scholarly journals Soil and plant phytoliths from the Acacia-Commiphora mosaics at Oldupai Gorge (Tanzania)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8211 ◽  
Author(s):  
Julio Mercader ◽  
Siobhán Clarke ◽  
Mariam Bundala ◽  
Julien Favreau ◽  
Jamie Inwood ◽  
...  
Keyword(s):  
Community Structure ◽  
Plant Species ◽  
Plant Community ◽  
Fossil Record ◽  
Statistical Significance ◽  
Categorical Variables ◽  
Plant Community Structure ◽  
Chi Square ◽  
The Relationship ◽  
Two Populations

This article studies soil and plant phytoliths from the Eastern Serengeti Plains, specifically the Acacia-Commiphora mosaics from Oldupai Gorge, Tanzania, as present-day analogue for the environment that was contemporaneous with the emergence of the genus Homo. We investigate whether phytolith assemblages from recent soil surfaces reflect plant community structure and composition with fidelity. The materials included 35 topsoil samples and 29 plant species (20 genera, 15 families). Phytoliths were extracted from both soil and botanical samples. Quantification aimed at discovering relationships amongst the soil and plant phytoliths relative distributions through Chi–square independence tests, establishing the statistical significance of the relationship between categorical variables within the two populations. Soil assemblages form a spectrum, or cohort of co-ocurring phytolith classes, that will allow identifying environments similar to those in the Acacia-Commiphora ecozone in the fossil record.

scholarly journals Soil and Plant Phytoliths from the Acacia-Commiphora Mosaics at Oldupai Gorge (Tanzania)

2018 ◽  
Author(s):  
Julio Mercader ◽  
Siobhan Clarke ◽  
Mariam Bundala ◽  
Julien Favreau ◽  
Jamie Inwood ◽  
...  
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Fossil Record ◽  
Statistical Significance ◽  
Categorical Variables ◽  
Plant Community Structure ◽  
Chi Square ◽  
Genus Homo ◽  
The Relationship ◽  
Two Populations

This paper studies soil and plant phytoliths from the Eastern Serengeti Plains, specifically the Acacia-Commiphora mosaics from Oldupai Gorge, Tanzania, as present-day analogue for the environment that was contemporaneous with the emergence of the genus Homo. We investigate whether phytolith assemblages from recent soil surfaces reflect plant community structure and composition with fidelity. The materials included 35 topsoil samples and 29 plant species (20 genera, 15 families). Phytoliths were extracted from both soil and botanical samples. Quantification aimed at discovering relationships amongst the soil and plant phytoliths relative distributions through Chi–square independence tests, establishing the statistical significance of the relationship between categorical variables within the two populations. Soil assemblages form a spectrum, or cohort of co-ocurring phytolith classes, that will allow identifying environments similar to those in the Acacia-Commiphora ecozone in the fossil record.

scholarly journals Altitudinally coordinated pattern of plant community structure in the Shivapuri National Park, Nepal

1970 ◽  
Vol 18 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Shalik Ram Sigdel
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Plant Species ◽  
Plant Community ◽  
National Park ◽  
Climatic Factors ◽  
Flower Colour ◽  
Basal Area ◽  
Plant Community Structure ◽  
Closed Canopy

Study on plant community structure was undertaken in different altitudinal ranges of Shivapuri National Park. The general objective of this study is to analyse different plant community structure in Shivapuri National Park with regards to altitudinal variation. The forest was divided into three distinct altitudinal ranges on the basis of dominancy. In each altitudinal range standard quadrats method was applied for vegetation analysis. The highest number of species was found in site II. All the ecological parameters of the plant species were higher in site II except Basal Area of tree that was highest in site III. The pattern of distribution of plant species was not uniform according to altitude. At higher elevation, the forest was mature with almost closed canopy and trees were large; so the tree density was low. Species richness was highest in site II. Species diversity among tree and shrub species was higher in site I. But for herb species diversity was higher in site II for both seasons. Such type of variations may be due to nature of soil i.e. acidity, nutrient availability and other micro-climatic factors. The most noteworthy thing was that variation in flower colour of Rhododendron arboreum i.e. deep scarlet at low altitude, but it gradually changed into pinkish white as altitude increased. Key words: Altitude, Density, Plant community, Species diversity doi: 10.3126/banko.v18i1.2161 Banko Janakari, Vol. 18, No. 1, 11-17

scholarly journals Index Analysis of Osteonecrosis and Related Causes

2020 ◽  
Author(s):  
Tingting Liu ◽  
Yuju Cao ◽  
Huiqiang Wu ◽  
Feimeng An ◽  
Changxu Han ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Population Sample ◽  
Onset Time ◽  
Categorical Variables ◽  
Control Group ◽  
Case Group ◽  
Chi Square ◽  
Chi Square Test ◽  
The Relationship

