Sample records for kattai alvar kangur
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Alvar soils and ecology in the boreal forest and taiga regions of Canada.
NASA Astrophysics Data System (ADS)
Ford, D.
2012-04-01
Alvars have been defined as "...a biological association based on a limestone plain with thin or no soil and, as a result, sparse vegetation. Trees and bushes are stunted or absent ... may include prairie spp." (Wikipedia). They were first described in southern Sweden, Estonia, the karst pavements of Yorkshire (UK) and the Burren (Eire). In North America alvars have been recognised and reported only in the Mixed Forest (deciduous/coniferous) Zone around the Great Lakes. An essential feature of the hydrologic controls on vegetation growth on natural alvars is that these terrains were glaciated in the last (Wisconsinan/Würm) ice age: the upper beds of any pre-existing epikarst were stripped away by glacier scour and there has been insufficient time for post-glacial epikarst to achieve the depths and densities required to support the deep rooting needed for mature forest cover. However, in the sites noted above, the alvars have been created, at least in part, by deforestation, overgrazing, burning to create browse, etc. and thus should not be considered wholly natural phenomena. There are extensive natural alvars in the Boreal Forest and Taiga ecozones in Canada. Their nature and variety will be illustrated with examples from cold temperate maritime climate settings in northern Newfoundland and the Gulf of St Lawrence and cold temperate continental to sub-arctic climates in northern Manitoba and the Northwest Territories.
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ERIC Educational Resources Information Center
2001
In the year 2000, Brazil celebrated the 500th anniversary of its discovery by the Portuguese navigator, Pedro Alvares Cabral, and subsequent settlement by the Portuguese and African, Western, and Asian immigrants. The seminar commemorating these events was designed for U.S. secondary and post-secondary teachers and curriculum specialists of the…
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Life-history variation in Crepis tectorum (Asteraceae).
Andersson, Stefan
1989-09-01
Populations of the monocarpic plant Crepis tectorum were grown in a series of uniform environments to test the hypothesis that weedy populations are more r-selected than populations from a more natural habitat. Weedy populations exhibited a combination of r- and K-selected traits. The relatively rapid growth, the potential for a summer annual habit, and the relatively high fecundity that characterized at least one of the two weed populations studied were considered as r-selected traits favored in habitats of unpredictable duration. However, high levels of competition from other weedy species or from the crop in arable fields may explain at least some presumably K-selected traits observed in the weedy populations, e.g. relatively large seeds and late flowering in the summer. Results indicated that stress due to abiotic factors (strong winds, desiccation and nutrient deficiency) has been a more important selective factor than r- or K-selection, in non-weedy populations from calcareous grasslands ("alvars") on the Baltic islands.
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[Auditory function in children with Brachmann-de Lange syndrom].
Kozłowski, Jacek; Wierzba, Jolanta; Narozny, Waldemar; Balcerska, Anna; Stankiewicz, Czesław; Kuczkowski, Jerzy
2006-01-01
The aim of the research work is the evaluation of auditory function in children with rare, genetically determined Brachmann-de Lange syndrome. Test material came from 18 children (7 girls and 11 boys) between 11 months and 18 years of age with Brachmann-de Lange syndrome who have been diagnosed and treated at ENT Department and Department of Paediatrics, Haematology, Oncology and Endocrinology Medical University of Gdansk with support of Cornelia de Lange Association - Poland. In all children examinations of brainstem auditory evoked potential have been carried out as well as tympanometric examination in case of finding hearing loss. All these examinations were carried out in ENT Department of Medical University of Gdansk, using Racia-Alvar Centor C apparatus and Madsen-Zodiak 901. 9 (50%) of patients demonstrated hearing loss. In 3 (16.7%) cases the conduction hearing loss was connected with the chronic diseases of middle ear which required medical treatment. In remaining 6 (33.3%) cases due to sensorineural hearing loss children had hearing aids applied and underwent rehabilitation. The results indicate that all children with Brachmann-de Lange syndrome should undergo examinations of brainstem auditory evoked potential. It enables to detect hypoacusis and initiate proper treatment. Lack of the opportunity of having a hearing aid applied and further rehabilitation deepens the social isolation of the little patients and inhibits their natural progress in communication. In such cases mental retardation may subsequently occur.
