  19. Numerical modeling of perched water under Yucca Mountain, Nevada

    USGS Publications Warehouse

    Hinds, J.J.; Ge, S.; Fridrich, C.J.

    1999-01-01

    The presence of perched water near the potential high-level nuclear waste repository area at Yucca Mountain, Nevada, has important implications for waste isolation. Perched water occurs because of sharp contrasts in rock properties, in particular between the strongly fractured repository host rock (the Topopah Spring welded tuff) and the immediately underlying vitrophyric (glassy) subunit, in which fractures are sealed by clays that were formed by alteration of the volcanic glass. The vitrophyre acts as a vertical barrier to unsaturated flow throughout much of the potential repository area. Geochemical analyses (Yang et al. 1996) indicate that perched water is relatively young, perhaps younger than 10,000 years. Given the low permeability of the rock matrix, fractures and perhaps fault zones must play a crucial role in unsaturated flow. The geologic setting of the major perched water bodies under Yucca Mountain suggests that faults commonly form barriers to lateral flow at the level of the repository horizon, but may also form important pathways for vertical infiltration from the repository horizon down to the water table. Using the numerical code UNSAT2, two factors believed to influence the perched water system at Yucca Mountain, climate and fault-zone permeability, are explored. The two-dimensional model predicts that the volume of water held within the perched water system may greatly increase under wetter climatic conditions, and that perched water bodies may drain to the water table along fault zones. Modeling results also show fault flow to be significantly attenuated in the Paintbrush Tuff non-welded hydrogeologic unit.

  20. Climbing's Newest Challenges. The Dawn of a New Age in Climbing.

    ERIC Educational Resources Information Center

    Holmes, Steve

    1990-01-01

    Because of their advantages over natural rock climbing, artificial climbing walls are contributing to the growing number of climbers nationwide. The artificial walls are safer, are portable, can be built anywhere, and allow the creation of routes of the desired difficulty. (SV)

  1. A new species of Henneguya, a gill parasite of a freshwater fish Anabas testudineus (Bloch) affected with ulcerative disease syndrome from Manipur, India.

    PubMed

    Hemanand, Th; Meitei, N Mohilal; Bandyopadhyay, Probir K; Mitra, Amlan K

    2008-01-01

    A new species of Henneguya parasitizing tissues affected by the ulcerative disease syndrome of a freshwater fish Anabas testudineus (Bloch) from Khiodum and Pumlen lakes of Manipur state is described. Of the fishes examined 75% were found to be infested with this myxozoan parasite. Mature spores of the new species are elongated, biconvex, and oval with bluntly rounded anterior end and gradually tapering posterior end with a caudal prolongation, measuring 12.6-15.4 (14.0+/- 1.1) microm in length. Length of the caudal prolongation is 11.2-12.6 (11.7+/- 0.6) microm. The width of the spores is 5.6-7.0 (6.3+/- 0.5) microm. The length of the polar capsules is 5.6-6.3 (5.5+/- 0.3) microm.

  2. Rapid regulatory effect of tri-iodothyronine (T3) on antioxidant enzyme activities in a fish Anabas testudineus (Bloch): short-term in vivo and in vitro study.

    PubMed

    Sreejith, P; Oommen, O V

    2006-04-01

    The short-term action of thyroid hormone tri-iodothyronine (T3) was studied in vivo and in vitro on antioxidant enzyme activities in a teleost Anabas testudineus (Bloch). T3 injection in vivo (200 ng) in normal fish decreased the lipid peroxidation products and increased superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities after 30 min. T3 in vitro (10(-6) M) increased the antioxidant activities of catalase, glutathione reductase (GR), GPx and glutathione level after 15/30 min, except SOD, substantiating in vivo effects in normal fish. The results suggest a rapid regulatory effect of thyroid hormone in vivo and in vitro, in the removal of reactive oxygen species in A testudineus.

  3. Food of alewives, yellow perch, spottail shiners, trout-perch, and slimy and fourhorn sculpins in southeastern Lake Michigan

    USGS Publications Warehouse

    Wells, LaRue

    1980-01-01

    Stomachs of 1,064 alewives (Alosa pseudoharengus), 1,103 yellow perch (Perca flavescens), 246 spottail shiners (Notropis hudsonius), 288 trout-perch (Percopsis omiscomaycus), 454 slimy sculpins (Cottus cognatus), and 562 fourhorn sculpins (Myoxocephalus quadricornis) from Lake Michigan were examined for food contents. Fish were sampled primarily from March to November and nearly all were caught at the bottom in the southeastern part of the lake near Saugatuck, Michigan. Depths of capture (m) were: alewives, 5 to 110; yellow perch, 5 to 26; spottail shiners, 5 to 31; trout-perch, 9 to 46; slimy sculpins, 31 to 91; and fourhorn sculpins, 73 to 110. Alewives, particularly those less than 140 mm long, fed chiefly on zooplankton; Pontoporeia usually constituted most of the rest of the food, although Mysis and immature midges were occasionally eaten in considerable quantity. Yellow perch ate primarily Pontoporeia, fish eggs, Mysis, and crayfish; Pontoporeia was consumed most heavily by perch less than 250 mm long and those in relatively deep water, fish (mainly slimy sculpins) by those 200 mm long or longer, Mysis by those in deep water, and crayfish by those on rocky bottom. Spottail shiners fed most commonly on immature midges, Pontoporeia, zooplankton, fingernail clams, and (in July only) fish eggs; immature midges were eaten mainly by shiners in shallow water; and Pontoporeia by those in deeper areas. The diet of trout-perch was strongly dominated by Pontoporeia and immature midges. Slimy sculpins ate Pontoporeia almost exclusively. Fourhorn sculpins fed almost entirely on Mysis and Pontoporeia; Pontoporeia was particularly important in the diet of the larger fish.

  4. Development of a bio-inspired UAV perching system

    NASA Astrophysics Data System (ADS)

    Xie, Pu

    Although technologies of unmanned aerial vehicles (UAVs) including micro air vehicles (MAVs) have been greatly advanced in the recent years, it is still very difficult for a UAV to perform some very challenging tasks such as perching to any desired spot reliably and agilely like a bird. Unlike the UAVs, the biological control mechanism of birds has been optimized through millions of year evolution and hence, they can perform many extremely maneuverability tasks, such as perching or grasping accurately and robustly. Therefore, we have good reason to learn from the nature in order to significantly improve the capabilities of UAVs. The development of a UAV perching system is becoming feasible, especially after a lot of research contributions in ornithology which involve the analysis of the bird's functionalities. Meanwhile, as technology advances in many engineering fields, such as airframes, propulsion, sensors, batteries, micro-electromechanical-system (MEMS), and UAV technology is also advancing rapidly. All of these research efforts in ornithology and the fast growing development technologies in UAV applications are motivating further interests and development in the area of UAV perching and grasping research. During the last decade, the research contributions about UAV perching and grasping were mainly based on fixed-wing, flapping-wing, and rotorcraft UAVs. However, most of the current researches in UAV systems with perching and grasping capability are focusing on either active (powered) grasping and perching or passive (unpowered) perching. Although birds do have both active and passive perching capabilities depending on their needs, there is no UAV perching system with both capabilities. In this project, we focused on filling this gap. Inspired by the anatomy analysis of bird legs and feet, a novel perching system has been developed to implement the bionics action for both active grasping and passive perching. In addition, for developing a robust and

  5. Hand Injury in Rock Climbing: Literature Review.

    PubMed

    Pozzi, A; Pivato, G; Pegoli, L

    2016-02-01

    With the amazing increasing in number of participants, rock climbing has become a popular sport in the last decade. A growing number of participants, with different skill level, inevitably leads to an increased number of injuries related to this practice. The kind of lesions that can be observed in rock-climbers is very specific and often involves the hand. For this reason is very important for any hand surgeon that is exposed to sport injuries to know which and the most common injuries related to this sport and which are the basic principles for the treatment of those. The aim of this article is to review the literature that has been published in the last ten year in this topic. On the NCBI database 22 articles where found that where related to rock climbing lesion affecting the hand or the whole body. Differences where found according to kind of rock climbing activity that was analyzed, alpine climb leads to more serious injuries, often affecting the lower limb, while in sport and recreational rock climbing the upper limb and the hand are definitely the most affected parts. Flexor pulley lesions, followed by fractures and strains are the most common lesions affecting the hand that are related to this practice.

  6. Adaptive Trajectory Prediction Algorithm for Climbing Flights

    NASA Technical Reports Server (NTRS)

    Schultz, Charles Alexander; Thipphavong, David P.; Erzberger, Heinz

    2012-01-01

    Aircraft climb trajectories are difficult to predict, and large errors in these predictions reduce the potential operational benefits of some advanced features for NextGen. The algorithm described in this paper improves climb trajectory prediction accuracy by adjusting trajectory predictions based on observed track data. It utilizes rate-of-climb and airspeed measurements derived from position data to dynamically adjust the aircraft weight modeled for trajectory predictions. In simulations with weight uncertainty, the algorithm is able to adapt to within 3 percent of the actual gross weight within two minutes of the initial adaptation. The root-mean-square of altitude errors for five-minute predictions was reduced by 73 percent. Conflict detection performance also improved, with a 15 percent reduction in missed alerts and a 10 percent reduction in false alerts. In a simulation with climb speed capture intent and weight uncertainty, the algorithm improved climb trajectory prediction accuracy by up to 30 percent and conflict detection performance, reducing missed and false alerts by up to 10 percent.

  7. Fate of a perched crystal layer in a magma ocean

    NASA Technical Reports Server (NTRS)

    Morse, S. A.

    1992-01-01

    The pressure gradients and liquid compressibilities of deep magma oceans should sustain the internal flotation of native crystals owing to a density crossover between crystal and liquid. Olivine at upper mantle depths near 250 km is considered. The behavior of a perched crystal layer is part of the general question concerning the fate of any transient crystal carried away from a cooling surface, whether this be a planetary surface or the roof of an intrusive magma body. For magma bodies thicker than a few hundred meters at modest crustal depths, the major cooling surface is the roof even when most solidification occurs at the floor. Importation of cool surroundings must also be invoked for the generation of a perched crystal layer in a magma ocean, but in this case the perched layer is deeply embedded in the hot part of the magma body, and far away from any cooling surface. Other aspects of this study are presented.

  8. REPRODUCTIVE PHYSIOLOGY OF YELLOW PERCH (PERCA FLAVESCENS): ENVIRONMENTAL AND ENDOCRINOLOGICAL CUES

    EPA Science Inventory

    An understanding of the mechanisms involved in the regulation of reproductive processes in yellow perch is fundamental for intensive culture of this commercially important, freshwater, perciform fish. This paper describes the annual reproductive cycle of female and male perch. It...

  9. Bioaccumulation of decamethylcyclopentasiloxane in perch in Swedish lakes.

    PubMed

    Kierkegaard, Amelie; Bignert, Anders; McLachlan, Michael S

    2013-10-01

    Decamethylcyclopentasiloxane (D5), a high production volume chemical used in personal care products, enters the environment both via air and sewage treatment plant (STP) recipients. It has been found in fish, and there is concern that it may be a bioaccumulative substance. In this work D5 was analyzed in perch from six Swedish lakes that did not receive STP effluent, and in perch and sediment from six lakes that received STP effluent. In the lakes receiving the STP effluent, the D5 concentrations in sediment varied over three orders of magnitude and were correlated with the number of persons connected to the STP normalized to the surface area of the receiving body. In the lakes not receiving effluent, the D5 levels in perch were all below the LOQ, while D5 was above the LOQ in almost all perch from lakes that received effluent. The D5 concentrations in perch and sediment from the lakes receiving STP effluent were correlated. This shows that STP effluent is a much more important source of D5 to aquatic ecosystems than atmospheric deposition, and that the risk of adverse effects of D5 on aquatic life will be greatest in small recipients receiving large amounts of STP effluent. The bioaccumulation of D5 was compared to that of PCB 180 on the basis of multimedia bioaccumulation factors (mmBAFs), which describe the fraction of the contaminant present in the whole aquatic environment (i.e. water and surface sediment) that is transferred to the fish. In four of the six lakes the mmBAF of D5 was >0.3 of the mmBAF of PCB 180. Given that PCB 180 is a known highly bioaccumulative chemical, this indicates that the bioaccumulation of D5 in perch is considerable.

  10. Energy system contributions in indoor rock climbing.

    PubMed

    Bertuzzi, Rômulo Cássio de Moraes; Franchini, Emerson; Kokubun, Eduardo; Kiss, Maria Augusta Peduti Dal Molin

    2007-10-01

    The present study cross-sectionally investigated the influence of training status, route difficulty and upper body aerobic and anaerobic performance of climbers on the energetics of indoor rock climbing. Six elite climbers (EC) and seven recreational climbers (RC) were submitted to the following laboratory tests: (a) anthropometry, (b) upper body aerobic power, and (c) upper body Wingate test. On another occasion, EC subjects climbed an easy, a moderate, and a difficult route, whereas RC subjects climbed only the easy route. The fractions of the aerobic (W(AER)), anaerobic alactic (W(PCR)) and anaerobic lactic (W[La(-)]) systems were calculated based on oxygen uptake, the fast component of excess post-exercise oxygen uptake, and changes in net blood lactate, respectively. On the easy route, the metabolic cost was significantly lower in EC [40.3 (6.5) kJ] than in RC [60.1 (8.8) kJ] (P < 0.05). The respective contributions of the W (AER), W (PCR), and W[La(-)] systems in EC were: easy route = 41.5 (8.1), 41.1 (11.4) and 17.4% (5.4), moderate route = 45.8 (8.4), 34.6 (7.1) and 21.9% (6.3), and difficult route = 41.9 (7.4), 35.8 (6.7) and 22.3% (7.2). The contributions of the W (AER), W (PCR), and W[La(-)] systems in RC subjects climbing an easy route were 39.7 (5.0), 34.0 (5.8), and 26.3% (3.8), respectively. These results indicate that the main energy systems required during indoor rock climbing are the aerobic and anaerobic alactic systems. In addition, climbing economy seems to be more important for the performance of these athletes than improved energy metabolism.

  11. Access to Barrier Perches Improves Behavior Repertoire in Broilers

    PubMed Central

    Ventura, Beth A.; Siewerdt, Frank; Estevez, Inma

    2012-01-01

    Restriction of behavioral opportunities and uneven use of space are considerable welfare concerns in modern broiler production, particularly when birds are kept at high densities. We hypothesized that increased environmental complexity by provision of barrier perches would help address these issues by encouraging perching and enhancing use of the pen space across a range of stocking densities. 2,088 day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over four replications: simple barrier, complex barrier, or control (no barrier) and low (8 birds/m2), moderate (13 birds/m2), or high (18 birds/m2) density. Data were collected on focal birds via instantaneous scan sampling from 2 to 6 weeks of age. Mean estimates per pen for percent of observations seen performing each behavior, as well as percent of observations in the pen periphery vs. center, were quantified and submitted to an analysis of variance with week as the repeated measure. Barrier perches, density and age affected the behavioral time budget of broilers. Both simple and complex barrier perches effectively stimulated high perching rates. Aggression and disturbances were lower in both barrier treatments compared to controls (P<0.05). Increasing density to 18 birds/m2 compared to the lower densities suppressed activity levels, with lower foraging (P<0.005), decreased perching (P<0.0001) and increased sitting (P = 0.001) earlier in the rearing period. Disturbances also increased at higher densities (P<0.05). Use of the central pen area was higher in simple barrier pens compared to controls (P<0.001), while increasing density above 8 birds/m2 suppressed use of the central space (P<0.05). This work confirms some negative effects of increasing density and suggests that barrier perches have the potential to improve broiler welfare by encouraging activity (notably by providing accessible opportunities to perch), decreasing aggression and disturbances

  12. Botany: specialized bird perch aids cross-pollination.

    PubMed

    Anderson, Bruce; Cole, William W; Barrett, Spencer C H

    2005-05-05

    Birds may hover over or perch on flowers when feeding on nectar, and this assists cross-pollination if they then visit other plants. Here we investigate the curious sterile inflorescence axis of the South African Cape endemic 'rat's tail' plant (Babiana ringens, Iridaceae), whose function--unlike in other bird-pollinated plants--is exclusively to provide a perch for foraging birds. We find that this structure promotes the plant's mating success by causing the malachite sunbird (Nectarinia famosa), its main pollinator, to adopt a position ideal for the cross-pollination of its unusual ground-level flowers.

  13. Aircraft rate-of-climb indicators

    NASA Technical Reports Server (NTRS)

    Johnson, Daniel P

    1939-01-01

    The theory of the rate-of-climb indicator is developed in a form adapted for application to the instrument in its present-day form. Compensations for altitude, temperature, and rate of change of temperature are discussed from the designer's standpoint on the basis of this theory. Certain dynamic effects, including instrument lag, and the use of the rate-of-climb indicator as a statoscope are also considered. Modern instruments are described. A laboratory test procedure is outlined and test results are given.

  14. The CLASSIC/CLIMB Data Reduction: The Software

    NASA Astrophysics Data System (ADS)

    ten Brummelaar, T.

    2014-09-01

    This is one of two chapters that describe the methods used to extract closure phase from CLIMB data and visibility amplitude from both the CLASSIC and CLIMB beam combiners. In this, the second chapter, I describe the pipeline software.

  15. 14 CFR 23.65 - Climb: All engines operating.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... engine; (2) The landing gear retracted; (3) The wing flaps in the takeoff position(s); and (4) A climb...; (3) The wing flaps in the takeoff position(s); and (4) A climb speed as specified in §...

  16. Artificial Rock Climbing Walls--Innovative Adventure Environments.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1989-01-01

    The history, advantages, and disadvantages of artificial rock climbing walls (used to instruct individuals in the sport of rock climbing) are discussed. Additional topics include designing an artificial wall, types of walls, various uses, and risk management. (IAH)

  17. Bergsteigen in den Alpen (Mountain Climbing in the Alps).

    ERIC Educational Resources Information Center

    Hawrysz, Ilse; Budzinski, Elisabeth

    German second language instructional materials contain a short text in German on mountain climbing in the Alps, a vocabulary list with translation, a simple German climbing song, a recipe for goulash soup in English, and a short text in English on mountain climbing. (MSE)

  18. 49 CFR 238.205 - Anti-climbing mechanism.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting...

  19. 14 CFR 27.67 - Climb: one engine inoperative.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Climb: one engine inoperative. 27.67... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.67 Climb: one engine inoperative. For multiengine helicopters, the steady rate of climb (or descent), at V y (or at the speed...

  20. 49 CFR 238.205 - Anti-climbing mechanism.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting...

  1. 14 CFR 27.67 - Climb: one engine inoperative.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Climb: one engine inoperative. 27.67... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.67 Climb: one engine inoperative. For multiengine helicopters, the steady rate of climb (or descent), at V y (or at the speed...

  2. 14 CFR 29.67 - Climb: One engine inoperative (OEI).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Climb: One engine inoperative (OEI). 29.67... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.67 Climb: One engine inoperative... path, the following apply: (1) The steady rate of climb without ground effect, 200 feet above...

  3. 14 CFR 29.67 - Climb: One engine inoperative (OEI).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Climb: One engine inoperative (OEI). 29.67... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.67 Climb: One engine inoperative... path, the following apply: (1) The steady rate of climb without ground effect, 200 feet above...

  4. 49 CFR 238.205 - Anti-climbing mechanism.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting...

  5. 49 CFR 238.205 - Anti-climbing mechanism.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting...

  6. 49 CFR 238.205 - Anti-climbing mechanism.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting...

  7. 14 CFR 29.67 - Climb: One engine inoperative (OEI).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Climb: One engine inoperative (OEI). 29.67... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.67 Climb: One engine inoperative... path, the following apply: (1) The steady rate of climb without ground effect, 200 feet above...

  8. 14 CFR 27.67 - Climb: one engine inoperative.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Climb: one engine inoperative. 27.67... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.67 Climb: one engine inoperative. For multiengine helicopters, the steady rate of climb (or descent), at V y (or at the speed...

  9. Comparative analysis of trunk muscle activities in climbing of during upright climbing at different inclination angles

    PubMed Central

    Park, Byung-Joon; Kim, Joong-Hwi; Kim, Jang-Hwan; Choi, Byeong-Ho

    2015-01-01

    [Purpose] This study was performed to provide evidence for the therapeutic exercise approach through a compative analysis of muscle activities according to climbing wall inclination. [Subjects and Methods] Twentyfour healthy adult subjects without climbing experience performed static exercises at a therapeutic climbing at with various inclination angles (0°, 10°, 20°), and the activities of the trunk muscles (rectus abdominis, obliquus externus abdominis, obliquus internus abdominis, erector spinae) were measured using surface electromyography (EMG) for 7 seconds. [Results] Significant differences were found between the inclination angles of 10° and 0°, as well as 20° in the rectus abdominis, obliquus internus abdominis, right obliquus externus abdominis, and right erector spinae. [Conclusion] Based on measurements of trunk muscle activity in a static climbing standing position at different angles, significant changes in muscle activity appear to be induced at 10 degrees. Therefore, the results appear to provide clinically relevant evidence. PMID:26644661

  10. Getting Off the Ground with Rock Climbing.

    ERIC Educational Resources Information Center

    McNamee, Jeff; Steffen, Jeff

    2001-01-01

    Describes how to teach rock climbing to elementary school students using balance dome cones, which are small, cylindrical- shaped cones that are rounded at the top, seven inches in diameter, and four inches high. Students step on the cones as they explore and discover their balance limits in various unnatural movement positions. Individual and…

  11. Artificial Climbing Wall Design and Use.

    ERIC Educational Resources Information Center

    Cinnamon, Jerry

    Climbing walls can be designed to satisfy the needs of both untrained and experienced climbers offering these people a place to learn their craft as well as a place for them to keep their skills honed during off seasons. Users of the artificial wall can be classified into special groups, such as "Youth at Risk," who are engaged in…

  12. 36 CFR 13.910 - Mountain climbing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Mountain climbing. 13.910 Section 13.910 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve...

  13. 36 CFR 13.910 - Mountain climbing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Mountain climbing. 13.910 Section 13.910 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve...

  14. 14 CFR 23.63 - Climb: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: General. 23.63 Section 23.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.63...

  15. 14 CFR 23.63 - Climb: General.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Climb: General. 23.63 Section 23.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.63...

  16. 14 CFR 23.63 - Climb: General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Climb: General. 23.63 Section 23.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.63...

  17. Grissom Climbs into Liberty Bell 7

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Astronaut Virgil I. Grissom climbs into 'Liberty Bell 7' spacecraft the morning of July 21, 1961. Backup Astronaut John Glenn assists in the operation. The Mercury-Redstone 4(MR-4) successfully launched the Liberty Bell 7 at 7:20 am EST on July 21, 1961. MR-4 was the second in a series of successful U.S. manned suborbital flights.

  18. 14 CFR 23.63 - Climb: General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: General. 23.63 Section 23.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.63...

  19. 36 CFR 13.910 - Mountain climbing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Mountain climbing. 13.910 Section 13.910 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve...

  20. 36 CFR 13.910 - Mountain climbing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Mountain climbing. 13.910 Section 13.910 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve...

  1. 36 CFR 13.910 - Mountain climbing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Mountain climbing. 13.910 Section 13.910 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve...

  2. 14 CFR 25.117 - Climb: general.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.117 Climb: general. Compliance with the... operational limits established for the airplane and with the most unfavorable center of gravity for...

  3. 14 CFR 25.117 - Climb: general.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.117 Climb: general. Compliance with the... operational limits established for the airplane and with the most unfavorable center of gravity for...

  4. 14 CFR 25.117 - Climb: general.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.117 Climb: general. Compliance with the... operational limits established for the airplane and with the most unfavorable center of gravity for...

  5. 14 CFR 25.117 - Climb: general.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.117 Climb: general. Compliance with the... operational limits established for the airplane and with the most unfavorable center of gravity for...

  6. 14 CFR 25.117 - Climb: general.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.117 Climb: general. Compliance with the... operational limits established for the airplane and with the most unfavorable center of gravity for...

  7. A bacterial disease of yellow perch (Peres flavescens)

    USGS Publications Warehouse

    Ross, A.J.; Nordstrom, P.R.; Bailey, J.E.; Heaton, J.H.

    1960-01-01

    Examination of the freshly dead perch revealed the presence of multiple petechiae, which were visible externally as well as in the dorsal musculature. The peritoneal cavity showed evidence of inflammation and contained a bloody ascitic fluid. A number of the dead fish were placed on ice and shipped to the Western Fish Disease Laboratory in Seattle for bacteriological studies.

  8. Demonstrations of bio-inspired perching landing gear for UAVs

    NASA Astrophysics Data System (ADS)

    Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

    2016-04-01

    Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

  9. The effect of perch availability during pullet rearing and egg laying on the behavior of caged White Leghorn hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enriched cages, compared to conventional cages, allow egg laying strains of chickens to meet some behavioral needs, including the high motivation to perch. The objective of this study was to determine if perch availability during rearing affected perch use as adults and if perch presence affected ea...

  10. Rock climbing-related subclavian vein thrombosis.

    PubMed

    Lutter, Christoph; Monasterio, Erik; Schöffl, Volker

    2015-10-01

    Paget-Schroetter syndrome, also known as upper extremity deep venous thrombosis (UEDVT), is a rare condition, characterised by a (sub-) total occlusion of the axillary-subclavian venous system due to thrombosis. UEDVT is the most common vascular condition among athletes so far; although the general incidence is low, this problem will become more frequent as a result of increased participation in climbing sports. The purpose of this report is to illustrate two cases in rock climbers where UEDVT developed during rock climbing or bouldering. Fortunately, both patients were diagnosed relatively early after the symptoms began, despite the ambiguity of UEDVT symptoms. This relatively unfamiliar condition may become more highly recognised as a potentially serious differential diagnosis of unspecific pain of the shoulder. Rock climbers are disposed to develop UEDVT due to frequent stress on the upper extremities during training or competition.

  11. Wing extensions for improving climb performance

    NASA Technical Reports Server (NTRS)

    Nicks, O. W.

    1983-01-01

    Recent wind tunnel studies have shown that significant improvements in wing efficiency and climb performance can be achieved using wing extensions having sharp edges and unmodified upper airfoil contours. Based on tests of six configurations, a simple tip shape provided the best wing efficiency at high lift conditions without penalty during cruise conditions. The best configuration tested exhibited more than 20 percent improvement in the maximum rate of climb, plus a reduction in stall speed and a slight improvement in cruise performance over a baseline tip with a round edge. In addition to measurements that were used to determine performance, flow visualization studies provided insight into reasons for improved wing efficiency. Tests were conducted using a high performance general aviation aircraft model with a tapered, cantilevered wing.

  12. Experimental Studies in Helicopter Vertical Climb Performance

    NASA Technical Reports Server (NTRS)

    McKillip, Robert M., Jr.

    1996-01-01

    Data and analysis from an experimental program to measure vertical climb performance on an eight-foot model rotor are presented. The rotor testing was performed using a unique moving-model facility capable of accurately simulating the flow conditions during axial flight, and was conducted from July 9, 1992 to July 16, 1992 at the Dynamic Model Track, or 'Long Track,' just prior to its demolition in August of 1992. Data collected during this brief test program included force and moment time histories from a sting-mounted strain gauge balance, support carriage velocity, and rotor rpm pulses. In addition, limited video footage (of marginal use) was recorded from smoke flow studies for both simulated vertical climb and descent trajectories. Analytical comparisons with these data include a series of progressively more detailed calculations ranging from simple momentum theory, a prescribed wake method, and a free-wake prediction.

  13. Rock climbing injury rates and associated risk factors in a general climbing population.

    PubMed

    Backe, S; Ericson, L; Janson, S; Timpka, T

    2009-12-01

    The objective was to examine injury rates and associated risk factors in a representative sample of climbers. A random sample (n=606) of the Swedish Climbing Association members was sent a postal survey, with an effective response rate of 63%. Self-reported data regarding climbing history, safety practices and retrospective accounts of injury events (recall period 1.5 years) were obtained. Descriptive statistical methods were used to calculate injury incidences, and a two-step method including zero-inflated Poisson's regression analysis of re-injuries was used to determine the combination of risk factors that best explained individual injury rates. Overall, 4.2 injuries per 1000 climbing hours were reported, overuse injuries accounting for 93% of all injuries. Inflammatory tissue damages to fingers and wrists were the most common injury types. The multivariate analysis showed that overweight and practicing bouldering generally implied an increased primary injury risk, while there was a higher re-injury risk among male climbers and a lower risk among the older climbers. The high percentage of overuse injuries implies that climbing hours and loads should be gradually and systematically increased, and climbers regularly controlled for signs and symptoms of overuse. Further study of the association between body mass index and climbing injury is warranted.

  14. Ultraviolet Radiation Influences Perch Selection by a Neotropical Poison-Dart Frog

    PubMed Central

    Kats, Lee B.; Bucciarelli, Gary M.; Schlais, David E.; Blaustein, Andrew R.; Han, Barbara A.

    2012-01-01

    Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy. PMID:23251505

  15. Ultraviolet radiation influences perch selection by a neotropical poison-dart frog.

    PubMed

    Kats, Lee B; Bucciarelli, Gary M; Schlais, David E; Blaustein, Andrew R; Han, Barbara A

    2012-01-01

    Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy.

  16. Habitat change in a perched dune system along Lake Superior

    USGS Publications Warehouse

    Loope, Walter L.; McEachern, A. Kathryn; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    Episodes of habitat change, driven by changes in levels of the Great Lakes, must be considered when assessing human effects upon coastal vegetation and rare species. Paleoecological studies, baseline inventories, and long-term monitoring programs within the Grand Sable Dunes, a perched-dune system along Lake Superior, provide a window on vegetation change at different spatial and temporal scales and also provide an illustrative case study.

  17. Water displacement during sparging under perched water-table conditions

    SciTech Connect

    DiGiulio, D.C.

    1995-12-31

    The feasibility of using sparging to purposefully displace perched water in silt loam soils was evaluated at a field site in northwestern Oklahoma. Soils and groundwater are contaminated with petroleum hydrocarbons, trichloroethene (TCE), and vinyl chloride. During sparging, a transient response in water level measurements was observed in observation wells which is attributed to water displacement. Evidence of water displacement was manifested by water-table collapse upon the cessation of sparging.

  18. The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage.

    PubMed

    Hester, P Y; Enneking, S A; Jefferson-Moore, K Y; Einstein, M E; Cheng, H W; Rubin, D A

    2013-02-01

    Enrichment of pullet cages with perches has not been studied. Our objective was to determine if access to metal perches during all or part of the life cycle of caged White Leghorns affected egg traits, foot health, and feather condition. Treatment 1 represented control chickens that never had access to perches during their life cycle. Treatment 2 hens had perches only during the egg laying phase of the life cycle (17 to 71 wk of age), whereas treatment 3 chickens had perches during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Comparisons between chickens that always had perches with controls that never had perches showed similar performance relative to egg production, cracked eggs, egg weight, shell weight, % shell, and shell thickness. More dirty eggs occurred in laying cages with perches. Feed usage increased resulting in poorer feed efficiency in hens with perch exposure during the pullet phase with no effect during egg laying. Perches did not affect hyperkeratosis of toes and feet. The back claw at 71 wk of age broke less if hens had prior experience with perches during the pullet phase. In contrast, during egg laying, the back claw at 71 wk of age broke more due to the presence of perches in laying cages. Perches in laying cages resulted in shorter trimmed claws and improved back feather scores, but caused poorer breast and tail feather scores. In conclusion, enriching conventional cages with perches during the entire life cycle resulted in similar hen performance compared with controls. Fewer broken back claws but poorer feed efficiency occurred because of prior experience with perches as pullets. Perch presence during egg laying improved back feather scores with more trimmed nails but caused more dirty eggs, broken back claws, and poorer breast and tail feather scores. Although perches allow chickens to express their natural perching instinct, it was not without causing welfare problems.

  19. Field test of two energetic models for yellow perch

    USGS Publications Warehouse

    Schaeffer, J.S.; Haas, R.C.; Diana, J.S.; Breck, J.E.

    1999-01-01

    Field data from a population of yellow perch Perca flavescens in Saginaw Bay, Lake Huron, were used to evaluate the ability of two energetic models to predict consumption by yellow perch. Field estimates of daily ration for age-l-4 fish during May through October 1987 and 1988 were compared with independent predictions made by the Wisconsin energetic model and an energetic model developed by Karas and Thoresson. Predictions of daily ration using the Wisconsin model were lower than daily rations estimated from field data for all ages, primarily due to poor model-field agreement at temperatures above 22??C. This caused estimates of cumulative consumption from the Wisconsin model to be 25-50% lower than field estimates. Predictions of daily ration by the Karas-Thoresson model agreed with field estimates over a temperature range of 1026??C for age-1-3 yellow perch but not for older fish. Despite improvement, model predictions of cumulative consumption were 2-35% lower than field estimates. Although these tests of predicted and estimated rations may provide insight into which model produced more accurate results, it must be emphasized that field measures of daily ration are also estimates and may be in error, particularly at temperatures above 22??C where gastric evacuation rates were estimated. The Karas-Thoresson modification of the Wisconsin energetic model produced better fits to field ration data and is recommended for model applications.

  20. The epidemiology of injury in mountaineering, rock and ice climbing.

    PubMed

    Schöffl, Volker; Morrison, Audry; Schöffl, Isabelle; Küpper, Thomas

    2012-01-01

    Climbing and mountaineering sports are gaining more and more public interest. This chapter reviews scientific studies on injuries and accidents in climbing and mountaineering sports to evaluate the danger of these sports and their specific injuries and preventive measures. An initial PubMed query was performed using the key words 'rock climbing', 'sport climbing', 'mountaineering', 'alpine injuries' and 'climbing injuries'. More than 500 extracted papers were analyzed which gave information on injury, mortality/fatality, prevention and risk factors. Cross-references were also scanned according to the above given criteria. Also the data sources of the UIAA and IFSC Medical Commissions were analyzed. Overall, alpine (traditional) climbing has a higher injury risk than sport climbing, especially indoor climbing. Alpine and ice climbing have more objective dangers which can affect climber safety. Overall injury rates are low, nevertheless fatalities do occur in all climbing disciplines. Altitude-related illnesses/injuries also occur in mountaineering. Most injuries in sport climbing are overstrain injuries of the upper extremity. In alpine climbing, injuries mostly occur through falls which affect the lower extremity. Objective reporting of the injury site and severity varied in most studies according to the injury definition and methodology used. This creates differences in the injury and fatality results and conclusions, which in turn makes inter-study comparisons difficult. In future studies, the UIAA MedCom score for mountain injuries should be used to guarantee inter-study comparability. Evidence in preventive measures is low and further studies must be performed in this field.

  1. Energy cost of sport rock climbing in elite performers

    PubMed Central

    Booth, J.; Marino, F.; Hill, C.; Gwinn, T.

    1999-01-01

    OBJECTIVES: To assess oxygen uptake (VO2), blood lactate concentration ([La(b)]), and heart rate (HR) response during indoor and outdoor sport climbing. METHODS: Seven climbers aged 25 (SE 1) years, with a personal best ascent without preview or fall (on sight) ranging from 6b to 7a were assessed using an indoor vertical treadmill with artificial rock hand/foot holds and a discontinuous protocol with climbing velocity incremented until voluntary fatigue. On a separate occasion the subjects performed a 23.4 m outdoor rock climb graded 5c and taking 7 min 36 s (SE 33 s) to complete. Cardiorespiratory parameters were measured using a telemetry system and [La(b)] collected at rest and after climbing. RESULTS: Indoor climbing elicited a peak oxygen uptake (VO2climb-peak) and peak HR (HRpeak) of 43.8 (SE 2.2) ml/kg/min and 190 (SE 4) bpm, respectively and increased blood lactate concentration [La(b)] from 1.4 (0.1) to 10.2 (0.6) mmol/l (p < 0.05). During outdoor climbing VO2 and HR increased to about 75% and 83% of VO2climb-peak and HRpeak, respectively. [La(b)] increased from 1.3 (0.1) at rest to 4.5 mmol/l (p < 0.05) at 2 min 32 s (8 s) after completion of the climb. CONCLUSIONS: The results suggest that for elite climbers outdoor sport rock climbs of five to 10 minutes' duration and moderate difficulty require a significant portion of the VO2climb-peak. The higher HR and VO2 for outdoor climbing and the increased [La(b)] could be the result of repeated isometric contractions, particularly from the arm and forearm muscles. 


 PMID:10027051

  2. Competition between nonindigenous ruffe and native yellow perch in laboratory studies

    USGS Publications Warehouse

    Savino, Jacqueline F.; Kolar, Cynthia S.

    1996-01-01

    The ruffe Gymnocephalus cernuus is a European percid that was accidently introduced in Duluth Harbor, Lake Superior. This nonindigenous species is closely related to yellow perch Perca flavescens, and because the two species have similar diets and habitat requirements, they are potential competitors. Laboratory studies in aquaria and pools were conducted to determine whether ruffe can compete with yellow perch for food. Ruffe had capture rates similar to those of yellow perch when food was unlimited. Ruffe spent more time than yellow perch over a feeding container before leaving it and searching again, and they also required less time to ingest (or handle) prey. However, the presence of yellow perch shortened the time ruffe spent over foraging areas when food was more limited. In addition, yellow perch were more active than ruffe, as indicated by their more frequent visits to a feeding container. Hence, the outcome of exploitative competition was not conclusive; ruffe appear to have the advantage in some behaviors, yellow perch in others. Ruffe were much more aggressive than yellow perch, and interference competition may be important in the interactions between these species. Our results indicate that ruffe might compete with native yellow perch.

  3. Ecology and population status of trout-perch (Percopsis omiscomaycus) in western Lake Erie

    USGS Publications Warehouse

    Kocovsky, Patrick; Stoneman, Andrea T.; Kraus, Richard T.

    2014-01-01

    Trout-perch Percopsis omiscomaycus is among the most abundant benthic species in Lake Erie, but comparatively little is known about its ecology. Although others have conducted extensive studies on trout-perch ecology, those efforts predated invasions of white perch Morone americana, Dreissena spp., Bythotrephes longimanus and round goby Neogobius melanostomus, suggesting the need to revisit past work. Trout-perch were sampled with bottom trawls at 56 sites during June and September 2010. We examined diets, fecundity, average annual mortality, sex ratio, and long-term population trends at sites sampled since 1961. Trout-perch abundance fluctuated periodically, with distinct shorter- (4-year) and longer-term (over period of 50 years) fluctuations. Males had higher average annual mortality than females. Both sexes were equally abundant at age 0, but females outnumbered males 4:1 by age 2. Diets of trout-perch were dominated by macroinvertebrates, particularly chironomids and Hexagenia sp. Size distributions of trout-perch eggs varied widely and exhibited multiple modes indicative of protracted batch spawning. A review of the few other studies of trout-perch revealed periodic fluctuations in sex ratio of adults, which in light of our evidence of periodicity in abundance suggests the potential for sex-ratio-mediated intrinsic population regulation. Despite the introduction of numerous invasive species in Lake Erie, trout-perch remain one of the most abundant benthic invertivores and the population is relatively stable.

  4. Domestication drive the changes of immune and digestive system of Eurasian perch (Perca fluviatilis)

    PubMed Central

    Chen, Xiaowen; Wang, Jun; Qian, Long; Gaughan, Sarah; Xiang, Wei; Ai, Tao; Fan, Zhenming; Wang, Chenghui

    2017-01-01

    Domestication has altered a variety of traits within the Eurasian perch (Perca fluviatilis), including phenotypic, physiological and behavioral traits of Eurasian perch (Perca fluviatilis). Little is known, however, about the genetic changes between domesticated and wild Eurasian perch. In this study, we assembled a high-quality de novo reference transcriptome and identified differentially expressed genes between wild and domesticated Eurasian perch. A total of 113,709 transcripts were assembled, and 58,380 transcripts were annotated. Transcriptomic comparison revealed 630 differentially expressed genes between domesticated and wild Eurasian perch. Within domesticated Eurasian perch there were 412 genes that were up-regulated including MHCI, MHCII, chia, ighm within immune system development. There were 218 genes including try1, ctrl, ctrb, cela3b, cpa1 and cpb1, which were down-regulated that were associated with digestive processes. Our results indicated domestication drives the changes of immune and digestive system of Eurasian perch. Our study not only provide valuable genetic resources for further studies in Eurasian perch, but also provide novel insights into the genetic basis of physiological changes in Eurasian perch during domestication process. PMID:28257494

  5. Domestication drive the changes of immune and digestive system of Eurasian perch (Perca fluviatilis).

    PubMed

    Chen, Xiaowen; Wang, Jun; Qian, Long; Gaughan, Sarah; Xiang, Wei; Ai, Tao; Fan, Zhenming; Wang, Chenghui

    2017-01-01

    Domestication has altered a variety of traits within the Eurasian perch (Perca fluviatilis), including phenotypic, physiological and behavioral traits of Eurasian perch (Perca fluviatilis). Little is known, however, about the genetic changes between domesticated and wild Eurasian perch. In this study, we assembled a high-quality de novo reference transcriptome and identified differentially expressed genes between wild and domesticated Eurasian perch. A total of 113,709 transcripts were assembled, and 58,380 transcripts were annotated. Transcriptomic comparison revealed 630 differentially expressed genes between domesticated and wild Eurasian perch. Within domesticated Eurasian perch there were 412 genes that were up-regulated including MHCI, MHCII, chia, ighm within immune system development. There were 218 genes including try1, ctrl, ctrb, cela3b, cpa1 and cpb1, which were down-regulated that were associated with digestive processes. Our results indicated domestication drives the changes of immune and digestive system of Eurasian perch. Our study not only provide valuable genetic resources for further studies in Eurasian perch, but also provide novel insights into the genetic basis of physiological changes in Eurasian perch during domestication process.

  6. Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

    USGS Publications Warehouse

    Blazer, Vicki; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

    2013-01-01

    Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

  7. Wall climbing in B. subtilis biofilms

    NASA Astrophysics Data System (ADS)

    Brenner, Michael P.; Branda, Steve

    2005-11-01

    B. subtilis produces surfactin which aids its spreading on the buffer, increasing the wetted area of a nutrient substrate. Synthesis of the surfactin polar group is regulated by a so called ``quorum sensing'' pathway so that effective quantities are produced only when the population density is high. We describe the implications for the simple case of wall-climbing swarms of bacteria, in which Marangoni stresses drive the swarm against gravity up an angled substrate, prior to the synthesis of an exopolysaccharide matrix that leads to the formation of a floating pellicle. Wrinkles observed on the mature pellicle are related to the familiar `tears of wine' instability.

  8. Bouldering: an alternative strategy to long-vertical climbing in root-climbing hortensias.

    PubMed

    Granados Mendoza, Carolina; Isnard, Sandrine; Charles-Dominique, Tristan; Van den Bulcke, Jan; Rowe, Nick P; Van Acker, Joris; Goetghebeur, Paul; Samain, Marie-Stéphanie

    2014-10-06

    In the Neotropics, the genus Hydrangea of the popular ornamental hortensia family is represented by climbing species that strongly cling to their support surface by means of adhesive roots closely positioned along specialized anchoring stems. These root-climbing hortensia species belong to the nearly exclusive American Hydrangea section Cornidia and generally are long lianescent climbers that mostly flower and fructify high in the host tree canopy. The Mexican species Hydrangea seemannii, however, encompasses not only long lianescent climbers of large vertical rock walls and coniferous trees, but also short 'shrub-like' climbers on small rounded boulders. To investigate growth form plasticity in root-climbing hortensia species, we tested the hypothesis that support variability (e.g. differences in size and shape) promotes plastic responses observable at the mechanical, structural and anatomical level. Stem bending properties, architectural axis categorization, tissue organization and wood density were compared between boulder and long-vertical tree-climbers of H. seemannii. For comparison, the mechanical patterns of a closely related, strictly long-vertical tree-climbing species were investigated. Hydrangea seemannii has fine-tuned morphological, mechanical and anatomical responses to support variability suggesting the presence of two alternative root-climbing strategies that are optimized for their particular environmental conditions. Our results suggest that variation of some stem anatomical traits provides a buffering effect that regulates the mechanical and hydraulic demands of two distinct plant architectures. The adaptive value of observed plastic responses and the importance of considering growth form plasticity in evolutionary and conservation studies are discussed.

