2,279 research outputs found

    The development of Daphnia magna

    Get PDF
    A general account is given of the development of Daphnia magna from the egg to the mature adult. A review of previous work reveals that authors have concentrated on the early development, neglecting the later development. An adequate technique has been developed.An account of the development based on living material gives a detailed series of stages. A summary of the present state of knowledge of the physiological aspects of development is included. The development of the parthenogenetic egg is described. The early development includes a superficial cleavage and gastrulation by immigration. The mesenteron develops from a solid rod of cells in the ventral part of the egg, and acquires a central cavity which never contains yolk. The yolk cells develop from the blastoderm. The mesoderm develops a single small pair of coelomic cavities, and the heart develops from a compact group of cells. The history of the dorsal organ is described. The development of the ephippial egg resembles that of the parthenogenetic egg except in some features related to the smaller and more even sized nature of the yolk globules.Daphnia magna hatches from the brood pouch of the mother as an immature adult. The account of the anatomy of the adult is a confirmation and extension of previous work, including histology and indicating function. The muscles of the mesenteron are striated, and the heart wall contains anincomplete longitudinal, as well as a circular, layer of muscles. A suggestion is made for a new interpretation of the cells of the branchial sacs. The results obtained and the importance of a large quantity of yolk are discussed.<p

    Differences between "geriatric" and "medical" patients aged 75 and over.

    Get PDF
    We analysed the characteristics of patients aged 75 and over admitted to the geriatric and general medical wards over a three month period in a teaching hospital. Patients admitted to the geriatric wards were slightly older, were more often female, more likely to be admitted during the day and during a week day, more likely to have been seen by their own general practitioner, had more chronic and multiple illness with non-specific presentations, and stayed longer in hospital. Referring doctors seem to discriminate between patients needing geriatric care and those more suitable for general medical care, but there is an overlap in the characteristics of the two groups

    Functional decline and survival in dependent elderly people.

    Get PDF
    A survey of dependency levels was carried out in 1985 and 1989 in 41 residents of old peoples homes and 25 patients in geriatric continuing care wards. There was an increase in all levels of dependency for those in both types of care. In the hospital patients surveyed in 1985, mortality was greatest in the most dependent, particularly those with impaired mental function. There was a positive correlation between length of survival and mental function. The results of this study emphasise the important role of dementia in the health and survival of old people

    A TRADE LIBERALIZATION IN INTERNATIONAL DAIRY MARKETS

    Get PDF
    International dairy industries remain among the most distorted agricultural sectors. Dairy average bound tariffs remain among the highest of all agricultural commodities, and dairy trade is characterized by a large number of megatariffs and tariff-rate quotas (TRQs). The objective of our study is to examine how the international dairy markets might respond to policy changes under various assumptions, using a partial equilibrium, multiple-commodity, multiple-region model of agricultural policy and trade. Our results indicate that liberalization will reduce supplies, increase dairy trade, and raise world prices.Dairy Markets, Trade Liberalization, Model, Policy, International Relations/Trade,

    Lack of Mutual Respect in Relationship The Endangered Partner

    Get PDF
    Violence in a relationship and in a family setting has been an issue of concern to various interest groups and professional organizations. Of particular interest in this article is violence against women in a relationship. While there is an abundance of knowledge on violence against women in general, intimate or partner femicide seems to have received less attention. Unfortunately, the incidence of violence against women, and intimate femicide in particular, has been an issue of concern in the African setting. This article examines the trends of intimate femicide in an African setting in general, and in Botswana in particular. The increase in intimate femicide is an issue of concern, which calls for collective effort to address. This article also examines trends offemicide in Botswana, and the antecedents and the precipitating factors. Some studies have implicated societal and cultural dynamics as playing significant roles in intimate femicide in the African setting. It is believed that the patriarchal nature of most African settings and the ideology of male supremacy have relegated women to a subordinate role. Consequently, respect for women in any relationship with men is lopsided in favor of men and has led to abuse of women, including intimate femicide. Other militating factors in intimate femicide ,are examined and the implications for counseling to assist the endangered female partner are discussed

    Normalization of Sequential Top-Down Tree-to-Word Transducers

    No full text
    International audienceWe study normalization of deterministic sequential top-down tree-to-word transducers (STWs), that capture the class of deterministic top-down nested-word to word transducers. We identify the subclass of earliest STWs (eSTWs) that yield normal forms when minimized. The main result of this paper is an effective normalization procedure for STWs. It consists of two stages: we first convert a given STW to an equivalent eSTW, and then, we minimize the eSTW. Keywords: formal language theory, tree automata, transformations, XML databases, XSLTExtended Version: A long version is available here.</p

    Quantification of cervical elasticity during pregnancy based on transvaginal ultrasound imaging and stress measurement

    Full text link
    Objective: Strain elastography and shear wave elastography are two commonly used methods to quantify cervical elasticity; however, they have limitations. Strain elastography is effective in showing tissue elasticity distribution in a single image, but the absence of stress information causes difficulty in comparing the results acquired from different imaging sessions. Shear wave elastography is effective in measuring shear wave speed (an intrinsic tissue property correlated with elasticity) in relatively homogeneous tissue, such as in the liver. However, for inhomogeneous tissue in the cervix, the shear wave speed measurement is less robust. To overcome these limitations, we develop a quantitative cervical elastography system by adding a stress sensor to an ultrasound imaging system. Methods: In an imaging session for quantitative cervical elastography, we use the transvaginal ultrasound imaging system to record B-mode images of the cervix showing its deformation and use the stress sensor to record the probe-surface stress simultaneously. We develop a correlation-based automatic feature tracking algorithm to quantify the deformation, from which the strain is quantified. After each imaging session, we calibrate the stress sensor and transform its measurement to true stress. Applying a linear regression to the stress and strain, we obtain an approximation of the cervical Young's modulus. Results: We validate the accuracy and robustness of this elastography system using phantom experiments. Applying this system to pregnant participants, we observe significant softening of the cervix during pregnancy (p-value < 0.001) with the cervical Young's modulus decreasing 3.95% per week. We estimate that geometric mean values of cervical Young's moduli during the first (11 to 13 weeks), second, and third trimesters are 13.07 kPa, 7.59 kPa, and 4.40 kPa, respectively.Comment: 26 pages, 8 figures, 1 tabl
    • …
    corecore