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Sample records for chick somitogenesis oscillator

  1. The chick somitogenesis oscillator is arrested before all paraxial mesoderm is segmented into somites

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    McGrew Michael J

    2010-02-01

    Full Text Available Abstract Background Somitogenesis is the earliest sign of segmentation in the developing vertebrate embryo. This process starts very early, soon after gastrulation has initiated and proceeds in an anterior-to-posterior direction during body axis elongation. It is widely accepted that somitogenesis is controlled by a molecular oscillator with the same periodicity as somite formation. This periodic mechanism is repeated a specific number of times until the embryo acquires a defined specie-specific final number of somites at the end of the process of axis elongation. This final number of somites varies widely between vertebrate species. How termination of the process of somitogenesis is determined is still unknown. Results Here we show that during development there is an imbalance between the speed of somite formation and growth of the presomitic mesoderm (PSM/tail bud. This decrease in the PSM size of the chick embryo is not due to an acceleration of the speed of somite formation because it remains constant until the last stages of somitogenesis, when it slows down. When the chick embryo reaches its final number of somites at stage HH 24-25 there is still some remaining unsegmented PSM in which expression of components of the somitogenesis oscillator is no longer dynamic. Finally, we identify a change in expression of retinoic acid regulating factors in the tail bud at late stages of somitogenesis, such that in the chick embryo there is a pronounced onset of Raldh2 expression while in the mouse embryo the expression of the RA inhibitor Cyp26A1 is downregulated. Conclusions Our results show that the chick somitogenesis oscillator is arrested before all paraxial mesoderm is segmented into somites. In addition, endogenous retinoic acid is probably also involved in the termination of the process of segmentation, and in tail growth in general.

  2. A Wnt oscillator model for somitogenesis

    DEFF Research Database (Denmark)

    Jensen, Peter B; Pedersen, Lykke; Krishna, Sandeep;

    2010-01-01

    . The model produces oscillatory states of the involved constituents with typical time periods of a few hours (ultradian oscillations). The oscillations are robust to changes in parameter values and are often spiky, where low concentration values of beta-catenin are interrupted by sharp peaks. Necessary...... for the oscillations is the saturated degradation of Axin2. Somite formation in chick and mouse embryos is controlled by a spatial Wnt gradient which we introduce in the model through a time-dependent decrease in Wnt3a ligand level. We find that the oscillations disappear as the ligand concentration decreases...

  3. Avian somitogenesis: translating time and space into pattern.

    Science.gov (United States)

    Brand-Saberi, Beate; Rudloff, Stefan; Gamel, Anton J

    2008-01-01

    Vertebrates have a metameric bodyplan that is based on the presence of paired somites. Somites develop from the segmental plate in a cranio-caudal sequence. At the same time, new material is added from Hensen's node, the primitive streak and the tailbud. In this way, the material residing in the segmental plate remains constant and comprises 12 prospective somites on each side. Prospective segment borders are not yet determined in the caudal segmental plate. Prior to segmentation, the cranial segmental plate undergoes epithelialization, which is controlled by signals from the neural tube and ectoderm. The bHLH transcription factor Paraxis is critically involved in this process. Formation of a new somite from the cranial end of the segmental plate is a highly controlled process involving complex cell movements in relation to each other. Hox genes specify regional identity of the somites and their derivatives. In the chicken a transposition of thoracic into cervical vertebrae has occurred as compared to the mouse. Transcription factors of the bHLH and homeodomain type also specify the cranio-caudal polarity and that of particular cell groups within the somites. According to segmentation models, somitogenesis is under the control of a "segmentation clock" in combination with a morphogen gradient. This hypothesis has recently found support from molecular data, especially the cycling expression of genes such as cHairy1 and Lunatic Fringe, which depend on the Notch/Delta pathway of signal transduction. FGF8 has been described to be distributed along a cranio-caudal gradient. The first oscillating gene described shown to be independent of Notch is Axin2, encoding a negative regulator of the canonical Wnt pathway and a target of Wnt3a. Wnt3a and Axin2 show a similar distribution as FGF8 with high levels in the tailbud. The chick embryo has recently become accessible to molecular approaches such as overexpression by electroporation and RNA interference which can be expected

  4. Somitogenesis clock-wave initiation requires differential decay and multiple binding sites for clock protein.

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    Mark Campanelli

    2010-04-01

    Full Text Available Somitogenesis is a process common to all vertebrate embryos in which repeated blocks of cells arise from the presomitic mesoderm (PSM to lay a foundational pattern for trunk and tail development. Somites form in the wake of passing waves of periodic gene expression that originate in the tailbud and sweep posteriorly across the PSM. Previous work has suggested that the waves result from a spatiotemporally graded control protein that affects the oscillation rate of clock-gene expression. With a minimally constructed mathematical model, we study the contribution of two control mechanisms to the initial formation of this gene-expression wave. We test four biologically motivated model scenarios with either one or two clock protein transcription binding sites, and with or without differential decay rates for clock protein monomers and dimers. We examine the sensitivity of wave formation with respect to multiple model parameters and robustness to heterogeneity in cell population. We find that only a model with both multiple binding sites and differential decay rates is able to reproduce experimentally observed waveforms. Our results show that the experimentally observed characteristics of somitogenesis wave initiation constrain the underlying genetic control mechanisms.

  5. Dynamic 3D cell rearrangements guided by a fibronectin matrix underlie somitogenesis.

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    Gabriel G Martins

    Full Text Available Somites are transient segments formed in a rostro-caudal progression during vertebrate development. In chick embryos, segmentation of a new pair of somites occurs every 90 minutes and involves a mesenchyme-to-epithelium transition of cells from the presomitic mesoderm. Little is known about the cellular rearrangements involved, and, although it is known that the fibronectin extracellular matrix is required, its actual role remains elusive. Using 3D and 4D imaging of somite formation we discovered that somitogenesis consists of a complex choreography of individual cell movements. Epithelialization starts medially with the formation of a transient epithelium of cuboidal cells, followed by cell elongation and reorganization into a pseudostratified epithelium of spindle-shaped epitheloid cells. Mesenchymal cells are then recruited to this medial epithelium through accretion, a phenomenon that spreads to all sides, except the lateral side of the forming somite, which epithelializes by cell elongation and intercalation. Surprisingly, an important contribution to the somite epithelium also comes from the continuous egression of mesenchymal cells from the core into the epithelium via its apical side. Inhibition of fibronectin matrix assembly first slows down the rate, and then halts somite formation, without affecting pseudopodial activity or cell body movements. Rather, cell elongation, centripetal alignment, N-cadherin polarization and egression are impaired, showing that the fibronectin matrix plays a role in polarizing and guiding the exploratory behavior of somitic cells. To our knowledge, this is the first 4D in vivo recording of a full mesenchyme-to-epithelium transition. This approach brought new insights into this event and highlighted the importance of the extracellular matrix as a guiding cue during morphogenesis.

  6. Revisiting the involvement of signaling gradients in somitogenesis.

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    Mallo, Moisés

    2016-04-01

    During embryonic development, formation of individual vertebrae requires that the paraxial mesoderm becomes divided into regular segmental units known as somites. Somites are sequentially formed at the anterior end of the presomitic mesoderm (PSM) resulting from functional interactions between the oscillatory activity of signals promoting segmentation and a moving wavefront of tissue competence to those signals, eventually generating a constant flow of new somites at regular intervals. According to the current model for somitogenesis, the wavefront results from the combined activity of two opposing functional gradients in the PSM involving the Fgf, Wnt and retinoic acid (RA) signaling pathways. Here, I use published data to evaluate the wavefront model. A critical analysis of those studies seems to support a role for Wnt signaling, but raise doubts regarding the extent to which Fgf and RA signaling contribute to this process. PMID:26662366

  7. Evolution of the Role of RA and FGF Signals in the Control of Somitogenesis in Chordates.

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    Stéphanie Bertrand

    Full Text Available During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together with tunicates and vertebrates, the dorsal paraxial mesendoderm also periodically forms somites, although this process is asymmetric and extends along the whole body. It has been previously shown that the formation of the most anterior somites in amphioxus is dependent upon FGF signalling. However, the signals controlling somitogenesis during posterior elongation in amphioxus are still unknown. Here we show that, contrary to vertebrates, RA and FGF signals act independently during posterior elongation and that they are not mandatory for posterior somites to form. Moreover, we show that RA is not able to buffer the left/right asymmetry machinery that is controlled through the asymmetric expression of Nodal pathway actors. Our results give new insights into the evolution of the somitogenesis process in chordates. They suggest that RA and FGF pathways have acquired specific functions in the control of somitogenesis in vertebrates. We propose that the "clock and wavefront" system was selected specifically in vertebrates in parallel to the development of more complex somite-derived structures but that it was not required for somitogenesis in the ancestor of chordates.

  8. Evolution of the role of RA and FGF signals in the control of somitogenesis in chordates

    OpenAIRE

    Stéphanie Bertrand; Daniel Aldea; Silvan Oulion; Lucie Subirana; de Lera, Angel R.; Ildiko Somorjai; Hector Escriva

    2015-01-01

    During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together ...

  9. Bulk elastic properties of chicken embryos during somitogenesis

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    Glazier James A

    2010-03-01

    Full Text Available Abstract We present measurements of the bulk Young's moduli of early chick embryos at Hamburger-Hamilton stage 10. Using a micropipette probe with a force constant k ~0.025 N/m, we applied a known force in the plane of the embryo in the anterior-posterior direction and imaged the resulting tissue displacements. We used a two-dimensional finite-element simulation method to model the embryo as four concentric elliptical elastic regions with dimensions matching the embryo's morphology. By correlating the measured tissue displacements to the displacements calculated from the in-plane force and the model, we obtained the approximate short time linear-elastic Young's moduli: 2.4 ± 0.1 kPa for the midline structures (notocord, neural tube, and somites, 1.3 ± 0.1 kPa for the intermediate nearly acellular region between the somites and area pellucida, 2.1 ± 0.1 kPa for the area pellucida, and 11.9 ± 0.8 kPa for the area opaca.

  10. The Netrin receptor Neogenin is required for neural tube formation and somitogenesis in zebrafish.

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    Mawdsley, David J; Cooper, Helen M; Hogan, Benjamin M; Cody, Stephen H; Lieschke, Graham J; Heath, Joan K

    2004-05-01

    The Netrin receptor Deleted in colon cancer (Dcc) has been shown to play a pivotal role in the guidance of nascent axons towards the ventral midline in the developing nervous systems of both vertebrates and invertebrates. In contrast, the function during embryogenesis of a second Dcc-like Netrin receptor Neogenin has not yet been defined. We used antisense morpholino oligonucleotides to knockdown Neogenin activity in zebrafish embryos and demonstrate that Neogenin plays an important role in neural tube formation and somitogenesis. In Neogenin knockdown embryos, cavitation within the neural rod failed to occur, producing a neural tube lacking a lumen. Somite formation was also defective, implicating Neogenin in the migration events underlying convergent extension during gastrulation. These observations suggest a role for Neogenin in determining cell polarity or migrational directionality of both neuroectodermal and mesodermal cells during early embryonic development.

  11. NDR Kinases Are Essential for Somitogenesis and Cardiac Looping during Mouse Embryonic Development.

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    Debora Schmitz-Rohmer

    Full Text Available Studies of mammalian tissue culture cells indicate that the conserved and distinct NDR isoforms, NDR1 and NDR2, play essential cell biological roles. However, mice lacking either Ndr1 or Ndr2 alone develop normally. Here, we studied the physiological consequences of inactivating both NDR1 and NDR2 in mice, showing that the lack of both Ndr1/Ndr2 (called Ndr1/2-double null mutants causes embryonic lethality. In support of compensatory roles for NDR1 and NDR2, total protein and activating phosphorylation levels of the remaining NDR isoform were elevated in mice lacking either Ndr1 or Ndr2. Mice retaining one single wild-type Ndr allele were viable and fertile. Ndr1/2-double null embryos displayed multiple phenotypes causing a developmental delay from embryonic day E8.5 onwards. While NDR kinases are not required for notochord formation, the somites of Ndr1/2-double null embryos were smaller, irregularly shaped and unevenly spaced along the anterior-posterior axis. Genes implicated in somitogenesis were down-regulated and the normally symmetric expression of Lunatic fringe, a component of the Notch pathway, showed a left-right bias in the last forming somite in 50% of all Ndr1/2-double null embryos. In addition, Ndr1/2-double null embryos developed a heart defect that manifests itself as pericardial edemas, obstructed heart tubes and arrest of cardiac looping. The resulting cardiac insufficiency is the likely cause of the lethality of Ndr1/2-double null embryos around E10. Taken together, we show that NDR kinases compensate for each other in vivo in mouse embryos, explaining why mice deficient for either Ndr1 or Ndr2 are viable. Ndr1/2-double null embryos show defects in somitogenesis and cardiac looping, which reveals their essential functions and shows that the NDR kinases are critically required during the early phase of organogenesis.

  12. Rbm24a and Rbm24b are required for normal somitogenesis.

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    Samantha Maragh

    Full Text Available We recently demonstrated that the gene encoding the RNA binding motif protein 24 (RBM24 is expressed during mouse cardiogenesis, and determined the developmental requirement for its zebrafish homologs Rbm24a and Rbm24b during cardiac development. We demonstrate here that both Rbm24a and Rbm24b are also required for normal somite and craniofacial development. Diminution of rbm24a or rbm24b gene products by morpholino knockdown resulted in significant disruption of somite formation. Detailed in situ hybridization-based analyses of a spectrum of somitogenesis-associated transcripts revealed reduced expression of the cyclic muscle pattering genes dlc and dld encoding Notch ligands, as well as their respective target genes her7, her1. By contrast expression of the Notch receptors notch1a and notch3 appears unchanged. Some RBM-family members have been implicated in pre-mRNA processing. Analysis of affected Notch-pathway mRNAs in rbm24a and rbm24b morpholino-injected embryos revealed aberrant transcript fragments of dlc and dld, but not her1 or her7, suggesting the reduction in transcription levels of Notch pathway components may result from aberrant processing of its ligands. These data imply a previously unknown requirement for Rbm24a and Rbm24b in somite and craniofacial development. Although we anticipate the influence of disrupting RBM24 homologs likely extends beyond the Notch pathway, our results suggest their perturbation may directly, or indirectly, compromise post-transcriptional processing, exemplified by imprecise processing of dlc and dld.

  13. Significance of chick quality score in broiler production

    OpenAIRE

    Ven, van de, J.; Wagenberg, van, A.V.; Uitdehaag, K.A.; Groot Koerkamp, P.W.G.; Kemp, B; Brand, van den, MGJ Mark

    2012-01-01

    The quality of day old chicks is crucial for profitable broiler production, but a difficult trait to define. In research, both qualitative and quantitative measures are used with variable predictive value for subsequent performance. In hatchery practice, chick quality is judged on a binomial scale, as chicks are divided into first grade (Q1-saleable) and second grade (Q2) chicks right after hatch. Incidences and reasons for classifying chicks as Q2, and potential of these chicks for survival ...

  14. Growth patterns of Hawaiian Stilt chicks

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    Reed, J.M.; Gray, E.M.; Lewis, D.; Oring, L.W.; Coleman, R.; Burr, T.; Luscomb, P.

    1999-01-01

    We studied chick growth and plumage patterns in the endangered Hawaiian Stilt (Himantopus mexicanus knudseni). Body mass of captive chicks closely fit a Gompertz growth curve, revealing a growth coefficient (K) of 0.065 day-1 and point of inflection (T) of 17 days. When chicks fledged about 28 days after hatching, they weighed only 60% of adult body mass; at 42 d, birds still were only 75% of adult mass; culmen, tarsus, and wing chord at fledging also were less than adult size. This trend of continued growth to adult size after fledging is typical for most shorebirds. After hatching, captive chicks grew more rapidly than wild chicks, probably because of an unlimited food supply. We found no evidence for adverse effects of weather on the growth of wild chicks. As with other shorebirds, the tarsus started relatively long, with culmen and then wing chord growing more rapidly in later development. Tarsal and wing chord growth were sigmoidal, whereas culmen growth was linear. We describe plumage characteristics of weekly age classes of chicks to help researchers age birds in the wild.

  15. Oscillatory control of Delta-like1 in somitogenesis and neurogenesis: A unified model for different oscillatory dynamics.

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    Shimojo, Hiromi; Kageyama, Ryoichiro

    2016-01-01

    During somite segmentation, mRNA expression of the mouse Notch ligand Delta-like1 (Dll1) oscillates synchronously in the presomitic mesoderm (PSM). However, the dynamics of Dll1 protein expression were rather controversial, and their functional significance was not known. Recent live-imaging analysis showed that Dll1 protein expression also oscillates synchronously in the PSM. Interestingly, accelerated or delayed Dll1 expression by shortening or elongating the Dll1 gene, respectively, dampens or quenches Dll1 oscillation at intermediate levels, a phenomenon known as "amplitude/oscillation death" of coupled oscillators in mathematical modeling. Under this condition, oscillation of the Notch effector Hes7 is also dampened, leading to severe fusion of somites and their derivatives, such as vertebrae and ribs. Thus, the appropriate timing of Dll1 expression is critical for its oscillatory expression, pointing to the functional significance of Dll1-mediated oscillatory cell-cell interactions in the segmentation clock. In neural stem cells, Dll1 expression is also oscillatory, but non-synchronous, and when Dll1 oscillation is dampened, oscillation of another Notch effector, Hes1, is also dampened, leading to defects of neural development. In this review, we discuss the underlying mechanism for the different oscillatory dynamics (synchronous versus non-synchronous) in the PSM and neural stem cells in a unified manner.

  16. Fast synchronization of ultradian oscillators controlled by delta-notch signaling with cis-inhibition.

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    Hendrik B Tiedemann

    2014-10-01

    Full Text Available While it is known that a large fraction of vertebrate genes are under the control of a gene regulatory network (GRN forming a clock with circadian periodicity, shorter period oscillatory genes like the Hairy-enhancer-of split (Hes genes are discussed mostly in connection with the embryonic process of somitogenesis. They form the core of the somitogenesis-clock, which orchestrates the periodic separation of somites from the presomitic mesoderm (PSM. The formation of sharp boundaries between the blocks of many cells works only when the oscillators in the cells forming the boundary are synchronized. It has been shown experimentally that Delta-Notch (D/N signaling is responsible for this synchronization. This process has to happen rather fast as a cell experiences at most five oscillations from its 'birth' to its incorporation into a somite. Computer simulations describing synchronized oscillators with classical modes of D/N-interaction have difficulties to achieve synchronization in an appropriate time. One approach to solving this problem of modeling fast synchronization in the PSM was the consideration of cell movements. Here we show that fast synchronization of Hes-type oscillators can be achieved without cell movements by including D/N cis-inhibition, wherein the mutual interaction of DELTA and NOTCH in the same cell leads to a titration of ligand against receptor so that only one sort of molecule prevails. Consequently, the symmetry between sender and receiver is partially broken and one cell becomes preferentially sender or receiver at a given moment, which leads to faster entrainment of oscillators. Although not yet confirmed by experiment, the proposed mechanism of enhanced synchronization of mesenchymal cells in the PSM would be a new distinct developmental mechanism employing D/N cis-inhibition. Consequently, the way in which Delta-Notch signaling was modeled so far should be carefully reconsidered.

  17. Hydrogen peroxide potentiates organophosphate toxicosis in chicks

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    Banan K. Al-Baggou

    2011-11-01

    Full Text Available Objective: The purpose of the present study was to examine the effect of hydrogen peroxide(H2O2 on the acute toxicity of organophosphate insecticides dichlorvos and diazinon and their inhibitoryactions on plasma, brain and liver cholinesterase activities. Material and Methods: H2O2 was given indrinking water (0.5% v/v for 2 weeks in unsexed day old chicks, a regimen known to induce oxidativestress in this species. A control group received drinking tap water. All experiments were conducted onthe chicks at the age of 15 days after exposure to H2O2. The acute (24 h oral LD50 values of dichlorvosand diazinon in the insecticidal preparations as determined by the up-and-down method in the controlchicks were 9.4 and 15.6 mg/kg, respectively. Results: The poisoned chicks manifested signs ofcholinergic toxicosis within one hour after the dosing including salivation, lacrimation, gasping, frequentdefecation, drooping of wings, tremors, convulsions and recumbency. The acute (24 h oral LD50 valuesof dichlorvos and diazinon in chicks provided with H2O2 were reduced to 3.5 and 6.5 mg/kg, by 63 and58%, respectively when compared to respective control LD50 values. The intoxicated chicks also showedcholinergic signs of toxicosis as described above. Plasma, brain and liver cholinesterase activities of thechicks exposed to H2O2 were significantly lower than their respective control (H2O values by 25, 28 and27%, respectively. Oral dosing of chicks with dichlorvos at 3 mg/kg significantly inhibited cholinesteraseactivities in the plasma, brain and liver of both control (42-67% and H2O2-treated (15-59% chicks.Diazinon at 5 mg/kg, orally also inhibited cholinesterase activities in the plasma, brain and liver of bothcontrol (36-66% and H2O2-treated (15-30% chicks. In the H2O2 groups, dichlorvos inhibition of livercholinesterase activity and diazinon inhibition of liver and brain cholinesterase activities weresignificantly lesser than those of the respective values of

  18. Neutrino oscillations

    International Nuclear Information System (INIS)

    Lecture notes on neutrino oscillations are given, including some background about neutrino mixing and masses, descriptions of flavour oscillations and experimental attempts to detect them, matter effects and neutrino-antineutrino oscillations. (U.K.)

  19. The adrenocortical response of tufted puffin chicks to nutritional deficits.

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    Kitaysky, Alexander S; Romano, Marc D; Piatt, John F; Wingfield, John C; Kikuchi, Motoshi

    2005-05-01

    In several seabirds, nutritional state of a nest-bound chick is negatively correlated with the activity of its hypothalamus-pituitary-adrenal (HPA) axis. Increased corticosterone (cort) secretion has been shown to facilitate changes in behavior that allow hungry chicks to obtain more food from parents. However, if parents are not willing/able to buffer their young from temporary food shortages, increased cort secretion could be detrimental to undernourished chicks. In a system where parents are insensitive to chick demands, low benefits and high costs of activation of the HPA-axis in hungry chicks should lead to a disassociation of the nutritional state of the young and the activity of its HPA-axis. We tested this novel hypothesis for the tufted puffin (Fratercula cirrhata), a seabird with intermittent provisioning of a nest-bound semi-precocial chick. We examined the HPA-axis activity of captive chicks exposed to the following: (1) a short-term (24 h) food deprivation; and (2) an array of prolonged (3 weeks) restrictions in feeding regimens. We found that in response to a short-term food deprivation chicks decreased baseline levels of cort and thyroid hormones. In response to prolonged restrictions, food-limited chicks exhibited signs of nutritional deficit: they had lower body mass, endogenous lipid reserves, and thyroid hormone titers compared to chicks fed ad libitum. However, baseline and maximum acute stress-induced levels of cort were also lower in food-restricted chicks compared to those of chicks fed ad libitum. These results support a major prediction of the study hypothesis that puffin chicks suppress HPA-axis activity in response to short- and long-term nutritional deficits. This physiological adaptation may allow a chick to extend its development in the nest, while eluding detrimental effects of chronic cort elevation. PMID:15811363

  20. CHICK PEAS EFFICIENCY IN HENS FEEDING

    OpenAIRE

    Nikolaev S. I.; Karapetyan A. K.; Kornilova E. V.; Struk M. V.

    2015-01-01

    This article presents the results of the chick peas use instead of sunflower cake, in feeding young and adult livestock hens-layers of the cross "Hajseks brown". The researches were carried out in the JSC "Agrofirm Vostok" of the Nikolayevskiy district in the Volgograd region. The sunflower cake replacement with legumes - chickpeas as the part of the experimental animal fodder for young and adult livestock hens-layers had a positive influence on productivity, physiological state of the birds,...

  1. West nile virus in American white pelican chicks: transmission, immunity, and survival

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    Sovada, Marsha A.; Pietz, Pamela J.; Hofmeister, Erik K.; Bartos, Alisa J.

    2013-01-01

    West Nile virus (WNV) causes significant mortality of American White Pelican chicks at northern plains colonies. We tested oropharyngeal/cloacal swabs from moribund chicks for shed WNV. Such shedding could enable chick-to-chick transmission and help explain why WNV spreads rapidly in colonies. WNV was detected on swabs from 11% of chicks in 2006 and 52% of chicks in 2007; however, viral titers were low. Before onset of WNV mortality, we tested blood from maternal antibodies. Among near-fledged chicks, 41% tested positive for anti-WNV antibodies, indicating that they survived infection. Among years and colonies, cumulative incidence of WNV in chicks varied from 28% to 81%, whereas the proportion of chicks surviving WNV (i.e., seropositive) was 64–75%. Our data revealed that WNV kills chicks that likely would fledge in the absence of WNV, that infection of chicks is pervasive, and that significant numbers of chicks survive infection.

  2. Killing day-old chicks? Public opinion regarding potential alternatives

    NARCIS (Netherlands)

    Leenstra, F.; Munnichs, G.M.; Beekman, V.; Vromans, E.; Aramyan, L.; Woelders, H.

    2011-01-01

    Throughout the world, male chicks from layer breeds are killed just after hatching, as they are not profitable as regards the production of meat. The Dutch and European parliaments have insisted on research into possible alternatives to the killing of day-old chicks. In the present study we have inv

  3. Measuring the style of chick lit and literature

    NARCIS (Netherlands)

    Jautze, K.J.

    2014-01-01

    This paper examines to what extent the distribution of the hundred most frequent function words of two novelistic genres (chick lit and literature) gives insight into the genre styles. The results shows that the literary style is more descriptive and informational, whereas the style of the chick-lit

  4. Gamma irradiation treatment of cereal grains for chick diets

    International Nuclear Information System (INIS)

    Wheat (W), triticale (T), hulled barley (HB), hull-less barley (HLB), hulled oats (HO), and hull-less oats (HLO) were gamma irradiated (60Co) at 0, 3, 6 and 9 Mrad to study the effect of irradiation on the nutritional value of cereal grains for chicks. A significant curvilinear relationship between radiation dose and 3-wk body weight of chicks fed irradiated cereals was noted for T, HB, HLB, HO and HLO. Chicks fed W or T showed no effect or lower body weight, respectively, while body weights of chicks fed barley or oat samples were higher with irradiation. The improvement tended to be maximal at the 6 Mrad level. Irradiation significantly improved the gain-to-feed ratio for chicks fed either HO or HLO. Apparent fat retention and tibia ash were higher in chicks fed irradiated HLO than in those fed untreated HLO. In a second experiment chick body weight, apparent amino acid and fat retention, tibia ash, and gain-to-feed ratios were lower in chicks fed autoclaved (121 degrees C for 20 min) barley than in those fed untreated barley. Irradiation (6 Mrad) subsequent to autoclaving barley samples eliminated these effects. Irradiation appears to benefit cereals containing soluble or mucilagenous fiber types as typified by beta-glucan of barley and oats. These fibers appear prone to irradiation-induced depolymerization, as suggested by increased beta-glucan solubility and reduced extract viscosity for irradiated barley and oat samples

  5. Toxicity of Kalanchoe spp to chicks.

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    Williams, M C; Smith, M C

    1984-03-01

    Leaves of Kalanchoe daigremontiana, K tubiflora, K fedtschenkoi, K tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were tested for toxicity to 2-week-old Leghorn chicks. These species were analyzed for percentage of alkaloids, aliphatic nitro compounds, soluble oxalates, and nitrates and were examined qualitatively for cyanogenic glycosides. The solubility of the toxic principle in K daigremontiana was determined. Leaves of K daigremontiana, K tubiflora, and K fedtschenkoi were toxic to chicks at dosage levels of 8 to 12 mg/g of body weight. Toxic signs included depression, muscular incoordination, twitching and spiraling of the neck, tremors, convulsions, paralysis, and death. Kalanchoe tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were nontoxic at the highest dosage levels tested. Aliphatic nitro compounds and cyanogenic glycosides were not detected in any species. Alkaloids, nitrates, and soluble oxalates were present only in nontoxic concentrations. The toxic principle in K daigremontiana was soluble in 50%, 80%, and 100% ethanol, slightly soluble in water and acetone, and insoluble in benzene, chloroform, and ether. PMID:6711983

  6. Neurodynamic oscillators

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    Espinosa, Ismael; Gonzalez, Hortensia; Quiza, Jorge; Gonazalez, J. Jesus; Arroyo, Ruben; Lara, Ritaluz

    1995-01-01

    Oscillation of electrical activity has been found in many nervous systems, from invertebrates to vertebrates including man. There exists experimental evidence of very simple circuits with the capability of oscillation. Neurons with intrinsic oscillation have been found and also neural circuits where oscillation is a property of the network. These two types of oscillations coexist in many instances. It is nowadays hypothesized that behind synchronization and oscillation there is a system of coupled oscillators responsible for activities that range from locomotion and feature binding in vision to control of sleep and circadian rhythms. The huge knowledge that has been acquired on oscillators from the times of Lord Rayleigh has made the simulation of neural oscillators a very active endeavor. This has been enhanced with more recent physiological findings about small neural circuits by means of intracellular and extracellular recordings as well as imaging methods. The future of this interdisciplinary field looks very promising; some researchers are going into quantum mechanics with the idea of trying to provide a quantum description of the brain. In this work we describe some simulations using neuron models by means of which we form simple neural networks that have the capability of oscillation. We analyze the oscillatory activity with root locus method, cross-correlation histograms, and phase planes. In the more complicated neural network models there is the possibility of chaotic oscillatory activity and we study that by means of Lyapunov exponents. The companion paper shows an example of that kind.

  7. Object Individuation in 3-Day-Old Chicks: Use of Property and Spatiotemporal Information

    Science.gov (United States)

    Fontanari, Laura; Rugani, Rosa; Regolin, Lucia; Vallortigara, Giorgio

    2011-01-01

    Object individuation was investigated in newborn domestic chicks. Chicks' spontaneous tendency to approach the larger group of familiar objects was exploited in a series of five experiments. In the first experiment newborn chicks were reared for 3 days with objects differing in either colour, shape or size. At test, each chick was presented with…

  8. Mass stranding of wedge-tailed shearwater chicks in Hawaii.

    Science.gov (United States)

    Work, T M; Rameyer, R A

    1999-07-01

    Unusual numbers of wedge-tailed shearwater (Puffinus pacificus) chicks stranded on Oahu (Hawaii, USA) in 1994. Compared to healthy wedge-tailed shearwater (WTSW) chicks, stranded chicks were underweight, dehydrated, leukopenic, lymphopenic, eosinopenic, and heterophilic; some birds were toxemic and septic. Stranded chicks also were hypoglycemic and had elevated aspartate amino transferase levels. Most chicks apparently died from emaciation, dehydration, or bacteremia. Because many birds with bacteremia also had severe necrosis of the gastrointestinal (GI) mucosa associated with bacteria, we suspect the GI tract to be the source of disseminated bacterial infection. The identity of the bacteria was not confirmed. The daily number of chicks stranded was significantly related to average wind speeds, and the mortality coincided with the fledging period for WTSW. Strong southeasterly winds were a distinguishing meteorologic factor in 1994 and contributed to the distribution of stranded chicks on Oahu. More objective data on WTSW demographics would enhance future efforts to determine predisposing causes of WTSW wrecks and their effects on seabird colonies. PMID:10479083

  9. Mass stranding of wedge-tailed shearwater chicks in Hawaii

    Science.gov (United States)

    Work, T.M.; Rameyer, R.A.

    1999-01-01

    Unusual numbers of wedge-tailed shearwater (Puffinus pacificus) chicks stranded on Oahu (Hawaii, USA) in 1994. Compared to healthy wedge-tailed shearwater (WTSW) chicks, stranded chicks were underweight, dehydrated, leukopenic, lymphopenic, eosinopenic, and heterophilic; some birds were toxemic and septic. Stranded chicks also were hypoglycemic and had elevated aspartate amino transferase levels. Most chicks apparently died from emaciation, dehydration, or bacteremia. Because many birds with bacteremia also had severe necrosis of the gastrointestinal (GI) mucosa associated with bacteria, we suspect the GI tract to be the source of disseminated bacterial infection. The identity of the bacteria was not confirmed. The daily number of chicks stranded was significantly related to average wind speeds, and the mortality coincided with the fledging period for WTSW. Strong southeasterly winds were a distinguishing meteorologic factor in 1994 and contributed to the distribution of stranded chicks on Oahu. More objective data on WTSW demographics would enhance future efforts to determine predisposing causes of WTSW wrecks and their effects on seabird colonies.

  10. Galactic oscillations

    Science.gov (United States)

    Miller, R. H.

    1991-01-01

    Long-lived oscillations that act like normal modes are described. The total kinetic energy is found to vary with time by amounts far in excess of the fluctuations expected from the virial theorem, and the variation shows periodic patterns that suggest oscillations. Experimental results indicate that oscillation amplitudes depend on the nature of the model. It is noted that it is difficult to answer questions about likely amplitudes in real galaxies with any confidence at the present time.

  11. Meixner oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Atakishiyev, N.M. [Instituto de Matematicas. Universidad Nacional Autonoma de Mexico. Cuernavaca, Morelos (Mexico); Jafarov, E.I.; Nagiyev, S.M. [Institute of Physics, Azerbaijan Academy of Sciences. Baku, Azerbaijan (Azerbaijan); Wolf, K.B. [Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas. Universidad Nacional Autonoma de Mexico. Cuernavaca, Morelos (Mexico)

    1998-10-01

    Meixner oscillators have a ground state and an energy spectrum that is equally spaced; they are a two-parameter family of models that satisfy a Hamiltonian equation with a difference operator. Meixner oscillators include as limits and particular cases the Charlier, Kravchuk and Hermite (common quantum-mechanical) harmonic oscillators. By the Sommerfeld-Watson transformation they are also related with a relativistic model of the linear harmonic oscillator, built in terms of the Meixner-Pollaczek polynomials, and their continuous weight function. We construct explicitly the corresponding coherent states with the dynamical symmetry group Sp(2,R). The reproducing kernel for the wavefunctions of these models is also found. (Author)

  12. Performance of Broiler Chicks Fed Irradiated Sorghum Grains

    International Nuclear Information System (INIS)

    Substitution of yellow corn with raw sorghum grains in chick diets resulted in decreases in live body weight, accumulative feed consumption and efficiency of feed utilization as compared with reference diet. Relative to raw sorghum diet, inclusion of sorghum grains irradiated at 60 and 100 kGy and/or supplemented with PEG in chick diets resulted in increases in accumulative feed consumption an efficiency feed utilization. The study suggested that irradiation treatment up to 100 kGy up grade broiler chicks performance and the combinations between radiation and PEG treatments sustain the effect of each other

  13. Interaction of human and chick DNA repair functions in UV-irradiated xeroderma pigmentosum-chick erythrocyte heterokaryons

    International Nuclear Information System (INIS)

    Fusion of chick erythrocytes with human primary fibroblasts results in the formation of heterokaryons in which the inactive chick nuclei become reactivated. The expression of chick DNA repair functions was investigated by the analysis of the DNA repair capacity after exposure to ultraviolet (UV) irradiation of such heterokaryons obtained after fusion of chick erythrocytes with normal human or xeroderma pigmentosum (XP) cells of complementation groups A, B, C and D. Unscheduled DNA synthesis (UDS) in normal human nuclei in these heterokaryons is suppressed during the first 2-4 days after fusion. The extent and duration of this suppression is positively correlated with the number of chick nuclei in the heterokaryons. Suppression is absent in heterokaryons obtained after fusion of chicken embryonic fibroblasts with XP cells (complementation group A and C). Restoration of DNA repair synthesis is found after fusion in XP nuclei of all complementation groups studied. It occurs rapidly in XP group A nuclei, starting one day after fusion and reaching near normal human levels after 5-8 days. In nuceli of the B, C and D group increased levels of UDS are found 5 days after fusion. At 8 days after fusion the UDS level is about 50% of that found in normal human nuclei. The pattern of UDS observed in the chick nuclei parallels that of the human counterpart in the fusion. In heterokaryons obtained after fusion of chick fibroblasts with XP group C cells UDS remains at the level of chick cells. These suggest that reactivation of chick erythrocyte nuclei results in expression of repair functions which are able to complement the defects in the XP complementation groups A, B, C and D

  14. Oscillate Boiling

    CERN Document Server

    Li, Fenfang; Nguyen, Dang Minh; Ohl, Claus-Dieter

    2016-01-01

    We report about an intriguing boiling regime occurring for small heaters embedded on the boundary in subcooled water. The microheater is realized by focusing a continuous wave laser beam to about $10\\,\\mu$m in diameter onto a 165\\,nm-thick layer of gold, which is submerged in water. After an initial vaporous explosion a single bubble oscillates continuously and repeatably at several $100\\,$kHz. The microbubble's oscillations are accompanied with bubble pinch-off leading to a stream of gaseous bubbles into the subcooled water. The self-driven bubble oscillation is explained with a thermally kicked oscillator caused by the non-spherical collapses and by surface pinning. Additionally, Marangoni stresses induce a recirculating streaming flow which transports cold liquid towards the microheater reducing diffusion of heat along the substrate and therefore stabilizing the phenomenon to many million cycles. We speculate that this oscillate boiling regime may allow to overcome the heat transfer thresholds observed dur...

  15. Predicting chick body mass by artificial intelligence-based models

    Directory of Open Access Journals (Sweden)

    Patricia Ferreira Ponciano Ferraz

    2014-07-01

    Full Text Available The objective of this work was to develop, validate, and compare 190 artificial intelligence-based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate-controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21-day-old chicks - with the variables dry-bulb air temperature, duration of thermal stress (days, chick age (days, and the daily body mass of chicks - was used for network training, validation, and tests of models based on artificial neural networks (ANNs and neuro-fuzzy networks (NFNs. The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age after they were subjected to the input variables, and they showed an R² of 0.9993 and a standard error of 4.62 g. The ANNs enable the simulation of different scenarios, which can assist in managerial decision-making, and they can be embedded in the heating control systems.

  16. Solar oscillations

    International Nuclear Information System (INIS)

    Amongst all stars observed to pulsate, the Sun has by far the largest number and variety of modes of oscillation. This presents a unique opportunity to apply and test stellar oscillation theory. To match the observational accuracy, very precise calculations of oscillation frequencies are needed. Asymptotic methods have proved useful in the analysis and interpretation of the frequencies. The results provide tight constraints on solar models; they may also enable a direct determination of properties of the solar interior. There are difficulties in reconciling the amplitudes obtained in Doppler velocity with those observed in the apparent position of the solar limb. The excitation of the oscillations is so far not well understood, although it is probable that the interaction between pulsation and convection plays an important role. (orig.)

  17. Power oscillator

    Science.gov (United States)

    Gitsevich, Aleksandr

    2001-01-01

    An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

  18. Proteome analysis of chick embryonic cerebrospinal fluid.

    Science.gov (United States)

    Parada, Carolina; Gato, Angel; Aparicio, Mariano; Bueno, David

    2006-01-01

    During early stages of embryo development, the brain cavity is filled with embryonic cerebrospinal fluid (E-CSF), a complex fluid containing different protein fractions that contributes to the regulation of the survival, proliferation and neurogenesis of the neuroectodermal stem cells. Using 2-DE, protein sequencing and database searches, we identified and analyzed the proteome of the E-CSF from chick embryos (Gallus gallus). We identified 26 different gene products, including proteins related to the extracellular matrix, proteins associated with the regulation of osmotic pressure and metal transport, proteins related to cell survival, MAP kinase activators, proteins involved in the transport of retinol and vitamin D, antioxidant and antimicrobial proteins, intracellular proteins and some unknown proteins. Most of these gene products are involved in the regulation of developmental processes during embryogenesis in systems other than E-CSF. Interestingly, 14 of them are also present in adult human CSF proteome, and it has been reported that they are altered in the CSF of patients suffering neurodegenerative diseases and/or neurological disorders. Understanding these molecules and the mechanisms they control during embryonic neurogenesis is a key contribution to the general understanding of CNS development, and may also contribute to greater knowledge of these human diseases. PMID:16287170

  19. Oscillation death in coupled oscillators

    Institute of Scientific and Technical Information of China (English)

    Wei ZOU; Xin-gang WANG; Qi ZHAO; Meng ZHAN

    2009-01-01

    We study dynamical behaviors in coupled nonlinear oscillators and find that under certain condi- tions, a whole coupled oscillator system can cease oscil- lation and transfer to a globally nonuniform stationary state [I.e., the so-called oscillation death (OD) state], and this phenomenon can be generally observed. This OD state depends on coupling strengths and is clearly differ- ent from previously studied amplitude death (AD) state, which refers to the phenomenon where the whole system is trapped into homogeneously steady state of a fixed point, which already exists but is unstable in the ab- sence of coupling. For larger systems, very rich pattern structures of global death states are observed. These Turing-like patterns may share some essential features with the classical Turing pattern.

  20. Enhanced learning of natural visual sequences in newborn chicks.

    Science.gov (United States)

    Wood, Justin N; Prasad, Aditya; Goldman, Jason G; Wood, Samantha M W

    2016-07-01

    To what extent are newborn brains designed to operate over natural visual input? To address this question, we used a high-throughput controlled-rearing method to examine whether newborn chicks (Gallus gallus) show enhanced learning of natural visual sequences at the onset of vision. We took the same set of images and grouped them into either natural sequences (i.e., sequences showing different viewpoints of the same real-world object) or unnatural sequences (i.e., sequences showing different images of different real-world objects). When raised in virtual worlds containing natural sequences, newborn chicks developed the ability to recognize familiar images of objects. Conversely, when raised in virtual worlds containing unnatural sequences, newborn chicks' object recognition abilities were severely impaired. In fact, the majority of the chicks raised with the unnatural sequences failed to recognize familiar images of objects despite acquiring over 100 h of visual experience with those images. Thus, newborn chicks show enhanced learning of natural visual sequences at the onset of vision. These results indicate that newborn brains are designed to operate over natural visual input. PMID:27079969

  1. Hypoxia adaptation and hemoglobin mutation in Tibetan chick embryo

    Institute of Scientific and Technical Information of China (English)

    GOU Xiao; LI Ning; LIAN Linsheng; YAN Dawei; ZHANG Hao; WU Changxin

    2005-01-01

    Tibetan chick lives at high altitudes between 2600 and 4200 m with a high hatchability and low land breeds survive rarely with a hatchability of 3.0% under hypoxia of simulated 4200 m. Under hypoxia of whole 21 d, the hatchability of Tibetan chick and Recessive White Feather broiler differed with a greatest disparity from day 4 to 11 and also significantly in other stages except from day 1 to 3. Hypoxia in each stage did not reduce significantly survival rate of this stage except hatchability. These two results indicated that the hypoxia in the early stage had an adverse effect on the later stage. All exons encoding chick hemoglobins were sequenced to analyze gene polymorphism. The functional mutation Met-32(B13)-Leu, related with hypoxia, was found in αD globin chain and the mutation frequency increased with increased altitude. In addition, under hypoxic conditions, the population with higher mutation frequency had a higher hatchability. The automated homology model building was carried out using crystal structure coordinates of chick HbD. The results indicated that the substitution Met-32(B13)-Leu provides a more hydrophobic environment which leads to higher stability of heme and oxygen affinity of hemoglobin. The occurrence of the mutation Met-32(B13)-Leu is related to the origin of Tibetan chick.

  2. Programmable Oscillator

    Science.gov (United States)

    Quirk, Kevin J.; Patawaran, Ferze D.; Nguyen, Danh H.; Lee, Clement G.; Nguyen, Huy

    2011-01-01

    A programmable oscillator is a frequency synthesizer with an output phase that tracks an arbitrary function. An offset, phase-locked loop circuit is used in combination with an error control feedback loop to precisely control the output phase of the oscillator. To down-convert the received signal, several stages of mixing may be employed with the compensation for the time-base distortion of the carrier occurring at any one of those stages. In the Goldstone Solar System Radar (GSSR), the compensation occurs in the mixing from an intermediate frequency (IF), whose value is dependent on the station and band, to a common IF used in the final stage of down-conversion to baseband. The programmable oscillator (PO) is used in the final stage of down-conversion to generate the IF, along with a time-varying phase component that matches the time-base distortion of the carrier, thus removing it from the final down-converted signal.

  3. Neutrino Oscillations

    Directory of Open Access Journals (Sweden)

    G. Bellini

    2014-01-01

    Full Text Available In the last decades, a very important breakthrough has been brought about in the elementary particle physics by the discovery of the phenomenon of the neutrino oscillations, which has shown neutrino properties beyond the Standard Model. But a full understanding of the various aspects of the neutrino oscillations is far to be achieved. In this paper the theoretical background of the neutrino oscillation phenomenon is described, referring in particular to the paradigmatic models. Then the various techniques and detectors which studied neutrinos from different sources are discussed, starting from the pioneering ones up to the detectors still in operation and to those in preparation. The physics results are finally presented adopting the same research path which has been crossed by this long saga. The problems not yet fixed in this field are discussed, together with the perspectives of their solutions in the near future.

  4. Circadian profiles in the embryonic chick heart: L-type voltage-gated calcium channels and signaling pathways.

    Science.gov (United States)

    Ko, Michael L; Shi, Liheng; Grushin, Kirill; Nigussie, Fikru; Ko, Gladys Y-P

    2010-10-01

    Circadian clocks exist in the heart tissue and modulate multiple physiological events, from cardiac metabolism to contractile function and expression of circadian oscillator and metabolic-related genes. Ample evidence has demonstrated that there are endogenous circadian oscillators in adult mammalian cardiomyocytes. However, mammalian embryos cannot be entrained independently to light-dark (LD) cycles in vivo without any maternal influence, but circadian genes are well expressed and able to oscillate in embryonic stages. The authors took advantage of using chick embryos that are independent of maternal influences to investigate whether embryonic hearts could be entrained under LD cycles in ovo. The authors found circadian regulation of L-type voltage-gated calcium channels (L-VGCCs), the ion channels responsible for the production of cardiac muscle contraction in embryonic chick hearts. The mRNA levels and protein expression of VGCCα1C and VGCCα1D are under circadian control, and the average L-VGCC current density is significantly larger when cardiomyocytes are recorded during the night than day. The phosphorylation states of several kinases involved in insulin signaling and cardiac metabolism, including extracellular signal-regulated kinase (Erk), stress-activated protein kinase (p38), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK-3β), are also under circadian control. Both Erk and p38 have been implicated in regulating cardiac contractility and in the development of various pathological states, such as cardiac hypertrophy and heart failure. Even though both Erk and phosphoinositide 3-kinase (PI3K)-Akt signaling pathways participate in complex cellular processes regarding physiological or pathological states of cardiomyocytes, the circadian oscillators in the heart regulate these pathways independently, and both pathways contribute to the circadian regulation of L-VGCCs.

  5. Generalization of visual regularities in newly hatched chicks (Gallus gallus).

    Science.gov (United States)

    Santolin, Chiara; Rosa-Salva, Orsola; Regolin, Lucia; Vallortigara, Giorgio

    2016-09-01

    Evidence of learning and generalization of visual regularities in a newborn organism is provided in the present research. Domestic chicks have been trained to discriminate visual triplets of simultaneously presented shapes, implementing AAB versus ABA (Experiment 1), AAB versus ABB and AAB versus BAA (Experiment 2). Chicks distinguished pattern-following and pattern-violating novel test triplets in all comparisons, showing no preference for repetition-based patterns. The animals generalized to novel instances even when the patterns compared were not discriminable by the presence or absence of reduplicated elements or by symmetry (e.g., AAB vs. ABB). These findings represent the first evidence of learning and generalization of regularities at the onset of life in an animal model, revealing intriguing differences with respect to human newborns and infants. Extensive prior experience seems to be unnecessary to drive the process, suggesting that chicks are predisposed to detect patterns characterizing the visual world. PMID:27287627

  6. Chromosperic oscillations

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    This review concentrates on the quiet-Sun chromosphere. Its internetwork areas are dynamically dominated by the so-called chromospheric three-minute oscillation. They are interpretationally dominated by the so-called Ca II K 2V and H 2V grains. The main points of this review are that the one phenome

  7. Immunization of young chicks using graded dose of wild strain of Eimeria tenella

    Directory of Open Access Journals (Sweden)

    E.N. Kimbita

    2005-09-01

    Full Text Available A wild strain of Eimeria tenella was isolated and utilized for immunization studies. Its optimal sporulation was attained at room temperature 24-25 °C after 24-48 h. Two groups of chicks were immunized by dosing a graded dose of five oocysts/chick/day for 6 days followed by 50 oocysts/chick/day for 7 days. A third group was not immunized and served as a negative control. Immunized chicks gained mass at the same rate as unimmunized ones, but when challenged with 200 000 oocysts/chick, mass gains declined in the unimmunized group. The growth rate of immunized chicks was not affected by challenge (P > 0.05. Upon challenge, unimmunized chicks produced significantly more oocysts than immunized chicks (P < 0.005. Immunized chicks withstood a challenged with 200 000 oocysts/chick without developing any clinical signs whereas the unimmunized chicks developed typical clinical signs of coccidiosis. Unimmunized chicks had significantly more severe lesions in the caecum than any other group (P > 0.005 and also produced significantly more oocysts than any other group (P > 0.005.

  8. STABILIZED OSCILLATOR

    Science.gov (United States)

    Jessen, P.L.; Price, H.J.

    1958-03-18

    This patent relates to sine-wave generators and in particular describes a generator with a novel feedback circuit resulting in improved frequency stability. The generator comprises two triodes having a common cathode circuit connected to oscillate at a frequency and amplitude at which the loop galn of the circutt ls unity, and another pair of triodes having a common cathode circuit arranged as a conventional amplifier. A signal is conducted from the osciliator through a frequency selective network to the amplifier and fed back to the osciliator. The unique feature of the feedback circuit is the amplifier operates in the nonlinear portion of its tube characteristics thereby providing a relatively constant feedback voltage to the oscillator irrespective of the amplitude of its input signal.

  9. Haemoproteus balearicae and other blood parasites of free-ranging Florida sandhill crane chicks

    Science.gov (United States)

    Dusek, R.J.; Spalding, M.G.; Forrester, Donald J.; Greiner, E.C.

    2004-01-01

    We obtained blood smears from 114 Florida sandhill crane (Grus canadensis pratensis) chicks in Osceola and Lake Counties, Florida, USA, during 1998-2000. Leucocytozoon grusi was observed in 11 (10%) chicks; Haemoproteus antigonis was observed in eight (7%) chicks; and three (3%) chicks were infected with Haemoproteus balearicae. One chick infected with H. balearicae suffered from severe anemia (packed cell volume=13%) and was later found moribund. At necropsy this bird also had severe anemia and damage to the heart possibly due to hypoxia. This is the first report of H. balearicae in free-ranging North American cranes. ?? Wildlife Disease Association 2004.

  10. Effects of Senna occidentalis on chick bursa of Fabricius.

    Science.gov (United States)

    Silva, Tereza C; Gorniak, Silvana L; Oloris, Silvia C S; Raspantini, Paulo C; Haraguchi, Mitsue; Dagli, Maria L Z

    2003-12-01

    Senna occidentalis (L) Link (formerly called Cassia occidentalis) is a toxic leguminous plant found ubiquitously as a contaminant of crops. All parts of the plant are toxic, but most of the S. occidentalis toxicity is found in the seeds. S. occidentalis has been shown to be toxic to several animal species, causing degenerative lesions mainly in muscles. This is the first report describing alterations in chick lymphoid organs caused by S. occidentalis seeds. The objectives of this study were to describe the effects of the treatment with seeds and its fraction external tegument (TE) on the development of chicks and their lymphoid organs bursa of Fabricius and spleen. Chicks that received a commercial ration with 1% TE had reduced body and lymphoid organ weights. The bursa of Fabricius presented reduction in the diameters of the follicles, and in the thickness of the cortical and medullary regions. The spleen presented depleted lymphoid tissue in the white pulp. These results indicate that the active principle of S. occidentalis is more concentrated on its TE fraction, and that it can cause weight loss as well as alterations in the lymphoid organs in chicks. The consequences of these alterations should be further investigated.

  11. Embryotoxic effects of crude oil in mallard ducks and chicks

    Science.gov (United States)

    Hoffman, D.J.

    1978-01-01

    Recent studies in this laboratory have revealed that surface applications of microliter amounts of some crude and fuel oils that coat less than 10% of the egg surface reduce hatching considerably in different avian species. Applications of paraffin compounds that coat equal areas of the egg surface do not reduce hatching suggesting that toxicity is due to causes other than asphyxia. In the present study, 1?10 :l of South Louisiana crude oil, an API reference oil, were applied to the surface of fertile mallard (Anas platyrhynchos) and chicken (Gallus gallus) eggs. Early embryolethality was greater in mallard embryos than in chick embryos, but later embryolethality that coincided with the time of rapid outgrowth of the chorioallantoic membrane was more prevalent in chick embryos. The overall incidence of embryolethality was similar in both species. Retardation of growth as reflected by embryonic body weight, crown-rump length, beak length, and general appearance was more pronounced in chick than mallard embryos. Teratogenic defects were more frequent in chick embryos, and incomplete or abnormal ossification of the skull was the most common. External application of equivalent amounts of a mixture of paraffin compounds present in crude oil had virtually no embryotoxic effects in either species, suggesting that other components including aromatic hydrocarbons and organometallics may cause the embryotoxicity.

  12. Neurotoxic effect of the dithiocarbamate tecoram on the chick embryo

    NARCIS (Netherlands)

    Steenis, G. van; Logten, M.J. van

    1971-01-01

    Tecoram, when administered at doses of 0.01, 0.1, 1 or 10 mg per egg in propylene glycol or in saline to chick embryos caused paralysis, shortening of the extremities, muscular atrophy, dwarfing and death. Microscopically there were signs of peripheral neuropathy, mainly confined to the distal parts

  13. Artificially Increased Yolk Hormone Levels and Neophobia in Domestic Chicks.

    Science.gov (United States)

    Bertin, Aline; Arnould, Cécile; Moussu, Chantal; Meurisse, Maryse; Constantin, Paul; Leterrier, Christine; Calandreau, Ludovic

    2015-11-30

    In birds there is compelling evidence that the development and expression of behavior is affected by maternal factors, particularly via variation in yolk hormone concentrations of maternal origin. In the present study we tested whether variation in yolk hormone levels lead to variation in the expression of neophobia in young domestic chicks. Understanding how the prenatal environment could predispose chicks to express fear-related behaviors is essential in order to propose preventive actions and improve animal welfare. We simulated the consequences of a maternal stress by experimentally enhancing yolk progesterone, testosterone and estradiol concentrations in hen eggs prior to incubation. The chicks from these hormone-treated eggs (H) and from sham embryos (C) that received the vehicle-only were exposed to novel food, novel object and novel environment tests. H chicks approached a novel object significantly faster and were significantly more active in a novel environment than controls, suggesting less fearfulness. Conversely, no effect of the treatment was found in food neophobia tests. Our study highlights a developmental influence of yolk hormones on a specific aspect of neophobia. The results suggest that increased yolk hormone levels modulate specifically the probability of exploring novel environments or novel objects in the environment.

  14. Artificially Increased Yolk Hormone Levels and Neophobia in Domestic Chicks

    Directory of Open Access Journals (Sweden)

    Aline Bertin

    2015-11-01

    Full Text Available In birds there is compelling evidence that the development and expression of behavior is affected by maternal factors, particularly via variation in yolk hormone concentrations of maternal origin. In the present study we tested whether variation in yolk hormone levels lead to variation in the expression of neophobia in young domestic chicks. Understanding how the prenatal environment could predispose chicks to express fear-related behaviors is essential in order to propose preventive actions and improve animal welfare. We simulated the consequences of a maternal stress by experimentally enhancing yolk progesterone, testosterone and estradiol concentrations in hen eggs prior to incubation. The chicks from these hormone-treated eggs (H and from sham embryos (C that received the vehicle-only were exposed to novel food, novel object and novel environment tests. H chicks approached a novel object significantly faster and were significantly more active in a novel environment than controls, suggesting less fearfulness. Conversely, no effect of the treatment was found in food neophobia tests. Our study highlights a developmental influence of yolk hormones on a specific aspect of neophobia. The results suggest that increased yolk hormone levels modulate specifically the probability of exploring novel environments or novel objects in the environment.

  15. Ex Ovo Model for Directly Visualizing Chick Embryo Development

    Science.gov (United States)

    Dorrell, Michael I.; Marcacci, Michael; Bravo, Stephen; Kurz, Troy; Tremblay, Jacob; Rusing, Jack C.