  9. Bouldering: an alternative strategy to long-vertical climbing in root-climbing hortensias

    PubMed Central

    Granados Mendoza, Carolina; Isnard, Sandrine; Charles-Dominique, Tristan; Van den Bulcke, Jan; Rowe, Nick P.; Van Acker, Joris; Goetghebeur, Paul; Samain, Marie-Stéphanie

    2014-01-01

    In the Neotropics, the genus Hydrangea of the popular ornamental hortensia family is represented by climbing species that strongly cling to their support surface by means of adhesive roots closely positioned along specialized anchoring stems. These root-climbing hortensia species belong to the nearly exclusive American Hydrangea section Cornidia and generally are long lianescent climbers that mostly flower and fructify high in the host tree canopy. The Mexican species Hydrangea seemannii, however, encompasses not only long lianescent climbers of large vertical rock walls and coniferous trees, but also short ‘shrub-like’ climbers on small rounded boulders. To investigate growth form plasticity in root-climbing hortensia species, we tested the hypothesis that support variability (e.g. differences in size and shape) promotes plastic responses observable at the mechanical, structural and anatomical level. Stem bending properties, architectural axis categorization, tissue organization and wood density were compared between boulder and long-vertical tree-climbers of H. seemannii. For comparison, the mechanical patterns of a closely related, strictly long-vertical tree-climbing species were investigated. Hydrangea seemannii has fine-tuned morphological, mechanical and anatomical responses to support variability suggesting the presence of two alternative root-climbing strategies that are optimized for their particular environmental conditions. Our results suggest that variation of some stem anatomical traits provides a buffering effect that regulates the mechanical and hydraulic demands of two distinct plant architectures. The adaptive value of observed plastic responses and the importance of considering growth form plasticity in evolutionary and conservation studies are discussed. PMID:25079869

  10. Performance evaluation of heat-stressed commercial broilers provided water-cooled floor perches.

    PubMed

    Reilly, W M; Koelkebeck, K W; Harrison, P C

    1991-08-01

    A study was conducted to determine whether water-cooled floor perches would be utilized by commercial broilers exposed to a constant hot ambient environment; and subsequently, whether utilization of these perches would improve performance beyond those provided uncooled floor perches. A total of 330 day-old commercial broiler chicks were randomly allocated to six pens (2.44 m2) in an environmentally controlled facility and maintained in a thermoneutral brooding environment for 16 days. Following this period, 240 birds were selected on a body weight basis and randomly assigned to the six pens. A perch constructed from steel pipe (2.44 m length, 5.0 cm diameter) was then placed diagonally on the litter covered floor of each pen. The birds were first exposed to a thermoneutral period (27.7 C), during which time cooling of the perches in three replicate pens was initiated by circulating tap water. The other three experimental pens received ambient perches. Ambient temperature was then raised to 32.6 C for the following 4 wk. The results of the present study showed that utilization of water-cooled perches by broilers was greater (P less than or equal to .01) than ambient perch utilization throughout the 32.6 C period. Average daily gain was greatest (P less than or equal to .01) for broilers exposed to cool perches. Additionally, they consume more feed (P less than or equal to .05), on a daily basis, than those given ambient perches during the heat-stress period. Broilers exposed to water-cooled perches also had a more efficient gain to feed ratio (P less than or equal to .01). At the completion of the study, final body weight and total body weight gain were greater (P less than or equal to .05) for broilers given water-cooled perches compared with those exposed to ambient perches. Total amount of feed consumed and total feed efficiency were only moderately affected (P less than or equal to .10) by perch treatments. These results indicated that water-cooled perches were

  11. Plasticity of climbing fibers after laser axotomy

    NASA Astrophysics Data System (ADS)

    Allegra Mascaro, A. L.; Cesare, P.; Sacconi, L.; Grasselli, G.; Strata, P.; Pavone, F. S.

    2010-02-01

    In the adult nervous system, different population of neurons corresponds to different regenerative behavior. Although previous works show that olivocerebellar fibers are capable of axonal regeneration in a suitable environment as a response to injury1, we have hitherto no details about the real dynamics of fiber regeneration. We coupled two photon imaging to laser-induced lesions to perform in vivo multiphoton nanosurgery in the CNS of living mice expressing fluorescent proteins to investigate the reparative properties of Climbing Fibers (CFs) in the adult CNS, following the time evolution of this plastic process in vivo. Here we show that a regenerative event may take place in a murine model in the days that follow a sub-micrometric lesion on the distal portion of the climbing fiber. Furthermore this unique model could allow, through manipulation of the viral vector, to explore in detail the biochemical mechanisms underlying the reparative process. The great potential of long-term two photon imaging, coupled to genetic manipulation, opens great opportunities to further investigate the dynamic properties of neurons and their rearrangement following an injury.

  12. Cool perch availability improves the performance and welfare status of broiler chickens in hot weather.

    PubMed

    Zhao, J P; Jiao, H C; Jiang, Y B; Song, Z G; Wang, X J; Lin, H

    2012-08-01

    A study was conducted to determine whether water-cooled perches would be preferred by commercial broilers exposed to a hot ambient environment, and subsequently, whether utilization of these perches would improve performance and the well-being of birds, beyond those provided by normal perches. Four hundred and thirty-two 14-d-old male chickens from a commercial fast-growing strain (Arbor Acres) were housed in the following conditions: 1) cool perches, 2) normal perches, and 3) control pens with no perches. The results showed that there was greater use of cool perches than normal perches for broiler chickens during summer (F1, 4=125, P=0.0004). Cool perches increased BW gain (F2, 6=5.44, P=0.0449) and breast (F2, 24=3.31, P=0.0539) and thigh muscle yields (F2, 24=6.29, P=0.0063), while decreasing abdominal fat deposition (F2, 24=7.57, P=0.0028), cooking loss (pectoralis major, F2, 24=3.30, P=0.0542; biceps femoris, F2, 24=3.42, P=0.0493), percentage of panting birds (F2, 6=102, P<0.0001), and scores of footpad (F2, 6=122, P<0.0001) and hock (F2, 6=68.2, P<0.0001) burn, and abdominal plumage condition (F2, 6=52.0, P=0.0002), particularly toward the end of the rearing period. In contrast, normal perches hardly affected growth performance, carcass composition, meat quality and behavioral patterns, and appeared to worsen the welfare status, including footpad and hock burns and abdominal plumage condition, due to a lower occupancy rate. Cool perches offer a thermoregulatory and performance advantage to broilers exposed to a hot environment and appear to be a management strategy for improving the production and well-being of commercial broilers.

  13. Perch compliance and experience affect destination choice of brown tree snakes (Boiga irregularis).

    PubMed

    Mauro, A Alexander; Jayne, C Bruce

    2016-04-01

    Arboreal animals often encounter branches with variable diameters that are highly correlated with stiffness, but how surface compliance affects the perch choice of animals is poorly understood. We used artificial branches to test the effects of different diameters and compliance on the choice between two destinations for twenty brown tree snakes as they bridged gaps. When both destinations were rigid, the diameters of the surfaces did not affect perch choice. However, with increased experience snakes developed a preference for a rigid, large-diameter perch compared to a compliant, small-diameter perch that collapsed under loads that were a small fraction of the weight of the snake. In hundreds of trials, with only one exception, the snakes proceeded to crawl entirely onto all rigid perches after first touching them, whereas the snakes commonly withdrew from the compliant perch even after touching it so lightly that it did not collapse. Hence, both tactile and visual cues appear to influence how these animals select a destination while crossing a gap. The preference for the rigid, large-diameter perch compared to the compliant, small-diameter perch developed mainly from short-term learning during three successive trials per testing session per individual. Furthermore, a preference for large diameters did not persist in the final treatment which used a rigid, large-diameter perch and a rigid, small-diameter perch. Hence, brown tree snakes appeared to be able to form short-term associations between the perch appearance and stiffness, the latter of which may have been determined via tactile sensory input.

  14. Ambient salinity modifies the action of triiodothyronine in the air-breathing fish Anabas testudineus Bloch: effects on mitochondria-rich cell distribution, osmotic and metabolic regulations.

    PubMed

    Peter, M C Subhash; Leji, J; Peter, Valsa S

    2011-04-01

    The hydromineral and metabolic actions of thyroid hormone on osmotic acclimation in fish is less understood. We, therefore, studied the short-term action of triiodothyronine (T(3)), the potent thyroid hormone, on the distribution and the function of gill mitochondria-rich (MR) cells and on the whole body hydromineral and metabolic regulations of air-breathing fish (Anabas testudineus) adapted to either freshwater (FW) or acclimated to seawater (SA; 30 g L(-1)). As expected, 24 h T(3) injection (100 ng g(-1)) elevated (P<0.05) plasma T(3) but classically reduced (P<0.05) plasma T(4). The higher Na(+), K(+)-ATPase immunoreactivity and the varied distribution pattern of MR cells in the gills of T(3)-treated FW and SA fish, suggest an action of T(3) on gill MR cell migration, though the density of these cells remained unchanged after T(3) treatment. The ouabain-sensitive Na(+), K(+)-ATPase activity, a measure of hydromineral competence, showed increases (P<0.05) in the gills of both FW and SA fish after T(3) administration, but inhibited (P<0.05) in the kidney of the FW fish and not in the SA fish. Exogenous T(3) reduced glucose (P<0.05) and urea (P<0.05) in the plasma of FW fish, whereas these metabolites were elevated (P<0.05) in the SA fish, suggesting a modulatory effect of ambient salinity on the T(3)-driven metabolic actions. Our data identify gill MR cell as a target for T(3) action as it promotes the spatial distribution and the osmotic function of these cells in both fresh water and in seawater. The results besides confirming the metabolic and osmotic actions of T(3) in fish support the hypothesis that the differential actions of T(3) may be due to the direct influence of ambient salinity, a major environmental determinant that alters the osmotic and metabolic strategies of fish.

  15. Comparison of lactate sampling sites for rock climbing.

    PubMed

    Fryer, S; Draper, N; Dickson, T; Blackwell, G; Winter, D; Ellis, G

    2011-06-01

    Comparisons of capillary blood lactate concentrations pre and post climb have featured in the protocols of many rock climbing studies, with most researchers obtaining samples from the fingertip. The nature of rock climbing, however, places a comparatively high physiological loading on the foreaand fingertips. Indeed, the fingertips are continually required for gripping and this makes pre-climb sampling at this site problematic. The purpose of our study was to examine differences in capillary blood lactate concentrations from samples taken at the fingertip and first (big) toe in a rock climbing context. 10 participants (9 males and 1 female) completed climbing bouts at 3 different angles (91°, 100° and 110°). Capillary blood samples were taken simultaneously from the fingertip and first toe pre and post climb. A limit of agreement plot revealed all data points to be well within the upper and lower bounds of the 95% population confidence interval. Subsequent regression analysis revealed a strong relationship (R (2)=0.94, y=0.940x + 0.208) between fingertip and first toe capillary blood lactate concentrations. Findings from our study suggest that the toe offers a valid alternative site for capillary blood lactate concentration analysis in a rock climbing context.

  16. Clay-shoveler's fracture during indoor rock climbing.

    PubMed

    Kaloostian, Paul E; Kim, Jennifer E; Calabresi, Peter A; Bydon, Ali; Witham, Timothy

    2013-03-01

    Indoor rock climbing is becoming more popular for people of all ages. Despite the tremendous interest in this competitive sport, participants are made aware of the dangers associated with participating. The authors present the first reported case of a clay-shoveler's fracture at the T1 spinous process during indoor rock climbing. They describe the management and natural history of this fracture and discuss management strategies for this increasingly popular recreational sport.A 14-year-old competitive indoor rock climber presented with acute-onset midline thoracic pain at T1 while indoor rock climbing. He reported no recent falls or trauma but stated that the pain came on abruptly while rock climbing. On examination, he was neurologically intact except for significant tenderness to palpation at the T1 spinous process. Magnetic resonance imaging demonstrated a minimally displaced T1 spinous process fracture with evidence of significant surrounding muscular edema, suggesting an acute fracture. He was treated conservatively with anti-inflammatory drugs, complete climbing restriction, and rest. He continued to have focal upper back pain at the level of the fracture over the next 4 months. He was unable to climb for 4 months until his pain resolved after conservative treatment of climbing restriction, pain control, and rest.This is the first documented case of a clay-shoveler's fracture sustained in a pediatric patient directly attributable to indoor rock climbing.

  17. Prediction of indoor climbing performance in women rock climbers.

    PubMed

    Wall, Christopher B; Starek, Joanna E; Fleck, Steven J; Byrnes, William C

    2004-02-01

    In an attempt to more clearly understand the strength characteristics of female rock climbers and whether those variables affect and predict climbing performance, 2 indoor climbing performance tests (route and bouldering) were compared to a series of muscular strength tests performed by moderate (n = 6), intermediate (n = 6), and expert (n = 6) female rock climbers. Significant differences (p < 0.05) were found between the expert group and the moderate and intermediate groups for climbing specific hand strength, as well as 1-arm lock-off strength when expressed as a strength-to-weight ratio. Multiple correlations showed that these variables (r > 0.426) as well as a questionnaire of past climbing performance (r > 0.86) significantly correlated to the tests of indoor climbing performance. In conclusion, climbing-specific tests of hand strength and of one arm lock-off strength reliably and sensitively measured 2 significant variables in the performance of indoor rock climbing, and a questionnaire of past best performance may be an accurate tool for the prediction of indoor climbing performance.

  18. 14 CFR 29.65 - Climb: All engines operating.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: All engines operating. 29.65 Section 29.65 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.65 Climb: All engines...

  19. 14 CFR 27.65 - Climb: all engines operating.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: all engines operating. 27.65 Section... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.65 Climb: all engines operating. (a...) With maximum continuous power on each engine; (ii) With the landing gear retracted; and (iii) For...

  20. 14 CFR 25.121 - Climb: One-engine-inoperative.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: One-engine-inoperative. 25.121...-engine-inoperative. (a) Takeoff; landing gear extended. In the critical takeoff configuration existing... steady gradient of climb must be positive for two-engine airplanes, and not less than 0.3 percent...

  1. 14 CFR 27.65 - Climb: all engines operating.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: all engines operating. 27.65 Section... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.65 Climb: all engines operating. (a...) With maximum continuous power on each engine; (ii) With the landing gear retracted; and (iii) For...

  2. 14 CFR 23.67 - Climb: One engine inoperative.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: One engine inoperative. 23.67... Climb: One engine inoperative. (a) For normal, utility, and acrobatic category reciprocating engine... 5,000 feet with the— (i) Critical engine inoperative and its propeller in the minimum drag...

  3. 14 CFR 27.67 - Climb: one engine inoperative.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: one engine inoperative. 27.67... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.67 Climb: one engine inoperative... minimum rate of descent), must be determined with— (a) Maximum weight; (b) The critical engine...

  4. 14 CFR 23.67 - Climb: One engine inoperative.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: One engine inoperative. 23.67... Climb: One engine inoperative. (a) For normal, utility, and acrobatic category reciprocating engine... 5,000 feet with the— (i) Critical engine inoperative and its propeller in the minimum drag...

  5. 14 CFR 29.65 - Climb: All engines operating.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: All engines operating. 29.65 Section 29.65 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.65 Climb: All engines...

  6. 14 CFR 27.67 - Climb: one engine inoperative.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: one engine inoperative. 27.67... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.67 Climb: one engine inoperative... minimum rate of descent), must be determined with— (a) Maximum weight; (b) The critical engine...

  7. 14 CFR 23.65 - Climb: All engines operating.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Climb: All engines operating. 23.65 Section... Climb: All engines operating. (a) Each normal, utility, and acrobatic category reciprocating engine... than maximum continuous power on each engine; (2) The landing gear retracted; (3) The wing flaps in...

  8. 14 CFR 23.65 - Climb: All engines operating.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: All engines operating. 23.65 Section... Climb: All engines operating. (a) Each normal, utility, and acrobatic category reciprocating engine... than maximum continuous power on each engine; (2) The landing gear retracted; (3) The wing flaps in...

  9. 14 CFR 25.121 - Climb: One-engine-inoperative.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Climb: One-engine-inoperative. 25.121...-engine-inoperative. (a) Takeoff; landing gear extended. In the critical takeoff configuration existing... steady gradient of climb must be positive for two-engine airplanes, and not less than 0.3 percent...

  10. A Unit Plan for A Basic Rock Climbing Course.

    ERIC Educational Resources Information Center

    Holcomb, Brian L.

    This instructional unit is comprised of four lessons dealing with conducting a four part class in basic rock climbing. The class is suitable, with modifications, for small private parties, small groups such as the Boy Scouts, or larger, organized groups such as climbing clubs. Four instructional methods are used: instructional media,…

  11. 14 CFR 23.67 - Climb: One engine inoperative.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... than maximum continuous power; (iii) Landing gear retracted; (iv) Wing flaps retracted; and (v) Climb... gear retracted; (iv) Wing flaps retracted; and (v) Climb speed not less than 1.2VS1. (b) For normal... engine(s) at takeoff power; (iii) Landing gear retracted; (iv) Wing flaps in the takeoff position(s);...

  12. 14 CFR 23.67 - Climb: One engine inoperative.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Wing flaps retracted; and (v) Climb speed not less than 1.2 VS1. (2) For each airplane that meets the... continuous power; (iii) Landing gear retracted; (iv) Wing flaps retracted; and (v) Climb speed not less than... position; (ii) Remaining engine(s) at takeoff power; (iii) Landing gear retracted; (iv) Wing flaps in...

  13. 14 CFR 23.67 - Climb: One engine inoperative.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Wing flaps retracted; and (v) Climb speed not less than 1.2 VS1. (2) For each airplane that meets the... continuous power; (iii) Landing gear retracted; (iv) Wing flaps retracted; and (v) Climb speed not less than... position; (ii) Remaining engine(s) at takeoff power; (iii) Landing gear retracted; (iv) Wing flaps in...

  14. Friction, Fear, Friends, and Falling: Contemplations of a Climbing Physicist.

    ERIC Educational Resources Information Center

    Wylie, John

    1992-01-01

    Uses the context of rock climbing to discuss the science concept of friction. Presents the mathematics equations that describe the concept. Examines the physics of different rock climbing situations encountered and equipment used. A series of related problems with answers is provided. (MDH)

  15. Physiological and anthropometric determinants of sport climbing performance

    PubMed Central

    Mermier, C.; Janot, J.; Parker, D.; Swan, J.

    2000-01-01

    Objective—To identify the physiological and anthropometric determinants of sport climbing performance. Methods—Forty four climbers (24 men, 20 women) of various skill levels (self reported rating 5.6–5.13c on the Yosemite decimal scale) and years of experience (0.10–44 years) served as subjects. They climbed two routes on separate days to assess climbing performance. The routes (11 and 30 m in distance) were set on two artificial climbing walls and were designed to become progressively more difficult from start to finish. Performance was scored according to the system used in sport climbing competitions where each successive handhold increases by one in point value. Results from each route were combined for a total climbing performance score. Measured variables for each subject included anthropometric (height, weight, leg length, arm span, % body fat), demographic (self reported climbing rating, years of climbing experience, weekly hours of training), and physiological (knee and shoulder extension, knee flexion, grip, and finger pincer strength, bent arm hang, grip endurance, hip and shoulder flexibility, and upper and lower body anaerobic power). These variables were combined into components using a principal components analysis procedure. These components were then used in a simultaneous multiple regression procedure to determine which components best explain the variance in sport rock climbing performance. Results—The principal components analysis procedure extracted three components. These were labelled training, anthropometric, and flexibility on the basis of the measured variables that were the most influential in forming each component. The results of the multiple regression procedure indicated that the training component uniquely explained 58.9% of the total variance in climbing performance. The anthropometric and flexibility components explained 0.3% and 1.8% of the total variance in climbing performance respectively. Conclusions—The variance

  16. Evolution of a climbing habit promotes diversification in flowering plants.

    PubMed Central

    Gianoli, Ernesto

    2004-01-01

    Key innovations are traits that are associated with the particular evolutionary 'success' of some taxonomic groups. Climbing plants depend on the availability of physical support to reach the canopy and thereby prevent shading by neighbouring plants. The present article shows that the evolution of a climbing habit in flowering plants constitutes a key innovation. A literature survey identified 48 pairs of sister groups from 45 families of flowering plants for which information on phylogenetic relationships, growth habit and species richness was available. In 38 cases, the climbing taxa were more diverse than their non-climbing sister groups. This pattern was highly significant. The same result was found when separate analyses were carried out for herbaceous and woody climbing plants, which differ in their constraints for successfully reaching a support. PMID:15451690

  17. Coupled glide-climb diffusion-enhanced crystal plasticity

    NASA Astrophysics Data System (ADS)

    Geers, M. G. D.; Cottura, M.; Appolaire, B.; Busso, E. P.; Forest, S.; Villani, A.

    2014-10-01

    This paper presents a fully coupled glide-climb crystal plasticity model, whereby climb is controlled by the diffusion of vacancies. An extended strain gradient crystal plasticity model is therefore proposed, which incorporates the climbing of dislocations in the governing transport equations. A global-local approach is adopted to separate the scales and assess the influence of local diffusion on the global plasticity problem. The kinematics of the crystal plasticity model is enriched by incorporating the climb kinematics in the crystallographic split of the plastic strain rate tensor. The potential of the fully coupled theory is illustrated by means of two single slip examples that illustrate the interaction between glide and climb in either bypassing a precipitate or destroying a dislocation pile-up.

  18. Was Lates late? A null model for the Nile perch boom in Lake Victoria.

    PubMed

    Downing, Andrea S; Galic, Nika; Goudswaard, Kees P C; van Nes, Egbert H; Scheffer, Marten; Witte, Frans; Mooij, Wolf M

    2013-01-01

    Nile perch (Lates niloticus) suddenly invaded Lake Victoria between 1979 and 1987, 25 years after its introduction in the Ugandan side of the lake. Nile perch then replaced the native fish diversity and irreversibly altered the ecosystem and its role to lakeshore societies: it is now a prised export product that supports millions of livelihoods. The delay in the Nile perch boom led to a hunt for triggers of the sudden boom and generated several hypotheses regarding its growth at low abundances--all hypotheses having important implications for the management of Nile perch stocks. We use logistic growth as a parsimonious null model to predict when the Nile perch invasion should have been expected, given its growth rate, initial stock size and introduction year. We find the first exponential growth phase can explain the timing of the perch boom at the scale of Lake Victoria, suggesting that complex mechanisms are not necessary to explain the Nile perch invasion or its timing. However, the boom started in Kenya before Uganda, indicating perhaps that Allee effects act at smaller scales than that of the whole Lake. The Nile perch invasion of other lakes indicates that habitat differences may also have an effect on invasion success. Our results suggest there is probably no single management strategy applicable to the whole lake that would lead to both efficient and sustainable exploitation of its resources.

  19. Was Lates Late? A Null Model for the Nile Perch Boom in Lake Victoria

    PubMed Central

    Downing, Andrea S.; Galic, Nika; Goudswaard, Kees P. C.; van Nes, Egbert H.; Scheffer, Marten; Witte, Frans; Mooij, Wolf M.

    2013-01-01

    Nile perch (Lates niloticus) suddenly invaded Lake Victoria between 1979 and 1987, 25 years after its introduction in the Ugandan side of the lake. Nile perch then replaced the native fish diversity and irreversibly altered the ecosystem and its role to lakeshore societies: it is now a prised export product that supports millions of livelihoods. The delay in the Nile perch boom led to a hunt for triggers of the sudden boom and generated several hypotheses regarding its growth at low abundances – all hypotheses having important implications for the management of Nile perch stocks. We use logistic growth as a parsimonious null model to predict when the Nile perch invasion should have been expected, given its growth rate, initial stock size and introduction year. We find the first exponential growth phase can explain the timing of the perch boom at the scale of Lake Victoria, suggesting that complex mechanisms are not necessary to explain the Nile perch invasion or its timing. However, the boom started in Kenya before Uganda, indicating perhaps that Allee effects act at smaller scales than that of the whole Lake. The Nile perch invasion of other lakes indicates that habitat differences may also have an effect on invasion success. Our results suggest there is probably no single management strategy applicable to the whole lake that would lead to both efficient and sustainable exploitation of its resources. PMID:24204684

  20. Complete Genome Sequence of a Giant Sea Perch Iridovirus in Kaohsiung, Taiwan

    PubMed Central

    Hong, Jiann-Ruey

    2016-01-01

    We report here the complete genome sequence of a megalocytivirus strain, GSIV-K1, isolated from a farmed giant sea perch (Lates calcarifer) in Kaohsiung, Taiwan. GSIV-K1 causes mortality in farmed marine fish, including giant sea perch and groupers. The genome sequence is nearly identical to the genome of the orange-spotted grouper iridovirus. PMID:27125488

  1. Complete Genome Sequence of a Giant Sea Perch Iridovirus in Kaohsiung, Taiwan.

    PubMed

    Wen, Chiu-Ming; Hong, Jiann-Ruey

    2016-04-28

    We report here the complete genome sequence of a megalocytivirus strain, GSIV-K1, isolated from a farmed giant sea perch (Lates calcarifer) in Kaohsiung, Taiwan. GSIV-K1 causes mortality in farmed marine fish, including giant sea perch and groupers. The genome sequence is nearly identical to the genome of the orange-spotted grouper iridovirus.

  2. Identification of gender in yellow perch Perca flavescens using external morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A non-lethal and rapid method for reliable identification of gender in yellow perch has been developed. On average, yellow perch females grow faster than males and undergo sexual maturity at an earlier age. Such size discrepancies in mixed culture situations pose difficulties with aquaculture produc...

  3. Genome Sequence of a Ranavirus Isolated from Pike-Perch Sander lucioperca

    PubMed Central

    Holopainen, Riikka; Steckler, Natalie K.; Claytor, Sieara C.; Ariel, Ellen

    2016-01-01

    The pike-perch iridovirus (PPIV) was isolated in Finland from apparently healthy pike-perch fingerlings during routine disease surveillance. Our phylogenomic analysis revealed that PPIV is the first fish member of a clade of ranaviruses previously described from European and Chinese amphibians. PMID:27856591

  4. Anadromous alewives, Alosa pseudoharengus, as prey for white perch, Morone americana

    USGS Publications Warehouse

    Moring, J.R.; Mink, L.H.

    2002-01-01

    The reintroduction of anadromous alewives, Alosa pseudoharengus, to their historic habitats in the inland waters of the United States and Canada, has prompted concerns about possible interactions with a popular sport fish, white perch, Morone americana. Both species are now widely distributed in northeastern North America. Diets of white perch in Lake George, Maine, U.S.A., where alewives were absent, were monitored and compared with those of white perch populations that were sympatric with anadromous alewives in two coastal Maine lakes, Biscay Pond and North Pond. In the presence of introduced alewives, the diet of adult white perch became almost exclusively juvenile alewives by late summer in ponds where both species were present. White perch that were sympatric with alewives were more piscivorus than were Lake George white perch, which primarily consumed Cladocera. Not only were alewives the principal prey item in the diet of white perch in Biscay and North ponds, but adult alewives were largely cannibalistic by August. Thus, success of reintroducing anadromous alewives in waters containing white perch may be negatively impacted by predation as well as cannibalism.

  5. Scaling the sublethal effects of methylmercury to yellow perchs population dynamics using adverse outcome pathway framework

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study sought to evaluate the effects of environmentally relevant dietary MeHg exposures on adult female yellow perch (Perca flavescens) and zebrafish (Danio rerio) reproduction. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, a...

  6. Comparative effects of constant versus fluctuating thermal regimens on yellow perch growth, feed conversion and survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of fluctuating or constant thermal regimens on growth, mortality, and feed conversion were determined for juvenile yellow perch (Perca flavescens). Yellow perch averaging 156mm total length and 43g body weight were held in replicate 288L circular tanks for 129 days under: 1) a diel therm...

  7. The effect of perch availability during pullet rearing and egg laying on the behavior of caged White Leghorn hens.

    PubMed

    Hester, P Y; Garner, J P; Enneking, S A; Cheng, H W; Einstein, M E

    2014-10-01

    Enriched cages, compared with conventional cages, allow egg laying strains of chickens to meet some behavioral needs, including a high motivation to perch. The objective of this study was to determine if perch availability during rearing affected perch use as adults and if perch presence affected eating and drinking in caged White Leghorn hens. Chickens were assigned to 14 cages each with and without 2 round metal perches from hatch to 16.9 wk of age. At 17 wk of age, pullets were assigned to laying cages consisting of 1 of 4 treatments. Treatment 1 chickens never had access to perches (controls). Treatment 2 chickens only had access to 2 round metal perches during the laying phase (17 to 71 wk of age). Treatment 3 chickens only had access to 2 round perches during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens had access to the perches during both the pullet and laying phase. Each treatment during the adult phase consisted of 9 cages with 9 birds/cage for a total of 36 cages. Automatic infrared cameras were used to monitor behavior of hens in each cage for a 24-h period at 19, 24, 29, 34, 39, 44, 49, 54, 59, 64, and 69 wk of age. Behavior was also recorded twice weekly by an observer in the room where the hens were housed during photophase from 25 to 68 wk of age. Behavioral data were analyzed using ANOVA with repeated measures and the MIXED model procedure. A greater proportion of hens without perches as pullets used the rear perch more during both photophase and scotophase than hens with prior pullet perching experience. Eating and drinking activities of caged adult Leghorns were not impaired by their prior experience to perches as pullets or by the presence of perches in laying cages. It is concluded that providing perches in cages to White Leghorns during pullet rearing did not facilitate use of perches as adults.

  8. A modeling study of perched water phenomena in the vadose zone

    SciTech Connect

    Wu, Y.-S.; Ritchey, A. C.; Bodvarsson, G. S.

    1997-12-16

    The presence of perched water bodies in the vicinity of the potential repository at Yucca Mountain has many implications, and however, it may provide insight into moisture movement, flow pathways, or surface infiltration history of the mountain. The first implication is that percolation flux does not travel vertically through the unsaturated zone to the water table, but has been trapped, blocked or diverted laterally. As a result, non-uniform recharge rates are expected at the water table. Another concern is that perched zones may divert water around low-permeability zeolitic lenses underlying the potential repository horizon. By-passing of these units, which are thought to have substantial capacity to retard radionuclide transport, could have important implications for the capability of the geologic system to mitigate radionuclide releases to the environment. We have conducted a series of 3-D modeling simulations to investigate the perched water occurrences at the Yucca Mountain site, using a numerical code and available perched water data from six boreholes. A spatially varying surface infiltration map (Flint et al., 1996) is used to describe areally distributed net infiltration at the model land surface. Perched water data observed in the field were used to calibrate the model in terms of matrix and fracture permeabilities, capillary functions, and relative permeabilities of gas within the perched zones. Calibrated parameter values were within the range of field and laboratory measurements. The steady-state simulation results are in agreement with the observed perched water data in terms of water saturation and perched water locations. Furthermore, the results of a transient numerical pumping test conducted, using a 3-D submodel, matched water level data observed during field pumping tests. Perched water may occur where percolation flux exceeds the capacity of the geologic media to transmit flux in unsaturated zones. The conceptual model of water movement in the

  9. Effects of stocking density, light and perches on broiler growth.

    PubMed

    Velo, Ramón; Ceular, Angel

    2017-02-01

    The aim of this study was to determine the effect of stocking density, light intensity and light color on broiler growth. The experiment consisted of four 35-day phases during each of which 320 chickens were surveyed. The research was performed at stocking densities of four and six birds/m(2) . Illuminances of 15 and 30 lx were obtained through commercial lamps with 4000 K and 6000 K color temperatures. Lighting was used 17 h a day, between 06.00 and 23.00 hours (17 L:7 D). The results showed a decrease in body, carcass, breast and thighs weight (P < 0.05) with the increase in stocking density. Body weight decreased by 10.5% and carcass weight decreased by 9.4% at six birds/m(2) stocking density. Contrastingly, no differences were found for the tested light colors. Increasing illuminance from 15 to 30 lx caused a 1.9% decrease in body weight. The analysis of the effect of perches revealed that using perches significantly increased body (2.5%) and breast weight (11.8%). The interactions between light intensity or color and stocking density and between light intensity and light color were analyzed.

  10. Effect of an on-sight lead on the physiological and psychological responses to rock climbing.

    PubMed

    Draper, Nick; Jones, Glenys A; Fryer, Simon; Hodgson, Chris; Blackwell, Gavin

    2008-01-01

    Rock climbing is a multi-discipline activity that encompasses forms such as bouldering, top roping and lead climbing on natural and artificial climbing surfaces. A major focus of research has been explanation of physiological functioning. More recent research indicates that anxiety levels are elevated for less experienced climbers and in response to lead climbing ascents. Research regarding the demands of rock climbing has placed a lesser focus on the interaction of psychological and physiological factors. The objective of this study was to examine the effects of an on-sight lead climb on the physiological and psychological demands of the climb in comparison with a subsequent lead climb. Ten intermediate level climbers volunteered to complete the two climbing trials, on-sight lead climb (OSLC) and second lead climb (LC2). Climb time, lactate concentrations (baseline, pre climb, post climb and 15 min post climb), heart rate (1 min pre climb, peak HR, 1 min post climb and average climb across the duration of the climb), oxygen consumption, pre climb anxiety (CSAI-2R) were assessed for each climber for both trials. Results indicated that there were significant differences in self reported pre climb somatic and cognitive anxiety (t(9) = 2.79, p = 0.01, t(9) = 1.94, p = 0.043), climb time (t(9) = 3.07, p = 0.0052) and post climb lactate concentrations between the climbs (t(9) = 2.58, p = 0.015). These results indicate that psychological as well as physiological stress impact upon the response to rock climbing. The higher anxiety levels associated with an OSLC are likely to have influenced the physiological responses for the intermediate climbers in this study. Future studies should take into account the type of climbing, experience of climbers and the number of ascents as well as taking into account the interaction between physiological and psychological factors in response to rock climbing. Key pointsFor intermediate climbers, there are significant differences in

  11. The influence of sex and environmental temperature on the acute stress response of juvenile yellow perch Perca flavescens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow perch are an ecologically and economically important fish in North America. At its peak, the Great Lakes yellow perch fishery constituted the largest inland capture fishery in North America. Even though wild populations have declined, consumer demand for yellow perch remains high, which has...

  12. 77 FR 41332 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... allowable catch (TAC) of Pacific ocean perch in the Western Regulatory Area of the GOA has been reached... 679. The 2012 TAC of Pacific ocean perch in the Western Regulatory Area of the GOA is 2,102 metric..., NMFS (Regional Administrator), has determined that the 2012 TAC of Pacific ocean perch in the...

  13. 75 FR 53608 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ... the 2010 total allowable catch (TAC) of Pacific ocean perch in the West Yakutat District of the GOA... CFR part 679. The 2010 TAC of Pacific ocean perch in the West Yakutat District of the GOA is 2,004... Region, NMFS (Regional Administrator), has determined that the 2010 TAC of Pacific ocean perch in...

  14. 77 FR 39649 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... the 2012 total allowable catch (TAC) of Pacific ocean perch in the Western Regulatory Area of the GOA... CFR part 679. The 2012 TAC of Pacific ocean perch in the Western Regulatory Area of the GOA is 2,102... Region, NMFS (Regional Administrator), has determined that the 2012 TAC of Pacific ocean perch in...

  15. 75 FR 42338 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... allowable catch (TAC) of Pacific ocean perch in the Western Regulatory Area of the GOA has been reached... CFR part 679. The 2010 TAC of Pacific ocean perch in the Western Regulatory Area of the GOA is 2,895... Region, NMFS (Regional Administrator), has determined that the 2010 TAC of Pacific ocean perch in...

  16. 77 FR 42439 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-19

    ... the 2012 total allowable catch (TAC) of Pacific ocean perch in the West Yakutat District of the GOA... CFR part 679. The 2012 TAC of Pacific ocean perch in the West Yakutat District of the GOA is 1,692... Region, NMFS (Regional Administrator), has determined that the 2012 TAC of Pacific ocean perch in...

  17. 78 FR 42718 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea and Aleutian Islands Management Area AGENCY.... ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch in... exceeding the 2013 total allowable catch (TAC) of Pacific ocean perch in this area allocated to...

  18. 75 FR 69599 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch by Vessels in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Zone Off Alaska; Pacific Ocean Perch by Vessels in the Amendment 80 Limited Access Fishery in the...: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by vessels.... The 2010 Pacific ocean perch TAC specified for vessels participating in the Amendment 80...

  19. 76 FR 65972 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Eastern Aleutian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-25

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Eastern Aleutian District of the Bering Sea and... directed fishing for Pacific ocean perch in the Eastern Aleutian District of the Bering Sea and Aleutian... action is necessary to prevent exceeding the 2011 allocation of Pacific ocean perch in this...

  20. 78 FR 39631 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Western Regulatory Area of the Gulf of Alaska AGENCY.... ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch in... the 2013 total allowable catch of Pacific ocean perch in the Western Regulatory Area of the GOA....

  1. 75 FR 69599 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch by Vessels in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Off Alaska; Pacific Ocean Perch by Vessels in the Amendment 80 Limited Access Fishery in the Eastern...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by vessels participating in.... The 2010 Pacific ocean perch TAC specified for vessels participating in the Amendment 80...

  2. 77 FR 39440 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Central Aleutian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Central Aleutian District of the Bering Sea and... directed fishing for Pacific ocean perch in the Central Aleutian District of the Bering Sea and Aleutian... action is necessary to prevent exceeding the 2012 allocation of Pacific ocean perch in this...

  3. 76 FR 43933 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian District of the Bering Sea and... directed fishing for Pacific ocean perch in the Western Aleutian District of the Bering Sea and Aleutian... action is necessary to prevent exceeding the 2011 allocation of Pacific ocean perch in this...

  4. 75 FR 69598 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch by Vessels in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Zone Off Alaska; Pacific Ocean Perch by Vessels in the Amendment 80 Limited Access Fishery in the...: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by vessels.... The 2010 Pacific ocean perch TAC specified for vessels participating in the Amendment 80...

  5. 77 FR 34262 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-11

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian District of the Bering Sea and... directed fishing for Pacific ocean perch in the Western Aleutian District of the Bering Sea and Aleutian... action is necessary to prevent exceeding the 2012 allocation of Pacific ocean perch in this...

  6. 76 FR 68658 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... Zone Off Alaska; Pacific Ocean Perch in the Bering Sea Subarea of the Bering Sea and Aleutian Islands... is opening directed fishing for Pacific ocean perch in the Bering Sea subarea of the Bering Sea and... Pacific ocean perch specified for the Bering Sea subarea of the Bering Sea and Aleutian Islands...

  7. 75 FR 39183 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-08

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Western Regulatory Area of the Gulf of Alaska AGENCY.... ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch in... the 2010 total allowable catch (TAC) of Pacific ocean perch in the Western Regulatory Area of the...

  8. 75 FR 69601 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Zone Off Alaska; Pacific Ocean Perch in the Western Aleutian District of the Bering Sea and Aleutian... for Pacific ocean perch in the Western Aleutian District of the Bering Sea and Aleutian Islands... necessary to prevent exceeding the 2010 allocation of Pacific ocean perch in this area allocated to...

  9. Physiological determinants of climbing-specific finger endurance and sport rock climbing performance.

    PubMed

    MacLeod, D; Sutherland, D L; Buntin, L; Whitaker, A; Aitchison, T; Watt, I; Bradley, J; Grant, S

    2007-10-01

    The aim of the study was to examine several physiological responses to a climbing-specific task to identify determinants of endurance in sport rock climbing. Finger strength and endurance of intermediate rock climbers (n = 11) and non-climbers (n = 9) were compared using climbing-specific apparatus. After maximum voluntary contraction (MVC) trials, two isometric endurance tests were performed at 40% (s = 2.5%) MVC until volitional exhaustion (continuous contractions and intermittent contractions of 10 s, with 3 s rest between contractions). Changes in muscle blood oxygenation and muscle blood volume were recorded in the flexor digitorum superficialis using near infra-red spectroscopy. Statistical significance was set at P < 0.05. Climbers had a higher mean MVC (climbers: 485 N, s = 65; non-climbers 375 N, s = 91) (P = 0.009). The group mean endurance test times were similar. The force-time integral, used as a measure of climbing-specific endurance, was greater for climbers in the intermittent test (climbers: 51,769 N x s, s = 12,229; non-climbers: 35,325 N x s, s = 9724) but not in the continuous test (climbers: 21,043 N x s, s = 4474; non-climbers: 15,816 N x s, s = 6263). Recovery of forearm oxygenation during rest phases (intermittent test) explained 41.1% of the variability in the force-time integral. Change in total haemoglobin was significantly greater in non-climbers (continuous test) than climbers (P = 0.023--40% test timepoint, P = 0.014--60% test timepoint). Pressor responses were similar between groups and not related to the force-time integral for either test. We conclude that muscle re-oxygenation during rest phases is a predictor of endurance performance.

  10. Climbing with adhesion: from bioinspiration to biounderstanding

    PubMed Central

    Cutkosky, Mark R.

    2015-01-01

    Bioinspiration is an increasingly popular design paradigm, especially as robots venture out of the laboratory and into the world. Animals are adept at coping with the variability that the world imposes. With advances in scientific tools for understanding biological structures in detail, we are increasingly able to identify design features that account for animals' robust performance. In parallel, advances in fabrication methods and materials are allowing us to engineer artificial structures with similar properties. The resulting robots become useful platforms for testing hypotheses about which principles are most important. Taking gecko-inspired climbing as an example, we show that the process of extracting principles from animals and adapting them to robots provides insights for both robotics and biology. PMID:26464786

  11. Bedform climbing in theory and nature.

    USGS Publications Warehouse

    Rubin, D.M.; Hunter, R.E.

    1982-01-01

    Where bedforms migrate during deposition, they move upward (climb) with respect to the generalized sediment surface. Sediment deposited on each lee slope and not eroded during the passage of a following trough is left behind as a cross-stratified bed. Where sediment is transported solely by downcurrent migration of two-dimensional bedforms the thickness of cross-stratified beds is equal to the decrease in bedform cross-sectional area divided by the migration distance over which that size decrease occurs; where bedforms migrate more than one spacing while depositing cross-strata, bed thickness is only a fraction of bedform height. Equations that describe this depositional process are used to explain observations on actual dunes and to predict dune sizes for ancient sandstones. -from Authors

  12. Dislocation climb models from atomistic scheme to dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Niu, Xiaohua; Luo, Tao; Lu, Jianfeng; Xiang, Yang

    2017-02-01

    We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment kinetics at jogs leading to the motion of jogs. Our mesoscopic model consists of the vacancy bulk diffusion equation and a dislocation climb velocity formula. The effects of these microscopic mechanisms are incorporated by a Robin boundary condition near the dislocations for the bulk diffusion equation and a new contribution in the dislocation climb velocity due to vacancy pipe diffusion driven by the stress variation along the dislocation. Our climb formulation is able to quantitatively describe the translation of prismatic loops at low temperatures when the bulk diffusion is negligible. Using this new formulation, we derive analytical formulas for the climb velocity of a straight edge dislocation and a prismatic circular loop. Our dislocation climb formulation can be implemented in dislocation dynamics simulations to incorporate all the above four microscopic mechanisms of dislocation climb.

  13. Bio-inspired step-climbing in a hexapod robot.

    PubMed

    Chou, Ya-Cheng; Yu, Wei-Shun; Huang, Ke-Jung; Lin, Pei-Chun

    2012-09-01

    Inspired by the observation that the cockroach changes from a tripod gait to a different gait for climbing high steps, we report on the design and implementation of a novel, fully autonomous step-climbing maneuver, which enables a RHex-style hexapod robot to reliably climb a step up to 230% higher than the length of its leg. Similar to the climbing strategy most used by cockroaches, the proposed maneuver is composed of two stages. The first stage is the 'rearing stage,' inclining the body so the front side of the body is raised and it is easier for the front legs to catch the top of the step, followed by the 'rising stage,' maneuvering the body's center of mass to the top of the step. Two infrared range sensors are installed on the front of the robot to detect the presence of the step and its orientation relative to the robot's heading, so that the robot can perform automatic gait transition, from walking to step-climbing, as well as correct its initial tilt approaching posture. An inclinometer is utilized to measure body inclination and to compute step height, thus enabling the robot to adjust its gait automatically, in real time, and to climb steps of different heights and depths successfully. The algorithm is applicable for the robot to climb various rectangular obstacles, including a narrow bar, a bar and a step (i.e. a bar of infinite width). The performance of the algorithm is evaluated experimentally, and the comparison of climbing strategies and climbing behaviors in biological and robotic systems is discussed.

  14. Molecular evidence for multiple paternity in a population of the Viviparous Tule Perch Hysterocarpus traski.

    PubMed

    Liu, Jin-Xian; Tatarenkov, Andrey; O'Rear, Teejay A; Moyle, Peter B; Avise, John C

    2013-03-01

    Population density might be an important variable in determining the degree of multiple paternity. In a previous study, a high level of multiple paternity was detected in the shiner perch Cymatogaster aggregata, a species with high population density and a high mate encounter rate. The tule perch Hysterocarpus traski is phylogenetically closely related to C. aggregata, but it has relatively lower population density, which may result in distinct patterns of multiple paternity in these 2 species. To test the hypothesis that mate encounter rate may affect the rate of successful mating, we used polymorphic microsatellite markers to identify multiple paternity in the progeny arrays of 12 pregnant females from a natural population of tule perch. Multiple paternity was detected in 11 (92%) of the 12 broods. The number of sires per brood ranged from 1 to 4 (mean 2.5) but with no correlation between sire number and brood size. Although the brood size of tule perch is considerably larger than that of shiner perch (40.7 vs. 12.9, respectively), the average number of sires per brood in tule perch is much lower than that in shiner perch (2.5 vs. 4.6, respectively). These results are consistent with the hypothesis that mate encounter rate is an important factor affecting multiple mating.

  15. Responses of Acilius sulcatus (Coleoptera: Dytiscidae) to chemical cues from perch (Perca fluviatilis).

    PubMed

    Åbjörnsson, Kajsa; Wagner, Bálint M A; Axelsson, Anna; Bjerselius, Rickard; Olsén, K Håkan

    1997-07-01

    In this study we tested the hypothesis that the presence of chemical stimuli from a hungry predator would initiate anti-predator responses, while stimuli from a satiated predator would not. We used chemical stimuli released from starved perch (Perca fluviatilis) and from satiated perch (predator). As prey we used adult Acilius sulcatus (Coleoptera: Dytiscidae). The reaction of the beetles to different predator conditions was tested during daytime. We also tested the reaction to starved perch during the night. A. sulcatus activity decreased when it was exposed to stimuli released from starved perch during daytime when visibility was poor, due to the presence of artificial vegetation. There was, however, no reaction to satiated perch under the same experimental conditions. These results indicate that A. sulcatus can discriminate between chemical cues from hungry and satiated fish predators. When visibility was good and the concentration of chemical cues was constant, the beetles did not react to starved perch in the daytime, but their activity decreased at night in response to stimuli released from starved perch. Visual as well as chemical cues seem to be important for detecting a potential predator. When visibility is good, beetles seem to rely on visual stimuli, while in darkness they seem to use chemical stimuli to detect the presence of predators.

