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Abstract

All previous reviews of research on light-emitting diodes (LEDs) have been focused on how different light spectra generally influence plant yield and quality. There are no or almost no reviews on the effect of spectra on sugars or pigment concentration, or yield and growth etc. The role of visible light in food production, as in agriculture and horticulture, is obvious, as light drives photosynthesis, which is crucial for plant growth and development. Solid state lighting using LEDs represents a fundamentally different technology from gaseous discharge-type lamps currently in use. LEDs are important lamp types because the concentration of the light spectrum they emit can be changed to provide plants at various developmental stages with the light spectrum needed. A great deal of studies have been done on the effect of wavelengths of light on growth, yield and nutritional quality of greenhouse vegetables. However, little is known about the mechanisms by which the spectra affect sugar and pigment concentration, and yield, and growth. This article provides a list of how spectra influence the yield, growth, and nutritional quality of greenhouse-grown vegetables. Based on the given information we can conclude that blue, green, and red light are the main light colours that influence positively plant yield, growth and nutrient quality. Sometimes in specific situations, some other light colours are also beneficial, like far red light, orange light and UVA light. Future work on light colour manipulation has potential for producing lamps and greenhouse covers that better support plant yield, growth, and nutrition.

Abstract

The cold-tolerance of ‘Kristall’ (Euro-Amur-American origin), ‘Dostoyniy’ and ‘Krasnostop AZOS’ (interspecific hybrids of Euro-American origin) grapevine varieties in the winter conditions of South Russia is characterised by the second (true dormancy) and third (induced dormancy) winter-resistance components. Here we used a complex approach to estimate plant adaptation to abiotic stress factors. We used the gravimetric method for humidity assessment and water content, spectral analysis for detection of the protein level and pigments and capillary electrophoresis to determine the level of carbohydrates, Krebs cycle organic acids, phenolcarbonic, ascorbic acids, and amino acids. The obtained results allow to suggest various mechanisms of adaptation of the studied varieties to the winter period stressors. The water content of shoots, levels of protein, amino acids, proline, sugars and the sum of phenolcarbonic acid and ascorbic acid are the most informative indicators of grape plants frost-resistance in the climate conditions of the Anapa–Taman region.

Abstract

Colonisation of gastrointestinal tract by extended spectrum beta lactamase (ESBL)-producing Gram-negative bacteria is a source for infections. The present work is a prospective study in Latvia aimed to determine the role of two surgical profile wards in transmission of ESBL-producing bacteria. Differences between hospital wards were not analysed due to low number of patients. We have also determined a correlation between the duration of hospitalisation and risk of ESBL colonisation. Tests for ESBL-producing bacteria were made twice for 136 patients — upon admission and upon discharge from the hospital. Of them, 21 (15.4%) patients already were ESBL-positive at the time of admission and 115 (84.6%) patients were ESBL-negative. Upon discharge from hospital, 45 (33.1%) patients were ESBL-positive, one patient was ESBL-negative, and 25 (18.4%) of ESBL-positive cases had emerged during hospitalisation. In total, 46 (33.8%) from 136 patients were ESBL-positive and ESBL was positive in 51 bacterial isolates. On discharge from hospital, the newly acquired ESBL-positive bacterial isolates were K. pneumoniae (n = 18), E. coli (n = 7) and P. mirabilis (n = 3). The prevalence of ESBL-positive E. coli from all detected E. coli was 7.0% and from all Klebsiella spp. — 88.9% in gut flora. Analysis of patientassociated wound infections did not show correlation between the ESBL-producing gut microbiota and the bacterial species involved in wound infection.