    2012-01-01

    We describe a technique for removing and growing chick embryos in culture that utilizes relatively inexpensive materials and requires little space. It can be readily performed in class by university, high school, or junior high students, and teachers of any grade level should be able to set it up for their students. Students will be able to…

  16. Development of Experimental Myopia in Chicks in a Natural Environment

    Science.gov (United States)

    Stone, Richard A.; Cohen, Yuval; McGlinn, Alice M.; Davison, Sherrill; Casavant, Susan; Shaffer, James; Khurana, Tejvir S.; Pardue, Machelle T.; Iuvone, P. Michael

    2016-01-01

    Purpose The hypothesis that outdoor exposure might protect against myopia has generated much interest, although available data find only modest clinical efficacy. We tested the effect of outdoor rearing on form-deprivation myopia in chicks, a myopia model markedly inhibited by high-intensity indoor laboratory lighting. Methods Unilaterally goggled cohorts of White Leghorn chicks were maintained in a species-appropriate, outdoor rural setting during daylight hours to the extent permitted by weather. Control chicks were reared indoors with incandescent lighting. Besides ocular refraction and ultrasound, we determined dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in retina and vitreous and measured mRNA expression levels of selected clock and circadian rhythm-related genes in the retina/RPE. Results Myopia developed in the goggled eyes of all cohorts. Whereas outdoor rearing lessened myopia by 44% at 4 days, a protective effect was no longer evident at 11 days. Outdoor rearing had no consistent effect on retinal or vitreous content of dopamine or DOPAC. Conforming to prior data on form-deprivation myopia, retina and vitreous levels of DOPAC were reduced in goggled eyes. Compared with contralateral eyes, the retinal expression of clock and circadian rhythm-related genes was modestly altered in myopic eyes of chicks reared indoors or outdoors. Conclusions Outdoor rearing of chicks induces only a partial decrease of goggle-induced myopia that is not maintained, without evidence that retinal dopamine metabolism accounts for the partial myopia inhibition under these outdoor conditions. Although modest, alterations in retinal gene expression suggest that studying circadian signals might be informative for understanding refractive mechanisms. PMID:27618415

  17. California gull chicks raised near colony edges have elevated stress levels

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  18. Effects of apomorphine and haloperidol on response suppression learning of young chicks.

    Science.gov (United States)

    McDougall, S A; Zolman, J F; Mattingly, B A

    1987-04-01

    In four experiments, the effects of augmenting or blocking dopamine receptor activity on response suppression learning of Colburn X Colburn chicks were determined. In each experiment, 4-day-old chicks were trained to key peck for heat reward and then tested for response suppression learning by using either a response-contingent punishment or an extinction-punishment task. Before response suppression testing, different groups of chicks were injected ip with apomorphine (1.0, 2.0, or 4.0 mg/kg) either alone or after pretreatment with haloperidol (0.5 or 1.0 mg/kg). Regardless of the response suppression task used, chicks injected with apomorphine had difficulty inhibiting their responding; whereas, chicks injected with haloperidol, either alone or before apomorphine treatment, responded on fewer trials than saline-treated chicks. During extinction testing, 4-day-old chicks given only apomorphine showed the typical suppressive effect of punishment on responding rather than the paradoxical punishment-induced increase in responding found in normal 1-day-old chicks. These results indicate that activation of dopamine receptors retards response suppression learning of the 4-day-old chick, but functional changes in central dopaminergic mechanisms are not primarily responsible for the normal age-dependent improvement in response suppression learning of the young chick. PMID:3580128

  19. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  20. Evaluation of vitamin E against deltamethrin toxicity in broiler chicks.

    Science.gov (United States)

    Jayasree, U; Reddy, A Gopala; Reddy, K S; Anjaneyulu, Y; Kalakumar, B

    2003-10-01

    Deltamethrin toxicity was studied in broilers and vitamin E was evaluated for therapeutic management. Day old male broiler chicks were randomly divided into 3 groups consisting of 6 chicks in each. Group 1 was maintained as control for 6 wks, group 2 was fed on deltamethrin (100 mg/kg feed) for 6 wks and group 3 was fed on deltamethrin for the first 4 wks and during the subsequent 2 wks with vitamin E (300 mg/kg feed) with out deltamethrin. Weekly body weights, feed conversion ratio, glutathione (GSH) concentration and high density lipoproteins (HDL) were significantly (P biomarkers were increased significantly (P feed is useful in treating accidental toxicity. PMID:15266958

  1. Lipid synthesis in the aorta of chick and other species

    International Nuclear Information System (INIS)

    The relative rate of fatty acid biosynthesis from labelled acetate in the adipose tissue of chicken is much lower than that in the rat (O'Hea and Leveille, 1968). To determine similar species differences in lipid synthesis in the aortas of cock, rat, rabbit and monkey, thoracic and abdominal segments of fresh aortas were incubated in vitro with (1-14C)-acetate for 3 h. Total lipids and their fractions (free and total cholesterol, free fatty acids, triglycerides and phospholipids) were counted for radioactivity. Incorporation of radioactivity into total as well as all classes of lipids was several times greater in chicken than in other species. Significant and consistent incorporation into cholesterol occurred only in chicks. Synthesis into total lipids and triglycerides was greater in the thoracic segment of chicks. These findings (Rao and Rao, 1968) are consistent with the ready susceptibility of chicken to atherosclerosis. (author)

  2. Newly hatched chicks solve the visual binding problem.

    Science.gov (United States)

    Wood, Justin N

    2014-07-01

    For an organism to perceive coherent and unified objects, its visual system must bind color and shape features into integrated color-shape representations in memory. However, the origins of this ability have not yet been established. To examine whether newborns can build an integrated representation of the first object they see, I raised newly hatched chicks (Gallus gallus) in controlled-rearing chambers that contained a single virtual object. This object rotated continuously, revealing a different color and shape combination on each of its two faces. Chicks were able to build an integrated representation of this object. For example, they reliably distinguished an object defined by a purple circle and yellow triangle from an object defined by a purple triangle and yellow circle. This result shows that newborns can begin binding color and shape features into integrated representations at the onset of their experience with visual objects. PMID:24840718

  3. The Mind Through Chick Eyes : Memory, Cognition and Anticipation

    OpenAIRE

    Matsushima, Toshiya; Izawa, Ei-Ichi; Aoki, Naoya; Yanagihara, Shin

    2003-01-01

    To understand the animal mind, we have to reconstruct how animals recognize the external world through their own eyes. For the reconstruction to be realistic, explanations must be made both in their proximate causes (brain mechanisms) as well as ultimate causes (evolutionary backgrounds). Here, we review recent advances in the behavioral, psychological, and system-neuroscience studies accomplished using the domestic chick as subjects. Diverse behavioral paradigms are compared (such as filial ...

  4. Paddy Straw as an Alternate Bedding Material for Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Navneet K

    2015-08-01

    Full Text Available Burning of agricultural residues especially paddy straw is now recognized as a major source of environmental concern in India. Burning of huge quantities of paddy straw annually leads to emission of obnoxious gases thus causing adverse impacts on, health of human, animal and bird population. This practice can be discouraged through its utilization as an alternate litter material to commonly used paddy husk which is now available at costly prices because of its use in different industries thus raising the cost of broiler production. This was evaluated through the experiment during winter season conducted on broiler chicks. Broiler chicks (n=144 were distributed into three treatment groups, each having 4 replicates of 12 chicks with equal sex and ratio and average group weight, and reared up to 42 days of age under similar conditions of housing and management except the variation in litter material. Paddy husk (PH, unchopped paddy straw (UPS and chopped paddy straw (CPS were used as different litter materials. The growth parameters tested in the experiment were body weight, weight gain, FCR, PER, EER and carcass characteristics (viz. evisceration rate and proportion of cut-up parts. The litter type had no significant effect on body weight, weight gain, FCR, PER and EER among all the treatments. The average body weight at 42 days of age was 1939, 1947 and 1960 g, respectively in PH, CPS, UCPS groups. The bedding type had no significant effect and no influence on the carcass characteristics viz. evisceration rate and proportion of cut-up parts of the carcass, so it was concluded that paddy straw can be used as good bedding material for broiler chicks.

  5. Detection and molecular characterization of chicken astrovirus associated with chicks that have an unusual condition known as "white chicks" in Brazil.

    Science.gov (United States)

    Nuñez, L F N; Santander Parra, S H; Carranza, C; Astolfi-Ferreira, C S; Buim, M R; Piantino Ferreira, A J

    2016-06-01

    Chicken astrovirus (CAstV) is one of many viruses related to enteric diseases in poultry that are associated with Runting-Stunting Syndrome (RSS), which affects young chickens. CAstV was also recently associated with an unusual condition in chicks called "white chicks." Some hatcheries in certain states of Brazil have reported several incubation problems, mortality, and the presence of chicks with white plumages over the past several months. These chicks were termed locally as "white chicks." The present work investigated 30 chicks with this unusual condition using a multidisciplinary approach. Postmortem examination of each chick showed enlarged livers and intestines that were full of liquid and gas (30/30). The pancreas, kidneys, and spleen were pale (30/30). The other organs did not show any macroscopic alterations. CAstV, chicken parvovirus (ChPV), avian nephritis virus (ANV), avian rotavirus (ARtV), avian reovirus (AReoV), infectious bronchitis virus (IBV), and fowl adenovirus group I (FAdV-1) were tested in the intestines, pancreas, proventriculus, gizzard, liver, spleen, bursa, kidneys, thymus, lung, heart, brain, and yolk sac in each chick. All organs and yolk sacs were positive for CAstV in different titres and negative for the other tested viruses. The partial molecular characterization of the ORF 1b gene of CAstV using 28 sequences revealed a high similarity of the nucleotides and amino acids with sequences of CAstV from North America, Europe, and Asia, and our CAstV sequences clustered into a unique group that was separate from the other sequences. These results demonstrated that CAstV was associated with the white chick condition in Brazil. The virus was distributed in most organs, including the brain and yolk sac. These results suggest that the virus could be transmitted vertically. The molecular characterization also revealed that the CAstV associated with white chick condition was molecularly related to other CAstV sequences found worldwide. PMID

  6. Introduction of DT40 cells into chick embryos

    Institute of Scientific and Technical Information of China (English)

    Mariko Toba; Fumio Ebara; Hiroki Furuta; Yuichi Matsushimal; Yasuo Kitagawa; Noboru Fujihara

    2001-01-01

    To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (ALV)-induced chicken B cell line DT40 to the production of chimeric birds. Methods: The DT40cells incorporated with exogenous gene (lacZ constructs encoding Escherichia coli β-galactosidase: β-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial 1 ) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of β-galactosidase and polymerase chain reaction (PCR) analysis. Results: The survival rates of the manipulated embryos incubated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively.The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, for the survived embryos. Conclusio: The rate of embryonic viability and expression rate of introduced genes were not so high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chick embryos.

  7. Numerical abstraction in young domestic chicks (Gallus gallus.

    Directory of Open Access Journals (Sweden)

    Rosa Rugani

    Full Text Available In a variety of circumstances animals can represent numerical values per se, although it is unclear how salient numbers are relative to non-numerical properties. The question is then: are numbers intrinsically distinguished or are they processed as a last resort only when no other properties differentiate stimuli? The last resort hypothesis is supported by findings pertaining to animal studies characterized by extensive training procedures. Animals may, nevertheless, spontaneously and routinely discriminate numerical attributes in their natural habitat, but data available on spontaneous numerical competence usually emerge from studies not disentangling numerical from quantitative cues. In the study being outlined here, we tested animals' discrimination of a large number of elements utilizing a paradigm that did not require any training procedures. During rearing, newborn chicks were presented with two stimuli, each characterized by a different number of heterogeneous (for colour, size and shape elements and food was found in proximity of one of the two stimuli. At testing 3 day-old chicks were presented with stimuli depicting novel elements (for colour, size and shape representing either the numerosity associated or not associated with food. The chicks approached the number associated with food in the 5vs.10 and 10vs.20 comparisons both when quantitative cues were unavailable (stimuli were of random sizes or being controlled. The findings emerging from the study support the hypothesis that numbers are salient information promptly processed even by very young animals.

  8. Study of the infectivity of saline-stored Campylobacter jejuni for day-old chicks

    DEFF Research Database (Denmark)

    Hald, Birthe; Knudsen, Katrine; Lind, Peter;

    2001-01-01

    The culturability of three Campylobacter jejuni strains and their infectivity for day-old chicks were assessed following storage of the strains in saline. The potential for colonization of chicks was weakened during the storage period and terminated 3 to 1 weeks before the strains became noncultu......The culturability of three Campylobacter jejuni strains and their infectivity for day-old chicks were assessed following storage of the strains in saline. The potential for colonization of chicks was weakened during the storage period and terminated 3 to 1 weeks before the strains became......-campylobacter outer membrane protein serum antibodies in day-old chicks did not protect the chicks from campylobacter colonization....

  9. Oscillators and Eigenvalues

    DEFF Research Database (Denmark)

    Lindberg, Erik

    1997-01-01

    In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear...... with negative resistance), Kennedy's Colpitts-oscillator (with and without chaos) and a new 4'th order oscillator with hyper-chaos....

  10. Development of teeth in chick embryos after mouse neural crest transplantations

    OpenAIRE

    Mitsiadis, Thimios A.; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

    2003-01-01

    Teeth were lost in birds 70–80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick ...

  11. Solar neutrinos: Oscillations or No-oscillations?

    CERN Document Server

    Smirnov, A Yu

    2016-01-01

    The Nobel prize in physics 2015 has been awarded "... for the discovery of neutrino oscillations which show that neutrinos have mass". While SuperKamiokande (SK), indeed, has discovered oscillations, SNO observed effect of the adiabatic (almost non-oscillatory) flavor conversion of neutrinos in the matter of the Sun. Oscillations are irrelevant for solar neutrinos apart from small $\

  12. Correlation between plasma steroids and chick visits by nonbreeding adult Nazca boobies.

    Science.gov (United States)

    Tarlow, Elisa M; Wikelski, Martin; Anderson, David J

    2003-03-01

    Nonbreeding adult Nazca boobies (Sula granti) often approach unattended chicks and perform parental and/or aggressive behaviors toward the chicks. Earlier descriptions of these encounters included sexual behaviors as well. We studied hormonal correlates of chick visits by such nonbreeding boobies during the breeding season. We compared the hormonal status of chick-visiting adults with that of nonvisiting adults in the colony. We determined levels of corticosterone (CORT), testosterone (T), androstendione, dihydrotestosterone, and estradiol as potential candidate hormones controlling parental, aggressive, or sexual behavior. Only T and CORT differed between chick-visiting and nonvisiting adults. Chick-visiting adults had higher CORT levels after the interaction than nonvisiting adults randomly caught in the colony. To the contrary. T levels after interactions were lower in chick-visiting compared to random nonvisiting adults. T levels, however, did not vary with level of aggression among chick-visiting adults. We suggest that chick-visiting behavior may be permitted by low T levels and activated by, or resulting in, high CORT levels.

  13. Indirect cannibalism by crèche-aged American White Pelican (Pelecanus erythrorhynchos) chicks

    Science.gov (United States)

    Bartos, Alisa J.; Sovada, Marsha A.; Igl, Lawrence D.; Pietz, Pamela J.

    2013-01-01

    At nesting colonies of American White Pelicans (Pelecanus erythrorhynchos), many chicks die from siblicide, severe weather, and disease; this results in carcasses available for scavenging by conspecifics (i.e., indirect cannibalism). Indirect cannibalism has not been reported previously for this species. We describe five cases of crèche-aged American White Pelican chicks consuming or attempting to consume dead younger chicks at two nesting colonies in the northern plains of North America. Cannibalism in the American White Pelican appears to be rare and likely plays no role in the species’ population ecology or dynamics; however, it might be an important survival strategy of individual chicks when food resources are limited.

  14. Effects of breeder age and egg weight on morphological changes in the small intestine of chicks during the hatch window.

    Science.gov (United States)

    Yalçin, S; Izzetoğlu, G T; Aktaş, A

    2013-01-01

    1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window. 2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed. 3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks. 4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.

  15. Changes in free amino acid and monoamine concentrations in the chick brain associated with feeding behavior.

    Science.gov (United States)

    Tran, Phuong V; Chowdhury, Vishwajit S; Nagasawa, Mao; Furuse, Mitsuhiro

    2015-01-01

    Domesticated chicks are precocial and therefore have relatively well-developed feeding behavior. The role of hypothalamic neuropeptides in food-intake regulation in chicks has been reported for decades. However, we hypothesized that nutrients and their metabolites in the brain may be involved in food intake in chicks because these animals exhibit a very frequent feeding pattern. Therefore, the purpose of this study was to examine the feeding behavior of chicks as well as the associated changes in free amino acid and monoamine concentrations in the chick brain. The feeding behavior of chicks was recorded continuously for 6 h. The next day, brain and blood samples were collected when the chicks either attempted to have food (hungry group) or turned food down (satiated group), in order to analyze the concentrations of the free amino acids and monoamines. We confirmed that the feeding behavior of neonatal chicks was characterized by short resting periods between very brief times spent on food intake. Several free amino acids in the mesencephalon were significantly lower in the satiated group than in the hungry group, while l-histidine and l-glutamine were significantly higher. Notably, there was no change in the free amino acid concentrations in other brain regions or plasma. As for monoamines, serotonin and norepinephrine were significantly lower in the mesencephalon of the hungry group compared with the satiated group, but 5 hydroxyindolacetic acid (5-HIAA) was higher. In addition, serotonin and norepinephrine levels were significantly higher in the brain stem of the hungry chicks compared with the satiated group, but levels of 5-HIAA and homovanillic acid were lower. Levels of both dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid, were significantly higher in the diencephalon and telencephalon of the chicks in the hungry group. In conclusion, the changes in the free amino acids and monoamines in the brain may have some role in the feeding behavior of

  16. Oscillations of Eccentric Pulsons

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Groenbech-Jensen, Niels; Lomdahl, Peter;

    1997-01-01

    Perturbation theory for elliptic pulsons is developed and predicts pulson and eccentricity oscillations. The pulson oscillation period is predicted qualitatively correct.......Perturbation theory for elliptic pulsons is developed and predicts pulson and eccentricity oscillations. The pulson oscillation period is predicted qualitatively correct....

  17. 9 CFR 147.17 - Laboratory procedure recommended for the bacteriological examination of cull chicks and poults...

    Science.gov (United States)

    2010-01-01

    ... poultry, and game bird flocks and poults from turkey flocks for salmonella. (a) For cull chicks, from 25 randomly selected 1- to 5-day-old chicks that have not been placed in a brooding house, prepare 5...

  18. Chick embryo fibroblasts produce two forms of hyaluronidase

    OpenAIRE

    Orkin, RW; Toole, BP

    1980-01-01

    Cultured chick embryo fibroblasts derived from skin and skeletal muscle exhibit hyaluronidase activity both associated with the cell layer and secreted into the medium. Although both forms of the enzyme have a number of similar characteristics (R.W. Orkin and B.P. Toole, 1980, J. Biol. CHem. 255), they differ in thermal stability at neutral pH and in behavior on ion-exchange chromatography. Both forms of the enzyme are equally stable at acidic pH for long intervals, but the cell-associated hy...

  19. Development of otoconia in the embryonic chick (Gallus domesticus)

    Science.gov (United States)

    Fermin, C. D.; Igarashi, M.

    1985-01-01

    In the chick (Gallus domesticus) embryo, otoconium formation started first over the macula sacculi around the 4th day of incubation, and a day later over the macula utriculi. It was determined that each otoconium formed as a result of the segmentation of the immature otolithic membrane, and that the calcium responsible for otoconium calcification was incorporated into the organic matrix of each otoconium in the form of small electron-dense granules (20-150 nm in. diameter). The presence of calcium in these granules was confirmed by histochemical staining with osmic-potassium pyroantimonate, by EDTA chelation, and by X-ray micronanalysis under the electron microscope.

  20. Effects of begging on growth rates of nestling chicks

    OpenAIRE

    Rodríguez-Gironés, Miguel Ángel; Jesús M Zúñiga; Redondo, T.

    2001-01-01

    We investigated whether an increase in begging levels delays growth of chicks. In experiment 1, we hand-reared nine pairs of ring dove squabs, divided into a control and a begging group. All squabs received similar amounts of food, but those in the begging group had to beg for a prolonged period in order to be fed, while squabs in the control group received food without begging. Squabs stopped responding to the treatment after 10 days and, at that time, there was no effect of induced begging ...

  1. Foraging behavior and physiological changes in precocial quail chicks in response to low temperatures

    NARCIS (Netherlands)

    Krijgsveld, KL; Visser, GH; Daan, S

    2003-01-01

    We examined whether low ambient temperatures influence foraging behavior of precocial Japanese quail chicks and alter the balance between investment in growth and thermogenic function. To test this, one group of chicks was exposed to 7 degreesC and one group to 24 degreesC during foraging throughout

  2. EFFECTS OF PRIMARY IMPRINTING ON THE SUBSEQUENT DEVELOPMENT OF SECONDARY FILIAL ATTACHMENTS IN THE CHICK

    NARCIS (Netherlands)

    DEVOS, GJ; VANKAMPEN, HS

    1993-01-01

    This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the developmen

  3. Influences of Feeding Lactobacillus on Colonization of the Lactobacillus in Chicks'Digestible Tracts

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    It was carried out with culture solution of Lactobacillus fed to the newborn chicks to observe the influences on colonization of the Lactobacillus in chicks′ digestible tracts. The results showed that after the chicks were fed Lactobacillus, the amount of the Lactobacillus in chicks′ digestible tracts significantly increased (P<0.01) and the Lactobacillus colonized 36h ahead of schedule

  4. Territory structure, parental provisioning, and chick growth in the American Black Oystercatcher Haematopus bachmani

    NARCIS (Netherlands)

    Hazlitt, S.L.; Ydenberg, R.C.; Lank, D.B.

    2002-01-01

    We investigate parental food provisioning and chick growth to better understand how parental effort and territory structure relate to reproductive success in the American Black Oystercatcher. American Black Oystercatcher chick diet was comprised mainly of limpets. Most prey items were 20 mm or short

  5. Social stimuli, testosterone, and aggression in gull chicks : Support for the challenge hypothesis

    NARCIS (Netherlands)

    Ros, AFH; Dieleman, SJ; Groothuis, TGG; Dieleman, Steph J.; Groothuis, Ton G.G.; Groothuis, A.G.G.

    2002-01-01

    We tested the challenge hypothesis for the hormonal regulation of aggression in chicks of the black-headed gull, Larus ridibundus. Chicks of this species are highly aggressive toward conspecifics, but never to peers that hatched from the same clutch (modal clutch size is three). Therefore, in the fi

  6. Protection of non-immunized broiler chicks housed with immunized cohorts against infection with Eimeria maxima and E. acervulina

    Science.gov (United States)

    The use of live oocyst vaccines is becoming increasingly important in the control of avian coccidosis in broiler chicks. Knowledge of the mechanisms of how chicks uptake oocysts and become immune is important for optimizing delivery of live vaccines. The current study tests the hypothesis that chick...

  7. Age-dependent improvement in passive avoidance learning of the young chick: cholinergic mediation?

    Science.gov (United States)

    Zolman, J F; Mattingly, B A

    1982-06-01

    Cholinergic mediation of the age-dependent improvement in response suppression of the young chick was studied by determining the performance of 4-day-old chicks, pretreated with scopolamine, during passive avoidance (PA) and extinction testing. In Experiment 1, chicks were trained briefly to key peck for heat reward (prepunishment training), and then tested for PA learning under immediate, 2-sec-delayed, or no shock condition. Half of the chicks in each wing-shock (5 mA, 5 sec) condition received saline injections before prepunishment training and .5 mg/kg scopolamine injections after prepunishment training. The rest of the chicks received .5 mg/kg scopolamine injections both before and after prepunishment training. For chicks in both scopolamine groups, delaying shock onset resulted in significantly less response suppression than immediate response-contingent shock. In Experiment 2, 4-day-old chicks injected with either saline or scopolamine were trained to key peck for heat reward and then tested for resistance to extinction under either response-contingent shock or nonshock conditions. Punishment decreased the number of extinction responses for both saline and scopolamine groups of chicks. Previous studies have shown that normal 1-day-old chicks do not show a significant delay of punishment effect during PA testing and that response-contingent punishment increases the number of their responses during extinction. Hence, the results of the present experiments indicate that the age-dependent improvement in response suppression of the young chick cannot be explained solely by a significant increase in central cholinergic functioning. PMID:7096681

  8. Experience and geometry: controlled-rearing studies with chicks.

    Science.gov (United States)

    Chiandetti, Cinzia; Vallortigara, Giorgio

    2010-05-01

    Animals can reorient making use of the geometric shape of an environment, i.e., using sense and metric properties of surfaces. Animals reared soon after birth either in circular or in rectangular enclosures (and thus affording different experiences with metric properties of the spatial layout) showed similar abilities when tested for spatial reorientation in a rectangular enclosure. Thus, early experience in environments with different geometric characteristics does not seem to affect animals' ability to reorient using sense and metric information. However, some results seem to suggest that when geometric and non-geometric information are set in conflict, rearing experience could affect the relative dominance of featural (landmark) and geometric information. In three separate experiments, newborn chicks reared either in circular- or in rectangular-shaped home-cages were tested for spatial reorientation in a rectangular enclosure, with featural information provided either by panels at the corners or by a blue-coloured wall. At test, when faced with affine transformations in the arrangement of featural information that contrasted with the geometric information, chicks showed no evidence of any effect of early experience on their relative use of geometric and featural information for spatial reorientation. These findings suggest that, at least for this highly precocial species, the ability to deal with geometry seems to depend more on predisposed mechanisms than on learning and experience after hatching. PMID:19960217

  9. Evaluation of Immunodulatory effect of Stresroak Premix in Broiler Chick

    Directory of Open Access Journals (Sweden)

    M.M.Gatne

    2010-06-01

    Full Text Available The present study was aimed to evaluate the immunomodulatory efficacy of polyherbal formulation Stresroak along with effect on performance in broiler chicken. Four hundred and fifty healthy days old chicks were randomly divided into three groups (each group consisting of 150 chicks. Group A served as a negative control while group B served as positive control supplemented with levamisole, a known immunomodulator @ 15 mg/kg body weight through water for four consecutive days from third day onwards. Group C birds supplemented with Stresroak were administered @ 1 kg /tone of feed for consecutively for 11 days i.e. 5 days before and 5 days after vaccination. Parameters under study were performance traits viz, body weight gain, feed consumption, FCR, blood samples were collected at weekly interval for evaluation of various haematological, biochemical immunological and histopathological examination parameters. Results revealed that the antibody titre, total proteins and globulins were increased significantly in the birds receiving Stresroak as compared to untreated control group. Performance parameters were improved non-significantly as compared to untreated control (Group A. Histopathologically varying degrees of lympho-proliferative changes noted which reveals increase number of lymphocytes. It was concluded that Stresroak exhibits hematinic, hepato-protective and Immunomodulator properties [Vet. World 2010; 3(3.000: 122-125

  10. IN VIVO TOXICITY ASSESSMENT OF SILICA NANOPARTICLES IN CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Chandrapragasam Vani

    2013-09-01

    Full Text Available Silica is one of the most effective stored seedand food grain protecting pesticide agent, usedfor ages Silica nanoparticles are hard and strong andresistant to brittle fracture under an imposed stress. The aim of our study is to synthesize and evaluate the toxicity of silica nanoparticles at various concentrations using chick embryo, as it serves as a bridging model between in vivo and ex vivo studies. Silica nanoparticles of 70 nm sizewith concentrations of 10, 20, 40 and 80 PPM were injected in vivo and incubated for 19 days as per IACUC guidelines. The study was carried out on dissected chick embryo after the 19th day of incubation. Vital tissues such as liver and heart tissues were subjected to toxicity assays. Biochemical assay of antioxidant enzymes like superoxide dismutase and glutathione peroxide were assessed. The results showed a decreased level of MDA (Malondialdehyde, an end product of lipid Peroxidation, whereas increased activity of superoxide dismutase and glutathione peroxide were observed. Therefore silica nanoparticles may be used as a pesticide and also as a biomaterial for therapeutic application in the field of medicine.

  11. The Effect of Aflatoxin B1 on the Vitamin A Storage in the Livers of Broiler Chicks

    OpenAIRE

    SALMANOĞLU, Berrin

    2002-01-01

    The effect of AFB1 in feed on the liver and serum vitamin A and b-carotene levels and the ability of the liver to stor vitamin A in broiler chicks were investigated. Twenty day-old Ross broiler chicks were randomly allocated into 4 groups with 5 each in the control group, group I, group II, and group III. The chicks of the control group and group I were fed ad libitum on broiler chick growing feed. The chicks of group II and group III were fed ad libitum on feed with AFB1 (4 ppm/kg) feed. On ...

  12. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  13. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    G Rajasekaran

    2000-07-01

    The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  14. Migratory mechanisms of chick primordial germ cells toward gonadal anlage.

    Science.gov (United States)

    Kuwana, T; Rogulska, T

    1999-07-01

    After appearing at the germinal crescent region, chick primordial germ cells (PGCs) migrate toward the presumptive gonads (pG) till stage 19 (Hamburger and Hamilton, 1951). This study seeks to elucidate the roles of passive and active factors in the PGC-migration, physical trapping of circulating PGCs by the capillary network and PGC attraction by chemotactic factor from presumptive gonads. Firstly, latex beads/pollens (the same size or larger than PGCs) were injected into the embryonic bloodstream at stage 13-19 (when PGCs are in the migrating and settlement phase to the presumptive gonad) in ovo in order to determine whether the PGCs passively reach pG. Most of such particles accumulated in the head region (60%), whereas the remainder did the same in the gonadal region (23% at the peak) at stage 16 when both the head and gonadal regions are rich in capillary plexus. After 3 days, most particles in the gonadal region were located at the angles of dorsal mesentery near the developing gonads where many extra-gonadal PGCs had been located, and a few particles were detected close to the gonad. These results suggest that one of the mechanisms of PGC-migration to the developing gonads is an autonomous trapping of PGCs by the capillary network quite close to the germinal epithelium (GE) and passive translocation by morphogenetic movement. Secondly, the attraction for PGCs by the gonadal anlage proper was examined in ovo using chick and quail embryos. Grafts of quail gonadal anlage containing gonadal epithelium and neighbouring mesenchymal tissue were excised from the quail embryo at stages 12 to 16 (staging by Zacchei, 1961). With the aims of eliminating the influence of surrounding tissue, the quail graft was ectopically transplanted into the posterior to the optic vesicle of 8 to 17 somite chick embryo from the point of a posterior region to the auditory vesicle by a fine tungsten needle under the illumination by the method of Hara (1971). Then the region posterior to

  15. MEMS based reference oscillator

    OpenAIRE

    Hedestig, Joel

    2005-01-01

    The interest in tiny wireless applications raises the demand for an integrated reference oscillator with the same performance as the macroscopic quartz crystal reference oscillators. The main challenge of the thesis is to prove that it is possible to build a MEMS based oscillator that approaches the accuracy level of existing quartz crystal oscillators. The MEMS resonator samples which Philips provides are measured and an equivalent electrical model is designed for them. This model is used in...

  16. Representation of two geometric features of the environment in the domestic chick ( Gallus gallus).

    Science.gov (United States)

    Tommasi, Luca; Polli, Camilla

    2004-01-01

    We report experiments based on a novel test in domestic chicks ( Gallus gallus), designed to examine the encoding of two different geometric features of an enclosed environment: relative lengths of the walls and amplitude of the corners. Chicks were trained to search for a food reward located in one corner of a parallelogram-shaped enclosure. Between trials, chicks were passively disoriented and the enclosure was rotated, making reorientation possible only on the basis of the internal spatial structure of the enclosure. In order to reorient, chicks could rely on two sources of information: the relative lengths of the walls of the enclosure (associated to their left-right sense order) and the angles subtended by walls at corners. Chicks learned the task choosing equally often the reinforced corner and its rotational equivalent. Results of tests carried out in novel enclosures, the shapes of which were chosen ad hoc (1) to induce reorientation based only on the ratio of walls lengths plus sense (rectangular enclosure), or (2) to induce reorientation based only on corner angles (rhombus-shaped enclosure), suggested that chicks encoded both features of the environment. In a third test, in which chicks faced a conflict between these geometric features (mirror parallelogram-shaped enclosure), reorientation seemed to depend on the salience of corner angles. These results shed light on the elements of the environmental geometry which control spatial reorientation, and broaden the knowledge on the geometric representation of space in animals. PMID:12884079

  17. Reorienting strategies in a rectangular array of landmarks by domestic chicks (Gallus gallus).

    Science.gov (United States)

    Pecchia, Tommaso; Vallortigara, Giorgio

    2010-05-01

    Spatial reorientation in a rectangular array of four landmarks located in the center of a circular enclosure was investigated in domestic chicks (Gallus gallus). One of the landmark possessed unique visual features, indicating the location of a food reward. After training, chicks were tested (a) with the same array as during the training; (b) with four identical landmarks of the type previously nonrewarded, of the type previously rewarded, or of a new type; (c) after having transformed one of the landmarks located at the geometric incorrect location into the type of landmark previously rewarded; or (d) with a fifth landmark of the rewarded type at a new location. Chicks encoded information provided by local featural cues but not the geometric information provided by the shape of the array. Moreover, when trained in a rectangular array of identical landmarks chicks failed to reorient. In a second series of experiments, the array was located in correspondence to the corners of a rectangular enclosure. This time chicks successfully learned to locate the reward using geometric information. However, when the rectangular array was located in the center of a larger rectangular enclosure, chicks failed to reorient, indicating that the geometric information given by the macroscopic layout of arena surfaces was not used to specify different locations. These results suggest that chicks reorient on the basis of a local representation of single landmarks and that encoding of the global aspects of geometry only occurs with respect to the large, extended surfaces of an enclosure. PMID:20476814

  18. Lead exposure in Laysan albatross adults and chicks in Hawaii: prevalence, risk factors, and biochemical effects.

    Science.gov (United States)

    Work, T.M.; Smith, M.R.

    1996-01-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme δ-amino-levulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 μg/ml was the no effect range for blood lead in albatross chicks.

  19. Penguin chicks benefit from elevated yolk androgen levels under sibling competition.

    Directory of Open Access Journals (Sweden)

    Maud Poisbleau

    Full Text Available Crested penguins (genus Eudyptes have a peculiar hatching pattern, with the first-laid egg (A-egg hatching after the second-laid egg (B-egg and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive superiority of the B-chick in southern rockhopper penguins Eudyptes chrysocome, given their important role in mediating sibling competition in other species. We therefore increased the yolk androgen levels in freshly-laid eggs and examined the consequences for sibling competition--via effects on embryonic developmental times, chick growth and early survival. We placed one androgen-treated egg and one control egg into each foster nest, matching them for mass, laying date and laying order. The androgen treatment did not significantly affect embryonic developmental times or chick measurements at hatching. However, elevated yolk androgen levels benefitted chick growth in interaction with the number of siblings in a brood. Chicks from androgen-treated eggs had faster growth in the presence of a sibling than chicks from control eggs. Under these circumstances they also had a higher survival probability. Thus maternal androgens appear to reinforce the observed hatching pattern, facilitating brood reduction. This contrasts to most previous studies in other species where yolk androgens have been shown to compensate for the negative consequences of delayed hatching within the brood hierarchy.

  20. Brain asymmetry modulates perception of biological motion in newborn chicks (Gallus gallus).

    Science.gov (United States)

    Rugani, Rosa; Rosa Salva, Orsola; Regolin, Lucia; Vallortigara, Giorgio

    2015-09-01

    Few light-points on the joints of a moving animal give the impression of biological motion (BM). Day-old chicks prefer BM to non-BM, suggesting a conserved predisposition to attend to moving animals. In humans and other mammals a network of regions, primarily in the right hemisphere, provides the neural substrate for BM perception. However, this has not been investigated in avians. In birds the information from each eye is mainly feeding to the contralateral hemisphere. To study brain asymmetry, we recorded the eye spontaneously used by chicks to inspect a BM stimulus. We also investigated the effect of lateralization following light exposure of the embryos. In Experiment 1, highly lateralized chicks aligned with the apparent direction of motion only when they were exposed to a BM-stimulus moving rightward first, monitoring it with the left-eye-system. In Experiment 2 weakly lateralized chicks did not show any behavioral asymmetry. Moreover, they counter aligned with the apparent direction of motion. Brain lateralization affects chicks behavior while processing and approaching a BM stimulus. Highly lateralized chicks aligned their body with the apparent direction of the BM, a behavior akin to a following response, monitoring the stimulus preferentially with their left eye. This suggests a right hemisphere dominance in BM processing. Weakly lateralized chicks counter-aligned with the apparent direction of the BM, facing it during interaction, and monitored it equally with both eyes. Environmental factors (light stimulation) seem to affect the development of lateralization, and consequently social behavior. PMID:25930217

  1. The colpitts oscillator family

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...

  2. Organochlorine concentrations in diseased vs. healthy gull chicks from the northern Baltic

    International Nuclear Information System (INIS)

    The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed. - Elevated DDE/PCB ratio correlates with a high rate of chick diseases in the endangered nominate lesser black-backed gull

  3. Effect of Low Dose Radiation Upon Antioxidant Parameters in Skeletal Muscle of Chick Embryo

    International Nuclear Information System (INIS)

    In this paper an attempt was made to determine the effect of irradiation of eggs with low dose ionizing radiation upon lipid peroxide (TBARS) level, glutathione (GSH) level, activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) in skeletal muscle of chick embryo and newly hatched chicks. The eggs of a heavy breeding chickens were irradiated with a dose of 0.3 Gy gamma radiation (60Co source) on the 19th day of incubation. Along with the irradiated chick embryos, there was a control group of non-irradiated chick embryos. The antioxidant parameters were measured in breast muscle (m. pectoralis superficialis) and thigh muscle (m. biceps femoris) of chick embryos on 1, 3, 6, 24 and 72 h after egg irradiation. All parameters were determined spectrophotometrically. Lipid peroxidation, GSH level and CAT activity decreased in the breast and thigh muscle of chick embryos on the first hour after irradiation, while the activity of GSH-Px increased in the thigh muscle on the 1st hour after irradiation. CAT activity decreased in the breast muscle of chick embryos on the hour 24 after irradiation. The GSH level increased in the breast and thigh muscle of chick embryos on the hour 72 after irradiation while the activity of GSH-Px increased in the breast muscle. At the same time CAT activity decreased in breast muscle while lipid peroxidation decreased in thigh muscle. The obtained results showed that acute irradiation of chicken eggs on the 19th day of incubation with the dose of 0.3 Gy gamma radiation could be an oxidative stress in both types of muscles immediately after irradiation. However, at the one-day old chicks (72 hours after irradiation) this dose could have a stimulating effect upon GSH level in both breast and thigh muscle.(author)

  4. Kittiwake diets and chick production signal a 2008 regime shift in the Northeast Pacific

    Science.gov (United States)

    Hatch, Scott A.

    2013-01-01

    I examined ~2700 food samples collected from adult and nestling black-legged kittiwakes Rissa tridactyla from 1978 through 2011 on Middleton Island in the Gulf of Alaska. The kittiwake diet was composed chiefly of fish, but invertebrates were taken in appreciable quantities in April and May. Upon spring arrival at the colony, adult kittiwakes foraged regularly at night on vertically migrating mesopelagic prey—lanternfishes (Myctophidae), squids, crustaceans, and polychaetes—a behavior they largely discontinued by egg-laying. During incubation and chick-rearing, food samples contained mostly (~85% by weight) Pacific sand lance Ammodytes hexapterus, capelin Mallotus villosus, Pacific herring Clupea pallasii, sablefish Anopoploma fimbria, krill (Euphausiidae), and juvenile salmon Onchorynchus gorboscha and O. keta. A salient finding over the longitudinal study was the emergence, twice, of capelin as a dominant forage species—once in 2000 to 2003, and again in 2008 through 2011. Kittiwakes responded to capelin availability by producing markedly higher numbers of fledged young. The 2000 to 2003 event corresponded to a previously documented shift to cooler conditions in the NE Pacific, which apparently was relatively limited in magnitude or duration. The more recent transition appears stronger and may be more lasting. I submit that 2008 was an important turning point, marking a substantive reversal of warm conditions that began with the well-documented regime shift of 1977. That interpretation is consistent with the existence of a ~60 yr cycle in ocean and atmospheric conditions in the North Pacific. All else being equal, it predicts the next 20 to 30 yr will be favorable for species such as kittiwakes and Steller sea lions, which seemed to respond negatively to the 1977 to 2007 warm phase of the Pacific Decadal Oscillation.

  5. The effect of insecticide Deltamethrin on development of chick embryos

    International Nuclear Information System (INIS)

    This study was conducted to evaluate the cyto and the embryo toxicity of Deltamethrin and its commercial formulation DECIS 50 EC in chick embryo during its critical embryonic development period before and in the organogenesis. The embryos were incubated in well closed plastic caps containing the complete egg composition at 38 o. the Deltamethrin and DECIS were found to cause histological and morphological malformations, specially in the brain, also they reduced the majority of the synthetic activities of the DNA, RNA, and proteins in the embryonic and the vascular areas. The flow cytometric analysis showed alterations in frequency of cells in both embryonic and vascular areas in the treated embryo during the cell cycle phases. Our study also showed that the DECIS had greater cyto and embryo toxicity than the Seltamethrin for analysis (author). 149 refs., 36 figs., 16 tabs

  6. The generation of vertebral segmental patterning in the chick embryo.

    Science.gov (United States)

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-06-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.

  7. Secondary imprinting in the domestic chick: Binocular and lateralized monocular performance

    OpenAIRE

    Vallortigara, Giorgio; Regolin, Lucia; Zucca, Paolo

    2000-01-01

    Newly-hatched chicks were reared with a coloured imprinting object on day 1 of life (primary imprinting) and then with an object of a different colour (secondary imprinting) on day 2. They were then tested on day 3 for preferences between the primary and the secondary imprinting object in binocular and in monocular conditions. The main results were that (1) left-eyed chicks usually showed clearer choice than right-eyed chicks; (2) there were colour preferences that appeared to affect choice d...

  8. Isolation and characterization of new collagens from chick cartilage.

    Science.gov (United States)

    von der Mark, K; van Menxel, M; Wiedemann, H

    1982-05-01

    Three unique collagen chains were isolated from chick sternal cartilage following pepsin solubilization of total cartilage collagens and removal of the predominant type II collagen by fractional salt precipitation. Native molecules containing 1 alpha, 2 alpha and 3 alpha chains precipitated between 0.7 M and 1.2 M NaCl at acidic pH and could be purified by chromatography on carboxymethyl-cellulose and agarose columns. Although similar to mammalian 1 alpha, 2 alpha and 3 alpha chains, differences in the mobilities on sodium dodecylsulfate gel electrophoresis, CNBr peptide profiles and amino acid composition were found. The 1 alpha and 2 alpha chains resemble, but are structurally distinct from, the chick alpha 1(V) and alpha 2(V) chains. The 3 alpha chain appears to be closely related to the alpha 1(II) chain, although some differences in the cyanogen bromide peptides suggest that they might be different gene products. In addition, two collagenous fragments of Mr 140 000 (M1) and 35 000 (M2) were found which precipitated at 2.0 m NaCl at acidic pH. Both fragments contain interchain disulfide bonds. The larger fragment was reducible to subunits of approximate Mr 120 000, 48 000, 28 000 and 11 000. The smaller fragment gave rise to peptides of Mr about 12 000 and 10 000 after reduction. By the technique of rotary shadowing the native, unreduced larger fragment M1 appeared as a slender rod-like molecule with a distinct bend approximately 40 nm from one end. We interpret this finding as indicative of a focal amino acid sequence irregularity, disrupting the triple-helical conformation. PMID:7084229

  9. Neutrino oscillations: theory and phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Akhmedov, E.K., E-mail: akhmedov@ictp.trieste.it [Department of Theoretical Physics, Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm (Sweden)

    2011-12-15

    A brief overview of selected topics in the theory and phenomenology of neutrino oscillations is given. These include: oscillations in vacuum and in matter; phenomenology of 3-flavour neutrino oscillations; CP and T violation in neutrino oscillations in vacuum and in matter; matter effects on {nu}{sub {mu}}{r_reversible}{nu}{sub {tau}} oscillations; parametric resonance in neutrino oscillations inside the earth; oscillations below and above the MSW resonance; unsettled issues in the theory of neutrino oscillations.

  10. Neutrino oscillations under gravity: mass independent oscillation

    OpenAIRE

    Mukhopadhyay, Banibrata

    2003-01-01

    I discuss the possibility of neutrino oscillation in presence of gravity. In this respect I consider the propagation of neutrinos in the early phase of universe and around black holes. It is seen that whether the rest masses of a neutrino and corresponding anti-neutrino are considered to be same or not due to space-time curvature effect non-zero oscillation probability between the neutrino and anti-neutrino states comes out. Therefore I can conclude that under gravity neutrino oscillation tak...

  11. 维生素A缺乏致斑马鱼胚胎体节不对称及后脑图式形成异常%Vitamin A deficiency causes asymmetric somitogenesis and abnormal hindbrain patterning in zebrafish embryos

    Institute of Scientific and Technical Information of China (English)

    曹莎莎; 贾文双; 赵庆顺

    2012-01-01

    Retinoic acid (RA) plays essential roles in vertebrate embryogenesis. However, vertebrates cannot synthesize RA de novo. They synthesize it by two oxidative steps, first converting the precursor vitamin A into retinal by retinol dehy-drogenase, and then oxidizing retinal into RA irreversibly by retinal dehydrogenase. It is known that vitamin A deficiency (VAD) causes Vitamin A Deficiency Syndrome in animals including quail, mouse, rat, and human. However, little is known about the effects of VAD on zebrafish embryogenesis. In this study, we obtained zebrafish VAD embryos from the zebrafish fed a retinoids-free diet. By analyzing the VAD embryos, we found that VAD caused asymmetric somitogenesis and abnormal hindbrain patterning in zebrafish embryos. However, the phenotype of defected hindbrain in VAD embryos was not as severe as that in the embryos in which aldhla2, the major gene that is responsible for RA synthesis in zebrafish early development, was knocked down, or the embryos treated with 10 nmol/L DEAB (diethylaminobenzaldehyde, inhibitor of retinal dehydrogenases). Our results indicated that the VAD embryos were short of but not free of vitamin A, and they might also have a RA generation pathway independent of retinal dehydrogenase.%视黄酸(RA)在脊椎动物胚胎发生过程中发挥着关键作用.但是脊椎动物不能从头合成RA,而必须以维生素A为前体通过视黄醇脱氢酶和视黄醛脱氢酶(Aldh1A)先将其氧化为视黄醛再氧化成RA.已知维生素A缺乏(VAD)会导致多种动物出现维生素A缺乏综合征,但有关VAD对斑马鱼胚胎发育的影响尚未见报道.文章通过用不含维生素A及其他视黄类前体的饲料饲喂斑马鱼获得斑马鱼VAD胚胎.分析表明,缺乏维生素A可导致斑马鱼胚胎体节出现不对称发育、胚胎的后脑图式形成异常.这些表型虽与aldh1a2基因敲落的及经醛脱氢酶抑制剂处理的斑马鱼胚胎表型类似,但远不及后二

  12. The Oscillator Principle of Nature

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2012-01-01

    Oscillators are found on all levels in Nature. The general oscillator concept is defined and investigated. Oscillators may synchronize into fractal patterns. Apparently oscillators are the basic principle in Nature. The concepts of zero and infinite are discussed. Electronic manmade oscillators...... are introduced by means of an example of an autonomous third-order chaotic oscillator....

  13. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  14. Fenugreek (Trigonella foenum-graecum L. effect on muscle growth of broiler chicks

    Directory of Open Access Journals (Sweden)

    Farman Ullah Khan,

    2011-01-01

    Full Text Available The purpose of this research work was to evaluate the aqueous seed extract of Trigonella foenum-graecum L. (Fenugreek on the weight of breast, thigh and leg of broiler chicks. One hundred and sixty, day old male broiler chicks were randomly assigned to four treatments i.e., A, B, C and D. Each treatment was replicated four times with 10 chicks per replicate. Groups B, C and D received the aqueous extract of fenugreek @ 10, 20 and 30 ml/L, respectively while group A served as a control. Chicks were reared in cages in an open sided house. The data showed that weight of breast, thigh and leg were significantly (P<0.05 heavier in group C compared to control. It was concluded from this study that Trigonella foenum-graecum at the rate of 30 ml/L aqueous extract has a beneficial impact on the growth of these muscle tissues.

  15. Invertebrate Availability and Preference by Northern Bobwhite Chicks in Mississippi Old Fields

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Invertebrate density, biomass, and diversity, northern bobwhite Colinus virginianus chick invertebrate preference, and vegetation stem density and biomass were...

  16. A detailed description of an economical setup for electroporation of chick embryos in ovo.

    Science.gov (United States)

    Borges, R M; Horne, J H; Melo, A; Vidal, J T; Vieceli, F M; Melo, M O; Kanno, T Y N; Fraser, S E; Yan, C Y I

    2013-09-01

    One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

  17. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-10-06

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  18. Efficacy of adsorbents (bentonite and diatomaceous earth) and turmeric (Curcuma longa) in alleviating the toxic effects of aflatoxin in chicks.

    Science.gov (United States)

    Dos Anjos, F R; Ledoux, D R; Rottinghaus, G E; Chimonyo, M

    2015-01-01

    A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B1 (AFB1). A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB1 (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB1, BC, DE and TUM. Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks. Aflatoxin B1 reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB1 and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB1 had lower FI (23.1%) and BWG (28.6%) compared with control chicks. Chicks fed on the combination of TUM and AFB1 also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB1, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks. Chicks fed on the combination of AFB1, DE and TUM diet had poorer growth performance than those fed on AFB1 alone. None of the combination diets reduced the severity of liver lesions.

  19. The importance of endogenous nutrition of chicks from divergent strains for growing tested by deutectomy

    Directory of Open Access Journals (Sweden)

    E Gonzales

    2008-09-01

    Full Text Available Effects of yolk sac removal (deutectomy upon performance of chicks from three divergent strains were tested to evaluate the importance of endogenous nutrition on the post-hatch phase. Chicks from three different strains (Hy-Line W98, Cobb 500, and JA57 were submitted to a surgery procedure after hatching. Half of them had the residual yolk removed, and the other constituted a sham-deutectomized group. After operation, chicks were designated to a 3 x 2 factorial design (3 strains x 2 presence/absence of yolk sac, in a total of six experimental groups and ten replications of two to four birds. During 14 experimental days all birds were fed ad libitum a 21% CP and 3050 kcal/kg EM mash diet. Data were analyzed by ANOVA, and Tukey's test (p<0.05. Relative yolk sac weights were similar among chicks from different breeders, averaging 11.7% to 13.5%. Comparing to sham-operated, deuctetomized chicks had lower weight gain at 7 and 14d, indicating that endogenous nutrition, via yolk sac, is very important to galliform birds whatever their strain. Hy-line deutectomized chicks gained 40% less body weight at the 7th day as compared to their sham counterparts. Analysis of the same criterion to Cobb and JA57 groups revealed a decrease of 16.1% and 10.8%, respectively, on weight gain efficiency. At the 14th rearing day, Hy-Line chicks had the lowest weight gain, followed by JA57s' and Cobbs'. The results suggested that chicks selected for fast growth are less dependent on endogenous nutrition, responding better when exogenous nutrition is associated to yolk assimilation.

  20. Bird mercury concentrations change rapidly as chicks age: toxicological risk is highest at hatching and fledging.

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.

    2011-01-01

    Toxicological risk of methylmercury exposure to juvenile birds is complex due to the highly transient nature of mercury concentrations as chicks age. We examined total mercury and methylmercury concentrations in blood, liver, kidney, muscle, and feathers of 111 Forster's tern (Sterna forsteri), 69 black-necked stilt (Himantopus mexicanus), and 43 American avocet (Recurvirostra americana) chicks as they aged from hatching through postfledging at wetlands that had either low or high mercury contamination in San Francisco Bay, California. For each waterbird species, internal tissue, and wetland, total mercury and methylmercury concentrations changed rapidly as chicks aged and exhibited a quadratic, U-shaped pattern from hatching through postfledging. Mercury concentrations were highest immediately after hatching, due to maternally deposited mercury in eggs, then rapidly declined as chicks aged and diluted their mercury body burden through growth in size and mercury depuration into growing feathers. Mercury concentrations then increased during fledging when mass gain and feather growth slowed, while chicks continued to acquire dietary mercury. In contrast to mercury in internal tissues, mercury concentrations in chick feathers were highly variable and declined linearly with age. For 58 recaptured Forster's tern chicks, the proportional change in blood mercury concentration was negatively related to the proportional change in body mass, but not to the amount of feathers or wing length. Thus, mercury concentrations declined more in chicks that gained more mass between sampling events. The U-shaped pattern of mercury concentrations from hatching to fledging indicates that juvenile birds may be at highest risk to methylmercury toxicity shortly after hatching when maternally deposited mercury concentrations are still high and again after fledging when opportunities for mass dilution and mercury excretion into feathers are limited.

  1. Short Copy Number Variations Potentially Associated with Tonic Immobility Responses in Newly Hatched Chicks

    OpenAIRE

    Hideaki Abe; Kenji Nagao; Miho Inoue-Murayama

    2013-01-01

    INTRODUCTION: Tonic immobility (TI) is fear-induced freezing that animals may undergo when confronted by a threat. It is principally observed in prey species as defence mechanisms. In our preliminary research, we detected large inter-individual variations in the frequency and duration of freezing behavior among newly hatched domestic chicks (Gallus gallus). In this study we aim to identify the copy number variations (CNVs) in the genome of chicks as genetic candidates that underlie the behavi...

  2. Avian myeloblastosis virus-induced lymphosarcoma producing erythroblastic leucosis in chicks

    Directory of Open Access Journals (Sweden)

    Kanzaki,Yoshito

    1975-10-01

    Full Text Available Acute myeloblastosis and several forms of tumor, including one case of lymphosarcoma occurred when avian myeloblastosis virus (BAI-A strain was inoculated into newly hatched chicks (SPF. The homogenate of lymphosarcoma inoculated intraperitoneally into other newly hatched chicks induced a high incidence of erythroblastic leucosis. Electron microscopy did not reveal the presence of C-type virus particles in the tumor tissue. The relationship between avian myeloblastosis virus, lymphosarcoma and erythroblastic leucosis is discussed.

  3. Effect of dietary glutamine supplementation on Salmonella colonization in the ceca of young broiler chicks.

    Science.gov (United States)

    Fasina, Y O; Bowers, J B; Hess, J B; McKee, S R

    2010-05-01

    Live poultry is an important vehicle for transmitting Salmonella Typhimurium to humans that have salmonellosis. It is therefore imperative to reduce Salmonella Typhimurium levels in the gastrointestinal tract of live chickens. Glutamine is an established immunonutrient that is capable of alleviating disease conditions in humans and rats. Thus, 2 experiments that used Ross broiler chicks were conducted to evaluate the effect of glutamine supplementation at 1% level of the diet on cecal Salmonella Typhimurium levels in young broiler chicks. Experiment 1 consisted of i) treatment 1 (control, CN), in which chicks were given an unmedicated corn-soybean meal basal starter diet without glutamine supplementation or Salmonella Typhimurium challenge; ii) treatment 2 (CST), in which chicks were given the same diet as CN but challenged with 3.6 x 10(6) cfu Salmonella Typhimurium/mL at 3 d of age; and iii) treatment 3 (GST), in which chicks were given the unmedicated corn-soybean meal basal starter diet supplemented with glutamine at 1% level, and challenged with 3.6 x 10(6) cfu at 3 d of age. Experiment 2 used similar treatments (CN, CST, and GST), except that chicks in CST and GST were challenged with 7.4 x 10(7) cfu Salmonella Typhimurium/mL, and a fourth treatment was added. The fourth treatment consisted of chicks that were not challenged with Salmonella Typhimurium but given the same diet as in GST. Duration of each experiment was 14 d. Growth performance of chicks was monitored weekly, and cecal Salmonella Typhimurium concentration was microbiologically enumerated on d 4, 10, or 11 postchallenge. Results showed that glutamine supplementation improved BW and BW gain in experiment 2 (P 0.05). The optimum supplemental level of glutamine that will enhance intestinal resistance to Salmonella Typhimurium colonization should be determined.

  4. The hormonal control of begging and early aggressive behavior: Experiments in black-headed gull chicks

    OpenAIRE

    Groothuis, TGG; Ros, AFH; Groothuis, Ton G.G

    2005-01-01

    The hormonal control of begging and sibling competition is largely unknown, but recent evidence suggests a role for steroid hormones. We tested the influence of the aromatizable androgen testosterone (T), the non-aromatizable androgen 5 alpha-dihydrotestosterone (DHT), and 17 beta-estradiol (E) on both begging behavior and aggressive behavior in black-headed gull chicks (Larus ridibundus). Chicks of this species have a conspicuous begging display, while their frequently performed early aggres...

  5. Are acoustical parameters of begging call elements of thin-billed prions related to chick condition?

    OpenAIRE

    Quillfeldt, Petra; Poisbleau, Maud; Mundry, Roger; Masello, Juan F.

    2010-01-01

    Chicks of burrowing petrels use begging calls to advertise their hunger levels when parents arrived at the nest. In a previous study, adult thin-billed prions Pachyptila belcheri responded to higher begging call rates of their single chick by regurgitating larger meals. We tested whether acoustic parameters of begging call elements may also be involved in signalling. To describe variation in begging, we determined begging session parameters, namely the duration, number of calls and the mean a...

  6. Feeding, fasting and foraging success during chick rearing in macaroni penguins

    OpenAIRE

    Green, J. A.; Boyd, I.L.; Woakes, A.J.; Green, C J; Butler, P.J.

    2007-01-01

    Foraging behaviour and energy expenditure were measured continuously throughout the chick-rearing period of free-ranging macaroni penguins Eudyptes chrysolophus. These data were integrated with values obtained from the literature on body mass, assimilation efficiency, body reserve consumption and deposition rates, chick growth and energy expenditure and energy content of food in a new type of algorithm to predict (with 95% confidence limits [CL]) foraging success and daily changes in body mas...

