scholarly journals Intra-Specific Variability in Whorl Growth-Rate among Land Gastropods with Conispirally-Coiled Shells

2021 ◽  
pp. 59-69
Author(s):  
Jean Béguinot
Keyword(s):  
Growth Rate ◽  
Statistical Significance ◽  
Repeated Measurements ◽  
Species Level ◽  
Shell Shape ◽  
Snail Species ◽  
Strong Positive Correlation ◽  
Shell Size ◽  
Strong Negative Correlation ◽  
Species Specific

For most conispirally-coiled Gastropods with determinate growth, the geometry of spirally-winding whorls is usually constrained by a strong negative correlation between whorl growth rate and the number of whorls reached at adulthood, as originally reported by the late S.J. Gould. Yet, beyond the tight control of shell-shape at the species level – resulting from this constraint – what about the amplitude of the intra-specific variability of whorl growth-rate, partly contributing to the variability of the overall shell-size at the species level? I address the issue by designing and implementing a new, indirect method for routinely evaluating whorl growth-rate, thereby aiming at considerably saving measurement time, and making it possible to easily achieve repeated measurements across samples large enough to reach statistical significance. This approach was applied to a series of eight common land snail species. The amplitude of intra-specific variability in whorl growth, evaluated this way, proves: (i) being markedly different among the eight investigated species (by a factor that can exceed 2x); (ii) being, yet, high enough, in all cases, to require compensating variations in the adult number of whorls, so as to limit the resulting consequences on the amplitude of the intra-specific variability of adult shell-size. Despite those marked differences in the amplitudes of intra-specific variability of whorl growth-rate among species, no significant relationship was observed between intraspecific variability of whorl growth rate and species-specific shell-shape types (discoidal/globular/elongate) and only weak positive relationship was observed with species-specific typical shell sizes. However, a rather strong positive correlation was found, as expected, between the degree of intra-specific variability of the whorl growth-rate and the degree of intra-specific variability of the number of whorls reached at adulthood (with the yet unexplained exception of one among the eight investigated species).

scholarly journals Adult Shell-size Regulation in Conispirally-coiled Shells: Evidence for a Widespread Negative Covariance between Whorls Growth-rate and the Final Number of Whorls in Land Snails

2021 ◽  
pp. 95-106
Author(s):  
Jean Béguinot
Keyword(s):  
Growth Rate ◽  
Present Report ◽  
Land Snail ◽  
Land Snails ◽  
Snail Species ◽  
Shell Size ◽  
Regulation Process ◽  
Intraspecific Variations ◽  
Taxonomic Range ◽  
Species Specific

As shown, in particular, by the late S.J. Gould, the involvement of a regulation process, aiming at limiting the range of intraspecific variations in adult shell size, in those land snail species with determinate growth, can be indirectly, but conveniently, diagnosed by highlighting a negative covariance between the whorls growth-rate and the whorls number reached at adulthood. However, up to now, such kind of regulation had only been demonstrated in very few cases among land snails and shelled Gastropods in general. Accordingly, quite more extensive checking is required, across both the taxonomic spectrum and the geometrical range of shell profiles. The present report is a very preliminary contribution addressing these issues, which have been neglected for too long. Considering a still limited number of eight species, yet largely encompassing both taxonomic range and shell profiles, it is shown that strong negative covariances between whorls growth-rate and whorls number are systematically highlighted, thereby supporting the involvement of an efficient regulation process of adult shell size and shape in each eight species. Moreover, the degree of regulation of the adult shell size has been quantified and this regulation proves being remarkably effective as a whole, while yet remaining highly species-specific, with very significant disparities among species – and this, somewhat surprisingly, being quite irrespective of the type of geometrical profiles of shells, among the studied species.

scholarly journals Some parameters of growth in the common intertidal barnacle, Balanus balanoides (L.)

