scholarly journals Demographic responses of boreal-montane orchid Malaxis monophyllos (L.) Sw. populations to contrasting environmental conditions

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Edyta Jermakowicz ◽  
Emilia Brzosko
Keyword(s):  
Anthropogenic Impacts ◽  
Reproductive Traits ◽  
Dynamic Structure ◽  
Reproductive Parameters ◽  
Regional Patterns ◽  
Geographical Regions ◽  
Ecological Type ◽  
Demographic Responses ◽  
Main Factor

<p>In an age of changes in species’ geographical ranges, compounded by climatic and anthropogenic impacts, it become important to know which processes and factors influence plant populations and their persistence in the long term.</p><p>Here we investigated dynamic and fitness components in twelve populations of <em>Malaxis monophyllos</em> (L.) Sw., situated in different geographical (regions) and ecological (type of habitat) units. Although <em>M. monophyllos</em> is a rare species, characterized by highly fragmented, boreal-montane distribution range, in last few decades it successfully colonized secondary habitats in Polish uplands. Our results indicate that <em>M. monophyllos</em> is represented mainly by small populations, which annual spatial and temporal changes might be very high, what affects the ephemeral character of these populations, regardless of the region and type of habitat. This dynamic structure, in turn, is caused by intensive exchange of individuals in populations, as well as by their short above-ground life span. Despite the large range of variation in size and reproductive traits, we can distinguish some regional patterns, which indicate boreal region as the most optimal for <em>M. monophyllos</em> growth and persistence in the long term, and with montane and upland/anthropogenic populations, due to lower reproductive parameters, as the most threatened. Although it should be considered that anthropogenic populations, despite their lower reproductive parameters and instability in the long term, present an intermediate, geographical and ecological character, therefore they may be valuable in shaping, both <em>M. monophyllos</em>’ future range, as well as its potential for response on ongoing and future changes. In general, reproduction is the main factor differentiating of <em>M. monophyllos</em> populations in regions, and we can suspect that it may become the cause of the future differentiation and isolation of these populations, occurring with progressive range fragmentation.</p>

Apophysites – Revue de la littérature et ­nouvelles directions

2014 ◽  
Vol 62 (3) ◽  
Keyword(s):  
Scientific Evidence ◽  
Ossification Center ◽  
Health Staff ◽  
Optimal Management ◽  
Long Term Effect ◽  
High Incidence ◽  
Youth Athlete ◽  
Pathology Education ◽  
Main Factor

Apophysitis are part of the growth-related diseases within youth athlete population. Despite their high incidence within this growing cohort, many doubts remain. The physiopathology is still debated. Initially, the fragmentation of the ossification center was seen as the main factor of the disease. For few years, this theory has been questioned due to consistent signs of tendon suffering. Apophysitis may have some negative long-term effect on a sporting career. There is currently poor scientific evidence on the optimal management and no treatment has been widely accepted. Prevention remains the most powerful intervention in this particular pathology. Education of the athlete’s sporting entourage (family, coaches and health staff) and the athlete himself is necessary to act quickly and adapt the training load to decrease mechanical stress on the suffering apophysis.

scholarly journals Two decades of in-situ temperature measurements in the upper troposphere and lowermost stratosphere from IAGOS long-term routine observation

2017 ◽  
Author(s):  
Florian Berkes ◽  
Patrick Neis ◽  
Martin G. Schultz ◽  
Ulrich Bundke ◽  
Susanne Rohs ◽  
...  
Keyword(s):  
Weather Forecast ◽  
Global Scale ◽  
Temperature Trend ◽  
Data Set ◽  
Medium Range Weather Forecast ◽  
Upper Troposphere ◽  
Temperature Trends ◽  
Geographical Regions

Abstract. Despite several studies on temperature trends in the tropopause region, a comprehensive understanding of the evolution of temperatures in this climate-sensitive region of the atmosphere remains elusive. Here we present a unique global-scale, long-term data set of high-resolution in-situ temperature data measured aboard passenger aircraft within the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System, www.iagos.org). This data set is used to investigate temperature trends within the global upper troposphere and lowermost stratosphere (UTLS) for the period 1995 to 2012 in different geographical regions and vertical layers of the UTLS. The largest amount of observations is available over the North Atlantic. Here, a neutral temperature trend is found within the lowermost stratosphere. This contradicts the temperature trend in the European Centre for Medium Range Weather Forecast (ECMWF) ERA-Interim reanalysis, where a significant (95 % confidence) temperature increase of +0.56 K/decade is obtained. Differences between trends derived from observations and reanalysis data can be traced back to changes in the temperature bias between observation and model data over the studied period. This study demonstrates the value of the IAGOS temperature observations as anchor point for the evaluation of reanalyses and its suitability for independent trend analyses.

scholarly journals Determining Long-Term Trends of Four Fast-Eutrophicated Lakes in China and Finland

