耕牛结肠盘排列异常一例

耕牛结肠盘排列异常一例宁长申（河南农大牧医系４５０００２）禹宝琴（郑州市医药总公司）牛的结肠盘为向心旋转约一圈半，再离心旋转约２圈，且向心回与离心回以同心圆的方式平行排列，这是兽医界所公认的。但在新郑县兽医院剖检一头因结肠中段和回肠后段阻塞、继发其前...

Ultrastructure of the Blepharoplast and the Multilayered Structure in Spermatogenesis in Osmunda cinnamomea var. asiatica

The ultrastructure of the blepharoplast and the multilayered structure (MLS) in the fern Osmunda cinnamomea var. asiatica Fernald have been studied by electron microscopy with respect to spermatogenesis. The blepharoplast appears in the young spermatid. The differentiating blepharoplast is approximately a spherical body, which is composed of densely stained granular material in the center and some cylinders outside of it. The differentiated blepharoplast is also a sphere, but without the densely stained material in the center, consisting of scattered or radially arranged cylinders. The MLS seen in the spermatid lies between the basal bodies and the giant mitochondrion. In the early developmental stage, the MLS only consists of lamellar layers, each of which runs parallel to one another and forms a strip. In the mid stage, the MLS is composed of the microtubular ribbon (MTr), the lamellar layers and a layer of plaque. In the late stage, the MLS forms accessory band, osmiophilic crest and a layer of osmiophilic material. The MTr grows out from the MLS and extends along the surface of the nucleus to unite with the nuclear envelope in a complex. The basal body coming from the cylinder produces the axoneme of the flagella in the distal end and the wedge-shaped structure in the proximal end, respectively. In the present study, the ultrastructural features of blepharoplast and the MLS of the protoleptosporangiopsida fern, O. cinnamomea var. asiatica, have been described and compared with those of other kinds of pteridophytes in detail. The lamellar layers appearing before the formation of the MTr was found and reported for the first time.

Structure of the Bovine ACAD8 Gene and the Association of Its Polymorphism with the Production Traits

Acyl-coenzyme A dehydrogenases （ACAD） are a family of nuclear-coded, mitochondrial flavoenzymes that catalyze the alpha, and beta-dehydrogenation of fatty acids. The eighth member of this family, ACAD8 catalyzes the valine catabolism. In this study, the bovine ACAD8 full-length mRNA and genomic DNA sequence were obtained and its gene structure was determined through alignment of the genomic DNA sequence to the mRNA sequence. The mRNA sequence consisted of a 1,251 bp open reading frame （ORF） flanked by a 37 bp 5＇-untranslated region （UTR） and a 444 bp 3＇-UTR; and its full-length genomic DNA sequence was 13,814 bp in length and included 11 exons and 10 introns. One A-G single nucleotide polymorphism （SNP） was revealed at nucleotide 13,408 （GenBank accession No. DQ435445） in the bovine ACAD8 gene by sequencing the polymerase chain reaction （PCR） products of 6 randomly selected individuals from the sample population. Different genotypes were determined by restriction fragment length polymorphism （RFLP）. The association analysis of this SNP in bovine ACAD8 with production traits in 178 unrelated steers from 5 breeds showed that it had a significant effect on the daily gain and the beef tenderness （P〈0.05）. Cattle with the G allele grew more rapidly and the beef they produced was more tender than those with the A allele. Thus, this SNP of the bovine ACAD8 gene can be used as an indicator to improve the growth rate and the beef tenderness.

耕牛的管理技术

“牛是农家宝,种田少不了。”要用好管好“农家宝”,主要抓好五个环节。 一、抓秋膘 双抢过后,牛体重减轻,又加冬种,体质较为瘦弱,必须给以丰富的青草,使之尽快恢复体力,膘肥力壮。这一时期要拖长放牧时间8—10小时,让牛在草地上吃饱,睡好。利用牧草未干枯以前,增加营养,俗语说“草膘,料劲,水精神”。

The Bovine Tuberculosis Campaign in Mexico： Present and Perspectives

Mexico is considered by different international organizations as a country where the bovine tuberculosis is an endemic problem. However, there are important and consistent improvements in eradicating the disease by the implementation of government policies and with the livestock organization support. The current situation of the program shows good results regarding decreasing the prevalence, and as a consequence, the risk of this disease for public health and animal health, as well as the improvement in animal production and international and national trade. Today, the bovine tuberculosis distribution is almost known in Mexico. In addition, a series of controls and indicators have been established, which allow maintain consistency and reliability in the data that are managed and analyzed.