  16. Intraspecific variation in gill morphology of juvenile Nile perch, Lates niloticus, in Lake Nabugabo, Uganda

    USGS Publications Warehouse

    Paterson, Jaclyn A.; Chapman, Lauren J.; Schofield, Pamela J.

    2010-01-01

    Several studies have demonstrated intraspecific variation in fish gill size that relates to variation in dissolved oxygen (DO) availability across habitats. In Lake Nabugabo, East Africa, ecological change over the past 12 years has coincided with a shift in the distribution of introduced Nile perch such that a larger proportion of the population now inhabits waters in or near wetland ecotones where DO is lower than in open waters of the lake. In this study, we compared gill size of juvenile Nile perch between wetland and exposed (open-water) habitats of Lake Nabugabo in 2007, as well as between Nile perch collected in 1996 and 2007. For Nile perch of Lake Nabugabo [<20 cm total length (TL)], there was a significant habitat effect on some gill traits. In general, fish from wetland habitats were characterized by a longer total gill filament length and average gill filament length than conspecifics from exposed habitats. Nile perch collected from wetland areas in 2007 had significantly larger gills (total gill filament length) than Nile perch collected in 1996, but there was no difference detected between Nile perch collected from exposed sites in 2007 and conspecifics collected in 1996.

  17. Food habits of stunted and non-stunted white perch (Morone americana)

    USGS Publications Warehouse

    Gosch, N.J.C.; Stittie, J.R.; Pope, K.L.

    2010-01-01

    We studied food habits of white perch (Morone americana) from two populations with different stable states (stunted [Branched Oak Lake, Nebraska] and nonstunted [Pawnee Lake, Nebraska]) to determine if change in food habits of white perch is likely to occur in situations where a stunted white perch population is altered to a nonstunted state and vice versa. Three approaches were used to quantitatively describe seasonal (spring = March-May, summer = June-August, autumn = September-November) diets of white perch - 1) frequency of occurrence, 2) percentage of composition by volume, and 3) mean stomach fullness. White perch diets were dominated by cladocerans and dipterans in both reservoirs during all seasons. Fish egg predation was similar between reservoirs, and white perch rarely consumed fishes in either the stunted or the non-stunted population. Shifting a white perch population between stunted and non-stunted states will likely cause little or no change in food habits; fish in both states will primarily consume invertebrates.

  18. Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

    PubMed

    Cullen, Joshua A; Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such

  19. A robin perches on a branch at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A robin perches on a branch in the Merritt Island National Wildlife Refuge, which shares a boundary with the space center. Robins range throughout North America, from Alaska to Florida. Although considered a harbinger of spring, they do winter in northern states, frequenting cedar bogs and swamps. They also winter in Florida, where they often can be seen in flocks of hundreds near KSC and the wildlife refuge, which comprises 92,000 acres, ranging from hardwood hammocks and pine flatwoods to fresh-water impoundments, salt-water estuaries and brackish marshes. The diverse landscape provides habitat for more than 310 species of birds, 25 mammals, 117 fishes, and 65 amphibians and reptiles, including such endangered species as Southern bald eagles, wood storks, Florida scrub jays, Atlantic loggerhead and leatherback turtles, osprey, and nearly 5,000 alligators.

  20. Lake phosphorus loading form septic systems by seasonally perched groundwater

    USGS Publications Warehouse

    Gilliom, R.J.; Patmont, C.R.

    1983-01-01

    The movement of effluent phosphorus (P) from old septic systems by seasonally perched groundwater was investigated. A previous study indicated a correlation between P loadings and the presence of old homes. Water samples were taken from shallow wells installed 10 to 50 m downgradient from seven septic systems 20 to 40 years old. The equivalent volumetric fraction of each sample consisting of undiluted effluent was estimated from chloride concentration. A Monte Carlo analysis was used to account for the various sources of uncertainty. Movement of diluted septic effluent to the lake was common, but transport of more than 1% of effluent P through the soil was probable for only 4 of 26 samples. The greatest apparent P movement was associated with persistently saturated conditions.

  1. Perched-Water Analysis Related to Deep Vadose Zone Contaminant Transport and Impact to Groundwater

    SciTech Connect

    Oostrom, Martinus; Truex, Michael J.; Carroll, KC; Chronister, Glen B.

    2013-11-15

    Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located just a few meters above the water table beneath the B-complex at the Hanford Site. The perched water, containing elevated concentrations of uranium and technetium-99, is important to consider in evaluating the future flux of contaminated water into the groundwater. A study was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and, 3) associated groundwater impact. Based on the current vertical transport pathways and large areal extent of the perched system, the evaluation was conducted using a one-dimensional (1-D) analysis. Steady-state scoping calculations showed that the perching-layer hydraulic conductivity is likely to be up to two orders of magnitude less than the base case value obtained from Hanford site literature. Numerical flow and transport simulations provided both steady-state and transient system estimates of water and contaminant behavior and were used to further refine the range of conditions consistent with current observations of perched water height and to provide estimates of future water and contaminant flux to groundwater. With a recharge rate of 6 cm/yr, representative of current disturbed surface conditions, contaminant flux from the perched water occurs over a time interval of tens of years. However, if the recharge rate is 0.35 cm/yr, representative of returning recharge to pre-Hanford Site levels, the contaminant flux into the groundwater is spread over hundreds of years. It was also demonstrated that removal of perched water by pumping would reduce the flux of water (and associated contaminants) to the groundwater, thereby impacting the long-term rate of contaminant movement to the groundwater.

  2. Energy-modelled climb and climb-dash - The Kaiser technique. [reviewed for Me 262 jet fighter aircraft trajectories

    NASA Technical Reports Server (NTRS)

    Merritt, S. R.; Cliff, E. M.; Kelley, H. J.

    1985-01-01

    F. Kaiser's germinal 1944 report on his 'resultant-height' concept, now known as energy modelling, is reviewed. The data base for the Me. 262 jet fighter is recreated via spline-lattice representation of specific excess power. Minimum-time and 'distance'-climb trajectories are generated in an attempt to check Kaiser's results. Agreement is good for the minimum-time calculations but only qualitative agreement is obtained for the mysterious 'distance climbs' whose documentation is fragmentary. The character of optimal climb-dash trajectories in energy approximation is examined and illustrated.

  3. Some implications of the particle and climb geometry on the climb resistance in nickel-base superalloys

    SciTech Connect

    Mukherji, D.; Wahi, R.P.

    1996-04-01

    Various dislocation climb models were developed for modeling the deformation processes in precipitation hardened alloys at elevated temperatures and low applied stresses. These models have been applied to alloy systems containing spherical, cubic and other precipitate shapes. However, in applying these models to alloys containing cubic precipitates, the particle orientation with respect to the slip plane and the slip geometry relevant to the nickel-base superalloys was not considered. In this paper the authors show that by taking into account the realistic climb and glide geometries, the value of the climb resistances considerably differ from those reported earlier on the basis of simplified geometries.

  4. Perched Soil Zone (PSZ) Aquifer Package for MODFLOW-2005

    NASA Astrophysics Data System (ADS)

    Henson, W.; Niswonger, R. G.

    2010-12-01

    An increasing number of investigators are looking at innovative ways to use precipitation data to calculate recharge to aquifer systems. Typically, simulation models are used to partition precipitation into evapotranspiration, runoff and recharge. Currently, the groundwater flow model, MODFLOW-2005, does not simulate dynamic near-surface hydrologic processes such as, infiltration, hortonian or dunnian runoff, return flow, or the effects of impervious surfaces on runoff. The Perched Soil-Zone package (PSZ) for MODFLOW-2005 is being developed to address these major components of hillslope hydrology for simulating watershed processes in the context of basin-scale groundwater flow modeling. This package extends MODFLOW-2005 capabilities to simulate soil zone processes in short time steps that are integrated to the much longer daily or weekly timesteps typically used in MODFLOW-2005. A perched aquifer often develops in the soil zone during periods of heavy rainfall, delivering interflow to channels in a watershed. The soil zone is the upper most region of the vadose zone where plant and soil processes enhance storage and permeability, providing a fast pathway for water and solutes to streams. The soil zone connects the watershed surface to the deeper unsaturated, and saturated zones. Modeling of soil zone processes has been used to gain understanding of watershed hydrologic processes. The PSZ package can use available data at finer time increments to ensure precipitation is properly distributed between infiltration and runoff. This physically based partitioning of precipitation allows for a more robust estimation of recharge. The PSZ package is intended to be used in basin scale MODFLOW-2005 simulations for efficiently simulating watershed hydrologic processes, especially those processes that partition rainfall into evapotranspiration, runoff, and recharge.

  5. The effect of perch access during pullet rearing and egg laying on physiological measurements of stress in 71-week-old White Leghorns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Egg laying strains of chickens have a strong motivation to perch. Providing caged chickens with perches allows them to perform their natural perching instinct and also improves their musculoskeletal health due to exercise. Little is known about the effect of perch access by hens on physiological mea...

  6. 14 CFR 23.69 - Enroute climb/descent.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...; (3) The wing flaps retracted; and (4) A climb speed not less than 1.3 VS1. (b) One engine inoperative... maximum continuous power; (3) The landing gear retracted; (4) The wing flaps retracted; and (5) A...

  7. 14 CFR 23.69 - Enroute climb/descent.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; (3) The wing flaps retracted; and (4) A climb speed not less than 1.3 VS1. (b) One engine inoperative... maximum continuous power; (3) The landing gear retracted; (4) The wing flaps retracted; and (5) A...

  8. 14 CFR 23.69 - Enroute climb/descent.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...; (3) The wing flaps retracted; and (4) A climb speed not less than 1.3 VS1. (b) One engine inoperative... maximum continuous power; (3) The landing gear retracted; (4) The wing flaps retracted; and (5) A...

  9. 14 CFR 23.69 - Enroute climb/descent.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...; (3) The wing flaps retracted; and (4) A climb speed not less than 1.3 VS1. (b) One engine inoperative... maximum continuous power; (3) The landing gear retracted; (4) The wing flaps retracted; and (5) A...

  10. 14 CFR 23.69 - Enroute climb/descent.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; (3) The wing flaps retracted; and (4) A climb speed not less than 1.3 VS1. (b) One engine inoperative... maximum continuous power; (3) The landing gear retracted; (4) The wing flaps retracted; and (5) A...

  11. Energy state revisited. [for minimum-time aircraft climbs

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Cliff, E. M.; Weston, A. R.

    1983-01-01

    Kaiser (1944) has introduced the concept of 'resultant height' in connection with aircraft minimum-time climbs. Its use as a state variable in trajectory work is attractive because it is a 'slower' variable than either altitude or velocity. Kelley (1972, 1973) has made an attempt to synthesize 'slow' state variables in connection with singular-perturbation procedures. In the present investigation, attempts are made to synthesize both 'fast' and 'slow' variables for the minimum-time-to-climb problem along lines explored by Kelley. Attention is given to climb equations, energy-modeling simplifications, 'slow'-variable choice, 'fast'-variable-choice considerations, a singular-perturbation analysis, the choice of a 'fast' variable, and the climb-dash problem.

  12. 31. ELEVATED PIPELINE CLIMBING TOWARDS KALAWAO. PIPE CAN BE SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. ELEVATED PIPELINE CLIMBING TOWARDS KALAWAO. PIPE CAN BE SEEN EXPOSED AT TOP OF ROCK WALL. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

  13. Drug Overdose Deaths Climb Dramatically in U.S.

    MedlinePlus

    ... medlineplus.gov/news/fullstory_162641.html Drug Overdose Deaths Climb Dramatically in U.S. Prescription painkillers and heroin ... TUESDAY, Dec. 20, 2016 (HealthDay News) -- Drug overdose deaths continue to surge in the United States, with ...

  14. 14 CFR 29.1045 - Climb cooling test procedures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... altitude and end at the higher of— (1) The maximum altitude at which level flight can be maintained with one engine operative; and (2) Sea level. (f) The climb or descent must be conducted at an...

  15. 14 CFR 29.1045 - Climb cooling test procedures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... altitude and end at the higher of— (1) The maximum altitude at which level flight can be maintained with one engine operative; and (2) Sea level. (f) The climb or descent must be conducted at an...

  16. 14 CFR 29.1045 - Climb cooling test procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... altitude and end at the higher of— (1) The maximum altitude at which level flight can be maintained with one engine operative; and (2) Sea level. (f) The climb or descent must be conducted at an...

  17. 14 CFR 29.1045 - Climb cooling test procedures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... altitude and end at the higher of— (1) The maximum altitude at which level flight can be maintained with one engine operative; and (2) Sea level. (f) The climb or descent must be conducted at an...

  18. 14 CFR 29.1045 - Climb cooling test procedures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... altitude and end at the higher of— (1) The maximum altitude at which level flight can be maintained with one engine operative; and (2) Sea level. (f) The climb or descent must be conducted at an...

  19. Reproductive health of yellow perch, Perca flavescens, in Chesapeake Bay Tributaries

    USGS Publications Warehouse

    Blazer, Vicki; Pinkney, A.E.; Uphoff, James H.

    2013-01-01

    Yellow perch live in creeks, rivers, ponds, lakes, and estuaries across the central and eastern United States and Canada. In Chesapeake Bay, they tolerate salinities up to one-third that of seawater. The adults reside in the brackish waters of the bay’s tributaries and migrate upstream to spawn. Yellow perch are eagerly sought by recreational fishermen for their excellent taste and, because their late winter spawning runs are the earliest of the year, they are regarded as a harbinger of spring. Yellow perch also support a small but valuable, tightly regulated commercial fishery in the part of Chesapeake Bay that lies in Maryland.

  20. Pesticide residues and heavy metals in Lake Victoria Nile perch, Lates niloticus, belly flap oil.

    PubMed

    Ogwok, P; Muyonga, J H; Sserunjogi, M L

    2009-05-01

    Oil was extracted from the belly flaps of varied sizes of Nile perch caught from Lake Victoria (Uganda). The oil was analyzed for pesticide residues and heavy metals. Total residual concentration of dichlorodiphenyltrichloroethane, endosulfan, hexachlorocyclohexane, hexachlorobenzene, heptachlor, chlordane, endrin, aldrin and chlorofenvinphos increased significantly (p < 0.05) with fish size. Mercury and lead were detected in most samples while arsenic and cadmium were below detection limits. Nile perch may, therefore, accumulate significant amount of chemical contaminants. Levels of contaminants in Nile perch oil were, in general, within limits considered acceptable by the stringent German Food Law for human consumption.

  1. The flexor tendon pulley system and rock climbing.

    PubMed

    Crowley, Timothy P

    2012-06-01

    Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers. This article reviews the anatomy and biomechanics of the finger flexor tendon pulleys, how they may be injured in rock climbing and how these injuries are best diagnosed and managed.

  2. Self-reported ability assessment in rock climbing.

    PubMed

    Draper, Nick; Dickson, Tabitha; Blackwell, Gavin; Fryer, Simon; Priestley, Sefton; Winter, David; Ellis, Greg

    2011-05-01

    Level of ability within rock climbing is generally expressed in terms of a "best ascent", rated using various grading systems within the sport. The most common method of obtaining this information is via self-report. The aim of this study was to examine the validity of self-reported climbing grades. Twenty-nine competitive rock climbers (17 males, 12 females) were first asked to report their current (defined as within the last 12 months) best on-sight lead ascent grade (Aus/NZ). The participants then climbed a specifically designed indoor route, under on-sight conditions (one attempt, no route practice or preview), to obtain an assessed grade. The route increased in difficulty, and was such that the distance achieved by the climber corresponded to a particular grade. The mean (±standard deviation) self-reported and assessed grade was 22.6 ± 3.4 and 22.0 ± 3.0 (Aus/NZ) respectively. Despite slight over- and underestimations in males and females respectively, there was no statistically significant difference between self-reported and assessed on-sight climbing grades. The results of this study suggest that self-reported climbing grades provide a valid and accurate reflection of climbing ability.

  3. Skill transfer, affordances and dexterity in different climbing environments.

    PubMed

    Seifert, L; Wattebled, L; L'hermette, M; Bideault, G; Herault, R; Davids, K

    2013-12-01

    This study explored how skills in one region of a perceptual-motor landscape of performance, created in part by previous experience in rock climbing, can shape those that emerge in another region (ice climbing). Ten novices in rock climbing and five intermediate rock climbers were observed climbing an icefall. Locations of right and left ice tools and crampons were videotaped from a frontal camera. Inter-individual variability of upper and lower limb couplings and types of action regarding icefall properties were assessed by cluster hierarchical analysis, distinguishing three clusters. Pelvis vertical displacement, duration and number of pelvis pauses were also analyzed. Experienced rock climbers were grouped in the same cluster and showed the highest range and variability of limb angular locations and coordination patterns, the highest vertical displacement and the shortest pelvis plateaux durations. Non-fluent climbers (clusters 2 and 3) showed low range and variability of limb angular locations and coordination patterns. In particular, climbers of cluster 3 exhibited the lowest vertical displacement, the longest plateaux durations and the greatest ratio between tool swinging and definitive anchorage. Our results exemplified the positive influence of skills in rock climbing on ice climbing performance, facilitated by the detection of affordances from environmental properties.

  4. Mercury accumulation in yellow perch in Wisconsin seepage lakes: Relation to lake characteristics

    USGS Publications Warehouse

    Cope, W.G.; Wiener, J.G.; Rada, R.G.

    1990-01-01

    We studied relations between lacustrine characteristics and the total mercury (Hg) content of calendar age- 2 yellow perch (Perca flavescens ) in 10 seepage lakes in north-central Wisconsin. Mean concentrations and burdens (masses) of Hg in whole perch varied widely among lakes, were negatively correlated with lake pH and were positively correlated with total Hg concentration in surficial profundal sediment. Approximately 80 to 90% of the variation in Hg concentration and burden in whole perch was explained with multiple regressions containing two independent variables: either lake pH or alkalinity, and Hg concentration in surficial sediment. The mean concentration of Hg in axial muscle tissue of age-5 walleyes (Stizostedion vitreum vitreum ) from five of the study lakes was highly correlated with the mean concentration in whole age-2 perch in the same lakes.

  5. Characterization and Extraction of Uranium Contamination Perched within the Deep Vadose Zone at the Hanford Site, Washington State

    NASA Astrophysics Data System (ADS)

    Williams, B. A.; Rohay, V. J.; Benecke, M. W.; Chronister, G. B.; Doornbos, M. H.; Morse, J.

    2012-12-01

    A highly contaminated perched water zone has been discovered in the deep vadose zone above the unconfined aquifer during drilling of wells to characterize groundwater contamination within the 200 East Area of the U.S. Department of Energy's Hanford Site in southeast Washington. The perched water, which contains nitrate, uranium, and technetium-99 at concentrations that have exceeded 100,000 μg/L, 70,000 μg/L, and 45,000 pCi/L respectively, is providing contamination to the underlying unconfined aquifer. A perched zone extraction well has been installed and is successfully recovering the contaminated perched water as an early remedial measure to reduce impacts to the unconfined aquifer. The integration and interpretation of various borehole hydrogeologic, geochemical, and geophysical data sets obtained during drilling facilitated the delineation of the perching horizon and determination of the nature and extent of the perched contamination. Integration of the borehole geologic and geophysical logs defined the structural elevation and thickness of the perching low permeability silt interval. Borehole geophysical moisture logs, gamma logs, and sample data allowed detailed determination of the elevation and thickness of the oversaturated zone above the perching horizon, and the extent and magnitude of the radiological uranium contamination within the perching interval. Together, these data sets resolved the nature of the perching horizon and the location and extent of the contaminated perched water within the perching zone, allowing an estimation of remaining contaminant extent. The resulting conceptual model indicates that the contaminated perched water is contained within a localized sand lens deposited in a structural low on top of a semi-regional low-permeability silt layer. The top of the sand lens is approximately 72 m (235 ft) below ground surface; the maximum thickness of the sand lens is approximately 3 m (10 ft). The lateral and vertical extent of the

  6. Nitrate-nitrogen concentrations in the perched ground water under seepage-irrigated potato cropping systems.

    PubMed

    Munoz-Arboleda, F; Mylavarapu, R; Hutchinson, C; Portier, K

    2008-01-01

    Excessive nitrogen rates for potato production in northeast Florida have been declared as a potential source of nitrate pollution in the St. Johns River watershed. This 3-yr study examined the effect of N rates (0, 168, and 280 kg ha(-1)) split between planting and 40 d after planting on the NO(3)-N concentration in the perched ground water under potato (Solanum tuberosum cv. Atlantic) in rotation with sorghum sudan grass hybrid (Sorghum vulgare x Sorghum vulgare var. sudanese, cv. SX17), cowpea (Vigna unguiculata cv. Iron Clay), and greenbean (Phaseolus vulgare cv. Espada). Soil solution from the root zone and water from the perched ground water under potato were sampled periodically using lysimeters and wells, respectively. Fertilization at planting increased the NO(3)-N concentration in the perched ground water, but no effect of the legumes in rotation with potatoes on nitrate leaching was detected. Fertilization of green bean increased NO(3)-N concentration in the perched ground water under potato planted in the following season. The NO(3)-N concentration in the soil solution within the potato root zone followed a similar pattern to that of the perched ground water but with higher initial values. The NO(3)-N concentration in the perched ground water was proportional to the rainfall magnitude after potato planting. A significant increase in NO(3)-N concentration in the perched ground water under cowpea planted in summer after potato was detected for the side-dressing of 168 kg ha(-1) N applied to potato 40 d after planting but not at the 56 kg ha(-1) N side-dress. Elevation in NO(3)-N concentration in the perched ground water under sorghum was not significant, supporting its use as an effective N catch crop.

  7. Investigation of groundwater recirculation for the removal of RDX from the Pantex Plant perched aquifer

    SciTech Connect

    Woods, A.L.; Barnes, D.L.; Boles, K.M.; Charbeneau, R.J.; Black, S.; Rainwater, K.

    1998-07-01

    The Pantex Plant near Amarillo, Texas, is a US Department of Energy (DOE) facility that has been in operation since 1942. Past and present operations at Pantex include the creation of chemical high explosives components for nuclear weapons and assembly and disassembly of nuclear weapons. The Pantex Plant is underlain by the Ogallala aquifer, which in this area, consists of the main water-bearing unit and a perched water zone. These are separated by a fine-grained zone of low permeability. Multiple contaminant plumes containing high explosive (HE) compounds have been detected in the perched aquifer beneath the plant. The occurrence of these contaminants is the result of past waste disposal practices at the facility. RDX is an HE compound, which has been detected in the groundwater of the perched aquifer at significant concentrations. A pilot-scale, dual-phase extraction treatment system has been installed at one location at the plant, east of Zone 12, to test the effectiveness of such a system on the removal of these contaminants from the subsurface. A tracer test using a conservative tracer, bromide (Br), was conducted at the treatment site in 1996. In addition to the bromide, RDX and water elevations in the aquifer were monitored. Using data from the tracer test and other relevant data from the investigations at Pantex, flow and contaminant transport in the perched aquifer were simulated with groundwater models. The flow was modeled using MODFLOW and the transport of contaminants in the aqueous phase was modeled using MT3D. Modeling the perched aquifer had been conducted to characterize the flow in the perched aquifer; estimate RDX retardation in the perched aquifer; and evaluate the use of groundwater re-circulation to enhance the extraction of RDX from the perched aquifer.

  8. Susceptibility of Koi and Yellow Perch to infectious hematopoietic necrosis virus by experimental exposure

    USGS Publications Warehouse

    Palmer, Alexander D.; Emmenegger, Eveline J.

    2014-01-01

    Infectious hematopoietic necrosis virus (IHNV) is a novirhabdoviral pathogen that originated in western North America among anadromous Pacific salmonids. Severe disease epidemics in the late 1970s resulting from IHNV's invasion into farmed Rainbow Trout Oncorhynchus mykiss in North America, Asia, and Europe emphasized IHNV's ability to adapt to new hosts under varying rearing conditions. Yellow Perch Perca flavescens and Koi Carp Cyprinus carpio (hereafter, “Koi”) are aquaculture-reared fish that are highly valued in sport fisheries and the ornamental fish trade, respectively, but it is unknown whether these fish species are vulnerable to IHNV infection. In this study, we exposed Yellow Perch, Koi, and steelhead (anadromous Rainbow Trout) to IHNV by intraperitoneal injection (106 PFU/fish) and by immersion (5.7×105 PFU/mL) for 7 h, and monitored fish for 28 d. The extended immersion exposure and high virus concentrations used in the challenges were to determine if the tested fish had any level of susceptibility. After experimental exposure, Yellow Perch and Koi experienced low mortality (35%). Virus was found in dead fish of all species tested and in surviving Yellow Perch by plaque assay and quantitative reverse transcription polymerase chain reaction (qPCR), with a higher prevalence in Yellow Perch than Koi. Infectious virus was also detected in Yellow Perch out to 5 d after bath challenge. These findings indicate that Yellow Perch and Koi are highly resistant to IHNV disease under the conditions tested, but Yellow Perch are susceptible to infection and may serve as possible virus carriers.

  9. Soft Perches in an Aviary System Reduce Incidence of Keel Bone Damage in Laying Hens

    PubMed Central

    Stratmann, Ariane; Fröhlich, Ernst K. F.; Harlander-Matauschek, Alexandra; Schrader, Lars; Toscano, Michael J.; Würbel, Hanno; Gebhardt-Henrich, Sabine G.

    2015-01-01

    Keel bone fractures and deviations are one of the major welfare and health issues in commercial laying hens. In non-cage housing systems like aviaries, falls and collisions with perches and other parts of the housing system are assumed to be one of the main causes for the high incidence of keel bone damage. The objectives of this study were to investigate the effectiveness of a soft perch material to reduce keel bone fractures and deviations in white (Dekalb White) and brown laying hens (ISA Brown) kept in an aviary system under commercial conditions. In half of 20 pens, all hard, metal perches were covered with a soft polyurethane material. Palpation of 20 hens per pen was conducted at 18, 21, 23, 30, 38, 44 and 64 weeks of age. Production data including egg laying rate, floor eggs, mortality and feed consumption were collected over the whole laying period. Feather condition and body mass was assessed twice per laying period. The results revealed that pens with soft perches had a reduced number of keel bone fractures and deviations. Also, an interaction between hybrid and age indicated that the ISA hybrid had more fractured keel bones and fewer non-damaged keel bones compared with the DW hybrid at 18 weeks of age, a response that was reversed at the end of the experiment. This is the first study providing evidence for the effectiveness of a soft perch material within a commercial setting. Due to its compressible material soft perches are likely to absorb kinetic energy occurring during collisions and increase the spread of pressure on the keel bone during perching, providing a mechanism to reduce keel bone fractures and deviations, respectively. In combination with genetic selection for more resilient bones and new housing design, perch material is a promising tool to reduce keel bone damage in commercial systems. PMID:25811980

  10. Growth and potential yield of perch (Perca spp.) in selected areas of Lake Baikal and the Laurentian Great Lakes

    USGS Publications Warehouse

    O'Gorman, Robert; Bronte, Charles R.; Hatcher, Charles O.; Pronin, Nikolai M.; Sokolnikov, Yury

    1998-01-01

    We compared growth, mortality, and potential yield of Eurasian perch (Perca fluviatilis) from Chivirkui Bay in Lake Baikal with that of yellow perch (P. flavescens) from three areas of the Laurentian Great Lakes --Chequamegon Bay in Lake Superior, northeastern Lake Ontario, and southwestern Lake Erie. Graded mesh gill nets were fished in August to sample perch in lakes Baikal (1993), Ontario (1985-93), and Erie (1994). Bottom trawls were fished in July-August to sample perch in Lake Superior (1973-93). Adult yellow perch from the Laurentian Great Lakes were heavier at most lengths than adult Eurasian perch from Lake Baikal. The increase in body weight per unit increase in length was greatest in Lake Erie. Total annual mortality of perch was low in Lake Baikal (0.31), intermediate in lakes Superior (0.41) and Ontario (0.54), and high in Lake Erie (0.66). Annual fishing mortality (u) for perch in Lake Baikal was 60%-70% lower than that for perch in the Great Lakes. At ages 1-3, perch in Lake Erie were longer than those in lakes Baikal, Superior, and Ontario but at ages 4-9 perch in Lake Baikal were longer than those in the other lakes. Although Eurasian perch in Lake Baikal were longer at age 4 and older, growth in length, as measured by the Brody growth coefficient, K, was lower there than in the other lakes and was similar to that in Lake Superior; yellow perch in Lake Erie grew the fastest. Yield-per-recruit was lowest in Lake Erie and highest in Lake Superior. Potential yield was influenced by growth rates and fishing mortality.

  11. Fish community dynamics in northeastern Lake Ontario with emphasis on the growth and reproductive success of yellow perch (Perca flavescens) and white perch (Morone americana), 1978 to1997

    USGS Publications Warehouse

    O'Gorman, Robert; Burnett, John A.D.

    2001-01-01

    Fishes were assessed in Guffin, Chaumount, and Black River bays in northeastern Lake Ontario with a 7.9-m (headrope) bottom trawl during late September and early October, 1978 to 1997. Fish density declined in the early 1990s with sharp declines in abundance of spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), and johnny darter (Etheostoma nigrum) occurring in 1993 to 1995. Rising numbers of piscivores, walleye (Stizostedion vitreum) and double-crested cormorant (Phalacrocorax auritus), increased predation pressure, presumably acting in concert with oligotrophication to lower fish density, particularly after 1991 when large numbers of adult alewife (Alosa pseudoharengus) no longer migrated to the northeast basin in spring. Annual mortality of yellow perch (Perca flavescens) from age 2 to 5 rose from 33% in 1980–83 to 65% in 1992–95 and was positively related to piscivore numbers (P = 0.01, r = 0.96, n = 5). Annual mortality of yellow perch from age 0 to 2 also peaked in 1992–95. Abundance of yellow perch YOY in fall varied 40 fold and was not related to water warming in spring (P = 0.45, r = −0.19, n = 18) but was negatively related to the abundance of adult alewives in spring (P = 0.04, r = −0.49, n = 18). Although yellow perch produced moderate to strong year classes each year during 1991–95, stock size failed to increase because of rapidly accelerating mortality. Fully 85% of the variation in mean length of yellow perch YOY was explained by a multiple regression model which included YOY abundance, mean total phosphorus, and cumulative degree days > 13.5°C (P < 0.01, n = 15). Abundance of white perch (Morone americana) YOY varied nearly 200 fold and was not related to water warming or spring alewife abundance (P > 0.15). Variation in mean length of white perch YOY was related to cumulative degree days > 15°C (P < 0.01, r = 0.69).

  12. Impact of impingement on the Hudson River white perch population. Final report

    SciTech Connect

    Barnthouse, L.W.; Van Winkle, W.; Kirk, B.L.; Vaughan, D.S.

    1982-02-01

    This report summarizes a series of analyses of the magnitude and biological significance of the impingement of white perch at the Indian Point Nuclear Generating Station and other Hudson River power plants. Included in these analyses were evaluations of: (1) two independent lines of evidence relating to the magnitude of impingement impacts on the Hudson River white perch population; (2) the additional impact caused by entrainment of white perch; (3) data relating to density-dependent growth among young-of-the-year white perch; (4) the feasibility of performing population-level analyses of impingement impacts on the white perch populations of Chesapeake Bay and the Delaware River; and (5) the feasibility of using simple food chain and food web models to evaluate community-level effects of impingement and entrainment. Estimated reductions in the abundances of the 1974 and 1975 white perch year classes, caused by impingement and entrainment, were high enough that the possibility of adverse long-term effects cannot be excluded.

  13. Hemodynamic and cardiorespiratory predictors of sport rock climbing performance.

    PubMed

    Fryer, Simon; Giles, David; Palomino, Inmaculada Garrido; Puerta, Alejandro de la O; Romero, Vanesa España

    2017-03-13

    Rock climbing performance has been suggested to involve a notable contribution from the aerobic metabolism. Previously it has been shown that forearm oxygenation kinetics can be used to distinguish ability groups and predict red-point sport climbing performance. Currently it is not known if forearm oxygenation kinetics, or a sport specific assessment of cardiorespiratory fitness best predicts sport rock climbing performance. The aim of the study was to determine whether forearm oxidative capacity index, maximal de-oxygenation (Δ score) during a treadwall V[Combining Dot Above]O[SUBSCRIPT TWO]peak test, treadwall V[Combining Dot Above]O[SUBSCRIPT TWO]peak, or running V[Combining Dot Above]O[SUBSCRIPT TWO]max best predicts self-reported sport climbing performance. Twenty-one male sport rock climbers completed a treadwall V[Combining Dot Above]O[SUBSCRIPT TWO]peak, running V[Combining Dot Above]O[SUBSCRIPT TWO]max and an assessment of near infrared spectroscopy derived oxidative capacity index. Linear regression, adjusted for age and experience (years), revealed that forearm oxidative capacity index, treadwall maximal de-oxygenation (Δ) and treadwall V[Combining Dot Above]O[SUBSCRIPT TWO]peak all significantly predicted self-reported red-point sport climbing ability (Adj R[SUBSCRIPT TWO] =-0.398; -0.255; 0.374 respectively), whereas treadmill running V[Combining Dot Above]O2max did not (Adj R[SUBSCRIPT TWO] =0.-0.052). Additionally, multiple regression suggested that the combined significant aerobic predictors accounted for 67% of the variance in red-point climbing ability. Findings suggest that training for sport rock climbing performance should look to incorporate modalities which focus on 1) improving local forearm aerobic capacity, and 2) improving whole body aerobic capacity using sport-specific apparatus such as treadwalls.

  14. Dynamics of a yellow perch population in western Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.; Selgeby, James H.; Swedberg, Donald V.

    1993-01-01

    Yellow perch Perca flavescens were sampled annually in 1973–1988 with bottom trawls in Chequamegon Bay, Lake Superior. Biomass averaged l.6 kg/hectare. Fish l–3 years old made up 64% of the biomass, whereas fish of harvestable size (≥4 years old) made up only 31% of the biomass. Year-class strength was variable among years, but a Ricker recruitment function described the relation between year-class strength and parental stock size, Age-specific mortality increased substantially as fish became sexually mature at age 4, perhaps as a result of energy depletion associated with high reproductive and maintenance costs in a suboptimal thermal environment. Yield-per-recruit analysis indicated that most of the age-specific annual mortality was due to natural causes. Natural mortality, rather than limited recruitment or fishing mortality, was the major factor controlling harvestable stock size, Regardless of the size of a year-class produced, natural mortality greatly reduced its abundance prior to maturity and recruitment to the fishable stock. This high mortality, combined with very slow growth, limits the biomass potential of the harvestable stock, and sustainable yields from this population are therefore low.

  15. A Southern Bald Eagle perches on a pole at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A Southern Bald Eagle perches on top of a utility pole at Kennedy Space Center. About a dozen bald eagles live in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The Southern Bald Eagle ranges throughout Florida and along the coasts of California, Texas, Louisiana, and the south Atlantic states. Bald Eagles are listed as endangered in the U.S., except in five states where they are listed as threatened. The number of nesting pairs of the southern race once numbered several thousand; recent estimates are only 350-375. Most of the southern race nest in Florida. Eagles arrive at KSC during late summer and leave for the north in late spring. They move to nest sites in October and November and lay one to three eggs. The young fledge from February to April. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  16. A Southern Bald Eagle perches on a pole at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A Southern Bald Eagle perched on top of a utility pole searches the area. About a dozen bald eagles live in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The Southern Bald Eagle ranges throughout Florida and along the coasts of California, Texas, Louisiana, and the south Atlantic states. Bald Eagles are listed as endangered in the U.S., except in five states where they are listed as threatened. The number of nesting pairs of the southern race once numbered several thousand; recent estimates are only 350-375. Most of the southern race nest in Florida. Eagles arrive at KSC during late summer and leave for the north in late spring. They move to nest sites in October and November and lay one to three eggs. The young fledge from February to April. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  17. Metabolic demands of rock climbing in transfemoral amputees.

    PubMed

    Highsmith, M J; Kahle, J T; Fox, J L; Shaw, K L; Quillen, W S; Mengelkoch, L J

    2010-01-01

    This pilot study compared the energy expenditure required to climb an indoor rock wall, in amputees utilizing five prosthetic configurations. Three experienced climbers (1M age 21 yr, 2F ages 30 and 49 yr) with unilateral transfemoral amputation climbed a 9.14 m indoor rock wall, 5.9 Yosemite Decimal Scale rating, using the following prosthetic configurations: 1. no prosthesis; 2. stubby prosthesis-foot forward; 3. stubby prosthesis-foot backward; 4. articulated prosthesis-knee unlocked; 5. articulated prosthesis-knee locked. Subjects climbed three times with each configuration resulting in 15 climbs per subject. Metabolic data was collected using the COSMED K4b(2) system. VO(2) was 15, 18 and 20% greater in the articulated unlocked condition (mean+/-SE: 20.5+/-0.8 ml.kg (-1).min (-1)), and 11, 13 and 15% greater in the articulated locked condition (19.7+/-0.9 ml.kg (-1).min (-1)), compared to the no prosthesis (17.8+/-0.7 ml.kg (-1).min (-1)), stubby backward (17.4+/-0.7 ml.kg (-1).min (-1)) and stubby forward (17.1+/-0.9 ml.kg (-1).min (-1)) conditions. Participants expended 11-20% more energy using the articulated prostheses than with the stubby and no prosthesis conditions. In persons with transfemoral amputation, use of an articulated prosthesis in indoor rock climbing may be a disadvantage in many aspects including competition, training, rehabilitation and satisfaction with the activity.

  18. Physiological responses to rock climbing in young climbers.

    PubMed

    Morrison, Audry Birute; Schöffl, Volker Rainer

    2007-12-01

    Key questions regarding the training and physiological qualities required to produce an elite rock climber remain inadequately defined. Little research has been done on young climbers. The aim of this paper was to review literature on climbing alongside relevant literature characterising physiological adaptations in young athletes. Evidence-based recommendations were sought to inform the training of young climbers. Of 200 studies on climbing, 50 were selected as being appropriate to this review, and were interpreted alongside physiological studies highlighting specific common development growth variables in young climbers. Based on injury data, climbers younger than 16 years should not participate in international bouldering competitions and intensive finger strength training is not recommended. The majority of climbing foot injuries result from wearing too small or unnaturally shaped climbing shoes. Isometric and explosive strength improvements are strongly associated with the latter stages of sexual maturation and specific ontogenetic development, while improvement in motor abilities declines. Somatotyping that might identify common physical attributes in elite climbers of any age is incomplete. Accomplished adolescent climbers can now climb identical grades and compete against elite adult climbers aged up to and >40 years. High-intensity sports training requiring leanness in a youngster can result in altered and delayed pubertal and skeletal development, metabolic and neuroendocrine aberrations and trigger eating disorders. This should be sensitively and regularly monitored. Training should reflect efficacious exercises for a given sex and biological age.

  19. Assessing controls on perched saturated zones beneath the Idaho Nuclear Technology and Engineering Center, Idaho

    USGS Publications Warehouse

    Mirus, Benjamin B.; Perkins, Kim S.; Nimmo, John R.

    2011-01-01

    Waste byproducts associated with operations at the Idaho Nuclear Technology and Engineering Center (INTEC) have the potential to contaminate the eastern Snake River Plain (ESRP) aquifer. Recharge to the ESRP aquifer is controlled largely by the alternating stratigraphy of fractured volcanic rocks and sedimentary interbeds within the overlying vadose zone and by the availability of water at the surface. Beneath the INTEC facilities, localized zones of saturation perched on the sedimentary interbeds are of particular concern because they may facilitate accelerated transport of contaminants. The sources and timing of natural and anthropogenic recharge to the perched zones are poorly understood. Simple approaches for quantitative characterization of this complex, variably saturated flow system are needed to assess potential scenarios for contaminant transport under alternative remediation strategies. During 2009-2011, the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, employed data analysis and numerical simulations with a recently developed model of preferential flow to evaluate the sources and quantity of recharge to the perched zones. Piezometer, tensiometer, temperature, precipitation, and stream-discharge data were analyzed, with particular focus on the possibility of contributions to the perched zones from snowmelt and flow in the neighboring Big Lost River (BLR). Analysis of the timing and magnitude of subsurface dynamics indicate that streamflow provides local recharge to the shallow, intermediate, and deep perched saturated zones within 150 m of the BLR; at greater distances from the BLR the influence of streamflow on recharge is unclear. Perched water-level dynamics in most wells analyzed are consistent with findings from previous geochemical analyses, which suggest that a combination of annual snowmelt and anthropogenic sources (for example, leaky pipes and drainage ditches) contribute to recharge of shallow and

  20. Ladder Climbing and Autoresonant Acceleration of Plasma Waves

    NASA Astrophysics Data System (ADS)

    Barth, I.; Dodin, I. Y.; Fisch, N. J.

    2015-08-01

    When the background density in a bounded plasma is modulated in time, discrete modes become coupled. Interestingly, for appropriately chosen modulations, the average plasmon energy might be made to grow in a ladderlike manner, achieving upconversion or downconversion of the plasmon energy. This reversible process is identified as a classical analog of the effect known as quantum ladder climbing, so that the efficiency and the rate of this process can be written immediately by analogy to a quantum particle in a box. In the limit of a densely spaced spectrum, ladder climbing transforms into continuous autoresonance; plasmons may then be manipulated by chirped background modulations much like electrons are autoresonantly manipulated by chirped fields. By formulating the wave dynamics within a universal Lagrangian framework, similar ladder climbing and autoresonance effects are predicted to be achievable with general linear waves in both plasma and other media.

  1. Ladder Climbing and Autoresonant Acceleration of Plasma Waves.

    PubMed

    Barth, I; Dodin, I Y; Fisch, N J

    2015-08-14

    When the background density in a bounded plasma is modulated in time, discrete modes become coupled. Interestingly, for appropriately chosen modulations, the average plasmon energy might be made to grow in a ladderlike manner, achieving upconversion or downconversion of the plasmon energy. This reversible process is identified as a classical analog of the effect known as quantum ladder climbing, so that the efficiency and the rate of this process can be written immediately by analogy to a quantum particle in a box. In the limit of a densely spaced spectrum, ladder climbing transforms into continuous autoresonance; plasmons may then be manipulated by chirped background modulations much like electrons are autoresonantly manipulated by chirped fields. By formulating the wave dynamics within a universal Lagrangian framework, similar ladder climbing and autoresonance effects are predicted to be achievable with general linear waves in both plasma and other media.

  2. Pure climb creep mechanism drives flow in Earth's lower mantle.

    PubMed

    Boioli, Francesca; Carrez, Philippe; Cordier, Patrick; Devincre, Benoit; Gouriet, Karine; Hirel, Pierre; Kraych, Antoine; Ritterbex, Sebastian

    2017-03-01

    At high pressure prevailing in the lower mantle, lattice friction opposed to dislocation glide becomes very high, as reported in recent experimental and theoretical studies. We examine the consequences of this high resistance to plastic shear exhibited by ringwoodite and bridgmanite on creep mechanisms under mantle conditions. To evaluate the consequences of this effect, we model dislocation creep by dislocation dynamics. The calculation yields to an original dominant creep behavior for lower mantle silicates where strain is produced by dislocation climb, which is very different from what can be activated under high stresses under laboratory conditions. This mechanism, named pure climb creep, is grain-size-insensitive and produces no crystal preferred orientation. In comparison to the previous considered diffusion creep mechanism, it is also a more efficient strain-producing mechanism for grain sizes larger than ca. 0.1 mm. The specificities of pure climb creep well match the seismic anisotropy observed of Earth's lower mantle.

  3. Strange Beta: Chaotic Variations for Indoor Rock Climbing Route Setting

    NASA Astrophysics Data System (ADS)

    Phillips, Caleb; Bradley, Elizabeth

    2011-04-01

    In this paper we apply chaotic systems to the task of sequence variation for the purpose of aiding humans in setting indoor rock climbing routes. This work expands on prior work where similar variations were used to assist in dance choreography and music composition. We present a formalization for transcription of rock climbing problems and a variation generator that is tuned for this domain and addresses some confounding problems, including a new approach to automatic selection of initial conditions. We analyze our system with a large blinded study in a commercial climbing gym in cooperation with experienced climbers and expert route setters. Our results show that our system is capable of assisting a human setter in producing routes that are at least as good as, and in some cases better than, those produced traditionally.

  4. Room-temperature dislocation climb in copper-niobium interfaces

    SciTech Connect

    Wang, Jian; Hoagland, Richard G; Hirth, John P; Misra, Amit

    2008-01-01

    Using atomistic simulations, we show that dislocations climb efficiently in metallic copper-niobium interfaces through absorption and emission of vacancies in the dislocation core, as well as an associated counter diffusion of Cu atoms in the interfacial plane. The high efficiency of dislocation climb in the interface is ascribed to the high vacancy concentration of 0.05 in the interfacial plane, the low formation energy of 0.12 e V with respect to removal or insertion of Cu atoms, as well as the low kinetic barrier of 0.10 eV for vacancy migration in the interfacial Cu plane. Dislocation climb in the interface facilitates reactions of interfacial dislocations, and enables interfaces to be in the equilibrium state with respect to concentrations ofpoint defects.

  5. Kasner solutions, climbing scalars and big-bang singularity

    SciTech Connect

    Condeescu, Cezar; Dudas, Emilian E-mail: emilian.dudas@cpht.polytechnique.fr

    2013-08-01

    We elaborate on a recently discovered phenomenon where a scalar field close to big-bang is forced to climb a steep potential by its dynamics. We analyze the phenomenon in more general terms by writing the leading order equations of motion near the singularity. We formulate the conditions for climbing to exist in the case of several scalars and after inclusion of higher-derivative corrections and we apply our results to some models of moduli stabilization. We analyze an example with steep stabilizing potential and notice again a related critical behavior: for a potential steepness above a critical value, going backwards towards big-bang, the scalar undergoes wilder oscillations, with the steep potential pushing it back at every passage and not allowing the scalar to escape to infinity. Whereas it was pointed out earlier that there are possible implications of the climbing phase to CMB, we point out here another potential application, to the issue of initial conditions in inflation.

