Interpair Differences Research Articles

Local-scale variability of seasonal mean and extreme values of in situ snow depth and snowfall measurements

Abstract. Daily measurements of snow depth and snowfall can vary strongly over short distances. However, it is not clear if there is a seasonal dependence in these variations and how they impact common snow climate indicators based on mean values, as well as estimated return levels of extreme events based on maximum values. To analyse the impacts of local-scale variations we compiled a unique set of parallel snow measurements from the Swiss Alps consisting of 30 station pairs with up to 77 years of parallel data. Station pairs are usually located in the same villages (or within 3 km horizontal and 150 m vertical distances). Investigated snow climate indicators include average snow depth, maximum snow depth, sum of new snow, days with snow on the ground, days with snowfall, and snow onset and disappearance dates, which are calculated for various seasons (December to February (DJF), November to April (NDJFMA), and March to April (MA)). We computed relative and absolute error metrics for all these indicators at each station pair to demonstrate the potential variability. We found the largest relative inter-pair differences for all indicators in spring (MA) and the smallest in DJF. Furthermore, there is hardly any difference between DJF and NDJFMA, which show median variations of less than 5 % for all indicators. Local-scale variability ranges between less than 24 % (DJF) and less than 43 % (MA) for all indicators and 75 % of all station pairs. The highest percentage (90 %) of station pairs with variability of less than 15 % is observed for days with snow on the ground. The lowest percentage (30 %) of station pairs with variability of less than 15 % is observed for average snow depth. Median differences of snow disappearance dates are rather small (3 d) and similar to the ones found for snow onset dates (2 d). An analysis of potential sunshine duration could not explain the higher variabilities in spring. To analyse the impact of local-scale variations on the estimation of extreme events, 50-year return levels were quantified for maximum snow depth and maximum 3 d new snow sum, which are often used for avalanche prevention measures. The found return levels are within each other's 95 % confidence intervals for all (but three) station pairs, revealing no striking differences. The findings serve as an important basis for our understanding of variabilities of commonly used snow indicators and extremal indices. Knowledge about such variabilities in combination with break-detection methods is the groundwork in view of any homogenization efforts regarding snow time series.

Evaluation of Inter-pair Differences in Caries among South Indian Monozygotic Twins: A Cross-sectional Study.

ABSTRACTIntroductionAssessment of difference in caries prevalence among twins may help determine the character and the extent of the influence exercised by the environment, as a complement of the genetic constitution.AimTo investigate the inter-pair differences in caries prevalence among South Indian monozygotic twins in relation to birth weight, birth order, and gender. Possible correlation among other attributes such as breastfeeding, socioeconomic status, oral habits, frequency of brushing, and sweet intake were also assessed.Materials and methodsA sample of 40 monozygotic children between the age group of 6 and 12 was selected. The parents were asked to complete the questionnaire and report with their children. Then dental examinations were carried out and the prevalence of dental caries among the twins were assessed.ResultsAmong the total samples, 61.5% exhibited caries. Lower birth weight twins showed an increased chance of caries (72.22%), compared to higher birth weight twins (68.18%). Second of the twins had an increased risk of dental caries (70%) compared to the first (60%). 90% of the male twins and 45% of the female twins had caries. The association between dental caries and other variables were also assessed; those who were exclusively breastfed had an increased risk (70%) of caries. Evaluation of socioeconomic status and caries revealed a risk of for the high (65%), middle (62.5%), and lower groups (58.33%). Children without oral habits showed a higher prevalence (73.3%) of caries when compared to those without any habits (50%). It was noticed that the brushing frequency is not related to the severity of caries. The strongest association was noticed between excessive sweet liking and prevalence of dental caries.ConclusionThe study revealed difference in caries prevalence among monozygotic twins in relation to birth weight, birth order, and gender. It was found that variations in caries prevalence existed with other attributes also.How to cite this articleZarina R, Kuriakose S, et al. Evaluation of Inter-pair Differences in Caries among South Indian Monozygotic Twins: A Cross-sectional Study. Int J Clin Pediatr Dent 2019;12(4):318–324.

Siberian crane duet as an individual signature of a pair: comparison of visual and statistical classification techniques

Vocal individuality varies between species and/or ontogenesis stages depending on needs in the vocal recognition, but also estimation of individual differences depends on the method of analysis. We studied pair-specific differences of duets elicited by mating pairs of Siberian crane Grus leucogeranus. We quantitatively described the duet structure and compared visual and statistical classification methods of pair identification by duet. Three methods were used: discriminant analysis, method of classification trees and visual classification of spectrogram. We found significant interpair differences. The pairs differ by duet structure that is by the ratio of male- and female-initiated duets and by the ratio of the number of male to female calls; temporal-frequency duet characteristics are pair-specific, too. All methods showed high interpair differences, which exceeded random values significantly. Discriminant analysis stepwise procedure based on 11 parameters resulted in 97.3% of correctly assigned duets. Human observers correctly assigned 80.7% of spectrograms. Our data provide a basis for remote monitoring of this endangered species with a wild population of only 3,000 birds.

