scholarly journals Effect of aridity on species assembly in gypsum drylands: a response mediated by the soil affinity of species

AoB Plants ◽  
2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Arantzazu L Luzuriaga ◽  
Pablo Ferrandis ◽  
Joel Flores ◽  
Adrián Escudero
Keyword(s):  
Plant Communities ◽  
Linear Models ◽  
Taxonomic Diversity ◽  
Mean Annual Precipitation ◽  
Change Models ◽  
Perennial Plant ◽  
Arid Conditions ◽  
The Mean ◽  
Maximum Temperatures ◽  
Selection Of

Abstract Previous studies found that plant communities on infertile soils are relatively resistant to climatic variation due to stress tolerance adaptations. However, the species assemblies in gypsum soil habitats require further investigation. Thus, we considered the following questions. (1) Do harsher arid conditions determine the characteristics of the species that form plant assemblages? (2) Is the selection of the species that assemble in arid conditions mediated by their ability to grow on gypsum soils? (3) Is the selection of species that assemble in harsher conditions related to phylogenetically conserved functional traits? Perennial plant communities were analysed in 89 gypsum-soil sites along a 400 km climate gradient from the central to southeastern Iberian Peninsula. Each local assemblage was analysed in 30 × 30 m plots and described based on taxonomic, functional (soil plant affinity) and phylogenetic parameters. The mean maximum temperatures in the hottest month, mean annual precipitation and their interaction terms were used as surrogates for the aridity conditions in generalized linear models. In the hottest locations, the gypsophily range narrowed and the mean gypsophily increased at the community level, thereby suggesting the filtering of species and the dominance of soil specialists in the actual plant assemblies. Drier sites had higher taxonomic diversity. The species that formed the perennial communities were close in evolutionary terms at the two ends of the aridity gradient. The mean maximum temperatures in the hottest month had the main abiotic filtering effect on perennial plant communities, which was mediated by the ability of species to grow on gypsum soils, and thus gypsum specialists dominated the species assemblies in the hottest locations. In contrast, the perennial communities on gypsum soils were relatively resistant to changes in precipitation. Our findings suggest that the warmer environmental conditions predicted by global change models will favour gypsum specialists over generalists.

scholarly journals Climate change effects and UV-B radiation in the Vojvodina region, Serbia under the SRES-A2

2015 ◽  
Vol 19 (suppl. 2) ◽  
pp. 289-298 ◽  
Author(s):  
Slavica Malinovic-Milicevic ◽  
Dragutin Mihailovic ◽  
Nusret Dreskovic ◽  
Vladimir Djurdjevic ◽  
Gordan Mimic ◽  
...  
Keyword(s):  
21St Century ◽  
Climate Model ◽  
Precipitation Amount ◽  
Mean Annual Precipitation ◽  
Strong Increase ◽  
Extreme Temperatures ◽  
Climate Conditions ◽  
Climate Change Effects ◽  
The Mean ◽  
Maximum Temperatures

In this article we considered the extreme temperatures, precipitation and UV-B radiation in Vojvodina region, Serbia. We describe the actual climate conditions for the period 1981?2007 and applied a dynamic downscaling technique using the EBU-POM regional coupled climate model under the SRES-A2 scenario to assess the changes for the period 2021-2100. The results indicate that a warmer and drier climate in the Vojvodina region can be expected at the end of the century. Projection of climate indicates to a strong increase in the mean annual minimum temperatures, and much smaller increase in the mean annual maximum temperatures. The increase of both extreme temperatures is predicted to be the highest in the winter and the lowest in the summer. Mean annual precipitation is projected to increase toward the end of the first half of the 21st century and to decrease for the last 30 years of the 21st century. Precipitation amount will be the highest during the winter and spring. The model simulations show that, by the end of this century, annual mean UV-B dose will recover by 5.2%. Recovery will be faster in the first half of the 21st century and more slowly later on. The UV-B doses recovery is expected to be the highest during the autumn and spring.

