Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

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Global change tipping points: above- and below-ground biotic interactions in a low diversity ecosystem

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2006.1950 ◽

2007 ◽

Vol 362 (1488) ◽

pp. 2291-2306 ◽

Cited By ~ 69

Author(s):

Diana H Wall

Keyword(s):

Global Change ◽

Biotic Interactions ◽

Ecosystem Processes ◽

Global Changes ◽

Tipping Points ◽

Low Diversity ◽

Dry Valley ◽

Below Ground ◽

The Antarctic ◽

High Diversity

Low diversity ecosystems are expected to be more vulnerable to global changes although they have received less attention than high diversity ecosystems. Addressing the present state of the Antarctic Dry Valley region by focusing on the potential global changes that may alter the coupling of above- and below-ground species and ecosystem processes is a realistic and critical need that has value beyond the Antarctic community. Presented here are suggested implications of global change on the Dry Valley terrestrial systems and how these effects might be manifested in the future.

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Plant diversity, composition, and rarity in the southern boreal peatlands of Manitoba, Canada

Canadian Journal of Botany ◽

10.1139/b06-049 ◽

2006 ◽

Vol 84 (6) ◽

pp. 940-955 ◽

Cited By ~ 17

Author(s):

David A. Locky ◽

Suzanne E. Bayley

Keyword(s):

Plant Diversity ◽

Environmental Variables ◽

Vascular Plants ◽

Black Spruce ◽

General Pattern ◽

Boreal Peatlands ◽

Environmental Extremes ◽

Low Diversity ◽

Total Diversity ◽

High Diversity

Plant diversity and rarity have been relatively well studied for bryophytes in Canadian western boreal peatlands, but little information exists for vascular plants. Diversity, community composition, and rarity of bryophytes and vascular plants were determined and relationships examined among these and environmental variables in five peatland types at Duck Mountain, Manitoba: wooded bogs, black spruce swamps, wooded moderate-rich fens, open moderate-rich fens, and open extreme-rich fens. Total diversity was 298 species comprising 86 bryophytes and 212 vascular plants. Mean diversity followed a unimodal distribution over a bog – rich fen gradient. Wooded moderate-rich fens (59.0) and black spruce swamps (53.4) had the highest mean diversity, whereas wooded bogs (32.3) and open extreme-rich fens (34.7) had the lowest mean diversity. Occurrences of locally rare species followed the same general pattern, and provincially rare vascular plants were found primarily in wooded moderate-rich fens and black spruce swamps and were mostly orchids. Reasons for these patterns are complex, but high diversity appears to be related to high habitat heterogeneity and moderate environmental variables, e.g., pH and alkalinity, and low diversity appears to be related to environmental extremes, e.g., pH and alkalinity. Boreal wooded moderate-rich fens and black spruce swamps have comparatively high plant diversity and rarity and require consideration if the focus is biodiversity conservation. This will become increasingly important in landscapes where development pressures are high.

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Pitting Corrosion of Biomedical Titanium and Titanium Alloys: A Brief Review

Current Nanoscience ◽

10.2174/1573413716999201125221211 ◽

2020 ◽

Vol 16 ◽

Author(s):

Yu-Wei Cui ◽

Liang-Yu Chen ◽

Xin-Xin Liu

Keyword(s):

Corrosion Resistance ◽

Pitting Corrosion ◽

Potential Temperature ◽

Growth Stages ◽

Factors Affecting ◽

Ti Alloys ◽

Pitting Corrosion Resistance ◽

Superior Mechanical Properties ◽

Good Biocompatibility ◽

Main Factors

Abstract:: Thanks to their excellent corrosion resistance, superior mechanical properties and good biocompatibility, titanium (Ti) and Ti alloys are extensively applied in biomedical fields. Pitting corrosion is a critical consideration for the reliability of Ti and Ti alloys used in the human body. Therefore, this article focuses on the pitting corrosion of Ti and Ti alloys, which introduces the growth stages of pitting corrosion and its main influencing factors. Three stages, i.e. (1) breakdown of passive film, (1) metastable pitting, and (3) propagation of pitting, are roughly divided to introduce the pitting corrosion. As reviewed, corrosive environment, applied potential, temperature and alloy compositions are the main factors affecting the pitting corrosion of Ti and Ti alloys. Moreover, the pitting corrosion of different types Ti alloys are also reviewed to correlate the types of Ti alloys and the main factors of pitting corrosion. Roughly speaking, β-type Ti alloys have the best pitting corrosion resistance among the three types of Ti alloys.