Leptin, insulin, insulin‐like growth factors and their binding proteins in cord serum: insight into fetal growth and discordancy

Singleton infants with intrauterine growth restriction have an adaptive hormonal profile characterized by decreased levels of IGF-1, IGF-2, IGFBP-3 and insulin and elevated levels of IGFBP-1 and IGFBP-2. This study examined the association between cord serum levels of six growth factors and anthropometric features at birth in twins in order to determine the intrauterine growth factor interactions and to characterize the specific hormonal profile of small discordant twins. Prevalent case-control study. Twenty pairs of discordant twins (5 monozygotic, 15 dizygotic) and 20 pairs of concordant twins (6 monozygotic, 14 dizygotic) matched for gestational age. Cord blood levels of IGF-1, IGF-2, IGFBP-1, IGFBP-3, insulin, leptin and anthropometric measurements at birth. Intra- and inter-pair differences and correlation coefficients were calculated, and the data were fitted to multivariate regression models. In both discordant and concordant groups, the smaller twins had a significantly lower level of IGF-1 (P < 0.03) and significantly higher level of IGFBP-1 (P < 0.02) than their larger cotwins. IGFBP-1 was inversely correlated with IGF-1 (P < 0.05). Insulin levels were significantly higher in the smaller discordant than the smaller concordant twins (P < 0.001) and in the larger discordant than the larger concordant twins (P < 0.004). Among the monozygotic twins, the leptin level was significantly higher in the larger discordant than the larger concordant twins (P < 0.025). Percentage birth weight discordancy was statistically correlated with twin-pair differences in IGF-1 and IGFBP-1. Of the six factors studied, IGF-1 appears to be the main indicator of intrauterine growth. Twin discordancy may involve compensatory rather than adaptive mechanisms or a multihormone relative resistance syndrome.

Parental foraging effort and offspring growth in Adélie Penguins: does working hard improve reproductive success?

SummaryStudying variability of parental foraging and provisioning behaviour in relation to reproductive success is fundamental to improving understanding of regulation of reproductive effort in animals. The hypothesis that parents with higher foraging effort have higher offspring growth rates was tested in chick‐provisioning Adélie Penguins in Antarctica over five consecutive years.Time spent diving per day, an index of foraging effort, varied among male and female parents, and among pairs. These daily interindividual or interpair differences in time spent diving appeared to be consistent over the 2‐week study period within each breeding season.Frequency of meals delivered by parents was positively correlated with their brood growth rate. Meal frequency was, however, independent of the amount of time spent diving per day by parents and the time spent diving did not affect brood growth rates.Rates of body mass loss of breeding pairs were positively correlated with brood growth rates.Our results did not support the hypothesis that parents with higher foraging effort have higher offspring growth rates. It is suggested that parental allocation of resources obtained during foraging, rather than the degree of foraging effort, is the more important process determining offspring growth rates in Adélie Penguins.

Liver expression in cystic fibrosis could be modulated by genetic factors different from the cystic fibrosis transmembrane regulator genotype.

During a multicentric study conducted in Southern Italy, we studied five sets of cystic fibrosis siblings bearing a strongly discordant liver phenotype, three with genotype DeltaF508/R553X, one with genotype DeltaF508/unknown, and one with genotype unknown/unknown. The siblings of each set were raised in the same family environment, and there were no interpair differences in nutritional state or in therapy compliance. All siblings had pancreatic insufficiency and moderate respiratory expression. One sibling of each of the five sets was free of liver involvement, and the other had severe liver expression. Other causes of liver disease (viral, metabolic, and genetic other than cystic fibrosis) were ruled out. Therefore, environmental factors, nutritional state, and therapy compliance are not involved in the liver expression of cystic fibrosis in the five unrelated sibships. This suggests that modifier genes, inherited independently of the cystic fibrosis transmembrane regulator gene, could modulate the liver expression in cystic fibrosis patients.

Rheumatoid arthritis, HLA identity, and age at menarche.

To determine whether women with rheumatoid arthritis (RA) had differences in obstetric and gynaecological histories when compared with sisters without RA (controls) Ninety eight RA discordant sister pairs, 36 of whom were identical for histocompatibility locus antigen (HLA-A, HLA-B, and HLA-Cw) types, were asked to recall their age of menarche, duration of use of contraceptive pill, pregnancy history, and age of menopause. The 98 siblings with RA had an older mean age of menarche (13.90 (95% confidence interval (95% CI) 13.56 to 14.24) years) than their sisters (13.49 (95% CI 13.22 to 13.76) years; mean difference within pairs 0.41, 95% CI 0.09 to 0.73 years, paired t test t = 2.54, p = 0.013). When the pairs were divided into identical HLA and non-identical HLA groups, the first showed no significant difference (mean difference 0.17 (95% CI -0.40 to 0.73) years), whereas the second did (mean difference 0.55 (95% CI 0.16 to 0.94) years, t = 2.80, p = 0.007). A multiple regression analysis to predict differences in menarche in the non-identical HLA sibling pairs failed to show any demographic or reproductive confounding variables. In 19 RA concordant sibling pairs, the seven HLA identical pairs had similar ages of menarche, whereas the 12 non-identical HLA pairs had interpair differences that narrowly missed significance (p = 0.054). All other obstetric and gynaecological variables were not significantly different within the pairs. The interpretations of these results are that either delayed menarche may predispose to or act as a marker of RA, or HLA linked genes are important in determining the age of menarche irrespective of disease state. This study fails to support a significant role for other obstetric and gynaecological variables in RA.

