Bulls

Distribution by Scientific Domains

Kinds of Bulls

  • holstein bull
  • young bull

  • Terms modified by Bulls

  • bull calf
  • bull spermatozoa
  • bull trout

  • Selected Abstracts


    Inhibitory functioning across ADHD subtypes: Recent findings, clinical implications, and future directions

    DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2008
    Zachary W. Adams
    Abstract Although growing consensus supports the role of deficient behavioral inhibition as a central feature of the combined subtype of ADHD (ADHD/C; Barkley 1997 Psychol Bull 121:65,94; Nigg 2001 Psychol Bull 127:571,598), little research has focused on how this finding generalizes to the primarily inattentive subtype (ADHD/I). This question holds particular relevance in light of recent work suggesting that ADHD/I might be better characterized as a disorder separate from ADHD/C (Diamond 2005 Dev Psychopathol 17:807,825; Milich et al. 2001 Clin Psychol Sci Pract 8:463,488). This article describes major findings in the area of inhibitory performance in ADHD and highlights recent research suggesting important areas of divergence between the subtypes. In particular, preliminary findings point to potential differences between the subtypes with respect to how children process important contextual information from the environment, such as preparatory cues that precede responses and rewarding or punishing feedback following behavior. These suggestive findings are discussed in the context of treatment implications, which could involve differential intervention approaches for each subtype targeted to the specific deficit profiles that characterize each group of children. Future research avenues aimed toward building a sound theoretical model of ADHD/I and a better understanding of its relation to ADHD/C are also presented. Specifically, investigators are encouraged to continue studying the complex interplay between inhibitory and attentional processes, as this area seems particularly promising in its ability to improve our understanding of the potentially distinct pathologies underlying the ADHD subtypes. © 2008 Wiley-Liss, Inc. Dev Disabil Res Rev 2008;14:268,275. [source]


    THE EVOLUTION OF ENVIRONMENTAL AND GENETIC SEX DETERMINATION IN FLUCTUATING ENVIRONMENTS

    EVOLUTION, Issue 12 2003
    Tom J. M. Van Dooren
    Abstract Twenty years ago, Bulmer and Bull suggested that disruptive selection, produced by environmental fluctuations, can result in an evolutionary transition from environmental sex determination (ESD) to genetic sex determination (GSD). We investigated the feasibility of such a process, using mutation-limited adaptive dynamics and individual-based computer simulations. Our model describes the evolution of a reaction norm for sex determination in a metapopulation setting with partial migration and variation in an environmental variable both within and between local patches. The reaction norm represents the probability of becoming a female as a function of environmental state and was modeled as a sigmoid function with two parameters, one giving the location (i.e., the value of the environmental variable for which an individual has equal chance of becoming either sex) and the other giving the slope of the reaction norm for that environment. The slope can be interpreted as being set by the level of developmental noise in morph determination, with less noise giving a steeper slope and a more switchlike reaction norm. We found convergence stable reaction norms with intermediate to large amounts of developmental noise for conditions characterized by low migration rates, small differential competitive advantages between the sexes over environments, and little variation between individual environments within patches compared to variation between patches. We also considered reaction norms with the slope parameter constrained to a high value, corresponding to little developmental noise. For these we found evolutionary branching in the location parameter and a transition from ESD toward GSD, analogous to the original analysis by Bulmer and Bull. Further evolutionary change, including dominance evolution, produced a polymorphism acting as a GSD system with heterogamety. Our results point to the role of developmental noise in the evolution of sex determination. [source]


    What sources contribute to variance in observer ratings?

    INFANT AND CHILD DEVELOPMENT, Issue 3 2008
    Using generalizability theory to assess construct validity of psychological measures
    Abstract Cronbach and Meehl (Psychol. Bull. 1955; 52:281,302) stated that the key question to be addressed when assessing construct validity is ,What sources contribute to variance in test performance?' We illustrate the utility of generalizability theory (GT) as a conceptual framework that encourages psychological researchers to address this question and as a flexible set of analytic tools that can provide answers to inform both substantive theory and measurement practice. To illustrate these capabilities, we analyze observer ratings of 27 caregiver,child dyads, focusing on the importance of situational (contextual) factors as sources of variance in observer ratings of caregiver,child behaviors. Cross-situational consistency was relatively low for the categories of behavior analyzed, indicating that dyads vary greatly in their interactional patterns from one situation to the next, so that it is difficult to predict behavioral frequencies in one context from behaviors observed in a different context. Our findings suggest that single-situation behavioral measures may have limited generalizability, either to behavior in other contexts or as measures of global interaction tendencies. We discuss the implications of these findings for research and measurement design in developmental psychology. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    The English School, International Relations, and Progress,

    INTERNATIONAL STUDIES REVIEW, Issue 2 2005
    Balkan Devlen
    This essay evaluates the English School,a prominent approach to the study of international relations,as a "research enterprise" (James 2002). Our exploration begins with an introduction of a "continuum of aggregation" that conveys a given research enterprise, such as the English School, at different conceptual levels. The English School's axioms along with its negative and positive heuristics are identified and evaluated based on the classics and more recent works from Wight, Bull, and others. Conclusions and prospects for further development of the English School complete the review. [source]


    The War against Iraq and International Order: From Bull to Bush,

    INTERNATIONAL STUDIES REVIEW, Issue 2 2004
    Galia Press-Barnathan
    This essay has two goals: (1) to examine US foreign policy leading to the war in Iraq through the lens of Bull's (1977) classic book, The Anarchical Society, and (2) to explore in a unipolar, hegemonic system the relevance and power of the institutional mechanisms that are supposed to preserve international society according to Bull. It also addresses the implications of the events from September 11, 2001, through the war in Iraq for the ongoing debate within the Grotian school regarding the limits of international society and the international society,world society divide. [source]


    Normative Power Europe: A Contradiction in Terms?

    JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 2 2002
    Ian Manners
    Twenty years ago, in the pages of the, Journal of Common Market Studies, Hedley Bull launched a searing critique of the European Community's ,civilian power' in international affairs. Since that time the increasing role of the European Union (EU) in areas of security and defence policy has led to a seductiveness in adopting the notion of ,military power Europe'. In contrast, I will attempt to argue that by thinking beyond traditional conceptions of the EU's international role and examining the case study of its international pursuit of the abolition of the death penalty, we may best conceive of the EU as a ,normative power Europe'. [source]


    Does an Energy Drink Modify the Effects of Alcohol in a Maximal Effort Test?

    ALCOHOLISM, Issue 9 2004
    Sionaldo Eduardo Ferreira
    Background: There are popular reports on the combined use of alcohol and energy drinks (such as Red Bull® and similar beverages, which contain caffeine, taurine, carbohydrates, etc.) to reduce the depressant effects of alcohol on central nervous system, but no controlled studies have been performed. The main purpose of this study was to verify the effects of alcohol, and alcohol combined with energy drink, on the performance of volunteers in a maximal effort test (cycle ergometer) and also on physiological indicators (oxygen uptake, ventilatory threshold, respiratory exchange rate, heart rate, and blood pressure), biochemical variables (glucose, lactate, insulin, cortisol, ACTH, dopamine, noradrenaline, and adrenaline), and blood alcohol levels. Methods: Fourteen healthy subjects completed a double-blind protocol made up of four sessions: control (water), alcohol (1.0 g/kg), energy drink (3.57 ml/kg Red Bull®), and alcohol + energy drink, each 1 week apart. The effort test began 60 min after drug or control ingestion, and the dependent variables were measured until 60 min after the test. Results: Heart rate at the ventilatory threshold was higher in the alcohol and alcohol + energy drink sessions in comparison with control and energy drink sessions. Although in comparison to the control session, the peak oxygen uptake was 5.0% smaller after alcohol ingestion, 1.4% smaller after energy drink, and 2.7% smaller after the combined ingestion, no significant differences were detected. Lactate levels (30 min after drug ingestion, 30 and 60 min after the effort test) and noradrenaline levels (30 min after the effort test) were higher in the alcohol and alcohol + energy drink sessions compared with the control session. Conclusions: The performance in the maximal effort test observed after alcohol + energy drink ingestion was similar to that observed after alcohol only. No significant differences between alcohol and alcohol + energy drink were detected in the physiological and biochemical parameters analyzed. Our findings suggest that energy drinks, at least in the tested doses, did not improve performance or reduce alterations induced by acute alcohol ingestion. [source]


    DNA Status on Thawed Semen from Fighting Bull: A Comparison Between the SCD and the SCSA Tests

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009
    F Martínez-Pastor
    Contents The assessment of sperm chromatin status is compulsory in a complete spermiogram. Here we applied the sperm chromatin structure assay (SCSA) and the sperm chromatin dispersion (SCD) test to assess the chromatin status of three fighting bulls. Cryopreserved semen (two straws/bull) were analysed by duplicate after thawing and after 6 h at 37°C with and without oxidative stress (1 mm FE2+). Results (SCD: percentage of spermatozoa with halo; SCSA: SD-DFI, %DFI and HDS) were analysed for differences between bulls and treatments, sensitivity and specificity (receiver operating characteristic curves) and repeatability (repeatability coefficients as 2SD of duplicate differences).%DFI for the three bulls was below 2% at 0 h, indicating no risk for fertility according to previous reports. It increased slightly for two of the bulls after FE2+ treatment (%DFI < 5%) and more pronouncedly for the other bull (C, %DFI,10%), which merits further investigation. SCD rendered higher percentage of halos for bull C, but could not discriminate between samples with and without oxidizing treatment (AUC: 0.52). SCSA (%DFI) showed a high discriminating ability between treatments (AUC: 0.96). The repeatability coefficient was also higher for SCD (5.9) than for %DFI (1.8), indicating lower repeatability for SCD. Overall, %DFI might be the most useful parameter for assessing sperm chromatin on fighting bull. SCD might yield different information than SCSA, hence further research is warranted. [source]


    Peracetylated ,- d -glucopyranosyl fluoride and peracetylated ,-maltosyl fluoride

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
    Simone Dedola
    The X-ray analyses of 2,3,4,6-tetra- O -acetyl-,- d -glucopyranosyl fluoride, C14H19FO9, (I), and the corresponding maltose derivative 2,3,4,6-tetra- O -acetyl-,- d -glucopyranosyl-(1,4)-2,3,6-tri- O -acetyl-,- d -glucopyranosyl fluoride, C26H35FO17, (II), are reported. These add to the series of published ,-glycosyl halide structures; those of the peracetylated ,-glucosyl chloride [James & Hall (1969). Acta Cryst. A25, S196] and bromide [Takai, Watanabe, Hayashi & Watanabe (1976). Bull. Fac. Eng. Hokkaido Univ.79, 101,109] have been reported already. In our structures, which have been determined at 140,K, the glycopyranosyl ring appears in a regular 4C1 chair conformation with all the substituents, except for the anomeric fluoride (which adopts an axial orientation), in equatorial positions. The observed bond lengths are consistent with a strong anomeric effect, viz. the C1,O5 (carbohydrate numbering) bond lengths are 1.381,(2) and 1.381,(3),Å in (I) and (II), respectively, both significantly shorter than the C5,O5 bond lengths, viz. 1.448,(2),Å in (I) and 1.444,(3),Å in (II). [source]