Characterization of Microbial Community Structure in Rhizosphere Soils of Cowskin Azalea(Rhododendron aureum Georgi)on Northern Slope of Changbai Mountains,China

The vegetation and soil are mutual environmental factors, soil characteristics, such as chemical properties and microorganism that affect the vegetation occurrence, development and succession speed. In this study, we evaluated the structure of microbial communities of rhizosphere of Cowskin Azalea(Rhododendron aureum Georgi) populations and compared with non-rhizosphere soils at four sample sites of the Changbai Mountains, China, and analyzed the correlation between chemical properties of soil and microbial communities. The results showed that microbial structure and soil chemical properties are significant superior to non-rhizosphere at all four sample sites. The rhizosphere microorganisms are mainly composed of bacteria, actinomycetes, followed by fungi least. The principal component analysis(PCA) biplot displayed that there are differences between rhizosphere and non-rhizosphere soils for microflora; Through correlation analysis, we found that the bacteria is clearly influenced by p H on the Changbai Mountains, besides p H, other soil features such as NO3–-N. These data highlight that R. aureum as the dominant vegetation living in the alpine tundra is a key factor in the formation of soil microorganism and improving soil fertility, and is of great significance for the maintenance of alpine tundra ecosystem.

Study on the Preparation of Decellularized Scaffold of Bovine Pericardium

Objective： To search for the best procedure on preparation ofacellular bovine pericardium,so to provide scaffolds for constructing tissue-engineering Methods： The bovine pericardiums were treated with 5 methods, which were divided into 6 groupsGroup A： Fresh bovinepericardium; Group B： Trypsin-detergent group;Group C： Freeze-thaw-detergent 24 h group; Group I）： Freeze-thaw-detergent 48 h group; Group Fz Freeze-thaw-nuclease group; Group F： Detergent-nuclease group. Then, by HE staining and scanning electron microscope to observe the effects ofdecellularization and fibrous changes among the 6 groups; by water content testingonechanical testing to observe the changes in physical properties of the matrix; by detecting the DNA content of each group to determine the effect of deeellularization qualitatively; by eytotoxieity test to detect the biocompatibility of bovine pericardium in each group. Results： The 5 methods can all remove the cellular components effectively, compared with the fresh bovine pericardium,the water content of each deeellularized group were increased （P〈0.05）, while the DNA content decreased （P〈0.05）, with statistically significant differences. Of group E, the fibers were a little disorder, with the largest tension and the elastic modulus increased, while the rupture tensile rate decreased. Compared with fresh bovine pericardium,the largest tension of the other decellularization groups were all decreased （P〈0.05）. The fibers of group B, group D were irregularly arranged and also with ruptures, both the elastic modulus and the rupture tensile rate decreased（P〈0.05）. In group C and F, the fibers were dense and their direction was normal, the elastic modulus and the rupture tensile rate were similar to the fresh bovine pericardium （P〉0.05）. Cytotoxicity results showed that the cell toxicity of group B, group C, group D, group E and group F were respectively 0.9, 0.6, 1.0, 1.0 and 0.5, each group were qualified toxicity test, in which group C and group F were with the lowest eytotoxieity. Conclusion： Group C and group F can remove the cell components of bovine pericardium successfully,while maintaining the major structural components and the histological and biological properties of bovine pericardium,and with low cytotoxicity.However, group C is more economical than group F,and easier to operate. So the method on freeze-thaw-detergent 24 h can be the best choice to produce a decellularized bovine pericardium.

Double Pyramidal Central Configurations with a Concave Quadrilateral Base

As for a double pyramidal central configuration in 6-body problems, the case when its base is a concave polygon is studied. By advancing several assumptions according to the definition of double pyramidal central configuration and deducing two theorems and two corollaries on this subject, the essential and sufficient conditions to form a double pyramidal central configuration with a concave quadrilateral base are demonstrated.

Symplectic Schemes for Birkhoffian System

A universal symplectic structure for a Newtonian system including nonconservative cases can be constructed in the framework of Birkhoffian generalization of Hamiltonian mechanics. In this paper the symplectic geometry structure of Birkhoffian system is discussed, then the symplecticity of Birkhoffian phase flow is presented. Based on these properties we give a way to construct symplectic schemes for Birkhoffian systems by using the generating function method.

