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Sample records for squat lobsters munida

  1. A new species of squat lobster of the genus Munida (Galatheoidea, Munididae) from the Red Sea

    KAUST Repository

    Macpherson, E.

    2017-08-30

    During a deep-water expedition to the Red Sea in 2013, an unusual specimen of squat lobster belonging to the genus Munida was collected off Thuwal, Saudi Arabia, at a depth of 320 m. This specimen is unique in having the pterygostomial flap visible from the dorsal side, the feature linking it to two eastern Pacific species, M. bapensis Hendrickx, 2000 and M. macrobrachia Hendrickx, 2003. The new species (M. tuerkayi) is readily distinguished from the eastern Pacific species by having the gastric region with numerous instead of less numerous spines, by having sternite 7 with three distinct carinae on each side, and by having the antennular basal article with two distal spines subequal instead of different in size. Munida tuerkayi was found associated with live colonies of the scleractinian coral Eguchipsammia fistula (Alcock, 1902).

  2. Function and functional groupings of the complex mouth apparatus of the squat lobsters Munida sarsi Huus and M. tenuimana G.O. Sars (Crustacea: Decapoda)

    DEFF Research Database (Denmark)

    Garm, A; Høeg, J T

    2001-01-01

    Like all other decapods, the anomuran squat lobsters Munida sarsi and M. tenuimana have a mouth apparatus composed of six pairs of mouthparts plus labrum and paragnaths (upper and lower lips). To study the functional significance of this complexity, we examined the mouthparts with scanning electron...

  3. Functional mouthpart morphology of the squat lobster Munida sarsi, with comparison to other anomurans

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Høeg, Jens Thorvald

    2000-01-01

    The mouthparts of Munida sarsi Huus, 1935, including the labrum and paragnaths, are described using LM and SEM, with special attention to the setal composition and its function. We also used high-resolution macrovideo equipment to record the feeding processes and monitor setae in action. This com...

  4. Growth and reproduction investment of the young of the year of the squat lobster Munida gregaria (Crustacea: Anomura in the Patagonian coast

    Directory of Open Access Journals (Sweden)

    Martin Varisco

    2015-09-01

    Full Text Available The growth and reproduction investment of the young of the year (0+ of the squat lobster Munida gregaria in San Jorge Gulf, Argentina, were analysed. Moult cycle and size frequency distribution were studied in monthly field samples. Experiments to determine moult increments and intermoult duration were conducted. Sexual maturity, fecundity and reproductive output were analysed in field samples. In addition, maturity experiments in laboratory cultures were conducted. After settlement (November, juveniles showed fast growth until winter (July and growth restarted in September-October. At the beginning of the mating period (early June, males 0+ exhibited mature gonads, whereas females 0+ only showed previtellogenic oocytes. Experimental data showed that females with developed gonads had smaller-size increments in the previous moult. Fecundity and reproductive output were significantly lower in females 0+ than in older females. The early life history of M. gregaria in San Jorge Gulf differs from that of southern populations as those of Beagle Channel and Strait of Magellan due to faster growth and early reproductive investment. Our results suggest that females 0+ of M. gregaria have two investment strategies: early maturity with low fecundity and delayed maturity with higher future fecundity.

  5. Galatheoid squat lobsters (Crustacea: Decapoda: Anomura from Korean waters

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    Jung Nyun Kim

    2016-10-01

    Full Text Available Abstract Ten species of Galatheoidea (squat lobsters, belonging to two families, were collected in the Korean exclusive economic zone: Galathea balssi Miyake and Baba, 1964, Galathea orientalis Stimpson, 1858, Galathea pubescens Stimpson, 1858, and Galathea rubromaculata Miyake and Baba, 1967 belonging to Galatheidae; Bathymunida brevirostris Yokoya, 1933, Cervimunida princeps Benedict, 1902, Munida caesura Macpherson and Baba, 1993, Munida japonica Stimpson, 1858, Munida pherusa Macpherson and Baba, 1993, and Paramunida scabra (Henderson, 1885 belonging to Munididae. The present study comprises the morphological description of these ten species, including drawings and color photographs, a brief review of their regional records, and a key for their identification. Although all species are common in Japanese waters, G. balssi, G. rubromaculata, B. brevirostris, C. princeps, M. caesura, and M. pherusa are new to Korean marine fauna.

  6. New sibling species and new occurrences of squat lobsters (Crustacea, Decapoda from the western Indian Ocean

    Directory of Open Access Journals (Sweden)

    Enrique Macpherson

    2017-08-01

    Full Text Available Numerous specimens of squat lobsters belonging to the families Munididae, Munidopsidae and Eumunididae were collected during several cruises along the eastern coasts of Africa. The study of these specimens revealed the presence of 10 new species (one Eumunida Smith, 1883, eight Munida Leach, 1820 and one Munidopsis Whiteaves, 1874. We describe and illustrate these new species, providing some new data on occurrences and colour patterns for previously described taxa. We have also included molecular data from two mitochondrial markers (16S rRNA and COI to support the taxonomic status of different species. Some deep-sea species show a clear increase in their geographic range distribution. Finally, a key to known species of the genus Munida from the western and central Indian Ocean is also presented.

  7. Squat lobsters (Crustacea: Anomura) from Mauritanian waters (West Africa), with the description of a new species of Munidopsis.

    Science.gov (United States)

    De Matos-Pita, Susana S; Ramil, Fran

    2014-02-20

    This paper is the result of the study of a squat lobsters collection obtained along the Mauritanian coast, between 91 and 1867 m depth, during the 'MAURIT' surveys carried out in the period from 2007 to 2010. Eumunida bella de Saint Laurent & Macpherson, 1990 (Chirostyloidea) and six species of Munida and Munidopsis (Galatheoidea) are reported in the present work.A new species, Munidopsis anaramosae n. sp. collected off northwestern Banc d'Arguin at 1000-1012 m depth, is described and illustrated. The presence of an eyespine that arises distally from the middle end of the cornea, walking legs merus spinose on dorsal and ventral margins and cheliped merus ventrally unarmed distinguish it from related species. Munida chunii Balss, 1913 is redescribed here and the new records of Munida guineae Miyake & Baba, 1970, M. speciosa von Martens, 1878 and Munidopsis chunii Balss, 1913 extend their geographical distribution northwards, and in the case of the last species, increase its bathymetric range.

  8. Reproductive biology of galatheoid and chirostyloid (Crustacea: Decapoda) squat lobsters from the Gulf of Mexico.

    Science.gov (United States)

    Kilgour, Morgan J; Shirley, Thomas C

    2014-01-16

    Reproductive timing, fecundity, and average egg sizes were examined for galatheoid and chirostyloid squat lobster collections from the Gulf of Mexico. While congeners did not always significantly differ in egg size or timing, each genus had a unique average egg diameter size which may indicate whether the developing embryos will be lecithotrophic or planktotrophic larvae. The eggs of Eumunididae, Galatheidae, and Munididae were more numerous and smaller than the larger and less abundant eggs of Chirostylidae and Munidopsidae. With the exception of members of the Munididae, members of genera within the same family had distinct egg diameters. Ovigerous females were significantly larger than non-ovigerous females in some species (i.e., Uroptychus nitidus, Munida forceps, Galacantha spinosa, Munidopsis abbreviata, M. alaminos, M., erinacea, M. robusta, M. sigsbei, and M. simplex). Munidopsis erinacea and Munida affinis males were significantly larger than females; the reverse was true for Munidopsis robusta and Munidopsis simplex. All other species studied did not have a significant difference between males and females. The spatial and bathymetric ranges for many species are extended in this study from prior reports. Seasonality of reproduction was evident in few species, but this may be a result of limited sample sizes.

  9. Variation in cheliped form in two species of squat lobsters (Decapoda: Anomura from Chile

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    Aníbal H. Lezcano

    2015-09-01

    Full Text Available AbstractThe current study describes the variation in cheliped form of two species of squat lobsters that inhabit the continental margin off Chile: Cervimunida johni and Pleuroncodes monodon. We compared their cheliped form in the context of the reproductive strategy. The general tendency of form variation of both species is similar: chelipeds change, on average, from longer and narrower pollex with short manus to a relatively shorter and wider pollex with longer manus from small to large individuals, respectively. The degree of cheliped arching was greater in males than in females of similar carapace length, and only C. johni males showed fully arched morphology. The allometric trajectories (cheliped shape vs. carapace length were largely aligned with vectors of mean shape difference in both species. Cheliped form variation of C. johni (extended mate-guarding resembles the cheliped morphology reported for the related species Munida rugosa more than P. monodon (short mate-guarding. Our results are consistent with previous finding and suggest that the cheliped form variation (from straight and slender to a fully arched morphology is, or has been, subject to sexual selection through male-male competition for mates.

  10. Southern high latitude squat lobsters II: description of Uroptychus macquariae sp. nov. from Macquarie Ridge.

    Science.gov (United States)

    Schnabel, Kareen E; Burghardt, Ingo; Ahyong, Shane T

    2017-11-23

    Squat lobsters have only recently been recorded from the Macquarie Ridge, which extends south between New Zealand and Antarctica. Among these, Uroptychus insignis (Henderson, 1885) was recorded for the first time outside the western Indian Ocean, exhibiting only subtle morphological differences. Reexamination of the Macquarie Ridge and Indian Ocean specimens attributed to U. insignis using morphological and molecular data revealed the Macquarie Ridge form to represent a separate species. Subtle but consistent morphological differences are evident and partial CO1 sequence data indicates that the specimens collected on Macquarie Ridge differ from those collected in the Indian Ocean by more than 7%. The Macquarie Ridge species is described herein as Uroptychus macquariae n.sp. Subtle morphological differences between the new species and U. insignis are discussed.

  11. Evolutionary morphology of the organ systems in squat lobsters and porcelain crabs (crustacea: Decapoda: Anomala): an insight into carcinization.

    Science.gov (United States)

    Keiler, Jonas; Richter, Stefan; Wirkner, Christian S

    2015-01-01

    Porcelain crabs (Porcellanidae) are one of three taxa within anomuran crustaceans (Anomala) which possess a crab-like body form. Curiously, these three lineages evolved this shape independently from true crabs (Brachyura) in the course of the evolutionary process termed carcinization. The entire pleon in porcelain crabs is flexed under the cephalothorax and the carapace is approximately as broad as long. Despite their crab-like habitus, porcelain crabs are phylogenetically nested within squat lobsters (Munidopsidae, Munididae, Galatheidae). With a pleon which is only partly flexed under the cephalothorax and a cephalothorax which is longer than it is broad, squat lobsters represent morphologically intermediate forms between lobster-like and crab-like body shapes. Carcinization has so far mostly been studied with respect to outer morphology; however, it is evident that internal anatomical features are influenced through this change of body shape too. In this paper, the situation in Galatheoidea is elucidated by adding more taxa to existing descriptions of the hemolymph vascular systems and associated structures and organs. Micro-computer tomography and 3D reconstruction provide new insights. Autapomorphic states of various internal anatomical characters are present in nearly all the studied species, also reflecting some degree of anatomical disparity found within Galatheoidea. The ventral vessel system of porcelain crabs differs distinctly from that of squat lobsters. The differences in question are coherent (i.e. structural dependent) with morphological transformations in the integument, such as the shortening of the sternal plastron, which evolved in the course of carcinization. Shifts in the gonads and the pleonal neuromeres are coherent with the loss of the caridoid escape reaction, which in turn is a consequence of carcinization. The arterial transformations, however, are minor compared to other instances of carcinization in anomuran crustaceans since the last

  12. Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys - a review, with description of a new species of Munidopsis.

    Science.gov (United States)

    Hyžný, M; Gašparič, R; Robins, C M; Schlögl, J

    2014-10-01

    All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri , from the Lower and Middle Miocene, respectively. Munidopsis is represented by two species in the study area; additional data for M. lieskovensis from the Lower Miocene of Slovakia are presented and a new species, M. palmuelleri , from the Middle Miocene of Slovenia is erected. Implications for palaeoenvironmental reconstructions are briefly discussed for each taxon.

  13. Galatheoidea are not monophyletic - molecular and morphological phylogeny of the squat lobsters (Decapoda: Anomura) with recognition of a new superfamily.

    Science.gov (United States)

    Schnabel, K E; Ahyong, S T; Maas, E W

    2011-02-01

    The monophyletic status of the squat lobster superfamily Galatheoidea has come under increasing doubt by studies using evidence as diverse as larval and adult somatic morphology, sperm ultrastructure, and molecular data. Here we synthesize phylogenetic data from these diverse strands, with the addition of new molecular and morphological data to examine the phylogeny of the squat lobsters and assess the status of the Galatheoidea. A total of 64 species from 16 of the 17 currently recognised anomuran families are included. Results support previous work pointing towards polyphyly in the superfamily Galatheoidea and Paguroidea, specifically, suggesting independent origins of the Galatheidae+Porcellanidae and the Chirostylidae+Kiwaidae. Morphological characters are selected that support clades resolved in the combined analysis and the taxonomic status of Galatheoidea sensu lato is revised. Results indicate that Chirostylidae are more closely related to an assemblage including Aegloidea, Lomisoidea and Paguroidea than to the remaining Galatheoidea and are referred to the superfamily Chirostyloidea to include the Chirostylidae and Kiwaidae. A considerable amount of research highlighting morphological differences supporting this split is discussed. The Galatheoidea sensu stricto is restricted to the families Galatheidae and Porcellanidae, and diagnoses for both Chirostyloidea and Galatheoidea are provided. Present results highlight the need for a detailed revision of a number of taxa, challenge some currently used morphological synapomorphies, and emphasise the need for integrated studies with wide taxon sampling and multiple data sources to resolve complex phylogenetic questions. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys – a review, with description of a new species of Munidopsis

    Science.gov (United States)

    Hyžný, M.; Gašparič, R.; Robins, C.M.; Schlögl, J.

    2015-01-01

    All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri, from the Lower and Middle Miocene, respectively. Munidopsis is represented by two species in the study area; additional data for M. lieskovensis from the Lower Miocene of Slovakia are presented and a new species, M. palmuelleri, from the Middle Miocene of Slovenia is erected. Implications for palaeoenvironmental reconstructions are briefly discussed for each taxon. PMID:26005283

  15. [Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys – a review, with description of a new species of Munidopsis

    NARCIS (Netherlands)

    Hyžný, M.; Gašparič, R.; Robins, C.M.; Schlögl, J.

    2014-01-01

    All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri, from the Lower and Middle Miocene,

  16. [Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys – a review, with description of a new species of Munidopsis: erratum

    NARCIS (Netherlands)

    Hyžný, M.; Gašparič, R.; Robins, C.M.; Schlögl, J.

    2015-01-01

    All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri, from the Lower and Middle Miocene,

  17. [Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Pristinaspinidae, a new family of Cretaceous kiwaiform stem-lineage squat lobster (Anomura, Chirostyloidea)

    NARCIS (Netherlands)

    Ahyong, S.T.; Roterman, C.N.

    2014-01-01

    The chirostyloid squat lobster Pristinaspina gelasina from the Upper Cretaceous of Alaska is most closely related to members of the genus Kiwa (Kiwaidae) as indicated by the presence of supraocular spines, a medially carinate rostrum and similar carapace groove patterns. Evidence from morphology,

  18. Ship Squat

    OpenAIRE

    Jelenko Švetak

    2012-01-01

    Although a recognised phenomenon affecting a vessel, particularlyin shallow and confined wate1ways, squat is difficult tocalculate, quantify and apply.Many different factors affect its impact. It is always a predictedfigure, depending on factors that may at any given timebe unknown or difficult to asce11ain with any degree of accuracy.It involves, but is not limited to the input of informationfrom the vessel's particulars, as well as those of the limitationsof the wale/Way to be transited, tr...

  19. Lobster Logbook Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NWHI lobster trap fishery, which commenced in the mid-1970s, is a multispecies fishery and primarily targets the Hawaiian spiny lobster (Panuliris marginatus)...

  20. Tamaños de muestra para estimar la estructura de tallas de las capturas de langostino colorado en la zona centro-norte de Chile: una aproximación a través de remuestreo Sample sizes for estimating the catch size distribution of squat lobster in north-central Chile: a resampling approach

    Directory of Open Access Journals (Sweden)

    Carlos Montenegro Silva

    2009-01-01

    Full Text Available Se analizó el desempeño de distintos tamaños de muestra para estimar la composición de tallas de las capturas del langostino colorado (Pleuroncodes monodon, a partir de un procedimiento de remuestreo computacional. Se seleccionaron datos recolectados en mayo de 2002 entre los 29°10'S y 32°10'S. A partir de éstos, se probaron siete escenarios de muestreo de viajes de pesca (1-7 viajes, 12 escenarios de número de ejemplares muestreados (25, 50,...300, cada 25 ejemplares y dos estrategias de muestreo de lances de pesca al interior de un viaje de pesca (censo de lances y muestreo sistemático. Se probó la combinación de todos estos escenarios, lo que permitió analizar el desempeño de 168 escenarios de tamaño de muestra para estimar la composición de tallas por sexo. Los resultados indicaron una disminución en el índice de error en la estimación de la distribución de frecuencia de tallas, conforme aumentó el número de viajes de pesca, con disminuciones progresivamente menores entre escenarios adyacentes. Del mismo modo, se verificó una disminución en el índice de error al aumentar el número de ejemplares muestreados, con mejoras marginales sobre los 175 ejemplares.The performances of different sample sizes for estimating the size distribution of squat lobster (Pleuroncodes monodon catches were analyzed using a computer resampling procedure. The data selected were gathered in May 2002 between 29°10'S and 32°10'S. These data were used to test seven sampling scenarios for fishing trips (1-7 trips, twelve scenarios of the number of individuals sampled per tow (25, 50,..., 300, and two within-trip sampling strategies (sampling all tows and systematic tow sampling. By testing the combination of all these scenarios, we were able to analyze the performance of 168 scenarios of sample size for estimating the composition of sizes by sex. The results indicate a lower error index for estimates of the size frequency distribution as the

  1. The Lobster Mission

    Science.gov (United States)

    Barthelmy, Scott

    2011-01-01

    I will give an overview of the Goddard Lobster mission: the science goals, the two instruments, the overall instruments designs, with particular attention to the wide-field x-ray instrument (WFI) using the lobster-eye-like micro-channel optics.

  2. A Better ARED Squat

    Science.gov (United States)

    Caldwell, E. E.; Newby, N. J.; Ploutz-Snyder, L.

    2014-01-01

    The 0-G ARED squat under loads the legs relative to the 1g ARED squat. In 1g the knee extensor/flexor muscles are primarily engaged due to the body's center of gravity is behind the knees during the motion of the squat. As body weight does not play a sufficient role 0 G, a crewmember's load exposure is limited by the load delivered by ARED through the exercise bar. Prescription loads for lowerbody resistance exercise in microgravity aim to include 1-G exercise bar load in addition to the crewmember's Earth body weight (BW); however, pressure points from the bar and the 1BW increased load at the shoulders translating to higher loads on the back have been a historical limitation for shoulders, requiring a decrease in exercise load at the start of the mission. Analogous to crewmembers, bed rest subjects report limitations of exercising with high loads on the back while performing squats on the horizontal exercise fixture (HEF), a custom exercise device that serves as an analog to 0-G ARED. Improvements for increasing loads on the HEF squat were suggested by distributing total exercise load between the hips and the bar1. The same is recommended for the 0-G ARED squat, with using current equipment on the ISS, which include the T2 running harness and T2 bungees. Quantification of this improvement has been accessed through computational modeling. The purpose of this study is to characterize joint torque during a squat with a distribution in exercise load on the ARED in 0 G. The analysis used existing models from NASA's Digital Astronaut Project. The biomechanics squat model was integrated with the ARED model and T2 bungees. The spring constant for the bungees were derived from ground testing. Forward dynamic simulation was performed for various conditions including anchor point attachments on the footplate of the ARED, bar load, hip load, and gravitational environment. The model confirms joint torques at knees is lower relative to 1G conditions primarily because the load

  3. Punk and Anarchist Squats in Poland

    OpenAIRE

    Donaghey, Jim

    2017-01-01

    Squats are of notable importance in the punk scene in Poland, and these spaces are a key aspect of the relationship between anarchism and punk. However, the overlap of squatting, punk, and anarchism is not without its tensions. This article, drawn from ethnographic research carried out between 2013 and 2014, explores the issues around punk and anarchist squats in Poland, looking at: criticisms levelled at punk squats by ‘non-punk’ squatting activists (e.g. Przychodnia in Warsaw); instances of...

  4. Lobster trap detection at the Saba Bank

    NARCIS (Netherlands)

    Beek, van I.J.M.

    2012-01-01

    According to previous studies and anecdotal evidence there are a lot of lost lobster traps at the Saba Bank. One study estimated the loss to be between 210 and 795 lobster traps per year. The Saba Bank is an approximately 2,200 km2 submerged area and spiny lobster (Panulirus argus) is one of the

  5. Entrer dans les squats ouverts

    OpenAIRE

    2015-01-01

    Au cœur des métropoles françaises émergent ici et là des squats, lieux d’habitation et de création affranchis, tournés vers la ville et ses habitants. Vivre en squat constitue un mode de vie, un choix subversif, une forme de résistance au système, autant qu’un recours face aux difficultés sociales. Ce livre nous plonge dans les squats « ouverts » et saisit, par la sociologie, le quotidien de ces populations mouvantes et fortement hétérogènes. Il répond à des questions simples. Qui sont ces sq...

  6. Optical sensor for measuring American Lobster vitality

    International Nuclear Information System (INIS)

    Tomassetti, Brian R. A.; Vetelino, John F.

    2011-01-01

    The vitality of the American Lobster (Homarus americanus) is correlated to the total hemolymph protein (THP) in lobster hemolymph (blood). The standard technique for determining lobster vitality is to draw blood from a lobster and measure THP with a refractometer. This technique is invasive and endangers the lobster's health since blood must be drawn from the lobster. In the present work an optical sensor is developed to measure a lobster's vitality in vivo. It is comprised of a broadband light source, a monochromator, a fiber optic reflection probe, a spectrometer and a computer. This sensor measures protein concentrations by exciting a lobster with 280 nm and 334 nm wavelength light sources and measuring the corresponding absorbance peaks for THP and the fluorescence peak for hemocyanin (Hc), the majority protein in hemolymph. In this work several lobsters are tested. For each lobster, absorbance and fluorescence peaks are measured using the sensor and compared to protein concentrations measured using a refractometer. It is found that the shell thickness and muscle density, which correspond directly to protein concentration and the molting stage of the lobster have a significant effect on the absorbance and fluorescence measurements. It is also found that within specific molting stages, such as pre-molt and post-molt, protein concentration measured with a refractometer correlates linearly to absorbance and fluorescence measurements with the optical sensor.

  7. Optical Sensor for Measuring American Lobster Vitality

    Science.gov (United States)

    Tomassetti, Brian R. A.; Vetelino, John F.

    2011-06-01

    The vitality of the American Lobster (Homarus americanus) is correlated to the total hemolymph protein (THP) in lobster hemolymph (blood). The standard technique for determining lobster vitality is to draw blood from a lobster and measure THP with a refractometer. This technique is invasive and endangers the lobster's health since blood must be drawn from the lobster. In the present work an optical sensor is developed to measure a lobster's vitality in vivo. It is comprised of a broadband light source, a monochromator, a fiber optic reflection probe, a spectrometer and a computer. This sensor measures protein concentrations by exciting a lobster with 280 nm and 334 nm wavelength light sources and measuring the corresponding absorbance peaks for THP and the fluorescence peak for hemocyanin (Hc), the majority protein in hemolymph. In this work several lobsters are tested. For each lobster, absorbance and fluorescence peaks are measured using the sensor and compared to protein concentrations measured using a refractometer. It is found that the shell thickness and muscle density, which correspond directly to protein concentration and the molting stage of the lobster have a significant effect on the absorbance and fluorescence measurements. It is also found that within specific molting stages, such as pre-molt and post-molt, protein concentration measured with a refractometer correlates linearly to absorbance and fluorescence measurements with the optical sensor.

  8. POSSIBILITIES OF CULTURING BIG SEA CRABS (LOBSTERS, SPINY LOBSTERS

    Directory of Open Access Journals (Sweden)

    Ivančica Strunjak-Perović

    1999-09-01

    Full Text Available By the end of the 19 th century an experimental work on culturing big sea crabs began in Europe and North America. Great demand for their flesh as well as their high price urged many institutions to explore the possibilities of a commercial production in varios parts of the world. Lobsters (Homarus sp. were mainly used for experimenting, so that the most data available refer to them. Because of the complicated larva stage spiny lobster culturing is mainly being carried out in experimental circumstances. Despite the promissing results this aquacultural activity faces many problems (long time until they achieve a commercial size, loss of eggs due to stress sensitivity during the process of moulting, canibalism. In order to minimize these problems various researches are being carried out, like temperature influence, influence of light, way of feeding, hormonal regulation of moulting frequency. Although both lobster and spiny lobsters live in the Adriatic Sea, there are no data on their culturing in our contry. Concernig conditions in our sea there are realistic possibilities for crabs production development. In this way this delicacy would be more affordable to broader population and could be a highly rated export product.

  9. A comparison of muscle activation between back squats and belt squats.

    Science.gov (United States)

    Evans, Thomas W; McLester, Cherilyn N; Howard, Jonathan H; McLester, John R; Calloway, Jimmy P

    2017-06-08

    A machine belt squat is a piece of equipment designed to allow the performance of squats while loading weight on the lifter's hips using a belt. The purpose of this investigation was to determine if belt squats differ from back squats in activation of the primary movers, and to determine the predictive capabilities of back squat load, training status, and anthropometric data on belt squat load. Thirty-one participants (16 males and 15 females) completed anthropometric measurements, a demographic questionnaire, a familiarization visit, and two testing visits, completing a 5 repetition maximum test for back squat and belt squat. Surface electromyography was used to measure muscle activation for the left and right vastus medialis (VMO), vastus lateralis (VLO), rectus femoris (RF), and gluteus maximus (GM). Comparison of muscle activation between the two exercises showed significant differences in the left GM (back squat: 0.84 ± 0.45, belt squat: 0.69 ± 0.22, p=0.015) and right GM (back squat: 0.86 ± 0.45, belt squat: 0.71 ± 0.29, p=0.004). Regression analysis computed significant prediction equations for belt squat load for general population, males, females, and advanced lifters. Overall, results indicate that belt squats may significantly differ in GM activation from back squats. Back squat load, as well as other variables, may be effective in accurately estimating appropriate belt squat load. These findings may help to more appropriately program for training with machine belt squats as a back squat alternative.

  10. EVALUATION OF FISHING LOBSTERS PALINURUS ELEPHAS (FABRICIUS, 1787 BY LOBSTER TRAPS IN THE MIDDLE ADRIATIC SEA

    Directory of Open Access Journals (Sweden)

    Perica Cetinić

    1997-04-01

    Full Text Available The work contains the results of fishing lobsters Palinurus elephas by lobsters traps from Komiža, island Vis with one eye side size of 60 mm as well as the evaluation of its effect to their population. The correct size of her eye was evaluated by the analysis of representation of immature lobsters in the catchs of the lobsters traps. 171 examples of lobsters were analyzed (116 males and 55 females with their lengths ranging from 22 to 45 cm. Total of 53 units (31% were less than 28 mm and at that length lobsters are barred from catch and transport. Such a length has been regulated by the valid Regulation on protection of fish and other sea organisms. Therefore, the lobster trap from Komiža, island Vis was evaluated as having the negative impact on the lobsters population.

  11. HOW MANY LOBSTERS ARE IN THE SEA?

    Directory of Open Access Journals (Sweden)

    Ernest Enns

    2011-05-01

    Full Text Available A lobster fishery must have a reasonable estimate of the number of lobsters within the fishery in order to regulate the annual harvest. Stereological sampling procedures are used to estimate the number of lobsters in a defined region of the sea. From a given point in the fishery, a selective sample in a random direction to the boundary of the fishery is taken. This is repeated to generate a systematic sample from which the total population is estimated.

  12. Decline eccentric squats increases patellar tendon loading compared to standard eccentric squats

    DEFF Research Database (Denmark)

    Kongsgaard, M; Aagaard, P; Roikjaer, S

    2006-01-01

    Recent studies have shown excellent clinical results using eccentric squat training on a 25 degrees decline board to treat patellar tendinopathy. It remains unknown why therapeutic management of patellar tendinopathy using decline eccentric squats offer superior clinical efficacy compared...

  13. Quantifying kinematic differences between land and water during squats, split squats, and single-leg squats in a healthy population.

    Science.gov (United States)

    Severin, Anna C; Burkett, Brendan J; McKean, Mark R; Wiegand, Aaron N; Sayers, Mark G L

    2017-01-01

    Aquatic exercises can be used in clinical and sporting disciplines for both rehabilitation and sports training. However, there is limited knowledge on the influence of water immersion on the kinematics of exercises commonly used in rehabilitation and fitness programs. The aim of this study was to use inertial sensors to quantify differences in kinematics and movement variability of bodyweight squats, split squats, and single-leg squats performed on dry land and whilst immersed to the level of the greater trochanter. During two separate testing sessions, 25 active healthy university students (22.3±2.9 yr.) performed ten repetitions of each exercise, whilst tri-axial inertial sensors (100 Hz) recorded their trunk and lower body kinematics. Repeated-measures statistics tested for differences in segment orientation and speed, movement variability, and waveform patterns between environments, while coefficient of variance was used to assess differences in movement variability. Between-environment differences in segment orientation and speed were portrayed by plotting the mean difference ±95% confidence intervals (CI) throughout the tasks. The results showed that the depth of the squat and split squat were unaffected by the changed environment while water immersion allowed for a deeper single leg squat. The different environments had significant effects on the sagittal plane orientations and speeds for all segments. Water immersion increased the degree of movement variability of the segments in all exercises, except for the shank in the frontal plane, which showed more variability on land. Without compromising movement depth, the aquatic environment induces more upright trunk and shank postures during squats and split squats. The aquatic environment allows for increased squat depth during the single-leg squat, and increased shank motions in the frontal plane. Our observations therefore support the use of water-based squat tasks for rehabilitation as they appear to

  14. Quantifying kinematic differences between land and water during squats, split squats, and single-leg squats in a healthy population.

    Directory of Open Access Journals (Sweden)

    Anna C Severin

    Full Text Available Aquatic exercises can be used in clinical and sporting disciplines for both rehabilitation and sports training. However, there is limited knowledge on the influence of water immersion on the kinematics of exercises commonly used in rehabilitation and fitness programs. The aim of this study was to use inertial sensors to quantify differences in kinematics and movement variability of bodyweight squats, split squats, and single-leg squats performed on dry land and whilst immersed to the level of the greater trochanter. During two separate testing sessions, 25 active healthy university students (22.3±2.9 yr. performed ten repetitions of each exercise, whilst tri-axial inertial sensors (100 Hz recorded their trunk and lower body kinematics. Repeated-measures statistics tested for differences in segment orientation and speed, movement variability, and waveform patterns between environments, while coefficient of variance was used to assess differences in movement variability. Between-environment differences in segment orientation and speed were portrayed by plotting the mean difference ±95% confidence intervals (CI throughout the tasks. The results showed that the depth of the squat and split squat were unaffected by the changed environment while water immersion allowed for a deeper single leg squat. The different environments had significant effects on the sagittal plane orientations and speeds for all segments. Water immersion increased the degree of movement variability of the segments in all exercises, except for the shank in the frontal plane, which showed more variability on land. Without compromising movement depth, the aquatic environment induces more upright trunk and shank postures during squats and split squats. The aquatic environment allows for increased squat depth during the single-leg squat, and increased shank motions in the frontal plane. Our observations therefore support the use of water-based squat tasks for rehabilitation as

  15. 50 CFR 697.18 - Lobster management areas.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Lobster management areas. 697.18 Section... Measures § 697.18 Lobster management areas. The following lobster management areas are established for... American lobster EEZ management areas is available upon request to the Office of the Regional Administrator...

  16. 50 CFR 300.132 - Lobster harvest limitations.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not be...

  17. Diseases of spiny lobsters: a review.

    Science.gov (United States)

    Shields, J D

    2011-01-01

    Spiny lobsters have few reported pathogens, parasites and symbionts. However, they do have a diverse fauna comprised of a pathogenic virus, several bacteria, protozoans, helminths and even symbiotic crustaceans. A few idiopathic syndromes have also been reported, but these appear correlated with lobsters held in poor conditions. Fungal and bacterial pathogens present significant threats for rearing spiny lobsters in aquaculture settings, but only one pathogen, Panulirus argus virus 1, is thought to have damaged a fishery for a spiny lobster. No doubt others will emerge as lobsters are brought into aquaculture setting and as fishing pressure intensifies with stocks become more susceptible to anthropogenic stressors. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. A comparison of free weight squat to Smith machine squat using electromyography.

    Science.gov (United States)

    Schwanbeck, Shane; Chilibeck, Philip D; Binsted, Gordon

    2009-12-01

    The purpose of this experiment was to determine whether free weight or Smith machine squats were optimal for activating the prime movers of the legs and the stabilizers of the legs and the trunk. Six healthy participants performed 1 set of 8 repetitions (using a weight they could lift 8 times, i.e., 8RM, or 8 repetition maximum) for each of the free weight squat and Smith machine squat in a randomized order with a minimum of 3 days between sessions, while electromyographic (EMG) activity of the tibialis anterior, gastrocnemius, vastus medialis, vastus lateralis, biceps femoris, lumbar erector spinae, and rectus abdominus were simultaneously measured. Electromyographic activity was significantly higher by 34, 26, and 49 in the gastrocnemius, biceps femoris, and vastus medialis, respectively, during the free weight squat compared to the Smith machine squat (p free weight and Smith machine squat for any of the other muscles; however, the EMG averaged over all muscles during the free weight squat was 43% higher when compared to the Smith machine squat (p free weight squat may be more beneficial than the Smith machine squat for individuals who are looking to strengthen plantar flexors, knee flexors, and knee extensors.

  19. Decline eccentric squats increases patellar tendon loading compared to standard eccentric squats.

    Science.gov (United States)

    Kongsgaard, M; Aagaard, P; Roikjaer, S; Olsen, D; Jensen, M; Langberg, H; Magnusson, S P

    2006-08-01

    Recent studies have shown excellent clinical results using eccentric squat training on a 25 degrees decline board to treat patellar tendinopathy. It remains unknown why therapeutic management of patellar tendinopathy using decline eccentric squats offer superior clinical efficacy compared to standard horizontal eccentric squats. This study aimed to compare electromyography activity, patellar tendon strain and joint angle kinematics during standard and decline eccentric squats. Thirteen subjects performed unilateral eccentric squats on flat-and a 25 degrees decline surface. During the squats, electromyography activity was obtained in eight representative muscles. Also, ankle, knee and hip joint goniometry was obtained. Additionally, patellar tendon strain was measured in vivo using ultrasonography as subjects maintained a unilateral isometric 90 degrees knee angle squat position on either flat or 25 degrees decline surface. Patellar tendon strain was significantly greater (Psquat position on the decline surface compared to the standard surface. The stop angles of the ankle and hip joints were significantly smaller during the decline compared to the standard squats (Psquats (Psquats. The use of a 25 degrees decline board increases the load and the strain of the patellar tendon during unilateral eccentric squats. This finding likely explains previous reports of superior clinical efficacy of decline eccentric squats in the rehabilitative management of patellar tendinopathy.

  20. MANAGEMENT OF LOBSTER FISHERY WITH EAFM APPROACH IN PALABUHANRATU BAY

    Directory of Open Access Journals (Sweden)

    Katarina Hesty Rombe

    2018-06-01

    Full Text Available This research was conducted in the Palabuhanratu Bay-Sukabumi in March 2016. The purpose of this study is to diagnose the Palabuhanratu Lobster Fishery using factors of Ecosystem Approach to Fisheries Management (EAFM. Water sampling was conducted at two lobster fishing ground. Measuring and weighing morphology lobster were conducted in collectors’s house. The results of this study showed that Palabuhanratu bay water quality was still within tolerable limits for live lobster. Panulirus homarus  is the most widely lobster caught below the size of a decent catch, reaching 2528.9 Kg. CPUE of lobster was declining which indicates a decline in the stock of lobster. The income of fishermen were still very far from the average wage and stakeholder participation was still lacking in the management of the lobster fishery. Keywords: EAFM factors, lobster, palabuhanratu

  1. Visual Vection does not Perturb Squatting Posture

    Directory of Open Access Journals (Sweden)

    Dietrich Gilles

    2011-12-01

    Full Text Available Vision contributes fundamentally to the control of the standing posture. The illusion of self motion falsely perceived (vection increases postural sway while standing. In this paper we examine the effect of vection on both standing and deep squatting with the hypothesis that the squatting posture should not be disturbed by the conflict of sensory information due to vection. The results show that standing posture only was affected by the visual stimuli. The widespread use of squatting for work as well as rest could be due in part to this lack of effect of sensory perturbation on postural stability.

  2. Pola Kemitraan Pemasaran Lobster di Kota Bengkulu

    OpenAIRE

    Romdhon, M. Mustopa; sukiyono, ketut

    2011-01-01

    Relationship among lobster marketing agents could determine partnership pattern, but how the relationship was build and run, its need depth explanation. The research was aims to synthesize partnership pattern, rights and obligations among agents under lobster marketing at Bengkulu Municipal. The Partnership pattern was explained descriptively through non-contractual, equipment and capital achieved. The research was employed at North Bengkulu Districts at three villages (Pasar Pedati, Pasar Ke...

  3. Lobster-eye infrared focusing optics

    Science.gov (United States)

    Grubsky, Victor; Gertsenshteyn, Michael; Jannson, Tomasz

    2006-08-01

    We propose a new imaging device for the long infrared spectral range, inspired by the natural eye of a lobster. Such a lobster-eye lens is composed of reflecting channels with a square cross section capable of wide angle of view and practically omni-directional imaging. As in large-aperture lenses, aberrations can significantly degrade the image. We show two methods of reducing aberrations: by selecting proper material for the mirrors and by making channels with absorbing sections.

  4. A new squat lobster of the genus Munidopsis (Crustacea: Decapoda: Munidopsidae from the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Enrique Macpherson

    2011-04-01

    Full Text Available A new species of Munidopsis Whiteaves, 1874 is reported from the south of Crete, at 2046-2104 m, in the eastern Mediterranean Sea. The species (M. ariadne is morphologically closely related to M. maunga Schnabel and Bruce, 2006, from New Zealand. The species is also close to M. polymorpha Koelbel, 1892, from Lanzarote, Canary Islands, and M. talismani A. Milne Edwards and Bouvier, 1894, from the NW Africa. The new species is described and illustrated and a diagnosis along with full illustration is provided for the latter 2 species.

  5. The Effects of Multiple Sets of Squats and Jump Squats on Mechanical Variables.

    Science.gov (United States)

    Rossetti, Michael L; Munford, Shawn N; Snyder, Brandon W; Davis, Shala E; Moir, Gavin L

    2017-07-28

    The mechanical responses to two non-ballistic squat and two ballistic jump squat protocols performed over multiple sets were investigated. One protocol from each of the two non-ballistic and ballistic conditions incorporated a pause between the eccentric and concentric phases of the movements in order to determine the influence of the coupling time on the mechanical variables and post-activation potentiation (PAP). Eleven men (age: 21.9 ± 1.8 years; height: 1.79 ± 0.05 m; mass: 87.0 ± 7.4 kg) attended four sessions where they performed multiple sets of squats and jump squats with a load equivalent to 30% 1-repeititon maximum under one of the following conditions: 1) 3 × 4 repetitions of non-ballistic squats (30N-B); 2) 3 × 4 repetitions of non-ballistic squats with a 3-second pause between the eccentric and concentric phases of each repetition (30PN-B); 3) 3 × 4 repetitions of ballistic jump squats (30B); 4) 3 × 4 repetitions of ballistic jump squats with a 3-second pause between the eccentric and concentric phases of each repetition (30PB). Force plates were used to calculate variables including average vertical velocity, average vertical force (GRF), and average power output (PO). Vertical velocities during the ballistic conditions were significantly greater than those attained during the non-ballistic conditions (mean differences: 0.21 - 0.25 m/s, p0.05). Ballistic jump squats may be an effective exercise for developing PO given the high velocities and forces generated in these exercises. Furthermore, the completion of multiple sets of jump squats may induce PAP to enhance PO. The coupling times between the eccentric and concentric phases of the jump squats should be short in order to maximize the GRF and PO across the sets.

  6. Partial pressure (or fugacity) of carbon dioxide, salinity and SEA SURFACE TEMPERATURE collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from Munida in the South Pacific Ocean from 2004-01-26 to 2006-07-30 (NODC Accession 0100218)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0100218 includes Surface underway data collected from Munida in the South Pacific Ocean from 2004-01-26 to 2006-07-30. These data include Partial...

  7. DIMENSI METRIK GRAPH LOBSTER Ln (q;r

    Directory of Open Access Journals (Sweden)

    PANDE GDE DONY GUMILAR

    2013-05-01

    Full Text Available The metric dimension of connected graph G is the cardinality of minimum resolving set in graph G. In this research, we study how to find the metric dimension of lobster graph Ln (q;r. Lobster graph Ln (q;r is a regular lobster graph with vertices backbone on the main path, every backbone vertex is connected to q hand vertices and every hand vertex is connected to r finger vertices, with n, q, r element of N. We obtain the metric dimension of lobster graph L2 (1;1 is 1, the metric dimension of lobster graph L2 (1;1 for n > 2 is 2.

  8. Detection of early squats by axle box acceleration

    OpenAIRE

    Molodova, M.

    2013-01-01

    This thesis discusses a new method for detection of short track irregularities, particularly squats, with axle box acceleration (ABA) measurements. A squat is a surface initiated short track defect, associated with high frequency vibrations of the wheel-rail system. High stresses in the contact patch at squats cause accumulation of plastic deformation of the rail and growth of cracks. Cracks growing in the subsurface can cause a rail fracture. Light squats can be treated by grinding of the ra...

  9. LOBSTER - New Space X-Ray telescopes

    International Nuclear Information System (INIS)

    Hudec, R.; Pina, L.; Simon, V.; Sveda, L.; Inneman, A.; Semencova, V.; Skulinova, M.

    2007-01-01

    We discuss the technological and scientific aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes of Lobster telescopes designed, developed and tested are very promising, allowing the proposals for space projects with very wide-field Lobster Eye X-ray optics to be considered for the first time. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. For example, the Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science

  10. 76 FR 71501 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; American Lobster Fishery

    Science.gov (United States)

    2011-11-18

    ... Lobster Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... American lobster regulations that would limit entry into the lobster trap fishery in Lobster Conservation... to fish in Area 1 with up to 800 lobster traps. The proposed limited entry program responds to the...

  11. LOBSTER: new space x-ray telescopes

    Science.gov (United States)

    Hudec, R.; Sveda, L.; Pína, L.; Inneman, A.; Semencova, V.; Skulinova, M.

    2017-11-01

    The LOBSTER telescopes are based on the optical arrangement of the lobster eye. The main difference from classical X-ray space telescopes in wide use is the very large field of view while the use of optics results in higher efficiency if compared with detectors without optics. Recent innovative technologies have enabled to design, to develop and to test first prototypes. They will provide deep sensitive survey of the sky in X-rays for the first time which is essential for both long-term monitoring of celestial high-energy sources as well as in understanding transient phenomena. The technology is now ready for applications in space.

  12. Ecology: avoidance of disease by social lobsters.

    Science.gov (United States)

    Behringer, Donald C; Butler, Mark J; Shields, Jeffrey D

    2006-05-25

    Transmissible pathogens are the bane of social animals, so they have evolved behaviours to decrease the probability of infection. There is no record, however, of social animals avoiding diseased individuals of their own species in the wild. Here we show how healthy, normally gregarious Caribbean spiny lobsters (Panulirus argus) avoid conspecifics that are infected with a lethal virus. Early detection and avoidance of infected, though not yet infectious, individuals by healthy lobsters confers a selective advantage and highlights the importance of host behaviour in disease transmission among natural populations.

  13. Larvas de Sergestes arcticus Kroyer, 1855, Neotrypaea uncinata (H. Milne-Edwards, 1837 y Munida gregaria (Fabricius, 1793, entre el seno Reloncaví y Boca del Guafo, sur de Chile Larvae of Sergestes arcticus Kroyer, 1855, Neotrypaea uncinata (H. Milne-Edwards, 1837, and Munida gregaria (Fabricius, 1793 between Seno Reloncaví and Boca del Guafo, southern Chile

    Directory of Open Access Journals (Sweden)

    Armando Mujica

    2011-01-01

    Full Text Available Se analiza la distribución de los estados de desarrollo de las larvas de Sergestes arcticus, Neotrypaea uncinata y Munida gregaria, capturadas entre el seno Reloncaví y la Boca del Guafo, durante noviembre de 2004. Se distinguieron tres zonas oceanógraficas, de acuerdo a los antecedentes relacionados con el grado de participación de aguas continentales y oceánicas. La distribución de las larvas de estas especies y sus estados de desarrollo, permitieron establecer diferencias significativas entre ellas respecto de las características oceanógraficas, lo que estaría relacionado con los lugares de desove y habitat de las poblaciones desovantes en el área de estudio.The distribution of developmental stages of Sergestes arcticus, Neotrypaea uncinata and Munida gregaria larvae caught between Seno Reloncaví and Boca del Guafo in November 2004 was analyzed. Three oceanographic zones were distinguished according to records showing the degree of participation of continental and oceanic waters. Significant differences were determined between larval distribution and development stages for these species with respect to oceanographic characteristics; said differences might be related to the spawning sites and the habitat of the spawning stock in the study area.

  14. The Case of Lobster Shell Disease

    Science.gov (United States)

    Hollen, Shawna; Toney, Jaime L.; Bisaccio, Daniel; Haberstroh, Karen Marie; Herbert, Timothy

    2011-01-01

    The authors combined content-driven and inquiry-based lessons into the framework of problem-based learning (PBL). They did this in eight third- through sixth-grade classrooms--two each from grades 3-5, one from sixth grade, and one mixed-grade special education. These older elementary students explored a local problem of lobsters infected by…

  15. Exploiting volatile opportunistic computing resources with Lobster

    Science.gov (United States)

    Woodard, Anna; Wolf, Matthias; Mueller, Charles; Tovar, Ben; Donnelly, Patrick; Hurtado Anampa, Kenyi; Brenner, Paul; Lannon, Kevin; Hildreth, Mike; Thain, Douglas

    2015-12-01

    Analysis of high energy physics experiments using the Compact Muon Solenoid (CMS) at the Large Hadron Collider (LHC) can be limited by availability of computing resources. As a joint effort involving computer scientists and CMS physicists at Notre Dame, we have developed an opportunistic workflow management tool, Lobster, to harvest available cycles from university campus computing pools. Lobster consists of a management server, file server, and worker processes which can be submitted to any available computing resource without requiring root access. Lobster makes use of the Work Queue system to perform task management, while the CMS specific software environment is provided via CVMFS and Parrot. Data is handled via Chirp and Hadoop for local data storage and XrootD for access to the CMS wide-area data federation. An extensive set of monitoring and diagnostic tools have been developed to facilitate system optimisation. We have tested Lobster using the 20 000-core cluster at Notre Dame, achieving approximately 8-10k tasks running simultaneously, sustaining approximately 9 Gbit/s of input data and 340 Mbit/s of output data.

  16. Modeling the dispersal of spiny lobster (

    NARCIS (Netherlands)

    Whomersley, P.; van der Molen, J.; Holt, D.; Trundle, C.; Clark, S.; Fletcher, D.

    2018-01-01

    Knowledge of larval dispersal, population dynamics and connectivity in relation to the management and conservation of commercially important species is vital if existing fisheries are to remain sustainable into the future. Larval dispersal of the commercially exploited spiny lobster, Palinurus

  17. Biomechanics of front and back squat exercises

    International Nuclear Information System (INIS)

    Braidot, A A; Brusa, M H; Lestussi, F E; Parera, G P

    2007-01-01

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0 deg. to 50 deg. because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture

  18. Biomechanics of front and back squat exercises

    Energy Technology Data Exchange (ETDEWEB)

    Braidot, A A [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Brusa, M H [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Lestussi, F E [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Parera, G P [Licenciatura en KinesiologIa y FisiatrIa Universidad Abierta Interamericana. Sede Regional Rosario (Argentina)

    2007-11-15

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0 deg. to 50 deg. because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  19. Biomechanics of front and back squat exercises

    Science.gov (United States)

    Braidot, A. A.; Brusa, M. H.; Lestussi, F. E.; Parera, G. P.

    2007-11-01

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0° to 50° because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  20. 75 FR 1597 - Western Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2010-01-12

    ... Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY.... ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS announces that the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year...

  1. Espécies do gênero Munida Leach (Crustacea, Decapoda, Galatheidae coletadas entre Torres (Rio Grande do Sul, Brasil e Maldonado (Uruguai pelo Programa Rio Grande do Sul (PRS I-II, GEDIP Species of the genus Munida Leach (Crustacea, Decapoda, Galatheidae collected between Torres (Rio Grande do Sul, Brazil and Maldonado (Uruguay, by the Project Rio Grande do Sul (PRS I-II, GEDIP

    Directory of Open Access Journals (Sweden)

    Gustavo A.S. de Melo-Filho

    2001-12-01

    Full Text Available The project PRS-GEDIP was carried out in the Rio Grande do Sul coast, with some few stations off Maldonado (Uruguay, by means of a convention between Instituto Oceanográfico USP (IOUSP and the Grupo Executivo do Desenvolvimento da Indústria da Pesca (GEDIP of Rio Grande do Sul. The purpose of this project was the acquisition of data in order to have a better biotic and abiotic characterization of the southern Brazilian coast. Among the Galatheidae, about 1200 specimens of the genus Munida Leach, 1820 were collected, including five species as follows: Munida flinti Benedict, 1902; M. forceps A. Milne Edwards, 1880; M. iris A. Milne Edwards, 1880; M. irrasa A. Milne Edwards. 1880 and M. longipes A. Milne Edwards, 1880. The description, material examined, remarks and maps of the stations where each species was collected are done.

  2. Effect of loading on peak power of the bar, body, and system during power cleans, squats, and jump squats.

    Science.gov (United States)

    McBride, Jeffrey M; Haines, Tracie L; Kirby, Tyler J

    2011-08-01

    Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus.

  3. Acute effects of heavy-load squats on consecutive squat jump performance.

    Science.gov (United States)

    Weber, Kurt R; Brown, Lee E; Coburn, Jared W; Zinder, Steven M

    2008-05-01

    Postactivation potentiation (PAP) and complex training have generated interest within the strength and conditioning community in recent years, but much of the research to date has produced confounding results. The purpose of this study was to observe the acute effects of a heavy-load back squat [85% 1 repetition maximum (1RM)] condition on consecutive squat jump performance. Twelve in-season Division I male track-and-field athletes participated in two randomized testing conditions: a five-repetition back squat at 85% 1RM (BS) and a five-repetition squat jump (SJ). The BS condition consisted of seven consecutive squat jumps (BS-PRE), followed by five repetitions of the BS at 85% 1RM, followed by another set of seven consecutive squat jumps (BS-POST). The SJ condition was exactly the same as the BS condition except that five consecutive SJs replaced the five BSs, with 3 minutes' rest between each set. BS-PRE, BS-POST, SJ-PRE, and SJ-POST were analyzed and compared for mean and peak jump height, as well as mean and peak ground reaction force (GRF). The BS condition's mean and peak jump height and peak GRF increased 5.8% +/- 4.8%, 4.7% +/- 4.8%, and 4.6% +/- 7.4%, respectively, whereas the SJ condition's mean and peak jump height and peak GRF decreased 2.7% +/- 5.0%, 4.0% +/- 4.9%, and 1.3% +/- 7.5%, respectively. The results indicate that performing a heavy-load back squat before a set of consecutive SJs may enhance acute performance in average and peak jump height, as well as peak GRF.

  4. Predation on hatchery-reared lobsters released in the wild

    OpenAIRE

    van der Meeren, Gro

    2000-01-01

    Predation on hatchery-reared lobsters (Homarus gammarus) in the wild was studied in order to identify predators in southwestern Norway on rocky and sandy substrates in winter and summer. Lobsters of 12–15 mm carapace length were tagged with magnetic microtags. About 51 000 juvenile lobsters were released on 10 occasions at three locations. Predator samplings were by trammel nets, eel traps, and videorecordings during the 24 h immediately following the releases. In summer, loss to ...

  5. BUDIDAYA LOBSTER (Panulirus sp. DI VIETNAM DAN APLIKASINYA DI INDONESIA

    Directory of Open Access Journals (Sweden)

    Akhmad Mustafa

    2013-12-01

    Full Text Available Desa Xuan Tun di Kecamatan Van Ninh Kota Nha Trang Provinsi Khanh Hoa merupakan lokasi pertama kegiatan budidaya lobster di Vietnam yang dilakuan pada tahun 1992. Secara umum di Kota Nha Trang, ada tiga jenis lobster yang dibudidayakan yaitu lobster mutiara (Panulirus ornatus, lobster pasir (Panulirus homarus, dan lobster batik (Panulirus longipes, karena benih lobster tersebut mudah didapat pada awalnya, cepat tumbuh, berukuran besar, warna cerah, dan memiliki harga yang tinggi. Kegiatan budidaya lobster pada dasarnya terdiri atas: penangkapan benih lobster, produksi tokolan lobster, dan pembesaran lobster yang masing-masing merupakan segmen usaha tersendiri. Pakan yang digunakan dalam produksi tokolan dan pembesaran lobster adalah berupa udang, kerang, tiram, cumi-cumi, dan ikan rucah, di mana sebagian besar dari pakan tersebut digunakan ikan rucah terutama pada pembesaran lobster. Sebagai akibat penggunaan pakan tersebut dan peningkatan jumlah keramba jaring apung yang cukup signifikan berdampak pada penurunan kualitas perairan yang memicu berkembangya penyakit susu (milky haemolymph disease sehingga terjadi penurunan produksi. Terkait dengan hasil yang didapatkan tersebut, ke depan diperlukan berbagai kegiatan termasuk untuk dapat diaplikasikan di Indonesia. Kegiatan tersebut meliputi: produksi benih lobster secara buatan di hatcheri dan penggunaan pakan buatan berupa moist pellet. Upaya pencegahan penyakit susu dan perlakuan-perlakuan praktis untuk mencegah perkembangan serangan penyakit susu juga perlu mendapat perhatian. Perkembangan budidaya lobster yang begitu cepat memicu terjadinya penurunan daya dukung lahan. Oleh karena itu, kegiatan untuk menentukan daya dukung lahan dan kesesuaian lahan menjadi penting untuk dilakukan untuk menentukan lokasi dan jumlah keramba jaring apung yang dapat dioperasikan. Penentuan daya dukung lahan dan evaluasi kesesuaian lahan tidak hanya dilakukan pada daerah yang

  6. Kinetic analysis of concurrent activation potentiation during back squats and jump squats.

    Science.gov (United States)

    Ebben, William P; Kaufmann, Clare E; Fauth, McKenzie L; Petushek, Erich J

    2010-06-01

    Concurrent activation potentiation enhances muscular force during open kinetic chain isometric and isokinetic exercises via remote voluntary contractions (RVCs). The purpose of this study was to evaluate the effect of RVCs on the performance of closed kinetic chain ground-based exercises. Subjects included 13 men (21.4+/-1.5 years) who performed the back squat and jump squat in 2 test conditions. The RVC condition included performing the test exercises while clenching the jaw on a mouth guard, forcefully gripping and pulling the barbell down into the trapezius, and performing a Valsalva maneuver. The normal condition (NO-RVC) included performing the test exercises without RVCs. Exercises were assessed with a force platform. Peak ground reaction force (GRF), rate of force development (RFD) during the first 100 milliseconds (RFD-100), RFD to peak GRF (RFD-P), and jump squat height (JH) were calculated from the force-time records. Data were analyzed using an analysis of variance. Results reveal that GRF and RFD-100 were higher in the RVC compared with the NO-RVC condition for both the back squat and jump squat (psquat (psquat (p=0.82). The JH was higher in the RVC compared to the NO-RVC condition for the jump squat (p

  7. Squat Ground Reaction Force on a Horizontal Squat Device, Free Weights, and Smith Machine

    Science.gov (United States)

    Scott-Pandorf, Melissa M.; Newby, Nathaniel J.; Caldwell, Erin; DeWitt, John K.; Peters, Brian T.

    2010-01-01

    Bed rest is an analog to spaceflight and advancement of exercise countermeasures is dependent on the development of exercise equipment that closely mimic actual upright exercise. The Horizontal Squat Device (HSD) was developed to allow a supine exerciser to perform squats that mimic upright squat exercise. PURPOSE: To compare vertical ground reaction force (GRFv) on the HSD with Free Weight (FW) or Smith Machine (SM) during squat exercise. METHODS: Subjects (3F, 3M) performed sets of squat exercise with increasing loads up to 1-repetition (rep) maximum. GRF data were collected and compared with previous GRF data for squat exercise performed with FW & SM. Loads on the HSD were adjusted to magnitudes comparable with FW & SM by subtracting the subject s body weight (BW). Peak GRFv for 45-, 55-, 64-, & 73-kg loads above BW were calculated. Percent (%) difference between HSD and the two upright conditions were computed. Effect size was calculated for the 45-kg load. RESULTS: Most subjects were unable to lift >45 kg on the HSD; however, 1 subject completed all loads. Anecdotal evidence suggested that most subjects shoulders or back failed before their legs. The mean % difference are shown. In the 45-kg condition, effect sizes were 0.37 & 0.83 (p>0.05) for HSD vs. FW and HSD vs. SM, respectively, indicating no differences between exercise modes. CONCLUSION: When BW was added to the target load, results indicated that vertical forces were similar to those in FW and SM exercise. The exercise prescription for the HSD should include a total external resistance equivalent to goal load plus subject BW. The HSD may be used as an analog to upright exercise in bed rest studies, but because most subjects were unable to lift >45 kg, it may be necessary to prescribe higher reps and lower loads to better target the leg musculature

  8. Spatio-temporal changes of Munida Rutllanti Zariquiey-Alvarez, 1952 (Decapoda: Galatheidae in the North-Western Ionian Sea (Central Mediterranean

    Directory of Open Access Journals (Sweden)

    P. MAIORANO

    2013-09-01

    Full Text Available The spatio-temporal pattern of Munida rutllanti distribution in the north-western Ionian Sea has been studied. Data were collected during 14 experimental trawl surveys conducted from 1997 to 2010 as part of the international MEDITS project. The hauls were carried out during day-light hours between depths of 10 and 800 m in the spring season. A progressive increase in the abundance index (N/km2 of M. rutllanti was observed from 2000 to 2008, then a sharp decrease was shown in the last two years. The greatest and lowest abundance indices were observed in the Apulian and central Calabrian sub-areas, respectively. The species was collected between 107 and 795 m in depth, with a significant increase and decrease over time in the maximum and minimum depth of finding, respectively. A highly significant increase over time in the mean carapace length was also observed in the whole study area. The widespread occurrence and increasing abundance of this species in the Ionian Sea could be related to the increase in temperature and the variation in hydrographic conditions which occurred in the Ionian basin during the EMT-BiOS phenomenon.

  9. Spatial distribution of Munida intermedia and M. sarsi (crustacea: Anomura) on the Galician continental shelf (NW Spain): Application of geostatistical analysis

    Science.gov (United States)

    Freire, J.; González-Gurriarán, E.; Olaso, I.

    1992-12-01

    Geostatistical methodology was used to analyse spatial structure and distribution of the epibenthic crustaceans Munida intermedia and M. sarsi within sets of data which had been collected during three survey cruises carried out on the Galician continental shelf (1983 and 1984). This study investigates the feasibility of using geostatistics for data collected according to traditional methods and of enhancing such methodology. The experimental variograms were calculated (pooled variance minus spatial covariance between samples taken one pair at a time vs. distance) and fitted to a 'spherical' model. The spatial structure model was used to estimate the abundance and distribution of the populations studied using the technique of kriging. The species display spatial structures, which are well marked during high density periods and in some areas (especially northern shelf). Geostatistical analysis allows identification of the density gradients in space as well as the patch grain along the continental shelf of 16-25 km diameter for M. intermedia and 12-20 km for M. sarsi. Patches of both species have a consistent location throughout the different cruises. As in other geographical areas, M. intermedia and M. sarsi usually appear at depths ranging from 200 to 500 m, with the highest densities in the continental shelf area located between Fisterra and Estaca de Bares. Althouh sampling was not originally designed specifically for geostatistics, this assay provides a measurement of spatial covariance, and shows variograms with variable structure depending on population density and geographical area. These ideas are useful in improving the design of future sampling cruises.

  10. 50 CFR 640.27 - Spiny lobster import prohibitions.

    Science.gov (United States)

    2010-10-01

    ... ATLANTIC Management Measures § 640.27 Spiny lobster import prohibitions. (a) Minimum size limits for... than Puerto Rico or the U.S. Virgin Islands, and a more restrictive minimum size limit that applies to Puerto Rico and the U.S. Virgin Islands. (1) No person may import a spiny lobster with less than a 5...

  11. 50 CFR 622.50 - Caribbean spiny lobster import prohibitions.

    Science.gov (United States)

    2010-10-01

    ... ATLANTIC Management Measures § 622.50 Caribbean spiny lobster import prohibitions. (a) Minimum size limits... States other than Puerto Rico or the U.S. Virgin Islands, and a more restrictive minimum size limit that applies to Puerto Rico and the U.S. Virgin Islands. (1) No person may import a Caribbean spiny lobster...

  12. First Report of Two Species of Genus Raymunida (Crustacea: Decapoda: Anomura from Korea

    Directory of Open Access Journals (Sweden)

    Sanghui Lee

    2013-10-01

    Full Text Available Two species of squat lobsters, Raymunida formosanus Lin, Chan and Chu, 2004 and Raymunida lineata Osawa, 2005, are newly added to the Korean decapod fauna. The genus Raymunida Macpherson and Machordom, 2000 is also reported for the first time in Korea. It differs morphologically from other Korean genera, Munida and Paramunida, in having the first to third pereopods with epipods and the carpus of the third maxilliped with a distal spine on flexor margin. Illustrations and pictures of these two species are provided with descriptions, and the key to the species of Korean Munidids is also provided.

  13. Factors affecting post-capture survivability of lobster Homarus americanus.

    Science.gov (United States)

    Basti, David; Bricknell, Ian; Hoyt, Ken; Chang, Ernest S; Halteman, William; Bouchard, Deborah

    2010-06-11

    Technological advances in gear and fishing practices have driven the global expansion of the American lobster live seafood market. These changes have had a positive effect on the lobster industry by increasing capture efficiency. However, it is unknown what effect these improved methods will have on the post-capture fitness and survival of lobsters. This project utilized a repeated measures design to compare the physiological changes that occur in lobsters over time as the result of differences in depth, hauling rate, and storage methodology. The results indicate that lobsters destined for long distance transport or temporary storage in pounds undergo physiological disturbance as part of the capture process. These changes are significant over time for total hemocyte counts, crustacean hyperglycemic hormone, L-lactate, ammonia, and glucose. Repeated measures multivariate analysis of variance (MANOVA) for glucose indicates a significant interaction between depth and storage methodology over time for non-survivors. A Gram-negative bacterium, Photobacterium indicum, was identified in pure culture from hemolymph samples of 100% of weak lobsters. Histopathology revealed the presence of Gram-negative bacteria throughout the tissues with evidence of antemortem edema and necrosis suggestive of septicemia. On the basis of these findings, we recommend to the lobster industry that if a reduction in depth and hauling rate is not economically feasible, fishermen should take particular care in handling lobsters and provide them with a recovery period in recirculating seawater prior to land transport. The ecological role of P. indicum is not fully defined at this time. However, it may be an emerging opportunistic pathogen of stressed lobsters. Judicious preemptive antibiotic therapy may be necessary to reduce mortality in susceptible lobsters destined for high-density holding facilities.

  14. Reliability and validity of two isometric squat tests.

    Science.gov (United States)

    Blazevich, Anthony J; Gill, Nicholas; Newton, Robert U

    2002-05-01

    The purpose of the present study was first to examine the reliability of isometric squat (IS) and isometric forward hack squat (IFHS) tests to determine if repeated measures on the same subjects yielded reliable results. The second purpose was to examine the relation between isometric and dynamic measures of strength to assess validity. Fourteen male subjects performed maximal IS and IFHS tests on 2 occasions and 1 repetition maximum (1-RM) free-weight squat and forward hack squat (FHS) tests on 1 occasion. The 2 tests were found to be highly reliable (intraclass correlation coefficient [ICC](IS) = 0.97 and ICC(IFHS) = 1.00). There was a strong relation between average IS and 1-RM squat performance, and between IFHS and 1-RM FHS performance (r(squat) = 0.77, r(FHS) = 0.76; p squat and FHS test performances (r squat and FHS test performance can be attributed to differences in the movement patterns of the tests

  15. Detection of early squats by axle box acceleration

    NARCIS (Netherlands)

    Molodova, M.

