scholarly journals Variation in Drosophila sensory bristle number at ‘Evolution Canyon’

2002 ◽  
Vol 80 (3) ◽  
pp. 215-223 ◽  
Author(s):  
RICHARD F. LYMAN ◽  
EVIATAR NEVO ◽  
TRUDY F. C. MACKAY
Keyword(s):  
Environmental Gradients ◽  
Extreme Environments ◽  
Geographic Scale ◽  
Thermal Environments ◽  
The North ◽  
Relative Contribution ◽  
Bristle Number ◽  
Evolution Canyon ◽  
The Difference ◽  
North And South

‘Evolution Canyon’ on Mount Carmel, Israel, displays highly contrasting physical and biotic environments on a micro-geographic scale, and is a natural laboratory for investigating genetic responses to variable and extreme environments across species. Samples of Drosophila melanogaster and D. simulans were collected from three sites each on the north- and south-facing slopes of the canyon along altitudinal transects, and one site on the valley floor. Numbers of abdominal and sternopleural sensory bristles were recorded for each of these subpopulations in three thermal environments. In D. simulans, sternopleural bristle number exhibited micro-geographic differentiation between the north- and south-facing slopes, while abdominal bristle number was stable across subpopulations. In D. melanogaster, the magnitudes of the difference in mean sternopleural bristle number between the north- and south-facing slopes and of mean abdominal bristle number along the altitudinal gradients were both conditional on rearing temperature. Thus, the pattern of genetic variation between sites was consistent with underlying heterogeneity of genetic mechanisms for response to the same environmental gradients between traits and sibling species. In contrast, the genetic architecture of bristle number at the level of variation within populations was very similar between species for the same bristle trait, although the two traits differed in the relative contribution of genotype by temperature and genotype by sex interaction.

The Difference of Being Overweight or Obese between the North and South of China

2020 ◽  
Author(s):  
Daisheng Tang ◽  
Tao Bu ◽  
Yahong Liu ◽  
Xuefan Dong
Keyword(s):  
Logistic Regression ◽  
Dietary Patterns ◽  
Odds Ratio ◽  
Nutrition Survey ◽  
High Intake ◽  
Related Information ◽  
The North ◽  
Health Related ◽  
The Difference ◽  
North And South

Abstract Objectives: The geographical environment, dietary culture, food patterns, and obesity rates are substantially different between the North and South of China. Determining the geographical distribution and local dietary patterns involved in being overweight or obese is useful for designing intervention strategies. Methods: Residents between 18 and 65 years old (n=10,863) from 11 Chinese provinces (five Northern provinces and six Southern provinces) were selected to compare dietary patterns, BMI, and health-related information from the China Health and Nutrition Survey packages in 2011. Linear and logistic regression analyses were performed to assess the strength of the association among geographic variables, the obesity problem, and dietary patterns. Results: The overall prevalence of being overweight or obese was 10.51% higher in the North than in the South. Northern dietary patterns feature a high intake of wheat and soybeans, whereas Southern dietary patterns feature a high intake of rice, vegetables, meat, and poultry. The estimated coefficient of regional variables surrounding dietary score is 1.494; surrounding the odds ratio for being overweight is 1.681, whereas surrounding the odds ratio for obesity is 2.035. Multivariate logistic regression including both the variable of South–North areas and Northern dietary patterns showed a significant correlation with being overweight or obese. Conclusion: Northern areas and their local dietary patterns are more likely to contribute to being overweight or obese. These findings provide support for tracking the progression of obesity, epidemics, and policies that target the ‘‘obesogenic’’ environment, promoting opportunities for persons to access healthy dietary patterns and nutritional balance.

scholarly journals Measuring the local dark matter density with LAMOST DR5 and Gaia DR2

2020 ◽  
Vol 495 (4) ◽  
pp. 4828-4844 ◽  
Author(s):  
Rui Guo ◽  
Chao Liu ◽  
Shude Mao ◽  
Xiang-Xiang Xue ◽  
R J Long ◽  
...  
Keyword(s):  
Dark Matter ◽  
Azimuthal Angle ◽  
Matter Density ◽  
Dwarf Stars ◽  
Dark Matter Density ◽  
The North ◽  
Vertical Data ◽  
Data Release ◽  
The Difference ◽  
North And South

