99 research outputs found
Ecological training set of freshwater ostracods in Canadian and Siberian periglacial regions
Quantified palaeoenvironmental reconstructions are essential to estimate the impact of future climate changes on ecosystems. Based on faunistic data from regional multireference sites and limnological surveys, ecological training sets can be used to build transfer functions to infer major environmental variables (e.g., temperature, conductivity, DOC, and pH value) in a greater study area. The remote Polar regions are affected by bigger amplitude of climate change than elsewhere on this planet and make ecological training sets in this region so important.Freshwater ostracods from Arctic nvironments have the potential to hindcast glacial/interglacial and stadial/interstadial alaeoclimate variations. Various methods can be applied to fossil assemblages such as indicator species approach, modern analoguetechniques and transfer functions based on ecological training sets.The present training set combines data from the Canadian (Southampton Island at 63-65°N; Bylot Island at 72-73°N) and the Siberian (Central Yakutia at 61°N; Northeast Yakutia at 66°N; Lena Delta at 72°N) high latitudes with reference areas in Central Canada (Whapmagoostui-Kuujjuarapik at 50-55°N; Churchill at 58°N). A total of 75 localities were sampled during field work in 2005-2007. In general, life conditions for aquatic organisms such as freshwater ostracods in the high latitude regions are extremeand limited by short open water periods during the summer and strong variations of water temperatures in the shallow waters. The host waters in periglacial regions are affected by permafrost and thermokarst processes and mostly represented as polygonal ponds or thermokarst lakes in different stages of their development. Generally, the waters in our study area have a mean pH-value of 7.6, ranging from pH 6.0 to pH 9.2. They are characterised by low ionic contents (Condmean = 231μS*cm−1), but the training set includes sites between 4.4 μS*cm−1 (e.g., on Bylot Island) and 1433 μS*cm−1 (e.g., in Central Yakutia). A principal component analysis reveals that 88.5 % of the variability of the environmental data is explained by the first ordination axis corresponding to pH, conductivity and major cations (i.e., Ca, Na). The studied ostracod assemblages are characterised by dominance of single species indifferent regions, e.g., Cyclocypris ovum on Bylot Island, Fabaeformiscandona pedata in the Lena Delta. In general, the species diversity in northern latitudes is relatively low due to the harsh environmental conditions affecting ostracods ontogeny. In total, 16 species were used in the presented data set.Further implementation of the ecological training set into transfer functions for one or more variables are prosperous
Ostracods as ecological and isotopic indicators of lake water salinity changes: the Lake Van example
Ostracods are common lacustrine calcitic microfossils. Their faunal
assemblage and morphological characteristics are important ecological
proxies, and their valves are archives of geochemical information related to
palaeoclimatic and palaeohydrological changes. In an attempt to assess
ostracod ecology (taxonomic diversity and valve morphology) combined with
valve geochemistry (δ18O and δ13C) as
palaeosalinity indicators, we analysed sedimentary material from the
International Continental Scientific Drilling Program (ICDP) Ahlat Ridge site
from a terminal and alkaline lake, Lake Van (Turkey), covering the last
150 kyr. Despite a low species diversity, the ostracod faunal assemblage
reacted sensitively to changes in the concentration of total dissolved salts
in their aquatic environment. Limnocythere inopinata is present
throughout the studied interval, while Limnocythere sp. A is
restricted to the Last Glacial period and related to increased lake water
salinity and alkalinity. The presence of species belonging to the genus
Candona is limited to periods of lower salinity. Valves of
Limnocytherinae species (incl. L. inopinata) display nodes (hollow
protrusions) during intervals of increased salinity. Both the number of noded
valves and the number of nodes per valve appear to increase with rising
salinity, suggesting that node formation is related to hydrological changes
(salinity and/or alkalinity). In contrast to Lake Van's bulk
δ18O record, the δ18O values of ostracod valves
do record relative changes of the lake volume, with lower values during high
lake level periods. The δ13C values of different species
reflect ostracod habitat preferences (i.e. infaunal vs. epifaunal) but are
less sensitive to hydrological changes. However, combined with other proxies,
decreasing Holocene δ13C values may indicate a freshening of
the lake water compared to the low lake level during the Last Glacial period.