    2013-01-01

    This thesis discusses a new method for detection of short track irregularities, particularly squats, with axle box acceleration (ABA) measurements. A squat is a surface initiated short track defect, associated with high frequency vibrations of the wheel-rail system. High stresses in the contact

  16. Praktik Trademark Squatting dalam Proses Pendaftaran Merek di Indonesia

    OpenAIRE

    Widya Justitia

    2016-01-01

    Penelitian ini bertujuan untuk mengetahui dan menganalisis mengapa praktik trademark squatting dapat terjadi dalam proses pendaftaran merek beserta cara mengatasinya. Selanjutnya, penelitian ini juga membahas mengenai konsepsi ideal terkait proses pendaftaran merek di Indonesia guna menghindari dan meminimalisasi praktik trademark squatting. Penelitian ini merupakan penelitian kualitatif yang bersifat yuridis empiris dan data yang terkumpul dianalisa dengan metode deskriptif kualitatif. Hasil...

  17. Urban squatting and migration in Peninsular Malaysia.

    Science.gov (United States)

    Johnstone, M

    1983-01-01

    "This article examines some of the links between the phenomena of urban migration and squatter settlements in the Third World city. This will be done by demonstrating that both are outcomes of fundamental social and political forces that have operated on these societies. Migration and squatting are placed in a context of the historical processes that led to the uneven development of Malaysia. The article offers some explanation for the origin of the inequalities observed in spatial structures--in this case urban housing--by focusing on one of the contributory factors, namely migration." excerpt

  18. Trunk muscle activity increases with unstable squat movements.

    Science.gov (United States)

    Anderson, Kenneth; Behm, David G

    2005-02-01

    The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL).

  19. Red Tide Strands South African Rock Lobsters

    Science.gov (United States)

    2002-01-01

    Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide. The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine. The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra

  20. Behavioral Immunity Suppresses an Epizootic in Caribbean Spiny Lobsters.

    Science.gov (United States)

    Butler, Mark J; Behringer, Donald C; Dolan, Thomas W; Moss, Jessica; Shields, Jeffrey D

    2015-01-01

    Sociality has evolved in a wide range of animal taxa but infectious diseases spread rapidly in populations of aggregated individuals, potentially negating the advantages of their social interactions. To disengage from the coevolutionary struggle with pathogens, some hosts have evolved various forms of "behavioral immunity"; yet, the effectiveness of such behaviors in controlling epizootics in the wild is untested. Here we show how one form of behavioral immunity (i.e., the aversion of diseased conspecifics) practiced by Caribbean spiny lobsters (Panulirus argus) when subject to the socially transmitted PaV1 virus, appears to have prevented an epizootic over a large seascape. We capitalized on a "natural experiment" in which a die-off of sponges in the Florida Keys (USA) resulted in a loss of shelters for juvenile lobsters over a ~2500km2 region. Lobsters were thus concentrated in the few remaining shelters, presumably increasing their exposure to the contagious virus. Despite this spatial reorganization of the population, viral prevalence in lobsters remained unchanged after the sponge die-off and for years thereafter. A field experiment in which we introduced either a healthy or PaV1-infected lobster into lobster aggregations in natural dens confirmed that spiny lobsters practice behavioral immunity. Healthy lobsters vacated dens occupied by PaV1-infected lobsters despite the scarcity of alternative shelters and the higher risk of predation they faced when searching for a new den. Simulations from a spatially-explicit, individual-based model confirmed our empirical results, demonstrating the efficacy of behavioral immunity in preventing epizootics in this system.

  1. Behavioral Immunity Suppresses an Epizootic in Caribbean Spiny Lobsters.

    Directory of Open Access Journals (Sweden)

    Mark J Butler

    Full Text Available Sociality has evolved in a wide range of animal taxa but infectious diseases spread rapidly in populations of aggregated individuals, potentially negating the advantages of their social interactions. To disengage from the coevolutionary struggle with pathogens, some hosts have evolved various forms of "behavioral immunity"; yet, the effectiveness of such behaviors in controlling epizootics in the wild is untested. Here we show how one form of behavioral immunity (i.e., the aversion of diseased conspecifics practiced by Caribbean spiny lobsters (Panulirus argus when subject to the socially transmitted PaV1 virus, appears to have prevented an epizootic over a large seascape. We capitalized on a "natural experiment" in which a die-off of sponges in the Florida Keys (USA resulted in a loss of shelters for juvenile lobsters over a ~2500km2 region. Lobsters were thus concentrated in the few remaining shelters, presumably increasing their exposure to the contagious virus. Despite this spatial reorganization of the population, viral prevalence in lobsters remained unchanged after the sponge die-off and for years thereafter. A field experiment in which we introduced either a healthy or PaV1-infected lobster into lobster aggregations in natural dens confirmed that spiny lobsters practice behavioral immunity. Healthy lobsters vacated dens occupied by PaV1-infected lobsters despite the scarcity of alternative shelters and the higher risk of predation they faced when searching for a new den. Simulations from a spatially-explicit, individual-based model confirmed our empirical results, demonstrating the efficacy of behavioral immunity in preventing epizootics in this system.

  2. Diseases of American lobsters (Homarus americanus): a review.

    Science.gov (United States)

    Cawthorn, Richard J

    2011-01-01

    The American lobster fishery is a significant economic driver in coastal communities of North America. Increasingly, the impacts of infectious disease are recognized as important components and factors in the population ecology and subsequent management of the lobster fishery. Both environmental and anthropogenic factors impact marine diseases. The review herein highlights aspects of several important bacterial, fungal and protistan diseases, including gaffkemia, shell disease, vibriosis, disease caused by species of Lagenidium, Haliphthoros and Fusarium, paramoebiasis and Bumper Car disease. As the global environment continues to change, these diseases could more severely affect both wild caught and impounded lobsters. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Studies on the diet of various lobster species have shown ...

    African Journals Online (AJOL)

    spamer

    However, the proportion of the population feeding showed marked seasonal trends at both sites, tracking the commercial ..... The general diet of crustaceans, molluscs and echino- .... habits of polychelid lobsters in the Western Mediterranean.

  4. True navigation and magnetic maps in spiny lobsters.

    Science.gov (United States)

    Boles, Larry C; Lohmann, Kenneth J

    2003-01-02

    Animals are capable of true navigation if, after displacement to a location where they have never been, they can determine their position relative to a goal without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey. So far, only a few animals, all vertebrates, have been shown to possess true navigation. Those few invertebrates that have been carefully studied return to target areas using path integration, landmark recognition, compass orientation and other mechanisms that cannot compensate for displacements into unfamiliar territory. Here we report, however, that the spiny lobster Panulirus argus oriented reliably towards a capture site when displaced 12-37 km to unfamiliar locations, even when deprived of all known orientation cues en route. Little is known about how lobsters and other animals determine position during true navigation. To test the hypothesis that lobsters derive positional information from the Earth's magnetic field, lobsters were exposed to fields replicating those that exist at specific locations in their environment. Lobsters tested in a field north of the capture site oriented themselves southwards, whereas those tested in a field south of the capture site oriented themselves northwards. These results imply that true navigation in spiny lobsters, and perhaps in other animals, is based on a magnetic map sense.

  5. Host susceptibility hypothesis for shell disease in American lobsters.

    Science.gov (United States)

    Tlusty, Michael F; Smolowitz, Roxanna M; Halvorson, Harlyn O; DeVito, Simone E

    2007-12-01

    Epizootic shell disease (ESD) in American lobsters Homarus americanus is the bacterial degradation of the carapace resulting in extensive irregular, deep erosions. The disease is having a major impact on the health and mortality of some American lobster populations, and its effects are being transferred to the economics of the fishery. While the onset and progression of ESD in American lobsters is undoubtedly multifactorial, there is little understanding of the direct causality of this disease. The host susceptibility hypothesis developed here states that although numerous environmental and pathological factors may vary around a lobster, it is eventually the lobster's internal state that is permissive to or shields it from the final onset of the diseased state. To support the host susceptibility hypothesis, we conceptualized a model of shell disease onset and severity to allow further research on shell disease to progress from a structured model. The model states that shell disease onset will occur when the net cuticle degradation (bacterial degradation, decrease of host immune response to bacteria, natural wear, and resorption) is greater than the net deposition (growth, maintenance, and inflammatory response) of the shell. Furthermore, lesion severity depends on the extent to which cuticle degradation exceeds deposition. This model is consistent with natural observations of shell disease in American lobster.

  6. Three new species of squat lobsters of the genus Fennerogalathea Baba, 1988 (Decapoda: Galatheidae) from the Pacific Ocean.

    Science.gov (United States)

    Rodriguez-Flores, Paula C; Machordom, Annie; Macpherson, Enrique

    2017-06-09

    The genus Fennerogalathea Baba, 1988 was known to contain two species: F. chacei Baba, 1988, the type species, from the Philippines, Taiwan and Indonesia and F. chirostyloides Tirmizi & Javed, 1993 from the Bay of Bengal. In the present study, three new species of the genus are described and illustrated: F. chani n. sp. from Papua New Guinea, F. cultrata n. sp. from New Caledonia and Vanuatu and F. ensifera n. sp. from Fiji. The new species are morphologically distinguishable on the basis of the shape and spination of the rostrum and the presence/absence of a small spine on the frontal margin of the carapace. The species also show clear genetic differences (COI and 16S rDNA) among them.

  7. Radioactive lobsters put squeeze on Sellafield

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-11-01

    British Nuclear Fuels is facing a new controversy over its Sellafield Works in Cumbria. Levels of the radioactive isotope technetium-99 in lobsters close to the works have risen 40-fold since 1993 -and now far exceed EC standards for contamination of food after a nuclear accident. Radioactive doses to local seafood consumers have been rising steeply since BNFL commissioned a new enhanced actinide removal plant (EARP) in 1994. The Environment Agency has now asked BNFL to consider ways of reducing technetium-99 discharges from the plant - but the company is also under pressure to maintain throughput to meet the safety concerns of the Nuclear Installations Inspectorate (NII) and avoid disrupting the reprocessing of spent Magnox reactor fuel. (UK).

  8. Radioactive lobsters put squeeze on Sellafield

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    British Nuclear Fuels is facing a new controversy over its Sellafield Works in Cumbria. Levels of the radioactive isotope technetium-99 in lobsters close to the works have risen 40-fold since 1993 -and now far exceed EC standards for contamination of food after a nuclear accident. Radioactive doses to local seafood consumers have been rising steeply since BNFL commissioned a new enhanced actinide removal plant (EARP) in 1994. The Environment Agency has now asked BNFL to consider ways of reducing technetium-99 discharges from the plant - but the company is also under pressure to maintain throughput to meet the safety concerns of the Nuclear Installations Inspectorate (NII) and avoid disrupting the reprocessing of spent Magnox reactor fuel. (UK)

  9. The efficacy of incorporating partial squats in maximal strength training.

    Science.gov (United States)

    Bazyler, Caleb D; Sato, Kimitake; Wassinger, Craig A; Lamont, Hugh S; Stone, Michael H

    2014-11-01

    The purpose of our study was to examine the effects of 2 different training methods on dynamic and isometric measures of maximal strength. Seventeen recreationally trained men (1 repetition maximum [1RM] squat: 146.9 ± 22.4 kg) were assigned to 2 groups: full range of motion (ROM) squat (F) and full ROM with partial ROM squat (FP) for the 7-week training intervention. Repeated measures analysis of variance revealed that there was a statistically significant group-by-time interaction for impulse scaled at 50, 90, and 250 milliseconds at 90° of knee flexion and rate of force development at 200 milliseconds with 120° of knee flexion (p ≤ 0.05). There was also a statistically significant time effect (p ≤ 0.05) for the 1RM squat, 1RM partial squat, isometric squat peak force allometrically scaled (IPFa) 90°, IPFa 120°, and impulse allometrically scaled at 50, 90, 200, and 250 milliseconds at 90° and 120° of knee flexion. Additionally, the FP group achieved statistically larger relative training intensities (%1RM) during the final 3 weeks of training (p ≤ 0.05). There was a trend for FP to improve over F in 1RM squat (+3.1%, d = 0.53 vs. 0.32), 1RM partial squat (+4.7%, d = 0.95 vs. 0.69), IPFa 120° (+5.7%, d = 0.52 vs. 0.12), and impulse scaled at 50, 90, 200, and 250 milliseconds at 90° (+6.3 to 13.2%, d = 0.50-1.01 vs. 0.30-0.57) and 120° (+3.4 to 16.8%, d = 0.45-1.11 vs. 0.08-0.37). These larger effect sizes in the FP group can likely be explained their ability to train at larger relative training intensities during the final 3 weeks of training resulting in superior training adaptations. Our findings suggest that partial ROM squats in conjunction with full ROM squats may be an effective training method for improving maximal strength and early force-time curve characteristics in men with previous strength training experience. Practically, partial squats may be beneficial for strength and power athletes during a strength-speed mesocycle while peaking

  10. Comparing the performance-enhancing effects of squats on a vibration platform with conventional squats in recreationally resistance-trained men.

    Science.gov (United States)

    Rønnestad, Bent R

    2004-11-01

    The purpose of this investigation was to compare the performance-enhancing effects of squats on a vibration platform with conventional squats in recreationally resistance-trained men. The subjects were 14 recreationally resistance-trained men (age, 21-40 years) and the intervention period consisted of 5 weeks. After the initial testing, subjects were randomly assigned to either the "squat whole body vibration" (SWBV) group (n = 7), which performed squats on a vibration platform on a Smith Machine, or the "squat"(S) group (n = 7), which performed conventional squats with no vibrations on a Smith Machine. Testing was performed at the beginning and the end of the study and consisted of 1 repetition maximum (1RM) in squat and maximum jump height in countermovement jump (CMJ). A modified daily undulating periodization program was used during the intervention period in both groups. Both groups trained at the same percentage of 1RM in squats (6-10RM). After the intervention, CMJ performance increased significantly only in the SWBV (p squats (p squats performed on a vibration platform compared with squats without vibrations regarding maximal strength and explosive power as long as the external load is similar in recreationally resistance-trained men.

  11. Quadriceps muscle use in the flywheel and barbell squat.

    Science.gov (United States)

    Norrbrand, Lena; Tous-Fajardo, Julio; Vargas, Roberto; Tesch, Per A

    2011-01-01

    Resistance exercise has been proposed as an aid to counteract quadriceps muscle atrophy in astronauts during extended missions in orbit. While space authorities have advocated the squat exercise should be prescribed, no exercise system suitable for in-flight use has been validated with regard to quadriceps muscle use. We compared muscle involvement in the terrestrial "gold standard" squat using free weights and a nongravity dependent flywheel resistance exercise device designed for use in space. The subjects were 10 strength-trained men who performed 5 sets of 10 repetitions using the barbell squat (BS; 10 repetition maximum) or flywheel squat (FS; each repetition maximal), respectively. Functional magnetic resonance imaging (MRI) and surface electromyography (EMG) techniques assessed quadriceps muscle use. Exercise-induced contrast shift of MR images was measured by means of transverse relaxation time (T2). EMG root mean square (RMS) was measured during concentric (CON) and eccentric (ECC) actions and normalized to EMG RMS determined during maximal voluntary contraction. The quadriceps muscle group showed greater exercise-induced T2 increase following FS compared with BS. Among individual muscles, the rectus femoris displayed greater T2 increase with FS (+24 +/- 14%) than BS (+8 +/- 4%). Normalized quadriceps EMG showed no difference across exercise modes. Collectively, the results of this study suggest that quadriceps muscle use in the squat is comparable, if not greater, with flywheel compared with free weight resistance exercise. Data appear to provide support for use of flywheel squat resistance exercise as a countermeasures adjunct during spaceflight.

  12. The acute potentiating effects of back squats on athlete performance.

    Science.gov (United States)

    Crewther, Blair T; Kilduff, Liam P; Cook, Christian J; Middleton, Matt K; Bunce, Paul J; Yang, Guang-Zhong

    2011-12-01

    Crewther, BT, Kilduff, LP, Cook, CJ, Middleton, MK, Bunce, PJ, and Yang, G-Z. The acute potentiating effects of back squats on athlete performance. J Strength Cond Res 25(12): 3319-3325, 2011-This study examined the acute potentiating effects of back squats on athlete performance with a specific focus on movement specificity and the individual timing of potentiation. Nine subelite male rugby players performed 3 protocols on separate occasions using a randomized, crossover, and counterbalanced design. Each protocol consisted of performance testing before a single set of 3 repetition maximum (3RM) back squats, followed by retesting at ∼15 seconds, 4, 8, 12, and 16 minutes. The 3 tests were countermovement jumps (CMJs), sprint performance (5 and 10 m), and 3-m horizontal sled pushes with a 100-kg load. Relationships between the individual changes in salivary testosterone and cortisol concentrations and performance were also examined. The 3RM squats significantly (p squats was found effective in acutely enhancing CMJ height in the study population, especially when the recovery period was individualized for each athlete. The study results also suggest that the potentiating effects of squats may exhibit some degree of movement specificity, being greater for those exercises with similar movement patterns. The current findings have practical implications for prescribing warm-up exercises, individualizing training programs, and for interpreting postactivation potentiation research.

  13. Disease effects on lobster fisheries, ecology, and culture: overview of DAO Special 6.

    Science.gov (United States)

    Behringer, Donald C; Butler, Mark J; Stentiford, Grant D

    2012-08-27

    Lobsters are prized by commercial and recreational fishermen worldwide, and their populations are therefore buffeted by fishery practices. But lobsters also remain integral members of their benthic communities where predator-prey relationships, competitive interactions, and host-pathogen dynamics push and pull at their population dynamics. Although lobsters have few reported pathogens and parasites relative to other decapod crustaceans, the rise of diseases with consequences for lobster fisheries and aquaculture has spotlighted the importance of disease for lobster biology, population dynamics and ecology. Researchers, managers, and fishers thus increasingly recognize the need to understand lobster pathogens and parasites so they can be managed proactively and their impacts minimized where possible. At the 2011 International Conference and Workshop on Lobster Biology and Management a special session on lobster diseases was convened and this special issue of Diseases of Aquatic Organisms highlights those proceedings with a suite of articles focused on diseases discussed during that session.

  14. The influence of knee alignment on lower extremity kinetics during squats.

    Science.gov (United States)

    Slater, Lindsay V; Hart, Joseph M

    2016-12-01

    The squat is an assessment of lower extremity alignment during movement, however there is little information regarding altered joint kinetics during poorly performed squats. The purpose of this study was to examine changes in joint kinetics and power from altered knee alignment during a squat. Thirty participants completed squats while displacing the knee medially, anteriorly, and with neutral alignment (control). Sagittal and frontal plane torques at the ankle, knee, and hip were altered in the descending and ascending phase of the squat in both the medial and anterior malaligned squat compared to the control squat. Ankle and trunk power increased and hip power decreased in the medial malaligned squat compared to the control squat. Ankle, knee, and trunk power increased and hip power decreased in the anterior malaligned squat compared to the control squat. Changes in joint torques and power during malaligned squats suggest that altered knee alignment increases ankle and trunk involvement to execute the movement. Increased anterior knee excursion during squatting may also lead to persistent altered loading of the ankle and knee. Sports medicine professionals using the squat for quadriceps strengthening must consider knee alignment to reduce ankle and trunk involvement during the movement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Difference in the recruitment of hip and knee muscles between back squat and plyometric squat jump.

    Directory of Open Access Journals (Sweden)

    Norihide Sugisaki

    Full Text Available Athletes who aim to improve both muscular endurance and power often perform exercises that involve similar joint actions under different lifting conditions, such as changes in the load or speed, which are implemented at different times during a periodized exercise program or simultaneously. The prescribed exercises are considered to recruit the same muscles even if the lifting conditions differ to each other. The present study aimed to clarify this by examining whether the recruitment of individual hip and knee muscles during the squat exercise differs between lifting conditions adopted for muscular endurance and power training regimens. Moderately trained men performed back squats (BS, with a load of approximately 60% of one repetition maximum, as a muscular endurance training exercise, and they performed plyometric squat jumping (PSJ for power training. During each exercise, the lower limb joint torques and the recruitment of five hip and knee muscles were determined with inverse-dynamics and T2-weighted magnetic resonance imaging, respectively. While the maximal and mean knee joint torques were greater during PSJ than during BS (p<0.01, the T2 values for the quadriceps femoris muscle did not differ between the exercises. In contrast, the T2 values of the gluteus maximus and hip adductor muscles were higher during PSJ (p<0.05 than during BS, although there was no significant difference in the mean hip extension torque between the two exercises. The current results indicate that the individual use of the agonist muscles differs between BS and PSJ, and it does not always correspond with the joint kinetics during the exercises. Therefore, in addition to the exercise type, the lifting condition should also be taken into consideration as a determinant of the major muscles trained during a resistance exercise.

  16. 76 FR 77214 - Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2011-12-12

    ... Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine...: Notification of lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2012 at zero...

  17. 50 CFR 665.249 - Lobster size and condition restrictions in Permit Area 2.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Lobster size and condition restrictions in... WESTERN PACIFIC Hawaii Fisheries § 665.249 Lobster size and condition restrictions in Permit Area 2. (a) Only spiny lobsters with a carapace length of 8.26 cm or greater may be retained (see Figure 1 to this...

  18. Animal behavior frozen in time: gregarious behavior of Early Jurassic lobsters within an ammonoid body chamber.

    Science.gov (United States)

    Klompmaker, Adiël A; Fraaije, René H B

    2012-01-01

    Direct animal behavior can be inferred from the fossil record only in exceptional circumstances. The exceptional mode of preservation of ammonoid shells in the Posidonia Shale (Lower Jurassic, lower Toarcian) of Dotternhausen in southern Germany, with only the organic periostracum preserved, provides an excellent opportunity to observe the contents of the ammonoid body chamber because this periostracum is translucent. Here, we report upon three delicate lobsters preserved within a compressed ammonoid specimen of Harpoceras falciferum. We attempt to explain this gregarious behavior. The three lobsters were studied using standard microscopy under low angle light. The lobsters belong to the extinct family of the Eryonidae; further identification was not possible. The organic material of the three small lobsters is preserved more than halfway into the ammonoid body chamber. The lobsters are closely spaced and are positioned with their tails oriented toward each other. The specimens are interpreted to represent corpses rather than molts. The lobsters probably sought shelter in preparation for molting or against predators such as fish that were present in Dotternhausen. Alternatively, the soft tissue of the ammonoid may have been a source of food that attracted the lobsters, or it may have served as a long-term residency for the lobsters (inquilinism). The lobsters represent the oldest known example of gregariousness amongst lobsters and decapods in the fossil record. Gregarious behavior in lobsters, also known for extant lobsters, thus developed earlier in earth's history than previously known. Moreover, this is one of the oldest known examples of decapod crustaceans preserved within cephalopod shells.

  19. 50 CFR 697.24 - Exempted waters for Maine State American lobster permits.

    Science.gov (United States)

    2010-10-01

    ... lobster permits. 697.24 Section 697.24 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT... lobster permits. A person or vessel holding a valid permit or license issued by the State of Maine that lawfully permits that person to engage in commercial fishing for American lobster may, with the approval of...

  20. Lower extremity muscle functions during full squats.

    Science.gov (United States)

    Robertson, D G E; Wilson, Jean-Marie J; St Pierre, Taunya A

    2008-11-01

    The purpose of this research was to determine the functions of the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. Muscle function was determined from joint kinematics, inverse dynamics, electromyography, and muscle length changes. The subjects were six experienced, male weight lifters. Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during scent. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent.

  1. Net joint moments and muscle activation in barbell squats without and with restricted anterior leg rotation.

    Science.gov (United States)

    Chiu, Loren Z F; vonGaza, Gabriella L; Jean, Liane M Y

    2017-01-01

    Muscle utilisation in squat exercise depends on technique. The purpose of this study was to compare net joint moments (NJMs) and muscle activation during squats without and with restricted leg dorsiflexion. Experienced men (n = 5) and women (n = 4) performed full squats at 80% one repetition maximum. 3D motion analysis, force platform and (EMG) data were collected. Restricting anterior leg rotation reduced anterior leg (P = 0.001) and posterior thigh (P squat depth, ankle plantar flexor (P squats. Hip extensor NJM (P = 0.14) was not different between squat types at maximum squat depth. Vastus lateralis (P > 0.05), vastus medialis (P > 0.05) and rectus femoris (P > 0.05) EMG were not different between squat types. Unrestricted squats have higher ankle plantar flexor and knee extensor NJM than previously reported from jumping and landing. However, ankle plantar flexor and knee extensor NJM are lower in restricted squats than previous studies of jumping and landing. The high NJM in unrestricted squat exercise performed through a full range of motion suggests this squat type would be more effective to stimulate adaptations in the lower extremity musculature than restricted squats.

  2. Lower Extremity Muscle Activation and Kinematics of Catchers When Throwing Using Various Squatting and Throwing Postures

    Directory of Open Access Journals (Sweden)

    Yi-Chien Peng, Kuo-Cheng Lo, Lin-Hwa Wang

    2015-09-01

    Full Text Available This study investigated the differences in joint motions and muscle activities of the lower extremities involved in various squatting postures. The motion capture system with thirty-one reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the quadriceps, biceps femoris, tibialis anterior, and gastrocnemius muscles of the pivot and stride leg. The joint extension and flexion in wide squatting are greater than in general squatting (p = 0.005. Knee joint extension and flexion in general squatting are significantly greater than in wide squatting (p = 0.001. The adduction and abduction of the hip joint in stride passing are significantly greater than in step squatting (p = 0.000. Furthermore, the adduction and abduction of the knee joint in stride passing are also significantly greater than in step squatting (p = 0.000. When stride passing is performed, the muscle activation of the hamstring of the pivot foot in general squatting is significantly greater than in wide squatting (p < 0.05, and this difference continues to the stride period. Most catchers use a general or wide squatting width, exclusive of a narrow one. Therefore, the training design for strengthening the lower extremity muscles should consider the appropriateness of the common squat width to enhance squat-up performance. For lower limb muscle activation, wide squatting requires more active gastrocnemius and tibialis anterior muscles. Baseball players should extend the knee angle of the pivot foot before catching the ball.

  3. Gas pipelines and the American lobster, Homarus americanus

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R.A. [Connecticut Univ., Groton, CT (United States); Clancy, M. [Boston Univ., MA (United States); Cobb, J.S. [Rhode Island Univ., Kingston, RI (United States)

    2003-07-01

    One of the main objectives of the megabenthic study of the New England continental shelf conducted during the 1970s and the 1980s was to define the migratory behavior and overall ecology of the offshore American lobster. The study involved more than 100 manned submersible divers on the outer continental shelf, upper continental slope, Georges Bank and submarine canyons. It also included an extensive lobster tagging program. The study provided valuable information on the ecology and behaviour of the lobster and several other megabenthic fauna that could be affected by the presence of a gas pipeline running parallel to the outer continental shelf, from eastern Georges Bank to northern New Jersey. The study showed that an exposed 2-4 diameter pipeline would impede the normal onshore and offshore migration of this deep water lobster species because its' migration is done by walking rather than swimming, and any overhanging structure would block its path. It was emphasized that it is extremely important to maintain spring to early summer onshore migration in the multi-million dollar lobster industry. This paper offered suggestions for modifying pipe encasements to solve the migration problem.

  4. Biomechanical, anthropometric, and psychological determinants of barbell back squat strength.

    Science.gov (United States)

    Vigotsky, Andrew D; Bryanton, Megan A; Nuckols, Greg; Beardsley, Chris; Contreras, Bret; Evans, Jessica; Schoenfeld, Brad J

    2018-02-27

    Previous investigations of strength have only focused on biomechanical or psychological determinants, while ignoring the potential interplay and relative contributions of these variables. The purpose of this study was to investigate the relative contributions of biomechanical, anthropometric, and psychological variables to the prediction of maximum parallel barbell back squat strength. Twenty-one college-aged participants (male = 14; female = 7; age = 23 ± 3 years) reported to the laboratory for two visits. The first visit consisted of anthropometric, psychometric, and parallel barbell back squat one-repetition maximum (1RM) testing. On the second visit, participants performed isometric dynamometry testing for the knee, hip, and spinal extensors in a sticking point position-specific manner. Multiple linear regression and correlations were used to investigate the combined and individual relationships between biomechanical, anthropometric, and psychological variables and squat 1RM. Multiple regression revealed only one statistically predictive determinant: fat free mass normalized to height (standardized estimate ± SE = 0.6 ± 0.3; t(16) = 2.28; p = 0.037). Correlation coefficients for individual variables and squat 1RM ranged from r = -0.79-0.83, with biomechanical, anthropometric, experiential, and sex predictors showing the strongest relationships, and psychological variables displaying the weakest relationships. These data suggest that back squat strength in a heterogeneous population is multifactorial and more related to physical rather than psychological variables.

  5. Revisiting Maine’s lobster commons: rescaling political subjects

    Directory of Open Access Journals (Sweden)

    Jennifer F. Brewer

    2012-08-01

    Full Text Available Calls for cross-scalar theoretical and methodological approaches are not new to commons scholarship. Such efforts might be hastened by channelling poststructuralist and critical theory perspectives through the geographic subfield of political ecology, including attention to political scales and subjects. Toward this end, this paper reconsiders Maine’s lobster fishery. This case has provided rich material for watershed commons scholarship, demonstrating the ability of social groups to conserve resources independent of government or markets, and it continues to offer new findings. Recent fieldwork shows that as lobster boat captains advance collective interests through state-supported co-management governance arrangements, concerns of crew and non-fishing community members may be marginalized. Regulatory exclusion prevents broader distribution of resource benefits at a time when employment alternatives are scarce. More pluralistic approaches to commons theory and its policy application have utility well beyond the lobster case.

  6. Systematics and position of Nephrops among the lobsters.

    Science.gov (United States)

    Tshudy, Dale

    2013-01-01

    This chapter presents and explains the position of Nephrops norvegicus in the classification of lobsters. Covered, in order, are systematic classification of Nephrops, taxonomic history of Nephrops, and analysis of Nephrops in nephropid phylogeny. The genus Nephrops was erected by Leach in 1814 and has a long and interesting taxonomic history. Prior to 1972, Nephrops was known by 14 Recent species. All but one of these, N. norvegicus, were removed to a new genus, Metanephrops, by Jenkins (1972). Today, N. norvegicus is still the only known living representative of the genus. Similarly, Nephrops is known by only one fossil species, the Miocene Nephrops kvistgaardae, although several other fossil species have been previously referred to this genus. Nephrops, along with the other familiar and commercially important marine clawed lobsters, is referred to Family Nephropidae, one of 17 marine clawed lobster families arrayed in 3 infraorders, 6 families each in the Astacidea and Glypheidea and 5 in the Polychelida. Infraorder Astacidea includes the Superfamily Nephropoidea, as well as the lesser known 'reef lobsters' of the Superfamily Enoplometopoidea, and the freshwater crayfish, Superfamily Astacoidea. In phylogenetic analyses, the freshwater crayfish form a sister group to the Nephropoidea. It is interpreted that freshwater crayfish evolved from nephropoid lobsters, but from which lobster group is uncertain. The taxonomic placement of N. norvegicus is stable at all levels, from species on up. Despite that, the phylogenetic relationships of Nephrops to other nephropid genera are unsettled due to conflicting results in morphological and molecular analyses. Currently, new morphological characters and new genes are being analysed in the hope of elucidating nephropid phylogeny. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Predation Risk within Fishing Gear and Implications for South Australian Rock Lobster Fisheries

    Science.gov (United States)

    Briceño, Felipe; Linnane, Adrian Joseph; Quiroz, Juan Carlos; Gardner, Caleb; Pecl, Gretta Tatyana

    2015-01-01

    Depredation of southern rock lobster (Jasus edwardsii) within fishing gear by the Maori octopus (Pinnoctopus cordiformis) has economic and ecological impacts on valuable fisheries in South Australia. In addition, depredation rates can be highly variable resulting in uncertainties for the fishery. We examined how in-pot lobster predation was influenced by factors such as lobster size and sex, season, fishing zone, and catch rate. Using mixed modelling techniques, we found that in-pot predation risk increased with lobster size and was higher for male lobsters. In addition, the effect of catch rate of lobsters on predation risk by octopus differed among fishing zones. There was both a seasonal and a spatial component to octopus predation, with an increased risk within discrete fishing grounds in South Australia at certain times of the year. Information about predation within lobster gear can assist fishery management decision-making, potentially leading to significant reduction in economic losses to the fishery. PMID:26489035

  8. Predation Risk within Fishing Gear and Implications for South Australian Rock Lobster Fisheries.

    Directory of Open Access Journals (Sweden)

    Felipe Briceño

    Full Text Available Depredation of southern rock lobster (Jasus edwardsii within fishing gear by the Maori octopus (Pinnoctopus cordiformis has economic and ecological impacts on valuable fisheries in South Australia. In addition, depredation rates can be highly variable resulting in uncertainties for the fishery. We examined how in-pot lobster predation was influenced by factors such as lobster size and sex, season, fishing zone, and catch rate. Using mixed modelling techniques, we found that in-pot predation risk increased with lobster size and was higher for male lobsters. In addition, the effect of catch rate of lobsters on predation risk by octopus differed among fishing zones. There was both a seasonal and a spatial component to octopus predation, with an increased risk within discrete fishing grounds in South Australia at certain times of the year. Information about predation within lobster gear can assist fishery management decision-making, potentially leading to significant reduction in economic losses to the fishery.

  9. Spiny lobster Panulirus versicolor filogenetic and genetic in Lombok waters, West Nusa Tenggara, Indonesia

    Directory of Open Access Journals (Sweden)

    Pranata B.

    2018-02-01

    Full Text Available This study aims to identify the phylogenetic spiny lobster Panulirus versicolor in Lombok waters, Indonesia and its association with P. versicolor spiny lobster from several regions of the Indian Ocean based on the cytochrome oxidase I (COI gene. The researchers collected tissue samples from 13 P. versicolor spiny lobster in Lombok waters. 9 haplotypes were identified with haplotype diversity values (Hd and nucleotides (Pi respectively Hd = 0.859 and Pi = 0.00509. Research results exhibit P. versicolor spiny lobster population from the waters of Lombok is closely related to the spiny lobster population in some regions of the Indian Ocean. In general, P. versicolor spiny lobster population formed a monophyletic clone with spiny lobsters from several regions of the Indian Ocean with genetic distance values (P-distance from 0.001 to 0.004. The reconstruction of the haplotype network exhibited no genetic structure, which means that each population is not genetically isolated from others.

  10. On the origin and variation of colors in lobster carapace

    OpenAIRE

    Begum, Shamima; Cianci, Michele; Durbeej, Bo; Falklöf, Olle; Haedener, Alfons; Helliwell, John R.; Helliwell, Madeleine; Regan, Andrew C.; Watt, Ian F.

    2015-01-01

    The chemical basis of the blue-black to pink-orange color change on cooking of lobster, due to thermal denaturation of an astaxanthin-protein complex, alpha-crustacyanin, in the lobster carapace, has so far been elusive. Here, we investigate the relaxation of the astaxanthin pigment from its bound enolate form to its neutral hydroxyketone form, as origin of the spectral shift, by analyzing the response of UV-vis spectra of a water-soluble 3-hydroxy-4-oxo-beta-ionone model of astaxanthin to in...

  11. The Existence of a Sticking Region in Free Weight Squats

    Directory of Open Access Journals (Sweden)

    Tillaar Roland van den

    2014-10-01

    Full Text Available The aim of this study was to investigate the existence of the sticking region in two legged free weight squats. Fifteen resistance-training males (age 24 ± 4 years, body mass 82 ± 11 kg, body height 179 ± 6 cm with 6 ± 3 years of resistance-training experience performed 6-RM in free weight squats. The last repetition was analyzed for the existence of a sticking region. Only in 10 out of 15 participants a sticking region was observed. The observed sticking region was much shorter than in the bench press. Furthermore, rectus femoris decreased the EMG activity in contrast to increased EMG activity in biceps femoris around the sticking and surrounding region. No significant change in EMG activity was found for the lateral and medial vastus muscles. It is suggested that a combination of these muscle activity changes could be one of the causes of the existence of the sticking region in free weight squats

  12. The existence of a sticking region in free weight squats.

    Science.gov (United States)

    van den Tillaar, Roland; Andersen, Vidar; Saeterbakken, Atle Hole

    2014-09-29

    The aim of this study was to investigate the existence of the sticking region in two legged free weight squats. Fifteen resistance-training males (age 24 ± 4 years, body mass 82 ± 11 kg, body height 179 ± 6 cm) with 6 ± 3 years of resistance-training experience performed 6-RM in free weight squats. The last repetition was analyzed for the existence of a sticking region. Only in 10 out of 15 participants a sticking region was observed. The observed sticking region was much shorter than in the bench press. Furthermore, rectus femoris decreased the EMG activity in contrast to increased EMG activity in biceps femoris around the sticking and surrounding region. No significant change in EMG activity was found for the lateral and medial vastus muscles. It is suggested that a combination of these muscle activity changes could be one of the causes of the existence of the sticking region in free weight squats.

  13. Squatting to end domicide? Resisting bulldozer urbanism in contemporary Shanghai

    Directory of Open Access Journals (Sweden)

    Zhang, Yunpeng

    2015-09-01

    Full Text Available For millions of Shanghainese on the lower rung of society, the history of the great urban transformation in the city since the 1990s is written with their tears for the loss of their homes, communities and livelihood. In this paper, I argue for squatting as a straightforward, effective and potentially radical strategy to redress the displacees’ suffering, to take a more active and progressive control of the violent accumulation process and to challenge the hegemonic discourse of private homeownership that underpins the rapid transformation of Shanghai’s urban landscape. The argument is built upon an in-depth study of a family evicted by the World Expo 2010 and squatted in a resettlement apartment. Their framing of justice and entitlement, embedded in local cultural and moral universes, not only lends legitimacy to their squatting but also mobilises popular sympathy, both of which are conducive to effective resistance.

  14. Dynamic Wheel/Rail Rolling Contact at Singular Defects with Application to Squats

    NARCIS (Netherlands)

    Zhao, X.

    2012-01-01

    Squats, as a kind of short wavelength rail surface defects, have become one of the main rolling contact fatigue problems in railways worldwide. The purpose of this work is to better understand the squatting phenomenon, contribute to reduction and even prevention of squat occurrence, and thereby

  15. Reap what you sow! - But what about SPC squatting?

    DEFF Research Database (Denmark)

    Schovsbo, Jens Hemmingsen; Klinge, Ulla Callesen; Minssen, Timo

    2018-01-01

    Regulations, as well as the practical and theoretical significance of this issue, the lack of judicial guidance is problematic. It is important to address such situations for the sake of legal certainty and in order to enable companies to make strategic decisions. SPC squatting also involves a crucial debate...... about the rationales underlying the SPC system and the question whether such activities are compatible with the very goals of the Regulations. This paper provides an overview on the legal status quo with regard to SPC squatting and discusses if - and if so, under what circumstances - such practices...

  16. Historical commercial West Coast rock lobster Jasus lalandii ...

    African Journals Online (AJOL)

    Historic data from 1891 to 2001 on the annual exports of rock lobster Jasus lalandii products (canned, frozen tails, raw whole frozen, cooked whole frozen and live) from the South African west coast are used to estimate the annual commercial landings by this fishery. Conversion factors were developed to convert canned, ...

  17. Distribution of slipper lobsters (Decapoda: Scyllaridae in Uruguayan waters

    Directory of Open Access Journals (Sweden)

    Fabrizio Scarabino

    2017-09-01

    Full Text Available Abstract Scyllarid lobsters are commonly found in tropical waters with scarce records from temperate zones in the southwestern Atlantic. Here, we provide new information about the distribution of Scyllarides deceptor Holthuis, 1963 along the Uruguayan continental shelf and include a new austral record for Scyllarus depressus (Smith, 1881.

  18. From Lobster Shells to Plastic Objects: A Bioplastics Activity

    Science.gov (United States)

    Hudson, Reuben; Glaisher, Samuel; Bishop, Alexandra; Katz, Jeffrey L.

    2015-01-01

    A multiple day activity for students to create large-scale plastic objects from the biopolymer chitin (major component of lobster, crab, and shrimp shells) is described. The plastic objects created are durable and made from benign materials, making them suitable for students to take home to play with. Since the student-created plastic objects are…

  19. Detection of Panulirus argus Virus 1 in Caribbean spiny lobsters.

    Science.gov (United States)

    Montgomery-Fullerton, Megan M; Cooper, Roland A; Kauffman, Kathryn M; Shields, Jeffrey D; Ratzlaff, Robert E

    2007-06-07

    Panulirus argus Virus 1 (PaV1) is a pathogenic virus that infects Caribbean spiny lobsters P. argus in the Florida Keys. We have developed a PCR detection assay for PaV1 for the purpose of studying the natural history of the virus and for monitoring the prevalence of infection. The detection of the virus in hemolymph and other tissues is based on the PCR amplification of a 499 bp product using specific primers designed from a cloned fragment of the PaV1 genome. The sensitivity limit for the assay was 1.2 fg of purified viral DNA. The PaV1 primers did not react with lobster DNA, oyster DNA, Ostreid Herpesvirus 1, or murine cytomegalovirus. Using this assay, we successfully followed the course of infection in lobsters inoculated with PaV1 and we detected infections in wild-caught lobsters from the Florida Keys. We have also established guidelines for interpreting infection results from the PCR assay for PaV1.

  20. The Lobster Tale: An Exercise in Critical Thinking

    Science.gov (United States)

    Stepanovich, Paul L.

    2009-01-01

    Professors in management and business are encouraged to incorporate critical thinking as an objective in their courses. "The Lobster Tale" provides an opportunity to engage students in various levels of critical thinking, ranging from a relatively superficial reading to an examination of the deeper, often hidden issues. Using the foundations of…

  1. Reproductive biology of spiny lobster Panulirus regius from the ...

    African Journals Online (AJOL)

    Reproductive biology of spiny lobster Panulirus regius from the northwestern Cape Verde Islands. R Freitas, A Medina, S Correira, M Castro. Abstract. No Abstract. African Journal of Marine Science Vol.29(2) 2007: pp. 201-208. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  2. Predation by West Coast rock lobsters (Jasus lalandit) on two ...

    African Journals Online (AJOL)

    opened black mussel to ensure that they were feeding. Each rock lobster was then starved for a further 24h to ensure equal starvation levels and complete clearance of the digestive tract. (Zoutendyk 1988). before each of the following experiments was performed. For all experiments described below, winkle measurements ...

  3. Aspects of Automation in a Lobster Farming Plant

    Directory of Open Access Journals (Sweden)

    Steinar Grimsen

    1987-01-01

    Full Text Available This paper describes the automation aspects of rearing juvenile lobsters for sea ranching. It gives an outline of rearing techniques and presents specifications for a feeding system. A description is given of the equipment that has been developed. Other automation and instrumentation tasks are briefly discussed.

  4. Parasites of crayfish ( P. clarki ) and lobsters ( Macrobrachium ...

    African Journals Online (AJOL)

    Studies on parasites of crayfish and lobsters as indicators of metal pollution in Great Kwa River, Nigeria was evaluated using appropriate instruments for determination of Physicochemical parameters and detection of metals. Formol ether centrifugation method was used for isolation of parasites. A total of 150 crayfish and ...

  5. Pengambilan Keputusan Waktu Panen Pada Usaha Pembesaran Lobster di Pulau Lombok Provinsi NTB

    Directory of Open Access Journals (Sweden)

    Deden Kurniawan

    2017-08-01

    Full Text Available Lobsters represent as a valuable commodity to be determined by their length and weight. In Indonesia, the minimum legal size of lobster is 7cm of carapace length and 200 grams of weight, and this is stipulated on regulation of Ministry of Marine Affairs and Fisheries No.1/2015. Instead of behaving in accordance with the rule, farmers still harvest lobsters as soon as they are of marketable size to reduce the risk of mortality and to generate income instantly. This paper develops a structural equation model partially least square (SEM PLS to analyze decision making process to harvest lobster in Indonesia. The study established by structural equation modeling partially least square shows that the decision making to harvest lobster is driven by patron-client relationship, time constraint, and working complexity.Keywords: lobster growing activities, decision to harvest, Lombok, SEM PLSABSTRAKLobster sebagai komoditas yang berharga ditentukan oleh ukuran panjang dan berat. Di Indonesia, berdasarkan Peraturan Menteri Kelautan dan Perikanan No.1 / 2015, ukuran minimal lobster adalah memiliki panjang karapas 7cm dan berat 200 gram. Pelaku usaha pembesaran lobster justru tidak mentaati aturan yang ada, ukuran lobster yang dipanen justru ditentukan oleh permintaan pasar yang dilakukan untuk mengurangi risiko kematian lobster dan mempercepat waktu dalam memperoleh penghsilan. Penelitian ini dilakukan untuk melakukan analisis keputusan waktu panen lobster di Indonesia. Metode yang digunakan adalah model persamaan struktural sebagian least square (SEM PLS. Hasil studi menunjukkan bahwa keputusan untuk memanen lobster ditentukan oleh hubungan patron dengan klien, keterbatasan waktu, dan kompleksitas pekerjaan.Kata kunci: kegiatan pembesaran lobster, keputusan waktu panen, Lombok, SEM PLS

  6. Methodological concerns for determining power output in the jump squat.

    Science.gov (United States)

    Cormie, Prue; Deane, Russell; McBride, Jeffrey M

    2007-05-01

    The purpose of this study was to investigate the validity of power measurement techniques during the jump squat (JS) utilizing various combinations of a force plate and linear position transducer (LPT) devices. Nine men with at least 6 months of prior resistance training experience participated in this acute investigation. One repetition maximums (1RM) in the squat were determined, followed by JS testing under 2 loading conditions (30% of 1RM [JS30] and 90% of 1RM [JS90]). Three different techniques were used simultaneously in data collection: (a) 1 linear position transducer (1-LPT); (b) 1 linear position transducer and a force plate (1-LPT + FP); and (c) 2 linear position transducers and a force place (2-LPT + FP). Vertical velocity-, force-, and power-time curves were calculated for each lift using these methodologies and were compared. Peak force and peak power were overestimated by 1-LPT in both JS30 and JS90 compared with 2-LPT + FP and 1-LPT + FP (p squat varies according to the measurement technique utilized. The 1-LPT methodology is not a valid means of determining power output in the jump squat. Furthermore, the 1-LPT + FP method may not accurately represent power output in free weight movements that involve a significant amount of horizontal motion.

  7. Biomechanical analysis of the single-leg decline squat

    NARCIS (Netherlands)

    Zwerver, J.; Bredeweg, S. W.; Hof, A. L.

    Background: The single-leg squat on a 25 decline board has been described as a clinical assessment tool and as a rehabilitation exercise for patients with patellar tendinopathy. Several assumptions have been made about its working mechanism on patellar load and patellofemoral forces, but these are

  8. Why is countermovement jump height greater than squat jump height?

    NARCIS (Netherlands)

    Bobbert, Maarten F.; Gerritsen, Karin G M; Litjens, Maria C A; Van Soest, Arthur J.

    1996-01-01

    In the literature, it is well established that subjects are able to jump higher in a countermovement jump (CMJ) than in a squat jump (SJ). The purpose of this study was to estimate the relative contribution of the time available for force development and the storage and reutilization of elastic

  9. Praktik Trademark Squatting dalam Proses Pendaftaran Merek di Indonesia

    Directory of Open Access Journals (Sweden)

    Widya Justitia

    2016-04-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui dan menganalisis mengapa praktik trademark squatting dapat terjadi dalam proses pendaftaran merek beserta cara mengatasinya. Selanjutnya, penelitian ini juga membahas mengenai konsepsi ideal terkait proses pendaftaran merek di Indonesia guna menghindari dan meminimalisasi praktik trademark squatting. Penelitian ini merupakan penelitian kualitatif yang bersifat yuridis empiris dan data yang terkumpul dianalisa dengan metode deskriptif kualitatif. Hasil penelitian menunjukkan bahwa praktik trademark squatting merupakan suatu tindakan mendaftarkan merek milik orang lain yang belum terdaftar, sehingga membuat pemilik merek yang sebenarnya tidak dapat lagi mendaftarkan mereknya. Setelah itu, pelaku menjual sertifikat hak atas merek tersebut kepada pemilik aslinya dengan harga melebihi biaya permohonan pendaftaran merek pada umumnya. Kendala yang ditemui dalam proses pendaftaran merek di Indonesia adalah kurangnya sumber daya manusia dalam menangani jumlah permohonan pendaftaran merek yang mencapai ribuan setiap harinya. Hal ini berdampak pada tidak optimalnya proses pendaftaran merek di Indonesia yaitu dengan menggagas suatu sistem yang bernama first to file based on use guna mengoptimalisasikan perlindungan pemilik merek, pertimbangan untuk meratifikasi Madrid System juga merupakan salah satu opsi lain untuk mencegah praktik trademark squatting. Abstract The purpose of this research is to identify and analyze why the practice of trademark squatting could occur in Indonesia's trademark registration process along with the constraints found in the trademark registration process in Indonesia and how to overcome them. Furthermore, it will also discuss the ideal conception related to trademark registration process to avoid and minimize the practice of trademark squatting. This research is an empirical legal research and all data were analyzed with qualitative methods. The results showed that trademark squatting is

  10. Patellar tendon load in different types of eccentric squats.

    Science.gov (United States)

    Frohm, A; Halvorsen, K; Thorstensson, A

    2007-07-01

    Differences in mechanical loading of the patellar tendon have been suggested as a reason for varying effects in rehabilitation of patellar tendinopathy using different eccentric squat exercises and devices. The aim was to characterize the magnitude and pattern of mechanical load at the knee and on the patellar tendon during four types of eccentric squat. Subjects performed squats with a submaximal free weight and with maximal effort in a device for eccentric overloading (Bromsman), on a decline board and horizontal surface. Kinematics was recorded with a motion-capture system, reaction forces with force plates, and electromyography from three leg muscles with surface electrodes. Inverse dynamics was used to calculate knee joint kinetics. Eccentric work, mean and peak patellar tendon force, and angle at peak force were greater (25-30%) for squats on decline board compared to horizontal surface with free weight, but not in Bromsman. Higher knee load forces (60-80%), but not work, were observed with Bromsman than free weight. Angular excursions at the knee and ankle were larger with decline board, particularly with free weight, and smaller in Bromsman than with free weight. Mean electromyography was greater on a decline board for gastrocnemius (13%) and vastus medialis (6%) with free weight, but in Bromsman only for gastrocnemius (7%). The results demonstrated clear differences in the biomechanical loading on the knee during different squat exercises. Quantification of such differences provides information that could be used to explain differences in rehabilitation effects as well as in designing more optimal rehabilitation exercises for patellar tendinopathy.

  11. Core strength and lower extremity alignment during single leg squats.

    Science.gov (United States)

    Willson, John D; Ireland, Mary Lloyd; Davis, Irene

    2006-05-01

    Muscles of the trunk, hip, and knee influence the orientation of the lower extremity during weight bearing activities. The purpose of this study was threefold: first, to compare the orientation of the lower extremity during a single leg (SL) squat among male and female athletes; second, to compare the strength of muscle groups in the trunk, hips, and knees between these individuals; and third, to evaluate the association between trunk, hip, and knee strength and the orientation of the knee joint during this activity. Twenty-four male and 22 female athletes participated in this study. Peak isometric torque was determined for the following muscle actions: trunk flexion, extension, and lateral flexion, hip abduction and external rotation, and knee flexion and extension. The frontal plane projection angle (FPPA) of the knee during a 45 degrees SL squat was determined using photo editing software. Males and females moved in opposite directions during the SL squat test (F(1,42) = 5.05, P = 0.03). Females typically moved toward more extreme FPPA during SL squats (P = 0.056), while males tended to move toward more neutral alignment (P = 0.066). Females also generated less torque in all muscle groups, with the exception of trunk extension. The projection angle of the knee during the SL squat test was most closely associated with hip external rotation strength. Using instruments suitable for a clinical setting, females were found to have greater FPPA and generally decreased trunk, hip, and knee isometric torque. Hip external rotation strength was most closely associated with the frontal plane projection angle.

  12. Animal behavior frozen in time: gregarious behavior of Early Jurassic lobsters within an ammonoid body chamber.

    Directory of Open Access Journals (Sweden)

    Adiël A Klompmaker

    Full Text Available Direct animal behavior can be inferred from the fossil record only in exceptional circumstances. The exceptional mode of preservation of ammonoid shells in the Posidonia Shale (Lower Jurassic, lower Toarcian of Dotternhausen in southern Germany, with only the organic periostracum preserved, provides an excellent opportunity to observe the contents of the ammonoid body chamber because this periostracum is translucent. Here, we report upon three delicate lobsters preserved within a compressed ammonoid specimen of Harpoceras falciferum. We attempt to explain this gregarious behavior. The three lobsters were studied using standard microscopy under low angle light. The lobsters belong to the extinct family of the Eryonidae; further identification was not possible. The organic material of the three small lobsters is preserved more than halfway into the ammonoid body chamber. The lobsters are closely spaced and are positioned with their tails oriented toward each other. The specimens are interpreted to represent corpses rather than molts. The lobsters probably sought shelter in preparation for molting or against predators such as fish that were present in Dotternhausen. Alternatively, the soft tissue of the ammonoid may have been a source of food that attracted the lobsters, or it may have served as a long-term residency for the lobsters (inquilinism. The lobsters represent the oldest known example of gregariousness amongst lobsters and decapods in the fossil record. Gregarious behavior in lobsters, also known for extant lobsters, thus developed earlier in earth's history than previously known. Moreover, this is one of the oldest known examples of decapod crustaceans preserved within cephalopod shells.

  13. Using squat testing to predict training loads for lower-body exercises in elite karate athletes.

    Science.gov (United States)

    Wong, Del P; Tan, Erik C H; Chaouachi, Anis; Carling, Christopher; Castagna, Carlo; Bloomfield, Jonathan; Behm, David G

    2010-11-01

    The purpose of this study was to determine the relationship between squat loads and 2 bilateral and 2 unilateral stepping lower-body exercises in predominantly unilateral movement elite athletes (Karate). Equations to predict loads for lower-body exercises based on the squat load were also determined. Fourteen male elite Karate athletes (age = 22.6 ± 1.2 years) performed 6 repetition maximum (RM) of the following free-weight bilateral exercises: back half squat, deadlift, leg press and unilateral stepping exercises, lunge; and step-up. Results showed that 6RM squat load was significantly (p squat load was a significant predictor for deadlift, leg press, lunge, and step-up (R2 range from 0.57 to 0.85, p squat load (1.12)-16.60 kg, (b) Leg press = squat load (1.66) + 16.10 kg, (c) Lunge = squat load (0.61) + 9.39 kg, and (d) step-up = squat load (0.85)-10.36 kg. Coaches and fitness professionals can use the 6RM squat load as a time effective and accurate method to predict training loads for both bilateral and unilateral lower-body exercises with quadriceps as the prime mover. Load prescriptions for unilateral exercises should take into account the type of athletic population.

  14. Effect of natural and laboratory diet on O : N ratio in juvenile lobsters (Homarus americanus).

    Science.gov (United States)

    Brown, Anne Christine

    2006-05-01

    Oxygen consumption and ammonia excretion rates of juvenile lobsters spanning the size range from shelter-restricted to vagile (7-60 mm CL, carapace length) were measured. There are no significant size-dependent break points in the slope of oxygen consumption or nitrogen excretion rates versus weight in freshly caught wild or laboratory fed lobsters. This suggests that there are no inherent changes in energy metabolism in juvenile lobster in the 7-60 mm CL range (stage V to adolescent lobsters), despite major behavioral shifts related to foraging and shelter use. In addition, the O : N ratio of freshly caught wild lobsters (15.7+/-7.4, mean+/-S.D.) is not significantly different from that of lobsters fed brown algae (13.4+/-4.9) or a mixed carbohydrate/protein diet (13.7+/-6.8) in lab. The O : N ratio of wild lobsters is significantly higher than lobsters fed a high protein diet (7.5+/-2.5) in the lab. This suggests that carbohydrates, particularly algal-derived carbohydrates, make up a significant portion of the metabolic fuel of wild juvenile lobsters from settlement through adolescence.

  15. Bait and the susceptibility of American lobsters Homarus americanus to epizootic shell disease.

    Science.gov (United States)

    Bethoney, N David; Stokesbury, Kevin D E; Stevens, Bradley G; Altabet, Mark A

    2011-05-24

    Shell disease (SD) has been observed in lobster populations for almost a hundred years, but recently, rates of an epizootic form of shell disease (ESD) have increased in the southern New England (USA) area. A large proportion of fish in the diet of American lobsters Homarus americanus has been linked to increased rates of SD. Therefore, the use of fish as lobster bait may be linked to increased ESD rates in lobsters. Lobsters from the western portion of Martha's Vineyard, MA (41 degrees N, 71 degrees W), were randomly divided into 3 groups of 16 and exposed to dietary treatments (100% herring; 48% crab, 48% blue mussel and 4% plant matter; or 50% herring, 24% crab, 24% mussel, 2% plant matter) to determine if lobster tissue delta15N levels reflected diet. The results of the feeding experiment confirmed that differences in diet are observed in the delta15N levels of lobster muscle tissue. The delta15N levels of tissue samples from 175 wild lobsters with varying degrees of ESD were unrelated to ESD severity but did indicate lobsters were eating large amounts of fish (bait). This result does not support the speculation that fish used as bait is contributing to ESD outbreaks in portions of the southern New England area.

  16. Size-dependent avoidance of a strong magnetic anomaly in Caribbean spiny lobsters.

    Science.gov (United States)

    Ernst, David A; Lohmann, Kenneth J

    2018-03-01

    On a global scale, the geomagnetic field varies predictably across the Earth's surface, providing animals that migrate long distances with a reliable source of directional and positional information that can be used to guide their movements. In some locations, however, magnetic minerals in the Earth's crust generate an additional field that enhances or diminishes the overall field, resulting in unusually steep gradients of field intensity within a limited area. How animals respond to such magnetic anomalies is unclear. The Caribbean spiny lobster, Panulirus argus , is a benthic marine invertebrate that possesses a magnetic sense and is likely to encounter magnetic anomalies during migratory movements and homing. As a first step toward investigating whether such anomalies affect the behavior of lobsters, a two-choice preference experiment was conducted in which lobsters were allowed to select one of two artificial dens, one beneath a neodymium magnet and the other beneath a non-magnetic weight of similar size and mass (control). Significantly more lobsters selected the control den, demonstrating avoidance of the magnetic anomaly. In addition, lobster size was found to be a significant predictor of den choice: lobsters that selected the anomaly den were significantly smaller as a group than those that chose the control den. Taken together, these findings provide additional evidence for magnetoreception in spiny lobsters, raise the possibility of an ontogenetic shift in how lobsters respond to magnetic fields, and suggest that magnetic anomalies might influence lobster movement in the natural environment. © 2018. Published by The Company of Biologists Ltd.

  17. Keanekaragaman dan Potensi Lobster (Malacostraca: Palinuridae di Pantai Pameungpeuk, Garut Selatan, Jawa Barat

    Directory of Open Access Journals (Sweden)

    Rianta Pratiwi

    2018-01-01

    Full Text Available Coral shrimp (Panulirus spp. or known as lobster is a potential fishery commodity and economic value. The demand for domestic and export market continues to increase both as local consumption and export. Indonesia is the largest lobster fishery producer in almost all Indonesian waters, from the west coast of Sumatra to the east coast Jayapura, one of which is Pameungpeuk beach, South Garut, West Java. As a result of increasing demand, fishermen try to catch as many lobsters and the impact of lobster prices also in creases and whereas fishermen continuously take it from nature. This study was conducted to determine the diversity and potential of lobster species especially living in high wavy waters along the southern coast of Garut (Pamengpeuk, West Java.The results of observation are only three types of crayfish, namely: a. Panulirus homarus (green lobster sand; b. Panulirus longipes (lobster flower/ red lobster and Panulirus versicolor (green lobster/bamboo; is most commonly found in the area of south Garut, Pameungpeuk beach with high and strong waves. The percentage of female P longipes species (42.88% was higher compared to male P. homarus (40% and ovigerous female of P. versicolor (37.14%. While the sexual ratio between P. homarus (1:2.0:2.0; P. longipes (1:1.2:1.0 and P. versicolor: 1:1.2:1.2  which statistically showed significantly different p <0.05.

  18. The use of the isometric squat as a measure of strength and explosiveness.

    Science.gov (United States)

    Bazyler, Caleb D; Beckham, George K; Sato, Kimitake

    2015-05-01

    The isometric squat has been used to detect changes in kinetic variables as a result of training; however, controversy exists in its application to dynamic multijoint tasks. Thus, the purpose of this study was to further examine the relationship between isometric squat kinetic variables and isoinertial strength measures. Subjects (17 men, 1-repetition maximum [1RM]: 148.2 ± 23.4 kg) performed squats 2 d · wk(-1) for 12 weeks and were tested on 1RM squat, 1RM partial squat, and isometric squat at 90° and 120° of knee flexion. Test-retest reliability was very good for all isometric measures (intraclass correlation coefficients > 0.90); however, rate of force development 250 milliseconds at 90° and 120° seemed to have a higher systematic error (relative technical error of measurement = 8.12%, 9.44%). Pearson product-moment correlations indicated strong relationships between isometric peak force at 90° (IPF 90°) and 1RM squat (r = 0.86), and IPF 120° and 1RM partial squat (r = 0.79). Impulse 250 milliseconds (IMP) at 90° and 120° exhibited moderate to strong correlations with 1RM squat (r = 0.70, 0.58) and partial squat (r = 0.73, 0.62), respectively. Rate of force development at 90° and 120° exhibited weak to moderate correlations with 1RM squat (r = 0.55, 0.43) and partial squat (r = 0.32, 0.42), respectively. These findings demonstrate a degree of joint angle specificity to dynamic tasks for rapid and peak isometric force production. In conclusion, an isometric squat performed at 90° and 120° is a reliable testing measure that can provide a strong indication of changes in strength and explosiveness during training.

  19. Forecasting the Seasonal Timing of Maine's Lobster Fishery

    Directory of Open Access Journals (Sweden)

    Katherine E. Mills

    2017-11-01

    Full Text Available The fishery for American lobster is currently the highest-valued commercial fishery in the United States, worth over US$620 million in dockside value in 2015. During a marine heat wave in 2012, the fishery was disrupted by the early warming of spring ocean temperatures and subsequent influx of lobster landings. This situation resulted in a price collapse, as the supply chain was not prepared for the early and abundant landings of lobsters. Motivated by this series of events, we have developed a forecast of when the Maine (USA lobster fishery will shift into its high volume summer landings period. The forecast uses a regression approach to relate spring ocean temperatures derived from four NERACOOS buoys along the coast of Maine to the start day of the high landings period of the fishery. Tested against conditions in past years, the forecast is able to predict the start day to within 1 week of the actual start, and the forecast can be issued 3–4 months prior to the onset of the high-landings period, providing valuable lead-time for the fishery and its associated supply chain to prepare for the upcoming season. Forecast results are conveyed in a probabilistic manner and are updated weekly over a 6-week forecasting period so that users can assess the certainty and consistency of the forecast and factor the uncertainty into their use of the information in a given year. By focusing on the timing of events, this type of seasonal forecast provides climate-relevant information to users at time scales that are meaningful for operational decisions. As climate change alters seasonal phenology and reduces the reliability of past experience as a guide for future expectations, this type of forecast can enable fishing industry participants to better adjust to and prepare for operating in the context of climate change.

  20. Potential production of the Caribbean spiny lobster (Decapoda, Palinura) fisheries

    OpenAIRE

    Chávez Ortiz, Ernesto Aarón

    2009-01-01

    Spiny lobster Panulirus argus (Latreille, 1804) constitutes the most important fishery of the Caribbean; it accounts for nearly 42,000 tonnes. Evidence suggests that high fishing mortality (F) may have been overexploiting most stocks. An assessment was carried out providing the basis for a sustainable exploitation of the nine most important producing countries. Values were assessed and each fishery was simulated; age structure was reconstructed linking biological, economic, and social variabl...

