Search Results

1 - 10 of 43 items :

  • General Interest x
  • Mathematics x
Clear All
Microbial Food Web Components as Potential Indicators of Urban Hydroecosystems / Mikrobiālās ķēdēs Komponentu Potenciāls Pielietojums Urbānās Vides Ūdeņu Ekosistēmas Kvalitātes Novērtējumam

References Aberle, N., Lengfellner, E. K., Sommer, E. U. (2007). Spring bloom succession, grazing impact and herbivore selectivity of ciliate communities in response to winter warming. Oecologia, 150, 668-681. Anonymous (1992). Standard methods for the examination of water and wastewater. 18th ed. APHA, AWWA, WPCEF. Washington, DC. 952 pp. Anonymous (2000). Current Protocols in Flow Cytometry. Supplement, 11, 16 pp. Azam, F. T., Fenchel, J. G., Field, J. S., Gray, L. A., Thingstad, F. (1983

Open access
Amber Particles as Living Plant Cell Markers in Flow Cytometry / Dzintara Daļiņas Kā Dzīvu Augu Šūnu Marķieri Plūsmas Citometrijā

oxidative stress in sand-grown wheat. J. Nanoparticle Res., 14 (9), 1-15. Djaković, T., Jovanoviã, Z. (2003). The role of cell wall peroxidase in the inhibition of leaf and fruit growth. Bulgarian J. Plant Phys., Special Issue, 264-272. Dožel, J., Greilhuber, J., Suda, J. (2007). Flow cytometry with plants: An overview. In: Doležel, J., Greilhuber, J., Suda J. (eds.). Flow cytometry with plant cells. WILEY- VCH Verlag Gmb H&Co, KGaA, pp. 41-65. Eenschooten, C., Guillaumie, F., Kontogeorgis, G. M., Stenby, E. H., Schwach

Open access
Analysis of the Genetic Diversity and Population Structure of Latvian Ash (Fraxinus excelsior L.) Stands using Nuclear and Chloroplast SSR Markers

Abstract

Common ash (Fraxinus excelsior L.) has a widespread distribution throughout Europe, and Latvia is almost at the north eastern edge of the distribution range. In Europe, ash is threatened by ash dieback, a disease caused by the introduced ascomycete Hymenoscyphus fraxineus. Chloroplast and nuclear DNA markers have been used to study the genetic diversity and population structure of ash both in a broader pan-European context as well as in more restricted regions. Some of the markers analysed in these previously published reports were also utilised in this study, enabling comparisons of the genetic parameters calculated from the nuclear SSR marker data and of the haplotypes identified with the chloroplast markers. Analysis of chloroplast markers revealed one dominant haplotype in Latvian stands, which corresponds to the haplotype previously found in Eastern Europe and Scandinavia. A second haplotype, corresponding to a previously reported central European haplotype was found in all individuals from the Ķemeri stand, indicating that this stand was naturally established from introduced germplasm, which was planted in a neighbouring park. The nuclear SSR markers revealed low levels of differentiation of Latvian F. excelsior stands, probably due efficient pollen flow between stands. The analysis of both chloroplast and nuclear DNA markers has revealed different aspects of the structure and provenance of Latvian F. excelsior populations.

Open access
Combined Effects of 50 Hz Electromagnetic Field and SiO2 Nanoparticles on Oxidative Stress in Plant’s Gametic Cells / Zemfrekvences (50 Hz) Elekromagnētiskā Lauka Un SiO2 Nanodaļiņu Kombinētā Ietekme Uz Augu Gametisko Šūnu Oksidatīvo Stresu

., (2007). Flow cytometry with plants: An overview. In: Doležel, J., Greilhuber, J., Suda, J. (eds.). Flow Cytometry With Plant Cells. WILEY-VCH Verlag, GmbH&Co, KGaA, pp. 41-65. Eom, H.-J., Choi, J. (2011). SiO2 nanoparticles induced cytotoxity by oxidative stress in human bronchial epithelial cell, Beas-2b. Available at: http://dx.dol.org/10.5620/eht.2011.26.e201013. Espinosa, J. M., Liberti, M., Lagroye, I., Veyret, B. (2006). Exposure to AC and DC magnetic fields induces changes in 5-HT1B receptor binding parameters in rat brain

Open access
Changes of total annual runoff distribution, high and low discharges in Latvian rivers

. 160-170). Reykyavik, Nordic Hydrological Programme, NHP Report No. 50. Kriaučiūniene, J., Kovalenkoviene, M., Meilutyte-Barauskiene, D. (2007). Changes of the low flow in Lithuanian rivers. Environ. Res. Eng. Manag. , 4 (42), 5-12. Lisbiseller, C., Grimvall, A. (2002). Performance of partial Mann-Kendall Test for trend detection in the presence of covariates. Environmetrics , 13 , 71-84. Lizuma, L., Kļaviņš, M., Briede, A., Rodinovs, V. (2007). Long-term changes of air temperature in

Open access
Wavelet analysis of the Baltic region river runoff longh-term trends and fluctuations