1959 ◽  
Vol 38 (3) ◽  
pp. 581-587 ◽  
Author(s):  
H. Barnes ◽  
Margaret Barnes
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Nitrogen Content ◽  
Repeated Measurements ◽  
Shell Size ◽  
Sedentary Animal ◽  
The Common ◽  
Living Material ◽  
Living Tissues ◽  
Balanus Balanoides

It is difficult to determine the weight or nitrogen content of the living tissues of an operculate barnacle without destroying it. It has been customary, there-fore, in ecological work to express growth in terms of various parameters determined from repeated measurements of the shell. Moore (1934) employed shell volume calculated from the height and basal diameters; others (Costlow & Bookhout, 1953, 1956; Mawatari, Hirosaki & Kobayashi, 1954a, b) have used the area of the basis. Most commonly, however, in growth-rate studies the length of the basis measured through the rostro-carinal axis has been used (Hatton, 1938; Barnes & Powell, 1953). Recently, working with animals cultured in the laboratory when the cast of an individual could be obtained subsequent to ecdysis, Costlow & Bookhout (1957) have used the size of the mouthparts as a measure of growth after first establishing their relation to body size. The space, both areal and volumetric, occupied by a sedentary animal is of primary importance in studies of its ecology and measurements of shell-size are, therefore, adequate for many purposes. For some aspects of growth and ecology it is, nevertheless, very desirable that the relation between such parameters and others, more directly connected with the living material, should be established.

scholarly journals Correlation between level of adipocytokines with body composition and heart rate recovery indices

2020 ◽  
Vol 71 (2) ◽  
pp. 26-33
Author(s):  
Marko Ristić ◽  
Marina Đelić
Keyword(s):  
Heart Rate ◽  
Body Composition ◽  
Heart Rate Recovery ◽  
Statistical Significance ◽  
Body Height ◽  
Rank Correlation ◽  
Strong Positive Correlation ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
National Team

Introduction: Adipose tissue as an endocrine organ primarily regulates metabolism of carbohydrates and lipids. Anorexigenic hormone leptin increases sympathetic activity and decreases insulin secretion, thereby reducing energy depots, while adiponectin elevates tissue sensitivity to insulin, which role visfatin imitates. Heart rate recovery index (DHRR), linked with insulin resistance syndrome, reflects parasympathetic function. Our goal was to analyze correlation between adipocytokines with body composition and DHRR in athletes and sedentary controls. Material and methods: Research included 19 volleyball and water polo national team members (mean age 19.26 ± 1.94 years) and 13 physically inactive male students (mean age 20.46 ± 1.13 years). Anthropometric data were measured and blood samples for hormone analysis were taken: at the beginning, the end and 30 minutes after finishing ergospirometry. Statistical evaluation was performed using: Student's t-test, Mann-Whitney, Wilcoxon's and Spearman's rank correlation test. Results: Adiponectin levels between dependent and independent variables didn't show statistical significance. Leptin level, noteworthy lower in athletes, at the beginning and the end of the test (p < 0.001 and p = 0.001, respectively), was declining in students in every before-after study aspect (p < 0.001 in each case). Visfatin was higher in sportsmen at the end of the test and 30 minutes later (p < 0.001 in both cases), but their levels decreased comparing the beginning and 30 minutes after the test (p = 0.02). Body height, VO2 max and DHRR3 were considerably higher in athletes, just as BMI, BF% and HR in the third minute of recovery were in controls (p < 0.05). Sportsmen had moderately strong negative correlation of visfatin with BF% (p = 0.002, RS = -0.674), whilst leptin showed moderately strong positive correlation with BMI and BF% (p = 0.002, RS = -0.657 and p = 0.011, RS = 0.567), respectively. Controls demonstrated strong and moderately strong positive correlation between leptin with DHRR1 (p = 0.008, RS = 0.702) and DHRR3 (p = 0.018, RS = 0.641), respectively. Conclusion: Research showed positive correlation between visfatin with BF% and leptin with BMI and BF% in athletes, considering small number of participants.

scholarly journals Change of Blink Rate in Viewing Virtual Reality with HMD

Symmetry ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 400 ◽  
Author(s):  
Jungho Kim ◽  
Yadav Sunil Kumar ◽  
Jisang Yoo ◽  
Soonchul Kwon
Keyword(s):  
Virtual Reality ◽  
Correlation Analysis ◽  
Negative Correlation ◽  
Statistical Significance ◽  
Near Field ◽  
Blink Rate ◽  
Strong Positive Correlation ◽  
Strong Negative Correlation ◽  
Eye Blink ◽  
Head Mounted Display

