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1.
Summary The histochemical activities of succinic dehydrogenase (SDH), myofibrillar Adenosine triphosphatase (ATPase) and alpha glycerophosphate dehydrogenase were studied in serial sections of rat vastus lateralis (red) (RVL), gastrocnemius and diaphragm muscles. Three main fibre-types were distinguished. The Type I fibres of RVL and gastrocnemius muscles fell into two distinct groups: one category-Type IA showed very low ATPase activity. The second category of Type IB fibres displayed moderate ATPase reaction. The Type IA fibres were divisible into two sub-groups when tested for SDH reaction. Type IA1 fibres possessed a homogenous distribution of diformazan·granules throughout the fibre: Type IA2 fibres displayed characteristic moth-eaten pattern of diformazan localization. The diaphragm muscle did not show either Type IB or Type IA2 varieties. The great majority of Type I fibres were sub-type IA1 in the three fast muscles studied. It is also demonstrated here that an inherent heterogeneity exists between Type I fibres of diaphragm and leg muscles in regard to -GPD localization. This histochemical data emphasizes the fact that subdivision of Type I striated muscle fibres of mammalian animals into two sub-types is only approximate and that a further subcategorization is possible.  相似文献   

2.
Biology cannot accommodate all aspects of culture. Aspects of culture that a biological approach can take into account can be covered by the biological categories of phenotype and environment. There is no need to treat culture as a separate category. Attempts to elaborate biological explanations of cultural variation will meet with success only if biologists expand theories of development, and integrate them in evolutionary biology. The alternative — elaborating the idea of so-called cultural inheritance — makes little sense from a biological point of view.  相似文献   

3.
In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.  相似文献   

4.
Ernest Hartmann 《Dreaming》2000,10(2):103-110
This report examines the extent to which dream recall involves the 3 R's (reading, writing, and arithmetic). Two separate studies were done. In the first study, two scorers rated, on a blind basis, a total of 456 written dream reports, available from five previous studies. There was perfect agreement between the two scorers. They agreed that there were no instances of reading, no instances of writing, and one instance of probable calculating in the 456 dreams. The second study was a questionnaire survey. Complete responses were obtained from 240 frequent dreamers (who reported remembering a mean of seven dreams per week). The study examined in two ways the frequency of the 3 R's in their recalled dreams. First, in answer to direct questions as to how frequently they dreamt about each activity, roughly 90% of the respondents reported that they never or hardly ever dreamt about each of four activities: reading, writing, typing, and calculating. In answers to other questions, this group reported spending a mean of six hours per day engaged in these activities. Second, responses as to the relative prominence of six activities (walking, writing, talking with friends, reading, sexual activity, typing) in dreaming versus waking produced two clear groupings of activities. Walking, talking with friends, and sexual activity were each rated almost as prominent in dreaming as in waking whereas the second group consisting of writing, reading, and typing were rated as far more prominent in waking than in dreaming. The two activity groups differed at p < .0001. Thus, the 3 R's appear to occur very infrequently in dreams. These findings are placed in a theoretical frame which suggests that dreaming (compared to waking) deals very little with serial activities characterized by input—rapid-processing—output in which the neural nets function in a feed-forward mode. Rather, dreaming may be characterized by relatively broad or loose connection making in which the nets function more in an autoassociative mode.  相似文献   

5.
Summary Intestinal lipid absorption and transport were investigated in albino rats. The observations point towards the existence of a continuity between plasma membrane invaginations and elements of the Golgi complex on its mature face. They also suggest a segregation of lipid droplets by paired Golgi membranes and plasma membrane invaginations. The following way for lipid transport is deduced: lipid droplets moving inside the smooth endoplasmic reticulum accumulate progressively and are condensed in Golgi cisternae of the forming face. Their limiting membrane ruptures and liberated lipid droplets are segregated by paired Golgi membranes of the mature face or by plasma membrane invaginations. Subsequently the inner of the two segregating membranes disappears while the lipid droplet is moved towards the intercellular space inside a canal communicating with this space. The suggestion is made that the Golgi apparatus is of double origin: one component representing a terminal plication of the endoplasmic reticulum; the second one—a terminal plication of the plasma membrane invagination. This concept explains the ultrastructural and histochemical differences between Golgi membranes of the forming and mature faces of the complex.  相似文献   

