Towards a mathematical model of limestone pavement vegetation. II. Microclimate, surface pH, and microtopography

1969 ◽  
Vol 47 (6) ◽  
pp. 959-974 ◽  
Author(s):  
G. A. Yarranton ◽  
W. J. Beasleigh

Microclimate and surface pH in limestone pavement fissures were investigated, with special attention to their correlation with topography. The diurnal cycles of light intensity at 60 points in the fissures were measured and variations in them explained by the interaction of topography and the position of the sun in the sky. Continuous recording of temperature and humidity in the grikes over a 5-day period suggested the presence of two air layers: an air layer in the lower two-thirds of each grike, characterized by stable temperature and humidity, with humidity decreasing upward; and a second layer continuous with the air above the surface and subject to much greater variation. This phenomenon was most pronounced in the narrowest grikes. Means and variances of light intensity, temperature, and humidity were selected as parameters of microclimate. Analyses of their variance with respect to topographic effects were performed, and all six parameters were shown to be highly correlated with topography. The pH determinations are not so correlated. The suitability of these seven variables for use in projected mathematical models of the determination of the probability of occurrence of species at defined points was investigated.

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.


1987 ◽  
Vol 252 (5) ◽  
pp. H1031-H1040 ◽  
Author(s):  
M. L. Ellsworth ◽  
R. N. Pittman ◽  
C. G. Ellis

We present a computer-aided videodensitometric method for the determination of oxygen saturation in red blood cells flowing through capillaries of the hamster cheek pouch retractor muscle. The optical density (OD) of red blood cells is determined at two wavelengths. At the first, 431 nm, there is a maximum difference between absorption by oxygen deoxyhemoglobin. At the second, 420 nm, absorption is equal for the two absorbing species (isosbestic wavelength). In capillaries of the retractor muscle a relationship between oxygen saturation (S) and the following OD ratio was obtained as S = -1.71 (OD431/OD420) + 2.20. The error (95% confidence interval) in oxygen saturation associated with a determination of the OD ratio is estimated to be +/- 4.8%. The computerization of the method employs a frame-by-frame analysis of the light intensity over a selected capillary segment. The light intensity waveform along the segment is digitized and the minimum (I) and maximum (I0) light intensities are used to compute an optical density (OD = log10 [I0/I]). These minimum and maximum intensities correspond to the presence and absence of a red blood cell, respectively. The method permits the off-line analysis of videotaped scenes and provides a means of assessing the extent of temporal and spatial heterogeneity of oxygen saturation in selected capillary networks. The method has been developed for use in capillaries in transilluminated striated muscle but should be generally applicable to the measurement of capillary oxygen saturation in other tissues.


1983 ◽  
Vol 69 (4) ◽  
pp. 305-308 ◽  
Author(s):  
Franco Zunino ◽  
Renato Marchesini ◽  
Elsa Melloni ◽  
Giuseppina Savi ◽  
Gabriella Pezzoni ◽  
...  

The effectiveness of laser photoradiation therapy with hematoporphyrin derivative sensitization was tested in the MS-2 sarcoma. This solid tumor, transplanted into the pad of the hind leg of BALB/c mice, was found to be a sensitive experimental model for a quantitative evaluation of response to phototherapy and for determination of critical parameters in laser phototherapy treatment. Under our experimental conditions, optimal therapeutic effects appeared to be critically dependent on drug dose, number of treatments, light intensity, and irradiation of the peripheral border of the tumor.


Blood ◽  
1985 ◽  
Vol 66 (6) ◽  
pp. 1463-1465
Author(s):  
D Labie ◽  
O Dunda-Belkhodja ◽  
F Rouabhi ◽  
J Pagnier ◽  
A Ragusa ◽  
...  

To test the hypothesis advanced by Gilman and Huisman that the -158 site 5′ to the G gamma gene determines the G gamma expression after the first 4 months of life, we have examined DNA from sickle cell anemia (SS) patients from Africa and beta-thalassemic homozygotes from Algeria. We find that the Xmnl site is strongly linked to the Senegal haplotype among SS patients, to haplotype IX (most probably identical to the Senegal haplotype), and to haplotype III among the Algerian thalassemics. Thalassemics with haplotypes I/I and V/V have no Xmnl site and low G gamma expression. In contrast, beta-thalassemia- associated haplotype II (also characterized by high G gamma expression) fails to exhibit the Xmnl site. We conclude that, although highly correlated, the -158 C----T substitution does not perfectly predict the presence of high G gamma expression. These findings also exclude the possibility that the Xmnl site is solely involved in the determination of high G gamma expression and suggest that either several different site substitutions in the area 5′ to the gamma gene might have the same effect or that, alternatively, the Xmnl site and its surrounding area is not involved in G gamma expression and may be only in linkage disequilibrium with a controlling sequence elsewhere.


Author(s):  
Kris Gillis ◽  
Jean-Yves Wielandts ◽  
Gabriela Hilfiker ◽  
Louisa O'Neill ◽  
Alina Vlase ◽  
...  

