Search results for "General interest"
showing 10 items of 107 documents
Dynamics and Impacting Factors of Ice Regimes in Latvia Inland and Coastal Waters
2016
Abstract The sea ice regime is considered to be a sensitive indicator of climate change. This study investigates long-term changes in the ice regimes of the Gulf of Riga along the coast of Latvia in comparison with those of inland waters. The ice regime of the studied region indicates the impact of climate change related to increasing air and sea water temperatures. Ice cover duration on both the sea and inland waters has decreased during recent decades. In addition, long-term records on ice break in the studied region exhibit a pattern of periodic changes in the intensity of ice regime, while trends of the sea ice regime are not consistent between periods of time. Alternating mild and seve…
Introduction and Breeding of Rhododendrons in Latvia
2017
Abstract Rhododendrons are relatively new beautiful ornamental plants in Latvia forming an essential part of public and private gardens, although they were introduced in Latvian territory already during the first half of 19th century. Rhododendrons deserve their immense popularity due to the diversity of their habitat, size and type of blossoms and leaves and their flowering season. There are about 1000 rhododendron species in the wild up to now whereas breeders in various countries have created more than 30 000 cultivars. Intensive rhododendrons introduction and acclimatization in Latvia started in 1957 when Rihards Kondratovičs, at the time director of the Botanical Garden, University of …
Light Conditions Affect NaCl-Induced Physiological Responses in a Clonal Plant Species Hydrocotyle vulgaris
2020
Abstract In order to understand if differences in light conditions can affect responses of a clonal plant species to increased soil salinity, the long-term effect of two substrate concentrations of NaCl on leaf growth, clonal plasticity and oxidative enzyme (peroxidase and polyphenol oxidase) activity in Hydrocotyle vulgaris L. plants grown at low, moderate and high light conditions was studied. H. vulgaris appeared to be a shade-tolerant species, since both leaf blade and petiole growth was inhibited at low light intensity. At low light intensity, H. vulgaris plants represented characteristics of halophytes with significant stimulation of leaf blade and petiole growth by NaCl, especially a…
Genetic Structure of the Limecola Balthica Population in the Gulf of Riga, Baltic Sea
2020
Abstract Samples of Limecola balthica with normal and deformed shells were collected from ten sites throughout the Gulf of Riga. Genetic diversity was evaluated by the retrotransposon-based iPBS method. Samples had close mutual genetic distances, which showed that all of them belong to one wider population of the Gulf of Rīga. No direct relationship between the activity of retrotransposons and deformation of shells was found.
Physiological Responses of Wetland Species Rumex Hydrolapathum to Increased Concentration of Biogenous Heavy Metals Zn and Mn in Substrate
2020
Abstract The aim of the present study was to determine if individuals of Rumex hydrolapathum Huds native to saline wetlands are able to tolerate high concentration of biogenous heavy metals Zn and Mn in substrate and to accumulate high concentration of these metals in aboveground parts. Plant physiological status was monitored by using non-destructive analysis of chlorophyll and chlorophyll a fluorescence. R. hydrolapathum plants accumulated up to 1840 mg·kg−1 Zn and 6400 mg·kg−1 Mn in older leaves. The usefulness of monitoring changes in chlorophyll concentration and chlorophyll a fluorescence parameters to predict physiological response of R. hydrolapathum plants to excess Zn and Mn was n…
Relationship Between Functional Traits, Functional Types, and Habitat in Boreonemoral Bryophytes
2020
Abstract The aim of the present study was to determine a relationship between physiological traits and functional types of bryophytes from five boreonemoral habitats with a particular emphasis on discriminative ability of these traits. Sampling of 25 species was performed four times during one season. Water content, chlorophyll a fluorescence and photosynthetic pigment concentration were measured in field and water-equilibrated samples. Principal component analysis indicated the existence of an inverse relationship between concentration of pigments and water content. Linear discriminant analysis showed that relatively high mean predicted posterior probabilities of correct classification of …
Effect of Vermicompost Extract and Vermicompost-Derived Humic Acids on Seed Germination and Seedling Growth of Hemp
2017
Abstract Hemp (Cannabis sativa L.) cultivars grown for industrial use have recently emerged as a sustainable alternative source of industrial fibre and bioenergy, and is a highly valuable food and animal feed resource. The aim of the present study was to evaluate the effect of vermicompost extract, vermicompost mineral nutrient composition, and vermicompost-derived humic and fulvic acids on seed germination and growth of hemp seedlings. In general, separate application of all vermicompost components stimulated seed germination and hypocotyl and radicle growth, as well as increased chlorophyll concentration in cotyledons. Effective concentration range and the degree of stimulation varied sig…
Conceptual Overview of an Anthropocentric Training Station for Manual Operations in Production
2019
Abstract The paper presents a conceptual overview of a human-centred training station for manual operations (ATASMO). It identifies the main users of the system but also the long-tern targeted features of ATASMO. Moreover, the current implementation, its limitations and future work on ATASMO is synthetically presented.
Improving the Effectiveness in Research and Developments Department from Automotive Industry
2019
Abstract The scope of this paper is to propose a solution for decreasing the rework that has to be made inside a team, in a new offshore Research and Development department, mainly because of assumptions and lack of experience. This is based on learning and applying the lessons learned. First, it will be presented an order assignment in an offshore branch in the field of automotive software companies. From the concept, further on, the usual process that takes place is presented and the potential flaws are analyzed. The major problems identified are random allocation of the orders and assumptions that are made in the branch offices. After inspecting the steps of the process, a model of proce…
Palliative Endoscopic Esophageal Stenting for Malignant Esophageal Tumour Complications: A Clinical Case and Single Centre Experience in Latvia
2020
Abstract Esophageal stenting is used in patients with malignant esophageal tumours to reduce dysphagia and inanition. The objective of this study was to analyse the main reasons for esophageal stenting in Rīga East Clinical University Hospital (RECUH) and their association with dysphagia and mortality. A cross-sectional study of all patients hospitalised in RECUH who received esophageal self-expanding metal stents (SEMS) from October 2013 to December 2015 was performed. A total of 29 patients, 24 (82.8%) male and 5 (17.2%) female, with mean age 63.7 ± 11.3 years, underwent the procedure. The most common indications for stenting were tumour-related stenosis (52.9%) and fistulae (17.6%). Mean…