6.
The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle.  相似文献   

7.
The properties of the -2-l-fucosyltransferases in submaxillary gland preparations from blood group ABH secrefors and non-secretors were compared. The level of activity in the non-secretor gland homogenates amounted to about 5% only of that found in the secretor gland preparations. The enzymes from the two sources differed in solubility properties, charge and affinities for donor and acceptor substrates. The enzyme from secretor glands showed a preference for acceptors with Type 1 [d-galactosyl(1–3)-N-acetyl-d-glucosamine] structures whereas the enzyme from non-secretor glands had a preference for Type 2 [d-galactosyl(1–4)-N-acetyl-d-glucosamine] structures.These results demonstrate that expression of the secretor gene (Se) is associated with a molecular form of the -2-l-fucosyltransferase that is different from the species present in the same tissue when theSe gene is not expressed.  相似文献   

8.
Interleukin 2-dependent alloreactive cytotoxic T cell lines, with activity predominantly directed against the HLA-A2 antigen, have been generated in vitro by stimulating blood mononuclear cells from donors nonimmune to the Epstein-Barr (EB) virus with appropriate numbers of EB virus-transformed B cells from A2-homozygous individuals. Such effector cells were tested against a panel of EB virus-transformed target cell lines all expressing the serologically defined A2 antigen but typed into common A2 and variant A2 subgroups on the basis of their recognition by A2-restricted EB virus-specific cytotoxic T cells. Variant A2 responder cells cocultivated with common A2-bearing stimulators gave rise to effector T cell lines which recognized only the common A2-bearing subgroup of targets. By contrast, responder cells from A2-negative donors stimulated with common A2-bearing cells produced effector T cell lines in which the strong lysis of common A2-bearing targets was accompanied by a lower, but still significant, lysis directed against all targets within the variant A2 subgroup. In both cases, lysis of the target cells was blocked equally well by the anti-A2-specific monoclonal antibody MA2.1 as by the monoclonal antibody W6/32 specific for HLA-A, -B, and -C determinants. This suggests that HLA-A2 molecules possess at least two distinct sets of epitopes capable of inducing alloreactive T cell cytotoxicity: first, epitopes probably associated with T cell-restricting sites, which generate subgroup-specific responses, and second, epitopes shared by all A2 molecules, and perhaps associated with serologically defined sites, which generate pan A2 group-specific responses.Abbreviations used in this paper EB Epstein-Barr - IL-2 Interleukin 2 - UM unfractionated mononuclear - AET aminoethylisothiouroniumbromide hydrobromide  相似文献   

9.
Using a cloning technique, we revealed the existence of three phototactically distinct types in Daphnia magna, viz. negatives, positives, and gipsies. The latter migrate continuously between a low and a high light intensity. The expression of this behaviour is genetically determined, although positives and negatives can reversibly switch into gipsies.It is proposed that two opposite genotypes exist, with the gipsy behaviour epigenetically induced. All juveniles behave more or less uniformly, irrespective of their origin. The phototactic responses develop rather late during ontogenesis.  相似文献   