    A benzene-rich pseudopolymorph of bis[,-1,3-bis(pentafluorophenyl)propane-1,3-dionato]-,3O,O,:O,;,3O:O,O,-bis{aqua[1,3-bis(pentafluorophenyl)propane-1,3-dionato-,2O,O,]nickel(II)} benzene tetrasolvate

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009
    Akiko Hori
    The title complex comprises two Ni2+ ions, four fluorinated ligands and two water molecules in a centrosymmetric dinuclear complex. This compound was crystallized from benzene,CH2Cl2, and two types of crystals, viz. the title benzene tetrasolvate, [Ni2(C15HF10O2)4(H2O)2]·4C6H6, (I), and the previously reported benzene disolvate, [Ni2(C15HF10O2)4(H2O)2]·2C6H6, (II) [Hori et al. (2009). Bull. Chem. Soc. Jpn, 82, 96,98], were obtained as pseudopolymorphs. In the crystal structure of (I), the four benzene solvent molecules interact closely with all the pentafluorophenyl groups of the complex through arene,perfluoroarene interactions. The molecular structures of the two compounds show essentially the same conformation, although the benzene molecules are accommodated in a columnar packing in (I), while they are isolated from each other in (II). [source]


    Fast enzymatic saccharification of switchgrass after pretreatment with ionic liquids

    BIOTECHNOLOGY PROGRESS, Issue 1 2010
    Hua Zhao
    Abstract The pretreatment of cellulose using ionic liquids (ILs) has been shown to be an effective method for improving the enzymatic hydrolysis of cellulose; this technique affords a fast and complete saccharification of cellulose into reducing sugars (Dadi et al., Biotechnol Bioeng. 2006; 95:904,910; Liu and Chen, Chinese Sci Bull. 2006; 51:2432,2436; Zhao et al., J Biotechnol. 2009; 139:47,54). Motivated by these advances, this study examines the effect of IL-pretreatment on the enzymatic hydrolysis of purified xylan (as a model system of hemicellulose) and switchgrass (as a real lignocellulose). The IL-pretreatment resulted in no improvement in the hydrolysis of xylan. The likely reason is that pure xylan has a low degree of polymerization (DP), and is readily biodegraded even without any pretreatment. However, in real cellulosic materials (such as switchgrass), xylan is entrapped within the cellulosic matrix, and cannot be conveniently accessed by enzymes. Our data demonstrate that the IL-pretreatment of switchgrass significantly improved the enzymatic saccharification of both cellulose (96% D -glucose yield in 24 h) and xylan (63% D -xylose yield in 24 h). The compositional analysis of switchgrass suggests a lower lignin content after IL-pretreatment. In addition, the infrared spectrum of regenerated switchgrass indicates a lower substrate crystallinity, whereas the enzyme adsorption isotherm further implies that the regenerated substrate is more accessible to enzymes. This study has further confirmed that IL-pretreatment is an effective tool in enhancing the enzymatic hydrolysis of cellulosic biomass, and allowing a more complete saccharification. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source]


    The War against Iraq and International Order: From Bull to Bush,

    INTERNATIONAL STUDIES REVIEW, Issue 2 2004
    Galia Press-Barnathan
    This essay has two goals: (1) to examine US foreign policy leading to the war in Iraq through the lens of Bull's (1977) classic book, The Anarchical Society, and (2) to explore in a unipolar, hegemonic system the relevance and power of the institutional mechanisms that are supposed to preserve international society according to Bull. It also addresses the implications of the events from September 11, 2001, through the war in Iraq for the ongoing debate within the Grotian school regarding the limits of international society and the international society,world society divide. [source]


    Effect of Aging Time on Volatile Compounds, Odor, and Flavor of Cooked Beef from Pirenaica and Friesian Bulls and Heifers

    JOURNAL OF FOOD SCIENCE, Issue 3 2002
    C. Gorraiz
    ABSTRACT: Volatile compounds, odor, and flavor produced by beef from bulls and heifers of the Pirenaica and Friesian breeds were studied during 7 d of aging. The Friesian breed beef had stronger fatty flavor and aftertaste than the Pirenaica, as well as differences in the content of several volatile compounds. Bull beef had stronger liver-like odor and flavor, and bloody flavor that were related to a higher 2-propanone content, while beef from heifers had stronger characteristic flavor. Aging of meat increased characteristic flavor and aftertaste. Ethanal showed a positive correlation with livery flavor and a negative correlation with the characteristic odor. The hexane seems to contribute to fatty flavor, 2-propanone was related to livery and bloody notes, and 2,2,4,6,6-pentamethylheptane to characteristic flavor. [source]


    Post-natal Changes in Testicular Concentrations of Interleukin-1 Alpha and Beta and Interleukin-6 during Sexual Maturation in Bulls