2015 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Mengna Liao ◽  
Ge Yu ◽  
Anne-Mari Ventelä ◽  
Xuhui Dong
Keyword(s):  
Water Quality ◽  
Anthropogenic Impacts ◽  
Turning Points ◽  
Dynamic Modelling ◽  
Sharp Change ◽  
Temperature Variations ◽  
Long Term Trends ◽  
Nutrient Changes ◽  
Water Quality Trends

<p>Lake eutrophication has increased in pace in recent decades and has caused serious environmental problems However, the development trends have not been fully determined as it is difficult to recognize complex effects emanating from both climate and human mechanisms. China has many lakes in different trophic stages, which represent three developing stages from forest- to agriculture-, and then to urban-lake, typically in Lakes Lugu, Taibai, and Taihu. To determine long-term water quality trends, the three lakes were chosen for statistic analysis on dominant effects on the diatom-inferred nutrient changes, and to undertake dynamic modelling regarding climate-controlled nutrient changes. The results indicate the significant turning points of water quality in Lakes Lugu, Taibai and Taihu occurring in the 1990s, 1950s and 1940s respectively, which were effected from human activities by increases in tourism, farming and urbanization respectively. Water quality changes in Lakes Lugu, Taibai and Taihu captured 68.4%, 54.9%, and 86.0% of the temperature variations before the turning points. The anthropogenic impacts explained 84.0%, 96.4% and 96.0% of the water quality variations after the turning points, where the sharp change of water quality by human activity has played an accelerated effect on the gentle change of temperature. Compared with the 4 phases of water quality development in Pyhäjärvi Lake (SW Finland), Lakes Lugu and Taibai have experienced the 1<sup>st</sup> and 2<sup>nd</sup> phases, and Taihu has experienced from the 2<sup>nd</sup> to 3<sup>rd</sup> phases during the last 150 years. Phase 4 has not occurred in the three lakes, but it is a key period during the eutropication we need to pay attentions.</p>

scholarly journals Variability of Cloudiness over Mountain Terrain in the Western United States

2017 ◽  
Vol 18 (5) ◽  
pp. 1227-1245 ◽  
Author(s):  
Edwin Sumargo ◽  
Daniel R. Cayan
Keyword(s):  
United States ◽  
Large Scale ◽  
Spatial Scales ◽  
High Elevation ◽  
Empirical Orthogonal Functions ◽  
Western United States ◽  
Spatial And Temporal Variability ◽  
Regional Patterns ◽  
Cloud Albedo

Abstract This study investigates the spatial and temporal variability of cloudiness across mountain zones in the western United States. Daily average cloud albedo is derived from a 19-yr series (1996–2014) of half-hourly Geostationary Operational Environmental Satellite (GOES) images. During springtime when incident radiation is active in driving snowmelt–runoff processes, the magnitude of daily cloud variations can exceed 50% of long-term averages. Even when aggregated over 3-month periods, cloud albedo varies by ±10% of long-term averages in many locations. Rotated empirical orthogonal functions (REOFs) of daily cloud albedo anomalies over high-elevation regions of the western conterminous United States identify distinct regional patterns, wherein the first five REOFs account for ~67% of the total variance. REOF1 is centered over Northern California and Oregon and is pronounced between November and March. REOF2 is centered over the interior northwest and is accentuated between March and July. Each of the REOF/rotated principal components (RPC) modes associates with anomalous large-scale atmospheric circulation patterns and one or more large-scale teleconnection indices (Arctic Oscillation, Niño-3.4, and Pacific–North American), which helps to explain why anomalous cloudiness patterns take on regional spatial scales and contain substantial variability over seasonal time scales.

scholarly journals Thickness and corrosion resistance optimization of Micro-ARC oxidation coating on Mg-Al-Li-Zn alloy using Taguchi approach

2020 ◽  
pp. 62-66
Author(s):  
Do Le Hung Toan, Shuo-Jen Lee Do
Keyword(s):  
Corrosion Resistance ◽  
Processing Time ◽  
Electrical Potential ◽  
Surface Protection ◽  
Alkaline Electrolytes ◽  
Micro Arc Oxidation ◽  
Corrosive Environments ◽  
Zn Alloy ◽  
Main Factor

Micro arc oxidation method has been developed in the field of surface protection of magnesium alloys and considered as a simple, highly effective, commercial and environmentally friendly method in industry. MAO coatings are fabricated on novel Mg-Al-Li-Zn alloy to improve the anti-corrosion performance of surface by using friendly alkaline electrolytes under a high electrical potential. The Taguchi method and optimal analysis are used to identify the effects of the three factors including current density, processing time and electrical frequency on coating’s characteristics. The results have shown that the main factor that affects coating thickness and corrosion resistance of coating is the processing time. The results obtained by optimal conditions are consistent with prediction values of Taguchi analysis. The thickness of the coating can help to improve the long-term corrosion protection of a MAO coating in corrosive environments.

scholarly journals Effect of EPSPS Gene Copy Number and Glyphosate Selection on Fitness of Glyphosate-Resistant Bassia Scoparia in The Field

