Sample records for jerky

  1. Control of lipid oxidation in extruded salmon jerky snacks.

    PubMed

    Kong, Jian; Perkins, L Brian; Dougherty, Michael P; Camire, Mary Ellen

    2011-01-01

    A shelf-life study was conducted to evaluate the effect of antioxidants on oxidative stability of extruded jerky-style salmon snacks. Deterioration of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) due to lipid oxidation is a major concern for this healthy snack. A control jerky with no added antioxidants and 4 jerkies with antioxidants (rosemary, mixed tocopherols, tertiary butylhydroquinone, and ascorbyl palmitate) added as 0.02% of the lipid content were extruded in duplicate in a Coperion ZSK-25 twin screw extruder. Salmon jerkies from each formulation were placed in 3 mil barrier pouches, flushed with nitrogen, and stored at 35 °C and 75% relative humidity. Lipid oxidation was evaluated as by peroxide value and malonaldehyde content. Other chemical analyses included total fatty acid composition, lipid content, moisture, water activity, pH, and salt. Astaxanthin and CIE L*, a*, b* color were also analyzed at 4-wk intervals. Rosemary inhibited peroxide formation better than did other antioxidants at week 8; no treatment inhibited malonaldehyde levels. All jerkies had lower astaxanthin levels after 8 wk, but rosemary-treated jerky had higher pigment concentrations than did the control at weeks 4 and 8. Protection of omega-3 lipids in these extruded jerkies must be improved to offer consumers a convenient source of these healthful lipids. Practical Application: Salmon flesh can be extruded to produce a jerky that provides 410 mg of omega-3 lipids per serving. Natural antioxidants such as rosemary should be added at levels over 0.02% of the lipid content to help control lipid oxidation. Astaxanthin and CIE a* values correlated well with lipid stability and could be used to monitor quality during storage if initial values are known.

  2. Antimicrobial Effect of Nisin against Bacillus cereus in Beef Jerky during Storage

    PubMed Central

    Lee, Na-Kyoung; Kim, Hyoun Wook; Lee, Joo Yeon; Ahn, Dong Uk; Kim, Cheon-Jei; Paik, Hyun-Dong

    2015-01-01

    The microbial distribution of raw materials and beef jerky, and the effect of nisin on the growth of Bacillus cereus inoculated in beef jerky during storage, were studied. Five strains of pathogenic B. cereus were detected in beef jerky, and identified with 99.8% agreement using API CHB 50 kit. To evaluate the effect of nisin, beef jerky was inoculated with approximately 3 Log CFU/g of B. cereus mixed culture and nisin (100 IU/g and 500 IU/g). During the storage of beef jerky without nisin, the number of mesophilic bacteria and B. cereus increased unlikely for beef jerky with nisin. B. cereus started to grow after 3 d in 100 IU nisin/g treatment, and after 21 d in 500 IU nisin/g treatment. The results suggest that nisin could be an effective approach to extend the shelf-life, and improve the microbial safety of beef jerky, during storage. PMID:26761838

  3. Utilization of smoked salmon trim in extruded smoked salmon jerky.

    PubMed

    Kong, J; Dougherty, M P; Perkins, L B; Camire, M E

    2012-06-01

    During smoked salmon processing, the dark meat along the lateral line is removed before packaging; this by-product currently has little economic value. In this study, the dark meat trim was incorporated into an extruded jerky. Three formulations were processed: 100% smoked trim, 75% : 25% smoked trim : fresh salmon fillet, and 50% : 50% smoked trim : fresh salmon blends (w/w basis). The base formulation contained salmon (approximately 83.5%), tapioca starch (8%), pregelatinized potato starch (3%), sucrose (4%), salt (1.5%), sodium nitrate (0.02%), and ascorbyl palmitate (0.02% of the lipid content). Blends were extruded in a laboratory-scale twin-screw extruder and then hot-smoked for 5 h. There were no significant differences among formulations in moisture, water activity, and pH. Protein was highest in the 50 : 50 blend jerky. Ash content was highest in the jerky made with 100% trim. Total lipids and salt were higher in the 100% trim jerky than in the 50 : 50 blend. Hot smoking did not adversely affect docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) content in lipids from 100% smoked trim jerky. Servings of salmon jerky made with 75% and 100% smoked trim provided at least 500 mg of EPA and DHA. The 50 : 50 formulation had the highest Intl. Commission on Illumination (CIE) L*, a*, and b* color values. Seventy consumers rated all sensory attributes as between "like slightly" and "like moderately." With some formulation and processing refinements, lateral line trim from smoked salmon processors has potential to be incorporated into acceptable, healthful snack products. Dark meat along the lateral line is typically discarded by smoked salmon processors. This omega-3 fatty acid rich by-product can be used to make a smoked salmon jerky that provides a convenient source of these healthful lipids for consumers. © 2012 Institute of Food Technologists®

  4. Characteristics of formed Atlantic salmon jerky.

    PubMed

    Oberholtzer, Ashlan S; Dougherty, Michael P; Camire, Mary Ellen

    2011-08-01

    Smoked salmon (Salmo salar L.) processing may generate large amounts of small pieces of trimmed flesh that has little economic value. Opportunities exist to develop new added-value foods from this by-product. Brining was compared with dry salting for the production of formed salmon jerky-style strips that were then smoked. The formulations also contained brown sugar and potato starch. Salted samples had higher salt concentrations and required less force to break using a TA-XT2 Texture Analyzer. Brined samples contained more fat and were darker, redder and more yellow than the salted samples. Processing concentrated omega-3 fatty acids compared with raw salmon, and the brined jerky had the highest omega-3 fatty acid content. A panel of 57 consumers liked the appearance and aroma of both samples equally (approximately 6.7 for appearance and 6.3 for aroma on the 9-point hedonic scale. Higher acceptability scores for taste, texture, and overall quality were given to the brined product (6.7 to 6.9 against 6.2 to 6.3). Salmon trim from smoking facilities can be utilized to produce a jerky that is a good source of omega-3 fatty acids, simultaneously adding value and reducing the waste stream. © 2011 Institute of Food Technologists®

  5. Development of a method to manufacture uncured, no-nitrate/nitrite-added whole muscle jerky.

    PubMed

    Sindelar, Jeffrey J; Terns, Matthew J; Meyn, Elizabeth; Boles, Jane A

    2010-10-01

    "Natural curing" is accomplished by use of vegetable juice/powder high in naturally occurring nitrates combined with a nitrate reducing starter culture to result in indirectly "cured" products. Since the starter culture used is not water soluble, making "naturally cured" whole muscle jerky with current manufacturing techniques has been found ineffective. The objective was to investigate processes for whole muscle beef jerky that might provide cured meat characteristics similar to those of a nitrite-added control. Treatments where jerky was placed in a barrier bag during incubation were found to be the least similar to the nitrite-added control. Jerky placed in a 40.6 degrees C smokehouse during incubation resulted in significantly more (P<0.05) converted cured pigment than the barrier bag treatments but less (P<0.05) than the control. The processing methods investigated to manufacture "naturally cured" whole muscle jerky in this study were ineffective in resulting in products similar to those cured with sodium nitrite. Published by Elsevier Ltd.

  6. Effects of Mechanically Deboned Chicken Meat (MDCM) and Collagen on the Quality Characteristics of Semi-dried Chicken Jerky

    PubMed Central

    Song, Dong-Heon; Choi, Ji-Hun; Choi, Yun-Sang; Kim, Hyun-Wook; Hwang, Ko-Eun; Kim, Yong-Jae; Ham, Youn-Kyung; Kim, Cheon-Jei

    2014-01-01

    This study was conducted to determine the effects of using mechanically deboned chicken meat (MDCM) and collagen on quality characteristics of semi-dried chicken jerky. In experiment I, semi-dried chicken jerky was prepared with the replacement of chicken breast with MDCM (0, 10, 20, and 30%). The pH value of the jerky formulated with only chicken breast was 5.94, while the replacement of chicken breast with MDCM significantly increased the pH (p<0.05). The protein content and shear force of the jerkies decreased with increasing amounts of MDCM, whereas the fat, ash content and processing yield showed the opposite tendency (p<0.05). Replacement with up to 10% MDCM had no adverse effects on the sensory characteristics of the semi-dried chicken jerky. In experiment II, four levels of pork collagen (0, 1, 2, and 3%) were added to the semi-dried chicken jerky formulated with 90% chicken breast and 10% MDCM. The addition of collagen increased the moisture content, but decreased the ash content of the jerkies produced (p<0.05). The processing yield of the jerkies increased with increasing added amounts of collagen (p<0.05). It was found that the jerkies formulated with 0-2% collagen had significantly higher overall acceptance score than those prepared with 3% collagen (p<0.05). In conclusion, MDCM and collagen could be useful ingredients to reduce the production cost and improve the processing yield of semi-dried chicken jerky. The optimal levels of MDCM and collagen which could be added without adverse effects on the sensory characteristics were up to 10% and 2%, respectively. PMID:26761667

  7. Screening for toxic phorbol esters in jerky pet treat products using LC-MS.

    PubMed

    Nishshanka, Upul; Jayasuriya, Hiranthi; Chattopadhaya, Chaitali; Kijak, Philip J; Chu, Pak-Sin; Reimschuessel, Renate; Tkachenko, Andriy; Ceric, Olgica; De Alwis, Hemakanthi G

    2016-05-01

    Since 2007, the U.S. FDA's Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats. Jerky used in pet treats contains glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Because some biodiesel is produced using oil from Jatropha curcas, a plant that contains toxic compounds including phorbol esters, CVM developed a liquid chromatography-mass spectrometry (LC-MS) screening method to evaluate investigational jerky samples for the presence of these toxins. Results indicated that the samples analyzed with the new method did not contain Jatropha toxins at or above the lowest concentration tested. Published by Elsevier B.V.

  8. Survival of Escherichia coli O157:H7 in ground beef jerky assessed on two plating media.

    PubMed

    Harrison, J A; Harrison, M A; Rose, R A

    1998-01-01

    Recent outbreaks of food-borne illness due to Salmonella spp. in beef jerky and Escherichia coli O157:H7 in venison jerky, coupled with the fact that a variety of preparation methods and dying procedures abound, raise concern over the safety of processed meat products made in the home. The potential of injured bacterial cells to regain the ability to cause illness is a particular threat with pathogens such as E. coli O157:H7, which is believed to have a low infectious dose. This study examined the efficacy of various methods of jerky preparation in reducing populations of E, coli O157:H7 in ground beef jerky and compared the recovery rate of E. coli O157:H7 on two selective plating media, modified sorbitol MacConkey agar (MSMA) and modified eosin methylene blue agar (MEMB). Populations of E. coli O157:H7 in both heated and unheated samples exhibited a greater decline during drying when a nitrite and salt cure mix was added during jerky preparation. When recovery of E. coli O157:H7 on MSMA and MEMB was compared, a trend toward slightly higher recovery rates with MEMB was observed. On the basis of these results, MEMB is a suitable alternative to MSMA for the recovery of E. coli O157:H7 from heated and dried meat samples similar to beef jerky.

  9. Human outbreak of Salmonella Typhimurium associated with exposure to locally made chicken jerky pet treats, New Hampshire, 2013.

    PubMed

    Cavallo, Steffany J; Daly, Elizabeth R; Seiferth, John; Nadeau, Alisha M; Mahoney, Jennifer; Finnigan, Jayne; Wikoff, Peter; Kiebler, Craig A; Simmons, Latoya

    2015-05-01

    Pet treats and pet food can be contaminated with Salmonella and other pathogens, though they are infrequently implicated as the source of human outbreaks. In 2013, the New Hampshire Department of Health and Human Services investigated a cluster of Salmonella Typhimurium infections associated with contaminated locally made pet treats. Case-patients were interviewed with standardized questionnaires to assess food, animal, and social histories. Laboratory and environmental investigations were conducted, including testing of clinical specimens, implicated product, and environmental swabs. Between June and October 2013, a total of 43 ill persons were identified. Sixteen patients (37%) were hospitalized. Among 43 case-patients interviewed, the proportion exposed to dogs (95%) and pet treats (69%) in the 7 days prior to illness was statistically higher than among participants in a U.S. population-based telephone survey (61%, p<0.0001 and 16%, p<0.0001, respectively). On further interview, 38 (88%) reported exposure to Brand X Chicken Jerky, the maker of Brand X chicken jerky, or the facility in which it was made. Product testing isolated the outbreak strain from four of four Brand X Chicken Jerky samples, including an unopened package purchased at retail, opened packages collected from patient households, and unpackaged jerky obtained from the jerky maker. A site visit revealed inadequate processing of the chicken jerky, bare-hand contact with the finished product prior to packaging, and use of vacuum-sealed packaging, which may have enabled facultative anaerobic bacteria to proliferate. Seven (78%) of nine environmental swabs taken during the site visit also yielded the outbreak strain. Brand X Chicken Jerky was voluntarily recalled on September 9, 2013. Consumers should be made aware of the potential for locally made products to be exempt from regulation and for animals and animal food to carry pathogens that cause human illness, and be educated to perform hand hygiene

  10. Flexible thin-layer plasma inactivation of bacteria and mold survival in beef jerky packaging and its effects on the meat's physicochemical properties.

    PubMed

    Yong, Hae In; Lee, Haelim; Park, Sanghoo; Park, Jooyoung; Choe, Wonho; Jung, Samooel; Jo, Cheorun

    2017-01-01

    The aims of the present study were to examine the use of a flexible thin-layer plasma system in inactivating bacteria and mold on beef jerky in a commercial package and to evaluate the physicochemical changes of the jerky. After plasma treatment for 10min, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Aspergillus flavus populations on the beef jerky were reduced by approximately 2 to 3Log CFU/g. No significant changes in metmyoglobin content, shear force, and myofibrillar fragmentation index were found in the plasma-treated beef jerky. On the other hand, the peroxide content and L ⁎ value were decreased whereas the a ⁎ and ΔE value were increased in the plasma-treated sample. Sensory evaluation indicated negative effects of plasma treatment on flavor, off-odor, and overall acceptability of the beef jerky. In conclusion, the flexible thin-layer plasma system could be employed as a means for decontamination of beef jerky, with slight changes to the physicochemical quality of the product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Virulence and antimicrobial resistance of Salmonella spp. and Escherichia coli in the beef jerky production line.

    PubMed

    Fernandes, Fernanda Pereira; Voloski, Flávia Liége Schütz; Ramires, Tassiana; Haubert, Louise; Reta, Giulia Giugliani; Mondadori, Rafael Gianella; Silva, Wladimir Padilha da; Conceição, Rita de Cássia Dos Santos da; Duval, Eduarda Hallal

    2017-05-01

    Intense manipulation during beef jerky production increases the possibility of contamination with pathogenic microorganisms. This study evaluated the contamination by thermotolerant coliforms, Escherichia coli and Salmonella spp., on processing surfaces and raw materials during beef jerky production, as well as in the final product. Thermotolerant coliforms were found on all surfaces tested and in the raw material. Escherichia coli was identified in 6.7% of the surface samples, while Salmonella spp. was found in 3.3% of the surface samples and 8.6% of raw material samples. Virulence genes were detected in Salmonella spp. isolates. One Salmonella spp. isolate was resistant to sulfonamide, while one E. coli isolate was multiresistant, including the presence of resistance genes sul2, strA, strB, tetA and tetB. The presence of coliforms demonstrates failings in hygienic-sanitary procedures. The presence of pathogenic microorganisms causing foodborne diseases in the production line indicates persistent contamination in the production plant. Although the drying process applied to beef jerky should guarantee the safety of the final product, the presence of multiresistant pathogenic microorganisms, presenting virulence genes, should be a matter of concern. Because beef jerky is a ready-to-eat product, a failure in the production process may cause such microorganisms to pose a public health risk. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Quality changes of chicken meat jerky with different sweeteners during storage.

    PubMed

    Wongwiwat, Pirinya; Wattanachant, Saowakon

    2015-12-01

    Chicken meat jerky with high sugar content is popular intermediate-moisture meat product in Asia. Different types of sugar, sucrose and mixed sugar (sucrose: fructose: sorbitol 70: 15: 15), were evaluated to improve the quality of product. Quality changes of chicken meat jerky stored in vacuum and aerobic (33 and 75 %relative humidity, %RH) conditions were studied for suitable condition to extend shelf-life of product. The samples were determined the physical and chemical characteristics, as well as sensory evaluation during storage at room temperature. The moisture content and water activity (aw) of samples stored in 33 %RH conditions was continuously diminished during storage that related to harder texture and unacceptable quality in sensory evaluation. All samples stored in vacuum and 75 %RH condition demonstrated the lower shear force value than that stored in 33%RH condition (p < 0.05). Samples stored in vacuum condition had the lowest lipid oxidation (p < 0.05.) which corresponding to the highest scores in less rancidity and overall acceptance attributes. All samples stored in vacuum condition also had the highest acceptability in all sensory attributes (taste, rancidity, color and overall acceptance) followed by 75 %RH storage condition (p < 0.05). Samples prepared with mixed sugar could improve color and retard rancidity in chicken jerky meat product. Sample prepared with mixed sugar kept in vacuum condition had the lowest lipid oxidation and highest sensory score in overall acceptance attributes along the extended storage.

  13. Application of class-modelling techniques to infrared spectra for analysis of pork adulteration in beef jerkys.

    PubMed

    Kuswandi, Bambang; Putri, Fitra Karima; Gani, Agus Abdul; Ahmad, Musa

    2015-12-01

    The use of chemometrics to analyse infrared spectra to predict pork adulteration in the beef jerky (dendeng) was explored. In the first step, the analysis of pork in the beef jerky formulation was conducted by blending the beef jerky with pork at 5-80 % levels. Then, they were powdered and classified into training set and test set. The second step, the spectra of the two sets was recorded by Fourier Transform Infrared (FTIR) spectroscopy using atenuated total reflection (ATR) cell on the basis of spectral data at frequency region 4000-700 cm(-1). The spectra was categorised into four data sets, i.e. (a) spectra in the whole region as data set 1; (b) spectra in the fingerprint region (1500-600 cm(-1)) as data set 2; (c) spectra in the whole region with treatment as data set 3; and (d) spectra in the fingerprint region with treatment as data set 4. The third step, the chemometric analysis were employed using three class-modelling techniques (i.e. LDA, SIMCA, and SVM) toward the data sets. Finally, the best result of the models towards the data sets on the adulteration analysis of the samples were selected and the best model was compared with the ELISA method. From the chemometric results, the LDA model on the data set 1 was found to be the best model, since it could classify and predict 100 % accuracy of the sample tested. The LDA model was applied toward the real samples of the beef jerky marketed in Jember, and the results showed that the LDA model developed was in good agreement with the ELISA method.

  14. Transient Fanconi syndrome with severe polyuria and polydipsia in a 4-year old Shih Tzu fed chicken jerky treats.

    PubMed

    Major, A; Schweighauser, A; Hinden, S E; Francey, T

    2014-12-01

    Acquired Fanconi syndrome is characterized by inappropriate urinary loss of amino acids, bicarbonate, electrolytes, and water. It has recently been described in dogs fed chicken jerky treats from China, a new differential diagnosis to the classical inciting infectious diseases (e.g. leptospirosis, pyelonephritis) and toxins. A dog fed exclusively chicken jerky treats purchased in Switzerland was presented to our clinic with severe polyuria, polydipsia and profound electrolyte and acid base disturbances. Other inciting causes of Fanconi syndrome were ruled out. The requirement of a very intensive supportive treatment in this dog stands in contrast to treatment of chronic forms of Fanconi syndrome as described in the Basenji. This intensive therapy and the associated monitoring can be a real challenge and a limiting factor for the prognosis of acquired Fanconi syndrome. Veterinarians should be aware of the risk of excessive feeding of chicken jerky treats.

  15. Effect of curing time on the physicochemical and sensory properties of beef jerky replaced salt with soy sauce, red pepper paste and soybean paste.