ABSTRACT We apply the vertical Jeans equation to the kinematics of Milky Way stars in the solar neighbourhood to measure the local dark matter density. More than 90 000 G- and K-type dwarf stars are selected from the cross-matched sample of LAMOST (Large Sky Area Multi-Object Fibre Spectroscopic Telescope) fifth data release and Gaia second data release for our analyses. The mass models applied consist of a single exponential stellar disc, a razor thin gas disc, and a constant dark matter density. We first consider the simplified vertical Jeans equation that ignores the tilt term and assumes a flat rotation curve. Under a Gaussian prior on the total stellar surface density, the local dark matter density inferred from Markov chain Monte Carlo simulations is $0.0133_{-0.0022}^{+0.0024}\ {\rm M}_{\odot }\, {\rm pc}^{-3}$. The local dark matter densities for subsamples in an azimuthal angle range of −10° < ϕ < 5° are consistent within their 1σ errors. However, the northern and southern subsamples show a large discrepancy due to plateaux in the northern and southern vertical velocity dispersion profiles. These plateaux may be the cause of the different estimates of the dark matter density between the north and south. Taking the tilt term into account has little effect on the parameter estimations and does not explain the north and south asymmetry. Taking half of the difference of σz profiles as unknown systematic errors, we then obtain consistent measurements for the northern and southern subsamples. We discuss the influence of the vertical data range, the scale height of the tracer population, the vertical distribution of stars, and the sample size on the uncertainty of the determination of the local dark matter density.

The growth pattern of the African tortoise Geochelone pardalis and other chelonians

1999 ◽  
Vol 77 (2) ◽  
pp. 181-193 ◽  
Author(s):  
Adrian Hailey ◽  
Ian M Coulson
Keyword(s):  
Growth Pattern ◽  
High Growth ◽  
Growth Patterns ◽  
Growth Rings ◽  
Frequency Distributions ◽  
The North ◽  
Body Sizes ◽  
Biased Sex Ratio ◽  
The Difference ◽  
North And South

Growth rings were measured in dead African leopard tortoises, Geochelone pardalis, collected in the seasonal tropics of Zimbabwe over an 11-year period. A series of Ford-Walford plots using growth measured from annuli showed that growth fitted a logistic by mass curve best, logistic by length and Gompertz curves less well, and a Bertalanffy curve least well. The Bertalanffy curve, often fitted to growth of chelonians, is characterised by particularly high growth rates of juveniles compared with larger individuals. It is suggested that this growth pattern is likely to be found in species showing a marked decrease in diet quality with size. This hypothesis is supported by a review of growth patterns in chelonians: Bertalanffy curves are associated with an omnivorous (and thus potentially variable) diet and other growth patterns with an obligate carnivorous or herbivorous diet. Geochelone pardalis in Zimbabwe showed significant sexual size dimorphism, the mean asymptotic mass of females being 1.7 times that of males, unlike populations with larger body sizes to the north and south. Annual survival estimated from age-frequency distributions was significantly higher in males (0.80) than in females (0.72), the difference being sufficient to account for the male-biased sex ratio of live animals.

scholarly journals Analysis of Screening Results of 1012 Sperm Donors in China: A Retrospective Cohort Study of Geographic Differences in Semen Quality

2021 ◽  
Author(s):  
Qian-Cheng Zhao ◽  
Zhe Zhang ◽  
Lian-Ming Zhao ◽  
Zhen-Feng Deng ◽  
Jiang-Man Gao ◽  
...  
Keyword(s):  
Semen Quality ◽  
Sperm Concentration ◽  
Strong Relationship ◽  
Male Reproduction ◽  
Geographical Differences ◽  
Sperm Donors ◽  
The North ◽  
Significant Difference ◽  
The Difference ◽  
North And South

Abstract Male reproductive health has become a concern in public health, and semen quality is essential to male reproduction. To investigate the geographical differences in semen quality of sperm donors from the north and south of China, a total of 1012 sperm donors from all over China were enrolled in this work, which were divided by their residential latitude. There were statistically significant differences in sperm concentration among men from different latitudes in China(P=0.04). The sperm concentrations of people from 18°-27° north latitude were lower than those from 36°-45°, and 45°-54° (median 131, 134, 146, respectively, P=0.021[18°-27° vs. 36°-45°] and P=0.01[18°-27° vs. 45°-54°]). It was further confirmed when the samples were re-divided into 2 groups (typically north and south) that contains 667 samples. The analysis also showed a significant difference in terms of the regions to which the samples belonged (the median of the north is 134; the median of the south is 125; P =0.015). Although other sperm parameters don’t show significant change with latitude, some of them possess a strong relationship with sperm concentration (r=-0.19364, P<0.001). Specifically, we suppose that environmental pollution and mental stress due to increased population may be the main factors in the difference.

