Search results for "bioma"
showing 10 items of 5541 documents
Możliwości energetycznego wykorzystania biomasy mikroalg
2016
Niniejsze opracowanie przedstawia możliwości zastosowania mikroalg do produkcji biopaliw III generacji - biodiesla, bioetanolu i biowodoru. Opisano parametry - CO2, temperatura, pH, światło i inne - zapewniające optymalne warunki hodowli mikroalg w fotobioreaktorach. Dokonano charakterystyki fotobioreaktorów, pod kątem ich przydatności do hodowli mikroalg na cele energetyczne. Przedstawiono metody termochemicznego i biochemicznego przetwarzania biomasy glonów stosowane do produkcji poszczególnych biopaliw.
Molekulārie mikroRNS faktori hipofīzes adenomas attīstībā
2021
Izmaiņas miRNS ekspresijā ir saistītas ar dažādu audzēju patoģenēzi, tāpēc tās ir iespējams izmantot kā biomarķierus. Lai pētītu, kādas miRNS ir saistītas ar hipofīzes adenomām (HA), darbā ar nākamās paaudzes sekvencēšanu (NGS) tika analizēts miRNS sastāvs 13 HA pacientu audos, kā arī analizēts cirkulējošo miRNS profils plazmā pirms un pēc HA rezekcijas operācijas 13 HA pacientos. Statistiski būtiskas (P < 0,05) miRNS sastāva izmaiņas asins plazmā 24 stundas pēc operācijas noteiktas piecām miRNS (hsa-miR-143-3p; hsa-miR-1290; hsa-miR-223-3p; hsa-miR-12136; hsa-miR-425-5p) un to izmaiņas pēc Log2 fold change bija robežās no 0,55 līdz 2,87. HA pacientu audos tika identificētas 70 statistiski …
Microwave-assisted conversion of novel biomass materials into levulinic acid
2018
Levulinic acid is considered one of the most important platform chemicals. It is currently produced mainly from lignocellulosic biomasses. However, there are also other abundant biomass materials, which could be used as raw materials for levulinic acid production. In this work, levulinic acid was produced from two novel biomasses in the presence of Brønsted (H2SO4) and Lewis acid (CrCl3·6H2O or AlCl3·6H2O) catalysts. The studied materials were carbohydrate-rich potato peel waste and sporocarps of the fungus Cortinarius armillatus. Reaction conditions, i.e., time, temperature, H2SO4, and Lewis acid concentrations, were studied by utilizing full 24-factorial experimental designs. Microwave ir…
Particle chemical properties in the vertical column based on aircraft observations in the vicinity of Cape Verde Islands
2011
During the second Saharan Mineral Dust Experiment (SAMUM-2) field campaign, particles with geometric diameters (d) between ∼0.1 and 25 μm were collected on board of the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR) Falcon aircraft. Size, chemical composition and mixing state of aerosols sampled (spatially and vertically resolved) along the West African coastline and in the Cape Verde Islands region were determined by electron microscopy. A pronounced layer structure of biomass-burning aerosol and desert dust was present for all days during the sampling period from 23 January to 6 February. The aerosol composition of the small particles (d < 0.5 μm) was highly v…
Slāpekļa mēslojuma ietekme uz zemsedzes veģetāciju skujkoku audzēs uz minerālaugsnēm
2019
Mežsaimniecība ir viena no svarīgākajām tautsaimniecības nozarēm Latvijā, tāpēc ir svarīgi veikt pareizu mežu apsaimniekošanu, paaugstinot to ražību tai pat laikā nenodarot būtiskus kaitējumus apkārtējai videi. Maģistra darba mērķis ir pētīt slāpekļa mēslojuma ietekmi uz meža zemsedzes veģetāciju skujkoku audzēs uz minerālaugsnēm Kalsnavas mežu novadā. Darbā aplūkoti dažādi vides piesārņojuma veidi, to izplatība un ietekme uz vides procesiem. Maģistra darba izstrādei, sadarbībā ar LVMI Silava pētniekiem, izraudzīti 4 objekti, kur koku augšanas apstākļu uzlabošanai izmantots slāpekļa mēslojums. Zemsedzes veģetācijas analizēšanai izvēlētas 5 audzes LVMI Silava un LLU valsts zinātniskās izpēte…
Toxicity of biomining effluents to Daphnia magna : Acute toxicity and transcriptomic biomarkers
2018