  7. Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity

    OpenAIRE

    van Hierden, YM; Koolhaas, JM; Kost'al, L; Vyboh, P; Sedlackova, M; Rajman, M.; Jurani, M; Korte, SM; Hierden, Yvonne M. van; Koolhaas, Jaap M.; Košt’ál, L’ubor; Sedlačková, Monika

    2005-01-01

    Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reactive cooing strategy, respectively. therefore, at approximately 4 weeks of age, the behavior of 48 LFP and 48 HFP chicks in response to an APO injection Was studied using an open field. Another objec...

  8. Evidence that coated vesicles transport acetylcholine receptors to the surface membrane of chick myotubes

    OpenAIRE

    1984-01-01

    Coated vesicles are present in the myoplasm of embryonic chick myotubes grown in vitro. They are most numerous beneath regions of the surface membrane that contain a high density of acetylcholine receptors (AChR). Prolonged exposure of myotubes to saline extract of chick brain increases the number of intracellular AChR and the number of coated vesicles. This suggests that coated vesicles contain AChR, and this hypothesis was tested with horseradish peroxidase-alpha-bungarotoxin (HRP-alpha BTX...

  9. Suppression of myofibrillar proteolysis in chick skeletal muscles by alpha-ketoisocaproate.

    Science.gov (United States)

    Nakashima, K; Yakabe, Y; Ishida, A; Yamazaki, M; Abe, H

    2007-09-01

    We previously reported that L-leucine suppresses myofibrillar proteolysis in chick skeletal muscles. In the current study, we compared the effects of L- and D-enantiomers of leucine on myofibrillar proteolysis in skeletal muscle of chicks. We also assessed whether leucine itself or its metabolite, alpha-ketoisocaproate (alpha-KIC), mediates the effects of leucine. Food-deprived (24 h) chicks were orally administered 225 mg/100 g body weight L-leucine, D-leucine or alpha-KIC and were sacrificed after 2 h. L-Leucine administration had an obvious inhibitory effect on myofibrillar proteolysis (plasma N(tau)-methylhistidine concentration) in chicks while D-leucine and alpha-KIC were much more effective. We also examined the expression of the proteolytic-related genes (ubiquitin, proteasome, m-calpain and cathepsin B) by real-time PCR of cDNA in chick skeletal muscles. Ubiquitin mRNA expression was decreased by D-leucine and alpha-KIC but not L-leucine. Proteasome and m-calpain mRNA expressions as well as cathepsin B mRNA expression were likewise decreased by L-leucine, D-leucine and alpha-KIC. These results indicate that D-leucine and alpha-KIC suppress proteolytic-related genes, resulting in an decrease in myofibrillar proteolysis while L-leucine is much less effective in skeletal muscle of chicks, may be explain by conversion of D-leucine to alpha-KIC. PMID:16998714

  10. Daily energy expenditures of free-ranging Common Loon (Gavia immer) chicks

    Science.gov (United States)

    Fournier, F.; Karasov, W.H.; Meyer, M.W.; Kenow, K.P.

    2002-01-01

    We measured the daily energy expenditure of free-living Common Loon (Gavia immer) chicks using doubly labeled water (DLW). Average body mass of chicks during the DLW measures were 425, 1,052, and 1,963 g for 10 day-old (n = 5), 21 day-old (n = 6), and 35 day-old (n = 6) chicks, respectively, and their mean daily energy expenditures (DEE) were 686 kJ day-1, 768 kJ day-1, and 1,935 kJ day-1, respectively. Variation in DEE was not due solely to variation in body mass, but age was also a significant factor independent of body mass. Energy deposited in new tissue was calculated from age-dependent tissue energy contents and measured gains in body mass, which were 51, 54, and 33 g day-1 from the youngest to oldest chicks. Metabolizable energy (the sum of DEE and tissue energy) was used to estimate feeding rates of loon chicks and their exposure to mercury in the fish they consume. We calculated that loon chicks in Wisconsin consumed between 162 and 383 g wet mass of fish per day (depending on age), corresponding to intakes of mercury of 16-192 ??g day-1.

  11. Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks.

    Science.gov (United States)

    Bertin, Aline; Meurisse, Maryse; Arnould, Cécile; Leterrier, Christine; Constantin, Paul; Cornilleau, Fabien; Vaudin, Pascal; Burlot, Thierry; Delaveau, Joel; Rat, Christophe; Calandreau, Ludovic

    2016-03-01

    In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors. PMID:26419601

  12. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  13. Slime mould electronic oscillators

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    We construct electronic oscillator from acellular slime mould Physarum polycephalum. The slime mould oscillator is made of two electrodes connected by a protoplasmic tube of the living slime mould. A protoplasmic tube has an average resistance of 3~MOhm. The tube's resistance is changing over time due to peristaltic contractile activity of the tube. The resistance of the protoplasmic tube oscillates with average period of 73~sec and average amplitude of 0.6~MOhm. We present experimental labor...

  14. Mesoscopic Capacitance Oscillations

    OpenAIRE

    Buttiker, Markus; Nigg, Simon

    2006-01-01

    We examine oscillations as a function of Fermi energy in the capacitance of a mesoscopic cavity connected via a single quantum channel to a metallic contact and capacitively coupled to a back gate. The oscillations depend on the distribution of single levels in the cavity, the interaction strength and the transmission probability through the quantum channel. We use a Hartree-Fock approach to exclude self-interaction. The sample specific capacitance oscillations are in marked contrast to the c...

  15. Self-oscillation

    Science.gov (United States)

    Jenkins, Alejandro

    2013-04-01

    Physicists are very familiar with forced and parametric resonance, but usually not with self-oscillation, a property of certain dynamical systems that gives rise to a great variety of vibrations, both useful and destructive. In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the velocity, causing a negative damping that feeds energy into the vibration: no external rate needs to be adjusted to the resonant frequency. The famous collapse of the Tacoma Narrows bridge in 1940, often attributed by introductory physics texts to forced resonance, was actually a self-oscillation, as was the swaying of the London Millennium Footbridge in 2000. Clocks are self-oscillators, as are bowed and wind musical instruments. The heart is a “relaxation oscillator”, i.e., a non-sinusoidal self-oscillator whose period is determined by sudden, nonlinear switching at thresholds. We review the general criterion that determines whether a linear system can self-oscillate. We then describe the limiting cycles of the simplest nonlinear self-oscillators, as well as the ability of two or more coupled self-oscillators to become spontaneously synchronized (“entrained”). We characterize the operation of motors as self-oscillation and prove a theorem about their limit efficiency, of which Carnot’s theorem for heat engines appears as a special case. We briefly discuss how self-oscillation applies to servomechanisms, Cepheid variable stars, lasers, and the macroeconomic business cycle, among other applications. Our emphasis throughout is on the energetics of self-oscillation, often neglected by the literature on nonlinear dynamical systems.

  16. Screening of central functions of amino acids and their metabolites for sedative and hypnotic effects using chick models.

    Science.gov (United States)

    Furuse, Mitsuhiro

    2015-09-01

    The chick has a practical advantage in the screening process in that chicks require only small quantities of drugs. The chick separation stress paradigm has traditionally been recognized as a valid form of anxiolytic screening. Further, chick behavior involving standing motionless with eyes closed or sitting motionless with head drooped is nearly always associated with electrophysiological sleep. When centrally administered, some DNA-encoded L-α-amino acids, as well as some DNA-non-encoded amino acids, such as metabolites of L-α-amino acids, D-amino acid and β-amino acid, have shown sedative and/or hypnotic effects in chicks. The effects of some of these amino acids have subsequently been confirmed in humans. In conclusion, the chick model is convenient and useful for screening central functions of amino acids and their metabolites for hypnosis and sedation.

  17. Influence of hydrogen peroxide in drinking water on diazepam pharmacokinetics in chicks

    Directory of Open Access Journals (Sweden)

    Yaareb J. Mousa

    Full Text Available Aim: Stressful conditions affect drug pharmacokinetics and pharmacodynamics. This study examines the effect of hydrogen peroxide (H2O2 in drinking water on the pharmacokinetics of diazepam in a chick model of oxidative stress. Materials and Methods: Day old chicks were either provided with plane tap water (control group or H2O2 in tap water as 0.5% v/v drinking solution for two weeks in order to produce oxidative stress. On treatment days 7–14, the chicks were treated with a sedative dose of diazepam at 10 mg/kg, intramuscularly. Blood samples were obtained from chicks (5/each sampling time at times of between 0.17 to 4 h. The concentrations of diazepam in the plasma were determined by an HPLC method with UV-detector. Pharmacokinetic parameters of diazepam were calculated from the mean drug concentrations in the plasma by a non-compartmental analysis using a Windows-based computer program. Results: Injection of diazepam resulted in the appearance of the drug in the plasma of control and H2O2 -treated chicks at mean concentrations ranging between 0.11 to 0.444 and 0.131 to 0.535 μg/ml, respectively when measured between 0.17 to 4 h after administration. Diazepam concentrations of the H O -treated chicks were significantly higher than those of the control group at the sampling times 0.5, 0.75, 1 and 4 h. The highest concentration of diazepam in the plasma of both the control and H2O2 treated chicks occurred one h after the injection. The elimination half-life, mean residence time, maximum plasma concentration, area under the moment curve and area under plasma concentration-time curve in the H2O2 -treated chicks were higher than those of the control group by 35, 28, 23, 91 and 49%, respectively. Correspondingly, the steady state volume of distribution, elimination rate constant and total body clearance in the H2O2 -treated chicks decreased from those of the respective control values by 15, 24 and 33%. Conclusion: The data suggest that oral

  18. Method of Electroporation for the Early Chick Embryo

    Science.gov (United States)

    Hatakeyama, Jun; Shimamura, Kenji

    Chick embryos have long been one of the favored model systems in the field of embryology and developmental biology. Recent advances in the gene manipulation technologies (Muramatsu et al., 1997; Nakamura et al., 2004) make this model system even more attractive for the developmental biologists (see review by Stern, 2005). Thanks to its two dimensional geometry, easiness in accessibility and observation, and well-established fate maps (e.g. Couly and Le Douarin, 1988; Garcia-Martinez et al., 1993; Hatada and Stern, 1994; Psychoyos and Stern, 1996; Sawada and Aoyama, 1999; Cobos et al., 2001; Lopez-Sanchez et al., 2001; Redkar et al., 2001; Fernandez-Garre et al., 2002; Kimura et al., 2006; Matsushita et al., 2008), it has great advantages especially for studies at the early embryonic stages, such as the processes of gastrulation, neural induction, left-right patterning, etc. For such purposes, a whole embryo culture system, originally invented by Dennis A. T. New (New, 1955), and its derivatives (Flamme, 1987; Sundin and Eichele, 1992; Stern, 1993; Chapman et al., 2001) have been widely used.

  19. A mechanistic link between chick diet and decline in seabirds?

    Science.gov (United States)

    Kitaysky, A.S.; Kitaiskaia, E.V.; Piatt, J.F.; Wingfield, J.C.

    2006-01-01

    A climatic regime shift during the mid-1970s in the North Pacific resulted in decreased availability of lipidrich fish to seabirds and was followed by a dramatic decline in number of kittiwakes breeding on the Pribilof Islands. Although production of chicks in the mid-1970s was adequate to sustain kittiwake populations in the early 1980s, the disappearance of birds from breeding colonies apparently exceeded recruitment. No mechanism has been proposed to explain why recruitment would differ among fledglings fed lipid-rich or lipid-poor fish during development. Here we show that diets low in lipids induce nutritional stress and impair cognitive abilities in young red-legged kittiwakes, Rissa brevirostris. Specifically, growth retardation, increased secretion of stress hormones and inferior ability to associate food distribution with visual cues were observed in individuals fed lipid-poor diets. We conclude that lipid-poor diets during development affect the quality of young seabirds, which is likely to result in their increased mortality and low recruitment. ?? 2005 The Royal Society.

  20. Corticosterone in thin-billed prion Pachyptila belcheri chicks: diel rhythm, timing of fledging and nutritional stress

    Science.gov (United States)

    Quillfeldt, Petra; Poisbleau, Maud; Chastel, Olivier; Masello, Juan F.

    2007-11-01

    Glucocorticosteroids (GCs) of the hypothalam-pituitary-adrenal axis play a role in association with both stressful events and daily life processes. However, relatively little is known about the role of GCs in relation to daily and seasonal life processes in animals in the wild. In this paper, we present data on basal levels of plasma corticosterone CORT in chicks of a pelagic seabird, the thin-billed prion, Pachyptila belcheri, during two predictable changes in demands, the daily activity pattern and the preparation for fledging. By comparing chicks fed recently with unfed chicks, we test how GC levels are modified according to nutritional condition. In accordance with their nocturnal feeding rhythm, chicks had a clear daily rhythm with increased CORT secretion at night, but CORT levels during the active phase were also highly elevated in unfed chicks compared with fed chicks. Close to fledging, chicks rapidly increased basal CORT levels, and again unfed chicks had higher levels than fed chicks, although the age effect here was stronger than the effect of recent feeding. The present data thus support the hypothesis that GC levels are adjusted to life stages with predictable changes in demands, but food availability and/or internal energy stores also affect the level to which GCs increase.

  1. Effects of prebiotic (Fermacto) in low protein diet on some blood parameters and intestinal microbiota of broiler chicks

    OpenAIRE

    Amir Attar; Farid Firouzbakhsh; Hadi Sayyahzadeh; Mansour Rezaei; Mahalam Ghiyasi

    2010-01-01

    This study was conducted to evaluate the effects of prebiotic (Fermacto) in low protein diet on serum cholesterol and intestinal microbiota of broiler chicks. One hundred and fifty six 1-day old Ross 308 broiler chicks of both sexes were used for 42 days. The chicks were randomly allocated to 12 pens containing 13 chicks each with 3 replicates and assigned to receive one of the 4 dietary treatments of 2 levels of protein (low and high) and 2 levels of prebiotic (0 and 0.2%) in a completely ra...

  2. Efficacy of pine leaves as an alternative bedding material for broiler chicks during summer season

    Directory of Open Access Journals (Sweden)

    Gourav Sharma

    2015-10-01

    Full Text Available Aim: The aim was to assess the efficacy of pine leaves as an alternative bedding material on the performance of broiler chicks. Materials and Methods: The present study was conducted in summer. Total 120, day old Vencobb straight run chicks were procured, and after 5 days of brooding, chicks were randomly distributed into four treatment groups viz. paddy husk (Group I, paddy straw (Group II, pine leaves (Group III, and combination of paddy straw and pine leaves (Group IV, each having 30 chicks with 3 replicates of 10 chicks each. Chicks were reared under intensive conditions in houses that have a semi-controlled environment, with optimum temperature and adequate ventilation. Food and water were provided as per NRC (1994 requirement. Results: The average body weight after 6 weeks of the experiment was 2018.83±31.11, 1983.80±33.27, 2007.36±35.73, and 1938.43±36.35 g. The bedding type had no significant effect on the carcass characteristics viz. evisceration rate and proportion of cut-up parts of the carcass except giblet yield. The experiment suggested that performance of broiler chicks reared on paddy straw and pine leaves as litter material, had improved body weight and feed conversion ratio as compared to rearing on paddy husk as bedding material. Bacterial count, parasitic load and the N, P, K value of manure of different bedding material shows no significant difference. Conclusion: Pine leaves have a potential to be used as an alternative source of litter material to economize poultry production in a sustainable way, so as to make poultry farming as a profitable entrepreneur.

  3. Effects of Landscape-Scale Environmental Variation on Greater Sage-Grouse Chick Survival.

    Directory of Open Access Journals (Sweden)

    Michael R Guttery

    Full Text Available Effective long-term wildlife conservation planning for a species must be guided by information about population vital rates at multiple scales. Greater sage-grouse (Centrocercus urophasianus populations declined substantially during the twentieth century, largely as a result of habitat loss and fragmentation. In addition to the importance of conserving large tracts of suitable habitat, successful conservation of this species will require detailed information about factors affecting vital rates at both the population and range-wide scales. Research has shown that sage-grouse population growth rates are particularly sensitive to hen and chick survival rates. While considerable information on hen survival exists, there is limited information about chick survival at the population level, and currently there are no published reports of factors affecting chick survival across large spatial and temporal scales. We analyzed greater sage-grouse chick survival rates from 2 geographically distinct populations across 9 years. The effects of 3 groups of related landscape-scale covariates (climate, drought, and phenology of vegetation greenness were evaluated. Models with phenological change in greenness (NDVI performed poorly, possibly due to highly variable production of forbs and grasses being masked by sagebrush canopy. The top drought model resulted in substantial improvement in model fit relative to the base model and indicated that chick survival was negatively associated with winter drought. Our overall top model included effects of chick age, hen age, minimum temperature in May, and precipitation in July. Our results provide important insights into the possible effects of climate variability on sage-grouse chick survival.

  4. Sex-based differences in Adelie penguin (Pygoscelis adeliae) chick growth rates.

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Catherine; Ballard, Grant; Ainley, David G.

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species—one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact

  5. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae.

    Directory of Open Access Journals (Sweden)

    Anna V Klenova

    Full Text Available Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs.

  6. Effect of soybean variety and processing on growth performance of young chicks and pigs.

    Science.gov (United States)

    Palacios, M F; Easter, R A; Soltwedel, K T; Parsons, C M; Douglas, M W; Hymowitz, T; Pettigrew, J E

    2004-04-01

    The objective of this study was to determine whether soybeans without the Kunitz trypsin inhibitor and lectins could be fed effectively to young chicks and pigs. Specifically, we compared the growth performance of chicks and pigs fed diets containing modified soybeans: Kunitz trypsin inhibitor-free (KF), lectin-free (LF), lectin and Kunitz trypsin inhibitor-free (LFKF), conventional soybeans (CSB), and commercially obtained, dehulled, solvent-extracted soybean meal (SBM). A 7-d chick experiment was conducted to evaluate the nutritional value of CSB, KF, LF, LFKF, and SBM. The experiment was conducted as a completely randomized design, with four replicates, five treatments, and six male chicks per pen (n = 120). The five treatments consisted of 23% CP dextrose-soybean-based diets containing KF, LF, LFKF, CSB, or SBM as the source of dietary protein. A 28-d pig experiment was conducted to evaluate the nutritional value of CSB, LF, LFKF, and SBM. Pens of four pigs were assigned randomly to a control, corn-SBM, or one of six corn-soybean diets containing raw or extruded soybean varieties as a 2 x 3 factorial arrangement of treatments in a randomized complete block design with five blocks per treatment (n = 140). Chicks fed diets containing any of the raw soybean varieties gained less weight (P lectins and Kunitz trypsin inhibitor (ADG of 16.56 g for LFKF) than by removing each antinutritional factor separately (ADG of 14.38 and 14.11 g for KF and LF, respectively). Pig growth performance was different (P antinutritional factor, lectin, was removed from the soybean and improved further (P = 0.045) when both lectins and Kunitz trypsin inhibitor were removed. The growth-inhibiting effect of feeding modified soybeans to young animals was more detrimental for pigs than for chicks in our experiments. Soybeans without the Kunitz trypsin inhibitor and lectins cannot be fed successfully to young chicks and pigs without heating. PMID:15080333

  7. Sex-Based Differences in Adelie Penguin (Pygoscelis adeliae Chick Growth Rates and Diet.

    Directory of Open Access Journals (Sweden)

    Scott Jennings

    Full Text Available Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11% as well as bill (~8% and flipper length (~3%. We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d(-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species--one krill (Euphausia crystallorophias and one fish (Pleuragramma antarctica, with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors

  8. Effects of Landscape-Scale Environmental Variation on Greater Sage-Grouse Chick Survival.

    Science.gov (United States)

    Guttery, Michael R; Dahlgren, David K; Messmer, Terry A; Connelly, John W; Reese, Kerry P; Terletzky, Pat A; Burkepile, Nathan; Koons, David N

    2013-01-01

    Effective long-term wildlife conservation planning for a species must be guided by information about population vital rates at multiple scales. Greater sage-grouse (Centrocercus urophasianus) populations declined substantially during the twentieth century, largely as a result of habitat loss and fragmentation. In addition to the importance of conserving large tracts of suitable habitat, successful conservation of this species will require detailed information about factors affecting vital rates at both the population and range-wide scales. Research has shown that sage-grouse population growth rates are particularly sensitive to hen and chick survival rates. While considerable information on hen survival exists, there is limited information about chick survival at the population level, and currently there are no published reports of factors affecting chick survival across large spatial and temporal scales. We analyzed greater sage-grouse chick survival rates from 2 geographically distinct populations across 9 years. The effects of 3 groups of related landscape-scale covariates (climate, drought, and phenology of vegetation greenness) were evaluated. Models with phenological change in greenness (NDVI) performed poorly, possibly due to highly variable production of forbs and grasses being masked by sagebrush canopy. The top drought model resulted in substantial improvement in model fit relative to the base model and indicated that chick survival was negatively associated with winter drought. Our overall top model included effects of chick age, hen age, minimum temperature in May, and precipitation in July. Our results provide important insights into the possible effects of climate variability on sage-grouse chick survival.

  9. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae).

    Science.gov (United States)

    Klenova, Anna V

    2015-01-01

    Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae) was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs. PMID:26536362

  10. Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly.

    Science.gov (United States)

    Arnold, Jennifer M; Tyerman, Donald J; Crump, Doug; Williams, Kim L; Oswald, Stephen A

    2016-01-01

    In July 2014, we observed premature feather loss (PFL) among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167), and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body) occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem) most likely fledged 10-20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns. PMID:27231646

  11. Forster's tern chick survival in response to a managed relocation of predatory California gulls

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, C. Alex; Herring, Garth

    2014-01-01

    Gull populations can severely limit the productivity of waterbirds. Relocating gull colonies may reduce their effects on nearby breeding waterbirds, but there are few examples of this management strategy. We examined gull predation and survival of Forster's tern (Sterna forsteri) chicks before (2010) and after (2011) the managed relocation of the largest California gull (Larus californicus) colony (24,000 adults) in San Francisco Bay, California. Overall, survival of radio-marked Forster's tern chicks from hatching to fledging was 0.22 ± 0.03 (mean ± SE), and daily survival rates increased with age. Gulls were the predominant predator of tern chicks, potentially causing 54% of chick deaths. Prior to the gull colony relocation, 56% of radio-marked and 20% of banded tern chicks from the nearest tern colony were recovered dead in the gull colony, compared to only 15% of radio-marked and 4% of banded chicks recovered dead from all other tern colonies. The managed relocation of the gull colony substantially increased tern chick survival (by 900%) in the nearby (3.8 km) reference tern colony (0.29 ± 0.10 in 2010 and 0.25 ± 0.09 in 2011). Among 19 tern nesting islands, fledging success was higher when gull abundance was lower at nearby colonies and when gull colonies were farther from the tern colony. Our results indicate that the managed relocation of gull colonies away from preferred nesting areas of sensitive waterbirds can improve local reproductive success, but this conservation strategy may shift gull predation pressure to other areas or species.

  12. Convection and oscillations

    CERN Document Server

    Houdek, G

    2010-01-01

    In this short review on stellar convection dynamics I address the following, currently very topical, issues: (1) the surface effects of the Reynolds stresses and nonadiabaticity on solar-like pulsation frequencies, and (2) oscillation mode lifetimes of stochastically excited oscillations in red giants computed with different time-dependent convection formulations.

  13. Synchronization of hyperchaotic oscillators

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Cenys, A.; Mykolaitis, G.;

    1997-01-01

    Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...... oscillators are investigated demonstrating synchronization by means of only one properly selected variable....

  14. Hyperchaotic Oscillator with Gyrators

    DEFF Research Database (Denmark)

    Tamasevicius, A; Cenys, A; Mykolaitis, G.;

    1997-01-01

    A fourth-order hyperchaotic oscillator is described. It contains a negative impedance converter, two gyratots, two capacitors and a diode. The dynamics of the oscillator is shown to be characterised by two positive Lyapunov exponents. The performance of the circuit is investigated by means...

  15. A Conspiracy of Oscillators

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2008-01-01

    We discuss nonlinear mechanical systems containing several oscillators whose frequecies are all much higher than frequencies associated with the remaining degrees of freedom. In this situation a near constant of the motion, an adiabatic invariant, exists which is the sum of all the oscillator act...

  16. Disentangling neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Andrew G. [Physics Department, Boston University, Boston, MA 02215 (United States)], E-mail: cohen@bu.edu; Glashow, Sheldon L. [Physics Department, Boston University, Boston, MA 02215 (United States)], E-mail: slg@bu.edu; Ligeti, Zoltan [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)], E-mail: ligeti@lbl.gov

    2009-07-13

    The theory underlying neutrino oscillations has been described at length in the literature. The neutrino state produced by a weak decay is usually portrayed as a linear superposition of mass eigenstates with, variously, equal energies or equal momenta. We point out that such a description is incorrect, that in fact, the neutrino is entangled with the other particle or particles emerging from the decay. We offer an analysis of oscillation phenomena involving neutrinos (applying equally well to neutral mesons) that takes entanglement into account. Thereby we present a theoretically sound proof of the universal validity of the oscillation formulae ordinarily used. In so doing, we show that the departures from exponential decay reported by the GSI experiment cannot be attributed to neutrino mixing. Furthermore, we demonstrate that the 'Moessbauer' neutrino oscillation experiment proposed by Raghavan, while technically challenging, is correctly and unambiguously describable by means of the usual oscillation formalae.

  17. Response of Chick B Islets to Insulin Secretagogues is Comparable to those of Human Islet Equivalents

    Directory of Open Access Journals (Sweden)

    Bhawna Chandravanshi

    2015-05-01

    Full Text Available Context The B islets isolated from 3-5 day old chick respond well to glucose challenge in a similar fashion to those isolated from mouse pancreas. Objective To compare insulin secretory response of chick B islets with that of human Islet Equivalents (hIEqs generated from stem cells. Methods Human Umbilical Cord Mesenchymal Stem Cells (UC-MSCs were differentiated into hIEqs employing three step sequential serum free protocols. Results Immunofluorescence staining demonstrated Insulin, C peptide and Glut 2 positivity of both these islets. Static insulin stimulation of these islets in response to glucose, metformin and Gama Amino Butyric Acid (GABA resulted in increased insulin secretion as compared to basal glucose stimulation. Our results demonstrate that insulin secretory response of Chick B islets to Metformin and GABA is comparable to those of hIEqs. Moreover, both chick and hIEqs could be successfully cryopreserved and revived in a commercially available cryomix - Cryostore 5, indicating resemblance in their behaviour at sub-zero temperatures. Inference Present study advocates Chick islets as an alternative source for diabetes research and islet banking.

  18. Aspects of chick growth in Gull-billed Terns in coastal Virginia

    Science.gov (United States)

    Erwin, R.M.; Eyler, T.B.; Stotts, D.B.; Hatfield, J.S.

    1999-01-01

    Because of concerns about apparent population declines and low productivity of Gull-billed Terns (Sterna nilotica) along the coast of Virginia, we investigated whether food limitations may result in retarded growth rates of young. Several colonies of Gull-billed Terns were monitored from May to July each year from 1994 to 1996 on both sandy barrier islands and marsh/shellpile islands in coastal Virginia. Nests were visited one to three times a week to monitor clutch size and hatching success, and enclosures were installed around selected nests to monitor chick growth from hatching to at least two weeks of age. When comparing chick growth, we found significant year, habitat and hatch order effects. Chicks from marsh shellpiles had higher mass and culmen growth rates than did those from barrier islands, and first-hatched (A) chicks had significantly higher culmen growth rates than did second-hatched (B) chicks. Year effects were only found for mass growth rates. Growth rates of Gull- billed Terns in these Virginia colonies seem to be low relative to those of six other North American tern species from other geographic areas. These findings suggest that growth rates of young Gull-billed Terns, as well as other reproductive parameters, need to be examined in detail in other coastal areas such as Texas, where the species is more abundant, to determine whether our growth results are species- or region-specific.

  19. Developmental expression of BK channels in chick cochlear hair cells

    Directory of Open Access Journals (Sweden)

    Tong Mingjie

    2009-12-01

    Full Text Available Abstract Background Cochlear hair cells are high-frequency sensory receptors. At the onset of hearing, hair cells acquire fast, calcium-activated potassium (BK currents, turning immature spiking cells into functional receptors. In non-mammalian vertebrates, the number and kinetics of BK channels are varied systematically along the frequency-axis of the cochlea giving rise to an intrinsic electrical tuning mechanism. The processes that control the appearance and heterogeneity of hair cell BK currents remain unclear. Results Quantitative PCR results showed a non-monotonic increase in BK α subunit expression throughout embryonic development of the chick auditory organ (i.e. basilar papilla. Expression peaked near embryonic day (E 19 with six times the transcript level of E11 sensory epithelia. The steady increase in gene expression from E11 to E19 could not explain the sudden acquisition of currents at E18-19, implicating post-transcriptional mechanisms. Protein expression also preceded function but progressed in a sequence from diffuse cytoplasmic staining at early ages to punctate membrane-bound clusters at E18. Electrophysiology data confirmed a continued refinement of BK trafficking from E18 to E20, indicating a translocation of BK clusters from supranuclear to subnuclear domains over this critical developmental age. Conclusions Gene products encoding BK α subunits are detected up to 8 days before the acquisition of anti-BK clusters and functional BK currents. Therefore, post-transcriptional mechanisms seem to play a key role in the delayed emergence of calcium-sensitive currents. We suggest that regulation of translation and trafficking of functional α subunits, near voltage-gated calcium channels, leads to functional BK currents at the onset of hearing.

  20. Patterning of the chick forebrain anlage by the prechordal plate.

    Science.gov (United States)

    Pera, E M; Kessel, M

    1997-10-01

    We analysed the role of the prechordal plate in forebrain development of chick embryos in vivo. After transplantation to uncommitted ectoderm a prechordal plate induces an ectopic, dorsoventrally patterned, forebrain-like vesicle. Grafting laterally under the anterior neural plate causes ventralization of the lateral side of the forebrain, as indicated by a second expression domain of the homeobox gene NKX2.1. Such a lateral ventralization cannot be induced by the secreted factor Sonic Hedgehog alone, as this is only able to distort the ventral forebrain medially. Removal of the prechordal plate does not reduce the rostrocaudal extent of the anterior neural tube, but leads to significant narrowing and cyclopia. Excision of the head process results in the caudal expansion of the NKX2.1 expression in the ventral part of the anterior neural tube, while PAX6 expression in the dorsal part remains unchanged. We suggest that there are three essential steps in early forebrain patterning, which culminate in the ventralization of the forebrain. First, anterior neuralization occurs at the primitive streak stage, when BMP-4-antagonizing factors emanate from the node and spread in a planar fashion to induce anterior neural ectoderm. Second, the anterior translocation of organizer-derived cells shifts the source of neuralizing factors anteriorly, where the relative concentration of BMP-4-antagonists is thus elevated, and the medial part of the prospective forebrain becomes competent to respond to ventralizing factors. Third, the forebrain anlage is ventralized by signals including Sonic Hedgehog, thereby creating a new identity, the prospective hypothalamus, which splits the eye anlage into two lateral domains.

  1. Hemicellulose does not affect iron bioavailability in chicks.

    Science.gov (United States)

    Fly, A D; Czarnecki-Maulden, G L; Fahey, G C; Titgemeyer, E C

    1996-01-01

    Two iron repletion experiments using hemoglobin as a response criterion were conducted to assess effects of hemicelluloses on iron bioavailability to chicks. In Experiment 1, iron bioavailability from intact fiber sources was determined by adding tomato pomace (14.6% hemicelluloses), soybean hulls (20.6% hemicelluloses), beet pulp (21.5% hemicelluloses), orchard grass (24.1% hemicelluloses) and corn fiber (55.2% hemicelluloses) to a casein dextrose basal diet providing 0.4-4.1% hemicelluloses to the diet. Test foods were analyzed for iron, total dietary fiber, neutral detergent residue, neutral detergent fiber, acid detergent fiber, acid detergent lignin, pectins and uronic acids. Hemicelluloses were determined by the difference of neutral detergent residue minus acid detergent fiber. Iron bioavailability was determined by the standard curve method to be (percent relative to ferrous sulfate using hemoglobin as the response criterion) as follows: tomato pomace, 82.0; soybean hulls, 94.0; beet pulp, 26.5; orchard grass, 68.9; corn fiber, 69.4. Iron bioavailability was not related to hemicellulose content of test foods or diets. In Experiment 2, the effect of psyllium husk (a fiber source that contains predominantly hemicelluloses) on iron bioavailability from ferrous sulfate was assessed. Bioavailability was determined by the slope ratio method where treatments consisted of graded levels of ferrous sulfate in the presence and absence of 5% dietary psyllium. Although iron intrinsic to psyllium was unavailable, bioavailability of ferrous sulfate iron was not affected (P > 0.05) by the presence of psyllium. Thus, there was no clear effect of hemicelluloses on iron bioavailability. However, some feeds that contained high levels of hemicelluloses had low intrinsic iron bioavailabilities, suggesting that other dietary factors are primarily responsible for determining iron bioavailability from these feed components. PMID:8558316

  2. Quasi-Fibonacci oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilik, A M; Kachurik, I I; Rebesh, A P, E-mail: omgavr@bitp.kiev.u [Bogolyubov Institute for Theoretical Physics, Kiev 03680 (Ukraine)

    2010-06-18

    We study the properties of the sequences of the energy eigenvalues for some generalizations of q-deformed oscillators including the p, q-oscillator, and the three-, four- and five-parameter deformed oscillators given in the literature. It is shown that most of the considered models belong to the class of so-called Fibonacci oscillators for which any three consecutive energy levels satisfy the relation E{sub n+1} = {lambda}E{sub n} + {rho}E{sub n-1} with real constants {lambda}, {rho}. On the other hand, for a certain {mu}-oscillator known since 1993, we prove its non-Fibonacci nature. Possible generalizations of the three-term Fibonacci relation are discussed, among which for the {mu}-oscillator we choose, as the most adequate, the so-called quasi-Fibonacci (or local Fibonacci) property of the energy levels. The property is encoded in the three-term quasi-Fibonacci (QF) relation with the non-constant, n-dependent coefficients {lambda} and {rho}. Various aspects of the QF relation are elaborated for the {mu}-oscillator and some of its extensions.

  3. Oscillating Filaments: I - Oscillation and Geometrical Fragmentation

    CERN Document Server

    Gritschneder, Matthias; Burkert, Andreas

    2016-01-01

    We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid based AMR-code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, e.g. with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process `geometrical fragmentation'. In our realization the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristical scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. ...

  4. Trivial or Commendable? : Women’s Writing, Popular Culture, and Chick Lit

    Directory of Open Access Journals (Sweden)

    Ryan, Mary

    2010-07-01

    Full Text Available There are a number of similarities between popular culture and women's writing: both have been dismissed as trivial and worthless, have traditionally received little respect from critics, and have been scorned because of theis apparently "low-brow" appeal. Additionally, both were long excluded from the literary Canon. In contemporary culture, the intersection of popular culture and women's writing takes the form of chick lit, the contemporary genre of fiction starring female characters in their 20s and 30s as they make their way through their lives and tackle all the obstacles in their way. As well as outlining the characteristics and history of chick lit, this paper will discuss the negative reception that popular culture, women's writing, and chick lit has often been subjected to, and will show how studies are now emerging with the aim of demonstrating how such genres may have more worth and potential than is typically suggested.

  5. AUGMENTATIVE EFFECT OF PROSTAGLANDIN E1 ON PENTOBARBITAL HYPNOSIS MEDIATED BY 5-HT IN CHICKS

    Directory of Open Access Journals (Sweden)

    Amalendu Chanda

    2012-01-01

    Full Text Available Prostaglandins (PG are present in different tissues specially in brain tissues endowed with different central nervous system activities. Similarly, 5-hydroxytryptamine (5-HT a biogenic amine with its presence in different central and peripheral tissues as neurotransmitter plays an important role in the regulation of physiological functions specially hypnosis, convulsions, analgesia in rats, mice, cats and chicks etc. Pentobarbitone (PB induced sleep appear to be a serotonergic modulator activity in different animals. PGE1 potentiates the pentobarbitone hypnosis also mediated through serotonin. In the present study, PGE1 induced sleeping time in chicks was evaluated. Drugs affecting 5-HT synthesis, metabolism and receptor activity modulate the potentiating response, while adrenergic receptor antagonists did not showed any response. This study suggest that PGE1 potentiate PB induced sleep through serotonergic signaling pathway as PGE1 increased 5-HT synthesis rate in chick brain.

  6. Development of a precision-fed ileal amino acid digestibility assay using 3-week-old broiler chicks

    Science.gov (United States)

    The objective of these studies was to develop a precision-fed ileal digestibility assay, primarily for amino acids (AA), using 3-wk-old broiler chicks. For all experiments, day-old Ross × Ross 708 broiler chicks were fed a standard corn-soybean meal starter diet until 21 d of age. In experiment 1, f...

  7. Campylobacter jejuni Gene Expression in the Chick Cecum: Evidence for Adaptation to a Low-Oxygen Environment

    Science.gov (United States)

    Woodall, C. A.; Jones, M. A.; Barrow, P. A.; Hinds, J.; Marsden, G. L.; Kelly, D. J.; Dorrell, N.; Wren, B. W.; Maskell, D. J.

    2005-01-01

    Transcriptional profiling of Campylobacter jejuni during colonization of the chick cecum identified 59 genes that were differentially expressed in vivo compared with the genes in vitro. The data suggest that C. jejuni regulates electron transport and central metabolic pathways to alter its physiological state during establishment in the chick cecum. PMID:16041056

  8. Oscillations in counting statistics

    CERN Document Server

    Wilk, Grzegorz

    2016-01-01

    The very large transverse momenta and large multiplicities available in present LHC experiments on pp collisions allow a much closer look at the corresponding distributions. Some time ago we discussed a possible physical meaning of apparent log-periodic oscillations showing up in p_T distributions (suggesting that the exponent of the observed power-like behavior is complex). In this talk we concentrate on another example of oscillations, this time connected with multiplicity distributions P(N). We argue that some combinations of the experimentally measured values of P(N) (satisfying the recurrence relations used in the description of cascade-stochastic processes in quantum optics) exhibit distinct oscillatory behavior, not observed in the usual Negative Binomial Distributions used to fit data. These oscillations provide yet another example of oscillations seen in counting statistics in many different, apparently very disparate branches of physics further demonstrating the universality of this phenomenon.

  9. High frequency nanotube oscillator

    Science.gov (United States)

    Peng, Haibing; Zettl, Alexander K.

    2012-02-21

    A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.

  10. Neutrino anomalies without oscillations

    Indian Academy of Sciences (India)

    Sandip Pakvasa

    2000-01-01

    I review explanations for the three neutrino anomalies (solar, atmospheric and LSND) which go beyond the `conventional' neutrino oscillations induced by mass-mixing. Several of these require non-zero neutrino masses as well.

  11. Neural Oscillators Programming Simplified

    Directory of Open Access Journals (Sweden)

    Patrick McDowell

    2012-01-01

    Full Text Available The neurological mechanism used for generating rhythmic patterns for functions such as swallowing, walking, and chewing has been modeled computationally by the neural oscillator. It has been widely studied by biologists to model various aspects of organisms and by computer scientists and robotics engineers as a method for controlling and coordinating the gaits of walking robots. Although there has been significant study in this area, it is difficult to find basic guidelines for programming neural oscillators. In this paper, the authors approach neural oscillators from a programmer’s point of view, providing background and examples for developing neural oscillators to generate rhythmic patterns that can be used in biological modeling and robotics applications.

  12. Effect of Pigeon pea and Cow pea on the performance and gut immunity of broiler chicks

    International Nuclear Information System (INIS)

    two experiments were conducted to examine the effect of pigeon pea and cow pea on the performance and gut immunity of broiler chicks. In experiment 1, 3 experimental diets were formulated containing graded levels of cow pea were maintained. Diets were prepared containing 18.21, 18.25 and 18.25% crude protein and 3076.41, 3062 Kel/Kg metabolizable energy for experiment 1, while diets of experiment 11 were prepared containing 18.21, 18.22, and 18.22% crude protein and 3076.41, 3080.5 and 3055.89 KEl/Kg metabolized energy. 120 Loghmann broiler chicks were equally allocated into 15 pens (8 chicks/pen). Then the experimental diets were randomly assigned to the pens. feed and water were provided ad libitum in both experiments. In experiment 1, the results showed no significant difference were found in chick performance at day 45. The feed conversation ratio increased with the level of pigeon pea used. The pancreas mass was increased as the level of pigeon pea increase. In experiment 2 the results showed significant decrease in the body weight and feed intake at day 45, while the pancreas mass tend to increase with increasing level of cow pea in the diet. Histological examination of small intestine slides showed no histopathological differences between the control and chicks fed cow pea and/or pigeon pea. Immunological test of the serum and mucous samples using ELISA techniques revealed no significant difference between the control and chicks given cow pea and / or pigeon pea

  13. Amelioration of scopolamine-induced amnesia by phosphatidylserine and curcumin in the day-old chick.

    Science.gov (United States)

    Barber, Teresa A; Edris, Edward M; Levinsky, Paul J; Williams, Justin M; Brouwer, Ari R; Gessay, Shawn A

    2016-09-01

    In the one-trial taste-avoidance task in day-old chicks, acetylcholine receptor activation has been shown to be important for memory formation. Injection of scopolamine produces amnesia, which appears to be very similar in type to that of Alzheimer's disease, which is correlated with low levels of acetylcholine in the brain. Traditional pharmacological treatments of Alzheimer's disease, such as cholinesterase inhibitors and glutamate receptor blockers, improve memory and delay the onset of impairments in memory compared with placebo controls. These agents also ameliorate scopolamine-induced amnesia in the day-old chick trained on the one-trial taste-avoidance task. The present experiments examined the ability of two less traditional treatments for Alzheimer's disease, phosphatidylserine and curcumin, to ameliorate scopolamine-induced amnesia in day-old chicks. The results showed that 37.9 mmol/l phosphatidylserine and 2.7 mmol/l curcumin significantly improved retention in chicks administered scopolamine, whereas lower doses were not effective. Scopolamine did not produce state-dependent learning, indicating that this paradigm in day-old chicks might be a useful one to study the effects of possible Alzheimer's treatments. In addition, chicks administered curcumin or phosphatidylserine showed little avoidance of a bead associated with water reward, indicating that these drugs did not produce response inhibition. The current results extend the findings that some nontraditional memory enhancers can ameliorate memory impairment and support the hypothesis that these treatments might be of benefit in the treatment of Alzheimer's disease. PMID:27388114

  14. Experimental evidence for chick discrimination without recognition in a brood parasite host.

    Science.gov (United States)

    Grim, Tomás

    2007-02-01

    Recognition is considered a critical basis for discriminatory behaviours in animals. Theoretically, recognition and discrimination of parasitic chicks are not predicted to evolve in hosts of brood parasitic birds that evict nest-mates. Yet, an earlier study showed that host reed warblers (Acrocephalus scirpaceus) of an evicting parasite, the common cuckoo (Cuculus canorus), can avoid the costs of prolonged care for unrelated young by deserting the cuckoo chick before it fledges. Desertion was not based on specific recognition of the parasite because hosts accept any chick cross-fostered into their nests. Thus, the mechanism of this adaptive host response remains enigmatic. Here, I show experimentally that the cue triggering this 'discrimination without recognition' behaviour is the duration of parental care. Neither the intensity of brood care nor the presence of a single-chick in the nest could explain desertions. Hosts responded similarly to foreign chicks, whether heterospecific or experimental conspecifics. The proposed mechanism of discrimination strikingly differs from those found in other parasite-host systems because hosts do not need an internal recognition template of the parasite's appearance to effectively discriminate. Thus, host defences against parasitic chicks may be based upon mechanisms qualitatively different from those operating against parasitic eggs. I also demonstrate that this discriminatory mechanism is non-costly in terms of recognition errors. Comparative data strongly suggest that parasites cannot counter-evolve any adaptation to mitigate effects of this host defence. These findings have crucial implications for the process and end-result of host-parasite arms races and our understanding of the cognitive basis of discriminatory mechanisms in general.

  15. The analgesic efficacy of xylazine and dipyrone in hydrogen peroxide-induced oxidative stress in chicks

    Directory of Open Access Journals (Sweden)

    Y.J. Mousa

    2012-01-01

    Full Text Available The effect of oxidative stress–induced by hydrogen peroxide (H2O2 on the analgesic effect of xylazine and dipyrone in 7-14 days old chicks was studied, compared with the control group that given plane tap water. H2O2, 0.5 % in water, induced oxidative stress in chicks by significantly lowering glutathione, rising malondialdehyde in plasma, whole brain during the day 7th, 10th, 14th of chicks old in comparison with the control group. The analgesic median effective doses (ED50 of xylazine and dipyrone in the control group were determined to be 0.79 and 65.3 mg/kg, intramuscularly (i.m., respectively whereas H2O2 treated groups decreased these values to be 0.31 and 37.2 mg/kg, i.m. by 61 and 43%, respectively. Intramuscular injection of xylazine and dipyrone at 0.5, 70 mg/kg respectively causes analgesia from electro-stimulation induced pain in 50, 66.67% respectively in control groups whereas H2O2 treated chicks increases the analgesic efficacy to be 83.33 and 83.33% respectively. Xylazine and dipyrone injection at 1 and 100 mg/kg, i.m. 15 minutes before formaldehyde injection in right planter foot of stressed chicks causes analgesia from pain induced by formaldehyde through significant increases in onset of lifting of formaldehyde injected foot, significantly decreases its lifting numbers, decreases the time elapsed of lifting of formaldehyde injected foot in comparison with the stressed control group that injected with saline in right planter foot. The data of this study indicate that H2O2-induced oxidative stress potentiate the analgesic efficacy of the central and peripheral analgesics of xylazine and dipyrone in chicks.

  16. Use of hyperimmune serum for passive immunization of chicks experimentally infected with newcastle disease virus

    International Nuclear Information System (INIS)

    Velogenic strains of Newcastle disease virus (NDV) were isolated from field outbreaks. ELD/sub 50/ of the VNDV was determined at 10/sup -5.33/. La Sota strain and Incomplete Freund's Adjuvant (IFA) were inoculated in adult chicks to raise hyper immune serum. The serum was purified and used to reduce the morbidity and mortality in experimentally infected broiler chicks with Newcastle disease virus (NDV). 120 day-old broiler chicks were divided into four groups i.e. A, B, C and D. At 14 The day of age, the chicks were infected with velogenic field isolate of Newcastle disease virus (ELD/sub 50/= 10/sup -5.33/0.1mL) and two hours post infection the birds were passively immunized with HIS at the rate 2mL, 3mL and 6mL, in group B, C and D, respectively, while group A was kept as control. Chicks received 2mL HIS exhibited severe respiratory and enteric signs of Newcastle disease, while chicks received 3mL and 6mL HIS were anorexic in early days and on 10th day post inoculation (DPI) they were recovered. Gross lesions in infected birds were hemorrhages in trachea, proventriculus and intestine, and congestion in infected lungs. Histo- athological examination showed epithelial sloughing, congestion of blood vessels in group A, mild tracheitis and alveoli of lungs filled with exudates along with lymphocytes in group B, mild lymphocytic infiltration in group C, while trachea and lungs showed no significant change in group D. Higher range of GMT values were observed in group D while low range of GMT values were observed in group A. It was concluded that HIS against NDV can be used to decrease the morbidity and mortality rate in experimentally infected birds. (author)

  17. Oscillators and operational amplifiers

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation...... of the general circuit is derived. The dynamic nonlinear transfer characteristic of the amplifier is investigated. Examples of negative resistance oscillators are discussed....

  18. From excitability to oscillations

    DEFF Research Database (Denmark)

    Postnov, D. E.; Neganova, A. Y.; Jacobsen, J. C. B.;

    2013-01-01

    One consequence of cell-to-cell communication is the appearance of synchronized behavior, where many cells cooperate to generate new dynamical patterns. We present a simple functional model of vasomotion based on the concept of a two-mode oscillator with dual interactions: via relatively slow......-dependent chloride channels in the plasma membrane may synchronize into whole-cell oscillations which subsequently may spread across a large population of cells. We show how heterogeneity of the system can induce new patterns....

  19. Entanglement in neutrino oscillations

    OpenAIRE

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2007-01-01

    Flavor oscillations in elementary particle physics are related to multi-mode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We disc...

  20. Self-oscillation

    CERN Document Server

    Jenkins, Alejandro

    2011-01-01

    Physicists are very familiar with forced and parametric resonance, but usually not with self-oscillation, a property of certain linear systems that gives rise to a great variety of vibrations, both useful and destructive. In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the velocity, causing a negative damping that feeds energy from the environment into the vibration: no external rate needs to be tuned to the resonant frequency. A paper from 1830 by G. B. Airy gives us the opening to introduce self-oscillation as a sort of "perpetual motion" responsible for the human voice. The famous collapse of the Tacoma Narrows bridge in 1940, often attributed by introductory physics texts to forced resonance, was actually a self-oscillation, as was the more recent swaying of the London Millenium Footbridge. Clocks are self-oscillators, as are bowed and wind musical instruments, and the heartbeat. We review the criterion that determines whether an arbitrary line...

  1. Actomyosin organisation for adhesion, spreading, growth and movement in chick fibroblasts

    DEFF Research Database (Denmark)

    Couchman, J R; Rees, D A

    1979-01-01

    Examination of the actomyosin structures and their relation to adhesion, movement and growth in the first fibroblasts migrating from chick heart explants shows striking differences with fibroblasts adapted to grow in culture. The latter have focal adhesions which seem to immobilize them for ancho......Examination of the actomyosin structures and their relation to adhesion, movement and growth in the first fibroblasts migrating from chick heart explants shows striking differences with fibroblasts adapted to grow in culture. The latter have focal adhesions which seem to immobilize them...

  2. Utilization of choline from crude soybean lecithin by chicks. 1. Growth and prevention of perosis.

    Science.gov (United States)

    Lipstein, B; Bornstein, S; Budowski, P

    1977-01-01

    Data obtained with growing chicks fed a semi-purified diet indicate that choline from crude soybean lecithin is as well utilized as synthetic choline chloride, on the basis of growth, relative liver weight and prevention of perosis. Extrapolation of the results on growth and perosis prevention, obtained between 1 and 3 weeks of age, to performance on practical-type diets yields choline requirements for broiler-type chicks ranging from 800 to 1000 mg./kg. diet (as choline chloride). The requirement seems to decrease with age. PMID:564504

  3. Immunization of chicks at various ages with irradiated infective eggs of Ascaridia galli

    International Nuclear Information System (INIS)

    The possibility of safe immunization of chicks at an appropriate age with a double-dose irradiated Ascaridia galli vaccine given orally at two weeks interval was explored. Chicks immunized at 7 or 10 days of age were not affected adversely since they did not develop any clinical signs and there was no worm establishment after challenge infection. Immunization also elicited detectable circulating antibody titres, with IHA and the conglutinating complement absorption test having a tendency to be enhanced after the booster dose. (author)

  4. In vitro prevention of chick pancreatic lipase activity by Abroma augusta extract

    Institute of Scientific and Technical Information of China (English)

    Nidhi Gupta; Aditya Ganeshpurkar; Nishikant Jatav; Divya Bansal; Nazneen Dubey

    2012-01-01

    Objective: To investigate chick pancreatic lipase inhibitory activities of the Abroma augusta (A. augusta). Methods: A. augusta was first extracted with methanol and subjected to phytochemical screenings. Quantitative estimation of flavonoids, phenolics and alkaloids was done. Pancreatic lipase from chick pancreas was isolated and used as substrate for anti-lipase studies. Results:A. augusta extract effectively inhibited concentration dependent lipase activity, whereby extract at concentration 100 μg/mL inhibited 88.6% enzyme activity. Conclusions: From these results, it could be concluded that A. augusta can be used as a potential source anti-lipase agents.

  5. Glutathione-Induced Calcium Shifts in Chick Retinal Glial Cells.

    Science.gov (United States)

    Freitas, Hercules R; Ferraz, Gabriel; Ferreira, Gustavo C; Ribeiro-Resende, Victor T; Chiarini, Luciana B; do Nascimento, José Luiz M; Matos Oliveira, Karen Renata H; Pereira, Tiago de Lima; Ferreira, Leonardo G B; Kubrusly, Regina C; Faria, Robson X; Herculano, Anderson Manoel; Reis, Ricardo A de Melo

    2016-01-01

    Neuroglia interactions are essential for the nervous system and in the retina Müller cells interact with most of the neurons in a symbiotic manner. Glutathione (GSH) is a low-molecular weight compound that undertakes major antioxidant roles in neurons and glia, however, whether this compound could act as a signaling molecule in neurons and/or glia is currently unknown. Here we used embryonic avian retina to obtain mixed retinal cells or purified Müller glia cells in culture to evaluate calcium shifts induced by GSH. A dose response curve (0.1-10 mM) showed that 5-10 mM GSH, induced calcium shifts exclusively in glial cells (later labeled and identified as 2M6 positive cells), while neurons responded to 50 mM KCl (labeled as βIII tubulin positive cells). BBG 100 nM, a P2X7 blocker, inhibited the effects of GSH on Müller glia. However, addition of DNQX 70 μM and MK-801 20 μM, non-NMDA and NMDA blockers, had no effect on GSH calcium induced shift. Oxidized glutathione (GSSG) at 5 mM failed to induce calcium mobilization in glia cells, indicating that the antioxidant and/or structural features of GSH are essential to promote elevations in cytoplasmic calcium levels. Indeed, a short GSH pulse (60s) protects Müller glia from oxidative damage after 30 min of incubation with 0.1% H2O2. Finally, GSH induced GABA release from chick embryonic retina, mixed neuron-glia or from Müller cell cultures, which were inhibited by BBG or in the absence of sodium. GSH also induced propidium iodide uptake in Müller cells in culture in a P2X7 receptor dependent manner. Our data suggest that GSH, in addition to antioxidant effects, could act signaling calcium shifts at the millimolar range particularly in Müller glia, and could regulate the release of GABA, with additional protective effects on retinal neuron-glial circuit. PMID:27078878

  6. Frequency of self-oscillations

    CERN Document Server

    Groszkowski, Janusz

    2013-01-01

    Frequency of Self-Oscillations covers the realm of electric oscillations that plays an important role both in the scientific and technical aspects. This book is composed of nine chapters, and begins with the introduction to the alternating currents and oscillation. The succeeding chapters deal with the free oscillations in linear isolated systems. These topics are followed by discussions on self-oscillations in linear systems. Other chapters describe the self-oscillations in non-linear systems, the influence of linear elements on frequency of oscillations, and the electro mechanical oscillato

  7. Trends and tactics of mouse predation on Tristan Albatross Diomedea dabbenena chicks at Gough Island, South Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Delia Davies

    2015-06-01

    Full Text Available The critically endangered Tristan Albatross Diomedea dabbenena breeds almost exclusively on Gough Island, in the central South Atlantic, where breeding success is much lower than other great albatrosses (Diomedea spp. worldwide. Most breeding failures occur during the chick-rearing stage, when other great albatrosses suffer few failures. This unusual pattern of breeding failure is assumed to be largely due to predation by introduced house mice Mus musculus, but there have been few direct observations of mouse attacks. We closely monitored the fates of 20 chicks in the Gonydale study colony (123 chicks in 2014 using motion-activated cameras to determine the causes of chick mortality. Only 5 of 20 chicks survived to fledge, and of the 15 failures, 14 (93% were due to mouse predation. One mouse-wounded chick was killed by a Southern Giant Petrel Macronectes giganteus; the rest died outright from their wounds within 3.9 ± 1.2 days of the first attack. Despite this high impact, most chicks were attacked by only 1-2 mice at once (maximum 9. The remaining 103 chicks in the study colony were checked less frequently, but the timing of failures was broadly similar to the 20 closely monitored nests, and the presence of mouse wounds on other chicks strongly suggests that mice were responsible for most chick deaths. Breeding success in the Gonydale study colony averages 28% from 2001 to 2014; far lower than the normal range of breeding success of Diomedea species occurring on islands free from introduced predators. Island-wide breeding success fell below 10% for the first time in 2014, making it even more urgent to eradicate mice from Gough Island.

  8. Coalescence in coupled Duffing oscillators

    Institute of Scientific and Technical Information of China (English)

    YANG Jun-Zhong

    2009-01-01

    The forced Duffing oscillator has a pair of symmetrical attractors in a proper parameter regime. When a lot of Duffing oscillators are coupled linearly, the system tends to form clusters in which the neighboring oscillators fall onto the same attractor. When the coupling strength is strong, all of the oscillators fall onto one attractor. In this work, we investigate coalescence in the coupled forced Duffing oscillators. Some phenomena are found and explanations are presented.