The eye blink rate, a major human physiological response, directly affects ocular diseases, such as keratitis and dry eye syndrome. It has been shown that the eye blink rate in normal eyes has a certain frequency for individuals, from 6–30 times/min. It was suggested in a previous study that the eye blink rate can be decreased during the viewing of high-intensity and realistic content. Therefore, in this paper, we examine the change of the eye blink rate during the HMD (head-mounted display) viewing of VR (virtual reality) contents; accordingly, we propose an algorithm to measure the eye blink rate as well as compare and analyze this rate in three different environments (natural, monitor, and HMD). We confirmed that IPD (interpupillary distance) and phoria affected the eye blink rate in each environment. In this experiment, 21 subjects (28.38 ± 6.87 years) were selected, and a paired t-test was performed for changes in the eye blink rate over 1 min for each environment. The IPD and phoria effects on the eye blink rate were confirmed using the Spearman’s correlation coefficient. In this experiment, the eye blink rate was decreased in the monitor and HMD environments compared with the natural environment, while that in the HMD environment was decreased compared with the monitor environment. The results of the correlation analysis of far IPD and the eye blink rate show no statistical significance or correlation. The correlation analysis of near IPD and the eye blink rate showed a strong positive correlation of the eye blink rate in the monitor environment. The correlation analysis of distance phoria and the eye blink rate showed a strong negative correlation of the eye blink rate in the HMD environment. The correlation analysis of near-field phoria and the eye blink rate showed a strong negative correlation of the eye blink rate in the HMD environment. It is expected that the results of this study will be used as a VR-viewing recommendation.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

scholarly journals Effect of genotype, age of hens and K/k allele on eggshell quality

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 242-249 ◽  
Author(s):  
Z. Ledvinka ◽  
L. Zita ◽  
M. Hubený ◽  
E. Tůmová ◽  
M. Tyller ◽  
...  
Keyword(s):  
Growth Rate ◽  
Egg Production ◽  
Statistical Significance ◽  
Live Weight ◽  
Shape Index ◽  
Feed Mixture ◽  
Eggshell Quality ◽  
Feather Growth ◽  
Two Factors ◽  
The Relationship

We assessed the influence of the particular genotype, age of layers, feather growth-rate gene, and their mutual interactions on selected indicators of eggshell quality in six groups of hens of the laying type Dominant. The following genotypes were examined in the experiment: Barred Plymouth Rock, Dominant BPR 951 (K) strain, slow-feathering; Barred Plymouth Rock, Dominant BPR 901 (k) strain, fast-feathering; Blue Plymouth Rock, Dominant BLPR 954 (K) strain, slow-feathering; Blue Plymouth Rock, Dominant BLPR 894 (k) strain, fast-feathering; crossbreds of the above strains in the F<sub>1</sub> generation Dominant D 107 blue (K), slow-feathering and Dominant D 107 blue (k), fast-feathering. The layers were fed a feed mixture NP1 (16.64 % CP) from the 20<sup>th</sup> week of age and a feed mixture NP2 (15.02% CP) from the 42<sup>nd</sup> week. Husbandry conditions met the regular requirements of laying hens. Egg production and live weight of hens were monitored for the duration of the experiment (12 months). Eggshell quality was examined at the layers' age of 27, 35 and 56 weeks. The average hen-day egg production for the duration of the experiment (12 months) was not significantly influenced by the particular genotype or the feather growth-rate gene. The varying representation of the feather growth-rate gene significantly (P &le; 0.001) influenced the live weight; similarly, the relationship between the genotype and the representation of K/k alleles was significant. The average egg weight was influenced statistically significantly (P &le; 0.001) by the age of hens, their genotype (P &le; 0.05), feather growth-rate gene (P &le; 0.001), and the relationship between the age and genotype (P &le; 0.001). The age of hens, genotype, and the interaction of these two factors affected the egg shape index, as did the incidence of the feather growth-rate gene within the population (with a statistical significance of P &le; 0.001). The age, genotype and the feather growth-rate gene incidence within the population also significantly affected the eggshell quality indicators. In the eggshell to egg ratio, eggshell thickness and strength, an interaction was determined between the age of hens and their particular genotype. The eggshell colour was also significantly (P &le; 0.001) affected by hens' age, genotype (P &le; 0.001), as well as by the feather growth-rate gene (P &le; 0.001). No significant interaction between the age and the genotype was found for this indicator.

scholarly journals Spatial Variation of the Relationship between PM2.5Concentrations and Meteorological Parameters in China

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Lin ◽  
Jingying Fu ◽  
Dong Jiang ◽  
Jianhua Wang ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Meteorological Parameters ◽  
Semiarid Region ◽  
Strong Positive Correlation ◽  
Annual Average ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Humid Region ◽  
The Relationship ◽  
Warm Temperate

Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5dataset, this paper explores the relationship between PM2.5concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5had a strong and stable correlation with meteorological parameters. In particular, PM2.5had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.