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2010
    ET Bagu
    Contents Based on observations in laboratory animals interleukins could be regulators of testicular development. The objects of this study were to see if interleukins (IL-1 and IL-6) are present in the developing bull testis and to establish the temporal patterns of concentrations of IL-1 and IL-6 in the bovine testis during development. Separate groups of six bull calves were castrated every 4 weeks from 5 to 33 weeks of age, and at 56 weeks of age. Mean testicular IL-1 alpha concentrations decreased (p < 0.01) from 5 to 9 weeks of age and 13 to 21 weeks of age. Mean testicular IL-1 beta concentrations decreased (p < 0.01) from 13 to 17 weeks of age and from 29 to 33 weeks of age. Mean IL-1 bioactivity increased from 13 to 17 weeks of age, decreased to 21 weeks, increased to 25 weeks, decreased to 29 weeks and decreased from 33 to 56 weeks of age (p < 0.05). Mean testicular IL-6 concentrations decreased (p < 0.05) from 9 to 13 weeks of age, increased (p < 0.05) to 21 weeks, decreased (p < 0.05) to 25 weeks, increased (p < 0.05) to 29 weeks and decreased (p < 0.01) to 56 weeks of age. In conclusion, testicular IL-1 alpha, IL-1 beta and IL-6 were found in the bovine testis and concentrations were age dependent. Testicular IL-1 alpha and IL-1 beta concentrations were highest in the early post-natal period; however, IL-1 bioactivity and IL-6 concentrations were greatest in the immediate pre-pubertal period. These findings suggest a functional role for interleukins in testicular development in the bull. [source]


    Assessment of Different Sperm Quality Parameters to Predict in vitro Fertility of Bulls

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2002
    S Tanghe
    Contents Frozen-thawed semen from six bulls with high (> 60%) and low (20,35%) in vitro fertility was used for studying the predictive value of simple sperm quality tests with respect to in vitro fertilization (IVF) outcome as assessed by pronucleus (PN) formation ability. Sperm quality parameters, such as sperm concentration, motility, progressive motility, live-dead sperm ratio, morphology, membrane integrity, mitochondrial activity and acrosomal status were analysed using both conventional and automatic techniques at three time points during the IVF process, namely after sperm thawing, Percoll differential gradient centrifugation and IVF. Associations between the sperm quality parameters before and after IVF, and PN formation ability were assessed by using linear regression analyses. The percentages of motility, progressive motility and normal morphology determined after sperm thawing, and the percentage of live spermatozoa assessed after Percoll preparation by using nigrosin-eosin (N-E) staining showed a good correlation with PN formation ability, but the regression parameters were borderline not significant. These parameters formed the most reliable basis for predicting IVF outcome. After IVF, the percentage of live spermatozoa determined by using N-E staining was the only sperm quality parameter showing a significant association with the PN formation ability of a given bull. This sperm quality test can be used as a non-invasive method to estimate the PN formation ability of oocytes which are further cultured to assess embryonic development. [source]


    Relationship between Sperm Response to Glycosaminoglycans in vitro and Non-return Rates of Swedish Dairy AI Bulls

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2000
    A Januskauskas
    Contents In this study, the relations between fertility (56-day non-return rates, 56-day NRR) after artificial insemination (AI) and bull sperm characteristics post-thaw, after swim-up and after co-incubation with heparin (Hep) and hyaluronan (HA), respectively, were determined, attempting to determine if such a procedure could be of value to evaluate the potential fertilizing ability of frozen-thawed AI bull spermatozoa. Spermatozoa from 20 semen batches derived from 20 Swedish Red and White AI bulls ranging widely in their field fertility after AI (55,79% 56-day NRRs) were evaluated with regards to post-thaw motility, membrane integrity, and migration through a simple swim-up procedure. Sperm viability and capacitation status were evaluated by two different vital staining procedures and chlortetracycline hydrochloride staining. Sperm motility and membrane integrity post-thaw (e.g. indicators of sperm viability) were significantly correlated (r = 0.53, p < 0.05 and r = 0.59, p < 0.01, respectively) with fertility. Heparin (5 µg/ml) significantly (p lt; 0.001) increased the frequencies of capacitation and acrosome-reaction (AR) among swim-up separated spermatozoa, whereas HA at a concentration of 50 ng/ml did not have any significant capacitating effect. The incidences of capacitated or AR-spermatozoa following Hep-treatment were not correlated with fertility. On the other hand, the percentage of viable spermatozoa was significantly (p < 0.001) lower in Hep-treated samples than in control and HA-treated samples and was significantly (r = 0.49, p < 0.05) correlated with fertility after AI (56-day NRR). The results indicate that the percentage of viable spermatozoa after swim-up separation and heparin-exposure from a selected population of AI bulls were significantly and positively related to the AI fertility of the donors and thus could be used as a parameter to determine the fertilizing ability of frozen,thawed AI bull spermatozoa. [source]


    Playing the Stockmarket in Tana Toraja

    THE AUSTRALIAN JOURNAL OF ANTHROPOLOGY, Issue 1 2000
    Robyn Thompson
    This paper describes the players and the play in a weekly stockmarket in Tana Toraja. South Sulawesi, where up to 600 buffalo bulls are bought and sold for exorbitant prices by any standards. These prices are partly determined by external, global economic forces. The buffaloes are all intended for sacrifice in elaborate funerals. Although contributed by individuals or families they are conceived as part of mana. the common wealth of tongkonan. the origin houses of the Toraja. Live bulls cannot be given away but are able to be lent in ceremonial exchanges at funerals. After sacrifice, their raw meat is distributed to participants in the funeral in a version of potlatch. Bulls mediate all exchange. apart from mundane commodity exchange, and are liquid assets. A mature black bull is an object of general equivalence able to be exchanged as payment for certain symbolic objects. In the past the production, distribution and circulation of buffaloes, both on the hoof and as meat, were controlled by the nobility. Buffaloes were said to be in finite supply. They derived from the Upperworld and accompanied the ancestors of the Toraja nobility to this world and were replenished through the ritual of the ways of the ancestors. Now the advent of the market has democratised buffaloes. There has been a dispersion of wealth and the power that the bulls embody. Any man,noble, commoner or former slave-who has sufficient cash is able to buy and sell buffaloes: to have a share in the stockmarket. The marketplace has become a new field of power play, one where innovative methods are being found for increasing the supply of buffaloes by importing hundreds of inferior quality buffaloes and by a program of artificial insemination which has been instigated by the local government. In the parlance of Wall Street this is a bull market. [source]


