A comparison of different charcoal production technology outputs

Charcoal is a renewable material, with a long history of use as the predecessor of fossil fuels, now beginning to regain its place in the market, as the global society is fighting the Climate change. Charcoal along with bio-oils, and pyrolysis gas or syngas is obtained through thermo-chemical conversion of biomass. There are several different turns the charcoal production development has taken. The oldest charcoal production technologies are the batch-type kilns, they are associated with lower costs, and are widely used in the world, mainly in developing countries. A more recent introduction in charcoal production is the continuous operation retort where the biomass is conveyed through different process stages, heating and drying, carbonization, and cooling. This technology draws up high capital investments, but can reach a high level of automation. Apart from these technologies charcoal can be also obtained as a by-product in liquid and gaseous fuel production via pyrolysis and gasification of biomass. Each of the production methods can yield variant quality charcoal with properties distinguishing different charcoal applications. The charcoal use varies from a high capacity fuel to a sustainable soil amendment, adsorbent, source of carbon in chemical reactions, and many more. In this study an evaluation of the charcoal quality parameters, depending on the applied technology, is carried out. The analysed data includes information retrieved from previous studies, as well as an experimental investigation of real life production facility. 

THE IMPACT OF DIFFERENT CHARACTERISTICS AND MODALITIES OF PHYSICAL ACTIVITY ON HEALTH VARIABLES IN ELDERLY PEOPLE WITH TYPE 2 DIABETES

Type 2 diabetes (T2D) comprises 90% of people with diabetes around the world, and is largely the result of excess body weight and physical inactivity (WHO, 2015). Objective: To evaluate and analyze evidence based research studies exploring the impact of physical activity on health variables in elderly population age 50-70 years with T2D.Data sources: Web of Science, CINAHL, SCOPUS, EMBASE, MEDLINE, PubMed and SPORTdiscus data bases were used for screening and selecting relevant research studies over the period 2005-2015.Study Selections: Randomized controlled trials (RCTs). Population: older adults or elderly with T2D. Intervention: All types of physical activity such as interval walking, aquatics or free living activity were included. Outcomes: glycemic control, lipid profile, insulin sensitivity, BMI, blood pressure and VO₂max. Methodological quality was assessed using the Delphi List.Data Synthesis: While 1773 potentially relevant studies were found and 213 RCTs were relevant to the topic, only 16 studies (patients n= 946) accepted to the review. Results: The circuit resistance training was associated with hemoglobin A1c (HbA1c) decrease (8.0 (.35) to 7.36 (.28)), body mass index (BMI) reduction from 22.0(.8) to 20.9 (.8) and body weight change from 53.3 (1.6) to 51.9 (1.7). Improvement of insulin sensitivity, VO2max and glycemic control were observable in 8 studies including 16-week aerobic exercise training, 16-week interval walking training, and combined aerobic and resistance training. Combination of aerobic and resistance exercises were associated with positive change in plasma fasting glucose and were 6.86 (1.40) and 6.19 (1.47).Conclusions: The most effective and time consuming physical activity is interval walking, circuit training or combination of different intensity and/or physical activity modalities

CONTENT AND COGNITIVE DEPTH IN TEACHING OF SOCIAL AND CIVIC STUDY AREA

Research problem - in Latvia from 2016 started Curriculum Development and Implementation project. For Social and civic study area (SCSA) subject context it means fundamental changes –social constructivist approach in teaching as well as new subjects and study courses were implemented.The research aim is to analyse clarity of the chosen content, cognitive activity (development of deeper thinking) and historical thinking concepts (HTC) in observed lessons (N=16) of SCS area subjects to preliminary define implementation outcomes of educational reform.In this research the authors wish to clarify:RQ1 How do teachers succeed in integrating the offered learning content and opportunities to delve into it in SCSA lessons?RQ 2 How is it possible to determine the extent to which teachers succeed in offering students the opportunity to develop historical thinking abilities in SCSA subjects?The primary method used was lesson study using lesson analysis rubric developed and previously validated by Interdisciplinary Centre for Educational Innovation (University of Latvia). Observed lessons took place in seven schools in different municipalities at the first semester of academic year 2022 - 2023.It was concluded that HTC are partially evident in observed lessons and the cognitive depth differs.

