Cyclostomatous Bryozoa from the Paleocene and Maestrichtian of Majunga Basin,Madagascar

Fourteen cyclostomatous Bryozoa from theMajunga Basin, Madagascar, are described. Seven of these (Diastopora madagascarensis, Pustulopora bonamaryi, Filisparsa majungensis, Canalipora cylindrica, Idmidronea bombetokensis, Pseudotervia delicatula, Lichenopora betsibokensis) are new. One new genus, Serpentipora, is described.Eleven cyclostomatous species are found in the Maestrichtian. Four of these occur also in Europe. Eight species are found in the Paleocene. Two of these occur also in Europe. The bryozoan fauna is composed of thin, delicate, erectly growing species, which suggests that the Bryozoa have probably lived in a moderately deep water, approximately 100–200 m deep.     

Pachyteichopora n. g. (Bryoz. Cyclostomata) aus der oberen Kreide

The cyclostome Bryozoan speciesPustulopora verrucosa, described by Roemer 1840, is combined with two other congeneric species within the new genusPachyteichopora (type-speciesP. verrucosa [Roemer]). This new genus characterized by its extremely highly calcified external walls of the erect massive cylindrical and dichotomously branched zoaria possessing maculae. The similarity of its gonozooid to that ofLeiosoecia counts for its provisional attribution to the Fam. Leiosoeciidae Canu & Bassler (1920).P. bugei n. g. n. sp. from the French Coniacian andP. punctata n. g. n. sp. from the Swedish Campanian are described.     

Time-Dependent Effects of Inosine on Competence Development in Haemophilus influenzae

The effect of inosine on the development of competence is dependent upon the time at which it is added to the competence medium. Competence is inhibited if inosine is added within 15 min after the development begins, but is stimulated if the addition is made at later times. Protein synthesis is stimulated by the addition of inosine, but the effect is quantitatively similar regardless of the time at which inosine is added.     

268例难治性下呼吸道感染的细菌学分析

通过本组２６８ 例难治性呼吸道感染病人标本培养结果分析,阳性２４６ 例占９１．８ ％ ,有１５４ 例检出厌氧菌,占５７ ％ ,１０４ 例检出需氧菌,占３９ ％ ,混合感染１３３ 例,占５０ ％ 。试验结果证实,厌氧菌感染在难治性下呼吸道感染病例中占了很大比例,这一结果为难治性下呼吸道感染的治疗提供了有价值的参考数据。     

两型豆花粉和叶表皮的扫描电镜观察

两型豆花粉和叶表皮在扫描电镜下的形态特征：花粉近球形至矩球形,三孔沟,外壁表面较粗糙,侧壁具疣状突起至块状突起,极面具粗网状纹饰,但两型豆祖山居群属于萌发沟不明显型,两型豆燕塞湖居群属于萌发沟明显型。叶表皮细胞不规则,排列紧密,叶脉表皮细胞长圆柱形,长轴与叶脉平行,角质膜薄,表皮毛均为单细胞非腺毛,气孔器仅分布在下表皮,属于平列型,偶见不规则型。表皮毛和气孔器在叶片上分布不均匀,两型豆祖山居群叶表皮毛和气孔器的平均密度大于两型豆燕塞湖居群叶表皮毛和气孔器的平均密度,自然生长的两型豆叶表皮毛和气孔器的平均密度大于遮光条件下的两型豆。     

Backward bifurcation of an epidemic model with treatment

An epidemic model with a limited resource for treatment is proposed to understand the effect of the capacity for treatment. It is assumed that treatment rate is proportional to the number of infectives below the capacity and is a constant when the number of infectives is greater than the capacity. It is found that a backward bifurcation occurs if the capacity is small. It is also found that there exist bistable endemic equilibria if the capacity is low.     

药敏药片对临床235株细菌实验观察报告

药敏药片经临床对金黄色葡萄球菌、大肠埃希氏菌、铜绿假单胞菌等２３５株考核．表明药片工艺研究先进,药片与培养基结合牢固,无断裂、崩解,不渗出颗粒,抑菌圈呈同心园扩散．边缘清楚。药物含量均匀,释放度好。药片抑菌差仅１～３ｍｍ;而纸片抑菌差为２～１２ｍｍ。药片变黑系数ＣＶ为２．７１～４．２１;而纸片ＣＶ为３．８２～１４．３６。表明纸片片间差大,药片精密度明显好于纸片。     

Autogenous control of Escherichia coli threonyl-tRNA synthetase expression in vivo