  6. Influence of climbing style on physiological responses during indoor rock climbing on routes with the same difficulty.

    PubMed

    de Geus, Bas; Villanueva O'Driscoll, Seán; Meeusen, Romain

    2006-11-01

    The objectives of this study were to (1) continuously assess oxygen uptake and heart rate; (2) quantify the extent to which maximal whole-body cardiorespiratory capacity is utilized during climbing on four routes with the same difficulty but different steepness and/or displacement. Fifteen expert climbers underwent a maximal graded exercise test (MT), on a treadmill, in order to assess their maximal physiological capacity. After MT, four sport routes, equal in difficulty rating but different in steepness and/or displacement, were climbed. Oxygen uptake and heart rate were continuously measured. Respiratory exchange ratio (RER) was calculated. Blood lactate concentration and rating of perceived exertion (RPE) were taken before and directly after climbing. Data were expressed as peak values (HRpeak, VO2peak and RERpeak) and as averages over the entire climb (HRavg, VO2avg and RERavg). During climbing, higher HRpeak and HRavg were found in routes with a vertical upward displacement in comparison to traversing routes with a horizontal displacement. The average absolute and relative oxygen uptake was significantly lower in the traversing route in comparison with the three other routes. The traverse is done at a lower percent of the running maximum. Comparing four routes with the same difficulty but different steepness and/or displacement shows that (1) routes with an upward displacement causes the highest peak and average heart rate; (2) routes with a vertical displacement on overhanging wall is physiologically the most demanding; (3) the traverse is physiologically the less demanding.

  7. Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption

    USGS Publications Warehouse

    Roberts, James J.; Grecay, Paul A.; Ludsin, Stuart A.; Pothoven, Steve A.; Vanderploeg, Henry A.; Höök, Tomas O.

    2012-01-01

    Previous studies in a variety of ecosystems have shown that ecologically and economically important benthic and bentho-pelagic fishes avoid hypoxic (−1) habitats by moving vertically or horizontally to more oxygenated areas. While avoidance of hypoxic conditions generally leads to a complete shift away from preferred benthic prey, some individual fish continue to consume benthic prey items in spite of bottom hypoxia, suggesting complex habitat utilisation and foraging patterns. For example, Lake Erie yellow perch (Perca flavescens) continue to consume benthic prey, despite being displaced vertically and horizontally by hypolimnetic hypoxia. We hypothesised that hypolimnetic hypoxia can negatively affect yellow perch by altering their distribution and inducing energetically expensive foraging behaviour. To test this hypothesis, we used drifting hydroacoustics and trawl sampling to quantify water column distribution, sub-daily vertical movement and foraging behaviour of yellow perch within hypoxic and normoxic habitats of Lake Erie’s central basin during August-September 2007. We also investigated the effects of rapid changes in ambient oxygen conditions on yellow perch consumption potential by exposing yellow perch to various static and fluctuating oxygen conditions in a controlled laboratory experiment. Our results indicate that, while yellow perch in general avoid hypoxic conditions, some individuals undertake foraging forays into hypoxic habitats where they experience greater fluctuations in abiotic conditions (pressure, temperature and oxygen concentration) than at normoxic sites. However, laboratory results suggest short-term exposure to low oxygen conditions did not negatively impact consumption potential of yellow perch. Detailed understanding of sub-daily individual behaviours may be crucial for determining interactive individual- and ecosystem-level effects of stressors such as hypoxia.

  8. Finding paradise: cues directing the migration of the waterfall climbing Hawaiian gobioid Sicyopterus stimpsoni.

    PubMed

    Leonard, G; Maie, T; Moody, K N; Schrank, G D; Blob, R W; Schoenfuss, H L

    2012-07-01

    A series of waterfall-climbing trials were conducted to identify cues that direct the climbing of juvenile Sicyopterus stimpsoni. In the first experiment, whether climbing juveniles preferentially ascend water sources with conspecifics or whether the presence of just stream water is sufficient to attract fish to ascend a climbing path were assessed. In the second experiment, whether climbing juveniles create a trail of mucus that facilitates the ability of conspecifics to follow their lead was determined. The results indicate that juvenile S. stimpsoni are less likely to climb in waters devoid of organic cues but are strongly attracted to stream water with or without the odour of conspecifics. Once climbing, performance did not differ for juveniles climbing in differing water choices, suggesting an all-or-nothing commitment once climbing commences. Climbing S. stimpsoni did produce a mucous trail while climbing that was associated with a mucous gland that dramatically increases in size just prior to juveniles gaining the ability to climb. The trail was not followed closely by subsequent juveniles traversing the same channel, however, suggesting only weak trail-following in waterfall climbing S. stimpsoni. Previous genetic studies suggest that juvenile S. stimpsoni do not home to natal streams in the face of strong near-shore oceanic currents. Instead, these fish appear primarily to rely on cues that suggest the presence of organic growth in streams, a factor that may indicate suitable habitat in an ever-changing stream environment but which may also be vulnerable to interference through human activity.

  9. Cool perches improve the growth performance and welfare status of broiler chickens reared at different stocking densities and high temperatures.

    PubMed

    Zhao, J P; Jiao, H C; Jiang, Y B; Song, Z G; Wang, X J; Lin, H

    2013-08-01

    The present study investigated the interaction of stocking density and cool perch availability on broiler chickens raised at high ambient temperature (>30.8°C). Behavior, live performance, and the incidence of footpad and hock burns and abdominal plumage damage were investigated over a 4-wk experimental period. A total of 1,152 one-day-old Arbor Acres chicks were subjected to a 2 (cool perches) × 3 (stocking densities) factorial arrangement of treatments. From 1 d of age, birds were provided with or without cool perches at each of 3 stocking densities (12, 16, or 20 birds/m(2); low, medium, or high stocking density, respectively) and corresponded to 48, 64, and 80 birds per pen. The perch design provided 380 cm of linear perching space in each treatment pen. The results showed that high stocking density decreased the growth (P < 0.05) and welfare (P < 0.01) of broilers. Cool perch availability increased BW gain and feed conversion efficiency of broilers (P < 0.05) regardless of stocking density. The birds' use of cool perches increased with age (P < 0.01) and decreased with higher stocking density (P < 0.05). The accessibility of cool perches changed birds' behavior patterns (P < 0.01) and reduced footpad or hock burns and damage to abdominal plumage (P < 0.05). These results suggest that cool perches have a favorable effect on the performance and welfare of broilers.

  10. Trends in fall injuries associated with children's outdoor climbing frames.

    PubMed

    Ball, David J

    2007-03-01

    Falls from publicly owned climbing equipment are often cited as the major cause of injury on children's outdoor playgrounds and have been the focus of substantial interventions in the UK since the early 1980s. Analysis of national data on falls from climbing frames for 1988 to 2002 shows that the main discernible trend during this period is an increase in the occurrence of injuries to the lower arm. Whether this is attributable to a behavioural response to some of the interventions, or to some other factor, is unknown.

  11. The CLASSIC/CLIMB Data Reduction: The Math

    NASA Astrophysics Data System (ADS)

    ten Brummelaar, T.

    2014-09-01

    This chapter describes the methods used to extract closure phase from CLIMB data and visibility amplitude from both the CLASSIC and CLIMB beam combiners. It also includes a rather exhaustive description of the theory behind these methods. This high degree of detail is partly because previous publications of this theory contain errors, and partly because having done all this work it*s nice to have it written up in full somewhere, and being slightly beyond the thesis writing stage, this is only possible for me in a chapter like this.

  12. Predicting dislocation climb and creep from explicit atomistic details.

    PubMed

    Kabir, Mukul; Lau, Timothy T; Rodney, David; Yip, Sidney; Van Vliet, Krystyn J

    2010-08-27

    Here we report kinetic Monte Carlo simulations of dislocation climb in heavily deformed, body-centered cubic iron comprising a supersaturation of vacancies. This approach explicitly incorporates the effect of nonlinear vacancy-dislocation interaction on vacancy migration barriers as determined from atomistic calculations, and enables observations of diffusivity and climb over time scales and temperatures relevant to power-law creep. By capturing the underlying microscopic physics, the calculated stress exponents for steady-state creep rates agree quantitatively with the experimentally measured range, and qualitatively with the stress dependence of creep activation energies.

  13. Perched groundwater at the northwestern coast of Egypt: a case study of the Fuka Basin

    NASA Astrophysics Data System (ADS)

    Yousif, Mohamed; Bubenzer, Olaf

    2012-03-01

    Perched groundwater resources on the northwestern coast of Egypt have thus far been little studied. However, if replenished by rainwater, they can provide a considerable amount of renewable water, i.e., for sustainable irrigation. These resources are limited, show different salinity contents and are endangered by overuse, pollution and by the sea level rising in the context of global warming. This paper presents new climatic data, geomorphologic, geologic, geochemical and hydrological researches in combination with remote sensing and GIS applications from Fuka Basin. Fuka constitutes a special synclinal basin where the interbedded limestone and clays have been folded into gentle synclinal structures. Fractured Middle Miocene limestone represents the bearing formation for the perched groundwater. According to the hydrogeochemical analysis and the PHREEQC model, the aquifer is recharged during the winter season by rainwater from the surrounding tableland and the chemical evolution of the perched water is attributed to water-rock interaction and mixing of fresh water with sea water. The salinity of the perched water ranges from 2,126 to 2,644 mg/L whereas for the deep groundwater it reaches 9,800 mg/L. The study explores origin and potential of the perched groundwater of Fuka Basin and gives recommendations for a future sustainable use and further investigations.

  14. Who Is Who: An Anomalous Predator-Prey Role Exchange between Cyprinids and Perch.

    PubMed

    Vejřík, Lukáš; Matějíčková, Ivana; Seďa, Jaromír; Blabolil, Petr; Jůza, Tomáš; Vašek, Mojmír; Ricard, Daniel; Matěna, Josef; Frouzová, Jaroslava; Kubečka, Jan; Říha, Milan; Čech, Martin

    2016-01-01

    Piscivory in cyprinids (Cyprinidae) is extremely rare. Specifically, common bream (Abramis brama) and common carp (Cyprinus carpio) are zooplanktivorous fish in deep lentic waters. Nevertheless, we observed predation by these two cyprinids under natural conditions in the Vír Reservoir, Czech Republic. We conducted diet analysis for cyprinids caught by trawling and gillnets and the large amount of young-of-the-year (YOY) perch (Perca fluviatilis), with sizes of 37-52 mm standard length, were found in their digestive tracts. In 2010, a large amount of YOY perch caused a significant decrease in Daphnia spp. size and abundance in the reservoir. Hence, a food deficit was induced for the cyprinids, apparent also from the poor nutritional condition of common bream which was much worse than the condition of those in similar reservoirs. Common carp and common bream shifted to forced piscivory, and they utilized the YOY perch as an alternative food source. In contrast, smaller species, such as roach (Rutilus rutilus) and bleak (Alburnus alburnus), widely utilized planktonic cyanobacteria. In the following year, YOY perch occurred in significantly lower numbers and conversely, Daphnia spp. size and abundance were significantly higher. The forced piscivory was not observed. Our results indicate a switch to forced piscivory by cyprinids, which was caused by a shortage of their natural food source. Moreover, this phenomenon presents an effective mechanism for reduction in the numbers of YOY perch, ensuring the stability of the ecosystem.

  15. Evaluating the low back biomechanics of three different office workstations: Seated, standing, and perching.

    PubMed

    Le, Peter; Marras, William S

    2016-09-01

    The objective of this study was to evaluate how different workstations may influence physical behavior in office work through motion and how that may affect spinal loads and discomfort. Twenty subjects performed a typing task in three different workstations (seated, standing, and perching) for one hour each. Measures of postural transitions, spinal loads, discomfort, and task performance were assessed in order to understand the effects of workstation interaction over time. Results indicated that standing had the most amount of motion (6-8 shifts/min), followed by perching (3-7 shifts/min), and then seating (<1 shift/min). Standing had the highest reports of discomfort and seating the least. However, spinal loads were highest in A/P shear during standing (190N posterior shear, 407N anterior shear) compared to perching (65N posterior shear, 288N anterior shear) and seating (106N posterior shear, 287 anterior shear). These loads are below the risk threshold for shear, but may still elicit a cumulative response. Perching may induce motion through supported mobility in the perching stool, whereas standing motion may be due to postural discomfort. Office workstation designs incorporating supported movement may represent a reasonable trade-off in the costs-benefits between seating and standing.

  16. Water Transparency Drives Intra-Population Divergence in Eurasian Perch (Perca fluviatilis)

    PubMed Central

    Bartels, Pia; Hirsch, Philipp E.; Svanbäck, Richard; Eklöv, Peter

    2012-01-01

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization. PMID:22912895

  17. Water transparency drives intra-population divergence in Eurasian Perch (Perca fluviatilis).

    PubMed

    Bartels, Pia; Hirsch, Philipp E; Svanbäck, Richard; Eklöv, Peter

    2012-01-01

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

  18. Who Is Who: An Anomalous Predator-Prey Role Exchange between Cyprinids and Perch

    PubMed Central

    Blabolil, Petr; Jůza, Tomáš; Vašek, Mojmír; Ricard, Daniel; Matěna, Josef; Frouzová, Jaroslava; Kubečka, Jan; Říha, Milan

    2016-01-01

    Piscivory in cyprinids (Cyprinidae) is extremely rare. Specifically, common bream (Abramis brama) and common carp (Cyprinus carpio) are zooplanktivorous fish in deep lentic waters. Nevertheless, we observed predation by these two cyprinids under natural conditions in the Vír Reservoir, Czech Republic. We conducted diet analysis for cyprinids caught by trawling and gillnets and the large amount of young-of-the-year (YOY) perch (Perca fluviatilis), with sizes of 37–52 mm standard length, were found in their digestive tracts. In 2010, a large amount of YOY perch caused a significant decrease in Daphnia spp. size and abundance in the reservoir. Hence, a food deficit was induced for the cyprinids, apparent also from the poor nutritional condition of common bream which was much worse than the condition of those in similar reservoirs. Common carp and common bream shifted to forced piscivory, and they utilized the YOY perch as an alternative food source. In contrast, smaller species, such as roach (Rutilus rutilus) and bleak (Alburnus alburnus), widely utilized planktonic cyanobacteria. In the following year, YOY perch occurred in significantly lower numbers and conversely, Daphnia spp. size and abundance were significantly higher. The forced piscivory was not observed. Our results indicate a switch to forced piscivory by cyprinids, which was caused by a shortage of their natural food source. Moreover, this phenomenon presents an effective mechanism for reduction in the numbers of YOY perch, ensuring the stability of the ecosystem. PMID:27276078

  19. Enzymatic correlates of energy status in wild yellow perch inhabiting clean and contaminated environments.

    PubMed

    Gauthier, Charles; Campbell, Peter G C; Couture, Patrice

    2011-09-01

    Enzymes representing a variety of metabolic pathways were examined in yellow perch (Perca flavescens) collected from a metal-contaminated region (Rouyn-Noranda, Québec, Canada) to determine which were most closely related to fish condition factor, pyloric caeca weight, and visceral lipid accumulation, as well to seek a better understanding of the influence of metal contamination on the physiology and biometrics of perch. Compared to laboratory fish, wild perch were under important energy restrictions. The condition factor of wild fish was correlated with indicators of aerobic metabolism (citrate synthase, cytochrome C oxidase), protein anabolism (nucleoside diphosphokinase), and indicators of lipid accumulation (glucose-6-phosphate dehydrogenase, visceral lipid index). Pyloric caeca weights were well correlated with indicators of protein anabolism, but only when both seasons were examined together, possibly indicating a lag in the response of enzymes to changes in diet. The addition of contaminant stress to existing energy restrictions led to changes in the relationships between enzymes and biometrics, reducing the predictive power of the models for perch in contaminated lakes. The present study broadens our knowledge of the impact of metal contamination on energy accumulation and tissue metabolic capacities in wild perch.

  20. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown... Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper...

  1. Relative Importance of Four Muscle Groups for Indoor Rock Climbing Performance.

    PubMed

    Deyhle, Michael R; Hsu, Hung-Sheng; Fairfield, Timothy J; Cadez-Schmidt, Taryn L; Gurney, Burke A; Mermier, Christine M

    2015-07-01

    Little research is available to guide training programs for rock climbers. To help meet this need, we sought to determine the relative importance of 4 muscle groups for rock climbing performance. Eleven male climbers were familiarized with an indoor climbing route before 5 separate days of testing. On testing days, subjects were randomly assigned to climb with no prefatiguing exercise (control climb) or after a prefatiguing exercise designed to specifically target the digit flexors (DF), shoulder adductors (SA), elbow flexors (EF), or lumbar flexors (LF). Immediately after the prefatiguing exercise, the subject climbed the route as far as possible without rest until failure. The number of climbing moves was recorded for each climb. Surface electromyography of the target muscles was recorded during the prefatigue. Fewer climbing moves were completed after prefatigue of the DF (50 ± 18%) and EF (78 ± 22%) (p ≤ 0.05) compared with the control climb. The number of moves completed after prefatigue of the LF and SA were not statistically significant compared with the control climb (p > 0.05). The short time lapse between the end of prefatiguing exercise and the start of climbing (transit time), which may have allowed for some recovery, was not different among trials (p > 0.05). Electromyography median frequency was reduced from beginning to end of each prefatiguing exercise. These results suggest that among the muscle groups studied in men, muscular endurance of DF and EF muscle groups is especially important for rock climbing on 40° overhanging terrain.

  2. 14 CFR 23.66 - Takeoff climb: One-engine inoperative.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Takeoff climb: One-engine inoperative. 23... Performance § 23.66 Takeoff climb: One-engine inoperative. For normal, utility, and acrobatic category... airplanes in the normal, utility, and acrobatic category, the steady gradient of climb or descent must...

  3. 14 CFR 23.66 - Takeoff climb: One-engine inoperative.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Takeoff climb: One-engine inoperative. 23... Performance § 23.66 Takeoff climb: One-engine inoperative. For normal, utility, and acrobatic category... airplanes in the normal, utility, and acrobatic category, the steady gradient of climb or descent must...

  4. 43 CFR 6302.14 - What authorization do I need to climb in BLM wilderness?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false What authorization do I need to climb in... Wilderness Areas § 6302.14 What authorization do I need to climb in BLM wilderness? (a) You do not need a permit or other authorization to climb in BLM wilderness. (b) (c) You must not use power drills...

  5. 14 CFR 23.66 - Takeoff climb: One-engine inoperative.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Takeoff climb: One-engine inoperative. 23... Performance § 23.66 Takeoff climb: One-engine inoperative. For normal, utility, and acrobatic category... airplanes in the normal, utility, and acrobatic category, the steady gradient of climb or descent must...

  6. 43 CFR 6302.14 - What authorization do I need to climb in BLM wilderness?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false What authorization do I need to climb in... Wilderness Areas § 6302.14 What authorization do I need to climb in BLM wilderness? (a) You do not need a permit or other authorization to climb in BLM wilderness. (b) (c) You must not use power drills...

  7. 43 CFR 6302.14 - What authorization do I need to climb in BLM wilderness?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false What authorization do I need to climb in... Wilderness Areas § 6302.14 What authorization do I need to climb in BLM wilderness? (a) You do not need a permit or other authorization to climb in BLM wilderness. (b) (c) You must not use power drills...

  8. 43 CFR 6302.14 - What authorization do I need to climb in BLM wilderness?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false What authorization do I need to climb in... Wilderness Areas § 6302.14 What authorization do I need to climb in BLM wilderness? (a) You do not need a permit or other authorization to climb in BLM wilderness. (b) (c) You must not use power drills...

  9. The Conversion of Exterior Wall Facings for Climbing Activities.

    ERIC Educational Resources Information Center

    March, Bill; Toft, Murray

    1979-01-01

    The conversion of existing exterior walls to provide facilities for outdoor rock climbing activities is described with particular emphasis on design to provide practice in basic movement skills such as correct use of holds, balance, controlled change of position, traversing, and moving up and down. (JMF)

  10. Leading Organizational Change Is Like Climbing a Mountain

    ERIC Educational Resources Information Center

    Zimmerman, Judith

    2004-01-01

    Leading organizational change is like climbing a mountain. Transformational leaders must prepare to lead change, understand the process and nature of change, and provide the essential gear so that those involved can be successful. The author draws on the literature and personal experiences as a hiker and change leader to provide a guide for…

  11. 21 CFR 890.3890 - Stair-climbing wheelchair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stair-climbing wheelchair. 890.3890 Section 890.3890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3890...

  12. 21 CFR 890.3890 - Stair-climbing wheelchair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stair-climbing wheelchair. 890.3890 Section 890.3890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3890...

  13. 21 CFR 890.3890 - Stair-climbing wheelchair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stair-climbing wheelchair. 890.3890 Section 890.3890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3890...

  14. 0g Climbing - The Challenge of Walking in Space

    NASA Technical Reports Server (NTRS)

    Ambrose, Robert O.; Rehnmark, Frederik; Goza, Michael

    2003-01-01

    Space walking is poorly named, as it has little in common with how animals walk on Earth. Space walking is more akin to mountain climbing in scuba gear, while parachuting in a freefall -- an odd combination of effects and equipment to help people do a demanding job. Robots are now being studied for service in this same domain, working on large scale space structures like the Space Station, servicing science or military platforms in high orbit, or riding on the outside of a space craft in transit to Mars, the Moon or other destinations. What have we learned about climbing in 0g? How should machines be controlled for serving in this role? What can they do to overcome the problems that humans have faced? In order to move about in this environment, a robot must be able to climb autonomously, using gaits that smoothly manage its momentum and that minimize contact forces (walking lightly) while providing for safety in the event of an emergency requiring the system to stop. All three of these objectives are now being explored at NASA's Johnson Space Center, using the Robonaut system and a set of mockups that emulate the 0g condition. NASA's goal for Robonaut is to develop the control technology that will allow it to climb on the outside of the Space Shuttle, the Space Station, and satellite mockups at JSC, enabling the robot to perform EVA task setups or serve as an Astronaut's assistant.

  15. 0g Climbing - The Challenge of Walking in Space

    NASA Technical Reports Server (NTRS)

    Ambrose, Robert O.; Rehnmark, Frederik; Goza, Michael

    2004-01-01

    Space walking is poorly named, as it has little in common with how animals walk on Earth. Space walking is more akin to mountain climbing in scuba gear, while parachuting in a freefall-an odd combination of effects and equipment to help people do a demanding job. Robots are now being studied for service in this same domain, working on large scale space structures like the Space Station, servicing science or military platforms in high orbit, or riding on the outside of a space craft in transit to Mars, the Moon or other destinations. What have we learned about climbing in 0g? How should machines be controlled for serving in this role? What can they do to overcome the problems that humans have faced? In order to move about in this environment, a robot must be able to climb autonomously, using gaits that smoothly manage its momentum and that minimize contact forces (walking lightly) while providing for safety in the event of an emergency requiring the system to stop. All three of these objectives are now being explored at NASA's Johnson Space Center, using the Robonaut system and a set of mockups that emulate the 0g condition. NASA's goal for Robonaut is to develop the control technology that will allow it to climb on the outside of the Space Shuttle, the Space Station, and satellite mockups at JSC, enabling the robot to perform EVA task setups or serve as an Astronaut's assistant.

  16. 21 CFR 890.3890 - Stair-climbing wheelchair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stair-climbing wheelchair. 890.3890 Section 890.3890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3890...

  17. 21 CFR 890.3890 - Stair-climbing wheelchair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stair-climbing wheelchair. 890.3890 Section 890.3890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3890...

  18. Rock Climbing Injuries: Acute and Chronic Repetitive Trauma.

    PubMed

    Chang, Connie Y; Torriani, Martin; Huang, Ambrose J

    2016-01-01

    Rock climbing has increased in popularity as a sport, and specific injuries related to its practice are becoming more common. Chronic repetitive injuries are more common than acute injuries, although acute injuries tend to be more severe. We review both acute and chronic upper and lower extremity injuries. Understanding the injury pattern in rock climbers is important for accurate diagnosis.

  19. 14 CFR 23.65 - Climb: All engines operating.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than maximum continuous power on each engine; (2) The landing gear retracted; (3) The wing flaps in the...) The wing flaps in the takeoff position(s); and (4) A climb speed as specified in § 23.65(a)(4)....

  20. 14 CFR 23.65 - Climb: All engines operating.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... than maximum continuous power on each engine; (2) The landing gear retracted; (3) The wing flaps in the...) The wing flaps in the takeoff position(s); and (4) A climb speed as specified in § 23.65(a)(4)....

  1. Climbing Ability of the Common Bed Bug (Hemiptera: Cimicidae).

    PubMed

    Hottel, B A; Pereira, R M; Gezan, S A; Qing, R; Sigmund, W M; Koehler, P G

    2015-05-01

    Little is known about what factors influence the climbing ability of bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae), in relation to the various surfaces they encounter. We examined how sex, time since last fed, and what surfaces the bed bugs were in contact with affected their climbing performance. The effects of sex and time since fed were tested by counting the number of bed bugs able to climb a 45° slope. The pulling force was recorded using an analytical balance technique that captured the sequential vertical pulling force output of bed bugs attached to various surfaces. Recently fed female bed bugs were found to have the most difficulty in climbing smooth surfaces in comparison with males. This difference can be explained by the larger weight gained from bloodmeals by female bed bugs. A variety of vertical pulling forces were observed on surfaces ranging from sandpaper to talc powder-covered glass. For surfaces not treated with talc powder, bed bugs generated the least amount of vertical pulling force from synthetically created 0.6-µm plastron surfaces. This vast range in the ability of bed bugs to grip onto various surfaces may have implications on limiting bed bugs dispersal and hitchhiking behaviors.

  2. Astronaut Charles Conrad climbs from spacecraft after splashdown

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronaut Charles Conrad Jr., command pilot of the Gemini 11 space mission, climbs from the spacecraft minutes after splashdown. Astronaut Richard F. Gordon Jr., pilot, still has his hatch closed. The U.S. Navy frogman team attached a flotation collar to the spacecraft.

  3. Project Hill-Climb: Drafting and Design in Motion

    ERIC Educational Resources Information Center

    Crowl, William F.

    2008-01-01

    This article describes the Hill-Climb project of a second level Computer-Aided Drafting and Design (CADD) class. The author primarily designed the activity to increase student understanding of the assembly drawing process and its components. The emphasis on problem solving adds a dimension that can aid students in their other classes as well. By…

  4. 14 CFR 27.65 - Climb: all engines operating.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; or (ii) At least 1:6 under standard sea level conditions. (b) Each helicopter must meet the following requirements: (1) VY must be determined— (i) For standard sea level conditions; (ii) At maximum weight; and...) At the climb speed selected by the applicant at or below VNE; (ii) Within the range from sea level...

  5. 14 CFR 27.65 - Climb: all engines operating.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...; or (ii) At least 1:6 under standard sea level conditions. (b) Each helicopter must meet the following requirements: (1) VY must be determined— (i) For standard sea level conditions; (ii) At maximum weight; and...) At the climb speed selected by the applicant at or below VNE; (ii) Within the range from sea level...

  6. 14 CFR 27.65 - Climb: all engines operating.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; or (ii) At least 1:6 under standard sea level conditions. (b) Each helicopter must meet the following requirements: (1) VY must be determined— (i) For standard sea level conditions; (ii) At maximum weight; and...) At the climb speed selected by the applicant at or below VNE; (ii) Within the range from sea level...

  7. 14 CFR 25.121 - Climb: One-engine-inoperative.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 25.121 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.121 Climb: One... along the flight path (between the points at which the airplane reaches V LOF and at which the...

  8. 14 CFR 25.121 - Climb: One-engine-inoperative.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 25.121 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.121 Climb: One... along the flight path (between the points at which the airplane reaches V LOF and at which the...

  9. 14 CFR 25.121 - Climb: One-engine-inoperative.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 25.121 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.121 Climb: One... along the flight path (between the points at which the airplane reaches V LOF and at which the...

  10. Population biology of yellow perch in southern Lake Michigan, 1971-79

    USGS Publications Warehouse

    Wells, LaRue; Jorgenson, Sherrell C.

    1983-01-01

    This study was based mainly on gill-net collections of yellow perch (Perca flavescens) made during July and August 1971-79, in southern Lake Michigan at Grand Haven, Saugatuck, South Haven, Benton Harbor, and New Buffalo, Michigan; Michigan City and Gary, Indiana; Waukegan, Illinois; and Milwaukee, Wisconsin. Abundance of yellow perch was above the 1971-79 average in 1971 and 1972, below average in 1979, and about average or in doubt in the other years. Abundance during 1976-79 was greatest at Saugatuck and decreased more or less progressively from Saugatuck southward and around the southern end of the lake. The geographical differences in abundance were attributable partly to differences in fishing mortality. Average lengths of fish caught were greatest at Saugatuck, and generally greater in Michigan waters than in other areas; they were greater for females than for males. Fish sampled ranged in age from I to IX, but 88% of the males and 81% of the females were of ages II-V. Older perch were generally more common in State of Michigan waters, particularly at Saugatuck, than elsewhere. Females grew faster than males after the second year of life. Average lengths of males and females at the end of 3 years were 197 and 214 mm, respectively, in Michigan waters and 186 and 195 mm in Indiana-Illinois (few perch were caught in Wisconsin). The relation of weight (W) to length (L) for combined sexes was W = 2.6761(10-6) x L3.2644. Perch in southeastern Lake Michigan spawned mainly from late May to mid June. Virtually all males were mature in their second year, but some females not until their fourth year. Perch 174 to 355 mm long contained 9, 300 to 136, 000 eggs. Approximate mortalities of males and females in Michigan waters were 52% and 48%, respectively; rates were higher in Indiana-Illinois.

  11. Age, growth, and production of the yellow perch, Perca flavescens (Mitchill), of Saginaw Bay

    USGS Publications Warehouse

    Hile, Ralph; Jobes, Frank W.

    1941-01-01

    Ages were determined and individual growth histories computed from the examination and measurement of scales from 820 yellow perch collected in 1929 and 1930. Calculated lengths greater than 101 millimeters were computed on the assumption (supported by empirical data) that the ratio of body length to scale length is constant. Lengths below 101 millimeters were determined with the aid of an empirical curve of the body-scale relationship of small fish. Yellow perch of age-groups III and IV (in the fourth and fifth years of life) made up the bulk of the collection (78 per cent). Females grew slightly more rapidly than males, but members of both sexes attained the legal length of 8 1/2 inches during the fourth year of life, just as they were entering on the period of most rapid growth in weight. The greatest growth in weight of both sexes occurred in the sixth year of life. In the combined samples of the two years the females exceeded the males in abundance in the ratio, 296:100. The weight of the Saginaw Bay yellow perch was found to increase as the 3.117 power of the length. The relative length of the tail decreased with increase in the length of the fish. The Saginaw Bay yellow perch is now far less abundant than it was in the early years of the fishery. The average annual production of 548,000 pounds over the period, 1917-1938, was only 28 per cent of the earlier (1891-1916) "normal" annual production of 1,961,000 pounds. A detailed analysis of statistical data available for more recent years made possible a description of annual fluctuations in the abundance and production of yellow perch and in the intensity of the yellow perch fishery in Saginaw Bay over the period, 1929-1938.

  12. Cormorant predation and the population dynamics of walleye and yellow perch in Oneida Lake

    USGS Publications Warehouse

    Rudstam, L. G.; VanDeValk, A.J.; Adams, C.M.; Coleman, J.T.H.; Forney, J.L.; Richmond, M.E.

    2004-01-01

    Double-crested Cormorants (Phalacrocorax auritus) increased dramatically in North America during the 1990s, providing the opportunity to study the effects of an increase of a top predator on an existing predator-prey system. In Oneida Lake, New York, USA, Double-crested Cormorants were first observed nesting in 1984 and had increased to over 360 nesting pairs by 2000. Concomitant with this increase in piscivorous birds was a decrease in the adult walleye (Stizostedion vitreum) and yellow perch (Perca flavescens) populations. Analysis of a 40-yr data series shows higher mortality of subadults (age 1-2 yr perch and age 1-3 yr walleye) for both species in the 1990s compared to the previous three decades. Cormorant diet was investigated from 1995 to 2000 using a combination of cast pellets, regurgitants, and stomach analysis. Walleye and yellow perch were a major portion of the cormorant diet during these years (40-82% by number). The number of subadult walleye and yellow perch consumed by cormorants suggests that the increase in subadult mortality can be explained by predation from cormorants. Mean mortality rates of adult percids attributed to cormorant predation were 1.1% per year for walleye and 7.7% per year for yellow perch. Our analysis suggests that predation by cormorants on subadult percids is a major factor contributing to the decline in both the walleye and the yellow perch populations in Oneida Lake. Other ecosystem changes (zebra mussels, lower nutrient loading, decrease in alternate prey) are not likely explanations because the potential mechanisms involved are not consistent with auxiliary data from the lake and would not affect subadult mortality. The likely impact of bird predation on percid populations in Oneida Lake occurs because cormorants feed on larger fish that are beyond the size range where compensatory mechanisms are important.

  13. 76 FR 39793 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Catcher... northern rockfish, Pacific ocean perch, and pelagic shelf rockfish for catcher vessels participating in the... necessary to prevent exceeding the 2011 total allowable catch (TAC) of northern rockfish, Pacific...

  14. 77 FR 65838 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea Subarea of the Bering Sea and Aleutian... directed fishing for Pacific ocean perch in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to fully use the 2012 total allowable catch of Pacific ocean...

  15. 75 FR 68726 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-09

    ... Zone Off Alaska; Pacific Ocean Perch in the Bering Sea Subarea of the Bering Sea and Aleutian Islands... directed fishing for Pacific ocean perch in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to fully use the 2010 total allowable catch of Pacific ocean...

  16. 76 FR 43934 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by catcher/processors...). This action is necessary to prevent exceeding the 2011 total allowable catch (TAC) of Pacific...

  17. 75 FR 42337 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by catcher/processors...). This action is necessary to prevent exceeding the 2010 total allowable catch (TAC) of Pacific...

  18. 75 FR 38938 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Catcher... northern rockfish, Pacific ocean perch, and pelagic shelf rockfish for catcher vessels participating in the... necessary to prevent exceeding the 2010 total allowable catch (TAC) of northern rockfish, Pacific...

  19. The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to determine if perch availability during all or part of the life cycle of caged Hy-Line W-36 chickens affected egg traits, foot health, and feather condition. Using a 2 x 2 factorial arrangement, treatment 1 represented control chickens which never had access to perches during the...

  20. 75 FR 41999 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level... vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of... perch for trawl catcher vessels participating in the rockfish entry level fishery in the...

  1. 75 FR 38936 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level... participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA... perch for trawl catcher vessels participating in the rockfish entry level fishery in the...

  2. 76 FR 40838 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level... vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of... Pacific ocean perch for trawl catcher vessels participating in the rockfish entry level fishery in...

  3. 76 FR 46207 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level... vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of... Pacific ocean perch for trawl catcher vessels participating in the rockfish entry level fishery in...

  4. Influences of microhabitat constraints and rock-climbing disturbance on cliff-face vegetation communities.

    PubMed

    Kuntz, Kathryn Lynne; Larson, Douglas W

    2006-06-01

    Many researchers report that rock climbing has significant negative effects on cliff biota. Most work on climbing disturbance, however has not controlled for variation in microsite characteristics when comparing areas with and without climbing presence. Additionally, some researchers do not identify the style or difficulty level of climbing routes sampled or select climbing routes that do not represent current trends in the sport. We solved these problems by sampling climbing areas used by advanced "sport" climbers and quantifying differences in microtopography between climbed and control cliffs. We determined whether differences in vegetation existed between pristine and sport-climbed cliff faces when microsite factors were not controlled. We then determined the relative influence of the presence of climbing, cliff-face microtopography, local physical factors, and regional geography on the richness, abundance, and community composition of cliff-face vascular plants, bryophytes, and lichens. When we did not control for microsite differences among cliffs, our results were consistent with the majority of prior work on impacts of climbing (i.e., sport-climbed cliff faces supported a lower mean richness of vascular plants and bryophytes and significantly different frequencies of individual species when compared with pristine cliff faces). When we investigated the relative influences of microtopography and climbing disturbance, however the differences in vegetation were not related to climbing disturbance but rather to the selection by sport climbers of cliff faces with microsite characteristics that support less vegetation. Climbed sites had not diverged toward a separate vegetation community; instead, they supported a subset of the species found on pristine cliff faces. Prior management recommendations to restrict development of new climbing routes should be reevaluated based on our results.

  5. Early evolution of avian flight and perching: new evidence from the lower cretaceous of china.

    PubMed

    Sereno, P C; Chenggang, R

    1992-02-14

    Fossil bird skeletons discovered in Lower Cretaceous lake deposits in China shed new light on the early evolution of avian flight and perching. The 135 million-year-old sparrow-sized skeletons represent a new avian, Sinornis santensis, n. gen. n. sp., that preserves striking primitive features such as a flexible manus with unguals, a footed pubis, and stomach ribs (gastralia). In contrast to Archaeoperyx, however, Sinornis exhibits advanced features such as a broad sternum, wing-folding mechanism, pygostyle, and large fully reversed hallux. Modern avian flight function and perching capability, therefore, must have evolved in small-bodied birds in inland habitats not long after Archaeopteryx.

  6. Effects of long-term changes in the benthic community on yellow perch in Saginaw Bay, Lake Huron

    USGS Publications Warehouse

    Schaeffer, Jeffrey S.; Diana, James S.; Haas, Robert C.

    2000-01-01

    Abundance, mortality, age and growth, food habits, and energetics of a yellow perch Perca flavescens population were investigated in eutrophic Saginaw Bay, Lake Huron during May to October, 1986 to 1988, and compared population characteristics with historical data from times when eutrophic conditions were less severe. During 1986 to 1988, yellow perch were abundant, but grew slowly and experienced high natural mortality. A size threshold was present at 150 to 180 mm beyond which few individuals survived, and sex ratios became biased toward males. An energetic model suggested that yellow perch were food limited; as they increased in size they spent a greater proportion of the growing season near maintenance ration. Low feeding rates were a consequence of subsistence on small chironomid larvae. Piscivory provided little energetic relief. Historical data suggested that availability of large benthic prey such as nymphs of the burrowing mayfly Hexagenia was important to yellow perch. Yellow perch formerly consumed Hexagenia, but mayflies were extirpated from Saginaw Bay during 1953 to 1965, and never recovered. When Hexagenia was present, yellow perch growth was moderate to fast depending on population size, size thresholds were not present, and yellow perch reached large size and older age despite moderate to high fishing mortality. Decreases in yellow perch growth rates during 1952 to 1955 coincided with extirpation of Hexagenia. Fast growth of yellow perch did occur after Hexagenia became extirpated, but only when fishing mortality was high, population size was small, and some large benthic invertebrates remained. Eutrophication of Saginaw Bay appeared to affect yellow perch by changing species composition and reducing size structure of the benthic community.

  7. The role of perched aquifers in hydrological connectivity and biogeochemical processes in vernal pool landscapes, Central Valley, California

    NASA Astrophysics Data System (ADS)

    Cable Rains, Mark; Fogg, Graham E.; Harter, Thomas; Dahlgren, Randy A.; Williamson, Robert J.

    2006-03-01

    Relatively little is known about the role of perched aquifers in hydrological, biogeochemical, and biological processes of vernal pool landscapes. The objectives of this study are to introduce a perched aquifer concept for vernal pool formation and maintenance and to examine the resulting hydrological and biogeochemical phenomena in a representative catchment with three vernal pools connected to one another and to a seasonal stream by swales. A combined hydrometric and geochemical approach was used. Annual rainfall infiltrated but perched on a claypan/duripan, and this perched groundwater flowed downgradient toward the seasonal stream. The upper layer of soil above the claypan/duripan is 0.6 m in thickness in the uplands and 0.1 m in thickness in the vernal pools. Some groundwater flowed through the vernal pools when heads in the perched aquifer exceeded 0.1 m above the claypan/duripan. Perched groundwater discharge accounted for 30-60% of the inflow to the vernal pools during and immediately following storm events. However, most perched groundwater flowed under or around the vernal pools or was recharged by annual rainfall downgradient of the vernal pools. Most of the perched groundwater was discharged to the outlet swale immediately upgradient of the seasonal stream, and most water discharging from the outlet swale to the seasonal stream was perched groundwater that had not flowed through the vernal pools. Therefore, nitrate-nitrogen concentrations were lower (e.g. 0.17 to 0.39 mg l-1) and dissolved organic carbon concentrations were higher (e.g. 5.97 to 3.24 mg l-1) in vernal pool water than in outlet swale water discharging to the seasonal stream. Though the uplands, vernal pools, and seasonal stream are part of a single surface-water and perched groundwater system, the vernal pools apparently play a limited role in controlling landscape-scale water quality.

  8. Rock climbers' attitudes toward management of climbing and the use of bolts.

    PubMed

    Schuster, R M; Thompson, J G; Hammitt, W E

    2001-09-01

    The purpose of this research was to verify that various segments of the rock climbing community have different attitudes toward resource management and to aid in the understanding of attitudinal differences that can affect rock-climbing management. Respondents were given an on-site questionnaire; 400 usable surveys were collected from 13 different locations in the United States. Respondents identified themselves according to the type of climbing they participated in (e.g., traditional climbing, sport climbing, and hybrid climbing). Factor analysis identified five usable factors: bolt placement/use, need for management, reservations about management, appropriateness of bolts, and climbers' self-perception. A repeated-measures analysis of variance identified significant differences among responses from traditional and sport climbers on four of the five scales used to measures attitudes. The variance among the climbing subgroups indicated that various climbing groups had significantly different attitudes toward management. All climbers surveyed had reservations about the management process. Results from the analysis indicated that climbers from all three groups (traditional, sport, and hybrid) felt that managers did not adequately understand the activity of climbing, climbers did not adequately understand the management process, climbing was not treated fairly in the management process in comparison to other activities, and climbing was micromanaged.

  9. Thyroid status alters gill ionic metabolism and chloride cell morphology as evidenced by scanning electron microscopy in a teleost Anabas testudineus (Bloch): short and long term in vivo study.

    PubMed

    Sreejith, P; Beyo, R S; Prasad, G; Sunny, F; Oommen, O V

    2007-12-01

    Gill is the main organ of osmotic regulation in teleosts and chloride cells are the sites of ion transport across gill epithelium. Thyroid hormones are implicated in the regulation of osmotic balance in teleosts also. Treatment with 6-propyl thiouracil (6-PTU) inhibited the membrane bound enzyme Na+K+ ATPase in the gill while triiodothyronine (T3) injection stimulated it in a short-term in vivo study in the teleost Anabas testudineus. Na+, K+ and Ca2+ ions were also decreased in the 6-PTU treated fish and the T3 treatment increased their concentrations in the gill lamellae. The gill morphology also changed according to the thyroid status in the long term study. 6-PTU treatment altered the typical serrated morphology of the gill lamellae, while the T3 treatment reversed it. T3 injection increased the density of pavement and chloride cells as evidenced by scanning electron microscopy. The results demonstrate that physiological status of the thyroid influences gill Na+ pump activity and chloride cell morphological changes. Further, the study suggests a regulatory role of T3 on gill ions (Na+, K+ and Ca2+), Na+K+ and Ca2+ ATPase activity and the different gill cell types in A. testudineus.

  10. Production of genetically defined perch broodstocks and their selection for fast growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The restrictions and closures of commercial freshwater fisheries in North America, coupled with continued high consumer demand, have fueled interest in yellow perch aquaculture. However, the general slow growth of this species and the lack of commercially available genetically improved broodstocks h...

  11. Morphological evidence for discrete stocks of yellow perch in Lake Erie

    USGS Publications Warehouse

    Kocovsky, Patrick M.; Knight, Carey T.

    2012-01-01

    Identification and management of unique stocks of exploited fish species are high-priority management goals in the Laurentian Great Lakes. We analyzed whole-body morphometrics of 1430 yellow perch Perca flavescens captured during 2007–2009 from seven known spawning areas in Lake Erie to determine if morphometrics vary among sites and management units to assist in identification of spawning stocks of this heavily exploited species. Truss-based morphometrics (n = 21 measurements) were analyzed using principal component analysis followed by ANOVA of the first three principal components to determine whether yellow perch from the several sampling sites varied morphometrically. Duncan's multiple range test was used to determine which sites differed from one another to test whether morphometrics varied at scales finer than management unit. Morphometrics varied significantly among sites and annually, but differences among sites were much greater. Sites within the same management unit typically differed significantly from one another, indicating morphometric variation at a scale finer than management unit. These results are largely congruent with recently-published studies on genetic variation of yellow perch from many of the same sampling sites. Thus, our results provide additional evidence that there are discrete stocks of yellow perch in Lake Erie and that management units likely comprise multiple stocks.

  12. Status and prospects for the yellow perch genetic improvement program in Milwaukee, Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2004, a broodstock improvement program was initiated with the aim of developing defined geographic strains of yellow perch that have been selected for improved growth. Following a survey of 19 populations ranging from the Mid-West to the Eastern coast of the United States, and subsequent efforts ...

