A study of sutural bones in Gujarati (Indian) crania

370 adult crania were examined to find the incidence of sutural bones in Gujarati (Indian) crania and to compare it with other populations to establish the distance between them. The mean measure of difference between Indian and other populations was statistically significant. Comparison of cranial capacity in skulls with and without sutural bones showed no significant difference, and this is interpreted as indicating that sutural bones are not formed secondary to stress.     

Frequency of acrocentric association in abnormal sexual development in males and females

A significant difference (P less than 0.05) was observed in a chi 2 comparison of DD, GG and DG-DI associations between male hypogonads and females with primary amenorrhea. This difference increased still further (P less than 0.01) when only DD and GG associations were compared between males and females with abnormal sexual development (ASD). Similarly, when normal males and females were compared for DI, TRI, TETRA, DD vs GG and DG vs GG acrocentric chromosome associations, a significant difference (P less than 0.05) was again observed. The sex difference was also apparent in TRI and TETRA acrocentric associations both in abnormal and normal sexual development males and females. These results suggested that probably sex difference (may be hormonal) influences the number and/or type of acrocentric chromosomes involved in association between males and females with ASD and also between normal males and females.     

Blood selenium and glutathione peroxidase activity of populations in New Zealand, Oregon, and South Dakota

The relationship of whole blood selenium (Se) to glutathione peroxidase (GPX) activity was examined for individuals in New Zealand, Oregon, and South Dakota who represented, respectively, populations with exposure to low, medium, and high amounts of Se. The mean (respective) blood Se levels were 60, 200, and 400 ng/ml. Intergroup differences in blood Se levels were highly significant (P less than 0.001). GPX assays were performed using two variations of an enzyme-coupled procedure to assess the equivalence of the two methods. Despite a fourfold difference in absolute activities measured by these methods, the GPX activities were highly correlated (r = .86) between procedures. Average blood GPX activity was significantly lower (P less than 0.001) for the New Zealand group compared with the other two groups, but there was no difference in GPX activities between the Oregon and South Dakota groups. Linear regression of GPX vs. Se values within each group indicated a significant correlation of these parameters only in the New Zealand group (r = .46, P less than 0.01). Comparison of these parameters for combined data from all three groups also showed a significant positive correlation (r = .60, P less than 0.001). A saturation model (In GPX = k1 + k2 (Se)-1)) fits the combined data better (r = .80, P less than 0.01) than does direct comparison of the two parameters. These results suggest that GPX activity is an appropriate indicator of human Se status only in populations with below normal exposure to Se, as activity of this enzyme is saturated at relatively low levels.     

The anthropological value of minor variants of the dental crown

The incidences of 31 minor variants of the dental crown were scored from dental casts of samples taken from six European populations. Although several variants showed significant sex bias in one or other sample, only one (pits instead of furrow on premolar₂) consistently favoured one sex. Associations between the variants were sought. Although few consistent associations were demonstrated, there was a possible tendency for extra cusps to occur together throughout the dentition. Distance statistics calculated between the samples were compatible with the expected genetical relationships of the samples, but only modern samples could be used since variants were destroyed by attrition in archeological samples. Before such distances can be considered reliable, it is necessary to know:

• i the extent to which environmental factors such as diet influence variant expression.
• ii whether or not variant bearing teeth are selectively destroyed by caries, which in civilised populations render a high proportion of most dentitions unscoreable.

     

Prevalence of patent Baylisascaris procyonis infection in raccoons (Procyon lotor) in Ithaca, New York

The prevalence of patent Baylisascaris procyonis infection in raccoons was determined by examining fecal samples collected between July 1986 and May 1987 in Ithaca, New York. September, October, and November had the highest prevalence of infection (35-48%). Significant differences (P less than 0.001) were found when months were grouped by season to test the hypothesis that a fecal sample's probability of being positive does not vary from month to month. Fall was the season contributing most to the overall chi-square statistic. Host sex/age class and prevalence of patent infection were investigated. The raccoons were aged as either juveniles or adults. A significantly higher prevalence of patent infection (P less than 0.001) was found in juveniles when compared to adults. No statistically significant difference was found in other comparisons of host sex and age. Contingency analysis tested the independence of sex/age class/season and presence of eggs. The results of the test were significant (P less than 0.001).     