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Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

Ecological Processes ◽

10.1186/s13717-020-00259-0 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Nabaz R. Khwarahm

Keyword(s):

Climate Change ◽

Habitat Suitability ◽

Environmental Variables ◽

Climate Changes ◽

Future Climate ◽

Annual Precipitation ◽

Future Climate Change ◽

Climate Change Scenarios ◽

Kurdistan Region ◽

Oak Tree

Abstract Background The oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables. Results The model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes. Conclusions The results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

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Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽

10.1177/2158244021989257 ◽

2021 ◽

Vol 11 (1) ◽

pp. 215824402198925

Author(s):

Isidoro Guzmán-Raja ◽

Manuela Guzmán-Raja

Keyword(s):

Data Envelopment Analysis ◽

High Efficiency ◽

Sport Performance ◽

Data Envelopment ◽

Professional Football ◽

Efficiency Measure ◽

Factors Affecting ◽

Football Clubs ◽

Main Factors ◽

Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

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Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽

10.3390/pr9050741 ◽

2021 ◽

Vol 9 (5) ◽

pp. 741

Author(s):

Doinita-Roxana Cioroiu Tirpan ◽

Ancaelena Eliza Sterpu ◽

Claudia Irina Koncsag ◽

Alina Georgiana Ciufu ◽

Tănase Dobre

Keyword(s):

Ethanol Production ◽

Alcoholic Fermentation ◽

Ethanol Yield ◽

Product Yield ◽

Liquid Ratio ◽

Experimental Conditions ◽

Factors Affecting ◽

Cystoseira Barbata ◽

Main Factors ◽

Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

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The role of serum β-trophin and endostatin in patients with polycystic ovary syndrome: Are they correlated?

BMC Women s Health ◽

10.1186/s12905-021-01198-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Wei Gong ◽

Aikmu Bilixzi ◽

Xinmei Wang ◽

Yanli Lu ◽

Li Wan ◽

...

Keyword(s):

Polycystic Ovary Syndrome ◽

Influencing Factors ◽

Polycystic Ovary ◽

Pearson Correlation ◽

Healthy Controls ◽

Newly Diagnosed ◽

Ovary Syndrome ◽

Factors Affecting ◽

Main Factors

Abstract Background It’s necessary to investigate the serum β-trophin and endostatin (ES) level and its influencing factors in patients with newly diagnosed polycystic ovary syndrome (PCOS). Methods Newly diagnosed PCOS patients treated in our hospital were selected, and healthy women who took physical examination during the same period as healthy controls. We detected and compared the related serum indicators between two groups, Pearson correlation were conducted to identify the factors associated with β-trophin and ES, and the influencing factors of β-trophin and ES were analyzed by logistic regression. Results A total of 62 PCOS patients and 65 healthy controls were included. The BMI, WHI, LH, FSH, TT, FAI, FBG, FINS, HOMA-IR, TC, TG, LDL, ES in PCOS patients were significantly higher than that of healthy controls, while the SHBG and HDL in PCOS patients were significantly lower than that of healthy controls (all p < 0.05). β-trophin was closely associated with BMI (r = 0.427), WHR (r = 0.504), FBG (r = 0.385), TG (r = 0.405) and LDL (r = 0.302, all p < 0.05), and ES was closely associated with BMI (r = 0.358), WHR (r = 0.421), FBG (r = 0.343), TC (r = 0.319), TG (r = 0.404, all p < 0.05). TG, BMI, WHR and FBG were the main factors affecting the serum β-trophin levels (all p < 0.05). FBG, TC and BMI were the main factors affecting the serum ES levels (all p < 0.05). The TG, β-trophin, ES level in PCOS patients with insulin resistance (IR) were significantly higher than that of those without IR (all p < 0.05). Conclusion Increased β-trophin is closely associated with increased ES in patients with PCOS, which may be the useful indicators for the management of PCOS.

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Laboratory Tests on Engineering Properties of Wind-Blown Sand

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.706 ◽

2012 ◽

Vol 170-173 ◽

pp. 706-709

Author(s):

Zhao Lin Jia ◽

Shu Wang Yan ◽

Zhi Liang Huo

Keyword(s):

Water Content ◽

Laboratory Tests ◽

Fine Sand ◽

Engineering Properties ◽

Grain Composition ◽

Factors Affecting ◽

Compaction Curve ◽

Main Factors ◽

Dry And Wet Conditions ◽

Compaction Properties

By means of laboratory tests and theoretical calculation, the physical, mechanical properties and compaction mechanism of the wind-blown sand are studied to deal with the problem of how to use the wind-blown sand as roadbed materials. It is revealed that water content doesn’t affect the compressibility and the shear strength of the wind-blown sand obviously and the wind-blown sand can be compacted both in dry and wet conditions. The compaction curve of the ordinary fine sand is consistent with that of wind-blown sand and the main factors affecting the compaction properties are the grain composition, water content and compaction work.

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