  13. Effect of Feeding-Fasting Cycles on Oxygen Consumption and Bioenergetics of Yellow Perch

    USGS Publications Warehouse

    Chipps, Steven R.; Travis W. Schaeffer,; Daniel E. Spengler,; Casey W. Schoenebeck,; Michael L. Brown,

    2012-01-01

    We measured growth and oxygen consumption of age-1 yellow perch Perca flavescenssubjected to ad libitum (control) or variable feeding cycles of 2 (i.e., 2 d of feed, 2 d of deprivation), 6, or 12 d for a 72-d period. Individual, female yellow perch (initial weight = 51.9 ± 0.9 g [mean ± SE]) were stocked in 110-L aquaria to provide six replicates per treatment and fed measured rations of live fathead minnow Pimephales promelas. Consumption, absolute growth rate, growth efficiency, and oxygen consumption were similar among feeding regimens. However, growth trajectories for fish on the 2-d cycle were significantly lower than other feed–fast cycles. Hyperphagia occurred in all treatments. Bioenergetics model simulations indicated that consumption was significantly underestimated (t = 5.4, df = 4, P = 0.006), while growth was overestimated (t = −5.5, df = 4, P = 0.005) for fish on the 12-d cycle. However, model errors detected between observed and predicted values were low, ranging from −10.1% to +7.8%. We found that juvenile yellow perch exhibited compensatory growth (CG), but none of the feed–fast treatments resulted in growth overcompensation. Likewise, we found no evidence that respiration rates varied with CG, implying that yellow perch bioenergetics models could be used to predict the effects of feeding history and CG response on food consumption and fish growth.

  14. Developmental expression and estrogen responses of endocrine genes in juvenile yellow perch (Perca flavescens)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study examines the expression of growth-regulating genes (gh, prl, smtl and igf1b), the estrogen receptors (esr1 and esr2a) and aromatase (cyp19a1a) in developing yellow perch. To gain an initial understanding into the endocrine control of growth preceding and involved with sexual size d...

  15. Yellow perch nutrient utilization and performance fed grower diet formulations with fermented soybean concentrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feeds formulated with fermented soybean concentrate (FSBC) were processed using a pilot-scale Wenger twin screw extruder, using a 1.9 cm diameter circular die, and then fed to juvenile yellow perch (Perca flavescens) (~26g) as a protein replacer for fish meal protein. Four fish-meal replacement lev...

  16. CHARACTERIZATION OF GENES INVOLVED WITH GROWTH AND IMMUNITY IN THE YELLOW PERCH (PERCA FLAVESCENS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In most vertebrates, growth hormone (GH) stimulates growth, metabolism and immunity. In yellow perch, GH does not appear to stimulate growth which suggests a condition of GH insensitivity. Furthermore, females grow faster and larger than males and estrogen preferentially stimulates this growth. T...

  17. Recruitment synchrony of yellow perch (Perca flavescens, Percidae) in the Great Lakes region, 1966–2008

    USGS Publications Warehouse

    Honsey, Andrew E.; Bunnell, David; Troy, Cary D.; Fielder, David G.; Thomas, Michael V.; Knight, Carey T.; Chong, Stephen; Hook, Tomas O.

    2016-01-01

    Population-level reproductive success (recruitment) of many fish populations is characterized by high inter-annual variation and related to annual variation in key environmental factors (e.g., climate). When such environmental factors are annually correlated across broad spatial scales, spatially separated populations may display recruitment synchrony (i.e., the Moran effect). We investigated inter-annual (1966–2008) variation in yellow perch (Perca flavescens, Percidae) recruitment using 16 datasets describing populations located in four of the five Laurentian Great Lakes (Erie, Huron, Michigan, and Ontario) and Lake St. Clair. We indexed relative year class strength using catch-curve residuals for each year-class across 2–4 years and compared relative year-class strength among sampling locations. Results indicate that perch recruitment is positively synchronized across the region. In addition, the spatial scale of this synchrony appears to be broader than previous estimates for both yellow perch and freshwater fish in general. To investigate potential factors influencing relative year-class strength, we related year-class strength to regional indices of annual climatic conditions (spring-summer air temperature, winter air temperature, and spring precipitation) using data from 14 weather stations across the Great Lakes region. We found that mean spring-summer temperature is significantly positively related to recruitment success among Great Lakes yellow perch populations.

  18. A note on the effects of perches and litter substrate on leg weakness in broiler chickens.

    PubMed

    Su, G; Sørensen, P; Kestin, S C

    2000-09-01

    Two trials were conducted to investigate the effect of availability of perches on indices of leg weakness in broiler chickens. A third trial investigated the effect of litter substrate on similar indices of leg weakness in broiler chickens. Leg weakness traits examined were walking ability and tibial dyschondroplasia, tibial curvature, foot burn, and hock burn. Body weight was also measured in all trials. The presence of perches in the rearing pens had no effect on any of the indices of leg weakness examined in either trial. There were no consistent effects of perches on BW. Litter substrate significantly affected some indices of leg weakness; birds reared on wheat straw had poorer walking ability and more foot burn than birds reared on wood shavings, and birds reared on hemp waste were intermediate between them. There was no effect of litter substrate on tibial dyschondroplasia or tibial curvature. Turning the straw litter regularly and adding fresh supplies when necessary did not significantly improve indices of leg weakness. It was concluded that wood shavings provide a better litter substrate than straw, but that perches have no beneficial effect on reducing leg weakness in broilers.

  19. Cooled perch effects on performance and well-being traits in caged White Leghorn hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We assessed the effects of chilled water cooling perches on hen performance, feather condition, foot health, and physiological and behavioral parameters during the 2013 summer with a 4-h acute heating episode. White Leghorn pullets at 16 wk of age were randomly assigned to 18 cages arranged into 3 b...

  20. Myxobolus neurophilus: a common myxosporidian parasite infecting yellow perch Perca flavacens (Mitchell) in Saskatchewan, Canada

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this study was to identify a myxosporidian parasite infecting the central nervous system of yellow perch Perca flavacens (Mitchell) observed while investigating a fish kill in Saskatchewan, Canada. Fish were collected from seven different lakes, from 2 distinct watersheds. Sixty-four p...

  1. 75 FR 53873 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Vessels Participating in the Rockfish Entry Level Fishery... entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary... participating in the rockfish entry level fishery in the Central Regulatory Area of the GOA. DATES:...

  2. How and when infants learn to climb stairs.

    PubMed

    Berger, Sarah E; Theuring, Carolin; Adolph, Karen E

    2007-02-01

    Seven hundred and thirty-two parents reported when and how their infants learned to climb stairs. Children typically mastered stair ascent (mean age=10.97 months) several months after crawling onset and several weeks prior to descent (mean age=12.53 months). Most infants (94%) crawled upstairs the first time they ascended independently. Most infants (76%) turned around and backed at initial descent. Other descent strategies included scooting down sitting, walking, and sliding down face first. Children with stairs in their home were more likely to learn to ascend stairs at a younger age, devise backing as a descent strategy, and be explicitly taught to descend by their parents than children without stairs in their home. However, all infants learned to descend stairs at the same age, regardless of the presence of stairs in their home. Parents' teaching strategies and infants' access to stairs worked together to constrain development and to influence the acquisition of stair climbing milestones.

  3. The Classic/climb Beam Combiner at the CHARA Array

    NASA Astrophysics Data System (ADS)

    Ten Brummelaar, T. A.; Sturmann, J.; Ridgway, S. T.; Sturmann, L.; Turner, N. H.; McAlister, H. A.; Farrington, C. D.; Beckmann, U.; Weigelt, G.; Shure, M.

    In the same way that every telescope has multiple instruments and cameras, an interferometric array like the CHARA Array will have numerous beam combiners at the back end. And like the instruments of a single telescope, each of these combiners will be optimized for a particular kind of observation or scientific program. In this paper we describe the CLASSIC and CLIMB beam combiners of the CHARA Array. Both are open air, aperture plane, wide bandwidth single spectral channel instruments optimized for sensitivity. CLASSIC is the original two beam combiner used for the first science at CHARA, and it still has the faintest magnitude limit. CLIMB is a three beam expansion of CLASSIC that can also provide closure phase measurements.

  4. Coracoid impingement syndrome due to intensive rock climbing training.

    PubMed

    Schöffl, Volker; Schneider, Hans; Küpper, Thomas

    2011-06-01

    Overuse and acute injuries to the upper body are common in rock climbing. Such injuries primarily affect the fingers; but shoulder problems are increasingly common, especially among more experienced and older climbers who climb at a high ability level. Such shoulder problems are often due to subacromial impingement, shoulder dislocations with bankart lesions, hyperlaxity, SLAP lesions or irritations of the long biceps tendon. In contrast to these known conditions, we describe a case of an ambitious female rock climber who trained intensively and developed a coracoid impingement caused by hypertrophied subscapularis tendon and muscle following sport-specific training. Diagnosis was made through clinical evaluation and confirmed by magnetic resonance tomography. Coracoid impingement syndrome is a less common cause of shoulder pain and occurs when the subscapularis tendon impinges between the coracoid and the lesser tuberosity of the humerus. The patient was treated successfully with a conservative therapy and returned to full activity within 6 weeks.

  5. Data analysis for the CHARA Array CLIMB beam combiner

    NASA Astrophysics Data System (ADS)

    ten Brummelaar, Theo A.; Sturmann, Judit; McAlister, Harold A.; Sturmann, Laszlo; Turner, Nils H.; Farrington, Chris D.; Schaefer, Gail; Goldfinger, P. J.; Kloppenborg, Brian

    2012-07-01

    The CHARA Array is a six telescope optical/IR interferometer run by the Center for High Angular Resolution Astronomy of Georgia State University and is located at Mount Wilson Observatory just to the north of Los Angeles California. The CHARA Array has the largest operational baselines in the world and has been in regular use for scientific observations since 2004. Our most sensitive beam combiner capable of measuring closure phases is the CLassic Interferometry with Multiple Baselines beam combiner known as CLIMB. In this paper we discuss the design and layout of CLIMB with a particular focus on the data analysis methodology. This analysis is presented in a very general form and will have applications in many other beam combiners. We also present examples of on sky data showing the precision and stability of both amplitude and closure phase measurements.

  6. Climbing favours the tripod gait over alternative faster insect gaits

    NASA Astrophysics Data System (ADS)

    Ramdya, Pavan; Thandiackal, Robin; Cherney, Raphael; Asselborn, Thibault; Benton, Richard; Ijspeert, Auke Jan; Floreano, Dario

    2017-02-01

    To escape danger or catch prey, running vertebrates rely on dynamic gaits with minimal ground contact. By contrast, most insects use a tripod gait that maintains at least three legs on the ground at any given time. One prevailing hypothesis for this difference in fast locomotor strategies is that tripod locomotion allows insects to rapidly navigate three-dimensional terrain. To test this, we computationally discovered fast locomotor gaits for a model based on Drosophila melanogaster. Indeed, the tripod gait emerges to the exclusion of many other possible gaits when optimizing fast upward climbing with leg adhesion. By contrast, novel two-legged bipod gaits are fastest on flat terrain without adhesion in the model and in a hexapod robot. Intriguingly, when adhesive leg structures in real Drosophila are covered, animals exhibit atypical bipod-like leg coordination. We propose that the requirement to climb vertical terrain may drive the prevalence of the tripod gait over faster alternative gaits with minimal ground contact.

  7. Optimum climb and descent trajectories for airline missions

    NASA Technical Reports Server (NTRS)

    Erzberger, H.

    1981-01-01

    The characteristics of optimum fixed-range trajectories whose structure is constrained to climb, steady cruise, and descent segments are derived by application of optimal control theory. The performance function consists of the sum of fuel and time costs, referred to as direct operating cost (DOC). The state variable is range to go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (400 n. mi. and less), a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur.

  8. Complete Spinal Accessory Nerve Palsy From Carrying Climbing Gear.

    PubMed

    Coulter, Jess M; Warme, Winston J

    2015-09-01

    We report an unusual case of spinal accessory nerve palsy sustained while transporting climbing gear. Spinal accessory nerve injury is commonly a result of iatrogenic surgical trauma during lymph node excision. This particular nerve is less frequently injured by blunt trauma. The case reported here results from compression of the spinal accessory nerve for a sustained period-that is, carrying a load over the shoulder using a single nylon rope for 2.5 hours. This highlights the importance of using proper load-carrying equipment to distribute weight over a greater surface area to avoid nerve compression in the posterior triangle of the neck. The signs and symptoms of spinal accessory nerve palsy and its etiology are discussed. This report is particularly relevant to individuals involved in mountaineering and rock climbing but can be extended to anyone carrying a load with a strap over one shoulder and across the body.

  9. [CLIMBING HIGHER--COMMON INJURIES IN ROCK CLIMBERS].

    PubMed

    Sobel, Dafna; Constantin, Naama; Or, Omer

    2016-06-01

    Rock climbing is becoming an increasingly popular sport in Israel with more and more climbing walls being built in the cities and new routes being traced on cliffs around the country. Our account describes the case of a 15 years old climber with chronic pain (without trauma) in the 3rd finger of the right hand. A stress fracture, involving the proximal interphalangeal joint (SH3) of the middle phalanx, was diagnosed. The fracture healed following two months of rest with gradual return to activity. As this sport becomes more common, there is an increasing need for knowledge about the characteristic injuries, their diagnosis and treatment. Although considered an extreme sport, most of the injuries are overuse injuries, mainly to the upper limbs. Finger flexor tendon pulley rupture being one of the most common. Diagnosis is based on history, physical examination and ultrasonography. Conservative treatment is successful for most injuries, while more complicated cases require surgical intervention.

  10. A Surface Singularity Method for Rotors in Hover or Climb.

    DTIC Science & Technology

    1981-12-01

    has come with the development of better analytical methods and experimental techniques . The theoretical methods available today are certainly much...ROUTINES In general, the prescribed wake methods and the relaxed wake techniques developed for the HOVER code have been carried over for ROTAIR. Basic...AD-AlO9 687 ANALYTICAL METHODS INC REDMOND WA F/G 20/4 SURFACE SINGULARITY METHOD FOR ROTORS IN HOVER OR CLIMB.(UDE 1 JMSUMMA, B MASKEW OAAJ02ඔ-C

  11. Watching Charlotte Climb: Little Steps toward Big Questions

    ERIC Educational Resources Information Center

    Connor, W. Robert

    2007-01-01

    In this article, the author talks about big questions of meaning and value that young people pose and how to respond to their concerns about big questions. He relates the story of his granddaughter, Charlotte, who, at the age of one, would climb up on the stairs not from choice or whim, but "because they're there." For her, it was not play, but…

  12. TOP OF MTR. MAN CLIMBS FRAME ON FOOT LADDER TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TOP OF MTR. MAN CLIMBS FRAME ON FOOT LADDER TO POSITION CRANE HOOK, WHICH WILL LIFT TOP PLUG FROM REACTOR AS A STEP IN REFUELING PROCEDURES. NOTE CRANE OPERATOR AT UPPER LEFT OF VIEW. ENTIRE APPARATUS, INCLUDING FRAME AND DRIVES FOR CONTROL RODS, WILL BE LIFTED. INL NEGATIVE NO. 6199. R.G. Larsen, Photographer, 6/22/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Carroll, KC; Chronister, Glen B.

    2013-06-28

    Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

  14. Ladder Climbing and Autoresonant Acceleration of Plasma Waves

    NASA Astrophysics Data System (ADS)

    Barth, Ido; Dodin, Ilya; Fisch, Nathaniel

    2015-11-01

    When the background density in a bounded plasma is modulated in time, discrete modes become coupled. Interestingly, for appropriately chosen modulations, the average plasmon energy might be made to grow in a ladder-like manner, achieving up-conversion or down-conversion of the plasmon energy. This reversible process is identified as a classical analog of the effect known as quantum ladder climbing, so that the efficiency and the rate of this process can be written immediately by analogy to a quantum particle in a box. In the limit of densely spaced spectrum, ladder climbing transforms into continuous autoresonance; plasmons may then be manipulated by chirped background modulations much like electrons are autoresonantly manipulated by chirped fields. By formulating the wave dynamics within a universal Lagrangian framework, similar ladder climbing and autoresonance effects are predicted to be achievable with general linear waves in both plasma and other media. Supported by NNSA grant DE274-FG52-08NA28553, DOE contract DE-AC02-09CH11466, and DTRA grant HDTRA1-11-1-0037.

  15. Upper-limb power test in rock-climbing.

    PubMed

    Laffaye, G; Collin, J-M; Levernier, G; Padulo, J

    2014-07-01

    The goal of the present study was to validate a new ecological power-test on athletes of different levels and to assess rock climbers' profiles (boulderers vs. route climbers). 34 athletes divided into novice, skilled and elite groups performed the arm-jump board test (AJ). Power, time, velocity, and efficiency index were recorded. Validity was assessed by comparing the distance with the value extracted from the accelerometer (500 Hz) and the reliability of intra- and inter-session scores. Moreover, a principal component analysis (PCA) was used to assess the climbers' profiles. The AJ test was quite valid, showing a low systematic bias of -0.88 cm (-1.25%) and low limits of agreement (< 6%), and reliable ( Intra-class correlation coefficient = 0.98 and CV < 5%), and was able to distinguish between the 3 samples (p < 0.0001). There was a good correlation between relative upper-limb power (r = 0.70; p < 0.01) and the AJ score. Moreover, the PCA revealed an explosive profile for boulderers and either a weak and quick or slow profile for route climbers, revealing a biomechanical signature of the sub-discipline. The AJ test provides excellent absolute and relative reliabilities for climbing, and can effectively distinguish between climbing athletes of different competitive levels. Thus, the AJ may be suitable for field assessment of upper limb strength in climbing practitioners.

  16. Metals in Nile perch (Lates niloticus) and suspended particulate matter from Lake Victoria, Tanzania.

    PubMed

    Machiwa, John F

    2005-01-01

    A study was conducted to assess the levels of pollutant metals in suspended particulate matter and Nile perch from Lake Victoria. The metals in particulate matter were determined to ascertain their concentrations at the base of the food chain. Nile perch samples were collected in September 2003 from five major fish processing factories at the shores of Lake Victoria in Mwanza and Musoma. The concentrations of total Hg, Pb, Cd, and Cu were generally low in particulate matter and in most locations were close to or below their limits of detection. The concentrations of Zn were high in suspended particulate matter, the highest being 219.4 +/- 153.0 microg L(-1) found in particulate matter from Nungwe Bay in the southern part of Lake Victoria. Nile perch generally contained low levels of heavy metals; the range for Pb was <0.01-0.08 microg g(-1) ww, Cd was <0.001-0.04 microg g(-1) ww, Cu was 0.01-0.97 microg g(-1) ww, and Zn was <0.01-18.94 microg g(-1) ww. The concentration of total mercury ranged between 31.0 and 684.2 ng g(-1) ww; generally, it was below the Food and Agriculture Organization of the United Nations/World Health Organization (1000 ng total Hg g(-1) ww for piscivorous fish species) maximum allowable level. Indeed, all Nile perch samples that weighed less than 10 kg had less than 200 ng total Hg g(-1) ww and therefore are safe for regular consumption by at-risk groups such as children and pregnant women. Levels of mercury and other heavy metals in Nile perch at present is, therefore, not a severe environmental issue; however, urgent regulatory measures should be taken to minimize metal input into the lake to maintain the current levels in the fish.

  17. Robust post-stall perching with a simple fixed-wing glider using LQR-Trees.

    PubMed

    Moore, Joseph; Cory, Rick; Tedrake, Russ

    2014-06-01

    Birds routinely execute post-stall maneuvers with a speed and precision far beyond the capabilities of our best aircraft control systems. One remarkable example is a bird exploiting post-stall pressure drag in order to rapidly decelerate to land on a perch. Stall is typically associated with a loss of control authority, and it is tempting to attribute this agility of birds to the intricate morphology of the wings and tail, to their precision sensing apparatus, or their ability to perform thrust vectoring. Here we ask whether an extremely simple fixed-wing glider (no propeller) with only a single actuator in the tail is capable of landing precisely on a perch from a large range of initial conditions. To answer this question, we focus on the design of the flight control system; building upon previous work which used linear feedback control design based on quadratic regulators (LQR), we develop nonlinear feedback control based on nonlinear model-predictive control and 'LQR-Trees'. Through simulation using a flat-plate model of the glider, we find that both nonlinear methods are capable of achieving an accurate bird-like perching maneuver from a large range of initial conditions; the 'LQR-Trees' algorithm is particularly useful due to its low computational burden at runtime and its inherent performance guarantees. With this in mind, we then implement the 'LQR-Trees' algorithm on real hardware and demonstrate a 95 percent perching success rate over 147 flights for a wide range of initial speeds. These results suggest that, at least in the absence of significant disturbances like wind gusts, complex wing morphology and sensing are not strictly required to achieve accurate and robust perching even in the post-stall flow regime.

  18. Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications

    USGS Publications Warehouse

    Vandergoot, C.S.; Bur, M.T.; Powell, K.A.

    2008-01-01

    Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared the precision associated with yellow perch (N = 251) age estimates from scales, sagittal otoliths, and anal spine sections and evaluated the time required to process and estimate age from each structure. Three readers of varying experience estimated ages. The precision (mean coefficient of variation) of estimates among readers was 1% for sagittal otoliths, 5-6% for anal spines, and 11-13% for scales. Agreement rates among readers were 94-95% for otoliths, 71-76% for anal spines, and 45-50% for scales. Systematic age estimation differences were evident among scale and anal spine readers; less-experienced readers tended to underestimate ages of yellow perch older than age 4 relative to estimates made by an experienced reader. Mean scale age tended to underestimate ages of age-6 and older fish relative to otolith ages estimated by an experienced reader. Total annual mortality estimates based on scale ages were 20% higher than those based on otolith ages; mortality estimates based on anal spine ages were 4% higher than those based on otolith ages. Otoliths required more removal and preparation time than scales and anal spines, but age estimation time was substantially lower for otoliths than for the other two structures. We suggest the use of otoliths or anal spines for age estimation in yellow perch (regardless of length) from Lake Erie and other systems where precise age estimates are necessary, because age estimation errors resulting from the use of scales could generate incorrect management decisions. ?? Copyright by the American Fisheries Society 2008.

  19. Fyke-net and gill-net size selectivities for yellow perch in Green Bay, Lake Michigan

    USGS Publications Warehouse

    Kraft, J.A.; Johnson, B.L.

    1992-01-01

    We estimated a fyke-net selectivity function for yellow perch Perca flavescens in Green Bay, Lake Michigan, by comparing length-frequency distributions of yellow perch captured in fyke nets with different mesh sizes in 1986. Using a length--girth relationship for Green Bay yellow perch, we expressed selectivity as the ratio of girth (G) to effective mesh perimeter (P), which was 5a??7% less than nominal mesh perimeter. Then, fitting an existing gill-net selectivity function to the Green Bay yellow perch fishery, we found fyke-net and gill-net selectivities were similar, with similar G /P ratios, but fyke nets had smaller effective mesh perimeters and thus were more efficient at capturing smaller yellow perch for any given mesh size, The derived fyke-net selectivity function can be used to determine mesh sizes that minimize the sublegal catch of yellow perch in this fishery and could be applied to entrapment gear in other yellow perch fisheries, given data on the lengtha??girth relationships and effective mesh perimeters.

  20. Comparison of bone volume and strength as measures of skeletal integrity in caged laying hens with access to perches.

    PubMed

    Hughes, B O; Wilson, S; Appleby, M C; Smith, S F

    1993-03-01

    Fractures in spent laying hens are now recognised as a major welfare problem; the objective of this work was to determine whether provision of perches for caged layers would increase bone strength, bone volume or both. Sixteen ISA Brown hens were housed from 18 to 72 weeks old in cages with perches and 16 in similar cages without perches. At the end of lay the birds' tibiotarsi were examined for strength by a three-point loading test and their tarsometatarsi for bone volume by histomorphometry. There was no significant effect of perches on tibiotarsal breaking strength. Hens from both groups showed evidence of osteoporosis, but it was more severe in the birds from conventional cages: tarsometatarsal trabecular bone volume was greater in the hens which had access to perches. A positive correlation was found between trabecular bone volume and the degree of day-time perch usage by individual hens. Provision of perches can have a slight but significant beneficial effect, at least for the leg bones, in increasing the bone volume of caged laying hens.

  1. Season-related changes in circulating androgen, brain aromatase, and perch-calling in male ring doves.

    PubMed

    Fusani, Leonida; Van't Hof, Thomas; Hutchison, John B

    2003-02-01

    The perch-call of ring doves (Streptopelia risoria) is related to territorial defence and mate attraction. Perch-calls are sexually dimorphic and individually different in structure. The expression of perch-call is androgen-dependent and is controlled by the action of testosterone on the preoptic-hypothalamic areas. However, it is not known whether the acoustic features of the call vary with the reproductive condition. We studied plasma androgen levels, brain steroid metabolism, and perch-calling of male ring doves kept in winter-like (low temperature, short days) or spring-like (mild temperature, long day) conditions. Circulating levels of androgen were higher in males kept on spring-like condition. Spring males spent more time in perch-calling than winter males. However, a detailed analysis of the call structure revealed no difference for any time or frequency parameter between groups. This work shows that in ring doves season-dependent variations in the circulating levels of androgen are correlated with differences in the amount of time males spend in perch-calling. In addition, the study suggests that in adult males the acoustic structure of the perch-calls is not influenced by season-related changes in androgen levels.

  2. Fast, vacancy-free climb of prismatic dislocation loops in bcc metals

    PubMed Central

    Swinburne, Thomas D.; Arakawa, Kazuto; Mori, Hirotaro; Yasuda, Hidehiro; Isshiki, Minoru; Mimura, Kouji; Uchikoshi, Masahito; Dudarev, Sergei L.

    2016-01-01

    Vacancy-mediated climb models cannot account for the fast, direct coalescence of dislocation loops seen experimentally. An alternative mechanism, self climb, allows prismatic dislocation loops to move away from their glide surface via pipe diffusion around the loop perimeter, independent of any vacancy atmosphere. Despite the known importance of self climb, theoretical models require a typically unknown activation energy, hindering implementation in materials modeling. Here, extensive molecular statics calculations of pipe diffusion processes around irregular prismatic loops are used to map the energy landscape for self climb in iron and tungsten, finding a simple, material independent energy model after normalizing by the vacancy migration barrier. Kinetic Monte Carlo simulations yield a self climb activation energy of 2 (2.5) times the vacancy migration barrier for 1/2〈111〉 (〈100〉) dislocation loops. Dislocation dynamics simulations allowing self climb and glide show quantitative agreement with transmission electron microscopy observations of climbing prismatic loops in iron and tungsten, confirming that this novel form of vacancy-free climb is many orders of magnitude faster than what is predicted by traditional climb models. Self climb significantly influences the coarsening rate of defect networks, with important implications for post-irradiation annealing. PMID:27549928

  3. Fast, vacancy-free climb of prismatic dislocation loops in bcc metals

    NASA Astrophysics Data System (ADS)

    Swinburne, Thomas D.; Arakawa, Kazuto; Mori, Hirotaro; Yasuda, Hidehiro; Isshiki, Minoru; Mimura, Kouji; Uchikoshi, Masahito; Dudarev, Sergei L.

    2016-08-01

    Vacancy-mediated climb models cannot account for the fast, direct coalescence of dislocation loops seen experimentally. An alternative mechanism, self climb, allows prismatic dislocation loops to move away from their glide surface via pipe diffusion around the loop perimeter, independent of any vacancy atmosphere. Despite the known importance of self climb, theoretical models require a typically unknown activation energy, hindering implementation in materials modeling. Here, extensive molecular statics calculations of pipe diffusion processes around irregular prismatic loops are used to map the energy landscape for self climb in iron and tungsten, finding a simple, material independent energy model after normalizing by the vacancy migration barrier. Kinetic Monte Carlo simulations yield a self climb activation energy of 2 (2.5) times the vacancy migration barrier for 1/2<111> (<100>) dislocation loops. Dislocation dynamics simulations allowing self climb and glide show quantitative agreement with transmission electron microscopy observations of climbing prismatic loops in iron and tungsten, confirming that this novel form of vacancy-free climb is many orders of magnitude faster than what is predicted by traditional climb models. Self climb significantly influences the coarsening rate of defect networks, with important implications for post-irradiation annealing.

  4. Fast, vacancy-free climb of prismatic dislocation loops in bcc metals.

    PubMed

    Swinburne, Thomas D; Arakawa, Kazuto; Mori, Hirotaro; Yasuda, Hidehiro; Isshiki, Minoru; Mimura, Kouji; Uchikoshi, Masahito; Dudarev, Sergei L

    2016-08-23

    Vacancy-mediated climb models cannot account for the fast, direct coalescence of dislocation loops seen experimentally. An alternative mechanism, self climb, allows prismatic dislocation loops to move away from their glide surface via pipe diffusion around the loop perimeter, independent of any vacancy atmosphere. Despite the known importance of self climb, theoretical models require a typically unknown activation energy, hindering implementation in materials modeling. Here, extensive molecular statics calculations of pipe diffusion processes around irregular prismatic loops are used to map the energy landscape for self climb in iron and tungsten, finding a simple, material independent energy model after normalizing by the vacancy migration barrier. Kinetic Monte Carlo simulations yield a self climb activation energy of 2 (2.5) times the vacancy migration barrier for 1/2〈111〉 (〈100〉) dislocation loops. Dislocation dynamics simulations allowing self climb and glide show quantitative agreement with transmission electron microscopy observations of climbing prismatic loops in iron and tungsten, confirming that this novel form of vacancy-free climb is many orders of magnitude faster than what is predicted by traditional climb models. Self climb significantly influences the coarsening rate of defect networks, with important implications for post-irradiation annealing.

  5. Functional morphology of the ankle and the likelihood of climbing in early hominins

    PubMed Central

    DeSilva, Jeremy M.

    2009-01-01

    Whether early hominins were adept tree climbers is unclear. Although some researchers have argued that bipedality maladapts the hominin skeleton for climbing, others have argued that early hominin fossils display an amalgamation of features consistent with both locomotor strategies. Although chimpanzees have featured prominently in these arguments, there are no published data on the kinematics of climbing in wild chimpanzees. Without these biomechanical data describing how chimpanzees actually climb trees, identifying correlates of climbing in modern ape skeletons is difficult, thereby limiting accurate interpretations of the hominin fossil record. Here, the first kinematic data on vertical climbing in wild chimpanzees are presented. These data are used to identify skeletal correlates of climbing in the ankle joint of the African apes to more accurately interpret hominin distal tibiae and tali. This study finds that chimpanzees engage in an extraordinary range of foot dorsiflexion and inversion during vertical climbing bouts. Two skeletal correlates of modern ape-like vertical climbing are identified in the ankle joint and related to positions of dorsiflexion and foot inversion. A study of the 14 distal tibiae and 15 tali identified and published as hominins from 4.12 to 1.53 million years ago finds that the ankles of early hominins were poorly adapted for modern ape-like vertical climbing bouts. This study concludes that if hominins included tree climbing as part of their locomotor repertoire, then they were performing this activity in a manner decidedly unlike modern chimpanzees. PMID:19365068

  6. To boldly climb: behavioural and cognitive differences in migrating European glass eels

    PubMed Central

    Podgorniak, T.; Blanchet, S.; De Oliveira, E.; Daverat, F.; Pierron, F.

    2016-01-01

    European eel (Anguilla anguilla) is a catadromous fish species that received substantial attention as its population has markedly declined in the last three decades. The possible causes of this decline include habitat fragmentation factors such as dams and weirs. In some cases, these obstacles are equipped with fish friendly passage devices that may select young eels according to their climbing behaviour. We tested how individual climbing tendency was related to the event of fishway passage experienced in the field and classified fish climbing profiles as climbing ‘leaders’, ‘followers’, ‘finishers’ and ‘no climbers’. Moreover, we analysed the brain transcription level of genes related to neurogenesis and synaptic plasticity and compared it to climbing profiles. We found that fish from the upstream segments of an impounded river had a higher climbing propensity. Their behaviour was also more repeatable throughout the whole test than the obstacle-naive fish from the downstream segment. Moreover, we found that boldly climbing ‘leaders’ had lower levels of transcription of synapse-related genes than the climbing ‘followers’. These differences could be related to coping styles of fish, where proactive ‘leaders’ express a routine and risky behaviour, whereas reactive fish need an environmental assessment before exploratory behaviour. Our study showed that differences in climbing propensity exist in glass eels separated by water obstacles. Moreover, eels could adopt climbing different strategies according to the way they deal with environmental stress and to the cognitive abilities they possess. PMID:26909192

  7. To boldly climb: behavioural and cognitive differences in migrating European glass eels.

    PubMed

    Podgorniak, T; Blanchet, S; De Oliveira, E; Daverat, F; Pierron, F

    2016-01-01

    European eel (Anguilla anguilla) is a catadromous fish species that received substantial attention as its population has markedly declined in the last three decades. The possible causes of this decline include habitat fragmentation factors such as dams and weirs. In some cases, these obstacles are equipped with fish friendly passage devices that may select young eels according to their climbing behaviour. We tested how individual climbing tendency was related to the event of fishway passage experienced in the field and classified fish climbing profiles as climbing 'leaders', 'followers', 'finishers' and 'no climbers'. Moreover, we analysed the brain transcription level of genes related to neurogenesis and synaptic plasticity and compared it to climbing profiles. We found that fish from the upstream segments of an impounded river had a higher climbing propensity. Their behaviour was also more repeatable throughout the whole test than the obstacle-naive fish from the downstream segment. Moreover, we found that boldly climbing 'leaders' had lower levels of transcription of synapse-related genes than the climbing 'followers'. These differences could be related to coping styles of fish, where proactive 'leaders' express a routine and risky behaviour, whereas reactive fish need an environmental assessment before exploratory behaviour. Our study showed that differences in climbing propensity exist in glass eels separated by water obstacles. Moreover, eels could adopt climbing different strategies according to the way they deal with environmental stress and to the cognitive abilities they possess.

  8. A wheelchair with lever propulsion control for climbing up and down stairs.

    PubMed

    Sasaki, Kai; Eguchi, Yosuke; Suzuki, Kenji

    2016-08-01

    This study proposes a novel stair-climbing wheelchair based on lever propulsion control using the human upper body. Wheelchairs are widely used as supporting locomotion devices for people with acquired lower limb disabilities. However, steps and stairs are critical obstacles to locomotion, which restrict their activities when using wheelchairs. Previous research focused on power-assisted, stair-climbing wheelchairs, which were large and heavy due to its large actuators and mechanisms. In the previous research, we proposed a wheelchair with lever propulsion mechanism and presented its feasibility of climbing up the stairs. The developed stair-climbing wheelchair consists of manual wheels with casters for planar locomotion and a rotary-leg mechanism based on lever propulsion that is capable of climbing up stairs. The wheelchair also has a passive mechanism powered by gas springs for posture transition to shift the user's center of gravity between the desired positions for planar locomotion and stair-climbing. In this paper, we present an advanced study on both climbing up and going down using lever propulsion control by the user's upper body motion. For climbing down the stairs, we reassembled one-way clutches used for the rotary-leg mechanism to help a user climb down the stairs through lever operation. We also equipped the wheelchair with sufficient torque dampers. The frontal wheels were fixed while climbing down the stairs to ensure safety. Relevant experiments were then performed to investigate its performance and verify that the wheelchair users can operate the proposed lever propulsion mechanism.

  9. Evaluation of injury and fatality risk in rock and ice climbing.

    PubMed

    Schöffl, Volker; Morrison, Audry; Schwarz, Ulrich; Schöffl, Isabelle; Küpper, Thomas

    2010-08-01

    Rock and ice climbing are widely considered to be 'high-risk' sporting activities that are associated with a high incidence of severe injury and even death, compared with more mainstream sports. However, objective scientific data to support this perception are questionable. Accordingly, >400 sport-specific injury studies were analysed and compared by quantifying the injury incidence and objectively grading the injury severity (using the National Advisory Committee for Aeronautics score) per 1000 hours of sporting participation. Fatalities were also analysed. The analysis revealed that fatalities occurred in all sports, but it was not always clear whether the sport itself or pre-existing health conditions contributed or caused the deaths. Bouldering (ropeless climbing to low heights), sport climbing (mostly bolt protected lead climbing with little objective danger) and indoor climbing (climbing indoors on artificial rock structures), showed a small injury rate, minor injury severity and few fatalities. As more objective/external dangers exist for alpine and ice climbing, the injury rate, injury severity and fatality were all higher. Overall, climbing sports had a lower injury incidence and severity score than many popular sports, including basketball, sailing or soccer; indoor climbing ranked the lowest in terms of injuries of all sports assessed. Nevertheless, a fatality risk remains, especially in alpine and ice climbing. In the absence of a standard definition for a 'high-risk' sport, categorizing climbing as a high-risk sport was found to be either subjective or dependent on the definition used. In conclusion, this analysis showed that retrospective data on sport-specific injuries and fatalities are not reported in a standardized manner. To improve preventative injury measures for climbing sports, it is recommended that a standardized, robust and comprehensive sport-specific scoring model should be developed to report and fully evaluate the injury risk, severity

  10. Global diversification of a tropical plant growth form: environmental correlates and historical contingencies in climbing palms

    PubMed Central

    Couvreur, Thomas L. P.; Kissling, W. Daniel; Condamine, Fabien L.; Svenning, Jens-Christian; Rowe, Nick P.; Baker, William J.

    2015-01-01

    Tropical rain forests (TRF) are the most diverse terrestrial biome on Earth, but the diversification dynamics of their constituent growth forms remain largely unexplored. Climbing plants contribute significantly to species diversity and ecosystem processes in TRF. We investigate the broad-scale patterns and drivers of species richness as well as the diversification history of climbing and non-climbing palms (Arecaceae). We quantify to what extent macroecological diversity patterns are related to contemporary climate, forest canopy height, and paleoclimatic changes. We test whether diversification rates are higher for climbing than non-climbing palms and estimate the origin of the climbing habit. Climbers account for 22% of global palm species diversity, mostly concentrated in Southeast Asia. Global variation in climbing palm species richness can be partly explained by past and present-day climate and rain forest canopy height, but regional differences in residual species richness after accounting for current and past differences in environment suggest a strong role of historical contingencies in climbing palm diversification. Climbing palms show a higher net diversification rate than non-climbers. Diversification analyses of palms detected a diversification rate increase along the branches leading to the most species-rich clade of climbers. Ancestral character reconstructions revealed that the climbing habit originated between early Eocene and Miocene. These results imply that changes from non-climbing to climbing habits may have played an important role in palm diversification, resulting in the origin of one fifth of all palm species. We suggest that, in addition to current climate and paleoclimatic changes after the late Neogene, present-day diversity of climbing palms can be explained by morpho-anatomical innovations, the biogeographic history of Southeast Asia, and/or ecological opportunities due to the diversification of high-stature dipterocarps in Asian TRFs

  11. First overview on chronic injuries in sport climbing: proposal for a change in reporting of injuries in climbing

    PubMed Central

    Grønhaug, Gudmund; Norberg, Marius

    2016-01-01

    Background Climbing as a youth sport is growing fast. This is mostly due to indoor walls for training attracting youngsters. With hard training from young ages it is vital to be able to pinpoint training regimes to avoid injuries in athletes. Furthermore, it is vital to know what injuries are most common in the sport to be able to prevent them. Such an overview on injuries does not exist to date. The aim of this overview is to summon the injuries described in published research and to extract the most common. Method Two literature searches were conducted in PubMed, on 11 August 2013 and 19 August 2015. Result The searches gave 1409 titles. All titles were carefully examined for the possible finding of descriptions of climbing-related chronic injuries. This led to the reading of 96 abstracts and then to a final inclusion of 47 papers of which 17 described chronic climbing-related injuries. We found descriptions of 45 chronic injuries in those 17 papers. Discussion Owing to methodological differences, lack of reporting strategies and non-use of control groups in the included papers, it is not possible to conclude on which groups of climbers are more prone to injuries or to state which injuries are the most prevalent among climbers. PMID:27900162

  12. Abnormal climbing fibre-Purkinje cell synaptic connections in the essential tremor cerebellum.

    PubMed

    Lin, Chi-Ying; Louis, Elan D; Faust, Phyllis L; Koeppen, Arnulf H; Vonsattel, Jean-Paul G; Kuo, Sheng-Han

    2014-12-01

    Structural changes in Purkinje cells have been identified in the essential tremor cerebellum, although the mechanisms that underlie these changes remain poorly understood. Climbing fibres provide one of the major excitatory inputs to Purkinje cells, and climbing fibre-Purkinje cell connections are essential for normal cerebellar-mediated motor control. The distribution of climbing fibre-Purkinje cell synapses on Purkinje cell dendrites is dynamically regulated and may be altered in disease states. The aim of the present study was to examine the density and distribution of climbing fibre-Purkinje cell synapses using post-mortem cerebellar tissue of essential tremor cases and controls. Using vesicular glutamate transporter type 2 immunohistochemistry, we labelled climbing fibre-Purkinje cell synapses of 12 essential tremor cases and 13 age-matched controls from the New York Brain Bank. Normally, climbing fibres form synapses mainly on the thick, proximal Purkinje cell dendrites in the inner portion of the molecular layer, whereas parallel fibres form synapses on the thin, distal Purkinje cell spiny branchlets. We observed that, compared with controls, essential tremor cases had decreased climbing fibre-Purkinje cell synaptic density, more climbing fibres extending to the outer portion of the molecular layer, and more climbing fibre-Purkinje cell synapses on the thin Purkinje cell spiny branchlets. Interestingly, in essential tremor, the increased distribution of climbing fibre-Purkinje cell synapses on the thin Purkinje cell branchlets was inversely associated with clinical tremor severity, indicating a close relationship between the altered distribution of climbing fibre-Purkinje cell connections and tremor. These findings suggest that abnormal climbing fibre-Purkinje cell connections could be of importance in the pathogenesis of essential tremor.

  13. Sport climbing with pre-existing cardio-pulmonary medical conditions.

    PubMed

    Kuepper, T; Morrison, A; Gieseler, U; Schoeffl, V

    2009-06-01

    Over the past 25 years sport climbing has developed from an elite extreme sport subculture pursued by few into a mainstream recreational sport enjoyed globally by climbers of all ages, climbing abilities, and with pre-existing health conditions. As the demands and grades of climbing difficulty have increased over this period, most scientific literature on sport climbing focused on acute injuries and overuse syndromes, or performance physiology in healthy adult males. The physiological response to sport climbing is more similar to that of resistance training (i.e., body building) rather than a predominantly aerobic sport (i.e., running, cycling), so that heart rate and blood pressure during a climb will be disproportionately high relative to the 'exercise' of climbing, and breathing may be irregular. Therefore this review sought evidence-based recommendations for recreational sport climbing participation by those individuals with pre-existing cardiopulmonary medical conditions including coronary heart disease, chronic heart failure, cardiac dysrhythmia, pulmonary diseases (i.e., asthma) or hypertension. This review defines the criteria that must be fulfilled for safe sport climbing by those with pre-existing cardiopulmonary conditions or those with hypertension.

  14. Single-step collision-free trajectory planning of biped climbing robots in spatial trusses.

    PubMed

    Zhu, Haifei; Guan, Yisheng; Chen, Shengjun; Su, Manjia; Zhang, Hong

    For a biped climbing robot with dual grippers to climb poles, trusses or trees, feasible collision-free climbing motion is inevitable and essential. In this paper, we utilize the sampling-based algorithm, Bi-RRT, to plan single-step collision-free motion for biped climbing robots in spatial trusses. To deal with the orientation limit of a 5-DoF biped climbing robot, a new state representation along with corresponding operations including sampling, metric calculation and interpolation is presented. A simple but effective model of a biped climbing robot in trusses is proposed, through which the motion planning of one climbing cycle is transformed to that of a manipulator. In addition, the pre- and post-processes are introduced to expedite the convergence of the Bi-RRT algorithm and to ensure the safe motion of the climbing robot near poles as well. The piecewise linear paths are smoothed by utilizing cubic B-spline curve fitting. The effectiveness and efficiency of the presented Bi-RRT algorithm for climbing motion planning are verified by simulations.

  15. Endocrine disruption and altered gonadal development in white perch (Morone americana) from the lower Great Lakes region.

    PubMed Central

    Kavanagh, Richard J; Balch, Gordon C; Kiparissis, Yiannis; Niimi, Arthur J; Sherry, Jim; Tinson, Cheryl; Metcalfe, Chris D

    2004-01-01

    High prevalences of gonadal intersex have been observed in wild fish populations in areas affected by domestic and industrial effluents. For this study, fish were collected in 1998 from the Cootes Paradise region of Hamilton Harbour in western Lake Ontario, Canada, to determine whether gonadal abnormalities, including intersex, were present in young of the year (YOY) fish. No gonadal abnormalities were observed in goldfish (Carassius auratus), common carp (Cyprinus carpio), gizzard shad (Dorosoma cepedianum), brown bullhead (Ictalurus ameiurus), pumpkinseed (Lepomis gibbosus), and bluegill (Lepomis macrochirus). However, intersex gonads were observed in 8 of 16 male white perch (Morone americana) examined in this survey. Subsequently, in 1999 and 2000 white perch estimated to be YOY to approximately 2 years of age were collected from Cootes Paradise and from two other sites in the lower Great Lakes region. Gonadal intersex was observed in male white perch collected from the Bay of Quinte (22-44%) and Lake St. Clair (45%), although the prevalence and the extent of the intersex condition were lower relative to the 83% prevalence in white perch collected in Cootes Paradise. Intersex was not observed in hatchery-reared white perch or in white perch collected from an uncontaminated reference site (i.e., Deal Lake) in the United States. An analysis of plasma collected in the spring of 2002 from male adult white perch in Cootes Paradise revealed high concentrations of vitellogenin, ranging from 49 to 1,711 microg/mL. These observations indicate that male white perch are exposed to estrogenic endocrine-disrupting substances that may be responsible for the induction of gonadal intersex. PMID:15175179

  16. Of Paleo-Genes and Perch: What if an “Alien” Is Actually a Native?

    PubMed Central

    Stager, J. Curt; Sporn, Lee Ann; Johnson, Melanie; Regalado, Sean

    2015-01-01

    Documenting whether a biotic taxon is native or alien to an ecosystem has theoretical value for ecological and evolutionary studies, and has practical value because it can potentially identify a taxon as a desirable component of an ecosystem or target it for removal. In some cases, however, such background information is inadequate or unavailable. Here we use paleo-DNA to re-evaluate the historical status of yellow perch in the 6 million acre Adirondack State Park of northern New York. Yellow perch DNA in a 2200-year sediment record reveals a long-term native status for these supposedly alien fish and challenges assumptions that they necessarily exclude native trout from upland lakes. Similar approaches could be applied to other species with uncertain historical distributions and could help to identify unrecognized pockets of biodiversity. PMID:25751263

  17. Retention of mercury in the muscle of yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris)

    USGS Publications Warehouse

    Laarman, Percy W.; Willford, Wayne A.; Olson, James R.