  1. Metelkova mon amour Reflections on the (Non-Culture of Squatting

    Directory of Open Access Journals (Sweden)

    Jasna Babić

    2013-09-01

    Full Text Available In some circles in Slovenia the name Autonomous Cultural Center Metelkova City is considered to be almost a synonym of squatting. Although Metelkova was not the first public squat, it definitely remains the oldest of those still around. Drawing comparisons with the international squatting movement, the squatter community in Metelkova is analyzed on different levels: to what extent it nurtures the culture of squatting, and what was and remains the role that Metelkova plays in a wider Slovenian context in terms of developing and sustaining the squatting culture. The article ends with the conclusion that the squatter movement in Metelkova (and elsewhere in Slovenia has so far failed to fully develop, nurture and maintain strict guidelines and principles, and that this can be attributed to the lack of squatting tradition, the large number of people involved in the project, and the internal division among them on the legalization issue.

  2. Changing Ocean, Changing Economics: Impact of Rising Temperatures on the American Lobster Landings and on the US-Canada Lobster Economics in the Emerging Chinese Market

    Science.gov (United States)

    Sun, C. H. J.

    2016-02-01

    Record high temperatures in 2012 pushed the start date of the Maine lobster fishing season three weeks earlier than normal. High landings during a compressed time period more than doubled the volume experienced in June and July. As supply outpaced demand, an average 40% decrease in ex-vessel price significantly reduced fishermen's profitability. This study examined how the timing and location of lobster landings is affected by ocean temperatures, number of trips, distance fished from shore, price, and seasonality. Weekly lobster landings and the number of fishing trips in eastern, central, and western Maine from 2008 to 2014 were combined with NERACOOS buoy temperatures to model the change in productivity. The model shows warming leads to significant increases in landings. We also used monthly landings, prices, and trade of live and processed lobster between the U.S. and Canada from 1990 to 2014 to specify a system of equations that captures how both markets are integrated and how they respond to changing market conditions. The model shows that an increase in landings in both areas leads to an increase in lobster trade and then to an increase in US imports of frozen lobster meat. Furthermore, lobster exports to the emerging Chinese market started to expand after 2012 and grew to account for 21% and 11% of the exports value from U.S. and Canada, respectively. From 2010 to 2014, a sub-system model is specified to address how increasing demand in the Chinese market for hard-shell lobster could create incentives to delay production and increase the supply of hard-shell live lobster. The full model was then used to explore ways in which this coastal social-ecological system can adapt to increasing ocean temperature and how the integrated global market might alter the economic implications of the next ocean heatwave.

  3. Muscle Activity in Single- vs. Double-Leg Squats.

    Science.gov (United States)

    DeFOREST, Bradley A; Cantrell, Gregory S; Schilling, Brian K

    Muscular activity, vertical displacement and ground reaction forces of back squats (BS), rear-leg elevated split squats (RLESS) and split squats (SS) were examined. Nine resistance-trained men reported for two sessions. The first session consisted of the consent process, practice, and BS 1-repetition maximum testing. In the second session, participants performed the three exercises while EMG, displacment and ground reaction force data (one leg on plate) were collected. EMG data were collected from the gluteus maximus (GMX), biceps femoris (BF), semitendinosus (ST), rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), and medial gastrocnemius (MGas) of the left leg (non-dominant, front leg for unilateral squats). Load for BS was 85% one repetition maximum, and RLESS and SS were performed at 50% of BS load. Repeated measures ANOVA was used to compare all variables for the three exercises, with Bonferroni adjustments for post hoc multiple comparisons, in addition to calculation of standardized mean differences (ES). Muscle activity was similar between exercises except for biceps femoris, which was significantly higher during RLESS than SS during both concentric and eccentric phases (ES = 2.11; p=0.012 and ES= 2.19; p=0.008), and significantly higher during BS than the SS during the concentric phase (ES = 1.78; p=0.029). Vertical displacement was similar between all exercises. Peak vertical force was similar between BS and RLESS and significantly greater during RLESS than SS (ES = 3.03; p=0.001). These findings may be helpful in designing resistance training programs by using RLESS if greater biceps femoris activity is desired.

  4. Determination of moulting events in rock lobsters from pleopod clipping.

    Science.gov (United States)

    Gardner, Caleb; Mills, David J

    2013-01-01

    Rock lobster growth is routinely measured for research to optimise management measures such as size limits and quotas. The process of estimating growth is complicated in crustaceans as growth only occurs when the animal moults. As data are typically collected by tag-recapture methods, the timing of moulting events can bias results. For example, if annual moulting events take place within a very short time-at-large after tagging, or if time-at-large is long and no moulting occurs. Classifying data into cases where moulting has / has not occurred during time-at-large can be required and can generally be determined by change in size between release and recapture. However, in old or slow growth individuals the moult increment can be too small to provide surety that moulting has occurred. A method that has been used since the 1970's to determine moulting in rock lobsters involves clipping the distal portion of a pleopod so that any regeneration observed at recapture can be used as evidence of a moult. We examined the use of this method in both tank and long-duration field trials within a marine protected area, which provided access to large animals with smaller growth increments. Our results emphasised that determination of moulting by change in size was unreliable with larger lobsters and that pleopod clipping can assist in identifying moulting events. However, regeneration was an unreliable measure of moulting if clipping occurred less than three months before the moult.

  5. Determination of moulting events in rock lobsters from pleopod clipping.

    Directory of Open Access Journals (Sweden)

    Caleb Gardner

    Full Text Available Rock lobster growth is routinely measured for research to optimise management measures such as size limits and quotas. The process of estimating growth is complicated in crustaceans as growth only occurs when the animal moults. As data are typically collected by tag-recapture methods, the timing of moulting events can bias results. For example, if annual moulting events take place within a very short time-at-large after tagging, or if time-at-large is long and no moulting occurs. Classifying data into cases where moulting has / has not occurred during time-at-large can be required and can generally be determined by change in size between release and recapture. However, in old or slow growth individuals the moult increment can be too small to provide surety that moulting has occurred. A method that has been used since the 1970's to determine moulting in rock lobsters involves clipping the distal portion of a pleopod so that any regeneration observed at recapture can be used as evidence of a moult. We examined the use of this method in both tank and long-duration field trials within a marine protected area, which provided access to large animals with smaller growth increments. Our results emphasised that determination of moulting by change in size was unreliable with larger lobsters and that pleopod clipping can assist in identifying moulting events. However, regeneration was an unreliable measure of moulting if clipping occurred less than three months before the moult.

  6. Microbiological evaluation of South Australian rock lobster meat.

    Science.gov (United States)

    Yap, A S

    1977-12-01

    Samples of frozen precooked rock lobster meat from five South Australian fish-processing plants situated in the West Coast and south-east regions were tested over a period of six months during the 1974/5 lobster fishing season. The most probable number (MPN) of E. coli and coliforms, Staphylococcus aureus and Salmonella, as well as total plate count (TPC) were determined in 480 samples. Monthly geometric mean TPC ranged from 1600/g to 25,000/g. The highest geometric mean of the MPN of coliforms and E. coli were 4.9/g and 1.8/g respectively. The highest geometric mean number of staphylococci was 18.6/g. Salmonella was not detected in the 480 units tested. Only 0.4% of the samples had TPC exceeding 100,000/g. Coliforms and E. coli were not present in 76.1% and 92.7% respectively of the samples tested. Staphylococcus aureus was not detected in 67.7% of the samples. The numbers of organisms in 82% of the samples fall within the microbiological standards proposed by the National Health and Medical Research Council of Australia for frozen precooked foods. The results of this study demonstrate the microbial quality of precooked lobster meat attainable when good manufacturing practices are used.

  7. Observations of the sound producing organs in achelate lobster larvae

    Directory of Open Access Journals (Sweden)

    John A. Fornshell

    2017-06-01

    Full Text Available The Achelata, lobsters lacking claws and having a phyllosoma larva, are divided into two families, the Palinuridae or spiny lobsters and the Scyllaridae or slipper lobsters. Within the Palinuridae adults of two groups were identified by Parker (1884, the Stridentesthat are capable of producing sounds, and the Silentesthat are not known to produce sounds. The Stridentes employ a file-like structure on the dorsal surface of the cephalon and a plectrum consisting of a series of ridges on the proximal segment of the second antenna to produce their sounds. All species of Achelata hatch as an unpigmented thin phyllosoma larva. The phyllosoma larva of the Stridentes have a presumptive file-like structure on the dorsal cephalon. A similar file-like structure is found on the cephalon of one species of Silentes, Palinurellus wienckki, and some but not all of the phyllosoma larvae of the Scyllaridae. No presumptive plectrum is found on the second antenna of any of the phyllosoma larvae. Presence of a presumptive file-like structure on phyllosoma larvae of Silentes and Scyllaridae suggests that the ability to produce sounds may have been lost secondarily in the Silentes and Scyllaridae.

  8. Electromyographic Comparison of Squats Using Constant or Variable Resistance.

    Science.gov (United States)

    Andersen, Vidar; Steiro Fimland, Marius; Knutson Kolnes, Maria; Jensen, Susanne; Laume, Martine; Hole Saeterbakken, Atle

    2016-12-01

    Andersen, V, Fimland, MS, Kolnes, MK, Jensen, S, Laume, M and Saeterbakken, AH. Electromyographic comparison of squats using constant or variable resistance. J Strength Cond Res 30(12): 3456-3463, 2016-The aim of the study was to compare the electromyographic (EMG) activity of vastus lateralis, vastus medialis, rectus femoris, and biceps femoris when performing the squat with constant resistance or variable resistance with 2 or 4 elastic bands, respectively, contributing with a mean of 39 and 73% of the total loads. Nineteen resistance-trained women performed 6 repetition maximum using 3 different experimental conditions: free weights (FW), free weights + 2 elastic bands (FW + 2EB), and free weights + 4 elastic bands (FW + 4EB). During analyses, each repetition was divided into 6 phases: upper (more extended knee), middle, and lower phase of the descending and ascending movements. Increased activation in the upper parts of the movement was observed for both variable resistance conditions compared with constant resistance (9-51%, p squat using free weights in combination with elastic bands seems to be preferable compared with free weights alone and more so with a high contribution from variable resistance to the total load.

  9. Muscle activation in the loaded free barbell squat: a brief review.

    Science.gov (United States)

    Clark, Dave R; Lambert, Mike I; Hunter, Angus M

    2012-04-01

    The purpose of this article was to review a series of studies (n = 18) where muscle activation in the free barbell back squat was measured and discussed. The loaded barbell squat is widely used and central to many strength training programs. It is a functional and safe exercise that is obviously transferable to many movements in sports and life. Hence, a large and growing body of research has been published on various aspects of the squat. Training studies have measured the impact of barbell squat loading schemes on selected training adaptations including maximal strength and power changes in the squat. Squat exercise training adaptations and their impact on a variety of performance parameters, in particular countermovement jump, acceleration, and running speed, have also been reported. Furthermore, studies have reported on the muscle activation of the lower limb resulting from variations of squat depth, foot placement, training status, and training intensity. There have also been studies on the impact of squatting with or without a weight belt on trunk muscle activation (TMA). More recently, studies have reported on the effect of instability on TMA and squat performance. Research has also shown that muscle activation of the prime movers in the squat exercise increases with an increase in the external load. Also common variations such as stance width, hip rotation, and front squat do not significantly affect muscle activation. However, despite many studies, this information has not been consolidated, resulting in a lack of consensus about how the information can be applied. Therefore, the purpose of this review was to examine studies that reported muscle activation measured by electromyography in the free barbell back squat with the goal of clarifying the understanding of how the exercise can be applied.

  10. Factors Contributing to Pelvis Instability in Female Adolescent Athletes During Unilateral Repeated Partial Squat Activity

    OpenAIRE

    Scarborough, Donna Moxley; Linderman, Shannon; Berkson, Eric M.; Oh, Luke S.

    2017-01-01

    Objectives: Unilateral partial squat tasks are often used to assess athletes? lower extremity (LE) neuromuscular control. Single squat biomechanics such as lateral drop of the non-stance limb?s pelvis have been linked to knee injury risk. Yet, there are limited studies on the factors contributing to pelvic instability during the unilateral partial squat such as anatomical alignment of the knee and hip strength. The purpose of this study was 1) to assess the influence of leg dominance on pelvi...

  11. PATELLOFEMORAL MODEL OF THE KNEE JOINT UNDER NON-STANDARD SQUATTING

    OpenAIRE

    FEKETE, GUSZTÁV; CSIZMADIA, BÉLA MÁLNÁSI; WAHAB, MAGD ABDEL; DE BAETS, PATRICK; VANEGAS-USECHE, LIBARDO V.; BÍRÓ, ISTVÁN

    2014-01-01

    The available analytical models for calculating knee patellofemoral forces are limited to the standard squat motion when the center of gravity is fixed horizontally. In this paper, an analytical model is presented to calculate accurately patellofemoral forces by taking into account the change in position of the trunk's center of gravity under deep squat (non-standard squatting). The accuracy of the derived model is validated through comparisons with results of the inverse dynamics technique. ...

  12. Knee Joint Kinetics in Relation to Commonly Prescribed Squat Loads and Depths

    Science.gov (United States)

    Cotter, Joshua A.; Chaudhari, Ait M.; Jamison, Steve T.; Devor, Steven T.

    2014-01-01

    Controversy exists regarding the safety and performance benefits of performing the squat exercise to depths beyond 90° of knee flexion. Our aim was to compare the net peak external knee flexion moments (pEKFM) experienced over typical ranges of squat loads and depths. Sixteen recreationally trained males (n = 16; 22.7 ± 1.1 yrs; 85.4 ± 2.1 kg; 177.6 ± 0.96 cm; mean ± SEM) with no previous lower limb surgeries or other orthopedic issues and at least one year of consistent resistance training experience while utilizing the squat exercise performed single repetition squat trials in a random order at squat depths of above parallel, parallel, and below parallel. Less than one week before testing, one repetition maximum (1RM) values were found for each squat depth. Subsequent testing required subjects to perform squats at the three depths with three different loads: unloaded, 50% 1RM, and 85% 1RM (nine total trials). Force platform and kinematic data were collected to calculate pEKFM. To assess differences among loads and depths, a two-factor (load and depth) repeated-measures ANOVA with significance set at the P Squat 1RM significantly decreased 13.6% from the above parallel to parallel squat and another 3.6% from the parallel to the below parallel squat (P squat depth and load were increased (P ≤ 0.02). Slopes of pEKFM were greater from unloaded to 50% 1RM than when progressing from 50% to 85% 1RM (P squat loads used with increasing depths are not enough to offset increases in pEKFM. PMID:23085977

  13. A biomechanical comparison of back and front squats in healthy trained individuals.

    Science.gov (United States)

    Gullett, Jonathan C; Tillman, Mark D; Gutierrez, Gregory M; Chow, John W

    2009-01-01

    The strength and stability of the knee plays an integral role in athletics and activities of daily living. A better understanding of knee joint biomechanics while performing variations of the squat would be useful in rehabilitation and exercise prescription. We quantified and compared tibiofemoral joint kinetics as well as muscle activity while executing front and back squats. Because of the inherent change in the position of the center of mass of the bar between the front and back squat lifts, we hypothesized that the back squat would result in increased loads on the knee joint and that the front squat would result in increased knee extensor and decreased back extensor muscle activity. A crossover study design was used. To assess the net force and torque placed on the knee and muscle activation levels, a combination of video and force data, as well as surface electromyographic data, were collected from 15 healthy trained individuals. The back squat resulted in significantly higher compressive forces and knee extensor moments than the front squat. Shear forces at the knee were small in magnitude, posteriorly directed, and did not vary between the squat variations. Although bar position did not influence muscle activity, muscle activation during the ascending phase was significantly greater than during the descending phase. The front squat was as effective as the back squat in terms of overall muscle recruitment, with significantly less compressive forces and extensor moments. The results suggest that front squats may be advantageous compared with back squats for individuals with knee problems such as meniscus tears, and for long-term joint health.

  14. Two-Segment Foot Model for the Biomechanical Analysis of Squat

    OpenAIRE

    Panero, E.; Gastaldi, L.; Rapp, W.

    2017-01-01

    Squat exercise is acquiring interest in many fields, due to its benefits in improving health and its biomechanical similarities to a wide range of sport motions and the recruitment of many body segments in a single maneuver. Several researches had examined considerable biomechanical aspects of lower limbs during squat, but not without limitations. The main goal of this study focuses on the analysis of the foot contribution during a partial body weight squat, using a two-segment foot model tha...

  15. 76 FR 54727 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

    Science.gov (United States)

    2011-09-02

    ... RIN 0648-AY72 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of...) have submitted Amendment 10 to the Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of... actions to revise the lobster species contained within the fishery management unit; revise definitions of...

  16. 76 FR 59102 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

    Science.gov (United States)

    2011-09-23

    ... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as... implemented, this rule would revise the lobster species contained within the fishery management unit...

  17. 77 FR 25116 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

    Science.gov (United States)

    2012-04-27

    ...-BB44 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf... (Councils) have submitted Amendment 11 to the Fishery Management Plan for the Spiny Lobster Fishery of the... proposes to limit spiny lobster fishing using trap gear in certain areas in the exclusive economic zone off...

  18. 50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.

    Science.gov (United States)

    2010-10-01

    ... vessels fishing with lobster traps. 697.19 Section 697.19 Wildlife and Fisheries FISHERY CONSERVATION AND... requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish... management area designation certificate or valid limited access American lobster permit specifying one or...

  19. 76 FR 75488 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

    Science.gov (United States)

    2011-12-02

    ... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as prepared and... the lobster species contained within the fishery management unit; establishes an annual catch limit...

  20. 77 FR 50642 - Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 11; Correction

    Science.gov (United States)

    2012-08-22

    .... 110908576-2240-02] RIN 0648-BB44 Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment... the final rule to implement Amendment 11 to the Fishery Management Plan for the Spiny Lobster Fishery..., 2012), incorrect latitudinal coordinates for Lobster Trap Gear Closed Areas 16 and 17, and longitudinal...

  1. Which Fishers Are Satisfied in the Caribbean? A Comparative Analysis of Job Satisfaction among Caribbean Lobster Fishers

    Science.gov (United States)

    Monnereau, Iris; Pollnac, Richard

    2012-01-01

    Lobster fishing (targeting the spiny lobster "Panulirus argus") is an important economic activity throughout the Wider Caribbean Region both as a source of income and employment for the local population as well as foreign exchange for national governments. Due to the high unit prices of the product, international lobster trade provides a…

  2. Familiarization, validity and smallest detectable difference of the isometric squat test in evaluating maximal strength.

    Science.gov (United States)

    Drake, David; Kennedy, Rodney; Wallace, Eric

    2018-02-06

    Isometric multi-joint tests are considered reliable and have strong relationships with 1RM performance. However, limited evidence is available for the isometric squat in terms of effects of familiarization and reliability. This study aimed to assess, the effect of familiarization, stability reliability, determine the smallest detectible difference, and the correlation of the isometric squat test with 1RM squat performance. Thirty-six strength-trained participants volunteered to take part in this study. Following three familiarization sessions, test-retest reliability was evaluated with a 48-hour window between each time point. Isometric squat peak, net and relative force were assessed. Results showed three familiarizations were required, isometric squat had a high level of stability reliability and smallest detectible difference of 11% for peak and relative force. Isometric strength at a knee angle of ninety degrees had a strong significant relationship with 1RM squat performance. In conclusion, the isometric squat is a valid test to assess multi-joint strength and can discriminate between strong and weak 1RM squat performance. Changes greater than 11% in peak and relative isometric squat performance should be considered as meaningful in participants who are familiar with the test.

  3. Manganese induced immune suppression of the lobster, Nephrops norvegicus

    International Nuclear Information System (INIS)

    Hernroth, Bodil; Baden, Susanne P.; Holm, Kristina; Andre, Tove; Soederhaell, Irene

    2004-01-01

    Manganese (Mn) is one of the most abundant elements on earth, particularly in the soft bottom sediments of the oceans. As a micronutrient Mn is essential in the metabolic processes of organisms. However, at high concentrations the metal becomes a neurotoxin with well-documented effects. As a consequence of euthrophication, manganese is released from bottom sediments of coastal areas and the Norway lobsters, Nephrops norvegicus, can experience high levels of bioavailable Mn 2+ . Here, we present the first report showing that Mn also affects several fundamental processes in the mobilisation and activation of immunoactive haemocytes. When N. norvegicus was exposed to a realistic [Mn 2+ ] of 20 mg l -1 for 10 days 24.1 μg ml -1 was recorded in the haemolymph. At this concentration the total haemocyte count was reduced by ca. 60%. By using BrdU as a tracer for cell division, it was shown that the proliferation rate in the haematopoietic tissue did not increase, despite the haemocytepenia. A gene coding for a Runt-domain protein, known to be involved in maturation of immune active haemocytes in a variety of organisms, was identified also in haemocytes of N. norvegicus. The expression of this gene was >40% lower in the Mn-exposed lobsters as judged by using a cDNA probe and the in situ hybridisation technique. In response to non-self molecules, like lipopolysaccharide (LPS), the granular haemocytes of arthropods are known to degranulate and thereby release and activate the prophenoloxidase system, necessary for their immune defence. A degranulation assay, tested on isolated granular haemocytes, showed about 75% lower activity in the Mn-exposed lobsters than that for the unexposed. Furthermore, using an enzymatic assay, the activation per se of prophenoloxidase by LPS was found blocked in the Mn-exposed lobsters. Taken together, these results show that Mn exposure suppressed fundamental immune mechanisms of Norway lobsters. This identifies a potential harm that also

  4. Manganese induced immune suppression of the lobster, Nephrops norvegicus

    Energy Technology Data Exchange (ETDEWEB)

    Hernroth, Bodil [Department of Marine Ecology, Goeteborg University, Kristineberg Marine Research Station, SE-450 34 Fiskebaeckskil (Sweden)]. E-mail: bodil.hernroth@kmf.gu.se; Baden, Susanne P. [Department of Marine Ecology, Goeteborg University, Kristineberg Marine Research Station, SE-450 34 Fiskebaeckskil (Sweden); Holm, Kristina [Department of Marine Ecology, Goeteborg University, Kristineberg Marine Research Station, SE-450 34 Fiskebaeckskil (Sweden); Andre, Tove [Department of Comparative Physiology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden); Soederhaell, Irene [Department of Comparative Physiology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden)

    2004-12-10

    Manganese (Mn) is one of the most abundant elements on earth, particularly in the soft bottom sediments of the oceans. As a micronutrient Mn is essential in the metabolic processes of organisms. However, at high concentrations the metal becomes a neurotoxin with well-documented effects. As a consequence of euthrophication, manganese is released from bottom sediments of coastal areas and the Norway lobsters, Nephrops norvegicus, can experience high levels of bioavailable Mn{sup 2+}. Here, we present the first report showing that Mn also affects several fundamental processes in the mobilisation and activation of immunoactive haemocytes. When N. norvegicus was exposed to a realistic [Mn{sup 2+}] of 20 mg l{sup -1} for 10 days 24.1 {mu}g ml{sup -1} was recorded in the haemolymph. At this concentration the total haemocyte count was reduced by ca. 60%. By using BrdU as a tracer for cell division, it was shown that the proliferation rate in the haematopoietic tissue did not increase, despite the haemocytepenia. A gene coding for a Runt-domain protein, known to be involved in maturation of immune active haemocytes in a variety of organisms, was identified also in haemocytes of N. norvegicus. The expression of this gene was >40% lower in the Mn-exposed lobsters as judged by using a cDNA probe and the in situ hybridisation technique. In response to non-self molecules, like lipopolysaccharide (LPS), the granular haemocytes of arthropods are known to degranulate and thereby release and activate the prophenoloxidase system, necessary for their immune defence. A degranulation assay, tested on isolated granular haemocytes, showed about 75% lower activity in the Mn-exposed lobsters than that for the unexposed. Furthermore, using an enzymatic assay, the activation per se of prophenoloxidase by LPS was found blocked in the Mn-exposed lobsters. Taken together, these results show that Mn exposure suppressed fundamental immune mechanisms of Norway lobsters. This identifies a potential

  5. Cuticles of European and American lobsters harbor diverse bacterial species and differ in disease susceptibility.

    Science.gov (United States)

    Whitten, Miranda M A; Davies, Charlotte E; Kim, Anita; Tlusty, Michael; Wootton, Emma C; Chistoserdov, Andrei; Rowley, Andrew F

    2014-06-01

    Diseases of lobster shells have a significant impact on fishing industries but the risk of disease transmission between different lobster species has yet to be properly investigated. This study compared bacterial biofilm communities from American (Homarus americanus) and European lobsters (H. gammarus), to assess both healthy cuticle and diseased cuticle during lesion formation. Culture-independent molecular techniques revealed diversity in the bacterial communities of cuticle biofilms both within and between the two lobster species, and identified three bacterial genera associated with shell lesions plus two putative beneficial bacterial species (detected exclusively in healthy cuticle or healing damaged cuticle). In an experimental aquarium shared between American and European lobsters, heterospecific transmission of potentially pathogenic bacteria appeared to be very limited; however, the claws of European lobsters were more likely to develop lesions when reared in the presence of American lobsters. Aquarium biofilms were also examined but revealed no candidate pathogens for environmental transmission. Aquimarina sp. 'homaria' (a potential pathogen associated with a severe epizootic form of shell disease) was detected at a much higher prevalence among American than European lobsters, but its presence correlated more with exacerbation of existing lesions rather than with lesion initiation. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  6. The Radioactivity α and β Evaluation in Fish, Lobster and Shrimps from Donan's River Cilacap

    International Nuclear Information System (INIS)

    Sutjipto; Zainul Kamal

    2002-01-01

    The radioactivity α and β total evaluation in fish, lobster and shrimps from Donan's river Cilacap have been done The determination of α and β total using α and β spectrometry. The result of experimentation showed that radioactivity α and β in fish, lobster and shrimps. Could not use as shore quality because unprepared of the threshold value. (author)

  7. Habitat surrounding patch reefs influences the diet and nutrition of the western rock lobster

    Science.gov (United States)

    In this study the influence of habitat on the diet and nutrition of a common reef-associated generalist consumer, the western rock lobster Panulirus cygnus, was tested. Stable isotopes (13C/12C and 15N/14N) and gut contents were used to assess the diet of lobsters collected from ...

  8. 50 CFR Figure 1 to Part 665 - Carapace Length of Lobsters

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Carapace Length of Lobsters 1 Figure 1 to Part 665 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Part 665—Carapace Length of Lobsters ER14JA10.126 ...

  9. Potential virulence factors of bacteria associated with tail fan necrosis in the spiny lobster, Jasus edwardsii.

    Science.gov (United States)

    Zha, H; Jeffs, A; Dong, Y; Lewis, G

    2018-05-01

    Tail fan necrosis (TFN) is a common condition found in commercially exploited spiny lobsters that greatly diminishes their commercial value. Bacteria possessing proteolytic, chitinolytic and lipolytic capabilities were associated with TFN in spiny lobsters, Jasus edwardsii. In this study, 69 bacterial isolates exhibiting all the three enzymatic capabilities from the haemolymph and tail fans of J. edwardsii with and without TFN were further characterized and compared, including morphology, biofilm formation, antimicrobial activity, antimicrobial resistance, and production of siderophores, melanin and ammonia. The genomic patterns of the most common Vibrio crassostreae isolates were also compared between TFN-affected and unaffected lobsters. Biofilm formation was stronger in bacterial isolates from both haemolymph and tail fans of TFN-affected lobsters compared to those from the unaffected lobsters, while melanin production and siderophore production were stronger in the isolates from tail fans of lobsters with TFN. By contrast, the other characteristics of isolates were similar in lobsters with and without TFN. The Vib. crassostreae isolates from the affected lobsters had similar genomic patterns. Overall, the results indicate that in addition to proteolytic, chitinolytic and lipolytic activities, the bacteria associated with TFN commonly have enhanced activity of important virulence factors, including biofilm formation, melanin production and siderophore production. © 2018 John Wiley & Sons Ltd.

  10. Bio-mechanical assessment toward throwing and lifting process of i-LOCA (Innovative Lobster Catcher)

    Science.gov (United States)

    Sudiarno, A.; Dewi, D. S.; Putri, M. A.

    2018-04-01

    Indonesia is the country rich in marine resource, one of which is lobster. East java, one of Indonesian province, especially in Region of Gresik and Lamogan, has very huge potential of lobster. Current condition shown that lobster catch by the fisherman mostly depend on lucky factor, which the lobster unintentionally trapped in fisherman’s fish net. By using this mechanism, the number of lobster catch cannot be optimum. Previous researches have produced two versions of i-LOCA, Innovative Lobster Catcher, a special tool for catching the lobster. Although produce more lobster catch, second version of i-LOCA still needs to be scrutinized, one of that is bio-mechanical assessment. The second version of i-LOCA still has no tool to ease throwing and lifting it into the sea. This condition cause Musculoskeletal Disorder (MSD) toward the fisherman. This research perform bio-mechanical assessment toward throwing and lifting process in order to suggest improvement for i-LOCA as the third version. Based on body moment calculation, we found that throwing and lifting process of third version of i-LOCA, each was 3 times and 2 times better than second version of i-LOCA. Meanwhile, Rapid Entire Body Assessment (REBA) score of throwing and lifting process for third version of i-LOCA can be reduced by 5 points compared to second version of i-LOCA.

  11. Effect of magnetic pulses on Caribbean spiny lobsters: implications for magnetoreception.

    Science.gov (United States)

    Ernst, David A; Lohmann, Kenneth J

    2016-06-15

    The Caribbean spiny lobster, Panulirus argus, is a migratory crustacean that uses Earth's magnetic field as a navigational cue, but how these lobsters detect magnetic fields is not known. Magnetic material thought to be magnetite has previously been detected in spiny lobsters, but its role in magnetoreception, if any, remains unclear. As a first step toward investigating whether lobsters might have magnetite-based magnetoreceptors, we subjected lobsters to strong, pulsed magnetic fields capable of reversing the magnetic dipole moment of biogenic magnetite crystals. Lobsters were subjected to a single pulse directed from posterior to anterior and either: (1) parallel to the horizontal component of the geomagnetic field (i.e. toward magnetic north); or (2) antiparallel to the horizontal field (i.e. toward magnetic south). An additional control group was handled but not subjected to a magnetic pulse. After treatment, each lobster was tethered in a water-filled arena located within 200 m of the capture location and allowed to walk in any direction. Control lobsters walked in seemingly random directions and were not significantly oriented as a group. In contrast, the two groups exposed to pulsed fields were significantly oriented in approximately opposite directions. Lobsters subjected to a magnetic pulse applied parallel to the geomagnetic horizontal component walked westward; those subjected to a pulse directed antiparallel to the geomagnetic horizontal component oriented approximately northeast. The finding that a magnetic pulse alters subsequent orientation behavior is consistent with the hypothesis that magnetoreception in spiny lobsters is based at least partly on magnetite-based magnetoreceptors. © 2016. Published by The Company of Biologists Ltd.

  12. A holistic view of dietary carbohydrate utilization in lobster: digestion, postprandial nutrient flux, and metabolism.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Casuso, Antonio; Perdomo-Morales, Rolando; Gutierrez, Odilia; Scull, Idania; Carrillo, Olimpia; Martos-Sitcha, Juan A; García-Galano, Tsai; Mancera, Juan Miguel

    2014-01-01

    Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2-6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6-12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other nutrients.

  13. A holistic view of dietary carbohydrate utilization in lobster: digestion, postprandial nutrient flux, and metabolism.

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    Full Text Available Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2-6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6-12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other

  14. Technetium-99 in lobsters from the western Irish sea

    International Nuclear Information System (INIS)

    Fegan, Mary

    1999-05-01

    Technetium-99, the most important radionuclide of technetium release to the environment, is a pure beta emitter with a half-life of 2.13 x 10(5) years. It behaves conservatively in seawater and is likely to remain available to biota for a long time. The dominant and most stable form of technetium in oxygenated seawater is the pertechnetate ion, Tco4. The principle source of radionuclide contamination of the Irish Sea has been the liquid waste discharges of low level radionuclide effluent from the spent nuclear fuel reprocessing plant at Sellafield on the Cumbria Coast. In 1994 the annual discharge authorization limit for 99Tc was increased from 10 TBq to 200 TBq. Lobster concentrates 99Tc to a high degree with concentration factors of 1x 10(3) reported in the literature. The mean 99Tc activity concentrations in lobsters caught close to Sellafield were reported to have risen by a factor of 20 in 2 years from 390 Bq/kg (wet weight) in 1993 to 8300 Bq/kg (wet weight) in 1995. This study was undertaken to determine the 99Tc activity concentration in lobsters from the western Irish Sea. Lobsters were collected from the east and north east coasts of Ireland over the period June 1997 to July 1998 and analysed using a radioanalytical method which was based on the anion-exchange seperation of technetium as pertechnetate. A gas-flow proportional counter was used to measure to 99Tc activity concentration in each sample. Technetium-99 activity concentrations were measured in the muscle from the tail, the right and the left claws and also in the green gland, the hepatopancreas and the cardiac fore-gut. The results of the measurements showed, as expected, that the 99Tc activity concentrations were not as high as those in the samples from the Cumbrian coast. The mean 99Tc activity concentrations, over the sampling period, in the tail, right and left claw muscles were 214, 124 and 136 BQ/kg (wet weight) respectively. The mean 99Tc activity concentrations in the green gland

  15. Effect of range of motion in heavy load squatting on muscle and tendon adaptations

    DEFF Research Database (Denmark)

    Bloomquist, K; Langberg, Henning; Karlsen, Stine

    2013-01-01

    Manipulating joint range of motion during squat training may have differential effects on adaptations to strength training with implications for sports and rehabilitation. Consequently, the purpose of this study was to compare the effects of squat training with a short vs. a long range of motion...

  16. Trunk position modulates anterior cruciate ligament forces and strains during a single-leg squat

    NARCIS (Netherlands)

    Kulas, Anthony S.; Hortobagyi, Tibor; DeVita, Paul

    Background: Although the squat exercise and its variations are commonly prescribed for anterior cruciate ligament rehabilitation, whether trunk position affects these ligament forces and strains during the squat is unclear. Our purpose was to evaluate the effects of trunk position on anterior

  17. Residual fatigue life evaluation of rail at squats seeds using 3D explicit finite element analysis

    NARCIS (Netherlands)

    Deng, X.; Naeimi, M.; Li, Z.; Qian, Z.

    2014-01-01

    A modeling procedure to predict the residual fatigue life of rail at squats seeds is developed in this article. Two models are involved: a 3D explicit Finite Element (FE) model to compute the stress and strain at squats in rail, and the J-S fatigue damage model to determine the residual fatigue life

  18. Effects of mannan oligosaccharide dietary supplementation on performances of the tropical spiny lobsters juvenile (Panulirus ornatus, Fabricius 1798).

    Science.gov (United States)

    Sang, Huynh Minh; Fotedar, Ravi

    2010-03-01

    The effects of dietary mannan oligosaccharide (MOS) (Bio-Mos, Alltech, USA) on the growth, survival, physiology, bacteria and morphology of the gut and immune response to bacterial infection of tropical rock lobsters (Panulirus ornatus) juvenile were investigated. Dietary inclusion level of MOS at 0.4% was tested against the control diet (trash fish) without MOS inclusion. At the end of 56 days of rearing period, a challenged test was also conducted to evaluate the bacterial infection resistant ability of the lobsters fed the two diets. Lobster juvenile fed MOS diet attained 2.86 +/- 0.07 g of total weigh and 66.67 +/- 4.76% survival rate which were higher (P lobsters fed control diet (2.35 +/- 0.14 g total weight and 54.76 +/- 2.38% survival rate, respectively) thus providing the higher (P lobsters fed MOS diet. Physiological condition indicators such as wet tail muscle index (Tw/B), wet hepatosomatic index (Hiw) and dry tail muscle index (Td/B) of the lobsters fed MOS supplemented diet were higher (P lobsters fed the control diet. Bacteria in the gut (both total aerobic and Vibrio spp.) and gut's absorption surface indicated by the internal perimeter/external perimeter ratio were also higher (P lobsters were fed MOS diet. Lobsters fed MOS diet were in better immune condition showed by higher THC and GC, and lower bacteraemia. Survival, THC, GC were not different among the lobsters fed either MOS or control diet after 3 days of bacterial infection while bacteraemia was lower in the lobsters fed MOS diet. After 7 days of bacterial infection the lobsters fed MOS diet showed higher survival, THC, GC and lower bacteraemia than the lobsters fed the control diet. The experimental trial demonstrated the ability of MOS to improve the growth performance, survival, physiological condition, gut health and immune responses of tropical spiny lobsters juveniles. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Lobster eye as a collector for water window microscopy

    Science.gov (United States)

    Pina, L.; Maršíková, V.; Inneman, A.; Nawaz, M. F.; Jančárek, A.; Havlíková, R.

    2017-08-01

    Imaging in EUV, SXR and XR spectral bands of radiation is of increasing interest. Material science, biology and hot plasma are examples of relevant fast developing areas. Applications include spectroscopy, astrophysics, Soft X-ray Ray metrology, Water Window microscopy, radiography and tomography. Especially Water Window imaging has still not fully recognized potential in biology and medicine microscopy applications. Theoretical study and design of Lobster Eye (LE) optics as a collector for water window (WW) microscopy and comparison with a similar size ellipsoidal mirror condensor are presented.

  20. Variable X-ray sky with Lobster Eye Telescopes

    International Nuclear Information System (INIS)

    Hudec, R.; Pina, L.; Inneman, A.; Sveda, L.

    2004-01-01

    The variable X-ray sky requires wide-field monitoring with high sensitivity. We refer on novel X-ray telescopes with high sensitivity as well as large field of view. The results are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study and to understand various astrophysical objects such as AGN, SNe, GRBs, X-ray flashes, galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc

  1. Relationship between relative net vertical impulse and jump height in jump squats performed to various squat depths and with various loads.

    Science.gov (United States)

    McBride, Jeffrey M; Kirby, Tyler J; Haines, Tracie L; Skinner, Jared

    2010-12-01

    The purpose of the current investigation was to determine the relationship between relative net vertical impulse (net vertical impulse (VI)) and jump height in the jump squat (JS) going to different squat depths and utilizing various loads. Ten males with two years of jumping experience participated in this investigation (Age: 21.8 ± 1.9 y; Height: 176.9 ± 5.2 cm; Body Mass: 79.0 ± 7.1 kg, 1RM: 131.8 ± 29.5 kg, 1RM/BM: 1.66 ± 0.27). Subjects performed a series of static jumps (SJS) and countermovement jumps (CMJJS) with various loads (Body Mass, 20% of 1RM, 40% of 1RM) in a randomized fashion to a depth of 0.15, 0.30, 0.45, 0.60, and 0.75 m and a self-selected depth. During the concentric phase of each JS, peak force (PF), peak power (PP), jump height (JH) and relative VI were recorded and analyzed. Increasing squat depth corresponded to a decrease in PF and an increase in JH, relative VI for both SJS and CMJJS during all loads. Across all squat depths and loading conditions relative VI was statistically significantly correlated to JH in the SJS (r = .8956, P squat depths and loading conditions PF was statistically nonsignificantly correlated to JH in the SJS (r = -0.1010, P = .2095, power = 0.2401) and CMJJS (r = -0.0594, P = .4527, power = 0.1131). Across all squat depths and loading conditions peak power (PP) was significantly correlated with JH during both the SJS (r = .6605, P squat depths. Results indicate that relative VI and PP can be used to predict JS performance, regardless of squat depth and loading condition. However, relative VI may be the best predictor of JS performance with PF being the worst predictor of JS performance.

  2. Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

    Directory of Open Access Journals (Sweden)

    Luz A. Avila-Villa

    2012-01-01

    Full Text Available Necrotizing hepatopancreatitis bacterium (NHPB is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo.

  3. Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

    Science.gov (United States)

    Avila-Villa, Luz A.; Gollas-Galván, Teresa; Martínez-Porchas, Marcel; Mendoza-Cano, Fernando; Hernández-López, Jorge

    2012-01-01

    Necrotizing hepatopancreatitis bacterium (NHPB) is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus) with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo. PMID:22645497

  4. Use of herring bait to farm lobsters in the Gulf of Maine.

    Science.gov (United States)

    Grabowski, Jonathan H; Clesceri, Erika J; Baukus, Adam J; Gaudette, Julien; Weber, Matthew; Yund, Philip O

    2010-04-15

    Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus) are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus) as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England. We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free) sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S. Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

  5. Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus): biochemical indication for limited carbohydrate utilization.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Montero-Alejo, Vivian; Perdomo-Morales, Rolando; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan M

    2017-01-01

    As other spiny lobsters, Panulirus argus is supposed to use preferentially proteins and lipids in energy metabolism, while carbohydrates are well digested but poorly utilized. The aim of this study was to evaluate the effect of dietary carbohydrate level on digestion and metabolism in the spiny lobster P. argus . We used complementary methodologies such as post-feeding flux of nutrients and metabolites, as well as measurements of α-amylase expression and activity in the digestive tract. Lobsters readily digested and absorbed carbohydrates with a time-course that is dependent on their content in diet. Lobster showed higher levels of free glucose and stored glycogen in different tissues as the inclusion of wheat flour increased. Modifications in intermediary metabolism revealed a decrease in amino acids catabolism coupled with a higher use of free glucose as carbohydrates rise up to 20%. However, this effect seems to be limited by the metabolic capacity of lobsters to use more than 20% of carbohydrates in diets. Lobsters were not able to tightly regulate α-amylase expression according to dietary carbohydrate level but exhibited a marked difference in secretion of this enzyme into the gut. Results are discussed to highlight the limitations to increasing carbohydrate utilization by lobsters. Further growout trials are needed to link the presented metabolic profiles with phenotypic outcomes.

  6. Use of herring bait to farm lobsters in the Gulf of Maine.

    Directory of Open Access Journals (Sweden)

    Jonathan H Grabowski

    2010-04-01

    Full Text Available Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England.We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S.Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

  7. Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus: biochemical indication for limited carbohydrate utilization

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    2017-11-01

    Full Text Available As other spiny lobsters, Panulirus argus is supposed to use preferentially proteins and lipids in energy metabolism, while carbohydrates are well digested but poorly utilized. The aim of this study was to evaluate the effect of dietary carbohydrate level on digestion and metabolism in the spiny lobster P. argus. We used complementary methodologies such as post-feeding flux of nutrients and metabolites, as well as measurements of α-amylase expression and activity in the digestive tract. Lobsters readily digested and absorbed carbohydrates with a time-course that is dependent on their content in diet. Lobster showed higher levels of free glucose and stored glycogen in different tissues as the inclusion of wheat flour increased. Modifications in intermediary metabolism revealed a decrease in amino acids catabolism coupled with a higher use of free glucose as carbohydrates rise up to 20%. However, this effect seems to be limited by the metabolic capacity of lobsters to use more than 20% of carbohydrates in diets. Lobsters were not able to tightly regulate α-amylase expression according to dietary carbohydrate level but exhibited a marked difference in secretion of this enzyme into the gut. Results are discussed to highlight the limitations to increasing carbohydrate utilization by lobsters. Further growout trials are needed to link the presented metabolic profiles with phenotypic outcomes.

  8. Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting.

    Science.gov (United States)

    Requena, Bernardo; García, Inmaculada; Requena, Francisco; de Villarreal, Eduardo Sáez-Sáez; Cronin, John B

    2011-08-01

    The purpose of this study was to quantify the magnitude of the relationship between vertical jumping and maximal sprinting at different distances with performance in the traditional and ballistic concentric squat exercise in well-trained sprinters. Twenty-one men performed 2 types of barbell squats (ballistic and traditional) across different loads with the aim of determining the maximal peak and average power outputs and 1 repetition maximum (1RM) values. Moreover, vertical jumping (countermovement jump test [CMJ]) and maximal sprints over 10, 20, 30, 40, 60, and 80 m were also assessed. In respect to 1RM in traditional squat, (a) no significant correlation was found with CMJ performance; (b) positive strong relationships (p ballistic and traditional squat exercises (r = 0.53-0.90); (c) negative significant correlations (r = -0.49 to -0.59, p ballistic or traditional squat exercises. Sprint time at 20 m was only related to ballistic and traditional squat performance when power values were expressed in relative terms. Moderate significant correlations (r = -0.39 to -0.56, p ballistic and traditional squat exercises. Sprint times at 60 and 80 m were mainly related to ballistic squat power outputs. Although correlations can only give insights into associations and not into cause and effect, from this investigation, it can be seen that traditional squat strength has little in common with CMJ performance and that relative 1RM and power outputs for both squat exercises are statistically correlated to most sprint distances underlying the importance of strength and power to sprinting.

  9. Comparison of acute countermovement jump responses after functional isometric and dynamic half squats.

    Science.gov (United States)

    Boyd, David A; Donald, Neil; Balshaw, Thomas G

    2014-12-01

    The purpose of this study was to compare acute countermovement jump (CMJ) responses after functional isometric (FI) and dynamic half (DH) squats. Ten strength-trained males (relative full back squat 1 repetition maximum [1RM]: 1.9 ± 0.2) participated in a randomized crossover design study. On 2 separate days, participants performed baseline CMJs followed by either FI or DH squats loaded with 150% of full back squat 1RM. Further CMJs were performed between 2 and 11 minutes after FI or DH squats. Kinematic and kinetic CMJ variables were measured. There were no differences observed between conditions when peak CMJ variables after FI or DH squats were compared with baseline values (p > 0.05). Countermovement jump time effects (p ≤ 0.05) were observed after squats. Increases in peak force (p ≤ 0.05; FI: 3.9%, range: -0.9 to 9.1%; DH: 4.2%, range: 0.0-11.5%) and decreases in peak power (p ≤ 0.05; FI: -0.4%, range: -5.1 to 4.0%; DH: -1.1%, range: -6.6 to 2.9%) occurred for combined condition data. Positive correlations between lower-body strength and the extent or timing of acute CMJ responses were not detected (p > 0.05). Because of the apparent lack of additive acute CMJ responses, the use of conventional DH squat protocols should be considered rather than FI squats in precompetition and training situations. Furthermore, the establishment of individual FI and DH squat protocols also seems to be necessary, rather than relying on relative lower-body strength to predict the nature of acute CMJ responses.

  10. Kinematics of the trunk and the lower extremities during restricted and unrestricted squats.

    Science.gov (United States)

    List, Renate; Gülay, Turgut; Stoop, Mirjam; Lorenzetti, Silvio

    2013-06-01

    Squatting is a common strength training exercise used for rehabilitation, fitness training, and in preparation for competition. Knowledge about the loading and the motion of the back during the squat exercise is crucial to avoid overuse or injury. The aim of this study was the measurement and comparison of the kinematics of the lower leg, trunk, and spine during unrestricted and restricted (knees are not allowed beyond toes) squats. A total of 30 subjects performed unrestricted and restricted barbell squats with an extra load of 0, 25, and 50% bodyweight. Motion was tracked using a 12-camera Vicon system. A newly developed marker set with 24 trunk and 7 pelvic markers allowed us to measure 3D segmental kinematics between the pelvic and the lumbar regions, between the lumbar and the thoracic segments, and the sagittal curvatures of the lumbar and the thoracic spine. In an unrestricted squat, the angle of the knee is larger and the range of motion (ROM) between the lumbar and the thoracic segments is significantly smaller compared with a restricted squat (p squats. The unrestricted execution of a squat leads to a larger ROM in the knee and smaller changes in the curvature of the thoracic spine and the range of smaller segmental motions within the trunk. This execution in turn leads to lower stresses in the back. To strengthen the muscles of the leg, the unrestricted squat may be the best option for most people. Thus, practitioners should not be overly strict in coaching against anterior knee displacement during performance of the squat.

  11. Trophic Cascades Induced by Lobster Fishing Are Not Ubiquitous in Southern California Kelp Forests

    Science.gov (United States)

    Guenther, Carla M.; Lenihan, Hunter S.; Grant, Laura E.; Lopez-Carr, David; Reed, Daniel C.

    2012-01-01

    Fishing can trigger trophic cascades that alter community structure and dynamics and thus modify ecosystem attributes. We combined ecological data of sea urchin and macroalgal abundance with fishery data of spiny lobster (Panulirus interruptus) landings to evaluate whether: (1) patterns in the abundance and biomass among lobster (predator), sea urchins (grazer), and macroalgae (primary producer) in giant kelp forest communities indicated the presence of top-down control on urchins and macroalgae, and (2) lobster fishing triggers a trophic cascade leading to increased sea urchin densities and decreased macroalgal biomass. Eight years of data from eight rocky subtidal reefs known to support giant kelp forests near Santa Barbara, CA, USA, were analyzed in three-tiered least-squares regression models to evaluate the relationships between: (1) lobster abundance and sea urchin density, and (2) sea urchin density and macroalgal biomass. The models included reef physical structure and water depth. Results revealed a trend towards decreasing urchin density with increasing lobster abundance but little evidence that urchins control the biomass of macroalgae. Urchin density was highly correlated with habitat structure, although not water depth. To evaluate whether fishing triggered a trophic cascade we pooled data across all treatments to examine the extent to which sea urchin density and macroalgal biomass were related to the intensity of lobster fishing (as indicated by the density of traps pulled). We found that, with one exception, sea urchins remained more abundant at heavily fished sites, supporting the idea that fishing for lobsters releases top-down control on urchin grazers. Macroalgal biomass, however, was positively correlated with lobster fishing intensity, which contradicts the trophic cascade model. Collectively, our results suggest that factors other than urchin grazing play a major role in controlling macroalgal biomass in southern California kelp forests, and

  12. Optimizing Half Squat Postactivation Potential Load in Squat Jump Training for Eliciting Relative Maximal Power in Ski Jumpers.

    Science.gov (United States)

    Gołaś, Artur; Wilk, Michal; Stastny, Petr; Maszczyk, Adam; Pajerska, Katarzyna; Zając, Adam

    2017-11-01

    Gołaś, A, Wilk, M, Stastny, P, Maszczyk, A, Pajerska, K, and Zając, A. Optimizing half squat postactivation potential load in squat jump training for eliciting relative maximal power in ski jumpers. J Strength Cond Res 31(11): 3010-3017, 2017-Training load manipulation in a single workout session can increase or decrease training effectiveness in terms of athletes' strength or power gains. In ski jumping, the complex training that elicits maximal power gains may take advantage of the postactivation potentiation (PAP) mechanism. The aim of this research was to evaluate the changes in rate of force development (RFD), rate of power development (RPD), and jump height during a complex training session consisted of the barbell half squat (Sq) as a conditioning exercise with loads ranged between 60 and 100% of 1 repetition maximum (1RM), followed by a body weight squat jump (SqJ) as a performance task. The study was conducted with 16 elite athletes from the Polish National Ski Jumping Team, age 23 ± 8 years, body mass 56 ± 9 kg, and height 172 ± 12 cm. Complex training session started with the Sq at 60% of 1RM as the conditioning exercise, followed by 3 minutes of rest and the SqJ. The conditioning barbell half Sq was performed with 70, 80, 90, and 100% of 1RM with 5 minutes of rest. The differences in RFD occurred between an SqJ following the application of 80% of 1RM and all other SqJs (p = 0.01), and in RPD between SqJ without conditioning, SqJ after 60% of 1RM and 80% of 1RM (p = 0.02). On average, the most effective load in inducing PAP during ski jumpers' SqJ training is 80% of 1RM. The intensity of the conditioning exercise that elicits the greatest PAP effect should be individualized (60-100% 1RM), as it is dependent on the level of maximal strength.

  13. The research of the style of angel lobster eye x-ray optical system

    Science.gov (United States)

    Cheng, HuaQi; Liu, YuJiao; Zhang, ShaoWei; Hou, LinBao; Li, XingLong

    2018-01-01

    This paper has developed the theory research of wide field Angel lobster eye X-ray optical system based on the principle of entirely incidence. Combine the configuration characteristic of lobster eye, recommend the conclusion of beam of light focus on the half of radius whether point or parallel light. Designed the microchannel through the principle of real ray trace and got the relationship among different parameters about it using numerical value emulation. Got pixels and illumination pictures validated the wide field focus characteristic of Angel lobster eye by simulating the optical system.

  14. Disposition of phenanthrene and octachlorostyrene in spiny lobsters, Panulirus argus, after intragastric administration

    International Nuclear Information System (INIS)

    Solbakken, J.E.; Knap, A.H.

    1986-01-01

    Spiny lobster (Panulirus argus) is a commercial crustacean in Bermuda. It was therefore of interest to study the fate of xenobiotics in the species as very little attention has been paid to toxicological studies with spiny lobsters. Earlier it was found that the temperate crustacean, Nephrops norveqicus (Norway lobster) had the ability to accumulate and eliminate phenanthrene. The aim of this investigation was to gain a better understanding of the fate of xenobiotics in crustaceans under different environmental conditions, and to compare the polycyclic aromatic hydrocarbon, phenenthrene, with the more environmentally persistent chlorinated compound octachlorostyrene, a by-product of magnesium metal production

  15. HUBUNGAN PANJANG-BERAT DAN FAKTOR KONDISI LOBSTER BATU (Panulirus penicillatus DI PERAIRAN SELATAN GUNUNG KIDUL DAN PACITAN

    Directory of Open Access Journals (Sweden)

    Moh Fauzi Fauzi

    2016-03-01

    Full Text Available Perairan di sebelah selatan Gunung Kidul dan Pacitan merupakan daerah penangkapan lobster yang cukup potensial. Analisis hubungan panjang berat, faktor kondisi dan sebaran kisaran panjang lobster batu (Panulirus penicillatus di perairan tersebut dilakukan pada bulan Maret 2010 hingga Maret 2012. Pengukuran panjang-berat terhadap 1.803 individu lobster batu menunjukkan pola pertumbuhan yang bersifat allometrik negatif. Faktor kondisi lobster memiliki kesamaan antara jenis kelamin jantan dan betina dan terdapat kecenderungan menurunnya faktor kondisi dengan bertambahnya panjang (umur. Panjang karapas dominan berada pada kisaran antara 45-50mm. Lobster betina yang membawa telur ditemukan pertama kali pada kelas panjang karapas antara 35-40mm. The waters in the south of Gunung Kidul and Pacitan were indicated as a potentially fishing ground of spiny lobster. Analysis of Length-weight relationship, condition factor and distribution of the pronghorn spiny lobster (Panulirus penicillatus in those waters were conducted in March 2010 through March 2012. Length-weight measurements on 1.803 individual lobsters showed allometric negative growth patterns. Lobster have in common condition factor between male and female, and there is a tendency condition factor decreased with increasing length (age. Dominant carapace length is in the range between 45-50mm. Female lobsters carrying eggs were first discovered in the class of carapace length between 35-40mm.

  16. DISTRIBUSI UKURAN DAN PARAMETER POPULASI LOBSTER PASIR (Panulirus homarus DI PERAIRAN ACEH BARAT

    Directory of Open Access Journals (Sweden)

    Duranta D Kembaren

    2015-12-01

    Full Text Available Penelitian tentang distribusi ukuran dan parameter populasi lobster pasir di perairan Aceh Barat dilakukan pada bulanApril sampai November 2013. Penelitian ini bertujuan untukmengkaji status lobster di perairan Aceh Barat dilihat dari aspek distribusi ukuran dan parameter populasinya. Pengamatan dan pengukuran lobster dilakukan di tempat pengumpul lobster dengan sistem sampling acak. Sebaran frekuensi panjang karapas selanjutnya ditabulasikan dan dianalisa dengan metode kurva logistik. Struktur ukuran lobster yang tertangkap menunjukkan bahwa lobster jantan dominan tertangkap dibawah ukuran nilai tengah 72,5 mm dan sebaliknya diatas ukuran nilai tengah 72,5 mm yang didominasi jenis kelamin betina. Lobster terlebih dahulu tertangkap sebelum mencapai ukuran matang gonad (Lc = 65,8mm< Lm= 76,8 mm. Puncak musim pemijahan terjadi pada bulan Mei dan Agustus. Panjang asimtosis (CL∞  sebesar 119,5 mm dengan laju pertumbuhan (K 0,39/tahun serta laju kematian total (Z 1,44/tahun, laju kematian alamiah (M 0,67/tahun dan laju keamatian akibat penangkapan (F 0,77/tahun. Laju eksploitasi sudah mengarah kepada penangkapan yang berlebih (E=0,54, oleh karena itu perlu dilakukan tindakan pengelolaan perikanan lobster yang berkelanjutan. Salah satu upaya yang dapat di tempuh adalah dengan menerapkan sistem penutupan musim penangkapan lobster pada saat terjadinya puncak musim pemijahan. Research on the length distribution and population parameters of scalloped spiny lobster conducted in the Aceh Barat waters during April to November 2013. The aim of this study was to assess lobster fishery status in this waters from the point of view their length size and population parameters. Sampel collected randomly in the lobster landing site. Distribution of carapace length frequency was tabulated and analysed using logistic curve method. Length composition of male lobster was dominated under 72,5 mm midlenght, while female lobster was dominated above 72

  17. Validity and reliability of simple measurement device to assess the velocity of the barbell during squats.

    Science.gov (United States)

    Lorenzetti, Silvio; Lamparter, Thomas; Lüthy, Fabian

    2017-12-06

    The velocity of a barbell can provide important insights on the performance of athletes during strength training. The aim of this work was to assess the validity and reliably of four simple measurement devices that were compared to 3D motion capture measurements during squatting. Nine participants were assessed when performing 2 × 5 traditional squats with a weight of 70% of the 1 repetition maximum and ballistic squats with a weight of 25 kg. Simultaneously, data was recorded from three linear position transducers (T-FORCE, Tendo Power and GymAware), an accelerometer based system (Myotest) and a 3D motion capture system (Vicon) as the Gold Standard. Correlations between the simple measurement devices and 3D motion capture of the mean and the maximal velocity of the barbell, as well as the time to maximal velocity, were calculated. The correlations during traditional squats were significant and very high (r = 0.932, 0.990, p squats and was less accurate. All the linear position transducers were able to assess squat performance, particularly during traditional squats and especially in terms of mean velocity and time to maximal velocity.

  18. Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

    Science.gov (United States)

    Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

    2012-04-01

    Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

  19. Effects of Different Lifting Cadences on Ground Reaction Forces during the Squat Exercise

    Science.gov (United States)

    Bentley, Jason R.; Amonette, William E.; Hagan, R. Donald

    2008-01-01

    The purpose of this investigation was to determine the effect of different cadences on the ground reaction force (GRF(sub R)) during the squat exercise. It is known that squats performed with greater acceleration will produce greater inertial forces; however, it is not well understood how different squat cadences affect GRF(sub R). It was hypothesized that faster squat cadences will result in greater peak GRF(sub R). METHODS: Six male subjects (30.8+/-4.4 y, 179.5+/-8.9 cm, 88.8+/-13.3 kg) with previous squat experience performed three sets of three squats using three different cadences (FC = 1 sec descent/1 sec ascent; MC = 3 sec descent/1 sec ascent; SC = 4 sec descent/2 sec ascent) with barbell mass equal to body mass. Ground reaction force was used to calculate inertial force trajectories of the body plus barbell (FI(sub system)). Forces were normalized to body mass. RESULTS: Peak GRF(sub R) and peak FI(sub system) were significantly higher in FC squats compared to MC (p=0.0002) and SC (p=0.0002). Range of GRF(sub R) and FI(sub system) were also significantly higher in FC compared to MC (psquat cadences result in significantly greater peak GRF(sub R) due to the inertia of the system. GRF(sub R) was more dependent upon decent cadence than on ascent cadence. PRACTICAL APPLICATION: This study demonstrates that faster squat cadences produce greater ground reaction forces. Therefore, the use of faster squat cadences might enhance strength and power adaptations to long-term resistance exercise training. Key Words: velocity, weight training, resistive exercise

  20. THE PHYSIOLOGICAL AND MORPHOLOGICAL BASIS FOR OLFACTORY PERCEPTION OF STEROIDS DURING AGONISITC BEHAVIOR IN LOBSTER

    Science.gov (United States)

    During fighting, American lobsters urinate on each other with antennule flicking highest during this period. Blocking excretion of urine obliterates previously established dominance relationships, suggesting that individual recognition requires a urine signal (Breithaupt et al.,...

  1. Deep-sea spiny lobster, Puerulus sewelli Ramadan: Its commercial potentialities

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.V.; George, M.J.

    Recent exploratory cruises carried out along and outside the continental shelf off the west coast of India have brought to light the existence of spiny lobster in considerable numbers The trawling operations conducted in areas of depths between 200...

  2. Chemosensory neurons in the mouthparts of the spiny lobsters Panulirus argus and Panulirus interruptus (Crustacea : Decapoda)

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Shabani, Shkelzen; Høeg, Jens Thorvald

    2005-01-01

    We studied electrophysiological properties of single chemosensory neurons in the mouthparts of the spiny lobsters Panulirus argus and Panulirus interruptus to complement our growing understanding of the behavioral roles of mouthparts of decapod crustaceans. Food mixtures and 13 single compounds...

  3. Field Grow-out of Juvenile American Lobsters in Long Island Sound

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Early benthic stage American lobsters, Homarus americanus, were held in a pilot nursery system in Long Island Sound (LIS) to test field grow-out, as a step toward...

  4. 78 FR 9327 - Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2013-02-08

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XC453 Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce...

  5. 76 FR 4551 - Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2011-01-26

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XA159 Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce...

  6. Effects of pipelines and gathering lines on snow crab and lobster : final report

    Energy Technology Data Exchange (ETDEWEB)

    Warner, J.L.; Covill, J.D. [Martec Ltd., Halifax, NS (Canada); Gilroy, L.; Wheaton, D.; Holtham, P.; Richards, T.; Lucas, C.; Schattschneider, G.; Religa, R.; Brannan, C. [Defence Research and Development Canada Atlantic, Dartmouth, NS (Canada); DeMont, E.; Schuegraf, M; King, K. [Saint Francis Xavier Univ., Antigonish, NS (Canada). Dept. of Biology

    2004-12-01

    A study investigating potential behavioural changes in lobster after the completion of the ExxonMobil natural gas pipeline in the vicinity of Goldboro, Nova Scotia was presented. The study was divided into 4 components: (1) field studies to measure underwater noise in the region associated with the operational gas pipeline; (2) a determination of the electromagnetic (EM) fields generated by the presence of a pipeline in the region through the creation of a numerical model; (3) a lobster catch-and-release field program to measure lobster catches, with concentrated sampling around the Goldboro pipeline landfall using 2 reference sites; and (4) a separate laboratory based study to determine the scaling and climbing ability of lobsters over 32 and 48 inch simulated gas pipelines with smooth and rough texture protective coatings. Offshore sections of the pipeline are partially or fully exposed above the sea-floor, and the laboratory experiments were conducted to asses the effects of unburied pipelines creating a barrier to lobster movement. Results of the acoustic surveys showed peaks of low frequency sound within the hearing range of lobster in the vicinity of the pipeline. The EM survey and resulting numerical model indicated that the pipeline created a narrow magnetic field affecting an area only 2 to 3 metres wide on either side of the pipeline which produced a field strength up to one third as strong as that of the earth's background magnetic field. The lobster catch and release program showed no statistically significant variation of catches between the pipeline locale and the 2 reference sites. In the laboratory testing, the rough surface coating was found to more scaleable for the lobsters than a smooth coating. 7 tabs., 7 figs.

  7. Epizootic shell disease in American lobsters Homarus americanus in southern New England: past, present and future.

    Science.gov (United States)

    Castro, Kathleen M; Cobb, J Stanley; Gomez-Chiarri, Marta; Tlusty, Michael

    2012-08-27

    The emergence of epizootic shell disease in American lobsters Homarus americanus in the southern New England area, USA, has presented many new challenges to understanding the interface between disease and fisheries management. This paper examines past knowledge of shell disease, supplements this with the new knowledge generated through a special New England Lobster Shell Disease Initiative completed in 2011, and suggests how epidemiological tools can be used to elucidate the interactions between fisheries management and disease.

  8. Culture-independent analysis of bacterial communities in hemolymph of American lobsters with epizootic shell disease.

    Science.gov (United States)

    Quinn, Robert A; Smolowitz, Roxanna; Chistoserdov, Andrei Y

    2013-03-26

    Epizootic shell disease (ESD) of the American lobster Homarus americanus H. Milne Edwards, 1837 is a disease of the carapace that presents grossly as large, melanized, irregularly shaped lesions, making the lobsters virtually unmarketable because of their grotesque appearance. We analyzed the bacterial communities present in the hemolymph of lobsters with and without ESD using nested-PCR of the 16S rRNA genes followed by denaturing gradient gel electrophoresis. All lobsters tested (n = 42) had bacterial communities in their hemolymph, and the community profiles were highly similar regardless of the sampling location or disease state. A number of bacteria were detected in a high proportion of samples and from numerous locations, including a Sediminibacterium sp. closely related to a symbiont of Tetraponera ants (38/42) and a Ralstonia sp. (27/42). Other bacteria commonly encountered included various Bacteroidetes, Pelomonas aquatica, and a Novosphingobium sp. One bacterium, a different Sediminibacterium sp., was detected in 20% of diseased animals (n = 29), but not in the lobsters without signs of ESD (n = 13). The bacteria in hemolymph were not the same as those known to be present in lesion communities except for the detection of a Thalassobius sp. in 1 individual. This work demonstrates that hemolymph bacteremia and the particular bacterial species present do not correlate with the incidence of ESD, providing further evidence that microbiologically, ESD is a strictly cuticular disease. Furthermore, the high incidence of the same species of bacteria in hemolymph of lobsters may indicate that they have a positive role in lobster fitness, rather than in disease, and further investigation of the role of bacteria in lobster hemolymph is required.