The regulation of the expression of thrS, the structural gene for threonyl-tRNA synthetase, was studied using several thrS-lac fusions cloned in lambda and integrated as single copies at att lambda. It is first shown that the level of beta-galactosidase synthesized from a thrS-lac protein fusion is increased when the chromosomal copy of thrS is mutated. It is also shown that the level of beta-galactosidase synthesized from the same protein fusion is decreased if wild-type threonyl-tRNA synthetase is overproduced from a thrS-carrying plasmid. These results strongly indicate that threonyl-tRNA synthetase controls the expression of its own gene. Consistent with this hypothesis it is shown that some thrS mutants overproduce a modified form of threonyl-tRNA synthetase. When the thrS-lac protein fusion is replaced by several types of thrS-lac operon fusions no effect of the chromosomal thrS allele on beta-galactosidase synthesis is observed. It is also shown that beta-galactosidase synthesis from a promoter-proximal thrS-lac operon fusion is not repressed by threonyl-tRNA synthetase overproduction. The fact that regulation is seen with a thrS-lac protein fusion and not with operon fusions indicates that thrS expression is autoregulated at the translational level. This is confirmed by hybridization experiments which show that under conditions where beta-galactosidase synthesis from a thrS-lac protein fusion is derepressed three- to fivefold, lac messenger RNA is only slightly increased.     

Influx of γ-Aminobutyric Acid and α-Aminoisobutyric Acid into Mouse Cerebrum Slices Incubated in a Pyruvate Medium with or without Added Glucose or Glucose Analogues Compared with Influx from a Glucose Medium

Concentrative influx of γ-aminobutyric acid (GABA) and α-aminoisobutyric acid (AIB) into incubated mouse cerebrum slices is decreased when pyruvate is substituted for glucose. Influx of GABA from pyruvate medium is not increased by presence of glucose, 2-deoxy-d -glucose (2-DOG), or 3-O-methyl-d -glucose (3-O-MeG). Influx of AIB is restored to the rate from glucose medium if 2-DOG is present initially, but is not restored if 2-DOG is added with AIB. Influx is not restored if 3-O-MeG is present initially, but is restored if 3-O-MeG is added with AIB. Influx is restored if glucose is present initially or is added with AIB.     

Colcemid-resistant mutants of fission yeast have an altered cell cycle

Cell-cycle progression is altered in some colcemid-resistant mutants of fission yeast. The duration of particular stages of the cell cycle is different but total doubling time is unchanged from that of wild type. Cell-plate formation is prolonged relative to wild type but concomitant DNA synthesis is not affected. Separation of daughter cells is inhibited in some strains, giving rise to unusual cell morphologies. Control of cell division is altered in two ways: Critical size for division is increased. The probability of division a function of size is decreased.     

Discrete three-stage population model: persistence and global stability results

A general three-stage discrete-time population model is studied. The inherent net reproductive number for this model is derived. Global stability of the origin is established provided that the inherent net reproductive number is less than one. If it is larger than one the existence of a unique positive fixed point is proved and the persistence of the system is established. Finally, for certain parameter ranges global stability of the positive fixed point is proved.     

矮沙冬青雌配子体及胚胎发育研究

矮沙冬青子房单心皮1室,边缘胎座,弯生胚珠,胚珠具双珠被、厚珠心。大孢子孢原细胞发生于珠心表皮下,大孢子母细胞减数分裂形成直线排列的四分体,合点端大孢子具功能,并按蓼型胚囊发育,雌配子体成熟于4月中旬。双受精后,胚乳发育为核型。在矮沙冬青大孢子发生、雌配子体和胚胎发育过程中未发现异常现象,因此认为矮沙冬青濒危不存在雌性生殖结构与发育过程异常的内在因素。     

杉木人工林水量平衡和蒸散的研究

 本文根据我们严密设计的小集水区径流场连续6年的水文测定数据,进行了杉木人工林水量平衡和蒸散的研究。结果表明：集水区年平均降雨量1065.5mm, 在林冠作用面降雨量的分配中,林冠截留雨量264.6mm,截留率24.8%;穿透过林冠层的雨量799.82mm,树干径流量1.08mm,分别占降雨量的75.1%和0.1%。林内降水到达林地时,在枯枝落叶层这个作用面上净降水进行再分配,其中,地表径流量9.27mm,地下径流量203.00mm,总径流系数0.199。土壤蓄水量月变化较大,但年变化很小,占降雨量的1.2%。系统水量最大的输出是蒸散,每年以气态形式返回大气的水量866.03mm,占降雨量81.3%。在蒸散的水量中,林冠截留雨量的直接物理蒸发量为264.6mm,占总蒸散量的31.6%。     

Selection intensity against deleterious mutations in RNA secondary structures and rate of compensatory nucleotide substitutions

A two-locus model of reversible mutations with compensatory fitness interactions is presented; single mutations are assumed to be deleterious but neutral in appropriate combinations. The expectation of the time of compensatory nucleotide substitutions is calculated analytically for the case of tight linkage between sites. It is shown that selection increases the substitution time dramatically when selection intensity Ns > 1, where N is the diploid population size and s the selection coefficient. Computer simulations demonstrate that recombination increases the substitution time, but the effect of recombination is small when selection is weak. The amount of linkage disequilibrium generated in the process of compensatory substitution is also investigated. It is shown that significant linkage disequilibrium is expected to be rare in natural populations. The model is applied to the mRNA secondary structure of the bicoid 3' untranslated region of Drosophila. It is concluded that average selection intensity Ns against single deleterious mutations is not likely to be much larger than 1.     