scholarly journals Indirect Selection of Tolerant Barley (Hordeum vulgare L.) Genotypes under Semi Arid Conditions Based on the Numerical Images Analysis Indices

2020 ◽  
Author(s):  
Hocine Bendada ◽  
Ali Guendouz ◽  
Ramdane Benniou ◽  
Nasreddine Louahdi
Keyword(s):  
Image Analysis ◽  
Analysis Of Variance ◽  
Indirect Selection ◽  
Kernel Weight ◽  
Hordeum Vulgare L ◽  
Arid Conditions ◽  
The Mean ◽  
Semi Arid ◽  
Selection Of ◽  
The Ideal

Image analysis systems have been increasingly utilized for the assessment of plant growth and health for decades. We used in this study the software Mesurim Pro to evaluate the variation of the leaf reflectance at Red, Green and Blue and the variation of the senescence parameters. The analysis of variance revealed that the reflectance at different wavelengths (Red, Blue and Green) was highly significant genotypes effects (P 0.001); for this parameter the good genotypes are those we have the lowest values such as G19. In addition, the preferable genotypes were those which have low values for the mean senescence and senescence velocity; based on this raison the best genotype was the introduce genotype G12. The genotypes effect was significant for the grain yield and thousand-kernel weight, for the chlorophyll content and the analysis of variance showed a significant effect of genotypes, the highest values registered by the introduced genotype G5 this one was in the same homogenize group of G2, G4, G8 and G18. The ranking of genotypes based on all parameters suggested that the genotypes G11, G12, G5, G15 and G18, respectively (introduce genotypes) were the ideal genotypes under these conditions.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

Study on Association between Height, Weight, Iodine Supplementation and Thyroid Volume

2021 ◽  
pp. 1-25
Author(s):  
Lanchun Liu ◽  
Lixiang Liu ◽  
Ming Li ◽  
Yang Du ◽  
Peng Liu ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Linear Models ◽  
Thyroid Volume ◽  
Salt Iodization ◽  
Iodine Supplementation ◽  
Random Pairing ◽  
Level Data ◽  
The Mean ◽  
Salt Iodine ◽  
The Difference

Abstract The policy of Universal Salt Iodization (USI) could reduce population’s thyroid volume (TVOL) in iodine deficiency areas. Conversely, the improved growth and developmental status of children might increase the TVOL accordingly. Whether the decreased TVOL by USI conceals the increase effect of height and weight on TVOL is unclear. The aim of this study was to analyse the association between height, weight, iodine supplementation and TVOL. Five national Iodine Deficiency Disorder surveys were matched into four pairs according to the purpose of analysis. County-level data of both detected by paired surveys were incorporated, 1: 1 random pairing method was used to match counties or individuals. The difference of TVOL between different height, weight, different iodine supplementation measures groups and the association between TVOL and them were studied. The mean height and weight of children aged 8-10 years increased from 129.9cm and 26.9kg in 2002 to 136.2cm and 32.1kg in 2019; while the median TVOL decreased from 3.10ml to 2.61ml. Iodine supplementation measures can affect TVOL; after exclude iodine effects, the median TVOL was increased with the height and weight. On the other side, after excluding the influence of height and weight, the median TVOL remained decreased. Only age, weight and salt iodine were significant associated with TVOL in multiple linear models. Development of height and weight in children is the evidence of improved nutrition. The decreased TVOL caused by iodized salt measures conceals the increase effect of height and weight on TVOL. Age, weight, and salt iodine affect TVOL significantly.

scholarly journals Deep-sea amphipods around cobalt-rich ferromanganese crusts: Taxonomic diversity and selection of candidate species for connectivity analysis

PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228483
Author(s):  
Akira Iguchi ◽  
Miyuki Nishijima ◽  
Yuki Yoshioka ◽  
Aika Miyagi ◽  
Ryuichi Miwa ◽  
...  
Keyword(s):  
Deep Sea ◽  
Taxonomic Diversity ◽  
Connectivity Analysis ◽  
Ferromanganese Crusts ◽  
Candidate Species ◽  
Selection Of