  9. Finite q-oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Atakishiyev, Natig M [Centro de Ciencias FIsicas, UNAM, Apartado Postal 48-3, 62251 Cuernavaca, Morelos (Mexico); Klimyk, Anatoliy U [Centro de Ciencias FIsicas, UNAM, Apartado Postal 48-3, 62251 Cuernavaca, Morelos (Mexico); Wolf, Kurt Bernardo [Centro de Ciencias FIsicas, UNAM, Apartado Postal 48-3, 62251 Cuernavaca, Morelos (Mexico)

    2004-05-28

    The finite q-oscillator is a model that obeys the dynamics of the harmonic oscillator, with the operators of position, momentum and Hamiltonian being functions of elements of the q-algebra su{sub q}(2). The spectrum of position in this discrete system, in a fixed representation j, consists of 2j + 1 'sensor'-points x{sub s} = 1/2 [2s]{sub q}, s element of {l_brace}-j, -j+1, ..., j{r_brace}, and similarly for the momentum observable. The spectrum of energies is finite and equally spaced, so the system supports coherent states. The wavefunctions involve dual q-Kravchuk polynomials, which are solutions to a finite-difference Schroedinger equation. Time evolution (times a phase) defines the fractional Fourier-q-Kravchuk transform. In the classical limit as q {yields} 1 we recover the finite oscillator Lie algebra, the N = 2j {yields} {infinity} limit returns the Macfarlane-Biedenharn q-oscillator and both limits contract the generators to the standard quantum-mechanical harmonic oscillator.

  10. Finite q-oscillator

    Science.gov (United States)

    Atakishiyev, Natig M.; Klimyk, Anatoliy U.; Wolf, Kurt Bernardo

    2004-05-01

    The finite q-oscillator is a model that obeys the dynamics of the harmonic oscillator, with the operators of position, momentum and Hamiltonian being functions of elements of the q-algebra suq(2). The spectrum of position in this discrete system, in a fixed representation j, consists of 2j + 1 'sensor'-points x_s={\\case12}[2s]_q, s\\in\\{-j,-j+1,\\ldots,j\\} , and similarly for the momentum observable. The spectrum of energies is finite and equally spaced, so the system supports coherent states. The wavefunctions involve dual q-Kravchuk polynomials, which are solutions to a finite-difference Schrödinger equation. Time evolution (times a phase) defines the fractional Fourier-q-Kravchuk transform. In the classical limit as q rarr 1 we recover the finite oscillator Lie algebra, the N = 2j rarr infin limit returns the Macfarlane-Biedenharn q-oscillator and both limits contract the generators to the standard quantum-mechanical harmonic oscillator.

  11. Oscillations in stellar superflares

    CERN Document Server

    Balona, L A; Kosovichev, A; Nakariakov, V M; Pugh, C E; Van Doorsselaere, T

    2015-01-01

    Two different mechanisms may act to induce quasi-periodic pulsations (QPP) in whole-disk observations of stellar flares. One mechanism may be magneto-hydromagnetic (MHD) forces and other processes acting on flare loops as seen in the Sun. The other mechanism may be forced local acoustic oscillations due to the high-energy particle impulse generated by the flare (known as `sunquakes' in the Sun). We analyze short-cadence Kepler data of 257 flares in 75 stars to search for QPP in the flare decay branch or post-flare oscillations which may be attributed to either of these two mechanisms. About 18 percent of stellar flares show a distinct bump in the flare decay branch of unknown origin. The bump does not seem to be a highly-damped global oscillation because the periods of the bumps derived from wavelet analysis do not correlate with any stellar parameter. We detected damped oscillations covering several cycles (QPP), in seven flares on five stars. The periods of these oscillations also do not correlate with any ...

  12. Oscillations of soap bubbles

    Science.gov (United States)

    Kornek, U.; Müller, F.; Harth, K.; Hahn, A.; Ganesan, S.; Tobiska, L.; Stannarius, R.

    2010-07-01

    Oscillations of droplets or bubbles of a confined fluid in a fluid environment are found in various situations in everyday life, in technological processing and in natural phenomena on different length scales. Air bubbles in liquids or liquid droplets in air are well-known examples. Soap bubbles represent a particularly simple, beautiful and attractive system to study the dynamics of a closed gas volume embedded in the same or a different gas. Their dynamics is governed by the densities and viscosities of the gases and by the film tension. Dynamic equations describing their oscillations under simplifying assumptions have been well known since the beginning of the 20th century. Both analytical description and numerical modeling have made considerable progress since then, but quantitative experiments have been lacking so far. On the other hand, a soap bubble represents an easily manageable paradigm for the study of oscillations of fluid spheres. We use a technique to create axisymmetric initial non-equilibrium states, and we observe damped oscillations into equilibrium by means of a fast video camera. Symmetries of the oscillations, frequencies and damping rates of the eigenmodes as well as the coupling of modes are analyzed. They are compared to analytical models from the literature and to numerical calculations from the literature and this work.

  13. Forced spaser oscillations

    Science.gov (United States)

    Lisyansky, Alexander A.; Andrianov, Eugeney S.; Dorofeenko, Alexander V.; Pukhov, Alexander A.; Vinogradov, Alexey P.

    2012-10-01

    We study oscillations of a spaser driven by an external optical wave. When the frequency of the external field is shifted from the frequency of an autonomous spaser, the spaser exhibits stochastic oscillations at low field intensity. The plasmon oscillations lock to the frequency of the external field only when the field amplitude exceeds a threshold value. We find a region of external field amplitude and the frequency detuning (the Arnold tongue) for which the spaser becomes synchronized with the external wave. We obtain the conditions upon the amplitude and frequency of the external field (the curve of compensation) at which the spaser's dipole moment oscillates with a phase shift of π relatively to the external wave. For these values of the amplitude and frequency, the loss in the metal nanoparticles within the spaser is exactly compensated for by the gain. It is expected that if these conditions are not satisfied, then due to loss or gain of energy, the amplitude of the wave travelling along the system of spasers either tends to the curve of compensation or leave the Arnold tongue. We also consider cooperative phenomena showing that in a chain of interacting spasers, depending on the values of the coupling constants, either all spasers oscillate in phase or a nonlinear autowave travels in the system. In the latter scenario, the traveling wave is harmonic, unlike excitations in other nonlinear systems. Due to the nonlinear nature of the system, any initial distribution of spaser states evolves into one of these steady states.

  14. Bioenergetic and pharmacokinetic model for exposure of common loon (Gavia immer) chicks to methylmercury

    Science.gov (United States)

    Karasov, W.H.; Kenow, K.P.; Meyer, M.W.; Fournier, F.

    2007-01-01

    A bioenergetics model was used to predict food intake of common loon (Gavia immer) chicks as a function of body mass during development, and a pharmacokinetics model, based on first-order kinetics in a single compartment, was used to predict blood Hg level as a function of food intake rate, food Hg content, body mass, and Hg absorption and elimination. Predictions were tested in captive growing chicks fed trout (Salmo gairdneri) with average MeHg concentrations of 0.02 (control), 0.4, and 1.2 ??g/g wet mass (delivered as CH3HgCl). Predicted food intake matched observed intake through 50 d of age but then exceeded observed intake by an amount that grew progressively larger with age, reaching a significant overestimate of 28% by the end of the trial. Respiration in older, nongrowing birds probably was overestimated by using rates measured in younger, growing birds. Close agreement was found between simulations and measured blood Hg, which varied significantly with dietary Hg and age. Although chicks may hatch with different blood Hg levels, their blood level is determined mainly by dietary Hg level beyond approximately two weeks of age. The model also may be useful for predicting Hg levels in adults and in the eggs that they lay, but its accuracy in both chicks and adults needs to be tested in free-living birds. ?? 2007 SETAC.

  15. Effects of purified dietary fiber sources on beta-carotene utilization by the chick.

    Science.gov (United States)

    Erdman, J W; Fahey, G C; White, C B

    1986-12-01

    Effects of various purified dietary fiber components on beta-carotene utilization by the chick were investigated in two experiments (expt.). Eight-day-old Columbian X New Hampshire male (expt. 1) or female (expt. 2) chicks were fed a vitamin A-deficient diet for 1 wk and then fed beta-carotene-supplemented diets containing 0% fiber, 7% arenaceous flour or 7% of a purified fiber source for 4 wk. Results of expt. 1 showed that hemicellulose, lignin and citrus pectin, but not arenaceous flour or polygalacturonic acid, depressed beta-carotene utilization by the chick, as measured by percentage of consumed beta-carotene stored in liver as vitamin A relative to the 0% fiber control. In expt. 2, effects of the methoxyl content of pectin were studied. High and medium methoxyl apple pectin, citrus pectin and polygalacturonic acid reduced storage of vitamin A in liver. Low methoxyl apple pectin had no significant effect on beta-carotene utilization. Thus, several purified forms of dietary fiber significantly reduced beta-carotene utilization by chicks when fed at the 7% supplementary level. Moreover, with pectin, there was an inverse relationship between methoxyl content of pectin and beta-carotene utilization. PMID:3027282

  16. Effect of growth rate and body mass on resting metabolic rate in galliform chicks

    NARCIS (Netherlands)

    Dietz, MW; Drent, RH

    1997-01-01

    In this study, we asked whether within-species variation in chick resting metabolic rate was related to variation in growth and whether this relationship changed during development in three galliform species (turkey, Meleagris gallopavo, guinea fowl, Numida meleagris, and Japanese quail, Coturnix co

  17. Generation of the Dimensional Embryology Application (App) for Visualization of Early Chick and Frog Embryonic Development

    Science.gov (United States)

    Webb, Rebecca L.; Bilitski, James; Zerbee, Alyssa; Symans, Alexandra; Chop, Alexandra; Seitz, Brianne; Tran, Cindy

    2015-01-01

    The study of embryonic development of multiple organisms, including model organisms such as frogs and chicks, is included in many undergraduate biology programs, as well as in a variety of graduate programs. As our knowledge of biological systems increases and the amount of material to be taught expands, the time spent instructing students about…

  18. AN EMBRYONIC CHICK PANCREAS ORGAN CULTURE MODEL: CHARACTERIZATION AND NEURAL CONTROL OF EXOCRINE RELEASE

    Science.gov (United States)

    An embryonic chick (Gallus domesticus) whole-organ pancreas culture system was developed for use as an in vitro model to study cholinergic regulation of exocrine pancreatic function. The culture system was examined for characteristic exocrine function and viability by measuring e...

  19. A STUDY ON THE PATHOGENESIS OF YOLK RETENTION IN BROILER CHICKS

    Directory of Open Access Journals (Sweden)

    Kashif Aziz Khan. Shakeel Akhtar Khan, Shahnaz Hamid2. Asim Aslam and Masood

    2002-04-01

    Full Text Available The present project was designed to identify the factors responsible for yolk retention in broiler chicks. Four different experiments were conducted to find out the effect of four factors (experimental yolk sac infection with Echerichia coli, off-feed period between hatching and housing. first feeding time in the poultry house and type of initial feed on yolk absorption. Results of these experiments showed that yolk sac infection with E. coli led to decrease in rate of yolk absorption. Moisture and protein percentage was increased in infected yolk but fat percentage was not affected by yolk sac infection. On the other hand, post hatch starvation due to delay in housing and delay in first feeding did not affect rate of yolk absorption. Moisture percentage was not affected while fat absorption increased and protein absorption decreased due to fasting. It was also observed that feeding ground corn in early life of chick led to slow absorption of yolk contents as compared to feeding commercial starter ration and 2% sugar solution. Yolk composition was not affected by feeding commercial starter ration, ground corn and 2% sugar solution in early life of chick. It is concluded that experimental infection with E. coli and ground corn as initial feed leads to slow absorption of yolk sac in young broiler chicks.

  20. Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity

    NARCIS (Netherlands)

    van Hierden, YM; Koolhaas, JM; Kost'al, L; Vyboh, P; Sedlackova, M; Rajman, M; Jurani, M; Korte, SM; Hierden, Yvonne M. van; Koolhaas, Jaap M.; Košt’ál, L’ubor; Sedlačková, Monika

    2005-01-01

    Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reacti

  1. Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity.

    Science.gov (United States)

    van Hierden, Yvonne M; Koolhaas, Jaap M; Kost'ál, L'ubor; Výboh, Pavel; Sedlacková, Monika; Rajman, Marek; Juráni, Marian; Mechiel Korte, S

    2005-03-16

    Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reactive coping strategy, respectively. Therefore, at approximately 4 weeks of age, the behavior of 48 LFP and 48 HFP chicks in response to an APO injection was studied using an open field. Another objective of the present study was to determine whether behavioral variation (in an open field) between HFP and LFP birds, after APO injection, is also reflected by variation of D(1) and D(2) receptor densities in the brain. Receptor binding capacities were assessed by measuring specific binding of tritiated D(1) and D(2) receptor ligands in different regions of the brain of control HFP and LFP chicks. In the present study, it is shown that indeed HFP chicks display a more enhanced behavioral response to acute APO treatment (0.5 mg/kg BW) than LFP birds in an open field. This difference was not reflected by variation of D(1) and D(2) receptor densities in the brain between both lines. PMID:15763586

  2. Ethical euthanasia and short-term anesthesia of the chick embryo.

    Science.gov (United States)

    Aleksandrowicz, Ewa; Herr, Ingrid

    2015-01-01

    Fertilized chicken eggs are suggested as an alternative to mammalian models. The chorioallantoic membrane (CAM) of the chick embryo is widely used for examination of angiogenesis, xenotransplants and for virus production. Unfortunately, it is mostly not taken into account, that the chick embryo's ability to experience pain starts to develop at day 7 of breeding. In our view, this model is only in accordance with the 3 R principles, if an appropriate anesthesia of the chick embryo in potentially painful procedures is provided. Although many experimental approaches are performed on the none-innervated CAM, the euthanasia of the embryo strongly requires a more human technique than the usually used freezing at -20°C, decapitation or in ovo fixation with paraformaldehyde without prior anesthesia. However, protocols regarding feasible and ethical methods for anesthesia and euthanasia of avian embryos are currently not available. Therefore, we established an easy and reliable method for the euthanasia and short-term anesthesia of the chick embryo.

  3. Penguin Chicks Benefit from Elevated Yolk Androgen Levels under Sibling Competition

    NARCIS (Netherlands)

    Poisbleau, Maud; Mueller, Wendt; Carslake, David; Demongin, Laurent; Groothuis, Ton G. G.; Van Camp, Jeff; Eens, Marcel; Müller, Martina S.; Roelofs, Yvonne; Erikstad, Kjell Einar; Deschner, Tobias; Müller, Wendt; Reina, Richard

    2012-01-01

    Crested penguins (genus Eudyptes) have a peculiar hatching pattern, with the first-laid egg (A-egg) hatching after the second-laid egg (B-egg) and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive super

  4. Adaptation of infectious bronchitis virus in primary cells of the chick embryo chorioallantoic membrane

    Directory of Open Access Journals (Sweden)

    M. H. Mohammed

    2013-06-01

    Full Text Available The susceptibility of the primary chick embryo chorioallontoic membrane cells to infectious bronchitis virus was evaluated after twenty consecutive passages in chick embryo chorioallontoic membrane cells. Virus replication was monitored by cytopathic observation, indirect immunoperoxidase, and reverse transcription polymerase chain reaction (RT-PCR. At 72 hours post-infection (p.i. in third passage, the cytopathic effect was characterized by rounding up of cells, monolayer detachment, intracytoplasmic brownish colouration was readily observed by immunoperoxidase from 24 hours p.i in third passage, and at all times the extracted viral RNA from IBV-infected monolayers was demonstrated by RT-PCR. Tissue culture ineffective dose50 (TCID50 was used to measure virus titration performed on primary chick embryo chorioallontoic membrane cells and the titre in twenty passage was 108.6 TCID50/ml. The results obtained in this study suggested that the primary chick embryo chorioallontoic membrane cells can be used for adaptation infectious bronchitis virus (IBV and may be considered a step forward for the use of these cells in the future for IBV vaccine production

  5. Nutritional implications of pectins in chicks in relation to esterification and origin of pectins.

    Science.gov (United States)

    Langhout, D J; Schutte, J B

    1996-10-01

    An experiment was conducted to examine the effect of feeding high-methylated (HM) and low-methylated (LM) pectin on performance and physiological characteristics in broiler chicks. Two levels each (1.5 and 3%) of HM citrus pectin (HMC), LM citrus pectin (LMC), or HM sugar beet pectin (HMS) were added to a semi-purified basal diet. The experiment was conducted in battery brooders, and chicks received the diets as pellets from 6 to 27 d of age. The inclusion of LMC or HMS in the diet had little or no effect on the performance of chicks; however, when HMC was added to the diet growth and feed utilization were reduced significantly (P Waterholding capacity of the diets and the excreta were increased significantly by including one (P 0.05) on the concentration of VFA. In contrast, inclusion of HMS in the diet significantly increased the concentration of VFA in the cecal content (P < 0.05) dose-dependently. Based on the results of the present study, it can be concluded that the effect of dietary pectin on chick performance is dependent on the degree of carboxyl groups that is esterified, the origin of the pectin product, and the amount added to the diet.

  6. Keep the chicks moving : how Sandwich terns can minimize kleptoparasitism by black-headed gulls

    NARCIS (Netherlands)

    Stienen, EWM; Brenninkmeijer, A

    1999-01-01

    sandwich terns, Sterna sandvicensis, often nest in association with black-headed gulls, Larus ridibundus. The gulls provide protection against predators, but can also adversely affect the terns' reproductive success through predation and piracy of fish. To test whether leading the chicks away from t

  7. Foraging Habitat and Chick Diets of Roseate Tern, Sterna dougallii, Breeding on Country Island, Nova Scotia

    Directory of Open Access Journals (Sweden)

    Jennifer C. Rock

    2007-06-01

    Full Text Available Breeding seabirds are threatened by human activities that affect nesting and foraging habitat. In Canada, one of the seabirds most at risk of extirpation is the Roseate Tern, Sterna dougallii. Although critical nesting habitat has been identified for the Roseate Tern in Canada, its foraging locations and the diet of its chicks are unknown. Therefore, our goal was to determine the foraging locations and diet of chicks of Roseate Tern breeding on Country Island, Nova Scotia, which is one of Canada's two main breeding colonies. In 2003 and 2004, we radio-tracked the Roseate Tern by plane to locate foraging areas and conducted feeding watches to determine the diet of chicks. Roseate Tern foraged approximately 7 km from the breeding colony over shallow water < 5 m deep. In both years, sand lance, Ammodytes spp., was the most common prey item delivered to chicks, followed by hake, Urophycis spp. Our results are consistent with previous work at colonies in the northeastern United States, suggesting that throughout its range, this species may be restricted in both habitat use and prey selection. The reliance on a specific habitat type and narrow range of prey species makes the Roseate Tern generally susceptible to habitat perturbations and reductions in the availability of prey.

  8. Bacterial enteritis in ostrich (Struthio Camelus) chicks in the Western Cape Province, South Africa.

    Science.gov (United States)

    Keokilwe, L; Olivier, A; Burger, W P; Joubert, H; Venter, E H; Morar-Leather, D

    2015-06-01

    Ostrich (Struthio camelus) chicks less than 3 mo age are observed to experience a high mortality rate that is often associated with enteritis. This study was undertaken to investigate the infectious bacteria implicated in ostrich chick enteritis. Postmortems were performed on 122 ostrich chicks aged from 1 d to 3 mo and intestinal samples were subjected to bacterial culture. Bacterial isolates were typed by PCR and serotyping. Escherichia coli (E. coli; 49%) was the most frequently isolated from the samples followed by Clostridium perfringens (C. perfringens; 20%), Enterococcus spp. (16%), and Salmonella spp. (7%). Of the E. coli, 39% were categorized as enteropathogenic E. coli, 4% enterotoxigenic E. coli, and no enterohaemorrhagic E. coli were found. The majority (93%) of C. perfringens was Type A and only 7% was Type E. C. perfringens Types B through D were not present. The netB gene that encodes NetB toxin was identified from 16% of the C. perfringens isolated. All the C. perfringens Type E harbored the netB gene and just 10% of the C. perfringens Type A had this gene. Three Salmonella serotypes were identified: Salmonella Muenchen (S. Muenchen; 80%), S. Hayindongo (13%), and S. Othmarschen (7%). The indication is that the cause of enteritis in ostrich chicks is bacterial-involving: enteropathogenic E. coli and enterotoxigenic E. coli; C. perfringens Types A and E (with the possible influence of netB gene); and S. Muenchen, S. Hayindongo, and S. Othmarschen.

  9. Acutely altered hemodynamics following venous obstruction in the early chick embryo

    NARCIS (Netherlands)

    S. Stekelenburg-de Vos (Sandra); N.T.C. Ursem (Nicolette); W.C.J. Hop (Wim); J.W. Wladimiroff (Juriy); A.C. Gittenberger-de Groot (Adriana); R.E. Poelmann (Robert)

    2003-01-01

    textabstractIn the venous clip model specific cardiac malformations are induced in the chick embryo by obstructing the right lateral vitelline vein with a microclip. Clipping alters venous return and intracardiac laminar blood flow patterns, with secondary effects on the mechanical

  10. Acutely altered hemodynamics following venous obstruction in the early chick embryo.

    Science.gov (United States)

    Stekelenburg-de Vos, Sandra; Ursem, Nicolette T C; Hop, Wim C J; Wladimiroff, Juriy W; Gittenberger-de Groot, Adriana C; Poelmann, Robert E

    2003-03-01

    In the venous clip model specific cardiac malformations are induced in the chick embryo by obstructing the right lateral vitelline vein with a microclip. Clipping alters venous return and intracardiac laminar blood flow patterns, with secondary effects on the mechanical load of the embryonic myocardium. We investigated the instantaneous effects of clipping the right lateral vitelline vein on hemodynamics in the stage-17 chick embryo. 32 chick embryos HH 17 were subdivided into venous clipped (N=16) and matched control embryos (N=16). Dorsal aortic blood flow velocity was measured with a 20 MHz pulsed Doppler meter. A time series of eight successive measurements per embryo was made starting just before clipping and ending 5h after clipping. Heart rate, peak systolic velocity, time-averaged velocity, peak blood flow, mean blood flow, peak acceleration and stroke volume were determined. All hemodynamic parameters decreased acutely after venous clipping and only three out of seven parameters (heart rate, time-averaged velocity and mean blood flow) showed a recovery to baseline values during the 5h study period. We conclude that the experimental alteration of venous return has major acute effects on hemodynamics in the chick embryo. These effects may be responsible for the observed cardiac malformations after clipping.

  11. Maternal testosterone influences a begging component that makes fathers work harder in chick provisioning.

    Science.gov (United States)

    Noguera, José C; Kim, Sin-Yeon; Velando, Alberto

    2013-06-01

    In species with biparental care, parents disagree evolutionarily over the amount of care that each of them is willing to provide to offspring. It has recently been hypothesised that females may try to manipulate their mates by modifying offspring begging behaviour through yolk hormone deposition, shifting the division of labour in their own favour. To test this hypothesis we first investigated how yellow-legged gull (Larus michaellis) parents feed offspring in relation to each component of complex begging behaviour and if feeding behaviour varies between sexes. Then we investigated the effect of yolk testosterone on chicks' begging by experimentally increasing yolk testosterone levels. Our results revealed that yolk testosterone has a component-specific effect on chicks' begging, specifically increasing the number of chatter calls. Parental feeding effort was influenced by the number of chatter calls emitted by chicks, but most importantly, the influence was stronger in male than in female parents. Moreover, chick body mass increased with the number of paternal feeds. In conclusion, these results show that female gulls may use yolk testosterone deposition to exploit their partners as predicted by the 'Manipulating Androgen Hypothesis (MAH)'. PMID:23651611

  12. Diurnal cycles in serotonin acetyltransferase activity and cyclic GMP content of cultured chick pineal glands.

    Science.gov (United States)

    Wainwright, S D

    1980-06-12

    Levels of serotonin N-acetyltransferase (NAT: acetul CoA:arylamine N-acetyltransferase; EC 2.1.1.5.) activity in the chick pineal gland exhibit a marked diurnal variation in birds kept under a diurnal cycle of ilumination. Activity begins to rise rapidly at the start of the dark phase of the cycle and reaches maximum levels at mid-dark phase about 25-fold greater than the minimum basal level at mid-light phase. Thereafter, the level of activity declines to the basal level about the start of the light phase. This diurnal cycle in chick pineal NAT activity found in vivo has recently been reproduced in vitro with intact glands incubated in organ culture. The mechanism of the 'biological clock' which regulates these variations in level of chick pineal NAT activity is unknown. However, I now report that chick pineal glands cultured under a diurnal cycle of illumination exhibit a diurnal cycle in content of cyclic GMP which roughly parallels the cycles in NAT activity. In contrast, there was no correlation between variations in pineal content of cyclic AMP and in level of NAT activity. PMID:6250035

  13. Discovering Music through Chick Corea in Early Learning Centers in Spain: Proposals and Materials

    Science.gov (United States)

    Moreno, Jessica Perez; Malagarriga i Rovira, Teresa

    2011-01-01

    A description of a listening activity for "Children's Song," a piece by Chick Corea, is introduced and developed. The use of materials and strategies for music making in early childhood settings was developed as a result of a teacher training and consultancy program implemented in a network of early learning centers in Spain. The main lines of…

  14. Instantaneous and cumulative influences of competition on impulsive choices in domestic chicks.

    Directory of Open Access Journals (Sweden)

    Hidetoshi eAmita

    2011-09-01

    Full Text Available This study examined instantaneous and cumulative effects of competitive interactions on impulsiveness in the inter-temporal choices in domestic chicks. Chicks were trained to peck colored beads to gain delayed food rewards (1 or 6 grains of millet delivered after a delay ranging between 0–4.5 s, and were tested in binary choices between a small-short delay option (SS and a large-long delay alternative (LL. To examine whether competitive foraging instantaneously changes impulsiveness, we intraindividually compared choices between two consecutive tests in different contexts, one with competitors and another without. We found that (1 the number of the choice of LL was not influenced by competition in the tests, but (2 the operant peck latency was shortened by competition, suggesting a socially enhanced incentive for food. To further examine the lasting changes, two groups of chicks were consecutively trained and tested daily for 2 weeks according to a behavioral titration procedure, one with competitors and another without. Inter-group comparisons of the choices revealed that (3 choice impulsiveness gradually decreased along development, while (4 the chicks trained in competition maintained a higher level of impulsiveness. These results suggest that competitive foraging causes impulsive choices not by direct/contextual modification. Causal link between the instantaneous enhancement of incentive and the gradual effects on impulsivity remains to be examined. Some (yet unspecified factors may be indirectly involved.

  15. From high heels to weed attics: a syntactic investigation of chick lit and literature

    NARCIS (Netherlands)

    Jautze, K.J.; Koolen, C.W.; van Cranenburgh, Andreas; de Jong, H.A.

    2013-01-01

    Stylometric analysis of prose is typically limited to classification tasks such as authorship attribution. Since the models used are typically black boxes, they give little insight into the stylistic diff erences they detect. In this paper, we characterize two prose genres syntactically: chick lit (

  16. HAEMATOLOGICAL VALUES AND PLASMA CHOLESTEROL AS AFFECTED BY MOULTING IN NICK CHICK LAYING HENS

    OpenAIRE

    Bashir Mahmood Bhatti and Tanzeela Talat

    2001-01-01

    This study was conducted to examine effect of moulting on haematological values and plasma cholesterol levels of 86 weeks old Nick Chick laying hens. Washington and California moulting methods were used. Young laying hens, 40 weeks old served as control group. There were 408 hens in each group. There was no significant (P

  17. Egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite.

    Directory of Open Access Journals (Sweden)

    Michael G Anderson

    Full Text Available BACKGROUND: Chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. Yet, efforts to evict nest contents by the blind and naked common cuckoo Cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents. METHODOLOGY/PRINCIPAL FINDINGS: Here we show experimentally that egg tossing imposed a recoverable growth cost of mass gain in common cuckoo chicks during the nestling period in nests of great reed warbler Acrocephalus arundinaceus hosts. Growth rates of skeletal traits and morphological variables involved in the solicitation of foster parental care remained similar between evictor and non-evictor chicks throughout development. We also detected no increase in predation rates for evicting nests, suggesting that egg tossing behavior by common cuckoo hatchlings does not increase the conspicuousness of nests. CONCLUSION: The temporary growth cost of egg eviction by common cuckoo hatchlings is the result of constraints imposed by rejecter host adults and competitive nestmates on the timing and mechanism of parasite virulence.

  18. Tissue distribution of heavy metals in heron and egret chicks from Pyeongtaek, Korea.

    Science.gov (United States)

    Kim, Jungsoo; Oh, Jong-Min

    2015-02-01

    Iron, zinc, manganese, lead and cadmium were measured in the liver, kidney and bone of Grey Heron (Ardea cinerea), Intermediate Egret (Egretta intermedia), Little Egret (Egretta garzetta) and Black-crowned Night Herons (Nycticorax nycticorax) from Korea. Iron, zinc, manganese, lead and cadmium concentrations had species- and tissue- specific accumulation. Lead concentrations in all tissues of Black-crowned Night Heron and cadmium in kidneys of Intermediate Egret chicks were relatively higher than in other species. Iron and manganese in the liver, zinc in the bone, and lead and cadmium in the kidney were relatively higher than other tissues and these results have been reported in other birds. Lead concentrations in all species were at a level associated with acute lead poisoning and cadmium concentrations except for Grey Heron chicks were at a level associated with chronic cadmium exposure. Lead concentrations in livers and bones of heron and egret chicks were within a range considered background level (poisoning (6.00-18 μg/g dw) and 7 of 37 chicks were compatible with death (>18.0 μg/g dw). For cadmium, all liver and kidney concentrations were at a level considered background for birds (iron, zinc and manganese concentrations were within the range observed in other birds. PMID:25504523

  19. 3-Dimensional modelling of chick embryo eye development and growth using high resolution magnetic resonance imaging.

    Science.gov (United States)

    Goodall, Nicola; Kisiswa, Lilian; Prashar, Ankush; Faulkner, Stuart; Tokarczuk, Paweł; Singh, Krish; Erichsen, Jonathan T; Guggenheim, Jez; Halfter, Willi; Wride, Michael A

    2009-10-01

    Magnetic resonance imaging (MRI) is a powerful tool for generating 3-dimensional structural and functional image data. MRI has already proven valuable in creating atlases of mouse and quail development. Here, we have exploited high resolution MRI to determine the parameters necessary to acquire images of the chick embryo eye. Using a 9.4 Tesla (400 MHz) high field ultra-shielded and refrigerated magnet (Bruker), MRI was carried out on paraformaldehyde-fixed chick embryos or heads at E4, E6, E8, and E10. Image data were processed using established and custom packages (MRICro, ImageJ, ParaVision, Bruker and mri3dX). Voxel dimensions ranged from 62.5 microm to 117.2 microm. We subsequently used the images obtained from the MRI data in order to make precise measurements of chick embryo eye surface area, volume and axial length from E4 to E10. MRI was validated for accurate sizing of ocular tissue features by direct comparison with previously published literature. Furthermore, we demonstrate the utility of high resolution MRI for making accurate measurements of morphological changes due to experimental manipulation of chick eye development, thereby facilitating a better understanding of the effects on chick embryo eye development and growth of such manipulations. Chondroitin sulphate or heparin were microinjected into the vitreous cavity of the right eyes of each of 3 embryos at E5. At E10, embryos were fixed and various eye parameters (volume, surface area, axial length and equatorial diameter) were determined using MRI and normalised with respect to the un-injected left eyes. Statistically significant alterations in eye volume (p < 0.05; increases with chondroitin sulphate and decreases with heparin) and changes in vitreous homogeneity were observed in embryos following microinjection of glycosaminoglycans. Furthermore, in the heparin-injected eyes, significant disturbances at the vitreo-retinal boundary were observed as well as retinal folding and detachment

  20. Investigation of the chick embryo as a potential alternative to the mouse for evaluation of radiopharmaceuticals

    International Nuclear Information System (INIS)

    Introduction: The chick embryo is an emerging in vivo model in several areas of pre-clinical research including radiopharmaceutical sciences. Herein, it was evaluated as a potential test system for assessing the biodistribution and in vivo stability of radiopharmaceuticals. For this purpose, a number of radiopharmaceuticals labeled with 18F, 125I, 99mTc, and 177Lu were investigated in the chick embryo and compared with the data obtained in mice. Methods: Chick embryos were cultivated ex ovo for 17–19 days before application of the radiopharmaceutical directly into the peritoneum or intravenously using a vein of the chorioallantoic membrane (CAM). At a defined time point after application of radioactivity, the embryos were euthanized by shock-freezing using liquid nitrogen. Afterwards they were separated from residual egg components for post mortem imaging purposes using positron emission tomography (PET) or single photon emission computed tomography (SPECT). Results: SPECT images revealed uptake of [99mTc]pertechnetate and [125I]iodide in the thyroid of chick embryos and mice, whereas [177Lu]lutetium, [18F]fluoride and [99mTc]-methylene diphosphonate ([99mTc]-MDP) were accumulated in the bones. [99mTc]-dimercaptosuccinic acid (99mTc-DMSA) and the somatostatin analog [177Lu]-DOTATOC, as well as the folic acid derivative [177Lu]-DOTA-folate showed accumulation in the renal tissue whereas [99mTc]-mebrofenin accumulated in the gall bladder and intestine of both species. In vivo dehalogenation of [18F]fallypride and of the folic acid derivative [125I]iodo-tyrosine-folate was observed in both species. In contrast, the 3′-aza-2′-[18F]fluorofolic acid ([18F]-AzaFol) was stable in the chick embryo as well as in the mouse. Conclusions: Our results revealed the same tissue distribution profile and in vivo stability of radiopharmaceuticals in the chick embryo and the mouse. This observation is promising with regard to a potential use of the chick embryo as an inexpensive

  1. Arbitrary Spin Galilean Oscillator

    CERN Document Server

    Hagen, C R

    2014-01-01

    The so-called Dirac oscillator was proposed as a modification of the free Dirac equation which reproduces many of the properties of the simple harmonic oscillator but accompanied by a strong spin-orbit coupling term. It has yet to be extended successfully to the arbitrary spin S case primarily because of the unwieldiness of general spin Lorentz invariant wave equations. It is shown here using the formalism of totally symmetric multispinors that the Dirac oscillator can, however, be made to accommodate spin by incorporating it into the framework of Galilean relativity. This is done explicitly for spin zero and spin one as special cases of the arbitrary spin result. For the general case it is shown that the coefficient of the spin-orbit term has a 1/S behavior by techniques which are virtually identical to those employed in the derivation of the g-factor carried out over four decades ago.

  2. Oscillations in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Hoeye, Gudrun Kristine

    1999-07-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  3. Oscillations in neutron stars

    International Nuclear Information System (INIS)

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l → 4) f-modes we were also able to derive a formula that determines IIl+1 from IIl and IIl-1 to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density nc, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  4. Familiarity perception call elicited under restricted sensory cues in peer-social interactions of the domestic chick.

    Directory of Open Access Journals (Sweden)

    Mamiko Koshiba

    Full Text Available Social cognitive mechanisms are central to understanding developmental abnormalities, such as autistic spectrum disorder. Peer relations besides parent-infant or pair-bonding interactions are pivotal social relationships that are especially well developed in humans. Cognition of familiarity forms the basis of peer socialization. Domestic chick (Gallus gallus studies have contributed to our understanding of the developmental process in sensory-motor cognition but many processes remain unknown. In this report, we used chicks, as they are precocial birds, and we could therefore focus on peer interaction without having to consider parenting. The subject chick behavior towards familiar and unfamiliar reference peers was video-recorded, where the subject and the reference were separated by either an opaque or transparent wall. Spectrogram and behavior correlation analyses based on principal component analysis, revealed that chicks elicited an intermediate contact call and a morphologically different distress call, more frequently towards familiar versus unfamiliar chicks in acoustic only conditions. When both visual and acoustic cues were present, subject chicks exhibited approaching and floor pecking behavior, while eliciting joyful (pleasant calls, irrespective of whether reference peers were familiar or unfamiliar. Our result showed that chicks recognized familiarity using acoustic cues and expressed cognition through modified distress calls. These finding suggests that peer affiliation may be established by acoustic recognition, independent of visual face recognition, and that eventually, both forms of recognition are integrated, with modulation of acoustic recognition.

  5. Friedel oscillations in graphene

    DEFF Research Database (Denmark)

    Lawlor, J. A.; Power, S. R.; Ferreira, M.S.

    2013-01-01

    Symmetry breaking perturbations in an electronically conducting medium are known to produce Friedel oscillations in various physical quantities of an otherwise pristine material. Here we show in a mathematically transparent fashion that Friedel oscillations in graphene have a strong sublattice...... asymmetry. As a result, the presence of impurities and/or defects may impact the distinct graphene sublattices very differently. Furthermore, such an asymmetry can be used to explain the recent observations that nitrogen atoms and dimers are not randomly distributed in graphene but prefer to occupy one...

  6. Modulatory effect of ascorbic acid on physiological responses of transported ostrich chicks

    Directory of Open Access Journals (Sweden)

    Minka N. Salka

    2012-02-01

    Full Text Available The aims of this study were to determine the modulating role of ascorbic acid (AA on rectal temperature (RT, heterophil to lymphocyte (H to L ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.

  7. Why Huddle? Ecological Drivers of Chick Aggregations in Gentoo Penguins, Pygoscelis papua, across Latitudes.

    Science.gov (United States)

    Black, Caitlin; Collen, Ben; Johnston, Daniel; Hart, Tom

    2016-01-01

    Aggregations of young animals are common in a range of endothermic and ectothermic species, yet the adaptive behavior may depend on social circumstance and local conditions. In penguins, many species form aggregations (aka. crèches) for a variety of purposes, whilst others have never been observed exhibiting this behavior. Those that do form aggregations do so for three known benefits: 1) reduced thermoregulatory requirements, 2) avoidance of unrelated-adult aggression, and 3) lower predation risk. In gentoo penguins, Pygoscelis papua, chick aggregations are known to form during the post-guard period, yet the cause of these aggregations is poorly understood. Here, for the first time, we study aggregation behavior in gentoo penguins, examining four study sites along a latitudinal gradient using time-lapse cameras to examine the adaptive benefit of aggregations to chicks. Our results support the idea that aggregations of gentoo chicks decrease an individual's energetic expenditure when wet, cold conditions are present. However, we found significant differences in aggregation behavior between the lowest latitude site, Maiviken, South Georgia, and two of the higher latitude sites on the Antarctic Peninsula, suggesting this behavior may be colony specific. We provide strong evidence that more chicks aggregate and a larger number of aggregations occur on South Georgia, while the opposite occurs at Petermann Island in Antarctica. Future studies should evaluate multiple seabird colonies within one species before generalizing behaviors based on one location, and past studies may need to be re-evaluated to determine whether chick aggregation and other behaviors are in fact exhibited species-wide.

  8. Why Huddle? Ecological Drivers of Chick Aggregations in Gentoo Penguins, Pygoscelis papua, across Latitudes.

    Directory of Open Access Journals (Sweden)

    Caitlin Black

    Full Text Available Aggregations of young animals are common in a range of endothermic and ectothermic species, yet the adaptive behavior may depend on social circumstance and local conditions. In penguins, many species form aggregations (aka. crèches for a variety of purposes, whilst others have never been observed exhibiting this behavior. Those that do form aggregations do so for three known benefits: 1 reduced thermoregulatory requirements, 2 avoidance of unrelated-adult aggression, and 3 lower predation risk. In gentoo penguins, Pygoscelis papua, chick aggregations are known to form during the post-guard period, yet the cause of these aggregations is poorly understood. Here, for the first time, we study aggregation behavior in gentoo penguins, examining four study sites along a latitudinal gradient using time-lapse cameras to examine the adaptive benefit of aggregations to chicks. Our results support the idea that aggregations of gentoo chicks decrease an individual's energetic expenditure when wet, cold conditions are present. However, we found significant differences in aggregation behavior between the lowest latitude site, Maiviken, South Georgia, and two of the higher latitude sites on the Antarctic Peninsula, suggesting this behavior may be colony specific. We provide strong evidence that more chicks aggregate and a larger number of aggregations occur on South Georgia, while the opposite occurs at Petermann Island in Antarctica. Future studies should evaluate multiple seabird colonies within one species before generalizing behaviors based on one location, and past studies may need to be re-evaluated to determine whether chick aggregation and other behaviors are in fact exhibited species-wide.

  9. A method for detecting MFO induction by Japanese pulp mill effluents with chick embryo

    Energy Technology Data Exchange (ETDEWEB)

    Tatarazako, Norihisa; Kamaya, Yasushi [Japan Pulp and Paper Research Inst. Inc., Tokodai, Tsukuba (Japan)

    1995-12-31

    As a biomarker of physiological responses in fish exposed to pulp and paper mill effluents, mixed function oxygenase (MFO) induction has been investigated by many researchers. The induction and/or inhibition of MFOs is generally affected by various factors of fish such as species, maturity, sex, size and spawning status, and by other environmental variables. Therefore, the method demands technical skills to get a constant result. In addition, the test is costly and also time consuming. In this paper, the authors propose a MFOs induction method using chick embryo, instead of fish, for the assessment of pulp mill effluent. The merits of this method are as follows; inexpensive and commercially available test organisms, easy maintenance of the organisms, no feeding, high uniformity of the developing stage, sensitive responses to xenobiotics, low sample volume requirements, easy testing of various samples at one time and minimal training. P450 1A1 has been found in the microsome of chick embryo. Metabolic function of the P450 1A1 can be regarded basically the same as that of fish. Small amount of xenobiotics, about 100 {micro}l, were injected into the air chamber of 16-day-old chick embryos. Liver microsomes were isolated 48 h after administration. Ethoxyresorufin-O-deethylase (EROD) activity was determined by the direct fluorimetric method. Using the chick embryo method, the authors analyzed various chloro-organics, model bleached kraft pulp mill effluents, model black liquor and several total effluents of Japanese pulp mills. Methylcholanthrene and 2,3,7,8-TCDD were used as positive controls. In this paper, the authors will report the details of the chick embryo method and also some results of the assessment using the method.

  10. Benefits and costs of increased levels of corticosterone in seabird chicks

    Science.gov (United States)

    Kitaysky, A.S.; Kitaiskaia, E.V.; Piatt, J.F.; Wingfield, J.C.

    2003-01-01

    Seabird chicks respond to food shortages by increasing corticosterone (cort) secretion, which is probably associated with fitness benefits and costs. To examine this, we experimentally increased levels of circulating cort in captive black-legged kittiwake chicks fed ad libitum. We found that cort-implanted chicks begged more frequently and were more aggressive compared to controls. These behavioral modifications must be beneficial to chicks as they facilitate acquisition of food from the parents and might trigger brood reduction and reduced competition for food. Cort-implanted chicks also increased food intake; however, their growth rates were similar to controls. To examine the costs of chronically increased circulating levels of cort, we removed cort implants and, after a 10-day recovery period, tested cognitive abilities of young kittiwakes. We found that the ability of kittiwakes to associate a visual cue with the presence of food in a choice situation was compromised by the experimental elevation of cort during development. To examine the long-term costs of increased levels of cort, 8 months later we tested the performance of the same individuals in a spatial task requiring them to make a detour around a barrier in order to escape from an enclosure. Individuals treated with cort during development took significantly more time to solve this task compared to controls. The results of this study suggest that the adrenocortical response of a developing bird to environmental stressors is associated with both benefits (increased food intake, foraging behavior, and aggression) and costs (low growth efficiency and compromised cognitive abilities later in life). This provides an evolutionary framework for relating juvenile physiological traits to fitness of birds in subsequent life-history stages. ?? 2003 Elsevier Science (USA). All rights reserved.

  11. EFFECT OF ADMINISTRATION OF ETIZOLAM ON THE DEVELOPMENT OF THE CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Shweta P. Alai et al.

    2012-02-01

    Full Text Available There are various drugs used in daily life. Some of them show hazardous effect on various organs and some of them shows even lethal effect. Such drugs are required to banned. One of them is Etizolam (marketed under the brand name Sedekopan, Pasaden or Depas is a drug which is a thiebenzothiodiazepines analog. The aim of this work is done to compare the effect of administration of the etizolam drug at (Zero-day before incubation and at the (5-day first week of incubation, to get an idea about the extent of the teratogenic effect of this drug on the development of chick embryo. So that morphological and biochemical studies were done on the chick embryo of 8- and 16-days old chick embryos treated with (0.5mg/ml egg of etizolam on the (zero and 5-th days of incubation. Etizolam caused abnormality in concentration dependent manner. Enlarged remains of primitive streak was seen at 0.1mg/ml and o.3mg/ml concentration of Etizolam embryo dies. Etizolam inhibit development of somites of the development of 5-day at of incubation also it does not allow the development of notochord. The toxic effects of the drug was seen also more at 16-days treated chick embryos and the drug induced death of chick embryo at both 8- and 16-days treated with 0.1mg/ml and o.3mg/ml. The conclusion from this study was the etizolam drug has dangerous effects on tissues and with powerful toxicity on the cells, because the drug absorbed rapidly with peak plasma levels achieved between 30 minutes and 2 hours and has a mean elimination half life of about 3 and a half hours.

  12. Centrosema (Centrosema pubescens leaf meal as a protein supplement for broiler chicks production

    Directory of Open Access Journals (Sweden)

    Friday Chima NWORGU

    2015-10-01

    Full Text Available Present study was conducted to find out the potential Centrosema (Centrosema pubescens leaf meal as a protein supplement for the broiler chicks production. For this, Ninety unsexed one week old Anak 2000 broiler chicks were used. These selected chicks were randomly allotted to 5 dietary treatments i.e. A (Centrosema free diet, B (3%, C (6%, D (9% and E (12% with different concentration of C. pubescens leaf meal (CLM. Each treatment was replicated 3 times with 6 birds per replicate. This CLM mainly used to replaced groundnut cake and soybean in the diets. Water and feeds were served adlibitum. The results of study revealed that dietary supplementation of CLM significantly (P<0.05 and progressively depressed final body weight, weight gain and feed conversion ratio unlike water and feed intakes. Dietary inclusion of 6-12% CLM for broiler chicks reduced weight gain averagely by 12.96% compared to control. The cost of feed per kg live weight gain was N91.86, N96.04 and NI07.59/kg for control, 3 and 12%, respectively. Profit margin was highest in control (N4.11 and birds placed on 3% CLM (N2.66 per bird compared to those fed 9.0-12.0% CLM dietary inclusion, in which average loss was N20.39 per bird. Hence results of study clearly advised that CLM can be add as protein supplements but it should not include more than 3% in the diet of broiler chicks

  13. Why Huddle? Ecological Drivers of Chick Aggregations in Gentoo Penguins, Pygoscelis papua, across Latitudes

    Science.gov (United States)

    Collen, Ben; Johnston, Daniel

    2016-01-01

    Aggregations of young animals are common in a range of endothermic and ectothermic species, yet the adaptive behavior may depend on social circumstance and local conditions. In penguins, many species form aggregations (aka. crèches) for a variety of purposes, whilst others have never been observed exhibiting this behavior. Those that do form aggregations do so for three known benefits: 1) reduced thermoregulatory requirements, 2) avoidance of unrelated-adult aggression, and 3) lower predation risk. In gentoo penguins, Pygoscelis papua, chick aggregations are known to form during the post-guard period, yet the cause of these aggregations is poorly understood. Here, for the first time, we study aggregation behavior in gentoo penguins, examining four study sites along a latitudinal gradient using time-lapse cameras to examine the adaptive benefit of aggregations to chicks. Our results support the idea that aggregations of gentoo chicks decrease an individual’s energetic expenditure when wet, cold conditions are present. However, we found significant differences in aggregation behavior between the lowest latitude site, Maiviken, South Georgia, and two of the higher latitude sites on the Antarctic Peninsula, suggesting this behavior may be colony specific. We provide strong evidence that more chicks aggregate and a larger number of aggregations occur on South Georgia, while the opposite occurs at Petermann Island in Antarctica. Future studies should evaluate multiple seabird colonies within one species before generalizing behaviors based on one location, and past studies may need to be re-evaluated to determine whether chick aggregation and other behaviors are in fact exhibited species-wide. PMID:26840252

  14. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources

    Science.gov (United States)

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P.; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P.; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin’s gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5–24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin’s gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  15. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources.

    Science.gov (United States)

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin's gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5-24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin's gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  16. Effect of egg weight on ostrich (Struthio camelus chick weight and growth

    Directory of Open Access Journals (Sweden)

    Gianluca Picco

    2010-01-01

    Full Text Available The aim of this paper is to evaluate the effects of the age of ostriches and month of laying on egg production and chickgrowth. On a small ostrich farm egg production, egg incubation and chick growth from hatching to 56 days of age wererecorded from 2000, when the breeders were 5 years old, until 2002. Ostriches were kept in groups and fed commercialfeed. In all, 568 eggs were laid and weighed at laying and during incubation (at 15th and 30th day of incubation, while353 chicks were weighed at hatching, 7, 14, 28 and 56 days of age.The female’s productivity was calculated assuming a laying of 3.5 eggs per week and ranged between 45% and 48%.The fertility was around 70% with a peak of 74% recorded in 2001. The hatchability of all eggs was higher than 62%with a peak of 72% in 2001, while the hatchability of fertile eggs was higher than 90%. In each year the number of eggslaid increased from March to July, productivity showed a positive trend from May to June, while the fertility and hatchabilityof all eggs, as well as fertile eggs, was unaffected by year and month. As the hens aged, the egg mass grew constantlywith an increase of about 8%. During the first 30 days of incubation the egg weight decreased with the percentagesof weight loss around 10.0%. At hatching, the weight of chick ranged between 765 g and 847 g, respectively, in2000 and 2002. Egg weight influenced the hatching weight showing a linear relationship (R2=0.84. The effect of eggweight on the chick weight decreased as the chick grew. At 56 days of age, only the effect of year is significant. Themonth of laying did not demonstrate any effect on chicken weight.

  17. Benefits and costs of increased levels of corticosterone in seabird chicks.

    Science.gov (United States)

    Kitaysky, A S; Kitaiskaia, E V; Piatt, J F; Wingfield, J C

    2003-01-01

    Seabird chicks respond to food shortages by increasing corticosterone (cort) secretion, which is probably associated with fitness benefits and costs. To examine this, we experimentally increased levels of circulating cort in captive black-legged kittiwake chicks fed ad libitum. We found that cort-implanted chicks begged more frequently and were more aggressive compared to controls. These behavioral modifications must be beneficial to chicks as they facilitate acquisition of food from the parents and might trigger brood reduction and reduced competition for food. Cort-implanted chicks also increased food intake; however, their growth rates were similar to controls. To examine the costs of chronically increased circulating levels of cort, we removed cort implants and, after a 10-day recovery period, tested cognitive abilities of young kittiwakes. We found that the ability of kittiwakes to associate a visual cue with the presence of food in a choice situation was compromised by the experimental elevation of cort during development. To examine the long-term costs of increased levels of cort, 8 months later we tested the performance of the same individuals in a spatial task requiring them to make a detour around a barrier in order to escape from an enclosure. Individuals treated with cort during development took significantly more time to solve this task compared to controls. The results of this study suggest that the adrenocortical response of a developing bird to environmental stressors is associated with both benefits (increased food intake, foraging behavior, and aggression) and costs (low growth efficiency and compromised cognitive abilities later in life). This provides an evolutionary framework for relating juvenile physiological traits to fitness of birds in subsequent life-history stages.

  18. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.;

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...

  19. [Oscillating physiotherapy for secretolysis].

    Science.gov (United States)

    Brückner, U

    2008-03-01

    Assisted coughing and mechanical cough aids compensate for the weak cough flow in patients with neuromuscular diseases (NMD). In cases with preserved respiratory muscles also breathing techniques and special devices, e. g., flutter or acapella can be used for secretion mobilisation during infections of the airways. These means are summarised as oscillating physiotherapy. Their mechanisms are believed to depend on separation of the mucus from the bronchial wall by vibration, thus facilitating mucus transport from the peripheral to the central airways. In mucoviscidosis and chronic obstructive pulmonary disease their application is established, but there is a paucity of data regarding the commitment in patients with neuromuscular diseases. The effective adoption of simple oscillation physiotherapeutic interventions demands usually a sufficient force of the respiratory muscles--exceptions are the application of the percussionaire (intrapulmonary percussive ventilator, IPV) or high frequency chest wall oscillation (HFCWO). In daily practice there is evidence that patients with weak respiratory muscles are overstrained with the use of these physiotherapeutic means, or get exhausted. A general recommendation for the adoption of simple oscillating physiotherapeutic interventions cannot be made in patients with NMDs. Perhaps in the future devices such as IPV or HFCWO will prove to be more effective in NMD patients.

  20. Neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L. [European Organization for Nuclear Research, Geneva (Switzerland)

    1996-11-01

    Neutrino oscillation experiments ({nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {tau}}) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs.

  1. Solar neutrino oscillations

    International Nuclear Information System (INIS)

    The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena

  2. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able to...

  3. Orthogonal polynomials and deformed oscillators

    Science.gov (United States)

    Borzov, V. V.; Damaskinsky, E. V.

    2015-10-01

    In the example of the Fibonacci oscillator, we discuss the construction of oscillator-like systems associated with orthogonal polynomials. We also consider the question of the dimensions of the corresponding Lie algebras.

  4. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A N; Mosekilde, E;

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  5. Neutrino Oscillations with Nil Mass

    Science.gov (United States)

    Floyd, Edward R.

    2016-09-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and ν ,bar{ν } oscillations are examined.

  6. Early Age Thermal Conditioning Improves Broiler Chick's Response to Acute Heat Stress at Marketing Age

    Directory of Open Access Journals (Sweden)

    Ahmed M. Hassan

    2012-01-01

    Full Text Available Problem statement: Acute heat stress at marketing age especially in broiler chickens raised in open houses with reduced means of heat exchange leads to economic losses. The objective of this study was to determine beneficial effects of early age thermal conditioning in reducing adverse effects of acute heat stress and decrease losses. Approach: Ninety one day-old broiler chicks were randomly assigned to one of three treatments (n = 30: (1 control (normally raised, (2 early age thermal conditioning (exposed to temperature of 40±1°C for 24 h at 5th day of age, then raised as control chicks and (3 chronic stress (exposed to 33±2°C from day one till 6 weeks of age. At 42nd day of age, all chicks were subjected to acute heat stress of 39±2°C for 2 h. Blood samples were collected from all groups before and after exposure to acute heat stress. Results: Blood pH increased in both controls and thermally-conditioned chicks after exposure to acute heat stress coinciding with significant decrease in blood carbon dioxide pressure (pCo2 in controls only. Blood potassium level decreased in controls, while in thermally-conditioned or chronically-stressed no significant changes were observed. Blood sodium level showed a trend toward decreased levels in controls while a trend toward increased levels was observed in both thermally-conditioned and chronically-stressed birds. Importantly, significant reductions were observed in total erythrocyte count and hemoglobin level in chronically-stressed birds as compared to other groups before and after acute stress exposure. Hetrophil/lymphocyte ratio increased in both controls and thermally-conditioned chicks after acute heat exposure, but not in chronically-stressed birds. Conclusion: When exposed to acute heat stress at marketing age, chicks subjected to early age thermal conditioning responded very similar to birds adapted to chronic heat stress indicating a protective role of early age thermal conditioning.

  7. Factors related to high levels of ostrich chick mortality from hatching to 90 days of age in an intensive rearing system

    Directory of Open Access Journals (Sweden)

    S.W.P. Cloete

    2001-07-01

    Full Text Available Ostrich chick mortality was studied in 2522 chicks that were hatched artificially during the 1999/2000 breeding season. High levels of mortality were observed, with 1978 (78.4 % of these chicks dying before 90 days after hatching. Atotal of 46.7 %(1177 of these chicks died before 28 days of age, and a further 30.7 %(801 died between 28 and 90 days post-hatching. Chick mortality to 28 days of age could not be conclusively related to sex, day of external pipping or breeder diet. Mortality rates were higher (P < 0.05 at the beginning and end of the breeding season than in the middle months. Differences in mortality levels of chicks incubated in different incubators could be related to the time of the breeding season during which the incubator was mostly used. The regression of chick mortality to 28 days of age on day-old chick mass followed a 2nd-degree polynomial. Chicks with day-old masses below 762.5 g were particularly at risk of dying before 28 days after hatching. Chicks hatching from eggs where excessive water loss to 35 days of incubation (>18 % was recorded were also at risk of succumbing before 28 days of age. Chick mortality percentages for the period from 28 to 90 days of age exceeded 80 %in chicks weighing an average of 1050 g at 28 days. Mortaliy percentages declined sharply at higher live masses, to between 20 and 30 % in chicks weighing ?1950 g. This 'core' level of mortality remained throughout, even in the heaviest chicks. It was concluded that the high levels of chick mortality could be related to stress in chicks, resulting from an inability to adapt to the rearing environment. The high subsequent mortality percentages of low live mass chicks that survived to 28 days after hatching could probably be attributed to residual setbacks suffered earlier. Abetter understanding of the underlying principles involved in ostrich chick mortality in intensive rearing environments is required for progress in this field, resulting in more

  8. Improved chaotic Colpitts oscillator for ultrahigh frequencies

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Bumeliene, S.; Lindberg, Erik

    2004-01-01

    A novel version of the Colpitts oscillator is presented generating chaotic oscillations at gigahertz frequencies.......A novel version of the Colpitts oscillator is presented generating chaotic oscillations at gigahertz frequencies....