Existence and Uniqueness of Nested Regular Quadrilateral Central Configurations

Two cases of the nested configurations in R3 consisting of two regular quadrilaterals are discussed. One case of them do not form central configuration, the other case can be central configuration. In the second case the existence and uniqueness of the central configuration are studied. If the configuration is a central configuration, then all masses of outside layer are equivalent, similar to the masses of inside layer. At the same time the following relation between r(the ratio of the sizes) and mass ratio b = m/m must be satisfied in which the masses at outside layer are not less than the masses at inside layer, and the solution of this kind of central configuration is unique for the given ratio (6) of masses.

Histological Investigation of Pelvic Symphysis in Holstein-Friesian Cattle

Knowledge of the changes in cattle pelvic symphysis during gestation and obstetrics gives valuable information about the age of optimal primary calving of cows. The aim of the study was to investigate the histological changes of pelvic symphysis in Estonian Holstein-Frisian＇s （EHF） of different ages. Eight EHF cows up to five years of their age were divided into three age groups： calved, in-calved and after calved bovines. Material for histological and histochemical investigation was taken from four places： （1） cranial part ofpubic bone; （2） pubo-ischiadic junction; （3） symphyseal eminence; （4） body of the interischiadic bone. In all study-groups, the cranial part of pubic bone consisted of cartilage. In pubo-ischiadic junction of calves connective tissue proper, fibrous and hyaline cartilage were noted. In in-calved cattle with gestation of 4-5 months and in after calved cattle group hyaline cartilage and bone tissue were noted, however in in-calved cattle with gestation of 7.5 months fibrous cartilage and connective tissue proper prevalated. In sympyseal eminence of calves connective cartilage osseous tissue was present. The region of interischiadic tissue proper and cartilage were noted; in other groups besides bone of calves consisted of connective tissue proper and fibrous cartilage, meanwhile in in-calved and after calved EHF＇s in the region hyaline cartilage and osseous tissue prevalated. These preliminary results demonstrate that the main changes in the pelvic symphysis histology, retardation of ossification, of EHF kines occur during the second-half of gestation in the pubo-ischiadic junction.

Ultrastructure of sperm in wild yak

The ultrastructure in sperm of wild yak can be used to examined and assess truly and all round the function and fertilization ability of the sperms. The ultrastructure in the sperm of wild yak was investigated under different states, such as fresh semen, frozen semen and capacitation sperm, and its characteristics were described by electron microscope. The sperm consisted of the head, neck and tail, the length was 78.34±7.24 μm. After capaeitation, the acrosome in sperm swelled and vesiculated, there were obvious vesicu]ation in the acrosome. The evagination on the ectoblast of acrosome formed the large vesiculation and inner membrane swelled. The evagination on the ectoblast of acrosome folded and tbrmed catenular vesiculation. The plasma membrane on the tail swelled. The head, neck and tail of the abnormal sperm were abnormal.

Pilot study on binding of bovine salivary proteins to grit silicates and plant phytoliths

Mostly fed with grass in fresh or conserved form, cattle and other livestock have to cope with silicate defence bodies from plants （phytoliths） and environmental silicates （grit）, which abrade tooth enamel and could additionally interact with various salivary proteins. To detect potential candidates for silicate-binding proteins, bovine whole saliva was incubated with grass-derived phytoliths and silicates. Interactions of salivary proteins with pulverized bovine dental enamel and dentine were additionally analysed. After intense washing, the powder fractions were loaded onto 1D-polyacrylamide gels, most prominent adhesive protein bands were cut out and proteins were identified by mass spectrometry within three independent replicates. All materials were mainly botmd by bovine odorant-binding protein, bovine salivary protein 30× 10^3 and carbonic anhydrase VI. The phytolith/silicate fraction showed additional stronger interaction with haemoglobin β and lactoperoxidase. Conceivably, the binding of these proteins to the surfaces may contribute to biological processes occurring on them.

Asymmetric Price Transmission and Structural Breaks in the Relationship between Costa Rican Markets of Livestock Cattle, Beef and Milk

The vertical price transmission is generally considered as the relationship between two markets of the same production chain However, we can expand this concept to another relation which has not been deeply investigated： the joint products. They are the products which are produced in a single production process, but not correspond to the same chain. An especial case is the beef and milk markets in Costa Rica. Even if these products usually correspond to disconnect chains, in Costa Rica farms make use of cattle to produce both meat and milk. The cointegration framework is applied in order to indentify the price transmission among these markets. In addition, the asymmetric behavior and structural breaks are taken into account. Price transmission between each market pair was found. First, the cattle prices adjust in the milk-cattle relationship, second, beef meat prices adjust in the cattle-beef meat and in the milk - beef meat relationship. Finally, the equations allowing for structural breaks affect the estimates in the following three ways： after the break the elasticities became higher than 1, there is more evidence of cointegration, and the adjustment coefficients are significant only when a change in the long run is allowed.