  9. 77 FR 44168 - Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 11

    Science.gov (United States)

    2012-07-27

    ... Trap Gear Closed Area 37. Point North Lat. West Long. A 25[deg]07'51.156'' 80[deg]17'27.910'' B 25[deg...'40.998'' A 25[deg]07'51.156'' 80[deg]17'27.910'' (xxxviii) Lobster Trap Gear Closed Area 38. Point...) Lobster Trap Gear Closed Area 51. Point North Lat. West Long. A 25[deg]16'33.006'' 80[deg]13'30.001'' B 25...

  10. 77 FR 28560 - Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 11

    Science.gov (United States)

    2012-05-15

    ...'' (xxxvii) Lobster Trap Gear Closed Area 37. Point North lat. West long. A 25[deg]07'51.156''. 80[deg]17'27... Trap Gear Closed Area 51. Point North lat. West long. A 25[deg]16'33.006''. 80[deg]13'30.001'' B 25[deg...) Lobster Trap Gear Closed Area 55. Point North lat. West long. A 25[deg]21'45.004''. 80[deg]09'51.998'' B...

  11. Microbial Degradation of Lobster Shells to Extract Chitin Derivatives for Plant Disease Management

    Directory of Open Access Journals (Sweden)

    Gayathri Ilangumaran

    2017-05-01

    Full Text Available Biodegradation of lobster shells by chitinolytic microorganisms are an environment safe approach to utilize lobster processing wastes for chitin derivation. In this study, we report degradation activities of two microbes, “S223” and “S224” isolated from soil samples that had the highest rate of deproteinization, demineralization and chitinolysis among ten microorganisms screened. Isolates S223 and S224 had 27.3 and 103.8 protease units mg-1 protein and 12.3 and 11.2 μg ml-1 of calcium in their samples, respectively, after 1 week of incubation with raw lobster shells. Further, S223 contained 23.8 μg ml-1 of N-Acetylglucosamine on day 3, while S224 had 27.3 μg ml-1 on day 7 of incubation with chitin. Morphological observations and 16S rDNA sequencing suggested both the isolates were Streptomyces. The culture conditions were optimized for efficient degradation of lobster shells and chitinase (∼30 kDa was purified from crude extract by affinity chromatography. The digested lobster shell extracts induced disease resistance in Arabidopsis by induction of defense related genes (PR1 > 500-fold, PDF1.2 > 40-fold upon Pseudomonas syringae and Botrytis cinerea infection. The study suggests that soil microbes aid in sustainable bioconversion of lobster shells and extraction of chitin derivatives that could be applied in plant protection.

  12. Temporal variation in the specific dynamic action of juvenile New Zealand rock lobsters, Jasus edwardsii.

    Science.gov (United States)

    Radford, Craig A; Marsden, Islay D; Davison, William

    2004-09-01

    To enhance the on-growing of Jasus edwardsii in culture, it is important to understand the feeding physiology of juveniles. In crustaceans, there is a loss of energy and an increase in oxygen consumption (specific dynamic action or SDA) associated with feeding. The present research measured the SDA of juvenile J. edwardsii fed either in the morning or at night held at 15 degrees C. Closed box respirometry was used to measure oxygen consumption (MO(2)) and ammonia excretion in juvenile lobsters. Juveniles exhibited a nocturnal rhythm in both MO(2) and ammonia excretion. The factorial rise in MO(2) (1.58+/-0.03 times) for lobsters fed in the morning was significantly less than lobsters fed at night (1.80+/-0.01 times). Lobsters fed in the morning had a significantly shorter SDA (30+/-1.2 h) response compared to lobsters fed at night (36+/-1 h). Energy loss as a result of digestion was less for lobsters fed in the morning. Therefore, if juvenile J. edwardsii are fed in the morning, they could optimise the energy content of the meal and this could result in increased growth.

  13. Relationship between dose of emamectin benzoate and molting response of ovigerous American lobsters (Homarus americanus).

    Science.gov (United States)

    Waddy, S L; Merritt, V A; Hamilton-Gibson, M N; Aiken, D E; Burridge, L E

    2007-05-01

    A widely-prescribed treatment to control sea lice on cultured salmon is the administration of feed medicated with SLICE (active ingredient emamectin benzoate (EMB)). High doses of EMB can disrupt the molt cycle of ovigerous American lobsters, causing them to enter proecdysis prematurely and lose their attached eggs when the shell is cast. To determine the dose response to EMB, lobsters were forced to ingest doses that ranged from 0.05 to 0.39 microg g(-1). A significant proportion of lobsters given doses of 0.39 and 0.22 microg g(-1) (37% and 23%, respectively) molted prematurely, almost a year earlier than the control group. All the lobsters in the 0.05 and 0.12 microg g(-1) groups molted at the normal time and the mean time of molt was similar to that of the control group. Thus, the no-observed-effect level (NOEL) and lowest-observed-effect level (LOEL) of EMB on the molt cycle were 0.12 and 0.22 microg EMB g(-1) lobster, respectively. To acquire the LOEL, a 500-g lobster would have to consume 22 g of salmon feed medicated with SLICE at a level of 5 microg EMB g(-1) feed.

  14. Detailed surface morphology of the 'lobster louse' copepod, Nicothoë astaci, a haematophagous gill parasite of the European lobster, Homarus gammarus.

    Science.gov (United States)

    Davies, Charlotte E; Thomas, Gethin R; Maffeis, Thierry G G; Wootton, Emma C; Penny, Mark W; Rowley, Andrew F

    2014-10-01

    The ectoparasitic copepod, Nicothoë astaci (the 'lobster louse'), infests the gills of the European lobster, Homarus gammarus. There have been limited studies on this haematophagous species; therefore knowledge of this parasite is rudimentary. The current study examines the surface morphology of this parasitic copepod, detached from the host, concentrating on adaptations of the suctorial mouthpart, the oral disc. Cryo-scanning electron microscopy revealed structural adaptations that facilitate attachment of these parasites to the gill filaments of their lobster host. The aperture of the feeding channel, through which host haemolymph is drawn, is only ca. 5μm in diameter. The edge of the oral disc is lined with numerous setae, whilst the surface of the disc is covered with large numbers of small (copepod host. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Estimated Muscle Loads During Squat Exercise in Microgravity Conditions

    Science.gov (United States)

    Fregly, Christopher D.; Kim, Brandon T.; Li, Zhao; DeWitt, John K.; Fregly, Benjamin J.

    2012-01-01

    Loss of muscle mass in microgravity is one of the primary factors limiting long-term space flight. NASA researchers have developed a number of exercise devices to address this problem. The most recent is the Advanced Resistive Exercise Device (ARED), which is currently used by astronauts on the International Space Station (ISS) to emulate typical free-weight exercises in microgravity. ARED exercise on the ISS is intended to reproduce Earth-level muscle loads, but the actual muscle loads produced remain unknown as they cannot currently be measured directly. In this study we estimated muscle loads experienced during squat exercise on ARED in microgravity conditions representative of Mars, the moon, and the ISS. The estimates were generated using a subject-specific musculoskeletal computer model and ARED exercise data collected on Earth. The results provide insight into the capabilities and limitations of the ARED machine.

  16. Muscular activity during dynamic squats in patients with ACL reconstruction.

    Science.gov (United States)

    Ceaglio, Sebastian; Alberto, Federico; Catalfamo, Paola Andrea; Braidot, Ariel Andres

    2010-01-01

    One of the most frequent injuries in subjects who practice sport is the rupture of the anterior cruciate ligament (ACL). Appropriate reconstruction and rehabilitation are key issues in full recovery of patients and their return to previous activities. This paper presents a new method to estimate muscle strength during a dynamic exercise from kinematic and electromyographic (EMG) data. Recovery of patients with ACL rupture and reconstruction was evaluated 4 and 6 months after surgery by assessing the differences in knee extensor and flexor muscle activity between the unimpaired and injured limbs. The results show that squat EMGs from the extensor muscles of the knee from the injured and unimpaired limb could help assess rehabilitation outputs in patients who had undergone an ACL reconstructive surgery.

  17. Estimating analytical variance in measurement of polycyclic aromatic hydrocarbons and application to monitoring in American lobster (Homarus americanus)

    Energy Technology Data Exchange (ETDEWEB)

    King, T.L.; Uthe, J.F.; Misra, R.K. [Department of Fisheries and Oceans, Halifax, NS (Canada). Biological Sciences Branch; Musial, C.J. [C. Musial Consulting Chemist Ltd., Monticello, MS (United States)

    1997-05-01

    Polycyclic aromatic hydrocarbon (PAH) concentration in American lobster was monitored. A method to estimate replicate PAH concentrations in the digestive gland tissue based on recoveries of added perdeutered surrogates from a single analysis was presented. Large variations in PAH concentrations were found among the different lobsters, even in specimens from the same place taken at the same time. PAH concentrations in lobsters were sensitive to animal size, sex and fishing site.

  18. Trophic interactions among grouper (Epinephelus marginatus), octopus (Octopus vulgaris) and red lobster (Palinurus elephas) in the Western Mediterranean

    OpenAIRE

    Quetglas, A. (Antoni); Reñones, O. (Olga); Goñi, R. (Raquel)

    2001-01-01

    In the present paper a first evaluation of the trophic interactions between grouper, octopus and spiny red lobster in the western Mediterranean is presented. The efficiency of octopus preying on lobsters is also estimated from trap catches. Grouper and octopus base their diet on the same major taxonomic groups and this is reflected in the values of diet overlap. Trophic diversity of grouper and octopus is also very similar. The estimation of the octopus efficiency preying on lobsters shows th...

  19. New species and new records of deepwater munidid squat lobsters from north-western Australia: Onconida, Bathymunida, Crosnierita, Plesionida and Torbenella.

    Science.gov (United States)

    Ahyong, Shane T; Taylor, Joanne; Mccallum, Anna W

    2013-11-04

    Seven species of Munididae are reported from the continental margin of north-western Australia. Three species are new to science: Crosnierita adela sp. nov., Onconida ariel sp. nov. and Plesionida aurelia sp. nov., each presently known only from Western Australia. Four species are reported for the first time from Australian waters, Bathymunida balssi Van Dam, 1838, Bathymunida dissimilis Baba & de Saint Laurent, 1996, Crosnierita yante (Macpherson, 1994) and Torbenella orbis (Baba, 2005). Keys to the world species of the genera represented are provided.

  20. Analog electronic model of the lobster pyloric central pattern generator

    Energy Technology Data Exchange (ETDEWEB)

    Volkovskii, A [Institute for Nonlinear Science, University of California San Diego, CA (United States); Brugioni, S [Institute for Nonlinear Science, University of California San Diego, CA (United States); Istituto Nazionale di Ottica Applicata Largo E. Fermi 6 50125 Florence (Italy); Levi, R [Institute for Nonlinear Science, University of California San Diego, CA (United States); Rabinovich, M [Institute for Nonlinear Science, University of California San Diego, CA (United States); Selverston, A [Institute for Nonlinear Science, University of California San Diego, CA (United States); Abarbane, H D I [Institute for Nonlinear Science, University of California San Diego, CA (United States)

    2005-01-01

    An electronic circuit intended to simulate the nonlinear dynamics of a simplified 3-cell model of the pyloric central pattern generator in California spiny lobster stomato gastric ganglion is presented. The model employs the synaptic phase locked loop (SPLL) concept where the frequency of oscillations of a postsynaptic cell is mainly controlled by the synaptic current which depends on the phase shift between the oscillations. The theoretical study showed that the system has a stable steady state with correct phase shifts between the oscillations and that this regime is stable when the frequency of the pacemaker cell is varied over a wide range. The main bifurcations in the system were studied analytically, in computer simulations, and in experiments with the electronic circuit. The experimental measurements are in good agreement with the expectations of the theoretical model.

  1. Genetic Diversity Approach to Fishery Management Spiny Lobster Southern Waters of Java Based on SWOT Analysis and AHP

    Directory of Open Access Journals (Sweden)

    Florensius Eko Haryono

    2017-05-01

    Full Text Available Indonesia as an archipelagic and tropical country, and known as the centre of megabiodiversity. Tropical spiny lobster consists of several species and able to survive without water for a certain period and this excess used to be distributed life conditions.  Spiny lobster fisheries is become an important issue in Indonesia now, due to the catch condition decrease for some decade, and need a policy to manage. Spiny lobster management strategy based on biodiversity genetic of lobster in Southern of Central Java (SCJ and Special  Region of Jogjakarta (SRJ waters done by collecting the lobster randomly, and collecting the questioner to fisherman, lobster collector, government and NGO from February-August 2015.  Data analyzed by SWOT and AHP methods.   The management priorities based on highest score. The first priority management based on genetic of lobster is not carried out on an isolated by each districts. Second priority management based on genetic lobster was avoid of each district management. Third priority was  optimizing new fishingground.  Fourth priority optimized of habitat utilization, optimized  fishing time, and increased number of fishing trips . Key word : Spiny lobster, diversity genetic, SWOT, AHP.

  2. Pengaruh Kepadatan dan Durasi dalam Kondisi Transportasi Sistem Kering Terhadap Kelulusan Hidup Lobster Air Tawar (Cherax quadricarinatus

    Directory of Open Access Journals (Sweden)

    Theresia Dwi Suryaningrum

    2008-12-01

    selama dalam kondisi transportasi. Kemasan dengan kepadatan 6 ekor/kotak plastik menghasilkan kelulusan hidup yang lebih baik dibandingkan dengan kemasan dengan kepadatan 8 ekor/kotak plastik. Semakin lama waktu dalam kondisi transportasi, semakin rendah kelulusan hidup dan bobot lobster. Durasi dalam kondisi transportasi sampai 7 hari dapat menurunkan bobot lobster sampai 10%. Transportasi lobster dengan kepadatan 6 ekor/kotak plastik selama 6 hari menghasilkan kelulusan hidup 97% dan tetap sehat setelah dibugarkan kembali. Oleh karena itu, lobster air tawar sebaiknya ditransportasikan dengan durasi tidak lebih dari 6 hari.

  3. Research Regarding Somatic Measurements at River Lobster Males (Astacus Fluviatilis

    Directory of Open Access Journals (Sweden)

    Marian Bura

    2010-10-01

    Full Text Available The body measurements was made on 20 males of river lobsters (Astacus fluviatilis or Astacus astacus. The lobsters on witch the study was made had an average total length of body of 12.72 cm ±0.19 cm (formed from: 6.07±0.10cm the length of cefalothorax, 4.73 ±0.10 cm the length of abdomen and 1.91 ±0.07 cm length of telson, and a body weight of 55.70±3.07 g. the males present a length of feelers of 8.53±0.34 cm, a antennas of 2.20±0.05 cm, and the stem of the eyes of 0.51±0.02 cm. The body of male present a average width of 3.35±0.07 cm at level of cefalothorax, and 2.40±0.05 cm at abdomen level. Average deepness of cefalothorax was 2.85±0.07cm, and abdomen deepness of 1.34±0.03cm. The 5 pairs of periopode had an average length of 10.91±0.42 cm, 6.06±0.22 cm, 7.21±0.21 cm, 6.57±0.16 cm and 5.85±0.15cm. The average length of pleopods was at first pear of 2.00±0.06 cm, at second pair of 2.11±0.05 cm, at third of 1.85±0.05 cm, at fourth of 1.73±0.04 cm and at fifth pair of 1.55±0.04 cm.

  4. Predicting a 10 repetition maximum for the free weight parallel squat using the 45 degrees angled leg press.

    Science.gov (United States)

    Willardson, Jeffrey M; Bressel, Eadric

    2004-08-01

    The purpose of this research was to devise prediction equations whereby a 10 repetition maximum (10RM) for the free weight parallel squat could be predicted using the following predictor variables: 10RM for the 45 degrees angled leg press, body mass, and limb length. Sixty men were tested over a 3-week period, with 1 testing session each week. During each testing session, subjects performed a 10RM for the free weight parallel squat and 45 degrees angled leg press. Stepwise multiple regression analysis showed leg press mass lifted to be a significant predictor of squat mass lifted for both the advanced and the novice groups (p squat mass lifted for the novice group and 55% of the variance in squat mass lifted for the advanced group. Limb length and body mass were not significant predictors of squat mass lifted for either group. The following prediction equations were devised: (a) novice group squat mass = leg press mass (0.210) + 36.244 kg, (b) advanced group squat mass = leg press mass (0.310) + 19.438 kg, and (c) subject pool squat mass = leg press mass (0.354) + 2.235 kg. These prediction equations may save time and reduce the risk of injury when switching from the leg press to the squat exercise.

  5. Kinematic and Electromyographic Activity Changes during Back Squat with Submaximal and Maximal Loading

    Science.gov (United States)

    Erdag, Deniz

    2017-01-01

    The aim of this study was to investigate the possible kinematic and muscular activity changes with maximal loading during squat maneuver. Fourteen healthy male individuals, who were experienced at performing squats, participated in this study. Each subject performed squats with 80%, 90%, and 100% of the previously established 1 repetition maximum (1RM). Electromyographic (EMG) activities were measured for the vastus lateralis, vastus medialis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, and erector spinae by using an 8-channel dual-mode portable EMG and physiological signal data acquisition system (Myomonitor IV, Delsys Inc., Boston, MA, USA). Kinematical data were analyzed by using saSuite 2D kinematical analysis program. Data were analyzed with repeated measures analysis of variance (p squat may not be necessary for focusing on knee extensor improvement and may increase the lumbar injury risk. PMID:28546738

  6. Computational Prediction of Muscle Moments During ARED Squat Exercise on the International Space Station.

    Science.gov (United States)

    Fregly, Benjamin J; Fregly, Christopher D; Kim, Brandon T

    2015-12-01

    Prevention of muscle atrophy caused by reduced mechanical loading in microgravity conditions remains a challenge for long-duration spaceflight. To combat leg muscle atrophy, astronauts on the International Space Station (ISS) often perform squat exercise using the Advanced Resistive Exercise Device (ARED). While the ARED is effective at building muscle strength and volume on Earth, NASA researchers do not know how closely ARED squat exercise on the ISS replicates Earth-level squat muscle moments, or how small variations in exercise form affect muscle loading. This study used dynamic simulations of ARED squat exercise on the ISS to address these two questions. A multibody dynamic model of the complete astronaut-ARED system was constructed in OpenSim. With the ARED base locked to ground and gravity set to 9.81 m/s², we validated the model by reproducing muscle moments, ground reaction forces, and foot center of pressure (CoP) positions for ARED squat exercise on Earth. With the ARED base free to move relative to the ISS and gravity set to zero, we then used the validated model to simulate ARED squat exercise on the ISS for a reference squat motion and eight altered squat motions involving changes in anterior-posterior (AP) foot or CoP position on the ARED footplate. The reference squat motion closely reproduced Earth-level muscle moments for all joints except the ankle. For the altered squat motions, changing the foot position was more effective at altering muscle moments than was changing the CoP position. All CoP adjustments introduced an undesirable shear foot reaction force that could cause the feet to slip on the ARED footplate, while some foot and CoP adjustments introduced an undesirable sagittal plane foot reaction moment that would cause the astronaut to rotate off the ARED footplate without the use of some type of foot fixation. Our results provide potentially useful information for achieving desired increases or decreases in specific muscle moments

  7. Baseline strength can influence the ability of salivary free testosterone to predict squat and sprinting performance.

    Science.gov (United States)

    Crewther, Blair T; Cook, Christian J; Gaviglio, Chris M; Kilduff, Liam P; Drawer, Scott

    2012-01-01

    The objective of this study was to determine if salivary free testosterone can predict an athlete's performance during back squats and sprints over time and the influence baseline strength on this relationship. Ten weight-trained male athletes were divided into 2 groups based on their 1 repetition maximum (1RM) squats, good squatters (1RM > 2.0 × body weight, n = 5) and average squatters (1RM squat 1RM and 10-m sprint times on 10 separate occasions over a 40-day period. A saliva sample was collected before testing and assayed for free testosterone and cortisol. The pooled testosterone correlations were strong and significant in the good squatters (r = 0.92 for squats, r = -0.87 for sprints, p squats, r = -0.18 for sprints). Cortisol showed no significant correlations with 1RM squat and 10-m sprint performance, and no differences were identified between the 2 squatting groups. In summary, these results suggest that free testosterone is a strong individual predictor of squat and sprinting performance in individuals with relatively high strength levels but a poor predictor in less strong individuals. This information can assist coaches, trainers, and performance scientists working with stronger weight-trained athletes, for example, the preworkout measurement of free testosterone could indicate likely training outcomes or a readiness to train at a certain intensity level, especially if real-time measurements are made. Our results also highlight the need to separate group and individual hormonal data during the repeated testing of athletes with variable strength levels.

  8. The acute effects of manipulating volume and load of back squats on countermovement vertical jump performance.

    Science.gov (United States)

    Moir, Gavin L; Mergy, David; Witmer, Ca; Davis, Shala E

    2011-06-01

    The acute effects of manipulating the volume and load of back squats on subsequent countermovement vertical jump performance were investigated in the present study. Eleven National Collegiate Athletic Association division II female volleyball players performed 10 countermovement vertical jumps (CMJs) on a force platform 2 minutes after the last squat repetition of a high-load (HL) or high-volume (HV) squat protocol. Two minutes of rest was provided between each CMJ. The HL protocol culminated in the subjects having to perform 3 repetitions with a load equivalent to 90% 1 repetition maximum (1RM) back squat, whereas 12 repetitions with a load equivalent to 37% 1RM were performed in the HV protocol. During an initial familiarization session, knee angles were recorded during a series of CMJs, and these angles were used to control the depth of descent during all subsequent back squats. Jump height (JH) and vertical stiffness (VStiff) were calculated during each of the 10 CMJ, and the change in these variables after the 2 squat protocols was assessed using an analysis of variance model with repeated measures on 2 factors (Protocol [2-levels]; Time [2-levels]). There was no significant difference in JH after the HL and HV protocols (p > 0.05). A significant Protocol × Time interaction for VStiff resulted from the increase after the HL protocol being greater than that after the HV protocol (p = 0.03). The knee angles before the HL and HV protocols were significantly greater than those measured during the initial familiarization session (p = 0.001). Although neither squat protocol provided any benefit in improving JH, the heavy squat protocol produced greater increases in VStiff during the CMJ. Because of the increased VStiff caused by the HL protocol, volleyball coaches may consider using such protocols with their players to improve performance in jumps performed from a run such as the spike and on-court agility.

  9. TRUNK LEAN DURING A SINGLE-LEG SQUAT IS ASSOCIATED WITH TRUNK LEAN DURING PITCHING.

    Science.gov (United States)

    Plummer, Hillary A; Oliver, Gretchen D; Powers, Christopher M; Michener, Lori A

    2018-02-01

    Impaired trunk motion during pitching may be a risk factor for upper extremity injuries. Specifically, increased forces about the shoulder and elbow have been observed in pitchers with excessive contralateral trunk lean during pitching. Because of the difficulty in identifying abnormal trunk motions during a high-speed task such as pitching, a clinical screening test is needed to identify pitchers who have impaired trunk motion during pitching. The purpose of this study was to determine the relationship between the degree of lateral trunk lean during the single-leg squat and amount of trunk lean during pitching and if trunk lean during pitching can be predicted from lean during the single-leg squat. Controlled Laboratory Study; Cross-sectional. Seventy-three young baseball pitchers (11.4 ± 1.7 years; 156.3 ± 11.9 cm; 50.5 ± 8.8 kg) participated. An electromagnetic tracking system was used to obtain trunk kinematic data during a single-leg squat task (lead leg) and at maximum shoulder external rotation of a fastball pitch. Pearson correlation coefficients for trunk lean during the single-leg squat and pitching were calculated. A linear regression analysis was performed to determine if trunk lean during pitching can be predicted from lean during the single-leg squat. There was a positive correlation between trunk lean during the single-leg squat and trunk lean during pitching (r = 0.53; plean during the single-leg squat predicted the amount of lateral trunk lean during pitching (R 2 = 0.28; p lean during an SLS and pitching. Trunk lean during the single-leg squat explained 28% of the variance in trunk lean during pitching. Diagnosis, level 3.

  10. Lobster processing by-products as valuable bioresource of marine functional ingredients, nutraceuticals, and pharmaceuticals.

    Science.gov (United States)

    Nguyen, Trung T; Barber, Andrew R; Corbin, Kendall; Zhang, Wei

    2017-01-01

    The worldwide annual production of lobster was 165,367 tons valued over $3.32 billion in 2004, but this figure rose up to 304,000 tons in 2012. Over half the volume of the worldwide lobster production has been processed to meet the rising global demand in diversified lobster products. Lobster processing generates a large amount of by-products (heads, shells, livers, and eggs) which account for 50-70% of the starting material. Continued production of these lobster processing by-products (LPBs) without corresponding process development for efficient utilization has led to disposal issues associated with costs and pollutions. This review presents the promising opportunities to maximize the utilization of LPBs by economic recovery of their valuable components to produce high value-added products. More than 50,000 tons of LPBs are globally generated, which costs lobster processing companies upward of about $7.5 million/year for disposal. This not only presents financial and environmental burdens to the lobster processors but also wastes a valuable bioresource. LPBs are rich in a range of high-value compounds such as proteins, chitin, lipids, minerals, and pigments. Extracts recovered from LPBs have been demonstrated to possess several functionalities and bioactivities, which are useful for numerous applications in water treatment, agriculture, food, nutraceutical, pharmaceutical products, and biomedicine. Although LPBs have been studied for recovery of valuable components, utilization of these materials for the large-scale production is still very limited. Extraction of lobster components using microwave, ultrasonic, and supercritical fluid extraction were found to be promising techniques that could be used for large-scale production. LPBs are rich in high-value compounds that are currently being underutilized. These compounds can be extracted for being used as functional ingredients, nutraceuticals, and pharmaceuticals in a wide range of commercial applications

  11. Strength, body composition, and functional outcomes in the squat versus leg press exercises.

    Science.gov (United States)

    Rossi, Fabrício E; Schoenfeld, Brad J; Ocetnik, Skyler; Young, Jonathan; Vigotsky, Andrew; Contreras, Bret; Krieger, James W; Miller, Michael G; Cholewa, Jason

    2018-03-01

    The purpose of this study was to compare strength, body composition, and functional outcome measures following performance of the back squat, leg press, or a combination of the two exercises. Subjects were pair-matched based on initial strength levels and then randomly assigned to 1 of 3 groups: a squat-only group (SQ) that solely performed squats for the lower body; a leg press-only group (LP) that solely performed leg presses for the lower body, or a combined squat and leg press group (SQ-LP) that performed both squats and leg presses for the lower body. All other RT variables were held constant. The study period lasted 10 weeks with subjects performing 2 lower body workouts per week comprising 6 sets per session at loads corresponding to 8-12 RM with 90- to 120-second rest intervals. Results showed that SQ had greater transfer to maximal squat strength compared to the leg press. Effect sizes favored SQ and SQ-LP versus LP with respect to countermovement jump while greater effect sizes for dynamic balance were noted for SQ-LP and LP compared to SQ, although no statistical differences were noted between conditions. These findings suggest that both free weights and machines can improve functional outcomes, and that the extent of transfer may be specific to the given task.

  12. Explosive force production during isometric squats correlates with athletic performance in rugby union players.

    Science.gov (United States)

    Tillin, Neale Anthony; Pain, Matthew Thomas Gerard; Folland, Jonathan

    2013-01-01

    This study investigated the association between explosive force production during isometric squats and athletic performance (sprint time and countermovement jump height). Sprint time (5 and 20 m) and jump height were recorded in 18 male elite-standard varsity rugby union players. Participants also completed a series of maximal- and explosive-isometric squats to measure maximal force and explosive force at 50-ms intervals up to 250 ms from force onset. Sprint performance was related to early phase (≤100 ms) explosive force normalised to maximal force (5 m, r = -0.63, P = 0.005; and 20 m, r = -0.54, P = 0.020), but jump height was related to later phase (>100 ms) absolute explosive force (0.51 squats (33-67%; 0.001 squats was associated with athletic performance. Specifically, sprint performance was most strongly related to the proportion of maximal force achieved in the initial phase of explosive-isometric squats, whilst jump height was most strongly related to absolute force in the later phase of the explosive-isometric squats.

  13. Automated Assessment of Dynamic Knee Valgus and Risk of Knee Injury During the Single Leg Squat

    Science.gov (United States)

    Lee, Alexander; Raina, Sachin; Kulić, Dana

    2017-01-01

    Many clinical assessment protocols of the lower limb rely on the evaluation of functional movement tests such as the single leg squat (SLS), which are often assessed visually. Visual assessment is subjective and depends on the experience of the clinician. In this paper, an inertial measurement unit (IMU)-based method for automated assessment of squat quality is proposed to provide clinicians with a quantitative measure of SLS performance. A set of three IMUs was used to estimate the joint angles, velocities, and accelerations of the squatting leg. Statistical time domain features were generated from these measurements. The most informative features were used for classifier training. A data set of SLS performed by healthy participants was collected and labeled by three expert clinical raters using two different labeling criteria: “observed amount of knee valgus” and “overall risk of injury”. The results showed that both flexion at the hip and knee, as well as hip and ankle internal rotation are discriminative features, and that participants with “poor” squats bend the hip and knee less than those with better squat performance. Furthermore, improved classification performance is achieved for females by training separate classifiers stratified by gender. Classification results showed excellent accuracy, 95.7 % for classifying squat quality as “poor” or “good” and 94.6% for differentiating between high and no risk of injury. PMID:29204327

  14. The geometric curvature of the lumbar spine during restricted and unrestricted squats.

    Science.gov (United States)

    Hebling Campos, Mário; Furtado Alaman, Laizi I; Seffrin-Neto, Aldo A; Vieira, Carlos A; Costa de Paula, Marcelo; Barbosa de Lira, Claudio A

    2017-06-01

    The main purpose of this study was to analyze the behavior of the geometric curvature of the lumbar spine during restricted and unrestricted squats, using a novel investigative method. The rationale for our hypothesis is that the lumbar curvature has different patterns at different spine levels depending on the squat technique used. Spine motion was collected via stereo-photogrammetric analysis in nineteen participants (11 males, 8 females). The reconstructed spine points at the upright neutral position and at the deepest position of the squat exercise were projected onto the sagittal plane of the trunk, a polynomial was fitted to the data, and were quantified the two-dimensional geometric curvature at lower, central and higher lumbar levels, besides the inclination of trunk and lumbosacral region, the overall geometric curvature and overall angle of the lumbar spine. The mean values for each variable were analysed with paired t-test (Psquat techniques and these effects are also reduced in unrestricted squats. The data collected in the study are evidence that during barbell squats the lumbar curvature has different patterns at different spinal levels depending on the exercise technique. The lower lumbar spine appears to be less overloaded during unrestricted squats.

  15. Changes in Lumbopelvic Movement and Muscle Recruitment Associated with Prolonged Deep Squatting: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Tim K. S. Lui

    2018-05-01

    Full Text Available This study examined the changes in spinal kinematics and muscle recruitment of the lumbopelvic region associated with prolonged squatting. Eight subjects with chronic nonspecific low back pain (LBP and eight asymptomatic subjects (AS performed squat-to-stand and reverse movements, before and immediately after 15 min deep-squatting. Within-group and between-group differences in lumbopelvic kinematics and electromyographic activity acquired in lumbar erector spinae (ES, gluteus maximus (GM, and vastus lateralis (VL were analyzed. During squat-to-stand after squatting, the LBP group showed slower then faster lumbar movement in the second and third quartiles, respectively. In the second quartile, the AS group moved with a significantly greater lumbar angle. However, significantly greater bilateral GM activity (+4–4.5% was found in the LBP group only. A more profound decrease in bilateral ES activity (−10% was also shown in the LBP group, yet this was nonsignificant compared to the AS group (−4%. In the third quartile, only the LBP group moved with a significantly greater lumbar angle, together with a significant increase in bilateral ES (+6–8% and GM muscle (+2–3% activity. The findings of the altered pattern of joint kinematics and recruitment of the key lumbopelvic muscles displayed in the LBP group inform on the possible mechanisms that may contribute to the increased risk of developing lumbar dysfunctions for people who work in prolonged squatting postures.

  16. Spatial Variability in Condition of Southern Rock Lobsters (Jasus edwardsii) at the Start of the Tasmanian Fishing Season.

    Science.gov (United States)

    Mendo, Tania; Simon, Cedric; Green, Bridget; Gardner, Caleb

    2016-01-01

    The southern rock lobster (Jasus edwardsii) industry in Australia favours red lobsters, which are usually caught in shallow waters, over paler (brindle) lobsters. This preference is driven partly by the Chinese market, where red is associated with luck and prosperity, and additionally, by the widely held perception within the industry that brindles have greater mortality rates during out of water transport than reds. Limited scientific evidence supports these industry observations; however, these studies did not evaluate the initial condition of lobsters. This study aimed first, to determine which variables better describe condition in J. edwardsii and second, to compare condition among lobsters in several sites around Tasmania at the typical time of high transport mortality. Male lobsters were collected from the South West, South East, East and North coast of Tasmania in late November/December 2014, which correspond to the start of the Tasmanian fishing season. A comprehensive condition assessment was applied by measuring tissue proximal composition, Brix index, Total Haemocyte Count, pH, haemocyanin and another 16 haemolymph parameters of interest. A useful framework to compare condition in J. edwardsii was established by first, using Brix index as a measure of nutritional condition, second, using pH, magnesium, and bicarbonate to evaluate differences in physiological condition and finally, using THC counts as a proxy for lobster health condition. Lobsters from different sites had different nutritional, physiological and health condition, consistent with industry observations, however our results indicate that some red shallow water lobsters exhibited poorer nutritional and health condition, while some deep water brindle lobsters were in good condition. Differences in condition could not be directly associated to catch depth of lobsters and was related to other spatially discrete factors which sometimes vary over distances <3 km.

  17. A noninvasive method for in situ determination of mating success in female American lobsters (Homarus americanus).

    Science.gov (United States)

    Goldstein, Jason S; Pugh, Tracy L; Dubofsky, Elizabeth A; Lavalli, Kari L; Clancy, Michael; Watson, Winsor H

    2014-02-07

    Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female's seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George's Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations.

  18. Comparison of the angles and corresponding moments in the knee and hip during restricted and unrestricted squats.

    Science.gov (United States)

    Lorenzetti, Silvio; Gülay, Turgut; Stoop, Mirjam; List, Renate; Gerber, Hans; Schellenberg, Florian; Stüssi, Edgar

    2012-10-01

    The aim of this study was to compare the angles and corresponding moments in the knee and hip during squats. Twenty subjects performed restricted and unrestricted squats with barbell loads that were 0, ¼, and ½ their body weight. The experimental setup consisted of a motion capture system and 2 force plates. The moments were calculated using inverse dynamics. During the unrestricted squats, the maximum moments in the knee were significantly higher, and those in the hip were significantly lower than during restricted squats. At the lowest position, the maximum knee flexion angles were approximately 86° for the restricted and approximately 106° for the unrestricted techniques, whereas the maximum hip flexion angle was between 95° and 100°. The higher moments in the hip during restricted squats suggest a higher load of the lower back. Athletes who aim to strengthen their quadriceps should consider unrestricted squats because of the larger knee load and smaller back load.

  19. Are Squats and Lunges Safe in the Rehabilitation of Patients with Patellofemoral Pain?

    Science.gov (United States)

    Wood, David; Metcalfe, Andrew; Dodge, Jen; Templeton-Ward, Oliver

    2016-01-01

    Objectives: Patello-femoral pain is a common presenting complaint in orthopaedic clinics, and initial management often involves exercise and quadriceps strengthening regimes. Squats and lunges have become a common part of physiotherapy regimes as well as many exercise programs. It has been our observation that some patients experience a deterioration in pain after starting squats and lunges, and there is no agreement about the safe use of these exercises. The aim of this paper is to review the clinical and biomechanical literature to assess the safety of squats and lunges of patients with patella-femoral or anterior knee pain. Methods: Systematic Review. A literature review was performed of the Pubmed and PEDro databases using a pre-defined search strategy. Titles were screened by both an orthopaedic surgeon and a physiotherapist, abstracts were reviewed and the final papers were selected for inclusion. Randomised trials or comparative cohort studies of exercise regimes were included from the clinical literature as well as systematic reviews or meta-analyses published in the last 5 years. Patello-femoral forces calculated either from in-vivo data or cadaveric simulations were included from the biomechanical literature. Results: The searches revealed 3237 titles, which were reduced to 27 papers for the literature review. The biomechanical literature clearly demonstrated increasing patello-femoral forces during squats with increasing flexion, peaking at 90° of flexion and then falling in deep flexion. Less data was available on lunges but findings were comparable to studies of squats. Forces in the PFJ experienced during squats and lunges are significantly greater than with open-chain exercises beyond 60° of knee flexion. There were 13 clinical studies and 8 systematic reviews identified, which demonstrated that exercise is an effective treatment for PF pain with no significant difference between closed or open chain exercises (one study only). However only one

  20. Field monitoring of rail squats using 3D ultrasonic mapping technique

    International Nuclear Information System (INIS)

    Kaewunruen, S.; Ishida, M.

    2014-01-01

    Rail squats and studs are typically classified as the propagation of any cracks .that have grown longitudinally through the subsurface. Some of the cracks could propagate to the bottom of rails transversely, which have branched from the initial longitudinal cracks with a depression of rail surface. The rail defects are commonly referred to as 'squats' when they were initiated from a damage layer caused by rolling contact fatigue, and as 'studs' when they were associated with a white etching layer caused by the transformation from pearlitic steel due to friction heat generated by wheel sliding or excessive traction. Such above-mentioned rail defects have been often observed in railway tracks catered for either light passenger or heavy freight traffics and for low, medium or high speed trains all over the world for over 60 years except some places such as sharp curves where large wear takes place under severe friction between the wheel flange and rail gauge face. It becomes a much-more significant issue when the crack grows and sometimes flakes off the rail (by itself or by insufficient rail grinding), resulting in a rail surface irregularity. Such rail surface defects induce wheel/rail impact and large amplitude vibration of track structure and poor ride quality. In Australia, Europe, and Japan, rail squats/studs have occasionally turned into broken rails. The root cause and preventive solution to this defect are still under investigation from the fracture mechanics and material sciences point of view. Some patterns of squat/stud development related to both curve and tangent track geometries have been observed and squat growth has been monitored for individual squats using ultrasonic mapping techniques. This paper highlights the field monitoring of squat/stud distribution and its growth. Squat/stud growth has been detected and scanned using the ultrasonic measurement device on a grid applied to the rail surface. The depths of crack paths at each grid node form a

  1. Field monitoring of rail squats using 3D ultrasonic mapping technique

    Energy Technology Data Exchange (ETDEWEB)

    Kaewunruen, S., E-mail: sakdirat.kaewunruen@transport.nsw.gov.au [NSW, Transport, Sydney (Australia); Ishida, M., E-mail: ishida-mk@n-koei.jp [Nippon Koei Co. Ltd., Railway Div., Railway Engineering Dept., Chiyoda-ku, Tokyo (Japan)

    2014-11-15

    Rail squats and studs are typically classified as the propagation of any cracks .that have grown longitudinally through the subsurface. Some of the cracks could propagate to the bottom of rails transversely, which have branched from the initial longitudinal cracks with a depression of rail surface. The rail defects are commonly referred to as 'squats' when they were initiated from a damage layer caused by rolling contact fatigue, and as 'studs' when they were associated with a white etching layer caused by the transformation from pearlitic steel due to friction heat generated by wheel sliding or excessive traction. Such above-mentioned rail defects have been often observed in railway tracks catered for either light passenger or heavy freight traffics and for low, medium or high speed trains all over the world for over 60 years except some places such as sharp curves where large wear takes place under severe friction between the wheel flange and rail gauge face. It becomes a much-more significant issue when the crack grows and sometimes flakes off the rail (by itself or by insufficient rail grinding), resulting in a rail surface irregularity. Such rail surface defects induce wheel/rail impact and large amplitude vibration of track structure and poor ride quality. In Australia, Europe, and Japan, rail squats/studs have occasionally turned into broken rails. The root cause and preventive solution to this defect are still under investigation from the fracture mechanics and material sciences point of view. Some patterns of squat/stud development related to both curve and tangent track geometries have been observed and squat growth has been monitored for individual squats using ultrasonic mapping techniques. This paper highlights the field monitoring of squat/stud distribution and its growth. Squat/stud growth has been detected and scanned using the ultrasonic measurement device on a grid applied to the rail surface. The depths of crack paths at each

  2. Biomechanical Modeling Analysis of Loads Configuration for Squat Exercise

    Science.gov (United States)

    Gallo, Christopher A.; Thompson, William K.; Lewandowski, Beth E.; Jagodnik, Kathleen; De Witt, John K.

    2017-01-01

    INTRODUCTION: Long duration space travel will expose astronauts to extended periods of reduced gravity. Since gravity is not present to assist loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft for travel to the Moon or to Mars is limited and therefore compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Biomechanical data collection and computational modeling aid the device design process by quantifying the joint torques and the musculoskeletal forces that occur during exercises performed on the prototype devices. METHODS The computational models currently under development utilize the OpenSim [1] software platform, consisting of open source code for musculoskeletal modeling, using biomechanical input data from test subjects for estimation of muscle and joint loads. The OpenSim Full Body Model [2] is used for all analyses. The model incorporates simplified wrap surfaces, a new knee model and updated lower body muscle parameters derived from cadaver measurements and magnetic resonance imaging of young adults. The upper body uses torque actuators at the lumbar and extremity joints. The test subjects who volunteer for this study are instrumented with reflective markers for motion capture data collection while performing squat exercising on the Hybrid Ultimate Lifting Kit (HULK) prototype device (ZIN Technologies, Middleburg Heights, OH). Ground reaction force data is collected with force plates under the feet, and device loading is recorded through load cells internal to the HULK. Test variables include

  3. 76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-09-26

    ... lobster, and aquarium trade species identified by the Secretary as not undergoing overfishing; allocate... effect of the 2011 Caribbean ACL Amendment is prevent overfishing of reef fish, spiny lobster and... be subject to overfishing, ACLs must be established at a level that prevents overfishing and helps to...

  4. Differences in technetium-99 accumulation and distribution between organs in male and female lobsters collected from Norwegian coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Kolstad, Anne Kathrine; Gjelsvik, Runhild; Rudjord, Anne Liv

    2006-07-01

    In this report, {sup 99}Tc results for lobsters caught along the Norwegian coast between 2001 and 2005 are presented. The high accumulation of {sup 99}Tc in lobsters compared to other crustecea is confirmed in this report, as well as the clear differences between males and females. Concentration factors have been estimated for each gender and also for different organs. (author)

  5. Differences in technetium-99 accumulation and distribution between organs in male and female lobsters collected from Norwegian coastal waters

    International Nuclear Information System (INIS)

    Kolstad, Anne Kathrine; Gjelsvik, Runhild; Rudjord, Anne Liv

    2006-01-01

    In this report, 99 Tc results for lobsters caught along the Norwegian coast between 2001 and 2005 are presented. The high accumulation of 99 Tc in lobsters compared to other crustecea is confirmed in this report, as well as the clear differences between males and females. Concentration factors have been estimated for each gender and also for different organs. (author)

  6. Movement patterns of the spiny lobster Palinurus elephas (Fabricius, 1787 from a central western Mediterranean protected area

    Directory of Open Access Journals (Sweden)

    Maria Cristina Follesa

    2009-09-01

    Full Text Available Movement patterns of the spiny lobster Palinurus elephas were determined from 389 individuals (total tagged 5666 tag-recaptured inside a no-take area of the central western Mediterranean and its surrounding zone. High site association and limited movements in tagged lobsters was observed; 60.4% of lobsters moved less than 2 km from the centre of the area (site of release. No clear relationship between lobster movement pattern and sex or size was observed; however, it seemed that the largest males and females tended to be more resident, thus contributing to the rebuilding of the biomass of local lobsters. Most lobsters undertook migrations in the southwest direction. The increased availability of shelters and food towards the southwest could have contributed to the lobsters’ movement. The results of our research indicate that the small size of the protected area and the scale of the movement exhibited by tagged lobsters allows a proportion of the lobster population to move out of the protected area and become susceptible to capture in the adjacent fishery.

  7. Driving a Fishery along the Bumpy Ride of Today's Globalisation: The Case of the Australian Southern Rock Lobster Association

    NARCIS (Netherlands)

    Dentoni, D.; Lu, J.; English, F.; McBride, R.

    2012-01-01

    The case of the Australian Southern Rock Lobster Association describes real issues faced by the Market Development Manager of a collective agri-food organization (SRL) representing all the southern rock lobster fishermen in Victoria, South Australia and Tasmania. The case deals with recent

  8. 77 FR 76458 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of Puerto...

    Science.gov (United States)

    2012-12-28

    ... the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of Puerto Rico and the U.S. Virgin Islands; Exempted Fishing Permit AGENCY: National Marine Fisheries Service (NMFS), National... in the U.S. Virgin Islands. Currently, data on U.S. Caribbean spiny lobster life history are limited...

  9. The accumulation of plutonium by the European lobster (Homarus gammarus L.)

    International Nuclear Information System (INIS)

    Swift, D.J.

    1992-01-01

    For 237 Pu accumulation from seawater, the whole body concentration factors (CFs) for juvenile lobsters at 18 o C did not exceed 250 over the 49 days of the study. Most 237 Pu was accumulated by the gills and exoskeleton. Since homarid lobsters eat their exuviae after ecdysis, the whole body 237 Pu content of recently moulted lobsters was also a function of the amount of 237 Pu ingested with the exuviae. Consequently, organ/tissue content and CF values for individual lobsters reflected both the time since their last moult and their exposure time to 237 Pu. These factors precluded the calculation of mean whole body CF values or the accurate estimate of a mean steady state (C ss ) CF value. Juvenile lobsters retained significantly more 237 Pu from labelled food at 7-10 o C than at 18 o C. At 7 o C, the biological half time for assimilated 237 Pu was about 28 days, at 10 o C about 15 days and at 18 o C about 8 days. Very little 237 Pu was transported from the gut to the internal tissues (about 1%); most was retained in the hepatopancreas. (author)

  10. Excretory calcinosis: a new fatal disease of wild American lobsters Homarus americanus.

    Science.gov (United States)

    Dove, Alistair D M; LoBue, Carl; Bowser, Paul; Powell, Mark

    2004-03-10

    A significant number of moribund and dead lobsters Homarus americanus were reported to New York state authorities by lobster fishers in Long Island Sound (LIS) during the summer of 2002. Morbid lobsters were characterised by an orange discolouration of the abdomen, lethargy, an excess of epibionts and poor post-capture survival. On necropsy, severe extensive multifocal or diffuse mineralised granulomatous inflammation of the gills and antennal glands was the most striking pathology. In the gills, granulomas often occluded the lumen of filaments, resulting in congestion, ischemia and coagulative necrosis of gill tissues. In the antennal glands, granulomas were concentrated along the border between the coelomosac and labyrinth. No significant pathogens were recovered from diseased individuals. In prechronic individuals, however, it was evident that granulomas were focused around calcium carbonate (aragonite) crystals. This disease may result from anomalously high sea-bottom temperatures in LIS (approximately 23 degrees C) during the summer of 2002 and associated disruptions of the calcium chemistry of lobsters in favour of deposition of minerals in soft tissues. The ultimate cause of death of affected lobsters is probably respiratory failure due to reduced effective surface area of the gills, exacerbated by hypermetabolic temperatures and an abundance of epibionts.

  11. Lesion bacterial communities in American lobsters with diet-induced shell disease.

    Science.gov (United States)

    Quinn, Robert A; Metzler, Anita; Tlusty, Michael; Smolowitz, Roxanna M; Leberg, Paul; Chistoserdov, Andrei Y

    2012-04-26

    In southern New England, USA, shell disease affects the profitability of the American lobster Homarus americanus fishery. In laboratory trials using juvenile lobsters, exclusive feeding of herring Clupea harengus induces shell disease typified initially by small melanized spots that progress into distinct lesions. Amongst a cohabitated, but segregated, cohort of 11 juvenile lobsters fed exclusively herring, bacterial communities colonizing spots and lesions were investigated by denaturing gradient gel electrophoresis of 16S rDNA amplified using 1 group-specific and 2 universal primer sets. The Bacteroidetes and Proteobacteria predominated in both spots and lesions and included members of the orders Flavobacteriales (Bacteriodetes), Rhodobacterales, Rhodospirillales and Rhizobiales (Alphaproteobacteria), Xanthomonadales (Gammaproteobacteria) and unclassified Gammaproteobacteria. Bacterial communities in spot lesions displayed more diversity than communities with larger (older) lesions, indicating that the lesion communities stabilize over time. At least 8 bacterial types persisted as lesions developed from spots. Aquimarina 'homaria', a species commonly cultured from lesions present on wild lobsters with epizootic shell disease, was found ubiquitously in spots and lesions, as was the 'Candidatus Kopriimonas aquarianus', implicating putative roles of these species in diet-induced shell disease of captive lobsters.

  12. The Evolution of the Maine Lobster V-Notch Practice: Cooperation in a Prisoner's Dilemma Game

    Directory of Open Access Journals (Sweden)

    James Acheson

    2011-03-01

    Full Text Available The Maine lobster industry is experiencing record high catches because, in all probability, of an effective management program. One of the most important conservation measures is the V-notch program that allows fishermen to conserve proven breeding females by notching the tails of egg-bearing lobsters. Such marked lobsters may never be taken. Although thousands of lobster fishermen participate, it is a voluntary practice. The genesis of this practice is not easily explained, because V-notching poses a prisoner's dilemma problem that gives fishermen an incentive to avoid the practice. The most common explanations for ways to overcome prisoner's dilemma problems will not work in the case of the V-notch. An unusual combination of factors explains the V-notch program: (1 a strong belief among those in the industry that the V-notch is effective in conserving the lobster stock; (2 a low discount rate because the long-term gains from V-notching are higher than the one-time gain from defection; (3 a gain in reputation for those who V-notch. At the start of the 20th century, fishermen did not V-notch; by the end of the century, V-notching was common. We explain the change in strategies using a three-parameter evolutionary model that emphasizes the importance of culture change.

  13. Effects of an oil spill on American lobster (Homarus americanus) from Placentia Bay, Newfoundland

    Energy Technology Data Exchange (ETDEWEB)

    Wiliams, U P; Kiceniuk, J W; Ryder, J E; Botta, J R

    1988-10-01

    In March 1988 an accidental spill of ca 500 bbl of crude oil occurred during the unloading of a tanker at a Newfoundland oil refinery. Studies of selected parameters were undertaken to determine the possible short-and long-term effects on the local lobster fishery. Sensory analyses were carried out to ascertain the effects of the oil on the taste and odor of lobster. Lobster muscle and hepatopancreas were analyzed for PAH (polycyclic aromatic hydrocarbon) content and levels of gill browning were determined. Sediments were sampled at various locations in the bay where the spill occurred and levels of PAHs were determined in an attempt to delineate the extent of contamination. Results from the sensory analyses indicate that there was no tainting of lobster samples obtained from the area. There was also no evidence of gill browning or of elevated levels of PAHs in either tail muscle or hepatopancreas. Elevated levels of PAH were not detected in any of the sediments from the bay. The results indicate that lobsters were not contaminated as a result of the oil spill. Based on the results of analyses of sediments for PAHs, future contamination, as a result of the spill at the oil refinery wharf, is not anticipated. 18 refs., 6 tabs.

  14. The accumulation of plutonium by the European lobster (Homarus gammarus L. )

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D J [Ministry of Agriculture, Fisheries and Food, Lowestoft (United Kingdom). Directorate of Fisheries Research

    1992-01-01

    For {sup 237}Pu accumulation from seawater, the whole body concentration factors (CFs) for juvenile lobsters at 18{sup o}C did not exceed 250 over the 49 days of the study. Most {sup 237}Pu was accumulated by the gills and exoskeleton. Since homarid lobsters eat their exuviae after ecdysis, the whole body {sup 237}Pu content of recently moulted lobsters was also a function of the amount of {sup 237}Pu ingested with the exuviae. Consequently, organ/tissue content and CF values for individual lobsters reflected both the time since their last moult and their exposure time to {sup 237}Pu. These factors precluded the calculation of mean whole body CF values or the accurate estimate of a mean steady state (C{sub ss}) CF value. Juvenile lobsters retained significantly more {sup 237}Pu from labelled food at 7-10{sup o}C than at 18{sup o}C. At 7{sup o}C, the biological half time for assimilated {sup 237}Pu was about 28 days, at 10{sup o}C about 15 days and at 18{sup o}C about 8 days. Very little {sup 237}Pu was transported from the gut to the internal tissues (about 1%); most was retained in the hepatopancreas. (author).

  15. Function of chemoreceptor organs in spatial orientation of the lobster, Homarus americanus: differences and overlap

    Energy Technology Data Exchange (ETDEWEB)

    Devine, D.V.; Atema, J.

    1982-08-01

    Three of the lobster's main chemoreceptor organs, the lateral and medial antennules (representing smell) and the dactylus-propodus segments of the walking legs (representing taste), are physiologically quite similar. The authors examined their role in spatial orientation in a food-odor stimulus field. Control animals almost always oriented correctly and immediately to an odor plume. Lobsters with unilateral ablations of lateral antennules lost this ability, but did not show preferential turning toward the intact side. Unilateral medial antennule ablation did not affect orientation. Removal of all aesthetasc hairs from one lateral antennule caused loss of orientation ability less severe than unilateral ablation of the entire lateral antennule. Lobsters with unilaterally ablated lateral antennules and blocked walking leg receptors turned preferentially toward the side of the intact antennule. Thus, it appears that intact lobsters orient in odor space by tropotaxis principally using aesthetasc receptor input. Since loss of appendages is relatively common in lobsters, this partial overlap of organ function may serve the animal well in nature.

  16. Relationship between 1RM back squat test results and explosive movements in professional basketball players

    Directory of Open Access Journals (Sweden)

    Saša Jakovljević

    2015-11-01

    Full Text Available The objectives of this study were related to the research of the relations between the abilities of professional basketball players in the performance of one repetition maximum (1RM back squat and explosive movements, such as 5, 10 and 20-metre running, and vertical jump; as well as the detection and comparison of these abilities between players who play on the outside and inside positions. The study involved 35 professional basketball players (22 outside and 13 inside who were selected as candidates for the national team of Bulgaria. Independent variables of muscular strength were obtained by applying the 1RM back squat test (142.06 ± 29.31 kg, and were normalized with respect to the body mass (1RM Squat/kg (1.51 ± 0.25 and by applying suitable allometric exponent (1RM SquatAl (6.86 ± 1.16. Dependent variables were obtained using two tests: 20-metre run (times registered at 5 and 10 metres and vertical jump (used to calculate the variable peak anaerobic power (PAPW. The results indicated that none of the variables of strength were significantly related to the speed performance, while moderate correlations occurred between the normalized strength variables (1RM Squat/kg and 1RM SquatAl and vertical jump (r = 0.310 and r = 0.308 / p < 0.05. The results obtained show greater correlation (r = 0.660 / p < 0.01 in the ability to deliver power when performing squat and mechanical work performed in vertical jumps. Outside and inside players were significantly different in three variables only: peak anaerobic power, body height and body weight.

  17. Lateral Squats Significantly Decrease Sprint Time in Collegiate Baseball Athletes

    Directory of Open Access Journals (Sweden)

    Jason B. White

    2016-03-01

    Full Text Available The purpose was to examine the effect of prior performance of dumbbell lateral squats (DBLS on an agility movement-into-a-sprint (AMS test. Twelve collegiate, resistance-trained, baseball athletes participated in three sessions separated by three days. Session One consisted of AMS baseline test, DBLS 5-RM test, and experimental protocol familiarization. Subjects were randomly assigned the protocol order for Sessions Two and Three, which consisted of warm up followed by 1-min sitting (no-DBLS or performing the DBLS for 1 × 5 repetitions @ 5RM for each leg. Four minutes of slow recovery walking preceded the AMS test, which consisted of leading off a base and waiting for a visual stimulus. In reaction to stimulus, subjects exerted maximal effort while moving to the right by either pivoting or drop stepping and sprinting for 10 yards (yd. In Session Three, subjects switched protocols (DBLS, no-DBLS. Foot contact time (FCT, stride frequency (SF, stride length (SL, and 10-yd sprint time were measured. There were no differences between conditions for FCT, SF, or SL. Differences existed between DBLS (1.85 ± 0.09 s and no-DBLS (1.89 ± 0.10 s for AMS (p = 0.03. Results from the current study support the use of DBLS for performance enhancement prior to performing the AMS test.

  18. Specific Adaptations in Performance and Muscle Architecture After Weighted Jump-Squat vs. Body Mass Squat Jump Training in Recreational Soccer Players.

    Science.gov (United States)

    Coratella, Giuseppe; Beato, Marco; Milanese, Chiara; Longo, Stefano; Limonta, Eloisa; Rampichini, Susanna; Cè, Emiliano; Bisconti, Angela V; Schena, Federico; Esposito, Fabio

    2018-04-01

    Coratella, G, Beato, M, Milanese, C, Longo, S, Limonta, E, Rampichini, S, Cè, E, Bisconti, AV, Schena, F, and Esposito, F. Specific adaptations in performance and muscle architecture after weighted jump-squat vs. body mass squat jump training in recreational soccer players. J Strength Cond Res 32(4): 921-929, 2018-The aim of the present study was to compare the effects of weighted jump-squat training (WJST) vs. body mass squat jump training (BMSJT) on quadriceps' muscle architecture, lower-limb lean-mass (LM) and muscle strength, performance in change of direction (COD), and sprint and jump in recreational soccer players. Forty-eight healthy soccer players participated in an offseason randomized controlled trial. Before and after an 8-week training intervention, vastus lateralis pennation angle, fascicle length, muscle thickness, LM, squat 1RM, quadriceps and hamstrings isokinetic peak torque, agility T-test, 10-and 30-m sprints, and squat-jump (SJ) were measured. Although similar increases were observed in muscle thickness, fascicle length increased more in WJST (Effect size [ES] = 1.18, 0.82-1.54) than in BMSJT (ES = 0.54, 0.40-0.68), and pennation angle increased only in BMSJT (ES = 1.03, 0.78-1.29). Greater increases in LM were observed in WJST (ES = 0.44, 0.29-0.59) than in BMSJT (ES = 0.21, 0.07-0.37). The agility T-test (ES = 2.95, 2.72-3.18), 10-m (ES = 0.52, 0.22-0.82), and 30-m sprints (ES = 0.52, 0.23-0.81) improved only in WJST, whereas SJ improved in BMSJT (ES = 0.89, 0.43-1.35) more than in WJST (ES = 0.30, 0.03-0.58). Similar increases in squat 1RM and peak torque occurred in both groups. The greater inertia accumulated within the landing phase in WJST vs. BMSJT has increased the eccentric workload, leading to specific eccentric-like adaptations in muscle architecture. The selective improvements in COD in WJST may be related to the increased braking ability generated by the enhanced eccentric workload.

  19. Modeling the focusing efficiency of lobster-eye optics for image shifting depending on the soft x-ray wavelength.

    Science.gov (United States)

    Su, Luning; Li, Wei; Wu, Mingxuan; Su, Yun; Guo, Chongling; Ruan, Ningjuan; Yang, Bingxin; Yan, Feng

    2017-08-01

    Lobster-eye optics is widely applied to space x-ray detection missions and x-ray security checks for its wide field of view and low weight. This paper presents a theoretical model to obtain spatial distribution of focusing efficiency based on lobster-eye optics in a soft x-ray wavelength. The calculations reveal the competition mechanism of contributions to the focusing efficiency between the geometrical parameters of lobster-eye optics and the reflectivity of the iridium film. In addition, the focusing efficiency image depending on x-ray wavelengths further explains the influence of different geometrical parameters of lobster-eye optics and different soft x-ray wavelengths on focusing efficiency. These results could be beneficial to optimize parameters of lobster-eye optics in order to realize maximum focusing efficiency.

  20. Influence of local habitat features on disease avoidance by Caribbean spiny lobsters in a casita-enhanced bay.

    Science.gov (United States)

    Briones-Fourzán, Patricia; Candia-Zulbarán, Rebeca I; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Huchin-Mian, Juan P; Lozano-Álvarez, Enrique

    2012-08-27

    In Bahía de la Ascensión, Mexico, 'casitas' (large artificial shelters) are extensively used to harvest Caribbean spiny lobsters Panulirus argus. After the discovery of a pathogenic virus, Panulirus argus virus 1 (PaV1), in these lobsters, laboratory experiments revealed that PaV1 could be transmitted by contact and through water, and that lobsters avoided shelters harboring diseased conspecifics. To examine these issues in the context of casitas, which typically harbor multiple lobsters of all sizes, we examined the distribution and aggregation patterns of lobsters in the absence/presence of diseased conspecifics (i.e. visibly infected with PaV1) in 531 casitas distributed over 3 bay zones, 1 poorly vegetated ('Vigía Chico', average depth: 1.5 m) and 2 more extensively vegetated ('Punta Allen': 2.5 m; 'Los Cayos': 2.4 m). All zones had relatively high indices of predation risk. Using several statistical approaches, we found that distribution parameters of lobsters were generally not affected by the presence of diseased conspecifics in casitas. Interestingly, however, in the shallower and less vegetated zone (Vigía Chico), individual casitas harbored more lobsters and lobsters were actually more crowded in casitas containing diseased conspecifics, yet disease prevalence was the lowest in lobsters of all sizes. These results suggest that (1) investment in disease avoidance by lobsters is partially modulated by local habitat features, (2) contact transmission rates of PaV1 may be lower in nature than in the laboratory, and (3) water-borne transmission rates may be lower in shallow, poorly vegetated habitats more exposed to solar ultraviolet radiation, which can damage viral particles.

  1. Characterising the fate of nitrogenous waste from the sea-cage aquaculture of spiny lobsters using numerical modelling.

    Science.gov (United States)

    Lee, Soxi; Hartstein, Neil D; Jeffs, Andrew

    2015-06-01

    Although the aquaculture of spiny lobsters has been expanding since the 1970s, very little is known about the potential environmental impacts on water quality of this activity. This study quantified the production of dissolved inorganic nitrogen (DIN) from Australasian red spiny lobsters, Jasus edwardsii, in the laboratory, and these data were then used in a numerical model to predict the dispersal pattern of DIN from a hypothetical commercial spiny lobster farm for a coastal site where such a farm would typically be located. Modelling scenarios were set up with combinations of two different stocking densities (3 and 5 kg m(-3)), two different diets (mussels and moist artificial diet) and three different feed conversion ratios (FCR = 3, 5 and 28). DIN excretion rate from unfed lobsters in the laboratory on average was 1.10 ± 0.12 μg N g(-1) h(-1) while feeding lobsters on mussels and artificial diet increased DIN excretion significantly by around eightfold and twofold, respectively. Ammonia was consistently the dominant contributor to measured DIN output from lobsters. Modelling results indicated that the mean elevated DIN from a hypothetical farm where the lobsters were fed with mussels ranged from 7 up to 20 μg N L(-1) with increasing stocking density and FCR and was 30-150 % higher than the mean elevated DIN resulting from lobsters fed with artificial diet. Overall, the results indicated that DIN output from the hypothetical spiny lobster sea-cage farming is unlikely to be problematic using the FCR, stocking density, and the number of cages modelled at the coastal site in this study. Furthermore, feeding lobsters with artificial diet can help maintain a lower DIN output than seafood, such as mussels or trash fish.

  2. Fishing for lobsters indirectly increases epidemics in sea urchins

    Science.gov (United States)

    Lafferty, Kevin D.

