New assessment tool for artificial plant lighting: case of tomato (Lycopersicon Esculentum Mill.)

Growing crops under artificial conditions need a very favourable environment, especially the spectral composition of radiation influencing the plant biometry greatly. The study objective was to find how to assess the closeness of real growing conditions to the optimal ones using a single coefficient, which would reflect several time dependencies of individual growth indicators. The plant growth friendliness factor (KG)was proposed for this purpose. Tomato transplants (Lycopersicon Esculentum Mill., ‘Polonaise F1’) were grown in a peat substrate under two lighting systems with different light quality.One system consisted of eight fluorescent lamps OSRAM L58W / 840 LUMILUX Cool White and eight lamps L58W / 77 FLUORA mounted on the standardframe, alternating the lamp types (Type I spectrum).In theother lighting system, the PCB Star LEDs with wavelengths of red 630 nm and far-red 735 nm were added(Type II spectrum). The irradiance level was maintained at 140 μmol m-2 s -1 , the photoperiod was 16 h. The ratio of long-wave flux to the total flux KL was calculated for these lighting systems (0.37 rel.units for Type I spectrum and 0.50 rel.units for Type II spectrum) and KG factor was determined by the proposed formula. The value ofKG was found to be twice as small for Type I spectrumthan for Type II spectrum. The significant difference in biometric parameters of tomato transplants grown under Type I and Type II spectrawas revealed. The plants grown in the environment characterized by higher KG, were higher; they had more significantwet mass and stem neck diameter

Irradiation level affects fluctuating asymmetry value of bilateral traits of cucumber in juvenile phase

ArticleLight is an important factor of the plant's environment. The aim of research was to confirm the hypothesis on the influence of different irradiation levels on the fluctuating asymmetry (FA) value of bilateral traits of plants cultivated in the indoor plant lighting. The object of research was the plants of cucumber ( Cucumis sativus L ) as one of the main glasshouse crops. Young 14 - day - old cucumber plants in the first true leaf phase were studied. Different irradiation levels (15.0, 22.5 and 30 W m - 2 ) were maintained by fluorescent lamps. An essential asymmetry of bilateral structures in plants grown under different irradiation levels was observed. It was found that statistically significant lower values of FA, that is greater stability of plant development, correspond to increased plant performance. When the irradiation level was switched from 15 to 30 W m - 2 (by 100%), the FA index for different bilateral structures varied by dif ferent amount: in terms of cotyledons mass it decreased from 0.046 to 0.032 relative units (by 30.2%), in terms of chlorophyll content in cotyledons it increased from 0.038 to 0.073 relative units (by 88.6%). In some bilateral structures the FA index varia tion was rather small: in terms of the cotyledon area it was zero, in terms of the cotyledon thickness – by 1.8%. I t was experimentally prove through the example of cucumber plants that FA index could be used as an indicator of plant developmental stability, characterizing the deviations of the growing environment parameters from the normal state in the indoor cultivating

The causes of low adherence in patients with antihypertensive therapy

Low adherence to antihypertensive therapy is a major cause of adverse cardiovascular outcomes by uncontrolled high blood pressure. If the most frequent causes of inappropriate taking of medicine are identified, possible improvements within the health care could be performed, promoting the safety and efficacy of antihypertensive therapy. The aim was to find the factors affecting patient's adherence during antihypertensive therapy. In the period from June to September 2014 a quantitative study was carried out including patients with diagnosed arterial hypertension who visited pharmacies in Riga to get the antihypertensive therapy. The study collected data of 152 patients with the mean antihypertensive treatment duration of 9.7 +/- 2.4 years. Most of the patients knew the reason for the use of the medication (n= 123, 80.8%), but it was also unclear for some patients (n= 29, 19.2%), more frequently with use of 2 or 3 medications at the same time, compared with the patients who received 4 or more medications (n= 26, 17.3% vs n= 3, 1.9%; p= 0.063). High medication load was more frequently associated with lower adherence during antihypertensive therapy. Awareness of antihypertensive therapy for an individual patient, reminders of prescribed medications and dosage instructions may contribute to adherence of patients.publishersversionPeer reviewe