An association between chloroplast DNA haplotypeand gender in a plant metapopulation

Theoretical models have shown that metapopulation structure can influence the evolution of the sex ratio in gynodioecious plants when the fitness of females and/or hermaphrodites varies among populations with the local sex ratio. Such frequency-dependent fitness has been demonstrated previously in natural populations of Silene vulgaris, a gynodioecious plant in which sex determination is cytonuclear. We investigated whether there was an association between chloroplast DNA (cpDNA) haplotype and sex expression, with the assumption that cpDNA haplotypes could be associated with specific male sterility variants likely found in the mitochondrial DNA, owing to co-transmission of the two cytoplasmic genomes. Two cpDNA haplotypes were studied in a collection of 111 individuals of known sex taken from 20 natural populations found in Virginia, USA. The set of haplotype 1 individuals consisted of 71.4% hermaphrodites, where as only 7.7% of the haplotype 2 individuals were hermaphroditic; a highly statistically significant difference. By extension of a previous model it was also shown that the differential clustering of these two haplotypes into local populations contributes to among-population sex ratio variation and has the potential to lower the fitness of haplotype 2 by greater than 50%, relative to that expected with no population structure. This revised version was published online in July 2006 with corrections to the Cover Date.     

Variations in the form of the hypoglossal canal in ancient Anatolian populations: Comparison of two recording methods

In this study, the frequency of bridging of the hypoglossal canal was investigated on 324 skulls belonging to 10 ancient Anatolian populations recovered from various archaeological sites and dated from Early Bronze Age to the first quarter of the 20th century. The change in the frequency of bridging trait in the hypoglossal canal that has already been recorded according to both the traditional method (absent or present) and the graded method (0-5) was analysed here in relationship to age, sex, skull side and population.The results revealed no significant relation between the bridging of hypoglossal canal and age or sex. Both recording methods showed that the studied samples of ancient Anatolian populations exhibited a homogenous structure and they were found to differ considerably from other populations which inhabited lands other than Anatolia. This indicates that these two recording methods produce similar results in comparing populations. The differences between the sides were found to be significant with the detailed recording method as opposed to the dichotomous method. This asymmetry emerging with the detailed recording method is considered to be important in determining the effect of environmental factors upon the trait.     

Genetic relationships between Indians and their neighboring populations

Using gene frequency data for 18 protein and blood group loci, we studied the genetic relationships of four Indian subcontinent populations (peoples from Punjab, Gujarati, Andhra Pradesh, and Bangladesh) with their neighboring populations (Iranians, Afghans, Sinhalese in Sri Lanka, Nepalese, Bhutanese, Malays, Bataks in northern Sumatra, and Chinese). The results obtained indicate that the four Indian subcontinent populations and the Sinhalese are genetically closer to Iranians and Afghans (Caucasoid) than to the other neighboring Mongoloid populations. Genetic distance analysis shows a clear-cut dichotomy between the Caucasoid and Mongoloid populations.     

Carnosine content of the middle gluteal muscle in thoroughbred horses with relation to age, sex and training

1. Muscle biopsies were collected from 85 thoroughbred horses and analysed for carnosine content by an automated HPLC method. 2. No significant sex difference was found between colts, geldings and fillies. 3. There was a trend towards lower muscle carnosine contents with age, which was only significant between 1-year-old untrained horses and 4+ year-old horses (P less than 0.002).     

Transferrin and haemoglobin polymorphism in domesticated goats in the USA

The distribution of transferrin (Tf) and haemoglobin (Hb) polymorphisms in five goat breeds in the USA is reported. Two Tf types, A and B, were identified. A significant difference in frequency (P less than 0.05) was observed only between the Spanish and Alpine goats. Haemoglobin beta-globin variants, Hb beta A, Hb beta D and Hb beta E were observed with isoelectric focusing at pH ranges 5-8 and 6.7-7.7. Hb beta D was not found in the Alpine and Angora breeds. Haemoglobin allelic frequencies varied widely and differed significantly (P less than 0.05) among breeds.     