Lapu sūnu, metabolītu sastāvs un vides stresa ietekme

Sūnas ir nozīmīga augu grupa ar plašu izplatību. Sūnu sastāva pētījumi ir kļuvuši aktuāli, ņemot vērā bioloģiski aktīvu savienojumu klātbūtni un augsto izturību pret vides apstākļu mainību. Promocijas darba mērķis ir analizēt sūnu sastāvu, to metabolītus un vides stresa ietekmes uz tiem. Veikta sūnu sekundāro metabolītu ekstrakcijas apstākļu izpēte, kas nodrošina liela skaita vielu identifikāciju. Sūnu lipīdi satur daudzas bioloģiski aktīvas vielas un veikta to aktivitātes izpēte. Sūnu sekundārie metabolīti uzrāda augstu antimikrobiālo aktivitāti un spējas inhibēt vairāku vēža šūnu līniju attīstību un līdz ar to satur perspektīvas vielu grupas izmantošanai biomedicīnā. Vides stresa ietekmes rada būtiskas izmaiņas sūnu sekundāro metabolītu kopā, kā arī ietekmē to metabolismu raksturojošos parametrus, un līdz ar to var tikt izmantoti vides stresa biomarķieru identifikācijai. Atslēgvārdi: sūnaugi, lapu sūnas, metabolītu sastāvs, ķīmiskais sastāvs, vides faktoru ietekmes, lipīdiMosses have worldwide distribution. The interest in moss composition and functions in the environment is growing as the presence of biologically active compounds has been demonstrated and their secondary metabolites can help to understand stress reactions. The aim of the work is to study the composition of mosses, their metabolites and impacts of pollutant stress on it. During the study a methodology for a complex characterization of moss composition was elaborated. Characterization of moss composition can be used to support the taxonomy of mosses. Obtained moss extracts contain high number of different biologically active substances. Moss secondary metabolites demonstrate high antimicrobial activity and ability to inhibit development of cancer cell lines. Environmental stress impacts result in a significant changes of moss secondary metabolite pool as well as parameters, characterising their composition and can support identification of environmental stress biomarkers. Key words: bryophytes, mosses, composition of metabolites, characterization, environmental impacts, lipid

Lapu sūnu, metabolītu sastāvs un vides stresa ietekme

Sūnas ir nozīmīga augu grupa ar plašu izplatību. Sūnu sastāva pētījumi ir kļuvuši aktuāli, ņemot vērā bioloģiski aktīvu savienojumu klātbūtni un augsto izturību pret vides apstākļu mainību. Promocijas darba mērķis ir analizēt sūnu sastāvu, to metabolītus un vides stresa ietekmes uz tiem. Veikta sūnu sekundāro metabolītu ekstrakcijas apstākļu izpēte, kas nodrošina liela skaita vielu identifikāciju. Sūnu lipīdi satur daudzas bioloģiski aktīvas vielas un veikta to aktivitātes izpēte. Sūnu sekundārie metabolīti uzrāda augstu antimikrobiālo aktivitāti un spējas inhibēt vairāku vēža šūnu līniju attīstību un līdz ar to satur perspektīvas vielu grupas izmantošanai biomedicīnā. Vides stresa ietekmes rada būtiskas izmaiņas sūnu sekundāro metabolītu kopā, kā arī ietekmē to metabolismu raksturojošos parametrus, un līdz ar to var tikt izmantoti vides stresa biomarķieru identifikācijai. Atslēgvārdi: sūnaugi, lapu sūnas, metabolītu sastāvs, ķīmiskais sastāvs, vides faktoru ietekmes, lipīdiMosses have worldwide distribution. The interest in moss composition and functions in the environment is growing as the presence of biologically active compounds has been demonstrated and their secondary metabolites can help to understand stress reactions. The aim of the work is to study the composition of mosses, their metabolites and impacts of pollutant stress on it. During the study a methodology for a complex characterization of moss composition was elaborated. Characterization of moss composition can be used to support the taxonomy of mosses. Obtained moss extracts contain high number of different biologically active substances. Moss secondary metabolites demonstrate high antimicrobial activity and ability to inhibit development of cancer cell lines. Environmental stress impacts result in a significant changes of moss secondary metabolite pool as well as parameters, characterising their composition and can support identification of environmental stress biomarkers. Key words: bryophytes, mosses, composition of metabolites, characterization, environmental impacts, lipid

ENDOPOLYPLOIDY OF ENDANGERED PLANT SPECIES LIGULARIA SIBIRICA IN DIFFERENT ENVIRONMENTS

The goal of this study was to detect endopolyploidy of Ligularia sibirica from populations existed in different ecological conditions. This is important step to elaborate the appropriate protection measures of rare and endangered species, which should be based on understanding of ongoing processes in populations. From this point of view the knowledge of genetic diversity, including endopolyploidy level between and within populations, is crucial. L. sibirica is endangered and protected plant species in Latvia which is included in the protected plants list of EU Habitat directive 92/43/EEK Annexes 2 and 4. Perennial herbaceous plant L. sibirica is one of two species of genus Ligularia in Europe. According to the previous data, this species has been disappeared from all previously known locations in Latvia. However, some new locations were found in central part of the country recently. Determination of edopolyploidy level of L. sibirica was performed by the BD FACSJazz® cell sorter (BD Biosciences, USA) with flow cytometer function. In young leafs nine relative fluorescence DNA peaks from 2C up to 64 C were detected. The most common was 2C peak presented in 93% and 63% of samples from Zušu-Staiņu sulphur spring and Krustkalni Nature reserve populations respectively