10.
Summary According to the program Palynological Italian Flora, Aeropalynological section, the pollen morphological card ofPinus pinea L. is presented. The study is carried out on pollen coming from three Italian localities and regards fresh and acetolyzed pollen. For each sample, measurements are carried out on 30 fresh pollen grains in glicerol jelly with fuchsin and on 30 acetolyzed pollen grains in water/glicerol (1/1); general observations regard 1000 fresh and 1000 acetolyzed pollen grains/sample. Some observations on the main differences between fresh and acetolyzed pollen are mentioned.
Riassunto Nell'ambito della Flora Palinologica Italiana, Sezione Aeropalinologica, è presentata la scheda morfopalinologica diPinus pinea L. nella versione su polline fresco e polline acetolizzato, su tre campioni di diversa provenienza. Vengono notate le principali differenze tra polline fresco e polline acetolizzato.
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11.
Summary The development of the compound eyes and nervous system of the penaeid shrimp,Penaeus duorarum, from the first nauplius to the first postlarva, has been studied. The first anlage of the compound eyes is a pair of optic discs on the front of the animal. These increase in size through cell-division until the second protozoea stage, where the eye-stalks appear with ommatidia and optic neuropiles developed. The original neuroectoderm of the optic discs is retained in the shape of a proliferation zone throughout the life of the animal. From the optic discs, develop the ommatidia, the lamina ganglionaris, and the medulla externa. The medullae interna and terminalis develop from cells coming from the brain anlage. From the second protozoea and onwards, the development is less rapid. The final shape of the adult eye is reached during the postlarval stages and includes the appearance of a few more pigments and a perfecting of several features. A scheme for the development of crustacean compound eyes is laid down. Further, the medulla externa of the Malacostraca and the single medulla of non-malacostracan crustaceans are homologized.The continuous growth of the nervous system is traced in the development of the neuropile. The appearance of glomeruli structures is reported, as are also, to some extent, neurosecretory organs. The development of the SPX-organ conforms to that of other decapods.For the sake of simplicity, the findings reported below in Results are grouped under two headings, namely the eye-stalk and the nervous system. Under the eye-stalk will be described both the structures coming from the optic discs comprising the ommatidia, the lamina ganglionaris, and the medulla externa, and the contributions from the nervous system comprising the medulla terminalis and medulla interna. Under the nervous system will be described the rest of the nervous system. The term anlage of the compound eyes is the same as the optic discs and denotes all contributions from this area in the early larva.  相似文献   

12.
Assignment of human ferritin genes to chromosomes 11 and 19q13.3→19qter   总被引:10,自引:0,他引:10  
Worwood  M.  Brook  J. D.  Cragg  S. J.  Hellkuhl  B.  Jones  B. M.  Perera  P.  Roberts  S. H.  Shaw  D. J. 《Human genetics》1985,69(4):371-374
Summary Extracts of hamster-human and mouse-human hybrids, some with translocations involving chromosome 19, have been assayed for both human spleen ferritin (rich in L subunits) and human heart ferritin (rich in H subunits). Hybrid lines retaining part of the long arm of chromosome 19 including the region 19q13.319qter produced human L type ferritin. This confirms the previous assignment of the ferritin gene to chromosome 19 (Caskey et al. 1983). However, lines retaining chromosome 11 were found to contain human H type ferritin suggesting that the gene for the H subunit is on this chromosome. The presence of chromosome 6 was not necessary for the expression of either H or L type human ferritin. It thus seems unlikely that the gene for idiopathic haemochromatosis is a ferritin gene.  相似文献   

13.
Myelin from adult rat brains was separated on a discontinuous sucrose gradient into three subfractions. Analysis of light, heavy and membrane fraction lipid classes was performed by HPTLC and densitometry while fatty acid composition was determinated by GLC. The more interesting results observed are: i) the membrane fraction resembles in its lipid and fatty acid composition other cell membranes (particulary oligodentrocytes); ii) light and heavy myelin are quite similar between them but the former has a higher content of sphingomyelin, a lower hydroxy/nohhydroxy cerebrosides ratio and a lower content of monoenoic fatty acids than the heavy subfraction. The results obtained could explain the different structures observed in each myelin subfraction since fatty acid composition, hydroxy fatty acids, sphingomyelin and cholesterol play a key role in the stability and structure of membranes.  相似文献   

14.
Idioms of distress refers to the popular expression of emotional tension that arises in the relationship between sickness and kinship. By reference to case studies and discussions among the Polynesian people of Tonga, the author shows where such tension arises and how it influences the sickness process. Sickness is necessarily a collective phenomenon which can best be understood not simply as a clinical event, but as an experience that is part of the experience of family. Various ways of expressing distress as a reflexive encounter between personal and cultural meaning systems are reviewed, as are several new concepts such as doing sickness as kinship, and turning in the process of decision making in the kinship management of sickness. The explanatory models of sickness in Tonga are shown to encompass culturally sanctioned expressions of distress as part of the adaptive coping mechanisms in that society. Distress frequently emerges in somatic form, as a number of studies have shown. However, the author emphasizes the kinship meaning of sickness, kinship management and sickness therapy, the adaptive process of idiomatic expressions of distress, which are expanded here and offered as potential avenues for elaboration in other cultural milieu. Two aspects of the notion idioms of distress are noted, and the phenomenon is understood as a process which acts as a prime mover in social change.  相似文献   