Genetic differentiation and inversion clines in Indian natural populations of Drosophila melanogaster

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Aparup Das ◽  
B. N. Singh
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Differentiation ◽  
Natural Populations ◽  
The South ◽  
The North ◽  
Chromosome Inversions ◽  
The Difference ◽  
And Inversion ◽  
First Time ◽  
North And South

To study the genetic differentiation and inversion clines in Indian natural populations of Drosophila melanogaster, 14 natural populations (6 from the north and 8 from the south) were screened for chromosome inversions. The chromosomal analysis revealed the presence of 23 paracentric inversions, which include 4 common cosmopolitan, 4 rare cosmopolitan, 2 recurrent endemic, and 13 unique endemic (new inversions detected for the first time) inversions. The difference in karyotype frequencies between populations from the north and south were highly significant and the level of inversion heterozygosity was higher in populations from the south. Statistically significant negative correlations were found between each of the four common cosmopolitan inversions and latitude. These findings are in accord with results from other worldwide geographic regions and show that Indian populations of D. melanogaster have undergone considerable genetic differentiation at the level of inversion polymorphism.Key words: Drosophila melanogaster, Indian natural populations, chromosome inversions, genetic differentiation, north–south clines.

Hemispheric Asymmetry in the Mars Summer Ionosphere at Various Solar Forcing Conditions

2020 ◽  
Author(s):  
Marcin Pilinski ◽  
Laila Andersson ◽  
Ed Thiemann
Keyword(s):  
Magnetic Fields ◽  
Electron Temperature ◽  
Southern Hemisphere ◽  
Polar Regions ◽  
The North ◽  
Northern Summer ◽  
Solar Wind Magnetic Field ◽  
The Difference ◽  
North And South ◽  
Ionospheric Dynamics

&lt;p&gt;The MAVEN satellite has now made two Martian-years of ionosphere-thermosphere (I-T) observations enabling limited studies of seasonal changes in the upper atmosphere. Before examining the ionospheric dynamics associated with space weather, we wish to understand the climatological conditions of the system.&amp;#160; For example, previous studies have revealed the morning electron temperature overshoot as well as a close dependence between electron temperatures and neutral densities in the equatorial regions. In this presentation, we will examine differences in the northern and southern dayside ionosphere during the summer season of each hemisphere. The differences between these two cases will be contrasted with the seasonal dependence at the equator. Differences between the equatorial and polar regions are expected due to (A) differences in neutral scale heights, (B) differences in the solar zenith angle, and (C) the equilibration of I-T coupling due to differences in solar illumination.&lt;/p&gt;&lt;p&gt;In this work, we present a statistical analysis of MAVEN measurements comparing the north and south summer I-T. We find that when controlling for neutral pressure and latitude, the north and south plasma densities and temperatures are nearly identical below the demagnetization altitude (higher neutral pressures). Above the demagnetization altitude (lower neutral pressures), the southern hemisphere electron densities are higher than those in the northern hemisphere by ~100%. A significantly lower electron temperature is also observed in the south at these lower pressures. Given that the difference in solar EUV (and corresponding neutral heating) is ~20% between the two summer seasons, we postulate that the significantly lower plasma densities (above the demagnetization altitude) in the northern summer are due in part to an increase in ionospheric loss. This loss may be associated with the acceleration of ionospheric particles by the draped magnetic fields at an altitude where ions are not demagnetized. Furthermore, the loss may be diminished in the southern hemisphere where crustal magnetic fields increase the standoff distance to the solar wind magnetic field.&lt;/p&gt;

scholarly journals Study of Social Capital in the North and South Neighborhoods (The Case of Sari City, Iran)

2016 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Ghorbanali Ebrahimi ◽  
Hadi Razeghimaleh ◽  
Ali Babazadeh ◽  
Sabah Motevalian
Keyword(s):  
Social Capital ◽  
Mean Value ◽  
Urban Neighborhoods ◽  
The South ◽  
Statistical Population ◽  
The North ◽  
Neighborhood Social Capital ◽  
Significant Difference ◽  
The Difference ◽  
North And South

The main objective of this study was to find answer to this question as whether there is a difference in the social capital between the North and South urban neighborhoods. The data of the current study were collected through a questionnaire. The statistical population of this study included subjects aged 18 and above, and sample size consisted of 450 people.The findings of this study indicated that there was a significant difference between North and South neighborhoods of Sari, Iran, with regard to the neighborhood social capital. This means that the mean social capital in the South of city (3.58 out of 5) was higher than that of North of city (1.78 out of 5). The difference was also true for all aspects of neighborhood social capital in North and South urban neighborhoods of Sari. Furthermore, in all aspects of neighborhood social capital, the South neighborhoods had a higher mean value than North urban neighborhoods.