The Lake Van example underscores the significance and value of coupling
ostracod ecology and valve geochemistry in palaeoenvironmental studies of
endorheic lake basins.</p
A new Middle Pleistocene interglacial sequence from Måløv, Sjælland, Denmark
Interglacial deposits in Denmark have traditionally been referred to the Cromerian complex (Hareskovian), Holsteinian or Eemian stages. However, based on studies of sediment cores from the deep sea many more than three Quaternary interglacials have been documented, and in other parts of north-western Europe it is becoming increasingly clear that the on-shore Quaternary sequences are much more complex than previously believed. Interglacial deposits are characterised by plant and animal remains indicating longer periods with climatic conditions similar to or warmer than today, whereas interstadial deposits were formed during shorter time spans and usually contain remains of relatively cold-adapted, arctic or sub-arctic species. Interglacial and interstadial deposits can be dated more or less precisely, and thus provide information about the relative age of glacial deposits
СУТНІСТЬ ТА ПРОЦЕС ФОРМУВАННЯ ІНТЕГРОВАНИХ МАРКЕТИНГОВИХ КОМУНІКАЦІЙ
Проаналізовано сутність, характеристика, принципи інтегрованих комунікацій та розкрито особливості процесу їх формування на підприємствах України.; The essence, characteristics and principles of integrated communications are analyzed. The peculiarities of the process of their formation on the enterprises are discovered
Spatial distribution and consequences of contaminants in harbour sediments:A case study from Richards Bay Harbour, South Africa
Characterizing ecoregions in Argentinian patagonia using extant continental ostracods
In order to characterize Patagonian (Argentina) ecoregions using non-marine ostracods, their associations in 69 environments were assessed. Twenty eight taxa were recorded, including 12 endemic of the Neotropical region. Our results indicate that Patagonian ostracods are mainly influenced by electrical conductivity (EC), altitude, pH, and temperature; and shows a correlation with Argentinian ecoregions. Assemblage I is composed of sites located at high altitude in the Andean Patagonian forest ecoregion. Host waters have low temperature, EC and pH, and support as representative species Cypris pubera, Eucypris virens, Bradleystrandesia fuscata, Tonacypris lutaria and Amphicypris nobilis. Assemblage II, related to mid-altitude environments in the Patagonian Steppe ecoregion, thrived in waters with moderate to high EC, and alkaline pH values. Dominant species includes Limnocythere rionegroensis, L. patagonica, E. virgata, Riocypris whatleyi, Riocypris sarsi, Newnhamia patagonica, Kapcypridopsis megapodus, Ilyocypris ramirezi and Penthesinelula incae. Assemblage III inhabited environments within Monte and Espinal ecoregions, situated in the eastern part of the study area at low altitude, EC moderate and temperate waters, supporting Heterocypris hyalinus, Amphicypris argentinensis, Sarscypridopsis aculeata, Cypridopsis vidua, Herpetocypris intermedia and Chlamidotheca incisa. Our results indicates that Argentinian Patagonia hosts a diverse ostracod fauna and highlights their capacity as proxies in ecological and palaeoenvironmental studies.Fil: Cusminsky, Gabriela Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Coviaga, Corina Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Ramos, Lorena Yésica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Perez, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Schwalb, Antje. Technische Universität Braunschweig; AlemaniaFil: Markgraf, Vera. University of Colorado; Estados UnidosFil: Ariztegui, Daniel. Universidad de Ginebra; SuizaFil: Viehberg, Finn. Universitat zu Köln; Alemania. Universität Greifswald; AlemaniaFil: Alperin, Marta Ines. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin
Recurrent explosive eruptions from a high risk Main Ethiopian Rift volcano throughout the Holocene
Corbetti caldera is the southernmost large volcanic system in Ethiopia, and has been
categorized at the highest level of uncertainty in terms of hazard and risk. Until now, the number
and frequency of past explosive eruptions at Corbetti has been unknown, due to limited studies
of frequently incomplete and patchy outcrop sequences. Here we use volcanic ash layers
preserved in sediments from three Main Ethiopian Rift lakes to provide the first detailed record
of volcanism for the Corbetti caldera. We show that lake sediments yield more comprehensive,
stratigraphically-resolved dossiers of long-term volcanism than often available in outcrop. Our
eruptive history for Corbetti spans the last 10 k.y. and reveals eruptions at an average return
period of ~900 years. The threat posed by Corbetti has, until now, been underestimated. Future
explosive eruptions, similar to those of the past 10 k.y. would blanket nearby Awassa and
Shashamene, currently home to ~260,000 people, with pumice fall deposits and would have
significant societal impacts. A lake sediment tephrostratigraphic approach shows significant
potential for application throughout the East African Rift system, and will be essential to better
understanding volcanic hazards in this rapidly developing region.</p
Distribution and ecology of freshwater ostracods from northern patagonia: An approach