Abstract Background: The pathogenesis of non-traumatic osteonecrosis of the femoral head (ONFH ) is related to the interruption of blood supply caused by lipid metabolism and hypercoagulability. The purpose of this study was to explore the relationship between clinical biochemical parameters and non-traumatic ONFH. Methods: The basic information and biochemical indexes of 1292 patients with non- traumatic ONFH and 1880 healthy controls were collected. SPSS software (version 22.0) was used to process and analyze the data. T-test was used for quantitative analysis. Chi-square test was used for categorical variables.p< 0.05 were the index with statistical significance. Results: In the population sample, TC (p= 0.00004), LDL (p= 0.014) and PLT (p= 0.000005) levels were statistically significant between the two groups.In men, levels of TC (p = 0.004), LDL (p= 0.011), and PLT (p= 0.00005) were statistically significant between the two groups.In women, TC (p= 0.001) and PLT (p= 0.048) levels were statistically significant between the two groups.There were differences in TC (p= 0.00001) and PLT (p= 0.031) levels between the case group and the control group in samples aged less than 45 years.There were differences in LDL (p= 0.00002) and PLT (p= 0.022) levels between the two groups in samples older than 45 years.Compared with the control group, patients with alcohol-induced ONFH had HDL (p = 0.002).LDL (p= 0.00002);The level of PLT (p= 0.0001) was significantly different.HDL (p = 0.005) was found in alcohol-induced ONFH patients younger than 45 years of age.The PLT level (p=0.045) was different from that of the control group.There was a difference in LDL (p= 0.000003) levels between control and alcohol-induced ONFH patients older than 45 years.The older the onset age, the TC in vivo;HDL;LDL;ApoA1;ApoB;The lower the PLT level.With the prolongation of the onset time, the PLT level in the patient's body is decreasing continuously.Conclusion: The changes of biochemical indexes are closely related to the occurrence of non-traumatic ONFH. Our research can provide a new direction for the prevention of ONFH.

Relating pine-litter intrusion to plant-community structure in native eucalypt woodland adjacent to Pinus radiata (Pinaceae) plantations

2007 ◽  
Vol 55 (5) ◽  
pp. 521 ◽  
Author(s):  
Andrew C. Baker ◽  
Brad R. Murray ◽  
Grant C. Hose
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Species ◽  
Plant Community ◽  
Plant Species Richness ◽  
Radiata Pine ◽  
Plant Community Structure ◽  
Native Plant ◽  
Native Plant Species ◽  
Eucalypt Woodland

Radiata pine (Pinus radiata D.Don) plantations are often found in close proximity to vegetation set aside for biodiversity conservation. We examined the intrusive effects of radiata pine beyond the confines of plantations by quantifying the penetration of pine litter (needles, cones, twigs and seeds) and wildings from plantations into adjacent eucalypt woodland in the Jenolan Caves Karst Conservation Reserve (south-eastern Australia). We then investigated the relationship between pine-litter intrusion and plant-community structure in adjacent woodland vegetation. We found significantly higher quantities of pine litter and wildings at all sites adjacent to plantations than at reference woodland sites that were not adjacent to plantations. At adjacent sites, pine litter decreased significantly with increasing distance from plantations. Alarmingly, native plant species richness declined and exotic plant species richness increased with increasing quantities of pine litter. Thus, there were fewer native plant species and more exotics in areas bordering pine plantations. Our findings suggest a potentially important link between the intrusion of pine litter and a loss of native biodiversity and facilitation of exotic-species invasion. We suggest the provision of a buffer zone around plantations in order to minimise intrusive impacts of plantations on native biodiversity.

scholarly journals Predictors and Motivation for Seat Belt Use – A Case Study in Bosnia and Herzegovina

2019 ◽  
Vol 31 (3) ◽  
pp. 355-366
Author(s):  
Zoran Injac ◽  
Milan Vujanić ◽  
Dalibor Pešić ◽  
Boris Antić
Keyword(s):  
Statistical Significance ◽  
Seat Belt ◽  
Categorical Variables ◽  
Chi Square ◽  
The Road ◽  
Low Degree ◽  
Chi Square Test ◽  
Seat Belt Use ◽  
The Relationship

The use of seat belts, for drivers and car occupants, results in reducing the rate of fatalities and severe road injuries. In this research, the methodology of the survey was applied through the self-reporting behaviour of the respondents who determined the subjective risk based on the attitudes of the traffic participants. To evaluate the statistical significance of the categorical variables, Pearson's chi-square test was used. For certain groups of examinees, the results of the relationship (association) between socio demographic characteristics were analysed as predictors of behaviour with the degree of seat belt use. Some other predictors of behaviour, such as the road and mood predictors were analysed as well. Interest was also focused on finding out what motivated certain groups of examinees to use the seat belt. Based on the results of this research, it is possible to classify the drivers and car occupants into certain groups with respect to the seat belt use while driving. This can help in determining the ways of eliminating problems related to the low degree of seat belt use.