2021 ◽  
Author(s):  
Charlemagne Ajoc Lim ◽  
Prashant Jha ◽  
Vipan Kumar ◽  
Alan T. Dyer
Keyword(s):  
Sugar Beet ◽  
Seed Production ◽  
Great Plains ◽  
Copy Number ◽  
Gene Copy Number ◽  
Reproductive Traits ◽  
Gene Copy ◽  
Epsps Gene ◽  
Gene Copies

Abstract The widespread evolution of glyphosate-resistant (GR) Bassia scoparia in the U.S. Great Plains poses a serious threat to the long-term sustainability of GR sugar beet. Glyphosate resistance in B. scoparia is due to an increase in the EPSPS (5-enolpyruvyl-shikimate-3-phosphate) gene copy number. The variation in EPSPS gene copies among individuals from within a single GR B. scoparia population indicated a differential response to glyphosate selection. We tested the hypothesis of reduced GR B. scoparia fitness (reproductive traits) to increasing glyphosate rates (applied as single or sequential applications) potentially experienced within a GR sugar beet field. The variation in EPSPS gene copy number and total glyphosate rate (single or sequential applications) did not influence any of the reproductive traits of GR B. scoparia, except seed production. Sequential applications of glyphosate with a total rate of 2,214 g ae ha− 1 or higher prevented seed production in B. scoparia plants with 2–4 (low levels of resistance) and 5–6 (moderate levels of resistance) EPSPS gene copies. Timely sequential applications of glyphosate (full recommended rates) can potentially slow down the evolution of GR B. scoparia with low to moderate levels of resistance (2–6 EPSPS gene copies), but any survivors (highly-resistant individuals with ≥ 8 EPSPS gene copies) need to be mechanically removed before flowering from GR sugar beet fields. This research warrants the need to adopt ecologically based, multi-tactic strategies to reduce exposure of B. scoparia to glyphosate in GR sugar beet.

scholarly journals Geographical variability of length-age structure of the Black Sea sprat Sprattus sprattus phalericus (Risso) (Pisces: Clupeidae) and intraspecific differentiation

2016 ◽  
Vol 1 (1) ◽  
pp. 24-35
Author(s):  
G. V. Zuyev ◽  
V. A. Bondarev ◽  
Yu. V. Samotoi
Keyword(s):  
Interannual Variability ◽  
Black Sea ◽  
Age Structure ◽  
The Black Sea ◽  
Population Parameter ◽  
Intraspecific Differentiation ◽  
Geographical Regions ◽  
The Crimea ◽  
Scientific Technical

Investigations of the Black Sea sprat intraspecific differentiation are the basis for the scientific substantiation of rational exploitation of its resource potential. This work is devoted to the study of spatial variability of length and age structure of sprat as specific population parameter reflecting its intraspecific differentiation. Our own data and materials of Scientific, Technical and Economic Committee for Fisheries (STECF) of the European Commission have been used. The first time long-term dynamics (2007–2012) and interannual variability of length and age structure of sprat in different geographical regions of the Black Sea (coastal waters of Bulgaria – Romania, Turkey and the Crimea) have been investigated. Differences of the long-term dynamics and interannual variability of length and age structure in these regions have been found. Sprat population from Bulgaria – Romania region is in better conditions (mean length 8.59 ± 0.01 cm; mean age 1.79  year), sprat population from Crimea region is in worse conditions (mean length 7.64 ± 0.01 cm; mean age 1.38 year). It has been shown that the main factor determining the interregional biological heterogeneity of sprat is the different fishery regulations. This fact disagrees with concept of united commercial sprat stock in the Black Sea.

scholarly journals A century of genetic homogenization in Baltic salmon—evidence from archival DNA

2021 ◽  
Vol 288 (1949) ◽  
Author(s):  
Johan Östergren ◽  
Stefan Palm ◽  
John Gilbey ◽  
Göran Spong ◽  
Johan Dannewitz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Isolation By Distance ◽  
Anthropogenic Impacts ◽  
Genetic Change ◽  
Past Century ◽  
The Baltic Sea ◽  
The Baltic ◽  
Archival Dna

Intra-species genetic homogenization arising from anthropogenic impacts is a major threat to biodiversity. However, few taxa have sufficient historical material to systematically quantify long-term genetic changes. Using archival DNA collected over approximately 100 years, we assessed spatio-temporal genetic change in Atlantic salmon populations across the Baltic Sea, an area heavily impacted by hydropower exploitation and associated with large-scale mitigation stocking. Analysis was carried out by screening 82 SNPs in 1680 individuals from 13 Swedish rivers. We found an overall decrease in genetic divergence and diminished isolation by distance among populations, strongly indicating genetic homogenization over the past century. We further observed an increase in genetic diversity within populations consistent with increased gene flow. The temporal genetic change was lower in larger wild populations than in smaller wild and hatchery-reared ones, indicating that larger populations have been able to support a high number of native spawners in relation to immigrants. Our results demonstrate that stocking practices of salmon in the Baltic Sea have led to the homogenization of populations over the last century, potentially compromising their ability to adapt to environmental change. Stocking of reared fish is common worldwide, and our study is a cautionary example of the potentially long-term negative effects of such activities.

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