    PubMed

    Lim, H J; Kim, G D; Jung, E Y; Seo, H W; Joo, S T; Jin, S K; Yang, H S

    2014-08-01

    This study was done to investigate the quality properties of beef jerky with soy sauce, red pepper paste, and soybean paste replacing salt. Sliced beef samples were cured in salt (control), soy sauce, red pepper paste, and soybean paste for 24 or 48 h and then dried at 70°C for 8 h. Treatments showed higher final moisture content and lower Na(+) concentration than the control after drying for 8 h. The lightness and shear force values were lower in all treatment samples than in the control during 48 h of curing time. In particular, lower lipid oxidation was found in the jerky cured with red pepper paste than in the control. Sensory evaluation showed that color, flavor, and tenderness of jerky samples were improved by replacing salt with soy sauce, red pepper paste and soybean paste, and higher likeability scores of the beef jerky were obtained among those treatments after 48 h of curing time.

  16. Application of chemometrics to assess the influence of ultrasound frequency, Lactobacillus sakei culture and drying on beef jerky manufacture: Impact on amino acid profile, organic acids, texture and colour.

    PubMed

    Shikha Ojha, K; Granato, Daniel; Rajuria, Gaurav; Barba, Francisco J; Kerry, Joseph P; Tiwari, Brijesh K

    2018-01-15

    The effects of ultrasound (US) frequency, addition of Lactobacillus sakei culture and drying time on key nutritional (protein, amino acids, and organic acids) and physicochemical properties (texture and colour) of cultured and uncultured beef jerky were evaluated. Cultured and uncultured jerky samples were subjected to US frequencies of 25kHz, 33kHz and 45kHz for 30min prior to marination and drying. Principal component analysis demonstrated a significant effect of beef jerky processing conditions on physicochemical properties. Taurine content of jerky samples was found to increase with an increase in ultrasonic frequencies for cultured samples. No significant changes in colour values were observed for ultrasound pre-treated and control samples. Interactive effects of culture treatment, drying and ultrasonic frequency were observed. This study demonstrates that the nutritional profile of beef jerky can be improved through the incorporation of L. sakei. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Lethality of home-style dehydrator processes against Escherichia coli O157:H7 and salmonella serovars in the manufacture of ground-and-formed beef jerky and the potential for using a pathogen surrogate in process validation.

    PubMed

    Borowski, A G; Ingham, S C; Ingham, B H

    2009-10-01

    Ground-and-formed beef jerky can be made easily at home with ground beef and kits that include spice, cure, and jerky-forming equipment. Ground beef poses inherent risks of illness due to Escherichia coli O157:H7 and Salmonella contamination, making adequate pathogen lethality important in jerky manufacturing. We evaluated the effectiveness of drying regimes at eliminating E. coli O157:H7 and Salmonella in seasoned ground-and-formed beef jerky manufactured with three home-style dehydrators and one small commercial unit. Inoculated jerky strips were dried for up to 12 or 24 h in a home-style or the commercial unit, respectively, with target drying temperatures ranging from 51.7 degrees C (125 degrees F) to 71.1 degrees C (160 degrees F). Pathogen lethality varied with seasoning, temperature, and drying time (n = 288 samples). Lethality against E. coli O157:H7 ranged from 1.5 log CFU (Jerky Xpress, 57.2 degrees C [135 degrees F], 4 h) to 6.4 log CFU (Gardenmaster, 68.3 degrees C [155 degrees F], 12 h), and varied with seasoning. Lethality against Salmonella ranged from 1.7 log CFU (Jerky Xpress, 57.2 degrees C [135 degrees F], 4 h) to 6.0 log CFU (Gardenmaster, 68.3 degrees C [155 degrees F], 12 h), and also varied with seasoning. There was a > or =5-log CFU reduction in both pathogens in 0, 10, and 27 % of samples at 4, 8, and 12 h, respectively. Heating jerky for 10 min at 135 degrees C (275 degrees F) 4 or 6 h postdrying increased lethality, on average, 2.99 log CFU for Salmonella and 3.02 log CFU for E. coli O157:H7. The use of a lactic acid bacterium culture (Pediococcus spp.) as a pathogen surrogate accurately predicted safety in 28 % of samples containing E. coli O157:H7 and 78% of Salmonella-inoculated samples.

  18. Improvement of microbiological safety and sensorial quality of pork jerky by electron beam irradiation and by addition of onion peel extract and barbecue flavor

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Joo; Jung, Samooel; Yong, Hae In; Bae, Young Sik; Kang, Suk Nam; Kim, Il Suk; Jo, Cheorun

    2014-05-01

    The combined effects of electron-beam (EB) irradiation and addition of onion peel (OP) extract and barbecue flavor (BF) on inactivation of foodborne pathogens and the quality of pork jerky was investigated. Prepared pork jerky samples were irradiated (0, 1, 2, and 4 kGy) and stored for 2 month at 25 °C. The D10 values of Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium observed in the OP treated samples were 0.19, 0.18, and 0.19 kGy, whereas those in control were 0.25, 0.23, and 0.20 kGy, respectively. Irradiated samples with OP extract and BF had substantially lower total aerobic bacterial counts than the control had. Samples with added OP extract and BF had lower peroxide values than the control had. Sensory evaluation indicated that overall acceptability of treated samples was not changed up to 2 kGy. Therefore, EB irradiation, combined with OP extract and BF, has improved the microbiological safety with no negative effects on the quality of pork jerky.

  19. Jerky spontaneous movements at term age in preterm infants who later developed cerebral palsy.

    PubMed

    Kanemaru, Nao; Watanabe, Hama; Kihara, Hideki; Nakano, Hisako; Nakamura, Tomohiko; Nakano, Junji; Taga, Gentaro; Konishi, Yukuo

    2014-08-01

    Assessment of spontaneous movements in infants has been a powerful predictor of cerebral palsy (CP). Recent advancements on computer-based video analysis can provide detailed information about the properties of spontaneous movements. The aim of this study was to investigate the relationship between spontaneous movements of the 4 limbs at term age and the development of CP at 3 years of age by using a computer-based video analysis system. We analyzed video recordings of spontaneous movements at 36-44 weeks postmenstrual age (PMA) for 145 preterm infants who were born preterm (22-36 weeks PMA with birthweights of 460-1498g). Sixteen of the infants developed CP by 3 years of age, while 129 developed normally. We compared 6 movement indices calculated from 2-dimensional trajectories of all limbs between the 2 groups. We found that the indices of jerkiness were higher in the CP group than in the normal group (p<0.1 for arms and p<0.01 for legs). No decline was observed in the average velocity and number of movement units in the CP group compared with to the normal group. Jerkiness of spontaneous movements at term age provides additional information for predicting CP in infants born preterm. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Characterization and Prediction of Flow Behavior in High-Manganese Twinning Induced Plasticity Steels: Part II. Jerky Flow and Instantaneous Strain Rate

    NASA Astrophysics Data System (ADS)

    Saeed-Akbari, A.; Mishra, A. K.; Mayer, J.; Bleck, W.

    2012-05-01

    The jerky and smooth flow curves in high-manganese twinning induced plasticity (TWIP) steels were investigated by comparing Fe-Mn-C and Fe-Mn-Al-C systems. The pronounced serrations on the flow curves of Fe-Mn-C TWIP steel, produced during tensile testing at 300 K (27 °C) and 373 K (100 °C), were shown to be the result of localized high-temperature Portevin Le-Chatelier (PLC) bands moving across the gage length throughout the deformation. The speed of the PLC bands and their temperature effects were found to be strongly dependent on the applied strain rate, which was controlled by adjusting the cross-head speed of the tensile testing machine. The localized temperature-dependent stacking fault energy (SFE) variations resulting from the PLC effect and adiabatic heating were analyzed and compared for both slow and fast deformation rates. The instabilities in the measured logarithmic strain values caused by jerky flow could cause the local strain rate to deviate systematically from the targeted (applied) strain rate. These instabilities are better observed by calculating the instantaneous strain rate (ISR) values for each instant of deformation along the entire gage length. Finally, a new type of diagram was developed by plotting the true stress against the ISR values. From the diagram, the onset of different mechanisms, such as deformation twinning, nonpronounced, and pronounced serrations, could be marked precisely.

  1. Effect of the cooking method (grilling, roasting, frying and sous-vide) on the oxidation of thiols, tryptophan, alkaline amino acids and protein cross-linking in jerky chicken.

    PubMed

    Silva, Fábio A P; Ferreira, Valquíria C S; Madruga, Marta S; Estévez, Mario

    2016-08-01

    Broiler breast ( pectoralis major ) meat was submitted to salting with NaCl + NaNO 3 followed by a drying process to produce jerky-type chicken. The final product (raw broiler charqui) was desalted and then cooked using grilled, roasted, fried and sous-vide techniques. Sous-vide cooked samples showed lowest results of moisture loss compared to roasted and fried ones. Fatty acid profile suffered minor changes after cooking of broiler charqui. Regarding to protein oxidation, tryptophan fluorescence, protein carbonylation and disulphide bonds formation of chicken charqui were affected by cooking temperature while free thiol groups, Schiff base formation and hardness were mostly impacted by the length of cooking. Instrumental color of broiler charqui was affected by the type of cooking, being closely related with Maillard products formation. In conclusion, sous-vide technique seems to be the most advantageous cooking method to obtain high-quality ready-to-eat chicken charqui.

  2. Plastic dynamics of the Al0.5CoCrCuFeNi high entropy alloy at cryogenic temperatures: Jerky flow, stair-like fluctuation, scaling behavior, and non-chaotic state

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoxiang; Xie, Xie; Ren, Jingli; Laktionova, Marina; Tabachnikova, Elena; Yu, Liping; Cheung, Wing-Sum; Dahmen, Karin A.; Liaw, Peter K.

    2017-12-01

    This study investigates the plastic behavior of the Al0.5CoCrCuFeNi high-entropy alloy at cryogenic temperatures. The samples are uniaxially compressed at 4.2 K, 7.5 K, and 9 K. A jerky evolution of stress and stair-like fluctuation of strain are observed during plastic deformation. A scaling relationship is detected between the released elastic energy and strain-jump sizes. Furthermore, the dynamical evolution of serrations is characterized by the largest Lyapunov exponent. The largest Lyapunov exponents of the serrations at the three temperatures are all negative, which indicates that the dynamical regime is non-chaotic. This trend reflects an ordered slip process, and this ordered slip process exhibits a more disordered slip process, as the temperature decreases from 9 K to 4.2 K or 7.5 K.

  3. Supplementary effects of higher levels of various disaccharides on processing yield, quality properties and sensory attributes of Chinese - style pork jerky.

    PubMed

    Chen, Chih-Ming; Lin, Hsien-Tang

    2017-12-01

    This study evaluated the supplementary effect of higher concentrations of various disaccharides on processing yield, major physicochemical properties, and sensory attributes of Chinese-style pork jerky (CSPJ). CSPJ samples were prepared by marinating sliced ham (4 mm) with three dissaccharides, including sucrose, lactose, and maltose, at 0%, 15%, 18%, 21%, and 24%. Subsequently, the CSPJ samples were dried and roasted. The moisture content, water activity, crude protein, moisture-to-protein ratio, pH, processing yield, shear force, color, and sensory attributes of the CSPJ samples were evaluated. The quality characteristics of CSPJ samples prepared with sucrose were more acceptable. By contrast, CSPJ samples prepared with lactose showed the lowest scores. However, the processing yield and moisture content were the highest for CSPJ samples prepared with lactose, which may be associated with improved benefits for cost reduction. Furthermore, sucrose and lactose supplementation resulted in contrasting quality characteristics; for example, CSPJ samples with sucrose and maltose supplementation had higher sensory scores for color than samples with lactose supplementation. Additionally, most quality characteristics of CSPJ samples with sucrose supplementation contrasted with those of the samples with lactose supplementation; for example, the samples with sucrose supplementation had higher scores for sensory attributes than those with lactose supplementation. Sucrose supplementation up to 21% to 24% was associated with the highest overall acceptability scores (5.19 to 5.80), enhanced quality characteristics, increased processing yield, and reduced production cost.

  4. Angelman Syndrome

    MedlinePlus

    ... heads, jerky movements, protruding tongues, and bouts of laughter." Infants with Angelman syndrome appear normal at birth, ... heads, jerky movements, protruding tongues, and bouts of laughter." Infants with Angelman syndrome appear normal at birth, ...

  5. The quality of fetal arm movements as indicators of fetal stress.

    PubMed

    Reissland, Nadja; Francis, Brian

    2010-12-01

    Although a number of studies have found that maternal stress affects the fetus, it is unclear whether jerky fetal movements observed on ultrasound scans are indicative of fetal stress, or whether they are part of normal development. The present study was designed to examine the relationship between jerky fetal arm movements in relation to fetal age and stress. Video recordings were made of routine ultrasound scans of 57 fetuses (age range 8 to 33 weeks) classified into three age groups: 1st trimester (8-12 weeks, N=9), 2nd trimester (13-24 weeks, N=38), and 3rd trimester (26-33 weeks, N=10). Following previous research on stress behaviour in neonates, a fetal index of stress was derived from frequency of hiccup, back arch and rhythmical mouthing. Results indicated that while stress level was unrelated to fetal age, jerkiness of arm movements was significantly associated with the fetal stress index but not age. Our findings suggest that jerky arm movements in fetuses are suggestive of fetal stress. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Movement - unpredictable or jerky

    MedlinePlus

    ... ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 410. Review Date 2/23/2017 Updated by: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony ... NY. Review provided by VeriMed Healthcare Network. Also reviewed by ...

  7. Motion onset does not capture attention when subsequent motion is "smooth".

    PubMed

    Sunny, Meera Mary; von Mühlenen, Adrian

    2011-12-01

    Previous research on the attentional effects of moving objects has shown that motion per se does not capture attention. However, in later studies it was argued that the onset of motion does capture attention. Here, we show that this motion-onset effect critically depends on motion jerkiness--that is, the rate at which the moving stimulus is refreshed. Experiment 1 used search displays with a static, a motion-onset, and an abrupt-onset stimulus, while systematically varying the refresh rate of the moving stimulus. The results showed that motion onset only captures attention when subsequent motion is jerky (8 and 17 Hz), not when it is smooth (33 and 100 Hz). Experiment 2 replaced motion onset with continuous motion, showing that motion jerkiness does not affect how continuous motion is processed. These findings do not support accounts that assume a special role for motion onset, but they are in line with the more general unique-event account.

  8. Glucagon Injection

    MedlinePlus

    Glucagon is a hormone produced in the pancreas. Glucagon is used to raise very low blood sugar. Glucagon is also used in diagnostic ... sudden hunger, clumsy or jerky movements). Try to eat or drink a food or beverage with sugar ...

  9. Jerky periods: myoclonus occurring solely during menses.

    PubMed

    Buijink, Arthur W G; Gelauff, Jeannette M; van der Salm, Sandra M A; Tijssen, Marina A J; van Rootselaar, Anne-Fleur

    2013-01-01

    In this case report, we describe an unusual case of a patient with myoclonus only occurring during menses. A 41-year-old female, known to have neurological sequelae after a car accident 1 year earlier, presented with myoclonic movements of the right arm and hand only during menses. Brain magnetic resonance imaging is compatible with head trauma. Electromyography shows brief irregular bursts with a duration of about 20 ms. This appears to be the first description of myoclonus appearing only during menses. We suggest a cortical origin for myoclonus.

  10. Jerky driving--An indicator of accident proneness?

    PubMed

    Bagdadi, Omar; Várhelyi, András

    2011-07-01

    This study uses continuously logged driving data from 166 private cars to derive the level of jerks caused by the drivers during everyday driving. The number of critical jerks found in the data is analysed and compared with the self-reported accident involvement of the drivers. The results show that the expected number of accidents for a driver increases with the number of critical jerks caused by the driver. Jerk analyses make it possible to identify safety critical driving behaviour or "accident prone" drivers. They also facilitate the development of safety measures such as active safety systems or advanced driver assistance systems, ADAS, which could be adapted for specific groups of drivers or specific risky driving behaviour. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Angelman syndrome

    MedlinePlus

    ... arm and leg movements In toddlers and older children: Unstable or jerky walking Little or no speech Happy, excitable personality Laughing and smiling often Light hair, skin, and eye color compared to rest of family Small head size compared to body, flattened back of head Severe ...

  12. American Involvement in the Filipino Resistance Movement on Mindanao during the Japanese Occupation, 1942-1945

    DTIC Science & Technology

    1982-05-20

    vinegar and brine, and ctied in the sun. The jerky-like substance, called tapa, cured in two days and would remain preserved indefinitely. 207 Another...coconut tree, then fermented it with pulverized tanbark from a mangrove tree. Alcohol was extracted by using a still made from a Socony can with bamboo

  13. Effect of irradiation on quality of vacuum packed spicy beef chops

    USDA-ARS?s Scientific Manuscript database

    To develop an alternative pasteurization process for the spicy beef jerky (SBJ), SBJ was treated with irradiation doses of 0, 0.5, 1.5, 3, 4, 6 and 8 kGy and the sensory attributes, texture properties, drip loss and the protein biological efficiency were studied. The results showed that lightness, d...

  14. Destruction of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus achieved during manufacture of whole-muscle beef Jerkyin home-style dehydrators.

    PubMed

    Dierschke, Sarah; Ingham, Steven C; Ingham, Barbara H

    2010-11-01

    Adequate lethality in jerky manufacture destroys appropriate levels of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus. Our goal was to evaluate the lethality of four home-style dehydrator processes against these pathogens. Whole-muscle beef strips were inoculated with L. monocytogenes (five strains), S. aureus (five strains), or a mixed inoculum of E. coli O157:H7 (five strains) and Salmonella (eight strains). After allowing for attachment, strips were marinated in Colorado-, Original-, or Teriyaki-seasoned marinade for 22 to 24 h and dried in three home-style dehydrators (Garden Master, Excalibur, and Jerky Xpress) at 57.2 to 68.3°C. Samples were taken postmarination; after 4, 6, and 8 h of drying; and after drying, followed by heating for 10 min in a 135°C oven. Surviving inocula were enumerated. With a criterion of ≥ 5.0-log CFU/cm² reduction as the standard for adequate process lethality, none of the samples achieved the target lethality for any pathogen after 4 h of drying, even though all samples appeared "done" (water activity of less than 0.85). A postdehydration oven-heating step increased the proportion of samples meeting the target lethality after 4 h of drying to 71.9, 88.9, 55.6, and 77.8% for L. monocytogenes-, S. aureus-, E. coli O157:H7-, and Salmonella-inoculated samples, respectively, and after an 8-h drying to 90.6, 94.4, 83.3, and 91.7% of samples, respectively. Significantly greater lethality was seen with higher dehydrator temperature and significantly lower with Teriyaki-marinated samples. Heating jerky dried in a home-style dehydrator for 10 min in a 135°C oven would be an effective way to help ensure safety of this product.

  15. Identification and Development of Simple Acceptance Tests for MRE Film Pouch Materials

    DTIC Science & Technology

    2006-01-26

    retort applications, such as wheat snack bread, shortbread cookies, and beef jerky. Film #2 (48 GA PET/10#PE/.00035F/2 mil sealant) was chosen as the...for polymers) is the melt flow direction and its relation to the direction of the scratch test. It is known that, when polymers are molded or extruded

  16. Development: Ages & Stages--Emerging Physical Skills

    ERIC Educational Resources Information Center

    Poole, Carla; Miller, Susan A.; Church, Ellen Booth

    2005-01-01

    In this article, the authors discuss how children develop their motor skills at different age levels. Newborn's movements are jerky and uncoordinated. Spending lots of floor time with a baby lying on her back or stomach helps her develop coordination, balance, and muscle strength during her earliest months. As locomotion enters a baby's life, she…

  17. Thermal and athermal crackling noise in ferroelastic nanostructures.

    PubMed

    Zhao, Z; Ding, X; Sun, J; Salje, E K H

    2014-04-09

    The evolution of ferroelastic microstructures under external shear is determined by large-scale molecular dynamics simulations in two and three dimensions. Ferroelastic pattern formation was found to be almost identical in two and three dimensions, with only the ferroelastic transition temperature changing. The twin patterns generated by shear deformation depend strongly on temperature, with high wall densities nucleating under optimized temperature conditions. The dynamical tweed and mobile kink movement inside the twin walls is continuous and thermally activated at high temperatures, and becomes jerky and athermal at low temperatures. With decreasing temperature, the statistical distributions of dynamical tweed and kinks vary from a Vogel-Fulcher law P(E)~exp-(E/(T-TVF)) to an athermal power-law distribution P(E)~E-E. During the yield event, the nucleation of needles and kinks is always jerky, and the energy of the jerks is power-law distributed. Low-temperature yield proceeds via one large avalanche. With increasing temperature, the large avalanche is thermally broken up into a multitude of small segments. The power-law exponents reflect the changes in temperature, even in the athermal regime.

