48 research outputs found

    Why do rabbits ingest their feces ?

    Get PDF
     The utilization of dietary energy and protein must depend on microbial activity in the gut in every herbivore. For animals adopting the cecum as a microbial habitat, from the viewpoint of the protein utilization, the position of the cecum in the digestive tract is less advantageous than that of foregut fermenters. As a solution to this problem, cecum fermenters perform cecotrophy in order to utilize microbial protein proliferating in the cecum. Cecotrophy is supported by the mechanism that separates microbes from digesta in the colon, sends them back into the cecum and promotes microbial proliferation in the cecum. The colonic separation mechanism can be classified into two types. One is the mucus-trap type separation of bacteria with mucus from digesta in the proximal colon of rodents. The other is the wash-back type separation of particle phase of the colonic contents and liquid phase containing microbes in the colon of rabbits. For microbes guaranteed to inhabit the cecum under colonic separation mechanism, it is necessary for them to obtain sufficient nutrients for survival and proliferation. The source of nitrogen is easily obtained as urea transfered from the blood flow. On the other hand, the energy source is considered to be the limiting factor for bacterial proliferation due to the limited amount of easily usable energy source. In fact, cecal microbial proliferation of rabbits and guinea pigs increases when adding indigestible but fermentable sugars to the feed. As a result, the amount of cecotrophy increases, and the percentage of nitrogen accumulation in the body tends to increase

    Studies on the Chemical Composition and Quality of Silage : (XII) The Influence of Fermentative Quality on the Digestibility and Nitrogen Utilization of Silage

    Get PDF
    出穂期のイタリアンライグラスを材料に用い,材料の細切度,埋蔵密度および重石の量を調節し,発酵的品質の異なる2区サイレージを調製した. ヒツジおよびin vitro法によって消化率を査定するとともにヒツジにより窒素出能を調査し,サイレージの発酵的品質と飼料価値との関係を検討した. 結果の要約は次のようである. (1)でき上がりサイレージのpH価は,A区4.39,B区4.79,評点は,A区60点,B区47点であった. (2)ヒツジによる消化試験の結果,サイレージの中期物の消化率はA区61.5%,B区58.8%であり,粗タンパク質の消化率は,A区48.4%,B区43.6%であった. そして,サイレージのDCP含量は,A区0.92%,B区0.75%,TDN含量は,A区14.62%,B区13.54%であった. (3)in vitro法による乾物の消化率は,A区64.6%,B区61.5%,同じくタンパク質の消化率は,A区56.0%,B区54.4%であった. (4)ヒツジの窒素蓄積率は劣質サイレージを給与した場合より,良質サイレージを給与した場合の方が高くなる傾向にあった

    土壌改質材 FFC エースによるオオムギの生育と収量の促進効果

    Get PDF
    The effects of a unique soil conditioner, FFC-ace, on photosynthesis, transpiration, growth and yield of barley were examined in a field experiment. FFC-ace well-mixed with sandy soil greatly enhanced root and shoot growth, tillering and the number of grains per stock. The total yield in the treated plot increased by about 172%. The plants grown in the FFC-ace plot were greener and contained a higher level of chlorophyll, compared with the control. Photosynthesis and transpiration, which are tightly linked to productivity were also significantly enhanced at the broad range of photon flux observed in our study. The quality of grain harvested from the FFC-ace plot was similar to the control plot in terms of nutritional and inorganic components. The increased photosynthesis in the FFC-ace treated barley reflects a higher absorption of CO(2) from the atmosphere. It was also noted that the efficiency of water utilization for photosynthesis was significantly greater under the high light intensity in the treated plot. The relationship between application of FFC-ace and absorption of atmospheric CO(2) is discussed. Our investigation provides data showing that application of FFC-ace to soil significantly reduces water requirements for plant growth and yield.本報は,㈱エフエフシー・ジャパンから販売されている土壌改質材FFCエースTMの作物の生長促進効果について,2006年11月から翌年6月,本学農学部内の実験圃場で実施された,オオムギの生育ならびに収量調査に関する試験結果をとりまとめたものである.実施圃場の砂土壌にFFCエースを所定量混和した区画を設け,オオムギの種子を播種した.なお,対照区は非導入土壌とした.定期的に行った生育調査の結果,FFCエースを導入した土壌では非導入の区画と比べて,生育初期における根の生育が良好となり,地上部における分けつ数の増加とともに穂の生長も旺盛となって,1穂当たりの収穫量(粒数)の著しい増加をもたらした.結果,FFCエース導入区における全収量は非導入区と比べて約1.7倍となった.また,それぞれから収穫したオオムギ粒に含まれる栄養価ならびに無機元素類の量には,FFCエースの導入,非導入によって大きな違いは認められず,導入の効果は収量に大きく反映された.事実,調査期間中に行った測定から,FFCエースを投入した土壌で生育するオオムギ葉は高いクロロフィル量を示しており,光合成が促進されているものと考えられた.実際,播種後4ヶ月目以降,光合成ならびに蒸散速度値を測定した結果,FFCエース導入区で生育したオオムギでは常に高い値を示した.また,FFCエースの導入によって強光条件下における水利用効率が促進された.本報告では,FFCエースの投与と空気中からの二酸化炭素の吸収量との関連について考察するとともに,併せて,FFCエースの土壌への導入によって作物の生育に必要な灌水量を大きく減らすことができる可能性についても言及したい