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Movements, Home-Range Size and Habitat Selection of Mallards during Autumn Migration
Bengtsson, Daniel; Avril, Alexis; Gunnarsson, Gunnar; Elmberg, Johan; Söderquist, Pär; Norevik, Gabriel; Tolf, Conny; Safi, Kamran; Fiedler, Wolfgang; Wikelski, Martin; Olsen, Björn; Waldenström, Jonas
2014-01-01
The mallard (Anas platyrhynchos) is a focal species in game management, epidemiology and ornithology, but comparably little research has focused on the ecology of the migration seasons. We studied habitat use, time-budgets, home-range sizes, habitat selection, and movements based on spatial data collected with GPS devices attached to wild mallards trapped at an autumn stopover site in the Northwest European flyway. Sixteen individuals (13 males, 3 females) were followed for 15–38 days in October to December 2010. Forty-nine percent (SD = 8.4%) of the ducks' total time, and 85% of the day-time (SD = 28.3%), was spent at sheltered reefs and bays on the coast. Two ducks used ponds, rather than coast, as day-roosts instead. Mallards spent most of the night (76% of total time, SD = 15.8%) on wetlands, mainly on alvar steppe, or in various flooded areas (e.g. coastal meadows). Crop fields with maize were also selectively utilized. Movements between roosting and foraging areas mainly took place at dawn and dusk, and the home-ranges observed in our study are among the largest ever documented for mallards (mean = 6,859 ha; SD = 5,872 ha). This study provides insights into relatively unknown aspects of mallard ecology. The fact that autumn-staging migratory mallards have a well-developed diel activity pattern tightly linked to the use of specific habitats has implications for wetland management, hunting and conservation, as well as for the epidemiology of diseases shared between wildlife and domestic animals. PMID:24971887
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High photobiont diversity in the common European soil crust lichen Psora decipiens.
Ruprecht, Ulrike; Brunauer, Georg; Türk, Roman
2014-01-01
The genetic diversity of green algal photobionts (chlorobionts) in soil crust forming lichens was studied as part of the SCIN-project (Soil Crust InterNational). A total of 64 lichen samples were collected from four different sites along latitudinal and altitudinal gradients in Europe (Tabernas/Spain; Hochtor-Großglockner/Austria; Gynge Alvar/Sweden; Ruine Homburg/Germany). The dominant lichen species at all four sites was Psora decipiens , often occurring with Buellia elegans, Fulgensia bracteata, F. fulgens and Peltigera rufescens. Genetic identification of chlorobionts was carried out using the nuclear marker (nrITS) and a chloroplast marker ( psb L-J). We found P. decipiens to be associated with several different species of Trebouxia and Asterochloris , although previously described to only have Asterochloris sp. The phylogenetic analyses revealed a high chlorobiont diversity with 12 well supported clades, including Trebouxia asymmetrica , T. jamesii , T. impressa and other, as yet taxonomically unidentified clades ( Trebouxia sp. URa1-4, T . sp. URa6, T . sp. URa7-13). Additionally, five clades of Asterochloris were identified ( A. magna, A. sp. URa14 -17). Most of the chlorobiont species appeared to be cosmopolitan, but five clades were unevenly distributed between the sampling sites with only Trebouxia being found in the warm and dry Spanish habitats and combinations of Trebouxia and Asterochloris in the cooler and more humid habitats. The wide range of chlorobiont species might contribute to the observed domination of P. decipiens at all four research sites of the SCIN project which range from a desert in Spain to an alpine site in the Alps of Austria.
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Four Weeks of Nordic Hamstring Exercise Reduce Muscle Injury Risk Factors in Young Adults.