There are only a few studies about the ostracod faunal assemblages and their environmental requirements from Patagonia (e.g. CUSMINSKY et al., 2011; RAMÓN MERCAU et al., 2012). Here we present the results of a survey of thirteen water bodies (streams, springs, temporary habitats) in Northern Patagonia (39° 52’ – 41°50’ S; 70°36’ – 71°27’ W) and their comparison with those of previous studies in the earstern Patagonia. The goal of this research is to enhance our understanding of the regional Patagonian ostracoda fauna and evaluate the relationship between ostracod species and physical and chemical (depth, temperature, pH, conductivity, dissolved oxygen concentration, seston and main ions) parameters of host waters along a W-E precipitation gradient (ranging from 1200 to 160mm/annually). To date, seven species were identified: Amphicypris nobilis Sars 1901, Bradleystrandesia fuscata (Jurine, 1820), Cypridopsis vidua (O. F. Müller, 1776), Cypris pubera O. F. Müller 1776, Eucypris virens (Jurine, 1820), Heterocypris incongruens (Ramdohr, 1808) and Tonnacypris lutaria (Koch, 1838). The more frequent species were T. lutaria and E. virens, while A. nobilis and C. vidua were only found in one site. Males of A. nobilis were found while the other species were represented only by females. The environment of this fauna is related to low conductivity and salinity in the water. Conversely, previous studies in the easternmost area of Patagonia have shown different fauna such us Penthesinelula incae (Delachaux, 1928), Potamocypris smaradigma (Vávra, 1891), Ilyocypris ramirezi Cusminsky and Whatley, 1996, Limnocythere patagonica Cusminsky and Whatley, 1996, Eucypris fontana (Graf, 1931), Kapcypridopsis megapodus Cusminsky et al. 2005 and Limnocythere rionegroensis, Cusminsky and Whatley, 1996 living in comparatively higher conductivity (CUSMINSKY et al., 2011). The latter suggest that the decreasing precipitation trend towards eastern Patagonia is reflected in the distribution of different ostracod fauna association. On the other hand, new distributions of cosmopolitan species are present, spreading out their geographical distribution to the Neotropical region (MARTENS et al., 2008). Some of the species such us C. pubera, E. virens and B. fuscata have been also described in the Neartic region, suggesting that birds could be responsible to their dispersion. However, the mode of dispersion of T. lutaria in this region is still an open question.Fil: Coviaga, Corina Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Cusminsky, Gabriela Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Perez, Alejandra Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Diaz, Analia Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Schwalb, Antje. Technische Universitat Carolo Wilhelmina Zu Braunschweig. Iinstitut fur Geosysteme und Bioindikation.; AlemaniaFil: Alperin, Marta Ines. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Estadística; ArgentinaFil: Viehberg, Finn. University of Cologne.Institute of Geology and Mineralogy; AlemaniaFil: Whatley, Robin. University Aberystwyth.Institute of Earth Studies.Department of Geology; Reino UnidoFil: Ariztegui, Daniel. University of Geneva.Department of Earth Sciences; SuizaFil: Markgraf, Vera. University of Colorado; Estados Unidos. Northern Arizona University.; Estados Unido
Совершенствование системы стимулирования персонала
Объект исследования - ООО "Партнеры-Ноябрьск". Предмет исследования – система стимулирования персонала на предприятии. Цель ВКР ? совершенствование системы стимулирования персонала на предприятии для активизации трудового потенциала на повышение производительности труда работников. В соответствии с поставленной целью решены следующие задачи: осуществлен обзор основных научных подходов к стимулированию трудовой активности сотрудника; проведен анализ процессов стимулирования трудовой активности сотрудника на примере ООО "Партнеры Ноябрьск"; разработаны основные направления совершенствования стимулирования трудовой активности сотрудника предприятия ООО "Партнеры-Ноябрьск".The object of the study - LLC "Partners-Noyabrsk." Subject of research - the system of incentives for staff in the enterprise. The purpose of the WRC is to improve the system of incentives for personnel in the enterprise to enhance the labor potential to increase the productivity of workers. In accordance with the goal, the following tasks have been accomplished: a review of the main scientific approaches to stimulating employee labor activity has been carried out; an analysis of the processes of stimulating employee labor activity was carried out using the example of Partners Noyabrsk LLC; developed the main directions of improving the stimulation of labor activity of the employee of the company Partners-Noyabrsk
Using multiple chronometers to establish a long, directly-dated lacustrine record:Constraining >600,000 years of environmental change at Chew Bahir, Ethiopia
Despite eastern Africa being a key location in the emergence of Homo sapiens and their subsequent dispersal out of Africa, there is a paucity of long, well-dated climate records in the region to contextualize this history. To address this issue, we dated a ∼293 m long composite sediment core from Chew Bahir, south Ethiopia, using three independent chronometers (radiocarbon, 40Ar/39Ar, and optically stimulated luminescence) combined with geochemical correlation to a known-age tephra. The site is located in a climatically sensitive region, and is close to Omo Kibish, the earliest documented Homo sapiens fossil site in eastern Africa, and to the proposed dispersal routes for H. sapiens out of Africa. The 30 ages generated by the various techniques are internally consistent, stratigraphically coherent, and span the full range of the core depth. A Bayesian age-depth model developed using these ages results in a chronology that forms one of the longest independently dated, high-resolution lacustrine sediment records from eastern Africa. The chronology illustrates that any record of environmental change preserved in the composite sediment core from Chew Bahir would span the entire timescale of modern human evolution and dispersal, encompassing the time period of the transition from Acheulean to Middle Stone Age (MSA), and subsequently to Later Stone Age (LSA) technology, making the core well-placed to address questions regarding environmental change and hominin evolutionary adaptation. The benefits to such studies of direct dating and the use of multiple independent chronometers are discussed.
Highlights
• Four independent dating methods applied to ∼293 m lake core from southern Ethiopia.
• Reveals 620 ka high-resolution sedimentary record near key fossil hominin sites.
• Mean accumulation rate of 0.47 mm/a comparable to other African lacustrine sediments.
• Accumulation rate fell to 0.1 mm/a during MIS 2, likely due to reduced sediment supply.
• Use of multiple independent chronometers is a powerful approach in lake settings
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