  9. The electrical soliton oscillator

    Science.gov (United States)

    Ricketts, David Shawn

    Solitons are a special class of pulse-shaped waves that propagate in nonlinear dispersive media while maintaining their spatial confinement. They are found throughout nature where the proper balance between nonlinearity and dispersion is achieved. Examples of the soliton phenomena include shallow water waves, vibrations in a nonlinear spring-mass lattice, acoustic waves in plasma, and optical pulses in fiber optic cable. In electronics, the nonlinear transmission line (NLTL) serves as a nonlinear dispersive medium that propagates voltage solitons. Electrical solitons on the NLTL have been actively investigated over the last 40 years, particularly in the microwave domain, for sharp pulse generation applications and for high-speed RF and microwave sampling applications. In these past studies the NLTL has been predominantly used as a 2-port system where a high-frequency input is required to generate a sharp soliton output through a transient process. One meaningful extension of the past 2-port NLTL works would be to construct a 1-port self-sustained electrical soliton oscillator by properly combining the NLTL with an amplifier (positive active feedback). Such an oscillator would self-start by growing from ambient noise to produce a train of periodic soliton pulses in steady-state, and hence would make a self-contained soliton generator not requiring an external high-frequency input. While such a circuit may offer a new direction in the field of electrical pulse generation, there has not been a robust electrical soliton oscillator reported to date to the best of our knowledge. In this thesis we introduce the first robust electrical soliton oscillator, which is able to self-generate a stable, periodic train of electrical solitons. This new oscillator is made possible by combining the NLTL with a unique nonlinear amplifier that is able to "tame" the unruly dynamics of the NLTL. The principle contribution of this thesis is the identification of the key instability

  10. The Effect of Choice Feeding Based on Threonine on Performance and Carcass Parameters of Male Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Tugay Ayasan

    2014-04-01

    Full Text Available The aim of this study was to evaluate the effect of choice feeding based on threonine on performance characteristics and carcass parameters of male broiler chicks. Day old, thirty Ross 308 male chicks were divided into two dietary treatment groups. In the experiment, choice feding did not affect on body weight gain, feed conversion ratio. Feed intake and carcass parameters significantly affected by experimental treatments.

  11. Physics of Neutrino Oscillation

    CERN Document Server

    Mondal, Spandan

    2015-01-01

    The Standard Model of particle physics describes neutrinos as massless, chargeless elementary particles that come in three different flavours. However, recent experiments indicate that neutrinos not only have mass, but also have multiple mass eigenstates that are not identical to the flavour states, thereby indicating mixing. As an evidence of mixing, neutrinos have been observed to change from one flavour to another during their propagation, a phenomenon called neutrino oscillation. We have studied the reasons and derived the probabilities of neutrino flavour change, both in vacuum and in matter. We have also studied the parameters affecting this probability. We have discussed the special case of two-neutrino oscillations. Lastly, we have discussed some basic properties of neutrinos that are reflected in the previous derivations and highlighted a few relevant open problems. To begin with, we have also studied the relevant topics in introductory High Energy Physics and Quantum Mechanics to familiarize with th...

  12. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  13. Stable local oscillator module.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2007-11-01

    This report gives a description of the development of a Stable Local Oscillator (StaLO) multi-chip module (MCM). It is a follow-on report to SAND2006-6414, Stable Local Oscillator Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. This report describes the development of an MCM-based version of the complete StaLO, fabricated on an alumina thick film hybrid substrate.

  14. Entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  15. Entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M.; Dell' Anno, F.; De Siena, S.; Illuminati, F. [Universita degli Studi di Salerno Via Ponte don Melillon, Dipt. di Matematica e Informatica, Fisciano SA (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno - Baronissi SA (Italy); Dell' Anno, F.; De Siena, S.; Illuminati, F. [CNR-INFM Coherentia - Napoli (Italy); Blasone, M. [ISI Foundation for Scientific Interchange, Torino (Italy)

    2009-03-15

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  16. Nonlinear (Anharmonic Casimir Oscillator

    Directory of Open Access Journals (Sweden)

    Habibollah Razmi

    2011-01-01

    Full Text Available We want to study the dynamics of a simple linear harmonic micro spring which is under the influence of the quantum Casimir force/pressure and thus behaves as a (an nonlinear (anharmonic Casimir oscillator. Generally, the equation of motion of this nonlinear micromechanical Casimir oscillator has no exact solvable (analytical solution and the turning point(s of the system has (have no fixed position(s; however, for particular values of the stiffness of the micro spring and at appropriately well-chosen distance scales and conditions, there is (are approximately sinusoidal solution(s for the problem (the variable turning points are collected in a very small interval of positions. This, as a simple and elementary plan, may be useful in controlling the Casimir stiction problem in micromechanical devices.

  17. CP Violating Baryon Oscillations

    OpenAIRE

    McKeen, David; Nelson, Ann E.

    2015-01-01

    We analyze neutron-antineutron oscillation in detail, developing a Hamiltonian describing the system in the presence of electromagnetic fields. While magnetic fields can couple states of different spin, we show that, because of Fermi statistics, this coupling of different spin states does not involve baryon-number--changing transitions and, therefore, a two-state analysis ignoring spin is sufficient even in the presence of electromagnetic fields. We also enumerate the conditions necessary for...

  18. Reconstructing baryon oscillations

    OpenAIRE

    Noh, Yookyung; White, Martin; Padmanabhan, Nikhil

    2009-01-01

    The baryon acoustic oscillation (BAO) method for constraining the expansion history is adversely affected by non-linear structure formation, which washes out the correlation function peak created at decoupling. To increase the constraining power of low z BAO experiments, it has been proposed that one use the observed distribution of galaxies to "reconstruct'' the acoustic peak. Recently Padmanabhan, White and Cohn provided an analytic formalism for understanding how reconstruction works withi...

  19. Coronal Waves and Oscillations

    OpenAIRE

    Nakariakov Valery M.; Verwichte Erwin

    2005-01-01

    Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD) wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves), theoretical modelling of interactio...

  20. Neutrino Oscillations for Dummies

    OpenAIRE

    Waltham, Chris

    2003-01-01

    The reality of neutrino oscillations has not really sunk in yet. The phenomenon presents us with purely quantum mechanical effects over macroscopic time and distance scales (milliseconds and 1000s of km). In order to help with the pedagogical difficulties this poses, I attempt here to present the physics in words and pictures rather than math. No disrespect is implied by the title; I am merely borrowing a term used by a popular series of self-help books.

  1. Coupled Oscillators with Chemotaxis

    CERN Document Server

    Sawai, S; Sawai, Satoshi; Aizawa, Yoji

    1998-01-01

    A simple coupled oscillator system with chemotaxis is introduced to study morphogenesis of cellular slime molds. The model successfuly explains the migration of pseudoplasmodium which has been experimentally predicted to be lead by cells with higher intrinsic frequencies. Results obtained predict that its velocity attains its maximum value in the interface region between total locking and partial locking and also suggest possible roles played by partial synchrony during multicellular development.

  2. Polychromatic optical Bloch oscillations.

    Science.gov (United States)

    Longhi, Stefano

    2009-07-15

    Bloch oscillations (BOs) of polychromatic beams in circularly curved optical waveguide arrays are smeared out owing to the dependence of the BO spatial period on the wavelength. Here it is shown that restoring of the self-imaging property of the array and approximate BOs over relatively broad spectral ranges can be achieved by the insertion of suitable lumped phase slips uniformly applied across the array.

  3. Pyridoxine treatment alters embryonic motility in chicks: Implications for the role of proprioception.

    Science.gov (United States)

    Sharp, Andrew A; Bekoff, Anne

    2015-03-01

    Somatosensory feedback is important for the modulation of normal locomotion in adult animals, but we do not have a good understanding of when somatosensory information is first used to modulate motility during embryogenesis or how somatosensation is first used to regulate motor output. We used pyridoxine administration (vitamin B6 ), which is known to mostly kill proprioceptive neurons in adult mammals and embryonic chicks, to explore the role of proprioceptive feedback during early embryonic motility in the chick. Injection of pyridoxine on embryonic day 7 (E7) and E8 reduced the amplitude of leg movements recorded on E9 and the number of large, healthy neurons in the ventral-lateral portion of the DRGs. We conclude that proprioception is initially used during embryogenesis to modulate the strength of motor output, but that it is not incorporated into other aspects of pattern generation until later in development as poly-synaptic pathways develop. PMID:25645095

  4. Eradication of Salmonella Typhimurium in broiler chicks by combined use of P22 bacteriophage and probiotic

    Directory of Open Access Journals (Sweden)

    Guilherme Augusto Marietto Gonçalves

    2011-06-01

    Full Text Available It has been reported that the phage therapy is effective in controlling the number of colony-forming unit (CFU of Salmonella spp. in chicken gut. This paper describes the protective effect of phage and Lactobacilli administration on Salmonella infection in 1-day-old chicks. We administered the bacteriophage P22 in a single dose and a probiotic mixture of four species of bacteriocin-producing Lactobacillus once a day for one week. Samples were analyzed every 48 hours, and intestinal eradication of S. Typhimurium was confirmed after treatments. We observed an increase in the size of duodenal villi and cecal crypts, as well as an increase in body weight in groups that received daily doses of Lactobacilli. This study confirms the efficiency of bacteriophage therapy in controlling salmonellosis in chicks and the beneficial effect of Lactobacilli mixtures in the weight gain of the birds.

  5. A Simple Method for Enema Administration in One-Day-Old Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Guilherme Augusto Marietto-Gonçalves

    2012-01-01

    Full Text Available The present study aimed to describe a simple technique for enema administration in one-day-old broiler chicks. For this purpose we used 455 unsexed health birds divided into four groups submitted to three different experimental protocols: in the first one, we measured the total length of the large intestine in order to establish a secure distance for probe introduction; in the second, we evaluated maximum compliance of large intestine and diffusion range; finally, based on results obtained we tested the hypothesis in 400 birds in order to standardize the method. Enema solutions applied in an intrarectal manner with a stainless steel gavage BD-10 probe into one-day-old broiler chicks at 0.2 mL at a distance of 1.5 cm proved to be a reliable method.

  6. Temperature sensitive oscillator

    Science.gov (United States)

    Kleinberg, L. L. (Inventor)

    1986-01-01

    An oscillator circuit for sensing and indicating temperature by changing oscillator frequency with temperature comprises a programmable operational amplifier which is operated on the roll-off portion of its gain versus frequency curve and has its output directly connected to the inverting input to place the amplifier in a follower configuration. Its output is also connected to the non-inverting input by a capacitor with a crystal or other tuned circuit also being connected to the non-inverting input. A resistor is connected to the program input of the amplifier to produce a given set current at a given temperature, the set current varying with temperature. As the set current changes, the gain-bandwidth of the amplifier changes and, in turn, the reflected capacitance across the crystal changes, thereby providing the desired change in oscillator frequency by pulling the crystal. There is no requirement that a crystal employed with this circuit display either a linear frequency change with temperature or a substantial frequency change with temperature.

  7. Coupled Classical and Quantum Oscillators

    CERN Document Server

    McDermott, R M; Dermott, Rachael M. Mc; Redmount, Ian H.

    2004-01-01

    Some of the most enduring questions in physics--including the quantum measurement problem and the quantization of gravity--involve the interaction of a quantum system with a classical environment. Two linearly coupled harmonic oscillators provide a simple, exactly soluble model for exploring such interaction. Even the ground state of a pair of identical oscillators exhibits effects on the quantum nature of one oscillator, e.g., a diminution of position uncertainty, and an increase in momentum uncertainty and uncertainty product, from their unperturbed values. Interaction between quantum and classical oscillators is simulated by constructing a quantum state with one oscillator initially in its ground state, the other in a coherent or Glauber state. The subsequent wave function for this state is calculated exactly, both for identical and distinct oscillators. The reduced probability distribution for the quantum oscillator, and its position and momentum expectation values and uncertainties, are obtained from thi...

  8. Nonlinear Oscillators in Space Physics

    Science.gov (United States)

    Lester,Daniel; Thronson, Harley

    2011-01-01

    We discuss dynamical systems that produce an oscillation without an external time dependent source. Numerical results are presented for nonlinear oscillators in the Em1h's atmosphere, foremost the quasi-biennial oscillation (QBOl. These fluid dynamical oscillators, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has particular form. of 3rd or odd power. It is shown that this form of nonlinearity can produce the fundamental li'equency of the internal oscillation. which has a period that is favored by the dynamical condition of the fluid. The fundamental frequency maintains the oscillation, with no energy input to the system at that particular frequency. Nonlinearities of 2nd or even power could not maintain the oscillation.

  9. EFFECT OF DIETARY LEVELS OF SPEARMINT (Mentha spicata) ON BROILER CHICKS PERFORMANCE

    OpenAIRE

    E.O. AMASAIB; B.H. ABD ELRAHMAN; Abdelhameed, A A; B.A. ATTA ELMNAN; A.G. MAHALA

    2013-01-01

    This study was conducted to determine the effect of addition different levels of spearmint (Mentha spicata) on broiler chick’s performance. One hundred and twenty eight day old unsexed (Cobb) broiler chicks were used in this experiment. Birds were distributed randomly into 16 pens (8/pen) as replicates, in a complete randomized design. The experimental diets were formulated with four levels of spearmint (Mentha spicata) of 0, 1, 1.5 and 2%. Feed and water were freely accessed. Feed intake, bo...

  10. Effects of magnesium and high dietary intakes of pyridoxine on the chick.

    Science.gov (United States)

    Rogerson, G; Singsen, E P

    1976-05-01

    Day-old broiler-type male chicks were used to determine what effects magnesium and high dietary pyridoxine had on the chick's performance. The chicks were randomly assigned to 15 treatments of magnesium at 875, 1375 and 1875 mg/kg. diet and pyridoxine at 1, 4, 31, 301, and 3001 mg/kg. diet in a 3 x 5 factorial block design. A regression was used to study some of the criteria. The highest mortality of 20% occurred in chicks on the 1875 mg. magnesium-3001 mg. pyridoxine treatment. Magnesium and pyridoxine had highly significant effects on body moisture. Effects due to magnesium and pyridoxine and the interaction between the two were highly significant for weight gain and the efficiency of feed utilization (E.F.U.) At 1875 mg. magnesium/kg diet, maximum growth response and E.F.U. were predicted to occur on 10 and 39 mg pyridoxine/kg diet, respectively, Neither magnesium nor the interaction between magnesium and pyridoxine had any significant effect on carcass protein. Pyridoxine had a highly significant effect on carcass protein. Maximum response in carcass protein occurred at 31 mg. pyridoxine/kg diet irrespective of magnesium level. Serum aminotransferase activity (S.A) was significant for magnesium, pyridoxine and the interaction between the two. Pyridoxine requirement for maximum S.A. was 49 mg/kg diet at 1875 mg magnesium/kg diet. Pyridoxine requirement for maximum response was highest for S.A. and least for growth. But S.A. had the highest R2 whereas growth had the least.

  11. Pyridoxine Treatment Alters Embryonic Motility in Chicks: Implications for the Role of Proprioception

    OpenAIRE

    Sharp, Andrew A.; Bekoff, Anne

    2015-01-01

    Somatosensory feedback is important for the modulation of normal locomotion in adult animals, but we do not have a good understanding of when somatosensory information is first used to modulate motility during embryogenesis or how somatosensation is first used to regulate motor output. We used pyridoxine administration (vitamin B6), which is known to mostly kill proprioceptive neurons in adult mammals and embryonic chicks, to explore the role of proprioceptive feedback during early embryonic ...

  12. Neuromuscular activity of Bothrops alcatraz snake venom in chick biventer cervicis preparations.

    Science.gov (United States)

    de Moraes, Delkia Seabra; Aparecido de Abreu, Valdemir; Rostelato-Ferreira, Sandro; Leite, Gildo B; Alice da Cruz-Höfling, Maria; Travaglia-Cardoso, Silvia R; Hyslop, Stephen; Rodrigues-Simioni, Léa

    2012-02-01

    Venom (10-100 μg/ml) from Bothrops alcatraz, a pitviper from the Alcatrazes Archipelago off the coast of southeastern Brazil, caused progressive, irreversible neuromuscular blockade in chick isolated biventer cervicis preparations. The venom also inhibited contractures to exogenous ACh (110 μM) and KCl (20 mM), caused myofiber damage and increased creatine kinase release. Commercial bothropic antivenom raised against mainland Bothrops species neutralized the neuromuscular activity, depending on the venom concentration. PMID:22155137

  13. Energy and Protein Requirements for - to -Week-Age Gushi Chicks

    Institute of Scientific and Technical Information of China (English)

    KANG Xiang-tao; TIAN Ya-dong; SONG Su-fang

    2002-01-01

    In this experiment, 540 male and female chicks of 1-day-age were selected respectively and reared separately. 3 × 3 factorial experiment was designed. Gushi chicks were fed with nine diets under different metabolizable energy (ME) and crude protein (CP). Effects of different diets on the performances and carcass ingredients of 0-to 4-week-age Gushi chicks were studied by rearing, comparative slaughter and metabolism experiments. Based on the results of three experiments, ME intake per kilogram metabolic weight was regarded as dependent variable (Y), and its corresponding net energy (NE) deposition per kilogram metabolic weight was regarded as independent variable (X), respectively. Lineal regressive analysis was made according to the mathematic model: Y=a+bX. Maintenance ME(MEm) and the converted coefficient from net energy for gain(NEg) to ME for gain(MEg) were found out, then ME requirement was divided into MErm+ MEg,which is ME = 359.14 W0.75 + 10.47/△W; CP intake and corresponding metabolic weight were regarded as dependent variable and independent variable respectively, and then regressive analysis was made. The result was CP = 0. 57 + 8.21 W0.75. Consequently, average daily gain (ADG), average daily feed intake and metabolic weight were put into the regressive equations, and then ME and CP requirements for 0- to 4-week-age Gushi chicks were obtained, 12.38 MJ kg-1 and 20.13%, respectively, the ratio of CP to ME was 16.26 g MJ-1.

  14. Low dose trichloroethylene alters cytochrome P450 - 2C subfamily expression in the developing chick heart

    OpenAIRE

    Makwana, Om; Ahles, Lauren; Lencinas, Alejandro; Selmin, Ornella I.; Runyan, Raymond B.

    2013-01-01

    Trichloroethylene (TCE) is an organic solvent and common environmental contaminant. TCE exposure is associated with heart defects in humans and animal models. Primary metabolism of TCE in adult rodent models is by specific hepatic cytochrome P450 enzymes (Lash et al., 2000). As association of TCE exposure with cardiac defects is in exposed embryos prior to normal liver development, we investigated metabolism of TCE in the early embryo. Developing chick embryos were dosed in ovo with environme...

  15. Effect of Enzyme Supplementation and Irradiation of Barley on Broiler Chicks Performance

    International Nuclear Information System (INIS)

    The experiments were conducted to study the influence of irradiation treatment at dose levels of 0.20 and 60 kGy on barley beta-glucan and the effect of enzyme supplementation and irradiation of barley on broiler chicks performance. The amount of total and water-soluble beta-glucan in raw barley was 36 kg-1, respectively. The effect of irradiation treatment on total beta-glucan was insignificant while the level of soluble beta-glucan was increased with increasing the dose levels of irradiation. The effect of irradiation treatment and enzyme supplementation of barley diets on growth and conversion performance of broiler chicks indicated that birds fed raw barley diet had lower body weight, body weight gain and feed conversion than those fed control diet throughout the experimental period. Irradiation of barley at dose of 20 kGy did not affect the chick performance (feed consumption, weight gain feed-gain ratio) that received the B 20 diet from 7 to 21 days of age, but when bird maintained on B 20 diet from 7 28 days of age, only feed-gain ratio was improved by 14.4%. The results indicate that there was a significant effect of irradiation of barley at 60 kGy (B 60) on feed -gain ratio of chicks when were fed B 60 diet from 7 to 21 days of age. The corresponding improvement in feed-gain ratio was 16.4%. When birds were fed B 60 diet from 7-28 days of age, the improvement in body weight and feed-gain ratio was 25.5 and 19.6%, respectively

  16. Endocrine cells in atresic chick embryo intestine: histochemical and immunohistochemical study

    Directory of Open Access Journals (Sweden)

    T. Renda

    2009-09-01

    Full Text Available Intestinal motility disorders are an important problem in the postoperative management of patients with intestinal atresia. Intestinal motility could be initiated by luminal factors that activate intrinsic and extrinsic primary afferent nerves involved in the peristaltic reflex. Endocrine cells act as a key point, because they transfer information regarding the intestinal contents and intraluminal pressure to nerve fibers lying in close proximity to the basolateral surface of the epithelium. In chick embryo, experimental intestinal atresia is associated with disorders in the development of the enteric nervous system, related to the severity of intestinal dilation. Our aim was to investigate the distribution pattern of endocrine cells in the developing endocrine system of chick embryo small intestine with experimentally-induced atresia on day 12 and on day 16. Changes in enteroendocrine population were examined in gut specimens (excised proximal and distal to the atresia from experimental embryos 19 days old and in control sham-operated chick embryos at the same age. Sections from proximal and distal bowel and control bowel were stained with Grimelius silver stain, a valuable histochemical method for detecting the argyrophil and argentophilic cells, and with an immunohistochemical procedure for detecting serotonin and neurotensin immunoreactive cells. In chick embryo proximal bowel, intestinal dilation differed in the various embryos. We found significantly higher enteroendocrine cell counts in proximal bowel than in distal and control bowel. The differences depended on the precociousness of surgery and the severity of dilation. Considering the major contribution of enteroendocrine cells to the peristaltic reflex, our data may help to explain the pathogenesis of motility disorders related to intestinal atresia.

  17. Effects of white light on the pineal gland of the chick embryo

    OpenAIRE

    Aige-Gil, Vicente; Murillo-Ferrol, Narciso

    1992-01-01

    Chick embryos were directly exposed to a source of white light during incubation and sacrificed before hatching. The light caused a number of teratological effects such as high mortality, delay in development, celosomy, hepatomegaly, auricular dilation and micrognatia. The pineal gland of the illuminated embryos showed an increase in number and size of the intracytoplasmic lipid droplets of the follicular pinealocytes. These findings suggest that the pineal...

  18. Developmental changes of Insulin-like growth factors in the liver and muscle of chick embryos.

    Science.gov (United States)

    Liu, Yanli; Guo, Wei; Pu, Zhenyu; Li, Xueyuan; Lei, Xinyu; Yao, Junhu; Yang, Xiaojun

    2016-06-01

    The insulin-like growth factors ( IGFS: ) are synthesized in tissues and play an important role in embryonic development of avian via autocrine/paracrine mechanisms. In the study, mRNA expression of IGFs were detected by real-time PCR in the muscle and liver from d 10 to 20 of chick embryo ( E10: to E20: ). Methylation of IGF1 promoter in the muscle was analyzed by bisulfite sequencing PCR as well as IGF2 promoter in the liver. These results showed that there was obviously IGF1 expression in liver at E19 and E20. The higher IGF1 expression in muscle was found during E15 to E18 with the peak on E17, and then declined. Correspondingly, the lowest methylation level of IGF1 promoter was detectable on the same embryonic d 17. Expression of IGF2 in muscle increased gradually during embryonic growth and showed higher level in the later stages (E17 to E20) when IGF1 expression began to decrease. IGF2 expression in liver reached the first peak on E14, then declined but gradually elevated from E17. IGF2 promoter methylation in liver showed gradual decline on d 12, 15, 17 and 19 of incubation, meanwhile IGF2 expression of liver increased gradually. These results suggested that IGF1 and IGF2 might separately be more important for muscle and liver growth in chick embryonic development. Variation of IGFs expression during the incubation might be concerned with the methylation of gene promoter. The profile of IGFs expression in chick embryonic tissues may be meaningful for understanding organ growth and embryonic development in chick. PMID:26944971

  19. Developmental changes of Insulin-like growth factors in the liver and muscle of chick embryos.

    Science.gov (United States)

    Liu, Yanli; Guo, Wei; Pu, Zhenyu; Li, Xueyuan; Lei, Xinyu; Yao, Junhu; Yang, Xiaojun

    2016-06-01

    The insulin-like growth factors ( IGFS: ) are synthesized in tissues and play an important role in embryonic development of avian via autocrine/paracrine mechanisms. In the study, mRNA expression of IGFs were detected by real-time PCR in the muscle and liver from d 10 to 20 of chick embryo ( E10: to E20: ). Methylation of IGF1 promoter in the muscle was analyzed by bisulfite sequencing PCR as well as IGF2 promoter in the liver. These results showed that there was obviously IGF1 expression in liver at E19 and E20. The higher IGF1 expression in muscle was found during E15 to E18 with the peak on E17, and then declined. Correspondingly, the lowest methylation level of IGF1 promoter was detectable on the same embryonic d 17. Expression of IGF2 in muscle increased gradually during embryonic growth and showed higher level in the later stages (E17 to E20) when IGF1 expression began to decrease. IGF2 expression in liver reached the first peak on E14, then declined but gradually elevated from E17. IGF2 promoter methylation in liver showed gradual decline on d 12, 15, 17 and 19 of incubation, meanwhile IGF2 expression of liver increased gradually. These results suggested that IGF1 and IGF2 might separately be more important for muscle and liver growth in chick embryonic development. Variation of IGFs expression during the incubation might be concerned with the methylation of gene promoter. The profile of IGFs expression in chick embryonic tissues may be meaningful for understanding organ growth and embryonic development in chick.

  20. Gene transfer to chicks using lentiviral vectors administered via the embryonic chorioallantoic membrane.

    Directory of Open Access Journals (Sweden)

    Gideon Hen

    Full Text Available The lack of affordable techniques for gene transfer in birds has inhibited the advancement of molecular studies in avian species. Here we demonstrate a new approach for introducing genes into chicken somatic tissues by administration of a lentiviral vector, derived from the feline immunodeficiency virus (FIV, into the chorioallantoic membrane (CAM of chick embryos on embryonic day 11. The FIV-derived vectors carried yellow fluorescent protein (YFP or recombinant alpha-melanocyte-stimulating hormone (α-MSH genes, driven by the cytomegalovirus (CMV promoter. Transgene expression, detected in chicks 2 days after hatch by quantitative real-time PCR, was mostly observed in the liver and spleen. Lower expression levels were also detected in the brain, kidney, heart and breast muscle. Immunofluorescence and flow cytometry analyses confirmed transgene expression in chick tissues at the protein level, demonstrating a transduction efficiency of ∼0.46% of liver cells. Integration of the viral vector into the chicken genome was demonstrated using genomic repetitive (CR1-PCR amplification. Viability and stability of the transduced cells was confirmed using terminal deoxynucleotidyl transferase (dUTP nick end labeling (TUNEL assay, immunostaining with anti-proliferating cell nuclear antigen (anti-PCNA, and detection of transgene expression 51 days post transduction. Our approach led to only 9% drop in hatching efficiency compared to non-injected embryos, and all of the hatched chicks expressed the transgenes. We suggest that the transduction efficiency of FIV vectors combined with the accessibility of the CAM vasculature as a delivery route comprise a new powerful and practical approach for gene delivery into somatic tissues of chickens. Most relevant is the efficient transduction of the liver, which specializes in the production and secretion of proteins, thereby providing an optimal target for prolonged study of secreted hormones and peptides.

  1. Synthesis of type III collagen by fibroblasts from the embryonic chick cornea

    OpenAIRE

    1980-01-01

    Synthesis of collagen types I, II, III, and IV in cells from the embryonic chick cornea was studied using specific antibodies and immunofluorescence. Synthesis of radioactively labeled collagen types I and III was followed by fluorographic detection of cyanogen bromide peptides on polyacrylamide slab gels and by carboxymethylcellulose chromatography followed by disc gel electrophoresis. Type III collagen had been detected previously by indirect immunofluorescence in the corneal epithelial cel...

  2. Pineal melatonin acts as a circadian zeitgeber and growth factor in chick astrocytes

    OpenAIRE

    Paulose, Jiffin K.; Peters, Jennifer L.; Karaganis, Stephen P.; Cassone, Vincent M.

    2009-01-01

    Melatonin is rhythmically synthesized and released by the avian pineal gland and retina during the night, targeting an array of tissues and affecting a variety of physiological and behavioral processes. Among these targets, astrocytes express two melatonin receptor subtypes in vitro, the Mel1A and Mel1C receptors, which play a role in regulating metabolic activity and calcium homeostasis in these cells. Molecular characterization of chick astrocytes has revealed the expression of orthologs of...

  3. Automated Analysis of Behavioural Variability and Filial Imprinting of Chicks (G. gallus), using Autonomous Robots

    OpenAIRE

    Gribovskiy, A.; Mondada, F.; Deneubourg, J. L.; Cazenille, L.; Bredeche, N.; Halloy, J.

    2015-01-01

    Inter-individual variability has various impacts in animal social behaviour. This implies that not only collective behaviours have to be studied but also the behavioural variability of each member composing the groups. To understand those effects on group behaviour, we develop a quantitative methodology based on automated ethograms and autonomous robots to study the inter-individual variability among social animals. We choose chicks of \\textit{Gallus gallus domesticus} as a classic social ani...

  4. High-resolution Magnetic Resonance Imaging analysis of breast cancer xenograft on the chick chorioallantoic membrane

    OpenAIRE

    ZUO, ZHI

    2015-01-01

    In this thesis an age-adapted cooling regime for immobilization of the chick embryo is proposed. Reliable immobilization completely avoided motion artifacts, enabling high resolution magnetic resonance imaging (MRI) of the chicken embryo and also tumor xenograft on the chorioallantoic membrane (CAM). Tumor growth monitoring was firstly evaluated after xenotransplantation of MDA-MB-231 cells on the CAM. Tumor volumes were monitored from day 4 to day 9 after grafting applying a T2-weighted R...

  5. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae)

    OpenAIRE

    Klenova, Anna V.

    2015-01-01

    Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous sp...

  6. Behavioral and physiological responses to male handicap in chick-rearing black-legged kittiwakes

    Science.gov (United States)

    Leclaire, S.; Bourret, V.; Wagner, R.H.; Hatch, Shyla A.; Helfenstein, F.; Chastel, O.; Danchin, E.

    2011-01-01

    Parental investment entails a trade-off between the benefits of effort in current offspring and the costs to future reproduction. Long-lived species are predicted to be reluctant to increase parental effort to avoid affecting their survival. We tested this hypothesis in black-legged kittiwakes Rissa tridactyla by clipping flight feathers of experimental males at the beginning of the chick-rearing period. We analyzed the consequences of this handicap on feeding and attendance behavior, body condition, integument coloration, and circulating levels of corticosterone and prolactin in handicapped males and their mates in comparison to unmanipulated controls. Chicks in both groups were compared in terms of aggressive behavior, growth, and mortality. Handicapped males lost more mass, had less bright integuments, and attended the nest less often than controls. Nevertheless, they fed their chicks at the same rate and had similar corticosterone and prolactin levels. Compared with control females, females mated with handicapped males showed a lower provisioning rate and higher nest attendance in the first days after manipulation. Their lower feeding rate probably triggered the increased sibling aggression and mortality observed in experimental broods. Our findings suggest that experimental females adaptively adjusted their effort to their mate's perceived quality or that their provisioning was constrained by their higher nest attendance. Overall, our results suggest that kittiwake males can decrease their condition for the sake of their chicks, which seems to contradict the hypothesis that kittiwakes should be reluctant to increase parental effort to avoid affecting their survival. ?? 2011 The Author. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

  7. Increased Intracellular [dATP] Enhances Cardiac Contraction in Embryonic Chick Cardiomyocytes

    OpenAIRE

    Schoffstall, Brenda; Chase, P. Bryant

    2008-01-01

    Although ATP is the physiological substrate for cardiac contraction, cardiac contractility is significantly enhanced in vitro when only 10% of ATP substrate is replaced with 2’-deoxy-ATP (dATP). To determine the functional effects of increased intracellular [dATP] ([dATP]i) within living cardiac cells, we used hypertonic loading with varying exogenous dATP/ATP ratios, but constant total nucleotide concentration, to elevate [dATP]i in contractile monolayers of embryonic chick cardiomyocytes. T...

  8. A receptor that is highly specific for extracellular ATP in developing chick skeletal muscle in vitro.

    OpenAIRE

    Thomas, S A; Zawisa, M. J.; Lin, X.; Hume, R. I.

    1991-01-01

    1. Extracellular adenosine 5'-triphosphate (ATP) activated an early excitatory conductance followed by a late potassium conductance in developing chick skeletal muscle. A series of ATP analogues were tested for their ability to activate these two conductances. All compounds tested were either agonists for both responses or for neither. Furthermore, the potency of agonists was similar for the two responses. 2. The order of potency for agonists was ATP approximately adenosine 5'-O-(3-thiotripho...

  9. From high heels to weed attics: a syntactic investigation of chick lit and literature

    OpenAIRE

    Jautze, K.J.; Koolen, C.W.; Cranenburgh, Andreas van; de Jong, H.A.

    2013-01-01

    Stylometric analysis of prose is typically limited to classification tasks such as authorship attribution. Since the models used are typically black boxes, they give little insight into the stylistic diff erences they detect. In this paper, we characterize two prose genres syntactically: chick lit (humorous novels on the challenges of being a modern-day urban female) and high literature. First, we develop a top-down computational method based on existing literary-linguistic theory. Using an o...

  10. Neurochemical phenotype and birthdating of specific cell populations in the chick retina

    OpenAIRE

    Karin da Costa calaza; Patricia F. Gardino

    2010-01-01

    The chick embryo is one of the most traditional models in developing neuroscience and its visual system has been one of the most exhaustively studied. The retina has been used as a model for studying the development of the nervous system. Here, we describe the morphological features that characterize each stage of the retina development and studies of the neurogenesis period of some specific neurochemical subpopulations of retinal cells by using a combination of immunohistochemistry and autor...

  11. Expansion, folding, and abnormal lamination of the chick optic tectum after intraventricular injections of FGF2

    OpenAIRE

    McGowan, Luke D.; Alaama, Roula A.; Freise, Amanda C.; Huang, Johnny C.; Charvet, Christine J.; Georg F Striedter

    2012-01-01

    Comparative research has shown that evolutionary increases in brain region volumes often involve delays in neurogenesis. However, little is known about the influence of such changes on subsequent development. To get at this question, we injected FGF2—which delays cell cycle exit in mammalian neocortex—into the cerebral ventricles of chicks at embryonic day (ED) 4. This manipulation alters the development of the optic tectum dramatically. By ED7, the tectum of FGF2-treated birds is abnormally ...

  12. Intra- and extracellular calcium modulates stereocilia stiffness on chick cochlear hair cells.

    OpenAIRE

    Pae, S S; Saunders, J. C.

    1994-01-01

    Segments of the chick basilar papilla were isolated and maintained in culture medium. The sensory hair bundle of individual hair cells was observed with light microscopy and stimulated with a water microjet at 600 Hz. Hair bundle motion was slowed by illuminating the microscope with stroboscopic light, and water jet intensity was systematically varied in decibel (dB) steps until a visual detection level (VDL) threshold of hair bundle motion was achieved. The VDL threshold of many hair cells w...

  13. The control of chick myoblast fusion by ion channels operated by prostaglandins and acetylcholine

    OpenAIRE

    1988-01-01

    Chick myoblast fusion in culture was investigated using prostanoid synthesis inhibitors to delay spontaneous fusion. During this delay myoblast fusion could be induced by prostaglandin E1 (PGE1), by raising extracellular potassium and by addition of carbachol. Carbachol-induced fusion, but not PGE-induced fusion, was prevented by the acetylcholine receptor blocker alpha-bungarotoxin. Fusion induced by any of these agents was prevented by the Ca channel blockers lanthanum and D600. The thresho...

  14. Biochemical and cytochemical evidence indicates that coated vesicles in chick embryo myotubes contain newly synthesized acetylcholinesterase

    OpenAIRE

    1985-01-01

    We have isolated highly purified coated vesicles from 17-d-old chick embryo skeletal muscle. These isolated coated vesicles contain acetylcholinesterase (AChE) in a latent, membrane-protected form as demonstrated enzymatically and morphologically using the Karnovsky and Roots histochemical procedure (J. Histochem. Cytochem., 1964, 12:219- 221). By the use of appropriate inhibitors the cholinesterase activity can be shown to be specific for acetylcholine. It also can be concluded that most of ...

  15. Systematic assessment of blood circulation time of functionalized upconversion nanoparticles in the chick embryo

    Science.gov (United States)

    Nadort, Annemarie; Liang, Liuen; Grebenik, Ekaterina; Guller, Anna; Lu, Yiqing; Qian, Yi; Goldys, Ewa; Zvyagin, Andrei

    2015-12-01

    Nanoparticle-based delivery of drugs and contrast agents holds great promise in cancer research, because of the increased delivery efficiency compared to `free' drugs and dyes. A versatile platform to investigate nanotechnology is the chick embryo chorioallantoic membrane tumour model, due to its availability (easy, cheap) and accessibility (interventions, imaging). In our group, we developed this model using several tumour cell lines (e.g. breast cancer, colon cancer). In addition, we have synthesized in-house silica coated photoluminescent upconversion nanoparticles with several functional groups (COOH, NH2, PEG). In this work we will present the systematic assessment of their in vivo blood circulation times. To this end, we injected chick embryos grown ex ovo with the functionalized UCNPs and obtained a small amount of blood at several time points after injection to create blood smears The UCNP signal from the blood smears was quantified using a modified inverted microscope imaging set-up. The results of this systematic study are valuable to optimize biochemistry protocols and guide nanomedicine advancement in the versatile chick embryo tumour model.

  16. Avian leukosis virus subgroup J triggers caspase-1-mediated inflammatory response in chick livers.

    Science.gov (United States)

    Liu, Xue-lan; Shan, Wen-jie; Jia, Li-juan; Yang, Xu; Zhang, Jin-jing; Wu, Ya-rong; Xu, Fa-zhi; Li, Jin-nian

    2016-04-01

    Many pathogens trigger caspase-1-mediated innate immune responses. Avian leukosis virus subgroup J (ALV-J) causes serious immunosuppression and diverse tumors in chicks. The caspase-1 inflammasome mechanism of response to ALV-J invading remains unclear. Here we investigated the expression of caspase-1, the inflammasome adaptor NLRP3, IL-1β and IL-18 in response to ALV-J infection in the liver of chick. We found caspase-1 mRNA expression was elevated at 5 dpi and peaked at 7 dpi in ALV-J infected animals. Corresponding to this, the expressions of NLRP3 and proinflammatory cytokines IL-1β and IL-18 were significantly increased at 5 or 7 dpi. In addition, caspase-1 protein expression and inflammatory cell infiltration were induced after virus infection. These results indicated that ALV-J infection could trigger the caspase-1- mediated inflammatory response in chicks. Thus, an understanding of the inflammatory responses can provide a better insight into the pathogenicity of ALV-J and a possible anti-virus target for ALV-J infection.

  17. Die Fledermaus: regarding optokinetic contrast sensitivity and light-adaptation, chicks are mice with wings.

    Directory of Open Access Journals (Sweden)

    Qing Shi

    Full Text Available BACKGROUND: Through adaptation, animals can function visually under an extremely broad range of light intensities. Light adaptation starts in the retina, through shifts in photoreceptor sensitivity and kinetics plus modulation of visual processing in retinal circuits. Although considerable research has been conducted on retinal adaptation in nocturnal species with rod-dominated retinas, such as the mouse, little is known about how cone-dominated avian retinas adapt to changes in mean light intensity. METHODOLOGY/PRINCIPAL FINDINGS: We used the optokinetic response to characterize contrast sensitivity (CS in the chick retina as a function of spatial frequency and temporal frequency at different mean light intensities. We found that: 1 daytime, cone-driven CS was tuned to spatial frequency; 2 nighttime, presumably rod-driven CS was tuned to temporal frequency and spatial frequency; 3 daytime, presumably cone-driven CS at threshold intensity was invariant with temporal and spatial frequency; and 4 daytime photopic CS was invariant with clock time. CONCLUSION/SIGNIFICANCE: Light- and dark-adaptational changes in CS were investigated comprehensively for the first time in the cone-dominated retina of an avian, diurnal species. The chick retina, like the mouse retina, adapts by using a "day/night" or "cone/rod" switch in tuning preference during changes in lighting conditions. The chick optokinetic response is an attractive model for noninvasive, behavioral studies of adaptation in retinal circuitry in health and disease.

  18. Maternal Antibody Protected Chicks from Growth Retardation and Immunosuppression Induced by Early Reticuloendotheliosis Virus Infection

    Institute of Scientific and Technical Information of China (English)

    SUN Shu-hong; GUI Zhi-zhong; QU Li-xin

    2007-01-01

    To determine if the maternal antibody from breeders vaccinated with cell culture-adapted reticuloendotheliosis virus (REV) could protect chicks from early REV infection, one-day-old chicks with or without anti-REV maternal antibodies were inoculated with REV, and then their growth rates and antibody tilers to Newcastle disease virus (NDV) and avian influenza virus (AIV), after vaccination with inactivated vaccines, were compared. This study indicated that REV infection could cause growth retardation and severely inhibit immune reactions to inactivated vaccines against NDV and Avian influenza virus (AIV, H9 and H5) in one-day-old broilers without maternal antibodies specific to REV. Maternal antibody from breeders vaccinated with an attenuated REV vaccine effectively protected REV-challenged birds from growth retardation and immunosuppression on antibody reactions to NDV and AIV vaccines. Four weeks after vaccination, the HI liters to NDV, AIV-H9, and AIV-H5 in maternal antibody positive and negative groups were 3.36±2.04 versus 1.58±1.69 (P<0.01), 6.27±3.87 versus 0.71±1.60(P<0.01), and 6.72 versus 0.54±1.44(p<0.01). Maternal antibodies from breeders vaccinated with REV vaccine could successfully protect chicks from REV infection and effectively prevent REV-induced growth retardation and immunosuppression in antibody responses to NDV and AIV.

  19. Who is who? Non-invasive methods to individually sex and mark altricial chicks.

    Science.gov (United States)

    Adam, Iris; Scharff, Constance; Honarmand, Mariam

    2014-01-01

    Many experiments require early determination of offspring's sex as well as early marking of newborns for individual recognition. According to animal welfare guidelines, non-invasive techniques should be preferred whenever applicable. In our group, we work on different species of song birds in the lab and in the field, and we successfully apply non-invasive methods to sex and individually mark chicks. This paper presents a comprehensive non-invasive tool-box. Sexing birds prior to the expression of secondary sexual traits requires the collection of DNA-bearing material for PCR. We established a quick and easy method to sex birds of any age (post hatching) by extracting DNA from buccal swabs. Results can be obtained within 3 hours. For individual marking chick's down feathers are trimmed in specific patterns allowing fast identification within the hatching order. This set of methods is easily applicable in a standard equipped lab and especially suitable for working in the field as no special equipment is required for sampling and storage. Handling of chicks is minimized and marking and sexing techniques are non-invasive thereby supporting the RRR-principle of animal welfare guidelines. PMID:24893585

  20. Productivity and Composition of Fatty Acids in Chicks fed with Azadirachta indica A. Juss

    Directory of Open Access Journals (Sweden)

    Imna Trigueros V

    2015-05-01

    Full Text Available ABSTRACT Objective. Evaluate the productivity and composition of fatty acids in chicks fed diets enriched with neem Azadirachta indica A. Juss seed flour. Materials and methods. 80 mixed broiler chicks of Arbor Acres stock and levels 0, 1, 3 and 5% neem seed flour added to a commercial diet were evaluated. 20 experimental units were included in each treatment for five weeks. The consumption and weight gain were recorded, as well as the composition of fatty acids in the fat by means of alkaline transesterification. Data was statistically analyzed by a completely random procedure and the measurements were compared with the Tukey test(p≤0.05. Results. The greatest weight gain, consumption and best feed conversion were found in the treatment that contains 1% neem seed flour. It also produced the increase in the proportion of polyunsaturated fatty acids, especially linoleic acid (C18:2 Omega-6 and eicosapentaenoic acid (C20:5 omega-3, and the proportion of palmitic acid (C16:0. The consumption of feed diminished when 5% of neem flour was added. Conclusions. It was demonstrated that incorporating 1% neem seed flour in the diet of broiler chicks modifies the consumption of fatty acids without harming its productive behavior.

  1. Development of the chick microbiome: How early exposure influences future microbial diversity

    Directory of Open Access Journals (Sweden)

    Anne L Ballou

    2016-01-01

    Full Text Available The concept of improving animal health through improved gut health has existed in food animal production for decades; however, only recently have we had the tools to identify microbes in the intestine associated with improved performance. Currently, little is known about how the avian microbiome develops or the factors that affect its composition. To begin to address this knowledge gap, the present study assessed the development of the cecal microbiome in chicks from hatch to 28 days of age with and without a live Salmonella vaccine and/or probiotic supplement; both are products intended to promote gut health. The microbiome of growing chicks develops rapidly from days 1-3, and the microbiome is primarily Enterobacteriaceae, but Firmicutes increase in abundance and taxonomic diversity starting around day 7. As the microbiome continues to develop, the influence of the treatments becomes stronger. Predicted metagenomic content suggests that functionally, treatment may stimulate more differences at day 14, despite the strong taxonomic differences at day 28. These results demonstrate that these live microbial treatments do impact the development of the bacterial taxa found in the growing chicks; however, additional experiments are needed to understand the biochemical and functional consequences of these alterations.

  2. Social predisposition dependent neuronal activity in the intermediate medial mesopallium of domestic chicks (Gallus gallus domesticus).

    Science.gov (United States)

    Mayer, Uwe; Rosa-Salva, Orsola; Lorenzi, Elena; Vallortigara, Giorgio

    2016-09-01

    Species from phylogenetically distant animal groups, such as birds and primates including humans, share early experience-independent social predispositions that cause offspring, soon after birth, to attend to and learn about conspecifics. One example of this phenomenon is provided by the behaviour of newly-hatched visually-naïve domestic chicks that preferentially approach a stimulus resembling a conspecific (a stuffed fowl) rather than a less naturalistic object (a scrambled version of the stuffed fowl). However, the neuronal mechanisms underlying this behaviour are mostly unknown. Here we analysed chicks' brain activity with immunohistochemical detection of the transcription factor c-Fos. In a spontaneous choice test we confirmed a significant preference for approaching the stuffed fowl over a texture fowl (a fowl that was cut in small pieces attached to the sides of a box in scrambled order). Comparison of brain activation of a subgroup of chicks that approached either one or the other stimulus revealed differential activation in an area relevant for imprinting (IMM, intermediate medial mesopallium), suggesting that a different level of plasticity is associated with approach to naturalistic and artificial stimuli. c-Fos immunoreactive neurons were present also in the intermediate layers of the optic tectum (a plausible candidate for processing early social predispositions) showing a trend similar to the results for the IMM. PMID:27173429

  3. Comparison of the Growth and Mineralization of the Femur, Tibia, and Metatarsus of Broiler Chicks

    Directory of Open Access Journals (Sweden)

    JC Han

    2015-09-01

    Full Text Available ABSTRACTThis study aimed at comparing the growth and mineralization of the femur, tibia, and metatarsus of male and female broiler chicks. On the day of hatch, 100 male and 100 female Ross 308 broiler chicks were transferred stainless cages with 10 birds per cage. On d 7, 14, 21, 28, 35, and 42, five males and five females were sacrificed and their femur, tibia, and metatarsus were collected. Results showed that the tibia was the heaviest and the longest and contained the highest content of ash and calcium (Ca among the three leg bones. The femur had the greatest diameter. The weight, length, diameter, and ash weight of the femur, tibia, and metatarsus linearly increased with age. The ash, Ca, and phosphorus (P content in the femur and the tibia quadratically increased with age; by contrast, these parameters in the metatarsus linearly increased with age. The bones grew faster in 1 to 21 d of age. The weight, diameter, and ash weight of the three bones of males were higher than those of females. The Ca to P ratio of the three bones (femur, tibia, and metatarsus was approximately 2.0:1. These data indicate that there are differences in bone growth and mineralization among the femur, tibia, and metatarsus of male or female broiler chicks.

  4. Levels of metabolizable energy and digestible lysine for broiler chicks 8-21 days of age

    Directory of Open Access Journals (Sweden)

    Ricardo Vianna Nunes

    2015-12-01

    Full Text Available The experiment was conducted with the objective of evaluating the effect of metabolizable energy (ME levels and digestible lysine (DL levels on the performance of 8-21 days old broiler chicks. Eight hundred and sixty four broiler chicks were used, with average weight of 160 ± 5g, randomly distributed in 48 boxes (experimental unit, experimental unit in a factorial 4x4 with four levels of ME (2,700, 2,825, 2,950, and 3,075 kcal kg-1 and four levels of DL (1,080; 1,187; 1,295 and 1,403% resulting in 16 treatments with three replications. Increases in levels of ME and DL in the diets caused significant interaction (P <0.05 in weight gain and feed conversion. Increasing levels of ME and DL caused significant interaction (P <0.05 for the deposition rate of protein and fat in the carcass. The simultaneous increases of ME and DL in the diet promoted a linear increase (P <0.05 in villus height of the duodenum, jejunum, and villous:crypt ileum. It is recommended the use of 3,075 kcal kg-1 ME and 1,403% of LD for best performance, protein deposition rate, and intestinal morphometric characteristics of 8-21 days old broiler chicks.

  5. Effect of Water Based Infusion of Aloe barbedensis, Pimpinella anisum, Berberis lycium, Trigonella foenum-graecum and Allium sativum on The Performance of Broiler Chicks

    OpenAIRE

    Fazal Raziq, Sarzamin Khan*, Naila Chand, Asad Sultan, Muhammad Mushtaq, Rafiullah, Sayed Muhammad Suhail1 and Alam Zeb2

    2012-01-01

    Present study explored the potentials of medicinal plants (Aloe barbedensis, Pimpinella anisum, Berberis lycium, Trigonella foenum-graecum, Allium sativum) mixture in broiler chicks at a ratio of 1:3:1:2:1, respectively. For this purpose 240 chicks were randomly assigned into four major groups, namely; A, B, C and D. Each group was further divided into two subgroups with three replicates of 10 chicks each. One of the subgroups was vaccinated against Newcastle disease (ND), Infectious bronchit...

  6. Theory of oscillators

    CERN Document Server

    Andronov, Aleksandr Aleksandrovich; Vitt, Aleksandr Adolfovich

    1966-01-01

    Theory of Oscillators presents the applications and exposition of the qualitative theory of differential equations. This book discusses the idea of a discontinuous transition in a dynamic process. Organized into 11 chapters, this book begins with an overview of the simplest type of oscillatory system in which the motion is described by a linear differential equation. This text then examines the character of the motion of the representative point along the hyperbola. Other chapters consider examples of two basic types of non-linear non-conservative systems, namely, dissipative systems and self-

  7. Kravchuk oscillator revisited

    Science.gov (United States)

    Atakishiyeva, Mesuma K.; Atakishiyev, Natig M.; Wolf, Kurt Bernardo

    2014-05-01

    The study of irreducible representations of Lie algebras and groups has traditionally considered their action on functions of a continuous manifold (e.g. the 'rotation' Lie algebra so(3) on functions on the sphere). Here we argue that functions of a discrete variable -Kravchuk functions- are on equal footing for that study in the case of so(3). They lead to a discrete quantum model of the harmonic oscillator, and offer a corresponding set of special function relations. The technique is applicable to other special function families of a discrete variable, which stem from low-dimensional Lie algebras and are stationary solutions for the corresponding discrete quantum models.

  8. Oscillations in nonlinear systems

    CERN Document Server

    Hale, Jack K

    2015-01-01

    By focusing on ordinary differential equations that contain a small parameter, this concise graduate-level introduction to the theory of nonlinear oscillations provides a unified approach to obtaining periodic solutions to nonautonomous and autonomous differential equations. It also indicates key relationships with other related procedures and probes the consequences of the methods of averaging and integral manifolds.Part I of the text features introductory material, including discussions of matrices, linear systems of differential equations, and stability of solutions of nonlinear systems. Pa

  9. CORE SATURATION BLOCKING OSCILLATOR

    Science.gov (United States)

    Spinrad, R.J.

    1961-10-17

    A blocking oscillator which relies on core saturation regulation to control the output pulse width is described. In this arrangement an external magnetic loop is provided in which a saturable portion forms the core of a feedback transformer used with the thermionic or semi-conductor active element. A first stationary magnetic loop establishes a level of flux through the saturation portion of the loop. A second adjustable magnet moves the flux level to select a saturation point giving the desired output pulse width. (AEC)

  10. Modeling microtubule oscillations

    DEFF Research Database (Denmark)

    Jobs, E.; Wolf, D.E.; Flyvbjerg, H.

    1997-01-01

    Synchronization of molecular reactions in a macroscopic volume may cause the volume's physical properties to change dynamically and thus reveal much about the reactions. As an example, experimental time series for so-called microtubule oscillations are analyzed in terms of a minimal model...... for this complex polymerization-depolymerization cycle. The model reproduces well the qualitatively different time series that result from different experimental conditions, and illuminates the role and importance of individual processes in the cycle. Simple experiments are suggested that can further test...... and define the model and the polymer's reaction cycle....

  11. Transport Equations for Oscillating Neutrinos

    CERN Document Server

    Zhang, Yunfan

    2013-01-01

    We derive a suite of generalized Boltzmann equations, based on the density-matrix formalism, that incorporates the physics of neutrino oscillations for two- and three-flavor oscillations, matter refraction, and self-refraction. The resulting equations are straightforward extensions of the classical transport equations that nevertheless contain the full physics of quantum oscillation phenomena. In this way, our broadened formalism provides a bridge between the familiar neutrino transport algorithms employed by supernova modelers and the more quantum-heavy approaches frequently employed to illuminate the various neutrino oscillation effects. We also provide the corresponding angular-moment versions of this generalized equation set. Our goal is to make it easier for astrophysicists to address oscillation phenomena in a language with which they are familiar. The equations we derive are simple and practical, and are intended to facilitate progress concerning oscillation phenomena in the context of core-collapse su...

  12. Brain Oscillations, Hypnosis, and Hypnotizability.

    Science.gov (United States)

    Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin

    2015-01-01

    This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

  13. Olfactory system oscillations across phyla.

    Science.gov (United States)

    Kay, Leslie M

    2015-04-01

    Neural oscillations are ubiquitous in olfactory systems of mammals, insects and molluscs. Neurophysiological and computational investigations point to common mechanisms for gamma or odor associated oscillations across phyla (40-100Hz in mammals, 20-30Hz in insects, 0.5-1.5Hz in molluscs), engaging the reciprocal dendrodendritic synapse between excitatory principle neurons and inhibitory interneurons in the olfactory bulb (OB), antennal lobe (AL), or procerebrum (PrC). Recent studies suggest important mechanisms that may modulate gamma oscillations, including neuromodulators and centrifugal input to the OB and AL. Beta (20Hz) and theta (2-12Hz) oscillations coordinate activity within and across brain regions. Olfactory beta oscillations are associated with odor learning and depend on centrifugal OB input, while theta oscillations are strongly associated with respiration.

  14. Sex-Based Differences in Adélie Penguin (Pygoscelis adeliae) Chick Growth Rates and Diet.

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Katie M; Ballard, Grant; Ainley, David G

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d(-1) faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species--one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact

  15. C P -violating baryon oscillations

    Science.gov (United States)

    McKeen, David; Nelson, Ann E.

    2016-10-01

    We enumerate the conditions necessary for C P violation to be manifest in n -n ¯ oscillations and build a simple model that can give rise to such effects. We discuss a possible connection between neutron oscillations and dark matter, provided the mass of the latter lies between mp-me and mp+me. We apply our results to a possible baryogenesis scenario involving C P violation in the oscillations of the Ξ0.

  16. Chimera States for Coupled Oscillators

    OpenAIRE

    Abrams, Daniel M.; Strogatz, Steven H.

    2004-01-01

    Arrays of identical oscillators can display a remarkable spatiotemporal pattern in which phase-locked oscillators coexist with drifting ones. Discovered two years ago, such "chimera states" are believed to be impossible for locally or globally coupled systems; they are peculiar to the intermediate case of nonlocal coupling. Here we present an exact solution for this state, for a ring of phase oscillators coupled by a cosine kernel. We show that the stable chimera state bifurcates from a spati...

  17. Stable And Oscillating Acoustic Levitation

    Science.gov (United States)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  18. Linearization of conservative nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Belendez, A; Alvarez, M L [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain); Fernandez, E; Pascual, I [Departamento de Optica, FarmacologIa y AnatomIa, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)], E-mail: a.belendez@ua.es

    2009-03-11

    A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid not only for small but also for large amplitudes and, sometimes, for the complete range of oscillation amplitudes. Some conservative nonlinear oscillators are analysed to illustrate the usefulness and effectiveness of the technique.

  19. Experiments on Deflecting & Oscillating Waterjet

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new type jet,the oscillating & deflecting jet ,is put forward and its oscillating and deflecting characteristics are investigated.The nozzle of the self-oscillating & deflecting water jet consists of an upstream nozzle,a downstream nozzle,an oscillating chamber and two switches,It is experimentally shown that the deflective angle may reach 9.53 degeree,the generated pressure fluctuation is very regular and the jet can efficiently increase the ability for bradking and cutting by eliminating the water cushion effect associated with a continuous jet.

  20. The Duffing oscillator with damping

    DEFF Research Database (Denmark)

    Johannessen, Kim

    2015-01-01

    An analytical solution to the differential equation describing the Duffing oscillator with damping is presented. The damping term of the differential equation and the initial conditions satisfy an algebraic equation, and thus the solution is specific for this type of damping. The nonlinear term....... It is established that the period of oscillation is shorter compared to that of a linearized model but increasing with time and asymptotically approaching the period of oscillation of the linear damped model. An explicit expression for the period of oscillation has been derived, and it is found to be very accurate....

