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.

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.

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.

Age and growth of the squid Todaropsis eblanae (Cephalopoda: Ommastrephidae) on the north-west African shelf

2000 ◽  
Vol 80 (4) ◽  
pp. 747-748 ◽  
Author(s):  
Alexander I. Arkhipkin ◽  
Vladimir V. Laptikhovsky
Keyword(s):  
High Growth ◽  
West African ◽  
Age And Growth ◽  
Length Frequency ◽  
Annual Life Cycle ◽  
Frequency Distributions ◽  
North West ◽  
The North ◽  
West African Coast ◽  
African Coast

Length composition, maturation and growth of the ommastrephid squid Todaropsis eblanae were studied using length–frequency distributions (LFDs) and statoliths of squid caught off the north-west African coast. Length–frequency distributions were quite similar in all seasons studied, indicating all year round spawning. However, both high proportions of mature squid in the winter and the hatching peak of squid from our sample in spring suggested the winter–spring peak of spawning. Immature and maturing squid had rather high growth rates, attaining 140—150 mm of dorsal mantle length (ML) by the age of 160—170 d. Todaropsis eblanae is likely to have an annual life cycle on the north-west African shelf.

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.

scholarly journals Analisis Dikotomi Ruang dan Ekonomi di Kabupaten Sragen, Jawa Tengah

2020 ◽  
Vol 3 (2) ◽  
pp. 175-189
Author(s):  
Nurfina Ike Ayuningtyas
Keyword(s):  
Economic Growth ◽  
Competitive Ability ◽  
High Growth ◽  
Spatial Feature ◽  
The North ◽  
Central Java ◽  
Final Output ◽  
North And South ◽  
Central Java Province

Sragen Regency can be divided into two areas based on its tiphologycal feature, that are the north and south part area of Bengawan Solo River. Those area not only have a different kind of soil based on tiphology but also have different degree of economic growth. The goals of this paper are to define which part of the Sragen Regency that has a high and low economic growth and what kind of policies that match with the problems of those areas. The method used in this paper is dividing the area of Sragen Regency into four part based on spatial feature and the economic growth. The result are, the area that have a high growth mostly located in south part of Bengawan solo and the area that have a low growth mostly located in north parth of Bengawan Solo.The policies for the low growth areas is driven to strengthen the main sector and to develop another promising sector that can be used to increase society income. While, the policies for the high growth areas mainly driven to find an indigenous product that can be used to determined the identity of the whole region, and also to make the final output resulted from the areas having a competitive ability against another region in the Central Java Province.

scholarly journals Spatio-temporal variability in growth of juvenile sparid fishes from the Mediterranean littoral zone

1999 ◽  
Vol 79 (1) ◽  
pp. 137-143 ◽  
Author(s):  
S. Planes ◽  
E. Macpherson ◽  
F. Biagi ◽  
A. Garcia-Rubies ◽  
J. Harmelin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Spatial Scales ◽  
Western Mediterranean ◽  
Underwater Visual Census ◽  
Frequency Distributions ◽  
Diplodus Puntazzo ◽  
The North ◽  
Western Mediterranean Sea ◽  
Spatio Temporal ◽  
The Difference

Populations of three species of juvenile Sparidae (Diplodus puntazzo, Diplodus sargus and Diplodus vulgaris) were sampled at different spatial scales in the north-western Mediterranean Sea over two years to follow growth after settlement. Length–frequency distributions were collected each week for periods of six months following the arrival of off-shore larvae in inshore habitats. Data were collected by underwater visual census along permanent transects.Growth rate measured as the slope of the linear relationship between mean size and time varied between species. Diplodus puntazzo (0.160 mm d−1) and D. vulgaris (0.202 mm d−1), which are settling in winter experienced slower growth than D. sargus (0.567 mm d−1) which settles in summer. It is concluded that the difference was in part due to water temperature. Analysis of growth rate within each species also revealed significant differences among sites probably related to the currents and the water mass temperatures.

Developmental and growth patterns in Xiphinema parasimile and X. simile (Nematoda: Dorylaimida), members of the X. americanum-group

Nematology ◽  
2009 ◽  
Vol 11 (2) ◽  
pp. 267-273
Author(s):  
László Barsi
Keyword(s):  
Body Length ◽  
Growth Pattern ◽  
Developmental Stages ◽  
Growth Patterns ◽  
Body Volume ◽  
Data Sets ◽  
Embryonic Growth ◽  
Juvenile Stages ◽  
The Mean ◽  
The Difference

AbstractXiphinema parasimile and X. simile are morphologically and morphometrically very similar, yet molecularly different, species with different developmental and growth patterns, a different number of juvenile developmental stages (four vs three) and a different post-embryonic growth pattern. Body length, body volume and odontostyle and replacement odontostyle lengths served for comparison of the post-embryonic growth patterns in these species. A percentage method was used to make the data sets comparable between one population of X. parasimile and three populations of X. simile. The mean body lengths of the first, second and pre-adult stages in X. simile showed similarity with those of the second, third and pre-adult stages in X. parasimile. In X. simile there was no unique growth pattern of body length and body volume from stage to stage applicable for all populations, just a similar trend with more or less similar values. The difference between replacement odontostyle and functional odontostyle lengths in all juvenile stages was higher in X. simile and lower in X. parasimile, despite the very similar mean odontostyle length in the female stage of both species.

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;

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