Increasing metal consumption is driving the introduction of new techniques such as biomining to exploit low grade ores. The biomining impacts notably aquatic ecosystems, yet, the applicability of ecotoxicological tests to study the complex mixture effects of mining waters is insufficiently understood. The aim of the present work was to test if transcriptomic biomarkers are suitable and sensitive for the ecotoxicity assessment of biomining affected waters. The study site had been affected by a multimetal biomine, and the studied water samples formed a concentration gradient of contamination downstream from the biomining site. Cadmium and nickel were used as positive controls in the toxicity …
Greater mitochondrial energy production provides resistance to ocean acidification in "winning" hermatypic corals
2021
Coral communities around the world are projected to be negatively affected by ocean acidification. Not all coral species will respond in the same manner to rising CO2 levels. Evidence from naturally acidified areas such as CO2 seeps have shown that although a few species are resistant to elevated CO2, most lack sufficient resistance resulting in their decline. This has led to the simple grouping of coral species into “winners” and “losers,” but the physiological traits supporting this ecological assessment are yet to be fully understood. Here using CO2 seeps, in two biogeographically distinct regions, we investigated whether physiological traits related to energy production [mitochondrial e…
Sur la piste des matériaux organiques grâce à la spectrométrie de masse
2018
Identifying the organic materials present, establishing their origin and degree of preservation, understanding their manufacturing process and their use, all of which require interdisciplinary studies involving closely specialists in materials and human sciences. In this very specific context, mass spectrometry has become a key tool to improve knowledge of past civilizations but also to better preserve and restore the discrete remains of archaeomaterials. The identification of diagnostic molecular markers of natural substances is now a recognized strategy for characterizing amorphous organic materials (fats, beeswaxes, vegetable substances such as resins and tars). New advances have also ma…
Light on the molecular and cellular mechanisms of bicuspid aortic valve to unveil phenotypic heterogeneity
2019
Research on bicuspid aortic valve disease (BAV) and related complications has grown in an exponential manner in the last decades. However, the current knowledge of the mechanisms underlying the development of this disease is still limited, since all clinical and surgical studies on BAV mainly focused their objects on its major vascular complications, such as ascending aortic aneurysms and dissection. It is now clear that a better understanding of the pivotal molecular and cellular pathophysiological aspects of bicuspid valve aortopathy, including natural history, phenotypic expression, histology, cellular mechanisms and pathways, is critical for improving its clinical management. This chang…
Sediment quality of the ecoregion Engure, Gulf of Riga, assessed by using ecotoxicity tests and biomarker responses
2014
Pētījuma mērķis bija novērtēt Engures ekoreģiona (Rīgas līča rietumu piekrastes) sedimentu kvalitāti, izmantojot sedimentu ekotoksicitātes testus. Lai noteiktu bioloģiskās atbildes reakcijas uz dažāda veida stresoriem, kā testorganismi pielietotas sānpeldes Monoporeia affinis and Pontogammarus robustoides, un izvēlēti biomarķieri (AChE, GST, GR, CAT, MT), kas noteikti gliemenēs Macoma balthica. Engures ekoreģionu varētu uzskatīt par nepiesārņotu rajonu, jo tā sedimentus raksturo salīdzinoši zemas smago metālu koncentrācijas. Engures ekoreģiona sedimentu ekotoksicitātes testu rezultāti neuzrādīja statistiski būtisku (>20% mirstība) toksisko efektu. Testorganismu izdzīvotība bija robežās no 8…