Temporal Noise Analysis of Charge-Domain Sampling Readout Circuits for CMOS Image Sensors.

This paper presents a temporal noise analysis of charge-domain sampling readout circuits for Complementary Metal-Oxide Semiconductor (CMOS) image sensors. In order to address the trade-off between the low input-referred noise and high dynamic range, a Gm-cell-based pixel together with a charge-domain correlated-double sampling (CDS) technique has been proposed to provide a way to efficiently embed a tunable conversion gain along the read-out path. Such readout topology, however, operates in a non-stationery large-signal behavior, and the statistical properties of its temporal noise are a function of time. Conventional noise analysis methods for CMOS image sensors are based on steady-state signal models, and therefore cannot be readily applied for Gm-cell-based pixels. In this paper, we develop analysis models for both thermal noise and flicker noise in Gm-cell-based pixels by employing the time-domain linear analysis approach and the non-stationary noise analysis theory, which help to quantitatively evaluate the temporal noise characteristic of Gm-cell-based pixels. Both models were numerically computed in MATLAB using design parameters of a prototype chip, and compared with both simulation and experimental results. The good agreement between the theoretical and measurement results verifies the effectiveness of the proposed noise analysis models.

[Shamanic healing in the age of modern medicine]. / Medecine chamanique et modernite medicale.

This study on the therapeutic aspects of shamanic medicine differentiates the anthropologic approaches used in the 19th and early 20th century from contemporary approaches developed since the n Central to Eastern Asia. In addition to reviewing the major works on shamanic practice, this study takes into account lesser-known data on contemporary shamanic practices in Nepal. Shamanism embraces special cosmogenic beliefs. From a biological standpoint the shamanic trance like various healing techniques raises interesting questions about the involvement of certain brain regions in the development of mental factors that may generate somatic symptoms. From the therapeutic standpoint it shows the importance of managing social and psychoaffective factors. The current resurgence of shamanism could signal the revival of the disrupted ethnic identities. The shaman and medical doctor occupy symmetric, inversed positions. The shaman is a master in the management of social and psychoaffective health determinants. Until now the physician may have tended to overlook the human side of disease.

Fibroblasts determine the fate of Fc epsilon RI+ cell populations in vitro by selectively supporting the viability of mast cells while internalizing and degrading basophils.

To determine the fate of Fc epsilon RI+ cells on fibroblasts in vitro, human bone marrow derived CD34+ cells were cultured in the presence of recombinant human interleukin 3 and recombinant human hematopoietic stem cell factor for 3 weeks, and Fc epsilon RI+ cells were purified by immunomagnetic selection. This enriched Fc epsilon RI+ cell population consisted of 92-94% basophils and 3-5% mast cells as determined by morphologic, immunohistochemical, and ultrastructural criteria. The Fc epsilon RI+ cells were then cocultured with 3T3 fibroblasts. Basophils decreased markedly by 1 week and were absent from cocultures by 2-3 weeks, while the mast cell numbers on the fibroblast monolayers remained constant. Ultrastructural examination of cocultures at 2 days demonstrated phagocytosis of basophils by fibroblasts. By 1 week, phagocytosed basophil membranes and granules gave fibroblasts the superficial appearance of mast cells by toluidine blue staining. Mast cells surviving in cocultures could be distinguished from granule-containing fibroblasts by IgE surface labeling and by ultrastructural demonstration of tryptase-positive granules. Thus, while mast cells remain viable in coculture with 3T3 fibroblasts, basophils do not survive and are internalized and degraded by the fibroblast monolayer.

The effects of stem cell factor on the ultrastructure of Fc epsilon RI+ cells developing in IL-3-dependent murine bone marrow-derived cell cultures.