Radiation use efficiency by tomato transplants grown under extended photoperiod

The study focused on the effect of an extended photoperiod on the radiation use efficiency (RUE) by the tomato transplants (Solanum lycopersicum L.) in the pre–reproductive period. In two consecutive series of experiments, the photoperiod was 16 and 22 hours. The photon irradiance at the plant tops was maintained at low, medium and high levels: 100, 170 and 240 μmol m–2 s –1 , respectively. The plants were grown under two lighting systems with different light quality. The difference was7% higher blue flux share in Spectrum II. The use of an extended photoperiod, especially in combination with high irradiance level, resulted in the plant leaf chlorosis. When varying the radiation dose components, the deviation from the reciprocity law was recorded. By the analysis results, the chlorophyll degradation was a response to the extended photoperiod rather than the radiation dose. Without additional blue flux, under a regular photoperiod, RUE reduced by 8% at the high irradiance level. Under extended photoperiod, the shift from the low to high irradiance level reduced RUE by 20–37%, with bigger reduction values being observed at higher irradiance levels. Seven percent addition of blue flux made it possible to increase RUE by 5–8% at the same and lower irradiance levels and under the regular photoperiod. With the extended photoperiod under these conditions, RUE decreased by 8–21%. The study results verify a great influence of an extended photoperiod on RUE, while the degree of influence depends on other parameters of light environment – light quality and irradiance level

Langmuir-Schaefer films of a polyaniline-gold nanoparticle composite material for applications in organic memristive devices

Langmuir-Shaefer films of a polyaniline-gold nanoparticle composite were fabricated and characterized. The thickness of each deposited monolayer, determined with AFM, was found to be about 0.8 nm. The film morphology was studied by SEM, revealing the presence of embedded spherical-shaped gold nanoparticles of about 5-10 nm in diameter. The fabricated films were used as the active channel of the organic memristor. Its electric characterisation has revealed new phenomena, such as an increased working voltage range and sigmoidal voltage current characteristics that were connected to the charge trappin

Evaluation of different lighting sources on the growth and chemical composition of lettuce

ArticleExperiment were carried out in Latvia University of Agriculture in plant growth room. Lettuce Lactuca sativa L. var foliosum cv. ‘Dubacek’ and L . sativa L. cv. ‘Michalina’ were grown under 4 types of lights (luminescence lamps, commercial light emitting diodes (LED) lamps (V - TAC premium series – for plant growing) and two different Lumigrow LED strips - dominant wavelength - blue or red with 14 h ph otoperiod and total photosynthetic active radiation (PAR) 100 μmol m - 2 s - 1 in all variants. Plant weight, length, amount of leaves were measured. Content of chlorophylls, carotenoids, phenols, flavonoids in lettuce was determined three times per vegetation period. In experiments were found that higher lettuce yield was under commercial LED (V - TAC premium series), but these plants contain less soluble sugars, pigments and phenols. Better plant quality was obtained with luminescence lamps. These lettuces have higher sugar, phenols and flavonoids content. Lettuce growth under blue dominate LED (LEDb) was delayed, but these plants contain higher chlorophylls content. The differences in plant growth, response to light and biochemical content b etween cultivars wer e detected