Ribeiro-Alvares, João Breno; Marques, Vanessa B; Vaz, Marco A; Baroni, Bruno M
2018-05-01
Ribeiro-Alvares, JB, Marques, VB, Vaz, MA, and Baroni, BM. Four weeks of Nordic hamstring exercise reduce muscle injury risk factors in young adults. J Strength Cond Res 32(5): 1254-1262, 2018-The Nordic hamstring exercise (NHE) is a field-based exercise designed for knee-flexor eccentric strengthening, aimed at prevention of muscle strains. However, possible effects of NHE programs on other hamstring injury risk factors remain unclear. The purpose of this study was to investigate the effects of a NHE training program on multiple hamstring injury risk factors. Twenty physically active young adults were allocated into 2 equal-sized groups: control group (CG) and training group (TG). The TG was engaged in a 4-week NHE program, twice a week, 3 sets of 6-10 repetitions; while CG received no exercise intervention. The knee flexor and extensor strength were assessed through isokinetic dynamometry, the biceps femoris long head muscle architecture through ultrasound images, and the hamstring flexibility through sit-and-reach test. The results showed that CG subjects had no significant change in any outcome. TG presented higher percent changes than CG for hamstring isometric peak torque (9%; effect size [ES] = 0.27), eccentric peak torque (13%; ES = 0.60), eccentric work (18%; ES = 0.86), and functional hamstring-to-quadriceps torque ratio (13%; ES = 0.80). The NHE program led also to increased fascicle length (22%; ES = 2.77) and reduced pennation angle (-17%; ES = 1.27) in biceps femoris long head of the TG, without significant changes on muscle thickness. In conclusion, a short-term NHE training program (4 weeks; 8 training sessions) counteracts multiple hamstring injury risk factors in physically active young adults.
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Life history of the Glanville fritillary butterfly in fragmented versus continuous landscapes
Duplouy, Anne; Ikonen, Suvi; Hanski, Ilkka
2013-01-01
Habitat loss and fragmentation threaten the long-term viability of innumerable species of plants and animals. At the same time, habitat fragmentation may impose strong natural selection and lead to evolution of life histories with possible consequences for demographic dynamics. The Baltic populations of the Glanville fritillary butterfly (Melitaea cinxia) inhabit regions with highly fragmented habitat (networks of small dry meadows) as well as regions with extensive continuous habitat (calcareous alvar grasslands). Here, we report the results of common garden studies on butterflies originating from two highly fragmented landscapes (FL) in Finland and Sweden and from two continuous landscapes (CL) in Sweden and Estonia, conducted in a large outdoor cage (32 by 26 m) and in the laboratory. We investigated a comprehensive set of 51 life-history traits, including measures of larval growth and development, flight performance, and adult reproductive behavior. Seventeen of the 51 traits showed a significant difference between fragmented versus CL. Most notably, the growth rate of postdiapause larvae and several measures of flight capacity, including flight metabolic rate, were higher in butterflies from fragmented than CL. Females from CL had shorter intervals between consecutive egg clutches and somewhat higher life-time egg production, but shorter longevity, than females from FL. These results are likely to reflect the constant opportunities for oviposition in females living in continuous habitats, while the more dispersive females from FL allocate more resources to dispersal capacity at the cost of egg maturation rate. This study supports theoretical predictions about small population sizes and high rate of population turnover in fragmented habitats selecting for increased rate of dispersal, but the results also indicate that many other life-history traits apart from dispersal are affected by the degree of habitat fragmentation. PMID:24455144
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NASA Astrophysics Data System (ADS)
Kriiska, Kaie; Uri, Veiko; Frey, Jane; Napa, Ülle; Kabral, Naima; Soosaar, Kaido; Rannik, Kaire; Ostonen, Ivika