OBESITY AND SELF-REPORTED OUTCOME AFTER MINIMALLY INVASIVE LUMBAR SPINAL FUSION SURGERY

Neurosurgery ◽  
2008 ◽  
Vol 63 (5) ◽  
pp. 956-960 ◽  
Author(s):  
David S. Rosen ◽  
Sherise D. Ferguson ◽  
Alfred T. Ogden ◽  
Dezheng Huo ◽  
Richard G. Fessler
Keyword(s):  
Minimally Invasive ◽  
Linear Models ◽  
Short Form ◽  
Length Of Hospital Stay ◽  
Fusion Surgery ◽  
Body Habitus ◽  
Short Form 36 ◽  
Spinal Fusion Surgery ◽  
The Mean ◽  
Lumbar Spinal

Abstract OBJECTIVE Many patients undergoing lumbar spine fusion are overweight or obese. The relationship between body habitus and outcome after lumbar spine fusion surgery is not well defined. METHODS We analyzed a prospectively maintained database of self-reported pain and quality of life measures, including Visual Analog Scale pain score, Short Form 36, and Oswestry Disability Index. We selected patients undergoing minimally invasive transforaminal lumbar interbody fusion between September 2002 and June 2006 at a single institution. We used linear regression models and mixed-effects linear models to examine the relationships between body habitus and self-reported outcomes. RESULTS The analysis identified 110 patients meeting the study criteria, with a median follow-up period of 14.8 months. The mean age was 56 years, mean height was 169 cm, and mean weight was 82.2 kg. The mean body mass index (BMI) was 28.7 kg/m2; 31% of patients were overweight (BMI, 25–29.9), and 32% of patients were obese (BMI, >30). Linear regression analysis did not identify a correlation between weight or BMI and pre- and postsurgery changes in any of the outcome measures. The significant findings observed in the mixed-effects linear models were that the changing patterns of Short Form 36 Body Pain subscale and Short Form 36 Vitality subscale varied significantly by category of BMI (P = 0.01 and P = 0.002, respectively), but not significantly if continuous BMI was used (P = 0.53 and P = 0.46, respectively). BMI correlated marginally with estimated blood loss (P = 0.08), but not operative time, length of hospital stay, or complications. CONCLUSION Among this cohort of minimally invasive lumbar fusion patients, body habitus measured by BMI, weight, or height did not have a significant relationship with most self-reported outcome measures, operative time, length of hospital stay, or complications. Obesity should not be considered a contraindication to minimally invasive lumbar spinal fusion surgery.

Important Factors for a Combined Neurovascular Team to Consider in Selecting a Treatment Modality for Patients with Previously Clipped Residual and Recurrent Intracranial Aneurysms

Neurosurgery ◽  
2003 ◽  
Vol 52 (4) ◽  
pp. 732-739 ◽  
Author(s):  
Brian L. Hoh ◽  
Bob S. Carter ◽  
Christopher M. Putman ◽  
Christopher S. Ogilvy
Keyword(s):  
Endovascular Treatment ◽  
Treatment Modality ◽  
Posterior Circulation ◽  
Neurological Deficits ◽  
Parent Vessel ◽  
Surgical Risk ◽  
Fatal Hemorrhage ◽  
The Mean ◽  
Selection Of