    1976-01-01

    Mercury-contaminated yellow perch (Perca flavescens) and rock bass (Ambloplites rupestris) were collected from Lake St. Clair and stocked in two earthen ponds in September 1970. Twenty-six months later, concentrations of total mercury in the fillets had declined 53% in the yellow perch and 59% in the rock bass; however, the mean weight of the fish increased 88 and 183%, respectively, during the same period. All of the reduction in mercury concentrations was attributable to dilution by growth. Slight discrepancies between the theoretical and observed reduction of mercury concentrations suggest an initial redistribution of residues from other tissues to the muscle and a continued incorporation of background amounts of mercury during growth.

  18. Onboard near-optimal climb-dash energy management

    NASA Technical Reports Server (NTRS)

    Weston, A.; Cliff, G.; Kelley, H.

    1985-01-01

    This paper studies optimal and near-optimal trajectories of high-performance aircraft in symmetric flight. Onboard, real-time, near-optimal guidance is considered for the climb-dash mission, using some of the boundary-layer structure and hierarchical ideas from singular perturbations. In the case of symmetric flight, this resembles neighborhood-optimal guidance using energy-to-go as the running variable. However, extension to three-dimensional flight is proposed, using families of nominal paths with heading-to-go as the additional running variable. Some computational results are presented for the symmetric case.

  19. Nondimensional forms for singular perturbation analyses of aircraft energy climbs

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Markopoulos, N.; Corban, J. E.

    1991-01-01

    This paper proposes a systematic approach for identifying the perturbation parameter in singular perturbation analysis of aircraft optimal guidance, and in particular considers a family of problems related to aircraft energy climbs. The approach, which is based on a nondimensionalization of the equations of motion, is used to evaluatae the appropriateness of forced singular perturbation formulations used in the past for transport and fighter aircraft, and to assess the applicability of energy state approximations and singular perturbation analysis for airbreathing transatmospheric vehicles with hypersonic cruise and orbital capabilities.

  20. Modeling turbidity type and intensity effects on the growth and starvation mortality of age-0 yellow perch

    USGS Publications Warehouse

    Manning, Nathan M; Bossenbroek, Jonathan M.; Mayer, Christine M.; Bunnell, David B.; Tyson, Jeff T.; Rudstam, Lars G.; Jackson, James R.

    2014-01-01

    We sought to quantify the possible population-level influence of sediment plumes and algal blooms on yellow perch (Perca flavescens), a visual predator found in systems with dynamic water clarity. We used an individual-based model (IBM), which allowed us to include variance in water clarity and the distribution of individual sizes. Our IBM was built with laboratory data showing that larval yellow perch feeding rates increased slightly as sediment turbidity level increased, but that both larval and juvenile yellow perch feeding rates decreased as phytoplankton level increased. Our IBM explained a majority of the variance in yellow perch length in data from the western and central basins of Lake Erie and Oneida Lake, with R2 values ranging from 0.611 to 0.742. Starvation mortality was size dependent, as the greatest daily mortality rates in each simulation occurred within days of each other. Our model showed that turbidity-dependent consumption rates and temperature are key components in determining growth and starvation mortality of age-0 yellow perch, linking fish production to land-based processes that influence water clarity. These results suggest the timing and persistence of sediment plumes and algal blooms can drastically alter the growth potential and starvation mortality of a yellow perch cohort.

  1. Effects of habitat on mercury concentrations in fish: a case study of Nile perch (Lates niloticus) in Lake Nabugabo, Uganda.

    PubMed

    Hanna, D E L; Buck, D G; Chapman, L J

    2016-01-01

    This study focused on variation in fish mercury (Hg) concentrations in 185 Nile perch (Lates niloticus) samples collected across four different habitat types in Lake Nabugabo, Uganda, a tropical lake located proximate to Lake Victoria. We quantified the stomach contents of Nile perch using the % index of relative importance, as well as, nitrogen and carbon isotopic concentrations to assess the role of diet and trophic level on Hg concentrations. In each habitat, we also evaluated a suite of chemical and physical characteristics that are commonly associated with variation in Hg bioavailability in temperate systems. Using linear mixed models and ANOVA, we demonstrate that habitat of capture is an important predictor of Hg concentrations in Nile perch from Lake Nabugabo and that the relationship between habitat and Hg is size and diet dependent. Nile perch diet as well as dissolved oxygen concentration and pH were also correlated with observed differences in fish Hg. Overall, Hg concentrations in Nile perch were all well below the WHO/FAO recommended guideline of 500 ng/g (mean 13.6 ± 0.4 ng/g wet weight; range 4.9 and 29.3 ng/g wet weight). This work contributes to a growing awareness of intra-lake divergence in Nile perch, as well as, divergence in Hg concentrations between varying aquatic habitat types, particularly wetlands.

  2. Movements of yellow perch marked in southern Green Bay, Lake Michigan, in 1950

    USGS Publications Warehouse

    Mraz, Donald

    1952-01-01

    These investigations have demonstrated that for studying migration of yellow perch, tagging is superior to fin-clipping as a method of marking. The technique of the tagging, however, needs to be improved, and better means must be found to trace tagged fish of small size. Furthermore certain small regions in the bay not at present open to commercial fishing must be explored in order to obtain more comprehensive information as to migration.

  3. Evaluation of daily creel and minimum length limits for Black Crappies and Yellow Perch in Wisconsin

    USGS Publications Warehouse

    Mosel, Kyle; Isermann, Daniel A.; Hansen, Jonathan F.

    2015-01-01

    Harvest regulations for Black Crappie Pomoxis nigromaculatus and Yellow Perch Perca flavescens in the northern USA and Canada have not been thoroughly evaluated, and specific guidance regarding where minimum length limits (MLLs) might improve these fisheries is lacking. We examined whether: (1) transitioning from an aggregate statewide daily creel limit of 25 panfish to species-specific daily creel limits of <25 fish or implementing statewide MLLs could reduce harvest of Black Crappie and Yellow Perch in Wisconsin by ≥25%, and (2) MLLs would improve yield by ≥10% and mean TL of harvested fish by ≥25 mm in Wisconsin fisheries. Creel surveys indicated that ≥94% of Wisconsin anglers did not harvest a Black Crappie or Yellow Perch, and ≤0.12% of anglers harvested a daily creel limit of 25 fish. Daily creel limits would need to be ≤7 fish/ angler to reduce harvest by ≥25%. Statewide MLLs would need to be ≥229 mm for Black Crappie and ≥203 mm for Yellow Perch to reduce harvest by ≥25%, but predicted responses to MLLs varied among simulated populations. In general, MLLs were not predicted to improve yield, indicating that growth overfishing was not a widespread problem. Minimum length limits could improve mean TL of harvested fish, but increases ≥25 mm were only observed under 254-mm and 279-mm MLLs, and anglers would have to accept predicted reductions in harvest of ≥30% to achieve these improvements. A 229-mm MLL offered a more equitable trade-off between increases in mean TLs of harvested fish (11–21-mm improvements) and reductions in harvest (22–37% reductions). Our modeling provides a framework for managers to make more informed decisions regarding harvest regulations, but more information regarding angler preferences is needed for selecting appropriate management objectives and harvest regulations.

  4. Dermal melanin concentration of yellow perch Perca flavescens in relation to water transparency.

    PubMed

    Rheault, G; Langevin, M; Cabana, G; Glémet, H

    2015-11-01

    A positive relationship was observed between Secchi disc depth and dermal melanin concentration in yellow perch Perca flavescens sampled from 11 humic lakes located on the Canadian Shield in southern Quebec (Canada). Secchi disc depth explained 23% of the variations of dermal melanin concentration. Secchi disc depth and thus water transparency appear to have a positive influence on melanin production in the dermis of P. flavescens.

  5. Echolocation intensity and directionality of perching and flying fringe-lipped bats, Trachops cirrhosus (Phyllostomidae)

    PubMed Central

    Surlykke, Annemarie; Jakobsen, Lasse; Kalko, Elisabeth K. V.; Page, Rachel A.

    2013-01-01

    The Neotropical frog-eating bat, Trachops cirrhosus, primarily hunts stationary prey, either by gleaning on the wing, or in a sit-and-wait mode hanging from a perch. It listens passively for prey-generated sounds, but uses echolocation in all stages of the hunt. Like other bats in the family Phyllostomidae, T. cirrhosus has a conspicuous nose leaf, hypothesized to direct and focus echolocation calls emitted from the nostrils. T. cirrhosus is highly flexible in its cognitive abilities and its use of sensory strategies for prey detection. Additionally, T. cirrhosus has been observed to echolocate both with closed and open mouth. We hypothesize that its flexibility extends to echolocation call design. We investigated the effect of hunting mode, perching or flying, as well as the effect of mouth opening, on the acoustic parameters and directionality of the echolocation call. We used a multi-microphone array, a high-speed video camera, and a microphone-diode-video system to directly visualize the echolocation sound beam synchronized with the bat's behavior. We found that T. cirrhosus emits a highly directional sound beam with half amplitude angle (HAM) of 12–18° and DI (directionality index) of ~17 dB, among the most directional bat sonar beams measured to date. The directionality was high both when flying and when perching. The emitted intensity was low, around 88 dB SPL at 10 cm from the mouth, when hanging, but higher, around 100 dB SPL at 10 cm, when flying or just before take-off. Our data suggests that the limited search volume of T. cirrhosus sonar beam defined by the high directionality and the rather low intensity of its echolocation calls is adapted to the highly cluttered hunting habitat and to the perch hunting mode. PMID:23825459

  6. Echolocation intensity and directionality of perching and flying fringe-lipped bats, Trachops cirrhosus (Phyllostomidae).

    PubMed

    Surlykke, Annemarie; Jakobsen, Lasse; Kalko, Elisabeth K V; Page, Rachel A

    2013-01-01

    The Neotropical frog-eating bat, Trachops cirrhosus, primarily hunts stationary prey, either by gleaning on the wing, or in a sit-and-wait mode hanging from a perch. It listens passively for prey-generated sounds, but uses echolocation in all stages of the hunt. Like other bats in the family Phyllostomidae, T. cirrhosus has a conspicuous nose leaf, hypothesized to direct and focus echolocation calls emitted from the nostrils. T. cirrhosus is highly flexible in its cognitive abilities and its use of sensory strategies for prey detection. Additionally, T. cirrhosus has been observed to echolocate both with closed and open mouth. We hypothesize that its flexibility extends to echolocation call design. We investigated the effect of hunting mode, perching or flying, as well as the effect of mouth opening, on the acoustic parameters and directionality of the echolocation call. We used a multi-microphone array, a high-speed video camera, and a microphone-diode-video system to directly visualize the echolocation sound beam synchronized with the bat's behavior. We found that T. cirrhosus emits a highly directional sound beam with half amplitude angle (HAM) of 12-18° and DI (directionality index) of ~17 dB, among the most directional bat sonar beams measured to date. The directionality was high both when flying and when perching. The emitted intensity was low, around 88 dB SPL at 10 cm from the mouth, when hanging, but higher, around 100 dB SPL at 10 cm, when flying or just before take-off. Our data suggests that the limited search volume of T. cirrhosus sonar beam defined by the high directionality and the rather low intensity of its echolocation calls is adapted to the highly cluttered hunting habitat and to the perch hunting mode.

  7. Comparison of nutritional quality in fish maw product of croaker Protonibea diacanthus and perch Lates niloticus

    NASA Astrophysics Data System (ADS)

    Wen, Jing; Zeng, Ling; Chen, Ziming; Xu, Youhou

    2016-08-01

    Fish maw (the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw being sold as croaker maw are in fact not from croaker, but from the Nile perch Lates niloticus. The present work determined and compared the proximate composition, amino acid and fatty acid composition of croaker Protonibea diacanthus maw and perch L. niloticus maw. The results indicated that both maws were high protein sources and low in fat content. The dominant amino acids in both maws were glycine, proline, glutamic acid, alanine and arginine. These amino acids constituted 66.2% and 66.4% of the total amino acids in P. diacanthus and L. niloticus, respectively. The ratio of FAA: TAA (functional amino acids: total amino acids) in both maws were 0.69. This is a good explanation for why fish maws have been widely utilized as a traditional tonic and remedy in Asia. Except valine and histidine, all the essential amino acid contents in P. diacanthus were higher than in L. niloticus. Moreover, croaker P. diacanthus maw contained more AA and DHA than perch L. niloticus maw, showing a higher ratio of n-3 / n-6, which is more desirable.

  8. Preferential flow, diffuse flow, and perching in an interbedded fractured-rock unsaturated zone

    NASA Astrophysics Data System (ADS)

    Nimmo, John R.; Creasey, Kaitlyn M.; Perkins, Kim S.; Mirus, Benjamin B.

    2017-03-01

    Layers of strong geologic contrast within the unsaturated zone can control recharge and contaminant transport to underlying aquifers. Slow diffuse flow in certain geologic layers, and rapid preferential flow in others, complicates the prediction of vertical and lateral fluxes. A simple model is presented, designed to use limited geological site information to predict these critical subsurface processes in response to a sustained infiltration source. The model is developed and tested using site-specific information from the Idaho National Laboratory in the Eastern Snake River Plain (ESRP), USA, where there are natural and anthropogenic sources of high-volume infiltration from floods, spills, leaks, wastewater disposal, retention ponds, and hydrologic field experiments. The thick unsaturated zone overlying the ESRP aquifer is a good example of a sharply stratified unsaturated zone. Sedimentary interbeds are interspersed between massive and fractured basalt units. The combination of surficial sediments, basalts, and interbeds determines the water fluxes through the variably saturated subsurface. Interbeds are generally less conductive, sometimes causing perched water to collect above them. The model successfully predicts the volume and extent of perching and approximates vertical travel times during events that generate high fluxes from the land surface. These developments are applicable to sites having a thick, geologically complex unsaturated zone of substantial thickness in which preferential and diffuse flow, and perching of percolated water, are important to contaminant transport or aquifer recharge.

  9. Are high perches in the blackcap Sylvia atricapilla song or listening posts? A sound transmission study

    NASA Astrophysics Data System (ADS)

    Mathevon, Nicolas; Dabelsteen, Torben; Blumenrath, Sandra H.

    2005-01-01

    Birds often sing from high perches referred to as song posts. However, birds also listen and keep a lookout from these perches. We used a sound transmission experiment to investigate the changes for receiving and sending conditions that a territorial songbird may experience by moving upwards in the vegetation. Representative song elements of the blackcap Sylvia atricapilla were transmitted in a forest habitat in spring using a complete factorial design with natural transmission distances and speaker and microphone heights. Four aspects of sound degradation were quantified: signal-to-noise ratio, excess attenuation, distortion within the sounds determined as a blur ratio, and prolongation of the sounds with ``tails'' of echoes determined as a tail-to-signal ratio. All four measures indicated that degradation decreased with speaker and microphone height. However, the decrease was considerably higher for the microphone than for the speaker. This suggests that choosing high perches in a forest at spring results in more benefits to blackcaps in terms of improved communication conditions when they act as receivers than as senders. .

  10. Rapid area change in pitch-up manoeuvres of small perching birds.

    PubMed

    Polet, D T; Rival, D E

    2015-10-26

    Rapid pitch-up has been highlighted as a mechanism to generate large lift and drag during landing manoeuvres. However, pitching rates had not been measured previously in perching birds, and so the direct applicability of computations and experiments to observed behaviour was not known. We measure pitch rates in a small, wild bird (the black-capped chickadee; Poecile atricapillus), and show that these rates are within the parameter range used in experiments. Pitching rates were characterized by the shape change number, a metric comparing the rate of frontal area increase to acceleration. Black-capped chickadees increase the shape change number during perching in direct proportion to their total kinetic and potential energy at the start of the manoeuvre. The linear relationship between dissipated energy and shape change number is in accordance with a simple analytical model developed for two-dimensional pitching and decelerating airfoils. Black-capped chickadees use a wing pitch-up manoeuvre during perching to dissipate energy quickly while maintaining lift and drag through rapid area change. It is suggested that similar pitch-and-decelerate manoeuvres could be used to aid in the controlled, precise landings of small manoeuvrable air vehicles.

  11. Dietary calcein marking of brook trout, Atlantic salmon, yellow perch, and coho salmon scales

    USGS Publications Warehouse

    Honeyfield, D.C.; Ostrowski, C.S.; Fletcher, J.W.; Mohler, J.W.

    2006-01-01

    Brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, coho salmon Oncorhynchus kisutch, and yellow perch Perca flavescens fed calcein for 5 d showed characteristic calcein scale marks 7-10 d postmarking. In fish fed 0.75 or 1.25 g of calcein per kilogram of feed, the percentage of fish that exhibited a calcein mark was 100% in brook trout, 93-98% in Atlantic salmon, 60% in yellow perch, and 0% in coho salmon. However, when coho salmon were fed 5.25 g calcein/kg feed, 100% marking was observed 7-10 d postmarking. Brook trout were successfully marked twice with distinct bands when fed calcein 5 months apart. Brook trout scale pixel luminosity increased as dietary calcein increased in experiment 2. For the second calcein mark, scale pixel luminosity from brook trout fed 1.25 g calcein/kg feed was numerically higher (P < 0.08) than scales from fish fed 0.75 g calcein/kg feed. Mean pixel luminosity of calcein-marked Atlantic salmon scales was 57.7 for fish fed 0.75 g calcein/kg feed and 55.2 for fish fed 1.25 g calcein/kg feed. Although feed acceptance presented a problem in yellow perch, these experiments provide evidence that dietary calcein is a viable tool for marking fish for stock identification. ?? Copyright by the American Fisheries Society 2006.

  12. Experimental manipulations of tissue oxygen supply do not affect warming tolerance of European perch.

    PubMed

    Brijs, Jeroen; Jutfelt, Fredrik; Clark, Timothy D; Gräns, Albin; Ekström, Andreas; Sandblom, Erik

    2015-08-01

    A progressive inability of the cardiorespiratory system to maintain systemic oxygen supply at elevated temperatures has been suggested to reduce aerobic scope and the upper thermal limit of aquatic ectotherms. However, few studies have directly investigated the dependence of thermal limits on oxygen transport capacity. By manipulating oxygen availability (via environmental hyperoxia) and blood oxygen carrying capacity (via experimentally induced anaemia) in European perch (Perca fluviatilis Linneaus), we investigated the effects of oxygen transport capacity on aerobic scope and the critical thermal maximum (CT(max)). Hyperoxia resulted in a twofold increase in aerobic scope at the control temperature of 23°C, but this did not translate to an elevated CT(max) in comparison with control fish (34.6±0.1 versus 34.0±0.5°C, respectively). Anaemia (∼43% reduction in haemoglobin concentration) did not cause a reduction in aerobic scope or CT(max) (33.8±0.3°C) compared with control fish. Additionally, oxygen consumption rates of anaemic perch during thermal ramping increased in a similar exponential manner to that in control fish, highlighting that perch have an impressive capacity to compensate for a substantial reduction in blood oxygen carrying capacity. Taken together, these results indicate that oxygen limitation is not a universal mechanism determining the CT(max) of fishes.

  13. Compartment proteomics analysis of white perch (Morone americana) ovary using support vector machines.

    PubMed

    Schilling, Justin; Nepomuceno, Angelito; Schaff, Jennifer E; Muddiman, David C; Daniels, Harry V; Reading, Benjamin J

    2014-03-07

    Compartment proteomics enable broad characterization of target tissues. We employed a simple fractionation method and filter-aided sample preparation (FASP) to characterize the cytosolic and membrane fractions of white perch ovary tissues by semiquantitative tandem mass spectrometry using label-free quantitation based on normalized spectral counts. FASP depletes both low-molecular-weight and high-molecular-weight substances that could interfere with protein digestion and subsequent peptide separation and detection. Membrane proteins are notoriously difficult to characterize due to their amphipathic nature and association with lipids. The simple fractionation we employed effectively revealed an abundance of proteins from mitochondria and other membrane-bounded organelles. We further demonstrate that support vector machines (SVMs) offer categorical classification of proteomics data superior to that of parametric statistical methods such as analysis of variance (ANOVA). Specifically, SVMs were able to perfectly (100% correct) classify samples as either membrane or cytosolic fraction during cross-validation based on the expression of 242 proteins with the highest ANOVA p-values (i.e., those that were not significant for enrichment in either fraction). The white perch ovary cytosolic and membrane proteomes and transcriptome presented in this study can support future investigations into oogenesis and early embryogenesis of white perch and other members of the genus Morone.

  14. Preferential flow, diffuse flow, and perching in an interbedded fractured-rock unsaturated zone

    USGS Publications Warehouse

    Nimmo, John R.; Creasey, Kaitlyn M; Perkins, Kimberlie; Mirus, Benjamin B.

    2017-01-01

    Layers of strong geologic contrast within the unsaturated zone can control recharge and contaminant transport to underlying aquifers. Slow diffuse flow in certain geologic layers, and rapid preferential flow in others, complicates the prediction of vertical and lateral fluxes. A simple model is presented, designed to use limited geological site information to predict these critical subsurface processes in response to a sustained infiltration source. The model is developed and tested using site-specific information from the Idaho National Laboratory in the Eastern Snake River Plain (ESRP), USA, where there are natural and anthropogenic sources of high-volume infiltration from floods, spills, leaks, wastewater disposal, retention ponds, and hydrologic field experiments. The thick unsaturated zone overlying the ESRP aquifer is a good example of a sharply stratified unsaturated zone. Sedimentary interbeds are interspersed between massive and fractured basalt units. The combination of surficial sediments, basalts, and interbeds determines the water fluxes through the variably saturated subsurface. Interbeds are generally less conductive, sometimes causing perched water to collect above them. The model successfully predicts the volume and extent of perching and approximates vertical travel times during events that generate high fluxes from the land surface. These developments are applicable to sites having a thick, geologically complex unsaturated zone of substantial thickness in which preferential and diffuse flow, and perching of percolated water, are important to contaminant transport or aquifer recharge.

  15. Individual-based model of yellow perch and walleye populations in Oneida Lake

    SciTech Connect

    Rose, K.A.; Rutherford, E.S.; McDermot, D.S.; Forney, J.L.; Mills, E.L.

    1999-05-01

    Predator-prey dynamics and density dependence are fundamental issues in ecology. The authors use a detailed, individual-based model of walleye and yellow perch to investigate the effects of alternative prey and compensatory responses on predator and prey population dynamics. The analyses focus on the numerical and developmental responses of the predator, rather than the traditional emphasis on functional responses. The extensive database for Oneida Lake, New York, USA was used to configure the model and ensure its realism. The model follows the daily growth, mortality, and spawning of individuals of each species through their lifetime. Three ecologically distinct periods in the history of Oneida Lake were simulated: baseline, high mayfly densities, and high forage fish densities. Mayflies and forage fish act as alternative prey for walleye. For model corroboration, the three periods were simulated sequentially as they occurred in Oneida Lake. Model predictions of abundances, size at age, and growth and survival rates compared favorably with Oneida Lake data. Three hypotheses suggested by the data were evaluated: alternative prey stabilizes yellow perch and walleye populations; alternative prey increases yellow perch and walleye recruitment; and density-dependent growth and survival compensate for changes in young-of-the-year mortality. Model simulations were performed under increased mayfly densities, increased forage fish densities, and increased egg mortality rates.

  16. Using consumption rate to assess potential predators for biological control of white perch

    USGS Publications Warehouse

    Gosch, N.J.C.; Pope, K.L.

    2011-01-01

    Control of undesirable fishes is important in aquatic systems, and using predation as a tool for biological control is an attractive option to fishery biologists. However, determining the appropriate predators for biological control is critical for success. The objective of this study was to evaluate the utility of consumption rate as an index to determine the most effective predators for biological control of an invasive fish. Consumption rate values were calculated for nine potential predators that prey on white perch Morone americana in Branched Oak and Pawnee reservoirs, Nebraska. The consumption rate index provided a unique and insightful means of determining the potential effectiveness of each predator species in controlling white perch. Cumulative frequency distributions facilitated interpretation by providing a graphical presentation of consumption rates by all individuals within each predator species. Largemouth bass Micropterus salmoides, walleye Sander vitreus and sauger S. canadensis were the most efficient white perch predators in both reservoirs; however, previous attempts to increase biomass of these predators have failed suggesting that successful biological control is unlikely using existing predator species in these Nebraska reservoirs. ?? 2011 ONEMA.

  17. Minimum size limits for yellow perch (Perca flavescens) in western Lake Erie

    USGS Publications Warehouse

    Hartman, Wilbur L.; Nepszy, Stephen J.; Scholl, Russell L.

    1980-01-01

    During the 1960's yellow perch (Perca flavescens) of Lake Erie supported a commercial fishery that produced an average annual catch of 23 million pounds, as well as a modest sport fishery. Since 1969, the resource has seriously deteriorated. Commercial landings amounted to only 6 million pounds in 1976, and included proportionally more immature perch than in the 1960's. Moreover, no strong year classes were produced between 1965 and 1975. An interagency technical committee was appointed in 1975 by the Lake Erie Committee of the Great Lakes Fishery Commission to develop an interim management strategy that would provide for greater protection of perch in western Lake Erie, where declines have been the most severe. The committee first determined the age structure, growth and mortality rates, maturation schedule, and length-fecundity relationship for the population, and then applied Ricker-type equilibrium yield models to determine the effects of various minimum length limits on yield, production, average stock weight, potential egg deposition, and the Abrosov spawning frequency indicator (average number of spawning opportunities per female). The committee recommended increasing the minimum length limit of 5.0 inches to at least 8.5 inches. Theoretically, this change would increase the average stock weight by 36% and potential egg deposition by 44%, without significantly decreasing yield. Abrosov's spawning frequency indicator would rise from the existing 0.6 to about 1.2.

  18. Preferential flow, diffuse flow, and perching in an interbedded fractured-rock unsaturated zone

    NASA Astrophysics Data System (ADS)

    Nimmo, John R.; Creasey, Kaitlyn M.; Perkins, Kim S.; Mirus, Benjamin B.

    2016-11-01

    Layers of strong geologic contrast within the unsaturated zone can control recharge and contaminant transport to underlying aquifers. Slow diffuse flow in certain geologic layers, and rapid preferential flow in others, complicates the prediction of vertical and lateral fluxes. A simple model is presented, designed to use limited geological site information to predict these critical subsurface processes in response to a sustained infiltration source. The model is developed and tested using site-specific information from the Idaho National Laboratory in the Eastern Snake River Plain (ESRP), USA, where there are natural and anthropogenic sources of high-volume infiltration from floods, spills, leaks, wastewater disposal, retention ponds, and hydrologic field experiments. The thick unsaturated zone overlying the ESRP aquifer is a good example of a sharply stratified unsaturated zone. Sedimentary interbeds are interspersed between massive and fractured basalt units. The combination of surficial sediments, basalts, and interbeds determines the water fluxes through the variably saturated subsurface. Interbeds are generally less conductive, sometimes causing perched water to collect above them. The model successfully predicts the volume and extent of perching and approximates vertical travel times during events that generate high fluxes from the land surface. These developments are applicable to sites having a thick, geologically complex unsaturated zone of substantial thickness in which preferential and diffuse flow, and perching of percolated water, are important to contaminant transport or aquifer recharge.

  19. Effects of altitude on the climbing performance of Monarch butterflies

    NASA Astrophysics Data System (ADS)

    Kang, Chang-Kwon; Sridhar, Madhu; Landrum, David; Aono, Hikaru

    2016-11-01

    Millions of Monarchs annually travel up to 4,000km, the longest migration distance among insects. They fly and overwinter at high altitudes. However, the aerodynamic mechanism enabling the long-range flight of Monarch butterflies is unknown. To study the effects of altitude on the aerodynamic performance of Monarch butterflies, a unique combination of a motion tracking system and a variable pressure chamber that allows controlling the density is used. The condition inside the chamber is systematically varied to simulate high altitude conditions up to 3,000 m. An optical tracking technique is used to characterize the climbing trajectories of freely flying Monarch butterflies. Customized reflective markers are designed to minimize the effects of marker addition. Flapping amplitude and frequency as well as climbing trajectories are measured. Lift acting on the butterfly is also determined by considering the force balance. Results show that the average flight speed and the Reynolds number, in general, decreased with the altitude, whereas, interestingly, the lift coefficient increased with the altitude. More detailed measurements and analyses will be performed in the future to explain the lift enhancement by flying at higher altitudes. This work is partly supported by NSF Grant CBET-1335572 and in part by CK's startup fund provided by UAH.

  20. Climbing favours the tripod gait over alternative faster insect gaits

    PubMed Central

    Ramdya, Pavan; Thandiackal, Robin; Cherney, Raphael; Asselborn, Thibault; Benton, Richard; Ijspeert, Auke Jan; Floreano, Dario

    2017-01-01

    To escape danger or catch prey, running vertebrates rely on dynamic gaits with minimal ground contact. By contrast, most insects use a tripod gait that maintains at least three legs on the ground at any given time. One prevailing hypothesis for this difference in fast locomotor strategies is that tripod locomotion allows insects to rapidly navigate three-dimensional terrain. To test this, we computationally discovered fast locomotor gaits for a model based on Drosophila melanogaster. Indeed, the tripod gait emerges to the exclusion of many other possible gaits when optimizing fast upward climbing with leg adhesion. By contrast, novel two-legged bipod gaits are fastest on flat terrain without adhesion in the model and in a hexapod robot. Intriguingly, when adhesive leg structures in real Drosophila are covered, animals exhibit atypical bipod-like leg coordination. We propose that the requirement to climb vertical terrain may drive the prevalence of the tripod gait over faster alternative gaits with minimal ground contact. PMID:28211509

  1. Can hippocampal neurites and growth cones climb over obstacles?

    PubMed

    Lien, Thuy Linh; Ban, Jelena; Tormen, Massimo; Migliorini, Elisa; Grenci, Gianluca; Pozzato, Alessandro; Torre, Vincent

    2013-01-01

    Guidance molecules, such as Sema3A or Netrin-1, can induce growth cone (GC) repulsion or attraction in the presence of a flat surface, but very little is known of the action of guidance molecules in the presence of obstacles. Therefore we combined chemical and mechanical cues by applying a steady Netrin-1 stream to the GCs of dissociated hippocampal neurons plated on polydimethylsiloxane (PDMS) surfaces patterned with lines 2 µm wide, with 4 µm period and with a height varying from 100 to 600 nm. GC turning experiments performed 24 hours after plating showed that filopodia crawl over these lines within minutes. These filopodia do not show staining for the adhesion marker Paxillin. GCs and neurites crawl over lines 100 nm high, but less frequently and on a longer time scale over lines higher than 300 nm; neurites never crawl over lines 600 nm high. When neurons are grown for 3 days over patterned surfaces, also neurites can cross lines 300 nm and 600 nm high, grow parallel to and on top of these lines and express Paxillin. Axons - selectively stained with SMI 312 - do not differ from dendrites in their ability to cross these lines. Our results show that highly motile structures such as filopodia climb over high obstacle in response to chemical cues, but larger neuronal structures are less prompt and require hours or days to climb similar obstacles.

  2. Biomechanics and functional morphology of a climbing monocot

    PubMed Central

    Hesse, Linnea; Wagner, Sarah T.; Neinhuis, Christoph

    2016-01-01

    Plants with a climbing growth habit possess unique biomechanical properties arising from adaptations to changing loading conditions connected with close attachment to mechanical supports. In monocot climbers, mechanical adaptation is restricted by the absence of a bifacial vascular cambium. Flagellaria indica was used to investigate the mechanical properties and adaptations of a monocot climber that, uniquely, attaches to the surrounding vegetation via leaf tendrils. Biomechanical methods such as three-point bending and torsion tests were used together with anatomical studies on tissue development, modification and distribution. In general, the torsional modulus was lower than the bending modulus; hence, torsional stiffness was less than flexural stiffness. Basal parts of mature stems showed the greatest stiffness while that of more apical stem segments levelled off. Mechanical properties were modulated via tissue maturation processes mainly affecting the peripheral region of the stem. Peripheral vascular bundles showed a reduction in the amount of conducting tissue while the proportion and density of the bundle sheath increased. Furthermore, adjacent bundle sheaths merged resulting in a dense ring of fibrous tissue. Although F. indica lacks secondary cambial growth, the climbing habit is facilitated by a complex interaction of tissue maturation and attachment. PMID:26819259

  3. Hopping and climbing gait of Japanese Pygmy Woodpeckers (Picoides kizuki).

    PubMed

    Fujita, Masaki; Kawakami, Kazuto; Higuchi, Hiroyoshi

    2007-12-01

    Single cycles of hopping and climbing were investigated in Japanese Pygmy Woodpeckers Picoides kizuki using motion analyses on video. Body movements on substrate angled from 0-90 degrees were compared for every 10 degrees. The body was inclined forward during stance phase for both small and large substrate angles, and the inclination amplitude increased when the substrate angle increased. The tail was bent ventrally almost simultaneously to this body inclination, and its amplitude was apparently high at large substrate angles. Most of the gait parameters changed when the stride length increased. The minimum body-tail angle and most of the parameters representing body movements during stance phase changed when the substrate angle increased, probably because gravity pulled the birds further backward when they were moving on a steeper slope. These parameters showed a clear difference between the data on substrate steeper than 40 degrees and lower than 30 degrees. The abrupt changes in these parameters most likely mean that the motor pattern changed from hopping to climbing between these angles.

  4. Biomechanics and functional morphology of a climbing monocot.

    PubMed

    Hesse, Linnea; Wagner, Sarah T; Neinhuis, Christoph

    2016-01-27

    Plants with a climbing growth habit possess unique biomechanical properties arising from adaptations to changing loading conditions connected with close attachment to mechanical supports. In monocot climbers, mechanical adaptation is restricted by the absence of a bifacial vascular cambium. Flagellaria indica was used to investigate the mechanical properties and adaptations of a monocot climber that, uniquely, attaches to the surrounding vegetation via leaf tendrils. Biomechanical methods such as three-point bending and torsion tests were used together with anatomical studies on tissue development, modification and distribution. In general, the torsional modulus was lower than the bending modulus; hence, torsional stiffness was less than flexural stiffness. Basal parts of mature stems showed the greatest stiffness while that of more apical stem segments levelled off. Mechanical properties were modulated via tissue maturation processes mainly affecting the peripheral region of the stem. Peripheral vascular bundles showed a reduction in the amount of conducting tissue while the proportion and density of the bundle sheath increased. Furthermore, adjacent bundle sheaths merged resulting in a dense ring of fibrous tissue. Although F. indica lacks secondary cambial growth, the climbing habit is facilitated by a complex interaction of tissue maturation and attachment.

  5. Mechanisms of Egg Yolk Formation and Implications on Early Life History of White Perch (Morone americana)

    PubMed Central

    Schilling, Justin; Loziuk, Philip L.; Muddiman, David C.; Daniels, Harry V.; Reading, Benjamin J.

    2015-01-01

    The three white perch (Morone americana) vitellogenins (VtgAa, VtgAb, VtgC) were quantified accurately and precisely in the liver, plasma, and ovary during pre-, early-, mid-, and post-vitellogenic oocyte growth using protein cleavage-isotope dilution mass spectrometry (PC-IDMS). Western blotting generally mirrored the PC-IDMS results. By PC-IDMS, VtgC was quantifiable in pre-vitellogenic ovary tissues and VtgAb was quantifiable in pre-vitellogenic liver tissues however, neither protein was detected by western blotting in these respective tissues at this time point. Immunohistochemistry indicated that VtgC was present within pre-vitellogenic oocytes and localized to lipid droplets within vitellogenic oocytes. Affinity purification coupled to tandem mass spectrometry using highly purified VtgC as a bait protein revealed a single specific interacting protein (Y-box binding protein 2a-like [Ybx2a-like]) that eluted with suramin buffer and confirmed that VtgC does not bind the ovary vitellogenin receptors (LR8 and Lrp13). Western blotting for LR8 and Lrp13 showed that both receptors were expressed during vitellogenesis with LR8 and Lrp13 expression highest in early- and mid-vitellogenesis, respectively. The VtgAa within the ovary peaked during post-vitellogenesis, while VtgAb peaked during early-vitellogenesis in both white perch and the closely related striped bass (M. saxatilis). The VtgC was steadily accumulated by oocytes beginning during pre-vitellogenesis and continued until post-vitellogenesis and its composition varies widely between striped bass and white perch. In striped bass, the VtgC accounted for 26% of the vitellogenin-derived egg yolk, however in the white perch it comprised only 4%. Striped bass larvae have an extended developmental window and these larvae have yolk stores that may enable them to survive in the absence of food for twice as long as white perch after hatch. Thus, the VtgC may play an integral role in providing nutrients to late stage

  6. 36 CFR 13.1312 - Climbing and walking on Exit Glacier.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Glacier. 13.1312 Section 13.1312 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... General Provisions § 13.1312 Climbing and walking on Exit Glacier. Except for areas designated by the Superintendent, climbing or walking on, in, or under Exit Glacier is prohibited within 1/2 mile of the...

  7. 36 CFR 13.1312 - Climbing and walking on Exit Glacier.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Glacier. 13.1312 Section 13.1312 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... General Provisions § 13.1312 Climbing and walking on Exit Glacier. Except for areas designated by the Superintendent, climbing or walking on, in, or under Exit Glacier is prohibited within 1/2 mile of the...

  8. 36 CFR 13.1312 - Climbing and walking on Exit Glacier.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Glacier. 13.1312 Section 13.1312 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... General Provisions § 13.1312 Climbing and walking on Exit Glacier. Except for areas designated by the Superintendent, climbing or walking on, in, or under Exit Glacier is prohibited within 1/2 mile of the...

  9. 36 CFR 13.1312 - Climbing and walking on Exit Glacier.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Glacier. 13.1312 Section 13.1312 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... General Provisions § 13.1312 Climbing and walking on Exit Glacier. Except for areas designated by the Superintendent, climbing or walking on, in, or under Exit Glacier is prohibited within 1/2 mile of the...

  10. 36 CFR 13.1312 - Climbing and walking on Exit Glacier.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Glacier. 13.1312 Section 13.1312 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... General Provisions § 13.1312 Climbing and walking on Exit Glacier. Except for areas designated by the Superintendent, climbing or walking on, in, or under Exit Glacier is prohibited within 1/2 mile of the...

  11. Physiological responses in rock climbing with repeated ascents over a 10-week period.

    PubMed

    España-Romero, Vanesa; Jensen, Randall L; Sanchez, Xavier; Ostrowski, Megan L; Szekely, Jay E; Watts, Phillip B

    2012-03-01

    The purpose was to analyze the physiological responses and energy expenditure during repeated ascents of the same climbing route over a 10-week period. Nine climbers completed nine ascents of a specific route spaced 1 week apart. Expired air was analyzed continuously during each ascent, and time of ascent was recorded to the nearest second. Energy expenditure during climbing (EE(CLM)), and during climbing +10 min recovery (EE(TOT)) was calculated by the Weir and Zuntz equations. Differences among ascents 1, 4, 6 and 9 were analyzed by repeated measures ANOVA. Climbing time was longer for ascent 1 compared with ascents 4, 6 and 9 (P < 0.001). Differences were found for EE(CLM) (kcal; P < 0.001), between ascent 1 versus 6 and 9 and ascent 4 versus 9, using both Zuntz and Weir equations. Also, differences were observed in EE for recovery (P < 0.05) and EE(TOT) (P < 0.05) using both equations. Repeated ascents of a climbing route decreased the climbing time and absolute energy expenditure during climbing. Initially, the decrease in climbing energy expenditure is accompanied by an increase in energy expenditure during recovery; however, by the ninth ascent, the total energy expenditure of the task is lower than for ascent 1.

  12. Plasma cortisol concentrations and perceived anxiety in response to on-sight rock climbing.

    PubMed

    Draper, N; Dickson, T; Fryer, S; Blackwell, G; Winter, D; Scarrott, C; Ellis, G

    2012-01-01

    Previous research suggested plasma cortisol concentrations in response to rock climbing have a cubic relationship with state anxiety and self-confidence. This research, however, was conducted in a situation where the climbers had previously climbed the route. The purpose of our study was to examine this relationship in response to on-sight climbing. Nineteen (13 male, 6 female) intermediate climbers volunteered to attend anthropometric and baseline testing sessions, prior to an on-sight ascent (lead climb or top-rope) of the test climb (grade 19 Ewbank/6a sport/5.10b YDS). Data recorded included state anxiety, self-confidence and cortisol concentrations prior to completing the climb. Results indicated that there were no significant differences in state anxiety, self-confidence and plasma cortisol concentration regardless of the style of ascent (lead climb or top-rope) in an on-sight sport climbing context. Regression analysis indicated there was a significant linear relationship between plasma cortisol concentrations and self-confidence (r= - 0.52, R2=0.267, p=0.024), cognitive (r=0.5, R2=0.253, p=0.028), and somatic anxieties (r=0.46, R2=0.210, p=0.049). In an on-sight condition the relationships between plasma cortisol concentrations with anxiety (cognitive and somatic) and self-confidence were linear.

  13. The influence of sampling site and assay method on lactate concentration in response to rock climbing.

    PubMed

    Draper, Nick; Brent, Simon; Hale, Beverley; Coleman, Ian

    2006-11-01

    The sport of rock climbing has increased in popularity and as a focus for research. Previous studies have examined the physiological determinants for successful performance. Variation is evident between studies over lactate sampling sites and assay methods. The aim of this study was to examine the limits of agreement between the YSI 2300 analyser and the Lactate Pro for finger and ear capillary blood samples in a climbing context. Forty-five (31 males and 14 females) participants volunteered to complete the climbing trial. Blood samples were collected simultaneously from finger and ear pre, post and 5 min post climb. The repeatability results indicated a good agreement across samples. Modelling analysis indicated the use of a -0.175 mmol l(-1) adjustment to move from Lactate Pro to YSI finger concentrations. To move from finger to ear concentrations, using the Lactate Pro, modelling analysis suggested a regression equation of Y = 0.827x + 0.769 adjustment for pre climb samples and Y = 0.955x + 0.566 for post climb concentrations. To better understand the physiological demands of climbing further research on natural rock is required. Results from this study suggest the Lactate Pro and blood sampling from the ear lobe could be of benefit to future rock climbing field studies.

  14. Oxygen uptake and energy expenditure for children during rock climbing activity.

    PubMed

    Watts, Phillip Baxter; Ostrowski, Megan L

    2014-02-01

    The purpose of this study was to measure oxygen uptake and energy expenditure in children during rock climbing activity. 29 children (age = 10.9 ± 1.7 yr) participated in the study. A commercially available rock climbing structure with ample features for submaximal effort climbing provided continuous terrain. Participants were instructed to climb at a comfortable pace. Following an initial 5-min rest, each child climbed one sustained 5-min bout followed by 5-min sitting recovery for a total of 10 min (SUS). This was immediately followed by five 1-min climbing + 1-min recovery intervals for a second total of 10 min (INT). Expired air was analyzed continuously. Energy expenditure (EE) was determined via the Weir method for 10-s intervals throughout the full protocol. The total energy expenditure in kilocalories during the 10-min SUS period was 34.3 ± 11.3 kcal. Energy expenditure during the 10-min INT period averaged 39.3 ± 13.1 kcal and was significantly higher than during SUS (p < .05). The mean total EE for SUS + INT was 73.7 ± 24.2 kcal. EE was correlated with body mass; r = .86. The rock climbing tasks employed in this study produced EE levels similar to what have been reported in children for stair climbing, sports/games activities, and easy jogging.

  15. Muscle fiber type distribution in climbing Hawaiian gobioid fishes: ontogeny and correlations with locomotor performance.

    PubMed

    Cediel, Roberto A; Blob, Richard W; Schrank, Gordon D; Plourde, Robert C; Schoenfuss, Heiko L

    2008-01-01

    Three species of Hawaiian amphidromous gobioid fishes are remarkable in their ability to climb waterfalls up to several hundred meters tall. Juvenile Lentipes concolor and Awaous guamensis climb using rapid bursts of axial undulation, whereas juvenile Sicyopterus stimpsoni climb using much slower movements, alternately attaching oral and pelvic sucking disks to the substrate during prolonged bouts of several cycles. Based on these differing climbing styles, we hypothesized that propulsive musculature in juvenile L. concolor and A. guamensis would be dominated by white muscle fibers, whereas S. stimpsoni would exhibit a greater proportion of red muscle fibers than other climbing species. We further predicted that, because adults of these species shift from climbing to burst swimming as their main locomotor behavior, muscle from adult fish of all three species would be dominated by white fibers. To test these hypotheses, we used ATPase assays to evaluate muscle fiber type distribution in Hawaiian climbing gobies for three anatomical regions (midbody, anal, and tail). Axial musculature was dominated by white muscle fibers in juveniles of all three species, but juvenile S. stimpsoni had a significantly greater proportion of red fibers than the other two species. Fiber type proportions of adult fishes did not differ significantly from those of juveniles. Thus, muscle fiber type proportions in juveniles appear to help accommodate differences in locomotor demands among these species, indicating that they overcome the common challenge of waterfall climbing through both diverse behaviors and physiological specializations.