Ultrastructural organization of the ocelloide of Nematodinium. Phylogenetic aspect of the evolution of Warnowiidae Lindemann dinoflagellates photoreceptor (author's transl)

In this study, more details of the different parts of the "ocelloide" of Nematodinium are given. The "hyalosome" which has a radial symmetry is made of endoplasmic reticulum, except the mitochondrial layer. There is only one constrictor ring and only a beginning of the periocellar gallery. The basal sheet on which the crystalline lens lies is a local differentiation of the cortical layer which is observed on the ceiling of the ocellar camera. This camera is related to the intercingular sulcus. There is also an ocellar fiber. The "melanosome" which is made of a double membrane and of many couples of thylakoids is flattened dorso-ventrally. The structure of the retina is similar to that observed in the other Warnowiidae. The pigmented ring is rather well developed and is in continuity with the upper part of the retina. Owing to the simpler organization of its ocelloide, Nematodinium is situated before the genera Warnowia and Erythropsidinium in the evolutionary series.     

Homology and function in the wings of Heteroptera

Abstract. The homology of veins and other wing characters in Heteroptera is reviewed in the light of palaeontology and new functional studies. A cladogram is given for the higher taxa of Hemiptera. It is probable that the vannus is an autapomorphy of Auchenorrhyncha+Heteropteroidea; that the leading edge vein of heteropteran fore- and hindwings is C+Sc; that Rs cannot be distinguished from R; that the hamus is part of M; that the glochis is a secondary structure. The difficulty of defining a vein is stressed. The functional significance of the hemielytron, cuneal fracture and longitudinal flexion lines is discussed. A preliminary ground-plan for Heteroptera wings is presented.     

Discrete three-stage population model: persistence and global stability results

A general three-stage discrete-time population model is studied. The inherent net reproductive number for this model is derived. Global stability of the origin is established provided that the inherent net reproductive number is less than one. If it is larger than one the existence of a unique positive fixed point is proved and the persistence of the system is established. Finally, for certain parameter ranges global stability of the positive fixed point is proved.     

大黄鱼精子的超微结构

大黄鱼的精子由头产和尾部两部分组成。头部结构较为独特,其腹侧有一较大的细胞核,背部有中心粒复合体。头部的后端是袖套。细胞核的腹面稍向外突出背面则稍向内凹。细胞核中的染以质浓缩成致密的团块状。团块状的染色质之间分布着松散的纤维状染色质。植入窝位于细胞核的背部表面,由细胞核背面向内凹陷而成,呈一沟状,其走向与精子的长轴平行。     

退休教师骨密度的超声研究

目的：了解老年教师骨质疏松病的情况,用超声骨密度仪对813例老年教师做跟骨超声振幅衰减值研究。方法：超声测量是一种新技术,利用不同密度的物体衰减值不同及穿过不同密度物体声速不同等特性对跟骨进行成像,并计算最具说明性区域的一系列数据。参数中BUA值为最主要的参数,三根等距离曲线的形态和宽度能直观分析出年龄与骨量变化的关系。结果：本文男性平均BUA为63.87dB/MHz,得出回归公式：体重=189.1417 0.2062BUA-0.0224SOS。女性平均BUA为58.9dB/MHz,各年龄分组的BUA值与参考值很接近,统计学显示无意义。结论：调查发现男性和女性的骨质不同,男性BUA骨峰值比女性高。BUA值与其体重有密切关系。在60岁以后（或绝经1-5年后）年龄增长与BUA值无明显关系,说明随着年龄的增加骨量减少很小或不减少。利用这种关系,假如BUA值突然下降则提示近期发生骨质疏松。     

扬子鳄视觉器官组织学研究

本文用光镜和电镜研究了扬子鳄(Alligator sinensis)的组织学,同时测量了其眼球的一些光学参数.扬子鳄眼球呈扁圆球形,角膜径与球径的比值为1:1.44;晶状体与角膜的比值为1:1.40。角膜内具鲍氏膜;虹膜内的括约肌、睫状体内的睫状肌均属横纹肌,视细胞椭圆体内线粒体嵴突与线粒体长轴相平行,这与报道的其它鳄类不同。虹膜内未见扩瞳肌纤维,角膜缘缺巩膜小骨片,晶状体环垫薄,因而其视觉调节能力仍然很弱。视网膜中视细胞由视杆细胞、单锥细胞、双锥细胞组成,其中以视杆细胞占多数。视细胞与神经节细胞核比值平均为2.5:1,表明扬子鳄的组织结构与其弱光视觉相适应。