Abstract OBJECTIVE Intracranial residual and recurrent aneurysms can occur after surgical clipping, with risks of growth and rupture. In the past, surgical reoperation, which can be associated with higher risk than the initial operation, was the only available treatment. A combined neurovascular team that uses both surgical and endovascular therapies could maximize efficacy and outcomes while minimizing risks in these difficult cases. The indications for which surgical or endovascular treatment should be used to treat patients with residual or recurrent aneurysms, however, have not been elucidated well. We have reviewed the 10-year experience of our combined neurovascular team to determine in a retrospective manner which factors were important to treatment modality selection for patients with these residual and recurrent lesions. METHODS From 1991 to 2001, the combined neurovascular unit at the Massachusetts General Hospital treated 25 residual and recurrent previously clipped aneurysms (15 had been clipped at other centers). Only patients in whom a clip had been placed were included in the study; patients who did not have a clip placed or whose aneurysms were wrapped or coated were excluded. The radiographic studies and clinical data were reviewed retrospectively to determine the efficacy, outcomes, and factors important to the selection of treatment strategy in these patients. RESULTS The patients' clinical presentations were radiographic follow-up, 17 patients; rehemorrhage, 3; mass effect, 3; and thromboembolism, 2. The mean aneurysm recurrence or residual size was 11 mm (range, 4–26 mm). The mean interval until representation was 6.6 years (range, 1 wk–25 yr). Treatment consisted of: coiling, 11 patients; reclipping, 8; proximal parent vessel balloon occlusion, 2; extracranial-intracranial bypass with coil occlusion of aneurysm and parent vessel, 2; extracranial-intracranial bypass with clip trapping, 1; and extracranial-intracranial bypass with proximal clip occlusion of parent vessel, 1. The mean radiographic follow-up period was 11 months. Complete angiographic occlusion was found in 19 aneurysms (76%), at least 90% occlusion was found in 4 aneurysms (16%), intentional partial coil obliteration was found in 1 fusiform lesion (4%), and intentional retrograde flow was found in 1 fusiform lesion (4%). Clinical outcomes were excellent or good in 19 patients (76%). Twenty-one patients (84%) were neurologically the same after retreatment (13 remained neurologically intact, and 8 had preexisting neurological deficits that did not change). Three patients (12%) had new neurological deficits after retreatment, and one patient (4%) died. There were four complications of retreatment (16%), one of which was a fatal hemorrhage in a patient 1 month after intentional partial coil obliteration of a fusiform vertebrobasilar junction aneurysm. Factors important to the selection of treatment modality were recurrence or residual location (all posterior circulation lesions were treated endovascularly), lesion size (lesions larger than 10 mm were treated endovascularly or with the use of combined techniques), and aneurysm morphology (fusiform and wide-necked lesions were treated endovascularly or with the use of combined techniques). CONCLUSION The proper selection of surgical or endovascular treatment for residual and recurrent previously clipped aneurysms can achieve excellent radiographic efficacy with low mortality. Factors important to the selection of treatment by this combined neurovascular team were posterior circulation location, aneurysm size larger than 10 mm, and fusiform morphology, which were treated endovascularly or with the use of combined techniques because of the higher surgical risk associated with these factors. For aneurysms with lower surgical risk, such as some anterior circulation aneurysms and aneurysms smaller than 10 mm, we prefer to perform a reoperation because of superior radiographic cure without compromising the outcome.

scholarly journals A comparison of two methods for predicting changes in the distribution of gene frequency when selection is applied repeatedly to a finite population

1969 ◽  
Vol 13 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Derek J. Pike
Keyword(s):  
Iterative Procedure ◽  
Gene Frequency ◽  
Finite Population ◽  
Transition Matrices ◽  
Single Cycle ◽  
Gene Frequencies ◽  
Mean And Variance ◽  
The Mean ◽  
The One ◽  
Selection Of

Robertson (1960) used probability transition matrices to estimate changes in gene frequency when sampling and selection are applied to a finite population. Curnow & Baker (1968) used Kojima's (1961) approximate formulae for the mean and variance of the change in gene frequency from a single cycle of selection applied to a finite population to develop an iterative procedure for studying the effects of repeated cycles of selection and regeneration. To do this they assumed a beta distribution for the unfixed gene frequencies at each generation.These two methods are discussed and a result used in Kojima's paper is proved. A number of sets of calculations are carried out using both methods and the results are compared to assess the accuracy of Curnow & Baker's method in relation to Robertson's approach.It is found that the one real fault in the Curnow-Baker method is its tendency to fix too high a proportion of the genes, particularly when the initial gene frequency is near to a fixation point. This fault is largely overcome when more individuals are selected. For selection of eight or more individuals the Curnow-Baker method is very accurate and appreciably faster than the transition matrix method.

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