464 research outputs found
Congenital anomalies from a physics perspective. The key role of "manufacturing" volatility
Genetic and environmental factors are traditionally seen as the sole causes
of congenital anomalies. In this paper we introduce a third possible cause,
namely random "manufacturing" discrepancies with respect to ``design'' values.
A clear way to demonstrate the existence of this component is to ``shut'' the
two others and to see whether or not there is remaining variability. Perfect
clones raised under well controlled laboratory conditions fulfill the
conditions for such a test. Carried out for four different species, the test
reveals a variability remainder of the order of 10%-20% in terms of coefficient
of variation. As an example, the CV of the volume of E.coli bacteria
immediately after binary fission is of the order of 10%. In short,
``manufacturing'' discrepancies occur randomly, even when no harmful mutation
or environmental factors are involved. Not surprisingly, there is a strong
connection between congenital defects and infant mortality. In the wake of
birth there is a gradual elimination of defective units and this screening
accounts for the post-natal fall of infant mortality. Apart from this trend,
post-natal death rates also have humps and peaks associated with various
inabilities and defects.\qL In short, infant mortality rates convert the
case-by-case and mostly qualitative problem of congenital malformations into a
global quantitative effect which, so to say, summarizes and registers what goes
wrong in the embryonic phase. Based on the natural assumption that for simple
organisms (e.g. rotifers) the manufacturing processes are shorter than for more
complex organisms (e.g. mammals), fewer congenital anomalies are expected.
Somehow, this feature should be visible on the infant mortality rate. How this
conjecture can be tested is outlined in our conclusion.Comment: 43 pages, 9 figure
A distributional analysis of out-of-pocket healthcare financing in Nigeria using a new decomposable Gini index
This study applies a new method of decomposing total redistributive effect of taxation proposed by Duclos et al. (2003) to assess the redistributive effects of direct healthcare financing in Nigeria. This new framework makes it possible not only to introduce into the conventional Gini Index estimation framework a flexible ethical measure of aversion to inequality but also a novel concepts of horizontal inequity and re-ranking. The empirical results indicate that when the decision to utilize healthcare is always linked to the decision to pay for healthcare, as is the case in Nigeria, out-of-pocket payment, contrary to existing literature, may indeed be progressive with high levels of horizontal inequity and re-ranking effect. But the progressivity may underlie the lack of ability to pay by poorer households. All the components of the redistributive effect are also likely to vary with the level of the social aversion to inequit
The Duals of *-Operator Frames for End*A(H)
Frames play significant role in signal and image processing, which leads to many applications in differents fields. In this paper we define the dual of ∗-operator frames and we show their propreties obtained in Hilbert A-modules and we establish some results
Autoantibodies against cardiac β(1)-adrenoceptor do not affect the low-affinity state β(1)-adrenoceptor-mediated inotropy in rat cardiomyocytes
Circulating autoantibodies directed against the 2nd extracellular loop (EL-2) of β(1)-adrenoceptors (β(1)-AABs) have been detected in the serum of patients with various cardiovascular pathologies. β(1)-AABs induce agonistic, positive inotropic effects via β(1)-adrenoceptors (β(1)ARs). In the mammalian heart, β(1)-AR can exist in 2 distinct activated configurations (the so-called high- and low-affinity states). The aim of the present study was to investigate whether the action of β(1)-AAB is dependent on the affinity state of β(1)AR in isolated ventricular cardiomyocytes of adult Wistar rats. Immunoglobulin G (IgG) containing β(1)-AAB obtained from animals immunized with a peptide corresponding to the EL-2 of human β(1)-AR, caused a dose-dependent increase in cell shortening. Isoproterenol-induced inotropy was significantly reduced in cardiomyocytes that had been preincubated with IgG containing β(1)-AAB and in cardiomyocytes isolated from immunized rats. The negative effects of preincubation with IgG containing β(1)-AAB on the response to isoproterenol was inhibited in the presence of bisoprolol. CGP 12177A and pindolol-induced inotropy was not affected by IgG preincubation or immunization. No detectable inotropic effect of cell shortening was obtained with IgG containing β(1)-AAB in the presence of propranolol and 3-isobutyl-1-methylxanthine. The present study demonstrates that β(1)-AABs have no agonist/antagonist-like effects upon low-affinity state β(1)-ARs. This result indicates that β(1)-AABs recognize and stabilize the high-affinity state, but are unable to stabilize and (or) induce the low-affinity state receptor
Species composition of sand flies and bionomics of Phlebotomus papatasi and P. sergenti (Diptera: Psychodidae) in cutaneous leishmaniasis endemic foci, Morocco
Detailed data set for sand fly species sampled in 48 sites across Morocco from April to June 2013. The specimens were sorted as male or female for each species. The coordinates (longitude and latitude) for each site is also presented in this data set. (XLSX 23 kb
Chemical composition, antimicrobial, antioxidant and anticancer activities of essential oil from Ammodaucus leucotrichus Cosson & Durieu (Apiaceae) growing in South Algeria
ABSTRACT. The chemical composition of the essential oil obtained by hydrodistillation from aerial parts of A. leucotrichus Cosson & Durieu (Apiaceae) grown in the south of Algeria (El-Oued) was determined by GC-MS analysis. The oil was found to be rich in perilladehyde 64.66% and D-Limonene 26.99%. The biological activity of A. leucotrichus Cosson & Durieu essential oil has been investigated. The in vitro antimicrobial activity of the essential oil sample was tested on eight strains, one yeast and one fungi. The test showed interesting antimicrobial properties, especially on Salmonella enterica and E. coli, the antioxidant capacity of the oil was measured using the cyclic voltammetry, and the AAT value of A. leucotrichus essential oil was evaluated 47.84 mg α-TE/L. In addition, the antitumor activity showed that the oil of A. leucotrichus was very significant against the HCT116 colon cancer cell line. KEY WORDS: Ammodaucus leucotrichus, Antioxidant activity, Anticancer activity, Cyclic voltammetry Bull. Chem. Soc. Ethiop. 2019, 33(3), 541-549. DOI: https://dx.doi.org/10.4314/bcse.v33i3.1
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