Abstract

We investigated how an abiotic factor, i.e. salinity, affects specific intracellular organelles of cells of the root cap. We focused on: 1) amyloplasts, which are specific plastids of the cap that perform important metabolic and sensory functions; and 2) mitochondria, which protect cells from ROS damage by changing their ultrastructure. In our work we studied the ultrastructural changes of these organelles in different areas of the root cap under NaCl and Na2SO4 impact. We showed that the amyloplasts (statoliths) and mitochondria of the columella and the peripheral zone of the cap change their structural organisation in the presence of NaCl. Under action of Na2SO4, in plastids of columella the number of starch grains decreases dramatically, the cells of the peripheral part of the cap do not contain the amyloplasts, and the proplastids that do not store or store a little starch grains, which is attributed to leucoplasts with typical lamellae characteristic for root cortex cells. Thus, Na2SO4 influence has the most significant effect on the plastids of the root cap, and plastids of the cells of the peripheral zone of the cap are subjected to the most significant changes under salinity stress.

Abstract

The aim of this study was to evaluate treatment of patients with moderate and severe heart failure (HF) who were resistant to pharmacotherapy in Latvia and to assess the cardiac resynchronisation therapy (CRT) by exploring the predisposing factors which provides CRT efficacy. We accomplished prospective analysis of left ventricle ejection fraction (LVEF) and other parameter changes 12 and 24 months after CRT device implantation, dividing the population into two groups: responders — to whom LVEF improvement was ≥10% and non-responders where ≥ 10% LVEF improvement was not achieved. The study included 50 chronic HF patients with preserved sinus rhythm, who underwent CRT device implantation in Latvia at the Pauls Stradiņš Clinical University Hospital from June 2009 to March 2012. In the group of patients where 12 and 24 months after CRT device implantation LVEF improvement ≥10% was achieved, there were statistically significantly more patients with left bundle branch block (LBBB) QRS morphology, wider QRS complex, nonischemic genesis of HF, and normal systolic blood pressure. Patients with LVEF improvement had more pronounced ventricular dyssynchrony measured by Echo before CRT device implantation and, accordingly, the CRT mode was programmed as left ventricle paced before right ventricle and close to 100% biventricular pacing was achieved and the patient was female.

Abstract

The purpose of this study was to determine how knee compression affected kinetic variables during vertical jumps. Ten healthy males, age 20s, performed a single maximum vertical jump and a ten-consecutive vertical jump trial without knee compression (control condition) and with knee compression. The collected data of ground reaction force were used to analyse the vertical jump height (VJH), peak active force (PAF), decay rate (DR), peak passive force (PPF), loading rate (LR), and the coefficient of variation (CV). During a maximum vertical jump, knee compression increased the magnitudes of DR, PAF, and VJH by 19.8%, 3.41%, and 4.87%, respectively, compared to those under a control condition. During ten consecutive vertical jumps, PAF and VJH showed statistically significant difference according to the repetition count. Also, the mean and CV of PAF, DR, LR, and VJH over consecutive jumps were higher in magnitude under knee compression condition than under the control condition.

Abstract

According to the Global Strategy for Plant Conservation, 75% of endangered species should be preserved in ex situ collections till 2020. The genus Liparis has a lot of recognised taxons, but only one species, Liparis loeselii (L.) Rich., grows in Europe. L. loeselii is a rare and endangered orchid species occurring in Europe. In Latvia L. loeselii is classified as the third category of endangered and protected species. To develop the best conservation strategy, the knowledge concerning the genetic differences of protected plants in a particular area is crucial. For this purpose, the genetic diversity of L. loeselii populations from different Latvian habitats was tested. The inter-retrotransposon amplified polymorphism method (iPBS) was used for population genetic diversity evolution. In total, 54 accessions from nine habitats were collected and analysed. L. loeselii leaves have a high content of phenols that reduce the quality of extracted DNA. It was found that the percentage of polymorph loci varied among the populations of L. loeselii growing in different habitats; some of the populations were genetically homogeneous. The genetic diversity levels of L. loeselii populations are related with the population age and the growing conditions.