大熊猫双胞胎生长发育影响因素的研究

为了研究影响大熊猫Ailuropoda melanoleuca双胞胎生长发育的因素,以2013—2016年成都大熊猫繁育研究基地出生的22对大熊猫双胞胎幼仔及其母兽为研究对象,分析母兽孕期增重、双胞胎个体性别和双胞胎性别类型与大熊猫双胞胎幼仔初生体质量之间的关系,以及双胞胎个体性别和大熊猫幼仔初生体质量与1~12月龄大熊猫幼仔体质量之间的关系。结果显示,不同双胞胎性别类型的大熊猫幼仔初生体质量的差异有统计学意义(P=0.015),但母兽孕期增重、双胞胎个体性别与幼仔初生体质量的差异无统计学意义(P=0.257、P=0.170);双胞胎2只个体的初生体质量不同(χ^2=9.043,P=0.041),且双胞胎性别类型与幼仔初生体质量差异程度呈中等强度相关(Cramer s V=0.492,P=0.030),双雌性双胞胎初生体质量差异为20%~40%(调整后标化残差:2.30),双雄性双胞胎初生体质量差异小于20%(调整后标化残差:2.60);双胞胎个体性别和初生体质量对1~12月龄大熊猫幼仔生长发育的影响无统计学意义(P>0.05)。对大熊猫双胞胎幼仔生长发育影响因素的研究,为大熊猫双胞胎的饲养管理提供理论依据。     

The spatial genetic structure of cytoplasmic (cpDNA) and nuclear (allozyme) markers within and among populations of the gynodioecious Thymus vulgaris (Labiatae) in southern France

Recent advances in molecular biology have allowed the development of techniques to contrast spatial differentiation in nuclear and cytoplasmic genes and thus provide important data on relative levels of gene flow by pollen and seed in higher plants. In this paper, we compare the spatial structure of nuclear (allozymes) and cytoplasmic (cpDNA) genes among populations of the gynodioecious Thymus vulgaris in southern France. Based on a combination of three restriction enzymes (CfoI, EcoRV, and PstI), eight chlorotypes (combination of three restriction enzyme patterns revealed by Southern hybridization of Beta vulgaris cpDNA) were identified in the 13 studied populations. One chlorotype was particularly abundant and was detected in nearly all populations. Only one chlorotype was specific to a single population. Up to four different chlorotypes were observed in some populations. An FST of 0.238 (P < 0.002) for cpDNA haplotypes indicates spatial structure of cytoplasmic genes among the studied populations. Similar patterns were found within a single young population (CAB) structured in patches and surrounded by a continuous cover of T. vulgaris where the FST is 0.546 (P < 0.002). No significant correlation between sex and chlorotype nor between cpDNA diversity and female frequency was detected. Allozyme markers showed markedly less spatial structure (FST = 0.021 among populations and 0.019 in the CAB population, P < 0.001). This difference between cpDNA and nuclear allozyme markers suggests that pollen dispersal is more important than seed dispersal both among and within populations.     

Diurnal rhythms in performance tests of school children with and without language disorders

Time-of-day related changes on four tests used by speech therapists and four other performance tests, in addition to oral temperature, were documented in 16 school children (7-9 years of age). Six of them had language disorders and were receiving speech therapy. Children were synchronized with diurnal activity from around 0730 to around 2100 and nocturnal rest. For each child, at each test time point (e.g. 0900, 1100, 1530 and 1930) tests were performed three times, with two different speech therapists, in a random order, with only one session per day. Conventional methods (t-tested mean differences; ANOVA; correlation tests) were used for statistical analyses. Among 29 parameters (items) which were analyzed, only nine exhibited time-of-day related changes, mainly in speed to-perform measures. In most detected rhythms best performance occurred either at 1100 or at 1530 with no difference in subgroups except for the fastest performance of the sentence repetition test. With regard to the daily mean M, controls performed better than children with language disorders for the word (syllabic) repetition test (P less than 0.0004) but this was reversed for both computing and colouring skill tests (P less than 0.04 and less than 0.002). A difference related to sex (but not to language disorders) was observed in the Ms of speed in sign reproduction (P less than 0.0000) and sorting cards (P less than 0.01), with boys being faster than girls. In children, as in adults, time-of-day effects should be considered when the quantification of performance is desired.     

局部环境增温对根田鼠冬季种群的影响

通过建立开顶式增温小室模拟全球变暖的实验, 对海北高寒草甸地区实验增温样地及其对照样地内根田鼠的冬季种群进行调查, 旨在研究局部增温对根田鼠冬季种群的可能影响。结果表明, 在冬季, 实验增温草甸样地和灌丛样地内根田鼠的种群密度均显著高于其对照( P < 0.05) ; 实验增温灌丛样地与对照间性比的差异不显著( P > 0.05) ; 增温样地和对照之间、不同植被类型的增温样地之间、对照样地之间, 根田鼠留存率、平均体重及年龄结构的差异均不显著( P > 0.05) ; 有从对照样地向增温样地单方向迁移的记录。总之, 局部环境增温导致实验样地内根田鼠的冬季种群密度明显上升, 而其性比、存活率、种群平均体重以及年龄结构无明显变化; 在冬季, 根田鼠有从对照样地向增温样地扩散或迁移的趋势。     