    2004-01-01

    Two ecological paradigms, the trophic cascade and the host-density threshold in disease, interact in the kelp-forest ecosystem to structure the community. To investigate what happens when a trophic cascade pushes a host population over a host-threshold density, I analyzed a 20-year data set of kelp forest communities at 16 sites in the region of the Channel Islands National Park, California, USA. Historically, lobsters, and perhaps other predators, kept urchin populations at low levels and kelp forests developed a community-level trophic cascade. In geographic areas where the main predators on urchins were fished, urchin populations increased to the extent that they overgrazed algae and starvation eventually limited urchin-population growth. Despite the limitation of urchin population size by food availability, urchin densities, at times, well exceeded the host-density threshold for epidemics. An urchin-specific bacterial disease entered the region after 1992 and acted as a density-dependent mortality source. Dense populations were more likely to experience epidemics and suffer higher mortality. Disease did not reduce the urchin population at a site to the density that predators previously did. Therefore, disease did not fully replace predators in the trophic cascade. These results indicate how fishing top predators can indirectly favor disease transmission in prey populations.

  3. Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus).

    Science.gov (United States)

    Ellis, Charlie D; Hodgson, David J; André, Carl; Sørdalen, Tonje K; Knutsen, Halvor; Griffiths, Amber G F

    2015-01-01

    Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding.

  4. Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus.

    Directory of Open Access Journals (Sweden)

    Charlie D Ellis

    Full Text Available Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding.

  5. STUDI MEMBRAN KITOSAN DARI KULIT LOBSTER BAMBU SEBAGAI MEMBRAN FILTRASI

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Putri Windari

    2016-02-01

    Full Text Available The study of the extraction and characterization of chitosan from skin waste of Bamboo Lobster (Panulirus versicolor has been done. Chitosan is extracted using conventional method, namely the initial process: cleaning and drying (pretreatment, demineralization, deproteination, and deacetylation. The chitosan obtained has been used to prepare chitosan membrane 2% with acetic acid 1% as solvent. The membrane prepared by phase inversion method withprecipitation through solvent evaporation. The prepared membranes were characterized by FTIR spectrophotometer, Nova 1200e by BJH method and filtration method. The results obtained that degree of deacetylation (DD of chitosan is 70.016%. The thickness of the membrane is 0.361 mm. The FTIR spectra show that functional groups obtained are -NH, -CH, C=O, C-O and -CN. From BJH method obtained that the pore radius is 1.69 nm and pore density is 8.95 x 105pores/m3. From the filtration method obtained that at each pressure, 80-85 kPa and 90-100 kPa, the PWF values are 381.232 and 454.545 L/m2.h, respectively.

  6. MC ray-tracing optimization of lobster-eye focusing devices with RESTRAX

    International Nuclear Information System (INIS)

    Saroun, Jan; Kulda, Jiri

    2006-01-01

    The enhanced functionalities of the latest version of the RESTRAX software, providing a high-speed Monte Carlo (MC) ray-tracing code to represent a virtual three-axis neutron spectrometer, include representation of parabolic and elliptic guide profiles and facilities for numerical optimization of parameter values, characterizing the instrument components. As examples, we present simulations of a doubly focusing monochromator in combination with cold neutron guides and lobster-eye supermirror devices, concentrating a monochromatic beam to small sample volumes. A Levenberg-Marquardt minimization algorithm is used to optimize simultaneously several parameters of the monochromator and lobster-eye guides. We compare the performance of optimized configurations in terms of monochromatic neutron flux and energy spread and demonstrate the effect of lobster-eye optics on beam transformations in real and momentum subspaces

  7. Are European lobsters (Homarus gammarus) susceptible to infection by a temperate Hematodinium sp.?

    Science.gov (United States)

    Davies, Charlotte E; Rowley, Andrew F

    2015-05-01

    Hematodinium spp. infect over 40 species of crustaceans worldwide, but have not been reported to infect the European lobster, Homarus gammarus. In this study, Hematodinium parasites (a mixture of uni- and multinucleate trophont-like stages) were taken from donor crabs (Cancer pagurus) and injected into juvenile H. gammarus. Juvenile C. pagurus were also injected with the same inoculum. Haemolymph was taken at regular intervals and examined for the presence of Hematodinium using light microscopy and PCR, in two separate experiments of duration 4 and 8months. All lobsters were negative for Hematodinium whilst the C. pagurus challenged became infected. It is concluded that European lobsters are not susceptible to infection with a clade of Hematodinium that infects C. pagurus. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Source and specificity of chemical cues mediating shelter preference of Caribbean spiny lobsters (Panulirus argus).

    Science.gov (United States)

    Horner, Amy J; Nickles, Scott P; Weissburg, Marc J; Derby, Charles D

    2006-10-01

    Caribbean spiny lobsters display a diversity of social behaviors, one of the most prevalent of which is gregarious diurnal sheltering. Previous research has demonstrated that shelter selection is chemically mediated, but the source of release and the identity of the aggregation signal are unknown. In this study, we investigated the source and specificity of the aggregation signal in Caribbean spiny lobsters, Panulirus argus. We developed a relatively rapid test of shelter choice in a 5000-l laboratory flume that simulated flow conditions in the spiny lobster's natural environment, and used it to examine the shelter preference of the animals in response to a variety of odorants. We found that both males and females associated preferentially with shelters emanating conspecific urine of either sex, but not with shelters emanating seawater, food odors, or the scent of a predatory octopus. These results demonstrate specificity in the cues mediating sheltering behavior and show that urine is at least one source of the aggregation signal.

  9. Lobster eye X-ray optics: Data processing from two 1D modules

    Science.gov (United States)

    Nentvich, O.; Urban, M.; Stehlikova, V.; Sieger, L.; Hudec, R.

    2017-07-01

    The X-ray imaging is usually done by Wolter I telescopes. They are suitable for imaging of a small part of the sky, not for all-sky monitoring. This monitoring could be done by a Lobster eye optics which can theoretically have a field of view up to 360 deg. All sky monitoring system enables a quick identification of source and its direction. This paper describes the possibility of using two independent one-dimensional Lobster Eye modules for this purpose instead of Wolter I and their post-processing into an 2D image. This arrangement allows scanning with less energy loss compared to Wolter I or two-dimensional Lobster Eye optics. It is most suitable especially for very weak sources.

  10. Improving the effectiveness of escape windows in directed Norway lobster Nephrops norvegicus trawl fisheries

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Frandsen, Rikke

    2012-01-01

    A substantial improvement in the bycatch selectivity of Norway lobster Nephrops norvegicus trawls is required, particularly with respect to cod Gadus morhua , whose stocks are at low levels in several areas. Conventional escape windows are not adequate to properly release cod and other bycatch...... species caught in the trawls. To address this issue, we developed a novel sorting box concept consisting of a four-panel section with a window on the top in order to improve the escape of cod and other bycatch species through an escape window while retaining the target catch of Norway lobster. The concept....... The reduction in bycatch decreased with decreasing mesh size and increasing height of the sorting box. Escape of Norway lobster through the escape window was limited. A modified version of the sorting box concept was implemented in the Kattegat fishery from 2009 onwards...

  11. Development and test of selective sorting grids used in the Norway lobster (Nephrops norvegicus) fishery

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Frandsen, Rikke

    2017-01-01

    Due to generally high discard rates in Norway lobster (Nephrops norvegicus) fisheries, a discard ban coming up and to the cod recovery plan in several areas, selective sorting grids have been tested in many areas and are specified by legislation for use in the Kattegat and Skagerrak area bordering...... Norway, Denmark and Sweden. Grids are very selective, but they can lead to loss of landable Norway lobster and valuable fish species. To improve retention of these species, we developed three new grids using made by polyurethane to make them flexible: One grid had horizontal bars, one had vertical bars....... More flatfish passed the grid with horizontal bars compared to that with vertical bars, but the retention rate was still low. Use of the guiding funnel increased the contact with the grid considerably for both target and unwanted species. In all three grid designs, there were losses of Norway lobster...

  12. Three-dimensional motion analysis of the lumbar spine during "free squat" weight lift training.

    Science.gov (United States)

    Walsh, James C; Quinlan, John F; Stapleton, Robert; FitzPatrick, David P; McCormack, Damian

    2007-06-01

    Heavy weight lifting using a squat bar is a commonly used athletic training exercise. Previous in vivo motion studies have concentrated on lifting of everyday objects and not on the vastly increased loads that athletes subject themselves to when performing this exercise. Athletes significantly alter their lumbar spinal motion when performing squat lifting at heavy weights. Controlled laboratory study. Forty-eight athletes (28 men, 20 women) performed 6 lifts at 40% maximum, 4 lifts at 60% maximum, and 2 lifts at 80% maximum. The Zebris 3D motion analysis system was used to measure lumbar spine motion. Exercise was performed as a "free" squat and repeated with a weight lifting support belt. Data obtained were analyzed using SAS. A significant decrease (P free squat or when lifting using a support belt in any of the groups studied. Weight lifting using a squat bar causes athletes to significantly hyperextend their lumbar spines at heavier weights. The use of a weight lifting support belt does not significantly alter spinal motion during lifting.

  13. Lock-in thermographic inspection of squats on rail steel head

    Science.gov (United States)

    Peng, D.; Jones, R.

    2013-03-01

    The development of squat defects has become a major concern in numerous railway systems throughout the world. Infrared thermography is a relatively new non-destructive inspection technique used for a wide range of applications. However, it has not been used for rail squat detection. Lock-in thermography is a non-destructive inspection technique that utilizes an infrared camera to detect the thermal waves. A thermal image is produced, which displays the local thermal wave variation in phase or amplitude. In inhomogeneous materials, the amplitude and phase of the thermal wave carries information related to both the local thermal properties and the nature of the structure being inspected. By examining the infrared thermal signature of squat damage on the head of steel rails, it was possible to generate a relationship matching squat depth to thermal image phase angle, using appropriate experimental/numerical calibration. The results showed that with the additional data sets obtained from further experimental tests, the clarity of this relationship will be greatly improved to a level whereby infrared thermal contours can be directly translated into the precise subsurface behaviour of a squat.

  14. Relationship Between Force Production During Isometric Squats and Knee Flexion Angles During Landing.

    Science.gov (United States)

    Fisher, Harry; Stephenson, Mitchell L; Graves, Kyle K; Hinshaw, Taylour J; Smith, Derek T; Zhu, Qin; Wilson, Margaret A; Dai, Boyi

    2016-06-01

    Decreased knee flexion angles during landing are associated with increased anterior cruciate ligament loading. The underlying mechanisms associated with decreased self-selected knee flexion angles during landing are still unclear. The purpose of this study was to establish the relationship between the peak force production at various knee flexion angles (35, 55, 70, and 90°) during isometric squats and the actual knee flexion angles that occur during landing in both men and women. A total of 18 men and 18 women recreational/collegiate athletes performed 4 isometric squats at various knee flexion angles while vertical ground reaction forces were recorded. Participants also performed a jump-landing-jump task while lower extremity kinematics were collected. For women, significant correlations were found between the peak force production at 55 and 70° of knee flexion during isometric squats and the knee flexion angle at initial contact of landing. There were also significant correlations between the peak force production at 55, 70, and 90° of knee flexion during isometric squats and the peak knee flexion angle during landing. These correlations tended to be stronger during isometric squats at greater knee flexion compared with smaller knee flexion. No significant correlations were found for men. Posture-specific strength may play an important role in determining self-selected knee flexion angles during landing for women.

  15. Evaluation of muscle activity for loaded and unloaded dynamic squats during vertical whole-body vibration.

    Science.gov (United States)

    Hazell, Tom J; Kenno, Kenji A; Jakobi, Jennifer M

    2010-07-01

    The purpose of this investigation was to examine if the addition of a light external load would enhance whole-body vibration (WBV)-induced increases in muscle activity during dynamic squatting in 4 leg muscles. Thirteen recreationally active male university students performed a series of dynamic squats (unloaded with no WBV, unloaded with WBV, loaded with no WBV, and loaded with WBV). The load was set to 30% of body mass and WBV included 25-, 35-, and 45-Hz frequencies with 4-mm amplitude. Muscle activity was recorded with surface electromyography (EMG) on the vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GC) and is reported as EMGrms (root mean square) normalized to %maximal voluntary exertion. During unloaded dynamic squats, exposure to WBV (45 Hz) significantly (p squat exercise in all muscles but decreased the TA. This loaded level of muscle activity was further increased with WBV (45 Hz) in all muscles. The WBV-induced increases in muscle activity in the loaded condition (approximately 3.5%) were of a similar magnitude to the WBV-induced increases during the unloaded condition (approximately 2.5%) demonstrating the addition of WBV to unloaded or loaded dynamic squatting results in an increase in muscle activity. These results demonstrate the potential effectiveness of using external loads with exposure to WBV.

  16. Activities of the Vastus Lateralis and Vastus Medialis Oblique Muscles during Squats on Different Surfaces.

    Science.gov (United States)

    Hyong, In Hyouk; Kang, Jong Ho

    2013-08-01

    [Purpose] The purpose of the present study was to examine the effects of squat exercises performed on different surfaces on the activity of the quadriceps femoris muscle in order to provide information on support surfaces for effective squat exercises. [Subjects and Method] Fourteen healthy subjects performed squat exercises for five seconds each on three different support surfaces: hard plates, foam, and rubber air discs. Their performance was measured using electromyography. As the subjects performed the squat exercises on each surface, data on the activity of the vastus medialis oblique and the vastus lateralis, and the vastus medials oblique/vastus lateralis ratio, were collected. [Results] The activity of the vastus medialis oblique and the vastus medialis oblique/vastus lateralis ratio were found to be statistically significantly higher on rubber air discs than when the squats were performed on hard plates or foam. [Conclusion] To activate the vastus medialis obilique, and to enhance the vastus medialis oblique/vastus lateralis ratio, unstable surfaces that are highly unstable should be selected.

  17. A Biomechanical Investigation of A Single-Limb Squat: Implications for Lower Extremity Rehabilitation Exercise

    Science.gov (United States)

    Richards, Jim; Thewlis, Dominic; Selfe, James; Cunningham, Andrew; Hayes, Colin

    2008-01-01

    Context: Single-limb squats on a decline angle have been suggested as a rehabilitative intervention to target the knee extensors. Investigators, however, have presented very little empirical research in which they have documented the biomechanics of these exercises or have determined the optimum angle of decline used. Objective: To determine the involvement of the gastrocnemius and rectus femoris muscles and the external ankle and knee joint moments at 60° of knee flexion while performing a single-limb squat at different decline angles. Design: Participants acted as their own controls in a repeated-measures design. Patients or Other Participants: We recruited 10 participants who had no pain, injury, or neurologic disorder. Intervention(s): Participants performed single-limb squats at different decline angles. Main Outcome Measure(s): Angle-specific knee and ankle moments were calculated at 60° of knee flexion. Angle-specific electromyography (EMG) activity was calculated at 60° of knee flexion. Integrated EMG also was calculated to determine the level of muscle activity over the entire squat. Results: An increase was seen in the knee moments (P squats at an angle greater than 16° may not reduce passive calf tension, as was suggested previously, and may provide no mechanical advantage for the knee. PMID:18833310

  18. Use of muscle synergies and wavelet transforms to identify fatigue during squatting.

    Science.gov (United States)

    Smale, Kenneth B; Shourijeh, Mohammad S; Benoit, Daniel L

    2016-06-01

    The objective of this study was to supplement continuous wavelet transforms with muscle synergies in a fatigue analysis to better describe the combination of decreased firing frequency and altered activation profiles during dynamic muscle contractions. Nine healthy young individuals completed the dynamic tasks before and after they squatted with a standard Olympic bar until complete exhaustion. Electromyography (EMG) profiles were analyzed with a novel concatenated non-negative matrix factorization method that decomposed EMG signals into muscle synergies. Muscle synergy analysis provides the activation pattern of the muscles while continuous wavelet transforms output the temporal frequency content of the EMG signals. Synergy analysis revealed subtle changes in two-legged squatting after fatigue while differences in one-legged squatting were more pronounced and included the shift from a general co-activation of muscles in the pre-fatigue state to a knee extensor dominant weighting post-fatigue. Continuous wavelet transforms showed major frequency content decreases in two-legged squatting after fatigue while very few frequency changes occurred in one-legged squatting. It was observed that the combination of methods is an effective way of describing muscle fatigue and that muscle activation patterns play a very important role in maintaining the overall joint kinetics after fatigue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Single-leg squats can predict leg alignment in dancers performing ballet movements in "turnout".

    Science.gov (United States)

    Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

    2016-01-01

    The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve "turning out" or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in "turned out" postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat.

  20. Ocean observing systems support operational forecasts for the timing of Maine's lobster fishery

    Science.gov (United States)

    Mills, K.; Hernandez, C.; Pershing, A. J.

    2016-02-01

    American lobster supports one of the most valuable fisheries in the United States, with a landed value in 2013 exceeding $460M. Although US lobstermen are free to fish throughout the year, the New England climate, lobster biology and fleet dynamics lead to a strong annual cycle with catch rates rising rapidly in early summer and landings peaking in late summer. When this annual cycle is disrupted, it can impact the supply and ultimately the price of lobsters. During the record warm conditions in 2012, the rise in catch rates occurred three weeks ahead of normal. Combined with higher than normal landings from the spring Canadian fishery, the early and high volume landings in 2012 led to a collapse in price that severely stressed the U. S. fishery, especially in Maine where over 85% of the landings occur. Based on this experience, we have been developing seasonal forecasts of the phenology of Maine lobster landings. Using temperatures at 50m from four NERACOOS buoys in the Gulf of Maine, we can reliably forecast the date when the Maine lobster fishery will `turn on' for the year, with prediction accuracy peaking in April. The high-landings period normally starts in July, and the 2-3 month lead-time provides some advance warning to dealers and processors of when their capacity needs to be ready and to fishermen of potential supply chain and market impacts such as we observed in 2012. We are currently working towards finer-scale regional forecasts along the Maine coast that may include other features that will provide information to help the lobster industry adapt to the rapid changes that are underway in the Gulf of Maine.

  1. Creation of a gilded trap by the high economic value of the Maine lobster fishery.

    Science.gov (United States)

    Steneck, R S; Hughes, T P; Cinner, J E; Adger, W N; Arnold, S N; Berkes, F; Boudreau, S A; Brown, K; Folke, C; Gunderson, L; Olsson, P; Scheffer, M; Stephenson, E; Walker, B; Wilson, J; Worm, B

    2011-10-01

    Unsustainable fishing simplifies food chains and, as with aquaculture, can result in reliance on a few economically valuable species. This lack of diversity may increase risks of ecological and economic disruptions. Centuries of intense fishing have extirpated most apex predators in the Gulf of Maine (United States and Canada), effectively creating an American lobster (Homarus americanus) monoculture. Over the past 20 years, the economic diversity of marine resources harvested in Maine has declined by almost 70%. Today, over 80% of the value of Maine's fish and seafood landings is from highly abundant lobsters. Inflation-corrected income from lobsters in Maine has steadily increased by nearly 400% since 1985. Fisheries managers, policy makers, and fishers view this as a success. However, such lucrative monocultures increase the social and ecological consequences of future declines in lobsters. In southern New England, disease and stresses related to increases in ocean temperature resulted in more than a 70% decline in lobster abundance, prompting managers to propose closing that fishery. A similar collapse in Maine could fundamentally disrupt the social and economic foundation of its coast. We suggest the current success of Maine's lobster fishery is a gilded trap. Gilded traps are a type of social trap in which collective actions resulting from economically attractive opportunities outweigh concerns over associated social and ecological risks or consequences. Large financial gain creates a strong reinforcing feedback that deepens the trap. Avoiding or escaping gilded traps requires managing for increased biological and economic diversity. This is difficult to do prior to a crisis while financial incentives for maintaining the status quo are large. The long-term challenge is to shift fisheries management away from single species toward integrated social-ecological approaches that diversify local ecosystems, societies, and economies. ©2011 Society for Conservation

  2. Additional slipper lobsters of the subfamily Scyllarinae Latreille, 1825 (Crustacea, Achelata, Scyllaridae) from Taiwan.

    Science.gov (United States)

    Yang, Chien-Hui; Lin, Chia-Wei; Chan, Tin-Yam

    2014-08-15

    Five scyllarine lobsters are recorded from Taiwan for the first time. They are Bathyarctus rubens (Alcock & Anderson, 1894), Biarctus sordidus (Stimpson, 1860), Chelarctus aureus (Holthuis, 1963), Crenarctus bicuspidatus (De Man, 1905) and Petrarctus veliger Holthuis, 2002. The distributions of B. rubens, C. aureus and P. veliger are extended northwards to Taiwan. Distinguishing characters of these five species are illustrated and color photographs of all but B. sordidus are provided. Altogether, nine genera and 17 species of scyllarine lobsters are now known from Taiwan. 

  3. Development and testing of a separator frame in a Norway lobster Nephrops norvegicus fishery

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René

    2017-01-01

    Norway lobster Nephrops norvegicus fisheries are often characterized by high bycatch and discard rates. However, fisheries species exhibit differences in vertical behaviour that can be used to develop selective devices. We developed a separator frame that can be inserted into the forward part...... the separator frame and ending up in the bottom cod-end, the top cod-end, or penetrating the window. The majority of Norway lobster and flatfish entered the bottom cod-end, and most gadoids entered the top cod-end. A relatively high proportion of gadoids and flatfish that entered the top cod-end penetrated...

  4. Chemosensitivity of walking legs of the lobster Homarus americanus: neurophysiological response spectrum and thresholds

    Energy Technology Data Exchange (ETDEWEB)

    Derby, C D; Atema, J

    1982-01-01

    Responses of chemoreceptors in the walking legs of the lobster Homarus americanus to 35 individual compounds and 3 mixtures (prey odours and extracts) were studied using extracellular recording techniques. Compared against a standard mussel (Mytilus edulis) extract, these receptors were most sensitive to the amino acids L-glutamate, hydroxy-L-proline, L-aspartate, L-arginine, glycine, taurine, and L-alanine, as well as such other compounds as ammonium chloride, betaine, and the tripeptide glutathione. Most of these excitants are among those compounds most prevalent in the prey of lobsters.

  5. Reliability assessment of ballistic jump squats and bench throws.

    Science.gov (United States)

    Alemany, Joseph A; Pandorf, Clay E; Montain, Scott J; Castellani, John W; Tuckow, Alexander P; Nindl, Bradley C

    2005-02-01

    The purpose of this investigation was to determine the test-retest reliability and coefficient of variation of 2 novel physical performance tests. Ten healthy men (22.0 +/- 3.0 years, 87.0 +/- 8.0 kg, 20.0 +/- 5.0% body fat) performed 30 continuous and dynamic jump squats (JS) and bench throws (BT) on 4 separate occasions. The movements were performed under loaded conditions utilizing 30% of subject's predetermined 1 repetition maximum in the back squat and bench press. Mean power (MP; W), peak power (PP; W), mean velocity (MV; m.s(-1)), peak velocity (PV; m.s(-1)), and total work (TW; J) were assessed using a ballistic measurement system (Innervations Inc., Muncie, IN). Data were analyzed using repeated measures analysis of variance with Duncan's post hoc test when mean differences were p < or = 0.05. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (CV%) were also calculated. All values are presented as mean +/- SE. BT variables were statistically similar across the 4 sessions: MP (350.0 +/- 13.9 W), PP (431.4 +/- 18.5 W) MV (1.6 +/- 0.03 m.s(-1)), PV (2.0 +/- 0.03 m.s(-1)), and TW (199.1 +/- 7.2 J). For JS, session 3 PP (1,669.8 +/- 111.2 W) was significantly greater vs. sessions 1, 2, and 4 (1,601.2 +/- 58.4 W). Session 4 MP (1,403.2 +/- 88.6 W) and MV (1.9 +/- 0.1 m.s(-1)) for JS were significantly lower during sessions 1, 2, and 3 (MP: 1,479.4.5 +/- 44.8 W, MV: 2.0 +/- 0.05 m.s(-1)). TW (834.7 +/- 24.3 J) and PV (2.2 +/- 0.04 m.s(-1)) were statistically similar during all sessions for JS. The CVs ranged from 3.0 to 7.6% for the BT and 3.2 to 5.7% for the JS. ICCs for MP, PP, MV, PV, and TW were 0.92, 0.95, 0.94, 0.91, and 0.95, respectively, during BT. ICCs during JS for MP, PP, MV, PV, and TW were 0.96, 0.98, 0.94, 0.94, and 0.89, respectively. The results of the current study support the use of a 30 continuous and dynamic BT protocol as a reliable upper-body physical performance test, which can be administered with

  6. Robust and predictive fuzzy key performance indicators for condition-based treatment of squats in railway infrastructures

    NARCIS (Netherlands)

    Jamshidi, A.; Nunez Vicencio, Alfredo; Dollevoet, R.P.B.J.; Li, Z.

    2017-01-01

    This paper presents a condition-based treatment methodology for a type of rail surface defect called squat. The proposed methodology is based on a set of robust and predictive fuzzy key performance indicators. A fuzzy Takagi-Sugeno interval model is used to predict squat evolution for different

  7. The influence of different footwear on 3-D kinematics and muscle activation during the barbell back squat in males.

    Science.gov (United States)

    Sinclair, Jonathan; McCarthy, Derek; Bentley, Ian; Hurst, Howard Thomas; Atkins, Stephen

    2015-01-01

    The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot-inspired footwear. This study aimed to determine how these footwear influence 3-D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3-D kinematics from the torso, hip, knee and ankle were measured using an eight-camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated-measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi-squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi-squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot-inspired footwear although no biomechanical evidence was found to support this notion.

  8. Maximal strength and cortisol responses to psyching-up during the squat exercise.

    Science.gov (United States)

    McGuigan, Michael R; Ghiagiarelli, Jamie; Tod, David

    2005-07-01

    We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6+/-1.4 years; mean+/-s) and ten women (age 22.4+/-2.8 years) with weight training experience of 4.5+/-2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104+/-50 kg) and cognitive distraction (106+/-52 kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (Psquat exercise in strength-trained individuals.

  9. Determining the optimal load for jump squats: a review of methods and calculations.

    Science.gov (United States)

    Dugan, Eric L; Doyle, Tim L A; Humphries, Brendan; Hasson, Christopher J; Newton, Robert U

    2004-08-01

    There has been an increasing volume of research focused on the load that elicits maximum power output during jump squats. Because of a lack of standardization for data collection and analysis protocols, results of much of this research are contradictory. The purpose of this paper is to examine why differing methods of data collection and analysis can lead to conflicting results for maximum power and associated optimal load. Six topics relevant to measurement and reporting of maximum power and optimal load are addressed: (a) data collection equipment, (b) inclusion or exclusion of body weight force in calculations of power, (c) free weight versus Smith machine jump squats, (d) reporting of average versus peak power, (e) reporting of load intensity, and (f) instructions given to athletes/ participants. Based on this information, a standardized protocol for data collection and reporting of jump squat power and optimal load is presented.

  10. Effects of load on ground reaction force and lower limb kinematics during concentric squats.

    Science.gov (United States)

    Kellis, Eleftherios; Arambatzi, Fotini; Papadopoulos, Christos

    2005-10-01

    The purpose of this study was to examine the effects of external load on vertical ground reaction force, and linear and angular kinematics, during squats. Eight males aged 22.1 +/- 0.8 years performed maximal concentric squats using loads ranging from 7 to 70% of one-repetition maximum on a force plate while linear barbell velocity and the angular kinematics of the hip, knee and ankle were recorded. Maximum, average and angle-specific values were recorded. The ground reaction force ranged from 1.67 +/- 0.20 to 3.21 +/- 0.29 times body weight and increased significantly as external load increased (P squat exercises is not achieved at the same position of the lower body as external load is increased. In contrast, joint velocity coordination does not change as load is increased. The force-velocity relationship was linear and independent from the set of data used for its determination.

  11. Effects of replacing free weights with elastic band resistance in squats on trunk muscle activation.

    Science.gov (United States)

    Saeterbakken, Atle H; Andersen, Vidar; Kolnes, Maria K; Fimland, Marius S

    2014-11-01

    The purpose of this study was to assess the effects of adding elastic bands to free-weight squats on the neuromuscular activation of core muscles. Twenty-five resistance trained women with 4.6 ± 2.1 years of resistance training experience participated in the study. In randomized order, the participants performed 6 repetition maximum in free-weight squats, with and without elastic bands (i.e., matched relative intensity between exercises). During free-weight squats with elastic bands, some of the free weights were replaced with 2 elastic bands attached to the lowest part of the squat rack. Surface electromyography (EMG) activity was measured from the erector spinae, external oblique, and rectus abdominis, whereas a linear encoder measured the vertical displacement. The EMG activities were compared between the 2 lifting modalities for the whole repetition and separately for the eccentric, concentric, and upper and lower eccentric and concentric phases. In the upper (greatest stretch of the elastic band), middle, and lower positions in squats with elastic bands, the resistance values were approximately 117, 105, and 93% of the free weight-only trial. Similar EMG activities were observed for the 2 lifting modalities for the erector spinae (p = 0.112-0.782), external oblique (p = 0.225-0.977), and rectus abdominis (p = 0.315-0.729) in all analyzed phases. In conclusion, there were no effects on the muscle activity of trunk muscles of substituting some resistance from free weights with elastic bands in the free-weight squat.

  12. Lower-limb and trunk muscle activation with back squats and weighted sled apparatus.

    Science.gov (United States)

    Maddigan, Meaghan E; Button, Duane C; Behm, David G

    2014-12-01

    The back squat is a traditional resistance training exercise, whereas the resisted sled exercise is a relatively new resistance exercise. However, as there are no studies comparing muscle activation between the exercises, the objective of this study was to examine activity of leg and trunk muscles for both exercises. Ten healthy resistance-trained men participated in a randomized crossover design study consisting of 2 preparation sessions and 2 testing sessions. Electromyographic (EMG) activity of the rectus femoris, biceps femoris, gastrocnemius, lower erector spinae, and the transversus abdominis/internal obliques (TrA/IO) were monitored during a 20-step maximum push with the weighted sled apparatus and a 10 repetition maximum with a bilateral back squat. There were nonsignificant trends for the rectus femoris (p = 0.092: 8.6-16.7%) and biceps femoris (p = 0.09: 10.5-32.8%) to demonstrate higher activity with the sled and squat exercises, respectively. There were main effects for condition with 61.2% greater gastrocnemius EMG with the sled exercise (p = 0.01) and 74.5% greater erector spinae EMG activity with the squat (p = 0.002). There were no significant differences between the exercises for the TrA/IO. In summary, the sled and squat exercises provided similar EMG activity for the quadriceps, hamstrings, and TrA/IO. The squat provided higher lower erector spinae activation, whereas the sled had superior gastrocnemius activation. Depending on the movement-training specificity of the sport, either exercise may be used in a training program while acknowledging the differences in gastrocnemius and erector spinae activity.

  13. Knee Kinetics during Squats of Varying Loads and Depths in Recreationally Trained Females.

    Science.gov (United States)

    Flores, Victoria; Becker, James; Burkhardt, Eric; Cotter, Joshua

    2018-03-06

    The back squat exercise is typically practiced with varying squat depths and barbell loads. However, depth has been inconsistently defined, resulting in unclear safety precautions when squatting with loads. Additionally, females exhibit anatomical and kinematic differences to males which may predispose them to knee joint injuries. The purpose of this study was to characterize peak knee extensor moments (pKEMs) at three commonly practiced squat depths of above parallel, parallel, and full depth, and with three loads of 0% (unloaded), 50%, and 85% depth-specific one repetition maximum (1RM) in recreationally active females. Nineteen females (age, 25.1 ± 5.8 years; body mass, 62.5 ± 10.2 kg; height, 1.6 ± 0.10 m; mean ± SD) performed squats of randomized depth and load. Inverse dynamics were used to obtain pKEMs from three-dimensional knee kinematics. Depth and load had significant interaction effects on pKEMs (p = 0.014). Significantly greater pKEMs were observed at full depth compared to parallel depth with 50% 1RM load (p = 0.001, d = 0.615), and 85% 1RM load (p = 0.010, d = 0.714). Greater pKEMs were also observed at full depth compared to above parallel depth with 50% 1RM load (p = 0.003, d = 0.504). Results indicate effect of load on female pKEMs do not follow a progressively increasing pattern with either increasing depth or load. Therefore, when high knee loading is a concern, individuals are must carefully consider both the depth of squat being performed and the relative load they are using.

  14. Effects of Loaded Squat Exercise with and without Application of Superimposed EMS on Physical Performance

    Directory of Open Access Journals (Sweden)

    Nicolas Wirtz, Christoph Zinner, Ulrike Doermann, Heinz Kleinoeder, Joachim Mester

    2016-03-01

    Full Text Available The aim of the present study was to investigate the effects of a multiple set squat exercise training intervention with superimposed electromyostimulation (EMS on strength and power, sprint and jump performance. Twenty athletes from different disciplines participated and were divided into two groups: strength training (S or strength training with superimposed EMS (S+E. Both groups completed the same training program twice a week over a six week period consisting of four sets of the 10 repetition maximum of back squats. Additionally, the S+E group had EMS superimposed to the squat exercise with simultaneous stimulation of leg and trunk muscles. EMS intensity was adjusted to 70% of individual pain threshold to ensure dynamic movement. Strength and power of different muscle groups, sprint, and vertical jump performance were assessed one week before (pre, one week after (post and three weeks (re following the training period. Both groups showed improvements in leg press strength and power, countermovement and squat jump performance and pendulum sprint (p < 0.05, with no changes for linear sprint. Differences between groups were only evident at the leg curl machine with greater improvements for the S+E group (p < 0.05. Common squat exercise training and squat exercise with superimposed EMS improves maximum strength and power, as well as jumping abilities in athletes from different disciplines. The greater improvements in strength performance of leg curl muscles caused by superimposed EMS with improvements in strength of antagonistic hamstrings in the S+E group are suggesting the potential of EMS to unloaded (antagonistic muscle groups.

  15. Tibiofemoral wear in standard and non-standard squat: implication for total knee arthroplasty.

    Science.gov (United States)

    Fekete, Gusztáv; Sun, Dong; Gu, Yaodong; Neis, Patric Daniel; Ferreira, Ney Francisco; Innocenti, Bernardo; Csizmadia, Béla M

    2017-01-01

    Due to the more resilient biomaterials, problems related to wear in total knee replacements (TKRs) have decreased but not disappeared. In the design-related factors, wear is still the second most important mechanical factor that limits the lifetime of TKRs and it is also highly influenced by the local kinematics of the knee. During wear experiments, constant load and slide-roll ratio is frequently applied in tribo-tests beside other important parameters. Nevertheless, numerous studies demonstrated that constant slide-roll ratio is not accurate approach if TKR wear is modelled, while instead of a constant load, a flexion-angle dependent tibiofemoral force should be involved into the wear model to obtain realistic results. A new analytical wear model, based upon Archard's law, is introduced, which can determine the effect of the tibiofemoral force and the varying slide-roll on wear between the tibiofemoral connection under standard and non-standard squat movement. The calculated total wear with constant slide-roll during standard squat was 5.5 times higher compared to the reference value, while if total wear includes varying slide-roll during standard squat, the calculated wear was approximately 6.25 times higher. With regard to non-standard squat, total wear with constant slide-roll during standard squat was 4.16 times higher than the reference value. If total wear included varying slide-roll, the calculated wear was approximately 4.75 times higher. It was demonstrated that the augmented force parameter solely caused 65% higher wear volume while the slide-roll ratio itself increased wear volume by 15% higher compared to the reference value. These results state that the force component has the major effect on wear propagation while non-standard squat should be proposed for TKR patients as rehabilitation exercise.

  16. A lobster-eye on the x-ray sky

    International Nuclear Information System (INIS)

    Peele, A. G.; Zhang, W.; Gendreau, K. C.; Petre, R.; White, N. E.

    1999-01-01

    We propose an x-ray all-sky monitor for the International Space Station (ISS) that will be ten times more sensitive than past monitors and that opens up a new band of the soft x-ray spectrum (0.1 -3.0 keV) for study. Taking advantage of the power telemetry and space available on the ISS we can use a telescope geometry and detectors that will provide better than 4 arc minute resolution of the entire sky in a 1.5 hr duty cycle. To achieve this sensitivity and resolution we use focusing optics based on the lobster-eye geometry. We propose two approaches to the construction of the optics. The first method, well within the reach of existing technology, is to approximate the lobster-eye geometry by building crossed arrays of planar reflectors, this gives great control over the reflecting surface but is limited in terms of resolution at the baseline 4 arc minute level. The second method is to use microchannel plates: this technology has the potential to greatly exceed the baseline resolution and sensitivity but is yet to be fully demonstrated. A simultaneous development of both approaches with selection of the superior candidate at the end of the development phase is suggested. The instrument is made of a number of modules based on a 2x2 cooled CCD detector array that covers an area of 6x6 cm 2 at the focal plane. Using optics with a radius of curvature of 0.75 m this gives each module a field of view of 9 deg. x 9 deg. The modular approach gives us enormous flexibility in terms of physical arrangement on the ISS so that we may take advantage of clear lines of sight and also in terms of built-in redundancy. We estimate that ∼50 such modules give us instantaneous coverage of 1/10 of the sky. The scientific case for this mission is almost too broad to state here. The instrument we describe will allow investigation of the long term light curves of thousands of AGN, it will detect thousands of transients, including GRBs and type II supernova, and the stellar coronae of

  17. West Coast rock lobster Jasus lalandii are dis- tributed from about ...

    African Journals Online (AJOL)

    spamer

    and a ban on the retention of lobster in a soft shell state or ... However, a diver operating from shore could also collect ... The permit system was discontinued during 1986 ... person's place of residence at any one time was re- ..... real situation.

  18. After an initial, localized decline in rock lobster Jasus lalandii growth ...

    African Journals Online (AJOL)

    spamer

    Pacific Ocean. In the southern Benguela, the most obvious signature of this ENSO was the reduced fre- quency and intensity of southerly, upwelling-inducing winds, with a concomitant increase in westerly winds. This study attempts to relate the reduction in lobster growth and productivity to environmental factors which.

  19. Accumulation of sup(95m)Tc from sea water by juvenile lobsters (Homarus gammarus L. )

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D.J. (Ministry of Agriculture, Fisheries and Food, Lowestoft (UK). Directorate of Fisheries Research)

    1985-01-01

    The uptake and retention of technetium from sea water by juvenile lobsters, and the effects of moulting on these processes, has been studied using sup(95m)Tc as a tracer. Accumulation was rapid with whole body concentration factors of over 2000 being measured in some lobsters. Uptake was highest immediately before a moult; post-moult there was a fall in accumulation. No simple mathematical equation for technetium accumulation with time was found. The technetium concentration in the moulted exoskeleton increased with time of exposure of the lobsters but never exceeded 2% of the whole body value. The highest percentage of the whole body activity was found in the digestive gland; the green gland had the highest concentration factor. Technetium excretion, following 64 d of accumulation, could be expressed as an exponential rate of loss. The biological half-time was calculated as 53 d. Moulted exoskeletons from these lobsters contained approximately 0.6% of the day zero whole body activity.

  20. A novel image processing method to determine the nutritional condition of lobsters.

    Science.gov (United States)

    Berillis, P; Simon, C; Mente, E; Sofos, F; Karapanagiotidis, I T

    2013-02-01

    The digestive gland of crustacean is involved in various metabolic activities, including the synthesis and secretion of digestive enzymes that begin the process of food digestion, intracellular digestion and absorption of nutrients, storage of reserves, and disposal of waste products. It consists of two glandular lobes which extensively subdivide to form a complex of blind-ending tubules, whose size, surface area, and digestive cells are associated with intracellular digestion and the nutritional status of the organism. The aim of this paper was to study the morphology of the digestive gland in various lobster species and calculate the surface area of tubules, lumen and digestive cells (R-, F-, and B-cells) and their ratios to total tubule surface area. The similarity in ratios obtained in this study between individual lobsters suggests that the method developed in this study can be successfully applied to a range of species. This study describes a novel image processing algorithm for the automatic measurement of the hepatopancreas structure using stained cross sections of digestive gland tubules. The proposed new methodology could be used for studying the physiology and nutrient metabolism of lobsters and other crustaceans. The computer-aided analysis described in this paper is accurate for the quantitative assessment of the lobster's digestive gland structure. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Assessment of predation risk through conspecific alarm odors by spiny lobsters

    Science.gov (United States)

    2009-01-01

    Strong “alarm odors” emanating from lethally injured conspecifics may indicate an imminent risk of predation to spiny lobsters. In laboratory trials,1 strong conspecific alarm odors elicited avoidance in Panulirus argus, a highly gregarious species that displays collective defense behavior, but not in Panulirus guttatus, a species that tends to aggregate when reproductive activity is high (spring) but not when it is low (late summer) and does not display collective defensive behavior. To reduce predation risk, however, lobsters may autotomize limbs, thus sustaining nonlethal injuries. I tested the response of these lobsters to scents emanating from intact, lethally-injured and non-lethally injured conspecifics. In P. argus, these scents elicited, respectively, attraction, avoidance and a random response, suggesting that, in P. argus, avoidance of conspecific alarm odors depends on their strength. In contrast, P. guttatus lobsters responded at random to scents of lethally injured conspecifics and showed a similar response to scents of intact and non-lethally injured conspecifics in the spring (attraction) and in the summer (random), reflecting the more cryptic defensive behavior of this species. Therefore, both species use conspecific alarm odors for risk-assessment, but each responds to these cues in the most effective way to reduce its risk of predation. PMID:19721871

  2. Finestkind: The American Lobster. A Learning Experience for Marine Education. Northern New England Marine Education Project.

    Science.gov (United States)

    Maine Univ., Orono. Coll. of Education.

    This interdisciplinary unit is intended for use in the fourth grade. Through discussion of the American Lobster, its economics, history, literature, and biology, the unit describes the effects of the marine environment on human history and culture. Sections deal with how marine organisms have evolved. Detailed descriptions are provided of lobster…

  3. Assessment of predation risk through conspecific alarm odors by spiny lobsters: How much is too much?

    Science.gov (United States)

    Briones-Fourzán, Patricia

    2009-07-01

    Strong "alarm odors" emanating from lethally injured conspecifics may indicate an imminent risk of predation to spiny lobsters. In laboratory trials,1 strong conspecific alarm odors elicited avoidance in Panulirus argus, a highly gregarious species that displays collective defense behavior, but not in Panulirus guttatus, a species that tends to aggregate when reproductive activity is high (spring) but not when it is low (late summer) and does not display collective defensive behavior. To reduce predation risk, however, lobsters may autotomize limbs, thus sustaining nonlethal injuries. I tested the response of these lobsters to scents emanating from intact, lethally-injured and non-lethally injured conspecifics. In P. argus, these scents elicited, respectively, attraction, avoidance and a random response, suggesting that, in P. argus, avoidance of conspecific alarm odors depends on their strength. In contrast, P. guttatus lobsters responded at random to scents of lethally injured conspecifics and showed a similar response to scents of intact and non-lethally injured conspecifics in the spring (attraction) and in the summer (random), reflecting the more cryptic defensive behavior of this species. Therefore, both species use conspecific alarm odors for risk-assessment, but each responds to these cues in the most effective way to reduce its risk of predation.

  4. THE MORPHOLOGICAL BASIS FOR OLFACTORY PERCEPTION OF STEROIDS DUING AGONISTIC BEHAVIOR IN LOBSTER: PRELIMINARY EXPERIMENTS

    Science.gov (United States)

    The morphological basis for olfactory perception of steroids during agonistic behavior in lobsters: preliminary experiments. Borsay Horowitz, DJ1, Kass-Simon, G2, Coglianese, D2, Martin, L2, Boseman, M2, Cromarty, S3, Randall, K3, Fini, A.3 1US EPA, NHEERL, ORD, Atlantic Ecology...

  5. Diet of the west coast rock lobster Jasus Lalandii : Influence of ...

    African Journals Online (AJOL)

    The diet of small lobsters (<75mm CL) consisted of a wide range of species, which included, in order of importance, coralline algae, barnacles Notomegabalanus algicola, sponges and ribbed mussels Aulacomya ater. However, prey items rich in inorganic material were not dominant in their diet, as had been predicted.

  6. Novel optics for conditioning neutron beams. II Focussing neutrons with a 'lobster-eye' optic

    International Nuclear Information System (INIS)

    Allman, B.E.; Cimmino, A.; Griffin, S.L.; Klein, A.G.; Nugent, K.A.

    1998-01-01

    Square-channel capillary, or 'Lobster-eye' arrays have been shown to be the optimum geometry for array optics. This configuration leads to a novel class of conditioning devices for X-ray and neutron beams. We present the first results of the focussing of neutrons with a Pb glass square-channel array. (authors)

  7. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor...

  8. The deep-water spiny lobster Palinurus gilchristi is one of five ...

    African Journals Online (AJOL)

    spamer

    The deep-water spiny lobster Palinurus gilchristi is one of five ... conditions because all features that can be used to determine the ... growth as a function of CL were calculated for each ..... (>85 mm CL) may bear eggs more than once per year.

  9. Microbiological aspects of phyllosoma rearing of the ornate rock lobster Panulirus ornatus

    DEFF Research Database (Denmark)

    Bourne, D.; Webster, N.; Payne, Matthew

    2007-01-01

    Rock lobsters of the Palinuridae are the most valuable wild fisheries sector in Australia and are currently target aquaculture species. Significant challenges exist however to produce commercial scale quantities of post-larvae due to an extended larval phase which acerbates a high rate of larval...

  10. Development of new concepts for escape windows to minimise cod catches in Norway lobster fisheries

    DEFF Research Database (Denmark)

    Madsen, Niels; Frandsen, Rikke; Holst, René

    2010-01-01

    Gear selectivity with regard to cod (Gadus morhua) needs to be improved in the Kattegat and Skagerrak Norway lobster (Nephrops norvegicus) fishery. One way to achieve this goal is to improve the selectivity of an escape window (henceforth window) in the gear. Our gear development focused particul......Gear selectivity with regard to cod (Gadus morhua) needs to be improved in the Kattegat and Skagerrak Norway lobster (Nephrops norvegicus) fishery. One way to achieve this goal is to improve the selectivity of an escape window (henceforth window) in the gear. Our gear development focused...... particularly on moving the window further back, gaining more stability in the codend to avoid loss of Norway lobster through the window, making a relatively narrow section where the window is located, and testing larger mesh sizes in the window. We designed a four panel sorting section—the sorting box......, but no improvement was observed for cod that came into contact with the window after reducing the distance from the window to the codline. The sorting box also showed a high reduction of flatfish and other roundfish species. The retention of Norway lobster above minimum landing size in the sorting box was higher...

  11. Adaptive behaviour of fishers to external perturbations: simulation of the Tasmanian rock lobster fishery

    NARCIS (Netherlands)

    Hamon, K.G.; Frusher, S.D.; Little, L.R.; Thebaud, O.; Punt, A.E.

    2014-01-01

    The rock lobster, Jasus edwardsii, lies on a global "hotspot" for climate change in the southeastern Australian state of Tasmania. The short-term effects of climate change are predicted to lead to an increasing exploitable biomass in the south and declining biomass in the north of the state. The

  12. Alternative supplementary biochemic food for growing up the fresh water lobster (Cherax quadricarinatus

    Directory of Open Access Journals (Sweden)

    PRABANG SETYONO

    2009-11-01

    Full Text Available Priyono E, Astirin OP, Setyono P. 2009. Alternative supplementary biochemic food for growing up the fresh water lobster (Cherax quadricarinatus. Nusantara Bioscience 1: 123-130. This research denotes to know the influence of biochemic composition to the rapid grow of fresh water lobster on the stadium of post larva (PL of 60 within three months. This research used the complete random planning dealing with 4 treatments and each treatment would get 3 times cycle. The treatments cover, group K tested animal was treted with 100% mill food containing 30% of protein. Group A is given with food and biochemic food containing 13,34% of protein. Group B is the treated with mill food which is mixed with biochemic food containing 10,7% of protein. While group C was tested by treating them with mill food and biochemic food containing 13,58%. After all the above mentioned would be set up within 3:1 comparation. The variable of this research were the length of the abdomen, cephalothorax, total length, and the wet weight. The data analysis is using ANOVA system on 95% power test completed by of SPSS version 13. The result of the research shows that mentioned treatments give us the same influence toward the growth of fresh water lobster. The composition of biochemic food with the containing protein around 10,7%,13.34% and 13,38% has given the same effect to the lobster growth on post larva 60 level. There is strong correlation between abdomen and cephalothorax and between the total length and the lobsters weight.Key words: Cherax quadricarinatus, suplementary food, water quality.Abstrak. Priyono E, Astirin OP, Setyono P. 2009. Alternatif penambahan suplemen hayati untuk meningkatkan pertumbuhan udang lobster air tawar (Cherax quadricarinatus. Nusantara Bioscience 1: 123-130. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian suplemen hayati sehingga dapat meningkatkan pertumbuhan lobster air tawar pada stadia post larva (PL 60 pada masa pertumbuhan 3

  13. Diversity of developmental patterns in achelate lobsters-today and in the Mesozoic.

    Science.gov (United States)

    Haug, Joachim T; Audo, Denis; Charbonnier, Sylvain; Haug, Carolin

    2013-11-01

    Modern achelate lobsters, slipper and spiny lobsters, have a specific post-embryonic developmental pattern with the following phases: phyllosoma, nisto (slipper lobsters) or puerulus (spiny lobsters), juvenile and adult. The phyllosoma is a peculiar larva, which transforms through a metamorphic moult into another larval form, the nisto or puerulus which largely resembles the juvenile. Unlike the nisto and puerulus, the phyllosoma is characterised by numerous morphological differences to the adult, e.g. a thin head shield, elongate appendages, exopods on these appendages and a special claw. Our reinvestigation of the 85 million years old fossil "Eryoneicus sahelalmae" demonstrates that it represents an unusual type of achelatan lobster larva, characterised by a mixture of phyllosoma and post-phyllosoma characters. We ascribe it to its own genus: Polzicaris nov. gen. We study its significance by comparisons with other cases of Mesozoic fossil larvae also characterised by a mixture of characters. Accordingly, all these larvae are interpreted as ontogenetic intermediates between phyllosoma and post-phyllosoma morphology. Remarkably, most of the larvae show a unique mixture of retained larval and already developed post-larval features. Considering the different-and incompatible-mixture of characters of each of these larvae and their wide geographical and temporal distribution, we interpret all these larvae as belonging to distinct species. The particular character combinations in the different larvae make it currently difficult to reconstruct an evolutionary scenario with a stepwise character acquisition. Yet, it can be concluded that a larger diversity of larval forms and developmental patterns occurred in Mesozoic than in modern faunas.

  14. Opportunistic Computing with Lobster: Lessons Learned from Scaling up to 25k Non-Dedicated Cores

    Science.gov (United States)

    Wolf, Matthias; Woodard, Anna; Li, Wenzhao; Hurtado Anampa, Kenyi; Yannakopoulos, Anna; Tovar, Benjamin; Donnelly, Patrick; Brenner, Paul; Lannon, Kevin; Hildreth, Mike; Thain, Douglas

    2017-10-01

    We previously described Lobster, a workflow management tool for exploiting volatile opportunistic computing resources for computation in HEP. We will discuss the various challenges that have been encountered while scaling up the simultaneous CPU core utilization and the software improvements required to overcome these challenges. Categories: Workflows can now be divided into categories based on their required system resources. This allows the batch queueing system to optimize assignment of tasks to nodes with the appropriate capabilities. Within each category, limits can be specified for the number of running jobs to regulate the utilization of communication bandwidth. System resource specifications for a task category can now be modified while a project is running, avoiding the need to restart the project if resource requirements differ from the initial estimates. Lobster now implements time limits on each task category to voluntarily terminate tasks. This allows partially completed work to be recovered. Workflow dependency specification: One workflow often requires data from other workflows as input. Rather than waiting for earlier workflows to be completed before beginning later ones, Lobster now allows dependent tasks to begin as soon as sufficient input data has accumulated. Resource monitoring: Lobster utilizes a new capability in Work Queue to monitor the system resources each task requires in order to identify bottlenecks and optimally assign tasks. The capability of the Lobster opportunistic workflow management system for HEP computation has been significantly increased. We have demonstrated efficient utilization of 25 000 non-dedicated cores and achieved a data input rate of 30 Gb/s and an output rate of 500GB/h. This has required new capabilities in task categorization, workflow dependency specification, and resource monitoring.

  15. The Effect of Initial Knee Angle on Concentric-Only Squat Jump Performance

    Science.gov (United States)

    Mitchell, Lachlan J.; Argus, Christos K.; Taylor, Kristie-Lee; Sheppard, Jeremy M.; Chapman, Dale W.

    2017-01-01

    Purpose: There is uncertainty as to which knee angle during a squat jump (SJ) produces maximal jump performance. Importantly, understanding this information will aid in determining appropriate ratios for assessment and monitoring of the explosive characteristics of athletes. Method: This study compared SJ performance across different knee…

  16. Modelling the joint torques and loadings during squatting at the Smith machine.

    Science.gov (United States)

    Biscarini, Andrea; Benvenuti, Paolo; Botti, Fabio; Mastrandrea, Francesco; Zanuso, Silvano

    2011-03-01

    An analytical biomechanical model was developed to establish the relevant properties of the Smith squat exercise, and the main differences from the free barbell squat. The Smith squat may be largely patterned to modulate the distributions of muscle activities and joint loadings. For a given value of the included knee angle (θ(knee)), bending the trunk forward, moving the feet forward in front of the knees, and displacing the weight distribution towards the forefoot emphasizes hip and lumbosacral torques, while also reducing knee torque and compressive tibiofemoral and patellofemoral forces (and vice versa). The tibiofemoral shear force φ(t) displays more complex trends that strongly depend on θ(knee). Notably, for 180° ≥ θ(knee) ≥ 130°, φ(t) and cruciate ligament strain forces can be suppressed by selecting proper pairs of ankle and hip angles. Loading of the posterior cruciate ligament increases (decreases) in the range 180° ≥ θ(knee) ≥ 150° (θ(knee) ≤ 130°) with knee extension, bending the trunk forward, and moving the feet forward in front of the knees. In the range 150° > θ(knee) > 130°, the behaviour changes depending on the foot weight distribution. The conditions for the development of anterior cruciate ligament strain forces are explained. This work enables careful use of the Smith squat in strengthening and rehabilitation programmes.

  17. Influence of variable resistance loading on subsequent free weight maximal back squat performance.

    Science.gov (United States)

    Mina, Minas A; Blazevich, Anthony J; Giakas, Giannis; Kay, Anthony D

    2014-10-01

    The purpose of the study was to determine the potentiating effects of variable resistance (VR) exercise during a warm-up on subsequent free-weight resistance (FWR) maximal squat performance. In the first session, 16 recreationally active men (age = 26.0 ± 7.8 years; height = 1.7 ± 0.2 m; mass = 82.6 ± 12.7 kg) were familiarized with the experimental protocols and tested for 1 repetition maximum (1RM) squat lift. The subjects then visited the laboratory on 2 further occasions under either control or experimental conditions. During these conditions, 2 sets of 3 repetitions of either FWR (control) or VR (experimental) squat lifts at 85% of 1RM were performed; during the experimental condition, 35% of the load was generated from band tension. After a 5-minute rest, 1RM, 3D knee joint kinematics, and vastus medialis, vastus lateralis, rectus femoris, and semitendinosus electromyogram (EMG) signals were recorded simultaneously. No subject increased 1RM after FWR, however, 13 of 16 (81%) subjects increased 1RM after VR (mean = 7.7%; p 0.05) or EMG amplitudes (mean = 5.9%; p > 0.05) occurred. Preconditioning using VR significantly increased 1RM without detectable changes in knee extensor muscle activity or knee flexion angle, although eccentric and concentric velocities were reduced. Thus, VR seems to potentiate the neuromuscular system to enhance subsequent maximal lifting performance. Athletes could thus use VR during warm-up routines to maximize squat performance.

  18. Humans make near-optimal adjustments of control to initial body configuration in vertical squat jumping

    NARCIS (Netherlands)

    Bobbert, M.F.; Casius, L.J.R.; Kistemaker, D.A.

    2013-01-01

    We investigated adjustments of control to initial posture in squat jumping. Eleven male subjects jumped from three initial postures: preferred initial posture (PP), a posture in which the trunk was rotated 18° more backward (BP) and a posture in which it was rotated 15° more forward (FP) than in PP.

  19. Characteristic MR image finding of squatting exercise-induced rhabdomyolysis of the thigh muscles.

    Science.gov (United States)

    Yeon, Eung K; Ryu, Kyung N; Kang, Hye J; Yoon, So H; Park, So Y; Park, Ji S; Jin, Wook

    2017-04-01

    To describe the characteristic MRI appearance of squatting-induced rhabdomyolysis involving the thigh muscles. This study consisted of 10 cases obtained at 3 institutions from 2005 to 2015. A retrospective review was performed to obtain clinical information and MR scans for rhabdomyolysis of the thigh muscles. MRI was analyzed according to the distribution and degree of muscle involvement; the degree was assessed and graded as normal, mild or prominent. The mean patient age was 20.2 years (range, 15-24 years), and 7 of the 10 patients were male. All patients had history of excessive squatting action, suffered clinically from bilateral thigh pain and were confirmed to have rhabdomyolysis through analysis of serum creatine kinase (CK) levels. All of the patients (10/10) exhibited diffuse mild to prominent degree involvement of the anterior thigh muscles according to fluid-sensitive MR sequences. Among the anterior thigh muscles, the rectus femoris was spared in 8 patients (8/10) and mild degree involved in 2 patients (2/10). Thus, no cases exhibited prominent degree involvement of the rectus femoris muscle. Preservation of the rectus femoris muscle on MRI in squatting-induced rhabdomyolysis may be useful for differentiating rhabdomyolysis from other aetiologies. Advances in knowledge: Preservation of rectus femoris on MRI is distinguishable finding in squatting-induced rhabdomyolysis and reflects the functional anatomy of anterior thigh muscles.

  20. Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy

    DEFF Research Database (Denmark)

    Kongsgaard, M.; Kovanen, V.; Aagaard, P.

    2009-01-01

    A randomized-controlled single-blind trial was conducted to investigate the clinical, structural and functional effects of peritendinous corticosteroid injections (CORT), eccentric decline squat training (ECC) and heavy slow resistance training (HSR) in patellar tendinopathy. Thirty-nine male...

  1. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance.

    Directory of Open Access Journals (Sweden)

    Amador García-Ramos

    Full Text Available This study evaluated the influence of an altitude training (AT camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men were allocated to both the control (Sea Level Training, SLT and experimental conditions (AT, 2320 m above sea level that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1% and 15 m (+4.0% were observed (P 0.05. Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20. Based on these results we can conclude that a traditional training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

  2. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance.

    Science.gov (United States)

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Calderón, Carmen; Bonitch-Góngora, Juan; Tomazin, Katja; Strumbelj, Boro; Strojnik, Vojko; Feriche, Belén

    2016-01-01

    This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

  3. The Micropolitics of Criminalisation: Power, Resistance and the Amsterdam Squatting Movement

    NARCIS (Netherlands)

    Dadusc, D.

    2017-01-01

    This research analyses how the criminalisation of the Amsterdam squatting movement works. The key research question addresses how criminalisation operates as a technology of government, what kind of relations of power are constituted through this processes, and how these are experienced and

  4. Kinematic and Electromyographic Activity Changes during Back Squat with Submaximal and Maximal Loading

    Directory of Open Access Journals (Sweden)

    Hasan U. Yavuz

    2017-01-01

    Full Text Available The aim of this study was to investigate the possible kinematic and muscular activity changes with maximal loading during squat maneuver. Fourteen healthy male individuals, who were experienced at performing squats, participated in this study. Each subject performed squats with 80%, 90%, and 100% of the previously established 1 repetition maximum (1RM. Electromyographic (EMG activities were measured for the vastus lateralis, vastus medialis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, and erector spinae by using an 8-channel dual-mode portable EMG and physiological signal data acquisition system (Myomonitor IV, Delsys Inc., Boston, MA, USA. Kinematical data were analyzed by using saSuite 2D kinematical analysis program. Data were analyzed with repeated measures analysis of variance (p<0.05. Overall muscle activities increased with increasing loads, but significant increases were seen only for vastus medialis and gluteus maximus during 90% and 100% of 1RM compared to 80% while there was no significant difference between 90% and 100% for any muscle. The movement pattern in the hip joint changed with an increase in forward lean during maximal loading. Results may suggest that maximal loading during squat may not be necessary for focusing on knee extensor improvement and may increase the lumbar injury risk.

  5. Deconstructing the power resistance relationship for squats: A joint-level analysis.

    Science.gov (United States)

    Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

    2016-07-01

    Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Effect of a submaximal half-squats warm-up program on vertical jumping ability.

    Science.gov (United States)

    Gourgoulis, Vassilios; Aggeloussis, Nickos; Kasimatis, Panagiotis; Mavromatis, Giorgos; Garas, Athanasios

    2003-05-01

    The purpose of the current research was to study the effect of a warm-up program including submaximal half-squats on vertical jumping ability. Twenty physically active men participated in the study. Each subject performed 5 sets of half-squats with 2 repetitions at each of the following intensities: 20, 40, 60, 80, and 90% of the 1 repetition maximum (1RM) load. Prior to the first set and immediately after the end of the last set, the subjects performed 2 countermovement jumps on a Kistler force platform; the primary goal was to jump as high as possible. The results showed that mean vertical jumping ability improved by 2.39% after the warm-up period. Subjects were then divided into 2 groups according to their 1RM values for the half-squat. Subjects with greater maximal strength ability improved their vertical jumping ability (4.01%) more than did subjects with lower maximal strength (0.42%). A warm-up protocol including half-squats with submaximal loads and explosive execution can be used for short-term improvements of vertical jumping performance, and this effect is greater in athletes with a relatively high strength ability.

  7. Kinetic and kinematic differences between squats performed with and without elastic bands.

    Science.gov (United States)

    Israetel, Michael A; McBride, Jeffrey M; Nuzzo, James L; Skinner, Jared W; Dayne, Andrea M

    2010-01-01

    The purpose of this investigation was to compare kinetic and kinematic variables between squats performed with and without elastic bands equalized for total work. Ten recreationally weight trained males completed 1 set of 5 squats without (Wht) and with (Band) elastic bands as resistance. Squats were completed while standing on a force platform with bar displacement measured using 2 potentiometers. Electromyography (EMG) was obtained from the vastus lateralis. Average force-time, velocity-time, power-time, and EMG-time graphs were generated and statistically analyzed for mean differences in values between the 2 conditions during the eccentric and concentric phases. The Band condition resulted in significantly higher forces in comparison to the Wht condition during the first 25% of the eccentric phase and the last 10% of the concentric phase (p squats equalized for total work with and without elastic bands significantly alter the force-time, power-time, velocity-time, and EMG-time curves associated with the movements. Specifically, elastic bands seem to increase force, power, and muscle activity during the early portions of the eccentric phase and latter portions of the concentric phase.

  8. Joint angles of the ankle, knee, and hip and loading conditions during split squats.

    Science.gov (United States)

    Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

    2014-06-01

    The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.

  9. Design of squat shear walls using continuous strut-and-tie resistant models

    International Nuclear Information System (INIS)

    Santos, S.H. de C; Silva, R.E. da

    1993-01-01

    A new approach is presented for designing squat shear walls, subjected to seismic loading. In this approach, the strut-and-tie resistant models, proposed by Schlaich et al., are generalized in order to analyze continuous fields of compression and tension stresses. The application of the presented methodology is illustrated through numerical examples. (author)

  10. Squat test performance and execution in children with and without cerebral palsy

    NARCIS (Netherlands)

    Eken, Maaike M; Harlaar, J.; Dallmeijer, A. J.; Waard, E.J.; van Bennekom, C.A.M.; Houdijk, H.

    2017-01-01

    Background Knowledge on lower extremity strength is imperative to informed decision making for children with cerebral palsy (CP) with mobility problems. However, a functional and clinically feasible test is not available. We aimed to determine whether the squat test is suitable for this purpose by

  11. Squat test performance and execution in children with and without cerebral palsy

    NARCIS (Netherlands)

    Eken, M. M.; Harlaar, J.; Dallmeijer, A. J.; de Waard, E.; van Bennekom, C. A. M.; Houdijk, H.

    2017-01-01

    Knowledge on lower extremity strength is imperative to informed decision making for children with cerebral palsy (CP) with mobility problems. However, a functional and clinically feasible test is not available. We aimed to determine whether the squat test is suitable for this purpose by

  12. Control of cracking in R.C. Structures: Numerical simulation of a squat shear wall

    NARCIS (Netherlands)

    Damoni, C.; Belletti, B.; Lilliu, G.