    Validation of whole genome linkage-linkage disequilibrium and association results, and identification of markers to predict genetic merit for twinning

    ANIMAL GENETICS, Issue 4 2010
    C. D. Bierman
    Summary A previous genome-wide search with a moderate density 10K marker set identified many marker associations with twinning rate, either through single-marker analysis or combined linkage-linkage disequilibrium (LLD; haplotype) analysis. The objective of the current study was to validate putative marker associations using an independent set of phenotypic data. Holstein bulls (n = 921) from 100 paternal half-sib families were genotyped. Twinning rate predicted transmitting abilities were calculated using calving records from 1994 to 1998 (Data I) and 1999 to 2006 (Data II), and the underlying liability scores from threshold model analysis were used as the trait in marker association analyses. The previous analysis used 201 bulls with daughter records in Data I. In the current analysis, this was increased to 434, providing a revised estimate of effect and significance. Bulls with daughter records in Data II totaled 851, and analysis of this data provided the validation of results from analysis of Data I. Single nucleotide polymorphisms (SNPs) were selected to validate previously significant single-marker associations and LLD results. Bulls were genotyped for a total of 306 markers. Nine of 13 LLD regions located on chromosomes 1, 2, 3, 6, 9, 22, 23(2) and 26 were validated, showing significant results for both Data I and II. Association analysis revealed 55 of 174 markers validated, equating to a single-marker validation rate of 31%. Stepwise backward elimination and cross-validation analyses identified 18 SNPs for use in a final reduced marker panel explaining 34% of the genetic variation, and to allow prediction of genetic merit for twinning rate. [source]


    Propagation of Tears in Pericardium From Young Bulls: Influence of the Suture

    ARTIFICIAL ORGANS, Issue 3 2010
    José María García Páez
    Abstract The tearing of the collagen fibers of biological materials utilized in implants or bioprostheses is an important, and sometimes early cause of the failure of these devices. We studied the force necessary to propagate a tear in a biomaterial, pericardium from young bulls, and the influence of the suture. An Elmendorf pendulum capable of measuring the force necessary to tear a given length of tissue was employed. We analyzed 112 trials (70%) that proved valid after achieving the homogeneity of the samples according to their thickness, thus making the results comparable. Mean forces ranging between 19.87 and 150 N were required to propagate tears measuring from 0.25 to 2.0 cm. In the samples with a 1-cm-long suture, sewn using an edge-to-edge technique, the propagation of the tear required a mean force of 15.75 N when the suture was made of nylon and 28.73 N when Prolene was utilized. When these results were compared with the mean recorded in an unsutured control series (56.76 N), the loss of resistance was significant in both sutured series (P = 0.000 and P = 0.011, respectively). Finally, the equation that relates the force (y) with the length of the tear made in unsutured tissue (x) was also obtained: y = 58.14 + 9.62x2 (R2 = 0.924). The force necessary to produce a microtear, thus estimated, can be utilized as a parameter for comparison. [source]


    Relative sensitivity of bull trout (Salvelinus confluentus) and rainbow trout (Oncorhynchus mykiss) to acute copper toxicity

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002
    James A. Hansen
    Abstract Bull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Past and present habitat for this species includes waterways contaminated with heavy metals released from mining activities. Because the sensitivity of this species to copper was previously unknown, we conducted acute copper toxicity tests with bull and rainbow trout (Oncorhynchus mykiss) in side-by-side comparison tests. Bioassays were conducted using water at two temperatures (8°C and 16°C) and two hardness levels (100 and 220 mg/L as CaCO3). At a water hardness of 100 mg/L, both species were less sensitive to copper when tested at 16°C compared to 8°C. The two species had similar sensitivity to copper in 100-mg/L hardness water, but bull trout were 2.5 to 4 times less sensitive than rainbow trout in 220-mg/L hardness water. However, when our results were viewed in the context of the broader literature on rainbow trout sensitivity to copper, the sensitivities of the two species appeared similar. This suggests that adoption of toxicity thresholds that are protective of rainbow trout would be protective of bull trout; however, an additional safety factor may be warranted because of the additional level of protection necessary for this federally threatened species. [source]


    Price Movers on the Stock Exchange of Thailand: Evidence from a Fully Automated Order-Driven Market

    FINANCIAL REVIEW, Issue 3 2010
    Charlie Charoenwong
    G12; G14; G15 Abstract This study examines which trade sizes move stock prices on the Stock Exchange of Thailand (SET), a pure limit order market, over two distinct market conditions of bull and bear. Using intraday data, the study finds that large-sized trades (i.e., those larger than the 75th percentile) account for a disproportionately large impact on changes in traded and quoted prices. The finding remains even after it has been subjected to a battery of robustness checks. In contrast, the results of studies conducted in the United States show that informed traders employ trade sizes falling between the 40th and 95th percentiles (Barclay and Warner, 1993; Chakravarty, 2001). Our results support the hypothesis that informed traders in a pure limit order market, such as the SET, where there are no market makers, also use larger-size trades than those employed by informed traders in the United States. [source]


    Accounting for uncertainty in QTL location in marker-assisted pre-selection of young bulls prior to progeny test

    JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2002
    A. STELLA
    The objective of this study was to evaluate whether the efficacy of marker assisted selection (MAS) could be improved by considering a confidence interval (CI) of QTL position. Specifically, MAS was applied for within-family selection in a stochastic simulation of a closed nucleus herd. The location and effect of the QTL were estimated by least squares interval mapping with a granddaughter design and marker information was then used in a top down scheme. Three approaches were used to select the best bull within full sibships of 3 or 40 bulls. All three were based on the probability of inheriting the favorable allele from the grandsire (PROB). The first method selected the sib with the highest PROB at the location with the highest F-ratio (MAX). The other two approaches were based on sums of estimated regression coefficients weighted by PROB at each cM within a 95% CI based on either bootstrapping (BOOT) or approximate LOD scores (LOD). Accounting for CI increased the relative genetic gain in all scenarios. The average breeding value (BV) of the selected bulls was increased by 2.00, 2.60 and 2.59% when MAS was applied using MAX, BOOT and LOD, respectively, compared to random selection (h2=0.30). Selected bulls carried the correct allele in 63.0, 68.5, 67.6 and 50.1% of the cases for MAX, BOOT, LOD and random selection, respectively. Berü;cksichtigung der Unsicherheit von QTL Positionen bei Marker-gestü;tzter Vorselektion von jungen Bullen vor der Nachkommenprü;fung Das Ziel dieser Studie war es zu prüfen, ob die Effizienz von MAS (Marker gestützte Selektion) durch Berücksichtigung des Konfidenzintervalls (CI) einer QTL Position verbessert werden kann. Es wurde MAS bei der Selektion innerhalb Familien in einer geschlossenen Nukleus Herde in einer stochastischen Simulation angewandt. Die Postition und der Effekt des QTL wurden in einem Granddaughter Design mit einer Least=Square Intervall Kartierung geschätzt. Die Marker Informationen wurden dann in einem top-down-Schema verwendet. Drei Ansätze fanden Verwendung, um den besten Bullen innerhalb von Vollgeschwistern von 3 oder 40 Bullen zu selektieren. Alle drei Ansätze basieren auf der Wahrscheinlichkeit, ein zu bevorzugendes Allel vom Grossvater zu erben (PROB). Bei der ersten Methode wurden die Geschwister mit der höchsten PROB an der Position mit dem höchsten F-Wert selektiert (MAX). Die beiden anderen Ansätze basierten auf den Summen der geschätzten Regressionskoeffizienten, gewichtet nach PROB an jedem cM innerhalb eines 95%igen CI, das entweder auf Bootstrapping (BOOT) oder approximativen LOD Scores (LOD) basiert. Die Berücksichtigung des CI vergrösserte den relativen genetischen Fortschritt in allen Szenarien. Bei Anwendung von MAS waren die durchschnittlichen Zuchtwerte der selektierten Bullen bei Verwendung von MAX, BOOT und LOD verglichen mit zufälliger Selektion (h2=0,30) um 2,00, 2,60 und 2,59% gestiegen. Die selektierten Bullen trugen das richtige Allel bei den entsprechenden Berechnungen MAX, BOOT, LOD und zufälliger Selektion in 63,0, 68,5, 67,6 und 50,1% der Fälle. [source]


    Plasma progesterone, oestradiol-17, and total oestrogen profiles in relation to oestrous behaviour during induced ovulation in Murrah buffalo heifers

    JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 4 2009
    K. S. Roy
    Summary The objectives of this study were to establish the characteristics of oestrous behaviour in Ovsynch (induction of ovulation through administration of GnRH-PGF2, -GnRH in a systemic manner on 0, seventh and ninth day respectively) and Ovsynch plus Norprolac (Quinagolide hydrochloride , an inhibitor of prolactin secretion) treated Murrah buffalo heifers and to determine the relationships between this behaviour and the plasma concentrations of oestradiol-17, (E2), total oestrogen, and progesterone. Oestrus was detected by visual observations of oestrus signs, per rectal examination of genitalia and bull parading thrice a day during treatment period. Among all the symptoms, it was observed that bull mounting of heifers in oestrus was highest. Examination of genital tracts per rectum revealed that the cervix was relaxed, uterus was turgid and ovaries had palpable follicle in animals with oestrus. The peak concentrations of E2 (10.81 ± 0.62 pg/ml) and total oestrogen (17.11 ± 1.21 pg/ml) occurred at 9.45 ± 0.85 and 9.64 ± 0.93 h after second GnRH administration, respectively, in Ovsynch treated animals. However, the peak levels of E2 (20.02 ± 2.87 pg/ml) and total oestrogen (32.71 ± 3.15 pg/ml) occurred at 10.18 ± 0.50 and 10.36 ± 0.75 h after second GnRH administration, respectively, in Ovsynch plus Norprolac treated animals. Plasma progesterone concentration was basal (0.20 ± 0.001 ng/ml) during the peri-oestrus period. The plasma progesterone concentration was the lowest on the day of oestrus and increased to register a peak on day 13 ± 2 of the cycle. Oestrous behaviour was positively correlated with the peak concentration of E2 (p < 0.001) and total oestrogen (p < 0.001) during the peri-oestrus period. Inhibition of prolactin by Norprolac administration significantly increased the concentration of E2 and total oestrogen during oestrus in buffaloes in comparison to those recorded in animals subjected to Ovsynch protocol alone. In conclusion, our results suggest that the peak concentrations of E2 and total oestrogen and mean level of E2 and total oestrogen during the peri-oestrus period are the important factors contributing the behavioural manifestation of oestrus in buffalo cows. [source]


    Application of white-beam X-ray microdiffraction for the study of mineralogical phase identification in ancient Egyptian pigments

    JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2007
    P. A. Lynch
    High-brightness synchrotron X-rays together with precision achromatic focusing optics on beamline 7.3.3 at the Advanced Light Source have been applied for Laue microdiffraction analysis of mineralogical phases in Egyptian pigments. Although this task is usually performed using monochromatic X-ray diffraction, the Laue technique was both faster and more reliable for the present sample. In this approach, white-beam diffraction patterns are collected as the sample is raster scanned across the incident beam (0.8,µm × 0.8,µm). The complex Laue diffraction patterns arising from illumination of multiple grains are indexed using the white-beam crystallographic software package XMAS, enabling a mineralogical map as a function of sample position. This methodology has been applied to determine the mineralogy of colour pigments taken from the ancient Egyptian coffin of Tjeseb, a priestess of the Apis bull dating from the Third Intermediate to Late period, 25th Dynasty to early 26th Dynasty (747 to 600 BC). For all pigments, a ground layer of calcite and quartz was identified. For the blue pigment, cuprorivaite (CuCaSi4O10) was found to be the primary colouring agent with a grain size ranging from ,10 to 50,µm. In the green and yellow samples, malachite [Cu2(OH)2CO3] and goethite [FeO(OH)] were identified, respectively. Grain sizes from these pigments were significantly smaller. It was possible to index some malachite grains up to ,20,µm in size, while the majority of goethite grains displayed a nanocrystalline particle size. The inability to obtain a complete mineralogical map for goethite highlights the fact that the incident probe size is considerably larger than the grain size. This limit will continue to improve as the present trend is toward focusing optics approaching the diffraction limit (,1000× smaller beam area). [source]


    An econometric model of nonlinear dynamics in the joint distribution of stock and bond returns

    JOURNAL OF APPLIED ECONOMETRICS, Issue 1 2006
    Massimo Guidolin
    This paper considers a variety of econometric models for the joint distribution of US stock and bond returns in the presence of regime switching dynamics. While simple two- or three-state models capture the univariate dynamics in bond and stock returns, a more complicated four-state model with regimes characterized as crash, slow growth, bull and recovery states is required to capture their joint distribution. The transition probability matrix of this model has a very particular form. Exits from the crash state are almost always to the recovery state and occur with close to 50% chance, suggesting a bounce-back effect from the crash to the recovery state. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Novel identification of peripheral dopaminergic D2 receptor in male germ cells,

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2007
    Carola Otth
    Abstract Dopamine is a recognized modulator in the central nervous system (CNS) and peripheral organ functions. The presence of peripheral dopamine receptors outside the CNS has suggested an intriguing interaction between the nervous system and other functional systems, such as the reproductive system. In the present study we analyzed the expression of D2R receptors in rat testis, rat spermatogenic cells and spermatozoa, in different mammals. The RT-PCR analysis of rat testis mRNA showed specific bands corresponding to the two dopamine receptor D2R (L and S) isoforms previously described in the brain. Using Western blot analysis, we confirmed that the protein is present in rat testis, isolated spermatogenic cells and also in spermatozoa of a range of different mammals, such as rat, mouse, bull, and human. The immunohistochemistry analysis of rat adult testis showed that the receptor was expressed in all germ cells (pre- and post-meiotic phase) of the tubule with staining predominant in spermatogonia. Confocal analysis by indirect immunofluorescence revealed that in non-capacitated spermatozoa of rat, mouse, bull, and human, D2R is mainly localized in the flagellum, and is also observed in the acrosomal region of the sperm head (except in human spermatozoa). Our findings demonstrate that the two D2 receptor isoforms are expressed in rat testis and that the receptor protein is present in different mammalian spermatozoa. The presence of D2R receptors in male germ cells implies new and unsuspected roles for dopamine signaling in testicular and sperm physiology. J. Cell. Biochem. 100: 141,150, 2007. © 2006 Wiley-Liss, Inc. [source]


    Home range and seasonal movements of Giraffa camelopardalis angolensis in the northern Namib Desert

    AFRICAN JOURNAL OF ECOLOGY, Issue 3 2009
    *Article first published online: 23 FEB 200, Julian Fennessy
    Abstract Estimates of home range size of giraffe in the northern Namib Desert were on average larger than those in other populations. In particular, the largest individual home range of any giraffe bull (1950 km2) was recorded , correlated with low population density, reduced forage density and increased searching for receptive cows. The predominant pattern of movement was linear, along the riparian environments, however, large-scale irregular movements into tributaries and other areas were also recorded. Small-scale movements by bulls into the mountains above the Hoarusib River as well as by cows into the northern tributaries of the Hoanib River were observed. Seasonal movements of giraffe were not as distinctive as those in other giraffe populations. Small-scale habitat segregation was observed in the Hoarusib River study area with giraffe cows foraging only in the Gomatum River during the hot-dry season. The first ever study of GPS satellite collared giraffe provided some of the highest resolution data on giraffe movements to date, including strong biphasic movement behaviour of giraffe over 24-h periods. Résumé Les estimations de la taille du domaine vital des girafes du nord du désert du Namib furent en général plus grandes que celles des autres populations. En particulier, on a enregistré le plus grand domaine vital individuel pour une girafe mâle (1950 km²) , lié avec une faible densité de population, une densité de nourriture réduite et une recherche accrue de femelles réceptives. Le schéma de déplacement dominant était linéaire, le long des environnements riverains, bien que l'on ait aussi enregistré d'importants déplacements irréguliers vers des affluents et vers d'autres régions. Des déplacements de faible ampleur furent aussi observés, de mâles dans les montagnes au-dessus de la rivière Hoarusib et de femelles vers les affluents plus au nord de la rivière Hoanib. Les déplacements saisonniers des girafes n'étaient pas aussi typiques que ceux d'autres populations de girafes. Une ségrégation de l'habitat à petite échelle fut observée dans la zone d'étude de la rivière Hoarusib, avec des femelles qui ne mangeaient que dans le bassin de la rivière Gomatum pendant la saison chaude et sèche. La première étude jamais réalisée d'une girafe équipée d'un collier àémetteur GPS a fourni certaines des données les plus précises sur les déplacements de girafes à ce jour, y compris un comportement en deux phases de déplacement très nettes par période de 24 heures. [source]