Fecal steroid excretion in chickens with hereditary hyperlipidemia

Plasma lipids (cholesterol, triglycerides, and phospholipids; mg/dl) and the fecal excretion (mg/day) of neutral steroids and bile acids were studied in layers (L), hereditary nonlayer hens (NL), and roosters (R) fed a basal cholesterol-free grain diet ad libitum. Each group had significantly (P less than 0.05) different levels of plasma cholesterol, triglycerides, and phospholipids when compared to the other groups. The highest lipid values were found in the NL group (cholesterol, 798 +/- 89; triglycerides, 8914 +/- 679; phospholipids, 2458 +/- 112). There was no difference in the fecal excretion of neutral steroids between L and NL; however, fecal bile acid excretion by these two groups was significantly different (P less than 0.05) (L, 13.1 +/- 1.7 vs NL, 26.9 +/- 3.4). Fecal neutral steroid excretion by R was significantly greater (P less than 0.05) than that by either L or NL (L, 6.4 +/- 1.3; NL, 6.0 +/- 1.4; R, 14.4 +/- 1.2). While fecal excretion of bile acids by R (36.1 +/- 4.0) was also greater than that by either L or NL, only the difference between R and L was statistically significant (P less than 0.05). Since, in the steady state, fecal bile acid excretion is equal to its synthesis, these results suggest that bile acid metabolism in these animals can be affected by both sex and egg-laying status.     

Sex differences in juvenile mouse social behavior are influenced by sex chromosomes and social context

Play behavior in juvenile primates, rats and other species is sexually dimorphic, with males showing more play than females. In mice, sex differences in juvenile play have only been examined in out-bred CD-1 mice. In this strain, contrary to other animals, male mice display less play soliciting than females. Using an established same-sex dyadic interaction test, we examined play in in-bred C57BL/6J (B6) 21-day-old mice. When paired with non-siblings, males tended to be more social than females, spending more time exploring the test cage. Females displayed significantly more anogenital sniffing and solicited play more frequently than did males. To determine if the origin of the sex difference was sex chromosome genes or gonadal sex, next we used the four core genotype mouse. We found significant interactions between gonadal sex and genotype for several behaviors. Finally, we asked if sibling pairs (as compared to non-siblings) would display qualitatively or quantitatively different behavior. In fact, XX females paired with a sibling were more social and less exploratory or investigative, whereas XY males exhibited less investigative and play soliciting behaviors in tests with siblings. Many neurobehavioral disorders, like autism spectrum disorder (ASD), are sexually dimorphic in incidence and patients interact less than normal with other children. Our results suggest that sex chromosome genes interact with gonadal hormones to shape the development of juvenile social behavior, and that social context can drastically alter sex differences. These data may have relevance for understanding the etiology of sexually dimorphic disorders such as ASD.     

Rhomboid fossa in the clavicles of North Indians

The incidence and size of the rhomboid fossa were studied in paired clavicles of North Indians obtained from 20 neonates, 60 children, and 789 adult bodies of known age and sex on which postmortem examinations had been performed by the senior author (except in cases of neonates). The fossa was absent in the newborns but was present bilaterally in 44% of male and 54% of female children below 18 years of age and in 16.5% of male and 20.8% of female children unilaterally. Statistically the sexual differences were not significant (P greater than 0.05). In the adults, the incidence of bilateral fossa was 58.70% in males and 54.14% in females and a unilateral fossa was seen in 13.29% of males and 16.56% of females, but the sexual difference in both cases was insignificant (P greater than 0.05). However, in unilateral cases, the incidence of the fossa was greater on the right than on the left side in both male (P less than 0.001) and female (P less than 0.001) bones. Although racial differences cannot be ruled out, no sexual or side differences in the incidence of the fossa could be found. Factors responsible for creating a deep fossa unilaterally are not understood.     

Sperm age, sex ratio, and hyperhaploidy frequency in mice.