    2013-01-01

    In this paper the behavior of a squat shear wall subjected to monotonic shear loading is investigated. The study fits into the experimental program driven by CEOS.fr on modeling of the behavior of the tested mocks-ups (monotonic and cycling loading-under prevented or free shrinkage). The shear wall

  13. SQUAT: A web tool to mine human, murine and avian SAGE data

    Directory of Open Access Journals (Sweden)

    Besson Jérémy

    2008-09-01

    Full Text Available Abstract Background There is an increasing need in transcriptome research for gene expression data and pattern warehouses. It is of importance to integrate in these warehouses both raw transcriptomic data, as well as some properties encoded in these data, like local patterns. Description We have developed an application called SQUAT (SAGE Querying and Analysis Tools which is available at: http://bsmc.insa-lyon.fr/squat/. This database gives access to both raw SAGE data and patterns mined from these data, for three species (human, mouse and chicken. This database allows to make simple queries like "In which biological situations is my favorite gene expressed?" as well as much more complex queries like: ≪what are the genes that are frequently co-over-expressed with my gene of interest in given biological situations?≫. Connections with external web databases enrich biological interpretations, and enable sophisticated queries. To illustrate the power of SQUAT, we show and analyze the results of three different queries, one of which led to a biological hypothesis that was experimentally validated. Conclusion SQUAT is a user-friendly information retrieval platform, which aims at bringing some of the state-of-the-art mining tools to biologists.

  14. Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat.

    Science.gov (United States)

    Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

    2017-01-01

    In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. III a.

  15. Squatting-Related Tibiofemoral Shear Reaction Forces and a Biomechanical Rationale for Femoral Component Loosening

    Directory of Open Access Journals (Sweden)

    Ashvin Thambyah

    2014-01-01

    Full Text Available Previous gait studies on squatting have described a rapid reversal in the direction of the tibiofemoral joint shear reaction force when going into a full weight-bearing deep knee flexion squat. The effects of such a shear reversal have not been considered with regard to the loading demand on knee implants in patients whose activities of daily living require frequent squatting. In this paper, the shear reversal effect is discussed and simulated in a finite element knee implant-bone model, to evaluate the possible biomechanical significance of this effect on femoral component loosening of high flexion implants as reported in the literature. The analysis shows that one of the effects of the shear reversal was a switch between large compressive and large tensile principal strains, from knee extension to flexion, respectively, in the region of the anterior flange of the femoral component. Together with the known material limits of cement and bone, this large mismatch in strains as a function of knee position provides new insight into how and why knee implants may fail in patients who perform frequent squatting.

  16. Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat

    Science.gov (United States)

    Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

    2017-01-01

    Summary Background In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Methods Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Results Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Conclusions Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. Level of evidence III a. PMID:29387646

  17. EFFECTS OF BODY MASS-BASED SQUAT TRAINING IN ADOLESCENT BOYS

    Directory of Open Access Journals (Sweden)

    Yohei Takai

    2013-03-01

    Full Text Available The purpose of this study was to determine the effects of body mass-based squat training on body composition, muscular strength and motor fitness in adolescent boys. Ninety-four boys (13.7 ± 0.6 yrs, 1.60 ± 0.09 m, 50.2 ± 9.6 kg participated in this study and were randomly assigned to training (n = 36 or control (n = 58 groups. The training group completed body mass-based squat exercise training (100 reps/day, 45 sessions for 8 weeks. Body composition and muscle thickness at the thigh anterior were determined by a bioelectrical impedance analyzer and ultrasound apparatus, respectively. Maximal voluntary knee extension strength and sprint velocity were measured using static myometer and non-motorized treadmill, respectively. Jump height was calculated using flight time during jumping, which was measured by a matswitch system. The 8-wk body mass-based squat training significantly decreased percent body fat (4.2% and significantly increased the lean body mass (2.7%, muscle thickness (3.2% and strength of the knee extensors (16.0%, compared to control group. The vertical jump height was also significantly improved by 3.4% through the intervention. The current results indicate that body mass-based squat training for 8 weeks is a feasible and effective method for improving body composition and muscular strength of the knee extensors, and jump performance in adolescent boys.

  18. Claw asymmetry in lobsters: case study in developmental neuroethology.

    Science.gov (United States)

    Govind, C K

    1992-12-01

    An enduring debate in the study of development is the relative contribution of genetic and epigenetic factors in the genesis of an organism, that is, the nature vs. nurture debate. The behavior of the paired claws in the lobster offers promising material for pursuing this debate because of the way they develop. The paired claws and their closer muscles are initially symmetrical; both are slender in appearance and have a mixture of fast and slow fibers in their closer muscles. During a critical period of development, they become determined into a major (crusher) and minor (cutter) claw and during subsequent development acquire their final form and behavior: The crusher becomes a stout, molar-toothed claw capable of closing only slowly because its closer muscle has 100% slow fibers while the cutter becomes a slender, incisor-toothed claw capable of closing rapidly because its closer muscle has 90% fast fibers. Our initial hypothesis was that the more active claw became the crusher and its less active counterpart the cutter. Presumably, nerve activity would influence muscle transformation, which in turn would influence the exoskeleton to which they attach and hence claw morphology. Curtailing nerve activity to the claw prevented crusher development, while reflex activation of a claw promoted its development; both results support the notion that nerve activity directly regulates claw form and function. This is not, however, the case, for when both claws were reflexly exercised neither formed a crusher, signifying rather that bilateral differences in predominantly mechanoreceptive input to the paired claws somehow lateralized the claw ganglion [central nervous system (CNS)] into a crusher and cutter side. The side experiencing the greater activity becomes the crusher side while the contralateral side becomes the cutter and is also inhibited from ever becoming a crusher. This initial lateralization in the CNS is expressed, via as yet unknown pathways, at the periphery in

  19. A model for the bioaccumulation of {sup 99}Tc in lobsters (Homarus gammarus) from the West Cumbrian coast

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Y.S.; Vives i Batlle, J. E-mail: jordi.vives@westlakes.ac.uk

    2003-07-01

    A biokinetic model is presented that simulates the uptake and release of {sup 99}Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for {sup 99}Tc. The model is designed to represent annually averaged {sup 99}Tc concentrations in lobsters from the Cumbrian coast, where significant levels of {sup 99}Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of {sup 99}Tc in lobsters.

  20. Diet and nutrition of western rock lobsters, Panulirus cygnus, in shallow coastal waters: the role of habitat

    Science.gov (United States)

    Generalist consumers often have diets that vary considerably over time and space, which reflects changes in resource availability. Predicting diets of consumers can therefore be difficult. The western rock lobster, Panulirus cygnus, is an omnivorous generalist consumer that uses ...

  1. A model for the bioaccumulation of 99Tc in lobsters (Homarus gammarus) from the West Cumbrian coast

    International Nuclear Information System (INIS)

    Olsen, Y.S.; Vives i Batlle, J.

    2003-01-01

    A biokinetic model is presented that simulates the uptake and release of 99 Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for 99 Tc. The model is designed to represent annually averaged 99 Tc concentrations in lobsters from the Cumbrian coast, where significant levels of 99 Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of 99 Tc in lobsters

  2. Characterization of the dominant bacterial communities during storage of Norway lobster and Norway lobster tails (Nephrops norvegicus) based on 16S rDNA analysis by PCR-DGGE.

    Science.gov (United States)

    Bekaert, Karen; Devriese, Lisa; Maes, Sara; Robbens, Johan

    2015-04-01

    The aim of this study was to investigate the microbial quality of whole Norway lobster (Nephrops norvegicus) and Norway lobster tails to optimize handling conditions. This was done by assessing the total viable count (TVC) and characterizing the dominant microbiota. The cultivable microorganisms were quantified via classical microbiological plating methods. To characterize as many bacterial species present as possible, we performed advanced molecular identification techniques (PCR-DGGE). The initial TVC of fresh Norway lobster meat was high (3.0 log cfu/g) as compared to fish. No significant difference between whole Norway lobster and Norway lobster tails could be found during the storage period. From day 6 of storage, a significant difference between Plate Count Agar (PCA) and Marine Agar (MA) was observed. The microbiota of Norway lobster was dominated by members of the Gram-negative genera such as Psychrobacter spp., Pseudoalteromonas spp., Pseudomonas spp., Luteimonas spp., and Aliivibrio spp. From these bacteria, mainly Psychrobacter spp. and Pseudomonas spp. remained present until the end of the storage period. These are known spoilage organisms in fishery products. Other known spoilage organisms of crustaceans such as Photobacterium spp. could not be identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Potentiation Effects of Half-Squats Performed in a Ballistic or Nonballistic Manner.

    Science.gov (United States)

    Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

    2016-06-01

    This study examined and compared the acute effects of ballistic and nonballistic concentric-only half-squats (COHSs) on squat jump performance. Fifteen resistance-trained men performed a squat jump 2 minutes after a control protocol or 2 COHSs at 90% of their 1 repetition maximum (1RM) COHS performed in a ballistic or nonballistic manner. Jump height (JH), peak power (PP), and allometrically scaled peak power (PPa) were compared using three 3 × 2 repeated-measures analyses of variance. Statistically significant condition × time interaction effects existed for JH (p = 0.037), PP (p = 0.041), and PPa (p = 0.031). Post hoc analysis revealed that the ballistic condition produced statistically greater JH (p = 0.017 and p = 0.036), PP (p = 0.031 and p = 0.026), and PPa (p = 0.024 and p = 0.023) than the control and nonballistic conditions, respectively. Small effect sizes for JH, PP, and PPa existed during the ballistic condition (d = 0.28-0.44), whereas trivial effect sizes existed during the control (d = 0.0-0.18) and nonballistic (d = 0.0-0.17) conditions. Large statistically significant relationships existed between the JH potentiation response and the subject's relative back squat 1RM (r = 0.520; p = 0.047) and relative COHS 1RM (r = 0.569; p = 0.027) during the ballistic condition. In addition, large statistically significant relationship existed between JH potentiation response and the subject's relative back squat strength (r = 0.633; p = 0.011), whereas the moderate relationship with the subject's relative COHS strength trended toward significance (r = 0.483; p = 0.068). Ballistic COHS produced superior potentiation effects compared with COHS performed in a nonballistic manner. Relative strength may contribute to the elicited potentiation response after ballistic and nonballistic COHS.

  4. THE ACUTE EFFECTS OF BACK SQUATS ON VERTICAL JUMP PERFORMANCE IN MEN AND WOMEN

    Directory of Open Access Journals (Sweden)

    Gavin L. Moir

    2010-06-01

    Full Text Available The aim of the present study was to investigate the acute effects of performing back squats on subsequent performance during a series of vertical jumps in men and women. Twelve men and 12 women were tested on three separate occasions, the first of which was used to determine their 1-repetition maximum (1-RM parallel back squat. Following this, subjects performed a potentiation and a control treatment in a counterbalanced order. The potentiation treatment culminated with subjects performing parallel back squats with a load equivalent to 70% 1- RM for three repetitions, following which they performed one countermovement vertical jump (CMJ for maximal height every three minutes for a total of 10 jumps. During the control treatment, subjects performed only the CMJs. Jump height (JH and vertical stiffness (VStiff were calculated for each jump from the vertical force signal recorded from a force platform. There were no significant changes in JH or VStiff following the treatments and no significant differences in the responses between men and women (p > 0.05. Correlations between normalized 1-RM back squat load and the absolute change in JH and VStiff were small to moderate for both men and women, with most correlations being negative. Large variations in response to the back squats were noted in both men and women. The use of resistance exercises performed prior to a series of vertical jumps can result in improvements in performance in certain individuals, although the gains tend to be small and dependent upon the mechanical variable measured. There does not seem to be any differences between men and women in the response to dynamic potentiation protocols

  5. Strength performance in youth: trainability of adolescents and children in the back and front squats.

    Science.gov (United States)

    Keiner, Michael; Sander, Andre; Wirth, Klaus; Caruso, Oliver; Immesberger, Peter; Zawieja, Martin

    2013-02-01

    A basic question for many athletic coaches pertains to the maximum attainable strength level for youth athletes. The aim of this investigation was to establish reference values for the strength performance in the front and back squats in youth athletes. The strength performance in front and back squats of 141 elite youth soccer players was tested by a 1 repetition maximum (1RM) and 1RM related to bodyweight (SREL). The subjects aged between 11 and 19 years and were divided into 2 groups and 4 subgroups (A = younger than 19 years, B = younger than 17 years, C = younger than 15 years, and D = younger than 13 years). For approximately 2 years, one group (control group [CG]) only participated in routine soccer training and the other group (strength training group [STG]) participated in an additional strength training program along with the routine soccer training. Additionally, the strength performance in a 5RM in both squat variants of 105 young elite weightlifters (National Weightlifting Organization Baden Württemberg, [BWG]) was examined to show the high level of trainability of children and adolescents and to determine the reference strength values for young athletes. The STG performed in the parallel front squat SREL in the subgroups A 1.7 +/- 0.2, B 1.6 +/- 0.2, C 1.4 +/-0.2 and D 0.9 +/- 0.3. The STG had significantly (p squat for young elite athletes with long-term training experience should be a minimum of 2.0 for 16- to 19-year-olds, 1.5 for 13- to 15-year-olds, and 0.7 for 11- to 12-year-olds.

  6. Towards evidence based strength training: a comparison of muscle forces during deadlifts, goodmornings and split squats.

    Science.gov (United States)

    Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

    2017-01-01

    To ensure an efficient and targeted adaptation with low injury risk during strength exercises, knowledge of the participant specific internal loading conditions is essential. The goal of this study was to calculate the lower limb muscles forces during the strength exercises deadlifts, goodmornings and splits squats by means of musculoskeletal simulation. 11 participants were assessed performing 10 different variations of split squats by varying the step length as well as the maximal frontal tibia angle, and 13 participants were measured performing deadlift and goodmorning exercises. Using individualised musculoskeletal models, forces of the Quadriceps ( four parts), Hamstrings (four parts) and m. gluteus maximus (three parts) were computed. Deadlifts resulted highest loading for the Quadriceps, especially for the vasti (18-34 N/kg), but not for the rectus femoris (8-10 N/kg), which exhibited its greatest loading during split squats (13-27 N/kg) in the rear limb. Hamstrings were loaded isometrically during goodmornings but dynamically during deadlifts. For the m. gluteus maximus , the highest loading was observed during split squats in the front limb (up to 25 N/kg), while deadlifts produced increasingly, large loading over large ranges of motion in hip and knee. Acting muscle forces vary between exercises, execution form and joint angle. For all examined muscles, deadlifts produced considerable loading over large ranges of motion, while split squats seem to be highly dependent upon exercise variation. This study provides key information to design strength-training programs with respect to loading conditions and ranges of motion of lower extremity muscles.

  7. Validation of jump squats as a practical measure of post-activation potentiation.

    Science.gov (United States)

    Nibali, Maria L; Chapman, Dale W; Robergs, Robert A; Drinkwater, Eric J

    2013-03-01

    To determine if post-activation potentiation (PAP) can augment sports performance, it is pertinent that researchers be confident that any enhancement in performance is attributable to the PAP phenomenon. However, obtaining mechanistic measures of PAP in the daily training environment of highly trained athletes is impractical. We sought to validate jump squats as a practical measure with ecological validity to sports performance against a mechanistic measure of PAP. We assessed the evoked muscle twitch properties of the knee extensors and jump squat kinetics of 8 physically trained males in response to a 5-repetition-maximum back squat conditioning stimulus (CS). Evoked muscle twitch, followed by 3 jump squats, was assessed before and at 4, 8, and 12 min post CS. Time intervals were assessed on separate occasions using a Latin square design. Linear regression was used to determine the relationship between post-pre changes in kinetic variables and muscle twitch peak force (Ft) and twitch rate of force development (RFDt). Large correlations were observed for both concentric relative and absolute mean power and Ft (r = 0.50 ± 0.30) and RFDt (r = 0.56 ± 0.27 and r = 0.58 ± 0.26). Concentric rate of force development (RFD) showed moderate correlations with Ft (r = 0.45 ± 0.33) and RFDt (r = 0.49 ± 0.32). Small-to-moderate correlations were observed for a number of kinetic variables (r = -0.42-0.43 ± 0.32-0.38). Jump squat concentric mean power and RFD are valid ecological measures of muscle potentiation, capable of detecting changes in athletic performance in response to the PAP phenomenon.

  8. Identification and prioritization of rail squat defects in the field using rail magnetisation technology

    Science.gov (United States)

    Kaewunruen, Sakdirat

    2015-04-01

    Inevitably, rail squats and studs are continuing to be a serious problem for railway organisations around the world in the 21st century. They are typically classified as the growth of any cracks that have grown longitudinally through the subsurface and some of the cracks propagating to the bottom of rails transversely, and have branched from initial longitudinal cracks with a depression of rail surface. The horizontal crack, which results in a depression of rail surface, induces increased maintenance level, more frequent monitoring, compromised rail testing (as the crack shields the signal echoes), and possible broken rails. This paper presents field investigations using a magnetised-rail testing device developed by MRX Technologies to identify and prioritise the rail squats. Most of the in situ squats were found on the high rail of the transition (variable-radius curved track), which is associated with rolling contact fatigue (RCF). This investigation highlights the field performance of the MRX's surface crack detection technology in comparison with the traditional ultrasonic method and detailed walking inspection. Visually, it was found in the field that the size of the RCF squats varies from very small to moderate. The predicted crack data were obtained by scanning the magnitised rails. The comparison of the actual crack depths (ultrasonic) and the predicted crack depths (MRX device) shows: • A possible correlation for small RCF/ squat cracks. • Poor interpretation of larger defects and welds. The field assessment also suggests some practical issues required for further development, including the detection of rail spalling, deep transverse crack, welding, and so on.

  9. A Comparative Study of the Uptake, Clearance and Metabolism of Technetium in Lobster (Homarus Gammarus) and Edible Crab (Cancer Paguras)

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, J.F.; Smith, D.L.; Winpenny, K

    1998-07-01

    Lobsters and edible crabs have been exposed to {sup 95}Tc{sup m} in their sea water or in their food, and the uptake, retention and distribution of the isotope in their bodies examined. The steady-state concentration factor C{sub ss} for uptake of {sup 95}Tc{sup m} from sea water was significantly greater for female crabs (C{sub ss}=17.9) than for males (C{sub ss}=14.4). There was no such sex difference in lobsters and they took up {sup 95}Tc{sup m} to much higher levels with a C{sub ss} of 1160. Retention of the isotope was similar for crabs and lobsters and for animals of both sexes. However the route of uptake was important with more rapid clearance after uptake from sea water (t{sub b1/2} = 51 days) than after uptake from food (t{sub b1/2} = 108 days). Technetium was found predominantly in the hepatopancreas of all crabs and most male lobsters. In a few male lobsters and all females it was mainly in muscle. Lobster ovaries consistently contained more activity than testes but this difference was not seen in crabs. At the subcellular level {sup 95}Tc{sup m} in hepatopancreas cells of both lobster and crab occurred mainly in the cytosol. Results of initial studies into the relationships between technetium and cytosol proteins are given and the possible basis for the much greater accumulation of the element by lobsters than crabs discussed. (author)

  10. EFFECT OF SPEED VARITION AND STRETCH-SHORTENING CYCLE ON LOWER MUSCLES ACTIVITY AND JOINT TORQUE DURING PARALLEL SQUAT

    OpenAIRE

    真鍋, 芳明; 横澤, 俊治; 島田, 一志; 尾縣, 貢

    2004-01-01

    The purpose of this study was to compare joint torque and the activity pattern of eight muscles crossing the ankle, knee and hip joints during three kinds of squats with different speeds (Slow, Normal, Quick). Ten male athletes performed squats at three different speeds. Variables such as net torque and power about the joint were calculated during the descending and ascending phase of each squat. At the same time, surface electrodes were placed over the eight lower extremity muscles,.and %iEM...

  11. RESPON IMUNITAS BENIH LOBSTER, Panulirus homarus DENGAN PENGGUNAAN PROBIOTIK PADA PAKAN MOIST

    Directory of Open Access Journals (Sweden)

    Haryanti Haryanti

    2017-05-01

    Full Text Available Pemeliharaan benih lobster P. homarus masih menghadapi beberapa permasalahan, di antaranya infeksi penyakit bakteri (red body disease dan mortalitas yang tinggi. Tujuan penelitian ini adalah untuk mengkaji respons imunitas benih lobster P. homarus yang diberi pakan pelet basah (moist diets dengan penambahan probiotik. Pemeliharaan benih lobster dilakukan secara individu (1 ekor/keranjang. Lama pemeliharaan selama tiga bulan. Bobot awal puerulus P. homarus adalah 0,37 ± 0,05 g. Perlakuan meliputi pemberian pakan moist yang ditambahkan (A ragi Saccharomyces cerevisiae, (B kombinasi probiotik, Alteromonas sp. BY-9 dan Bacillus cereus BC, dan (C tanpa probiotik. Respons imunitas dianalisis dengan RT-qPCR melalui tujuh gen target terkait ekspresi imunitas, setelah diuji tantang dengan Vibrio harveyi (penyebab red body disease. Hasil penelitian menunjukkan bahwa sintasan benih lobster sebesar (A 32,22%; (B 29,63%; dan (C 33,33%. Pertumbuhan panjang dan bobot benih lobster tidak berbeda nyata (P>0,05. Respons imunitas benih lobster P. homarus pada perlakuan A dan B menunjukkan nilai ekspresi imun yang lebih tinggi dibandingkan dengan perlakuan C (tanpa probiotik. Ekspresi gen penyandi anti lipopolisakarida (ALFHa-1 meningkat pada (A rata-rata sebesar 3,44 kali dan (B 3,25 kali dibandingkan dengan perlakuan C (2,43 kali. Kelipatan ekspresi profenoloksidase (proPO benih lobster meningkat pada perlakuan A (penambahan ragi rata-rata sebesar 5,27 kali, sedangkan pada perlakuan B (kombinasi probiotik sebesar 12,92 kali. Ekspresi Clotting sistem (transglutaminase, clotting protein dan antioxidant defense mechanism (glutathione peroxidase/GPO dan SAA juga mengalami peningkatan pada perlakuan A dan B. A number of contrains including disease infections and significant mortality have been occurring in lobster aquaculture. The aim of this research was to observe the immune response of juvenile lobster P. homarus culture fed by moist pellet supplemented with

  12. Induced resistance to infection of lobsters Homarus americanus by Aerococcus viridans (var.) homari, the bacterium causing gaffkemia.

    Science.gov (United States)

    Stewart, James E; Arie, B; Marks, L J

    2004-12-13

    A vaccine composed of steam sterilized (autoclaved) cells of a virulent strain of Aerococcus viridans (var.) homari was effective in protecting lobsters Homarus americanus against gaffkemia. At 15 degrees C the heat-killed vaccines (HKV) at concentrations between 1 and 5 x 10(7) particles kg(-1) lobster body wt induced maximal protection in induction periods ranging from 7 to 11 d. Protection was substantial over the course of a 30 d post-induction trial period. Spring-caught lobsters (i.e. those more fully rehabilitated following ecdysis) gained more protection (LD50 = 1.9 x 10(4)) from the vaccination than did those caught in the late fall-early winter period (lobsters that were not yet fully recovered from ecdysis) (LD50 = 3.2 x 10(3)). The protection offered by the HK vaccine was comparable to that induced by a vaccine produced by incubating the pathogen with low concentrations (2 pg ml(-1)) of the antibiotic vancomycin. The bacterins produced by both methods exhibited similar new properties: (1) agglutination at low titres by lobster hemolymph serum, suggesting an impaired capsule layer, and (2) increased permeability to the large Alcian Blue molecule. With both vaccines, the protection may be a direct result of increased exposure to intact bacterial cell structures by the lobster defences, an exposure which otherwise would be prevented by an intact capsule.

  13. Ranking harbours in the maritime provinces of Canada for potential to contaminate American lobster (Homarus americanus) with polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Prouse, N.J.

    1994-01-01

    Polycyclic aromatic hydrocarbons (PAHs) comprise a suite of contaminants that enter the marine environment through a variety of natural and anthropogenic sources. PAHs, including carcinogenic compounds, bioaccumulate in the tissues of exposed American lobsters (Homarus americanus). High PAH concentrations in lobster tissues necessitated the closure of the lobster fishery in the South Arm of Sydney Harbour, Nova Scotia, in 1982. A study was conducted to assess harbors in Nova Scotia, New Brunswick, and Prince Edward Island to determine if there might be a reason for concern about PAH contamination of lobsters. Adjacent commercial and industrial activity, harbor uses, the surrounding population, and PAH point sources were evaluated for each harbor selected for study. Areas of lobster fishing and the number of permanent lobster holding facilities within each harbor were also determined. Harbors were then ranked according to their potential for PAH contamination. Point sources for PAHs within these harbors included petroleum and coal products plants, oil refineries, chemical plants, coal-fired generating stations, and fuel combustion in land vehicles and ships. After Sydney, the harbors with the highest potential for PAH contamination were determined to be Halifax, Saint John, Pictou, and Port Hawkesbury Ship Harbour. 60 refs., 15 figs., 7 tabs.

  14. TOTAL HEMOCYTE COUNT AND HEMOLYMPH GLUCOSE CONCENRATION RESPONSE OF SPINY LOBSTER Panulirus homarus ON RATIO OF SHELTER

    Directory of Open Access Journals (Sweden)

    Suhaiba Djai

    2017-11-01

    Full Text Available This research was conducted to assess the physiological response of the lobster Panulirus homarus for the ratio of the shelters. The method used completely randomized design with two replicates of each treatments with shelter ratio (A 1 : 5, (B 3 : 5, (C 4 : 5, (D 5 : 5. Weight average for 184 lobsters with the stocking density of 23 lobsters for each treatment was 32.64 ± 0.58 g. The experiment was conducted for 60 days. The lobster was fed with trash fish and acclimatized for 7 days before the experiment. Observations on the physiologycal of every 10 days. The physiological responses that observed were total hemocyte count (THC and hemolymph glucose concentration. The results showed that 4:5 was the best lobster shelter ratio because it could reduce stress levels. This is indicated by the stable values of THC and hemolymph glucose level during the experiment and supported by the growth of 57.28 ± 0.15 g and survival rate of 91.31 ± 2.60%. Keywords: lobster, Panulirus homarus, ratio, shelter, THC, glucose

  15. Effects of drilling muds on behavior of the American lobster, Homarus americanus, in water column and substrate exposures

    Energy Technology Data Exchange (ETDEWEB)

    Atema, J; Leavitt, D F; Barshaw, D E; Cuomo, M C

    1982-01-01

    Studies were conducted to explore the effects of drilling muds on various aspects of lobster behavior directly related to survival in the field. Toxicity of different drilling muds varied from immediately lethal to adult lobsters to apparently harmless to postlarval stages, with a variety of intermediate effects. Both the chemical toxicity in the water column and the physical effects of covering the substrate with drilling mud were studied, and both interfered with normal lobster behavior. The studies are mainly concerned with postlarval lobsters (stages IV and V), just after settling on the bottom. They were tested in 36-d chronic exposures (7 mg/L) and in seminatural aquaria with 1-mm layers of drilling mud covering the substrate. Toxicity in the water column manifested itself in feeding and molting delays, severe delays in shelter construction, increased walking and swimming, unprovoked tail flipping, and lethargy. A natural bay mud used as a control caused no such effects. Physical effects of substrate cover were apparent in experiments with 1-, 2-, and 4-mm layers of drilling mud and similar layers of a mixture of bentonite and barite covering a natural mud substrate. In depths of 4mm both kinds of substrate cover caused severe delays in shelter construction and in quality of burrows constructed. Thus, substrates with 4-mm to perhaps as little as 1-mm covering of drilling mud may cause increased exposure of lobsters to predators and currents, resulting in the substrate becoming unsuitable for lobster settling and survival.

  16. Factors Contributing to Pelvis Instability in Female Adolescent Athletes During Unilateral Repeated Partial Squat Activity

    Science.gov (United States)

    Scarborough, Donna Moxley; Linderman, Shannon; Berkson, Eric M.; Oh, Luke S.

    2017-01-01

    Objectives: Unilateral partial squat tasks are often used to assess athletes’ lower extremity (LE) neuromuscular control. Single squat biomechanics such as lateral drop of the non-stance limb’s pelvis have been linked to knee injury risk. Yet, there are limited studies on the factors contributing to pelvic instability during the unilateral partial squat such as anatomical alignment of the knee and hip strength. The purpose of this study was 1) to assess the influence of leg dominance on pelvic drop among female athletes during the repeated unilateral partial squat activity and 2) to investigate the contributions that lower limb kinematics and hip strength have on pelvis drop. Methods: 42 female athletes (27= softball pitchers, 15=gymnasts, avg age=16.48 ± 2.54 years) underwent lower limb assessment. The quadriceps angle (Q angle) and the average of 3 trials for hip abduction and extension strength (handheld dynamometer measurements) were used for analyses. 3D biomechanical analysis of the repeated unilateral partial squat activity followed using a 20 motion capture camera system which created a 15 segment model of each subject. The subject stood on one leg at the lateral edge of a 17.78 cm box with hands placed on the hips and squatted so that the free hanging contralateral limb came as close to the ground without contact for 5 continuous repetitions. One trial for each limb was performed. Peak pelvic drop and ankle, knee and hip angles and torques (normalized by weight) at this time point were calculated using Visual 3D (C-Motion) biomechanical software. Paired T-test, Spearman correlations and multiple regression model statistical analyses were performed. Results: Peak pelvic drop during the unilateral partial squat did not differ significantly on the basis of limb dominance (p=0.831, Dom: -3.40 ± 5.10° , ND: -3.46 ± 4.44°). Peak pelvic drop displayed a Spearman correlation with the functional measure of hip abduction/adduction (ABD/ADD) angle (rs= 0

  17. Limb symmetry during double-leg squats and single-leg squats on land and in water in adults with long-standing unilateral anterior knee pain; a cross sectional study.

    Science.gov (United States)

    Severin, Anna C; Burkett, Brendan J; McKean, Mark R; Wiegand, Aaron N; Sayers, Mark G L

    2017-01-01

    The presence of pain during movement typically results in changes in technique. However, the physical properties of water, such as flotation, means that water-based exercise may not only reduce compensatory movement patterns but also allow pain sufferers to complete exercises that they are unable to perform on land. The purpose of this study was to assess bilateral kinematics during double-leg squats and single-leg squats on land and in water in individuals with unilateral anterior knee pain. A secondary aim was to quantify bilateral asymmetry in both environments in affected and unaffected individuals using a symmetry index. Twenty individuals with unilateral knee pain and twenty healthy, matched controls performed body weight double- and single-leg squats in both environments while inertial sensors (100 Hz) recorded trunk and lower body kinematics. Repeated-measures statistics tested for environmental effects on movement depths and peak angles within the anterior knee pain group. Differences in their inter-limb symmetry in each environments was compared to the control group using analysis of variance tests. Water immersion allowed for greater movement depths during both exercises (double-leg squat: +7 cm, p  = 0.032, single-leg squat: +9 cm, p  = 0.002) for the knee pain group. The double-leg squat was symmetrical on land but water immersion revealed asymmetries in the lower body frontal plane movements. The single-leg squat revealed decreased hip flexion and frontal plane shank motions on the affected limb in both environments. Water immersion also affected the degree of lower limb asymmetry in both groups, with differences also showing between groups. Individuals with anterior knee pain achieved increased squat depth during both exercises whilst in water. Kinematic differences between the affected and unaffected limbs were often increased in water. Individuals with unilateral anterior knee pain appear to utilise different kinematics in the affected

  18. Limb symmetry during double-leg squats and single-leg squats on land and in water in adults with long-standing unilateral anterior knee pain; a cross sectional study

    OpenAIRE

    Severin, Anna C.; Burkett, Brendan J.; McKean, Mark R.; Wiegand, Aaron N.; Sayers, Mark G. L.

    2017-01-01

    Background The presence of pain during movement typically results in changes in technique. However, the physical properties of water, such as flotation, means that water-based exercise may not only reduce compensatory movement patterns but also allow pain sufferers to complete exercises that they are unable to perform on land. The purpose of this study was to assess bilateral kinematics during double-leg squats and single-leg squats on land and in water in individuals with unilateral anterior...

  19. RPE and Velocity Relationships for the Back Squat, Bench Press, and Deadlift in Powerlifters.

    Science.gov (United States)

    Helms, Eric R; Storey, Adam; Cross, Matt R; Brown, Scott R; Lenetsky, Seth; Ramsay, Hamish; Dillen, Carolina; Zourdos, Michael C

    2017-02-01

    Helms, ER, Storey, A, Cross, MR, Browm, SR, Lenetsky, S, Ramsay, H, Dillen, C, and Zourdos, MC. RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. J Strength Cond Res 31(2): 292-297, 2017-The purpose of this study was to compare average concentric velocity (ACV) and rating of perceived exertion (RPE) based on repetitions in reserve on the squat, bench press, and deadlift. Fifteen powerlifters (3 women and 12 men, mean age 28.4 ± 8.5 years) worked up to a one repetition maximum (1RM) on each lift. Rating of perceived exertion was recorded on all sets, and the ACV was recorded for all sets performed at 80% of estimated 1RM and higher, up to 1RM. Rating of perceived exertion at 1RM on squat, bench press, and deadlift was 9.6 ± 0.5, 9.7 ± 0.4, and 9.6 ± 0.5, respectively and was not significantly different (p > 0.05). The ACV at 1RM on squat, bench press and deadlift was 0.23 ± 0.05, 0.10 ± 0.04, and 0.14 ± 0.05 m·second, respectively. Squat was faster than both bench press and deadlift (p > 0.001), and deadlift was faster than bench press (p = 0.05). Very strong relationships (r = 0.88-0.91) between percentage 1RM and RPE were observed on each lift. The ACV showed strong (r = -0.79 to -0.87) and very strong (r = -0.90 to 92) inverse relationships with RPE and percentage 1RM on each lift, respectively. We conclude that RPE may be a useful tool for prescribing intensity for squat, bench press, and deadlift in powerlifters, in addition to traditional methods such as percentage of 1RM. Despite high correlations between percentage 1RM and ACV, a "velocity load profile" should be developed to prescribe intensity on an individual basis with appropriate accuracy.

  20. The effect of sodium bicarbonate ingestion on back squat and bench press exercise to failure.

    Science.gov (United States)

    Duncan, Michael J; Weldon, Anthony; Price, Michael J

    2014-05-01

    This study examined the acute effects of NaHCO3 ingestion on repetitions to failure and rating of perceived exertion in the back squat and bench press in trained men. Eight resistance-trained men took part in this double-blind, randomized crossover experimental study whereby they ingested NaHCO3 (0.3 g·kg(-1) body mass) or placebo (sodium chloride NaCl: 0.045 g·kg(-1) body mass) solution 60 minutes before completing a bout of resistance exercise (3 sets of bench press and back squat exercise to failure at an intensity of 80% 1 repetition maximum). Experimental conditions were separated by at least 48 hours. Participants completed more repetitions to failure in the back squat after NaHCO3 ingestion (p = 0.04) but not for bench press (p = 0.679). Mean ± SD of total repetitions was 31.3 ± 15.3 and 24.6 ± 16.2 for back squat and 28.7 ± 12.2 and 26.7 ± 10.2 for bench press in NaHCO3 and placebo conditions, respectively. Repetitions to failure decreased as set increased for the back squat and bench press (p = 0.001, both). Rating of perceived exertion significantly increased with set for the back squat and bench press (p = 0.002, both). There was no significant change in blood lactate across time or between conditions. There were however treatment × time interactions for blood pH (p = 0.014) and blood HCO3 concentration (p = 0.001). After ingestion, blood pH and HCO3 (p = 0.008) concentrations were greater for the NaHCO3 condition compared with the placebo condition (p < 0.001). The results of this study suggest that sodium bicarbonate ingestion can enhance resistance exercise performance using a repetition to failure protocol in the first exercise in a resistance exercise session.

  1. Differences in Lower Extremity and Trunk Kinematics between Single Leg Squat and Step Down Tasks.

    Directory of Open Access Journals (Sweden)

    Cara L Lewis

    Full Text Available The single leg squat and single leg step down are two commonly used functional tasks to assess movement patterns. It is unknown how kinematics compare between these tasks. The purpose of this study was to identify kinematic differences in the lower extremity, pelvis and trunk between the single leg squat and the step down. Fourteen healthy individuals participated in this research and performed the functional tasks while kinematic data were collected for the trunk, pelvis, and lower extremities using a motion capture system. For the single leg squat task, the participant was instructed to squat as low as possible. For the step down task, the participant was instructed to stand on top of a box, slowly lower him/herself until the non-stance heel touched the ground, and return to standing. This was done from two different heights (16 cm and 24 cm. The kinematics were evaluated at peak knee flexion as well as at 60° of knee flexion. Pearson correlation coefficients (r between the angles at those two time points were also calculated to better understand the relationship between each task. The tasks resulted in kinematics differences at the knee, hip, pelvis, and trunk at both time points. The single leg squat was performed with less hip adduction (p ≤ 0.003, but more hip external rotation and knee abduction (p ≤ 0.030, than the step down tasks at 60° of knee flexion. These differences were maintained at peak knee flexion except hip external rotation was only significant in the 24 cm step down task (p ≤ 0.029. While there were multiple differences between the two step heights at peak knee flexion, the only difference at 60° of knee flexion was in trunk flexion (p < 0.001. Angles at the knee and hip had a moderate to excellent correlation (r = 0.51-0.98, but less consistently so at the pelvis and trunk (r = 0.21-0.96. The differences in movement patterns between the single leg squat and the step down should be considered when selecting a

  2. Optical metrology for analysis of lobster-eye x-ray optics

    International Nuclear Information System (INIS)

    Irving, Thomas H.K.; Peele, Andrew G.; Nugent, Keith A.

    2003-01-01

    A new method that uses optical microscopy to determine the physical structure of lobster-eye x-ray optics is described. This approach offers the ability to predict x-ray performance without having to take an x-ray measurement. An overlapping series of images of the entrance and exit faces of an optic are obtained and examined by purpose-built software. A 24-parameter description of each channel is obtained from which a quantitative analysis of all the major optic defects, except surface roughness, is performed. Results for a planar lobster-eye optic are used to illustrate this technique and discuss its abilities as well as directions for future enhancements

  3. Tests of lobster eye optics for small space X-ray telescope

    International Nuclear Information System (INIS)

    Tichy, Vladimir; Barbera, Marco; Collura, Alfonso; Hromcik, Martin; Hudec, Rene; Inneman, Adolf; Jakubek, Jan; Marsik, Jiri; Marsikova, Veronika; Pina, Ladislav; Varisco, Salvatore

    2011-01-01

    The Lobster eye design for a grazing incidence X-ray optics provides wide field of view of the order of many degrees, for this reason it can be a convenient approach for the construction of space all-sky X-ray monitors. We present preliminary results of tests of prototype lobster eye X-ray optics in quasi parallel beam full imaging mode conducted using the 35 m long X-ray beam-line of INAF-OAPA in Palermo (Italy). X-ray images at the focal plane have been taken with a microchannel plate (MCP) detector at several energy values from 0.3 to 8 keV. The gain, the field of view and the angular resolution have been measured and compared with theoretical values.

  4. Narrow-spectrum chemoreceptor cells in the walking legs of the lobster Homarus americanus: taste specialists

    Energy Technology Data Exchange (ETDEWEB)

    Derby, C D; Atema, J

    1982-01-01

    The chemoreceptors in the legs of lobsters function in the localization and handling of food. By single-unit extracellular recording techniques, the specificity of single primary chemoreceptor cells is described here in detail. In contrast to what is known in vertebrates, narrow-spectrum chemoreceptors of several different types were found, each type responding with maximal sensitivity to only one of the following compounds: L-glutamate, L-glutamine, L-arginine, taurine, betaine, and ammonium chloride. Ammonium chloride sensitive cells were also highly specific. Other groups of narrow-spectrum cells - L-arginine, L-glutamine, taurine, and betaine sensitive chemoreceptors - showed equally strong specificity. These results indicate that the peripheral coding system in the legs of lobsters is based largely but perhaps not exclusively on narrow-spectrum chemoreceptor cells.

  5. Function of chemo- and mechanoreceptors in lobster (Homarus americanus) feeding behavior

    Energy Technology Data Exchange (ETDEWEB)

    Derby, C D; Atema, J

    1982-01-01

    The behavior of lobsters preying on live mussels (Mytilus edulis) was observed before and after chemosensory-mechanosensory deafferentation of different sensory appendages. Deafferentation of the antennules, leg tips, or maxillipeds (but not the carapace or proximal leg segments) interfered with feeding performance by causing an increase in the time necessary to crush a mussel after search initiation. In addition, deafferentation of the leg tips or the maxillipeds caused a decline in number of mussels crushed but for different reasons. Deafferentation of leg chemoreceptors resulted in the same behavioural deficiencies as deafferentation of leg chemo- and mechanoreceptors, demonstrating that it is the leg chemoreceptors that are essential in releasing this grasping response. Chemoreceptors on different appendages of lobsters therefore fulfill different functional roles in their feeding behavior.

  6. Liminal cosmopolitanisms: Identity strategies and categorization of culture and class in multi-ethnic squats in Rome

    Directory of Open Access Journals (Sweden)

    Piero Vereni

    2016-08-01

    Full Text Available In the last twenty years, the squatting movement in Rome has witnessed a steady increase of foreign participants as regular members but a scarce presence among the leadership. Moreover, the incidence of immigrants among squatters is typically not marked in the public self-representation of the movement yet overemphasized and disputed by mainstream media. The essay attempts an interpretation of this peculiar distribution of foreign immigrants among squatters. On the one side, their being foreigners within Italian welfare puts them at risk of higher exclusion; on the other, political leaders in the squats may see the foreigners (as bearers of a shared class condition as a suitable pool for the wider political aim of squatting, namely the implementation of an alternative urban lifestyle. Furthermore, foreigners may take part into squats just as a self-attained form of social emancipation, since the act of squatting may equal an otherwise inaccessible house possession. Within these apparently contradictory aims, multi-ethnic squats turn into cosmopolitan spaces of identities that accept transcending their specificities to pour into a common kiln of class identity, between revolutionary proletariat and pity bourgeoisie seeking full social integration.

  7. Electrophysiological Investigation of Different Methods of Anesthesia in Lobster and Crayfish

    Science.gov (United States)

    Fregin, Torsten; Bickmeyer, Ulf

    2016-01-01

    Objectives In search for methods of anesthesia of crustaceans, an implanted electrode into lobster and crayfish CNS enabled us to monitor signal propagation in the nerve system of animals undergoing different protocols. Results Cooling (tap water 0°C, sea water -1,8°C) and anesthesia with MgCl2 (10%) were both discarded as anesthetic procedures because responses to external stimuli were still detectable under treatment. Contrarily, bubbling the aquarium water with CO2 can be considered a “partially successful” anesthesia, because signal propagation is inhibited but before that the animals show discomfort. The procedure of “electro-stunning” induces epileptic-form seizures in the crustacean CNS (lobster, crayfish), which overlay but do not mitigate the response to external stimuli. After several minutes the activity declines before the nervous system starts to recover. A feasible way to sacrifice lobsters is to slowly raise the water temperature (1°C min-1), as all electrical activities in the CNS cease at temperatures above ~30°C, whereas below this temperature the animals do not show signs of stress or escape behavior (e.g. tail flips) in the warming water. Conclusion CO2 is efficient to anaesthetize lobster and crayfish but due to low pH in water is stressful to the animals previous to anesthesia. Electrical stunning induces epileptiform seizures but paralyses the animals and leads to a reversible decline of nerve system activity after seizure. Electric stunning or slowly warming just before preparation may meet ethical expectations regarding anaesthesia and to sacrifice crustaceans. PMID:27642755

  8. Genetic isolation between the Western and Eastern Pacific populations of pronghorn spiny lobster Panulirus penicillatus.

    Directory of Open Access Journals (Sweden)

    Seinen Chow

    Full Text Available The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142-1,207 bp and 16S rDNA (535-546 bp regions were determined for adult and phyllosoma larval samples collected from the Eastern Pacific (EP(Galápagos Islands and its adjacent water, Central Pacific (CP(Hawaii and Tuamotu and the Western Pacific (WP(Japan, Indonesia, Fiji, New Caledonia and Australia. Phylogenetic analyses revealed two distinct large clades corresponding to the geographic origin of samples (EP and CP+WP. No haplotype was shared between the two regional samples, and average nucleotide sequence divergence (Kimura's two parameter distance between EP and CP+WP samples was 3.8±0.5% for COI and 1.0±0.4% for 16S rDNA, both of which were much larger than those within samples. The present results indicate that the Pacific population of the pronghorn spiny lobster is subdivided into two distinct populations (Eastern Pacific and Central to Western Pacific, with no gene flow between them. Although the pronghorn spiny lobster have long-lived teleplanic larvae, the vast expanse of Pacific Ocean with no islands and no shallow substrate which is known as the East Pacific Barrier appears to have isolated these two populations for a long time (c.a. 1MY.

  9. Coupling Recruitment Forecasts with Economics in the Gulf of Maine's American Lobster Fishery

    Science.gov (United States)

    Wahle, R.; Oppenheim, N.; Brady, D. C.; Dayton, A.; Sun, C. H. J.

    2016-02-01

    Accurate predictions of fishery recruitment and landings represent an important goal of fisheries science and management, but linking environmental drivers of fish population dynamics to financial markets remains a challenge. A fundamental step in that process is understanding the environmental drivers of fishery recruitment. American lobster (Homarus americanus) populations of the northwest Atlantic have been undergoing a dramatic surge, mostly driven by increases the Gulf of Maine. Settler-recruit models that track cohorts after larvae settle to the sea bed are proving useful in predicting subsequent fishery recruitment some 5-7 years later. Here we describe new recruitment forecasting models for the lobster fishery at 11 management areas from Southern New England to Atlantic Canada. We use an annual survey of juvenile year-class strength and environmental indicators to parameterize growth and mortality terms in the model. As a consequence of a recent widespread multi-year downturn in larval settlement, our models suggest that the peak in lobster abundance in the Gulf of Maine will be passed in the near future. We also present initial steps in the coupling of forecast data with economic models for the fishery. We anticipate that these models will give stakeholders and policy makers time to consider their management choices for this most valuable of the region's fisheries. Our vision is to couple our forecast model outputs to an economic model that captures the dynamics of market forces in the New England and Canadian Maritime lobster fisheries. It will then be possible to estimate the financial status of the fishery several years in advance. This early warning system could mitigate the adverse effects of a fluctuating fishery on the coastal communities that are perilously dependent upon it.

  10. The Influence of Mark-Recapture Sampling Effort on Estimates of Rock Lobster Survival.

    Directory of Open Access Journals (Sweden)

    Ziya Kordjazi

    Full Text Available Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day and four levels of the number of sampling-days (2, 4, 6 and 7 days. The most parsimonious Cormack-Jolly-Seber (CJS model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery.

  11. The Influence of Mark-Recapture Sampling Effort on Estimates of Rock Lobster Survival

    Science.gov (United States)

    Kordjazi, Ziya; Frusher, Stewart; Buxton, Colin; Gardner, Caleb; Bird, Tomas

    2016-01-01

    Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters) were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day) and four levels of the number of sampling-days (2, 4, 6 and 7 days). The most parsimonious Cormack-Jolly-Seber (CJS) model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery. PMID:26990561

  12. Artisanal fishing of spiny lobsters with gillnets — A significant anthropic impact on tropical reef ecosystem

    Directory of Open Access Journals (Sweden)

    Bruno Welter Giraldes

    2015-07-01

    Full Text Available Artisanal fishing activity with gillnets to capture the spiny lobster is a common practice along the coastal reefs of Brazil. This research aims to understand the impact that this artisanal fishing practice is having on the coastal reef systems analysing its associated fauna (bycatch and the stock of the target species Panulirus echinatus. The study compared an area which was subjected to intense gillnet fishing against one were the practice was absent. The analysis of target species using nocturnal visual census demonstrated a significantly higher number of P. echinatus at the site where gillnet use was virtually absent within three sampled habitats, fringe, cave and soft bottom. The analysis of bycatch species from artisanal fishermen’s gillnet landings recorded 4 lobster species and 10 crab species. These decapod species play an important ecological role as detritivores, herbivorous and first consumers within the reef ecosystem as well as being natural prey items for several reef fishes. The study concludes that this non-discriminatory fishing technique impacts directly on populations of P. echinatus, P. argus and P. laevicauda as well as other lobster and crab species which in-turn indirectly affects the ecological role of the tropical coastal reefs of Brazil.

  13. Characterization of X-ray Lobster Optics with a Hybrid CMOS sensor

    Science.gov (United States)

    Chattopadhyay, Tanmoy; Falcone, Abraham; Burrows, David N.; Bray, Evan; McQuaide, Maria; Kern, Matthew; Wages, Mitchell; Hull, Samuel; Inneman, Adolf; Hudec, Rene; Stehlikova, Veronika

    2018-01-01

    X-ray lobster optics provide a unique way to focus X-rays onto a small focal plane imager with wide field of view imaging. Such an instrument with angular resolution of a few arcminutes can be used to study GRB afterglows, as well as the variability and spectroscopic characteristics for various astrophysical objects. At Penn State University, we have characterized a lobster optic with an H1RG X-Ray hybrid CMOS detector (100 μm thick Silicon with 18 μm pixel size). The light-weight compact lobster optic with a 25 cm focal length provides two dimensional imaging with ~25 cm2 effective area at 2 keV. We utilize a 47 meter long X-ray beam line at Penn state University to do our experiments where we characterize the overall effective area of the instrument at 1.5 - 8 keV for both on-axis and off-axis angles. In this presentation, we will describe the characterization test stand and methods, as well as the detailed results. While this is simply a proof-of-concept experiment, such an instrument with significant collecting area can be explored for future rocket or CubeSat experiments.

  14. Changes in heart rate associated with contest outcome in agonistic encounters in lobsters.

    Science.gov (United States)

    Hernáindez-Falcón, Jesús; Basu, Alo C; Govindasamy, Siddhartan; Kravitz, Edward A

    2005-03-01

    Agonistic contests between lobsters housed together in a confined space progress through encounters of increasing intensity until a dominance relationship is established. Once this relationship is established, losing animals continually retreat from the advances of winners. These encounters are likely to consume much energy in both winning and losing animals. Therefore, one might expect involvement of many physiological systems before, during and after fights. Here, we report effects of agonistic encounters on cardiac frequency in winning and losing adult lobsters involved in dyadic interactions. The results show that: (i) small but significant increases in heart rate are observed upon chemical detection of a conspecific; (ii) during agonistic interactions, further increases in heart rate are seen; and (iii) ultimate winners exhibit greater increases in heart rate lasting longer periods of time compared to ultimate losers. Heart rate in winners remains elevated for at least 15 min after the contests have ended and animals have been returned to their home tanks. Reduced effects are seen in second and third pairings between familiar opponents. The sustained changes in heart rate that we observe in winning lobsters may result from hormonal modulation of cardiac function related to the change in social status brought about by contest outcome.

  15. American Lobsters (Homarus Americanus) not Surviving During Air Transport: Evaluation of Microbial Spoilage.

    Science.gov (United States)

    Tirloni, Erica; Stella, Simone; Gennari, Mario; Colombo, Fabio; Bernardi, Cristian

    2016-04-19

    Eighteen American lobsters ( Homarus americanus ), dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters' meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these not-surviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1%) and Photobacterium spp. (24.1%), and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3%) and lipolytic ability (75.5%), suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  16. ASPEK REPRODUKSI LOBSTER (Panulirus sp. DI PERAIRAN TELUK EKAS PULAU LOMBOK

    Directory of Open Access Journals (Sweden)

    M Junaidi

    2010-04-01

    Full Text Available Purposes of this research are to know some reproduction aspects of lobster, including sex ratio, gonad maturity level, size of first gonad mature, fekundity, and relationship of length-weight some. This research was conducted in June until November 2009 in Ekas Bay. During research 5 lobsters species were obtained, they are Panulirus homarus, P. versicolor, P. ornatus P. penicillatus and P. longiceps, with their of is well-balanced (1:1. Size of first gonad mature of P. homarus at carapace length 77,44 mm that happened during June - November with fekundity 28.000 - 96.000 granule, P. versicolor at carapace length 82,20 mm that happened during June - September with fekundity 16.500 - 71.000 granule, P. ornatus at carapace length 76,74 mm that happened during September - November with fekundity 47.000 - 87.000 granule, P. penicillatus at carapace length 69,84 mm that happened during June - November with fekundity 31.000 - 150.000 granule and P. longiceps at carapace length 68,47 mm that happened in June - August with fekundity 47.000 - 140.000 granule. Relationship of carapace length and body weight of five species, also male and female was described using linier regression equation and have negative allometrict pattern, where accretion of carapace length was quicker than body weight accretion.Keyword : reproduction aspect, lobster, Ekas Bay

  17. Shelf life extension of whole Norway lobster Nephrops norvegicus using modified atmosphere packaging.

    Science.gov (United States)

    Gornik, Sebastian G; Albalat, Amaya; Theethakaew, Chonchanok; Neil, Douglas M

    2013-11-01

    Once a nuisance by-catch, today the Norway lobster (Nephrops norvegicus) is a valuable UK fisheries commodity. Unfortunately, the species is very susceptible to quality deterioration post harvest as it quickly develops black spots and also spoils rapidly due to bacterial growth. Treatment with chemicals can stop the blackening and carefully monitored cold storage can result in a sensory shelf life of up to 6.5 days. The high susceptibility to spoilage greatly restricts the extent to which N. norvegicus can be distributed to retailers and displayed for sale. The application of modified atmosphere (MA) could be extremely beneficial, allowing the chilled product to stay fresh for a long period of time, thus ensuring higher sales. In the present study, we identified a gas mix for the MA packaging (MAP) of whole N. norvegicus lobster into 200 g retail packs. Our results show that a shelf life extension to 13 days can be achieved when retail packs are stored in MAP at 1 °C. Effectiveness of the MAP was evaluated by using a newly developed QIM for MA-packaged whole N. norvegicus and also by analyzing bacterial plate counts. Changes in the microflora and effects of different storage temperatures on the quality of the MA packs are also presented. The main specific spoilage organism (SSO) of modified atmosphere packaged Norway lobster is Photobacterium phosphoreum. © 2013.

  18. Sex Diversity Approach of Spiny Lobster (Panulirus spp) to Marine Oil Spill Pollution in Southern Waters of Java

    Science.gov (United States)

    Haryono, F. E. D.; Ambariyanto; Sulistyo, I.

    2018-02-01

    Coastal of southern Java waters is known as inhabit area of spiny lobster. Accumulation of hydrocarbon frequently occurs at the coastal waters as impact of oil pollution caused by oil leak from supplying ship of crude oil to Cilacap refinery. As shipping channel of oil, presence of oil spills is often detected at coastal areas of Cilacap. It can be indicated by range of sediment in the area which has risk levels in range of low to medium-low. It was, therefore, found that some locations suffered a greater impact on the ecological which giving high risk for marine organism life. Spiny lobster is one of many organism living at sea bed which threatened its life due to the presence of oil. Population of Spiny Lobster has to be protected because it has commercially valuable commodity for producing high nutrition. Considering the matters, it is therefore important to find a method for alleviating the problem. Investigation should be focused on biological aspect of spiny lobster in encountering extreme pollution at the coastal. For that purpose, a field research was conducted from January until July 2015. Using gillnet with 1 inch mesh size, the lobsters were randomly collected from southern Java districts waters. There were 1137 lobsters collected from six districts waters. Furthermore, the sample was morphologically identified and it was found that there were six species in the areas. In all area, P. homarus was found as dominant species, except in Gunung kidul district which was dominated by P. penicillatus. In term of sex diversity, there is statistically difference in number of female and male, each species no significant. Even though environment quality was very worse, there was found existence of ovigerous female in the research area as about 12% of the population. Those facts strongly indicated that the lobsters has a unique adaptation to survive in extremely low quality of environment due to marine oil spill.

  19. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus

    Science.gov (United States)

    Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-01-01

    Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase. PMID:27391425

  20. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    Full Text Available Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

  1. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-01-01

    Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

  2. ISS Squat and Deadlift Kinematics on the Advanced Resistive Exercise Device

    Science.gov (United States)

    Newby, N.; Caldwell, E.; Sibonga, J.; Ploutz-Snyder, L.

    2014-01-01

    Visual assessment of exercise form on the Advanced Resistive Exercise Device (ARED) on orbit is difficult due to the motion of the entire device on its Vibration Isolation System (VIS). The VIS allows for two degrees of device translational motion, and one degree of rotational motion. In order to minimize the forces that the VIS must damp in these planes of motion, the floor of the ARED moves as well during exercise to reduce changes in the center of mass of the system. To help trainers and other exercise personnel better assess squat and deadlift form a tool was developed that removes the VIS motion and creates a stick figure video of the exerciser. Another goal of the study was to determine whether any useful kinematic information could be obtained from just a single camera. Finally, the use of these data may aid in the interpretation of QCT hip structure data in response to ARED exercises performed in-flight. After obtaining informed consent, four International Space Station (ISS) crewmembers participated in this investigation. Exercise was videotaped using a single camera positioned to view the side of the crewmember during exercise on the ARED. One crewmember wore reflective tape on the toe, heel, ankle, knee, hip, and shoulder joints. This technique was not available for the other three crewmembers, so joint locations were assessed and digitized frame-by-frame by lab personnel. A custom Matlab program was used to assign two-dimensional coordinates to the joint locations throughout exercise. A second custom Matlab program was used to scale the data, calculate joint angles, estimate the foot center of pressure (COP), approximate normal and shear loads, and to create the VIS motion-corrected stick figure videos. Kinematics for the squat and deadlift vary considerably for the four crewmembers in this investigation. Some have very shallow knee and hip angles, and others have quite large ranges of motion at these joints. Joint angle analysis showed that crewmembers

  3. Informal settlements and squatting in Romania: socio-spatial patterns and typologies

    Directory of Open Access Journals (Sweden)

    Bogdan Suditu

    2013-11-01

    Full Text Available The emergence of informal settlements in Romania is the result of a mix of factors, including some social and urban planning policies from the communist and post-communist period. Squatting was initially a secondary effect of the relocation process and demolition of housing in communist urban renewal projects, and also a voluntary social and housing policy for the poorest of the same period. Extension and multiple forms of informal settlements and squatting were performed in the post-communist era due to the inappropriate or absence of the legislative tools on urban planning, properties’ restitution and management, weak control of the construction sector. The study analyzes the characteristics and spatial typologies of the informal settlements and squatters in relationship with the political and social framework of these types of housing development.

  4. The Relationship between Repeated Sprint Performance and Velocity Values during Loaded-Squat Jump Exercise

    Science.gov (United States)

    Can, Ibrahim; Sadik, Seda; Bayrakdaroglu, Serdar

    2018-01-01

    The purpose of this study is to investigate the relationship between repeated sprint performance and velocity values during loaded-squat jump exercise. In accordance with this purpose, 23 kickboxing athletes (age: 21,1 ± 2,10 years; height: 178,7 ± 5,01 cm; weight: 70,8 ± 7,85 kg) participated voluntarily in this study. Participants were performed…

  5. Optimal Testing Intervals in the Squatting Test to Determine Baroreflex Sensitivity

    OpenAIRE

    Ishitsuka, S.; Kusuyama, N.; Tanaka, M.

    2014-01-01

    The recently introduced “squatting test” (ST) utilizes a simple postural change to perturb the blood pressure and to assess baroreflex sensitivity (BRS). In our study, we estimated the reproducibility of and the optimal testing interval between the STs in healthy volunteers. Thirty-four subjects free of cardiovascular disorders and taking no medication were instructed to perform the repeated ST at 30-sec, 1-min, and 3-min intervals in duplicate in a random sequence, while the systolic blood p...

  6. Oxidative stress response in trained men following repeated squats or sprints.

    Science.gov (United States)

    Bloomer, Richard J; Falvo, Michael J; Fry, Andrew C; Schilling, Brian K; Smith, Webb A; Moore, Christopher A

    2006-08-01

    The purpose of this investigation was to measure the oxidative stress response to similarly matched work bouts of squat and sprint exercise. Twelve anaerobically trained men performed six 10-s sprints and, on a separate occasion, repeated barbell squats to approximately equal the amount of work performed during the sprints. Blood lactate, heart rate, and perceived exertion was measured before and following each exercise bout. Muscle soreness, muscle force, and creatine kinase activity was determined preexercise and through 48 h of recovery. Desmin cytoskeletal protein was determined via muscle biopsy of the vastus lateralis before and at 24 h following each exercise. Plasma protein carbonyls (PC) and malondialdehyde (MDA) were measured as biomarkers of oxidative stress. Heart rate and perceived exertion was not different between exercise sessions (P > 0.05), although lactate was higher following sprinting compared with squatting (P = 0.002). Muscle soreness was greater for squatting than sprinting (P = 0.003) and reached a peak immediately postexercise for both sessions (P = 0.0003). Muscle force was unaffected by either exercise session (P > 0.05), and creatine kinase activity was elevated to a similar extent following both sessions. Desmin-negative fibers were virtually nonexistent after either exercise bout, indicating no loss of this cytoskeletal protein. Neither PC nor MDA was affected by the exercise (P > 0.05). These results suggest that in anaerobically trained men, the oxidative stress and muscle injury response to similarly matched anaerobic exercise bouts is minimal, and not different between exercise modes. Furthermore, when compared with previous literature on untrained subjects, the response is significantly attenuated, possibly because of adaptations occurring as a result of chronic, strenuous anaerobic training.

  7. Reliability of performance velocity for jump squats under feedback and nonfeedback conditions.

    Science.gov (United States)

    Randell, Aaron D; Cronin, John B; Keogh, Justin Wl; Gill, Nicholas D; Pedersen, Murray C

    2011-12-01

    Randell, AD, Cronin, JB, Keogh, JWL, Gill, ND, and Pedersen, MC. Reliability of performance velocity for jump squats under feedback and nonfeedback conditions. J Strength Cond Res 25(12): 3514-3518, 2011-Advancements in the monitoring of kinematic and kinetic variables during resistance training have resulted in the ability to continuously monitor performance and provide feedback during training. If equipment and software can provide reliable instantaneous feedback related to the variable of interest during training, it is thought that this may result in goal-oriented movement tasks that increase the likelihood of transference to on-field performance or at the very least improve the mechanical variable of interest. The purpose of this study was to determine the reliability of performance velocity for jump squats under feedback and nonfeedback conditions over 3 consecutive training sessions. Twenty subjects were randomly allocated to a feedback or nonfeedback group, and each group performed a total of 3 "jump squat" training sessions with the velocity of each repetition measured using a linear position transducer. There was less change in mean velocities between sessions 1-2 and sessions 2-3 (0.07 and 0.02 vs. 0.13 and -0.04 m·s), less random variation (TE = 0.06 and 0.06 vs. 0.10 and 0.07 m·s) and greater consistency (intraclass correlation coefficient = 0.83 and 0.87 vs. 0.53 and 0.74) between sessions for the feedback condition as compared to the nonfeedback condition. It was concluded that there is approximately a 50-50 probability that the provision of feedback was beneficial to the performance in the squat jump over multiple sessions. It is suggested that this has the potential for increasing transference to on-field performance or at the very least improving the mechanical variable of interest.

  8. Effect of functional isometric squats on vertical jump in trained and untrained men.

    Science.gov (United States)

    Berning, Joseph M; Adams, Kent J; DeBeliso, Mark; Sevene-Adams, Patricia G; Harris, Chad; Stamford, Bryant A

    2010-09-01

    Functional isometrics (FIs) combine dynamic and isometric muscle actions and may hyperstimulate the nervous system leading to an enhanced postactivation potentiation (PAP) and improved subsequent performance. The purpose of this study was to investigate the impact of an FI squat on the countermovement vertical jump (CMVJ) in resistance trained and untrained men. Thirteen trained men (age: 22.8 +/- 3.2 years, mass: 90.0 +/- 16.3 kg, and height: 178.9 +/- 7.1 cm) and 8 untrained men (age: 28.5 +/- 5.9 years, mass: 101.5 +/- 23.0 kg, and height: 177.0 +/- 4.8 cm) participated. On separate days, subjects performed CMVJs after 2 different warm-up conditions. The warm-up conditions consisted of either 5 minutes of low-intensity cycling or 5 minutes of low-intensity cycling plus a 3-second FI squat with 150% of their 1 repetition maximum (1RM). A 2 x 3 repeated-measures analysis of variance with Bonferroni post hoc revealed that when comparing the 2 warm-up conditions in the trained subjects, a significant increase (p squat. This increase was maintained when subjects were retested at 5 minutes post (2.6 cm, + 5.5%). No significant difference in CMVJ was detected in the untrained group (p = 0.49). Results support the addition of an FI squat performed at 150% of 1RM to a low-intensity cycling warm-up to enhance PAP in resistance trained but not in untrained men as measured by CMVJ. Practically, adding functional isometrics to a warm-up scheme may significantly enhance acute, short-term power output in resistance trained men.