  1. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.;

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  2. Heat exchanger with oscillating flow

    Science.gov (United States)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1993-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  3. A Matterwave Transistor Oscillator

    CERN Document Server

    Caliga, Seth C; Zozulya, Alex A; Anderson, Dana Z

    2012-01-01

    A triple-well atomtronic transistor combined with forced RF evaporation is used to realize a driven matterwave oscillator circuit. The transistor is implemented using a metalized compound glass and silicon substrate. On-chip and external currents produce a cigar-shaped magnetic trap, which is divided into transistor source, gate, and drain regions by a pair of blue-detuned optical barriers projected onto the magnetic trap through a chip window. A resonant laser beam illuminating the drain portion of the atomtronic transistor couples atoms emitted by the gate to the vacuum. The circuit operates by loading the source with cold atoms and utilizing forced evaporation as a power supply that produces a positive chemical potential in the source, which subsequently drives oscillation. High-resolution in-trap absorption imagery reveals gate atoms that have tunneled from the source and establishes that the circuit emits a nominally mono-energetic matterwave with a frequency of 23.5(1.0) kHz by tunneling from the gate, ...

  4. Policy oscillation is overshooting.

    Science.gov (United States)

    Wagner, Paul

    2014-04-01

    A majority of approximate dynamic programming approaches to the reinforcement learning problem can be categorized into greedy value function methods and value-based policy gradient methods. The former approach, although fast, is well known to be susceptible to the policy oscillation phenomenon. We take a fresh view to this phenomenon by casting, within the context of non-optimistic policy iteration, a considerable subset of the former approach as a limiting special case of the latter. We explain the phenomenon in terms of this view and illustrate the underlying mechanism with artificial examples. We also use it to derive the constrained natural actor-critic algorithm that can interpolate between the aforementioned approaches. In addition, it has been suggested in the literature that the oscillation phenomenon might be subtly connected to the grossly suboptimal performance in the Tetris benchmark problem of all attempted approximate dynamic programming methods. Based on empirical findings, we offer a hypothesis that might explain the inferior performance levels and the associated policy degradation phenomenon, and which would partially support the suggested connection. Finally, we report scores in the Tetris problem that improve on existing dynamic programming based results by an order of magnitude. PMID:24491826

  5. Scanning for oscillations

    Science.gov (United States)

    de Cheveigné, Alain; Arzounian, Dorothée

    2015-12-01

    Objective. Oscillations are an important aspect of brain activity, but they often have a low signal-to-noise ratio (SNR) due to source-to-electrode mixing with competing brain activity and noise. Filtering can improve the SNR of narrowband signals, but it introduces ringing effects that may masquerade as genuine oscillations, leading to uncertainty as to the true oscillatory nature of the phenomena. Likewise, time-frequency analysis kernels have a temporal extent that blurs the time course of narrowband activity, introducing uncertainty as to timing and causal relations between events and/or frequency bands. Approach. Here, we propose a methodology that reveals narrowband activity within multichannel data such as electroencephalography, magnetoencephalography, electrocorticography or local field potential. The method exploits the between-channel correlation structure of the data to suppress competing sources by joint diagonalization of the covariance matrices of narrowband filtered and unfiltered data. Main results. Applied to synthetic and real data, the method effectively extracts narrowband components at unfavorable SNR. Significance. Oscillatory components of brain activity, including weak sources that are hard or impossible to observe using standard methods, can be detected and their time course plotted accurately. The method avoids the temporal artifacts of standard filtering and time-frequency analysis methods with which it remains complementary.

  6. Extinction of oscillating populations.

    Science.gov (United States)

    Smith, Naftali R; Meerson, Baruch

    2016-03-01

    Established populations often exhibit oscillations in their sizes that, in the deterministic theory, correspond to a limit cycle in the space of population sizes. If a population is isolated, the intrinsic stochasticity of elemental processes can ultimately bring it to extinction. Here we study extinction of oscillating populations in a stochastic version of the Rosenzweig-MacArthur predator-prey model. To this end we develop a WKB (Wentzel, Kramers and Brillouin) approximation to the master equation, employing the characteristic population size as the large parameter. Similar WKB theories have been developed previously in the context of population extinction from an attracting multipopulation fixed point. We evaluate the extinction rates and find the most probable paths to extinction from the limit cycle by applying Floquet theory to the dynamics of an effective four-dimensional WKB Hamiltonian. We show that the entropic barriers to extinction change in a nonanalytic way as the system passes through the Hopf bifurcation. We also study the subleading pre-exponential factors of the WKB approximation. PMID:27078294

  7. Nanoscale relaxation oscillator

    Science.gov (United States)

    Zettl, Alexander K.; Regan, Brian C.; Aloni, Shaul

    2009-04-07

    A nanoscale oscillation device is disclosed, wherein two nanoscale droplets are altered in size by mass transport, then contact each other and merge through surface tension. The device may also comprise a channel having an actuator responsive to mechanical oscillation caused by expansion and contraction of the droplets. It further has a structure for delivering atoms between droplets, wherein the droplets are nanoparticles. Provided are a first particle and a second particle on the channel member, both being made of a chargeable material, the second particle contacting the actuator portion; and electrodes connected to the channel member for delivering a potential gradient across the channel and traversing the first and second particles. The particles are spaced apart a specified distance so that atoms from one particle are delivered to the other particle by mass transport in response to the potential (e.g. voltage potential) and the first and second particles are liquid and touch at a predetermined point of growth, thereby causing merging of the second particle into the first particle by surface tension forces and reverse movement of the actuator. In a preferred embodiment, the channel comprises a carbon nanotube and the droplets comprise metal nanoparticles, e.g. indium, which is readily made liquid.

  8. Comparative study on immunoglobulin Y transfer from breeding hens to egg yolk and progeny chicks in different breeds of poultry

    Science.gov (United States)

    Agrawal, Ritu; Hirpurkar, S. D.; Sannat, C.; Gupta, Amit Kumar

    2016-01-01

    Aim: This study was undertaken to compare the immunoglobulin Y (IgY) level and its efficacy in laying hens of four different breeds of poultry (viz., Vanraja, Gramapriya, BlackRock, and KalingaBrown) and its relative transfer in egg yolk and chick. Materials and Methods: This study was conducted in 48 apparently healthy laying hens vaccinated with Salmonella inactivated polyvalent vaccine, eggs and progeny chicks; 12 each from four different breeds of poultry, viz., Vanraja, Gramapriya, BlackRock, and KalingaBrown. The methodology included measurement of egg and yolk weight, total protein and IgY in egg yolk, total serum protein and IgY in breeding hens, and progeny chicks and extent of IgY transfer from hens to yolk then to chicks. Further, Salmonella-specific antibodies in breeding hens, egg yolk and progeny chicks were assessed using O and H antigen by tube agglutination test. Results: The egg weight differed nonsignificantly (p>0.05) among breeds, however, breed wise significant variation (p0.05) difference among breed was found in total protein of egg yolk and chick. The IgY concentration in hens, egg yolk and chick was found to be in the range of 5.35±0.63-5.83±0.65, 2.3±0.1-2.6±0.2, and 1.3±0.11-1.7±0.16 mg/ml, respectively which is uniform and independent of total protein concentration at all the three levels. Significant breed variations were not observed in maternal IgY transfer from breeding hens to chicks and were 25.62±1.42-36.06±4.34% of total IgY in parent flock. Moderate to higher rate of seroprevalence with peak titers of 1:640 against Salmonella-specific antibodies was observed in only 41.6% of breeding hens. Conclusion: No significant difference in the rate of transfer of IgY was observed in four breeds studied (viz., Vanraja, Gramapriya, BlackRock, and KalingaBrown) and moderate seropositivity was detected for Salmonella-specific antibodies in progeny chicks. PMID:27182141

  9. The Use of Fermented Soybean Meals during Early Phase Affects Subsequent Growth and Physiological Response in Broiler Chicks.

    Science.gov (United States)

    Kim, S K; Kim, T H; Lee, S K; Chang, K H; Cho, S J; Lee, K W; An, B K

    2016-09-01

    The objectives of this experiment was to evaluate the subsequent growth and organ weights, blood profiles and cecal microbiota of broiler chicks fed pre-starter diets containing fermented soybean meal products during early phase. A total of nine hundred 1-d-old chicks were randomly assigned into six groups with six replicates of 25 chicks each. The chicks were fed control pre-starter diet with dehulled soybean meal (SBM) or one of five experimental diets containing fermented SBM products (Bacillus fermented SBM [BF-SBM], yeast by product and Bacillus fermented SBM [YBF-SBM]; Lactobacillus fermented SBM 1 [LF-SBM 1]; Lactobacillus fermented SBM 2 [LF-SBM 2]) or soy protein concentrate (SPC) for 7 d after hatching, followed by 4 wk feeding of commercial diets without fermented SBMs or SPC. The fermented SBMs and SPC were substituted at the expense of dehulled SBM at 3% level on fresh weight basis. The body weight (BW) during the starter period was not affected by dietary treatments, but BW at 14 d onwards was significantly higher (p0.05) by dietary treatments. During total rearing period, the daily weight gains in six groups were 52.0 (control), 57.7 (BF-SBM), 58.5 (YBF-SBM), 52.0 (LF-SBM 1), 56.7 (LF-SBM 2), and 53.3 g/d (SPC), respectively. The daily weight gain in chicks fed diet containing BF-SBM, YBF-SBM, and LF-SBM 2 were significantly higher values (pratio compared with the control group. There were no significant differences in the relative weight of various organs and blood profiles among groups. Cecal microbiota was altered by dietary treatments. At 35 d, chicks fed on the pre-starter diets containing BF-SBM and YBF-SBM had significantly increased (p<0.001) lactic acid bacteria, but lowered Coli-form bacteria in cecal contents compared with those fed the control diet. The number of Bacillus spp. was higher (p<0.001) in all groups except for LF-SBM 1 compared with control diet-fed chicks. At 7 d, jejunal villi were significantly lengthened (p<0.001) in

  10. Effects of prebiotic (Fermacto in low protein diet on some blood parameters and intestinal microbiota of broiler chicks

    Directory of Open Access Journals (Sweden)

    Amir Attar

    2010-01-01

    Full Text Available This study was conducted to evaluate the effects of prebiotic (Fermacto in low protein diet on serum cholesterol and intestinal microbiota of broiler chicks. One hundred and fifty six 1-day old Ross 308 broiler chicks of both sexes were used for 42 days. The chicks were randomly allocated to 12 pens containing 13 chicks each with 3 replicates and assigned to receive one of the 4 dietary treatments of 2 levels of protein (low and high and 2 levels of prebiotic (0 and 0.2% in a completely randomised design with factorial arrangement. There were no significant differences in serum HDL and LDL levels among treatments. Significant differences were observed in serum cholesterol and intestinal microflora between the high protein diet without prebiotic and the low protein diet containing prebiotic (P<0.05. The results of the present experiment showed that the addition of prebiotic to broiler diets containing 90% of the NRC protein recommendation significantly affects serum cholesterol and intestinal microflora of broiler chicks (P<0.05.

  11. Temperature mapping of trucks transporting fertile eggs and day-old chicks: Efficiency and/or acclimatization?

    Directory of Open Access Journals (Sweden)

    Aérica C. Nazareno

    2015-02-01

    Full Text Available The aim of this study was to evaluate the thermal profiles of trucks used for transporting fertile eggs and day-old chicks. This study was carried out in a broiler hatchery in the State of Sao Paulo. The experiment was conducted during three months, in which six egg loads and 11 chick loads were observed. Thermal profile assessments were performed in an environmental controlled trucks with thermal control and following dimensions: 7.5 x 2.6 x 2.5 m for eggs, and 8.0 x 2.5 x 2.5 m for chicks. The maximum transport capacities were approximately of 592 boxes of eggs and 630 boxes of chicks, distributed all over the lorry. The thermal profiles were assessed at five-minutes-interval for eggs and in ten-minutes-interval for chicks, using thermal variables such as temperature, relative humidity and specific enthalpy. Geostatistics was used to model spatial dependency (by kriging. The results showed that the acclimatization in trucks was deficient. The loads were found to be submitted to an incompatible temperature, showing a huge thermal variety in the body trucks.

  12. Age and food deprivation affects expression of the glucocorticosteroid stress response in Magellanic penguin (Spheniscus magellanicus) chicks.

    Science.gov (United States)

    Walker, Brian G; Wingfield, John C; Boersma, P Dee

    2005-01-01

    We examined how the glucocortical stress response in free-living Magellanic penguin (Spheniscus magellanicus) chicks changes with age and whether adrenocortical function of chicks within a brood varies in relation to food provisioned by adults. Chicks showed little corticosterone response to capture stress shortly after hatching, an intermediate response around 45-d posthatch, and a robust stress response near fledging. However, in response to an adrenocorticotropic hormone (ACTH) challenge, hatchlings were capable of secreting corticosterone at adult-like levels. The larger sibling in broods of two showed a similar gradual stress-response development pattern. In contrast, by day 45, when differences in body condition were well established between siblings, the smaller, food-deprived chicks significantly increased baseline levels of corticosterone but showed normal stress-induced levels. Near fledging, baseline levels had returned to normal, but stress-induced levels were lower than expected. Similar to altricial species, normally developing semialtricial Magellanic penguin chicks do not express a robust corticosterone stress response until near fledging. Chronic stressors such as food deprivation cause corticosterone use to be up-regulated earlier than expected. However, in cases of extended chronic stress, down-regulation may ensue, thus avoiding the negative effects of chronically elevated levels of corticosterone. PMID:15702466

  13. Chicks prefer to peck at insect-like elongated stimuli moving in a direction orthogonal to their longer axis.

    Science.gov (United States)

    Clara, Elena; Regolin, Lucia; Vallortigara, Giorgio; Rogers, Lesley J

    2009-11-01

    Spontaneous preferences towards possible prey have been little investigated using targets in motion. Preferences of domestic chicks (Gallus gallus) to peck at video-images of stimuli representing live insects moving along their longer body axis (i.e. "forwards") or along the shorter body axis (i.e. "sideways") were investigated. Chicks presented with both types of stimulus displayed a significant preference for pecking at stimuli moving sideways. This preference was already present on day 1 post-hatching, and it strengthened on day 6 for those chicks that had experienced pecking at live insects. Head angles used to fixate the stimuli prior to pecking were also analysed and were consistent (i.e. 30 degrees -35 degrees and 60 degrees -65 degrees ) with those reported for fixation of non-edible targets (larger stimuli at a distance). In a first control experiment the same video-presented stimuli were used but the insect's legs were removed to reduce flickering. In a second control experiment, paper-printed images of the whole insect were used. In both cases, the sideways direction of movement was clearly preferred. Overall, our data show that chicks have a spontaneous preference to peck at video-images resembling live insects moving along their shorter body axis. Sideways movement may constitute a crucial signal attracting chicks' attention and enhancing predatory responses possibly because of stronger stimulation of motion detectors.

  14. Phycoremediation of waste water from a plastic manufacturing industry with Chlorella pyrenoidosa H.Chick in laboratory study

    Directory of Open Access Journals (Sweden)

    Kenanga Sari

    2014-04-01

    Full Text Available Abstrack - The plastic industries has increased by 7-8% per year, it will cause a negative impact for the environment. The wastewater of plastic industrial contain many pollutants such as hazardous substances bensen, formaldehyde and heavy metals (Cd, Cu, Cr and Pb. Heavy metals Cu is the most dangerous heavy metals since Cu can inhibit enzyme systems, remediation are needed to reduce the pollutants in the environment. One effective way is by using Chlorella pyrenoidosa H.Chick as phycoremediation agent. This study aims to assess the percentage of population growth and decline of heavy metals Cu after inoculation with C. pyrenoidosa H.Chick. The method used is to cultivate C. pyrenoidosa H.Chick in plastic wastewater for 8 days and observed a decrease of percentage heavy metal Cu and population growh of C.pyrenoidosa H.Chick. Environmental factors such as temperature, salinity, pH, light intensity is maintained in order to remain stable. The data obtained with T test. After 8 days of the study turned out that C. pyrenoidosa H.Chick able to reduce Cu of 0.435 mg / l to 0.24 mg / l within 8 days and decrease percentage is 44.83%, thus meeting the criteria of the quality standard of waste according to the PP. 82 of 2001 in the amount of 0.2 ppm and safe for environment. Keywords: Chlorella pyrenoidosa, phycoremediation, water, plastic, copper.

  15. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

    Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.

  16. Solar neutrino oscillation phenomenology

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2004-02-01

    This article summarises the status of the solar neutrino oscillation phenomenology at the end of 2002 in the light of the SNO and KamLAND results. We first present the allowed areas obtained from global solar analysis and demonstrate the preference of the solar data towards the large-mixing-angle (LMA) MSW solution. A clear confirmation in favour of the LMA solution comes from the KamLAND reactor neutrino data. the KamLAND spectral data in conjunction with the global solar data further narrows down the allowed LMA region and splits it into two allowed zones - a low $ m^{2}$ region (low-LMA) and high $ m^{2}$ region (high-LMA). We demonstrate through a projected analysis that with an exposure of 3 kton-year (kTy) KamLAND can remove this ambiguity.

  17. Collective supernova neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [Max Planck Institute for Physics, Munich (Germany)

    2009-07-01

    Neutrinos emitted by core-collapse supernovae (SNe) represent an important laboratory for both particle physics and astrophysics. While propagating in the dense SN environment, they can feel not only the presence of background matter (via ordinary Mikheev-Smirnov-Wolfenstein effects) but also of the gas of neutrinos and antineutrinos (via neutrino-neutrino interaction effects). The neutrino-neutrino interactions appear to modify the flavor evolution of SN neutrinos in a collective way, completely different from the ordinary matter effects. In these conditions, the flavor evolution equations become highly nonlinear, sometimes resulting in surprising phenomena when the entire neutrino system oscillates coherently as a single collective mode. In this talk, I present the recent results on collective supernova neutrino flavor conversions and I discuss about the sensitivity of these effects to the ordering of the neutrino mass spectrum.

  18. Oscillations in the immune system.

    Science.gov (United States)

    Stark, Jaroslav; Chan, Cliburn; George, Andrew J T

    2007-04-01

    Oscillations are surprisingly common in the immune system, both in its healthy state and in disease. The most famous example is that of periodic fevers caused by the malaria parasite. A number of hereditary disorders, which also cause periodic fevers, have also been known for a long time. Various reports of oscillations in cytokine concentrations following antigen challenge have been published over at least the past three decades. Oscillations can also occur at the intracellular level. Calcium oscillations following T-cell activation are familiar to all immunologists, and metabolic and reactive oxygen species oscillations in neutrophils have been well documented. More recently, oscillations in nuclear factor kappaB activity following stimulation by tumor necrosis factor alpha have received considerable publicity. However, despite all of these examples, oscillations in the immune system still tend to be considered mainly as pathological aberrations, and their causes and significance remained largely unknown. This is partly because of a lack of awareness within the immunological community of the appropriate theoretical frameworks for describing and analyzing such behavior. We provide an introduction to these frameworks and give a survey of the currently known oscillations that occur within the immune system. PMID:17367345

  19. Hyperchaotic system with unstable oscillators

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; Mykolaitis, G.;

    2000-01-01

    A simple electronic system exhibiting hyperchaotic behaviour is described. The system includes two nonlinearly coupled 2nd order unstable oscillators, each composed of an LC resonance loop and an amplifier. The system is investigated by means of numerical integration of appropriate differential...... equations, PSPICE simulations and hardware experiments. The Lyapunov exponents are presented to confirm hyperchaotic mode of the oscillations....

  20. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  1. The El Nino Stochastic Oscillator

    CERN Document Server

    Burgers, G

    1997-01-01

    Anomalies during an El Nino are dominated by a single, irregularly oscillating, mode. Equatorial dynamics has been linked to delayed-oscillator models of this mode. Usually, the El Nino mode is regarded as an unstable mode of the coupled atmosphere system and the irregularity is attributed to noise and possibly chaos. Here a variation on the delayed oscillator is explored. In this stochastic-oscillator view, El Nino is a stable mode excited by noise. It is shown that the autocorrelation function of the observed NINO3.4 index is that of a stochastic oscillator, within the measurement uncertainty. Decadal variations as would occur in a stochastic oscillator are shown to be comparable to those observed, only the increase in the long-term mean around 1980 is rather large. The observed dependence of the seasonal cycle on the variance and the correlation is so large that it can not be attributed to the natural variability of a stationary stochastic oscillator. So the El Niño stochastic-oscillator parameters must d...

  2. Lorentz violation and neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Mewes, Matthew [Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States)

    2011-12-15

    Lorentz violation naturally leads to neutrino oscillations and provides an alternative mechanism that may explain current data. This contribution to the proceedings of The XXII International Conference on Neutrino Physics and Astrophysics provides a brief review of possible signals of Lorentz violation in neutrino-oscillation experiments.

  3. Neutrino Oscillations with Nil Mass

    CERN Document Server

    Floyd, Edward R

    2016-01-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and $\\bar{\

  4. Fano Interference in Classical Oscillators

    Science.gov (United States)

    Satpathy, S.; Roy, A.; Mohapatra, A.

    2012-01-01

    We seek to illustrate Fano interference in a classical coupled oscillator by using classical analogues of the atom-laser interaction. We present an analogy between the dressed state picture of coherent atom-laser interaction and a classical coupled oscillator. The Autler-Townes splitting due to the atom-laser interaction is analogous to the…

  5. Mechanical Parametric Oscillations and Waves

    Science.gov (United States)

    Dittrich, William; Minkin, Leonid; Shapovalov, Alexander S.

    2013-01-01

    Usually parametric oscillations are not the topic of general physics courses. Probably it is because the mathematical theory of this phenomenon is relatively complicated, and until quite recently laboratory experiments for students were difficult to implement. However parametric oscillations are good illustrations of the laws of physics and can be…

  6. Chick embryos have the same pattern of hypoxic lower-brain activation as fetal mammals.

    Science.gov (United States)

    Landry, Jeremy P; Hawkins, Connor; Lee, Aaron; Coté, Alexandra; Balaban, Evan; Pompeiano, Maria

    2016-01-01

    cFos expression (indicating a particular kind of neuronal activation) was examined in embryonic day (E) 18 chick embryos after exposure to 4 h of either normoxia (21% O2), modest hypoxia (15% O2), or medium hypoxia (10% O2). Eight regions of the brainstem and hypothalamus were surveyed, including seven previously shown to respond to hypoxia in late-gestation mammalian fetuses (Breen et al., 1997; Nitsos and Walker, 1999b). Hypoxia-related changes in chick embryo brain activation mirrored those found in fetal mammals with the exception of the medullary Raphe, which showed decreased hypoxic activation, compared with no change in mammals. This difference may be explained by the greater anapyrexic responses of chick embryos relative to mammalian fetuses. Activation in the A1/C1 region was examined in more detail to ascertain whether an O2-sensitive subpopulation of these cells containing heme oxygenase 2 (HMOX2) may drive hypoxic brain responses before the maturation of peripheral O2-sensing. HMOX2-positive and -negative catecholaminergic cells and interdigitating noncatecholaminergic HMOX2-positive cells all showed significant changes in cFos expression to hypoxia, with larger population responses seen in the catecholaminergic cells. Hypoxia-induced activation of lower-brain regions studied here was significantly better correlated with activation of the nucleus of the solitary tract (NTS) than with that of HMOX2-containing A1/C1 neurons. Together, these observations suggest that (1) the functional circuitry controlling prenatal brain responses to hypoxia is strongly conserved between birds and mammals, and (2) NTS neurons are a more dominant driving force for prenatal hypoxic cFos brain responses than O2-sensing A1/C1 neurons.

  7. The Pinay as Fun, Fearless Female: Philippine Chick Literature in the Age of the Transnation

    Directory of Open Access Journals (Sweden)

    Katrina Stuart Santiago

    2009-12-01

    Full Text Available The paper analyzes Philippine chick literature by Summit Publishing – the first to come out with local chick literature via the Summit Books – and as a by-product of its magazine Cosmopolitan Philippines.This study delves into chick lit’s existence given these context(s: 1. the dynamics of publication in this country, i.e., the “literary” versus the “popular”, works in English versus works in Filipino, the “artsy” versus the bestseller; 2. the various kinds of feminism(s of which the middle class Filipina of today is necessarily part; and 3. the facts of globalization and the transnation that are the bases of the Summit Books’ existence, given its links to Cosmopolitan Philippines, and the latter’s existence as a local franchise of a transnational magazine. This paper also looks at the marginalization and suppression that is contingent upon these perspectives of the Summit Books with a view of seeing the possibilities of resistance and rebellion within them. This project uses as backbone contemporary third world feminist and current Philippine cultural theories that insist on the urgent tasks of relevance and involvement that all contemporary cultural productions by women must face. More particularly, this study uses notions of subjectivity and agency, and the processes of negotiation these allow, towards an analysis of where these women’s texts necessarily belong to. This kind of analysis is utilized precisely because these texts traverse across the oppressive and the empowering, the status quo and the possibilities of rebellion, and the powerless and the powerful. In the end, such negotiation is seen as Summit Books’ contribution to the contemporary creation of the Philippine feminine – one that demands that no text be reduced to just its class origins, or just the popular.

  8. Analysis of cerebro-spinal fluid protein composition in early developmental stages in chick embryos.

    Science.gov (United States)

    Gato, A; Martín, P; Alonso, M I; Martín, C; Pulgar, M A; Moro, J A

    2004-04-01

    Foetal cerebro-spinal fluid (CSF) has a very high protein concentration when compared to adult CSF, and in many species five major protein fractions have been described. However, the protein concentration and composition in CSF during early developmental stages remains largely unknown. Our results show that in the earliest stages (18 to 30 H.H.) of chick development there is a progressive increase in CSF protein concentration until foetal values are attained. In addition, by performing electrophoretic separation and high-sensitivity silver staining, we were able to identify a total of 21 different protein fractions in the chick embryo CSF. In accordance with the developmental pattern of their concentration, these can be classified as follows: A: high-concentration fractions which corresponded with the ones described in foetal CSF by other authors; B: low-concentration fractions which remained stable throughout the period studied; C: low-concentration fractions which show changes during this period. The evolution and molecular weight of the latter group suggest the possibility of an important biological role. Our data demonstrate that all the CSF protein fractions are present in embryonic serum; this could mean that the specific transport mechanisms in neuroepithelial cells described in the foetal period evolve in very early stages of development. In conclusion, this paper offers an accurate study of the protein composition of chick embryonic CSF, which will help the understanding of the influences on neuroepithelial stem cells during development and, as a result, the appropriate conditions for the in vitro study of embryonic/foetal nervous tissue cells. PMID:15039986

  9. Effect of species-specific sound stimulation on the development and hatching of broiler chicks.

    Science.gov (United States)

    Tong, Q; McGonnell, I M; Romanini, C E B; Bergoug, H; Roulston, N; Exadaktylos, V; Berckmans, D; Bahr, C; Guinebretière, M; Eterradossi, N; Garain, P; Demmers, T

    2015-04-01

    1. Previous research has reported that chicken embryos develop a functionary auditory system during incubation and that prenatal sound may play an important role in embryo development and alter the hatch time. In this study the effects of prenatal auditory stimulation on hatch process, hatch performance, the development of embryo and blood parameters were investigated. 2. Four batches of Ross 308 broiler breeder eggs were incubated either in control or in sound-stimulated groups. The sound-stimulated embryos were exposed to a discontinuous sound of species-specific calls by means of a speaker at 72 dB for 16 h a day: maternal calls from d 10 to d 19 of incubation time and embryo/chick calls from d 19 until hatching. The species-specific sound was excluded from the control group. 3. The onset of hatch was delayed in the sound-stimulated group compared to the controls. This was also supported by comparison of the exact hatching time of individual focal chicks within the two groups. However, the sound-stimulated embryos had a lower hatchability than the control group, mainly due to significantly increased numbers of late deaths. 4. The embryos exhibited a similar growth pattern between the sound-stimulated group and the control group. Although sound exposure decreased body weight at d 16, no consistent effect of sound on body weight at incubation stage was observed. Species-specific sound stimulation also had no impact on chick quality, blood values and plasma corticosterone concentrations during hatch. PMID:25559058

  10. Early expression of hypocretin/orexin in the chick embryo brain.

    Directory of Open Access Journals (Sweden)

    Kyle E Godden

    Full Text Available Hypocretin/Orexin (H/O neuropeptides are released by a discrete group of neurons in the vertebrate hypothalamus which play a pivotal role in the maintenance of waking behavior and brain state control. Previous studies have indicated that the H/O neuronal development differs between mammals and fish; H/O peptide-expressing cells are detectable during the earliest stages of brain morphogenesis in fish, but only towards the end of brain morphogenesis (by ∼ 85% of embryonic development in rats. The developmental emergence of H/O neurons has never been previously described in birds. With the goal of determining whether the chick developmental pattern was more similar to that of mammals or of fish, we investigated the emergence of H/O-expressing cells in the brain of chick embryos of different ages using immunohistochemistry. Post-natal chick brains were included in order to compare the spatial distribution of H/O cells with that of other vertebrates. We found that H/O-expressing cells appear to originate from two separate places in the region of the diencephalic proliferative zone. These developing cells express the H/O neuropeptide at a comparatively early age relative to rodents (already visible at 14% of the way through fetal development, thus bearing a closer resemblance to fish. The H/O-expressing cell population proliferates to a large number of cells by a relatively early embryonic age. As previously suggested, the distribution of H/O neurons is intermediate between that of mammalian and non-mammalian vertebrates. This work suggests that, in addition to its roles in developed brains, the H/O peptide may play an important role in the early embryonic development of non-mammalian vertebrates.

  11. BMP is an important regulator of proepicardial identity in the chick embryo.

    Science.gov (United States)

    Schlueter, Jan; Männer, Jörg; Brand, Thomas

    2006-07-15

    The proepicardium (PE) is a transient structure formed by pericardial coelomic mesothelium at the venous pole of the embryonic heart and gives rise to several cell types of the mature heart. In order to study PE development in chick embryos, we have analyzed the expression pattern of the marker genes Tbx18, Wt1, and Cfc. During PE induction, the three marker genes displayed a left-right asymmetric expression pattern. In each case, expression on the right side was stronger than on the left side. The left-right asymmetric gene expression observed here is in accord with the asymmetric formation of the proepicardium in the chick embryo. While initially the marker genes were expressed in the primitive sinus horn, subsequently, expression became confined to the PE mesothelium. In order to search for signaling factors involved in PE development, we studied Bmp2 and Bmp4 expression. Bmp2 was bilaterally expressed in the sinus venosus. In contrast, Bmp4 expression was initially expressed unilaterally in the right sinus horn and subsequently in the PE. In order to assess its functional role, BMP signaling was experimentally modulated by supplying exogenous BMP2 and by inhibiting endogenous BMP signaling through the addition of Noggin. Both supplying BMP and blocking BMP signaling resulted in a loss of PE marker gene expression. Surprisingly, both experimental situations lead to cardiac myocyte formation in the PE cultures. Careful titration experiments with exogenously added BMP2 or Noggin revealed that PE-specific marker gene expression depends on a low level of BMP signaling. Implantation of BMP2-secreting cells or beads filled with Noggin protein into the right sinus horn of HH stage 11 embryos resulted in downregulation of Tbx18 expression, corresponding to the results of the explant assay. Thus, a distinct level of BMP signaling is required for PE formation in the chick embryo. PMID:16677627

  12. Regulation of phosphatidylcholine biosynthesis in cultured chick embryonic muscle treated with phospholipase C.

    Science.gov (United States)

    Sleight, R; Kent, C

    1980-11-25

    Cultures of embryonic chick muscle cells grown in medium containing phospholipase C from Clostridium perfringens incorporated [3H]choline into lipid at a rate 3- to 5-fold higher than control cultures. To determine the mechanism by which stimulation of phosphatidylcholine synthesis occurred in phospholipase C-treated cells, activities of enzymes and levels of intermediates in the biosynthetic pathway for phosphatidylcholine were examined. Activities of choline kinase, choline phosphotransferase, glycerol-3-phosphate dehydrogenase, glycerol-3-phosphate acyltransferase, acylglycerol-3-phosphate acyltransferase, and phosphatidic acid phosphatase in phospholipase C-treated cells were the same or only slightly higher than in control cells. CTP:phosphocholine cytidylyltransferase, on the other hand, was 3 times as active in homogenates from phospholipase C-treated cells. Levels of phosphocholine decreased and levels of CDP-choline increased in phospholipase C-treated cells, and a calculation of the disequilibrium ratio indicated that the cytidylyltransferase reaction was not at equilibrium. The cytidylyltransferase was, thus, identified as the regulatory enzyme for choline flux in these cells. The cytidylyltransferase was located in both the cytosolic and particulate fractions from cultured muscle cells and a much larger portion of enzyme activity was associated with the particulate fraction in cells treated with phospholipase C. Sonicated preparations of total chick lipids, phosphatidylethanolamine, and phosphatidylserine greatly stimulated the cytosolic cytidylyltransferase activity but had no effect on the particulate enzyme. Neither stimulation of incorporation of [3H]choline into lipid nor activation of the cytidylyltransferase was dependent on protein synthesis. A model for the mechanism of regulation of phosphatidylcholine synthesis in embryonic chick muscle is presented.

  13. Environmental influences on Adelie penguin breeding schedules, endocrinology, and chick survival.

    Science.gov (United States)

    Ninnes, C E; Waas, J R; Ling, N; Nakagawa, S; Banks, J C; Bell, D G; Bright, A; Carey, P W; Chandler, J; Hudson, Q J; Ingram, J R; Lyall, K; Morgan, D K J; Stevens, M I; Wallace, J; Möstl, E

    2011-08-01

    To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens, testosterone, and corticosterone), timing of breeding, and chick survival, in Adelie penguins (Pygoscelis adeliae) at two colonies in two different years. Clutch initiation at Cape Bird South (CBS; year 1, ~14,000 pairs) occurred later than at Cape Crozier East (CCE; year 2, ~ 25,000 pairs); however, breeding was more synchronous at CBS. This pattern was probably generated by the persistence of extensive sea ice at CBS (year 1). Higher corticosterone metabolite and lower sex hormone concentrations at CBS correlated with later breeding and lower chick survival compared to at CCE - again, a likely consequence of sea ice conditions. Within colonies, sub-colony size (S, 50-100; M, 200-300; L, 500-600; XL, >1000 pairs) did not influence the onset or synchrony of breeding, chick survival, or hormone concentrations. We showed that the endocrine profiles of breeding Adelie penguins can differ markedly between years and/or colonies, and that combining measures of endocrinology, behaviour, and offspring survival can reveal the mechanisms and consequences that different environmental conditions can have on breeding ecology.

  14. Photoacoustic elastic oscillation and characterization

    CERN Document Server

    Gao, Fei; Zheng, Yuanjin

    2014-01-01

    Photoacoustic imaging and sensing have been studied extensively to probe the optical absorption of biological tissue in multiple scales ranging from large organs to small molecules. However, its elastic oscillation characterization is rarely studied and has been an untapped area to be explored. In literature, photoacoustic signal induced by pulsed laser is commonly modelled as a bipolar "N-shape" pulse from an optical absorber. In this paper, the photoacoustic damped oscillation is predicted and modelled by an equivalent mass-spring system by treating the optical absorber as an elastic oscillator. The photoacoustic simulation incorporating the proposed oscillation model shows better agreement with the measured signal from an elastic phantom, than conventional photoacoustic simulation model. More interestingly, the photoacoustic damping oscillation effect could potentially be a useful characterization approach to evaluate biological tissue's mechanical properties in terms of relaxation time, peak number and ra...

  15. Immunogenicity of formaldehyde and binary ethylenimine inactivated infectious bursal disease virus in broiler chicks

    Institute of Scientific and Technical Information of China (English)

    HABIB Mudasser; HUSSAIN Iftikhar; IRSHAD Hamid; YANG Zong-zhao; SHUAI Jiang-bing; CHEN Ning

    2006-01-01

    Infectious bursal disease virus (IBDV) was inactivated by two different chemicals-formaldehyde and binary ethylenimine (BEI). Formaldehyde was used at 0.1% and 0.2%, while BEI was used at concentrations of 0.001 and 0.002 mol/L.These four vaccines were tested for their efficiency in generating humoral immune response in different groups of broiler chicks.Both BEI-inactivated vaccines gave relatively higher antibody titers and were almost twice as efficient as formaldehyde-inactivated ones.

  16. Na/K pump current in aggregates of cultured chick cardiac myocytes

    OpenAIRE

    1990-01-01

    Spontaneously beating aggregates of cultured embryonic chick cardiac myocytes, maintained at 37 degrees C, were voltage clamped using a single microelectrode switching clamp to measure the current generated by the Na/K pump (Ip). In resting, steady-state preparations an ouabain- sensitive current of 0.46 +/- 0.03 microA/cm2 (n = 22) was identified. This current was not affected by 1 mM Ba, which was used to reduce inward rectifier current (IK1) and linearize the current-voltage relationship. ...

  17. Intracellular sodium affects ouabain interaction with the Na/K pump in cultured chick cardiac myocytes

    OpenAIRE

    1990-01-01

    Whether a given dose of ouabain will produce inotropic or toxic effects depends on factors that affect the apparent affinity (K0.5) of the Na/K pump for ouabain. To accurately resolve these factors, especially the effect of intracellular Na concentration (Nai), we have applied three complementary techniques for measuring the K0.5 for ouabain in cultured embryonic chick cardiac myocytes. Under control conditions with 5.4 mM Ko, the value of the K0.5 for ouabain was 20.6 +/- 1.2, 12.3 +/- 1.7, ...

  18. Bioavailability of Phosphorus in Two Cultivars of Pea for Broiler Chicks

    OpenAIRE

    Woyengo, T. A.; Emiola, I. A.; Kim, I. H.; Nyachoti, C. M.

    2016-01-01

    The aim was to determine the relative bioavailability of phosphorus (P) in peas for 21-day old broiler chickens using slope-ratio assay. One hundred and sixty eight male Ross 308 broiler chicks were divided into 42 groups 4 balanced for body weight and fed 7 diets in a completely randomized design (6 groups/diet) from day 1 to 21 of age. The diets were a corn-soybean meal basal diet, and the corn-soybean meal basal diet to which monosodium phosphate, brown- or yellow-seeded pea was added at t...

  19. Effect of L-arginine on neuromuscular transmission of the chick biventer cervicis muscle

    Directory of Open Access Journals (Sweden)

    B. Esfandiar

    2008-01-01

    Full Text Available biventer cervicis muscleD. Effect of L-arginine on neuromuscular transmission of the chick EsfandiarAbstractBackground and Purpose: NO is a short-lived gas molecule generated by degradation of L-arg to citrulline and by the activation of enzyme NOS Ca2+/calmodulin-dependent. There are multiple NOS isoforms that strongly are expressed in skeletal muscle, suggesting the crucial role of NO in regulating muscular metabolism and function. In this study, the effect of L-arginine was examined at the neuromuscular junction of the chick biventer cervicis muscle.Materials and Methods: Biventer cervicis muscle preparations from chick’s age of 3 weeks were set up in the organ bath. The organ bath had a vessel with volume of about 70 ml; it contained Tyrode solution aerated with oxygen and was kept at 37º C. NO levels was also measured in the chick biventer cervicis muscle homogenates, using spectrophotometer method for the direct detection of NO, nitrite and nitrate. Total nitrite (nitrite+nitrate was measured by a spectrophotometer at 540 nm after the conversion of nitrate to nitrite by copperized cadmium granules.Results: L-Arginine at 500 µg/ml, decreased twitch response to electrical stimulation, and produced rightward shift of the dose-response curve for acetylcholine or carbachol. L-arginine at 1000 µg/ml produced a strong shift to the right of the dose-response curve for acetylcholine or carbachol with a reduction in efficacy. The inhibitory effect of L-arginine on the twitch response was blocked by caffeine (200 µg/ml. NO levels were found to be significantly increased in concentrations 500 and 1000 µg/ml of L-arginine in comparison with the control group (p < 0.001.Conclusion: These findings indicate a possible role of increased NO levels in the suppressive action of L-arginie on the twitch response. In addition, the results indicate that the post-junctional antagonistic action of L-arginine is probably the result of impaired sarcoplasmic

  20. Effectiveness of noise in blocking electromagnetic effects on enzyme activity in the chick embryo.

    Science.gov (United States)

    Martin, A H; Moses, G C

    1995-05-01

    We have previously demonstrated that exposure of the chick embryo to a 60 Hz, 4 microT split sine wave for the first 72 hours of development causes a significant reduction in the activity of the ectoenzyme 5'-nucleotidase. This reduced activity persisted, throughout the embryonic period, despite further incubation in a field free environment. We also showed that the reduction in 5'NT activity can be localized in the developing brain to the Cerebellum. The present study reveals that superimposition of an electromagnetic noise, of similar amplitude and frequency, can mitigate the effect of the field on 5'NT activity.

  1. Formation of lentoid body from retinal pigment epithelium of chick embryo in floating culture

    OpenAIRE

    筒井, 康子

    1997-01-01

    We observed the morphologic changes of tissue fragments of retinal pigment epithelium (RPE) of chick embryos in floating culture under the presence of bacic fibroblast growth factor (bFGF). At higher concentration (10 and 200 ng/ml) of bFGF, rolled up RPE sheets grew to develop non-pigmented lumps with the structure like onions, while dissociated RPE cells did not from such structure. Histologically, the onion-like structure consisted of lens-fiber-like cells, positive for anti-crystallin ant...

  2. Faecal microbiota of domestic cats fed raw whole chicks v. an extruded chicken-based diet*

    OpenAIRE

    Kerr, K. R.; Dowd, S. E.; Swanson, K. S.

    2014-01-01

    Extruded cat foods differ greatly in macronutrient distribution compared with wild-type diets (i.e. small mammals, reptiles, birds and insects). Based on the literature, this variability likely impacts faecal microbial populations. A completely randomised design was utilised to test the impacts of two dietary treatments on faecal microbial populations: (1) chicken-based extruded diet (EXT; n 3 cats) and (2) raw 1–3-d-old chicks (CHI; n 5 cats). Cats were adapted to diets for 10 d. Bacterial D...

  3. Feeding and growth of Japanese quail (Coturnix c. japonica) chicks with unpredictable food access

    OpenAIRE

    Boon, P.; Visser, GH; Daan, S

    1999-01-01

    We investigated the effect of unpredictable feeding times on feeding activity and body mass gain in fast growing Japanese quail (Coturnix c. japonica) from 7 to 31 d of age. Quail chicks were subjected to a long day length (18L:6D) with ad libitum food during (1) 17.5 h of the light period, starting 0.5 h after lights-on (group A, n = 14), (2) 6 h of the light period, starting 0.5 h after lights-on (group B, n = 14), and (3) 6 h of the light period, starting pseudorandomly either 0.5, 6, or 1...

  4. Mechanoelectrical Transducer Has Discrete Conductances in the Chick Vestibular Hair Cell

    Science.gov (United States)

    Ohmori, Harunori

    1984-03-01

    Properties of mechanoelectrical transduction were studied at the single-cell level by applying a whole-cell recording variation of the patch-clamp technique to dissociated vestibular hair cells of chicks. The hair bundle was directly stimulated by a glass rod, and transduction currents were recorded from the cell body. After a triangular movement of the stimulating probe, the transduction current was generated stepwise between discrete levels of amplitude. The minimum step amplitude was -1.8 pA at -27 mV in Na-containing normal saline.

  5. Free oscillation of the Earth

    Directory of Open Access Journals (Sweden)

    Y. Abedini

    2000-06-01

    Full Text Available   This work is a study of the Earths free oscillations considering a merge of solid and liquid model. At the turn of 19th century Geophysicists presented the theory of the free oscillations for a self-gravitating, isotropic and compressible sphere. Assuming a steel structure for an Earth size sphere, they predicted a period of oscillation of about 1 hour. About 50 years later, the free oscillations of stars was studied by Cowling and others. They classified the oscillation modes of the stars into acoustic and gravity modes on the basis of their driving forces. These are pressure and buoyancy forces respectively. The earliest measurements for the period of the free oscillations of the Earth was made by Benyove from a study of Kamchathca earthquake. Since then, the Geophysicists have been trying to provide a theoretical basis for these measurements. Recently, the theory concerning oscillations of celestial fluids is extended by Sobouti to include the possible oscillations of the Earthlike bodies. Using the same technique, we study the free oscillations of a spherically symmetric, non-rotating and elastic model for the Earth.   We used the actual data of the Earths interior structure in our numerical calculations. Numerical results show that there exist three distinct oscillation modes namely acoustic, gravity and toroidal modes. These modes are driven by pressure, buoyancy and shear forces respectively. The shear force is due to the elastic properties of the solid part of the Earth. Our numerical results are consistent with the seismic data recorded from earthquake measurements.

  6. The Chick as a Model for the Study of the Cellular Mechanisms and Potential Therapies for Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Radmila Mileusnic

    2010-01-01

    Full Text Available While animal experiments have contributed much to our understanding of the mechanisms of Alzheimer's disease (AD, their value in predicting the effectiveness of treatment strategies in clinical trials has remained controversial. The disparity between the results obtained in animal models and clinical trials may in part be explained by limitations of the models and species-specific differences. We propose that one trial passive avoidance in the day-old chick is a useful system to study AD because of the close sequence homologies of chick and human amyloid precursor protein (APP. In the chick, APP is essential for memory consolidation, and disrupting its synthesis or structure results in amnesia. RER, a tripeptide sequence corresponding to part of the growth domain of APP, can restore memory loss and act as a cognitive enhancer. We suggest that RER and its homologues may form the basis for potential pharmacological protection against memory loss in AD.

  7. [Non-invasive method of sex identification of crane chicks by the DNA from capillary vessels of alantois].

    Science.gov (United States)

    2013-01-01

    The non-invasive method of determining the sex of chicks after hatching based on the DNA isolated from capillary vessels of allantois of the egg-shell membranes was demonstrated on four crane species (Gruinae, Aves), which were bred in the Crane Breeding Centre of the Oka Nature Reserve in 2009-2012. Using the EE0.6 molecular marker of sex, the gender of 26 Siberian (Grus leucogeranus), 15 Red-crowned (G. japonensis), 4 Common (G. grus) and 1 Demoiselle (Anthropoides virgo) crane chicks was identified. This method can be recommended for determining the sex of chicks and the ratio of sexes in cranes that reproduce both in captivity and natural populations. PMID:25507804

  8. A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

    Directory of Open Access Journals (Sweden)

    Bogomolnaya Lydia M

    2008-10-01

    Full Text Available Abstract Background Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with Salmonella enterica serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small. Results We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and Salmonella-resistant CBA/J mice during infection with Salmonella enterica serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic invA mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and Salmonella-resistant mice. Additionally we show that only a small minority of Salmonellae are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models. Conclusion In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models.

  9. Immunological Changes of Chicks Immunized with Marek‘s Disease Vaccines and Challenged with Virulent MD Virus

    Institute of Scientific and Technical Information of China (English)

    LiuZhonggui; GaoRong; 等

    1995-01-01

    The experiment was conducted to inoculate one-day old chicks with Marek's disecae(MD) trivalent and herpesvirus of turkey(HVT) vaccines separately,and then to challenge them with virulent MD virus(vMDV) at the age of 15 days,and 5,25,45,and 75 days after the challenge with vMDV,comparing with the cotrol-challenged chicks without immunization,to detect the immunoprotetive efficacy and dynamic changes of the inductive activity of interleukin-2(IL-2),expression of IL-2 receptor and proliferative function of T cells in thymus and spleen;the number of ANAET,APT,cells and IgG,IgM,IgA antibody-producing cells in Bursa Fabricius,spleen,thymus,cecal tonsil and Harder gland;as the amount of T cells and IgG,IgA in peripheral blood as well as the content of IgG,IgM and IgA in the tear,trachea washings,bile and intestinal fluids of the experimental chicks.The experimental results firstly demonstrate that the immunoregulation of IL-2,and IL-2 receptor,the cellualr and humoral immune resposes were significantly enhanced in the central and peripheral immune organs;the local mucosal immune funcsignificantly enhanced in the central and peripheral immune organs;the local mucosal immune function were markedly amplified in the respiratory and digestive tracts of the immunized-challenged,chicks,which were closely correlated with the immunoprotection against MD;the immune response and immunoprotective effect of the trivalent vaccine-immunized chicks wrer much better than those of HVT vaccine-immunized chicks.

  10. Long-term effects of corn, soybean meal, wheat bran, and fish meal on manganese utilization in the chick.

    Science.gov (United States)

    Halpin, K M; Baker, D H

    1986-07-01

    A 7-week assay was conducted to investigate the long-term effects of several natural feed ingredients on Mn utilization. Chicks were fed a Mn-deficient casein-dextrose diet supplemented with fish meal, wheat bran, or a corn-soybean meal mixture. Although these feed ingredients contain significant quantities of Mn, they actually depressed performance and reduced the Mn concentration in key tissues when dietary Mn was near the chick's minimal requirement. At deficient levels of dietary Mn, fish meal also had detrimental effects on those parameters, and it increased the severity of perosis as well. PMID:3748949

  11. Investigation of the Effects of Pre-Incubation Formaldehyde Fumigation on the Tracheal Epithelium of Chicken Embryos and Chicks

    OpenAIRE

    HAYRETDAĞ, Sibel; KOLANKAYA, Dürdane

    2008-01-01

    This study aimed to evaluate the effects of pre-incubation formaldehyde fumigation on the tracheal epithelium of chicken embryos and chicks. Throughout the study pre-incubation formaldehyde fumigation was applied to 18-day-old embryos and 1-day-old chicks only once, at 1 of 2 different concentrations (3x, 42 ml of formalin and 21 g of potassium permanganate per m3 and 4x, 56 ml of formalin and 28 g of potassium permanganate per m3) for 1 of 2 different durations (20 min and 40 min). Tracheal ...

  12. Hippocampus and medial striatum dissociation during goal navigation by geometry or features in the domestic chick: An immediate early gene study.

    Science.gov (United States)

    Mayer, Uwe; Pecchia, Tommaso; Bingman, Verner Peter; Flore, Michele; Vallortigara, Giorgio

    2016-01-01

    We employed a standard reference memory task to study the involvement of the hippocampal formation (HF) of domestic chicks that used the boundary geometry of a test environment to orient to and locate a reward. Using the immediate early gene product c-Fos as a neuronal activity marker, we found enhanced HF activation in chicks that learned to locate rewarded corners using the shape of a rectangular arena compared to chicks trained to solve the task by discriminating local features in a square-shaped arena. We also analyzed neuronal activity in the medial part of the medial striatum (mMSt). Surprisingly, in mMSt we observed a reverse pattern, with higher activity in the chicks that were trained to locate the goal by local features. Our results identify two seemingly parallel, memory systems in chicks, with HF central to the processing of spatial-geometrical information and mMSt important in supporting local feature discrimination. PMID:26135386

  13. A theory of generalized Bloch oscillations.

    Science.gov (United States)

    Duggen, Lars; Lew Yan Voon, L C; Lassen, Benny; Willatzen, Morten

    2016-04-20

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact calculation is given to confirm this phenomenon. Our results allow for a greater freedom of design for experimentally observing Bloch oscillations. For strongly coupled oscillator systems displaying Bloch oscillations, it is further demonstrated that reordering of oscillators leads to destruction of Bloch oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics.

  14. A theory of generalized Bloch oscillations

    DEFF Research Database (Denmark)

    Duggen, Lars; Lew Yan Voon, L. C.; Lassen, Benny;

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact...... calculation is given to confirm this phenomenon. Our results allow for a greater freedom of design for experimentally observing Bloch oscillations. For strongly coupled oscillator systems displaying Bloch oscillations, it is further demonstrated that reordering of oscillators leads to destruction of Bloch...... oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics....

  15. Cosmological constraints on neutrino oscillations

    International Nuclear Information System (INIS)

    Solar, atmospheric and terrestrial neutrino experiments have provided evidence for neutrino oscillations. These neutrino anomalies were successfully explained in terms of neutrino oscillations, the dominant channels being flavour neutrino oscillations. The role of sterile neutrinos and the active-sterile subdominant channels are being explored presently. Therefore, we discuss all cosmological effects of active-sterile neutrino oscillations on the early Universe evolution, and particularly the effects on the nucleosynthesis epoch. Numerical analysis of the cosmological production of He-4, Yp in the presence of νe ↔ νs, effective after νe decoupling from the equilibrium, was provided for the full neutrino oscillations parameter range. These neutrino oscillations lead always to an overproduction of He-4. We have obtained isohelium contours corresponding to different levels of He-4 overproduction, δYp/Yp, for initial population of the sterile state in the range 0 ≤ δNs ≤ 0.5. Cosmological constraints on oscillation parameters, obtained on the base of the calculated isohelium contours and Yp observational data, are discussed. We present the constraints corresponding toδNs = 0.0 and 0.5, and helium overproduction δYp/Yp = 3%. These cosmological constraints, being more stringent than the ones provided from the neutrino experimental data, provide valuable information for the impact of sterile neutrino in the neutrino anomalies and for the neutrino physics in general. (author)

  16. Effect of chick weight, geometric mean diameter and sodium level in prestarter diets (1 to 7 days on broiler perfomance up to 21 days of age

    Directory of Open Access Journals (Sweden)

    AML Ribeiro

    2004-12-01

    Full Text Available Seven hundred and twenty Ross 308 chicks were raised in a controlled environment room, distributed in a factorial design with 3 hatching chick weights (37, 40 and 44 g, 3 geometric mean diameter (GMD (0.561; 0.783 and 0.997 mm and 4 total sodium levels (Na (0.12; 0.24; 0.36 and 0.48% in the pre-starter diet (1 to 7 days. From 8 to 21 days (d one single basal diet was used for all treatments. The thirty seven-gram chicks had the smallest yolk sack weight at 4d, smallest body weight (BW and feed intake (FI at 7d and 21d, but the same feed conversion (FC than the other groups of hatching weight. Chicks receiving diet with intermediate GMD had the greatest BW and FI at 7d, but at 21d this effect was no longer seen. The diet with finest particle size resulted in birds with the smallest gizzard weight at 7d. The 0.12%Na diet was statistically different from the other Na levels, resulting in chicks at 7d with the worst FC and lowest body weights. At 21d, BW still was the lowest for this group of chicks. Birds with 0.48%Na produced more watery excreta and less dry matter in the carcass at 7d. Water consumption (C H2O was influenced linearly by chick weight up to 0.36%Na level. In the 0.48%Na level, 40 and 44 g chicks had similar C H2O, which was different from 37-g chicks. For best performance, Na values were set from 0.31 to 0.48%. The three studied factors influenced quality of pre-starter diet and consequently chick performance.

  17. Nkx2.2+ Progenitors Generate Somatic Motoneurons in the Chick Spinal Cord

    Science.gov (United States)

    Gotoh, Hitoshi; Ono, Katsuhiko; Nomura, Tadashi; Takebayashi, Hirohide; Harada, Hidekiyo; Nakamura, Harukazu; Ikenaka, Kazuhiro

    2012-01-01

    Heterogeneous classes of neurons are present in the spinal cord and are essential for its function. Expression patterns of transcription factors in neural progenitor cells determine neuron subtypes during development. Nkx2.2 is expressed in the progenitor cell pool located just ventrally to the Olig2-positive pool and is indispensable for V3 interneuron generation in the spinal cord and also for visceral motoneuron generation in the hindbrain. However, whether Nkx2.2-positive progenitor cells generate diverse classes of neuron is not fully understood. Using a chick lineage tracing method in a genetically-defined manner, we found that Nkx2.2-expressing progenitor cells differentiate into general visceral motoneurons as well as sim1-positive V3 interneurons. Surprisingly, we further observed that Nkx2.2-expressing progenitors differentiate into somatic motoneuron. Our findings suggest that the different classes of motoneurons are derived from more complex sources than were previously expected in the chick spinal cord. PMID:23284718

  18. Chicks, like children, spontaneously reorient by three-dimensional environmental geometry, not by image matching.

    Science.gov (United States)

    Lee, Sang Ah; Spelke, Elizabeth S; Vallortigara, Giorgio

    2012-08-23

    Spatial reorientation by layout geometry occurs in numerous species, but its underlying mechanisms are debated. While some argue that navigating animals' sense of place is based on geometric computations over three-dimensional representations, others claim it depends on panoramic image-matching processes. Because children reorient by subtle three-dimensional perturbations of the terrain and not by salient two-dimensional brightness contours on surfaces or freestanding columns, children's sense of place cannot be explained by image matching. To test image-matching theories in a different species, the present experiment investigates the reorientation performance of domestic chicks (Gallus gallus) in environments similar to those used with children. Chicks, like children, spontaneously reoriented by geometric relationships of subtle three-dimensional terrains, and not by salient two-dimensional brightness contours on surfaces or columns. These findings add to the evidence for homologous navigation systems in humans and other vertebrates, and they cast doubt on image-matching theories of reorientation in these species. PMID:22417791

  19. Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

    Directory of Open Access Journals (Sweden)

    Harald van Lintel

    2010-01-01

    Full Text Available We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.