Stem cell factor (SCF) is known to alter the proteoglycans, proteases, and cytokines synthesized by mast cells and to activate basophils. To determine whether SCF could also effect the ultrastructural characteristics of basophils and mast cells, we examined the ultrastructure of these Fc epsilon RI+ cells over 42 days in IL-3-dependent murine bone marrow-derived cell cultures in the presence or absence of SCF. Initial experiments revealed that the addition of SCF to IL-3-dependent cells enhanced their proliferative rate without influencing the percentage of Fc epsilon RI+ or metachromatic cells. We next isolated the Fc epsilon RI+ cells using flow cytometry. Light microscopy of these cells revealed mixed cultures of both immature and mature mast cells and basophils with mature mast cells predominating by 3 wk. One hundred to 150 Fc epsilon RI+ cells were then photographed by electron microscopy at 3, 10, 21, and in some cases, 42 days of culture, and the ultrastructure of each cells was evaluated by morphometry. Each cell was scored as a mast cell or basophil using standard criteria. Analysis of this data revealed that SCF in the presence of IL-3 promoted the development of mast cells, although a significant number of basophils were noted at day 21 but were absent by day 42. When bone marrow cells cultured in IL-3 + SCF were compared with cells cultured in IL-3 alone, a significant decrease in cell and nuclear size and granule number and size was noted in both mast cells and basophils cultured in IL-3 + SCF, and basophils and mast cells under these conditions most resemble their in vivo counterparts. Thus, SCF in the presence of IL-3 increases the ratio of mast cells to basophils and alters the ultrastructural characteristics of mast cells and basophils toward a more mature phenotype.

Worldwide prevalence of lentivirus infection in wild feline species: epidemiologic and phylogenetic aspects.

The natural occurrence of lentiviruses closely related to feline immunodeficiency virus (FIV) in nondomestic felid species is shown here to be worldwide. Cross-reactive antibodies to FIV were common in several free-ranging populations of large cats, including East African lions and cheetahs of the Serengeti ecosystem and in puma (also called cougar or mountain lion) populations throughout North America. Infectious puma lentivirus (PLV) was isolated from several Florida panthers, a severely endangered relict puma subspecies inhabiting the Big Cypress Swamp and Everglades ecosystems in southern Florida. Phylogenetic analysis of PLV genomic sequences from disparate geographic isolates revealed appreciable divergence from domestic cat FIV sequences as well as between PLV sequences found in different North American locales. The level of sequence divergence between PLV and FIV was greater than the level of divergence between human and certain simian immunodeficiency viruses, suggesting that the transmission of FIV between feline species is infrequent and parallels in time the emergence of HIV from simian ancestors.

Putative site for the acquisition of human herpesvirus 6 virion tegument.

The virion of human herpesvirus 6 (HHV-6) contains a very distinct tegument layer, occupying the space between the nucleocapsid and the virion envelope. Ultrastructural analyses of thymocytes infected with HHV-6 revealed the presence of intranuclear spherical compartments, approximately 1.5 microns in diameter, in which tegumentation seems to take place. These compartments, termed tegusomes, were bounded by two membranes and contained ribosomes, consistent with their derivation by cytoplasmic invagination into the nucleus. Capsids located within the nucleus outside the tegusomes were all naked, while those located in the cytoplasm were uniformly tegumented. In contrast, capsids present inside the tegusomes contains teguments of variable thicknesses. In addition, nucleocapsids were documented in the process of budding into the tegusomes. We thus suggest that the tegusomes represent a cellular site in which HHV-6 virions acquire their tegument.

[Infant mortality in the town of Djibouti--risks, risk factors and risk markers]. / La mortalité infantile à Djibouti-ville--risques, facteurs et marqueurs de risque.

The authors report the results of the first survey on infancy mortality rate carried out in the town of Djibouti since the Republic of Djibouti became independent. Infancy mortality rate is 141 +/- 11o/00, and in correlation with some risk factors well identified: jobless, lack of fecal hygiene, bottle-feeding of infant, vaccinal coverage not adequate. It is mainly a post-natal mortality of exogenous origin and therefore possible to be reduced in the framework of the strategy of Primary Health Cares progressively set up by the Government of the Republic of Djibouti.