Ecophenotypic plasticity in shell growth direction of asari clam Ruditapes philippinarum

2021 ◽  
pp. 1-6
Author(s):  
Takeshi Tomiyama
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Shell Height ◽  
Growth Direction ◽  
Ruditapes Philippinarum ◽  
Shell Morphology ◽  
Individual Growth ◽  
Shell Size ◽  
Internal Factors ◽  
Suitable Habitats

Abstract Asari clam (or Manila clam) Ruditapes philippinarum is an important bivalve for local fisheries. This species exhibits a large variation in shell morphology, and the shell roundness tends to be greater in more unsuitable habitats. To test whether the increments in shell size parameters (length, height and width) were affected solely by environmental conditions or by internal factors such as initial shell shapes or growth rate, a field caging experiment was conducted at two different sites of unsuitable and suitable habitats in Matsukawaura Lagoon, Japan, where shell shapes of wild clams were significantly different between the habitats. In the experiment, clams were released from the two sites to the same site or to the other site and were re-collected after 3, 6 and 12 months of caging. Caged clams originating from unsuitable habitats and released to suitable habitats showed a reduction in shell height relative to shell length, while clams from suitable habitats introduced to unsuitable habitats showed marked increases in both shell height and width. Generalized linear mixed models suggested that the increase in shell height was affected largely by the release habitat (environment) whereas the increase in shell width was affected largely by the individual growth rate. These results suggest that marginal growths in shell height and width respond differently to external and internal factors of clams, resulting in plasticity in their shell shapes according to the environments to which they are translocated.

Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata)

2013 ◽  
Vol 449 ◽  
pp. 470-481 ◽  
Author(s):  
Magdalena Boshoff ◽  
Kurt Jordaens ◽  
Thierry Backeljau ◽  
Suzanna Lettens ◽  
Filip Tack ◽  
...  
Keyword(s):  
Land Snail ◽  
Snail Species ◽  
Specific Accumulation ◽  
Accumulation Of Metals ◽  
Species Specific

Examining of the Effects of Target-Oriented Circular Training on Biomotor Features by using Tennis Ball Throwing Machine at 12-14 Age Tennis Performance Sportsmen for 10 weeks

2021 ◽  
Vol 15 (11) ◽  
pp. 3174-3180
Author(s):  
Turgut Çamlibel ◽  
Mehmet Özal
Keyword(s):  
Statistical Significance ◽  
Vertical Jump ◽  
Repeated Measurements ◽  
T Test ◽  
Training Data ◽  
Control Group ◽  
Tennis Ball ◽  
Package Program ◽  
Visual Reaction ◽  
Experimental Group

Aim: In this work, it is aimed that examining the effects of target-oriented circular training on biomotoric features by using a tennis ball throwing machine at 12-14 age tennis performance sportsmen for ten weeks. Method: This research was implemented on sixteen active licensed athletes who played tennis for at least four years in Ankara. The athletes were randomly divided into two separate groups as the experimental group (n=8) and the control group (n=8). After measuring the height, weight, and fat rate of the athletes, biometric tests were started. Flamingo balance, sit-reach, reaction time, five meters and twenty meters sprints, T-test, and standing long jump tests were performed, respectively. Athletes were get heated for ten minutes before the tests and they were given a trying chance. The best scores were recorded by repeating each test twice. In the statistical analysis of the collected data, IBM SPSS 19 package program was used. In repeated measurements, the results were compared by two-way ANOVA with intergroup, intragroup and post-training data. Results: As a result, between the experimental group and control group data; on averages of T-Test (p<0.139), visual reaction (p<0.001), Flexibility (p<0.024), Vertical Jump (p<0.022), Flamingo Balance right foot (p<0.046) and left foot (p<0.045) statistical significance was confirmed. Keywords: Biomotoric features, ITN test, Tennis, Tennis ball machine

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