    Buyers' perceptions of importance and willingness-to-pay for certain attributes of source and production verified bred heifers

    AGRICULTURAL ECONOMICS, Issue 5 2010
    Joe L. Parcell
    Cattle; Distribution-free estimation; Willingness-to-pay Abstract This research reports buyers' perceptions of and willingness-to-pay for replacement heifers produced through a rigorous, third-party verified production protocol. Survey respondents attended and registered to purchase heifers at sanctioned Missouri Show-Me-Select Replacement Heifer Program® sales between 1997 and 2002. Responses indicate that pen uniformity, artificially inseminated to calving ease bull, synchronized calving, and heifer size are perceived as important, and their willingness-to-pay for these characteristics is economically significant. Though prior research suggests willingness-to-pay estimates particularly for inexperienced consumers may be biased, we find little difference between inexperienced and experienced buyers and also little difference from hedonic estimates of heifer characteristics' value. [source]


    Effect of adding an anaerobic fungal culture isolated from a wild blue bull (Boselophus tragocamelus) to rumen fluid from buffaloes on in vitro fibrolytic enzyme activity, fermentation and degradation of tannins and tannin-containing Kachnar tree (Bauhinia variegata) leaves and wheat straw

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2006
    Shyam S Paul
    Abstract The study investigated the effects of adding an anaerobic fungus (Piromyces sp FNG5; isolated from the faeces of a wild blue bull) to the rumen fluid of buffaloes consuming a basal diet of wheat straw and concentrates on in vitro enzyme activities, fermentation and degradation of tannins and tannin-rich tree leaves and wheat straw. In experiment 1, strained rumen fluid was incubated for 24 and 48 h, in quadruplicate, with or without fungal culture using condensed tannin-rich Bauhinia variegata leaves as substrates. In experiment 2, in vitro incubation medium containing wheat straw and different concentrations of added tannic acid (0,1.2 mg mL,1) were incubated for 48 h, in quadruplicate, with strained buffalo rumen fluid with or without fungal culture. In experiment 3, tolerance of the fungal isolate to tannic acid was tested by estimating fungal growth in pure culture medium containing different concentrations (0,50 g L,1) of tannic acid. In in vitro studies with Bauhinia variegata tree leaves, addition of the fungal isolate to buffalo strained rumen liquor resulted in significant (P < 0.01) increase in neutral detergent fibre (NDF) digestibility and activities of carboxymethyl cellulase (P < 0.05) and xylanase (P < 0.05) at 24 h fermentation. There was 12.35% increase (P < 0.01) in condensed tannin (CT) degradation on addition of the fungal isolate at 48 h fermentation. In in vitro studies with wheat straw, addition of the fungus caused an increase in apparent digestibility (P < 0.01), true digestibility (P < 0.05), NDF digestibility (P < 0.05), activities of carboxymethyl cellulase (P < 0.001), ,-glucosidase (P < 0.001), xylanase (P < 0.001), acetyl esterase (P < 0.001) and degradation of tannic acid (P < 0.05). Rumen liquor from buffaloes which had never been exposed to tannin-containing diet had been found to have substantial inherent tannic acid-degrading ability (degraded 55.3% of added tannic acid within 24 h of fermentation). The fungus could tolerate tannic acid concentration up to 20 g L,1 in growth medium. The results of this study suggest that introduction of an anaerobic fungal isolate with superior lignocellulolytic activity isolated from the faeces of a wild herbivore may improve fibre digestion from tannin-containing feeds and degradation of tannins in the rumen of buffaloes. Copyright © 2005 Society of Chemical Industry [source]


    Cytochrome c oxidase of mammals contains a testes-specific isoform of subunit VIb,the counterpart to testes-specific cytochrome c?,

    MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2003
    Maik Hüttemann
    Abstract Sperm motility is highly dependent on aerobic energy metabolism, of which the apparent rate-limiting step of the mitochondrial respiratory chain is catalyzed by cytochrome c oxidase (COX). COX is the only electron transport chain complex to display isoforms, consistent with its suggested rate-limiting role. Isoforms were previously described for four of the 13 subunits. We now report the discovery that COX subunit VIb displays a testes-specific isoform in human, bull, rat, and mouse (COX VIb-2). Analysis of a variety of rat and mouse tissues, including ovaries, demonstrates exclusive expression of VIb-2 in testes, whereas VIb-1 transcripts are absent in rodent testes, even at early developmental stages. In contrast, both isoforms are transcribed in human testes. In situ hybridizations with human, rat, and mouse testes sections reveal VIb-2 transcripts in all testicular cell types. Within the seminiferous tubules, VIb-1 shows stronger signals in the periphery than in the lumen. Previously, cytochrome c was the only component of the mitochondrial respiratory chain known to express a testes-specific isoform in mammals. COX subunit VIb connects the two COX monomers into the physiological dimeric form, and is the only COX subunit that, like cytochrome c, is solely located in the inter-membrane space. Significant differences between the isoform sequences, in particular changes in charged amino acids, suggest interactions with cytochrome c and sperm-specific energy requirements. Mol. Reprod. Dev. 66: 8,16, 2003. © 2003 Wiley-Liss, Inc. [source]