scholarly journals Significant variations of dangerous exposures during COVID-19 pandemic in Italy: a possible association with the containment measures implemented to reduce the virus transmission

2021 ◽  
Author(s):  
Felice Giordano ◽  
Valeria Margherita Petrolini ◽  
Domenico Spagnolo ◽  
Rosanna Maria Fidente ◽  
Lucrezia Lanciotti ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Laundry Detergent ◽  
Virus Transmission ◽  
Occupational Exposures ◽  
Categorical Variables ◽  
Chi Square ◽  
Specific Product ◽  
Product Categories ◽  
Containment Measures ◽  
The Relationship

Abstract Background: In response to the COVID-19 health emergency, mass media widely spread guidelines to stop the virus transmission, leading to an excessive and unaware use of detergents and disinfectants. In Italy and in other countries this tendency caused a significant increase of exposures to these products in 2020. Evaluating data collected by the Italian Pavia Poison Centre (PPC), this study intends to examine the relationship between the COVID-19 lockdown and the variations of exposures to specific product categories possibly associated to the containment measures implemented.Simultaneously, this work shows the effectiveness of the European Products Categorisation System (EuPCS) in surveillance activities of dangerous chemicals.Methods: Exposure cases managed by the PPC during March-May 2020 (lockdown) and during the same months of 2017-2018-2019 were compared. Differences in categorical variables were tested with the Chi-square test. The level of significance was set at Alpha = 0.05. The study included all EuPCS groups but specifically focused on cleaners, detergents, biocides and cosmetics. Results: During the lockdown calls from private citizens significantly increased (+11.5%, p<0.001) and occupational exposures decreased (-11.7%, p<0.05). Among Cleaners, exposures to Bleaches slightly increased while Drain cleaning products went through a significant reduction (-13.9%, p<0.05). An increase of exposures to Disinfectants was observed (+7.7%, p<0.01), particularly to those for surfaces (+6.8%, p<0.05). Regarding Cosmetics, both handwashing soaps and gel products significantly increased (respectively: +25.0 and +9.7%, p<0.05).Among children 1-5 years, the statistical significance is reached with exposures to Dishwashing detergents (+13.1%), handwashing soaps (+28.6%, p<0.05) and handwashing gel products (+16.8%, p=0.01). Contrarily, Liquid Laundry Detergent Capsules significantly decreased (-25%; p=0.001). The general severity of exposures decreased (Moderate: -10.1%, p<0.001). Conclusions: This study investigated the relationship between the COVID-19 lockdown and the variations of exposures to some product categories related to the containment measures. The results obtained support any action to be taken by Competent Authorities to implement measures for a safer use of cleaners/disinfectants. This paper shows the benefit in applying the EuPCS to categorize products according to their intended use, though an extension of this system to products not covered by CLP Regulation may be a further advantage.

scholarly journals Linkage Disequilibrium in Domestic Sheep

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1113-1122
Author(s):  
A F McRae ◽  
J C McEwan ◽  
K G Dodds ◽  
T Wilson ◽  
A M Crawford ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Type I Error ◽  
Statistical Significance ◽  
Domestic Sheep ◽  
Type I ◽  
Single Nucleotide ◽  
Microsatellite Genotype ◽  
Marker Distance ◽  
The Relationship ◽  
Two Populations

Abstract The last decade has seen a dramatic increase in the number of livestock QTL mapping studies. The next challenge awaiting livestock geneticists is to determine the actual genes responsible for variation of economically important traits. With the advent of high density single nucleotide polymorphism (SNP) maps, it may be possible to fine map genes by exploiting linkage disequilibrium between genes of interest and adjacent markers. However, the extent of linkage disequilibrium (LD) is generally unknown for livestock populations. In this article microsatellite genotype data are used to assess the extent of LD in two populations of domestic sheep. High levels of LD were found to extend for tens of centimorgans and declined as a function of marker distance. However, LD was also frequently observed between unlinked markers. The prospects for LD mapping in livestock appear encouraging provided that type I error can be minimized. Properties of the multiallelic LD coefficient D′ were also explored. D′ was found to be significantly related to marker heterozygosity, although the relationship did not appear to unduly influence the overall conclusions. Of potentially greater concern was the observation that D′ may be skewed when rare alleles are present. It is recommended that the statistical significance of LD is used in conjunction with coefficients such as D′ to determine the true extent of LD.

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