Search results for " biota"

Ģeogrāfija. Ģeoloģija. Vides zinātne: referātu tēzes

2008

A century of research on micro-organisms from the inland waters of the largest mediterranean island

2022

The first studies on the micro-organisms inhabiting Sicilian inland waters date back to the middle of the XIX century. However, these were based on single samples and mainly addressed at compiling faunistic and floristic inventories. It was in the first decades of the XX century that the first methodical studies were performed, which focussed on assessing microbial diversity in saline and hypersaline inland waters. Studies on plankton dynamics in ponds and reservoirs of the island started at the beginning of the 1980s and, since the end of the 1990s, temporary waters have also been intensively sampled, especially as regards phytoplankton and micro-crustaceans. These intensified sampling eff…

Trace elements and PAHs in surface sediments and biota from a contamination hot spot (Augusta Bay, Italy): potential export to the adjoining coastal …

2013

Morphogenetic characteristics of chernozem leached in mining enterprises pollution conditions

2019

The article presents the results of comparative studies on the uncontaminated (virgin) leached chernozem soil in terms of heavy metal contamination due to zinc plant operations. Study object location is given. The territory under the influence of plant emissions is devoid of vegetation. Everywhere on the soil surface there are manifestations of deep erosion processes and continuous erosion of the topsoil. Soil cuts with morphogenetic descriptions, physical, physico-chemical and biological characteristics of the soil were laid at the objects. The soil cover under the influence of pollution has undergone degradation and led to transformational processes of particle size distribution, humus co…

Zemes un vides zinātnes (Latvijas Universitātes Raksti; 783. sēj.)

2012

Šis LU Rakstu speciālais sējums satur rakstus, kas balstās uz dažiem 8. Baltijas stratigrāfijas konferences sniegtiem ziņojumiem un aptver galvenokārt paleontoloģijas un stratigrāfijas tēmas, kā arī lietišķās ģeoloģijas aspektus. Daži no ziņojumiem jau ir publicēti vai tuvākā nākotnē tiks iespiesti arī citos zinātniskos žurnālos. The current special volume of the Acta Universitatis Latviensis comprises the papers submitted by participants of the Eighth Baltic Stratigraphical Conference (8 th BSC) held in Riga, Latvia, on 28 August – 2 September 2011.

Animal rennets as sources of dairy lactic acid bacteria

2014

ABSTRACT The microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB), Streptococcus thermophilus and some lactobacilli, mainly Lactobacillus crispatus and Lactobacillus reuteri , were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH …

Middle Triassic conodont apparatus architecture revealed by synchrotron X-ray microtomography

2018

Abstract The composition of conodont apparatuses is crucial for understanding the feeding mechanisms of these early vertebrates. However, the multielement apparatus reconstructions of most species remain equivocal because they have been inferred from loose element collections, guided by knowledge from rare articulated ‘bedding plane assemblages’ and fused clusters, often from distantly related taxa. Even these natural assemblages can be difficult to interpret because the component elements can be closely juxtaposed or embedded in matrix, making it hard to discern the morphology of each element and their relative positions within the architecture of the feeding apparatus. Here we report five…

Impact of deoxynivalenol on soil microflora and fauna

2012

F. graminearum is an important pathogen that causes head blight of cereal crops as wheat and maize. It also produces the mycotoxins (as Deoxynivalenol=DON) which are toxic to the human and animals. During the off season the pathogen survives in the soil, on weeds and in crop residues. A 24 weeks study was conducted in controlled conditions (microcosms of natural soil, 17 °C, 80% WHC) to test whether the presence of DON in the wheat crop residues gives competitive advantage to F. graminearum over the other soil microflora and fauna to survive and develop a primary inoculum during the decomposition process. This study was carried out in the presence of the whole soil biota (i.e. fungi, bacter…

Insular endemism in the Mediterranean vascular flora: the case of the Aeolian Islands (Sicily, Italy)

2012

The present paper briefly provides the state of the art of the knowledge on vascular plant endemism in the oceanic (“thalassogenous”) Aeolian Archipelago (Sicily). Preliminary analysis of distribution areas and review of recent literature on biosystematics of endemic species revealed that: (a) Aeolian strictly endemic taxa are just 6, i.e. about the 0.7 % of the local vascular flora; among them, just 4 can be considered (with doubt) derived from in situ evolution. (b) The other 18 endemics are taxa occurring in wider areas, so they cannot be generally considered “locally evolved” but relicts. This preliminary analysis confirms that not only continental (“chersogenous”) but all Mediterranean…

Soil forming factors

2007

The Russian geologist Vasily Dokuchaev (1846–1903), considered the father of soil science, was the first to identify and discuss, at the end of 19th century, what we know today as the “factors of soil formation”. He introduced the idea that soil is not something inert and stable, but it develops and evolves under the influence of climatic agents and vegetation that operate over time on a given geological substrate