  9. Muscle force output and electromyographic activity in squats with various unstable surfaces.

    Science.gov (United States)

    Saeterbakken, Atle H; Fimland, Marius S

    2013-01-01

    The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.

  10. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers

    Science.gov (United States)

    Pauli, Carole A.; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R.

    2016-01-01

    Abstract Pauli, CA, Keller, M, Ammann, F, Hübner, K, Lindorfer, J, Taylor, WR, and Lorenzetti, S. Kinematics and kinetics of squats, drop jumps and imitation jumps of ski jumpers. J Strength Cond Res 30(3): 643–652, 2016—Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance. PMID:26418370

  11. COMPARATIVE BIOMECHANICAL ANALYSES OF SQUAT JUMP WITHOUT AND WITH FLEXION IN KNEE JOINT

    Directory of Open Access Journals (Sweden)

    Saša Bubanj

    2009-11-01

    Full Text Available In sports hall of Faculty of sports and physical education in Niš, student demon- strated technique of squat jump – without and with flexion in knee joint. Elements of technique were recorded by using one digital video camera in sagital plane. By using comparative kinematics analyses, there were establish differences in values of kinema- tics parametres of different body segments. Bigger elevation of body centre of gravity was ascertain at bounce without flexion in knee joint.

  12. Chain-loaded variable resistance warm-up improves free-weight maximal back squat performance.

    Science.gov (United States)

    Mina, Minas A; Blazevich, Anthony J; Giakas, Giannis; Seitz, Laurent B; Kay, Anthony D

    2016-11-01

    The acute influence of chain-loaded variable resistance exercise on subsequent free-weight one-repetition maximum (1-RM) back squat performance was examined in 16 recreationally active men. The participants performed either a free-weight resistance (FWR) or chain-loaded resistance (CLR) back squat warm-up at 85% 1-RM on two separate occasions. After a 5-min rest, the participants attempted a free-weight 1-RM back squat; if successful, subsequent 5% load additions were made until participants failed to complete the lift. During the 1-RM trials, 3D knee joint kinematics and knee extensor and flexor electromyograms (EMG) were recorded simultaneously. Significantly greater 1-RM (6.2 ± 5.0%; p  .05) was found in concentric EMG, eccentric or concentric knee angular velocity, or peak knee flexion angle. Performing a CLR warm-up enhanced subsequent free-weight 1-RM performance without changes in knee flexion angle or eccentric and concentric knee angular velocities; thus a real 1-RM increase was achieved as the mechanics of the lift were not altered. These results are indicative of a potentiating effect of CLR in a warm-up, which may benefit athletes in tasks where high-level strength is required.

  13. Effect of hang cleans or squats paired with countermovement vertical jumps on vertical displacement.

    Science.gov (United States)

    Andrews, Tedi R; Mackey, Theresa; Inkrott, Thomas A; Murray, Steven R; Clark, Ida E; Pettitt, Robert W

    2011-09-01

    Complex training is characterized by pairing resistance exercise with plyometric exercise to exploit the postactivation potentiation (PAP) phenomenon, thereby promising a better training effect. Studies on PAP as measured by human power performances are equivocal. One issue may be the lack of analyses across multiple sets of paired exercises, a common practice used by athletes. We evaluated countermovement vertical jump (CMJ) performance in 19 women, collegiate athletes in 3 of the following trials: (a) CMJs-only, where 1 set of CMJs served as a conditioning exercise, (b) heavy-load, back squats paired with CMJs, and (c) hang cleans paired with CMJs. The CMJ vertical displacement (3-attempt average), as measured with digital video, served as the dependent variable of CMJ performance. Across 3 sets of paired-exercise regimens, CMJ-only depreciated 1.6 cm and CMJ paired with back squats depreciated 2.0 cm (main effect, p squats or CMJs in and of themselves. Future research on exercise modes of complex training that best help athletes preserve and train with the highest power possible, in a given training session, is warranted.

  14. Load Variation Influences on Joint Work During Squat Exercise in Reduced Gravity

    Science.gov (United States)

    DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.; Guilliams, Mark E.; Ploutz-Snyder, Lori L.

    2011-01-01

    Resistance exercises that load the axial skeleton, such as the parallel squat, are incorporated as a critical component of a space exercise program designed to maximize the stimuli for bone remodeling and muscle loading. Astronauts on the International Space Station perform regular resistance exercise using the Advanced Resistive Exercise Device (ARED). Squat exercises on Earth entail moving a portion of the body weight plus the added bar load, whereas in microgravity the body weight is 0, so all load must be applied via the bar. Crewmembers exercising in microgravity currently add approx.70% of their body weight to the bar load as compensation for the absence of the body weight. This level of body weight replacement (BWR) was determined by crewmember feedback and personal experience without any quantitative data. The purpose of this evaluation was to utilize computational simulation to determine the appropriate level of BWR in microgravity necessary to replicate lower extremity joint work during squat exercise in normal gravity based on joint work. We hypothesized that joint work would be positively related to BWR load.

  15. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers.

    Science.gov (United States)

    Pauli, Carole A; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R; Lorenzetti, Silvio

    2016-03-01

    Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance.

  16. Force production during squats performed with a rotational resistance device under stable versus unstable conditions.

    Science.gov (United States)

    Moras, Gerard; Vázquez-Guerrero, Jairo

    2015-11-01

    [Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Forcemean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The forcepeak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in forcemean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar forcemean and forcepeak under stable and unstable conditions. The forcepeak produced is also similar in concentric and eccentric phases.

  17. Conditioning exercises in ski jumping: biomechanical relationship of squat jumps, imitation jumps, and hill jumps.

    Science.gov (United States)

    Lorenzetti, Silvio; Ammann, Fabian; Windmüller, Sabrina; Häberle, Ramona; Müller, Sören; Gross, Micah; Plüss, Michael; Plüss, Stefan; Schödler, Berni; Hübner, Klaus

    2017-11-22

    As hill jumps are very time-consuming, ski jumping athletes often perform various imitation jumps during training. The performed jumps should be similar to hill jumps, but a direct comparison of the kinetic and kinematic parameters has not been performed yet. Therefore, this study aimed to correlate 11 common parameters during hill jumps (Oberstdorf Germany), squat jumps (wearing indoor shoes), and various imitation jumps (rolling 4°, rolling flat, static; jumping equipment or indoor shoes) on a custom-built instrumented vehicle with a catch by the coach. During the performed jumps, force and video data of the take-off of 10 athletes were measured. The imitation and squat jumps were then ranked. The main difference between the hill jumps and the imitation and squat jumps is the higher maximal force loading rate during the hill jumps. Imitation jumps performed on a rolling platform, on flat ground were the most similar to hill jumps in terms of the force-time, and leg joint kinematic properties. Thus, non-hill jumps with a technical focus should be performed from a rolling platform with a flat inrun with normal indoor shoes or jumping equipment, and high normal force loading rates should be the main focus of imitation training.

  18. Two-Segment Foot Model for the Biomechanical Analysis of Squat.

    Science.gov (United States)

    Panero, E; Gastaldi, L; Rapp, W

    2017-01-01

    Squat exercise is acquiring interest in many fields, due to its benefits in improving health and its biomechanical similarities to a wide range of sport motions and the recruitment of many body segments in a single maneuver. Several researches had examined considerable biomechanical aspects of lower limbs during squat, but not without limitations. The main goal of this study focuses on the analysis of the foot contribution during a partial body weight squat, using a two-segment foot model that considers separately the forefoot and the hindfoot. The forefoot and hindfoot are articulated by the midtarsal joint. Five subjects performed a series of three trials, and results were averaged. Joint kinematics and dynamics were obtained using motion capture system, two force plates closed together, and inverse dynamics techniques. The midtarsal joint reached a dorsiflexion peak of 4°. Different strategies between subjects revealed 4° supination and 2.5° pronation of the forefoot. Vertical GRF showed 20% of body weight concentrated on the forefoot and 30% on the hindfoot. The percentages varied during motion, with a peak of 40% on the hindfoot and correspondently 10% on the forefoot, while the traditional model depicted the unique constant 50% value. Ankle peak of plantarflexion moment, power absorption, and power generation was consistent with values estimated by the one-segment model, without statistical significance.

  19. 'Gay times': identity, locality, memory, and the Brixton squats in 1970's London.

    Science.gov (United States)

    Cook, Matt

    2013-01-01

    Through a thick description of a gay squatting community in south London in the 1970s, this piece explores the ways in which local histories complicate broader accounts of gay life, politics, and culture. Such a focus alerts us to the impact of personal encounters, of local politics, and material circumstances, of coincident local communities, of jobs (or the lack of them), and of major local events (like the Brixton riots of 1981). The local focus and the oral history sources also illuminate the complex ways in which unspoken and often unconscious imperatives associated with ethnicity, class, and the familial, social, and cultural contexts of our upbringings are played out under new and changing circumstances. Taking this approach fractures homogenizing assumptions about gay identity and community--even of a self-identified gay community like this squatting collective. It can also decentre sexuality as a primary category of identity and analysis as other factors come into sharper focus and shed light on the ebb and flow of identification and on the ways in which broader histories are woven into everyday lives. The piece thus considers different scales of analysis, the limits of identification, the inclusions and exclusions enacted when communities come together and identities coalesce, the continuities and discontinuities between broader and counter cultures (especially in relation to ideas and lived experiences of home), and the way memories of the squats and of the 1970s are modulated by subsequent national and gay politics, by AIDS, and by a profound sense of loss.

  20. Effect of squatting velocity on hip muscle latency in women with patellofemoral pain syndrome.

    Science.gov (United States)

    Orozco-Chavez, Ignacio; Mendez-Rebolledo, Guillermo

    2018-03-01

    [Purpose] Neuromuscular activity has been evaluated in patellofemoral pain syndrome but movement velocity has not been considered. The aim was to determine differences in onset latency of hip and knee muscles between individuals with and without patellofemoral pain syndrome during a single leg squat, and whether any differences are dependent on movement velocity. [Subjects and Methods] Twenty-four females with patellofemoral pain syndrome and 24 healthy females participated. Onset latency of gluteus maximus, anterior and posterior gluteus medius, rectus femoris, vastus medialis, vastus lateralis and biceps femoris during a single leg squat at high and low velocity were evaluated. [Results] There was an interaction between velocity and diagnosis for posterior gluteus medius. Healthy subjects showed a later posterior gluteus medius onset latency at low velocity than high velocity; and also later than patellofemoral pain syndrome subjects at low velocity and high velocity. [Conclusion] Patellofemoral pain syndrome subjects presented an altered latency of posterior gluteus medius during a single leg squat and did not generate adaptations to velocity variation, while healthy subjects presented an earlier onset latency in response to velocity increase.

  1. Two-Segment Foot Model for the Biomechanical Analysis of Squat

    Directory of Open Access Journals (Sweden)

    E. Panero

    2017-01-01

    Full Text Available Squat exercise is acquiring interest in many fields, due to its benefits in improving health and its biomechanical similarities to a wide range of sport motions and the recruitment of many body segments in a single maneuver. Several researches had examined considerable biomechanical aspects of lower limbs during squat, but not without limitations. The main goal of this study focuses on the analysis of the foot contribution during a partial body weight squat, using a two-segment foot model that considers separately the forefoot and the hindfoot. The forefoot and hindfoot are articulated by the midtarsal joint. Five subjects performed a series of three trials, and results were averaged. Joint kinematics and dynamics were obtained using motion capture system, two force plates closed together, and inverse dynamics techniques. The midtarsal joint reached a dorsiflexion peak of 4°. Different strategies between subjects revealed 4° supination and 2.5° pronation of the forefoot. Vertical GRF showed 20% of body weight concentrated on the forefoot and 30% on the hindfoot. The percentages varied during motion, with a peak of 40% on the hindfoot and correspondently 10% on the forefoot, while the traditional model depicted the unique constant 50% value. Ankle peak of plantarflexion moment, power absorption, and power generation was consistent with values estimated by the one-segment model, without statistical significance.

  2. Joint torques and joint reaction forces during squatting with a forward or backward inclined Smith machine.

    Science.gov (United States)

    Biscarini, Andrea; Botti, Fabio M; Pettorossi, Vito E

    2013-02-01

    We developed a biomechanical model to determine the joint torques and loadings during squatting with a backward/forward-inclined Smith machine. The Smith squat allows a large variety of body positioning (trunk tilt, foot placement, combinations of joint angles) and easy control of weight distribution between forefoot and heel. These distinctive aspects of the exercise can be managed concurrently with the equipment inclination selected to unload specific joint structures while activating specific muscle groups. A backward (forward) equipment inclination decreases (increases) knee torque, and compressive tibiofemoral and patellofemoral forces, while enhances (depresses) hip and lumbosacral torques. For small knee flexion angles, the strain-force on the posterior cruciate ligament increases (decreases) with a backward (forward) equipment inclination, whereas for large knee flexion angles, this behavior is reversed. In the 0 to 60 degree range of knee flexion angles, loads on both cruciate ligaments may be simultaneously suppressed by a 30 degree backward equipment inclination and selecting, for each value of the knee angle, specific pairs of ankle and hip angles. The anterior cruciate ligament is safely maintained unloaded by squatting with backward equipment inclination and uniform/forward foot weight distribution. The conditions for the development of anterior cruciate ligament strain forces are clearly explained.

  3. Hygienic-sanitary working practices and implementation of a Hazard Analysis and Critical Control Point (HACCP plan in lobster processing industries

    Directory of Open Access Journals (Sweden)

    Cristina Farias da Fonseca

    2013-03-01

    Full Text Available This study aimed to verify the hygienic-sanitary working practices and to create and implement a Hazard Analysis Critical Control Point (HACCP in two lobster processing industries in Pernambuco State, Brazil. The industries studied process frozen whole lobsters, frozen whole cooked lobsters, and frozen lobster tails for exportation. The application of the hygienic-sanitary checklist in the industries analyzed achieved conformity rates over 96% to the aspects evaluated. The use of the Hazard Analysis Critical Control Point (HACCP plan resulted in the detection of two critical control points (CCPs including the receiving and classification steps in the processing of frozen lobster and frozen lobster tails, and an additional critical control point (CCP was detected during the cooking step of processing of the whole frozen cooked lobster. The proper implementation of the Hazard Analysis Critical Control Point (HACCP plan in the lobster processing industries studied proved to be the safest and most cost-effective method to monitor each critical control point (CCP hazards.

  4. Influence of natural inshore and offshore thermal regimes on egg development and time of hatch in American lobsters, Homarus americanus.

    Science.gov (United States)

    Goldstein, Jason S; Watson, Winsor H

    2015-02-01

    Some egg-bearing (ovigerous) American lobsters (Homarus americanus) make seasonal inshore-to-offshore movements, subjecting their eggs to different thermal regimes than those of eggs carried by lobsters that do not make these movements. Our goal was to determine if differences in thermal regimes influence the rate of egg development and the subsequent time of hatch. We subjected ovigerous lobsters to typical inshore or offshore water temperatures from September to August in the laboratory (n=8 inshore and 8 offshore, each year) and in the field (n=8 each, inshore and offshore), over 2 successive years. Although the rate of egg development did not differ significantly between treatments in the fall (P∼0.570), eggs exposed to inshore thermal regimes developed faster in the spring (Plobsters exposed to offshore thermal regimes accumulated more GDD in the winter than did eggs carried by inshore lobsters, while eggs exposed to inshore temperatures acquired them more rapidly in the spring. Results suggest that seasonal movements of ovigerous lobsters influence the time and location of hatching, and thus the transport and recruitment of larvae to coastal and offshore locations. © 2015 Marine Biological Laboratory.

  5. Near-Infrared Spectroscopy as a Novel Non-Invasive Tool to Assess Spiny Lobster Nutritional Condition

    Science.gov (United States)

    Rodemann, Thomas; Carter, Chris G.

    2016-01-01

    Rapid non-invasive monitoring of spiny lobster nutritional condition has considerable application in the established fishery, live market and prospective aquaculture. The aim of this research was to test the feasibility of near-infrared spectroscopy (NIRS) as a novel non-invasive tool to assess the nutritional condition of three lobster species. Lobster (n = 92) abdominal muscle dry matter (AMDM) and carbon content (AMC) correlated significantly with indices of nutritional condition including hepatopancreas dry matter (HPDM; rho = 0.83, 0.78), total lipid content (HPTL; rho = 0.85, 0.87) and haemolymph total protein (TP; rho = 0.89, 0.87 respectively). Abdominal muscle nitrogen content (AMN) was a poor correlate of nutritional condition. Models based on FT-NIR scanning of whole lobster tails successfully predicted AMDM, AMN and AMC (RMSECV = 1.41%, 0.35% and 0.91%; R2 = 0.75, 0.65, 0.77, respectively), and to a lower accuracy HPDM, HPTL and TP (RMSECV = 6.22%, 8.37%, 18.4 g l-1; R2 = 0.51, 0.70, 0.83, respectively). NIRS was applied successfully to assess the condition of spiny lobsters non-invasively. This pilot study paves the way for the development of crustacean condition models using portable non-invasive devices in the laboratory or in the field. PMID:27442242

  6. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

    International Nuclear Information System (INIS)

    Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

    2016-01-01

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  7. The acute effects of back squats on vertical jump performance in men and women.

    Science.gov (United States)

    Witmer, Chad A; Davis, Shala E; Moir, Gavin L

    2010-01-01

    The aim of the present study was to investigate the acute effects of performing back squats on subsequent performance during a series of vertical jumps in men and women. Twelve men and 12 women were tested on three separate occasions, the first of which was used to determine their 1-repetition maximum (1-RM) parallel back squat. Following this, subjects performed a potentiation and a control treatment in a counterbalanced order. The potentiation treatment culminated with subjects performing parallel back squats with a load equivalent to 70% 1- RM for three repetitions, following which they performed one countermovement vertical jump (CMJ) for maximal height every three minutes for a total of 10 jumps. During the control treatment, subjects performed only the CMJs. Jump height (JH) and vertical stiffness (VStiff) were calculated for each jump from the vertical force signal recorded from a force platform. There were no significant changes in JH or VStiff following the treatments and no significant differences in the responses between men and women (p > 0.05). Correlations between normalized 1-RM back squat load and the absolute change in JH and VStiff were small to moderate for both men and women, with most correlations being negative. Large variations in response to the back squats were noted in both men and women. The use of resistance exercises performed prior to a series of vertical jumps can result in improvements in performance in certain individuals, although the gains tend to be small and dependent upon the mechanical variable measured. There does not seem to be any differences between men and women in the response to dynamic potentiation protocols. Key pointsSubstantial individual responses were noted in both men and women in response to the PAP protocol used in the present study.The choice of dependent variable influences the ef-ficacy of the PAP protocol, with JH and VStiff demonstrating disparate responses in individual sub-jects.Such individual responses

  8. Comparison of muscle force production using the Smith machine and free weights for bench press and squat exercises.

    Science.gov (United States)

    Cotterman, Michael L; Darby, Lynn A; Skelly, William A

    2005-02-01

    The Smith machine (SM) (vertical motion of bar on fixed path; fixed-form exercise) and free weights (FWs) (free-form path) are commonly used strength training modes. Exercisers may need to alternate between types of equipment, depending on testing, training, rehabilitation, and/or the exercisers' goals. The purposes of this study were to compare muscle force production for SM and FWs using a 1 repetition maximum (1RM) for the parallel back squat and supine bench press exercises and to predict the 1RM for one mode from 1RM on the other mode. Men (n = 16) and women (n = 16) alternately completed 1RM testing for squat and bench press using SM and FWs. Analyses of variance (type of equipment x sex) and linear regression models were calculated. A significant difference was found between bench press and squat 1RMs for each mode of equipment for all participants. The squat 1RM was greater for the SM than the FWs; conversely, the bench 1RM was greater for FWs than the SM. When sex was considered, bench 1RM for FWs was greater than SM for men and women. The squat 1RM was greater for SM than FWs for women only. The 1RM on one mode of equipment was the best predictor of 1RM for the other mode. For both sexes, the equation SM bench 1RM (in kilograms) = -6.76 + 0.95 (FW bench 1RM) can be used. For women only, SM squat 1RM (in kilograms) = 28.3 + 0.73 (FW squat 1RM). These findings provide equations for converting between SM and FW equipment for training.

  9. Task-Dependent Intermuscular Motor Unit Synchronization between Medial and Lateral Vastii Muscles during Dynamic and Isometric Squats.

    Science.gov (United States)

    Mohr, Maurice; Nann, Marius; von Tscharner, Vinzenz; Eskofier, Bjoern; Nigg, Benno Maurus

    2015-01-01

    Motor unit activity is coordinated between many synergistic muscle pairs but the functional role of this coordination for the motor output is unclear. The purpose of this study was to investigate the short-term modality of coordinated motor unit activity-the synchronized discharge of individual motor units across muscles within time intervals of 5ms-for the Vastus Medialis (VM) and Lateralis (VL). Furthermore, we studied the task-dependency of intermuscular motor unit synchronization between VM and VL during static and dynamic squatting tasks to provide insight into its functional role. Sixteen healthy male and female participants completed four tasks: Bipedal squats, single-leg squats, an isometric squat, and single-leg balance. Monopolar surface electromyography (EMG) was used to record motor unit activity of VM and VL. For each task, intermuscular motor unit synchronization was determined using a coherence analysis between the raw EMG signals of VM and VL and compared to a reference coherence calculated from two desynchronized EMG signals. The time shift between VM and VL EMG signals was estimated according to the slope of the coherence phase angle spectrum. For all tasks, except for singe-leg balance, coherence between 15-80Hz significantly exceeded the reference. The corresponding time shift between VM and VL was estimated as 4ms. Coherence between 30-60Hz was highest for the bipedal squat, followed by the single-leg squat and the isometric squat. There is substantial short-term motor unit synchronization between VM and VL. Intermuscular motor unit synchronization is enhanced for contractions during dynamic activities, possibly to facilitate a more accurate control of the joint torque, and reduced during single-leg tasks that require balance control and thus, a more independent muscle function. It is proposed that the central nervous system scales the degree of intermuscular motor unit synchronization according to the requirements of the movement task at hand.

  10. Task-Dependent Intermuscular Motor Unit Synchronization between Medial and Lateral Vastii Muscles during Dynamic and Isometric Squats.

    Directory of Open Access Journals (Sweden)

    Maurice Mohr

    Full Text Available Motor unit activity is coordinated between many synergistic muscle pairs but the functional role of this coordination for the motor output is unclear. The purpose of this study was to investigate the short-term modality of coordinated motor unit activity-the synchronized discharge of individual motor units across muscles within time intervals of 5ms-for the Vastus Medialis (VM and Lateralis (VL. Furthermore, we studied the task-dependency of intermuscular motor unit synchronization between VM and VL during static and dynamic squatting tasks to provide insight into its functional role.Sixteen healthy male and female participants completed four tasks: Bipedal squats, single-leg squats, an isometric squat, and single-leg balance. Monopolar surface electromyography (EMG was used to record motor unit activity of VM and VL. For each task, intermuscular motor unit synchronization was determined using a coherence analysis between the raw EMG signals of VM and VL and compared to a reference coherence calculated from two desynchronized EMG signals. The time shift between VM and VL EMG signals was estimated according to the slope of the coherence phase angle spectrum.For all tasks, except for singe-leg balance, coherence between 15-80Hz significantly exceeded the reference. The corresponding time shift between VM and VL was estimated as 4ms. Coherence between 30-60Hz was highest for the bipedal squat, followed by the single-leg squat and the isometric squat.There is substantial short-term motor unit synchronization between VM and VL. Intermuscular motor unit synchronization is enhanced for contractions during dynamic activities, possibly to facilitate a more accurate control of the joint torque, and reduced during single-leg tasks that require balance control and thus, a more independent muscle function. It is proposed that the central nervous system scales the degree of intermuscular motor unit synchronization according to the requirements of the movement

  11. The vertical and the longitudinal dynamic responses of the vehicle-track system to squat-type short wavelength irregularity

    Science.gov (United States)

    Zhao, Xin; Li, Zili; Dollevoet, Rolf

    2013-12-01

    The squat, a kind of rolling contact fatigue occurring on the rail top, can excite the high-frequency vehicle-track interaction effectively due to its geometric deviations with a typical wavelength of 20-40 mm, leading to the accelerated deterioration of a track. In this work, a validated 3D transient finite element model is employed to calculate in the time domain the vertical and the longitudinal dynamic contact forces between the wheel and the rail caused by squats. The vehicle-track structure and the wheel-rail continua are both considered in order to include all the important eigencharacteristics of the system related to squats. By introducing the rotational and translational movements of the wheel, the transient wheel-rail rolling contact is solved in detail by a 3D frictional contact model integrated. The contact filter effect is considered automatically in the simulations by the finite size of the contact patch. The present work focuses on the influences of the length, width and depth of a light squat on the resulted dynamic contact forces, for which idealised defect models are used. The growth of a squat is also modelled to a certain extent by a series of defects with different dimensions. The results show that the system is mainly excited at two frequencies separately in the vertical and the longitudinal dynamics. Their superposition explains the typical appearance of mature squats. As a squat grows up, the magnitude of the excited vibration at the lower frequency increases faster than the one at the higher frequency.

  12. Validity of the Myotest® in measuring force and power production in the squat and bench press.

    Science.gov (United States)

    Comstock, Brett A; Solomon-Hill, Glenn; Flanagan, Shawn D; Earp, Jacob E; Luk, Hui-Ying; Dobbins, Kathryn A; Dunn-Lewis, Courtenay; Fragala, Maren S; Ho, Jen-Yu; Hatfield, Disa L; Vingren, Jakob L; Denegar, Craig R; Volek, Jeff S; Kupchak, Brian R; Maresh, Carl M; Kraemer, William J

    2011-08-01

    The purpose of this study was to verify the concurrent validity of a bar-mounted Myotest® instrument in measuring the force and power production in the squat and bench press exercises when compared to the gold standard of a computerized linear transducer and force platform system. Fifty-four men (bench press: 39-171 kg; squat: 75-221 kg) and 43 women (bench press: 18-80 kg; squat: 30-115 kg) (age range 18-30 years) performed a 1 repetition maximum (1RM) strength test in bench press and squat exercises. Power testing consisted of the jump squat and the bench throw at 30% of each subject's 1RM. During each measurement, both the Myotest® instrument and the Celesco linear transducer of the directly interfaced BMS system (Ballistic Measurement System [BMS] Innervations Inc, Fitness Technology force plate, Skye, South Australia, Australia) were mounted to the weight bar. A strong, positive correlation (r) between the Myotest and BMS systems and a high correlation of determination (R2) was demonstrated for bench throw force (r = 0.95, p bench throw power (r = 0.96, p < 0.05) (R2 = 0.93); squat jump force (r = 0.98, p < 0.05) (R2 = 0.97); and squat jump power (r = 0.91, p < 0.05) (R2 = 0.82). In conclusion, when fixed on the bar in the vertical axis, the Myotest is a valid field instrument for measuring force and power in commonly used exercise movements.

  13. Modelling Deep Water Habitats to Develop a Spatially Explicit, Fine Scale Understanding of the Distribution of the Western Rock Lobster, Panulirus cygnus

    Science.gov (United States)

    Hovey, Renae K.; Van Niel, Kimberly P.; Bellchambers, Lynda M.; Pember, Matthew B.

    2012-01-01

    Background The western rock lobster, Panulirus cygnus, is endemic to Western Australia and supports substantial commercial and recreational fisheries. Due to and its wide distribution and the commercial and recreational importance of the species a key component of managing western rock lobster is understanding the ecological processes and interactions that may influence lobster abundance and distribution. Using terrain analyses and distribution models of substrate and benthic biota, we assess the physical drivers that influence the distribution of lobsters at a key fishery site. Methods and Findings Using data collected from hydroacoustic and towed video surveys, 20 variables (including geophysical, substrate and biota variables) were developed to predict the distributions of substrate type (three classes of reef, rhodoliths and sand) and dominant biota (kelp, sessile invertebrates and macroalgae) within a 40 km2 area about 30 km off the west Australian coast. Lobster presence/absence data were collected within this area using georeferenced pots. These datasets were used to develop a classification tree model for predicting the distribution of the western rock lobster. Interestingly, kelp and reef were not selected as predictors. Instead, the model selected geophysical and geomorphic scalar variables, which emphasise a mix of terrain within limited distances. The model of lobster presence had an adjusted D2 of 64 and an 80% correct classification. Conclusions Species distribution models indicate that juxtaposition in fine scale terrain is most important to the western rock lobster. While key features like kelp and reef may be important to lobster distribution at a broad scale, it is the fine scale features in terrain that are likely to define its ecological niche. Determining the most appropriate landscape configuration and scale will be essential to refining niche habitats and will aid in selecting appropriate sites for protecting critical lobster habitats. PMID

  14. Ulcerative enteritis in Homarus americanus: case report and molecular characterization of intestinal aerobic bacteria of apparently healthy lobsters in live storage.

    Science.gov (United States)

    Battison, Andrea L; Després, Béatrice M; Greenwood, Spencer J

    2008-10-01

    An intermoult male American lobster, Homarus americanus, with severe intestinal lesions was encountered while collecting samples of aerobic intestinal bacteria from lobsters held in an artificial sea-water recirculation aquarium system. Grossly, the intestine was firm, thickened, and white. Histologic examination revealed a severe, diffuse, ulcerative enteritis which spared the chitin-lined colon, somewhat similar to hemocytic enteritis of shrimp. The bacterial isolates from this lobster were compared to 11 other lobsters lacking gross intestinal lesions. Two organisms, one identified as Vibrio sp. and another most similar to an uncultured proteobacterium (98.9%), clustering with Rhanella and Serratia species using 16S rDNA PCR, were isolated from the intestines of the 11, grossly normal, lobsters and the affected lobster. An additional two intestinal isolates were cultured only from the lobster with ulcerative enteritis. One, a Flavobacterium, similar to Lutibacter litoralis (99.3%), possibly represented a previously described commensal of the distal intestine. The second, a Vibrio sp., was unique to the affected animal. While the etiology of the ulcerative enteritis remains undetermined, this report represents the first description of gross and histologic findings in H. americanus of a condition which has morphologic similarities to hemocytic enteritis of shrimp. An additional observation was a decrease in the number of intestinal isolates recovered from the 11 apparently healthy lobsters compared to that previously reported for recently harvested lobster. More comprehensive studies of the relationship between the health of lobsters, gut microbial flora and the husbandry and environment maintained within holding units are warranted.

  15. Modelling deep water habitats to develop a spatially explicit, fine scale understanding of the distribution of the western rock lobster, Panulirus cygnus.

    Directory of Open Access Journals (Sweden)

    Renae K Hovey

    Full Text Available BACKGROUND: The western rock lobster, Panulirus cygnus, is endemic to Western Australia and supports substantial commercial and recreational fisheries. Due to and its wide distribution and the commercial and recreational importance of the species a key component of managing western rock lobster is understanding the ecological processes and interactions that may influence lobster abundance and distribution. Using terrain analyses and distribution models of substrate and benthic biota, we assess the physical drivers that influence the distribution of lobsters at a key fishery site. METHODS AND FINDINGS: Using data collected from hydroacoustic and towed video surveys, 20 variables (including geophysical, substrate and biota variables were developed to predict the distributions of substrate type (three classes of reef, rhodoliths and sand and dominant biota (kelp, sessile invertebrates and macroalgae within a 40 km(2 area about 30 km off the west Australian coast. Lobster presence/absence data were collected within this area using georeferenced pots. These datasets were used to develop a classification tree model for predicting the distribution of the western rock lobster. Interestingly, kelp and reef were not selected as predictors. Instead, the model selected geophysical and geomorphic scalar variables, which emphasise a mix of terrain within limited distances. The model of lobster presence had an adjusted D(2 of 64 and an 80% correct classification. CONCLUSIONS: Species distribution models indicate that juxtaposition in fine scale terrain is most important to the western rock lobster. While key features like kelp and reef may be important to lobster distribution at a broad scale, it is the fine scale features in terrain that are likely to define its ecological niche. Determining the most appropriate landscape configuration and scale will be essential to refining niche habitats and will aid in selecting appropriate sites for protecting critical

  16. Modelling deep water habitats to develop a spatially explicit, fine scale understanding of the distribution of the western rock lobster, Panulirus cygnus.

    Science.gov (United States)

    Hovey, Renae K; Van Niel, Kimberly P; Bellchambers, Lynda M; Pember, Matthew B

    2012-01-01

    The western rock lobster, Panulirus cygnus, is endemic to Western Australia and supports substantial commercial and recreational fisheries. Due to and its wide distribution and the commercial and recreational importance of the species a key component of managing western rock lobster is understanding the ecological processes and interactions that may influence lobster abundance and distribution. Using terrain analyses and distribution models of substrate and benthic biota, we assess the physical drivers that influence the distribution of lobsters at a key fishery site. Using data collected from hydroacoustic and towed video surveys, 20 variables (including geophysical, substrate and biota variables) were developed to predict the distributions of substrate type (three classes of reef, rhodoliths and sand) and dominant biota (kelp, sessile invertebrates and macroalgae) within a 40 km(2) area about 30 km off the west Australian coast. Lobster presence/absence data were collected within this area using georeferenced pots. These datasets were used to develop a classification tree model for predicting the distribution of the western rock lobster. Interestingly, kelp and reef were not selected as predictors. Instead, the model selected geophysical and geomorphic scalar variables, which emphasise a mix of terrain within limited distances. The model of lobster presence had an adjusted D(2) of 64 and an 80% correct classification. Species distribution models indicate that juxtaposition in fine scale terrain is most important to the western rock lobster. While key features like kelp and reef may be important to lobster distribution at a broad scale, it is the fine scale features in terrain that are likely to define its ecological niche. Determining the most appropriate landscape configuration and scale will be essential to refining niche habitats and will aid in selecting appropriate sites for protecting critical lobster habitats.

  17. Effects of Short-Term Jump Squat Training With and Without Chains on Strength and Power in Recreational Lifters

    Directory of Open Access Journals (Sweden)

    David C. Archer

    2016-10-01

    Full Text Available Background: The use of chains in resistance training is a way to accommodate the muscular strength curve. Short-term training and jump squats have been shown to increase back squat strength, but not in conjunction with each other or with chains. Jump squats have also been used to increase jump height and power. Objectives: The purpose of this study was to investigate the effects of short-term jump squat training with and without chains on strength and power. Methods: Thirty-one resistance-trained men volunteered to participate (age = 23.87 ± 2.2 years, height=174.87 ± 6.94 cm, mass = 82.74 ± 14.95 kg and were randomly assigned to one of three groups [control (C = 10, no chains (NC =10, or chains (CH = 11]. Participants had their jump height (VJ and back squat strength (BS tested before and after a week of training. The NC and CH groups performed three training sessions consisting of five sets of three reps of jump squats at 30% 1RM with 30s rest between sets. The CH group had 20% of their load added by chains when standing erect. The C group did not train. Results: A 3 (group: CH, NC, C x 2 (time: pre, post mixed factor ANOVA revealed a significant (p = 0.006 interaction for back squat 1RM. Both the CH (pre 142.56 ± 20.40 kg; post 145.66 ± 19.59 kg and NC (pre 150.00 ± 15.23 kg; post 154.77 ± 15.09 kg groups significantly increased while the C (pre 157.27 ± 25.35 kg; post 156.36 ± 24.85 kg group showed no difference. There were no significant interactions (p =0.32 or main effects for VJ (C = pre 50.59 ± 9.39cm; post 51.29 ± 9.68cm; NC = pre 55.29 ± 5.23cm; post 57.39 ± 5.22cm; CH = pre 46.19 ± 5.02; post 47.45 ± 4.62. Conclusions: The CH group was able to increase strength while lifting less overall weight. Coaches may use short-term training with chains to yield a similar increase in back squat strength as without chains. Keywords: variable resistance, back squats, novel, vertical jump

  18. Predicting transport survival of brindle and red rock lobsters Jasus edwardsii using haemolymph biochemistry and behaviour traits.

    Science.gov (United States)

    Simon, Cedric J; Mendo, Tania C; Green, Bridget S; Gardner, Caleb

    2016-11-01

    Mortality events during live transport of Jasus edwardsii rock lobsters are common around the time of season openings in Tasmania, with lobsters from deeper fishing areas with pale shell colouration (brindle) being perceived as more susceptible than shallow-water, red-coloured (red) lobsters. The aims of this study were to assess and predict the vulnerability of brindle and red lobsters to extended emersion exposure using pre- and post-emersion data which included 28 haemolymph biochemical parameters and 5 behaviour traits. No effect of lobster shell colour on haemolymph biochemistry, behaviour traits and their vulnerability to emersion was found. A combined survival of 97% after 40h and 57% after 64h in a first experiment, and 37% after 64h in a second experiment, was observed. Behaviour traits (i.e., righting response, tail flips and three reflex behaviours) were poor indicator of survival. Haemolymph parameters were either unaffected by emersion (e.g., Brix index, protein and lipids), affected by emersion but not associated with mortality (e.g., total haemocyte counts, calcium, magnesium, bicarbonate, glucose and uric acid), or associated with mortality following a recovery period (e.g., pH, the sodium to potassium ratio, urea, and the activity of amylase). A build-up of anaerobic end-products and nitrogenous waste most likely resulted in the mortality. A model based on lobster size and the pre-emersion concentration of haemolymph bicarbonate and haemocyanin was found to be a useful indicator of future survival. This study provides promising leads towards the development of a blood based vulnerability test for live crustacean prior transport. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. The effect of heavy- vs. light-load jump squats on the development of strength, power, and speed.

    Science.gov (United States)

    McBride, Jeffrey M; Triplett-McBride, Travis; Davie, Allan; Newton, Robert U

    2002-02-01

    The purpose of this investigation was to examine the effect of an 8-week training program with heavy- vs. light-load jump squats on various physical performance measures and electromyography (EMG). Twenty-six athletic men with varying levels of resistance training experience performed sessions of jump squats with either 30% (JS30, n = 9) or 80% (JS80, n = 10) of their one repetition maximum in the squat (1RM) or served as a control (C, n = 7). An agility test, 20-m sprint, and jump squats with 30% (30J), 55% (55J), and 80% (80J) of their 1RM were performed before and after training. Peak force, peak velocity (PV), peak power (PP), jump height, and average EMG (concentric phase) were calculated for the jumps. There were significant increases in PP and PV in the 30J, 55J, and 80J for the JS30 group (p squats results in increased movement velocity capabilities and that velocity-specific changes in muscle activity may play a key role in this adaptation.

  20. The Effects of Mental Imagery with Video-Modeling on Self-Efficacy and Maximal Front Squat Ability

    Directory of Open Access Journals (Sweden)

    Daniel J. M. Buck

    2016-04-01

    Full Text Available This study was designed to assess the effectiveness of mental imagery supplemented with video-modeling on self-efficacy and front squat strength (three repetition maximum; 3RM. Subjects (13 male, 7 female who had at least 6 months of front squat experience were assigned to either an experimental (n = 10 or a control (n = 10 group. Subjects′ 3RM and self-efficacy for the 3RM were measured at baseline. Following this, subjects in the experimental group followed a structured imagery protocol, incorporating video recordings of both their own 3RM performance and a model lifter with excellent technique, twice a day for three days. Subjects in the control group spent the same amount of time viewing a placebo video. Following three days with no physical training, measurements of front squat 3RM and self-efficacy for the 3RM were repeated. Subjects in the experimental group increased in self-efficacy following the intervention, and showed greater 3RM improvement than those in the control group. Self-efficacy was found to significantly mediate the relationship between imagery and front squat 3RM. These findings point to the importance of mental skills training for the enhancement of self-efficacy and front squat performance.

  1. The Effects of Mental Imagery with Video-Modeling on Self-Efficacy and Maximal Front Squat Ability.

    Science.gov (United States)

    Buck, Daniel J M; Hutchinson, Jasmin C; Winter, Christa R; Thompson, Brian A

    2016-04-14

    This study was designed to assess the effectiveness of mental imagery supplemented with video-modeling on self-efficacy and front squat strength (three repetition maximum; 3RM). Subjects (13 male, 7 female) who had at least 6 months of front squat experience were assigned to either an experimental ( n = 10) or a control ( n = 10) group. Subjects' 3RM and self-efficacy for the 3RM were measured at baseline. Following this, subjects in the experimental group followed a structured imagery protocol, incorporating video recordings of both their own 3RM performance and a model lifter with excellent technique, twice a day for three days. Subjects in the control group spent the same amount of time viewing a placebo video. Following three days with no physical training, measurements of front squat 3RM and self-efficacy for the 3RM were repeated. Subjects in the experimental group increased in self-efficacy following the intervention, and showed greater 3RM improvement than those in the control group. Self-efficacy was found to significantly mediate the relationship between imagery and front squat 3RM. These findings point to the importance of mental skills training for the enhancement of self-efficacy and front squat performance.

  2. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

    Science.gov (United States)

    Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

    2016-01-01

    The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. PMID:27895518

  3. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

    Directory of Open Access Journals (Sweden)

    Hopper LS

    2016-11-01

    Full Text Available Luke S Hopper,1 Nahoko Sato,2 Andries L Weidemann1 1Western Australian Academy of Performing Arts, Edith Cowan University, Mt Lawley, WA, Australia; 2Department of Physical Therapy, Nagoya Gakuin University, Seto, Japan Abstract: The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. Keywords: injury, motion capture, clinical assessment

  4. ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

    Science.gov (United States)

    Camp, Jordan

    2012-01-01

    The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

  5. Mechanosensory Neurons With Bend- and Osmo-sensitivity in Mouthpart Setae From the Spiny Lobster Panulirus argus

    DEFF Research Database (Denmark)

    Garm, Anders; Derby, Charles D; Høeg, Jens T

    2004-01-01

    The mouthparts of the spiny lobster Panulirus argus hold primarily two types of setae--simple setae and cuspidate setae. Mechanosensory neurons from these setae were examined by electrophysiological recordings. The population of simple setae contained two types of mechanosensory neurons: displace......The mouthparts of the spiny lobster Panulirus argus hold primarily two types of setae--simple setae and cuspidate setae. Mechanosensory neurons from these setae were examined by electrophysiological recordings. The population of simple setae contained two types of mechanosensory neurons...

  6. Low-coverage MiSeq next generation sequencing reveals the mitochondrial genome of the Eastern Rock Lobster, Sagmariasus verreauxi.

    Science.gov (United States)

    Doyle, Stephen R; Griffith, Ian S; Murphy, Nick P; Strugnell, Jan M

    2015-01-01

    The complete mitochondrial genome of the Eastern Rock lobster, Sagmariasus verreauxi, is reported for the first time. Using low-coverage, long read MiSeq next generation sequencing, we constructed and determined the mtDNA genome organization of the 15,470 bp sequence from two isolates from Eastern Tasmania, Australia and Northern New Zealand, and identified 46 polymorphic nucleotides between the two sequences. This genome sequence and its genetic polymorphisms will likely be useful in understanding the distribution and population connectivity of the Eastern Rock Lobster, and in the fisheries management of this commercially important species.

  7. Effects of starvation on moult cycle and hepatopancreas of Stage I lobster (Homarus americanus) larvae

    Science.gov (United States)

    Anger, K.; Storch, V.; Anger, V.; Capuzzo, J. M.

    1985-06-01

    Effects of feeding and starvation on the moult cycle and on the ultrastructure of hepatopancreas cells were studied in Stage I lobster larvae ( Homarus americanus Milne-Edwards). The relative significance of yolk and first food was quite different in larvae originating from two females. This difference was evident also in the amounts of stored lipid in the R-cells of the larval hepatopancreas. Most larvae from one hatch were, in principle, able to develop exclusively with yolk reserves (without food) to the second instar. The larvae from the second hatch showed lecithotrophic development only to the transition between late intermoult and early premoult (Stages C/D0 of Drachs's moult cycle) of the first larval instar. When initial starvation in this group lasted for 3 days or more, the point of no return (PNR) was exceeded. After the PNR, consumption of food was still possible, but development ceased in the transition C/D0 or in late premoult (D3 4). It is suggested that these stages of the moult cycle are critical points were cessation of development and increased mortality are particularly likely in early larval lobsters under nutritional stress. Examination of hepatopancreas R-cells suggested that the PNR is caused by an irreversible loss of the ability to restore lipid reserves depleted during initial starvation. Initial periods of starvation ending before the PNR prolonged mainly Stage D0 of the same instar (I). During this delay, structural changes in the R-cells caused by the preceding period of starvation were reversed: reduced lipid inclusions, swollen mitochondria, an increased number of residual bodies indicating autolysis, and a reduction of the microvillous processes. Continually starved larvae which showed lecithotrophic development throughout the first instar and were then re-fed after moulting successfully, had later a prolonged intermoult (Stage C) period in the second instar. This shows that, despite occasional lecithotrophy, food is an important

  8. Effects of Prior Experience on Shelter-Seeking Behavior of Juvenile American Lobsters.

    Science.gov (United States)

    Bayer, Skylar R; Bianchi, Katherine M; Atema, Jelle; Jacobs, Molly W

    2017-04-01

    Shelter-seeking behaviors are vital for survival for a range of juvenile benthic organisms. These behaviors may be innate or they may be affected by prior experience. After hatching, American lobsters Homarus americanus likely first come into contact with shelter during the late postlarval (decapodid) stage, known as stage IV. After the subsequent molt to the first juvenile stage (stage V), they are entirely benthic and are thought to be highly cryptic. We hypothesized that postlarval (stage IV) experience with shelter would carry over into the first juvenile stage (stage V) and reduce the time needed for juveniles to locate and enter shelters (sheltering). We found some evidence of a carryover effect, but not the one we predicted: stage V juveniles with postlarval shelter experience took significantly longer to initiate sheltering. We also hypothesized that stage V juveniles would demonstrate learning by relocating shelters more quickly with immediate prior experience. Our findings were mixed. In a maze, juveniles with immediate prior experience were faster to regain visual contact with shelter, suggesting that they had learned the location of the shelter. In contrast, there was no significant effect of immediate prior experience on time to initiate sheltering in an open arena, or in the maze after juveniles had regained visual contact. We conclude that very young (stage V) juvenile lobsters modify their shelter-seeking behavior based on prior experiences across several timescales. Ecologically relevant variation in habitat exposure among postlarval and early juvenile lobsters may influence successful recruitment in this culturally and commercially important fishery species.

  9. Lobster and Conch Fisheries of Belize: a History of Sequential Exploitation

    Directory of Open Access Journals (Sweden)

    Miriam Huitric

    2005-06-01

    Full Text Available This article presents a historical review of the lobster and conch fisheries in Belize, Central America. In terms of yield and value, these are the main wild-caught targets of the national fisheries, a small-scale commercial fishery of around 3000 fishermen. Data were collected during interviews with key informants involved with the fisheries and through literature and archive research. The goal was to study how the fishing industry has responded to environmental signals from these resources and from their ecosystems and ecosystem dynamics. National yields for both lobster and conch have been relatively stable, however, individuals' yields have been declining despite increased effort since the 1980s. This study concludes that the use of fossil fuel-based technology and organizational change, with the establishment of fishermen's cooperatives, have masked environmental signals. This masking, together with economic incentives, has led to the "pathology of resource use." As a symptom of this pathology, four forms of sequential exploitation in these fisheries were identified. A major conclusion is that social resilience may not confer ecological resilience. The development of the cooperatives was needed in order to improve equity in the industry. Before their impacts could be assessed, this organizational change, together with new technology, led to very important and rapid changes in the industry. Together with existing regulations that allow de facto open access to lobster and conch, these changes resulted in a short-term boom that has resulted in the pathology of resource use, with over-capitalization and dependence on maintained yields, regardless of environmental feedback.

  10. Kinematics and Kinetics of Squat and Deadlift Exercises with Varying Stance Widths

    Science.gov (United States)

    DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.

    2011-01-01

    The primary motion of squat and deadlift exercise involves flexion and extension of the hips, knees, and ankles, but each exercise can be performed with variations in stance width. These variations may result in differing kinematics and ground reaction forces (GRF), which may in turn affect joint loading. PURPOSE: The purpose of this investigation was to compare ankle, knee, and hip kinematics and kinetics of normal squat (NS), wide-stance squat (WS), normal deadlift (ND), and sumo deadlift (SD). We hypothesized that hip joint kinematics and work at each joint would differ between exercise variations. METHODS: Six subjects (3 m/3 f; 70.0 plus or minus 13.7 kg; 168 plus or minus 9.9 cm) performed each lift in normal gravity on the ground-based version of the Advanced Resistive Exercise Device (ARED) used on the International Space Station. The ARED provided resistance with a combination vacuum tube/flywheel mechanism designed to replicate the gravitational and inertial forces of free weights. Subjects completed each lift with their 10-repetition maximum load. Kinematic data were collected at 250 Hz by a 12-camera motion-capture system (Smart-D, BTS Bioengineering, Milan, Italy), and GRF data were collected at 1000 Hz with independent force platforms for each leg (Model 9261, Kistler Instruments AG, Winterhur, Switzerland). All data were captured simultaneously on a single workstation. The right leg of a single lift for each motion was analyzed. Modeling software (OpenSim 2.2.0, Simbios, Palo Alto, CA) determined joint kinematics and net positive and negative work at each lower extremity joint. Total work was found as the sum of work across all joints and was normalized by system mass. Effect sizes and their 95% confidence intervals were computed between conditions. RESULTS: Peak GRF were similar for each lift. There were no differences between conditions in hip flexion range of motion (ROM). For hip adduction ROM, there were no differences between the NS, WS, and SD

  11. Lumbar lordosis angle and trunk and lower-limb electromyographic activity comparison in hip neutral position and external rotation during back squats.

    Science.gov (United States)

    Oshikawa, Tomoki; Morimoto, Yasuhiro; Kaneoka, Koji

    2018-03-01

    [Purpose] To compare the lumbar lordosis angle and electromyographic activities of the trunk and lower-limb muscles in the hip neutral position and external rotation during back squats. [Subjects and Methods] Ten healthy males without severe low back pain or lower-limb injury participated in this study. The lumbar lordosis angle and electromyographic activities were measured using three-dimensional motion-capture systems and surface electrodes during four back squats: parallel back squats in the hip neutral position and external rotation and full back squats in the hip neutral position and external rotation. A paired t-test was used to compare parallel and full back squats measurements in the hip neutral position and external rotation, respectively. [Results] During parallel back squats, the average lumbar lordosis angle was significantly larger in hip external rotation than in the hip neutral position. During full back squats, lumbar erector spinae and multifidus activities were significantly lower in hip external rotation than in the hip neutral position, whereas gluteus maximus activity was significantly higher in hip external rotation than in the hip neutral position. [Conclusion] The back squat in hip external rotation induced improvement of lumbar kyphosis, an increasing of the gluteus maximus activity and a decrease of both lumbar erector spinae and multifidus activities.

  12. Is the institutionalization of urban movements inevitable? : A comparison of the opportunities for sustained squatting in New York City and Amsterdam

    NARCIS (Netherlands)

    H.D. Pruijt (Hans)

    2003-01-01

    textabstractAbstract: In this article the opportunity structures of New York City and Amsterdam for organized squatting are compared. New York City knew two distinct squatting waves, with an intermission of several years. The literature on US urban movements predicts transformation through

  13. X-ray astronomy 2000: Wide field X-ray monitoring with lobster-eye telescopes

    International Nuclear Information System (INIS)

    Inneman, A.; Hudec, R.; Pina, L.; Gorenstein, P.

    2001-01-01

    The recently available first prototypes of innovative very wide field X-ray telescopes of Lobster-Eye type confirm the feasibility to develop such flight instruments in a near future. These devices are expected to allow very wide field (more than 1000 square degrees) monitoring of the sky in X-rays (up to 10 keV and perhaps even more) with faint limits. We will discuss the recent status of the development of very wide field X-ray telescopes as well as related scientific questions including expected major contributions such as monitoring and study of X-ray afterglows of Gamma Ray Bursts

  14. LOBSTER AIR TAWAR (Parastacidae: Cherax, ASPEK BIOLOGI, HABITAT, PENYEBARAN, DAN POTENSI PENGEMBANGANNYA

    Directory of Open Access Journals (Sweden)

    Titin Kurniasih

    2008-06-01

    Full Text Available Lobster air tawar (genus Cherax berasal dari Australia, Papua New Guinea, dan Irian Jaya, dengan spesies yang berbeda-beda. Salah satu spesiesnya yang bernilai ekonomis paling tinggi adalah Cherax quadricarinatus (red claw. Habitat Cherax adalah perairan tawar yang dangkal, dengan substrat berlumpur dan banyak terdapat celah serta rongga untuk menyembunyikan diri. Kelebihan terbaiknya adalah teknik budidayanya yang relatif mudah, toleransi terhadap lingkungan cukup tinggi dengan masalah penyakit yang relatif sedikit. Hanya disayangkan hingga saat ini perkembangan kegiatan budidaya Cherax masih sangat terbatas.

  15. Effects of drilling muds on lobster behavior. Progress report, 1 January-1 October 1979

    Energy Technology Data Exchange (ETDEWEB)

    Atema, J; Ashkenas, L; Beale, E

    1979-01-01

    Drilling muds, used and discarded in great quantities during the drilling phase of exploration and production of oil wells, represent an unknown threat to the marine environment. The compositions of the muds vary greatly with drilling requirements. The toxicity of their components are largely unknown, but can range from apparently harmless to immediately lethal, as found recently in toxicity tests on a number of marine animals. This report contains eight sections, each describing an aspect of studies of lobster behavior, ecology, physiology and the effects of exposure to various levels of different drilling muds.

  16. The Kansas Squat Test Modality Comparison: Free Weights vs. Smith Machine.

    Science.gov (United States)

    Luebbers, Paul E; Fry, Andrew C

    2016-08-01

    Luebbers, PE and Fry, AC. The Kansas squat test modality comparison: free weights vs. smith machine. J Strength Cond Res 30(8): 2186-2193, 2016-Standardized methods of testing power are instrumental in planning and implementing training regimens for many athletes, and also in tracking training adaptations. Previous work has demonstrated that the Kansas squat test (KST) is a valid test for measuring indices of mean and peak power when compared with the Wingate anaerobic cycle test. Although the KST was designed for use with a Smith machine (SM), many power athletes use free weights for training. The purpose of this study was to determine the feasibility of using free weights (FW) for the KST by comparing it with the SM modality. Twenty-three track and field athletes participated (mean ± SD; weight, 69.7 ± 10.6 kg; age, 20.1 ± 1.1 years) in this study. Each completed familiarization sessions with the FW and SM modalities before data collection. A 1-repetition maximum squat was also determined for both the FW and SM. Correlation coefficients indicated significant relationships between the FW KST and SM KST on measures of peak test power (r = 0.955; p 0.05) or posttest lactate (r = 0.109; p > 0.05). Paired samples t-tests indicated that the FW KST resulted in significantly higher measures of peak power and mean power (p ≤ 0.01), although no differences were observed for relative fatigue or lactate (p > 0.05). These data indicate that the FW KST is a valid and feasible alternative to the SM KST in measuring peak and mean power.

  17. The acute effects of moderately loaded concentric-only quarter squats on vertical jump performance.

    Science.gov (United States)

    Crum, Aaron J; Kawamori, Naoki; Stone, Michael H; Haff, G Gregory

    2012-04-01

    Limited research exists examining the effect of moderately loaded conditioning activities that are employed as part of a strength-power potentiating complex (SPPC). Additionally, no studies to date have explored the effects of using a concentric-only quarter back squat protocol as part of an SPPC. Therefore, the purpose of this study was to examine the effects of a moderately loaded (50-65% of 1RM) concentric-only quarter back squat protocol on the occurrence of potentiation effects at various time points. Twenty men who could quarter back squat a minimum of 2.4 times their body mass (3.7 ± 0.7 kg·per body mass) participated in this investigation. All subjects participated in 3 conditions: control (CT), a 50% of 1RM trial (50POT), and a 65% of 1RM trial (65POT). One minute before each condition, a maximal countermovement vertical jump (CMJ) was performed. One minute later, the subject performed 1 of 3 conditions: CT condition, 50POT, or 65POT, followed by vertical jumps at 0.5, 3, 5, 10, and 15 minutes after conditioning activity. A force plate was used to quantify displacement, peak power output, peak force, and the rate of force development for each CMJ. There were no significant differences (p > 0.05) in any of the performance measures quantified during the CMJ trials when comparing the CT, 50POT, and 65POT treatment conditions. However, 48% of the subjects demonstrated some degree of potentiation at the 30 seconds after completing the 65POT trial, but this percent increase was not statistically significant. From a practical perspective, if the goal of the SPPC is to create a maximization of the potentiation effect, moderately loaded activities may not be the best alternative.

  18. Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

    Science.gov (United States)

    Wyland, Timothy P; Van Dorin, Joshua D; Reyes, G Francis Cisco

    2015-11-01

    Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

  19. Effect of squatting on sprinting performance and repeated exposure to complex training in male rugby players.

    Science.gov (United States)

    Comyns, Thomas M; Harrison, Andrew J; Hennessy, Liam K

    2010-03-01

    This study was undertaken to examine the effect of a heavy weight training exercise on sprinting performance and on the effect of repeated exposure to a complex training protocol. Eleven male rugby union players (age 20.9 +/- 3.1 years) participated in the study, which involved 5 separate testing sessions. Back squat 3 repetition maximum (3RM) was established in session 1. Sessions 2-5 were identical and involved the subjects completing a 30-m sprint before and after a 3RM back squat protocol. Four minutes of rest was given between the back squatting and the posttest 30-m sprint. All sprint trials were measured with a laser measurement device (LAVEG, Jenoptik, Jena, Germany). Sprint time and instantaneous, average, and maximum velocity were the dependent variables. The criterion for significance was set at an alpha level of p > or = 0.05. No significant improvement was evident for any of the testing sessions (p > or = 0.05). In session 1, there was a significant increase in 30-m time and a significant reduction in average 30-m velocity and maximum velocity (p benefits in sprinting may not have been realized because of intra and intersubject variations in sprint technique. The session x phase interaction revealed a significant improvement in the pre to posttest changes in instantaneous velocity at 20 m (p = 0.035) and 30 m (p = 0.036) from session 1 to session 4. This indicates that the rugby players may be able to learn to apply the potentiation effects of complex training. From a practical perspective, players may need repeated exposure to this training modality to gain benefit from it, and this should be reflected in program planning.

  20. A pilot study of the eccentric decline squat in the management of painful chronic patellar tendinopathy.

    Science.gov (United States)

    Purdam, C R; Jonsson, P; Alfredson, H; Lorentzon, R; Cook, J L; Khan, K M

    2004-08-01

    This non-randomised pilot study investigated the effect of eccentric quadriceps training on 17 patients (22 tendons) with painful chronic patellar tendinopathy. Two different eccentric exercise regimens were used by subjects with a long duration of pain with activity (more than six months). (a) Nine consecutive patients (10 tendons; eight men, one woman; mean age 22 years) performed eccentric exercise with the ankle joint in a standard (foot flat) position. (b) Eight patients (12 tendons; five men, three women; mean age 28 years) performed eccentric training standing on a 25 degrees decline board, designed to increase load on the knee extensor mechanism. The eccentric training was performed twice daily, with three sets of 15 repetitions, for 12 weeks. Primary outcome measures were (a) 100 mm visual analogue scale (VAS), where the subject recorded the amount of pain during activity, and (b) return to previous activity. Follow up was at 12 weeks, with a further limited follow up at 15 months. Good clinical results were obtained in the group who trained on the decline board, with six patients (nine tendons) returning to sport and showing a significantly reduced amount of pain over the 12 week period. Mean VAS scores fell from 74.2 to 28.5 (p = 0.004). At 15 months, four patients (five tendons) reported satisfactory results (mean VAS 26.2). In the standard squat group the results were poor, with only one athlete returning to previous activity. Mean VAS scores in this group were 79.0 at baseline and 72.3 at 12 weeks (p = 0.144). In a small group of patients with patellar tendinopathy, eccentric squats on a decline board produced encouraging results in terms of pain reduction and return to function in the short term. Eccentric exercise using standard single leg squats in a similar sized group appeared to be a less effective form of rehabilitation in reducing pain and returning subjects to previous levels of activity.

  1. The effects of squatting footwear on three-dimensional lower limb and spine kinetics.

    Science.gov (United States)

    Southwell, Daniel J; Petersen, Shane A; Beach, Tyson A C; Graham, Ryan B

    2016-12-01

    Altering footwear worn during performance of the barbell back squat has been shown to change motion patterns, but it is not completely understood how this affects biomechanical loading demands. The primary objective was to compare lower back and extremity net joint moments in 24 experienced weightlifters (12M, 12F) who performed 80% one-repetition maximum back squats under three different footwear conditions (barefoot, running shoes, weightlifting shoes). Results showed that there was a significant main effect of footwear condition on the knee extension moment (p=0.001), where the running and weightlifting shoes produced significantly larger moments than the barefoot condition. There was also a main effect of footwear condition on knee external rotation moments (p=0.002), where the weightlifting shoe produced significantly larger moments than both other conditions. At the hip, there was also a main effect of footwear condition on the extension moment (p=0.004), where the barefoot condition produced significantly larger moments than either the running shoe or weightlifting shoe condition. Lastly, there was also a significant main effect of footwear condition on both hip external (p=0.005) and internal (p=0.003) rotation moments, where the barefoot condition produced greater internal rotation and less external rotation moments than either shod condition. This study indicates that altering footwear conditions while performing the barbell back squat may redistribute the internal biomechanical loading patterns amongst the lower extremity joints and perhaps alter the musculoskeletal adaptations elicited. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Peak power, force, and velocity during jump squats in professional rugby players

    OpenAIRE

    Turner, Anthony P; Unholz, Cedric N; Potts, Neill; Coleman, Simon

    2012-01-01

    Training at the optimal load for peak power output (PPO) has been proposed as a method for enhancing power output, although others argue that the force, velocity, and PPO are of interest across the full range of loads. The aim of this study was to examine the influence of load on PPO, peak barbell velocity (BV), and peak vertical ground reaction force (VGRF) during the jump squat (JS) in a group of professional rugby players. Eleven male professional rugby players (age, 26 ± 3 years; height, ...

  3. Ground Reaction Forces Generated During Rhythmical Squats as a Dynamic Loads of the Structure

    Science.gov (United States)

    Pantak, Marek

    2017-10-01

    Dynamic forces generated by moving persons can lead to excessive vibration of the long span, slender and lightweight structure such as floors, stairs, stadium stands and footbridges. These dynamic forces are generated during walking, running, jumping and rhythmical body swaying in vertical or horizontal direction etc. In the paper the mathematical models of the Ground Reaction Forces (GRFs) generated during squats have been presented. Elaborated models was compared to the GRFs measured during laboratory tests carried out by author in wide range of frequency using force platform. Moreover, the GRFs models were evaluated during dynamic numerical analyses and dynamic field tests of the exemplary structure (steel footbridge).

  4. Variability in prevalence of Cymatocarpus solearis (Trematoda, Brachycoeliidae) in Caribbean spiny lobsters Panulirus argus (Decapoda: Palinuridae) from Bahía de la Ascensión (Mexico).

    Science.gov (United States)

    Briones-Fourzán, Patricia; Muñoz de Cote-Hernández, Rubén; Lozano-Álvarez, Enrique

    2016-06-01

    Cymatocarpus solearis, a brachycoeliid trematode that parasitizes sea turtles, uses spiny lobsters Panulirus argus as second intermediate hosts. We examined variability in infection by C. solearis in Bahía de la Ascensión, Mexico, a tropical bay with a highly productive fishery for P. argus that is based on the extensive use of casitas (large artificial shelters), which can harbor multiple juveniles and adults of this gregarious lobster species. We sampled 3956 lobsters from 466 casitas distributed over three bay zones within two closed seasons and one fishing season. In these lobsters (9.5-115.2mm carapace length, CL), the average infection prevalence was 11.7% but the probability of infection increased significantly with size. Prevalence varied with season but was consistently higher in one zone than in the other two zones. Infection with C. solearis was negatively related with clinical infection with Panulirus argus Virus 1 (PaV1). We also sampled 405 lobsters from the commercial catch obtained throughout the bay at the onset of the fishing season. In these relatively larger lobsters (70.3-168.0mm CL), average prevalence of C. solearis was higher (23.5%) but was not affected by lobster size or sex. Encysted metacercariae occurred in both abdominal and cephalothoracic muscles. The effects of C. solearis on phenotypic traits of P. argus that may potentially impact the host population dynamics and fisheries remain to be investigated. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Physiological and immunological characterization of Caribbean spiny lobsters Panulirus argus naturally infected with Panulirus argus Virus 1 (PaV1).