2017-04-01
Carbon (C) allocation plays a critical role in forest ecosystem carbon cycling. Changes in C allocation alter ecosystems carbon sequestration and plant-soil-atmosphere gas exchange, hence having an impact on the climate. Currently, there is lack of reliable indicators that show the direction of C accumulation patterns in forest ecosystems on regional scale. The first objective of our study was to determine the variability of carbon allocation in hemiboreal coniferous forests along the gradient of soil fertility in Estonia. We measured C stocks and fluxes, such as litter, fine root biomass and production, soil respiration etc. in 8 stands of different site types - Scots pine (Cladonia, Vaccinium, Myrtillus, Fragaria) and Norway spruce (Polytrichum, Myrtillus, Oxalis, Calamagrostis alvar). The suitability of above- and belowground litter production (AG/BG) ratio was analysed as a carbon allocation indicator. The second aim of the study was to analyse forest C allocation patterns along the north-south gradient from northern boreal Finland to hemiboreal Estonia. Finally, C sequestration in silver birch and grey alder stands were compared with coniferous stands in order to determine the impact of tree species on carbon allocation. Preliminary results indicate that estimated AG/BG ratio (0.5 ... 3.0) tends to decrease with increasing soil organic horizon C/N ratio, indicating that in less fertile sites more carbon is allocated into belowground through fine root growth and in consequence the soil organic carbon stock increases. Similar trends were found on the north-south forest gradient. However, there was a significant difference between coniferous and broadleaf stands in C allocation patterns. Net ecosystem exchange in Estonian coniferous stands varied from -1.64 ... 3.95 t C ha-1 yr-1, whereas older stands tended to be net carbon sources.
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[The first three Nordic Nobel laureates in physiology or medicine].
Pernow, B
1997-01-01
Among all the Nobel Laureates in physiology or medicine there are five from Denmark and seven from Sweden. The first three Laureates are presented in this paper. Over 50 years have elapsed since they were awarded and the Nobel archives are now open for scrutiny, providing insight into how the Nobel committee interpreted the instruction given in Nobel's will at that time. Niels Finsen (1860-1904, Nobel Laureate 1903) devoted his short life to a continuous study of the biological effects of sunshine, which resulted in a method aimed at utilizing the bacteriocide properties of sun rays in the treatment of various skin diseases and especially tuberculosis. Finsen published his first paper on this topic in 1896 and his method revolutionized the current treatment of this disease. Approximately forty Finsen Institutes were established in Europe and the USA within the subsequent five years. Alvar Gullstrand (1869-1930, Nobel Laureate 1911) was an ophthalmologist but his main interest was mathematical physics, where he achieved results of utmost importance for clinical opthalmology. He systematically studied the optical system, from the physical properties of light rays to optimal images in different media of the eye. He formulated general laws if image, which he extrapolated to the human eye. He also devised several techniques, some of which still used in ophthalmology. August Krogh (1874-1949, Nobel Laureate 1920) was a zoological physiologist, actively involved in various fields, including human muscle physiology and metabolism, capillary circulation in the frog, water regulation in the desert rat and the jumping capacity of the grasshopper. He was the founder of modern human exercise physiology and sport medicine. Krogh received the Nobel prize the year after he published his first paper on the regulation of the motor activity of capillaries, which reflected the Nobel committee's desire at that time to support a young scientist in the most successul period of his career
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ERIC Educational Resources Information Center
Bonvillian, John D.; Ingram, Vicky L.; McCleary, Brendan M.