References Amarasekera, K.N., Lee, R.L., Williams, E.R., Eltahir, E.E.B. (1997). ENSO and the natural variability in the flow of tropical rivers. J. Hydrol. , 200 , 24-39. Bayazit, M., Onoz, B., Aksoy, H. (2001). Nonparametric streamflow simulation by wavelet or Fourier analysis. Hydrol. Sci. , 46 (4), 623-634. Benit, G., Diez-Herrero, A., de Villalta, M.F. (2003). Magnitude and frequency of flooding in the Tagus basin (Central Soain) over the last millennium. Clim. Change

Open access
Role of Interferon-Gamma (Ifn-γ) in Immune Response Regulation in Hiv-1 and Hiv-1 + Mycobacterium Tuberculosis (Tb) Infected Patients / Interferona-gamma (Ifn-γ) Loma Imūnās Atbildes Regulēšanā Pacientiem Ar HIV-1 un HIV-1 + mycobacterium Tuberculosis

Th1 to Th2 cytokine shift during the course of HIV-1 infection using cytoplasmic cytokine detection on single cell level by flow cytometry. AIDS, 11, 1111-1118. Li, J. C. B., Au, K., Fang, J., Yim, H. C. H., Chow, K., Ho, P., Lau, A. S. Y. (2011). HIV-1 trans-activator protein dysregulates IFN-g signaling and contributes to the suppression of autophagy induction. AIDS, 25, 15-25. Modjarrad, K., Vermund, S. H. (2010). Effect of treating co-infections on HIV-1 viral load: A systematic review. Lancet Infect. Dis., 10, 455

Open access
Regional Lung Blood Perfusion Measured With Laser Doppler Method During Body Position Change, Valsalva Manoeuvre and Cardiopulmonary Bypass

References Agostoni, P., Arena, V., Biglioli, P., Doria, E., Sala, A., Susini, G. (1989). Increase of alveolar pressure reduces systemic-to-pulmonary bronchial blood flow in humans. Chest , 96(5), 1081-1085. Angdin, M., Settergren, G., Astudillo, R., Liska, J. (1998). Altered reactivity to acetylcholine in the pulmonary circulation after cardiopulmonary bypass is part of reperfusion injury. J. Clin. Anesth. , 10(2), 126-132. Baile, E. M., Godden, D. J., Pare, P. D. (1988). Non

Open access
Assessment of Tissue Perfusion During Cardiopulmonary Bypass

Assessment of Tissue Perfusion During Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) remains essential for all valvular operations and the vast majority of coronary bypass surgeries. Inadequate CPB results in tissue underperfusion, activation of anaerobic metabolism and increased lactate production. The goal of the study was to determine the factors influencing oxygen delivery to and consumption in tissue. Fifty-six patients (41 male and 14 female patients of 27 to 84 years of age) scheduled to undergo cardiac surgery with CPB were enrolled in this prospective study. No operation-based selection was applied. The following data have been collected and analysed: demographics, preoperative cardiovascular profile. Arterial and venous blood gas tests, including blood glucose and lactate concentrations were obtained. We have assessed DO2 (mL/min/m2) and VO2 (mL/min/m2), venous oxygen content (CvO2) (mL/dL), arterial oxygen content (CaO2) (mL/dL) calculated according to standard equations based on haemoglobin concentration and saturation in arterial blood, cardiac output or pump flow. The main factors of organ dysoxia during CPB are the haemodilution degree and low peripheral oxygen delivery (DO2). Our study confirmed that hematocrit on pump and systemic flow rate determine the amount of oxygen delivery to the body, i.e. DO2 decrease is correlated with decrease of both hematocrit (Ht) and pump flow.

Open access
Echocardiographic Follow up After Surgical Correction of Aortic Coarctation During The First Year of Life

Abstract

Coarctation of the aorta (AoCo) accounts for 6–10% of congenital heart diseases in infants. We analysed echocardiographic findings of patients operated on for AoCo in the University Hospital for Children in Riga during the first year of life to evaluate the long-term findings. Fifty-nine children underwent surgical correction of AoCo at the age of 55 ± 61 days. The methods of surgical correction were anastomosis end-to-end (ETE) in 29% (n = 17), subclavian flap aortoplasty (SFA) in 64% (n = 38) and extended anastomosis end-to-end (EETE) in 7% (n = 4). Recoarctation developed in 15 patients (25%) with no difference between surgical techniques (P > 0.05). The recoarcation patients had left ventricle hypertrophy (left ventricle mass index (LVMi) 76 ± 19 g/m2.7) normalising after angioplasty (LVMi 42 ± 7 g/m2.7). Patients with recoarctation had a decreased pulsed wave (PW) Doppler systolic/diastolic ratio in abdominal aorta 2.3 ± 0.4 versus patientswithout recoarctation 5.3 ± 1.2 and the control group 6.3 ± 1.4 (P < 0.05). A high incidence of recoarctation exists in patients operated on for AoCo as small infants. Life-long surveillance is required to monitor and to intervene in a timely way. Supplementation of the echocardiographic protocol with an evaluation of PW Doppler flow pattern in abdominal aorta can provide additional information about the presence of obstruction.

Open access