    Science.gov (United States)

    Pascual Jiménez, Cristina; Huchin-Mian, Juan Pablo; Simões, Nuno; Briones-Fourzán, Patricia; Lozano-Álvarez, Enrique; Sánchez Arteaga, Ariadna; Pérez-Vega, Juan Antonio; Simá-Álvarez, Raúl; Rosas Vazquez, Carlos; Rodríguez-Canul, Rossanna

    2012-08-27

    The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten of the 13 variables differed significantly between the 2 groups. Using these variables, a principal component analysis yielded 2 separate clusters: one corresponding to the healthy group and the other corresponding to the infected group. In particular, infected lobsters exhibited significantly lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxidase (PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglycerides. These features are consistent with metabolic wasting, hyperlipidemia, and presumed immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the healthy group. Infected lobsters also showed significantly higher levels of total PO activity in degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune response by the PO system during the systemic infection with PaV1.

  6. A Review of the Biomechanical Differences Between the High-Bar and Low-Bar Back-Squat.

    Science.gov (United States)

    Glassbrook, Daniel J; Helms, Eric R; Brown, Scott R; Storey, Adam G

    2017-09-01

    Glassbrook, DJ, Helms, ER, Brown, SR, and Storey, AG. A review of the biomechanical differences between the high-bar and low-bar back-squat. J Strength Cond Res 31(9): 2618-2634, 2017-The back-squat is a common exercise in strength and conditioning for a variety of sports. It is widely regarded as a fundamental movement to increase and measure lower-body and trunk function, as well as an effective injury rehabilitation exercise. There are typically 2 different bar positions used when performing the back-squat: the traditional "high-bar" back-squat (HBBS) and the "low-bar" back-squat (LBBS). Different movement strategies are used to ensure that the center of mass remains in the base of support for balance during the execution of these lifts. These movement strategies manifest as differences in (a) joint angles, (b) vertical ground reaction forces, and (c) the activity of key muscles. This review showed that the HBBS is characterized by greater knee flexion, lesser hip flexion, a more upright torso, and a deeper squat. The LBBS is characterized by greater hip flexion and, therefore, a greater forward lean. However, there are limited differences in vertical ground reaction forces between the HBBS and LBBS. The LBBS can also be characterized by a greater muscle activity of the erector spinae, adductors, and gluteal muscles, whereas the HBBS can be characterized by greater quadriceps muscle activity. Practitioners seeking to develop the posterior-chain hip musculature (i.e., gluteal, hamstring, and erector muscle groups) may seek to use the LBBS. In comparison, those seeking to replicate movements with a more upright torso and contribution from the quadriceps may rather seek to use the HBBS in training.

  7. Effects of Heavy Squat Training on a Vibration Platform on Maximal Strength and Jump Performance in Resistance-Trained Men.

    Science.gov (United States)

    Hammer, Roger L; Linton, Joshua T; Hammer, Adam M

    2018-03-06

    The purpose of this investigation was to determine maximal strength and jump performance outcomes of heavy squat training on a low-amplitude (<1.0 mm peak-to-peak) vibration platform (VP). Nineteen recreationally resistance-trained college-aged men (22.3 ± 1.66 years) completed the 6-week study. Participants were randomly assigned to one of two training groups: SQT (n = 10) performed conventional back squats on the floor; SQTV (n = 9) performed back squats on the VP. Supervised training took place over 12 sessions (2 days/week) which utilized an aggressive strength development protocol (85-95 % 1-RM), which was identically followed by both groups. After the intervention, both groups showed (via t-test) a marked increase (p < 0.001) in 1-RM squat strength (SQT = 34.5 kg vs SQTV = 36.2 kg), but there was no significant difference (via mixed ANOVA) between groups (p = 0.875). Standing broad jump performance increased by an average of 5-6 cm, but was not significantly changed in either group (SQT; p = 0.199, SQTV; p = 0.087). In conclusion, squats performed with whole body vibration (WBV) were not superior to conventional squats with respect to maximal strength and jump performance outcomes. It appears that there was no additive effect of superimposed WBV training in strength beyond that caused by strength training alone. This study can help strength conditioning professionals and athletes make an informed decision on whether to invest in a VP and use WBV as an alternative or a complementary mode of training.

  8. Activity of Lower Limb Muscles During Squat With and Without Abdominal Drawing-in and Pilates Breathing.

    Science.gov (United States)

    Barbosa, Alexandre C; Martins, Fábio M; Silva, Angélica F; Coelho, Ana C; Intelangelo, Leonardo; Vieira, Edgar R

    2017-11-01

    Barbosa, AC, Martins, FM, Silva, AF, Coelho, AC, Intelangelo, L, and Vieira, ER. Activity of lower limb muscles during squat with and without abdominal drawing-in and Pilates breathing. J Strength Cond Res 31(11): 3018-3023, 2017-The purpose of this study was to assess the effects of abdominal drawing-in and Pilates breathing on the activity of lower limb muscles during squats. Adults (n = 13, 22 ± 3 years old) with some Pilates experience performed three 60° squats under each of the following conditions in a random order: (I) normal breathing, (II) drawing-in maneuver with normal breathing, and (III) drawing-in maneuver with Pilates breathing. Peak-normalized surface electromyography of the rectus femoris, biceps femoris, gastrocnemius medialis, and tibialis anterior during the knee flexion and extension phases of squat exercises was analyzed. There were significant differences among the conditions during the knee flexion phase for the rectus femoris (p = 0.001), biceps femoris (p = 0.038), and tibialis anterior (p = 0.001), with increasing activation from conditions I to III. For the gastrocnemius medialis, there were significant differences among the conditions during the knee extension phase (p = 0.023), with increased activity under condition I. The rectus and biceps femoris activity was higher during the extension vs. flexion phase under conditions I and II. The tibialis anterior activity was higher during the flexion compared with the extension phase under all conditions, and the medial gastrocnemius activity was higher during the extension phase under condition I. Doing squats with abdominal drawing-in and Pilates breathing resulted in increased rectus, biceps femoris, and tibialis anterior activity during the flexion phase, increasing movement stability during squat exercises.

  9. Validity and Reliability of a Wearable Inertial Sensor to Measure Velocity and Power in the Back Squat and Bench Press.

    Science.gov (United States)

    Orange, Samuel T; Metcalfe, James W; Liefeith, Andreas; Marshall, Phil; Madden, Leigh A; Fewster, Connor R; Vince, Rebecca V

    2018-05-08

    Orange, ST, Metcalfe, JW, Liefeith, A, Marshall, P, Madden, LA, Fewster, CR, and Vince, RV. Validity and reliability of a wearable inertial sensor to measure velocity and power in the back squat and bench press. J Strength Cond Res XX(X): 000-000, 2018-This study examined the validity and reliability of a wearable inertial sensor to measure velocity and power in the free-weight back squat and bench press. Twenty-nine youth rugby league players (18 ± 1 years) completed 2 test-retest sessions for the back squat followed by 2 test-retest sessions for the bench press. Repetitions were performed at 20, 40, 60, 80, and 90% of 1 repetition maximum (1RM) with mean velocity, peak velocity, mean power (MP), and peak power (PP) simultaneously measured using an inertial sensor (PUSH) and a linear position transducer (GymAware PowerTool). The PUSH demonstrated good validity (Pearson's product-moment correlation coefficient [r]) and reliability (intraclass correlation coefficient [ICC]) only for measurements of MP (r = 0.91; ICC = 0.83) and PP (r = 0.90; ICC = 0.80) at 20% of 1RM in the back squat. However, it may be more appropriate for athletes to jump off the ground with this load to optimize power output. Further research should therefore evaluate the usability of inertial sensors in the jump squat exercise. In the bench press, good validity and reliability were evident only for the measurement of MP at 40% of 1RM (r = 0.89; ICC = 0.83). The PUSH was unable to provide a valid and reliable estimate of any other criterion variable in either exercise. Practitioners must be cognizant of the measurement error when using inertial sensor technology to quantify velocity and power during resistance training, particularly with loads other than 20% of 1RM in the back squat and 40% of 1RM in the bench press.

  10. Variability in clinical prevalence of PaV1 in Caribbean spiny lobsters occupying commercial casitas over a large bay in Mexico.

    Science.gov (United States)

    Candia-Zulbarán, Rebeca I; Briones-Fourzán, Patricia; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Lozano-Álvarez, Enrique

    2012-08-27

    In Bahía de la Ascensión, Mexico, the fishery for spiny lobsters Panulirus argus is based on the extensive use of casitas, large artificial shelters that can harbor the full size range of these highly gregarious lobsters. The discovery of a pathogenic virus in these lobsters (Panulirus argus virus 1, or PaV1) has raised concern about its potential effects on casita-based fisheries. Because in Bahía de la Ascensión visibly infected lobsters represent an immediate loss of revenue, we examined variability in clinical prevalence of PaV1 (percentage of lobsters visibly infected) in thousands of lobsters sampled from the commercial catch at the onset of 3 consecutive fishing years, and from 530 casitas distributed over 3 zones within the bay during 2 fishing and 2 closed seasons. In the commercial catch (lobsters 67 to 147 mm carapace length [CL]), clinical prevalence of PaV1 was low and was not affected by year or sex. In lobsters (9.2 to 115.0 mm CL) that occupied casitas, clinical prevalence of PaV1 varied with sampling season and was always higher in juveniles than in subadults or adults, but was consistently lower in one zone relative to the other 2 zones. The average clinical prevalence of PaV1 in this bay was statistically similar to the average clinical prevalence reported in Cuba, where casitas are also used, and in Florida Bay, USA, where casitas are not used. To date, PaV1 has had no discernible impact on the lobster fishery in Bahía de la Ascensión, suggesting that clinical prevalence is not influenced by the use of casitas per se.

  11. The accumulation, retention and distribution of 95mTc in crab (Cancer pagurus L.) and lobster (Homarus gammarus L.). A comparative study

    International Nuclear Information System (INIS)

    Smith, D.L.; Knowles, J.F.; Winpenny, K.

    1988-01-01

    The accumulation, retention and distribution of 95m Tc has been compared in lobsters and edible crabs kept under identical experimental conditions. The steady-state concentration factor (C ss ) for the uptake of 95m Tc from seawater was significantly greater for female crabs (C ss =17·9) than for males (C ss =14·4), whereas in lobsters there was no such sex difference and the C ss of 1161 was much greater than in crabs. The uptake of technetium from food (as indicated by whole body counts) was only moderately greater in lobsters than crabs. Retention of 95m Tc was similar for crabs and lobsters of both sexes but the clearance rate was greater after the nuclide had been taken up from seawater (t b1/2 =51 days) than from food (t b1/2 =108 days). In all crabs and most male lobsters 95m Tc was predominantly in the hepatopancreas while in a few male and all female lobsters it was mainly in muscle. Lobster ovaries consistently contained more activity than testes but this difference was not seen in crabs. In hepatopancreas cells of both species 95m Tc occurred mainly in the cytosol and some initial steps were taken to determine the relationship between technetium and cytosol proteins. The results for crab and lobster are compared with those from previous studies on these and other crustacean species. The possible basis for the much higher concentrations of technetium in lobsters than crabs is discussed and further research suggested. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Prevalence of Panulirus argus Virus 1 (PaV1) and habitation patterns of healthy and diseased Caribbean spiny lobsters in shelter-limited habitats.

    Science.gov (United States)

    Lozano-Alvarez, Enrique; Briones-Fourzán, Patricia; Ramírez-Estévez, Aurora; Placencia-Sánchez, David; Huchin-Mian, Juan Pablo; Rodríguez-Canul, Rossana

    2008-07-07

    Caribbean spiny lobsters Panulirus argus are socially gregarious, preferring shelters harboring conspecifics over empty shelters. In laboratory trials, however, healthy lobsters strongly avoided shelters harboring lobsters infected with the highly pathogenic Panulirus argus Virus 1 (PaV1). Because PaV1 is transmitted by contact, this behavior may thwart its spread in wild lobsters. In a field experiment conducted from 1998 to 2002 in a shelter-poor reef lagoon (Puerto Morelos, Mexico), densities of juvenile P. argus increased significantly on sites enhanced with artificial shelters (casitas) but not on control sites. Because PaV1 emerged in this location during 2000, we reexamined these data to assess whether casitas could potentially increase transmission of PaV1. In 2001, PaV1 prevalence was 2.5% and the cohabitation level (percentage of healthy lobsters cohabiting with diseased lobsters) was similar between natural shelters (3.5%) and casitas (2.4 %). The relative lobster densities in casita sites and control sites did not change significantly before (1998-1999) or after (2001-2002) the disease emergence. In late 2006, data from casita sites showed a significant increase in prevalence (10.9%) and cohabitation level (29.4%), but no significant changes in lobster density. In May 2006, casitas were deployed on shelter-poor sites within Chinchorro Bank, 260 km south of Puerto Morelos. In late 2006, prevalence and cohabitation level were 7.4 and 21.7%, respectively. Our results are inconclusive as to whether or not casitas increase PaV1 transmission, but suggest that across shelter-poor habitats, lobsters make a trade-off between avoiding diseased conspecifics and avoiding predation risk.

  13. The accumulation, retention and distribution of {sup 95m}Tc in crab (Cancer pagurus L.) and lobster (Homarus gammarus L.). A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D L; Knowles, J F; Winpenny, K [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk (United Kingdom)

    1988-08-01

    The accumulation, retention and distribution of {sup 95m}Tc has been compared in lobsters and edible crabs kept under identical experimental conditions. The steady-state concentration factor (C{sub ss}) for the uptake of {sup 95m}Tc from seawater was significantly greater for female crabs (C{sub ss}=17{center_dot}9) than for males (C{sub ss}=14{center_dot}4), whereas in lobsters there was no such sex difference and the C{sub ss} of 1161 was much greater than in crabs. The uptake of technetium from food (as indicated by whole body counts) was only moderately greater in lobsters than crabs. Retention of {sup 95m}Tc was similar for crabs and lobsters of both sexes but the clearance rate was greater after the nuclide had been taken up from seawater (t{sub b1/2}=51 days) than from food (t{sub b1/2}=108 days). In all crabs and most male lobsters {sup 95m}Tc was predominantly in the hepatopancreas while in a few male and all female lobsters it was mainly in muscle. Lobster ovaries consistently contained more activity than testes but this difference was not seen in crabs. In hepatopancreas cells of both species {sup 95m}Tc occurred mainly in the cytosol and some initial steps were taken to determine the relationship between technetium and cytosol proteins. The results for crab and lobster are compared with those from previous studies on these and other crustacean species. The possible basis for the much higher concentrations of technetium in lobsters than crabs is discussed and further research suggested. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Validity and inter-rater reliability of medio-lateral knee motion observed during a single-limb mini squat

    DEFF Research Database (Denmark)

    Ageberg, Eva; Bennell, Kim L; Hunt, Michael A

    2010-01-01

    Muscle function may influence the risk of knee injury and outcomes following injury. Clinical tests, such as a single-limb mini squat, resemble conditions of daily life and are easy to administer. Fewer squats per 30 seconds indicate poorer function. However, the quality of movement, such as the ......, such as the medio-lateral knee motion may also be important. The aim was to validate an observational clinical test of assessing the medio-lateral knee motion, using a three-dimensional (3-D) motion analysis system. In addition, the inter-rater reliability was evaluated....

  15. DIFFERENCES IN THE KNEE TORQUE BETWEEN HIGH- AND LOW-BAR BACK SQUAT TECHNIQUES. A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    Janez Logar

    2015-01-01

    Full Text Available Purpose: The squat is one of the most frequently used exercises in sports training and competitions. There are several squat variations: i the front squat (FS, ii the high-bar back squat (HBS and iii the low-bar back squat (LBS. As the biomechanics of the LBS technique have been studied to a lesser extent, therefore the purpose of this pilot study was to analyze the differences in knee joint net muscle torque between the HBS and LBS. Methods: One healthy male subject (180.0 cm, 76.0 kg, 26 years performed 10 steady paced squats (5 HBS and 5 LBS with additional weight (40.4 kg to a 90° knee angle. Kinematic and kinetic data were gathered using a high-speed camcorder and a force plate, respectively. The maximal and average knee joint net muscle torques (Mmax and Mavg were then calculated via 2-dimensional inverse dynamics. Results: A significantly greater Mavg was observed using the HBS technique as compared to the LBS, both during the entire range of the squat (MavgHBS = 221.6 ± 5.1 Nm, MavgLBS= 203.3 ± 10.2 Nm; p = 0.026 as well as during the eccentric (MavgHBS = 226.0 ± 5.9 Nm, MavgLBS= 202.0 ± 14.0 Nm; p = 0.043 and concentric (MavgHBS = 216.2 ± 3.6 Nm, MavgLBS= 205.0 ± 7.9 Nm; p = 0.021 phase separately. Conclusions: It can be concluded that the lower Mavg during the LBS could be due to the load transfer to the hip joint, most likely because of the greater anterior tilt of the torso, which is a direct response to a lower and more posterior bar placement on the back to finally maintain an unchanged centre of mass. Confirmation of these findings in a larger sample would imply that the LBS could be a more appropriate squat technique when knee joint relief is desired.

  16. The accumulation of sup(95m)Tc from sea water by juvenile lobsters (Homarus gammarus L.)

    International Nuclear Information System (INIS)

    Swift, D.J.

    1985-01-01

    The uptake and retention of technetium from sea water by juvenile lobsters, and the effects of moulting on these processes, has been studied using sup(95m)Tc as a tracer. Accumulation was rapid with whole body concentration factors of over 2000 being measured in some lobsters. Uptake was highest immediately before a moult; post-moult there was a fall in accumulation. No simple mathematical equation for technetium accumulation with time was found. The technetium concentration in the moulted exoskeleton increased with time of exposure of the lobsters but never exceeded 2% of the whole body value. The highest percentage of the whole body activity was found in the digestive gland; the green gland had the highest concentration factor. Technetium excretion, following 64 d of accumulation, could be expressed as an exponential rate of loss. The biological half-time was calculated as 53 d. Moulted exoskeletons from these lobsters contained approximately 0.6% of the day zero whole body activity. (author)

  17. "Intermetamorphic" developmental stages in 150 million-year-old achelatan lobsters--The case of the species tenera Oppel, 1862.

    Science.gov (United States)

    Haug, Joachim T; Haug, Carolin

    2016-03-01

    We re-investigated the fossil species tenera Oppel, 1862, an achelatan lobster (traditionally named Palinurina tenera) found in 150 million years old limestones of southern Germany. All known specimens attributed to this species show a mixture of characters, which in modern forms occur either in larvae or post-larval juveniles. Hence these specimens provide insight into a phase in ontogeny that is no longer present in the developmental sequence of any modern achelatan lobster, as the latter ones skip this phase and replace it by a drastic metamorphosis. Comparable cases have been described earlier, yet did only comprise single stages or two successive ones at most. In the here described case four developmental stages are preserved. The reconstructed ontogeny of tenera therefore represents the currently best known sequence of an early achelatan lobster that covers this specific intermediate phase. The largest known stage most likely still represents an immature of a yet undiscovered adult. These findings support the interpretation that early achelatan lobsters developed in a more gradual ontogenetic sequence than modern forms. It furthermore demonstrates that it was even more gradual than anticipated previously. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Ultrastructure and functional organization of mouthpart sensory setae of the spiny lobster Panulirus argus: new features of putative mechanoreceptors

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Høeg, Jens T

    2006-01-01

    In comparison with other decapods, the Caribbean spiny lobster Panulirus argus has little diversity in the external morphology of the setae on the mouth apparatus. In mouthpart areas that frequently touch food items only two types of setae can be distinguished: simple setae and cuspidate setae...

  19. Comparative electron microscopy and image analysis of oxy- and deoxy-hemocyanin from the spiny lobster Panulirus interruptus

    NARCIS (Netherlands)

    Haas, Felix de; Breemen, Jan F.L. van; Boekema, Egbert J.; Keegstra, Wilko; Bruggen, Ernst F.J. van

    1993-01-01

    Structural differences between oxy-hemocyanin and deoxy-hemocyanin from the spiny lobster P. interruptus were studied by electron microscopy and image analysis of negatively stained preparations. Projections of the hexameric P. interruptus hemocyanin from electron microscopy were compared with

  20. Scyllarides obtusus spec. nov., the scyllarid lobster of Saint Helena, Central South Atlantic (Crustacea: Decapoda Reptantia: Scyllaridae)

    NARCIS (Netherlands)

    Holthuis, L.B.

    1993-01-01

    A new species of slipper lobster is described from Saint Helena, where the species seems to be endemic. Known under the vernacular name Stump, the species forms the subject of a local fishery, carried out since early times. Previously the species has been identified with various Scyllarides species

  1. Polycyclic aromatic hydrocarbon contamination of American lobster, Homarus americanus, in the proximity of a coal-coking plant

    Energy Technology Data Exchange (ETDEWEB)

    Uthe, J F; Musial, C J

    1986-11-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental contaminants resulting predominantly from anthropogenic pyrolytic and combustion processes. In addition to the usual methods of aerial and aqueous transport to the coastal marine environment substantial amounts of PAH are added through the use of products such as creosote, coal tar and coal tar pitch as preservative and antifouling agents in the marine environment. Many PAH compounds are known carcinogenic agents and are rapidly taken up by fish and shellfish from water. Therefore as human foodstuffs many of these shellfish species warrant monitoring for PAH. A study of PAH in lobster tissues has been carried out using lobsters captured in Sydney harbour, Nova Scotia, Canada. Two coal-coking ovens on the shore have discharged their liquid effluents into the harbour. Lobsters from this area were sampled in 1982 and 1984. This paper presents the materials and methods used in the sampling, the results and discussion of them. The results confirmed the ability of lobsters to accumulate extremely high amounts of PAH in their tissues. 14 references.

  2. Influence of twin and multi-rig trawl systems on CPUE in the Danish Norway lobster (Nephrops norvegicus) fishery

    DEFF Research Database (Denmark)

    Feekings, Jordan P.; Berg, Casper Willestofte; Krag, Ludvig Ahm

    2016-01-01

    analyse catchrates of four target species, Norway lobster (Nephrops norvegicus), cod (Gadus morhua), plaice (Pleuronectesplatessa) and haddock (Melanogrammus aeglefinus), to try and understand how the use of multi-rig trawlshave altered catch rates within the Danish demersal trawl fishery over the last 16...

  3. American lobsters (Homarus americanus not surviving during air transport: evaluation of microbial spoilage

    Directory of Open Access Journals (Sweden)

    Erica Tirloni

    2016-05-01

    Full Text Available Eighteen American lobsters (Homarus americanus, dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters’ meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these notsurviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1% and Photobacterium spp. (24.1%, and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3% and lipolytic ability (75.5%, suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  4. Phylogenetic relationships, character evolution, and taxonomic implications within the slipper lobsters (Crustacea: Decapoda: Scyllaridae).

    Science.gov (United States)

    Yang, Chien-Hui; Bracken-Grissom, Heather; Kim, Dohyup; Crandall, Keith A; Chan, Tin-Yam

    2012-01-01

    The slipper lobsters belong to the family Scyllaridae which contains a total of 20 genera and 89 species distributed across four subfamilies (Arctidinae, Ibacinae, Scyllarinae, and Theninae). We have collected nucleotide sequence data from regions of five different genes (16S, 18S, COI, 28S, H3) to estimate phylogenetic relationships among 54 species from the Scyllaridae with a focus on the species rich subfamily Scyllarinae. We have included in our analyses at least one representative from all 20 genera in the Scyllaridae and 35 of the 52 species within the Scyllarinae. Our resulting phylogenetic estimate shows the subfamilies are monophyletic, except for Ibacinae, which has paraphyletic relationships among genera. Many of the genera within the Scyllarinae form non-monophyletic groups, while the genera from all other subfamilies form well supported clades. We discuss the implications of this history on the evolution of morphological characters and ecological transitions (nearshore vs. offshore) within the slipper lobsters. Finally, we identify, through ancestral state character reconstructions, key morphological features diagnostic of the major clades of diversity within the Scyllaridae and relate this character evolution to current taxonomy and classification. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi.

    Science.gov (United States)

    Ventura, Tomer; Fitzgibbon, Quinn P; Battaglene, Stephen C; Elizur, Abigail

    2015-08-27

    The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation.

  6. Grow-out of spiny lobster Panulirus sp. with high stocking density in controlled tanks

    Directory of Open Access Journals (Sweden)

    Rio Yusufi Subhan

    2018-05-01

    Full Text Available ABSTRACTThe aim of this research was to determine optimum stocking density for growing-out of spiny lobster Panulirus sp. in controlled tanks that conducted for 30 days. The experimental spiny lobsters have the initial average weight of 130.39 ± 0.32 g and initial average total length of 140.70 ± 0.06 mm. This study used completely randomized design with three different stocking densities (KT10: 10 ind/m3; KT18: 18 ind/m3; and KT26: 26 ind/m3 and two replications. The parameters observed in this study included water quality (temperature, pH, salinity, dissolved oxygen, and total ammonia nitrogen, physiological responses (total haemocyte count, haemolymph glucose, and frequency of molt, and production performances, such as growth, specific growth rate, feed conversion ratio, and survival rate. The results showed that the spiny lobster could be reared in high stocking density in controlled tanks. Water quality during the study in each treatment was; temperature 26.56–28.65oC, salinity 29.7–33.6 g/L, pH 7.5–8.5, dissolved oxygen 6.15–6.58 mg/L, and total ammonia nitrogen 0.11–0.34 mg/L. The best stocking densities for spiny lobster was 18 ind/m3 (KT18 with 2.5‒3.5×106cells/mL total haemocyte counts, 24.6‒28.3 mg/dL haemolymph glucose, and 38.37 ± 3.20% frequency of molt. The final average body weight and length were 145.06 ± 0.42 g and 142.77 ± 0.19 mm, respectively. The survival rate reached 86.11 ± 3.92% with a specific growth rate 0.35 ± 0.01%/day, and feed conversion ratio 7.87 ± 0.31.Keywords: high stocking density, Panulirus sp., physiological responses, productivity.  ABSTRAKTujuan dari penelitian ini adalah untuk menentukan kepadatan terbaik dalam pembesaran lobster laut Panulirus sp. yang dipelihara dalam bak terkontrol selama 30 hari. Lobster laut yang digunakan pada awal penelitian memiliki bobot 130,39 ± 0,32 g dan panjang total 140,70 ± 0,06 mm. Penelitian dilakukan menggunakan rancangan acak lengkap dengan

  7. Structural characterization of recombinant crustacyanin subunits from the lobster Homarus americanus

    International Nuclear Information System (INIS)

    Ferrari, Michele; Folli, Claudia; Pincolini, Elisa; McClintock, Timothy S.; Rössle, Manfred; Berni, Rodolfo; Cianci, Michele

    2012-01-01

    The two recombinant apo subunits H1 and H2 from H. americanus have been structurally characterized. Reconstitution studies with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits. Crustacean crustacyanin proteins are linked to the production and modification of carapace colour, with direct implications for fitness and survival. Here, the structural and functional properties of the two recombinant crustacyanin subunits H 1 and H 2 from the American lobster Homarus americanus are reported. The two subunits are structurally highly similar to the corresponding natural apo crustacyanin CRTC and CRTA subunits from the European lobster H. gammarus. Reconstitution studies of the recombinant crustacyanin proteins H 1 and H 2 with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits from H. gammarus in complex with astaxanthin. Moreover, correlations between the presence of crustacyanin genes in crustacean species and the resulting carapace colours with the spectral properties of the subunits in complex with astaxanthin confirmed this genotype–phenotype linkage

  8. Spiny lobsters detect conspecific blood-borne alarm cues exclusively through olfactory sensilla.

    Science.gov (United States)

    Shabani, Shkelzen; Kamio, Michiya; Derby, Charles D

    2008-08-01

    When attacked by predators, diverse animals actively or passively release molecules that evoke alarm and related anti-predatory behavior by nearby conspecifics. The actively released molecules are alarm pheromones, whereas the passively released molecules are alarm cues. For example, many insects have alarm-signaling systems that involve active release of alarm pheromones from specialized glands and detection of these signals using specific sensors. Many crustaceans passively release alarm cues, but the nature of the cues, sensors and responses is poorly characterized. Here we show in laboratory and field experiments that injured Caribbean spiny lobsters, Panulirus argus, passively release alarm cues via blood (hemolymph) that induce alarm responses in the form of avoidance and suppression of feeding. These cues are detected exclusively through specific olfactory chemosensors, the aesthetasc sensilla. The alarm cues for Caribbean spiny lobsters are not unique to the species but do show some phylogenetic specificity: P. argus responds primarily with alarm behavior to conspecific blood, but with mixed alarm and appetitive behaviors to blood from the congener Panulirus interruptus, or with appetitive behaviors to blood from the blue crab Callinectes sapidus. This study lays the foundation for future neuroethological studies of alarm cue systems in this and other decapod crustaceans.

  9. Aspartic cathepsin D endopeptidase contributes to extracellular digestion in clawed lobsters Homarus americanus and Homarus gammarus.

    Science.gov (United States)

    Rojo, Liliana; Muhlia-Almazan, Adriana; Saborowski, Reinhard; García-Carreño, Fernando

    2010-11-01

    Acid digestive proteinases were studied in the gastric fluids of two species of clawed lobster (Homarus americanus and Homarus gammarus). An active protein was identified in both species as aspartic proteinase by specific inhibition with pepstatin A. It was confirmed as cathepsin D by mass mapping, N-terminal, and full-length cDNA sequencing. Both lobster species transcribed two cathepsin D mRNAs: cathepsin D1 and cathepsin D2. Cathepsin D1 mRNA was detected only in the midgut gland, suggesting its function as a digestive enzyme. Cathepsin D2 mRNA was found in the midgut gland, gonads, and muscle. The deduced amino acid sequence of cathepsin D1 and cathepsin D2 possesses two catalytic DTG active-site motifs, the hallmark of aspartic proteinases. The putatively active cathepsin D1 has a molecular mass of 36.4 kDa and a calculated pI of 4.14 and possesses three potential glycosylation sites. The sequences showed highest similarities with cathepsin D from insects but also with another crustacean cathepsin D. Cathepsin D1 transcripts were quantified during a starvation period using real-time qPCR. In H. americanus, 15 days of starvation did not cause significant changes, but subsequent feeding caused a 2.5-fold increase. In H. gammarus, starvation caused a 40% reduction in cathepsin D1 mRNA, and no effect was observed with subsequent feeding.

  10. Agonistic behaviour in juvenile southern rock lobster, Jasus edwardsii (Decapoda, Palinuridae: implications for developing aquaculture

    Directory of Open Access Journals (Sweden)

    Chris Carter

    2014-11-01

    Full Text Available The Southern rock lobster, Jasus edwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasus edwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11, avoidance (6 and others (12. Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture.

  11. Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi

    Science.gov (United States)

    Ventura, Tomer; Fitzgibbon, Quinn P.; Battaglene, Stephen C.; Elizur, Abigail

    2015-01-01

    The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation. PMID:26311524

  12. Patterns of deep-sea genetic connectivity in the New Zealand region: implications for management of benthic ecosystems.

    Directory of Open Access Journals (Sweden)

    Eleanor K Bors

    Full Text Available Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ, deep-sea communities at upper bathyal depths (<2000 m are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand's EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region.

  13. Lower-limb kinematics of single-leg squat performance in young adults.

    Science.gov (United States)

    Horan, Sean A; Watson, Steven L; Carty, Christopher P; Sartori, Massimo; Weeks, Benjamin K

    2014-01-01

    To determine the kinematic parameters that characterize good and poor single-leg squat (SLS) performance. A total of 22 healthy young adults free from musculoskeletal impairment were recruited for testing. For each SLS, both two-dimensional video and three-dimensional motion analysis data were collected. Pelvis, hip, and knee angles were calculated using a reliable and validated lower-limb (LL) biomechanical model. Two-dimensional video clips of SLSs were blindly assessed in random order by eight musculoskeletal physiotherapists using a 10-point ordinal scale. To facilitate between-group comparisons, SLS performances were stratified by tertiles corresponding to poor, intermediate, and good SLS performance. Mean ratings of SLS performance assessed by physiotherapists were 8.3 (SD 0.5), 6.8 (SD 0.7), and 4.0 (SD 0.8) for good, intermediate, and poor squats, respectively. Three-dimensional analysis revealed that people whose SLS performance was assessed as poor exhibited increased hip adduction, reduced knee flexion, and increased medio-lateral displacement of the knee joint centre compared to those whose SLS performance was assessed as good (p≤0.05). Overall, poor SLS performance is characterized by inadequate knee flexion and excessive frontal plane motion of the knee and hip. Future investigations of SLS performance should consider standardizing knee flexion angle to illuminate other influential kinematic parameters.

  14. Effect of repetitive yogic squats with specific hand position (Thoppukaranam) on selective attention and psychological states.

    Science.gov (United States)

    Chandrasekeran, Angelica; Rajesh, Sasidharan K; Srinivasan, Tm

    2014-01-01

    Research on the effect of Thoppukaranam is limited despite it being practiced as a form of worship to the elephant-headed deity Lord Ganapati and punishment in schools. The purpose of this study was to examine the effect of Thoppukaranam on selective attention and psychological states in a sample of young adults. A randomized self-as-control within subjects design was employed. Thirty undergraduate students (4 females and 26 males) from a residential Yoga University in Southern India were recruited for this study (group mean age ± standard deviation, 20.17 ± 2.92). The d2 test, State Anxiety Inventory-Short Form and State Mindful Attention Awareness Scale (SMAAS) were used to measure cognitive performance and psychological states. Assessments were made in three sessions: Baseline, control (squats), and experimental (Thoppukaranam) on 3 separate days. Data were analyzed using one-way repeated measures analyses of variance between three sessions, that is, baseline, squat, and Thoppukaranam. There was a significant improvement in all measures of the d2 test of attention (TN, E, TN-E, E%, and concentration performance) and state mindfulness after Thoppukaranam. Further state anxiety reduced significantly after the experimental session. These findings indicate Thoppukaranam results in enhancement of cognitive functioning and psychological states.

  15. Relationships Between Potentiation Effects After Ballistic Half-Squats and Bilateral Symmetry.

    Science.gov (United States)

    Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

    2016-05-01

    The purposes of this study were to examine the effect of ballistic concentric-only half-squats (COHS) on subsequent squat-jump (SJ) performances at various rest intervals and to examine the relationships between changes in SJ performance and bilateral symmetry at peak performance. Thirteen resistance-trained men performed an SJ immediately and every minute up to 10 min on dual force plates after 2 ballistic COHS repetitions at 90% of their 1-repetition-maximum COHS. SJ peak force, peak power, net impulse, and rate of force development (RFD) were compared using a series of 1-way repeated-measures ANOVAs. The percent change in performance at which peak performance occurred for each variable was correlated with the symmetry index scores at the corresponding time point using Pearson correlation coefficients. Statistical differences in peak power (P = .031) existed between rest intervals; however, no statistically significant pairwise comparisons were present (P > .05). No statistical differences in peak force (P = .201), net impulse (P = .064), and RFD (P = .477) were present between rest intervals. The relationships between changes in SJ performance and bilateral symmetry after the rest interval that produced the greatest performance for peak force (r = .300, P = .319), peak power (r = -.041, P = .894), net impulse (r = -.028, P = .927), and RFD (r = -.434, P = .138) were not statistically significant. Ballistic COHS may enhance SJ performance; however, the changes in performance were not related to bilateral symmetry.

  16. SURGICAL TREATMENT FOR FEMOROACETABULAR IMPINGEMENT IN A GROUP THAT PERFORMS SQUATS.

    Science.gov (United States)

    Polesello, Giancarlo Cavalli; Cinagawa, Eduardo Hitoshi Tsuge; Cruz, Paulo Daniel Sousa Santa; de Queiroz, Marcelo Cavalheiro; Borges, Cristian Jandrey; Junior, Walter Ricioli; Daniachi, Daniel; Guimarães, Rodrigo Pereira; Honda, Emerson Kiyoshi; Ono, Nelson Keiske

    2012-01-01

    Describe the results from arthroscopic surgical treatment on a group of patients who developed symptoms after repetitive physical activity of moving their hips in a position of hyperflexion, as in leg presses and squats. The study group comprised 47 individuals (48 hips) who developed the onset of painful symptoms associated with hip hyperflexion exercises (leg presses or squats) and underwent arthroscopic treatment. The patients were evaluated radiographically and clinically according to the "Harris Hip Score", as modified by Byrd (MHHS), pre and postoperatively, and were asked about their return to sports activities and the surgical findings. The mean preoperative and postoperative MHHS, respectively, were 60 points (SD 11.0, range 38.5 to 92.4) and 95.9 points (SD 7.7, range 63.8 to 100), with an increase of 35.9 points (P < 0.001). Regarding physical activity, 30 individuals (71.5%) resumed sports activities after surgery, and 25 of them (83.4%) at the previous level. Six patients (12.8%) did not resume activities because of persistent pain. During arthroscopy, 48 hips (100%) presented lesions of the acetabular labrum, and 41 hips (85.4%) had acetabular chondral lesions. The patients with painful symptoms after hip hyperflexion exercises associated with femoroacetabular impingement presented improvements after arthroscopic treatment.

  17. Muscle damage and repeated bout effect induced by enhanced eccentric squats.

    Science.gov (United States)

    Coratella, Giuseppe; Chemello, Alessandro; Schena, Federico

    2016-12-01

    Muscle damage and repeated bout effect have been studied after pure eccentric-only exercise. The aim of this study was to evaluate muscle damage and repeated bout effect induced by enhanced eccentric squat exercise using flywheel device. Thirteen healthy males volunteered for this study. Creatine kinase blood activity (CK), quadriceps isometric peak torque and muscle soreness were used as markers of muscle damage. The dependent parameters were measured at baseline, immediately after and each day up to 96 hours after the exercise session. The intervention consisted of 100 repetitions of enhanced eccentric squat exercise using flywheel device. The same protocol was repeated after 4 weeks. After the first bout, CK and muscle soreness were significantly greater (P0.05), while isometric peak torque and muscle soreness returned to values similar to baseline after respectively 48 and 72 hours. All muscle damage markers were significantly lower after second compared to first bout. The enhanced eccentric exercise induced symptoms of muscle damage up to 96 hours. However, it provided muscle protection after the second bout, performed four weeks later. Although it was not eccentric-only exercise, the enhancement of eccentric phase provided muscle protection.

  18. Jump Squat is More Related to Sprinting and Jumping Abilities than Olympic Push Press.

    Science.gov (United States)

    Loturco, I; Kobal, R; Maldonado, T; Piazzi, A F; Bottino, A; Kitamura, K; Abad, C C C; Pereira, L A; Nakamura, F Y

    2017-07-01

    The aim of this study was to test the relationships between jump squat (JS) and Olympic push press (OPP) power outputs and performance in sprint, squat jump (SJ), countermovement jump (CMJ) and change of direction (COD) speed tests in elite soccer players. 27 athletes performed a maximum power load test to determine their bar mean propulsive power (MPP) and bar mean propulsive velocity (MPV) in the JS and OPP exercises. Magnitude-based inference was used to compare the exercises. The MPV was almost certainly higher in the OPP than in the JS. The MPP relative to body mass (MPP REL) was possibly higher in the OPP. Only the JS MPP REL presented very large correlations with linear speed ( r> 0.7, for speed in 5, 10, 20 and 30 m) and vertical jumping abilities ( r> 0.8, for SJ and CMJ), and moderate correlation with COD speed ( r= 0.45). Although significant (except for COD), the associations between OPP outcomes and field-based measurements (speed, SJ and CMJ) were all moderate, ranging from 0.40 to 0.48. In a group composed of elite soccer players, the JS exercise is more associated with jumping and sprinting abilities than the OPP. Longitudinal studies are needed to confirm if these strong relationships imply superior training effects in favor of the JS exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Water-filled training tubes increase core muscle activation and somatosensory control of balance during squat.

    Science.gov (United States)

    Ditroilo, Massimiliano; O'Sullivan, Rory; Harnan, Brian; Crossey, Aislinn; Gillmor, Beth; Dardis, William; Grainger, Adam

    2018-09-01

    This study examined trunk muscle activation, balance and proprioception while squatting with a water-filled training tube (WT) and a traditional barbell (BB), with either closed (CE) or open eyes (OE). Eighteen male elite Gaelic footballers performed an isometric squat under the following conditions: BB-OE, BB-CE, WT-OE and WT-CE. The activity of rectus abdominis (RA), external oblique (EO) and multifidus (MF) was measured using electromyography, along with sway of the centre of pressure (CoP) using a force platform. Only the EO and the MF muscles exhibited an increased activity with WT (p velocity and range of the CoP increased significantly with WT (p velocity of the CoP was marginally reduced (d = 0.29). WT elicited a greater level core muscle activation and created a greater challenge to postural stability when compared to a BB. It appears that WT does not benefit from vision but emphasises the somatosensory control of balance. The use of WT may be beneficial in those sports requiring development of somatosensory/proprioceptive contribution to balance control.

  20. Electromyography of the thigh muscles during lifting tasks in kneeling and squatting postures

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, S.; Pollard, J.; Porter, W.L. [NIOSH, Pittsburgh, PA (United States). Pittsburgh Research Laboratory

    2011-07-01

    Underground coal miners who work in low-seam mines frequently handle materials in kneeling or squatting postures. To assess quadriceps and hamstring muscle demands in these postures, nine participants performed lateral load transfers in kneeling and squatting postures, during which electromyographic (EMG) data were collected. EMG activity was obtained at five points throughout the transfer for three quadriceps muscles and two hamstring muscles from each thigh. ANOVA results indicated that EMG data for nine of 10 thigh muscles were affected by an interaction between posture and angular position of the load lifted (p <0.001). Muscles of the right thigh were most active during the lifting portion of the task (lifting a block from the participant's right) and activity decreased as the block was transferred to the left. Left thigh muscles showed the opposite pattern. EMG activity for the majority of thigh muscles was affected by the size of the base of support provided by different postures, with lower EMG activity observed with a larger base of support and increased activity in postures where base of support was reduced (p<0.05). Thigh EMG activity was lowest in postures with fully flexed knees, which may explain worker preference for this posture. However, such postures are also associated with increased risk of meniscal damage.

  1. Effect of squat depth on performance and biomechanical parameters of countermovement vertical jump

    Directory of Open Access Journals (Sweden)

    Rodrigo Ghedini Gheller

    2014-10-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2014v16n6p658   The aim of this study was to analyze the effect of different squat depths in the performance and biomechanical parameters at counter movement jump (CMJ. Twenty-two male volleyball or basketball players volunteered to participate in this study and all were currently competing at the college level. The CMJ was performed in three different conditions: 1 with relative knee flexion at the end of counter movement phase smaller than 90° (90°, and; 3 preferred position (PREF. During the CMJ, kinematic, kinetic, and electromyography parameters were assessed. ANOVA for repeated measures with post-hoc Bonferroni´s test was used for variables comparison, with a significance level set at p≤0.05. The higher performance was on PREF and 90°. Average and peak power, as well as absolute and normalized peak forces, were higher in >90° CMJ. The peak velocity of CG and angular velocities of hip and knee were higher in the 90°. Recuts femoris and biceps femoris did not show difference in any jump phases. In conclusion, the knee flexion interferes the performance and the biomechanical variables at the CMJ. The highest jumps were got at a deeper squat, so this technique could be used for athletes in order to optimize the vertical jump performance in the training and competitions.

  2. Applying Fishers' ecological knowledge to construct past and future lobster stocks in the Juan Fernandez Archipelago, Chile.

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    Tyler D Eddy

    Full Text Available Over-exploited fisheries are a common feature of the modern world and a range of solutions including area closures (marine reserves; MRs, effort reduction, gear changes, ecosystem-based management, incentives and co-management have been suggested as techniques to rebuild over-fished populations. Historic accounts of lobster (Jasus frontalis on the Chilean Juan Fernández Archipelago indicate a high abundance at all depths (intertidal to approximately 165 m, but presently lobsters are found almost exclusively in deeper regions of their natural distribution. Fishers' ecological knowledge (FEK tells a story of serial depletion in lobster abundance at fishing grounds located closest to the fishing port with an associated decline in catch per unit effort (CPUE throughout recent history. We have re-constructed baselines of lobster biomass throughout human history on the archipelago using historic data, the fishery catch record and FEK to permit examination of the potential effects of MRs, effort reduction and co-management (stewardship of catch to restore stocks. We employed a bioeconomic model using FEK, fishery catch and effort data, underwater survey information, predicted population growth and response to MR protection (no-take to explore different management strategies and their trade-offs to restore stocks and improve catches. Our findings indicate that increased stewardship of catch coupled with 30% area closure (MR provides the best option to reconstruct historic baselines. Based on model predictions, continued exploitation under the current management scheme is highly influenced by annual fluctuations and unsustainable. We propose a community-based co-management program to implement a MR in order to rebuild the lobster population while also providing conservation protection for marine species endemic to the Archipelago.

  3. Determining the diet of larvae of western rock lobster (Panulirus cygnus using high-throughput DNA sequencing techniques.

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    Richard O'Rorke

    Full Text Available The Western Australian rock lobster fishery has been both a highly productive and sustainable fishery. However, a recent dramatic and unexplained decline in post-larval recruitment threatens this sustainability. Our lack of knowledge of key processes in lobster larval ecology, such as their position in the food web, limits our ability to determine what underpins this decline. The present study uses a high-throughput amplicon sequencing approach on DNA obtained from the hepatopancreas of larvae to discover significant prey items. Two short regions of the 18S rRNA gene were amplified under the presence of lobster specific PNA to prevent lobster amplification and to improve prey amplification. In the resulting sequences either little prey was recovered, indicating that the larval gut was empty, or there was a high number of reads originating from multiple zooplankton taxa. The most abundant reads included colonial Radiolaria, Thaliacea, Actinopterygii, Hydrozoa and Sagittoidea, which supports the hypothesis that the larvae feed on multiple groups of mostly transparent gelatinous zooplankton. This hypothesis has prevailed as it has been tentatively inferred from the physiology of larvae, captive feeding trials and co-occurrence in situ. However, these prey have not been observed in the larval gut as traditional microscopic techniques cannot discern between transparent and gelatinous prey items in the gut. High-throughput amplicon sequencing of gut DNA has enabled us to classify these otherwise undetectable prey. The dominance of the colonial radiolarians among the gut contents is intriguing in that this group has been historically difficult to quantify in the water column, which may explain why they have not been connected to larval diet previously. Our results indicate that a PCR based technique is a very successful approach to identify the most abundant taxa in the natural diet of lobster larvae.

  4. MOLECULAR DETECTION AND CLONING FOR RICKETTSIA-LIKE BACTERIA OF MILKY HAEMOLYMPH DISEASE OF SPINY LOBSTER Panulirus spp.

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    Isti Koesharyani

    2017-01-01

    Full Text Available Spiny lobster (Panulirus homarus and Panulirus ornatus are important commodities for Indonesia. The aquaculture of lobster is susceptible for several diseases like parasite, fungi, bacteria, and virus. Among those diseases, milky haemolymph disease (MHD is often seen as a symptom to mass mortality occurred at lobster farms in Gerupuk Bay of Lombok. The purpose of this study was to determine the lobster diseases on cage culture in Gerupuk Bay of Lombok, West Nusa Tenggara. The study was undertaken from January to March 2015. Diseases status was determined by application of molecular plat-form, polymerase chain reaction (PCR with designation of specific primer for MHD (254F/R, 254F: 5’-CGA-GGA-CCA-GAG-ATG-GAC-CTT-3’ and 254R: 5’-GCT-CAT-TGT-CAC-CGC-CAT-TGT-3’ with PCR size product of 254 bp. and for cloned the pathogen was used TA-cloning Invitrogen for the DNA plasmid as positive control for other analysis. Several tissue samples i.e hepatopancreas, haemolymph, part of muscle hepatopancreas P. homarus and P. ornatus were taken from cage culture farms at Gerupuk Bay then preserved on 90% ethanol for further analysis by PCR and then the amplificated DNA were cloned into pCR®2.1 plasmid and transformed into competent E. coli. The result showed that almost all lobster samples from Gerupuk Bay were positive infected by MHD, as the results of PCR amplification whereas the band appeared at 254bp. Also MHD plasmid has been successfully cloned and will be used for further examination. Histopathologically in hepatopancreas infection have seen necrosis that contain numerous of rickettsia-like bacteria.

  5. Ground reaction force comparison of bilateral symmetry with pneumatic resistance squat device and free weights - biomed 2009.

    Science.gov (United States)

    Paulus, David C; Schilling, Brian K

    2009-01-01

    The unloading of spaceflight leads to bone and muscle atrophy, and a pneumatic resistance squat exercise countermeasure has the potential to provide optimized controllable resistance in a lightweight and compact configuration. However each end of the barbell in the proposed device is connected to a separate resistance cylinder which could lead to bilaterally asymmetric loading. Therefore, the purpose of the study is to compare the unilateral ground reaction forces (GRF) of the new squat device compared to free weights. Four previously trained men (mean +/- SD; age = 20+/-2 years, body mass = 99+/-18 kg) performed three sets of three repetitions of maximal exertion squat exercises with pneumatically controlled constant resistance and free weights each with a resistance level set to half of the body weight of each subject. Unilateral GRF data for each lifting modality at the negative to positive transition of the squat exercise was measured with a force plate under each foot. The pneumatic resistance GRF (N; mean +/- SD) was 749+/-114 on the left leg and 786+/-123 on the right leg and the free weight GRF was 786+/-114 left and 861+/-111 right resulting in a 5% difference between left and right GRF with pneumatics and 9% difference with free weights. The correlation coefficient between left and right GRF was 0.92 with pneumatics and 0.80 with free weights. Because the pneumatic device elicited more bilaterally symmetric GRF than traditional free weights, the separate resistance cylinders are an acceptable design configuration.

  6. Comparison of Kinematics and Muscle Activation in Free-Weight Back Squat With and Without Elastic Bands.

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    Saeterbakken, Atle H; Andersen, Vidar; van den Tillaar, Roland

    2016-04-01

    The purpose of the study was to compare kinematic muscle activation when performing 6 repetition maximum (6RM) squats using constant (free weights) or variable resistance (free weights + elastic bands). Twenty recreationally trained women were recruited with 4.6 ± 2.1 years of resistance training experience and a relative strength (6RM/body mass) of 1.1. After a familiarization session identifying the 6RM loads, the participants performed 6RM squats using constant and variable resistance in a randomized order. The total resistance in the variable resistance group was similar to the constant resistance in the presticking region (98%), but greater in the sticking region (105%) and the poststicking region (113%). In addition, the presticking barbell velocity was 21.0% greater using variable than constant resistance, but 22.8% lower in the poststicking region. No significant differences in muscle electromyographic activity, time occurrence, and vertical displacement between the squat modalities were observed, except for higher barbell displacement poststicking using variable resistance. It was concluded that, due to differences in total resistance in the different regions performing variable compared with constant resistance, greater barbell velocity was observed in the presticking region and lower resistance was observed in the poststicking region. However, the extra resistance in the sticking and poststicking regions during the variable resistance modality did not cause increased muscle activity. When performing squats with heavy resistance, the authors recommend using variable resistance, but we suggest increasing the percentage resistance from the elastic bands or using chains.

  7. Effects of squat exercise and branched-chain amino acid supplementation on plasma free amino acid concentrations in young women.

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    Shimomura, Yoshiharu; Kobayashi, Hisamine; Mawatari, Kazunori; Akita, Keiichi; Inaguma, Asami; Watanabe, Satoko; Bajotto, Gustavo; Sato, Juichi

    2009-06-01

    The present study was conducted to examine alterations in plasma free amino acid concentrations induced by squat exercise and branched-chain amino acid (BCAA) supplementation in young, untrained female subjects. In the morning on the exercise session day, participants ingested drinks containing either BCAA (isoleucine:leucine:valine=1:2.3:1.2) or dextrin (placebo) at 0.1 g/kg body weight 15 min before a squat exercise session, which consisted of 7 sets of 20 squats, with 3 min intervals between sets. In the placebo trial, plasma BCAA concentrations were decreased subsequent to exercise, whereas they were significantly increased in the BCAA trial until 2 h after exercise. Marked changes in other free amino acids in response to squat exercise and BCAA supplementation were observed. In particular, plasma concentrations of methionine and aromatic amino acids were temporarily decreased in the BCAA trial, being significantly lower than those in the placebo trial. These results suggest that BCAA intake before exercise affects methionine and aromatic amino acid metabolism.

  8. Effects of squats accompanied by hip joint adduction on the selective activity of the vastus medialis oblique.

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    Hyong, In Hyouk

    2015-06-01

    [Purpose] This study evaluated the effective selective activation method of the vastus medialis oblique for knee joint stabilization in patients with patellofemoral pain syndrome. [Subjects and Methods] Fifteen healthy college students (9 males, 6 females); mean age, height, and weight: 22.2 years, 167.8 cm, and 61.4 kg, respectively) participated. The knee angle was held at 60°. Muscle activities were measured once each during an ordinary squat and a squat accompanied by hip joint adduction. The muscle activities of the vastus medialis oblique and vastus lateralis were measured by electromyography for five seconds while maintaining 60° knee flexion. Electromyography signals were obtained at a sampling rate of 1,000 Hz and band pass filtering at 20-50 Hz. The obtained raw root mean square was divided by the maximal voluntary isometric contraction and expressed as a percentage. The selective activity of the vastus medialis oblique was assessed according to the muscle activity ratio of the vastus medialis oblique to the vastus lateralis. [Results] The activity ratio of the vastus medialis oblique was higher during a squat with hip joint adduction than without. [Conclusion] A squat accompanied by hip joint adduction is effective for the selective activation of the vastus medialis oblique.

  9. Influence of Different Hip Joint Centre Locations on Hip and Knee Joint Kinetics and Kinematics During the Squat

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    Sinclair Jonathan

    2014-12-01

    Full Text Available Identification of the hip joint centre (HJC is important in the biomechanical examination of human movement. However, there is yet to be any published information regarding the influence of different HJC locations on hip and knee joint kinetics during functional tasks. This study aimed to examine the influence of four different HJC techniques on 3- D hip and knee joint kinetics/kinematics during the squat. Hip and knee joint kinetics/kinematics of the squat were obtained from fifteen male participants using an eight camera motion capture system. The 3-D kinetics/kinematics of the squat were quantified using four hip joint centre estimation techniques. Repeated measures ANOVAs were used to compare the discrete parameters as a function of each HJC location. The results show that significant differences in joint angles and moment parameters were evident at both the hip and knee joint in the coronal and transverse planes. These observations indicate that when calculating non-sagittal joint kinetics/kinematics during the squat, researchers should carefully consider their HJC method as it may significantly affect the interpretation of their data.

  10. Comparison of the Velocity and Power Parameters during Loaded-Squat Jump Exercise of National Athletes in Different Branches*

    Science.gov (United States)

    Can, Ibrahim; Cihan, Hamit; Ari, Erdal; Bayrakdaroglu, Serdar

    2018-01-01

    The aim of this investigation is to compare velocity and power variables during loaded-squat jump (SJ[subscript Loaded]) exercise of national athletes dealing with different sports branches and to identify whether velocity and power parameters become different or not according to branches. In accordance with this purpose, a total of 36 national…

  11. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

    Science.gov (United States)

    Vázquez-Guerrero, Jairo; Moras, Gerard; Baeza, Jennifer; Rodríguez-Jiménez, Sergio

    2016-01-01

    The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

  12. Tainting and depuration of taint by lobsters (Homarus americanus) exposed to water contaminated with a No.2 Fuel Oil: Relationship with aromatic hydrocarbon content in tissue

    International Nuclear Information System (INIS)

    Williams, U.P.; Kiceniuk, J.W.; Fancey, L.L.; Botta, J.R.

    1989-01-01

    Lobsters (Homarus americanus) were exposed to a pulse of diesel oil and held for 21 days to depurate. Taste panels revealed a highly significant difference between samples, as well as a preferences for, the untreated samples at days 10 and 11. The odor of the raw treated samples differed significantly from that of the control at each of the sampling times. Cooking appeared to remove the oily odor from the raw lobster. Significantly elevated concentrations of total aromatics were found in the hepatopancreas of both sexes at days 3-4 and 10-11 and in the tail muscle of male and female lobsters 10-11 days after initial exposure and decreased thereafter. Tainting of lobsters can occur within 10 days of exposure to diesel, and this effect can be reversed within 20 days after initial exposure

  13. From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

    DEFF Research Database (Denmark)

    Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes....... A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide...... with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the test codend compared with the standard codend. The decrease in damages may also improve quality indirectly by inflicting...

  14. Bubbles & Squat

    DEFF Research Database (Denmark)

    Højbjerre Larsen, Signe

    , a new concept called ‘Bubbles & Squat’, where fitness training is combined with Champagne and a live DJ. One of the invitations for this event describes how “we spice up your friday training with live DJ and lots of refreshing bubbles, to make sure that you are ready for the weekend (...).” Before New...

  15. Balance assessment during squatting exercise: A comparison between laboratory grade force plate and a commercial, low-cost device.

    Science.gov (United States)

    Mengarelli, Alessandro; Verdini, Federica; Cardarelli, Stefano; Di Nardo, Francesco; Burattini, Laura; Fioretti, Sandro

    2018-04-11

    Testing balance through squatting exercise is a central part of many rehabilitation programs and sports and plays also an important role in clinical evaluation of residual motor ability. The assessment of center of pressure (CoP) displacement and its parametrization is commonly used to describe and analyze squat movement and the laboratory-grade force plates (FP) are the gold standard for measuring balance performances from a dynamic view-point. However, the Nintendo Wii Balance Board (NWBB) has been recently proposed as an inexpensive and easily available device for measuring ground reaction force and CoP displacement in standing balance tasks. Thus, this study aimed to compare the NWBB-CoP data with those obtained from a laboratory FP during a dynamic motor task, such as the squat task. CoP data of forty-eight subjects were acquired simultaneously from a NWBB and a FP and the analyses were performed over the descending squatting phase. Outcomes showed a very high correlation (r) and limited root-mean-square differences between CoP trajectories in anterior-posterior (r > 0.99, 1.63 ± 1.27 mm) and medial-lateral (r > 0.98, 1.01 ± 0.75 mm) direction. Spatial parameters computed from CoP displacement and ground reaction force peak presented fixed biases between NWBB and FP. Errors showed a high consistency (standard deviation < 2.4% of the FP outcomes) and a random spread distribution around the mean difference. Mean velocity is the only parameter which exhibited a tendency towards proportional values. Findings of this study suggested the NWBB as a valid device for the assessment and parametrization of CoP displacement during squatting movement. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

    Directory of Open Access Journals (Sweden)

    Jairo Vázquez-Guerrero

    Full Text Available The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010 and peak force output differed between all loads for each condition (P < 0.045. Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001. There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

  17. Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

    Science.gov (United States)

    Marián, Vanderka; Katarína, Longová; Dávid, Olasz; Matúš, Krčmár; Simon, Walker

    2016-01-01

    The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, psquats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term. Key points Jump squat exercise is one of many exercises to develop explosive strength that has been the focus of several researches, while the load used during the training seem to be an important factor that affects training outcomes. Experimental group improved performance in all assessed parameters, such as Fmax, RFD100, CMJ, SJ and 50 m sprint time. However, improvements in CMJ and SJ were recorded after the entire power training period and thereafter plateau occurred. The portable FitroDyne could serve as a valuable device to individualize the load that maximizes mean power output and visual feedback can be provided to athletes during the training. PMID:27803628

  18. Predicting lower body power from vertical jump prediction equations for loaded jump squats at different intensities in men and women.

    Science.gov (United States)

    Wright, Glenn A; Pustina, Andrew A; Mikat, Richard P; Kernozek, Thomas W

    2012-03-01

    The purpose of this study was to determine the efficacy of estimating peak lower body power from a maximal jump squat using 3 different vertical jump prediction equations. Sixty physically active college students (30 men, 30 women) performed jump squats with a weighted bar's applied load of 20, 40, and 60% of body mass across the shoulders. Each jump squat was simultaneously monitored using a force plate and a contact mat. Peak power (PP) was calculated using vertical ground reaction force from the force plate data. Commonly used equations requiring body mass and vertical jump height to estimate PP were applied such that the system mass (mass of body + applied load) was substituted for body mass. Jump height was determined from flight time as measured with a contact mat during a maximal jump squat. Estimations of PP (PP(est)) for each load and for each prediction equation were compared with criterion PP values from a force plate (PP(FP)). The PP(est) values had high test-retest reliability and were strongly correlated to PP(FP) in both men and women at all relative loads. However, only the Harman equation accurately predicted PP(FP) at all relative loads. It can therefore be concluded that the Harman equation may be used to estimate PP of a loaded jump squat knowing the system mass and peak jump height when more precise (and expensive) measurement equipment is unavailable. Further, high reliability and correlation with criterion values suggest that serial assessment of power production across training periods could be used for relative assessment of change by either of the prediction equations used in this study.

  19. Reliability and Validity of the Load-Velocity Relationship to Predict the 1RM Back Squat.

    Science.gov (United States)

    Banyard, Harry G; Nosaka, Kazunori; Haff, G Gregory

    2017-07-01

    Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load-velocity relationship to predict the 1RM back squat. J Strength Cond Res 31(7): 1897-1904, 2017-This study investigated the reliability and validity of the load-velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-trained males performed three 1RM assessments on 3 separate days. All repetitions were performed to full depth with maximal concentric effort. Predicted 1RMs were calculated by entering the mean concentric velocity of the 1RM (V1RM) into an individualized linear regression equation, which was derived from the load-velocity relationship of 3 (20, 40, 60% of 1RM), 4 (20, 40, 60, 80% of 1RM), or 5 (20, 40, 60, 80, 90% of 1RM) incremental warm-up sets. The actual 1RM (140.3 ± 27.2 kg) was very stable between 3 trials (ICC = 0.99; SEM = 2.9 kg; CV = 2.1%; ES = 0.11). Predicted 1RM from 5 warm-up sets up to and including 90% of 1RM was the most reliable (ICC = 0.92; SEM = 8.6 kg; CV = 5.7%; ES = -0.02) and valid (r = 0.93; SEE = 10.6 kg; CV = 7.4%; ES = 0.71) of the predicted 1RM methods. However, all predicted 1RMs were significantly different (p ≤ 0.05; ES = 0.71-1.04) from the actual 1RM. Individual variation for the actual 1RM was small between trials ranging from -5.6 to 4.8% compared with the most accurate predictive method up to 90% of 1RM, which was more variable (-5.5 to 27.8%). Importantly, the V1RM (0.24 ± 0.06 m·s) was unreliable between trials (ICC = 0.42; SEM = 0.05 m·s; CV = 22.5%; ES = 0.14). The load-velocity relationship for the full depth free-weight back squat showed moderate reliability and validity but could not accurately predict 1RM, which was stable between trials. Thus, the load-velocity relationship 1RM prediction method used in this study cannot accurately modify sessional training loads because of large V1RM variability.

  20. Effects of fatigue on bilateral ground reaction force asymmetries during the squat exercise.

    Science.gov (United States)

    Hodges, Stephanie J; Patrick, Ryan J; Reiser, Raoul F

    2011-11-01

    Physical performance and injury risk have been related to functional asymmetries of the lower extremity. The effect of fatigue on asymmetries is not well understood. The goal of this investigation was to examine asymmetries during fatiguing repetitions and sets of the free-weight barbell back squat exercise. Seventeen healthy recreationally trained men and women (age = 22.3 ± 2.5 years; body mass = 73.4 ± 13.8 kg; squat 8 repetition maximum [8RM] = 113 ± 35% body mass [mean ± SD]) performed 5 sets of 8 repetitions with 90% 8RM while recording bilateral vertical ground reaction force (GRFv). The GRFv asymmetry during the first 2 (R1 and R2) and the last 2 (R7 and R8) repetitions of each set was calculated by subtracting the % load on the right foot from that of the left foot. Most subjects placed more load on their left foot (also their preferred non-kicking foot). Average absolute asymmetry level across all sets was 4.3 ± 2.5 and 3.6 ± 2.3% for R1 and R2 and R7 and R8, respectively. There were no effects of fatigue on GRFv asymmetries in whole-group analysis (n = 17). However, when initially highly symmetric subjects (±1.7% Left-Right) were removed, average absolute GRFv asymmetry dropped from the beginning to the end of a set (n = 12, p = 0.044) as did peak instantaneous GRFv asymmetry when exploring general shifts toward the left or right leg (n = 12, p = 0.042). The GRFv asymmetries were highly repeatable for 8 subjects that repeated the protocol (Cronbach's α ≥ 0.733, p ≤ 0.056). These results suggest that functional asymmetries, though low, are present in healthy people during the squat exercise and remain consistent. Asymmetries do not increase with fatigue, potentially even decreasing, suggesting that healthy subjects load limbs similarly as fatigue increases, exposing each to similar training stimuli.