  18. In Defense of Memorization: The Role of Periodization in Historical Inquiry

    ERIC Educational Resources Information Center

    Neumann, Dave

    2011-01-01

    The author is a master packer. Last summer, anticipating the thousand-mile drive from southern California to Colorado, he packed their Sienna so that everything had its logical place, from the DVDs to the audio books, from the beef jerky to the bottled Starbucks mocha. Of course, at first he had to explain to everyone else where things were, since…

  19. Agriculture and Food: Critical Infrastructure and Key Resources Sector-Specific Plan as Input to the National Infrastructure Protection Plan

    DTIC Science & Technology

    2007-05-01

    sliced egg sand- wich (closed-faced), frozen fish dinner, rabbit stew, shrimp-flavored instant noodles , venison jerky, buffalo burgers, alligator...meat or 2% or more poultry (e.g., chicken noodle ) Other products Cheese, onion, mushroom pizza; spaghetti sauces (less than 3% red meat), spaghetti...sauce with mushrooms and 2% meat, pork and beans, sliced egg sandwich (closed-faced), frozen fish dinner, rabbit stew, shrimp-flavored instant

  20. Restless Legs Symptoms and Pregnancy and Neonatal Outcomes.

    PubMed

    Oyieng'o, D Onentia; Kirwa, Kipruto; Tong, Iris; Martin, Susan; Antonio Rojas-Suarez, José; Bourjeily, Ghada

    2016-02-01

    Restless legs syndrome (RLS) is a commonly occurring neurologic disorder that affects up to one third of women during pregnancy. RLS has been associated with increased sympathetic tone in the nonpregnant population. We examined whether a RLS surrogate is associated with a higher prevalence of pregnancy and neonatal outcomes. Data were analyzed from a cross-sectional survey of 1000 women interviewed soon after delivery by using an RLS surrogate question. Women were asked how frequently (0 = none, 1 = rarely [<1 time/week], 2 = sometimes [1-2 times/week], 3 = frequently [3-4 times/week], and 4 = always [5-7 times/week]) they had "experienced jumpy or jerky leg movements" in the last 3 months of pregnancy. Clinical charts were reviewed to obtain relevant demographic and clinical data, including the presence of gestational hypertensive disorders and neonatal outcomes at birth. Subjects who "always" experienced RLS were compared with subjects experiencing symptoms less frequently or not at all with respect to prevalence of gestational hypertensive disorder. The mean ([SD]) age, prepregnancy body mass index (BMI), and BMI at delivery were 29.0 (6.1) years, 26.1 (6.2) kg/m(2), and 32.0 (6.3) kg/m(2), respectively. The overall prevalence of the RLS surrogate (jumpy or jerky leg movements) was 35.5% with the following distribution on a Likert scale: score 1 = 6.4%; score 2 = 10.2%; score 3 = 8.1%; and score 4 = 10.8%. Chronic hypertension was present in 2.1%, pregnancy-induced hypertension in 9.5%, and preeclampsia in 4.5% of respondents. Subjects who reported "always" having sensations of jumpy or jerky legs were more likely to have gestational hypertensive disorders compared with those who reported less frequent occurrence of the symptoms. Adjusted odds ratios were 3.74 (95% CI, 1.31-10.72; P = 0.014) for chronic hypertension; 1.26 (95% CI, 0.65-2.46; P = 0.487) for pregnancy-induced hypertension; and 2.15 (95% CI, 0.97-4.75; P = 0.060) for preeclampsia. There was a

  1. Impact of elicited mood on movement expressivity during a fitness task.

    PubMed

    Giraud, Tom; Focone, Florian; Isableu, Brice; Martin, Jean-Claude; Demulier, Virginie

    2016-10-01

    The purpose of the present study was to evaluate the impact of four mood conditions (control, positive, negative, aroused) on movement expressivity during a fitness task. Motion capture data from twenty individuals were recorded as they performed a predefined motion sequence. Moods were elicited using task-specific scenarii to keep a valid context. Movement qualities inspired by Effort-Shape framework (Laban & Ullmann, 1971) were computed (i.e., Impulsiveness, Energy, Directness, Jerkiness and Expansiveness). A reduced number of computed features from each movement quality was selected via Principal Component Analyses. Analyses of variance and Generalized Linear Mixed Models were used to identify movement characteristics discriminating the four mood conditions. The aroused mood condition was strongly associated with increased mean Energy compared to the three other conditions. The positive and negative mood conditions showed more subtle differences interpreted as a result of their moderate activation level. Positive mood was associated with more impulsive movements and negative mood was associated with more tense movements (i.e., reduced variability and increased Jerkiness). Findings evidence the key role of movement qualities in capturing motion signatures of moods and highlight the importance of task context in their interpretations. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Sporadic frame dropping impact on quality perception

    NASA Astrophysics Data System (ADS)

    Pastrana-Vidal, Ricardo R.; Gicquel, Jean Charles; Colomes, Catherine; Cherifi, Hocine

    2004-06-01

    Over the past few years there has been an increasing interest in real time video services over packet networks. When considering quality, it is essential to quantify user perception of the received sequence. Severe motion discontinuities are one of the most common degradations in video streaming. The end-user perceives a jerky motion when the discontinuities are uniformly distributed over time and an instantaneous fluidity break is perceived when the motion loss is isolated or irregularly distributed. Bit rate adaptation techniques, transmission errors in the packet networks or restitution strategy could be the origin of this perceived jerkiness. In this paper we present a psychovisual experiment performed to quantify the effect of sporadically dropped pictures on the overall perceived quality. First, the perceptual detection thresholds of generated temporal discontinuities were measured. Then, the quality function was estimated in relation to a single frame dropping for different durations. Finally, a set of tests was performed to quantify the effect of several impairments distributed over time. We have found that the detection thresholds are content, duration and motion dependent. The assessment results show how quality is impaired by a single burst of dropped frames in a 10 sec sequence. The effect of several bursts of discarded frames, irregularly distributed over the time is also discussed.

  3. Subthalamic nucleus detects unnatural android movement.

    PubMed

    Ikeda, Takashi; Hirata, Masayuki; Kasaki, Masashi; Alimardani, Maryam; Matsushita, Kojiro; Yamamoto, Tomoyuki; Nishio, Shuichi; Ishiguro, Hiroshi

    2017-12-19

    An android, i.e., a realistic humanoid robot with human-like capabilities, may induce an uncanny feeling in human observers. The uncanny feeling about an android has two main causes: its appearance and movement. The uncanny feeling about an android increases when its appearance is almost human-like but its movement is not fully natural or comparable to human movement. Even if an android has human-like flexible joints, its slightly jerky movements cause a human observer to detect subtle unnaturalness in them. However, the neural mechanism underlying the detection of unnatural movements remains unclear. We conducted an fMRI experiment to compare the observation of an android and the observation of a human on which the android is modelled, and we found differences in the activation pattern of the brain regions that are responsible for the production of smooth and natural movement. More specifically, we found that the visual observation of the android, compared with that of the human model, caused greater activation in the subthalamic nucleus (STN). When the android's slightly jerky movements are visually observed, the STN detects their subtle unnaturalness. This finding suggests that the detection of unnatural movements is attributed to an error signal resulting from a mismatch between a visual input and an internal model for smooth movement.

  4. Size and Crystallographic Orientation Effects on the Mechanical Behavior of 4H-SiC Micro-/nano-pillars

    NASA Astrophysics Data System (ADS)

    Guo, Xiaolei; Guo, Qiang; Li, Zhiqiang; Fan, Genlian; Xiong, Ding-Bang; Su, Yishi; Zhang, Jie; Tan, Zhanqiu; Guo, Cuiping; Zhang, Di

    2018-02-01

    Single crystalline 4H-SiC micro-/nano-pillars of various sizes and different crystallographic orientations were fabricated and tested by uniaxial compression. The pillars with zero shear stress resolved on the basal slip system were found to fracture in a brittle manner without showing significant size dependence, while the pillars with non-zero resolved shear stress showed a "smaller is stronger" behavior and a jerky plastic flow. These observations were interpreted by homogeneous dislocation nucleation and dislocation glide on the basal plane.

  5. Objective assessment of actual chewing side by measurement of bilateral masseter muscle electromyography.

    PubMed

    Yamasaki, Yo; Kuwatsuru, Rika; Tsukiyama, Yoshihiro; Matsumoto, Hiroshi; Oki, Kyosuke; Koyano, Kiyoshi

    2015-12-01

    The aim of this study was to examine the validity of objective assessment of actual chewing side by measurement of electromyographic (EMG) activity of the bilateral masseter muscles upon chewing test foods. The sample consisted of 19 healthy, dentate individuals. The subjects were asked to chew three types of test foods (peanuts, beef jerky, and chewing gum) for 10 strokes on the right side and then on the left side, and instructed to perform maximum voluntary clenching for 3s, three times. EMG activity from the bilateral masseter muscles was recorded. The data were collected in three different days. The root mean square EMG amplitude obtained from the maximum clenching task was used as the maximum voluntary contraction (MVC). Then, the level of amplitude against the MVC (%MVC) was calculated for the right and left sides on each stroke. The side with the larger %MVC value was judged as the chewing side, and the concordance rates (CRs) for the instructed chewing side (ICS) and the judged chewing side (JCS) were calculated. Intraclass correlation coefficients (ICCs) of the CRs were calculated to evaluate the reproducibility of the method. High CRs between the ICS and JCS for each test food were recognized. There were significant ICCs for beef jerky (R=0.761, P<0.001) and chewing gum (R=0.785, P<0.001). The results suggested that the measurement of EMG activity from the bilateral masseter muscles may be a useful method for the objective determination of the actual chewing side during mastication. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Mechanism of work hardening in Hadfield manganese steel

    NASA Astrophysics Data System (ADS)

    Dastur, Y. N.; Leslie, W. C.

    1981-05-01

    When Hadfield manganese steel in the single-phase austenitic condition was strained in tension, in the temperature range - 25 to 300 °C, it exhibited jerky (serrated) flow, a negative (inverse) strain-rate dependence of flow stress and high work hardening, characteristic of dynamic strain aging. The strain rate-temperature regime of jerky flow was determined and the apparent activation energies for the appearance and disappearance of serrations were found to be 104 kJ/mol and 146 kJ/mol, respectively. The high work hardening cannot be a result of mechanical twinning because at -50 °C numerous twins were produced, but the work hardening was low and no twins were formed above 225 °C even though work hardening was high. The work hardening decreased above 300 °C because of the cessation of dynamic strain aging and increased again above 400 °C because of precipitation of carbides. An apparent activation energy of 138 kJ/mol was measured for static strain aging between 300 and 400 °C, corresponding closely to the activation energies for the disapperance of serrations and for the volume diffusion of carbon in Hadfield steel. Evidence from the present study, together with the known effect of manganese on the activity of carbon in austenite and previous internal friction studies of high-manganese steels, lead to the conclusion that dynamic strain aging, brought about by the reorientation of carbon members of C-Mn couples in the cores of dislocations, is the principal cause of rapid work hardening in Hadfield steel.

  7. Two career chaos

    NASA Astrophysics Data System (ADS)

    Tauxe, L.

    2002-12-01

    When I finished graduate school I suppose I imagined myself as my dad. He worked hard, loved his job and family, made a good living. But I also saw myself as my mom - making a home, raising kids, cooking dinner, saving the world. I thought: I can handle being my mom and my dad. I can handle being a scientist and a mother. I can DO this.ÿ What I never imagined was the chaotic dynamic of the two career couple. The motions of bodies moving in response to the force of gravity cannot be predicted exactly if there are too many bodies. They dance in a jerky jumble, now faster, then slowly, bouncing, jostling, bumping and flying apart. Just so are the career trajectories of the two career couple. One rises up, the other, slower, pulls it down; overtaking, blocking preventing, now supporting, pulling along, now holding back - not moving, leap frogging, racing in opposite directions and snapping back together with a crack.ÿ The problem is non-linear. The outcome depends on feedback, whether positive or negative. The outcome cannot be predicted. Cannot be determined.ÿ Perhaps it cannot be done. Perhaps both husband and wife cannot be both mother and father. Too many mothers, too many fathers. Chaos.ÿ But I believe it can be done. Not like our mothers and fathers but a different way. And maybe our jerky paths will keep us sharp, make us work harder, and lead us through lives that at least cannot be described as dull.ÿ

  8. Oscillations in a half-empty bottle

    NASA Astrophysics Data System (ADS)

    Bourges, Andréane; Chardac, Amélie; Caussarieu, Aude; Plihon, Nicolas; Taberlet, Nicolas

    2018-02-01

    When a half-empty bottle of water is pushed to roll on a flat surface, the oscillations of the fluid inside the bottle induce an overall jerky motion. These velocity fluctuations of the bottle are studied through simple laboratory experiments accessible to undergraduate students and can help them to grasp fundamental concepts in mechanics and hydrodynamics. We first demonstrate through an astute experiment that the rotation of the fluid and the bottle is decoupled. The equations of motion are then derived using a mechanical approach, while the hydrodynamics of the fluid motion is explained. Finally, the theory is tested against two benchmark experiments.

  9. Silicon Ingot Casting - Heat Exchanger Method Multi-wire Slicing - Fixed Abrasive Slicing Technique. Phase 3 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-cost Solar Array Project

    NASA Technical Reports Server (NTRS)

    Schmid, F.; Khattak, C. P.

    1979-01-01

    Several 20 cm diameter silicon ingots, up to 6.3 kg. were cast with good crystallinity. The graphite heat zone can be purified by heating it to high temperatures in vacuum. This is important in reducing costs and purification of large parts. Electroplated wires with 45 um synthetic diamonds and 30 um natural diamonds showed good cutting efficiency and lifetime. During slicing of a 10 cm x 10 cm workpiece, jerky motion occurred in the feed and rocking mechanisms. This problem is corrected and modifications were made to reduce the weight of the bladeheat by 50%.

  10. Investigation of Listeria, Salmonella, and toxigenic Escherichia coli in various pet foods.

    PubMed

    Nemser, Sarah M; Doran, Tara; Grabenstein, Michael; McConnell, Terri; McGrath, Timothy; Pamboukian, Ruiqing; Smith, Angele C; Achen, Maya; Danzeisen, Gregory; Kim, Sun; Liu, Yong; Robeson, Sharon; Rosario, Grisel; McWilliams Wilson, Karen; Reimschuessel, Renate

    2014-09-01

    The Veterinary Laboratory Investigation and Response Network (Vet-LIRN), in collaboration with the Food Emergency Response Network (FERN) and its Microbiology Cooperative Agreement Program (MCAP) laboratories, conducted a study to evaluate the prevalence of selected microbial organisms in various types of pet foods. The goal of this blinded study was to help the Center for Veterinary Medicine prioritize potential future pet food-testing efforts. The study also increased the FERN laboratories' screening capabilities for foodborne pathogens in animal feed matrices, since such pathogens may also be a significant health risk to consumers who come into contact with pet foods. Six U.S. Food and Drug Administration FERN MCAP laboratories analyzed approximately 1056 samples over 2 years. Laboratories tested for Salmonella, Listeria, Escherichia coli O157:H7 enterohemorrhagic E. coli, and Shiga toxin-producing strains of E. coli (STEC). Dry and semimoist dog and cat foods purchased from local stores were tested during Phase 1. Raw dog and cat foods, exotic animal feed, and jerky-type treats purchased through the Internet were tested in Phase 2. Of the 480 dry and semimoist samples, only 2 tested positive: 1 for Salmonella and 1 for Listeria greyii. However, of the 576 samples analyzed during Phase 2, 66 samples were positive for Listeria (32 of those were Listeria monocytogenes) and 15 samples positive for Salmonella. These pathogens were isolated from raw foods and jerky-type treats, not the exotic animal dry feeds. This study showed that raw pet foods may harbor food safety pathogens, such as Listeria monocytogenes and Salmonella. Consumers should handle these products carefully, being mindful of the potential risks to human and animal health.

  11. Investigation of Listeria, Salmonella, and Toxigenic Escherichia coli in Various Pet Foods

    PubMed Central

    Doran, Tara; Grabenstein, Michael; McConnell, Terri; McGrath, Timothy; Pamboukian, Ruiqing; Smith, Angele C.; Achen, Maya; Danzeisen, Gregory; Kim, Sun; Liu, Yong; Robeson, Sharon; Rosario, Grisel; McWilliams Wilson, Karen; Reimschuessel, Renate

    2014-01-01

    Abstract The Veterinary Laboratory Investigation and Response Network (Vet-LIRN), in collaboration with the Food Emergency Response Network (FERN) and its Microbiology Cooperative Agreement Program (MCAP) laboratories, conducted a study to evaluate the prevalence of selected microbial organisms in various types of pet foods. The goal of this blinded study was to help the Center for Veterinary Medicine prioritize potential future pet food–testing efforts. The study also increased the FERN laboratories' screening capabilities for foodborne pathogens in animal feed matrices, since such pathogens may also be a significant health risk to consumers who come into contact with pet foods. Six U.S. Food and Drug Administration FERN MCAP laboratories analyzed approximately 1056 samples over 2 years. Laboratories tested for Salmonella, Listeria, Escherichia coli O157:H7 enterohemorrhagic E. coli, and Shiga toxin–producing strains of E. coli (STEC). Dry and semimoist dog and cat foods purchased from local stores were tested during Phase 1. Raw dog and cat foods, exotic animal feed, and jerky-type treats purchased through the Internet were tested in Phase 2. Of the 480 dry and semimoist samples, only 2 tested positive: 1 for Salmonella and 1 for Listeria greyii. However, of the 576 samples analyzed during Phase 2, 66 samples were positive for Listeria (32 of those were Listeria monocytogenes) and 15 samples positive for Salmonella. These pathogens were isolated from raw foods and jerky-type treats, not the exotic animal dry feeds. This study showed that raw pet foods may harbor food safety pathogens, such as Listeria monocytogenes and Salmonella. Consumers should handle these products carefully, being mindful of the potential risks to human and animal health. PMID:24824368

  12. Pleiotropy in microdeletion syndromes: Neurologic and spermatogenic abnormalities in mice homozygous for the p{sup 6H} deletion are likely due to dysfunction of a single gene

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rinchik, E.M.; Carpenter, D.A.; Handel, M.A.