Consistency in maternal behavior within families of free-ranging rhesus monkeys: An extension of the concept of maternal style.

This paper assesses the extent to which free-ranging rhesus monkeys (Macaca mulatta) on Cayo Santiago show consistent mother-infant interaction with individual infants over time and consistent maternal styles from one infant to another. Inter-pair differences in several measures of mother-infant interaction related to proximity and contact were correlated positively and highly significantly between 6-week age periods. Analysis of variance methods were used to show that, after the first 6 weeks, these measures of interaction were also more similar among pairs with the same mother (i.e., families) than among pairs with different mothers. Differences between families were also consistent between age periods, and appeared to be due primarily to differences between mothers rather than to differences between sets of infant siblings. The results suggest that the concept of maternal style can be used to describe variation between both individual Cayo Santiago mother-infant pairs and between individual Cayo Santiago mothers.

Possible Genetic Control of the Proportions of Branched-Chain Fatty Acids in Human Sebaceous Wax Esters

The composition of human sebum varies among individuals with respect to the proportions of various types of fatty acids in the ester lipid classes. Iso-branched fatty acids with even numbers of carbons (iso-even) are particularly variable. However, in 13 identical twin pairs, intrapair differences in the proportions of iso-even fatty acids in sebaceous wax esters were found to be very small, while interpair differences were as large as in the nontwin population. Intrapair differences in iso-even fatty acids were also quite small in 4 of 8 fraternal twin pairs. Heritability estimates suggested that proportions of iso-even fatty acids in human sebum are controlled, at least in part, by genotype.

Chemical castration with cyproterone acetate (Androcur ®) and sexual behavior in the laboratory-housed male stumptailed maceque ( Macaca arctoides)

Seven pairs of stumptailed monkeys were tested twice weekly (30-min behavior tests) and female-male interactions scored while males received IM injections of CA for 12 weeks, or oil vehicle. Paris served as their own controls. CA was injected in increasing doses: 6 weeks, 100 mg/week/♂, 2 weeks 150 mg/week/♂, 4 weeks 210 mg/week/♂. Serum testosterone levels were significantly lowered during CA, whereas serum cortisol was not affected by CA. Testis size also decreased with CA. Male sexual behavior (frequency of mounts and ejaculations) was increased significantly with CA. Sexual motivation, as measured by latency to first mount and to first ejaculation was not affected. During CA treatment the males became more social: they significantly groomed their female partner longer. This study also revealed striking intra-pair consistencies and inter-pair differences. It is concluded that cyproterone acetate does not diminish libido and potency in the male stumptailed monkey. It is discussed that in the human male CA probably does exert its sexual inhibition through anxyolitic-tranquilizing action, rather than through its hormonal action.

EFFECTS OF SEQUENTIAL ORDERING OF ADDED PAIRS AND OF CORRECTION V. NON‐CORRECTION PROCEDURES ON PAIRED‐ASSOCIATE PERFORMANCE

An 8‐pair list was learned with fewer errors to criterion under a correction procedure, which equated number of correct responses for each individual pair, than the standard non‐correction procedure. Both interpair differences in degree of learning and retention, and variability between subjects, were reduced under the correction procedure. Each of 7 non‐correction conditions was then used for a second list of 6 new pairs, learned either alone or in conjunction with the 6 best‐learned list 1 pairs (either grouped together, alternated with new pairs, or randomly intermixed), in either constant or varied serial order. Neither sequential grouping nor alternation facilitated list 2 performance, and alternation after non‐correction learning of list 1 elicited significantly more errors after the first correct response. Constant serial order for list 2 required fewer trials to criterion than varied serial order.

Evidence for coding processes in “Rote” paired-associate learning

Evidence from several recent paired-associate experiments is reviewed demonstrating the importance of (a) coding and grouping processes even in paired-associate tasks where extensive efforts have been made to eliminate any basis for such grouping, and (b) interpair differences in learning difficulty and/or degree of learning as a widely-used and unavoidable basis for grouping pairs together as a means of combating interpair interference in paired-associate tasks. On the basis of these results, it is concluded that the formation of simple stimulus-response associations represents a minor portion of what is learned in paired-associate tasks, and that such tasks may provide a useful experimental technique for investigating the development of coding or grouping processes in human subjects.