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The Spatial Distribution of Perch (Perca fluviatilis) Ectoparasites and the Effect of Chemical Water Quality Parameters on Ectoparasite Spatial Niche Size

Abstract

Seasonal changes of abiotic factors and their influence on parasite occurrence have repeatedly been studied. Most of the studies have been conducted to evaluate the effect of water physicochemical parameters on changes in the intensity of infection, prevalence and component community of a number of parasite species. However, insufficient attention has been paid to the link between water quality parameters and spatial niche size of ectoparasites. The distribution of ectoparasite species on perch (Perca fluviatilis L.) was studied to establish whether seasonal changes of water quality parameters are associated with ectoparasite spatial niche size. The concentration of phosphates (PO4 3−), nitrates (NO 3), sulphates (SO4 2−) and dissolved oxygen (DO) in the water of Lake Sila (Latvia) was measured every month throughout the year and recorded all ectoparasites on perch. Zero-inflated mixed models were used to evaluate which of the water parameters influence the spatial niche size of ectoparasites. Our findings showed that spatial niche size of some ectoparasite species is affected by a set of water quality parameters and that this effect is negative. The spatial niche size of Anodonta cygnea was negatively associated with phosphate, nitrate, sulphate and dissolved oxygen concentration. The spatial niche size of Ancyrocephalus percae was negatively associated with sulphate, and the spatial niche size of Ergasilus sieboldi was negatively associated with nitrate concentration.

Open access
Survey of Presence of Non-Indigenous Eurytemora Carolleeae in the Gulf of Riga (Baltic Sea) Five Years After its First Discovery

Abstract

In the brackish ecosystem of the Gulf of Riga, the calanoid copepod Eurytemora affinis is a key species, but recently a new non-indigenous species Eurytemora carolleeae was discovered in the region. In the present study, we aimed to validate the presence of E. carolleeae in the southern part of the Gulf of Riga five years after its first discovery. The study area is the closest region to the Rīga harbour — the main source of non-indigenous species arrival in the Gulf. Recent studies have predicted the possible potential of E. carolleeae invasion due to its physiological plasticity. Male and female specimens of Eurytemora were collected in spring, summer, and autumn of 2013, and analysed based on three morphological indicators. Despite the higher reproduction rate of E. carolleeae, this intrusive species does not seem to have succeeded in establishing during the five-year period after its first discovery in the Gulf of Riga, and hence does not present a threat to the native E. affinis population in the study area.

Open access
Alcohol Use Disorder and Depression in Patients with Alcohol-Related Seizures

Abstract

Both alcohol use disorder and depression are important aspects of health in the general population and among patients with epilepsy. Depression is the most prevalent psychiatric comorbidity in epilepsy, thereby increasing morbidity as well as mortality rate. From our experience, we can see that one third of epilepsy inpatients experience seizures that are alcohol-related. There have been no studies conducted in Latvia about alcohol use disorder and depression in patients with alcohol-related seizures (ARS) and epilepsy. We recruited 108 patients with ARS, 44 of whom had comorbid epilepsy. 75% of patients in our study had depression according to the Hamilton depression scale. Higher score in the Alcohol Use Disorder Identification Test was associated with thoughts of self-harm. Greater consumption of alcohol on a typical day when drinking was associated with a higher risk of alcohol dependence. Of patients without epilepsy, 60% received antiepileptic drugs (AEDs) and 17% even used 2–3 different drugs to overcome ARS. A large part of patients had not been warned by their physician that alcohol provokes seizures. Our data could help to identify greater suicidality risk and alcohol dependence risk cases in patients with ARS, as well as improve care for this group of patients in general.

Open access
Assimilation of Selenium, Copper, and Zinc in Rye Malt

Abstract

Trace elements selenium, copper, and zinc are essential minerals for the human body. One of the means to increase the micronutrient content in diets is to add them to food raw materials, for example, to enrich grain with micronutrients during malt production. To obtain rye malt, 3 kg grain was soaked in 10 l water with addition of three mineral salts — sodium selenate (Na2SeO4), copper sulphate (CuSO4 5H2O), and zinc sulphate (ZnSO4 7H2O) at different concentrations and different combination of salts. The concentration of selenium, copper, and zinc was determined in rye malt. The obtained results were used to calculate the degree of assimilation of trace elements in rye malt. The interaction of trace elements selenium/copper and copper/zinc was studied. The total amount of selenium, copper, and zinc was analysed by inductively coupled plasma mass spectrometry (ICP-MS). Sample preparation for elemental analysis was performed by wet acid digestion in a closed microwave mineralisation system. The selenium assimilation degree in rye malt was within 10.6 to 12.2%. Accordingly, copper assimilation was 32.8 to 38.0% and zinc 49.3 to 57.0%. Simultaneous presence of selenium/copper and copper/zinc during rye grain soaking promoted the assimilation of each mineral, compared with only one mineral additive.

Open access
Bioactive Compounds in Tomatoes at Different Stages of Maturity

Abstract

Tomato is known as a vegetable with several health benefits due to its high level of bioactive compounds, especially lycopene, phenolics, and vitamin C. The effect of tomato variety and stage of maturity on the bioactive compounds concentration was studied. Ten tomato varieties were grown and collected from a greenhouse at two different stages of ripening. The obtained results showed that there were significant differences in the mean values between analysed parameters according to the stage of ripening and variety. The highest concentration of vitamin C was determined for variety Sakura F1 at maturity stage, and the lowest for variety Sunstreem F1 for unripe fruits. The concentration of phenols and flavonoids increased during tomato ripening and the highest rate was observed for variety Naget F1 (from 7.86 mg·100g−1 to 14.34 mg·100 g−1 (phenols) and flavonoids from 6.09 mg·100 g−1 to 10.03 mg·100 g−1. The concentration of lycopene in the unripe stage was low (mostly about 1 mg·100 g−1) and the most quantitative changes and the highest concentration of lycopene in full maturity stage was determined for variety SV0946TS (27.11 mg·100 g−1) and variety NectarF1 (16.81 mg·100 g−1).