    1995-07-03

    Variability and complexity of phenotypes observed in microdeletion syndromes can be due to deletion of a single gene whose product participates in several aspects of development or can be due to the deletion of a number of tightly linked genes, each adding its own effect to the syndrome. The p{sup 6H} deletion in mouse chromosome 7 presents a good model with which to address this question of multigene vs. single-gene pleiotropy. Mice homozygous for the p{sup 6H} deletion are diluted in pigmentation, are smaller than their littermates, and manifest a nervous jerky-gait phenotype. Male homozygotes are sterile and exhibit profoundmore » abnormalities in spermiogenesis. By using N-ethyl-N-nitrosourea (EtNU) mutagenesis and a breeding protocol designed to recover recessive mutations expressed hemizygously opposite a large p-locus deletion, we have generated three noncomplementing mutations that map to the p{sup 6H} deletion. Each of these EtNU-induced mutations has adverse effects on the size, nervous behavior, and progression of spermiogenesis that characterize p{sup 6H} deletion homozygotes. Because etNU is thought to induce primarily intragenic (point) mutations in mouse stem-cell spermatogonia, we propose that the trio of phenotypes (runtiness, nervous jerky gait, and male sterility) expressed in p{sup 6H} deletion homozygotes is the result of deletion of a single highly pleiotropic gene. We also predict that a homologous single locus, quite possibly tightly linked and distal to the D15S12 (P) locus in human chromosome 15q11-q13, may be associated with similar developmental abnormalities in humans. 29 refs., 3 figs., 1 tab.« less

  13. Deimatic Display in the European Swallowtail Butterfly as a Secondary Defence against Attacks from Great Tits

    PubMed Central

    Olofsson, Martin; Eriksson, Stephan; Jakobsson, Sven; Wiklund, Christer

    2012-01-01

    Background Many animals reduce the risk of being attacked by a predator through crypsis, masquerade or, alternatively, by advertising unprofitability by means of aposematic signalling. Behavioural attributes in prey employed after discovery, however, signify the importance of also having an effective secondary defence if a predator uncovers, or is immune to, the prey’s primary defence. In butterflies, as in most animals, secondary defence generally consists of escape flights. However, some butterfly species have evolved other means of secondary defence such as deimatic displays/startle displays. The European swallowtail, Papilio machaon, employs what appears to be a startle display by exposing its brightly coloured dorsal wing surface upon disturbance and, if the disturbance continues, by intermittently protracting and relaxing its wing muscles generating a jerky motion of the wings. This display appears directed towards predators but whether it is effective in intimidating predators so that they refrain from attacks has never been tested experimentally. Methodology/Principal Findings In this study we staged encounters between a passerine predator, the great tit, Parus major, and live and dead swallowtail butterflies in a two-choice experiment. Results showed that the dead butterfly was virtually always attacked before the live butterfly, and that it took four times longer before a bird attacked the live butterfly. When the live butterfly was approached by a bird this generally elicited the butterfly’s startle display, which usually caused the approaching bird to flee. We also performed a palatability test of the butterflies and results show that the great tits seemed to find them palatable. Conclusions/Significance We conclude that the swallowtail’s startle display of conspicuous coloration and jerky movements is an efficient secondary defence against small passerines. We also discuss under what conditions predator-prey systems are likely to aid the

  14. Deimatic display in the European swallowtail butterfly as a secondary defence against attacks from great tits.

    PubMed

    Olofsson, Martin; Eriksson, Stephan; Jakobsson, Sven; Wiklund, Christer

    2012-01-01

    Many animals reduce the risk of being attacked by a predator through crypsis, masquerade or, alternatively, by advertising unprofitability by means of aposematic signalling. Behavioural attributes in prey employed after discovery, however, signify the importance of also having an effective secondary defence if a predator uncovers, or is immune to, the prey's primary defence. In butterflies, as in most animals, secondary defence generally consists of escape flights. However, some butterfly species have evolved other means of secondary defence such as deimatic displays/startle displays. The European swallowtail, Papilio machaon, employs what appears to be a startle display by exposing its brightly coloured dorsal wing surface upon disturbance and, if the disturbance continues, by intermittently protracting and relaxing its wing muscles generating a jerky motion of the wings. This display appears directed towards predators but whether it is effective in intimidating predators so that they refrain from attacks has never been tested experimentally. In this study we staged encounters between a passerine predator, the great tit, Parus major, and live and dead swallowtail butterflies in a two-choice experiment. Results showed that the dead butterfly was virtually always attacked before the live butterfly, and that it took four times longer before a bird attacked the live butterfly. When the live butterfly was approached by a bird this generally elicited the butterfly's startle display, which usually caused the approaching bird to flee. We also performed a palatability test of the butterflies and results show that the great tits seemed to find them palatable. We conclude that the swallowtail's startle display of conspicuous coloration and jerky movements is an efficient secondary defence against small passerines. We also discuss under what conditions predator-prey systems are likely to aid the evolution of deimatic behaviours in harmless and palatable prey.

  15. Long-period long-duration seismic events during hydraulic fracturing: Implications for tensile fracture development

    NASA Astrophysics Data System (ADS)

    Hu, Hongru; Li, Aibing; Zavala-Torres, Ricardo

    2017-05-01

    Long-period long-duration (LPLD) seismic events are observed from a microseismic data set acquired by surface receivers in the Eagle Ford Shale. These events are characterized by low frequencies of 10-60 Hz and long durations of 30-60 s. The seismograms are dominated with P waves, and the frequency spectra have peaks at several isolated frequencies, similar to volcanic tremors. The LPLD events are located close to the horizontal hydraulic treatment well and migrate away from the well with time. These observations suggest that the LPLD events are related to hydraulic fracturing and are possibly caused by the jerky opening and resonance of fluid-filled cracks. Imaging this type of LPLD events can potentially map fluid flow and tensile fracture development during hydraulic fracturing.

  16. Virtual reality and telerobotics applications of an Address Recalculation Pipeline

    NASA Technical Reports Server (NTRS)

    Regan, Matthew; Pose, Ronald

    1994-01-01

    The technology described in this paper was designed to reduce latency to user interactions in immersive virtual reality environments. It is also ideally suited to telerobotic applications such as interaction with remote robotic manipulators in space or in deep sea operations. in such circumstances the significant latency is observed response to user stimulus which is due to communications delays, and the disturbing jerkiness due to low and unpredictable frame rates on compressed video user feedback or computationally limited virtual worlds, can be masked by our techniques. The user is provided with highly responsive visual feedback independent of communication or computational delays in providing physical video feedback or in rendering virtual world images. Virtual and physical environments can be combined seamlessly using these techniques.

  17. Judder-Induced Edge Flicker at Zero Spatial Contrast

    NASA Technical Reports Server (NTRS)

    Larimer, James; Feng, Christine; Gille, Jennifer; Cheung, Victor

    2004-01-01

    Judder is a motion artifact that degrades the quality of video imagery. Smooth motion appears jerky and can appear to flicker along the leading and trailing edge of the moving object. In a previous paper, we demonstrated that the strength of the edge flicker signal depended upon the brightness of the scene and the contrast of the moving object relative to the background. Reducing the contrast between foreground and background reduced the flicker signal. In this report, we show that the contrast signal required for judder-induced edge flicker is due to temporal contrast and not simply to spatial contrast. Bars made of random dots of the same dot density as the background exhibit edge flicker when moved at sufficient rate.

  18. Tsallis q-triplet, intermittent turbulence and Portevin-Le Chatelier effect

    NASA Astrophysics Data System (ADS)

    Iliopoulos, A. C.; Aifantis, E. C.

    2018-05-01

    In this paper, we extend a previous study concerning Portevin-LeChatelier (PLC) effect and Tsallis statistics (Iliopoulos et al., 2015). In particular, we estimate Tsallis' q-triplet, namely {qstat, qsens, qrel} for two sets of stress serration time series concerning the deformation of Cu-15%Al alloy corresponding to different deformation temperatures and thus types (A and B) of PLC bands. The results concerning the stress serrations analysis reveal that Tsallis q- triplet attains values different from unity ({qstat, qsens, qrel} ≠ {1,1,1}). In particular, PLC type A bands' serrations were found to follow Tsallis super-q-Gaussian, non-extensive, sub-additive, multifractal statistics indicating that the underlying dynamics are at the edge of chaos, characterized by global long range correlations and power law scaling. For PLC type B bands' serrations, the results revealed a Tsallis sub-q-Gaussian, non-extensive, super-additive, multifractal statistical profile. In addition, our results reveal also significant differences in statistical and dynamical features, indicating important variations of the stress field dynamics in terms of rate of entropy production, relaxation dynamics and non-equilibrium meta-stable stationary states. We also estimate parameters commonly used for characterizing fully developed turbulence, such as structure functions and flatness coefficient (F), in order to provide further information about jerky flow underlying dynamics. Finally, we use two multifractal models developed to describe turbulence, namely Arimitsu and Arimitsu (A&A) [2000, 2001] theoretical model which is based on Tsallis statistics and p-model to estimate theoretical multifractal spectrums f(a). Furthermore, we estimate flatness coefficient (F) using a theoretical formula based on Tsallis statistics. The theoretical results are compared with the experimental ones showing a remarkable agreement between modeling and experiment. Finally, the results of this study verify, as

  19. Tales told by tails: watching DNA driven through a random medium

    NASA Astrophysics Data System (ADS)

    Guan, Juan; Wang, Bo; Bae, Sung Chul; Granick, Steve

    2013-03-01

    DNA ligation is used to label separately the ends and centers of monodisperse DNA 16 μm in contour length, and 2-color fluorescence microscopy is used to follow with nm resolution how chains migrate through agarose networks driven by electric fields, at both whole chain and segment level. We observe that the leading segment is always a physical chain end which stretches and pulls out slack in the still-quiescent remainder of the chain until the other end is taken up. Heads and tails behave strikingly differently: the leading end of migrating chains migrates more smoothly, whereas motion of the trailing end shows intermittent pauses and jerky recoil. None of the mechanisms imagined classically for this situation - chain reptation, hooking or entropic trapping, appears to fully describe these data obtained from single-molecule visualization.

  20. A Case of Hemiabdominal Myoclonus.

    PubMed

    Nociti, Viviana; Servidei, Serenella; Luigetti, Marco; Iorio, Raffaele; Lo Monaco, Mauro; Mirabella, Massimiliano; Frisullo, Giovanni; Della Marca, Giacomo

    2015-10-01

    Myoclonus consists of sudden, brief, involuntary jerky muscular contractions. Central and peripheral nervous system lesions are involved in the pathogenesis of this movement disorder. Symptomatic or secondary spinal myoclonus is the most common form. A 68-year-old woman was diagnosed with hemiabdominal spinal myoclonus. Occasional and very mild involuntary repetitive movements of the hemiabdomen began immediately after surgery for uterine cancer. After surgery for laparocele, secondary to the uterine cancer surgery, performed under spinal anesthesia, there was severe worsening of movements. Neuroradiological investigations failed to demonstrate spinal injury, while neurophysiological studies showed impairment of the right central somatosensory pathway. Considering the low resolution of magnetic resonance imaging in the evaluation of thoracic level, we suggest an extensive neurophysiological evaluation in patients with spinal myoclonus. © EEG and Clinical Neuroscience Society (ECNS) 2014.

  1. Swallowing endoscopy findings in Huntington's disease: a case report.

    PubMed

    Alves, Thaís Coelho; Cola, Paula Cristina; Santos, Rarissa Rúbia Dallaqua Dos; Motonaga, Suely Mayumi; Silva, Roberta Gonçalves da

    2016-01-01

    Huntington's disease (HD) is a degenerative genetic disorder with autosomal-dominant transmission. The triad of symptoms of this disease consists of psychiatric disorders, jerky movements, and dementia. Oropharyngeal dysphagia, which is more evident with disease progression, is also present. Few studies have addressed the swallowing characteristics using objective analysis in this population. The purpose of this research was to describe the swallowing endoscopic findings of the pharyngeal phase in HD. This is a cross-sectional study addressing a clinical case which included two individuals of the same family, male, 32 and 63 years old, designated as individual A and individual B, with progression of the disease for five and 13 years, respectively. Consistent liquid, nectar, and puree were offered during the evaluation. There was presence of posterior oral spillage in liquid and nectar, small amount of pharyngeal residues, and no laryngeal penetration or aspiration in the individuals with HD in this study.

  2. Experiments and Model for Serration Statistics in Low-Entropy, Medium-Entropy, and High-Entropy Alloys

    DOE PAGES

    Carroll, Robert; Lee, Chi; Tsai, Che-Wei; ...

    2015-11-23

    In this study, high-entropy alloys (HEAs) are new alloys that contain five or more elements in roughly-equal proportion. We present new experiments and theory on the deformation behavior of HEAs under slow stretching (straining), and observe differences, compared to conventional alloys with fewer elements. For a specific range of temperatures and strain-rates, HEAs deform in a jerky way, with sudden slips that make it difficult to precisely control the deformation. An analytic model explains these slips as avalanches of slipping weak spots and predicts the observed slip statistics, stress-strain curves, and their dependence on temperature, strain-rate, and material composition. Themore » ratio of the weak spots’ healing rate to the strain-rate is the main tuning parameter, reminiscent of the Portevin- LeChatellier effect and time-temperature superposition in polymers. Our model predictions agree with the experimental results. The proposed widely-applicable deformation mechanism is useful for deformation control and alloy design.« less

  3. Effects of phencyclidine, secobarbital and diazepam on eye tracking in rhesus monkeys.

    PubMed

    Ando, K; Johanson, C E; Levy, D L; Yasillo, N J; Holzman, P S; Schuster, C R

    1983-01-01

    Rhesus monkeys were trained to track a moving disk using a procedure in which responses on a lever were reinforced with water delivery only when the disk, oscillating in a horizontal plane on a screen at a frequency of 0.4 Hz in a visual angle of 20 degrees, dimmed for a brief period. Pursuit eye movements were recorded by electrooculography (EOG). IM phencyclidine, secobarbital, and diazepam injections decreased the number of reinforced lever presses in a dose-related manner. Both secobarbital and diazepam produced episodic jerky-pursuit eye movements, while phencyclidine had no consistent effects on eye movements. Lever pressing was disrupted at doses which had little effect on the quality of smooth-pursuit eye movements in some monkeys. This separation was particularly pronounced with diazepam. The similarities of the drug effects on smooth-pursuit eye movements between the present study and human studies indicate that the present method using rhesus monkeys may be useful for predicting drug effects on eye tracking and oculomotor function in humans.

  4. [Study on the first translated obstetrics book Tai chan ju yao (Essentials in Obstetrics)].

    PubMed

    Wu, M

    2018-01-28

    In 1893, Wan Tsun-mo translated and published Tai chan ju yao ( Essentials in Obstetrics ), the first monograph of western obstetrics in modern China, symbolizing the independence of obstetrics from such maternal and child books as Fu ying xin shuo and Fu ke jing yun tu shuo , which occupies an important position in the history of the development of modern Chinese obstetrics. The book introduced anatomy, physiology, pathology, embryology, diagnostics, surgery, pharmacology and other knowledge of obstetrics in a catechismal form, and had a detailed discussion of such advanced obstetrical technologies as antiseptic, anesthesia, forceps and cesarean section for the first time.Judging from the content and translation of Tai chan ju yao , this book has already possessed the basic knowledge system of modern obstetrics, though the translation appeared to be somewhat jerky and not elegant and the terminology needing to be further improved, it was not only used as an important medium for the introduction of obstetrical knowledge, but also of great clinical value.However, its influence was so weak that later researchers seldom mentioned this book.

  5. Tuned critical avalanche scaling in bulk metallic glasses

    DOE PAGES

    Antonaglia, James; Xie, Xie; Schwarz, Gregory; ...

    2014-03-17

    In this study, ingots of the bulk metallic glass (BMG), Zr 64.13Cu 15.75Ni 10.12Al 10 in atomic percent (at. %), are compressed at slow strain rates. The deformation behavior is characterized by discrete, jerky stress-drop bursts (serrations). Here we present a quantitative theory for the serration behavior of BMGs, which is a critical issue for the understanding of the deformation characteristics of BMGs. The mean-field interaction model predicts the scaling behavior of the distribution, D(S), of avalanche sizes, S, in the experiments. D(S) follows a power law multiplied by an exponentially-decaying scaling function. The size of the largest observed avalanchemore » depends on experimental tuning-parameters, such as either imposed strain rate or stress. Similar to crystalline materials, the plasticity of BMGs reflects tuned criticality showing remarkable quantitative agreement with the slip statistics of slowly-compressed nanocrystals. The results imply that material-evaluation methods based on slip statistics apply to both crystalline and BMG materials.« less

  6. Trade-off between jerk and time headway as an indicator of driving style

    PubMed Central

    Pekkanen, Jami; Lappi, Otto; Kosonen, Iisakki; Luttinen, Tapio; Summala, Heikki

    2017-01-01

    Variation in longitudinal control in driving has been discussed in both traffic psychology and transportation engineering. Traffic psychologists have concerned themselves with “driving style”, a habitual form of behavior marked by it’s stability, and its basis in psychological traits. Those working in traffic microsimulation have searched for quantitative ways to represent different driver-car systems in car following models. There has been unfortunately little overlap or theoretical consistency between these literatures. Here, we investigated relationships between directly observable measures (time headway, acceleration and jerk) in a simulated driving task where the driving context, vehicle and environment were controlled. We found individual differences in the way a trade-off was made between close but jerky vs. far and smooth following behavior. We call these “intensive” and “calm” driving, and suggest this trade-off can serve as an indicator of a possible latent factor underlying driving style. We posit that pursuing such latent factors for driving style may have implications for modelling driver heterogeneity across various domains in traffic simulation. PMID:29040291

  7. Twitching in Sensorimotor Development from Sleeping Rats to Robots

    PubMed Central

    Marques, Hugo Gravato; Iida, Fumiya

    2013-01-01

    It is still not known how the “rudimentary” movements of fetuses and infants are transformed into the coordinated, flexible, and adaptive movements of adults. In addressing this important issue, we consider a behavior that has been perennially viewed as a functionless by-product of a dreaming brain: the jerky limb movements called myoclonic twitches. Recent work has identified the neural mechanisms that produce twitching as well as those that convey sensory feedback from twitching limbs to the spinal cord and brain. In turn, these mechanistic insights have helped inspire new ideas about the functional roles that twitching might play in the self-organization of spinal and supraspinal sensorimotor circuits. Striking support for these ideas is coming from the field of developmental robotics: When twitches are mimicked in robot models of the musculoskeletal system, basic neural circuitry self-organizes. Mutually inspired biological and synthetic approaches promise not only to produce better robots, but also to solve fundamental problems concerning the developmental origins of sensorimotor maps in the spinal cord and brain. PMID:23787051

  8. Nutrients Composition in Fit Snacks Made from Ostrich, Beef and Chicken Dried Meat.

    PubMed

    Zdanowska-Sąsiadek, Żaneta; Marchewka, Joanna; Horbańczuk, Jarosław Olav; Wierzbicka, Agnieszka; Lipińska, Paulina; Jóźwik, Artur; Atanasov, Atanas G; Huminiecki, Łukasz; Sieroń, Aleksander; Sieroń, Karolina; Strzałkowska, Nina; Stelmasiak, Adrian; De Smet, Stefaan; Van Hecke, Thomas; Hoffman, Louwrens C

    2018-05-25

    The aim of the study was to compare three types of meat snacks made from ostrich, beef, and chicken meat in relation to their nutrients content including fat, fatty acids, heme iron, and peptides, like anserine and carnosine, from which human health may potentially benefit. Dry meat samples were produced, from one type of muscle, obtained from ostrich ( m. ambiens ), beef ( m. semimembranosus ), and broiler chicken meat ( m. pectoralis major ). The composition of dried ostrich, beef, and chicken meat, with and without spices was compared. We show that meat snacks made from ostrich, beef, and chicken meat were characterized by high concentration of nutrients including proteins, minerals (heme iron especially in ostrich, than in beef), biologically active peptides (carnosine-in beef, anserine-in ostrich then in chicken meat). The, beneficial to human health, n -3 fatty acids levels differed significantly between species. Moreover, ostrich jerky contained four times less fat as compared to beef and half of that in chicken. In conclusion we can say that dried ostrich, beef, and chicken meat could be a good source of nutritional components.

  9. Serration Behavior of a Zr-Based Metallic Glass Under Different Constrained Loading Conditions

    NASA Astrophysics Data System (ADS)

    Yang, G. N.; Gu, J. L.; Chen, S. Q.; Shao, Y.; Wang, H.; Yao, K. F.

    2016-11-01

    To understand the plastic behavior and shear band dynamics of metallic glasses (MGs) being tuned by the external constraint, uniaxial compression tests were performed on Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 MG samples with aspect ratios of 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, and 3:1. Better plasticity was observed for the samples with smaller aspect ratio (under higher constraint degree). In the beginning of yielding, increasing serration (jerky stress drop) size on the loading curves was noticed for all samples. Statistical analysis of the serration patterns indicated that the small stress-drop serrations and large stress-drop serrations follow self-organized critical and chaotic dynamics, respectively. Under constrained loading, the large stress-drop serrations are depressed, while the small stress-drop serrations are less affected. When changing the external constraint level by varying the sample aspect ratio, the serration pattern, shear band dynamics, and plastic behavior will change accordingly. This study provides a perspective from tuning shear band dynamics to understand the plastic behavior of MGs under different external constraint.

  10. Practical low-cost visual communication using binary images for deaf sign language.

    PubMed

    Manoranjan, M D; Robinson, J A

    2000-03-01

    Deaf sign language transmitted by video requires a temporal resolution of 8 to 10 frames/s for effective communication. Conventional videoconferencing applications, when operated over low bandwidth telephone lines, provide very low temporal resolution of pictures, of the order of less than a frame per second, resulting in jerky movement of objects. This paper presents a practical solution for sign language communication, offering adequate temporal resolution of images using moving binary sketches or cartoons, implemented on standard personal computer hardware with low-cost cameras and communicating over telephone lines. To extract cartoon points an efficient feature extraction algorithm adaptive to the global statistics of the image is proposed. To improve the subjective quality of the binary images, irreversible preprocessing techniques, such as isolated point removal and predictive filtering, are used. A simple, efficient and fast recursive temporal prefiltering scheme, using histograms of successive frames, reduces the additive and multiplicative noise from low-cost cameras. An efficient three-dimensional (3-D) compression scheme codes the binary sketches. Subjective tests performed on the system confirm that it can be used for sign language communication over telephone lines.