2009-01-01
The accounts of two men who participated in several Spanish-led expeditions to the New World in the early 1500s document the frequent use of manual signs and gestures in the initial interactions between European explorers and the indigenous peoples of North America. Bernal Diaz del Castillo described the events that occurred during three…
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NASA Astrophysics Data System (ADS)
Trondman, Anna-Kari; Gaillard, Marie-José; Sugita, Shinya; Mazier, Florence; Fyfe, Ralph; Nielsen, Anne-Birgitte; Leydet, Michelle; Members, Landclim
2010-05-01
) number of pollen taxa, 3) PPEs dataset, and 4) number of dates per record used to establish the chronology (≥3 or ≥5) was tested (see Mazier et al. CL 1.21). Following the results of these tests, the first maps are based on REVEALS runs using pollen records from both lakes and bogs with ≥3 dates, 24 taxa (entomophilous taxa excluded), and the mean of all PPEs available in the study area. The maps are produced for 10 PFTs (LPJ-GUESS) and 3 PFTs (RCA3) at a spatial resolution of 1o x 1o for five selected time windows of the Holocene with contrasting human-induced land-cover (0-100 cal BP, 100-350 cal BP, 350-700 cal BP, 2700-3200 cal BP and 5700-6200 cal BP). The maps of PFTs show significant changes in the degree of human-induced vegetation openness through the Holocene over most of the study area. There are large discrepancies between these first quantitative land-cover maps and earlier maps based on pollen data and other methods such as biomization and the modern analogue approach. * The following LANDCLIM members are acknowledged for providing pollen records and for help with pollen databases: Teija Alenius (Espoo), Heather Almquist-Jacobson (Montana, USA), Lena Barnekow and Thomas Persson (Lund), Jonas Bergman (Stockholm), Anne Bjune and John Birks (Bergen), Thomas Giesecke (Göttingen), Rixt de Jong (Bern), Mihkel Kangur and Tiiuu Koff (Tallinn), Malgorzata Latalowa (Gdansk), Ann-Marie Robertsson (Stockholm), Ulf Segerström and Henrik von Stedingk (Umeå), Heikki Seppä (Helsinki). Sugita, S. 2007. The Holocene, 17, 229-241.
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NASA Astrophysics Data System (ADS)
Gaillard, Marie-Jose; Sugita, Shinya; Rundgren, Mats; Smith, Benjamin; Mazier, Florence; Trondman, Anna-Kari; Fyfe, Ralph; Kokfelt, Ulla; Nielsen, Anne-Birgitte; Strandberg, Gustav
2010-05-01
of ca. 1o x 1o. The REVEALS estimates of the past cover of PFTs will be 1) compared with the outputs of the LPJ-GUESS (10 PFTs), a widely-used dynamic vegetation model and 2) used as an alternative to the LPJ-GUESS-simulated vegetation (3 PFTs) to run for the past the regional climate model RCA3 developed at the Rossby Centre, Norrköping, Sweden. The study will evaluate and further refine these models (RCA3 and LPJ-GUESS) using a data-model comparison approach that incorporates new syntheses of palaeoclimatic data as well. It will lead to new assessments of the possible effect of various factors on climate, such as deforestations and afforestations, and changes in vegetation composition and spatial patterns of land cover/land use. Refined climate models and empirical land-cover reconstructions will shed new light on controversial hypotheses of past climate change and human impacts, such as the "Ruddiman hypothesis". First maps of REVEALS estimates of plant functional types (PFTs) are now available for Sweden, Norway, Finland, Denmark, Estonia, Poland, Germany, The Czech Republic, Switzerland and Britain (see Mazier et al. C1.21 and Trondman et al. C1.22). Correlation tests show that the REVEALS estimates are robust in terms of ranking of the PFTs' abundance (see Mazier et al, C1.21). The LANDCLIM project and network are a contribution to the IGBP-PAGES-Focus 4 PHAROS programme on human impact on environmental changes in the past. The following LANDCLIM members are acknowledged for providing pollen records, for help with pollen databases, and for providing results to the project: Mihkel Kangur and Tiiu Koff (Univ. Tallinn, Tallinn); Erik Kjellström (SMHI, Norrköping), Anna Broström, Lena Barnekow and Thomas Persson (GeoBiosphere Science Centre, Lund University); Anneli Poska (Physical Geography and Ecosystems Analysis, Lund University); Thomas Giesecke (Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen), Anne Bjune and John Birks (Dept. of