[Malaria in the Republic of Djibouti. Strategy for control using a biological antilarval campaign: indigenous larvivorous fishes (Aphanius dispar) and bacterial toxins]. / Le paludisme en république de Djibouti. Stratégie de contrôle par la lutte antilarvaire biologique: poissons larvivores autochtones (Aphanius dispar) et toxines bactériennes.

The authors take stock of the present situation of malaria in the Republic of Djibouti which, after several decades of silence, seems to have been reintroduced at the beginning of the seventies. Actually it is hypo-endemic malaria with Plasmodium falciparum of which the only vector seems to be Anopheles arabiensis, gambiae complex. The specificity of the larvae nests allows a control strategy based on the only treatment of larvae sites by biological control: larvivorous fishes (Aphanius Dispar) and in addition the pin-point use of bacterial toxins as a complementary measure. The first results obtained in the rural zones around the capital are encouraging and permit to envisage the extensions of such a strategy to the whole of the territory of the Republic.

[Diagnosis of extraintestinal amebiasis by an indirect ELISA method]. / Diagnostic de l'amibiase extraintestinale par une méthode ELISA indirecte.

Immunoglobulins G and M, parenchymal lysis witness, are searched by Indirect ELISA technique. This methodology, epidemiologic studies applied, presents with reference technique: Indirect Hemagglutination a good correlation (r = 0.93). Other qualities are big specificity and good reproducibility .

[On the etiology of water excretion inhibition in Addison's disease]. / Zur Atiologie der Wasserausscheidungsstörung bei Morbus Addison.

Micropuncture experiments, performed on adrenalectomized rats disclosed an impairment of the hypertonic sodium chloride transport of the thick ascending limb of Henle's loop (the diluting segment). This transport inhibition was documented by a delayed time course of NaCl-concentration decrease within the diluting segment. Assuming a pump leak model of the hypertonic NaCl-transport, we calculated a 50% inhibition of the NaCl-transport velocity compared with controls. Dexamethasone treatment for 3 days led to a normalization of the impaired transport velocity. Both, the reduced GFR as well as the impaired free water clearance are functionally linked to the diminished transport capacity of the diluting segment by the tubuloglomerular feedback mechanism and the ADH mechanism respectively. A new hypothesis on the pathogenesis of the water excretion inhibition in adrenal insufficiency is discussed.

[What role does secondary hyperaldosteronism play in decompensated liver cirrhosis?]. / Welche Rolle spielt der sekundäre Hyperaldosteronismus bei der dekompensierten Leberzirrhose?

In 29 untreated resting patients with cirrhosis of the liver and ascites plasma aldosterone levels were determined. The determinations were performed with a radioimmunoassay using highly specific antibodies without chromatography. Seven aldosterone values were decreased, 18 were normal and only four were increased. The median of the values was 107 pg/ml and differed not from that of healthy persons. In 20 other patients, in which application of diuretics had already been started, 14 plasma aldosterone levels were increased. The median was 332 pg/ml und thus far above the normal range. Secondary aldosteronism in connection with decompensated cirrhosis of the liver arises mainly under therapy with diuretics.

[Extended ACTH rapid test for differentiation of primary and secondary adrenal insufficiency]. / Erweiterter ACTH-Kurztest zur Unterscheidung von primärer und sekundärer Nebennierenrinden-Insuffizienz.

In 30 resting normal persons, 5 ambulant normal persons and 3 patients with disorders of the pituitary-adrenal-system before and 30 minutes after intravenous injection of 0,25 mg synthetic adrenocorticotrophin (tetracosactid, Synacthen) plasma cortisol and aldosterone levels were evaluated. The evaluation of the corticoids was continued over 240 minutes in intervals of 30 minutes. The basal cortisol and aldosterone levels of the resting normal persons and ambulant persons ordinarily doubled 30 minutes after ACTH application. The plasma cortisol level of a steroid-treated patient with lupus erythematodes disseminatus rose subnormally but his aldosterone level increased normally. 2 patients with untreated hypopituitarism had subnormal plasma cortisol and normal aldosterone responses after ACTH administration. In contrast with patients with primary adrenal insufficiency, whose plasma aldosterone levels fail to rise, patients with secondary adrenal insufficiency had normal corticotrophin-stimulated aldosterone increments. Thus the extended ACTH test can be useful in differential diagnosis of primary and secondary adrenal insufficiency.