    Correlators of Vertex Operators for Circular Strings with Winding Numbers in AdS5xS5

    Full text link
    We compute semiclassically the two-point correlator of the marginal vertex operators describing the rigid circular spinning string state with one large spin and one windining number in AdS_5 and three large spins and three winding numbers in S^5. The marginality condition and the conformal invariant expression for the two-point correlator obtained by using an appropriate vertex operator are shown to be associated with the diagonal and off-diagonal Virasoro constraints respectively. We evaluate semiclassically the three-point correlator of two heavy circular string vertex operators and one zero-momentum dilaton vertex operator and discuss its relation with the derivative of the dimension of the heavy circular string state with respect to the string tension.Comment: 16 pages, LaTeX, no figure

    Correlation function of null polygonal Wilson loops with local operators

    Full text link
    We consider the correlator of a light-like polygonal Wilson loop with n cusps with a local operator (like the dilaton or the chiral primary scalar) in planar N =4 super Yang-Mills theory. As a consequence of conformal symmetry, the main part of such correlator is a function F of 3n-11 conformal ratios. The first non-trivial case is n=4 when F depends on just one conformal ratio \zeta. This makes the corresponding correlator one of the simplest non-trivial observables that one would like to compute for generic values of the `t Hooft coupling \lambda. We compute F(\zeta,\lambda) at leading order in both the strong coupling regime (using semiclassical AdS5 x S5 string theory) and the weak coupling regime (using perturbative gauge theory). Some results are also obtained for polygonal Wilson loops with more than four edges. Furthermore, we also discuss a connection to the relation between a correlator of local operators at null-separated positions and cusped Wilson loop suggested in arXiv:1007.3243.Comment: 36 pages, 2 figure

    On semiclassical approximation for correlators of closed string vertex operators in AdS/CFT

    Full text link
    We consider the 2-point function of string vertex operators representing string state with large spin in AdS_5. We compute this correlator in the semiclassical approximation and show that it has the expected (on the basis of state-operator correspondence) form of the strong-coupling limit of the 2-point function of single trace minimal twist operators in gauge theory. The semiclassical solution representing the stationary point of the path integral with two vertex operator insertions is found to be related to the large spin limit of the folded spinning string solution by a euclidean continuation, transformation to Poincare coordinates and conformal map from cylinder to complex plane. The role of the source terms coming from the vertex operator insertions is to specify the parameters of the solution in terms of quantum numbers (dimension and spin) of the corresponding string state. Understanding further how similar semiclassical methods may work for 3-point functions may shed light on strong-coupling limit of the corresponding correlators in gauge theory as was recently suggested by Janik et al in arXiv:1002.4613.Comment: 19 pages, 1 figure; minor corrections, references added, footnote below eq. (4.5) adde

    CAR-T cell. the long and winding road to solid tumors

    Get PDF
    Adoptive cell therapy of solid tumors with reprogrammed T cells can be considered the "next generation" of cancer hallmarks. CAR-T cells fail to be as effective as in liquid tumors for the inability to reach and survive in the microenvironment surrounding the neoplastic foci. The intricate net of cross-interactions occurring between tumor components, stromal and immune cells leads to an ineffective anergic status favoring the evasion from the host's defenses. Our goal is hereby to trace the road imposed by solid tumors to CAR-T cells, highlighting pitfalls and strategies to be developed and refined to possibly overcome these hurdles

    Anatomical classification of the shape and topography of the stomach

    Get PDF
    The aim of the study was to present the classification of anatomical variations of the stomach, based on the radiological and historical data. In years 2006–2010, 2,034 examinations of the upper digestive tract were performed. Normal stomach anatomy or different variations of the organ shape and/or topography without any organic radiologically detectable gastric lesions were revealed in 568 and 821 cases, respectively. Five primary groups were established: abnormal position along longitudinal (I) and horizontal axis (II), as well as abnormal shape (III) and stomach connections (IV) or mixed forms (V). The first group contains abnormalities most commonly observed among examined patients such as stomach rotation and translocation to the chest cavity, including sliding, paraesophageal, mixed-form and upside-down hiatal diaphragmatic hernias, as well as short esophagus, and the other diaphragmatic hernias, that were not found in the evaluated population. The second group includes the stomach cascade. The third and fourth groups comprise developmental variations and organ malformations that were not observed in evaluated patients. The last group (V) encloses mixed forms that connect two or more previous variations
    corecore