  11. Self-assembly of robotic micro- and nanoswimmers using magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Cheang, U. Kei; Kim, Min Jun

    2015-03-01

    Micro- and nanoscale robotic swimmers are very promising to significantly enhance the performance of particulate drug delivery by providing high accuracy at extremely small scales. Here, we introduce micro- and nanoswimmers fabricated using self-assembly of nanoparticles and control via magnetic fields. Nanoparticles self-align into parallel chains under magnetization. The swimmers exhibit flexibility under a rotating magnetic field resulting in chiral structures upon deformation, thereby having the prerequisite for non-reciprocal motion to move about at low Reynolds number. The swimmers are actuated wirelessly using an external rotating magnetic field supplied by approximate Helmholtz coils. By controlling the concentration of the suspended magnetic nanoparticles, the swimmers can be modulated into different sizes. Nanoscale swimmers are largely influenced by Brownian motion, as observed from their jerky trajectories. The microswimmers, which are roughly three times larger, are less vulnerable to the effects from Brownian motion. In this paper, we demonstrate responsive directional control of micro- and nanoswimmers and compare their respective diffusivities and trajectories to characterize the implications of Brownian disturbance on the motions of small and large swimmers. We then performed a simulation using a kinematic model for the magnetic swimmers including the stochastic nature of Brownian motion.

  12. Quantitative detection of pork in commercial meat products by TaqMan® real-time PCR assay targeting the mitochondrial D-loop region.

    PubMed

    Kim, Miju; Yoo, Insuk; Lee, Shin-Young; Hong, Yeun; Kim, Hae-Yeong

    2016-11-01

    The TaqMan® real-time PCR assay using the mitochondrial D-loop region was developed for the quantitative detection of pork in processed meat products. The newly designed primers and probe specifically amplified pork without any cross-reactivity with non-target animal species. The limit of detection of the real-time PCR assay was 0.1pg of heat-treated pork meat and 0.1% (w/w) pork meat in beef and chicken meat mixtures. The quantitative real-time PCR assay was applied to analyze the pork meat content in 22 commercial processed meat products including jerkies, press hams, sausages, hamburger patties and steaks, grilled short rib patties, and nuggets. The developed real-time PCR method was able to detect pork meat in various types of processed meat products that declared the use of pork meat on their label. All processed meat products that declared no use of pork meat showed a negative result in the assay. The method developed in this study showed sensitivity and specificity in the quantification of pork meat in commercial processed meat products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Perceptual video quality assessment in H.264 video coding standard using objective modeling.

    PubMed

    Karthikeyan, Ramasamy; Sainarayanan, Gopalakrishnan; Deepa, Subramaniam Nachimuthu

    2014-01-01

    Since usage of digital video is wide spread nowadays, quality considerations have become essential, and industry demand for video quality measurement is rising. This proposal provides a method of perceptual quality assessment in H.264 standard encoder using objective modeling. For this purpose, quality impairments are calculated and a model is developed to compute the perceptual video quality metric based on no reference method. Because of the shuttle difference between the original video and the encoded video the quality of the encoded picture gets degraded, this quality difference is introduced by the encoding process like Intra and Inter prediction. The proposed model takes into account of the artifacts introduced by these spatial and temporal activities in the hybrid block based coding methods and an objective modeling of these artifacts into subjective quality estimation is proposed. The proposed model calculates the objective quality metric using subjective impairments; blockiness, blur and jerkiness compared to the existing bitrate only calculation defined in the ITU G 1070 model. The accuracy of the proposed perceptual video quality metrics is compared against popular full reference objective methods as defined by VQEG.

  14. Emergence of complex behavior in pili-based motility in early stages of P. aeruginosa surface adaptation

    NASA Astrophysics Data System (ADS)

    Brill-Karniely, Yifat; Jin, Fan; Wong, Gerard C. L.; Frenkel, Daan; Dobnikar, Jure

    2017-04-01

    Pseudomonas aeruginosa move across surfaces by using multiple Type IV Pili (TFP), motorized appendages capable of force generation via linear extension/retraction cycles, to generate surface motions collectively known as twitching motility. Pseudomonas cells arrive at a surface with low levels of piliation and TFP activity, which both progressively increase as the cells sense the presence of a surface. At present, it is not clear how twitching motility emerges from these initial minimal conditions. Here, we build a simple model for TFP-driven surface motility without complications from viscous and solid friction on surfaces. We discover the unanticipated structural requirement that TFP motors need to have a minimal amount of effective angular rigidity in order for cells to perform the various classes of experimentally-observed motions. Moreover, a surprisingly small number of TFP are needed to recapitulate movement signatures associated with twitching: Two TFP can already produce movements reminiscent of recently observed slingshot type motion. Interestingly, jerky slingshot motions characteristic of twitching motility comprise the transition region between different types of observed crawling behavior in the dynamical phase diagram, such as self-trapped localized motion, 2-D diffusive exploration, and super-diffusive persistent motion.

  15. CVD2014-A Database for Evaluating No-Reference Video Quality Assessment Algorithms.

    PubMed

    Nuutinen, Mikko; Virtanen, Toni; Vaahteranoksa, Mikko; Vuori, Tero; Oittinen, Pirkko; Hakkinen, Jukka

    2016-07-01

    In this paper, we present a new video database: CVD2014-Camera Video Database. In contrast to previous video databases, this database uses real cameras rather than introducing distortions via post-processing, which results in a complex distortion space in regard to the video acquisition process. CVD2014 contains a total of 234 videos that are recorded using 78 different cameras. Moreover, this database contains the observer-specific quality evaluation scores rather than only providing mean opinion scores. We have also collected open-ended quality descriptions that are provided by the observers. These descriptions were used to define the quality dimensions for the videos in CVD2014. The dimensions included sharpness, graininess, color balance, darkness, and jerkiness. At the end of this paper, a performance study of image and video quality algorithms for predicting the subjective video quality is reported. For this performance study, we proposed a new performance measure that accounts for observer variance. The performance study revealed that there is room for improvement regarding the video quality assessment algorithms. The CVD2014 video database has been made publicly available for the research community. All video sequences and corresponding subjective ratings can be obtained from the CVD2014 project page (http://www.helsinki.fi/psychology/groups/visualcognition/).

  16. Genital Autocleaning in the Male Cricket Gryllus bimaculatus (2): Rhythmic Movements of the Genitalia and Their Motor Control.

    PubMed

    Kumashiro, Mikihiko; Sakai, Masaki

    2016-12-01

    Three types of genital movement, their neural controls, and functional roles were investigated to gain a better understanding of the mechanism underlying autocleaning in the male cricket. The membrane complex consisting of the median pouch and genital chamber floor shows peculiar undulation that is composed of two types of movements: a right-left large shift and small crease-like movements. The large shift was caused by contraction of a pair of muscles (MPA) located anterior to the median pouch, while the crease-like movements were caused by numerous muscle fibers extending over the membrane complex. The MPA and muscle fibers were each innervated by efferent neurons in the terminal abdominal ganglion. Experiments with artificial dirt mimicking a foreign object revealed that the crease-like movements were responsible for dirt transport, while the large shift participated in sweeping the dirt into the lateral pouch as a trash container. On the other hand, the dorsal pouch serving as a template for the spermatophore showed a jerky bending movement. Simultaneous monitoring of the membrane complex and dorsal pouch activities suggested that their movements cooperate to enable the efficient evacuation of waste in the dorsal pouch. Based on the results, we conclude that genital autocleaning supports the production of the spermatophore.

  17. Cervical Spine Mechanism for Reproduction of the Biomechanical Behaviours of the Human Neck during Rotation-Traction Manipulation

    PubMed Central

    Zhu, Liguo

    2017-01-01

    Rotation-traction (RT) manipulation is a commonly used physical therapy procedure in TCM (traditional Chinese medicine) for cervical spondylosis. This procedure temporarily separates the C3 and C4 cervical vertebrae from each other when a physician applies a jerky action while the neck is voluntarily turned by the patient to a specific position as instructed by the physician, where the cervical vertebrae are twisted and locked. However, a high rate of cervical injury occurs due to inexperienced physician interns who lack sufficient training. Therefore, we developed a cervical spine mechanism that imitates the dynamic behaviours of the human neck during RT manipulation. First, in vivo and in vitro experiments were performed to acquire the biomechanical feature curves of the human neck during RT manipulation. Second, a mass-spring-damper system with an electromagnetic clutch was designed to emulate the entire dynamic response of the human neck. In this system, a spring is designed as rectilinear and nonlinear to capture the viscoelasticity of soft tissues, and an electromagnetic clutch is used to simulate the sudden disengagement of the cervical vertebrae. Test results show that the mechanism can exhibit the desired behaviour when RT manipulation is applied in the same manner as on humans. PMID:29259395

  18. Compliant-linkage kinematic design for multi-degree-of-freedom mobile robots

    NASA Astrophysics Data System (ADS)

    Borenstein, Johann

    1993-05-01

    Multi-degree-of-freedom (MDOF) vehicles have many potential advantages over conventional (i.e., 2-DOF) vehicles. For example, MDOF vehicles can travel sideways and they can negotiate tight turns more easily. In addition, some MDOF designs provide better payload capability, better traction, and improved static and dynamic stability. However, MDOF vehicles with more than three degrees-of-freedom are difficult to control because of their overconstrained nature. These difficulties translate into severe wheel slippage or jerky motion under certain driving conditions. In the past, these problems limited the use of MDOF vehicles to applications where the vehicle would follow a guide-wire, which would correct wheel slippage and control errors. By contrast, autonomous or semi-autonomous mobile robots usually rely on dead-reckoning between periodic absolute position updates and their performance is diminished by excessive wheel slippage. This paper introduces a new concept in the kinematic design of MDOF vehicles. This concept is based on the provision of a compliant linkage between drive wheels or drive axles. Simulation results indicate that compliant linkage allows to overcome the control problems found in conventional MDOF vehicles and reduces the amount of wheel slippage to the same level (or less) than the amount of slippage found on a comparable 2-DOF vehicle.

  19. Phenotype of a child with Angelman syndrome born to a woman with Prader-Willi syndrome.

    PubMed

    Ostergaard, John R

    2015-09-01

    This report describes the phenotype, from early childhood to adolescence, of a girl with Angelman syndrome (AS) born following a maternal transmission of a germline paternal 15q11.2-q13 deletion. During early childhood, she showed a typical AS phenotype, such as jerky movements, poor sleep, high voltage electroencephalography pattern, epilepsy, and a severe developmental disability. As she grew older, indications of phenotypical traits similar to Prader-Willi syndrome (PWS) appeared, in particular hyperphagic behavior and a body fat distribution similar to that reported in PWS. She generally showed cheerful AS behavior and had the characteristic outbursts of laughter, but her attitude to other people did not reflect the usual shared enjoyment of interaction seen in children with AS. In unfamiliar surroundings, she withdrew socially, similar to children with PWS, and her insistence on the same, rigid routines was similar to behavior patterns in PWS. The dysmorphic facial features that characterize AS were blurred in adolescence. The specified features that this AS patient had in common with PWS were hardly incidental and, if verified by upcoming case reports of children born to women with a paternal 15q11.2-q13 deletion, they may show new aspects of genetic imprinting. © 2015 Wiley Periodicals, Inc.

  20. Modeling Seismic Cycles of Great Megathrust Earthquakes Across the Scales With Focus at Postseismic Phase

    NASA Astrophysics Data System (ADS)

    Sobolev, Stephan V.; Muldashev, Iskander A.

    2017-12-01

    Subduction is substantially multiscale process where the stresses are built by long-term tectonic motions, modified by sudden jerky deformations during earthquakes, and then restored by following multiple relaxation processes. Here we develop a cross-scale thermomechanical model aimed to simulate the subduction process from 1 min to million years' time scale. The model employs elasticity, nonlinear transient viscous rheology, and rate-and-state friction. It generates spontaneous earthquake sequences and by using an adaptive time step algorithm, recreates the deformation process as observed naturally during the seismic cycle and multiple seismic cycles. The model predicts that viscosity in the mantle wedge drops by more than three orders of magnitude during the great earthquake with a magnitude above 9. As a result, the surface velocities just an hour or day after the earthquake are controlled by viscoelastic relaxation in the several hundred km of mantle landward of the trench and not by the afterslip localized at the fault as is currently believed. Our model replicates centuries-long seismic cycles exhibited by the greatest earthquakes and is consistent with the postseismic surface displacements recorded after the Great Tohoku Earthquake. We demonstrate that there is no contradiction between extremely low mechanical coupling at the subduction megathrust in South Chile inferred from long-term geodynamic models and appearance of the largest earthquakes, like the Great Chile 1960 Earthquake.

  1. Cases of acute mercury poisoning by mercury vapor exposure during the demolition of a fluorescent lamp factory.

    PubMed

    Do, Sang Yoon; Lee, Chul Gab; Kim, Jae Yoon; Moon, Young Hoon; Kim, Min Sung; Bae, In Ho; Song, Han Soo

    2017-01-01

    In 2015, workers dismantling a fluorescent lamp factory in Korea were affected by mercury poisoning from exposure to mercury vapor. Eighteen out of the 21 workers who participated in the demolition project presented with symptoms of poisoning and, of these, 10 had persistent symptoms even at 18 months after the initial exposure to mercury vapor. Early symptoms of 18 workers included a general skin rash, pruritus, myalgia, sleep disturbance, and cough and sputum production. Following alleviation of these initial symptoms, late symptoms, such as easy fatigue, insomnia, bad dreams, and anxiety disorder, began to manifest in 10 out of 18 patients. Seven workers underwent psychiatric care owing to sleep disturbance, anxiety disorder, and depression, and three workers underwent dermatologic treatment for hyperpigmentation, erythematous skin eruption, and chloracne-like skin lesions. Furthermore, three workers developed a coarse jerky movement, two had swan neck deformity of the fingers, and two received care at an anesthesiology clinic for paresthesia, such as burning sensation, cold sensation, and pain. Two workers underwent urologic treatment for dysfunction of the urologic system and impotence. However, symptomatic treatment did not result in satisfactory relief of these symptoms. Awareness of the perils of mercury and prevention of mercury exposure are critical for preventing health hazards caused by mercury vapor. Chelation therapy should be performed promptly following mercury poisoning to minimize damage.

  2. In-simulator training of driving abilities in a person with a traumatic brain injury.

    PubMed

    Gamache, Pierre-Luc; Lavallière, Martin; Tremblay, Mathieu; Simoneau, Martin; Teasdale, Normand

    2011-01-01

    This study reports the case of a 23-year-old woman (MC) who sustained a severe traumatic brain injury in 2004. After her accident, her driving license was revoked. Despite recovering normal neuropsychological functions in the following years, MC was unable to renew her license, failing four on-road evaluations assessing her fitness to drive. In hope of an eventual license renewal, MC went through an in-simulator training programme in the laboratory in 2009. The training programme aimed at improving features of MC's driving behaviour that were identified as being problematic in prior on-road evaluations. To do so, proper driving behaviour was reinforced via driving-specific feedback provided during the training sessions. After 25 sessions in the simulator (over a period of 4 months), MC significantly improved various components of her driving. Notably, compared to early sessions, later ones were associated with a reduced cognitive load, less jerky speed profiles when stopping at intersections and better vehicle control and positioning. A 1-year retention test showed most of these improvements were consistent. The learning principles underlying well conducted simulator-based education programmes have a strong scientific basis. A simulator training programme like this one represents a promising avenue for driving rehabilitation. It allows individuals without a driving license to practice and improve their skills in a safe and realistic environment.

  3. Motor contagion during human-human and human-robot interaction.

    PubMed

    Bisio, Ambra; Sciutti, Alessandra; Nori, Francesco; Metta, Giorgio; Fadiga, Luciano; Sandini, Giulio; Pozzo, Thierry

    2014-01-01

    Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of "mutual understanding" that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot). After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner.

  4. Design of hair-like appendages and comparative analysis on their coordination toward steady and efficient swimming.

    PubMed

    Kwak, Bokeon; Bae, Joonbum

    2017-05-22

    The locomotion of water beetles has been widely studied in biology owing to their remarkable swimming skills. Inspired by the oar-like legs of water beetles, designing a robot that swims under the principle of drag-powered propulsion can lead to highly agile mobility. But its motion can easily be discontinuous and jerky due to backward motions (i.e. retraction) of the legs. Here we proposed novel hair-like appendages and consider their coordination to achieve steady and efficient swimming on the water surface. First of all, we propose several design schemes and fabrication methods of the hair-like appendages, which can passively adjust their projected area while obtaining enough thrust. The coordination between the two pairs of legs, as with water beetles in nature, were also investigated to achieve steady swimming without backward movement by varying the beating frequency and phase of the legs. To verify the functionality of the hair-like appendages and their coordinations, six different types of appendages were fabricated, and two robots (one with a single pair of legs and the other with two pairs of legs) were built. Locomotion of the robots was extensively compared through experiments, and it was found that steady swimming was achieved by properly coordinating the two pairs of legs without sacrificing their speed. Also, owing to the lower velocity fluctuation during swimming, it was shown that using two pairs of legs was more energy efficient than the robot with single pair of legs.

  5. Solute drag in polycrystalline materials: Derivation and numerical analysis of a variational model for the effect of solute on the motion of boundaries and junctions during coarsening

    NASA Astrophysics Data System (ADS)

    Wilson, Seth Robert

    A mathematical model that results in an expression for the local acceleration of a network of sharp interfaces interacting with an ambient solute field is proposed. This expression comprises a first-order differential equation for the local velocity that, given the appropriate initial conditions, may be used to predict the subsequent time evolution of the system, including non-steady state absorption and desorption of solute. Evolution equations for both interfaces and the junction of interfaces are derived by maximizing a functional approximating the rate at which the local Gibbs free energy density decreases, as a function of the local solute content and the instantaneous velocity. The model has been formulated in three dimensions, and non-equilibrium effects such as grain boundary diffusion, solute gradients, and time-dependant segregation are taken into account. As a consequence of this model, it is shown that both interfaces and the junctions between interfaces obey evolution equations that closely resemble Newton's second law. In particular, the concept of "thrust" in variable-mass systems is shown to have a direct analog in solute-interface interaction. Numerical analysis of the equations that result reveals that a double cusp catastrophe governs the behavior of the solute-interface system, for which trajectories that include hysteresis, slip-stick motion, and jerky motion are all conceivable. The geometry of the cusp catastrophe is quantified, and a number of relations between physical parameters and system behavior are consequently predicted.

  6. Atomic Species Associated with the Portevin-Le Chatelier Effect in Superalloy 718 Studied by Mechanical Spectroscopy

    NASA Astrophysics Data System (ADS)

    Max, B.; San Juan, J.; Nó, M. L.; Cloue, J. M.; Viguier, B.; Andrieu, E.

    2018-06-01

    In many Ni-based superalloys, dynamic strain aging (DSA) generates an inhomogeneous plastic deformation resulting in jerky flow known as the Portevin-Le Chatelier (PLC) effect. This phenomenon has a deleterious effect on the mechanical properties and, at high temperature, is related to the diffusion of substitutional solute atoms toward the core of dislocations. However, the question about the nature of the atomic species responsible for the PLC effect at high temperature still remains open. The goal of the present work is to answer this important question; to this purpose, three different 718-type and a 625 superalloy were studied through a nonconventional approach by mechanical spectroscopy. The internal friction (IF) spectra of all the studied alloys show a relaxation peak P 718 (at 885 K for 0.1 Hz) in the same temperature range, 700 K to 950 K, as the observed PLC effect. The activation parameters of this relaxation peak have been measured, E a( P 718) = 2.68 ± 0.05 eV, τ 0 = 2·10-15 ± 1 s as well as its broadening factor β = 1.1. Experiments on different alloys and the dependence of the relaxation strength on the amount of Mo attribute this relaxation to the stress-induced reorientation of Mo-Mo dipoles due to the short distance diffusion of one Mo atom by exchange with a vacancy. Then, it is concluded that Mo is the atomic species responsible for the high-temperature PLC effect in 718 superalloy.

  7. Friction of atomically stepped surfaces

    NASA Astrophysics Data System (ADS)

    Dikken, R. J.; Thijsse, B. J.; Nicola, L.