scholarly journals The True North Urgency of the Earth in Determining the Direction of the Qibla According to Fiqh and Falak Science

2020 ◽  
Vol 3 (4) ◽  
pp. 3353-3358
Author(s):  
Asmuni Asmuni ◽  
Hasan Matsum ◽  
Imamul Muttaqin
Keyword(s):  
North Pole ◽  
The North ◽  
Axis Of Rotation ◽  
The Earth ◽  
North Direction ◽  
Magnetic Declination ◽  
Magnetic Model ◽  
The Difference ◽  
Magnetic North ◽  
North And South

True North true north is any point on the earth to the North pole, this is because the North and South poles point precisely to the earth's axis of rotation. Therefore true north is North based on the earth's axis not North based on the earth's magnetism. So the difference is true North shows the true north direction of the earth while magnetic North is the North direction of the magnetic compass needle. Magnetic north does not coincide with Earth's true north. To find out the true North of the earth using a compass, you need to know the magnetic declination first. To know the magnetic declination can be done through a magnetic declination calculator such as WMM (world magnetic model) which can be downloaded through the crowdmag application playstore. In determining the direction of the Qibla it is required to determine the True North point of the earth.

Geological conditions of coal bed methane occurrence in Handan - Fengfeng Mining area

2014 ◽  
Vol 11 (5) ◽  
pp. 481-486
Author(s):  
Guoqiang Hao ◽  
Yifeng Yang ◽  
Chao Jin
Keyword(s):  
Mining Area ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
The North ◽  
Geological Conditions ◽  
Resources Distribution ◽  
Cap Rock ◽  
Geological Factors ◽  
The Difference ◽  
North And South

The coal bed methane resources distribution of Handan - Fengfeng Mining area has the features of "richness in the midland and north while poorness in the south, and richness in the east while poorness in the west. Through the analysis of the geological factors causing the above phenomena, we get that: the coal metamorphism and hydrogeological condition are the major controlling factors, the former controls the north and south difference of coal bed methane resources distribution from the two aspects covering gas-generated quantity and adsorption capacity, while the latter controls the east and west difference of coal bed methane resources distribution; syncline and good cap rock conditions are necessary conditions for coal bed methane enrichment, but not the reason for causing the difference of coal bed methane resources distribution.

scholarly journals Fruitfulness of Georgian Oak (Quvercus iberica Stev.) in Kakheti Region

2021 ◽  
Author(s):  
Malkhaz Samadashvili
Keyword(s):  
Sea Level ◽  
Seed Yield ◽  
Forest Type ◽  
Tree Trunk ◽  
Seed Material ◽  
The North ◽  
The Difference ◽  
Average Size ◽  
North And South

We studied the fruitfulness of Georgian Oak in Kakheti Region: in the gorge of the river Batsara in Akhmeta municipality at an altitude of 650-700m above the sea level, with oak dominance in a grove represented by a slope of up to 150 slopes of south-western exposure. Akhmeta municipality of Kakheti region was selected for the study of the issue, where in two different ecotopes and forest-type groves, sample areas with a size of 50 X 50 m were taken..In addition, we have divided the model tree drills allocated to the sample areas into two parts, namely, the parts facing the north and south exposures, and several sections of the tree trunk - the lower, middle and upper sections. Separately, we studied the seed yield and the difference between these indicators in terms of both exposure and vertical parts of the exercise - both quantitatively and by weight. We also observed the shape, size and other characteristics of the oak fruits on the sample areas, according to which the shape of the oak is oval, slightly elongated, with an average size of 2.8 cm. Length and 1.1 cm. Width. On average, 655 pieces (65.5%) of the fruit were found to be fit - healthy, and the rest (34.5%) - underdeveloped, damaged and incapable of emergence. These indicators are of great importance in the production of forestry and cultural works. In all sample areas, due to the better quality of insolation, the oak productivity is better in the southern part than in the north. With proper protection and care in the Georgian oak groves of Kakheti, it is possible to get an average of 1 ton of fruit per 1 ha, which is quite enough to achieve the best indicators of its natural renewal and to prevent these difficult problems. As we can see from the Georgian oak cultivations we have studied, in the vicinity of Akhmeta municipality (Batsari River gorge) it is possible to get an average of 1 ton of seed material, which is quite enough to get a reliable adult in terms of protecting the farm and promoting natural renewal.

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