  20. Measurement of strain and strain rate in embryonic chick heart using spectral domain optical coherence tomography

    Science.gov (United States)

    Dou, Shidan; Suo, Yanyan; Liang, Chengbo; Wang, Yi; Zhao, Yuqian; Liu, Jian; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

    2016-03-01

    It is important to measure embryonic heart myocardial wall strain and strain rate for understanding the mechanisms of embryonic heart development. Optical coherence tomography (OCT) can provide depth resolved images with high spatial and temporal resolution, which makes it have the potential to reveal the complex myocardial activity in the early stage embryonic heart. We develop a novel method to measure strain in embryonic chick heart based on spectral domain OCT images and subsequent image processing. We perform 4D(x,y,z,t) scanning on the outflow tract (OFT) of chick embryonic hearts in HH18 stage (~3 days of incubation). Only one image sequence acquired at the special position is selected based on the Doppler blood flow information where the probe beam penetrates through the OFT perpendicularly. For each image of the selected sequence, the cross-section of the myocardial wall can be approximated as an annulus. The OFT is segmented with a semi-automatic boundary detection algorithm, thus the area and mean circumference of the annular myocardial wall can be achieved. The myocardial wall thickness was calculated using the area divided by the mean circumference, and then the strain was obtained. The results demonstrate that OCT can be a useful tool to describe the biomechanical characteristics of the embryonic heart.

  1. Modeling gastrulation in the chick embryo: formation of the primitive streak.

    Directory of Open Access Journals (Sweden)

    Bakhtier Vasiev

    Full Text Available The body plan of all higher organisms develops during gastrulation. Gastrulation results from the integration of cell proliferation, differentiation and migration of thousands of cells. In the chick embryo gastrulation starts with the formation of the primitive streak, the site of invagination of mesoderm and endoderm cells, from cells overlaying Koller's Sickle. Streak formation is associated with large-scale cell flows that carry the mesoderm cells overlying Koller's sickle into the central midline region of the embryo. We use multi-cell computer simulations to investigate possible mechanisms underlying the formation of the primitive streak in the chick embryo. Our simulations suggest that the formation of the primitive streak employs chemotactic movement of a subpopulation of streak cells, as well as differential adhesion between the mesoderm cells and the other cells in the epiblast. Both chemo-attraction and chemo-repulsion between various combinations of cell types can create a streak. However, only one combination successfully reproduces experimental observations of the manner in which two streaks in the same embryo interact. This finding supports a mechanism in which streak tip cells produce a diffusible morphogen which repels cells in the surrounding epiblast. On the other hand, chemotactic interaction alone does not reproduce the experimental observation that the large-scale vortical cell flows develop simultaneously with streak initiation. In our model the formation of large scale cell flows requires an additional mechanism that coordinates and aligns the motion of neighboring cells.

  2. FT-IR microscopic mappings of early mineralization in chick limb bud mesenchymal cell cultures

    Science.gov (United States)

    Boskey, A. L.; Camacho, N. P.; Mendelsohn, R.; Doty, S. B.; Binderman, I.

    1992-01-01

    Chick limb bud mesenchymal cells differentiate into chondrocytes and form a cartilaginous matrix in culture. In this study, the mineral formed in different areas within cultures supplemented with 4 mM inorganic phosphate, or 2.5, 5.0, and 10 mM beta-glycerophosphate (beta GP), was characterized by Fourier-transform infrared (FT-IR) microscopy. The relative mineral-to-matrix ratios, and distribution of crystal sizes at specific locations throughout the matrix were measured from day 14 to day 30. The only mineral phase detected was a poorly crystalline apatite. Cultures receiving 4 mM inorganic phosphate had smaller crystals which were less randomly distributed around the cartilage nodules than those in the beta GP-treated cultures. beta GP-induced mineral consisted of larger, more perfect apatite crystals. In cultures receiving 5 or 10 mM beta GP, the relative mineral-to-matrix ratios (calculated from the integrated intensities of the phosphate and amide I bands, respectively) were higher than in the cultures with 4 mM inorganic phosphate or in the in vivo calcified chick cartilage.

  3. EFFECT OF SELENIUM SUPPLEMENTATION ON ANTIBODY TITRES AGAINST INFECTIOUS BURSAL DISEASE VACCINE IN BROILER CHICKS

    Directory of Open Access Journals (Sweden)

    M. Arshad, M. Siddique, M. Ashraf and H. A. Khan

    2005-10-01

    Full Text Available A total of 200 chicks were raised upto 43 days of age under controlled experimental conditions. The birds were randomly divided into four groups A, B, C and D of 50 birds each at the age of day one. Birds of groups A and B were not supplemented with selenium, while those of groups C and D were given selenium @ 0.06 mg/Kg of feed from day one to day 43. The birds of groups B and D were vaccinated against infectious bursal disease (IBD at the age of day 10 and boosted at the age of day 25. The effect of selenium on humoral immune response was evaluated by recording weekly serum antibody titres against IBD through indirect haemagglutination (IHA test. The cumulative mean titres (CMT recorded in groups A, B, C and D were 15, 53, 16 and 61, respectively (P<0.05. These results indicate that selenium supplementation may help to increase post vaccination humoral immune response against IBD in broiler chicks.

  4. Central administration of dipeptides, beta-alanyl-BCAAs, induces hyperactivity in chicks

    Directory of Open Access Journals (Sweden)

    Denbow D Michael

    2007-05-01

    Full Text Available Abstract Background Carnosine (β-alanyl-L-histidine is a putative neurotransmitter and has a possible role in neuron-glia cell interactions. Previously, we reported that carnosine induced hyperactivity in chicks when intracerebroventricularly (i.c.v. administered. In the present study, we focused on other β-alanyl dipeptides to determine if they have novel functions. Results In Experiment 1, i.c.v. injection of β-alanyl-L-leucine, but not β-alanyl-glycine, induced hyperactivity behavior as observed with carnosine. Both carnosine and β-alanyl-L-leucine stimulated corticosterone release. Thus, dipeptides of β-alanyl-branched chain amino acids were compared in Experiment 2. The i.c.v. injection of β-alanyl-L-isoleucine caused a similar response as β-alanyl-L-leucine, but β-alanyl-L-valine was somewhat less effective than the other two dipeptides. β-Alanyl-L-leucine strongly stimulated, and the other two dipeptides tended to stimulate, corticosterone release. Conclusion These results suggest that central β-alanyl-branched chain amino acid stimulates activity in chicks through the hypothalamus-pituitary-adrenal axis. We named β-alanyl-L-leucine, β-alanyl-L-isoleucine and β-alanyl-L-valine as Excitin-1, Excitin-2 and Excitin-3, respectively.

  5. Clinical and biochemical effects of aflatoxin in feed ration of chicks.

    Science.gov (United States)

    Chattopadhyay, S K; Taskar, P K; Schwabe, O; Das, Y T; Brown, H D

    1985-06-01

    Aflatoxin carcinogenesis appears to relate to multiple factors. This includes bulky adduct formation at DNA guanine N-7. The process also requires more extensive physiological degradation, possibly by the toxin alone as the active principle, but in instances also involving other assaults (e.g., hepatitis B virus). Since aflatoxin carcinogenesis involves complex effects, we have undertaken to define the range of influence of this common food contaminant upon a susceptible model, the broiler-type chick. Aflatoxicosis in two treated groups was indicated by jaundice, coagulopathy, dehydration of combs and shanks, retardation of body weight, and decrease in bursa weight. Blood clotting time, hemoglobin content, erythrocyte and packed-cell volume were affected. Hepatocytes were swollen and had undergone fatty degeneration. Bile duct hyperplasia was evident. Total serum protein, alkaline phosphatase, creatine, lactate dehydrogenase, serum glutamic oxalacetic transaminase and glutamyl transpeptidase were similarly abnormal in birds receiving the contaminated (0.5 and 2.5 micrograms/g aflatoxin B1) feed rations. The aflatoxin B1 and its metabolites were isolated by HPLC from chick serum, liver and muscle.

  6. Spatiotemporal distribution of 1P1 antigen expression in the plexiform layers of developing chick retina

    Institute of Scientific and Technical Information of China (English)

    WANGHOUHUA; QIUBAOSONG; 等

    1993-01-01

    Changes in the distribution of 1P1-antigen in the developing chick retina have been examined by indriect immunofluorescence staining technique using the novel monoclonal antibody(MAb)1P1.Expression of the 1P1 antigen was found to be regulated in radial as well as in tangential dimension of the retina,being preferentially or exclusively located in the inner and outer plexiform layers of the neural retina depending on the stages of development ,With the onset of the formation of the inner plexiform layer 1P1 antigen becomes expressed in the retina.With progressing differentiation of the inner plexiform layer 1P1 immunofluorescence revealed 2 subbands at E9 and 6 subands at E18,At postnatal stages(after P3) immunoreactivity was reduced in an inside-outside sequence leading to the complete absence of the 1P1 antigen in adulthood.1P1 antigen expression in the outer plexiform layer was also subject to developmental regulation.The spation-temporal pattern of 1P1 antigen expression was correlated with the time course of histological differentation of chick retina,namely the synapse rich plexiform layers.Whether the 1P1 antigen was functionally involved in dendrite extension and synapse formation was discussed.

  7. Rediscovering the chick embryo as a model to study retinal development

    Directory of Open Access Journals (Sweden)

    Vergara M Natalia

    2012-06-01

    Full Text Available Abstract The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system.

  8. Proanthocyanidins Prevent High Glucose-Induced Eye Malformation by Restoring Pax6 Expression in Chick Embryo

    Directory of Open Access Journals (Sweden)

    Rui-Rong Tan

    2015-08-01

    Full Text Available Gestational diabetes mellitus (GDM is one of the leading causes of offspring malformations, in which eye malformation is an important disease. It has raised demand for therapy to improve fetal outcomes. In this study, we used chick embryo to establish a GDM model to study the protective effects of proanthocyanidins on eye development. Chick embryos were exposed to high glucose (0.2 mmol/egg on embryo development day (EDD 1. Proanthocyanidins (1 and 10 nmol/egg were injected into the air sac on EDD 0. Results showed that both dosages of proanthocyanidins could prevent the eye malformation and rescue the high glucose-induced oxidative stress significantly, which the similar effects were showed in edaravone. However, proanthocyanidins could not decrease the glucose concentration of embryo eye. Moreover, the key genes regulating eye development, Pax6, was down-regulated by high glucose. Proanthocyanidins could restore the suppressed expression of Pax6. These results indicated proanthocyanidins might be a promising natural agent to prevent high glucose-induced eye malformation by restoring Pax6 expression.

  9. Protein expression profiling during chick retinal maturation: a proteomics-based approach

    Directory of Open Access Journals (Sweden)

    Stitt Alan W

    2008-12-01

    Full Text Available Abstract Background The underlying pathways that drive retinal neurogenesis and synaptogenesis are still relatively poorly understood. Protein expression analysis can provide direct insight into these complex developmental processes. The aim of this study was therefore to employ proteomic analysis to study the developing chick retina throughout embryonic (E development commencing at day 12 through 13, 17, 19 and post-hatch (P 1 and 33 days. Results 2D proteomic and mass spectrometric analysis detected an average of 1514 spots per gel with 15 spots demonstrating either modulation or constitutive expression identified via MS. Proteins identified included alpha and beta-tubulin, alpha enolase, B-creatine kinase, gamma-actin, platelet-activating factor (PAF, PREDICTED: similar to TGF-beta interacting protein 1, capping protein (actin filament muscle Z line, nucleophosmin 1 (NPM1, dimethylarginine dimethylaminohydrolase, triosphoaphate isomerase, DJ1, stathmin, fatty acid binding protein 7 (FABP7/B-FABP, beta-synuclein and enhancer of rudimentary homologue. Conclusion This study builds upon previous proteomic investigations of retinal development and represents the addition of a unique data set to those previously reported. Based on reported bioactivity some of the identified proteins are most likely to be important to normal retinal development in the chick. Continued analysis of the dynamic protein populations present at the early stages and throughout retinal development will increase our understanding of the molecular events underpinning retinogenesis.

  10. Imprinting modulates processing of visual information in the visual wulst of chicks

    Directory of Open Access Journals (Sweden)

    Uchimura Motoaki

    2006-11-01

    Full Text Available Abstract Background Imprinting behavior is one form of learning and memory in precocial birds. With the aim of elucidating of the neural basis for visual imprinting, we focused on visual information processing. Results A lesion in the visual wulst, which is similar functionally to the mammalian visual cortex, caused anterograde amnesia in visual imprinting behavior. Since the color of an object was one of the important cues for imprinting, we investigated color information processing in the visual wulst. Intrinsic optical signals from the visual wulst were detected in the early posthatch period and the peak regions of responses to red, green, and blue were spatially organized from the caudal to the nasal regions in dark-reared chicks. This spatial representation of color recognition showed plastic changes, and the response pattern along the antero-posterior axis of the visual wulst altered according to the color the chick was imprinted to. Conclusion These results indicate that the thalamofugal pathway is critical for learning the imprinting stimulus and that the visual wulst shows learning-related plasticity and may relay processed visual information to indicate the color of the imprint stimulus to the memory storage region, e.g., the intermediate medial mesopallium.

  11. Advanced light source master oscillator

    International Nuclear Information System (INIS)

    The Master Oscillator of the Advanced Light Source operates at a frequency of 499.654 MHz which is the 328th harmonic of the storage ring. The oscillator is capable of providing up to a maximum of ± 500 KHz frequency deviation for various experimental purposes. Provisions for external signal injection as well as using an external signal source have been designed into the unit. A power distribution system has also been included to provide signals for various parts of the ALS machine and user requirements. The Master Oscillator is made up with modules housed in a Euro chassis. 4 refs., 7 figs

  12. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    Lin Xiao-Gang; Liu Wen-Jun; Lei Ming

    2016-03-01

    Oscillating solitons are obtained in nonlinear optics. Analytical study of the variable coefficient nonlinear Schrödinger equation, which is used to describe the soliton propagation in those systems, is carried out using the Hirota’s bilinear method. The bilinear forms and analytic soliton solutions are derived, and the relevant properties and features of oscillating solitons are illustrated. Oscillating solitons are controlled by the reciprocal of the group velocity and Kerr nonlinearity. Results of this paper will be valuable to the study of dispersion-managed optical communication system and mode-locked fibre lasers.

  13. Gravitational Wave - Gauge Field Oscillations

    CERN Document Server

    Caldwell, R R; Maksimova, N A

    2016-01-01

    Gravitational waves propagating through a stationary gauge field transform into gauge field waves and back again. When multiple families of flavor-space locked gauge fields are present, the gravitational and gauge field waves exhibit novel dynamics. At high frequencies, the system behaves like coupled oscillators in which the gravitational wave is the central pacemaker. Due to energy conservation and exchange among the oscillators, the wave amplitudes lie on a multi-dimensional sphere, reminiscent of neutrino flavor oscillations. This phenomenon has implications for cosmological scenarios based on flavor-space locked gauge fields.

  14. Modeling Oscillations of Magnetizable Microdrops

    Directory of Open Access Journals (Sweden)

    G.V. Shagrova

    2015-12-01

    Full Text Available Developed a system of computer simulation of oscillations of magnetizable microdrops in a wide range of changing their parameters: surface tension, viscosity, magnetic permeability, density, and radius. Computational experiments of oscillations of magnetizable drops in an alternating magnetic field and the influence of various forces of nature (inertial, viscous, surface and magnetic on the nature of the oscillations were carried out. Adequacy of the model, used as the basis for the developed system of computer simulation was shown on the basis of computational and experimental data.

  15. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik;

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular...... feedback. We investigate the intra- and internephron entrainment of the two time scales. In addition to full synchronization, both wavelet analyses of experimental data and numerical simulations reveal a partial entrainment in which neighboring nephrons attain a state of chaotic synchronization...

  16. Collective oscillations in a plasma

    CERN Document Server

    Akhiezer, A I; Polovin, R V; ter Haar, D

    2013-01-01

    International Series of Monographs in Natural Philosophy: Collective Oscillations in a Plasma, Volume 7 presents specific topics within the general field of radio waves propagation. This book contains five chapters that address the theory of linear oscillations in a plasma, the spectra of the eigen oscillations, and the mechanism of high-frequency heating. The opening chapters deal with the self-consistent fields; development of initial perturbation; dispersion permittivity tensor of a plasma in a magnetic field; effect of thermal motion of particles on low-frequency resonances; excitation of

  17. Current Self-Oscillations in Negative Effective Mass Terahertz Oscillators

    Institute of Scientific and Technical Information of China (English)

    曹俊诚

    2002-01-01

    We theoretically study current self-oscillations and spatiotemporal current patterns in quantum-well negativeeffective mass (NEM) p+ pp+ diodes by considering scattering contributions from impurity, acoustic phonons andoptic phonons. It is indicated that both the applied bias and the doping concentration strongly influence thepatterns and self-oscillating frequencies. The NEM p+pp+ diode presented here may be used as an electricallytunable terahertz source.

  18. Fission waves can oscillate

    CERN Document Server

    Osborne, Andrew G

    2016-01-01

    Under the right conditions, self sustaining fission waves can form in fertile nuclear materials. These waves result from the transport and absorption of neutrons and the resulting production of fissile isotopes. When these fission, additional neutrons are produced and the chain reaction propagates until it is poisoned by the buildup of fission products. It is typically assumed that fission waves are soliton-like and self stabilizing. However, we show that in uranium, coupling of the neutron field to the 239U->239Np->239Pu decay chain can lead to a Hopf bifurcation. The fission reaction then ramps up and down, along with the wave velocity. The critical driver for the instability is a delay, caused by the half-life of 239U, between the time evolution of the neutron field and the production of 239Pu. This allows the 239Pu to accumulate and burn out in a self limiting oscillation that is characteristic of a Hopf bifurcation. Time dependent results are obtained using a numerical implementation of a reduced order r...

  19. Galactic oscillator symmetry

    Science.gov (United States)

    Rosensteel, George

    1995-01-01

    Riemann ellipsoids model rotating galaxies when the galactic velocity field is a linear function of the Cartesian coordinates of the galactic masses. In nuclear physics, the kinetic energy in the linear velocity field approximation is known as the collective kinetic energy. But, the linear approximation neglects intrinsic degrees of freedom associated with nonlinear velocity fields. To remove this limitation, the theory of symplectic dynamical symmetry is developed for classical systems. A classical phase space for a self-gravitating symplectic system is a co-adjoint orbit of the noncompact group SP(3,R). The degenerate co-adjoint orbit is the 12 dimensional homogeneous space Sp(3,R)/U(3), where the maximal compact subgroup U(3) is the symmetry group of the harmonic oscillator. The Hamiltonian equations of motion on each orbit form a Lax system X = (X,F), where X and F are elements of the symplectic Lie algebra. The elements of the matrix X are the generators of the symplectic Lie algebra, viz., the one-body collective quadratic functions of the positions and momenta of the galactic masses. The matrix F is composed from the self-gravitating potential energy, the angular velocity, and the hydostatic pressure. Solutions to the hamiltonian dynamical system on Sp(3,R)/U(3) are given by symplectic isospectral deformations. The Casimirs of Sp(3,R), equal to the traces of powers of X, are conserved quantities.

  20. Oscillations in Mathematical Biology

    CERN Document Server

    1983-01-01

    The papers in this volume are based on talks given at a one day conference held on the campus of Adelphi University in April 1982. The conference was organized with the title "Oscillations in Mathematical Biology;" however the speakers were allowed considerable latitutde in their choice of topics. In the event, the talks all concerned the dynamics of non-linear systems arising in biology so that the conference achieved a good measure of cohesion. Some of the speakers cho~e not to submit a manuscript for these proceedings, feeling that their material was too conjectural to be committed to print. Also the paper of Rinzel and Troy is a distillation of the two separate talks that the authors gave. Otherwise the material reproduces the conference proceedings. The conference was made possible by the generous support of the Office of the Dean of the College of Arts and Sciences at Adelphi. The bulk of the organization of the conference was carried out by Dr. Ronald Grisell whose energy was in large measure responsib...

  1. Redistribution of calbindin-D28k in chick intestine in response to calcium transport.

    Science.gov (United States)

    Nemere, I; Leathers, V L; Thompson, B S; Luben, R A; Norman, A W

    1991-12-01

    Vitamin D and its hormonally active metabolite 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] are known to alter several parameters associated with stimulated intestinal Ca2+ transport: levels of calbindin-D28K, tubulin, and endosomal-lysosomal organelles containing Ca2+, and calbindin-D28K. In the present study the as yet unexamined relationship among Ca2+ transport, calbindin-D28K, and microtubules was studied by immunofluorescence microscopy. In vitamin D3-treated or 1,25-(OH)2D3-treated chicks, in the absence of Ca2+ transport, immunofluorescence microscopy of intestinal tissue fixed at 25 C indicated a colocalization of calbindin-D28K and tubulin along epithelial cell brush border and basal-lateral membranes. Initiation of in situ Ca2+ absorption for 10, 20, or 30 min before tissue fixation resulted first in increased punctate calbindin-D28K staining and then in a progressive decrease in intestinal cell- and microtubule-associated calbindin-D28K, with a concomitant increase in calbindin-D28K labeling in the villus core. When intestinal tissue from 1,25-(OH)2D3-treated chicks was chilled to 4 C before fixation (a procedure shown by others to cause microtubule depolymerization), evaluation by immunofluorescence microscopy revealed diffuse cytoplasmic staining of both the immunoreactive tubulin and its associated calbindin-D28K. These results indicate the possible involvement of calbindin-D28K with tubulin during the process of Ca2+ transport and the secretion of the calbindin-D28K as a consequence of the overall transport process. Electron microscopy with immunogold labeling revealed intestinal epithelial calbindin-D28K to be localized inside of small vesicles and lysosome-like structures, with sparse cytoplasmic labeling. Subsequent electron microscopic analysis of intestinal epithelial microtubules prepared by polymerization and depolymerization revealed immunogold labeling in coprecipitated vesicular remnants, with consistently light staining of filaments traversing

  2. Radiation damping of betatron oscillations

    International Nuclear Information System (INIS)

    The emission of synchrotron radiation damps the incoherent betatron oscillations of a pinched beam, causing its radius to shrink. However, the rate of shrinkage is small compared with the rate of expansion caused by scattering for typical propagation parameters

  3. An Oscillating Magnet Watt Balance

    CERN Document Server

    Ahmedov, H

    2015-01-01

    We establish the principles for a new generation of simplified and accurate watt balances in which an oscillating magnet generates Faraday's voltage in a stationary coil. A force measuring system and a mechanism providing vertical movements of the magnet are completely independent in an oscillating magnet watt balance. This remarkable feature allows to establish the link between the Planck constant and a macroscopic mass by a one single experiment. Weak dependence on variations of environmental and experimental conditions, weak sensitivity to ground vibrations and temperature changes, simple force measuring procedure, small sizes and other useful features offered by the novel approach considerably reduce the complexity of the experimental setup. We formulate the oscillating magnet watt balance principle and establish the measurement procedure for the Planck constant. We discuss the nature of oscillating magnet watt balance uncertainties and give a brief description of the National Metrology Institute (UME) wa...

  4. Matter Effects On Neutrino Oscillations

    Science.gov (United States)

    Gordon, Michael

    An introduction to neutrino oscillations in vacuum is presented, followed by a survey of various techniques for obtaining either exact or approximate expressions for numu → nue oscillations in matter. The method developed by Arafune, Koike, and Sato uses a perturbative analysis to find an approximation for the evolution operator. The method used by Freund yields an approximate oscillation probability by diagonalizing the Hamiltonian, finding the eigenvalues and eigenvectors, and then using those to find modified mixing angles with the matter effect taken into account. The method devised by Mann, Kafka, Schneps, and Altinok produces an exact expression for the oscillation by determining explicitly the evolution operator. These methods are compared to each other using the T2K, MINOS, NOnuA, and LBNE parameters.

  5. Strongly nonlinear oscillators analytical solutions

    CERN Document Server

    Cveticanin, Livija

    2014-01-01

    This book provides the presentation of the motion of pure nonlinear oscillatory systems and various solution procedures which give the approximate solutions of the strong nonlinear oscillator equations. The book presents the original author’s method for the analytical solution procedure of the pure nonlinear oscillator system. After an introduction, the physical explanation of the pure nonlinearity and of the pure nonlinear oscillator is given. The analytical solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter is considered. Special attention is given to the one and two mass oscillatory systems with two-degrees-of-freedom. The criteria for the deterministic chaos in ideal and non-ideal pure nonlinear oscillators are derived analytically. The method for suppressing chaos is developed. Important problems are discussed in didactic exercises. The book is self-consistent and suitable as a textbook for students and also for profess...

  6. Atmospheric Neutrino Oscillations in Antares

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, J.

    2013-04-15

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximum mixing, a mass difference of Δm{sub 32}{sup 2}=(3.1±0.9)⋅10{sup −3}eV{sup 2} is obtained, in good agreement with the world average value.

  7. Gamma Oscillations and Visual Binding

    Science.gov (United States)

    Robinson, Peter A.; Kim, Jong Won

    2006-03-01

    At the root of visual perception is the mechanism the brain uses to analyze features in a scene and bind related ones together. Experiments show this process is linked to oscillations of brain activity in the 30-100 Hz gamma band. Oscillations at different sites have correlation functions (CFs) that often peak at zero lag, implying simultaneous firing, even when conduction delays are large. CFs are strongest between cells stimulated by related features. Gamma oscillations are studied here by modeling mm-scale patchy interconnections in the visual cortex. Resulting predictions for gamma responses to stimuli account for numerous experimental findings, including why oscillations and zero-lag synchrony are associated, observed connections with feature preferences, the shape of the zero-lag peak, and variations of CFs with attention. Gamma waves are found to obey the Schroedinger equation, opening the possibility of cortical analogs of quantum phenomena. Gamma instabilities are tied to observations of gamma activity linked to seizures and hallucinations.

  8. Analysis of Rattleback Chaotic Oscillations

    OpenAIRE

    Michael Hanias; Stavrinides, Stavros G.; Santo Banerjee

    2014-01-01

    Rattleback is a canoe-shaped object, already known from ancient times, exhibiting a nontrivial rotational behaviour. Although its shape looks symmetric, its kinematic behaviour seems to be asymmetric. When spun in one direction it normally rotates, but when it is spun in the other direction it stops rotating and oscillates until it finally starts rotating in the other direction. It has already been reported that those oscillations demonstrate chaotic characteristics. In this paper, rattleback...

  9. Hyperchaos in coupled Colpitts oscillators

    DEFF Research Database (Denmark)

    Cenys, Antanas; Tamasevicius, Arunas; Baziliauskas, Antanas;

    2003-01-01

    chaotic signals, v(t) = (v(1) + v(2))/2. The corresponding differential equations have been derived. The results of both, numerical simulations and hardware experiments are presented. The coupling coefficient k proportional to 1/R-k should be small to avoid mutual synchronisation of the individual...... oscillators. The spectrum of the Lyapunov exponents (LE) have been calculated versus the coefficient k. For weakly coupled oscillators there are two positive LE indicating hyperchaotic behaviour of the overall system....

  10. The Great Season Climatic Oscillation

    OpenAIRE

    Boucenna, Ahmed

    2007-01-01

    The variations of water density and thermal conductivity of the oceans cold region waters according to their salinity lead to suggest an hypothesis of an oscillating climate between two extreme positions: a maximum of hot temperatures and a minimum of cold ones. It will be shown that the distance separating the surface hot streams from the depth cold ones oscillate between two limit values linked to the optimal melting and regeneration glaciers. The melting and regeneration glaciers cycle lea...

  11. Harmonic Oscillators and Elementary Particles

    CERN Document Server

    Sobouti, Y

    2016-01-01

    Two dynamical systems with same symmetry should have features in common, and as far as their shared symmetry is concerned, one may represent the other. The three light quark constituents of the hadrons, a) have an approximate flavor SU(3) symmetry, b) have an exact color SU(3) symmetry, and c) as spin 1/2 particles, have a Lorentz SO(3,1) symmetry. So does a 3D harmonic oscillator. a) Its Hamiltonian has the SU(3) symmetry, breakable if the 3 fundamental modes of oscillation are not identical. b) The 3 directions of oscillation have the permutation symmetry. This enables one to create three copies of unbreakable SU(3) symmetry for each mode of the oscillation, and mimic the color of the elementary particles. And c) The Lagrangian of the 3D oscillator has the SO(3,1) symmetry. This can be employed to accommodate the spin of the particles. In this paper we draw up a one-to-one correspondence between the eigen modes of the Poisson bracket operator of the 3D oscillator and the flavor multiplets of the particles, ...

  12. Sedative effect of central administration of Coriandrum sativum essential oil and its major component linalool in neonatal chicks.

    Science.gov (United States)

    Gastón, María Soledad; Cid, Mariana Paula; Vázquez, Ana María; Decarlini, María Florencia; Demmel, Gabriela I; Rossi, Laura I; Aimar, Mario Leandro; Salvatierra, Nancy Alicia

    2016-10-01

    Context Coriandrum sativum L. (Apiaceae) (coriander) is an herb grown throughout the world as a culinary, medicinal or essential crop. In traditional medicine, it is used for the relief of anxiety and insomnia. Systemic hydro-alcoholic and aqueous extract from aerial parts and seeds had anxiolytic and sedative action in rodents, but little is known about its central effect in chicks. Objective To study the effects of intracerebroventricular administration of essential oil from coriander seeds and its major component linalool on locomotor activity and emotionality of neonatal chicks. Materials and methods The chemical composition of coriander essential oil was determined by a gas-chromatographic analysis (> 80% linalool). Behavioural effects of central administration of coriander oil and linalool (both at doses of 0.86, 8.6 and 86 μg/chick) versus saline and a sedative diazepam dose (17.5 μg/chick, standard drug) in an open field test for 10 min were observed. Results Doses of 8.6 and 86 μg from coriander oil and linalool significantly decreased (p linalool, which also induced a similar sedative effect, and, therefore, could be considered as a potential therapeutic agent similar to diazepam.

  13. Identification of Gelatinases involved in the Rous sarcoma Virus-induced Tumors in Chicks as Prognostic Markers

    Directory of Open Access Journals (Sweden)

    A.M. Kotresh and Meena Kataria

    Full Text Available The present work is undertaken to study the expression of levels of gelatinases in tumorogenesis by Rous sarcoma virus(RSV in layer chicks and explored the possibility of using gelatinases as potential biological markers in metastatic neoplasms. Two days old chicks (40 were divided into two groups (Gp I and Gp II. Gp-I (20 treated with Rous sarcoma virus for tumor induction. The Gp II (control was inoculated with RPMI-1640. Tumors appeared earliest by three days post infection with RSV and were progressive leading to mortality of birds by twenty eight days. Distant tumors were observed in liver, heart, lung, and kidney on post mortem. A prominent band of gelatinase of around 75 kDa was detected in plasma of infected chicks by gelatin zymography. Results indicate over expression of gelatinases and are leaked into plasma on Rous sarcoma virus infection. Expression of gelatinases in primary tumors, metastasized liver, heart, lung and kidney and corresponding tissues in healthy control chicks was determined by RT-PCR analysis. Over expression of gelatinase gene was observed in metastaic tissues and primary tumors than control. The described assays could be used as a prognostic assay method for detection of proteases in metastatic neoplasms of animals. [Veterinary World 2010; 3(11.000: 500-502

  14. Dietary boron modified the effects of magnesium and molybdenum on mineral metabolism in the cholecalciferol-deficient chick.

    Science.gov (United States)

    Hunt, C D

    1989-11-01

    The metabolic effects of dietary boron, magnesium, and molybdenum on mineral metabolism in the cholecalciferol-deficient chick, with emphasis on growth cartilage histology, were studied. One-day-old cockerel chicks were assigned to groups in a fully-crossed, three factor, 2 x 2 x 2 design. The basal diet was based on ground corn, high-protein casein, and corn oil and contained 125 IU cholecalciferol (inadequate), 0.465 mg B, 2.500 mg Mg, and 0.420 mg Mo/kg. The treatments were the supplementation of the basal diet with B at O or 3; Mg at 300 (inadequate) or 500 (adequate); and Mo at 0 or 20 mg/kg. At d 25, B depressed mortality, alleviated the cholecalciferol-deficiency induced distortion of the marrow sprouts (MS) of the proximal tibial epiphysial plate, and elevated the numbers of osteoclasts within the MS. Adequate Mg exacerbated the cholecalciferol-deficiency induced bone lesions. Mo widened the MS markedly. In Mg-deficient chicks, B elevated plasma Ca and Mg concentrations and growth, but inhibited initiation of cartilage calcification; B had the opposite effect in Mg-adequate chicks. An interaction among B, Mg, and Mo affected plasma uric acid and glucose concentrations. B may function to modify mineral metabolism in cholecalciferol deficiency, suppressing bone anabolism in concurrent Mg deficiency and bone catabolism in concurrent Mg adequacy.

  15. Prenatal complex rhythmic music sound stimulation facilitates postnatal spatial learning but transiently impairs memory in the domestic chick.

    Science.gov (United States)

    Kauser, H; Roy, S; Pal, A; Sreenivas, V; Mathur, R; Wadhwa, S; Jain, S

    2011-01-01

    Early experience has a profound influence on brain development, and the modulation of prenatal perceptual learning by external environmental stimuli has been shown in birds, rodents and mammals. In the present study, the effect of prenatal complex rhythmic music sound stimulation on postnatal spatial learning, memory and isolation stress was observed. Auditory stimulation with either music or species-specific sounds or no stimulation (control) was provided to separate sets of fertilized eggs from day 10 of incubation. Following hatching, the chicks at age 24, 72 and 120 h were tested on a T-maze for spatial learning and the memory of the learnt task was assessed 24 h after training. In the posthatch chicks at all ages, the plasma corticosterone levels were estimated following 10 min of isolation. The chicks of all ages in the three groups took less (p memory after 24 h of training, only the music-stimulated chicks at posthatch age 24 h took a significantly longer (p music sounds facilitates spatial learning, though the music stimulation transiently impairs postnatal memory. PMID:21212638

  16. Relationships between organohalogen contaminants and blood plasma clinical-chemical parameters in chicks of three raptor species from Northern Norway

    DEFF Research Database (Denmark)

    Sonne, Christian; Bustnes, Jan Ove; Herzke, Dorte;

    2010-01-01

    Organohalogen contaminants (OHCs) may affect various physiological parameters in birds including blood chemistry. We therefore examined blood plasma clinical-chemical parameters and OHCs in golden eagle, white-tailed eagle and goshawk chicks from Northern Norway. Correlation analyses on pooled data......:creatinine were significantly positively correlated to various OHCs (all: pbone...

  17. Effect of reduced food intake on toxicokinetics of halogenated organic contaminants in herring gull (Larus argentatus) chicks

    NARCIS (Netherlands)

    Routti, H.; Helgason, L.B.; Arukwe, A.; Wolkers, J.; Heimstad, E.S.; Harju, M.; Berg, V.; Gabrielsen, G.W.

    2013-01-01

    The aim of the present study was to investigate how contaminant exposure and reduced food intake affect tissue distribution and biotransformation of halogenated organic contaminants (HOCs) in Arctic seabirds using herring gull (Larus argentatus) as a model species. Herring gull chicks were exposed f

  18. The influence of sex hormones on the pineal gland of the chick: a histochemical and ultrastructural study.

    OpenAIRE

    Boya, J; Calvo, J.; Zamorano, L.

    1980-01-01

    The pineal gland of chicks treated with oestrogens and androgens has been studied histochemically and ultrastructurally from post-hatching until 90 days of age. The results obtained may demonstrate a precocious maturity of the gland caused by its response to the early high level of sex hormones circulating in the blood.

  19. The Determination of Vitamin D-Dependent Calcium Binding Protein in Chick Intesting: An Undergraduate Biochemistry Laboratory Experiment.

    Science.gov (United States)

    Lessard, George M.

    1980-01-01

    Described is an experiment used in an undergraduate biochemistry laboratory involving inducing rickets in chicks and correlating the disease to a reduction in vitamin D-dependent calcium binding protein. Techniques involved are hormone induction, protein isolation, and radioisotope methodology. (Author/DS)

  20. Immunological evaluation of the intestinal mucosa of broiler chicks treated with Lactobacillus Spp. and challenged with Salmonella Enteritidis

    Directory of Open Access Journals (Sweden)

    AS Okamoto

    2007-12-01

    Full Text Available This study aimed at the antibody production by intestinal mucosa of broilers chicks were orally inoculated with Lactobacillus spp. at one and/or 21 days of age, and subsequently challenged with Salmonella enterica, subspecies enterica, serotype Enteritidis (S. Enteritidis. A total number of 288 drug-free broiler chicks was divided into 6 groups (groups A, B, C, D, E, and F, according to age at Lactobacillus spp. inoculation and SE challenge. The intestinal mucosa immune response was determined as the production of immunoglobulin A against S. Enteritidis, and evaluated by the Enzyme-Linked Immunosorbent Assay (ELISA technique in intestinal washing fluid. Groups treated with Lactobacillus spp. presented higher IgA production only when the chicks were challenged with S. Enteritidis at 21 days of age. Nevertheless, the expected stimulus for intestinal mucosa antibody production induced by Lactobacillus spp was observed in only some of the treated groups, demonstrating that the protocol utilized in the present experiment resulted in few beneficial effects for chicks, particularly during the first days of life.

  1. Colonization of day-of-hatch broiler chicks with antimicrobial resistant strains of salmonella Heidelberg and Kentucky

    Science.gov (United States)

    Salmonella is a major foodborne pathogen linked to poultry and poultry products. However, limited research regarding the in vivo interactions of non-host adapted Salmonella serotypes in broiler chicks is available. In order to evaluate the effect of two serotypes on colonization, 600 day-of-hatch ...

  2. Prenatal complex rhythmic music sound stimulation facilitates postnatal spatial learning but transiently impairs memory in the domestic chick.

    Science.gov (United States)

    Kauser, H; Roy, S; Pal, A; Sreenivas, V; Mathur, R; Wadhwa, S; Jain, S

    2011-01-01

    Early experience has a profound influence on brain development, and the modulation of prenatal perceptual learning by external environmental stimuli has been shown in birds, rodents and mammals. In the present study, the effect of prenatal complex rhythmic music sound stimulation on postnatal spatial learning, memory and isolation stress was observed. Auditory stimulation with either music or species-specific sounds or no stimulation (control) was provided to separate sets of fertilized eggs from day 10 of incubation. Following hatching, the chicks at age 24, 72 and 120 h were tested on a T-maze for spatial learning and the memory of the learnt task was assessed 24 h after training. In the posthatch chicks at all ages, the plasma corticosterone levels were estimated following 10 min of isolation. The chicks of all ages in the three groups took less (p memory after 24 h of training, only the music-stimulated chicks at posthatch age 24 h took a significantly longer (p music sounds facilitates spatial learning, though the music stimulation transiently impairs postnatal memory.

  3. Study of the relationship between Toxoplasma gondii infection and food source in seagull chicks from breeding areas from Spain

    Science.gov (United States)

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Sera from 525 seagull chicks from 6 ...

  4. A Comparison of the Anorexic Effects of Chicken, Porcine, Human and Bovine Insulin on the Central Nervous System of Chicks

    Science.gov (United States)

    The aim of the present study was to determine if some naturally-occurring substitutions of amino acid residues of insulin could act differentially within the central nervous system (CNS) of neonatal chicks to control ingestive behavior. Intracerebroventricular (ICV) administration of chicken insuli...

  5. THE INFLUENCE OF ENVIRONMENTAL TEMPERATURE ON THE UTILIZATION OF FOOD ENERGY IN BABY CHICKS.

    Science.gov (United States)

    Kleiber, M; Dougherty, J E

    1934-05-20

    1. An optimum of environmental temperature is to be expected for the utilization of food energy in warm blooded animals if their food intake is determined by their appetite. 2. Baby chicks were kept in groups of five chicks in a climatic cabinet at environmental temperatures of 21 degrees , 27 degrees , 32 degrees , 38 degrees , and 40 degrees C. during the period of 6 to 15 days of age. The intake of qualitatively complete food was determined by their appetite. Food intake, excretion, and respiratory exchange were measured. Control chicks from the same hatch as the experimental groups were raised in a brooder and were given the same food as the experimental chicks. The basal metabolism of each experimental group was determined from 24 to 36 hours without food at the age of 16 days. 3. The daily rate of growth increased with decreasing environmental temperature from 2.74 gm. at 40 degrees C. to 4.88 gm. at 21 degrees C. This was 4.2 to 6.5 per cent of their body weight. 4. The amount of food consumed increased in proportion to the decrease in temperature. 5. The availability of the food, used for birds instead of the digestibility and defined as See PDF for Structure showed an optimum at 38 degrees C. 6. The CO(2) production increased from 2.95 liters CO(2) per day per chick at 40 degrees C. to 6.25 liters at 21 degrees C. Per unit of the 3/4 power of the body weight, 23.0 liters CO(2) per kilo(3/4) was produced at 40 degrees C. and 43.4 liters per kilo(3/4) at 21 degrees C. The CO(2) production per unit of 3/4 power of the weight increased at an average rate of approximately 1 per cent per day increase in age. The R.Q. was, on the average, 1.04 during the day and 0.92 during the night. 7. The net energy is calculated on the basis of C and N balances. A maximum of 11.8 Cal. net energy per chick per day was found at 32 degrees C. At 21 degrees C. only 6.9 Cal. net per day per chick was produced and at 40 degrees C. an average of 6.7 Cal. 8. The composition of the

  6. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  7. Nonlinear oscillations of coalescing magnetic flux ropes.

    Science.gov (United States)

    Kolotkov, Dmitrii Y; Nakariakov, Valery M; Rowlands, George

    2016-05-01

    An analytical model of highly nonlinear oscillations occurring during a coalescence of two magnetic flux ropes, based upon two-fluid hydrodynamics, is developed. The model accounts for the effect of electric charge separation, and describes perpendicular oscillations of the current sheet formed by the coalescence. The oscillation period is determined by the current sheet thickness, the plasma parameter β, and the oscillation amplitude. The oscillation periods are typically greater or about the ion plasma oscillation period. In the nonlinear regime, the oscillations of the ion and electron concentrations have a shape of a narrow symmetric spikes. PMID:27300993

  8. Innate Immune Responses in ALV-J Infected Chicks and Chickens with Hemangioma In Vivo.

    Science.gov (United States)

    Feng, Min; Dai, Manman; Xie, Tingting; Li, Zhenhui; Shi, Meiqing; Zhang, Xiquan

    2016-01-01

    Avian leukosis virus subgroup J (ALV-J) infection can cause tumors and immunosuppression. Since the precise mechanism of the innate immune response induced by ALV-J is unknown, we investigated the antiviral innate immune responses induced by ALV-J in chicks and chickens that had developed tumors. Spleen levels of interleukin-6 (IL-6), IL-10, IL-1β, and interferon-β (IFN-β) were not significantly different between the infected chick groups and the control groups from 1 day post hatch to 7 days post hatch. However, IL-6, IL-1β, and IFN-β protein levels in the three clinical samples with hemangiomas were dramatically increased compared to the healthy samples. In addition, the anti-inflammatory cytokine IL-10 increased sharply in two of three clinical samples. We also found a more than 20-fold up-regulation of ISG12-1 mRNA at 1 day post infection (d.p.i.) and a twofold up-regulation of ZC3HAV1 mRNA at 4 d.p.i. However, there were no statistical differences in ISG12-1 and ZC3HAV1 mRNA expression levels in the tumorigenesis phase. ALV-J infection induced a significant increase of Toll-like receptor 7 (TLR-7) at 1 d.p.i. and dramatically increased the mRNA levels of melanoma differentiation-associated gene 5 (MDA5) in the tumorigenesis phase. Moreover, the protein levels of interferon regulatory factor 1 (IRF-1) and signal transducer and activator of transcription 1 (STAT1) were decreased in chickens with tumors. These results suggest that ALV-J was primarily recognized by chicken TLR7 and MDA5 at early and late in vivo infection stages, respectively. ALV-J strain SCAU-HN06 did not induce any significant antiviral innate immune response in 1 week old chicks. However, interferon-stimulated genes were not induced normally during the late phase of ALV-J infection due to a reduction of IRF1 and STAT1 expression.

  9. Effect of dietary vitamin A and Nigella sativa on the performance of broiler chicks

    International Nuclear Information System (INIS)

    A study was conducted to assess the effect of feeding different added levels of vitamin A and Nigella sativa seeds on broiler performance, blood chemistry and carcass characteristics. One- hundred forty four, one-day old unsexed (Lohman) broiler chicks were divided randomly into eight groups, each represented a treatment (18 birds/treatment), with 2 replicates for each treatment 2x4 factorial arrangement in a completely randomised design was used. The experimental basal rations were formulated to meet requirement for essential nutrients for broiler chicks according to NCR (1984) recommendation. Four graded levels of added vitamin A (0,3000,4500 and 9000 IU/kg) and two levels of Nigella sativa (0, 0.25%) were used. The experiment lasted for eight weeks. Body weight, weight gain, feed intake and feed conversion ratio were determined. In addition blood chemistry, absolute weight of internal organs and carcass characteristics were measured. The added level 3000 IU of vitamin A significantly increased weight gain (P≤ 0.01) decreased feed conversion ratio (P≤ 0.01) and increased muscle: bone ratio (P≤ 0.05). The level 0.25% of Nigella sativa with no added vitamin A significantly (P ≤ 0.01) increased body weight and weight gain. High level of added vitamin A decreased absolute weight of liver (P≤ 0.01), and increased fat content of muscles (P≤ 0.01) and abdominal fat (P≤ 0.01). Vitamin A and Nigella sativa significantly affect serum Ca (which was determined according to the calorimetric method), P, Zn , and alkaline phosphates(alk.ase) and cholesterol (P≤ 0.05) which was determined according to the Enzymatic Calometric Test . Addition of 0.25% Nigella sativa significantly affect serum cholestrol (P ≤0.01). The treatments had no significant affect on serum glucose and ash content of meat. Significant interaction between vitamin A and Nigella sativa were observed on body weight gain, feed conversion ratio, feed intake (P≤ 0.01, P≤0.05, and P≤0

  10. Salmonella enterica serovars Enteritidis infection alters the indigenous microbiota diversity in young layer chicks

    Directory of Open Access Journals (Sweden)

    Khin Khine Zar Mon

    2015-11-01

    Full Text Available Avian gastrointestinal tracts are highly populated with a diverse array of microorganisms that share a symbiotic relationship with their hosts and contribute to the overall health and disease state of the intestinal tract. The microbiome of the young chick is easily prone to alteration in its composition by both exogenous and endogenous factors especially during the early post-hatch period. The genetic background of the host and exposure to pathogens can impact the diversity of the microbial profile that consequently contributes to the disease progression in the host. The objective of this study was to profile the composition and structure of the gut microbiota in young chickens from two genetically distinct highly inbred lines. Furthermore, the effect of the Salmonella Enteritidis infection on altering the composition makeup of the chicken microbiome was evaluated through the 16S rRNA gene sequencing analysis. One-day-old layer chicks were challenged with S. Enteritidis and the host cecal microbiota profile as well as the degree of susceptibility to Salmonella infection was examined at 2 and 7 days post-infection. Our result indicated that host genotype had a limited effect on resistance to S. Enteritidis infection. Alpha diversity, beta diversity, and overall microbiota composition were analyzed for four factors: host genotype, age, treatment, and post-infection time-points. S. Enteritidis infection in young chicks was found to significantly reduce the overall diversity of the microbiota population with expansion of Enterobacteriaceae family. These changes indicated that Salmonella colonization in the gastrointestinal tract of the chickens has a direct effect on altering the natural development of the gastrointestinal microbiota. The impact of S. Enteritidis infection on microbial communities was also more substantial in late stage of infection. Significant inverse correlation between Enterobacteriaceae and Lachnospiraceae family in both non

  11. Toxicity and EROD-inducing potency of 24 polycyclic aromatic hydrocarbons (PAHs) in chick embryos

    Energy Technology Data Exchange (ETDEWEB)

    Brunstroem, B. (Uppsala Univ. (Sweden). Dept. of Zoophysiology); Broman, D. (Stockholm Univ. (Sweden). Dept. of Zoology); Naef, C. (Stockholm Univ. (Sweden). Dept. of Analytical Chemistry)

    1991-08-01

    The toxicities (embryolethality) of 24 polycyclic aromatic hydrocarbons (PAHs) were determined in chick embryos using a 72-h test. The substances, dissolved in peanut oil, were injected into the air sacs of eggs preincubated for 7 days. LD{sub 50} values were determined for the four most toxic of the 24 compounds. Benzo(k)fluoranthene was the most potent, with an LD{sub 50} of 14 {mu}g (56 nmol)/kg egg. Dibenz(a,h)anthracene, benz(a)lanthracene and benzol(b)naphtho(2,3-d)thiophene were a few times less toxic (LD{sub 50} = 39 {mu}g (140 nmol)/kg, 79 {mu}g (349 nmol)/kg and 82 {mu}g (350 nmol)/kg, respectively). The LD{sub 50} of benzo(k)fluoranthene was only about 5 times higher than that previously found for the most potent coplanar polychlorinated biphenyl (PCB), 3,3',4,4',5-pentachlorobiphenyl (LD{sub 50} = 3.1 {mu}g (9.4 nmol)/kg), in the same kind of test. The toxicities of 18 of the PAHs in this study have also been evaluated previously using a 2-week test in chick embryos. Dibenz(a,h)anthracene, which had not been studied earlier in the 2-week test, proved to be almost as toxic as previously found for benzo(k)fluoranthene in that test. Several of the PAHs studied induced EROD activity in chick embryos, and, in general, the most toxic PAHs were also the most potent inducers of EROD. The highest enzyme activities were found after treatment with indeno(1,2,3-c,d)pyrene (12 times the control value) and dibenz(a,h)anthracene (8 times the control value). However, due to the high toxicity of dibenz(a,h)anthracene, the dose used was 7 times lower than that of indeno(1,2,3-c,d)pyrene. Following injection of PAHs on day 7, the EROD activities on day 10 were considerably lower than those obtained after a corresponding treatment with coplanar PCBs in an earlier study. Of the PAHs studied, some exhibited very high embryotoxicity. The most toxic PAHs induced EROD activity, suggesting that their toxicity was at least partly mediated via binding to the Ah receptor

  12. Growth prior to thermogenesis for a quick fledging of Adelie penguin chicks (Pygoscelis adeliae.

    Directory of Open Access Journals (Sweden)

    Cyril Dégletagne

    Full Text Available The evolutionary trade-off between tissue growth and mature function restricts the post natal development of polar birds. The present study uses an original integrative approach as it includes gene expression, plus biochemical and physiological analysis to investigate how Adélie penguin chicks achieve a rapid growth despite the energetic constraints linked to the cold and the very short breeding season in Antarctica. In pectoralis muscle, the main thermogenic tissue in birds, our data show that the transition from ectothermy to endothermy on Day 15 post- hatching is associated with substantial and coordinated changes in the transcription of key genes. While the early activation of genes controlling cell growth and differentiation (avGHR, avIGF-1R, T3Rβ is rapidly down-regulated after hatching, the global increase in the relative expression of genes involved in thermoregulation (avUCP, avANT, avLPL and transcriptional regulation (avPGC1α, avT3Rβ underlie the muscular acquisition of oxidative metabolism. Adélie chicks only become real endotherms at 15 days of age with the development of an oxidative muscle phenotype and the ability to shiver efficiently. The persistent muscular expression of IGF-1 throughout growth probably acts as a local mediator to adjust muscle size and its oxidative capacity to anticipate the new physiological demands of future Dives in cold water. The up-regulation of T3Rβ mRNA levels suggests that circulating T3 may play an important role in the late maturation of skeletal muscle by reinforcing, at least in part, the paracrine action of IGF-1. From day 30, the metabolic shift from mixed substrate to lipid metabolism, with the markedly increased mRNA levels of muscle avLPL, avANT and avUCP, suggests the late development of a fatty acid-enhanced muscle non-shivering thermogenesis mechanism. This molecular control is the key to this finely-tuned strategy by which the Adélie penguin chick successfully heads for the sea

  13. Effect of vegetable wastage and energy in ostrich chick diet on performance and hematology.

    Science.gov (United States)

    Tasirnafas, Mohammadebrahim; Seidavi, Alireza; Rasouli, Behrouz; Kawka, Magdalena

    2015-08-01

    This study evaluated the effects of different levels of dietary vegetable wastage and energy on ostrich chick performance and hematology. Twenty-four ostrich chicks (blue and black African breed) were allocated to eight treatments. The diet in treatments T1 to T4 had 2,500 kcal/kg of metabolizable energy, while treatments T5 to T8 had 2,700 kcal/kg. Each treatment had 0, 10, 20, and 30% of vegetable wastage. Vegetable wastage included parsley (Petroselinum crispum, 51.3 %), cress (Lepidium sativum, 15.0%), spinach (Spinacia oleracea, 15.0%), wild leek (Allium ampeloprasum, 14.0%), fenugreek (Trigonella foenum-graecum, 2.5%), and basil (Ocimum basilicum, 2.2 %). The body weight gain and food intake were assessed weekly. Blood was analyzed for total cholesterol, triglycerides, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterols, LDL/HDL, ratio and alkaline phosphatase. The highest level of weight was seen in the second treatment (2,500 kcal/kg dietary energy and 10% dietary wastage). The hematological parameters were different depending on the treatment used. The lowest level of total cholesterol was observed in eighth treatment (2,700 kcal/kg dietary energy and 30% dietary wastage), while the lowest level of triglycerides was in fourth treatment (2,500 kcal/kg dietary energy and 30 % of wastage). The level of alkaline phosphatise was the lowest in seventh treatment (2,700 kcal/kg dietary energy and 20% wastages). The energy level had no effect (P < 0.05) on feed intake, weight gain, and feed efficiency for each week and for all experimental period. The level of vegetable wastage showed effect (P = 0.033) on feed intake, but the increase of this level showed depressive effect on the feed intake. This is the first report on the performance and blood parameters of commercial ostrich chicks fed diets differing in vegetable wastage. Further studies are needed to confirm these results. PMID:25877259

  14. A General $q$-Oscillator Algebra

    OpenAIRE

    Kwek, L. C.; Oh, C. H.

    1998-01-01

    It is well-known that the Macfarlane-Biedenharn $q$-oscillator and its generalization has no Hopf structure, whereas the Hong Yan $q$-oscillator can be endowed with a Hopf structure. In this letter, we demonstrate that it is possible to construct a general $q$-oscillator algebra which includes the Macfarlane-Biedenharn oscillator algebra and the Hong Yan oscillator algebra as special cases.

  15. The source of solar oscillations

    Science.gov (United States)

    Nigam, R.

    1999-05-01

    In this study the role of line asymmetry and phase difference between velocity and intensity helioseismic spectra for understanding the excitation of solar oscillations is discussed. The solar intensity and velocity oscillations are usually observed from variations in an absorption line. These variations consist of two parts: solar oscillation modes and granulation noise. Because the oscillation modes are excited by granulation, we argue that the granulation signal (noise) is partially correlated with the oscillations. The data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory (SOHO) have clearly revealed a reversal of asymmetry between velocity and intensity power spectra. We have shown that the cause of reversal in asymmetry between velocity and intensity power spectra is due to the presence of the correlated noise in the intensity data. This noise is also responsible for the high-frequency shift in the two spectra at and above the acoustic cutoff frequency. Our theory also explains the deviation of the observed phase difference between velocity and intensity from that predicted by simple adiabatic theory of solar oscillations. The observed phase, jumps in the vicinity of an eigenfrequency, but theory does not explain such jumps. We studied different types of excitation sources at various depths and found that monopole and quadrupole acoustic sources when placed in the superadiabatic layer (at a depth of 75 km below the photosphere) match the observations. For these source types, the sign of the correlation is negative corresponding to photospheric darkening. Finally, an asymmetric fitting formula is used to determine the eigenfrequencies of solar oscillations by fitting both the velocity and intensity power spectra.

  16. Regulation Mechanisms of Stomatal Oscillation

    Institute of Scientific and Technical Information of China (English)

    Hui-Min YANG; Jian-Hua ZHANG; Xiao-Yan ZHANG

    2005-01-01

    Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption,but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist: (i) a quicker responsive pattern; and (ii) a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.