15.
Summary A set of mitochondrial antibiotic-resistant mutants of Paramecium have been analyzed with respect to their growth-rates, cytochromic content and respiratory properties. The mutants could be arranged in a continuous series ranging from strains equivalent to wild-type to severely affected ones; affected strains display longer generation times, reduced amount of cytochrome oxidase and very high levels of cyanideinsensitive respiration. Perfect phenocopies of the mutants were obtained by treating wild-type cells with low concentrations of erythromycin suggesting that the mutations exert their pleiotrophic effect by perturbating mitochondrial protein synthesis in agreement with the idea that these mutations affect the mitochondrial ribosomes. In the mitochondria of some of the mutants, electrons can be channelled with equal efficiency into the classical cyanide-sensitive pathway and the alternate cyanide insensitive (and SHAM_sensitive) one, providing direct demonstration of the branching of these two respiratory pathways. In the absence of any added inhibitor, however, electrons tend to be channelled in the cyanide-sensitive pathway.All the physiological data fit perfectly the genetic data concerning the stability of the various mutations in mixed mitochondrial populations, i.e., markers that were known to be strongly counter-selected with respect to wild-type in such populations correspond to severely affected strains, while markers that were known to be stable correspond to healthy strains. A more quantitative analysis of the data shows that that there is little or no complementation between wild-type and mutated mitochondria in mixed cells indicating a high extent of functional autonomy of mitochondria in Paramecium.  相似文献   

16.
Zusammenfassung An Laboratoriumszuchten vonReticulitermes lucifugus Rossi undReticulitermes flavipes Kollar (aus den Hamburger Befallsgebieten) werden Beobachtungen zur Biologie der Ersatzgeschlechtstiere mitgeteilt. Für die Durchführung dieser Beobachtungen wurden besondere Schaunester eingerichtet. Folgende Punkte der beobachteten Verhaltensweisen werden hier hervorgehoben: Die Nymphen der Ersatzgeschlechtstiere sammeln sich stets in Herden von 80–100 Einzeltieren und werden von einer Gruppe Arbeiter (als Hütehunde) bewacht. Die Arbeiter halten die Nymphen auf einem engen Raum zusammen und versuchen andere Nestgenossen von den Nymphen fernzuhalten. Alle ein bis zwei Tage wechseln die Herden ihren Standort. Das Weiterziehen geschieht gleichfalls in Form von Herden.Die Ernährung der Nymphen geschieht auf stomodealem Wege durch die Arbeiter. *** DIRECT SUPPORT *** A0180089 00007  相似文献   