Abstract

High molecular weight glutenin subunits (HMW-GS) of wheat are important factors in the determination of bread-making quality. They are responsible for elasticity and polymer formation of wheat dough. In the present study, 43 winter and 40 spring common wheat (Triticum aestivum L.) cultivars originated from Estonia, Belarus, Finland, Denmark, France, Germany, the Great Britain, Latvia, Lithuania, the Netherlands, Norway, Poland, Russia, Sweden, and New Zealand were characterised for Glu-A1 and Glu-D1 allelic composition using PCR method. Analyses were conducted with one DNA marker for identification of Glu-D1 allele encoding subunit Dx5, three DNA markers for Glu-A1 Ax1, Ax2* and AxNull subunits. It was determined that 32 (74.4%) winter and 35 (83.3%) spring cultivars had allele Glu-D1d, and 23 (53.5%) winter and 33 (78.6%) spring — Glu-A1a or Glu-A1b alleles, which have positive effect on dough properties. Polymorphism at Glu-A1 locus was detected in 15 cultivars, and 9 cultivars were polymorphic for locus Glu-D1. The obtained results were compared with published SDS-PAGE data. Complete or partial agreements were found for 78.1% of Glu-A1 and 70.6% of Glu-D1 alleles. Rapid and accurate identification of wheat Glu-1 alleles by molecular markers can be used for selection of wheat genotypes with good bread-making potential.

Abstract

Histamine has an important role in the process of the gastric mucosa inflammation acting via histamine receptor H2 (encoded by the gene HRH2). Single nucleotide polymorphism of the enhancer element of HRH2 gene promoter rs2067474 (1018G>A)may be associated with changes of expression of the receptor. We attempted to clarify the association of this polymorphism with gastric cancer and/or atrophic gastritis in the Latvian (Caucasian) population. The study group consisted of 121 gastric cancer patients and 650 patients with no evidence of gastric neoplasia on upper gastrointestinal endoscopy. Genotyping for rs2067474 was performed with the TaqMan probe-based system using a commercially available probe for RT-PCR. The frequency of the A allele in the gastric cancer group was 0.41% and in the control group — 1.54% (p = 0.231). No significant differences were found comparing genotypes between gastric cancer versus control patients (OR = 0.236, CI95% = 0.030–1.896), patients with (n = 165) versus without (n = 485) gastric metaplastic lesions (OR = 0.854, CI95% = 0.288–2.540) and patients with (n = 297) and without (n = 353) gastric atrophic lesions (OR = 1.145, CI95% = 0.451–2.906). Our findings suggest that the HRH2 -1018G>A polymorphism (rs2067474) is neither associated with gastric cancer nor the grade of atrophic gastritis in the Latvian (Caucasian) population.

Abstract

Recently we have showed that the expression of the mammalian CYP11A1 cDNA in plants confers their resistance to abiotic and biotic stresses. To determine the role of heterologous expression of cytochrome P450scc cDNA in resistance to ROS (radical oxygen species) dependent abiotic stresses, the structural changes of mitochondria and peroxisomes were studied under 150 mM NaCl-induced 14-day salinity treatment on juvenile tobacco plants in in vitro culture. Ultrastructural analysis of mesophyll cells of transgenic tobacco leaves constitutively expressing CYP11A1 cDNA was performed. Under NaCl stress, a change in shape from rounded to elon-gated, reduced section area, formation of branched mitochondria, as well as the emergence of triangular and rhomboid cristae, densification of a mitochondrial matrix, increase in density of contrasting membranes and their thickness were observed in non-transgenic plants. Transgenic plants without stress applied had mitochondria with rounded and elongated shape, twice as small as in non-transgenic plants, with a dense matrix and sinuous cristae. Surprisingly, the effect of NaCl led to increase in size of mitochondria by 1.5 times, decomposition of matrix and the emergence in organelles of light zones presumably containing mitochondrial DNA strands. Thus, the structural organisation of transgenic plant mitochondria under salinity treatment was comparable to that of non-transgenic plants under native conditions. It was also noted that the transgenic plant peroxisomes differed in non-transgenic tobacco both in normal condition and under the action of NaCl. The observed differences in ultrastructural organisation of mitochondria not only support our earlier notion about successful incorporation of the mature P450scc into this organelle, but for the first time demonstrate that the mammalian CYP11A1 signal peptide sequence could be efficiently used in the formation of targeted mitochondria protection of plants from salinity-induced damage.