[Effect of x-ray contrast media on the blood coagulation and fibrinolysis systems]. / Einfluss von Röntgenkontrastmitteln auf das Blutgerinnungs- und Fibrinolysesystem.

The intravenous application of x-ray contrast media during arteriographies resulted in a small, statistically significant, however clinically and biologically not relevant prolongation of the thromboplastin time and of the thrombincoagulase time. Contrast media applied for the examination of the kidneys and of the gall bladder did not induce any comparable changes of coagulation parameters. In vitro addition of iodinated contrast media to citrated plasmas was inhibitory to the coagulation process. Further analysis demonstrated that contrast media did not influence coagulation by enzyme inhibition but by inhibition of fibrin polymerization. Euglobulin lysis time was not only shortened by diagnostic applications of contrast media but also by other diagnostic procedures (gastroscopies, rectoscopies, laparoscopies) which involved physical exercise and thereby activation of the fibrinolytic system. Finally it is discussed that thrombotic complications following angiographies might be induced by the punction and injury of the vessel with the liberation of thrombokinase and subendothelial collagen.

[Plasma aldosterone and electrolytes in primary and secondard aldosteronism (author's transl)]. / Plasmaaldosteron und Elektrolyte beim primären und sekundären Hyperaldosteronismus.

Plasma aldosterone levels and the serum electrolytes potassium, sodium and magnesium of 38 patients with healthy adrenals were determined. Under physiological conditions there were no significant correlations between these parameters. In two patients with an aldosterone producing adenoma of the adrenals (syndrome of Conn) we found very low levels of potassium and low levels of magnesium. The levels of sodium lay in the upper normal range. Plasma aldosterone levels are raised strongly. After resection of the tumors the mentioned parameters normalized. In 16 patients with cirrhosis and ascites we generally found values of aldosterone, potassium, sodium and magnesium which lay in the lowest normal range. Under treatment with spironolactone the aldosterone levels raised and reached values which are characteristical of the syndrome of Conn. Potassium raised to the upper normal range, magnesium raised significantly, sodium diminished slightly.

[Does low-dosage heparin treatment require serial haematological controls? (author's transl)]. / Erfordert die Behandlung mit niedrig dosiertem Heparin eine Laboratoriumskontrolle?

Blanket serial controls are not necessary in low-dosage heparin treatment. It would, in any case, be difficult under normal clinical conditions and would run counter to the whole conception of low-dose heparin treatment. However, in problem cases with an increased thrombo-embolic risk, sensitive methods for monitoring the heparin effect are recommended. A study on 150 patients has indicated that the most sensitive method is the use of chromogenic substrates. Thrombin time, using low-concentration thrombin solution of 1.5 NIH units/ml, thrombelastogram and activated partial thromboplastin time are less sensitive. Antithrombin III levels should be determined in all cases of increased heparin tolerance. With reduced antithrombin III levels and higher body weight an increase of the standard dose from 5000 U.S.P. units heparin t. i. d. subcutaneously to 7500 U.S.P. units t. i. d. should be considered.

[Investigations concerning the hypothalamic-hypophysial regulation of aldosterone secretion (author's transl)]. / Untersuchungen zur hypothalamisch-hypophysären Steuerung der Aldosteronsekretion.

In 17 patients with retrospectively healthy adrenals we performed a LHRH-test, a TRF-test and an ACTH-test in the short modification. Additionally we determined plasma aldosterone and renine levels. Concerning the LHRH-tests and the TRF-tests we did not find any differences on the aldosterone values. Concerning the ACTH-tests in the short modification we found an increase of the aldosterone values which resembled that of the cortisol levels (increase of cortisol 104.7%, increase of aldosterone 93.3%). The renin values remained unchanged. Therefore the plasma aldosterone levels are modified in accordance with the cortisol levels by hypophysial influences.