    2017-03-01

    The friction behavior of atomically stepped metal surfaces under contact loading is studied using molecular dynamics simulations. While real rough metal surfaces involve roughness at multiple length scales, the focus of this paper is on understanding friction of the smallest scale of roughness: atomic steps. To this end, periodic stepped Al surfaces with different step geometry are brought into contact and sheared at room temperature. Contact stress that continuously tries to build up during loading, is released with fluctuating stress drops during sliding, according to the typical stick-slip behavior. Stress release occurs not only through local slip, but also by means of step motion. The steps move along the contact, concurrently resulting in normal migration of the contact. The direction of migration depends on the sign of the step, i.e., its orientation with respect to the shearing direction. If the steps are of equal sign, there is a net migration of the entire contact accompanied by significant vacancy generation at room temperature. The stick-slip behavior of the stepped contacts is found to have all the characteristic of a self-organized critical state, with statistics dictated by step density. For the studied step geometries, frictional sliding is found to involve significant atomic rearrangement through which the contact roughness is drastically changed. This leads for certain step configurations to a marked transition from jerky sliding motion to smooth sliding, making the final friction stress approximately similar to that of a flat contact.

  8. Magnetic field induced random pulse trains of magnetic and acoustic noises in martensitic single-crystal Ni2MnGa

    NASA Astrophysics Data System (ADS)

    Daróczi, Lajos; Piros, Eszter; Tóth, László Z.; Beke, Dezső L.

    2017-07-01

    Jerky magnetic and acoustic noises were evoked in a single variant martensitic Ni2MnGa single crystal (produced by uniaxial compression) by application of an external magnetic field along the hard magnetization direction. It is shown that after reaching the detwinning threshold, spontaneous reorientation of martensite variants (twins) leads not only to acoustic emission but magnetic two-directional noises as well. At small magnetic fields, below the above threshold, unidirectional magnetic emission is also observed and attributed to a Barkhausen-type noise due to magnetic domain wall motions during magnetization along the hard direction. After the above first run, in cycles of decreasing and increasing magnetic field, at low-field values, weak, unidirectional Barkhausen noise is detected and attributed to the discontinuous motion of domain walls during magnetization along the easy magnetization direction. The magnetic noise is also measured by constraining the sample in the same initial variant state along the hard direction and, after the unidirectional noise (as obtained also in the first run), a two-directional noise package is developed and it is attributed to domain rotations. From the statistical analysis of the above noises, the critical exponents, characterizing the power-law behavior, are calculated and compared with each other and with the literature data. Time correlations within the magnetic as well as acoustic signals lead to a common scaled power function (with β =-1.25 exponent) for both types of signals.

  9. An extended 3D discrete-continuous model and its application on single- and bi-crystal micropillars

    NASA Astrophysics Data System (ADS)

    Huang, Minsheng; Liang, Shuang; Li, Zhenhuan

    2017-04-01

    A 3D discrete-continuous model (3D DCM), which couples the 3D discrete dislocation dynamics (3D DDD) and finite element method (FEM), is extended in this study. New schemes for two key information transfers between DDD and FEM, i.e. plastic-strain distribution from DDD to FEM and stress transfer from FEM to DDD, are suggested. The plastic strain induced by moving dislocation segments is distributed to an elementary spheroid (ellipsoid or sphere) via a specific new distribution function. The influence of various interfaces (such as free surfaces and grain boundaries (GBs)) on the plastic-strain distribution is specially considered. By these treatments, the deformation fields can be solved accurately even for dislocations on slip planes severely inclined to the FE mesh, with no spurious stress concentration points produced. In addition, a stress correction by singular and non-singular theoretical solutions within a cut-off sphere is introduced to calculate the stress on the dislocations accurately. By these schemes, the present DCM becomes less sensitive to the FE mesh and more numerically efficient, which can also consider the interaction between neighboring dislocations appropriately even though they reside in the same FE mesh. Furthermore, the present DCM has been employed to model the compression of single-crystal and bi-crystal micropillars with rigid and dislocation-absorbed GBs. The influence of internal GB on the jerky stress-strain response and deformation mode is studied in detail to shed more light on these important micro-plastic problems.

  10. Atomic Species Associated with the Portevin-Le Chatelier Effect in Superalloy 718 Studied by Mechanical Spectroscopy

    NASA Astrophysics Data System (ADS)

    Max, B.; San Juan, J.; Nó, M. L.; Cloue, J. M.; Viguier, B.; Andrieu, E.

    2018-03-01

    In many Ni-based superalloys, dynamic strain aging (DSA) generates an inhomogeneous plastic deformation resulting in jerky flow known as the Portevin-Le Chatelier (PLC) effect. This phenomenon has a deleterious effect on the mechanical properties and, at high temperature, is related to the diffusion of substitutional solute atoms toward the core of dislocations. However, the question about the nature of the atomic species responsible for the PLC effect at high temperature still remains open. The goal of the present work is to answer this important question; to this purpose, three different 718-type and a 625 superalloy were studied through a nonconventional approach by mechanical spectroscopy. The internal friction (IF) spectra of all the studied alloys show a relaxation peak P 718 (at 885 K for 0.1 Hz) in the same temperature range, 700 K to 950 K, as the observed PLC effect. The activation parameters of this relaxation peak have been measured, E a(P 718) = 2.68 ± 0.05 eV, τ 0 = 2·10-15 ± 1 s as well as its broadening factor β = 1.1. Experiments on different alloys and the dependence of the relaxation strength on the amount of Mo attribute this relaxation to the stress-induced reorientation of Mo-Mo dipoles due to the short distance diffusion of one Mo atom by exchange with a vacancy. Then, it is concluded that Mo is the atomic species responsible for the high-temperature PLC effect in 718 superalloy.

  11. Motor Contagion during Human-Human and Human-Robot Interaction

    PubMed Central

    Bisio, Ambra; Sciutti, Alessandra; Nori, Francesco; Metta, Giorgio; Fadiga, Luciano; Sandini, Giulio; Pozzo, Thierry

    2014-01-01

    Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of “mutual understanding” that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot). After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner. PMID:25153990

  12. Objective assessment of mastication predominance in healthy dentate subjects and patients with unilateral posterior missing teeth.

    PubMed

    Yamasaki, Y; Kuwatsuru, R; Tsukiyama, Y; Oki, K; Koyano, K

    2016-08-01

    We aimed to investigate mastication predominance in healthy dentate individuals and patients with unilateral posterior missing teeth using objective and subjective methods. The sample comprised 50 healthy dentate individuals (healthy dentate group) and 30 patients with unilateral posterior missing teeth (partially edentulous group). Subjects were asked to freely chew three kinds of test foods (peanuts, beef jerky and chewing gum). Electromyographic activity of the bilateral masseter muscles was recorded. The chewing side (right side or left side) was judged by the level of root mean square electromyographic amplitude. Mastication predominance was then objectively assessed using the mastication predominant score and the mastication predominant index. Self-awareness of mastication predominance was evaluated using a modified visual analogue scale. Mastication predominance scores of the healthy dentate and partially edentulous groups for each test food were analysed. There was a significant difference in the distribution of the mastication predominant index between the two groups (P < 0·05). The mastication predominant score was weakly correlated with self-awareness of mastication predominance in the healthy dentate group, whereas strong correlation was observed in the partially edentulous group (P < 0·05). The results suggest that the individuals with missing unilateral posterior teeth exhibited greater mastication predominance and were more aware of mastication predominance than healthy dentate individuals. Our findings suggest that an objective evaluation of mastication predominance is more precise than a subjective method. © 2016 John Wiley & Sons Ltd.

  13. Properties of Cu-Based Shape-Memory Alloys Prepared by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Gustmann, T.; dos Santos, J. M.; Gargarella, P.; Kühn, U.; Van Humbeeck, J.; Pauly, S.

    2017-03-01

    Two shape-memory alloys with the nominal compositions (in wt.%) Cu-11.85Al-3.2Ni-3Mn and Cu-11.35Al-3.2Ni-3Mn-0.5Zr were prepared by selective laser melting (SLM). The parameters were optimised to identify the process window, in which almost fully dense samples can be obtained. Their microstructures were analysed and correlated with the shape-memory behaviour as well as the mechanical properties. Suction-cast specimens were also produced for comparison. Mainly, β 1' martensite forms in all samples, but 0.5 wt.% of Zr stabilises the Y phase (Cu2AlZr), and its morphology depends on the thermal history and cooling rate. After annealing, the Y phase is primarily found at the grain boundaries hampering grain coarsening. Due to the relative high cooling rates applied here, Zr is mostly dissolved in the martensite in the as-prepared samples and it has a grain-refining effect only up to a critical cooling rate. The Zr-containing samples have increased transformation temperatures, and the Y phase seems to be responsible for the jerky martensite-to-austenite transformation. All the samples are relatively ductile because they mostly fracture in a transgranular manner, exhibiting the typical double yielding. Selective laser melting allows the adjustment of the transformation temperatures and the mechanical properties already during processing without the need of a subsequent heat treatment.

  14. Sex differences in neuromuscular androgen receptor expression and sociosexual behavior in a sex changing fish

    PubMed Central

    Pradhan, Devaleena S.; Thonkulpitak, Kevin; Drilling, Cathleen; Black, Michael; Grober, Matthew S.

    2017-01-01

    Androgen signaling, via receptor binding, is critical for regulating the physiological and morphological foundations of male-typical reproductive behavior in vertebrates. Muscles essential for male courtship behavior and copulation are highly sensitive to androgens. Differences in the distribution and density of the androgen receptor (AR) are important for maintaining dimorphic musculature and thus may provide for anatomical identification of sexually selected traits. In Lythrypnus dalli, a bi-directional hermaphroditic teleost fish, both sexes produce agonistic approach displays, but reproductive behavior is sexually dimorphic. The male-specific courtship behavior is characterized by rapid jerky movements (involving dorsal fin erection) towards a female or around their nest. Activation of the supracarinalis muscle is involved in dorsal fin contributions to both agonistic and sociosexual behavior in other fishes, suggesting that differences in goby sexual behavior may be reflected in sexual dimorphism in AR signaling in this muscle. We examined sex differences in the local distribution of AR in supracarinalis muscle and spinal cord. Our results demonstrate that males do express more AR in the supracarinalis muscle relative to females, but there was no sex difference in the number of spinal motoneurons expressing AR. Interestingly, AR expression in the supracarinalis muscle was also related to rates of sociosexual behavior in males, providing evidence that sexual selection may influence muscle androgenic sensitivity to enhance display vigor. Sex differences in the distribution and number of cells expressing AR in the supracarinalis muscle may underlie the expression of dimorphic behaviors in L. dalli. PMID:28520775

  15. Composition and consumer acceptability of a novel extrusion-cooked salmon snack.

    PubMed

    Kong, J; Dougherty, M P; Perkins, L B; Camire, M E

    2008-04-01

    The objectives of this study were to develop a value-added jerky-style snack from salmon flesh and to minimize loss of healthful lipids during processing. Three formulations were extruded in a laboratory-scale twin-screw extruder. The base formulation included Atlantic salmon (82%, w/w), sucrose (4%), pregelatinized starch (3%), modified tapioca starch (3%), salt (2%), and teriyaki flavoring (2%). Three oil binding agents (tapioca starch, high-amylose cornstarch, oat fiber) were each studied at the 4% level. Barrel temperature, from feed to die, was 65, 155, 155, and 80 degrees C. Screw speed was 250 rpm. Feed rate was 220 g/min. Extrudates were convection-dried at 93 degrees C for 40 min. A texture analyzer was used to evaluate textural properties. Sixty-three consumers evaluated the hedonic attributes of the snacks. Extrusion cooking did not adversely affect content of omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in Atlantic salmon. The oat fiber formulation had the highest lipid (17.49%) content. The other formulations had higher moisture content. A serving (28 g) of the oat formulation provides 0.6 g EPA + DHA. Snacks containing oat fiber had the highest CIE L* and b* values. Snacks containing oat fiber required greater force to bend, cut, and puncture. The oat fiber formulation had the lowest overall acceptability. This portable snack could appeal to consumers who are interested in the health benefits of fish and omega-3 fatty acids and provide salmon processors with a value-added solution for processing by-products.

  16. Significance of finger forces and kinematics during handwriting in writer's cramp.

    PubMed

    Hermsdörfer, Joachim; Marquardt, Christian; Schneider, Alexandra S; Fürholzer, Waltraud; Baur, Barbara

    2011-08-01

    Muscular hyperactivity during handwriting, irregular and jerky scripts, as well as awkward and slowed pen movements are the cardinal symptoms of writer's cramp. Accordingly, impaired kinematics and increased force have been reported in writer's cramp. However, the relationship between these symptoms has rarely been investigated. In addition, measurements of finger forces have been restricted to the vertical pen pressure. In the present study, the pen of a graphic tablet was equipped with a force sensor matrix to measure also the grip force produced against the pen barrel despite highly variable pen grips of the patients. Kinematics of writing movements, vertical pen pressure, and grip force were compared in 27 patients with writer's cramp and normal control writers during writing of a test sentence. As expected, all measures revealed a significantly worse writing performance in the patients compared to the control subjects. Exaggerated forces were more frequent than abnormal kinematics, and evidenced by prolonged movement times and reduced writing frequencies. Correlations were found neither between kinematics and force measures nor between the two forces. Interestingly, patients relaxed the grip force during short periods of non-writing by the same relative amount as control subjects. The finding of a large heterogeneity of performances patterns in writer's cramp may reflect the variability of dystonic symptoms as well as the highly variable compensatory strategies of individual patients. Measurements of finger force and in particular of the grip force are valuable and important descriptors of individual impairment characteristics that are independent of writing kinematics. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Chronic therapy in gastrointestinal stromal tumours (GISTs): the big gap between theory and practice.

    PubMed

    Saponara, Maristella; Pantaleo, Maria Abbondanza; Nannini, Margherita; Biasco, Guido

    2012-12-01

    The advent of imatinib mesilate, an oral target therapy, has dramatically changed the natural history of gastrointestinal stromal tumours (GISTs). This rare neoplasm has become the paradigm of targeted therapies in solid tumours, also introducing a home-based cure concept in oncology. However, it should be retained that oral drug administration entails new and relevant management problems. Multiple studies have demonstrated the efficacy of imatinib in GISTs associated with a good toxicity profile. However, the efficacy of imatinib, according to its mechanism of action and pharmacokinetics, is closely related to daily assumption. No interruption or "jerky" assumption is permitted in order to avoid efficacy loss. Thus, the issue of treatment adherence is crucial for a successful strategy and should not be overlooked. We think that dealing with the problem means assessing a wide spectrum of not only clinical and general but also psychological and individual aspects. Furthermore, both patient and family should play an active role in the "cure process" and physicians should reduce the distance separating them from their patients due to home-based target therapy, promoting communication and consolidation of a trust-based physician-patient relationship. Several advantages have been introduced by oral target therapies in oncology. However, chronic drug administration, even if generally well tolerated, when prolonged for an undetermined time could heavily impact on patients' quality of life. This could induce non-prescribed drug suspension, with negative impact on disease control. More studies would be necessary in order to detect real patients' adherence, to correlate drug assumption with clinical outcome and to optimize imatinib treatment strategy.

  18. Functional MRI of the Olfactory System in Conscious Dogs

    PubMed Central

    Jia, Hao; Pustovyy, Oleg M.; Waggoner, Paul; Beyers, Ronald J.; Schumacher, John; Wildey, Chester; Barrett, Jay; Morrison, Edward; Salibi, Nouha; Denney, Thomas S.; Vodyanoy, Vitaly J.; Deshpande, Gopikrishna

    2014-01-01

    We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology. PMID:24466054

  19. Prediction of plastic instabilities under thermo-mechanical loadings in tension and simple shear

    NASA Astrophysics Data System (ADS)

    Manach, P. Y.; Mansouri, L. F.; Thuillier, S.

    2016-08-01

    Plastic instabilities like Portevin-Le Châtelier were quite thoroughly investigated experimentally in tension, under a large range of strain rates and temperatures. Such instabilities are characterized both by a jerky flow and a localization of the strain in bands. Similar phenomena were also recorded for example in simple shear [1]. Modelling of this phenomenon is mainly performed at room temperature, taking into account the strain rate sensitivity, though an extension of the classical Estrin-Kubin-McCormick was proposed in the literature, by making some of the material parameters dependent on temperature. A similar approach is considered in this study, furthermore extended for anisotropic plasticity with Hill's 1948 yield criterion. Material parameters are identified at 4 different temperatures, ranging from room temperature up to 250°C. The identification procedure is split in 3 steps, related to the elasticity, the average stress level and the magnitude of the stress drops. The anisotropy is considered constant in this temperature range, as evidenced by experimental results [2]. The model is then used to investigate the temperature dependence of the critical strain, as well as its capability to represent the propagation of the bands. Numerical predictions of the instabilities in tension and simple shear at room temperature and up to 250°C are compared with experimental results [3]. In the case of simple shear, a monotonic loading followed by unloading and reloading in the reverse direction (“Bauschinger-type” test) is also considered, showing that (i) kinematic hardening should be taken into account to fully describe the transition at re-yielding (ii) the modelling of the critical strain has to be improved.

  20. Sweeprate and temperature effects on crackling noise

    NASA Astrophysics Data System (ADS)

    White, Robert Allen

    Crackling noise, defined as separate bursts characterized by power law behavior of the frequency histograms over many decades, is observed in many driven systems far from equilibrium. Examples of such systems pepper a remarkable range of length and energy scales from jerky domain wall motion of disordered magnets, to the sometimes devastating crackling of the earth to the bursty release of energy in the photosphere of the sun dwarfing that of our most horrible WMD. Typically, crackling noise is modeled in the infinitely slow driving rate limit at zero temperature. In this dissertation I investigate the effects of relaxing these limits. First I consider the crackling system at zero temperature and finite sweeprate. I discuss how the temporal overlap of power law bursts can account for a wide range of scaling behavior and provide a criterion for sweeprate controlled exponents based on exponents obtained in the infinitely slowly driven limit. I also discuss scaling arguments for hitherto unexplained results in the power spectrum of crackling response in disordered magnets, commonly referred to as Barkhausen noise. Scaling arguments and numerical results are compared to Barkhausen noise measurements in two materials representing distinct adiabatically driven universality classes. Relaxation of the zero temperature constraint cannot be done without considering finite sweeprates due to global relaxation timescales that arise at finite temperatures. We investigate the connection between sweeprate and thermal fluctuations in the far from equilibrium limit typical of crackling systems. Again, using scaling arguments and numerical simulations of the random field Ising model near a disorder-induced critical point we analyze interesting crossover phenomena in the power spectra which are also observed in Barkhausen noise but have yet to be explained.