Solution of an Inverse Eigenvalue Problem by Newton＇s Method on a Fibre Bundle with Structure Group SO（n）

We present a differential geometric perspective of the IEP for symmetric matrices in the framework of a fibre bundle with structure group SO（n）. In particular, a Newton type algorithm is developed to construct a non singular symmetric matrix for given target eigenvalues using a singular symmetric matrix as the initial matrix for the iteration. Explicit computations are performed for 2 x 2 non singular symmetric matrix to illustrate the result.

斗牛士

剧情: 故事发生在西班牙。胡安是一个喜欢斗牛的年轻人。有一次,他上场斗牛,牛没有被他杀死,他却被牛撂倒了。幸好有朋友赶到场子里救他。他被救了,他的朋友卡里巴却被牛踩死了。 朋友们都十分恨他,因为如果不是为了救他,卡里巴也不会死。胡安自己也十分自责。

Study on the binding of novel antitumor drug Ethaselen to bovine serum albumin

The binding pattern of Ethaselen to bovine serum albumin （BSA） was studied by fluorescence spectroscopic technique and Autodock 3.0.5 analysis. The result showed that the binding constant K of Ethaselen and BSA is 3.5×10^4L/mol and the number of binding sites n = 0.9. The binding between Ethaselen and BSA or human serum albumin （HSA） is mainly through hydrophobic interactions.

Finite particle method for kinematically indeterminate bar assemblies

This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combination of the vector mechanics and numerical calculations. It models the analyzed domain composed of finite particles. Newton＇s second law is adopted to describe the motions of all particles. A convected material flame and explicit time integration for the solution procedure is also adopted in this method. By using the FPM, there is no need to solve any nonlinear equations, to calculate the stiffness matrix or equilibrium matrix, which is very helpful in the analysis of kinematically indeterminate structures. The basic formulations for the space bar are derived, following its solution procedures for bar assemblies. Three numerical examples are analyzed using the FPM. Results obtained from both the straight pretension cable and the suspension cable assembly show that the FPM can produce a more accurate analysis result. The motion simulation of the four-bar space assembly demonstrates the capability of this method in the analysis ofkinematically indeterminate structures.

On Regularity of Incompressible Fluid with Shear Dependent Viscosity

The authors consider a non-Newtonian fluid governed by equations with p-structure in a cubic domain.A fluid is said to be shear thinning(or pseudo-plastic) if 1 < p < 2,and shear thickening(or dilatant) if p > 2.The case p > 2 is considered in this paper.To improve the regularity results obtained by Crispo,it is shown that the secondorder derivatives of the velocity and the first-order derivative of the pressure belong to suitable spaces,by appealing to anisotropic Sobolev embeddings.

New indicators from bedding-parallel beef veins for the fault valve mechanism

Beef structures(bedding-parallel veins of fibrous calcite)are widespread within the Lower Triassic carbonate rocks in the Sichuan Basin of China,especially within clay-rich strata of low permeability.In the veins,fibrous calcite occurs in the outer zones,and coarse equant calcite in the inner zones.At least two generations of calcite crystallization took place during aqueous alteration,at the same time as deformation recorded by the calcite.The first-generation calcite fibers are at steep angles to the hydrocarbon-bearing host beds,and they grew vertically against the force of gravity at a time when the source rocks were maturing.Second-generation calcite occurs as coarse equant grains that sealed pores via localized fluid flow during horizontal tectonic compression,so that shear stresses acted at the fracture margins.Shearing of the host rock was accommodated in part by dissolution-precipitation creep(DPC),grain rotation,and grain slippage,recorded in crystallographic preferred orientations(CPOs)of the host calcite grains beside the crack walls.The beef veins formed during high pore-fluid overpressures along hydrofractures.We propose that the bedding-parallel veins with beef structures are evidence of a"crack-seal slip"fault valve process during hydrocarbon generation.The hydrocarbon-bearing calcite beef structure may be a good indicator of oil or gas migration,and of the flow direction of aqueous solutions.