Introduction. During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics validates LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. Methods. Thirty patients (mean age 76 ± 14 years) were implanted with stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (validation-group) conventional, interrupted implantation was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (feasibility-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were analyzed. Results. In the validation-group, LS and CP-pacing impedances were highly correlated (R=0.95, p<0.0001, bias 12±37Ω). Pacing characteristics from LS and CP showed comparable sensed electrograms and paced QRS morphologies. In the feasibility-group, continuous LS-pacing allowed beat-to-beat monitoring of impedance and QRS morphology to guide implantation. This resulted in successful LBBAP in all patients, after a mean of 1±0 attempts, with mean threshold 0.81 ± 0.4V, median sensing 6.5mV [IQR 4.4-9.5] and mean impedance 624 ± 101Ω, and positive LBBAP-criteria with median paced QRS duration 120ms [IQR 112-152ms] and median pLVAT 73ms [IQR 68-80.5ms]. No septal perforation occurred. Conclusion. Unipolar pacing from the LS allows accurate determination of pacing impedance and generates similar paced QRS morphologies and equal sensed electrograms, compared to CP pacing. Continuous LS pacing allows real-time monitoring of impedance and paced QRS morphology, which facilitates a safe and successful LBBAP lead implantation.


2017 ◽  
Vol 8 (4) ◽  
pp. 64-72
Author(s):  
Anastasia V. Koziy ◽  
Alexander I. Olesin ◽  
Vadim A. Litvinenko ◽  
Irina V. Konstantinova

Aim. The aim of the study was a clinical assessment of the integrated determination of predictors of life-threatening ventricular arrhythmias (LVA) in patients with ventricular extrasystole (VE) without structural changes in the heart to predict the development of cardiovascular disease in a prospective study. Material and methods. From 1997 to 2014 199 patients with neurocirculatory dystonia (NCD), complicated with VE II-V class EE at the age of 18-35 years (mean 27.3-2.6 years) were observed in District Military Clinical Hospital of the Ministry of Defense of the Russian Federation, City Hospital named after St. Martyr Elizabeth. All patients, in addition to a general clinical examination, determined late potentials of the ventricles (LPV), QT interval variability (QTd), heart rate turbulence (HRT), and also indicators reflecting the possible mechanism of VE development. Results. The results of the study showed that in patients with NCD complicated by VE, the detection of indicators reflecting the presence of VE caused by the mechanisms of early post-depolarization and re-entry is a predictor of the development of coronary heart disease (CHD) and hypertension (HB). The positive prognostic significance of the indicators showing the presence of VE with these development mechanisms for the development of CHD and HB averaged 74% and 44% respectively, and with the appointment of сlass III drugs for elimination of VE and (or) development of unstable ventricular tachycardia, the risk of developing CHD increased to an average of 93%. Identification of NDC patients with indicators reflecting the presence of VE due to delayed post-depolarization is a predictor of the development of gastrointestinal tract (GT) diseases with positive prognostic significance, averaging 61%. Positive prognostic significance with respect to the development of CHD, HB, GT diseases for the detected LPV, QTd > 80 ms, pathological values of HRT VE did not exceed 30%. Indicators and predictors, which characterize the mechanism of development of VE and the risk of LVA occurrence in patients with NCD complicated by VE, were highly correlated (r > 0.50) with risk factors for cardiovascular and gastrointestinal system diseases.


2020 ◽  
Vol 36 (2) ◽  
pp. 205-214
Author(s):  
Violeta Caro-Petrovic ◽  
Milan Petrovic ◽  
Dragana Ruzic-Muslic ◽  
Nevena Maksimovic ◽  
Irina Sycheva ◽  
...  

Records of female lambs and their parents of the Mis sheep breed have used. All animals are approximately have weaned at 90 days of age. Descriptive statistics, paired sample test, paired differences, measures of association, correlations and regression of body weights between female lambs and their parents have done. A complementary least body weights at 30 days and weaning between dams and lambs but utmost weight at 30 days, the lambs were higher while at weaning, the dams had higher weight. It can observe that the averages on body weights the rams were the highest, followed by lambs and the lowest the dams? body weights. The coefficient of determination of R2 varies from low to high, indicating that the lamb's body weight has more influenced by other factors that we have not considered. There were significant correlations between lamb body weight at birth and sire/dam body weight at birth. The results showed highly significant correlations of lamb's body weight at 30 days with dams but with sires, positive and very low. There had positive but no significant correlation between lamb body weight at weaning and sire body weight at weaning. Lamb body weight at weaning and dam body weight at weaning are highly correlated.


1980 ◽  
Vol 90 ◽  
pp. 55-60
Author(s):  
A. Mujica ◽  
G. Lôpez ◽  
F. Sánchez

SummaryA method of determination of the scattered light intensity, , by a unit-volume of interplanetary space is presented. From ground base Zodiacal Light measurements and the experimental results of Pioneer X the density, ρ(r), and phase, σ(θ), functions are obtained without any previous assumptions about them.


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