ECTOMYCORRHIZAS OF NORWAY SPRUCE (PICEA ABIES (L.) KARST.) IN MANAGED FOREST STANDS OF LATVIA

Elektroniskā versija nesatur pielikumusDisertācijā apkopoti sešu pētījumu rezultāti par parastās egles stādmateriāla mikorizāciju un ektomikorizas (ECM) sēnēm audzēs, kurās veikta saimnieciskā darbība. Galvenās pētījuma metodes ir īssakņu morfotipēšana un sēņu sugu identificēšana ar molekulārām metodēm. Kopumā iegūtas 148 sēņu sugu sekvences. Jaunos stādījumos dominēja ECM sēnes Thelephora terrestris, Amphinema byssoides un Wilcoxina spp., savukārt analizētajās pieaugušās audzēs ECM pamatā veidoja Tylospora, Amphinema, Lactarius un Tomentella ģints sugas. Vairākas ECM sēņu sugas Latvijā konstatētas pirmo reizi. Īssakņu morfoloģiskie parametri un mikorizācijas rādītāji ir saistīti ar egļu veselības stāvokli un var tikt izmantoti kā koku vitalitātes rādītāji. Atšķirības ECM sugu sastopamības ziņā daļēji skaidrojamas arī ar augsnes faktoriem. Jaunos egļu stādījumos stādmateriāla izcelsme, audzēšanas tehnoloģija un stādvietu sagatavošanas veids ietekmē stādu mikorizāciju un augšanas gaitu. Atslēgas vārdi: parastā egle, ektomikorizas sēnes, īssaknes, stādmateriāls, kūdras augsnesEctomycorrhizas of Norway spruce (Picea abies (L.) H. Karst. in managed forest stands of Latvia This thesis assembles six studies on ectomycorrhizal fungi (ECMf) of Norway spruce in mature managed forest stands or young plantings. The main methods used were fine root morphotyping and sequencing of the fungal ITS region. In total, 148 fungal species were identified. In young tree plantings ECMf species Thelephora terrestris, Amphinema byssoides and Wilcoxina species were the main root symbionts observed. In contrast, in mature stands analysed dominant ECMf were species from genera Tylospora, Amphinema, Lactarius and Tomentella. Several ECM species were detected for the first time in Latvia. Fine root morphological parameters and mycorrhization can be related with health status of Norway spruce. Some observed differences in ECMf species abundance could be attributed to soil conditions. Provenience of spruce seedlings, their cultivation system and site preparation method were suggested to have impact on seedling mycorrhization and early growth. Key words: Norway spruce; ectomycorrhizal fungi; fine roots; seedlings; organic soi

Extraction of biologically active components from freshwater sapropel

Publisher Copyright: © 2019 Aneka Klavina, Agris Auce, Ivars Vanadzins, Alise Silova, Linda Dobkevica. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.Sapropel has been used for different purposes-in agriculture as fertilizer, in construction as building material, in cosmetic products, in balneology also in medicine and pharmaceuticals as bioactive component. Previously sapropel has been commonly used in raw form and there is no general accepted method or standard method for obtaining sapropel extract. However, most extraction methods follow the same path. Currently, there are few extraction methods using several extractants for obtaining bioactive components from raw sapropel. The most commonly used extractant is alkaline solution. When sapropel is subjected to alkaline environment, the humic and fulvic acids, together with some lipids, vitamins and sugar, present in the raw sapropel become soluble, however other organic and mineral content present in the sapropel remain solid. Alkaline extraction is followed by filtration and water present in the aqueous mixture is evaporated off. Latvian freshwater sapropel can be used as raw material for obtaining sapropel extract and use it as remedy. But the main question for sapropel usage in medicine, balneology and pharmacy is to develop quality criteria for raw sapropel and its extracts. The quality criteria should include minimum requirements for biologically active substance concentration, pH values, antioxidants as well as physical characteristics. In future studies the differences in extract characteristics of the various deposit sites, as well as the stability of the extracts under different storage conditions should be defined; also, there is need for a common approach to develop method of extraction process for active substances from sapropel and analysis procedures of its extract.publishersversionPeer reviewe

The Influence of the Degree of Forest Management on Methylmercury and the Composition of Microbial Communities in the Sediments of Boreal Drainage Ditches

Funding: This work was supported by the Latvian Council of Science project no. lzp-2018/1-0434 “Interaction of microbial diversity with methane turnover and mercury methylation in organic soils”.Peer reviewedPublisher PD