  16. 77 FR 33777 - General Aviation Safety Forum: Climbing to the Next Level

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-07

    ... From the Federal Register Online via the Government Publishing Office ] NATIONAL TRANSPORTATION SAFETY BOARD General Aviation Safety Forum: Climbing to the Next Level The National Transportation Safety...-20, 2012 in Washington, DC. The event, ``General Aviation Safety: Climbing to the Next Level,''...

  17. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Pile Perch, Striped Seaperch, and Rubberlip Seaperch

    DTIC Science & Technology

    1989-07-01

    indicated that pile perch were con- 1975 114 40 sistent predators on intertidal snails 1976 142 57 in British Columbia; they also ate barnacles , small crabs...35 large pile perch because it supported 1969 ib6 36 few barnacles and no mussels. Wares 1970 241 43 (1971) listed six phyla in the diet at 1971 185 43...the same area. Striped seaperch prefer shallow water (< 6 m) even when black perch are removed from deeper water. Both species are substrate feeders

  18. A Critical Review of the Incidence and Risk Factors for Finger Injuries in Rock Climbing.

    PubMed

    Jones, Gareth; Johnson, Mark I

    Rock climbing is a popular sporting activity and indoor sport climbing has been accepted for inclusion in the 2020 Olympic Games. The aim of this article is to critically review research on the incidence and risk factors associated with injuries during rock climbing. A semisystematic approach in reviewing literature on incidence and prevalence was applied. Articles were identified after searches of the following electronic databases: Discover, Academic Search Complete (EBSCO), PubMed, Embase, SPORTDiscus, and ScienceDirect. Despite methodological shortcomings of the studies contained within the review, the frequency of climbing-related injuries is high and can be challenging to diagnose. The fingers are the most common site of injury with previous injury a significant risk factor for reinjury. The annular pulleys of the fingers are the most commonly injured structure and evidence suggests epiphyseal fractures in adolescent sport climbers is increasing. A diagnostic and therapeutic algorithm for climbing-related finger injuries is proposed.

  19. Decrease of Population Divergence in Eurasian Perch (Perca fluviatilis) in Browning Waters: Role of Fatty Acids and Foraging Efficiency

    PubMed Central

    Scharnweber, Kristin; Strandberg, Ursula; Karlsson, Konrad; Eklöv, Peter

    2016-01-01

    Due to altered biogeochemical processes related to climate change, highly colored dissolved organic carbon (DOC) from terrestrial sources will lead to a water “brownification” in many freshwater systems of the Northern Hemisphere. This will create deteriorated visual conditions that have been found to affect habitat-specific morphological variations in Eurasian perch (Perca fluviatilis) in a previous study. So far, potential drivers and ultimate causes of these findings have not been identified. We conducted a field study to investigate the connection between morphological divergence and polyunsaturated fatty acid (PUFA) composition of perch from six lakes across a gradient of DOC concentration. We expected a decrease in the prevalence of PUFAs, which are important for perch growth and divergence with increasing DOC concentrations, due to the restructuring effects of DOC on aquatic food webs. In general, rate of morphological divergence in perch decreased with increasing DOC concentrations. Proportions of specific PUFAs (22:6n-3, 18:3n-3, 20:5n-3, and 20:4n-6) identified to primarily contribute to overall differences between perch caught in clear and brown-water lakes tended to be connected to overall decline of morphological divergence. However, no overall significant relationship was found, indicating no severe limitation of essential fatty acids for perch inhabiting brown water lakes. We further broaden our approach by conducting a laboratory experiment on foraging efficiency of perch. Therefore, we induced pelagic and littoral phenotypes by differences in habitat-structure and feeding mode and recorded attack rate in a feeding experiment. Generally, fish were less efficient in foraging on littoral prey (Ephemeroptera) when visual conditions were degraded by brown water color. We concluded that browning water may have a strong effect on the forager’s ability to find particular food resources, resulting in the reduced development of evolutionary traits

  20. Performance and scaling of a novel locomotor structure: adhesive capacity of climbing gobiid fishes.

    PubMed

    Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2012-11-15

    Many species of gobiid fishes adhere to surfaces using a sucker formed from fusion of the pelvic fins. Juveniles of many amphidromous species use this pelvic sucker to scale waterfalls during migrations to upstream habitats after an oceanic larval phase. However, adults may still use suckers to re-scale waterfalls if displaced. If attachment force is proportional to sucker area and if growth of the sucker is isometric, then increases in the forces that climbing fish must resist might outpace adhesive capacity, causing climbing performance to decline through ontogeny. To test for such trends, we measured pressure differentials and adhesive suction forces generated by the pelvic sucker across wide size ranges in six goby species, including climbing and non-climbing taxa. Suction was achieved via two distinct growth strategies: (1) small suckers with isometric (or negatively allometric) scaling among climbing gobies and (2) large suckers with positively allometric growth in non-climbing gobies. Species using the first strategy show a high baseline of adhesive capacity that may aid climbing performance throughout ontogeny, with pressure differentials and suction forces much greater than expected if adhesion were a passive function of sucker area. In contrast, large suckers possessed by non-climbing species may help compensate for reduced pressure differentials, thereby producing suction sufficient to support body weight. Climbing Sicyopterus species also use oral suckers during climbing waterfalls, and these exhibited scaling patterns similar to those for pelvic suckers. However, oral suction force was considerably lower than that for pelvic suckers, reducing the ability for these fish to attach to substrates by the oral sucker alone.

  1. Climbing Fiber Burst Size and Olivary Sub-threshold Oscillations in a Network Setting

    PubMed Central

    de Jeu, Marcel T. G.; De Zeeuw, Chris I.

    2012-01-01

    The inferior olivary nucleus provides one of the two main inputs to the cerebellum: the so-called climbing fibers. Activation of climbing fibers is generally believed to be related to timing of motor commands and/or motor learning. Climbing fiber spikes lead to large all-or-none action potentials in cerebellar Purkinje cells, overriding any other ongoing activity and silencing these cells for a brief period of time afterwards. Empirical evidence shows that the climbing fiber can transmit a short burst of spikes as a result of an olivary cell somatic spike, potentially increasing the information being transferred to the cerebellum per climbing fiber activation. Previously reported results from in vitro studies suggested that the information encoded in the climbing fiber burst is related to the occurrence of the spike relative to the ongoing sub-threshold membrane potential oscillation of the olivary cell, i.e. that the phase of the oscillation is reflected in the size of the climbing fiber burst. We used a detailed three-compartmental model of an inferior olivary cell to further investigate the possible factors determining the size of the climbing fiber burst. Our findings suggest that the phase-dependency of the burst size is present but limited and that charge flow between soma and dendrite is a major determinant of the climbing fiber burst. From our findings it follows that phenomena such as cell ensemble synchrony can have a big effect on the climbing fiber burst size through dendrodendritic gap-junctional coupling between olivary cells. PMID:23271962

  2. Effect of Two Types of Active Recovery on Fatigue and Climbing Performance.

    PubMed

    Valenzuela, Pedro L; de la Villa, Pedro; Ferragut, Carmen

    2015-12-01

    Performing intra-session recovery is important in rock climbing due to the multiple efforts that climbers are required to make in competitions, as well as repeated climbing trials that they carry out during training sessions. Active recovery has been shown to be a better option than passive recovery. However, the type of active recovery that should be done and the influence of the type and quantity of muscle mass activated are not clear. The aim of this study was to compare the effects of recovering with easy climbing (CR) or walking (WR) on markers of fatigue and climbing performance. For this purpose, 14 subjects participated in this randomly assigned crossover protocol completing three two-minute climbing trials separated by two minutes of active recovery with the assigned method. Seven days later participants carried out the same protocol with the other recovery method. Blood lactate (La(-)), rating of perceived exertion (RPE), and heart rate (HR) were analyzed as markers of fatigue and recovery, while meters climbed (MC) and handgrip force (HF) were analyzed for performance. La- values before the last climbing trial (p < 0.05; d = 0.69) and Peak La- values (p < 0.05; d = 0.77) were lower for CR than for WR. Climbers were able to ascend more meters in the set time when following the CR protocol (p < 0.01; d = 0.6), which shows the important role of the active recovery method carried out on climbing performance. There were no differences in HR, HF or RPE between protocols. A more sport-specific recovery protocol, in addition to moving great muscle mass (e.g. lower limbs), seems to enhance recovery and to facilitate lactate removal. For this reason, CR appears to be a more effective active recovery method than WR in sport rock climbing. Key pointsClimbing recovery improved lactate removal in comparison with walking recovery.Subjects were able to climb more meters in a determined time when easy climbing instead of walking during recoveries.Activating both great

  3. Effect of Two Types of Active Recovery on Fatigue and Climbing Performance

    PubMed Central

    Valenzuela, Pedro L.; de la Villa, Pedro; Ferragut, Carmen

    2015-01-01

    Performing intra-session recovery is important in rock climbing due to the multiple efforts that climbers are required to make in competitions, as well as repeated climbing trials that they carry out during training sessions. Active recovery has been shown to be a better option than passive recovery. However, the type of active recovery that should be done and the influence of the type and quantity of muscle mass activated are not clear. The aim of this study was to compare the effects of recovering with easy climbing (CR) or walking (WR) on markers of fatigue and climbing performance. For this purpose, 14 subjects participated in this randomly assigned crossover protocol completing three two-minute climbing trials separated by two minutes of active recovery with the assigned method. Seven days later participants carried out the same protocol with the other recovery method. Blood lactate (La-), rating of perceived exertion (RPE), and heart rate (HR) were analyzed as markers of fatigue and recovery, while meters climbed (MC) and handgrip force (HF) were analyzed for performance. La- values before the last climbing trial (p < 0.05; d = 0.69) and Peak La- values (p < 0.05; d = 0.77) were lower for CR than for WR. Climbers were able to ascend more meters in the set time when following the CR protocol (p < 0.01; d = 0.6), which shows the important role of the active recovery method carried out on climbing performance. There were no differences in HR, HF or RPE between protocols. A more sport-specific recovery protocol, in addition to moving great muscle mass (e.g. lower limbs), seems to enhance recovery and to facilitate lactate removal. For this reason, CR appears to be a more effective active recovery method than WR in sport rock climbing. Key points Climbing recovery improved lactate removal in comparison with walking recovery. Subjects were able to climb more meters in a determined time when easy climbing instead of walking during recoveries. Activating both great

  4. The Effect of Cooled Perches on Immunological Parameters of Caged White Leghorn Hens during the Hot Summer Months

    PubMed Central

    Strong, Rebecca A.; Hester, Patricia Y.; Eicher, Susan D.; Hu, Jiaying; Cheng, Heng-Wei

    2015-01-01

    The objective of this study was to determine if thermally cooled perches improve hen immunity during hot summer. White Leghorn pullets at 16 week of age were randomly assigned to 18 cages of 3 banks at 9 hens per cage. Each bank was assigned to 1 of the 3 treatments up to 32 week of age: 1) thermally cooled perches, 2) perches with ambient air, and 3) cages without perches. Hens were exposed to natural ambient temperatures from June through September 2013 in Indiana with a 4 h acute heat episode at 27.6 week of age. The packed cell volume, heterophil to lymphocyte (H/L) ratio, plasma concentrations of total IgG, and cytokines of interleukin-1β and interleukin-6, plus lipopolysaccharide-induced tumor necrosis factor-α factor were measured at both 27.6 and 32 week of age. The mRNA expressions of these cytokines, toll-like receptor-4, and inducible nitric oxide synthase were also examined in the spleen of 32 week-old hens. Except for H/L ratio, thermally cooled perches did not significantly improve currently measured immunological indicators. These results indicated that the ambient temperature of 2013 summer in Indiana (24°C, 17.1 to 33.1°C) was not high enough and the 4 h heat episode at 33.3°C (32 to 34.6°C) was insufficient in length to evoke severe heat stress in hens. However, cooled perch hens had a lower H/L ratio than both air perch hens and control hens at 27.6 week of age and it was still lower compared to control hens (P < 0.05, respectively) at 32 week of age. The lowered H/L ratio of cooled perch hens may suggest that they were able to cope with acute heat stress more effectively than control hens. Further studies are needed to evaluate the effectiveness of thermally cooled perches on hen health under higher ambient temperatures. PMID:26495988

  5. A circuit for gradient climbing in C. elegans chemotaxis

    PubMed Central

    Larsch, Johannes; Flavell, Steven W.; Liu, Qiang; Gordus, Andrew; Albrecht, Dirk R.; Bargmann, Cornelia I.

    2016-01-01

    Animals have a remarkable ability to track dynamic sensory information. For example, the nematode Caenorhabditis elegans can locate a diacetyl odor source across a 100,000-fold concentration range. Here, we relate neuronal properties, circuit implementation, and behavioral strategies underlying this robust navigation. Diacetyl responses in AWA olfactory neurons are concentration- and history-dependent; AWA integrates over time at low odor concentrations, but as concentrations rise it desensitizes rapidly through a process requiring cilia transport. After desensitization, AWA retains sensitivity to small odor increases. The downstream AIA interneuron amplifies weak odor inputs and desensitizes further, resulting in a stereotyped response to odor increases over three orders of magnitude. The AWA-AIA circuit drives asymmetric behavioral responses to odor increases that facilitate gradient climbing. The adaptation-based circuit motif embodied by AWA and AIA shares computational properties with bacterial chemotaxis and the vertebrate retina, each providing a solution for maintaining sensitivity across a dynamic range. PMID:26365196

  6. Robotic End Effectors for Hard-Rock Climbing

    NASA Technical Reports Server (NTRS)

    Kennedy, Brett; Leger, Patrick

    2004-01-01

    Special-purpose robot hands (end effectors) now under development are intended to enable robots to traverse cliffs much as human climbers do. Potential applications for robots having this capability include scientific exploration (both on Earth and other rocky bodies in space), military reconnaissance, and outdoor search and rescue operations. Until now, enabling robots to traverse cliffs has been considered too difficult a task because of the perceived need of prohibitively sophisticated planning algorithms as well as end effectors as dexterous as human hands. The present end effectors are being designed to enable robots to attach themselves to typical rock-face features with less planning and simpler end effectors. This advance is based on the emulation of the equipment used by human climbers rather than the emulation of the human hand. Climbing-aid equipment, specifically cams, aid hooks, and cam hooks, are used by sport climbers when a quick ascent of a cliff is desired (see Figure 1). Currently two different end-effector designs have been created. The first, denoted the simple hook emulator, consists of three "fingers" arranged around a central "palm." Each finger emulates the function of a particular type of climbing hook (aid hook, wide cam hook, and a narrow cam hook). These fingers are connected to the palm via a mechanical linkage actuated with a leadscrew/nut. This mechanism allows the fingers to be extended or retracted. The second design, denoted the advanced hook emulator (see Figure 2), shares these features, but it incorporates an aid hook and a cam hook into each finger. The spring-loading of the aid hook allows the passive selection of the type of hook used. The end effectors can be used in several different modes. In the aid-hook mode, the aid hook on one of the fingers locks onto a horizontal ledge while the other two fingers act to stabilize the end effector against the cliff face. In the cam-hook mode, the broad, flat tip of the cam hook is

  7. Normal-stress coefficients and rod climbing in colloidal dispersions

    NASA Astrophysics Data System (ADS)

    Farage, T. F. F.; Reinhardt, J.; Brader, J. M.

    2013-10-01

    We calculate tractable microscopic expressions for the low-shear normal-stress coefficients of colloidal dispersions. Although restricted to the low rate regime, the presented formulas are valid for all volume fractions below the glass transition and for any interaction potential. Numerical results are presented for a system of colloids interacting via a hard-core attractive Yukawa potential, for which we explore the interplay between attraction strength and volume fraction. We show that the normal-stress coefficients exhibit nontrivial features close to the critical point and at high volume fractions in the vicinity of the reentrant glass transition. Finally, we exploit our formulas to make predictions about rod-climbing effects in attractive colloidal dispersions.

  8. On the static structural design of climbing robots: part 2.

    PubMed

    Ahmed, Ausama Hadi; Menon, Carlo

    This manuscript is the second of two parts of a work investigating optimal configurations of legged climbing robots while loitering on vertical surfaces. In this Part 2, a structural analysis based on the finite element method, specifically the stiffness method, is performed to address the problem. Parameters that are investigated in this Part 2 include the inclination of both the body and the legs of the robot. Outcomes of the performed study are validated by analyzing the posture of 150 ants when loitering on vertical surfaces. The obtained validation ensures the predictions of the developed structural model are correct and can be used to identify optimal configurations of legged robots when loitering on vertical surfaces.

  9. A time motion analysis of bouldering style competitive rock climbing.

    PubMed

    White, Dominic J; Olsen, Peter D

    2010-05-01

    Limited research has been performed on competitive bouldering. The aim of this study was to quantify the movement dynamics of elite boulder climbers. Six climbers were filmed during a national competition consisting of 5 novel climbing problems or routes. Two problems were randomly selected and film footage was analyzed using Kandle Swinger Pro software to determine type and duration (seconds) of bouldering movements. All subjects provided consent, and the study had ethical approval. The mean +/- SD were determined for number of attempts per problem, duration of attempt, time on hold, and time to reach between holds. Exercise:recovery ratios were also calculated. On average, climbers attempted a problem 3.0 +/- 0.5 times, with an attempt lasting 28.9 +/- 10.8 seconds and rest periods of 114 +/- 31 seconds between attempts. Average time gripping holds was 7.9 +/- 1.3 seconds, with approximately 0.5 +/- 0.1 seconds recovery between reaching for holds. The exercise-to-recovery ratio was approximately 1:4 for attempting a problem and approximately 13:1 for forearm muscles during climbing. The exercise-to-recovery ratios allow sufficient time for recovery during and after a problem. However, the prolonged contraction of forearm muscles indicates the importance of strength and endurance in these muscles. Video analysis was found to be a useful tool for the quantification of movement characteristics of competitive elite boulders. Data collected could be utilized in the design of sport-specific tests and training programs. Future research could examine a larger number of athletes and problems and help develop performance tests and training interventions for bouldering.

  10. Evidence of impaired health in yellow perch (Perca flavescens) from a biological mercury hotspot in northeastern North America.

    PubMed

    Batchelar, Katharina L; Kidd, Karen A; Drevnick, Paul E; Munkittrick, Kelly R; Burgess, Neil M; Roberts, Aaron P; Smith, James D

    2013-03-01

    Few studies have investigated the effects of mercury (Hg) on wild fish from remote areas, even though these fish can have high total Hg concentrations. In Kejimkujik National Park and National Historic Site (KNPNHS), Nova Scotia, Canada, concentrations of total Hg in many yellow perch (Perca flavescens) currently exceed the estimated threshold level for adverse effects in fish (0.2 µg Hg g(-1) (wet wt), whole body). To determine whether Hg exposure is adversely affecting the general health of these fish, the authors collected male and female perch in the fall of 2009 and 2010 from 12 lakes within KNPNHS. The health endpoints condition, liver somatic index (LSI), and macrophage aggregates (MAs; indicators of oxidative stress and tissue damage) in the liver, kidney, and spleen were examined, and in female perch were compared between lakes and related to Hg concentrations measured in the muscle and liver tissue. No negative relationships between fish condition or LSI and Hg were found. However, within the liver, kidney, and spleen tissues of females, the relative area occupied by MAs was positively related to both muscle and liver Hg concentrations, indicating the health of these perch was adversely affected at the cellular level. These findings raise concerns for the health of these perch as well as for other wild fish populations known to have similarly elevated Hg concentrations.

  11. Hypoxia tolerance of introduced Nile perch: Implications for survival of indigenous fishes in the Lake Victoria basin

    USGS Publications Warehouse

    Schofield, P.J.; Chapman, L.J.

    2000-01-01

    The introduction of predatory Nile perch (Lates niloticus) into the Lake Victoria basin coincided with a dramatic decline in fish diversity. However, remnant populations of indigenous fishes persist in lagoons and satellite lakes separated from the main lakes by extensive areas of swamp, while other indigenous species find refuge in ecotonal areas at edges of marginal swamps in the main lakes. Low-oxygen conditions in these wetlands may physiologically stress Nile perch and therefore minimize its interaction with prey species. This study examined the low-oxygen tolerance of Nile perch collected from Lake Nabugabo, Uganda, by documenting behavioural and physiological strategies that relate to oxygen uptake. In response to hypoxia, Nile perch used aquatic surface respiration (ASR) at the air-water interface, ventilating their gills with water from the surface. However, several lines of evidence suggest that Nile perch in Lake Nabugabo are inefficient at ASR and relatively intolerant of low oxygen conditions. These include high thresholds for ASR relative to other indigenous fishes of the Lake Victoria basin, no decrease in gill ventilation rate with the onset of ASR, a faster time to loss of equilibrium in hypoxic conditions than other species from the region, and a high critical oxygen tension (24 mm Hg).

  12. Zymosan-induced immune challenge modifies the stress response of hypoxic air-breathing fish (Anabas testudineus Bloch): Evidence for reversed patterns of cortisol and thyroid hormone interaction, differential ion transporter functions and non-specific immune response.

    PubMed

    Simi, S; Peter, Valsa S; Peter, M C Subhash

    2016-11-18

    Fishes have evolved physiological mechanisms to exhibit stress response, where hormonal signals interact with an array of ion transporters and regulate homeostasis. As major ion transport regulators in fish, cortisol and thyroid hormones have been shown to interact and fine-tune the stress response. Likewise, in fishes many interactions have been identified between stress and immune components, but the physiological basis of such interaction has not yet delineated particularly in air-breathing fish. We, therefore, investigated the responses of thyroid hormones and cortisol, ion transporter functions and non-specific immune response of an obligate air-breathing fish Anabas testudineus Bloch to zymosan treatment or hypoxia stress or both, to understand how immune challenge modifies the pattern of stress response in this fish. Induction of experimental peritonitis in these fish by zymosan treatment (200ngg(-1)) for 24h produced rise in respiratory burst and lysozomal activities in head kidney phagocytes. In contrast, hypoxia stress for 30min in immune-challenged fish reversed these non-specific responses of head kidney phagocytes. The decline in plasma cortisol in zymosan-treated fish and its further suppression by hypoxia stress indicate that immune challenge suppresses the cortisol-driven stress response of this fish. Likewise, the decline in plasma T3 and T4 after zymosan-treatment and the rise in plasma T4 after hypoxia stress in immune-challenged fish indicate a critical role for thyroid hormone in immune-stress response due to its differential sensitivity to both immune and stress challenges. Further, analysis of the activity pattern of ion-dependent ATPases viz. Na(+)/K(+)-ATPase, H(+)/K(+)-ATPase and Na(+)/NH4(+)-ATPase indicates a functional interaction of ion transport system with the immune response as evident in its differential and spatial modifications after hypoxia stress in immune-challenged fish. The immune-challenge that produced differential pattern

  13. Relative importance of perch and facilitative effects on nucleation in tropical woodland in Malawi

    NASA Astrophysics Data System (ADS)

    Fujita, Tomohiro

    2016-01-01

    Individual trees in open vegetation such as woodlands can act as "nuclei" for the colonization of forest tree species, which consequently lead to the formation of forest patches. This phenomenon is known as nucleation. The mechanism of nucleation is generally attributed to two factors: trees provide perches for frugivores that increase seed deposition (perch effect), and tree crowns ameliorate environmental conditions, which improves seedling establishment (facilitative effect). Few studies have attempted to distinguish the relative importance of these two factors. In this study, I separated these two effects in a woodland in northern Malawi. I chose Ficus natalensis as a potential nuclei tree because large individuals of this species are commonly located at the center of forest patches within open woodland at the study site. I monitored several environmental variables, seedling survival, seedling composition, and seed rain at three microsites: under F. natalensis, under Brachystegia floribunda (a dominant woodland species), and in open sites. Both tree species provided similar favorable conditions for the establishment of forest species compared to open sites. Thus, the survival of forest tree seedlings under F. natalensis and B. floribunda was similar, and substantially higher than seedling survival in open sites. However, communities of naturally occurring seedlings differed significantly between F. natalensis and B. floribunda. These results indicate that the facilitative effect alone cannot explain the nucleation pattern. I attribute this result to the perch effect of F. natalensis because the forest seedling species recorded under F. natalensis reportedly have small, brightly colored diaspores, which are indicative of dispersal by birds. Seed deposition of forest species under F. natalensis was significantly higher than that under B. floribunda or in open sites. My findings reinforce the idea that trees will lead to nucleation when they enhance seed

  14. Chronic environmental warming alters cardiovascular and haematological stress responses in European perch (Perca fluviatilis).

    PubMed

    Ekström, Andreas; Jutfelt, Fredrik; Fredrik Sundström, L; Adill, Anders; Aho, Teija; Sandblom, Erik

    2016-12-01

    Environmental warming and acute stress increase cardiorespiratory activity in ectothermic animals like fish. While thermal acclimation can buffer the direct thermal effects on basal cardiorespiratory function during chronic warming, little is known about how acclimation affects stress-induced cardiorespiratory responses. We compared cardiovascular and haematological responses to chasing stress in cannulated wild European perch (Perca fluviatilis) from a reference area at natural temperature (16 °C) with perch from the 'Biotest enclosure'; an experimental system chronically warmed (22 °C) by effluents from a nuclear power plant. Routine blood pressure was similar, but Biotest perch had slightly higher resting heart rate (59.9 ± 2.8 vs 51.3 ± 2.9 beats min(-1)), although the Q 10 for heart rate was 1.3, indicating pronounced thermal compensation. Chasing stress caused hypertension and a delayed tachycardia in both groups, but the maximum heart rate increase was 2.5-fold greater in Biotest fish (43.3 ± 4.3 vs 16.9 ± 2.7 beats min(-1)). Moreover, the pulse pressure response after stress was greater in reference fish, possibly due to the less pronounced tachycardia or a greater ventricular pressure generating capacity and thermally mediated differences in aortic compliance. Baseline haematological status was also similar, but after chasing stress, the haematocrit was higher in Biotest fish due to exacerbated red blood cell swelling. This study highlights that while eurythermal fishes can greatly compensate routine cardiorespiratory functions through acclimation processes, stress-induced responses may still differ markedly. This knowledge is essential when utilising cardiorespiratory variables to quantify and compare stress responses across environmental temperatures, and to forecast energetic costs and physiological constraints in ectothermic animals under global warming.

  15. Nourishment of perched sand dunes and the issue of erosion control in the Great Lakes

    NASA Astrophysics Data System (ADS)

    Marsh, William M.

    1990-09-01

    Although limited in coverage, perched sand dunes situated on high coastal bluffs are considered the most prized of Great Lakes dunes. Grand Sable Dunes on Lake Superior and Sleeping Bear Dunes on Lake Michigan are featured attractions of national lakeshores under National Park Service management. The source of sand for perched dunes is the high bluff along their lakeward edge. As onshore wind crosses the bluff, flow is accelerated upslope, resulting in greatly elevated levels of wind stress over the slope brow. On barren, sandy bluffs, wind erosion is concentrated in the brow zone, and for the Grand Sable Bluff, it averaged 1 m3/yr per linear meter along the highest sections for the period 1973 1983. This mechanism accounts for about 6,500 m3 of sand nourishment to the dunefield annually and clearly has been the predominant mechanism for the long-term development of the dunefield. However, wind erosion and dune nourishment are possible only where the bluff is denuded of plant cover by mass movements and related processes induced by wave erosion. In the Great Lakes, wave erosion and bluff retreat vary with lake levels; the nourishment of perched dunes is favored by high levels. Lake levels have been relatively high for the past 50 years, and shore erosion has become a major environmental issue leading property owners and politicians to support lake-level regulation. Trimming high water levels could reduce geomorphic activity on high bluffs and affect dune nourishment rates. Locally, nourishment also may be influenced by sediment accumulation associated with harbor protection facilities and by planting programs aimed at stabilizing dunes.

  16. Climbing Fiber Regulation of Spontaneous Purkinje Cell Activity and Cerebellum-Dependent Blink Responses123

    PubMed Central

    Bengtsson, Fredrik

    2016-01-01

    Abstract It has been known for a long time that GABAergic Purkinje cells in the cerebellar cortex, as well as their target neurons in the cerebellar nuclei, are spontaneously active. The cerebellar output will, therefore, depend on how input is integrated into this spontaneous activity. It has been shown that input from climbing fibers originating in the inferior olive controls the spontaneous activity in Purkinje cells. While blocking climbing fiber input to the Purkinje cells causes a dramatic increase in the firing rate, increased climbing fiber activity results in reduced Purkinje cell activity. However, the exact calibration of this regulation has not been examined systematically. Here we examine the relation between climbing fiber stimulation frequency and Purkinje cell activity in unanesthetized decerebrated ferrets. The results revealed a gradual suppression of Purkinje cell activity, starting at climbing fiber stimulation frequencies as low as 0.5 Hz. At 4 Hz, Purkinje cells were completely silenced. This effect lasted an average of 2 min after the stimulation rate was reduced to a lower level. We also examined the effect of sustained climbing fiber stimulation on overt behavior. Specifically, we analyzed conditioned blink responses, which are known to be dependent on the cerebellum, while stimulating the climbing fibers at different frequencies. In accordance with the neurophysiological data, the conditioned blink responses were suppressed at stimulation frequencies of ≥4 Hz. PMID:26839917

  17. The role of the perch effect on the nucleation process in Mediterranean semi-arid oldfields

    NASA Astrophysics Data System (ADS)

    Pausas, Juli G.; Bonet, Andreu; Maestre, Fernando T.; Climent, Anna

    2006-05-01

    Oldfield succession in Mediterranean ecosystems has been studied extensively in mesic conditions. However, this phenomenon is still poorly understood in semi-arid Mediterranean areas, where reduced plant cover, the importance of facilitation processes and the role of abiotic factors make these environments distinct. We first test whether the carob tree ( Ceratonia siliqua) generates nucleation patterns in semi-arid oldfields, and to what extent such patterns change with abandonment age. Then we test to what extent nucleation can be explained by the perch effect. And finally, we test whether the nucleated pattern around carob trees is a source of diversity in the oldfields studied. To answer these questions we located oldfields abandoned 25 and 50 years ago (20 in each case) in the Alacant Province (SE Spain, Iberian Peninsula) on the basis of aerial photographs and personal interviews with local landowners and managers. In each oldfield woody plant density and richness were sampled on two microsites: under the carob tree and in the open field. Analysis was performed on all woody plants and by separating the species in two functional groups: fleshy-fruited (with fleshy mesocarp) and non-fleshy-fruited species. The results suggest that woody vegetation colonising abandoned C. siliqua fields in SE Spain is not randomly distributed but follows a nucleation pattern with higher plant density under the trees. However, the nucleation pattern is only significant for fleshy-fruited species, suggesting that facilitative interactions alone cannot explain the nucleation pattern and that the perch effect plays an important role. The results also show that the nucleation pattern (total plant density and density of non-fleshy-fruited plants) did not increase with abandonment age, while the perch effect (density of fleshy-fruited plants) did increase significantly. Furthermore, the results also show that the nucleation pattern is not only a loci of high plant density but also a

  18. Improved COI barcoding primers for Southeast Asian perching birds (Aves: Passeriformes).

    PubMed

    Lohman, David J; Prawiradilaga, Dewi M; Meier, Rudolf

    2009-01-01

    The All Birds Barcoding Initiative aims to assemble a DNA barcode database for all bird species, but the 648-bp 'barcoding' region of cytochrome c oxidase subunit I (COI) can be difficult to amplify in Southeast Asian perching birds (Aves: Passeriformes). Using COI sequences from complete mitochondrial genomes, we designed a primer pair that more reliably amplifies and sequences the COI barcoding region of Southeast Asian passerine birds. The 655-bp region amplified with these primers overlaps the COI region amplified with other barcoding primer pairs, enabling direct comparison of sequences with previously published DNA barcodes.

  19. Hormone responses to a continuous bout of rock climbing in men.

    PubMed

    Sherk, Vanessa D; Sherk, Kyle A; Kim, SoJung; Young, Kaelin C; Bemben, Debra A

    2011-04-01

    Rock climbing is rapidly increasing in popularity as a recreational activity and as a competitive sport. Few studies have tested acute physiological responses to climbing, and no studies to date have tested hormone responses to a climbing-based workout. This study aimed to measure testosterone (T), growth hormone (GH), and cortisol (C) responses to continuous vertical climbing in young male rock climbers. Ten male rock climbers, aged between 21 and 30 years, climbed laps on a submaximal 55' climbing route for 30 min, or until exhaustion, whichever came first. Heart rate (HR) was recorded after every lap. Blood samples were collected by venipuncture before (Pre), immediately post (IP), and 15 min after the climbing exercise (P15) to assess blood lactate and plasma GH, T, and C. Subjects climbed 24.9 ± 1.9 min and 507.5 ± 82.5 feet. Peak HR was 182.1 ± 2.3 bpm, and lactate (Pre: 2.9 ± 0.6 mmol/dL, IP: 11.1 ± 1.0 mmol/dL) significantly (P < 0.05) increased from Pre to IP. T concentrations significantly (P < 0.05) increased from Pre (6.04 ± 0.31 ng/mL) to IP (7.39 ± 0.40 ng/mL) and returned to baseline at P15 (6.23 ± 0.33 ng/mL). Cortisol levels did not significantly change during the protocol. GH significantly (P < 0.01) increased from Pre (0.63 ± 0.17 ng/mL) to IP (19.89 ± 4.53 ng/mL) and remained elevated at P15 (15.03 ± 3.89 ng/mL). An acute, short-term bout of high-intensity continuous climbing was an effective exercise stimulus for elevating plasma testosterone and growth hormone levels in young males.

  20. Capillary climb dynamics in the limits of prevailing capillary and gravity force.

    PubMed

    Bijeljic, B; Markicevic, B; Navaz, H K

    2011-05-01

    The dynamics of capillary climb of a wetting liquid into a porous medium that is opposed by gravity force is studied numerically. We use the capillary network model, in which an actual porous medium is represented as a network of pores and throats, each following a predefined size distribution function. The liquid potential in the pores along the liquid interface within the network is calculated as a result of capillary and gravity forces. The solution is general, and accounts for changes in the climbing height and climbing velocity. The numerical results for the capillary climb reveal that there are at least two distinct flow mechanisms. Initially, the flow is characterized by high climbing velocity, in which the capillary force is higher than the gravity force, and the flow is the viscous force dominated. For this single-phase flow, the Washburn equation can be used to predict the changes of climbing height over time. Later, for longer times and larger climbing height, the capillary and gravity forces become comparable, and one observes a slower increase in the climbing height as a function of time. Due to the two forces being comparable, the gas-liquid sharp interface transforms into flow front, where the multiphase flow develops. The numerical results from this study, expressed as the climbing height as a power law function of time, indicate that the two powers, which correspond to the two distinct mechanisms, differ significantly. The comparison of the powers with experimental data indicates good agreement. Furthermore, the power value from the Washburn solution is also analyzed, where it should be equal to 1/2 for purely viscous force driven flow. This is in contrast to the power value of ∼0.43 that is found experimentally. We show from the numerical solution that this discrepancy is due to the momentum dissipation on the liquid interface.

  1. 3D analysis of the body center of mass in rock climbing.

    PubMed

    Sibella, F; Frosio, I; Schena, F; Borghese, N A

    2007-12-01

    The purpose of the present study was to search for common patterns and for differences in climbing strategies in a group of recreational climbers. Twelve participants were involved in the study. Each participant climbed a simple indoor route consisting of a 3m horizontal shift followed by a 3m ascent for five times. Climbers could choose their own style, their preferred speed and holds. Their motion was recorded through motion capture based on passive markers. Results suggested that two main climbing strategies were used: the first preferring agility over force and the second preferring force over agility. We also found that our best climbers tried to minimize power during all trials.

  2. Impact of different colours of artificial light at night on melatonin rhythm and gene expression of gonadotropins in European perch.

    PubMed

    Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

    2016-02-01

    The distribution and intensity of artificial light at night, commonly referred to as light pollution, is consequently rising and progressively also ecological implications come to light. Low intensity light is known to suppress nocturnal melatonin production in several fish species. This study aims to examine the least suppressive light colour for melatonin excreted into the holding water and the influence of different light qualities and quantities in the night on gene expression of gonadotropins in fish. European perch (Perca fluviatilis) were exposed to light of different wavelengths during the night (blue, green, and red). Melatonin concentrations were measured from water samples every 3h during a 24h period. Gene expression of gonadotropins was measured in perch exposed to different light colours and was additionally examined for perch subjected to different intensities of white light (0 lx, 1 lx, 10 lx, 100 lx) during the night. All different light colours caused a significant drop of melatonin concentration; however, blue light was least suppressive. Gene expression of gonadotropins was not influenced by nocturnal light of different light colours, but in female perch gonadotropin expression was significantly reduced by white light already at the lowest level (1 lx). We conclude that artificial light with shorter wavelengths at night is less effective in disturbing biological rhythms of perch than longer wavelengths, coinciding with the light situation in freshwater habitats inhabited by perch. Different light colours in the night showed no significant effect on gonadotropin expression, but white light in the night can disturb reproductive traits already at very low light intensities. These findings indicate that light pollution has not only the potential to disturb the melatonin cycle but also the reproductive rhythm and may therefore have implications on whole species communities.

  3. Impact of tannery effluents on the aquatic environment of the Buriganga River in Dhaka, Bangladesh.

    PubMed

    Asaduzzaman, Mohammad; Hasan, Imtiaj; Rajia, Sultana; Khan, Nazneen; Kabir, Kazi Ahmed

    2016-06-01

    This study presents an overview of the existence and effects of six heavy metals, chromium (Cr), lead (Pb), cadmium (Cd), mercury (Hg), manganese (Mn), and aluminum (Al), in tannery effluents released to the Buriganga River in Dhaka, Bangladesh. The pollutants were found in three different sources, such as effluents from tanneries, contaminated river water and three species of fish-climbing perch (Anabas testudineus), spotted snakehead (Channa punctata), and Black tilapia (Oreochromis mossambicus) caught from the river. Tannery effluents, water, and fish samples were collected from three different factories, five sample stations, and three different harvesting points, respectively. Effluents from all three factories contained significant amounts of heavy metals, especially Cr (374.19 ppm in average), whereas lesser amounts were found in the tissues of the three fish species studied. The trends in tissue elemental concentrations of fish were Cr > Pb > Al > Hg > Mn > Cd. In most cases (Cr, Cd, Mn, and Al), heavy metal concentrations were found to be greater in climbing perch than in Black tilapia and spotted snakehead. Although the river water contained high concentrations of harmful heavy metals, the fish species under study had concentrations well below the permissible Food and Agriculture Organization/World Health Organization levels for those metals and seemed to be safe for human consumption.

  4. Seasonal and Sex-Specific mRNA Levels of Key Endocrine Genes in Adult Yellow Perch (Perca flavescens) from Lake Erie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow perch exhibit a sexual size dimorphism (SSD) where females grow faster and larger than males and estrogen preferentially stimulates growth in females. In an effort to gain more understanding of yellow perch endocrinology, real-time quantitative PCR (qPCR) was used to measure pituitary, liver...

  5. Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

    PubMed Central

    Backus, Spencer B.; Sustaita, Diego; Odhner, Lael U.; Dollar, Aaron M.

    2015-01-01

    The grasping capability of birds' feet is a hallmark of their evolution, but the mechanics of avian foot function are not well understood. Two evolutionary trends that contribute to the mechanical complexity of the avian foot are the variation in the relative lengths of the phalanges and the subdivision and variation of the digital flexor musculature observed among taxa. We modelled the grasping behaviour of a simplified bird foot in response to the downward and upward forces imparted by carrying and perching tasks, respectively. Specifically, we compared the performance of various foot geometries performing these tasks when actuated by distally inserted flexors only, versus by both distally inserted and proximally inserted flexors. Our analysis demonstrates that most species possess relative phalanx lengths that are conducive to grasps actuated only by a single distally inserted tendon per digit. Furthermore, proximally inserted flexors are often required during perching, but the distally inserted flexors are sufficient when grasping and carrying objects. These results are reflected in differences in the relative development of proximally and distally inserted digital flexor musculature among ‘perching’ and ‘grasping’ taxa. Thus, our results shed light on the relative roles of variation in phalanx length and digit flexor muscle distribution in an integrative, mechanical context. PMID:26064598

  6. Changes in HTO and OBT activity concentrations in the Perch Lake aquatic ecosystem.

    PubMed

    Kim, S B; Farrow, F; Bredlaw, M; Stuart, M

    2016-12-01

    Perch Lake, a small shallow shield lake located on the Chalk River Laboratories (CRL) site, contains elevated levels of tritium due to inputs from a nearby nuclear waste management area. The releases have been going on for many years but tritium levels in Perch Lake have been gradually decreasing since about year 2000. Lake water, sediments, aquatic plants, clams and fish were collected during the summer and fall of 2003 and 2013 at three locations in the lake. HTO activity concentrations were measured in all samples and OBT activity concentrations were measured in sediments, plants, clams and fish. In 2003, 2013, HTO activity concentrations in lake water were roughly uniform in time and space, except close to the shoreline where concentrations were fluctuating according to stream water and groundwater tritium levels in streams entering the lake. HTO activity concentrations of biota were similar to concentrations in lake water at the site where they were collected. OBT activity concentrations in biota were not always correlating with the lake water HTO levels. OBT to HTO ratios were found to be less than 1 for aquatic plants, around 1 for clams and fish and above 1 for birds reared on the shore of the lake.

  7. Methylmercury content of eggs in yellow perch related to maternal exposure in four Wisconsin lakes

    USGS Publications Warehouse

    Hammerschmidt, Chad R.; Wiener, James G.; Frazier, Brdaley E.; Rada, Ronald G.

    1999-01-01

    We examined the influence of maternal mercury and selected lacustrine variables on the mercury content of eggs from yellow perch (Perca flavescens). Total mercury, methylmercury, and inorganic mercury were determined in eggs and carcasses (less eggs) from three seepage lakes with a pH range of 6.1a??7.0 and a fourth lake in which pH was experimentally increased from 5.5 to 6.8 by addition of alkaline groundwater. The concentration of total mercury in eggs was strongly correlated with that in the maternal carcass. Concentrations and burdens of mercury in eggs and carcasses were inversely correlated with lake water pH, acid-neutralizing capacity, calcium, and dissolved organic carbon. In eggs containing more than 30 ng/g dry weight (4.5 ng/g wet weight) of total mercury, methylmercury averaged 91% of total mercury and ranged from 85% to 96%. Mean burdens of total mercury in individual eggs varied greatly among lakes (range, 2.3a??63 pg), and the egg mass averaged 1.9% of the whole-body burden. We conclude that exposure of the developing yellow perch embryo to methylmercury is strongly affected by maternal bioaccumulation, which can vary substantially among and within lakes; however, the toxicological significance of the observed exposure of embryos to methylmercury is unclear.

  8. Approaches to the simulation of unconfined flow and perched groundwater flow in MODFLOW.

    PubMed

    Bedekar, Vivek; Niswonger, Richard G; Kipp, Kenneth; Panday, Sorab; Tonkin, Matthew

    2012-01-01

    Various approaches have been proposed to manage the nonlinearities associated with the unconfined flow equation and to simulate perched groundwater conditions using the MODFLOW family of codes. The approaches comprise a variety of numerical techniques to prevent dry cells from becoming inactive and to achieve a stable solution focused on formulations of the unconfined, partially-saturated, groundwater flow equation. Keeping dry cells active avoids a discontinuous head solution which in turn improves the effectiveness of parameter estimation software that relies on continuous derivatives. Most approaches implement an upstream weighting of intercell conductance and Newton-Raphson linearization to obtain robust convergence. In this study, several published approaches were implemented in a stepwise manner into MODFLOW for comparative analysis. First, a comparative analysis of the methods is presented using synthetic examples that create convergence issues or difficulty in handling perched conditions with the more common dry-cell simulation capabilities of MODFLOW. Next, a field-scale three-dimensional simulation is presented to examine the stability and performance of the discussed approaches in larger, practical, simulation settings.

  9. Approaches to the simulation of unconfined flow and perched groundwater flow in MODFLOW

    USGS Publications Warehouse

    Bedekar, Vivek; Niswonger, Richard G.; Kipp, Kenneth; Panday, Sorab; Tonkin, Matthew

    2012-01-01

    Various approaches have been proposed to manage the nonlinearities associated with the unconfined flow equation and to simulate perched groundwater conditions using the MODFLOW family of codes. The approaches comprise a variety of numerical techniques to prevent dry cells from becoming inactive and to achieve a stable solution focused on formulations of the unconfined, partially-saturated, groundwater flow equation. Keeping dry cells active avoids a discontinuous head solution which in turn improves the effectiveness of parameter estimation software that relies on continuous derivatives. Most approaches implement an upstream weighting of intercell conductance and Newton-Raphson linearization to obtain robust convergence. In this study, several published approaches were implemented in a stepwise manner into MODFLOW for comparative analysis. First, a comparative analysis of the methods is presented using synthetic examples that create convergence issues or difficulty in handling perched conditions with the more common dry-cell simulation capabilities of MODFLOW. Next, a field-scale three-dimensional simulation is presented to examine the stability and performance of the discussed approaches in larger, practical, simulation settings.

  10. Improved Low-Order Models of Bio-inspired Pitching and Perching

    NASA Astrophysics Data System (ADS)

    Wang, Chengjie; Eldredge, Jeff D.

    2011-11-01

    To study the flying of small creatures, their simplest flapping motions, pitching and perching, are investigated by low-order inviscid point vortex models. These motions induce coherent vortex shedding at the leading edge, which has a profound influence on the generated force. Instead of fully recovering the flow field around wing, the reduced models track only small number of discrete vortices with time-varying strength to account for the unsteady aerodynamics. The idea of impulse matching is introduced to develop the new governing equation, different from the previously-developed Brown-Michael equation. For both pitching and perching motions, the results from the impulse matching model are compared with high fidelity simulations under different pitching rate and axis position, and this comparison shows a good qualitative agreement, which is better than obtained with the Brown-Michael approach. The results are also compared with previous experiments conducted in a water tunnel, and good qualitative agreement is achieved. Further, some detailed analysis of the high fidelity simulation has been performed to get intuition about the leading edge vortex, which can help us in improving the low-order model.