  1. Early detection of Angelman syndrome resulting from de novo paternal isodisomic 15q UPD and review of comparable cases

    PubMed Central

    2013-01-01

    Background Angelman syndrome is a rare neurogenetic disorder that results in intellectual and developmental disturbances, seizures, jerky movements and frequent smiling. Angelman syndrome is caused by two genetic disturbances: either genes on the maternally inherited chromosome 15 are deleted or inactivated or two paternal copies of the corresponding genes are inherited (paternal uniparental disomy). A 16-month-old child was referred with minor facial anomalies, neurodevelopmental delay and speech impairment. The clinical symptoms suggested angelman syndrome. The aim of our study was to elucidate the genetic background of this case. Results This study reports the earliest diagnosed angelman syndrome in a 16-month-old Hungarian child. Cytogenetic results suggested a de novo Robertsonian-like translocation involving both q arms of chromosome 15: 45,XY,der(15;15)(q10;q10). Molecular genetic studies with polymorphic short tandem repeat markers of the fibrillin-1 gene, located in the 15q21.1, revealed that both arms of the translocated chromosome were derived from a single paternal chromosome 15 (isodisomy) and led to the diagnosis of angelman syndrome caused by paternal uniparental disomy. Conclusions AS resulting from paternal uniparental disomy caused by de novo balanced translocation t(15q;15q) of a single paternal chromosome has been reported by other groups. This paper reviews 19 previously published comparable cases of the literature. Our paper contributes to the deeper understanding of the phenotype-genotype correlation in angelman syndrome for non-deletion subclasses and suggests that patients with uniparental disomy have milder symptoms and higher BMI than the ones with other underlying genetic abnormalities. PMID:24011290

  2. Extrapyramidal symptoms following accidental ingestion of risperidone in a child.

    PubMed

    Cheslik, T A; Erramouspe, J

    1996-04-01

    To describe the development of extrapyramidal symptoms (EPS) precipitated by an accidental overdose of risperidone in a 3.5-year-old boy. The boy presented to the emergency department with bilateral upward eye gaze, jerky movements of his extremities, and motor restlessness following an accidental ingestion of a single 4-mg risperidone tablet. Decontamination with NaCl 0.9% lavage and activated charcoal with sorbitol was performed. His symptoms responded immediately to intravenous diphenhydramine (on 3 different occasions) during his first 9.5 hours of hospitalization. He experienced no additional EPS, and was discharged home approximately 33 hours following initial presentation. At home, he received three oral doses of diphenhydramine in the 24 hours following hospital discharge because of hand tremor, total body shivering, and eye wandering. These signs resolved without further complications. Although the incidence of EPS associated with therapeutic risperidone use is low, its occurrence following overdose is less clearly defined. This represents the first published case, to our knowledge, of risperidone overdose in a child and highlights the potential for dystonic reactions at low doses in this population. Seven intentional overdoses of risperidone in adults (aged 21-68 y) have been reported in the literature and are reviewed. Amounts ingested ranged from 5 to 270 mg. All adult patients appeared to have a relatively benign course. Reported symptoms included drowsiness, slurred speech, altered levels of consciousness, hypertension, tachycardia, electrocardiogram abnormalities, atypical motor behavior, tremors, and other EPS (not specified). Accidental ingestion of low doses of risperidone can cause EPS in children that may respond well to an anticholinergic agent. Overdose management includes gastrointestinal lavage, activated charcoal with cathartic, cardiovascular monitoring, and supportive therapy.

  3. Grey nurse shark (Carcharias taurus) diving tourism: Tourist compliance and shark behaviour at Fish Rock, Australia.

    PubMed

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  4. Indigenous Food Systems and Climate Change: Impacts of Climatic Shifts on the Production and Processing of Native and Traditional Crops in the Bolivian Andes.

    PubMed

    Keleman Saxena, Alder; Cadima Fuentes, Ximena; Gonzales Herbas, Rhimer; Humphries, Debbie L

    2016-01-01

    Inhabitants of the high-mountain Andes have already begun to experience changes in the timing, severity, and patterning of annual weather cycles. These changes have important implications for agriculture, for human health, and for the conservation of biodiversity in the region. This paper examines the implications of climate-driven changes for native and traditional crops in the municipality of Colomi, Cochabamba, Bolivia. Data were collected between 2012 and 2014 via mixed methods, qualitative fieldwork, including participatory workshops with female farmers and food preparers, semi-structured interviews with local agronomists, and participant observation. Drawing from this data, the paper describes (a) the observed impacts of changing weather patterns on agricultural production in the municipality of Colomi, Bolivia and (b) the role of local environmental resources and conditions, including clean running water, temperature, and humidity, in the household processing techniques used to conserve and sometimes detoxify native crop and animal species, including potato (Solanum sp.), oca (Oxalis tuberosa), tarwi (Lupinus mutabilis), papalisa (Ullucus tuberosus), and charke (llama or sheep jerky). Analysis suggests that the effects of climatic changes on agriculture go beyond reductions in yield, also influencing how farmers make choices about the timing of planting, soil management, and the use and spatial distribution of particular crop varieties. Furthermore, household processing techniques to preserve and detoxify native foods rely on key environmental and climatic resources, which may be vulnerable to climatic shifts. Although these findings are drawn from a single case study, we suggest that Colomi agriculture characterizes larger patterns in what might be termed, "indigenous food systems." Such systems are underrepresented in aggregate models of the impacts of climate change on world agriculture and may be under different, more direct, and more immediate threat

  5. Indigenous Food Systems and Climate Change: Impacts of Climatic Shifts on the Production and Processing of Native and Traditional Crops in the Bolivian Andes

    PubMed Central

    Keleman Saxena, Alder; Cadima Fuentes, Ximena; Gonzales Herbas, Rhimer; Humphries, Debbie L.

    2016-01-01

    Inhabitants of the high-mountain Andes have already begun to experience changes in the timing, severity, and patterning of annual weather cycles. These changes have important implications for agriculture, for human health, and for the conservation of biodiversity in the region. This paper examines the implications of climate-driven changes for native and traditional crops in the municipality of Colomi, Cochabamba, Bolivia. Data were collected between 2012 and 2014 via mixed methods, qualitative fieldwork, including participatory workshops with female farmers and food preparers, semi-structured interviews with local agronomists, and participant observation. Drawing from this data, the paper describes (a) the observed impacts of changing weather patterns on agricultural production in the municipality of Colomi, Bolivia and (b) the role of local environmental resources and conditions, including clean running water, temperature, and humidity, in the household processing techniques used to conserve and sometimes detoxify native crop and animal species, including potato (Solanum sp.), oca (Oxalis tuberosa), tarwi (Lupinus mutabilis), papalisa (Ullucus tuberosus), and charke (llama or sheep jerky). Analysis suggests that the effects of climatic changes on agriculture go beyond reductions in yield, also influencing how farmers make choices about the timing of planting, soil management, and the use and spatial distribution of particular crop varieties. Furthermore, household processing techniques to preserve and detoxify native foods rely on key environmental and climatic resources, which may be vulnerable to climatic shifts. Although these findings are drawn from a single case study, we suggest that Colomi agriculture characterizes larger patterns in what might be termed, “indigenous food systems.” Such systems are underrepresented in aggregate models of the impacts of climate change on world agriculture and may be under different, more direct, and more immediate

  6. Gust Alleviation Using Direct Gust Measurement

    NASA Technical Reports Server (NTRS)

    Hoppe, Sven Marco

    2000-01-01

    The increasing competition in the market of civil aircraft leads to operating efficiency and passenger comfort being very important sales arguments. Continuous developments in jet propulsion technology helped to reduce energy consumption, as well as noise and vibrations due to the engines. The main problem with respect to ride comfort is, however, the transmittance of accelerations and jerkiness imposed by atmospheric turbulence from the wings to the fuselage. This 'gust' is also a design constraint: Light airplane structures help to save, energy, but are more critical to resist the loads imposed by turbulence. For both reasons, efficient gust alleviation is necessary to improve the performance of modern aircraft. Gust can be seen as a change in the angle of attack or as an additional varying vertical component of the headwind. The effect of gust can be very strong, since the same aerodynamic forces that keep the airplane flying are involved. Event though the frequency range of those changes is quite low, it is impossible for the pilot to alleviate gust manually. Besides, most of the time during the flight, the, autopilot maintains course and the attitude of flight. Certainly, most autopilots should be capable of damping the roughest parts of turbulence, but they are unable to provide satisfactory results in that field. A promising extension should be the application of subsidiary, control, where the inner (faster) control loop alleviates turbulence and the outer (slower) loop controls the attitude of flight. Besides the mentioned ride comfort, another reason for gust alleviation with respect to the fuselage is the sensibility of electrical devices to vibration and high values of acceleration. Many modern airplane designs--especially inherently instable military aircraft--are highly dependent on avionics. The lifetime and the reliability of these systems is thus essential.

  7. Morphometric magnetic resonance imaging and genetic testing in cerebellar abiotrophy in Arabian horses

    PubMed Central

    2013-01-01

    Background Cerebellar abiotrophy (CA) is a rare but significant disease in Arabian horses caused by progressive death of the Purkinje cells resulting in cerebellar ataxia characterized by a typical head tremor, jerky head movements and lack of menace response. The specific role of magnetic resonance imaging (MRI) to support clinical diagnosis has been discussed. However, as yet MR imaging has only been described in one equine CA case. The role of MR morphometry in this regard is currently unknown. Due to the hereditary nature of the disease, genetic testing can support the diagnosis of CA. Therefore, the objective of this study was to perform MR morphometric analysis and genetic testing in four CA-affected Arabian horses and one German Riding Pony with purebred Arabian bloodlines in the third generation. Results CA was diagnosed pathohistologically in the five affected horses (2 months - 3 years) supported by clinical signs, necropsy, and genetic testing which confirmed the TOE1:g.2171G>A SNP genotype A/A in all CA-affected horses. On MR images morphometric analysis of the relative cerebellar size and relative cerebellar cerebrospinal fluid (CSF) space were compared to control images of 15 unaffected horses. It was demonstrated that in MR morphometric analyses, CA affected horses displayed a relatively smaller cerebellum compared to the entire brain mass than control animals (P = 0.0088). The relative cerebellar CSF space was larger in affected horses (P = 0.0017). Using a cut off value of 11.0% for relative cerebellar CSF space, the parameter differentiated between CA-affected horses and controls with a sensitivity of 100% and a specificity of 93.3%. Conclusions In conclusion, morphometric MRI and genetic analysis could be helpful to support the diagnosis of CA in vivo. PMID:23702154

  8. High prevalence of abnormal motor repertoire at 3 months corrected age in extremely preterm infants.

    PubMed

    Fjørtoft, Toril; Evensen, Kari Anne I; Øberg, Gunn Kristin; Songstad, Nils Thomas; Labori, Cathrine; Silberg, Inger Elisabeth; Loennecken, Marianne; Møinichen, Unn Inger; Vågen, Randi; Støen, Ragnhild; Adde, Lars

    2016-03-01

    To compare early motor repertoire between extremely preterm and term-born infants. An association between the motor repertoire and gestational age and birth weight was explored in extremely preterm infants without severe ultrasound abnormalities. In a multicentre study, the early motor repertoire of 82 infants born extremely preterm (ELGAN:<28 weeks) and/or with extremely low birth weight (ELBW:<1000 g) and 87 term-born infants were assessed by the "Assessment of Motor Repertoire - 2 to 5 Months" (AMR) which is part of Prechtl's "General Movement Assessment", at 12 weeks post-term age. Fidgety movements were classified as normal if present and abnormal if absent, sporadic or exaggerated. Concurrent motor repertoire was classified as normal if smooth and fluent and abnormal if monotonous, stiff, jerky and/or predominantly fast or slow. Eight-teen ELBW/ELGAN infants had abnormal fidgety movements (8 absent, 7 sporadic and 3 exaggerated fidgety movements) compared with 2 control infants (OR:12.0; 95%CI:2.7-53.4) and 46 ELBW/ELGAN infants had abnormal concurrent motor repertoire compared with 17 control infants (OR:5.3; 95%CI:2.6-10.5). Almost all detailed aspects of the AMR differed between the groups. Results were the same when three infants with severe ultrasound abnormalities were excluded. In the remaining ELBW/ELGAN infants, there was no association between motor repertoire and gestational age or birth weight. ELBW/ELGAN infants had poorer quality of early motor repertoire than term-born infants.The findings were not explained by severe abnormalities on neonatal ultrasound scans and were not correlated to the degree of prematurity. The consequences of these abnormal movement patterns remain to be seen in future follow-up studies. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  9. Grey Nurse Shark ( Carcharias taurus) Diving Tourism: Tourist Compliance and Shark Behaviour at Fish Rock, Australia

    NASA Astrophysics Data System (ADS)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks ( Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  10. Modeling the complexity of acoustic emission during intermittent plastic deformation: Power laws and multifractal spectra

    NASA Astrophysics Data System (ADS)

    Kumar, Jagadish; Ananthakrishna, G.

    2018-01-01

    Scale-invariant power-law distributions for acoustic emission signals are ubiquitous in several plastically deforming materials. However, power-law distributions for acoustic emission energies are reported in distinctly different plastically deforming situations such as hcp and fcc single and polycrystalline samples exhibiting smooth stress-strain curves and in dilute metallic alloys exhibiting discontinuous flow. This is surprising since the underlying dislocation mechanisms in these two types of deformations are very different. So far, there have been no models that predict the power-law statistics for discontinuous flow. Furthermore, the statistics of the acoustic emission signals in jerky flow is even more complex, requiring multifractal measures for a proper characterization. There has been no model that explains the complex statistics either. Here we address the problem of statistical characterization of the acoustic emission signals associated with the three types of the Portevin-Le Chatelier bands. Following our recently proposed general framework for calculating acoustic emission, we set up a wave equation for the elastic degrees of freedom with a plastic strain rate as a source term. The energy dissipated during acoustic emission is represented by the Rayleigh-dissipation function. Using the plastic strain rate obtained from the Ananthakrishna model for the Portevin-Le Chatelier effect, we compute the acoustic emission signals associated with the three Portevin-Le Chatelier bands and the Lüders-like band. The so-calculated acoustic emission signals are used for further statistical characterization. Our results show that the model predicts power-law statistics for all the acoustic emission signals associated with the three types of Portevin-Le Chatelier bands with the exponent values increasing with increasing strain rate. The calculated multifractal spectra corresponding to the acoustic emission signals associated with the three band types have a maximum

  11. Performance-based robotic assistance during rhythmic arm exercises.

    PubMed

    Leconte, Patricia; Ronsse, Renaud

    2016-09-13

    Rhythmic and discrete upper-limb movements are two fundamental motor primitives controlled by different neural pathways, at least partially. After stroke, both primitives can be impaired. Both conventional and robot-assisted therapies mainly train discrete functional movements like reaching and grasping. However, if the movements form two distinct neural and functional primitives, both should be trained to recover the complete motor repertoire. Recent studies show that rhythmic movements tend to be less impaired than discrete ones, so combining both movement types in therapy could support the execution of movements with a higher degree of impairment by movements that are performed more stably. A new performance-based assistance method was developed to train rhythmic movements with a rehabilitation robot. The algorithm uses the assist-as-needed paradigm by independently assessing and assisting movement features of smoothness, velocity, and amplitude. The method relies on different building blocks: (i) an adaptive oscillator captures the main movement harmonic in state variables, (ii) custom metrics measure the movement performance regarding the three features, and (iii) adaptive forces assist the patient. The patient is encouraged to improve performance regarding these three features with assistance forces computed in parallel to each other. The method was tested with simulated jerky signals and a pilot experiment with two stroke patients, who were instructed to make circular movements with an end-effector robot with assistance during half of the trials. Simulation data reveal sensitivity of the metrics for assessing the features while limiting interference between them. The assistance's effectiveness with stroke patients is established since it (i) adapts to the patient's real-time performance, (ii) improves patient motor performance, and (iii) does not lead the patient to slack. The smoothness assistance was by far the most used by both patients, while it provided

  12. Modeling the complexity of acoustic emission during intermittent plastic deformation: Power laws and multifractal spectra.

    PubMed

    Kumar, Jagadish; Ananthakrishna, G

    2018-01-01

    Scale-invariant power-law distributions for acoustic emission signals are ubiquitous in several plastically deforming materials. However, power-law distributions for acoustic emission energies are reported in distinctly different plastically deforming situations such as hcp and fcc single and polycrystalline samples exhibiting smooth stress-strain curves and in dilute metallic alloys exhibiting discontinuous flow. This is surprising since the underlying dislocation mechanisms in these two types of deformations are very different. So far, there have been no models that predict the power-law statistics for discontinuous flow. Furthermore, the statistics of the acoustic emission signals in jerky flow is even more complex, requiring multifractal measures for a proper characterization. There has been no model that explains the complex statistics either. Here we address the problem of statistical characterization of the acoustic emission signals associated with the three types of the Portevin-Le Chatelier bands. Following our recently proposed general framework for calculating acoustic emission, we set up a wave equation for the elastic degrees of freedom with a plastic strain rate as a source term. The energy dissipated during acoustic emission is represented by the Rayleigh-dissipation function. Using the plastic strain rate obtained from the Ananthakrishna model for the Portevin-Le Chatelier effect, we compute the acoustic emission signals associated with the three Portevin-Le Chatelier bands and the Lüders-like band. The so-calculated acoustic emission signals are used for further statistical characterization. Our results show that the model predicts power-law statistics for all the acoustic emission signals associated with the three types of Portevin-Le Chatelier bands with the exponent values increasing with increasing strain rate. The calculated multifractal spectra corresponding to the acoustic emission signals associated with the three band types have a maximum

  13. Phenotypic consequences of deletion of the {gamma}{sub 3}, {alpha}{sub 5}, or {beta}{sub 3} subunit of the type A {gamma}-aminobutyric acid receptor in mice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Culia, C.T.; Stubbs, L.J.; Montgomery, C.S.

    1994-03-29

    Three genes (Gabrg3, Gabra5, and Gabrb3) encoding the {gamma}{sub 3}, {alpha}{sub 5}, and {beta}{sub 3} subunits of the type A {gamma}-aminobutyric acid receptor, respectively, are known to map near the pink-eyed dilution (p) locus in mouse chromosome 7. This region shares homology with a segment of human chromosome 15 that is implicated in Angelman syndrome, an inherited neurobehavioral disorder. By mapping Gabrg3-Gabra5-Gabrb3-telomere. Like Gabrb3, neither the Gabra5 nor Gabrg3 gene is functionally imprinted in adult mouse brain. Mice deleted for all three subunits die at birth with a cleft palate, although there are rare survivors ({approximately} 5%) that do notmore » have a cleft palate but do exhibit a neurological abnormality characterized by tremor, jerky gait, and runtiness. The authors have previously suggested that deficiency of the {beta}{sub 3} subunit may be responsible for the clefting defect. Most notably, however, in this report they describe mice carrying two overlapping, complementing p deletions that fail to express the {gamma}{sub 3} transcript, as well as mice from another line that express neither the {gamma}{sub 3} nor {alpha}{sub 5} transcripts. Surprisingly, mice from both of these lines are phenotypically normal and do not exhibit any of the neurological symptoms characteristic of the rare survivors that are deleted for all three ({gamma}{sub 3}, {alpha}{sub 5}, and {beta}{sub 3}) subunits. These mice therefore provide a whole-organism type A {gamma}-aminobutyric-acid receptor background that is devoid of any receptor subtypes that normally contain the {gamma}{sub 3} and/or {alpha}{sub 5} subunits. The absence of an overt neurological phenotype in mice lacking the {gamma}{sub 3} and/or {alpha}{sub 5} subunits also suggests that mutations in these genes are unlikely to provide useful animal models for Angelman syndrome in humans.« less

  14. Hydration Status and Sodium Balance of Endurance Runners Consuming Postexercise Supplements of Varying Nutrient Content.

    PubMed

    Pryor, J Luke; Johnson, Evan C; Del Favero, Jeffery; Monteleone, Andrew; Armstrong, Lawrence E; Rodriguez, Nancy R

    2015-10-01

    Postexercise protein and sodium supplementation may aid recovery and rehydration. Preserved beef provides protein and contains high quantities of sodium that may alter performance related variables in runners. The purpose of this study was to determine the effects of consuming a commercial beef product postexercise on sodium and water balance. A secondary objective was to characterize effects of the supplementation protocols on hydration, blood pressure, body mass, and running economy. Eight trained males (age = 22 ± 3 y, VO2max = 66.4 ± 4.2 ml·kg-1·min-1) completed three identical weeks of run training (6 run·wk-1, 45 ± 6 min·run-1, 74 ± 5% HRR). After exercise, subjects consumed either, a beef nutritional supplement (beef jerky; [B]), a standard recovery drink (SRD), or SRD+B in a randomized counterbalanced design. Hydration status was assessed via urinary biomarkers and body mass. No main effects of treatment were observed for 24 hr urine volume (SRD, 1.7 ± 0.5; B, 1.8 ± 0.6; SRD+B, 1.4 ± 0.4 L·d-1), urine specific gravity (1.016 ± 0.005, 1.018 ± 0.006, 1.017 ± 0.006) or body mass (68.4 ± 8.2, 68.3 ± 7.7, 68.2 ± 8.1 kg). No main effect of treatment existed for sodium intake-loss (-713 ± 1486; -973 ± 1123; -980 ± 1220 mg·d-1). Mean arterial pressure (81.0 ± 4.6, 81.1 ± 7.3, 83.8 ± 5.4 mm Hg) and average exercise running economy (VO2: SRD, 47.9 ± 3.2; B, 47.2 ± 2.6; SRD+B, 46.2 ± 3.4 ml·kg-1·min-1) was not affected. Urinary sodium excretion accounted for the daily sodium intake due to the beef nutritional supplement. Findings suggest the commercial beef snack is a viable recovery supplement following endurance exercise without concern for hydration status, performance decrements, or cardiovascular consequences.