  17. Effect of fenitrothion and disulfoton on lipid metabolism in tissues of white leghorn chicks (Gallus domesticus)

    International Nuclear Information System (INIS)

    The effects of acute and chronic toxicity due to Disulfoton (diethyl S-(2-ehtyl thio) ethyl phosphorothionate) and Fenitrothion (dimethyl P-3-methyl-4 nitrophenyl phosphorothionate) on the lipid metabolism in tissues of white leghorn chicks (Gallus domesticus) was studied by using 32P-phosphate, 2-14C-acetate and U-14C-glucose as precursors. During acute toxicity, the biosynthesis of fatty acids and aerobic oxidation of glucose appear to be inhibited in nervous tissues. However, during chronic toxicity, the biosynthesis of fatty acids is not inhibited. The biosynthesis of phospholipids is depressed in certain tissues due to decreased availability of diglyceride precursors during acute toxicity. During chronic toxicity, the formation of diglyceride from phosphatidic acid appears to be inhibited. (author). 14 refs., 4 tabs

  18. Spontaneous and light-induced photon emission from intact brains of chick embryos

    Institute of Scientific and Technical Information of China (English)

    张锦珠; 于文斗; 孙彤

    1997-01-01

    Photon emission (PE) and light-induced photon emission(LPE) of intact brains isolated from chick embryos have been measured by using the single photon counting device. Experimental results showed that the intensi-ty level of photon emission was detected to be higher from intact brain than from the medium in which the brain was immerged during measuring, and the emission intensity was related to the developmental stages, the healthy situation of the measured embryos, and the freshness of isolated brains as well. After white light illumination, a short-life de-layed emission from intact brains was observed, and its relaxation behavior followed a hyperbolic rather than an expo-nential law. According to the hypothesis of biophoton emission originating from a delocalized coherent electromagnetic field and Frohlich’s idea of coherent long-range interactions in biological systems, discussions were made on the signifi-cance of photon emission in studying cell communication, biological regulation, living system’

  19. A 'tool box' for deciphering neuronal circuits in the developing chick spinal cord.

    Science.gov (United States)

    Hadas, Yoav; Etlin, Alex; Falk, Haya; Avraham, Oshri; Kobiler, Oren; Panet, Amos; Lev-Tov, Aharon; Klar, Avihu

    2014-10-29

    The genetic dissection of spinal circuits is an essential new means for understanding the neural basis of mammalian behavior. Molecular targeting of specific neuronal populations, a key instrument in the genetic dissection of neuronal circuits in the mouse model, is a complex and time-demanding process. Here we present a circuit-deciphering 'tool box' for fast, reliable and cheap genetic targeting of neuronal circuits in the developing spinal cord of the chick. We demonstrate targeting of motoneurons and spinal interneurons, mapping of axonal trajectories and synaptic targeting in both single and populations of spinal interneurons, and viral vector-mediated labeling of pre-motoneurons. We also demonstrate fluorescent imaging of the activity pattern of defined spinal neurons during rhythmic motor behavior, and assess the role of channel rhodopsin-targeted population of interneurons in rhythmic behavior using specific photoactivation.

  20. Visual hierarchical processing and lateralization of cognitive functions through domestic chicks' eyes.

    Directory of Open Access Journals (Sweden)

    Cinzia Chiandetti

    Full Text Available Hierarchical stimuli have proven effective for investigating principles of visual organization in humans. A large body of evidence suggests that the analysis of the global forms precedes the analysis of the local forms in our species. Studies on lateralization also indicate that analytic and holistic encoding strategies are separated between the two hemispheres of the brain. This raises the question of whether precedence effects may reflect the activation of lateralized functions within the brain. Non-human animals have perceptual organization and functional lateralization that are comparable to that of humans. Here we trained the domestic chick in a concurrent discrimination task involving hierarchical stimuli. Then, we evaluated the animals for analytic and holistic encoding strategies in a series of transformational tests by relying on a monocular occlusion technique. A local precedence emerged in both the left and the right hemisphere, adding further evidence in favour of analytic processing in non-human animals.

  1. Visual hierarchical processing and lateralization of cognitive functions through domestic chicks' eyes.

    Science.gov (United States)

    Chiandetti, Cinzia; Pecchia, Tommaso; Patt, Francesco; Vallortigara, Giorgio

    2014-01-01

    Hierarchical stimuli have proven effective for investigating principles of visual organization in humans. A large body of evidence suggests that the analysis of the global forms precedes the analysis of the local forms in our species. Studies on lateralization also indicate that analytic and holistic encoding strategies are separated between the two hemispheres of the brain. This raises the question of whether precedence effects may reflect the activation of lateralized functions within the brain. Non-human animals have perceptual organization and functional lateralization that are comparable to that of humans. Here we trained the domestic chick in a concurrent discrimination task involving hierarchical stimuli. Then, we evaluated the animals for analytic and holistic encoding strategies in a series of transformational tests by relying on a monocular occlusion technique. A local precedence emerged in both the left and the right hemisphere, adding further evidence in favour of analytic processing in non-human animals. PMID:24404163

  2. A study on increasing the breeding rate of chicks with low-dosage stimulation

    International Nuclear Information System (INIS)

    During the years 1985 ∼ 1990, the semen of male fowl was irradiated by β-rays, the survival time of the spermatozoa was prolonged and fertility increased by 2% to 5%. The breeding eggs of 'Harbin White hen' were irradiated by 60Co γ-rays to stimulate the growth of the blastoderm of fertilized eggs, the hatching rate increased by 6.86%, the healthy bird rate increased by 5.52%, and the chick weight increased by 5% to 6%. The egg production rate of the first irradiated generation hens increased by 8.03%, the first-egg age of the second irradiated generation hens shifted 6 to 7 weeks earlier and the egg production period prolonged. 72-week egg production was raised by 10.48%

  3. Embryonic cerebrospinal fluid regulates neuroepithelial survival, proliferation, and neurogenesis in chick embryos.

    Science.gov (United States)

    Gato, Angel; Moro, J A; Alonso, M I; Bueno, D; De La Mano, A; Martín, C

    2005-05-01

    Early in development, the behavior of neuroepithelial cells is controlled by several factors, which act in a developmentally regulated manner. Diffusible factors are secreted locally by the neuroepithelium itself, although other nearby structures may also be involved. Evidence suggests a physiological role for the cerebrospinal fluid in the development of the brain. Here, using organotypic cultures of chick embryo neuroepithelial explants from the mesencephalon, we show that the neuroepithelium in vitro is not able to self-induce cell survival, replication, and neurogenesis. We also show that the embryonic cerebrospinal fluid (E-CSF) promotes neuroepithelial stem cell survival and induces proliferation and neurogenesis in mesencephalic explants. These data strongly suggest that E-CSF is involved in the regulation of neuroepithelial cells behavior, supporting the hypothesis that this fluid plays a key role during the early development of the central nervous system. PMID:15803475

  4. Ethanol- and/or Taurine-Induced Oxidative Stress in Chick Embryos

    OpenAIRE

    Berning, Emily J.; Noah Bernhardson; Kelly Coleman; Farhat, Dina A.; Courtney M. Gushrowski; Alison Lanctot; Maddock, Benjamin H.; Michels, Kathryn G.; Luke A. Mugge; Nass, Catherine M.; Yearsley, Sarah M.; Miller, Robert R.

    2013-01-01

    Because taurine alleviates ethanol- (EtOH-) induced lipid peroxidation and liver damage in rats, we asked whether exogenous taurine could alleviate EtOH-induced oxidative stress in chick embryos. Exogenous EtOH (1.5 mmol/Kg egg or 3 mmol/Kg egg), taurine (4 μmol/Kg egg), or EtOH and taurine (1.5 mmol EtOH and 4 μmol taurine/Kg egg or 3 mmol EtOH and 4 μmol taurine/Kg egg) were injected into fertile chicken eggs during the first three days of embryonic development (E0–2). At 11 days of develop...

  5. Audouin's gull chicks as bioindicators of mercury pollution at different breeding locations in the western Mediterranean

    International Nuclear Information System (INIS)

    Mercury levels of Audouin's gull are amongst the highest for Mediterranean seabirds, and have been mainly attributed to its piscivorous habits in these naturally Hg rich waters. Moreover, two additional factors could enhance its mercury intake: the consumption of discarded fish (which attain higher concentrations) and/or feeding in areas receiving Hg anthropogenic inputs. In order to differentiate the relevance of both sources we analysed Hg and stable isotopes of chick feathers from different breeding locations in western Mediterranean: one in its northern part (Ebro Delta) and two southern (Chafarinas Isl. and Alboran Isl.). The results from stable isotopes indicate that consumption of discards is higher at Alboran Isl., followed by the Ebro Delta and Chafarinas Isl. Thus, the higher mercury levels found in the Ebro Delta cannot be explained uniquely by the contribution of discarded fish to diet, but local pollution caused by the river Ebro waters accounts for Hg differences observed

  6. NMR Based Cerebrum Metabonomic Analysis Reveals Simultaneous Interconnected Changes during Chick Embryo Incubation.

    Directory of Open Access Journals (Sweden)

    Yue Feng

    Full Text Available To find out if content changes of the major functional cerebrum metabolites are interconnected and formed a network during the brain development, we obtained high-resolution magic-angle-spinning (HR-MAS 1H NMR spectra of cerebrum tissues of chick embryo aged from incubation day 10 to 20, and postnatal day 1, and analyzed the data with principal component analysis (PCA. Within the examined time window, 26 biological important molecules were identified and 12 of them changed their relative concentration significantly in a time-dependent manner. These metabolites are generally belonged to three categories, neurotransmitters, nutrition sources, and neuronal or glial markers. The relative concentration changes of the metabolites were interconnected among/between the categories, and, more interestingly, associated with the number and size of Nissl-positive neurons. These results provided valuable biochemical and neurochemical information to understand the development of the embryonic brain.

  7. The Comparison of Performance of Three Hybrid Combinations of Broiler Chicks at Different Dose of Probiotic

    Directory of Open Access Journals (Sweden)

    Ján Weis

    2010-10-01

    Full Text Available If we want to find replacement to use of antibiotics, we must search more naturally alternative methods. Such method can be also used with probiotics in poultry nutrition. By the help of them we can achieve better health state and higher increase of live and slaughter weight. We tested the effect of probiotic Propoul in the experiment. We applied two different doses of probiotic at three hybrid combinations broiler chicks (Ross 308, Hubbard JV, Cobb 500. We watched difference among live weight, body symmetry and feed conversation. In all hybrids we found statistically significant difference (P<0,05 between experimental groups and control group, only experimental group 2 and control group at hybrid Ross 308 we found statistically significant difference (P<0,05. We did not find the difference between experimental groups. With the application of probiotics are reached better feed conversation in experimental groups against control group. We did not find statistically significant difference in body symmetry.

  8. Effects of 17beta-estradiol on distribution of primordial germ cell migration in male chicks

    Institute of Scientific and Technical Information of China (English)

    Xiu-Mei Jin; Yi-Xiang Zhang; Zan-Dong Li

    2008-01-01

    Aim: To assess whether exogenous estradiol has any effect on migration of primordial germ cells (PGCs) in the chick. Methods: Fertilized eggs were treated with 17beta-estradiol (Ez) (80 lag/egg) at stage X (day 0 of incubation),stages 8-10 (incubation 30 h) and 13-15 (incubation 55 h). Controls received vehicle (emulsion) only. Changes in PGC number were measured on different days according to developmental stages. Results: In male right gonads,but not in female left gonads, at stages 28-30 (incubation 132 h) significant decreases in the mean number of PGCs aggregating were observed compared with the controls (P 0.05). Conclusion: The present study provides evidence that E2 has significant effects on the localization of PGCs in male fight, but not female left, gonads of chicken embryos at stages28-30, compared with controls.

  9. Effect of mobile phone electromagnetic radiation on somitogenesis of birds

    International Nuclear Information System (INIS)

    We have assessed the early embryo development of quails after the irradiation of incubation eggs by a standard mobile phone handset. Fresh fertilized quail eggs of exposed groups were irradiated periodically during 2 days before the incubation and in the first day of incubation by commercial mobile phone in the 'receiving a call' position (Motorola W230, GSM 850 MHz, SAR 0.75 W/kg, intensity of RF radiation in the zone of exposure 5-15 μW/cm2, total duration of exposure 20 h). Microscopic analysis of 40-hour embryos revealed that embryos of the exposed groups did not differ significantly from the control in the stage of development according to the quantity of pairs of differentiated somites. But embryos of the exposed groups had more abnormalities of their development as compared with the control. Consolidated data of two experiments revealed a statistically significant (p<0.05) increase of abnormalities in exposed embryos (33.33%) as compared with the control (9.68%). Most malformations in the exposed embryos appeared as the deformations of the first few pairs of differentiated somites. Such a kind of malformations was not found in control embryos.

  10. Analysis of somitogenesis using multiphoton laser scanning microscopy (MPLSM)

    Science.gov (United States)

    Dickinson, Mary E.; Longmuir, Kenneth J.; Fraser, Scott E.

    2001-04-01

    In order to study complex cellular interactions in the developing somite and nervous system, we have been refining techniques for labeling and imaging individual cells within the living vertebrate embryo. Most recently, we have been using MPLSM to analyze cellular behaviors, such as cell migration, filopodial extension, cell process collapse, and neuron pathfinding using time-lapse microscopy in 3-dimensions (3-d). To enhance the efficiency of two-photon excitation in these samples, we have been using a Zeiss LSM 510 NLO fiber delivery system with a Grating Dispersion Compensator (GDC). This system not only offers the convenience of fiber delivery for coupling our Ti:Sapphire laser to the microscope, but also affords us precise control over the pulsewidth of the mode- locked beam. In addition, we have developed a novel peptide/non-cationic lipid gene delivery system to introduce GFP plasmid into somite cells. This approach has allowed us to generate detailed 3-d images of somite cell morphologies at various stages of somite development in a way that best preserves the vitality of the cells being imaged.

  11. El Nino Southern Oscillation as Sporadic Oscillations between Metastable States

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The main objective of this article is to establish a new mechanism of ENSO,as a self-organizing and self-excitation system,with two highly coupled processes.The first is the oscillation between the two metastable warm(El Ni(?)o phase) and cold events(La Ni(?)a phase),and the second is the spatiotemporal oscillation of the sea surface temperature(SST) field.The symbiotic interplay between these two processes gives rises the climate variability associated with the ENSO,leads to both the random and deterministic features of the ENSO,and defines a new natural feedback mechanism,which drives the sporadic oscillation of the ENSO.The new mechanism is rigorously derived using a dynamic transition theory developed recently by the authors,which has also been successfully applied to a wide range of problems in nonlinear sciences.

  12. El Nino Southern Oscillation as Sporadic Oscillations between Metastable States

    Institute of Scientific and Technical Information of China (English)

    MA Tian; Shouhong WANG

    2011-01-01

    The main objective of this article is to establish a new mechanism of ENSO, as a self-organizing and selfexcitation system, with two highly coupled processes. The first is the oscillation between the two mctastable warm (El Nino phase) and cold events (La Nina phase), and the second is the spatiotemporal oscillation of the sea surface temperature (SST) field. The symbiotic interplay between these two processes gives rises the climate variability associated with the ENSO, leads to both the random and deterministic features of the ENSO, and defines a new natural feedback mechanism, which drives the sporadic oscillation of the ENSO. The new mechanism is rigorously derived using a dynamic transition theory developed recently by the authors, which has also been successfully applied to a wide range of problems in nonlinear sciences.

  13. Wide range of mercury contamination in chicks of southern ocean seabirds.

    Science.gov (United States)

    Blévin, Pierre; Carravieri, Alice; Jaeger, Audrey; Chastel, Olivier; Bustamante, Paco; Cherel, Yves

    2013-01-01

    Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ~102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ(13)C) and trophic positions (reflected by δ(15)N) on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ(15)N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic). However, when focusing on oceanic seabirds, Hg concentration was related to feather δ(13)C values, with species feeding in colder waters (lower δ(13)C values) south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ(13)C values). Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology. PMID:23349912

  14. Wide range of mercury contamination in chicks of southern ocean seabirds.

    Directory of Open Access Journals (Sweden)

    Pierre Blévin

    Full Text Available Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ~102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ(13C and trophic positions (reflected by δ(15N on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ(15N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic. However, when focusing on oceanic seabirds, Hg concentration was related to feather δ(13C values, with species feeding in colder waters (lower δ(13C values south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ(13C values. Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology.

  15. Effects of harmane, norharmane and harmine on apomorphine-induced pecking behavior in chick

    Directory of Open Access Journals (Sweden)

    Davood Farzin

    2009-01-01

    Full Text Available .(Received 3 January, 2009; Accepted 27 May, 2009AbstractBackground and purpose: -carboline alkaloids, also known as harmala's alkaloids have a wide spectrum of pharmacological actions including a stimulatory action on release of dopamine and other catecholamines in several brain regions and an inhibitory action on monoamine oxidase (MAO. These findings suggest that -carbolines should alleviate at least some of the dopaminergic stereotyped behaviors. The purpose of present study is to determine the effects of -carbolines harmane, norharmane and harmine on apomorphine-induced pecking behavior in chick.Materials and methods: All experiments were carried out on male/female chicks (40-60 g. The modulatory effects of -Carbolines on stereotyped behavior were assessed using the pecking behavior induced by apomorphine. Subcutaneous (s.c. injection of apomorphaine (0.025 mg/kg, mixed agonist of dopamine D1/D2 receptors induced pecking. The pecking response was counted by direct observation and recorded for a 40-minute period.Results: S.C. injection of harmane (2.5-10 mg/kg and harmine (1.25-5 mg/kg significantly decreased the pecking behavior induced by apomorphine (0.25 mg/kg. The norharmane (2.5-15 mg/kg, i.p. response was biphasic. The inhibitory effects of harmane, norharmane and harmine were blocked by flumazenil (5 mg/kg, i.e., 30 minutes before the test or reserpine (5 mg/kg, i.e., 18 hours before the test.Conclusion: Results suggest that the modulatory effect of harmane, norharmane and harmine on the pecking behavior may be mediated through an inverse agonistic/monoaminergic mechanism.J Mazand Univ Med Sci 2009; 19(70: 1-8 (Persian

  16. Chick embryo xenograft model reveals a novel perineural niche for human adipose-derived stromal cells

    Directory of Open Access Journals (Sweden)

    Ingrid R. Cordeiro

    2015-09-01

    Full Text Available Human adipose-derived stromal cells (hADSC are a heterogeneous cell population that contains adult multipotent stem cells. Although it is well established that hADSC have skeletal potential in vivo in adult organisms, in vitro assays suggest further differentiation capacity, such as into glia. Thus, we propose that grafting hADSC into the embryo can provide them with a much more instructive microenvironment, allowing the human cells to adopt diverse fates or niches. Here, hADSC spheroids were grafted into either the presumptive presomitic mesoderm or the first branchial arch (BA1 regions of chick embryos. Cells were identified without previous manipulations via human-specific Alu probes, which allows efficient long-term tracing of heterogeneous primary cultures. When grafted into the trunk, in contrast to previous studies, hADSC were not found in chondrogenic or osteogenic territories up to E8. Surprisingly, 82.5% of the hADSC were associated with HNK1+ tissues, such as peripheral nerves. Human skin fibroblasts showed a smaller tropism for nerves. In line with other studies, hADSC also adopted perivascular locations. When grafted into the presumptive BA1, 74.6% of the cells were in the outflow tract, the final goal of cardiac neural crest cells, and were also associated with peripheral nerves. This is the first study showing that hADSC could adopt a perineural niche in vivo and were able to recognize cues for neural crest cell migration of the host. Therefore, we propose that xenografts of human cells into chick embryos can reveal novel behaviors of heterogeneous cell populations, such as response to migration cues.

  17. Measurement of wall shear stress in chick embryonic heart using optical coherence tomography

    Science.gov (United States)

    Ma, Zhenhe; Dou, Shidan; Zhao, Yuqian; Wang, Yi; Suo, Yanyan; Wang, Fengwen

    2015-03-01

    The cardiac development is a complicated process affected by genetic and environmental factors. Wall shear stress (WSS) is one of the components which have been proved to influence the morphogenesis during early stages of cardiac development. To study the mechanism, WSS measurement is a step with significant importance. WSS is caused by blood flow imposed on the inner surface of the heart wall and it can be determined by calculating velocity gradients of blood flow in a direction perpendicular to the wall. However, the WSS of the early stage embryonic heart is difficult to measure since the embryonic heart is tiny and beating fast. Optical coherence tomography (OCT) is a non-invasive imaging modality with high spatial and temporal resolution, which is uniquely suitable for the study of early stage embryonic heart development. In this paper, we introduce a method to measure the WSS of early stage chick embryonic heart based on high speed spectral domain optical coherence tomography (SDOCT). 4D (x,y,z,t) scan was performed on the outflow tract (OFT) of HH18 (~3 days of incubation) chick embryonic heart. After phase synchronization, OFT boundary segmentation, and OFT center line calculation, Doppler angle of the blood flow in the OFT can be achieved (This method has been described in previous publications). Combining with the Doppler OCT results, we calculate absolute blood flow velocity distribution in the OFT. The boundary of the OFT was segmented at each cross-sectional structural image, then geometrical center of the OFT can be calculated. Thus, the gradients of blood flow in radial direction can be calculated. This velocity gradient near the wall is termed wall shear rate and the WSS value is proportional to the wall shear rate. Based on this method, the WSS at different heart beating phase are compare. The result demonstrates that OCT is capable of early stage chicken embryonic heart WSS study.

  18. Effect of Saffron aqua Extract on Angiogenesis in Chick Chorioalantoic Membrane

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2014-03-01

    Full Text Available Background: Studies confirmed anticancer properties of saffron extract. Angiogenesis, formation of new blood vessels which is necessary in many physiological stages and pathological events such as tumor growth. So it would be an effective strategy to inhibit angiogenesis to treat many cancers and metastasis. In this experimental study, effects of saffron on angiogenesis in chick chorioalantoic membrane (CAM were investigated. Materials and Methods: Fifity ross fertilized eggs divided in 5 groups, including: control, sham exposed, experimental group 1, 2 and 3. In second day of incubation window was opened on eggs. In day 8 gelatin sponges contain gelatin and albumin was put on chorioalantoic membrane and was soaked with Saffron aqua extract in concentration 100, 400 and 800 μg/ml. In 12th day all cases were photographed by photo stereomicroscope. Numbers and lengths of vessels around the sponges were measured by Image J software. Data were analyzed with SPSS-16 in significant level p<0.05. Results: According to data analysis, changes had no correlation on the average length of blood vessels in the first experimental group (41.5±5.5 mm, compared with the control group, (44.5±2.4 mm. While in the second and third experimental group (40.2±2.1 mm and (38.4±3.8 mm these changes were significant (p=0.001. On the other hand, the average number of blood vessels in the first experimental group (22.07±5.2 in compare with the control group (27.46±4.4 shows a significant reduction (p=0.02, this decline between the second (18.80±4.4 and third (15.87±3.8 experimental groups was significant at the level of p=0.001. Conclusion: Saffron extract has a dose dependent inhibitory effect on angiogenesis in chick chorioalantoic membrane.

  19. Effects of zinc and PGE sub 2 on bone metabolism in chick tibia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.; Pierce, W.M. Jr. (Univ. of Louisville, KY (United States))

    1991-03-15

    The effects of zinc and prostaglandin E{sub 2} (PGE{sub 2}) on bone metabolism were investigated. Tibiae were removed from 19 day chicks and cultured for periods up to 72 hours in a chemically defined medium. Calcium release from tibiae cultured in the presence of 50-100 ug/dl zinc or 10{sup {minus}9}-10{sup {minus}7} M PGE{sub 2} between 24 and 48 hours increased significantly in a concentration dependent fashion. When 100 ug/dl zinc was added with 10{sup {minus}9}-10{sup {minus}7} M PGE{sub 2} to the culture bone, no additive effect was observed. Flurbiprofen decreased calcium release from chick tibiae significantly in the 24-48 hour incubation period in a concentration dependent fashion, suggesting that endogenous PG's have stimulatory effect on bone calcium release. When 10{sup {minus}6} M flurbiprofen was added with 25-100 ug/dl zinc, the calcium release from tibiae was not changed significantly. Bone release from tibiae was not changed significantly. Bone alkaline phosphatase activity was elevated by 50-100 ug/dl zinc. Addition of PGE{sub 2} did not increase the zinc stimulated elevation of alkaline phosphatase activity. The authors propose the following: zinc stimulates bone cell proliferation; PGE{sub 2} stimulates calcium release from the limited number of osteoclasts in cultured embryonic tibiae; and most bone organ culture system are models of zinc deficiency, since incubation of physiological concentrations of zinc has significant effect.

  20. Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

    Directory of Open Access Journals (Sweden)

    Kweon-Ho Nam

    Full Text Available Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with

  1. Effects of probiotics and maternal vaccination on Salmonella enteritidis infection in broiler chicks.

    Science.gov (United States)

    Avila, L A F; Nascimento, V P; Salle, C T P; Moraes, H L S

    2006-12-01

    The effects of probiotics and maternal vaccination with an inactivated Salmonella Enteritidis (SE) vaccine on day-old chicks challenged with SE were evaluated. A 2 X 3 factorial arrangement was used (with or without probiotics; breeders nonvaccinated, vaccinated intramuscularly, or vaccinated intraperitoneally). Three trials were conducted in isolation cabinets and SE challenge was different between trials. The number of SE organisms per chick and the time interval between housing and introduction of seeder birds (hereafter called challenge) were 1.6 X 10(8) and 1 hr (Trial I), 1.8 X 10(6) and 12 hr (Trial II), and 1.2 X 10(4) and 24 hr (Trial III). SE recovery was assessed in ceca and liver at 3, 5, and 7 days postchallenge, and the number of colony-forming units (CFU) in ceca was evaluated at 5 and 7 days postchallenge. The number of SE (log CFU) in the ceca reduced 0.56 log (from 7.59 to 7.03) and 1.45 log (7.62 to 6.17) because of the treatment with probiotics in Trials II and III, respectively. The greater reduction in Trial III indicates the importance of the early use of probiotics on the prevention of SE infection. Treatment with probiotics resulted in a smaller number of SE-positive livers after 5 days postchallenge on Trial III. Although there was no significant effect of maternal vaccination on the number of SE CFU in the ceca, a significant effect of maternal vaccination on the SE CFU was observed in the liver, but not in the ceca at 5 days after challenge. PMID:17274302

  2. Gap junction signalling mediated through connexin-43 is required for chick limb development.

    Science.gov (United States)

    Makarenkova, H; Patel, K

    1999-03-15

    During chick limb development the gap junction protein Connexin-43 (Cx43) is expressed in discrete spatially restricted domains in the apical ectodermal ridge (AER) and mesenchyme of the zone of polarising activity. Antisense oligonucleotides (ODNs) were used to investigate the role of Connexin-43 (Cx43) in the development of the chick limb bud. We have used unmodified ODNs in Pluronic F-127 gel, which is liquid at low temperature but sets at room temperature and so remains situated at the point of application. As a mild surfactant, the gel increases antisense ODN penetration and supplies ODNs to the embryo continually for 12-18 h. We have shown a strong decrease in Cx43 protein expression after application of specific antisense oligonucleotides but the abundance of a closely related protein, Connexin-32 (Cx32), was not affected. Application of antisense Cx43 ODNs at stages 8-15 HH before limb outgrowth resulted in dramatic limb phenotypes. About 40% of treated embryos exhibited defects such as truncation of the limb bud, fragmentation into two or more domains, or complete splitting of the limb bud into two or three branches. Molecular analysis of antisense treated embryos failed to detect Shh or Bmp-2 in anterior structures and suggested that extra lobes seen in nicked and split limbs were not a result of establishment of new signalling centres as found after the application of FGF to the flank. However, examination of markers for the AER showed a number of abnormalities. In severely truncated specimens we were unable to detect the expression of either Fgf-4 or Fgf-8. In both nicked and split limbs the expression of these genes was discontinuous. Down-regulation of Cx43 after the antisense application could be comparable to AER removal and results in distal truncation of the limb bud. Taken together these data suggest the existence of a feedback loop between the FGFs and signalling mediated by Cx43.

  3. Bioavailability of Phosphorus in Two Cultivars of Pea for Broiler Chicks.

    Science.gov (United States)

    Woyengo, T A; Emiola, I A; Kim, I H; Nyachoti, C M

    2016-03-01

    The aim was to determine the relative bioavailability of phosphorus (P) in peas for 21-day old broiler chickens using slope-ratio assay. One hundred and sixty eight male Ross 308 broiler chicks were divided into 42 groups 4 balanced for body weight and fed 7 diets in a completely randomized design (6 groups/diet) from day 1 to 21 of age. The diets were a corn-soybean meal basal diet, and the corn-soybean meal basal diet to which monosodium phosphate, brown- or yellow-seeded pea was added at the expense of cornstarch to supply 0.5% or 1% total phosphorus. Monosodium phosphate was included as a reference, and hence the estimated bioavailability of P in pea cultivars was relative to that in the monosodium phosphate. Birds and feed were weighed weekly and on d 21 they were killed to obtain tibia. The brown-seeded pea contained 23.4% crude protein, 0.47% P, whereas the yellow-seeded pea contained 24.3% crude protein and 0.38% P. Increasing dietary P supply improved (p<0.05) chick body weight gain and tibia ash and bone density. The estimated relative bioavailability of p values for brown- and yellow-seeded peas obtained using final body weight, average daily gain, tibia ash, and bone mineral density were 31.5% and 36.2%, 35.6% and 37.3%, 23.0% and 5.60%, and 40.3% and 30.3%, respectively. The estimated relative bioavailability of p values for brown- and yellow-seeded peas did not differ within each of the response criteria measured in this study. In conclusion, the relative bioavailability of P in pea did not differ depending on the cultivar (brown- vs yellow-seed). However, the relative bioavailability of P in pea may vary depending on the response criterion used to measure the bioavailability. PMID:26950872

  4. Investigation of Interaction between Deferoxamine and Low Frequency Electromagnetic Field on Angiogenesis in Chick Embryo

    Directory of Open Access Journals (Sweden)

    Atena Dashtizadeh

    2015-02-01

    Full Text Available Background: Deferoxamine (DFO is an iron chelator. In the present research, the synergic effects of deferoxamine and electromagnetic field (with 50 H frequency and 100 Gauss intensity on angiogenesis of chick chorioallantoic membrane were investigated. Materials and Methods: In this experimental study 80 fertilized egg used and randomly divided 8 group: control group, laboratory control groups of 1 and 2, experimental group 1 (treatment with electromagnetic field, 2 and 3 (treatment with deferoxamine 10, 100 µmol, respectively, 4 and 5 (treatment both deferoxamine 10 and 100 µmol respectively and electromagnetic field. On 8th day of incubation, 2 and 4 groups were incubated with 10 µL deferoxamine and for 3 and 5 groups were incubated with 10 µL deferoxamine 100 µmol. On 10th day, 1, 4 and 5 groups were put in electromagnetic field. On 12th day, the number and length of vessels in all samples was measured by Image J software. Data were analyzed by SPSS-19, ANOVA and t-test. Results: The mean number and length of vessels in the control and experimental cases did not show any significant differences. Comparison between mean number of vessels in the control and group 2, 3, 4, 5 showed a significant decrease (p<0.05 and groups 2 and 4 was showed a significant decrease in the mean length of vessels compared with the controls (p<0.05. Conclusion: Using deferoxamine with low frequency electromagnetic field (50 Hz and 100 G cause inhibition of angiogenesis in chick embryo chorioallantoic membrane.

  5. Arrays of coupled chemical oscillators

    CERN Document Server

    Forrester, Derek Michael

    2016-01-01

    Oscillating chemical reactions result from complex periodic changes in the concentration of the reactants. In spatially ordered ensembles of candle flame oscillators the fluctuations in the ratio of oxygen atoms with respect to that of carbon, hydrogen and nitrogen produces an oscillation in the visible part of the flame related to the energy released per unit mass of oxygen. Thus, the products of the reaction vary in concentration as a function of time, giving rise to an oscillation in the amount of soot and radiative emission. Synchronisation of interacting dynamical sub-systems occurs as arrays of flames that act as master and slave oscillators, with groups of candles numbering greater than two, creating a synchronised motion in three-dimensions. In a ring of candles the visible parts of each flame move together, up and down and back and forth, in a manner that appears like a "worship". Here this effect is shown for rings of flames which collectively empower a central flame to pulse to greater heights. In ...

  6. Arrays of coupled chemical oscillators

    Science.gov (United States)

    Forrester, Derek Michael

    2015-11-01

    Oscillating chemical reactions result from complex periodic changes in the concentration of the reactants. In spatially ordered ensembles of candle flame oscillators the fluctuations in the ratio of oxygen atoms with respect to that of carbon, hydrogen and nitrogen produces an oscillation in the visible part of the flame related to the energy released per unit mass of oxygen. Thus, the products of the reaction vary in concentration as a function of time, giving rise to an oscillation in the amount of soot and radiative emission. Synchronisation of interacting dynamical sub-systems occurs as arrays of flames that act as master and slave oscillators, with groups of candles numbering greater than two, creating a synchronised motion in three-dimensions. In a ring of candles the visible parts of each flame move together, up and down and back and forth, in a manner that appears like a “worship”. Here this effect is shown for rings of flames which collectively empower a central flame to pulse to greater heights. In contrast, situations where the central flames are suppressed are also found. The phenomena leads to in-phase synchronised states emerging between periods of anti-phase synchronisation for arrays with different columnar sizes of candle and positioning.

  7. ALG-2 oscillates in subcellular localization, unitemporally with calcium oscillations

    DEFF Research Database (Denmark)

    la Cour, Jonas Marstrand; Mollerup, Jens; Berchtold, Martin Werner

    2007-01-01

    localization in an oscillatory fashion unitemporally with Ca2+ oscillations, whereas a Ca2+-binding deficient mutant of ALG-2 did not redistribute. Using tagged ALG-2 as bait we identified its novel target protein Sec31A and based on the partial colocalization of endogenous ALG-2 and Sec31A we propose that ALG......A variety of stimuli can trigger intracellular calcium oscillations. Relatively little is known about the molecular mechanisms decoding these events. We show that ALG-2, a Ca2+-binding protein originally isolated as a protein associated with apoptosis, is directly linked to Ca2+ signalling. We...

  8. Magnetically coupled magnet-spring oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, G; Ladera, C L; Martin, P [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)], E-mail: clladera@usb.ve, E-mail: pmartin@usb.ve

    2010-05-15

    A system of two magnets hung from two vertical springs and oscillating in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled oscillators. The electromagnetically coupled oscillations of these oscillators are experimentally and theoretically studied. Its coupling is electromagnetic instead of mechanical, and easily adjustable by the experimenter. The coupling of this new coupled oscillator system is determined by the currents that the magnets induce in two coils connected in series, one to each magnet. It is an interesting case of mechanical oscillators with field-driven coupling, instead of mechanical coupling. Moreover, it is both a coupled and a damped oscillating system that lends itself to a detailed study and presentation of many properties and phenomena of such a system of oscillators. A set of experiments that validates the theoretical model of the oscillators is presented and discussed.

  9. The periodically oscillating plasma sphere

    International Nuclear Information System (INIS)

    A new method of operating an inertial electrostatic confinement (IEC) device is proposed, and its performance is evaluated. The scheme involved an oscillating thermal cloud of ions immersed in a bath of electrons that form a harmonic oscillator potential. The scheme is called the periodically oscillating plasma sphere, and it appears to solve many of the problems that may limit other IEC systems to low gain. A set of self-similar solutions to the ion fluid equations is presented, and plasma performance is evaluated. Results indicate that performance enhancement of gridded IEC systems such as the Los Alamos intense neutron source device is possible as well as high-performance operation for low-loss systems such as the Penning trap experiment. Finally, a conceptual idea for a massively modular Penning trap reactor is also presented

  10. Classical scattering from oscillating targets

    Energy Technology Data Exchange (ETDEWEB)

    Papachristou, P.K.; Diakonos, F.K.; Constantoudis, V.; Schmelcher, P.; Benet, L

    2002-12-30

    We study planar classical scattering from an oscillating heavy target whose dynamics defines a five-dimensional phase space. Although the system possesses no periodic orbits, and thus topological chaos is not present, the scattering functions display a variety of structures on different time scales. These structures are due to scattering events with a strong energy transfer from the projectile to the moving disk resulting in low-velocity peaks. We encounter initial conditions for which the projectile exhibits infinitely many bounces with the oscillating disk. Our numerical investigations are supported by analytical results on a specific model with a simple time-law. The observed properties possess universal character for scattering off oscillating targets.

  11. Prediction of pilot induced oscillations

    Directory of Open Access Journals (Sweden)

    Valentin PANĂ

    2011-03-01

    Full Text Available An important problem in the design of flight-control systems for aircraft under pilotedcontrol is the determination of handling qualities and pilot-induced oscillations (PIO tendencieswhen significant nonlinearities exist in the vehicle description. The paper presents a method to detectpossible pilot-induced oscillations of Category II (with rate and position limiting, a phenomenonusually due to a misadaptation between the pilot and the aircraft response during some tasks in whichtight closed loop control of the aircraft is required from the pilot. For the analysis of Pilot in the LoopOscillations an approach, based on robust stability analysis of a system subject to uncertainparameters, is proposed. In this analysis the nonlinear elements are substituted by linear uncertainparameters. This approach assumes that PIO are characterized by a limit cycle behavior.

  12. Bloch oscillations in carbon nanotubes.

    Science.gov (United States)

    Jódar, Esther; Pérez-Garrido, Antonio; Rojas, Fernando

    2009-05-27

    Bloch oscillations arise when electrons are in a one-dimensional linear chain of atoms under a constant electric field. In this paper we show numerically that electrons in different types of carbon nanotubes show oscillations with a Bloch frequency proportional to the constant electric field applied along the nanotube axis. We show these oscillations, calculating the quadratic displacement as a function of the electric field. Because of the double periodicity of the nanotubes' geometry (the lattice constant and the lines of atoms) two frequencies appear, one twice the value of the other. These frequencies coincide perfectly with those predicted for a linear chain of atoms, taking into account the periodicity considered in each case.

  13. Fano interference in classical oscillators

    International Nuclear Information System (INIS)

    We seek to illustrate Fano interference in a classical coupled oscillator by using classical analogues of the atom-laser interaction. We present an analogy between the dressed state picture of coherent atom-laser interaction and a classical coupled oscillator. The Autler-Townes splitting due to the atom-laser interaction is analogous to the splitting of normal-mode frequencies of a coupled oscillator. Using this analogy, we simulate and experimentally demonstrate Fano interference and the associated phenomena in three-level atoms in a coupled electrical resonator circuit. This work aims to highlight analogies between classical and quantum systems for students at the postgraduate and graduate levels. Also, the reported technique can be easily realized in undergraduate laboratories. (paper)

  14. Magnetically insulated transmission line oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, Larry D. (Albuquerque, NM); Ballard, William P. (Albuquerque, NM); Clark, M. Collins (Albuquerque, NM); Marder, Barry M. (Albuquerque, NM)

    1988-01-01

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields arfe produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap.

  15. LYAPUNOV SPECTRA FOR KAPITZA OSCILLATOR

    Directory of Open Access Journals (Sweden)

    Nayyer Iqbal

    2012-02-01

    Full Text Available Here we purpose a simple but realistic model of one dimensional nonlinear Kapitza oscillator driven by sin- or cos- rapidly external oscillating periodical force. The model has a parameter 2gl=a22 of dimension one, depending on the amplitude a and frequency of modulation . Changing its value we construct phase portraits of the system in the neighbourhood of fixed points and demonstrate the changing in Lyapunov spectrum. Our purpose is to observe the behavior of system at fixed points due to the different structures of the Lyapunov spectra

  16. LYAPUNOV SPECTRA FOR KAPITZA OSCILLATOR

    OpenAIRE

    Nayyer Iqbal; Shahid Ahmad; Muhammad Hussain

    2012-01-01

    Here we purpose a simple but realistic model of one dimensional nonlinear Kapitza oscillator driven by sin- or cos- rapidly external oscillating periodical force. The model has a parameter 2gl=a22 of dimension one, depending on the amplitude a and frequency of modulation . Changing its value we construct phase portraits of the system in the neighbourhood of fixed points and demonstrate the changing in Lyapunov spectrum. Our purpose is to observe the behavior of system at fixed points due to t...

  17. Stochastic excitation of stellar oscillations

    CERN Document Server

    Samadi, R

    2001-01-01

    Excitation of solar oscillations is attribued to turbulent motions in the solar convective zone. It is also currently believed that oscillations of low massive stars (M <2 Mo) - which possess an upper convective zone - are stochastically excited by turbulent convection in their outer layers. A recent theoretical work (Samadi & Goupil, 2001 ; Samadi et al, 2001) supplements and reinforces this theory. This allows the use of any available model of turbulence and emphasizes some recent unsolved problems which are brought up by these new theoretical developments.

  18. Oscillator strengths for Be I

    Energy Technology Data Exchange (ETDEWEB)

    Ates, Sule, E-mail: suleates@selcuk.edu.tr; Oezarslan, Selma; Celik, Gueltekin; Taser, Mehmet

    2012-07-15

    The electric dipole oscillator strengths for lines between some singlet and triplet levels have been calculated using the weakest bound electron potential model theory and the quantum defect orbital theory for Be I. In the calculations both multiplet and fine structure transitions are studied. We employed both the numerical Coulomb approximation method and numerical non-relativistic Hartree-Fock wavefunctions for expectation values of radii. The necessary energy values have been taken from experimental energy data in the literature. The calculated oscillator strengths have been compared with available theoretical results. A good agreement with the results in the literature has been obtained.

  19. Oscillations in molecular motor assemblies

    CERN Document Server

    Vilfan, A; Vilfan, Andrej; Frey, Erwin

    2005-01-01

    Autonomous oscillations in biological systems may have a biochemical origin or result from an interplay between force-generating and visco-elastic elements. In molecular motor assemblies the force-generating elements are molecular engines and the visco-elastic elements are stiff cytoskeletal polymers. The physical mechanism leading to oscillations depends on the particular architecture of the assembly. Existing models can be grouped into two distinct categories: systems with a {\\em delayed force activation} and {\\em anomalous force-velocity relations}. We discuss these systems within phase plane analysis known from the theory of dynamic systems and by adopting methods from control theory, the Nyquist criterion.

  20. Sound oscillation of dropwise cluster

    Science.gov (United States)

    Shavlov, A. V.; Dzhumandzhi, V. A.; Romanyuk, S. N.

    2012-06-01

    There was registered sound oscillation of a dropwise cluster formed over the warmed-up water surface. We have calculated the electrical charge of drops on the basis of experimental data on ion-sound oscillation. It was demonstrated that the charge is proportional to surface area of the drops and does not depend on intensity of their evaporation (condensation) in the range of 60-100 °C. The charge of drops reaches 102-103 units of elementary charge and coincides on magnitude order with the literary value of a charge calculated by another method.

  1. Primordial Lepton Oscillations and Baryogenesis

    CERN Document Server

    Hamada, Yuta

    2016-01-01

    The baryon asymmetry of the Universe should have been produced after the inflation era. We consider the possibility that the asymmetry is generated by the flavor oscillations in the reheating process after inflation, so that the baryon asymmetry is realized already at the beginning of the radiation dominated era. In the seesaw model, we show that the propagators of the left-handed leptons generically have flavor mixings in the thermal background, that can generate flavor-dependent lepton asymmetry through the $CP$ violation in the oscillation phenomena. The flavor dependent rates for the wash-out process can leave the net asymmetry today.

  2. IMMUNO-MODULATORY EFFECT OF INACTIVATED EIMERIA TENELLA VACCINE AND LIVE IMPPORTED COCCIDIAL VACCINE ON NEWCASTLE DISEASE VIRUS VACCINA TED BROILER CHICKS

    Directory of Open Access Journals (Sweden)

    Muhammad Akram Muneer, Haji Ahmad Hashmi, Masood Rabbani, Zahid Munir Chaudhry and Ali M. Bahrami

    2001-01-01

    Full Text Available A total of 160 one-day-old broiler chicks were used to evaluate the immunomodulatory effects of an inactivated Eimeria tenella vaccine and a live polyvalent imported antiococcidial vaccine (Coccivac. This study indicated that both of these vaccines did not adversely affect the development of serum antibody against Newcastle disease virus (NDV and the chicks vaccinated with either of the anticoccidial vaccines resisted the virulent NDV challenge. A study of the lymphoid organs such as bursa of fabricuis: thymus and spleen from the experimental chicks indicated that those organs were comparable with those from the chicks not vaccinated with these coccidial vaccines. The overall findings of this study indicate that anticoccidial vaccines do not have any effects on the immune functions of the vaccinates. In fact these vaccines prevented the occurrence of clinical coccidiosis in the vaccinates.

  3. Bambi and Sp8 Expression Mark Digit Tips and Their Absence Shows That Chick Wing Digits 2 and 3 Are Truncated

    OpenAIRE

    Jesús C Casanova; Claudio Badia-Careaga; Verónica Uribe; Juan José Sanz-Ezquerro

    2012-01-01

    An often overlooked aspect of digit development is the special nature of the terminal phalanx, a specialized structure with characteristics distinct from other phalanges, for example the presence of ectodermal derivatives such as nails and claws. Here, we describe the unique ossification pattern of distal phalanges and characteristic gene expression in the digit tips of chick and duck embryos. Our results show that the distal phalanx of chick wing digit 1 is a genuine tip with a characteristi...

  4. A new approach to study of seabird-fishery overlap: Connecting chick feeding with parental foraging and overlap with fishing vessels

    Directory of Open Access Journals (Sweden)

    Junichi Sugishita

    2015-07-01

    Full Text Available Incidental fisheries bycatch is recognised as a major threat to albatross populations worldwide. However, fishery discards and offal produced in large quantities might benefit some scavenging seabirds. Here, we demonstrate an integrated approach to better understand the ecological ramifications of fine-scale overlap between seabirds and fisheries. As a case study, we examined whether foraging in association with a fishing vessel is advantageous for chick provisioning in terms of quantity of food delivered to chicks, in northern royal albatross (Diomedea sanfordi at Taiaroa Head, New Zealand. Fine-scale overlap between albatrosses and vessels was quantified by integrating GPS tracking and Vessel Monitoring Systems (VMS. Meal size delivered to chicks was measured using custom-designed nest balances, and monitoring of attendance of adults fitted with radio transmitters was used in conjunction with time-lapse photography at the nest allowed us to allocate each feeding event to a specific parent. The combination of these techniques enabled comparison of meal sizes delivered to chicks with parental foraging trip durations with or without fishing vessels association. A total of 45 foraging trips and associated chick feeding events were monitored during the chick-rearing period in 2012. Differences in the meal size and foraging trip duration relative to foraging overlap with fisheries were examined using a linear mixed-effect model, adjusted for chick age. Our results, based on three birds, suggest that foraging in association with vessels does not confer an advantage for chick feeding for this population that demonstrated low rates of overlap while foraging. The integrated research design presented can be applied to other seabird species that are susceptible to bycatch, and offers a valuable approach to evaluate habitat quality by linking habitat use and foraging success in terms of total amount of food delivered to offspring.

  5. Moral ‘Lock-In’ in Responsible Innovation: The Ethica land Social Aspects of Killing Day-Old Chicks and its Alternatives

    OpenAIRE

    Bruijnis, M.R.N.; Blok, V.; Stassen, E.N.; Gremmen, H.G.J.

    2015-01-01

    The aim of this paper is to provide a conceptual framework that will help in understanding and evaluating, along social and ethical lines, the issue of killing day-old male chicks and two alternative directions of responsible innovations to solve this issue. The following research questions are addressed: Why is the killing of day-old chicks morally problematic? Are the proposed alternatives morally sound? To what extent do the alternatives lead to responsible innovation? The conceptual frame...

  6. Rotationally acquired four-dimensional optical coherence tomography of embryonic chick hearts using retrospective gating on the common central A-scan

    DEFF Research Database (Denmark)

    Happel, Christoph M.; Thommes, Jan; Thrane, Lars;

    2011-01-01

    We introduce a new method of rotational image acquisition for four-dimensional (4D) optical coherence tomography (OCT) of beating embryonic chick hearts. The rotational axis and the central A-scan of the OCT are identical. An out-of-phase image sequence covering multiple heartbeats is acquired at.......We demonstrate this approach and provide a video of a beating Hamburger and Hamilton stage 16 embryonic chick heart generated from a 4D OCT data set using rotational image acquisition....

  7. The relationship between gene expression of cationic and neutral amino acid transporters in the small intestine of chick embryos and chick breed, development, sex, and egg amino acid concentration.

    Science.gov (United States)

    Zeng, P L; Li, X G; Wang, X Q; Zhang, D X; Shu, G; Luo, Q B

    2011-11-01

    This study was conducted to investigate the gene expression of cationic and neutral amino acid (AA) transporters in the small intestine of chick embryos with different genetic backgrounds [Wenshi Yellow-Feathered chick (WYFC) and White Recessive Rock chick (WRRC)]. The study also investigated the correlation between the abundance of AA transporter mRNA and the AA content of fertilized eggs. Intestinal samples were collected on embryonic d 9, 12, 14, 17, and 19 and the day of hatch. The results showed that, before incubation, the AA content of WRRC eggs was lower (P CAT-1 [solute carrier (SLC) family 7 member 1], CAT-4 (SLC family 7 member 4), rBAT (SLC family 3 member 1), y(+)LAT-1 (SLC family 7 member 7), y(+)LAT-2 (SLC family 7 member 6), LAT-4 (SLC family 43 member 2), and SNAT-2 (SLC family 38 member 2), as detected by real-time reverse transcriptase PCR, was greater (P CAT-1, CAT-4, y(+)LAT-2, and LAT-4 in WYFC and on CAT-4 and B(0)AT-1 (SLC family 6 member 19) mRNA expression in WRRC. In WYFC, only CAT-1 mRNA expression was negatively correlated (r = -0.68 to -0.84, P < 0.05) with all AA content. However, few correlations were detected between AA content and the mRNA expression of multiple transporters in WRRC. These findings provide a comprehensive profile of the temporal and spatial mRNA expression of AA transporters in the small intestine of chick embryos. Few correlations were detected between the AA content of the eggs and mRNA expression of specific AA transporters in the small intestine.

  8. Linearization of Conservative Nonlinear Oscillators

    Science.gov (United States)

    Belendez, A.; Alvarez, M. L.; Fernandez, E.; Pascual, I.

    2009-01-01

    A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid not only for small but also for large amplitudes and, sometimes, for…

  9. Cubication of Conservative Nonlinear Oscillators

    Science.gov (United States)

    Belendez, Augusto; Alvarez, Mariela L.; Fernandez, Elena; Pascual, Immaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear…

  10. Teleportation using coupled oscillator states

    OpenAIRE

    Cochrane, P. T.; Milburn, G. J.; Munro, W. J.

    2000-01-01

    We analyse the fidelity of teleportation protocols, as a function of resource entanglement, for three kinds of two mode oscillator states: states with fixed total photon number, number states entangled at a beam splitter, and the two-mode squeezed vacuum state. We define corresponding teleportation protocols for each case including phase noise to model degraded entanglement of each resource.

  11. Sound oscillation of dropwise cluster

    International Nuclear Information System (INIS)

    There was registered sound oscillation of a dropwise cluster formed over the warmed-up water surface. We have calculated the electrical charge of drops on the basis of experimental data on ion-sound oscillation. It was demonstrated that the charge is proportional to surface area of the drops and does not depend on intensity of their evaporation (condensation) in the range of 60–100 °C. The charge of drops reaches 102–103 units of elementary charge and coincides on magnitude order with the literary value of a charge calculated by another method. -- Highlights: ► The present investigation registered short-wave sound oscillations of water drops in a dropwise cluster in the range of 60–100 °C. ► We have found autocorrelation functions and Fourier transforms of time series of interdroplet distance; defined oscillation frequencies. ► Calculated electrical charge of drops and specified that the charge is proportional to the drop surface area.

  12. Oscillating Flavors in Massless Neutrinos

    CERN Document Server

    Welch, Lester C

    2016-01-01

    By considering Dirac's equation using quaternions ($\\mathbb{H}$) with their greater degree of freedom in imaginaries, it is shown that a model can be created with oscillations among flavors even if the particles, are massless. Furthermore the solutions are spin $\\frac{1}{2}$ and have helicities depending on whether their energy is positive or negative.

  13. Sound oscillation of dropwise cluster

    Energy Technology Data Exchange (ETDEWEB)

    Shavlov, A.V., E-mail: shavlov@ikz.ru [Institute of the Earth Cryosphere, RAS Siberian Branch, P.O. 1230, 625000 Tyumen (Russian Federation); Dzhumandzhi, V.A.; Romanyuk, S.N. [Institute of the Earth Cryosphere, RAS Siberian Branch, P.O. 1230, 625000 Tyumen (Russian Federation)

    2012-06-04

    There was registered sound oscillation of a dropwise cluster formed over the warmed-up water surface. We have calculated the electrical charge of drops on the basis of experimental data on ion-sound oscillation. It was demonstrated that the charge is proportional to surface area of the drops and does not depend on intensity of their evaporation (condensation) in the range of 60–100 °C. The charge of drops reaches 10{sup 2}–10{sup 3} units of elementary charge and coincides on magnitude order with the literary value of a charge calculated by another method. -- Highlights: ► The present investigation registered short-wave sound oscillations of water drops in a dropwise cluster in the range of 60–100 °C. ► We have found autocorrelation functions and Fourier transforms of time series of interdroplet distance; defined oscillation frequencies. ► Calculated electrical charge of drops and specified that the charge is proportional to the drop surface area.

  14. [Forced Oscillations of DNA Bases].

    Science.gov (United States)

    Yakushevich, L V; Krasnobaeva, L A

    2016-01-01

    This paper presents the results of the studying of forced angular oscillations of the DNA bases with the help of the mathematical model consisting of two coupled nonlinear differential equations that take into account the effects of dissipation and the influence of an external periodic field. The calculation results are illustrated for sequence of gene encoding interferon alpha 17 (IFNA 17). PMID:27192830

  15. Lepton textures and neutrino oscillations

    CERN Document Server

    Verma, Rohit

    2014-01-01

    Systematic analyses of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.

  16. Observation of anharmonic Bloch oscillations.

    Science.gov (United States)

    Dreisow, Felix; Wang, Gang; Heinrich, Matthias; Keil, Robert; Tünnermann, Andreas; Nolte, Stefan; Szameit, Alexander

    2011-10-15

    We report on the experimental observation of Bloch oscillations of an optical wave packet in a lattice with second-order coupling. To this end, we employ zigzag waveguide arrays, in which the second-order coupling can be precisely tuned.

  17. B0s Oscillation Results

    CERN Document Server

    Willocq, S

    2002-01-01

    We review new studies of the time dependence of B0s - B0s-bar mixing by the ALEPH, DELPHI and SLD Collaborations, with an emphasis on the different analysis methods used. Combining all available results yields a preliminary lower limit on the oscillation frequency of dms > 14.4 ps-1 at the 95% C.L.

  18. Optoelectronic Oscillators for Communication Systems

    Science.gov (United States)

    Romeira, Bruno; Figueiredo, José

    We introduce and report recent developments on a novel five port optoelectronic voltage controlled oscillator consisting of a resonant tunneling diode (RTD) optical-waveguide integrated with a laser diode. The RTD-based optoelectronic oscillator (OEO) has both optical and electrical input and output ports, with the fifth port allowing voltage control. The RTD-OEO locks to reference radio-frequency (RF) sources by either optical or electrical injection locking techniques allowing remote synchronization, eliminating the need of impedance matching between traditional RF oscillators. RTD-OEO functions include generation, amplification and distribution of RF carriers, clock recovery, carrier recovery, modulation and demodulation and frequency synthesis. Self-injection locking operation modes, where small portions of the output electrical/optical signals are fed back into the electrical/optical input ports, are also proposed. The self-phase locked loop configuration can give rise to low-noise high-stable oscillations, not limited by the RF source performance and with no need of external optoelectronic conversion.

  19. Neutrino Oscillation Experiment at JHF

    CERN Multimedia

    2002-01-01

    The first stage of a next-generation long baseline neutrino oscillation experiment is proposed to explore the physics beyond the Standard Model. The experiment will use the high intensity proton beam from the JHF 50 GeV proton synchrotron (JHF PS), and Super-Kamiokande as a far detector. The baseline length will be 295 km. The beam power of JHF PS is capable of delivering 3.3 x 10$^{14}$ 50 GeV protons every 3.5 seconds (0.75 MW). The experiment assumes 130 days of operation at full intensity for five years. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of $\\sim$ 0.8 GeV to maximize the sensitivity to neutrino oscillations. The merits of this experiment can be summarized as follows: \\begin{itemize} \\item The off-axis beam can produce the highest possible intensity with a narrow energy spread. The oscillation maximum will be $\\sim$ 0.8 GeV for the distance of 295 km and $\\Delta m^{2} \\sim$ 3 x 10$^{-3}$eV$^{2}$. The corre...

  20. Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium.

    Science.gov (United States)

    Faber, T A; Dilger, R N; Iakiviak, M; Hopkins, A C; Price, N P; Fahey, G C

    2012-09-01

    Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively affect immune status and prevent colonization and shedding in Salmonella typhimurium-infected chicks. Using a completely randomized design, 1-d-old commercial broiler chicks (n = 240 chicks; 4 replications/treatment; 5 chicks/replication) were assigned to 1 of 6 dietary treatments differing in concentration of GGMO-AX (0, 1, 2, or 4%) or containing 2% Safmannan or 2% short-chain fructooligosaccharides. Cellulose was used to make diets iso-total dietary fiber. On d 10 posthatch, an equal number of chicks on each diet were inoculated with either phosphate-buffered saline (sham control) or Salmonella typhimurium (1 × 10(8) cfu). All birds were euthanized on d 10 postinoculation (PI) for collection of intestinal contents and select tissues. Body weight gain and feed intake of chicks were greater (P Salmonella typhimurium populations on d 5 and 10 PI, and ileal and cecal Salmonella typhimurium populations, tended to be affected (P Salmonella typhimurium virulence was suppressed. Dietary supplementation with GGMO-AX resulted in prebiotic-like effects but did not limit Salmonella typhimurium intestinal colonization or shedding, but possibly decreased the virulence of Salmonella typhimurium within the digestive tract.