  11. Low-order Modeling of Bio-inspired Pitching and Perching at Low Reynolds Number

    NASA Astrophysics Data System (ADS)

    Wang, Chengjie; Eldredge, Jeff D.

    2010-11-01

    A low-order inviscid point vortex model is used to simulate the pitching and perching motion of a thin flat plate at low Reynolds number. These motions induce coherent vortex shedding at the leading edge, which has a profound influence on the generated force. The low-order method is based on the inviscid Brown-Michael point vortex model, which accounts for the unsteady aerodynamics by tracking a small number of vortices with time-varying strengths. For the pitching motion, the results from the low-order model are compared with high fidelity simulations under different pitching rate and axis position, and this comparison shows a good qualitative agreement. The perching motion is characterized by larger rotations and an unsteady translation. The low-order model results are compared with previous experiments conducted in a water tunnel, and good qualitative agreement is achieved. To investigate the mechanism of force generation, the force obtained from the model is decomposed into inertial reaction and circulatory components, and their relative contributions are inspected.

  12. Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.

    2012-01-01

    Effusion rate is a primary measurement used to judge the expected advance rate, length, and hazard potential of lava flows. At basaltic volcanoes, the rapid draining of lava stored in rootless shields and perched ponds can produce lava flows with much higher local effusion rates and advance velocities than would be expected based on the effusion rate at the vent. For several months in 2007–2008, lava stored in a series of perched ponds and rootless shields on Kīlauea Volcano, Hawai'i, was released episodically to produce fast-moving 'a'ā lava flows. Several of these lava flows approached Royal Gardens subdivision and threatened the safety of remaining residents. Using time-lapse image measurements, we show that the initial time-averaged discharge rate for one collapse-triggered lava flow was approximately eight times greater than the effusion rate at the vent. Though short-lived, the collapse-triggered 'a'ā lava flows had average advance rates approximately 45 times greater than that of the pāhoehoe flow field from which they were sourced. The high advance rates of the collapse-triggered lava flows demonstrates that recognition of lava accumulating in ponds and shields, which may be stored in a cryptic manner, is vital for accurately assessing short-term hazards at basaltic volcanoes.

  13. A Red-Tailed Hawk perches on a stump at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Near a road at Kennedy Space Center, a red-tailed hawk perches on a weathered tree stump. The red-tailed hawk has a stocky build and broad, rounded wings. Its broad range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  14. Perching but not foraging networks predict the spread of novel foraging skills in starlings.

    PubMed

    Boogert, Neeltje J; Nightingale, Glenna F; Hoppitt, William; Laland, Kevin N

    2014-11-01

    The directed social learning hypothesis suggests that information does not spread evenly through animal groups, but rather individual characteristics and patterns of physical proximity guide the social transmission of information along specific pathways. Network-based diffusion analysis (NBDA) allows researchers to test whether information spreads following a social network. However, the explanatory power of different social networks has rarely been compared, and current models do not easily accommodate random effects (e.g. allowing for individuals within groups to correlate in their asocial solving rates). We tested whether the spread of two novel foraging skills through captive starling groups was affected by individual- and group-level random and fixed effects (i.e. sex, age, body condition, dominance rank and demonstrator status) and perching or foraging networks. We extended NBDA to include random effects and conducted model discrimination in a Bayesian context. We found that social learning increased the rate at which birds acquired the novel foraging task solutions by 6.67 times, and acquiring one of the two novel foraging task solutions facilitated the asocial acquisition of the other. Surprisingly, the spread of task solutions followed the perching rather than the foraging social network. Upon acquiring a task solution, foraging performance was facilitated by the presence of group mates. Our results highlight the importance of considering more than one social network when predicting the spread of information through animal groups. This article is part of a Special Issue entitled: Cognition in the wild.

  15. Thirty-Year-Old Paradigm about Unpalatable Perch Egg Strands Disclaimed by the Freshwater Top-Predator, the European Catfish (Silurus glanis)

    PubMed Central

    Kočvara, Luboš; Sajdlová, Zuzana; Hoang The, Son Chung; Šmejkal, Marek; Peterka, Jiří

    2017-01-01

    So far, perch egg strands have been considered unpalatable biological material. However, we repeatedly found egg strands of European perch (Perca fluviatilis) in the diet of European catfish (Silurus glanis) caught by longlines in Milada and Most Lakes, Czech Republic. The finding proves that perch egg strands compose a standard food source for this large freshwater predatory fish. It extends the present knowledge on catfish foraging plasticity, showing it as an even more opportunistic feeder. Utilization of perch egg strands broadens the catfish diet niche width and represents an advantage against other fish predators. Comparison of datasets from extensive gillnet and SCUBA diver sampling campaigns gave the evidence that at least in localities where food sources are limited, multilevel predation by catfish may have an important impact on the perch population. PMID:28060862

  16. Rock Climbing Robot for Exploration and Sample Acquisition at Lava Tubes, Steep Slopes, and Cliff Walls

    NASA Astrophysics Data System (ADS)

    Parness, A.; Frost, M.; Boston, P.; Cutkosky, M.

    2012-06-01

    The rock climbing robot utilizes a unique technology, microspines, that enables gravity-independent access to some of the most interesting locations on the Martian surface. Inverted rock coring has also been demonstrated with this technology.

  17. Strange beta: an assistance system for indoor rock climbing route setting.

    PubMed

    Phillips, C; Becker, L; Bradley, E

    2012-03-01

    This paper applies the mathematics of chaos to the task of designing indoor rock-climbing routes. Chaotic variation has been used to great advantage on music and dance, but the challenges here are quite different, beginning with the representation. We present a formalized system for transcribing rock climbing problems and then describe a variation generator that is designed to support human route-setters in designing new and interesting climbing problems. This variation generator, termed strange beta, uses chaos to introduce novelty. We validated this approach with a large blinded study in a commercial climbing gym, in cooperation with experienced climbers and expert route setters. The results show that strange beta can help a human setter produce routes that are at least as good as, and in some cases better than, those produced in the traditional manner.

  18. The "Heel Hook"-A Climbing-Specific Technique to Injure the Leg.

    PubMed

    Schöffl, Volker; Lutter, Christoph; Popp, Dominik

    2016-06-01

    Acute injuries in rock climbing either come from a fall onto the lower leg or from performing a hard move and injuring the upper extremity. Further evaluations of lower leg injuries in rock climbing athletes have been performed recently finding sport characteristics such as peroneal tendon dislocations or chronic deformations of the feet. One injury mechanism described in case reports is the so-called heel hook position, which is used more frequently today compared with the beginngs of rock climbing. In addition, the number of these injuries is expected to rise with the increase in popularity of climbing and bouldering. Therefore, it is important to further analyze this pathology. We investigated 17 patients with injuries of the lower extremities after performing a heel hook.

  19. strange beta: An assistance system for indoor rock climbing route setting

    NASA Astrophysics Data System (ADS)

    Phillips, C.; Becker, L.; Bradley, E.

    2012-03-01

    This paper applies the mathematics of chaos to the task of designing indoor rock-climbing routes. Chaotic variation has been used to great advantage on music and dance, but the challenges here are quite different, beginning with the representation. We present a formalized system for transcribing rock climbing problems and then describe a variation generator that is designed to support human route-setters in designing new and interesting climbing problems. This variation generator, termed strange beta, uses chaos to introduce novelty. We validated this approach with a large blinded study in a commercial climbing gym, in cooperation with experienced climbers and expert route setters. The results show that strange beta can help a human setter produce routes that are at least as good as, and in some cases better than, those produced in the traditional manner.

  20. STS-38 Mission Specialist Gemar climbs into T-38A cockpit at Ellington Field

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Mission Specialist (MS) Charles D. Gemar, smiling, pauses before climbing into T-38A aft cockpit at Ellington Field. The crewmembers are preparing for their departure to the Kennedy Space Center (KSC).

  1. Pre-performance psychological states and performance in an elite climbing competition.

    PubMed

    Sanchez, X; Boschker, M S J; Llewellyn, D J

    2010-04-01

    The purpose of the present study was to assess the relationship between pre-performance psychological states and expert performance in non-traditional sport competition. Nineteen elite male sport climbers (M=24.6, SD=4.0 years of age) completed the Competitive State Anxiety Inventory-2 and the Positive and Negative Affect Schedule before an international rock climbing competition. Climbing performances were video-recorded to calculate movement fluency (entropy) and obtain ascent times. Official route scores were also obtained. Successful climbers reported higher pre-performance levels of somatic anxiety and climbed the most difficult part of the route more slowly than their unsuccessful counterparts. The psychological states preceding elite climbing competition appeared to be an important factor in determining success, even when differences in baseline ability were taken into account.

  2. Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes

    SciTech Connect

    Zarkevich, Nikolai A.; Johnson, Duane D.

    2015-01-09

    The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. Improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP. In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.

  3. Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes

    DOE PAGES

    Zarkevich, Nikolai A.; Johnson, Duane D.

    2015-01-09

    The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. Improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP.more » In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.« less

  4. The excitatory synaptic action of climbing fibres on the Purkinje cells of the cerebellum

    PubMed Central

    Eccles, J. C.; Llinás, R.; Sasaki, K.

    1966-01-01

    1. A single climbing fibre makes an extraordinarily extensive synaptic contact with the dendrites of a Purkinje cell. Investigation of this synaptic mechanism in the cerebellum of the cat has been based on the discovery by Szentagothai & Rajkovits (1959) that the climbing fibres have their cells of origin in the contralateral inferior olive. 2. Stimulation in the accessory olive selectively excites fibres that have a powerful synaptic excitatory action on Purkinje cells in the contralateral vermis, evoking a repetitive spike discharge of 5-7 msec duration. Almost invariably this response had an all-or-nothing character. In every respect it corresponds with the synaptic action that is to be expected from climbing fibres. 3. Intracellular recording from Purkinje cells reveals that this climbing fibre stimulation evokes a large unitary depolarization with an initial spike and later partial spike responses superimposed on a sustained depolarization. 4. Typical climbing fibre responses can be excited, but in a much less selective manner, by stimulation of the olive-cerebellar pathway in the region of the fastigial nucleus, there being often a preceding antidromic spike potential of the Purkinje cell under observation. 5. Impaled Purkinje cells rapidly deteriorate with loss of all spike discharge, the climbing fibre response being then reduced to an excitatory post-synaptic potential. This potential shows that stimulation of the inferior olive may evoke two or more discharges at about 2 msec intervals in the same climbing fibre. The complexity of neuronal connexions in the inferior olive is also indicated by the considerable latency range in responses. 6. A further complication is that, with stimulation in the region of the fastigial nucleus, the initial direct climbing fibre response is often followed by a reflex discharge, presumably from the inferior olive, which resembles the responses produced by inferior olive stimulation in being often repetitive. 7. Typical

  5. Ladder-Climbing Training Prevents Bone Loss and Microarchitecture Deterioration in Diet-Induced Obese Rats.

    PubMed

    Tang, Liang; Gao, Xiaohang; Yang, Xiaoying; Liu, Chentao; Wang, Xudan; Han, Yanqi; Zhao, Xinjuan; Chi, Aiping; Sun, Lijun

    2016-01-01

    Resistance exercise has been proved to be effective in improving bone quality in both animal and human studies. However, the issue about whether resistance exercise can inhibit obesity-induced bone loss has not been previously investigated. In the present study, we have evaluated the effects of ladder-climbing training, one of the resistance exercises, on bone mechanical properties and microarchitecture in high-fat (HF) diet-induced obese rats. Twenty-four rats were randomly assigned to the Control, HF + sedentary (HF-S) and HF + ladder-climbing training (HF-LCT) groups. Rats in the HF-LCT group performed ladder-climbing training for 8 weeks. The results showed that ladder-climbing training significantly reduced body and fat weight, and increased muscle mass along with a trend toward enhanced muscle strength in diet-induced obese rats. MicroCT analysis demonstrated that obesity-induced bone loss and architecture deterioration were significantly mitigated by ladder-climbing training, as evidenced by increased trabecular bone mineral density, bone volume over total volume, trabecular number and thickness, and decreased trabecular separation and structure model index. However, neither HF diet nor ladder-climbing training had an impact on femoral biomechanical properties. Moreover, ladder-climbing training significantly increased serum adiponectin, decreased serum leptin, TNF-α, IL-6 levels, and downregulated myostatin (MSTN) expression in diet-induced obese rats. Taken together, ladder-climbing training prevents bone loss and microarchitecture deterioration in diet-induced obese rats through multiple mechanisms including increasing mechanical loading on bone due to improved skeletal muscle mass and strength, regulating the levels of myokines and adipokines, and suppressing the release of pro-inflammatory cytokines. It indicates that resistance exercise may be a promising therapy for treating obesity-induced bone loss.

  6. Aero acoustic analysis and community noise. HSCT climb to cruise noise assessment

    NASA Technical Reports Server (NTRS)

    Mortlock, Alan K.

    1992-01-01

    The widely accepted industry High Speed Civil Transport (HSCT) design goal for exterior noise is to achieve Federal Aviation Regulation (FAR) Part 36 Stage 3 noise limits currently required for new subsonic aircraft. The three phases of the concern are as follows: (1) airport noise abatement at communities close to the airport, (2) climb power opening-up procedures, and (3) the climb to cruise phase affecting communities far from the airport.

  7. Best-range flight conditions for cruise-climb flight of a jet aircraft

    NASA Technical Reports Server (NTRS)

    Hale, F. J.

    1976-01-01

    The Breguet range equation was developed for cruise climb flight of a jet aircraft to include the climb angle and is then maximized with respect to the no wind true airspeed. The expression for the best range airspeed is a function of the specific fuel consumption and minimum drag airspeed and indicates that an operational airspeed equal to the fourth root of three times the minimum-drag airspeed introduces range penalties of the order of one percent.

  8. Beneficial aerodynamic effect of wing scales on the climbing flight of butterflies.

    PubMed

    Slegers, Nathan; Heilman, Michael; Cranford, Jacob; Lang, Amy; Yoder, John; Habegger, Maria Laura

    2017-01-30

    It is hypothesized that butterfly wing scale geometry and surface patterning may function to improve aerodynamic efficiency. In order to investigate this hypothesis, a method to measure butterfly flapping kinematics optically over long uninhibited flapping sequences was developed. Statistical results for the climbing flight flapping kinematics of 11 butterflies, based on a total of 236 individual flights, both with and without their wing scales, are presented. Results show, that for each of the 11 butterflies, the mean climbing efficiency decreased after scales were removed. Data was reduced to a single set of differences of climbing efficiency using are paired t-test. Results show a mean decrease in climbing efficiency of 32.2% occurred with a 95% confidence interval of 45.6%-18.8%. Similar analysis showed that the flapping amplitude decreased by 7% while the flapping frequency did not show a significant difference. Results provide strong evidence that butterfly wing scale geometry and surface patterning improve butterfly climbing efficiency. The authors hypothesize that the wing scale's effect in measured climbing efficiency may be due to an improved aerodynamic efficiency of the butterfly and could similarly be used on flapping wing micro air vehicles to potentially achieve similar gains in efficiency.

  9. Kinetics of crimp and slope grip in rock climbing.

    PubMed

    Schweizer, Andreas; Hudek, Robert

    2011-05-01

    The aim was to investigate differences of the kinetics of the crimp and the slope grip used in rock climbing. Nine cadaver fingers were prepared and fixated with the proximal phalanx in a frame. The superficial (FDS) and deep (FDP) flexor tendons were loaded selectively and together with 40 N in the crimp grip (PIP joint flexed 90°/DIP joint hyperextended) and the slope grip position (<25° flexed/50° flexed respectively). Five different grip sizes were tested and the flexion force which was generated to the grip was measured. In the crimp grip the FDP generated more flexion force in small sized holds whereas the FDS generated more force in the larger holds. During the slope grip the FDP was more effective than the FDS. While both tendons were loaded, the flexion force was always greater during crimp grip compared with the slope grip. The FDP seems to be most important for very small holds using the crimp grip but also during slope grip holds whereas the FDS is more important for larger flat holds.

  10. Scaling and biomechanics of surface attachment in climbing animals

    PubMed Central

    Labonte, David; Federle, Walter

    2015-01-01

    Attachment devices are essential adaptations for climbing animals and valuable models for synthetic adhesives. A major unresolved question for both natural and bioinspired attachment systems is how attachment performance depends on size. Here, we discuss how contact geometry and mode of detachment influence the scaling of attachment forces for claws and adhesive pads, and how allometric data on biological systems can yield insights into their mechanism of attachment. Larger animals are expected to attach less well to surfaces, due to their smaller surface-to-volume ratio, and because it becomes increasingly difficult to distribute load uniformly across large contact areas. In order to compensate for this decrease of weight-specific adhesion, large animals could evolve overproportionally large pads, or adaptations that increase attachment efficiency (adhesion or friction per unit contact area). Available data suggest that attachment pad area scales close to isometry within clades, but pad efficiency in some animals increases with size so that attachment performance is approximately size-independent. The mechanisms underlying this biologically important variation in pad efficiency are still unclear. We suggest that switching between stress concentration (easy detachment) and uniform load distribution (strong attachment) via shear forces is one of the key mechanisms enabling the dynamic control of adhesion during locomotion. PMID:25533088

  11. Visual targeting of motor actions in climbing Drosophila.

    PubMed

    Triphan, Tilman; Poeck, Burkhard; Neuser, Kirsa; Strauss, Roland

    2010-04-13

    Drosophila melanogaster flies cross surmountable gaps in their walkway of widths exceeding their body length with an astounding maneuver but avoid attempts at insurmountable gaps by visual width estimation. Different mutant lines affect specific aspects of this maneuver, indicating a high complexity and modularity of the underlying motor control. Here we report on two mutants, ocelliless(1) and tay bridge(1), that, although making a correct decision to climb, fail dramatically in aiming at the right direction. Both mutants show structural defects in the protocerebral bridge, a central complex neuropil formed like a handlebar spanning the brain hemispheres. The bridge has been implicated in step-length control in walking flies and celestial E-vector orientation in locusts. In rescue experiments using tay bridge(1) flies, the integrity of the bridge was reestablished, concomitantly leading to a significant improvement of their orientation at the gap. Although producing directional scatter, their attempts were clearly aimed at the landing site. However, this partial rescue was lost in these flies at a reduced-visibility landing site. We therefore conclude that the protocerebral bridge is an essential part of a visual targeting network that transmits directional clues to the motor output via a known projection system.

  12. Autonomous stair-climbing with miniature jumping robots.

    PubMed

    Stoeter, Sascha A; Papanikolopoulos, Nikolaos

    2005-04-01

    The problem of vision-guided control of miniature mobile robots is investigated. Untethered mobile robots with small physical dimensions of around 10 cm or less do not permit powerful onboard computers because of size and power constraints. These challenges have, in the past, reduced the functionality of such devices to that of a complex remote control vehicle with fancy sensors. With the help of a computationally more powerful entity such as a larger companion robot, the control loop can be closed. Using the miniature robot's video transmission or that of an observer to localize it in the world, control commands can be computed and relayed to the inept robot. The result is a system that exhibits autonomous capabilities. The framework presented here solves the problem of climbing stairs with the miniature Scout robot. The robot's unique locomotion mode, the jump, is employed to hop one step at a time. Methods for externally tracking the Scout are developed. A large number of real-world experiments are conducted and the results discussed.

  13. Human climbing with efficiently scaled gecko-inspired dry adhesives.

    PubMed

    Hawkes, Elliot W; Eason, Eric V; Christensen, David L; Cutkosky, Mark R

    2015-01-06

    Since the discovery of the mechanism of adhesion in geckos, many synthetic dry adhesives have been developed with desirable gecko-like properties such as reusability, directionality, self-cleaning ability, rough surface adhesion and high adhesive stress. However, fully exploiting these adhesives in practical applications at different length scales requires efficient scaling (i.e. with little loss in adhesion as area grows). Just as natural gecko adhesives have been used as a benchmark for synthetic materials, so can gecko adhesion systems provide a baseline for scaling efficiency. In the tokay gecko (Gekko gecko), a scaling power law has been reported relating the maximum shear stress σmax to the area A: σmax ∝ A(-1/4). We present a mechanical concept which improves upon the gecko's non-uniform load-sharing and results in a nearly even load distribution over multiple patches of gecko-inspired adhesive. We created a synthetic adhesion system incorporating this concept which shows efficient scaling across four orders of magnitude of area, yielding an improved scaling power law: σmax ∝ A(-1/50). Furthermore, we found that the synthetic adhesion system does not fail catastrophically when a simulated failure is induced on a portion of the adhesive. In a practical demonstration, the synthetic adhesion system enabled a 70 kg human to climb vertical glass with 140 cm(2) of adhesive per hand.

  14. The effect of cooled perches on immunological parameters of caged White Leghorn hens during the hot summer months

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine if thermally cooled perches improved hen immunity during the hot summer months. White Leghorn pullets at 16 weeks of age were randomly assigned to 18 cages of 3 banks at 9 hens per cage. Each bank was assigned to 1 of the 3 treatments up to 32 weeks of ag...

  15. Sensory and textural attributes and fatty acid profiles of fillets of extensively and intensively farmed Eurasian perch (Percafluviatilis L.).

    PubMed

    Stejskal, V; Vejsada, P; Cepak, M; Spička, J; Vacha, F; Kouril, J; Policar, T

    2011-12-01

    Sensory attributes, texture and fatty acid profiles of fillets of Eurasian perch (Percafluviatilis L.) reared under two conditions were compared. Perch were reared either in an extensive pond-based (EC) system in polyculture with carp, or intensively cultured (IC) in a recirculation system. Attributes of raw and cooked fillets of marketable perch (120-150g) were compared. No significant differences were found between groups for odour, flavour, aftertaste, or consistency in subjective evaluation of cooked fillets. The texture profile analysis (TPA) showed raw fillets from the EC group to exhibit higher values of hardness, springiness, cohesiveness, and gumminess than the IC group. Fish from the IC group had a lower content of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) and a higher content of monounsaturated fatty acids (MUFA) in comparison to EC perch. The proportion of iso- and anteiso-SFAs was 2.6% in the EC group and 0.75% in the IC group. The content of n-3 PUFA was lower in IC than in EC, while the content of n-6 PUFA was higher in IC than in EC. The ratio of n-3:n-6 PUFA was 1.42 for the IC group and 2.85 for the EC group.

  16. 76 FR 39791 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... the most recent fisheries data in a timely fashion and would delay the closure of Pacific ocean perch... National Oceanic and Atmospheric Administration 50 CFR Part 679 RIN 0648-XA542 Fisheries of the Exclusive...: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA),...

  17. 76 FR 45709 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-01

    ... from responding to the most recent fisheries data in a timely fashion and would delay the closure of... Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the West Yakutat District of the Gulf of Alaska AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  18. Identification of gender in yellow perch by external morphology: validation in four geographic strains and effects of estradiol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    External morphological criteria that enable the rapid determination of gender have been developed for yellow perch (Perca flavescens). Criteria are based upon 1) shape of the urogenital papilla (UGP), 2) relative size of the UGP to the anal (AN) opening, and 3) coloration of the UGP. In females, t...

  19. 75 FR 43090 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Western Yakutat...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... catcher/processors participating in the limited access or opt-out fisheries that are subject to sideboard... ocean perch established for catcher/ processors participating in the limited access or opt-out fisheries... established for catcher/processors participating in the limited access or opt-out fisheries that are...

  20. 75 FR 69361 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch in the Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... available data and finds that the ITAC for Pacific ocean perch in the Bering Sea subarea needs to be... fisheries data in a timely fashion and would delay the apportionment of the non-specified reserves of... plan for the fishing season, and to avoid potential disruption to the fishing fleet and...

  1. Parasite identification, succession and infection pathways in perch fry (Perca fluviatilis): new insights through a combined morphological and genetic approach.

    PubMed

    Behrmann-Godel, Jasminca

    2013-04-01

    Identification of parasite species is particularly challenging in larval and juvenile hosts, and this hampers the understanding of parasite acquisition in early life. The work described here employs a new combination of methods to identify parasite species and study parasite succession in fry of perch (Perca fluviatilis) from Lake Constance, Germany. Classical morphological diagnostics are combined with sequence comparisons between parasite life-stages collected from various hosts within the same ecosystem. In perch fry at different stages of development, 13 different parasite species were found. Incomplete morphological identifications of cestodes of the order Proteocephalidea, and trematodes of the family Diplostomatidae were complemented with sequences of mitochondrial DNA (cytochrome oxidase 1) and/or nuclear (28 s rDNA) genes. Sequences were compared to published data and used to link the parasites in perch to stages from molluscs, arthropods and more easily identifiable developmental stages from other fishes collected in Lake Constance, which both aided parasite identification and clarified transmission pathways. There were distinct changes in parasite community composition and abundance associated with perch fry age and habitat shifts. Some parasites became more abundant in older fish, whereas the composition of parasite communities was more strongly affected by the ontogenetic shifts from the pelagic to the littoral zone.

  2. Host-parasite relationships as determinants of heavy metal concentrations in perch (Perca fluviatilis) and its intestinal parasite infection.

    PubMed

    Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana; Šalamún, Peter; Vidal-Martínez, Víctor M

    2015-12-01

    The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn and their bioconcentration factors (BCFs) were determined in two intestinal parasites, an acanthocephalan, Acanthocephalus lucii, a tapeworm, Proteocephalus percae, present in the same host, the European perch (Perca fluviatilis, L.), in the heavily polluted Ružín reservoir in eastern Slovakia. The bioaccumulation of heavy metals in the fish organs and parasites was studied for acanthocephalan and tapeworm monoinfections or mixed infections by the two parasites and for the size of their parasitic infrapopulations. Bioconcentration factors (c[parasite]/c[muscle tissue]) showed that the concentrations of As, Ni, Pb and Zn were higher in mixed infections than in monoinfections. Negative correlations between heavy metal concentrations in perch organs and the parasites were found. For example, higher concentrations of Ni and Zn in both parasite species corresponded with lower metal concentrations in perch and hard roe. Likewise, significant negative relationships between metal concentrations in fish organs and number of parasites were noticed with lower levels of Pb in fish harbouring higher numbers of tapeworms. Similarly, in both parasite species the concentrations of some essential elements (Cr, Mn) were lower at high infection intensities compared to low intensities. Our study revealed that the differential concentration of heavy metals in perch organs was affected by the type of infection (mono- or mixed-infection), and needs to be considered in field ecotoxicological and parasitological studies as a potentially important factor influencing the pollutant concentrations in fish.

  3. Use of Diets Containing Graded Levels of Distillers Dried Grains with Solubles and Soybean Meal by Yellow Perch (Perca flavescens)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A feeding trial was performed to investigate inclusion levels of distillers dried grains with solubles (DDGS) and soybean meal (SM) used in the diets of juvenile yellow perch (Perca flavescens). Six isocaloric (3.22 ± 0.02 kcal/g SE), isonitrogenous (30.1 ± 0.2% SE) experimental diets were formulate...

  4. Genetic Variation of 17 Wild Yellow Perch Populations from the Midwest and East Coast Analyzed Via Microsatellites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used microsatellite loci, including seven newly developed by us, to analyze the population genetic structure of wild yellow perch Perca flavescens from 17 sampling areas in the Upper Midwest and East Coast of the United States. Our results revealed greater genetic differentiation and finer-scale ...

  5. Influence of mineral supplementation on growth in yellow perch Perca flavescens fed a soy-based diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the nutritional requirements for the growth of yellow perch in intensive aquaculture. Consequently, commercial feed formulations are based on nutritional requirements for rainbow trout, containing large quantities of fish meal and oil which are not optimal for other species. Plant...

  6. Composition and Use of Common Carp Meal as a Marine Fish Meal Replacement in Yellow Perch Diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the use of fish meal derived from a locally abundant, non-native fish species – common carp Cyprinus carpio – with the objective of offsetting the cost of marine fish meal (MFM, ~$1,200/ton) in yellow perch Perca flavescens feed. Biochemical analyses of meals showed that crude protein a...

  7. Evolutionary change driven by metal exposure as revealed by coding SNP genome scan in wild yellow perch (Perca flavescens).

    PubMed

    Bélanger-Deschênes, Sébastien; Couture, Patrice; Campbell, Peter G C; Bernatchez, Louis

    2013-07-01

    Pollution can drive rapid evolutionary change in wild populations. This study targets functional polymorphisms of chronically metal-contaminated wild yellow perch (Perca flavescens). A de novo transcriptome scan contrasted subsets of individuals from clean (n = 16) and contaminated (n = 16) lakes to identify 87 candidate annotated coding SNPs. Candidate genotypes and liver [metal] were obtained in 10 populations (n = 1,052) and a genome scan distinguished outliers: one nuclear (cyclin G1 gene) and two mitochondrial (cytochrome b and NADH dehydrogenase subunit 2 genes) also displaying allelic correlation to mean population [cadmium]. Whole mtDNA and 17 kb surrounding cyclin G1 were characterised through 454 sequencing thus revealing two non-synonymous substitutions involving dissimilar amino acids. Based on associated functions and inter-population differentiation, contaminated perch may have been selected for fast life cycle completion (p53 pathway) and memorization impairment mitigation (long-term potentiation pathway). In accordance with predicted evolutionary trajectory for stressed and energy deprived organisms, adapted perch would not compensate for repair mechanism inhibition, instead reallocating energy towards growth and favouring inexpensive impairment mitigation adaptations over costly detoxification. Overall, 85 years of selection could have driven rapid, potentially adaptive evolution by selecting alleles increasing perch fitness in polluted environments.

  8. Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?

    USGS Publications Warehouse

    Larson, James H.; Staples, David F.; Maki, Ryan P.; Vallazza, Jon M.; Knights, Brent C.; Peterson, Kevin E.

    2016-01-01

    Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens, are unlikely to be affected in the same way by WL fluctuations because their spawning requirements are quite different. We used 11–23 years of data from six northern Minnesota lakes to assess the effects of WL fluctuations on the abundances of young-of-the-year (age-0) Walleyes and Yellow Perch. In two lakes (Rainy Lake and Lake Kabetogama), a change in WL management occurred in 2000, after which these lakes saw increased age-0 Walleye abundance, while the other study lakes experienced decreases or no change. Rainy Lake and Lake Kabetogama also had increases in age-0 Yellow Perch, but another study lake did also. We used partial least-squares regression to assess whether WL metrics were associated with variation in age-0 Walleye and Yellow Perch abundances, but WL metrics were seldom associated with age-0 abundance for either species. Our analysis suggested a potential influence of WL regulation on age-0 Walleye abundance, but we found no evidence that early spring access to spawning shoals was the mechanism by which this occurred.

  9. Development of sperm vitrification protocols for freshwater fish (Eurasian perch, Perca fluviatilis) and marine fish (European eel, Anguilla anguilla).

    PubMed

    Kása, Eszter; Bernáth, Gergely; Kollár, Tímea; Żarski, Daniel; Lujić, Jelena; Marinović, Zoran; Bokor, Zoltán; Hegyi, Árpád; Urbányi, Béla; Vílchez, M Carmen; Morini, Marina; Peñaranda, David S; Pérez, Luz; Asturiano, Juan F; Horváth, Ákos

    2016-05-09

    Vitrification was successfully applied to the sperm of two fish species, the freshwater Eurasian perch (Perca fluviatilis) and marine European eel (Anguilla anguilla). Sperm was collected, diluted in species-specific non-activating media and cryoprotectants and vitrified by plunging directly into liquid nitrogen without pre-cooling in its vapor. Progressive motility of fresh and vitrified-thawed sperm was evaluated with computer-assisted sperm analysis (CASA). Additional sperm quality parameters such as sperm head morphometry parameters (in case of European eel) and fertilizing capacity (in case of Eurasian perch) were carried out to test the effectiveness of vitrification. The vitrification method for Eurasian perch sperm resulting the highest post-thaw motility (14±1.6%) was as follows: 1:5 dilution ratio, Tanaka extender, 30% cryoprotectant (15% methanol+15% propylene-glycol), cooling device: Cryotop, 2μl droplets, and for European eel sperm: dilution ratio 1:1, with 40% cryoprotectant (20% MeOH and 20% PG), and 10% FBS, cooling device: Cryotop, with 2μl of sperm suspension. Viable embryos were produced by fertilization with vitrified Eurasian perch sperm (neurulation: 2.54±1.67%). According to the ASMA analysis, no significant decrease in head area and perimeter of vitrified European eel spermatozoa were found when compared to fresh spermatozoa.

  10. Comparative population genetic structure and diversity of Yellow Perch and Walleye: Broad- and fine-scale patterns across North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yellow perch Perca flavescens and the walleye Sander vitreus are native North American percid fishes, which have considerable fishery and ecological importance across their wide geographic ranges. Over the past century, they were stocked into new habitats, often with relative disregard for conse...

  11. Complete Genome Sequence of a Fish Nervous Necrosis Virus Isolated from Sea Perch (Lateolabrax japonicus) in China

    PubMed Central

    Jia, Peng

    2015-01-01

    We sequenced and analyzed the complete genome of a fish nervous necrosis virus isolated from diseased sea perch (Lateolabrax japonicus) in Guangdong Province, China. The virus genome contains RNA1 (3,103 bp) and RNA2 (1,433 bp). Phylogenetic analysis shows that the virus belongs to the redspotted grouper nervous necrosis virus genotype of betanodavirus. PMID:26044411

  12. Twin screw extrusion processing of distillers dried grains with solubles (DDGS)-based Yellow Perch (Perca flavescens) feeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increases in global aquaculture production, compounded with limited availabilities of fish meal for fish feed, has created the need for alternative protein sources. Twin-screw extrusion studies were performed to investigate the production of nutritionally-balanced feeds for juvenile yellow perch (Pe...

  13. Live transport of Yellow Perch and Nile Tilapia in AQUI-S 20E (10% Eugenol) at high loading densities

    USGS Publications Warehouse

    Cupp, Aaron R.; Schreier, Theresa M.; Schleis, Sue M.

    2017-01-01

    Fish transport costs are a substantial portion of the operational expenses for aquaculture facilities in the USA. Safely transporting higher loading densities of fish would benefit haulers by increasing efficiency and reducing costs, but research evaluating transport for individual species is generally lacking. In this study, Yellow Perch Perca flavescens and Nile Tilapia Oreochromis niloticus were transported for 6 h immersed in water containing AQUI-S 20E (10% eugenol) at fish loading densities of 240 g/L (2 lb/gal) for perch and 480 g/L (4 lb/gal) for tilapia. Survival was quantified for fish transported in AQUI-S 20E concentrations of (1) control or 0 mg/L of water, (2) 100 mg/L, or (3) 200 mg/L. Yellow Perch had 98–100% survival, and Nile Tilapia had 100% survival up to through 14 d after transport across all AQUI-S 20E levels, including the control. Eugenol concentrations decreased rapidly in transport tank water, and fish showed no signs of sedation by the end of transport. We conclude that live transport of Yellow Perch and Nile Tilapia at higher loading densities resulted in high survival regardless of the AQUI-S 20E concentrations we tested.

  14. Buzzcut or Fossil? Exploring the Origin of Perched Low-Relief Landscapes in the Tropics

    NASA Astrophysics Data System (ADS)

    Cunningham, M.; Stark, C. P.; Kaplan, M. R.; Schaefer, J. M.

    2014-12-01

    Throughout the tropics, high mountain regions have a "buzzcut" appearance, with low-relief spines perched high (>2500m) above deeply incised ridge-and-valley topography. Many of these mountain ranges intersect the local LGM ELA, but few studies have speculated on the role glacial erosion may have played in shaping their perched, low-relief landforms. Instead, multiple studies have invoked an abrupt increase tectonic uplift that switched the orogen from a low-relief, low erosion rate regime to a high-relief, high erosion rate mode. In this model context, perched landscapes are fossil remnants of the low-erosion rate regime, and the presence of glacial/paraglacial landforms is coincidental. However, an alternative interpretation is possible: rather than a tectonically-forced switch in erosion rate regime, low-relief spines were cut by alpine glacial erosion. To assess the influence of glacial/paraglacial processes on the formation of low-relief topography in a tropical mountain range, we conducted fieldwork at Mount Chirripó (3819m), Costa Rica. At Mount Chirripó, the estimated LGM ELA is ~3500m. River profile analysis shows a conspicuous cluster of knickpoints at ~2500m, which has been used to infer a rapid increase in regional tectonic uplift between 1-2 Ma that produced high-relief landscapes fringing ancient, low-relief landscapes. As an alternative, we hypothesize that glacial/postglacial processes acting throughout the Pleistocene played a dominant role in the formation and preservation of Mount Chirripó's low-relief spine. At Mount Chirripó, we identified glacial erosion features between 3400-3800m, including moraines, striated bedrock, glacial till, glaciofluvial outwash and post-glacial landslides. Additionally, we observed a low-sloping valley floored by angular debris at ~3100m that we interpret to be of glacial origin. We collected samples for surface exposure age dating from erratics, striated bedrock, and landslide debris boulders. Mapping of

  15. Perched water during steady infiltration in a gradually layered soil: some theoretical results

    NASA Astrophysics Data System (ADS)

    Barontini, Stefano; Ranzi, Roberto

    2010-05-01

    Due to the genetic layering, the hydraulic conductivity at saturation Ks is usually expected to decrease across the upper soil layers. Its effect on the soil hydrological properties is related to a number of landslide triggering mechanisms. Key information in order to evaluate the soil stability are the threshold of the infiltration rate for a saturated layer or a perched water to onset, its depth, the maximum pressure head and the water content profile above the saturated soil. Anyway if Ks is gradually decreasing, as often observed in the uppermost soil layers or in mountain not-mature soils, the position of a perched water can be a priori not known, nor could be the position of the maximum pressure head. These topics were theoretically discussed considering an undeformable soil layer of finite depth, characterised by gradually and monotonically decreasing Ks, in which a steady one-dimensional infiltration takes place at a rate i. At the bottom of the domain a saturation condition was assumed. Two classes of soil constitutive laws were considered in order to represent the unsaturated soil behaviour. They are respectively characterised by a finite and by an infinite slope of the hydraulic conductivity K(φ) (where φ is the matric potential) as approaching the soil saturation. The theoretical results were particularized for a soil with exponentially decreasing Ks and the profiles of the hydrological properties were determined by analytical solutions of the Darcy's law. The analyses suggested the definition of a threshold for the infiltration rate i for the perched water to onset, and allowed to determine the characteristics of the saturated layer, its pressure head profile and the position of the maximum pressure head as a function of the infiltration rate. Moreover, the hydrological properties profiles obtained for the overlaying unsaturated soil stressed the high sensitivity of the solution to the K(φ) model near saturation. The stronger is the reduction of K

  16. Lipophilic antioxidants and lipid peroxidation in yellow perch subjected to various anthropogenic influences along the St. Lawrence River (QC, Canada).

    PubMed

    Landry, Catherine; Houde, Magali; Brodeur, Philippe; Spear, Philip; Boily, Monique

    2017-05-01

    In Lake Saint-Pierre (LSP), the last great widening of the St. Lawrence River (province of Québec, Canada), the yellow perch has been experiencing a significant decline since the mid-1990s. The combined effect of several stressors (deterioration of habitats appropriate for reproduction and growth, invasive species and poor water quality) seems to exert considerable influence on the yellow perch population in LSP, characterized by low recruitment. To better understand possible stressor effects at the biochemical level, LSP yellow perch were compared with other sites along a gradient of increasing human influences from upstream to downstream along the St. Lawrence River. Morphometry (size, weight, circumference and Fulton's condition factor) and biomarkers associated to the peroxidation of lipids, lipophilic antioxidants (α-tocopherol and carotenoids), along with retinoids (vitamins A1and A2) and proteins were compared between sites at the larval, juvenile and adult stages. Fulton's condition factor was similar between sites for juveniles but was significantly lower in LSP adults, suggesting a weakened physiological condition. In most contaminated sites as LSP, lipid peroxidation tended to be higher in juveniles and adults whereas the lipophilic antioxidant lycopene and proteins content were lower. Retinyl esters were significantly lower for LSP fish compared to other sites, not only in larvae but also in the livers of juveniles and adults. These results are consistent with possible altered metabolism in the retinoid system of LSP yellow perch. The overall results reflect the "pressure" gradient tested, where the yellow perch from the most affected sites located downstream had impaired physiological and biochemical conditions compared to the upstream sectors.

  17. Tropical fish in a warming world: thermal tolerance of Nile perch Lates niloticus (L.) in Lake Nabugabo, Uganda

    PubMed Central

    Chrétien, Emmanuelle; Chapman, Lauren J.

    2016-01-01

    Key to predicting the response of fishes to climate change is quantifying how close fish are to their critical thermal limits in nature and their ability to adjust their thermal sensitivity to maintain performance. Here, we evaluated the effects of body size and habitat on aerobic scope (AS) and thermal tolerance of Nile perch Lates niloticus (L.), a fish of great economic and food security importance in East Africa, using respirometry and critical thermal maximum (CTmax) trials. Juvenile Nile perch from distinct habitats (high or low dissolved oxygen concentrations) of Lake Nabugabo, Uganda were exposed for 4.6 ± 0.55 days to a temperature treatment (25.5, 27.5, 29.5 or 31.5°C) prior to experimentation, with the lowest temperature corresponding to the mean annual daytime temperature in Lake Nabugabo and the highest temperature being 3°C higher than the maximal monthly average. As expected, metabolic rates increased with body mass. Although resting metabolic rate increased with temperature, maximal metabolic rate showed no change. Likewise, AS did not vary across treatments. The CTmax increased with acclimation temperature. There was no effect of habitat on maximal metabolic rate, AS or CTmax; however, there was a trend towards a lower resting metabolic rate for Nile perch captured in the low-dissolved oxygen habitat than in well-oxygenated waters. This study shows that juvenile Nile perch maintain a large AS at temperatures near the upper limit of their natural thermal range and provides evidence that Nile perch have physiological mechanisms to deal with acute exposure to thermal stress. PMID:27990290

  18. Identifying across-system sources of variation in a generalist freshwater fish: Correlates of total and size-specific abundance of yellow perch

    USGS Publications Warehouse

    Carey, M.P.; Mather, M. E.

    2009-01-01

    Variation in fish abundance across systems presents a challenge to our understanding of fish populations because it limits our ability to predict and transfer basic ecological principles to applied problems. Yellow perch (Perca flavescens) is an ideal species for exploring environmental and biotic correlates across system because it is widely distributed and physiologically tolerant. In 16 small, adjacent systems that span a wide range of environmental and biotic conditions, yellow perch were sampled with a standard suite of gear. Water quality, morphometry, vegetation, invertebrates and fish communities were concurrently measured. Multimodel inference was used to prioritise regressors for the entire yellow perch sample and three size groups (35-80, 81-180, ???181 mm TL). Across systems, pH and fish richness were identified as the key drivers of yellow perch abundance. At very low pH (4.8) had many other species and few yellow perch. Similar patterns for pH and fish community were observed for the two largest-size classes. Negative interactions were observed between the medium- and large-sized yellow perch and between the largest and smallest yellow perch, although interspecific interactions were weaker than expected. This examination of variability for an indicator species and its component-size classes provides ecological understanding that can help frame the larger-scale sampling programs needed for the conservation of freshwater fish. ?? 2008 Blackwell Munksgaard.

  19. Individuals' diet diversity influences gut microbial diversity in two freshwater fish (threespine stickleback and Eurasian perch)

    PubMed Central

    Bolnick, Daniel I; Snowberg, Lisa K; Hirsch, Philipp E; Lauber, Christian L; Knight, Rob; Caporaso, J Gregory; Svanbäck, Richard; Post, David

    2014-01-01

    Vertebrates' diets profoundly influence the composition of symbiotic gut microbial communities. Studies documenting diet-microbiota associations typically focus on univariate or categorical diet variables. However, in nature individuals often consume diverse combinations of foods. If diet components act independently, each providing distinct microbial colonists or nutrients, we expect a positive relationship between diet diversity and microbial diversity. We tested this prediction within each of two fish species (stickleback and perch), in which individuals vary in their propensity to eat littoral or pelagic invertebrates or mixtures of both prey. Unexpectedly, in most cases individuals with more generalised diets had less diverse microbiota than dietary specialists, in both natural and laboratory populations. This negative association between diet diversity and microbial diversity was small but significant, and most apparent after accounting for complex interactions between sex, size and diet. Our results suggest that multiple diet components can interact non-additively to influence gut microbial diversity. PMID:24847735

  20. Parameterization of European perch Perca fluviatilis length-at-age data using stochastic Gompertz growth models.

    PubMed

    Troynikov, V S; Gorfine, H K; Ložys, L; Pūtys, Z; Jakubavičiūtė, E; Day, R W

    2011-12-01

    Three stochastic versions of the Gompertz growth model were used to parameterize total length (L(T) )-at-age data for perch Perca fluviatilis, an important target species for commercial and recreational fishers and a food species for predatory fishes and aquatic birds. Each model addresses growth heterogeneity by incorporating random parameters from a specific positive distribution: Weibull, gamma or log-normal. The modelling outputs for each version of the model provide L(T) distributions for selected ages and percentiles of L(T) at age for both males and females. The results highlight the importance of using a stochastic approach and the logistic-like growth pattern for analysing growth data for P. fluviatilis in Curonian Lagoon (Lithuania). Outputs from this modelling can be extended to a stochastic analysis of fish cohort dynamics, incorporating all length-based biological relationships, and the selectivity-related interactions between fish cohorts and fishing gear.