  15. Assessment of specific characteristics of abnormal general movements: does it enhance the prediction of cerebral palsy?

    PubMed

    Hamer, Elisa G; Bos, Arend F; Hadders-Algra, Mijna

    2011-08-01

    Abnormal general movements at around 3 months corrected age indicate a high risk of cerebral palsy (CP). We aimed to determine whether specific movement characteristics can improve the predictive power of definitely abnormal general movements. Video recordings of 46 infants with definitely abnormal general movements at 9 to 13 weeks corrected age (20 males; 26 females; median gestational age 30wks; median birthweight 1200g) were analysed for the following characteristics: presence of fidgety, cramped synchronized, stiff, or jerky movements and asymmetrical tonic neck reflex pattern. Neurological condition (presence or absence of CP), gross motor development (Alberta Infant Motor Scales), quality of motor behaviour (Infant Motor Profile), functional mobility (Pediatric Evaluation of Disability Inventory), and Mental Developmental Index (Bayley Scales) were assessed at 18 months corrected age. Infants were excluded from participating in the study if they had severe congenital anomalies or if their caregivers had an insufficient knowledge of the Dutch language. Of the 46 assessed infants, 10 developed spastic CP (Gross Motor Function Classification System levels I to V; eight bilateral spastic CP, two unilateral spastic CP). The absence of fidgety movements and the presence of predominantly stiff movements were associated with CP (Fisher's exact test, p=0.018 and p=0.007 respectively) and lower Infant Motor Profile scores (Mann-Whitney U test, p=0.015 and p=0.022 respectively); stiff and predominantly stiff movements were associated with lower Alberta Infant Motor Scales scores (Mann-Whitney U test, p=0.01 and p=0.004 respectively). Cramped synchronized movements and the asymmetrical tonic neck reflex pattern were not related to outcome. None of the movement characteristics were associated with Pediatric Evaluation of Disability Inventory scores or the Mental Developmental Index. The assessment of fidgety movements and movement stiffness may improve the predictive

  16. Performance adaptive training control strategy for recovering wrist movements in stroke patients: a preliminary, feasibility study

    PubMed Central

    2009-01-01

    Background In the last two decades robot training in neuromotor rehabilitation was mainly focused on shoulder-elbow movements. Few devices were designed and clinically tested for training coordinated movements of the wrist, which are crucial for achieving even the basic level of motor competence that is necessary for carrying out ADLs (activities of daily life). Moreover, most systems of robot therapy use point-to-point reaching movements which tend to emphasize the pathological tendency of stroke patients to break down goal-directed movements into a number of jerky sub-movements. For this reason we designed a wrist robot with a range of motion comparable to that of normal subjects and implemented a self-adapting training protocol for tracking smoothly moving targets in order to facilitate the emergence of smoothness in the motor control patterns and maximize the recovery of the normal RoM (range of motion) of the different DoFs (degrees of Freedom). Methods The IIT-wrist robot is a 3 DoFs light exoskeleton device, with direct-drive of each DoF and a human-like range of motion for Flexion/Extension (FE), Abduction/Adduction (AA) and Pronation/Supination (PS). Subjects were asked to track a variable-frequency oscillating target using only one wrist DoF at time, in such a way to carry out a progressive splinting therapy. The RoM of each DoF was angularly scanned in a staircase-like fashion, from the "easier" to the "more difficult" angular position. An Adaptive Controller evaluated online performance parameters and modulated both the assistance and the difficulty of the task in order to facilitate smoother and more precise motor command patterns. Results Three stroke subjects volunteered to participate in a preliminary test session aimed at verify the acceptability of the device and the feasibility of the designed protocol. All of them were able to perform the required task. The wrist active RoM of motion was evaluated for each patient at the beginning and at the end

  17. Proximal movements compensate for distal forelimb movement impairments in a reach-to-eat task in Huntington's disease: new insights into motor impairments in a real-world skill.

    PubMed

    Klein, Alexander; Sacrey, Lori-Ann R; Dunnett, Stephen B; Whishaw, Ian Q; Nikkhah, Guido

    2011-02-01

    Huntington's disease (HD) causes severe motor impairments that are characterized by chorea, dystonia, and impaired fine motor control. The motor deficits include deficits in the control of the forelimb, but as yet there has been no comprehensive assessment of the impairments in arm, hand and digit movements as they are used in every-day tasks. The present study investigated the reaching of twelve HD subjects and twelve age-matched control subjects on a reach-to-eat task. The subjects were asked to reach for a small food item, with the left or the right hand, and then bring it to the mouth for eating. The task assesses the major features of skilled forelimb use, including orienting to a target, transport of the hand to a target, use of a precision grasp of the target, limb withdrawal to the mouth, and release of the food item into the mouth, and the integration of the movements into a smooth act. The movements were analyzed frame-by-frame by scoring the video record using an established movement element rating scale and by biometric analysis to describe limb trajectory. All HD subjects displayed greater reliance on more proximal movements in reaching. They also displayed overall jerkiness, a significant impairment in end point error correction (i.e. no smooth trajectories), deficits in timing and terminating motion (overshooting the target), impairments in rotation of the hand, abnormalities in grasping, and impairments in releasing the food item to the mouth. Although impairment in the control of the distal segments of the limb was common to all subjects, the intrusion of choreatic movements produced a pattern of highly variable performance between subjects. The quantification of reaching performance as measured by this analysis provides new insights into the impairments of HD subjects, allows an easily administered and inexpensive way to document the many skilled limb movement abnormalities, and relates the impairments to a real-world context. The protocol can

  18. Cervical syndrome - the effectiveness of physical therapy interventions.

    PubMed

    Kasumovic, Mersija; Gorcevic, Emir; Gorcevic, Semir; Osmanovic, Jasna

    2013-12-01

    The cervical syndrome refers to a set of disorders caused by the changes in the cervical spine and the soft-tissue surrounding it, with pain as the predominant symptom. Sore neck has been a common problem among a large section of today`s population. The factors contributing to this issue include the modern lifestyle, prolonged sitting and incorrect, fixed or constrained working postures. The root of these difficulties is found in the mechanical disorders of the cervical spine structures, poor body posture and jerky body movements. In the Scandinavian countries neck pain is considered to be a public health problem. The study evaluated 25 patients with an established diagnosis of cervical syndrome. The research was conducted at the PI Institute of Occupational and Sports Medicine of Zenica-Doboj Canton. Each patient received twenty physical therapy treatment sessions. The study included 25 patients suffering from the cervical syndrome. The statistical analysis of gender distribution indicated that 36% of the patients were male, while 64% were female. The mean age of study participants was 46.76±4,23. The patients ranged in age from 39 to 54 years, with no statistically significant difference in the mean age of male and female patients, p=0.691. Analysing the types of occupational activities performed by the patients, the study found a positive relation between neck pain and prolonged sitting at work. The patients who performed office work made up 76% of the total number. Each method of physical therapy applied in the treatment of neck pain patients proved useful. However, the combination of electrotherapy, kinesiotherapy and manual massage proved to be most effective. The cervical syndrome is a common medical condition primarily affecting adult population, with prevalence being higher among women and office workers. The condition places a considerable socioeconomic burden on the afflicted. Cervical pain ranges greatly in severity - from moderate to unbearable, thus

  19. Appraisal of Environmental Influence on Radon Variability in 10 m deep Borehole at Ghuttu, Northwest Himalaya, India

    NASA Astrophysics Data System (ADS)

    Arora, B.. R.; Choubey, V. M.; Barbosa, S. M.

    2009-04-01

    concentrations show fair stability. Long pauses in rainfall give jerky variability during rainy season with no clear pattern of daily variation. During rest of the seasons when surface temperature are always higher that water temperature, the nature of observed pattern can be reconciled in terms of the form and amplitude of daily progression in temperature gradient. An accurate description of the effect of environmental variables is essential if we to wish decipher information related to stress/strain accumulation.

  20. The improvement of movement and speech during rapid eye movement sleep behaviour disorder in multiple system atrophy.

    PubMed

    De Cock, Valérie Cochen; Debs, Rachel; Oudiette, Delphine; Leu, Smaranda; Radji, Fatai; Tiberge, Michel; Yu, Huan; Bayard, Sophie; Roze, Emmanuel; Vidailhet, Marie; Dauvilliers, Yves; Rascol, Olivier; Arnulf, Isabelle

    2011-03-01

    atrophy revealed more expressive faces, and movements that were faster and more ample in comparison with facial expression and movements during wakefulness. These movements were still somewhat jerky but lacked any visible parkinsonism. Cerebellar signs were not assessable. We conclude that parkinsonism also disappears during rapid eye movement sleep behaviour disorder in patients with multiple system atrophy, but this improvement is not due to enhanced dopamine transmission because these patients are not levodopa-sensitive. These data suggest that these movements are not influenced by extrapyramidal regions; however, the influence of abnormal cerebellar control remains unclear. The transient disappearance of parkinsonism here is all the more surprising since no treatment (even dopaminergic) provides a real benefit in this disabling disease.

  1. Development of a validated clinical case definition of generalized tonic-clonic seizures for use by community-based health care providers.

    PubMed

    Anand, Krishnan; Jain, Satish; Paul, Eldho; Srivastava, Achal; Sahariah, Sirazul A; Kapoor, Suresh K

    2005-05-01

    To develop and test a clinical case definition for identification of generalized tonic-clonic seizures (GTCSs) by community-based health care providers. To identify symptoms that can help identify GTCSs, patients with history of a jerky movements or rigidity in any part of the body ever in life were recruited from three sites: the community, secondary care hospital, and tertiary care hospital. These patients were administered a 14-item structured interview schedule focusing on the circumstances surrounding the seizure. Subsequently, a neurologist examined each patient and, based on available investigations, classified them as GTCS or non-GTCS cases. A logistic regression analysis was performed to select symptoms that were to be used for case definition of GTCSs. Validity parameters for the case definition at different cutoff points were calculated in another set of subjects. In total, 339 patients were enrolled in the first phase of the study. The tertiary care hospital contributed the maximal number of GTCS cases, whereas cases of non-GTCS were mainly from the community. At the end of phase I, the questionnaire was shortened from 14 to eight questions based on statistical association and clinical judgment. After phase II, which was conducted among 170 subjects, three variables were found to be significantly related to the presence of GTCSs by logistic regression: absence of stress (13.1; 4.1-41.3), presence of frothing (13.7; 4.0-47.3), and occurrence in sleep (8.3; 2.0-34.9). As a case definition using only three variables did not provide sufficient specificity, three more variables were added based on univariate analysis of the data (incontinence during the episode and unconsciousness) and review of literature (injury during episode). A case definition consisting of giving one point to an affirmative answer for each of the six questions was tested. At a cutoff point of four, sensitivity was 56.9 (47.4-66.0) and specificity, 96.3 (86.2-99.4). Among the 197 GTCS

  2. Biochemical Benefits, Diagnosis, and Clinical Risks Evaluation of Kratom.

    PubMed

    Fluyau, Dimy; Revadigar, Neelambika

    2017-01-01

    intrahepatic cholestasis, seizure, arrhythmia, impair memory function, coma, and death. Psychological manifestations described are euphoria and feeling relaxed to severe symptoms such as aggression, hostility, and psychosis. Medical manifestations described are polyuria, dry mouth, vomiting, and jerky movements. Currently, liquid chromatography/mass spectrometry and ion mobility spectrometry (IMS) are suggested as the most promising to rapidly screen kratom products providing a positive success rate. Our data analysis has not determined if biochemical benefits of kratom may prove to outweigh its toxicity and risks. On the contrary, it seems that its potential side effects outweigh the benefits, and severe and real health hazards can, insidiously, lead to death. Kratom clinical, psychological, and medical manifestations can be disturbing. Kratom ( M. speciosa ) use, among multiple compounds of the leaf, appear to be increasing in the Western world. Promising methods to accurately identify kratom compounds are still ongoing.

  3. Gravity Shifting Due to Distribution of Momentum in Black Hole and its Relation with Time Flux

    NASA Astrophysics Data System (ADS)

    Gholibeigian, Hassan; Gholibeygian, Mohammad Hossein

    2017-04-01

    There are many local convection systems of heat and mass in black holes. These large scale coupled systems including planets and molten masses which generate momentum in black hole and consequently generate coupled gravitational and electromagnetic waves. Therefore black hole's gravity is shifting due to distribution of masses/momentum in its convection systems. Two massive black holes which merged at a distance of 1.3 billion light years far from the Earth, produced different momentum and energy before, during, and after the event in different locations of the black hole. This energy and momentum produced gravitational waves which radiated away and recorded on September 14, 2015 by two detectors of the Laser Interferometry Gravitational Observatories (LIGO) in USA. On the other hand, the nature of time is wavy-like motion of the matter and nature of space is jerky-like motion of the matter. These two natures of space-time can be matched on wave-particle duality in quantum mechanics. And also magnitude of the time for an atom is momentum of its involved fundamental particles [Gholibeigian, adsabs.harvard.edu/abs/2016APS.APR.D1032G]. ∑ ⃗R(mv, σ,τ ) = (pnucleons + pelectrons) In which ⃗Ris time flux, σ&τare space and time coordinates on the string world sheet and p is momentum. Therefore, gravitational waves which travel from black hole to us including different fluxes of time which accompaniment propagated gravitational waves of momentum. As an observable factor, we can look at the 7 milliseconds difference of recorded at the time of arrival of the signals on September 14, 2015 by detector in Livingston before detector in Hanford. This difference of recorded time of signal GW150914 by LIGO cannot be due to warped space-time, because 3002 kilometers distance between two detectors with respect to the 1.3 billion light years (distance of black hole to detectors) is like zero! So, this 7 milliseconds difference between two time's fluxes can be due to

  4. The neurological underpinnings of cluttering: Some initial findings.

    PubMed

    Ward, David; Connally, Emily L; Pliatsikas, Christos; Bretherton-Furness, Jess; Watkins, Kate E

    2015-03-01

    Cluttering is a fluency disorder characterised by overly rapid or jerky speech patterns that compromise intelligibility. The neural correlates of cluttering are unknown but theoretical accounts implicate the basal ganglia and medial prefrontal cortex. Dysfunction in these brain areas would be consistent with difficulties in selection and control of speech motor programs that are characteristic of speech disfluencies in cluttering. There is a surprising lack of investigation into this disorder using modern imaging techniques. Here, we used functional MRI to investigate the neural correlates of cluttering. We scanned 17 adults who clutter and 17 normally fluent control speakers matched for age and sex. Brain activity was recorded using sparse-sampling functional MRI while participants viewed scenes and either (i) produced overt speech describing the scene or (ii) read out loud a sentence provided that described the scene. Speech was recorded and analysed off line. Differences in brain activity for each condition compared to a silent resting baseline and between conditions were analysed for each group separately (cluster-forming threshold Z>3.1, extent p<0.05, corrected) and then these differences were further compared between the two groups (voxel threshold p<0.01, extent>30 voxels, uncorrected). In both conditions, the patterns of activation in adults who clutter and control speakers were strikingly similar, particularly at the cortical level. Direct group comparisons revealed greater activity in adults who clutter compared to control speakers in the lateral premotor cortex bilaterally and, as predicted, on the medial surface (pre-supplementary motor area). Subcortically, adults who clutter showed greater activity than control speakers in the basal ganglia. Specifically, the caudate nucleus and putamen were overactive in adults who clutter for the comparison of picture description with sentence reading. In addition, adults who clutter had reduced activity relative

  5. The Steens Mountain (Oregon) geomagnetic polarity transition, 2. Field intensity variations and discussion of reversal models

    USGS Publications Warehouse

    Prevot, M.; Mankinen, Edward A.; Coe, Robert S.; Gromme, C. Sherman

    1985-01-01

    for the transitional field and the historical nondipole field at the site latitude. However, a field intensity increase to pretransitional values occurs when the field temporarily reaches normal directions, which suggests that dipolar structure could have been briefly regenerated during the transition in an aborted attempt to reestablish a stationary field. Changes in the field vector are progressive but jerky, with at least two, and possibly three, large swings at astonishingly high rates. Each of those transitional geomagnetic impulses occurs when the field intensity is low (less than 10 μT) and is followed by an interval of directional stasis during which the magnitude of the field increases greatly. For the best documented geomagnetic impulse the rapid directional change corresponds to a vectorial intensity change of 6700±2700 nT yr−1, which is about 15–50 times larger than the maximum rate of change of the nondipole field observed during the last centuries. The occurrence of geomagnetic impulses seems to support reversal models assuming an increase in the level of turbulence within the liquid core during transitions. The record closes with an estimated several thousand years of normal polarity with an average intensity of 46.7±20.1 μT, agreeing with the expected Miocene value. However, the occurrence of rather large and apparently rapid intensity fluctuations accompanied by little change in direction suggests that the newly reestablished dipole was still somewhat unstable.

  6. Results of Performance Tests Performed on the John Watts WW Casing Connection on 7" Pipe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    John D. Watts

    2000-02-01

    lubricant applied to the connection by applying it to the box or pin only and reducing the amount applied. Samples 3 and 4 received one makeup only. Sample 5 initially received two make/breaks to test for galling resistance before final makeup, No galling was observed. Later, three additional make/breaks were performed with no pin end collapse and galling over 1/2 a thread occurring on one of the breakouts. During the make/break tests, the stabbing and hand tight makeup of the WW connection was found to be very easy and trouble free. There was no tendency to crossthread, even when stabbed at an angle, and it screwed together very smoothly up to hand tight. During power tight makeup, there was no heat generated in the box (as checked by hand contact) and no jerkiness associated with any of the makeups or breakouts. Sample 2 was tested in pure compression. The maximum load obtained was 1,051 kips and the connection was beginning to significantly deform as the sample buckled. Actual pipe yield was 1,226 kips. Sample 3 was capped-end pressure tested to failure. The capped-end yield pressure of the pipe was 16,572 psi and the sample began to leak at 12,000 psi. Sample 4 was tested in pure tension. The maximum load obtained was 978 kips and the connection failed by fracture at the pin critical section. Actual pipe yield was 1,226 kips. Sample 5 was tested in combined tension/compression and internal gas pressure. The sample was assembled, setup and tested four times. The first time was with a torque of 7,298 ft-lbs and the connection leaked halfway to ISO Load Point 2 with loads of 693 kips and 4,312 psi. The second time the torque was increased to 14,488 ft-lbs and a leak occurred at 849 kips and 9,400 psi, which was ISO Load Point 2. The third time the makeup torque was again increased, to 20,456 ft-lbs, and a leak occurred at 716 kips and 11,342 psi, ISO Load Point 4. The fourth test was with the same torque as before, 20,617 ft-lbs, and the connection successfully tested up

  7. Is subduction really in the plate tectonics driving seat, or do two other global mechanisms do the driving? A review in the 'deep-keeled cratons' frame for global dynamics

    NASA Astrophysics Data System (ADS)

    Osmaston, M. F.

    2012-04-01

    of the upper mantle? Nature 319, 309-310. [7] Hirth G. & Kohlstedt D. L. (1996) Water in the oceanic upper mantle: implication for rheology, melt extraction, and the evolution of the lithosphere. EPSL 144, 93-108. [8] Osmaston M. F. (2010) On the actual variety of plate dynamical mechanisms and how mantle evolution affected them through time, from core formation to the Indian collision. Geophys. Res. Abstr. 12, EGU2010-6101. [9] Osmaston M. F. (1995) A straightness mechanism for MORs: a new view of ocean plate genesis and evolution XXI IUGG, Abstracts p. A472. [10] Osmaston M. (2005) The ridge push mechanism of MORs as the agent of seismic coupling, tsunami, convergence partitioning and landward thrusting at subduction zones; insights on an interactive family of mostly-jerky mechanisms. IASPEI 2005 Gen. Assy, Santiago, Chile, Abstr. No 303. [11] Osmaston M. F. (2008) Basal subduction tectonic erosion (STE), butter mélanges and the construction and exhumation of HP-UHP belts: the Alps example and some comparisons. Internat. Geol. Rev. 50(8), 685-754 DOI: 10.2747/00206814.50.8.685. [12] Osmaston M. F. (2012) Did clockwise rotation of Antarctica cause the break-up of Gondwanaland? An investigation in the 'deep-keeled cratons' frame for global dynamics. GD6.1. Geophys. Res. Abstr. 14, EGU2012-2170.