Novel germline MLH1 and MSH2 mutations in latvian Lynch syndrome families

Background/Aims: Hereditary non-polyposis colorectal cancer or Lynch syndrome is an autosomal dominantly inherited disease with high penetrance, mostly due to mutations in the MLH1 and MSH2 genes. The aim of this study is to investigate the mutation spectrum of the MLH1 and MSH2 genes. Methodology: High risk colorectal cancer families were selected from overall 1053 consecutive patients. Screening of germline mutations in the MLH1 and MSH2 was performed by direct sequencing and multiplex ligation-dependent probe amplification. Results: Ten patients fulfilled the Amsterdam I/II criteria and Bethesda guidelines of the Lynch syndrome. Three novel mutations were identified in MLH1 and MSH2 genes, as well as two known mutations in the MLH1 gene. Large rearrangements in the MLH1 gene were found in two patients. Conclusions: The mutations in the MLH1 and MSH2 genes in Latvian high-risk families are highly heterogeneous. Combination of direct sequencing and MLPA is the most appropriate molecular method of detecting hereditary nonpolyposis colorectal cancer patients and family members at risk

BRCA1/2 mutation screening in high-risk breast/ovarian cancer families and sporadic cancer patient surveilling for hidden high-risk families

Background: The estimated ratio of hereditary breast/ovarian cancer (HBOC) based on family history is 1.5% in Latvia. This is significantly lower than the European average of 5-10%. Molecular markers like mutations and SNPs can help distinguish HBOC patients in the sporadic breast and ovarian cancer group.Methods: 50 patients diagnosed with HBOC in the Latvian Cancer Registry from January 2005 to December 2008 were screened for BRCA1 founder mutation-negatives and subjected to targeted resequencing of BRCA1 and BRCA2 genes. The newly found mutations were screened for in the breast and ovarian cancer group of 1075 patients by Real Time-PCR/HRM analysis and RFLP.Results: Four BRCA2 mutations including three novel BRCA2 frameshift mutations and one previously known BRCA2 frameshift mutation and one BRCA1 splicing mutation were identified. Two of the BRCA2 mutations were found in a group of consecutive breast cancer patients with a frequency of 0.51% and 0.38%.Conclusions: Molecular screening of sequential cancer patients is an important tool to identify HBOC families.publishersversionPeer reviewe

High frequency of pathogenic non-founder germline mutations in BRCA1 and BRCA2 in families with breast and ovarian cancer in a founder population

Funding Information: This work was supported by State Research Program “Biomedicine for the public health (BIOMEDICINE)” project 5 “Personalised cancer diagnostics and treatment effectiveness evaluation”. Publisher Copyright: © 2018 The Author(s).Background: Pathogenic BRCA1 founder mutations (c.4035delA, c.5266dupC) contribute to 3.77% of all consecutive primary breast cancers and 9.9% of all consecutive primary ovarian cancers. Identifying germline pathogenic gene variants in patients with primary breast and ovarian cancer could significantly impact the medical management of patients. The aim of the study was to evaluate the rate of pathogenic mutations in the 26 breast and ovarian cancer susceptibility genes in patients who meet the criteria for BRCA1/2 testing and to compare the accuracy of different selection criteria for second-line testing in a founder population. Methods: Fifteen female probands and 1 male proband that met National Comprehensive Cancer Network (NCCN) criteria for BRCA1/2 testing were included in the study and underwent 26-gene panel testing. Fourteen probands had breast cancer, one proband had ovarian cancer, and one proband had both breast and ovarian cancer. In a 26-gene panel, the following breast and/or ovarian cancer susceptibility genes were included: ATM, BARD1, BLM, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, FAM175A, MEN1, MLH1, MRE11A, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53, and XRCC2. All patients previously tested negative for BRCA1 founder mutations. Results: In 44% (7 out of 16) of tested probands, pathogenic mutations were identified. Six probands carried pathogenic mutations in BRCA1, and one proband carried pathogenic mutations in BRCA2. In patients, a variant of uncertain significance was found in BRCA2, RAD50, MRE11A and CDH1. The Manchester scoring system showed a high accuracy (87.5%), high sensitivity (85.7%) and high specificity (88.9%) for the prediction of pathogenic non-founder BRCA1/2 mutations. Conclusion: A relatively high incidence of pathogenic non-founder BRCA1/2 mutations was observed in a founder population. The Manchester scoring system predicted the probability of non-founder pathogenic mutations with high accuracy.publishersversionPeer reviewe