Open access
Characterisation and In Vivo Safety of Canine Adipose-Derived Stem Cells

Abstract

The study characterises canine adipose-derived stem cells (cASCs) in comparison to human ASCs (hASCs) and tests their safety in a canine model after intravenous administration. cASCs from two dogs were cultured under hypoxic conditions in a medium supplemented with autologous serum. They were plastic adherent, spindle-shaped cells that expressed CD73, CD90, and CD44 but lacked CD45, CD14, HLA-DR, and CD34. cASCs differentiated toward adipogenic, osteogenic, and chondrogenic lineages, although adipogenic differentiation capacity was low. Blast transformation reaction demonstrated that these cells significantly suppress T-cell proliferation, and this ability is dose-dependent. Intravenous administration of a cell freezing medium, therapeutic dose of cASCs (2 × 106 live cells/kg), and five times higher dose of cASCs showed no significant side effects in two dogs. Microscopic tissue lesions were limited to only mild, non-specific changes. There were no signs of malignancy. The results of the study indicate that cASCs are similar to hASCs and are safe for therapeutic applications in a canine model. The proposed methodology for ASC preparation on a non-routine basis, which includes individually optimised cell culture conditions and offers risk-adapted treatment, could be used for future personalised off-the-shelf therapies, for example, in myocardial infarction or stroke.

Open access
Comparative Study of Dark Beer Before and After Freeze Drying Rehydration Cycle

Abstract

The aim of the study was to compare dark beer before and after a freeze drying rehydration cycle. The pH, colour, and concentrations of extract, organic acids, and phenolic compounds were determined. Dark beer before and after freeze drying was analysed using standard brewing analysis methods of the Mitteleuropäische Brautechnische Analysenkommision (MEBAK) and two types of chromatography: high-performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC/MS). Increase of pH was not observed in dark beer after freeze drying. Dissolved powdered beer in deionised water was clear, dark brown, without sediments, and reproduced the original commercially available dark beer, with original extract substance content 8.88%. Concentrations of the following organic acids were determined: oxalic, tartaric, quinic, malic, ascorbic, lactic, acetic, citric, fumaric, and succinic. Volatile compounds by GC/MS analysis were isolated from dark beer before and after freeze drying.

Open access
Crispbreads with Carrot and Pumpkin Processing by-Products

Abstract

The results of carrot and pumpkin processing are by-products like bark and peel. Therefore, food processing waste has the potential to be converted into useful products and utilised as a source of functional compounds for consumers. Carrot and pumpkin by-products contain carotenoids, precursors of vitamin A, and dietary fibre. The consumption of these is linked to decreased incidence of cardiovascular disease, diverticulosis, and colon cancer. The aim of the study was to investigate means to increase nutritional compound content in extruded crispbread with carrot and pumpkin processing by-products. Samples were prepared from wheat flour 70%, rice flour 24%, and wheat bran 4% as control with addition of 5%, 10%, 15%, 20 % dried and grinded carrot and pumpkin by-products. Products were extruded in GÖTTFERT 1 screw Extrusiometer L series. The temperatures for extrusion zones were set at 78/83/98 °C. Total carotenoid content of the new products was determined by spectrophotometry. Total dietary fibre content was determined with Enzymatic-Gravimetric Method, AOAC 985.29. The total carotenoid content increased significantly with addition of pumpkin and carrot by-products in crispbread samples. The increase of dietary fibre content was from 9.3 mg·100 g−1 in wheat crispbread to 15.89–16.08 mg·100 g−1 in products with added carrot and pumpkin by-products.

Open access
Determination of Biological and Sensory Profiles of Biscuits Enriched with Tea (Camellia sinensis L.) Powder

Abstract

The aim of this work was to characterise the biological and sensory profile of biscuits enriched with green (1 and 3%) and black tea (1 and 3%) powders. Biscuits without the addition of tea were used as a control. Phenolic concentration, flavonoid concentration, and antioxidant activity were determined spectrophotometrically. Amino acid composition was determined using automatic amino acid analyser AAA 400 and crude fibre content using an Ancom analyser. Sensory profiles were evaluated by comparison of enriched and control biscuit samples. The enriched biscuits showed higher phenolic and flavonoid concentration and antioxidant activity estimated by DPPH and phospholybdenum method in comparison with levels in the control group. The best results for antioxidant activity estimated by DPPH and phosphomolybdenum methods were achieved in biscuits enriched with black tea powder (3%): 2.25 and of 32.64 mg TEAC·g−1, respectively. Total phenolic concentration was 1.16 mg GAE·g−1, and total flavonoid concentration was 0.13 mg QE·g−1. These biscuits had higher concentration of crude fibre in comparison with the control group and the highest concentration (0.64%) was found in biscuits with addition of 3% green tea powder. The amino acid composition in samples, including in the control sample was balanced, with slightly higher concentration of threonine, serine, and methionine in enriched samples, but this parameter was not statistically significant. Biscuits enriched with green and black tea had higher sensory scores for taste, smell and aftertaste.

Open access