17.
Zusammenfassung Die beschriebenen experimentellen Befunde zeigen, daß die höhere Pflanze grundsätzlich in der Lage ist, organische Verbindungen aus dem Wurzelraum (Rhizosphäre) aufzunehmen, diese als Zwischenprodukte nutzt und in ihr biochemisches Zellgeschehen einschleust. Die organische Substanz (Humus) in natürlichen Standorten bietet somit unter Umständen vielfältige Möglichkeiten des direkten Einflusses organischer Verbindungen auf das Stoffwechselgeschehen der höhere Pflanze. Hier bieten sich eventuell auch Möglichkeiten, die Ausbildung von Ökotypen auf dieser Basis zu deuten.Mixotrophie der höheren Pflanze bedeutet also eine noch stärkere Verflechtung des Bio-Geo-Systems Pflanze-Boden und stellt den klassischen Begriff des Nährhumus unter einen neuen organodynamischen Gesichtspunkt.
Summary The experimental results described above show, that the higher plant can take up organic compounds from the rhizosphere and utilize them in cell metabolism.Thus another type of chemical interaction between plant and the organic matter of soil is existing, by which the close integration of the bio-geosystem plant and soil can be demonstrated and a modern view of the classical concept of the nutritional functions of humus can be given.
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18.
Summary This study attempts to elucidate the mechanism through which lysosomal accumulation occurs with age in the epithelial cells of the thyroid gland and especially in the active follicles of the aging mouse thyroid. Thyroid morphology and function in old CBA (at least 24 months of age) male mice were compared with those in young (2 months of age) animals. The effects of different intake of iodine were tested and compared in both cohorts, each of which was divided into three groups: (i) low iodine group, (ii) moderate iodine group, and (iii) high iodine group. As expected, the present work confirmed the well-known accumulation with age of cold follicles coexisting with active follicles in the old mouse thyroid. Attention has been focused on the active follicles whose follicular cells contained in their cytoplasm a large number of pleomorphic dense bodies. The lysosomal nature of these bodies, referred to as secondary lysosomes, was confirmed by histochemistry; however, they displayed variability in acid phosphatase staining. In old animals, regardless of the type of iodine regimen, the ratio between relative follicular volume and relative colloid volume as determined by morphometry remained unchanged. Ultrastructurally, the relative volume occupied by secondary lysosomes in active follicles was always higher than in the young groups. Autoradiographic studies with 125I revealed that a large part of the radioactivity was located in secondary lysosomes of thyroid cells in active follicels of old mice when radioiodine was injected 3 weeks before death. Two different types of vacuoles were present in a non-negligible number of thyrocytes of the active follicles in aged cohorts. The first type was made up of grossly dilated rough endoplasmic cisternae, the second corresponded to intracytoplasmic microfollicular vacuoles. Both aspects have been described in conditions of chronic stimulation. It is concluded (1) that different intake of iodine for 6 weeks does not modulate the thyroid morphology in old mice; (2) that in the thyrocytes of the active follicles in old mice accumulation of secondary lysosomes occurs due to a slowdown of turnover; and (3) that the follicular cells of active follicles feature morphological aspects suggesting a hyperactive state compensating the lack of hormone production in the cold follicles.  相似文献   

19.
The purpose of this study was to investigate whether subjects who self-report high levels of stress have lower immunity, and whether low-immunity subjects under high stress could enhance phagocytic activity through biofeedback-assisted relaxation (BAR). During Phase 1, the level of stress and the level of phagocytic immune functioning (nitroblue tetrazolium test) were assessed as high or low. Significant chi-square analysis (x2=3.8624, df=1, p<.05) showed that subjects with high stress had low immunity. Sixteen high-stress, low-immunity subjects were randomly assigned to BAR and control groups during Phase 2. Following treatment, NBT changes showed significant increases (F=11.11, p<.003) for experimental group as compared to control group. White blood cell count and white blood cell differential were unchanged across blood samples for both groups. Experimental subjects reported significant decreases in tension-anxiety and increases in overall coping. BAR was concluded to have improved coping skills and phagocytic capacity. BAR affected the quality, rather than the quantity, of phagocytic neutrophils.  相似文献   

20.
At the transition from early reptilian ancestors to primordial mammals, the areas of sensory cortex that process topographic modalities acquire the laminar structure of isocortex. A prominent step in lamination is granulation, whereby the formerly unique principal layer of pyramidal cells is split by the insertion of a new layer of excitatory, but intrinsic, granule cells, layer IV. I consider the hypothesis that granulation, and the differentiation between supra- and infra-granular pyramidal layers, may be advantageous to support fine topography in their sensory maps. Fine topography implies a generic distinction between where information, explicitly mapped on the cortical sheet, and what information, represented in a distributed fashion as a distinct firing pattern across neurons. These patterns can be stored on recurrent collaterals in the cortex, and such memory can help substantially in the analysis of current sensory input. The simulation of a simplified network model demonstrates that a non-laminated patch of cortex must compromise between transmitting where information or retrieving what information. The simulation of a modified model including differentiation of a granular layer shows a modest but significant quantitative advantage, expressed as a less severe trade-off between what and where. The further connectivity differentiation between infra-granular and supra-granular pyramidal layers is shown to match the mix of what and where information optimal for their respective target structures.  相似文献   

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