Physiologically aged and unaged sperm from each of 12 sexually mature B6SJLF1/J mice were used to fertilize oocytes from females of the same strain, with each male serving as its own control. Male genomes in 323 and 307 first-cleavage metaphases obtained by in vivo and in vitro fertilization, respectively, were analyzed cytogenetically, using C-banding for detection of the Y chromosome. The sex (X:Y) ratio among all zygotes resulting from in vivo fertilization was 1.18; in zygotes resulting from in vivo fertilization by aged (14-d mating intervals) sperm, however, the ratio was 1.53, which differed significantly (chi 2 = 6.72, P less than 0.01) from the theoretical value of 1.00. Comparison of the sex ratio in zygotes resulting from in vivo fertilization by unaged sperm (3-d mating intervals), 0.94, with that in zygotes resulting from fertilization by aged sperm (using a 2 x 2 contingency table) showed a significant (chi c2 = 4.19, P less than 0.05) relationship between sex ratio and sperm age. In vitro neither the combined nor the individual 3- and 14-d data deviated significantly from the expected sex ratio of 1.00. The frequency of sperm-derived hyperhaploidy did not differ significantly between the in vivo (3.4%) and in vitro (5.9%) populations, but did between unaged (2.5%) and aged (6.8%) sperm (chi c2 = 5.74, P less than 0.01). All hyperhaploid zygotes had a complement of n + 1 chromosomes, except the 14-d in vitro group, where complements of n + 2 and n + 3 chromosomes were seen. Sperm-derived polyploidy, which was observed only in the in vitro group, was independent of sperm age and occurred in 6.8% of the zygotes. These data provide support for the sperm-aging hypothesis and indicate, for the first time, an influence of sperm aging in the male genital tract on the X:Y ratio of conceptuses resulting from natural matings of chromosomally normal males.     

Does Landscape Fragmentation Influence Sex Ratio of Dioecious Plants? A Case Study of Pistacia chinensis in the Thousand-Island Lake Region of China

The Thousand-Island Lake region in Zhejiang Province, China is a highly fragmented landscape with a clear point-in-time of fragmentation as a result of flooding to form the reservoir. Islands in the artificial lake were surveyed to examine how population sex ratio of a dioecious plant specie Pistacia chinensis B. was affected by landscape fragmentation. A natural population on the mainland near the lake was also surveyed for comparison. Population size, sex ratio and diameter at breast height (DBH) of individuals were measured over 2 years. More than 1,500 individuals, distributed in 31 populations, were studied. Soil nitrogen in the different populations was measured to identify the relationship between sex ratio and micro-environmental conditions. In accordance with the results of many other reports on biased sex ratio in relation to environmental gradient, we found that poor soil nitrogen areas fostered male-biased populations. In addition, the degree of sex ratio bias increased with decreasing population size and population connectivity. The biased sex ratios were only found in younger individuals (less than 50 years old) in small populations, while a stable 1∶1 sex ratio was found in the large population on the mainland. We concluded that the effects of landscape fragmentation on the dioecious population sex ratio were mainly achieved in relation to changing soil nitrogen conditions in patches and pollen limitation within and among populations. Large populations could maintain a more suitable environment in terms of nutrient conditions and pollen flow, subsequently maintaining a stable sex ratio in dioecious plant populations. Both micro-environmental factors and spatial structure should be considered in fragmented landscape for the conservation of dioecious plant species.     

Skin responses to ultraviolet radiation: effects of constitutive pigmentation,sex, and ancestry

Constitutive skin pigmentation and skin responses to ultraviolet radiation were measured on a sample of volunteers (n=250) living in State College, PA, USA. The sample was composed of individuals of European American (n=190), Hispanic (n=45), and East Asian ancestry (n=15). Constitutive pigmentation was measured using the Adjusted Melanin Index (AMI), Erythemal Dose Response (EDR) was measured using the slope of a* at 24 h (Deltaa*), and Melanogenic Dose-Response (MDR) was measured using DeltaAM, the slope of AMI at 7 d. The relationships between constitutive skin pigmentation, EDR, MDR, sex, age, and ancestry were investigated. European Americans showed a lower constitutive pigmentation, had a significantly higher burn response (EDR), and had a significantly lower tanning response (MDR) than Hispanics and East Asians. No significant difference is seen between Hispanics and East Asians for either constitutive pigmentation or EDR. Constitutive pigmentation in females was slightly lower than in males in all three samples, but the difference was not significant. While no differences were observed in MDR between sexes, males had a stronger EDR than females regardless of population or constitutive pigmentation level, and this difference was significant in European Americans and Hispanics. We observed no age-related differences in any of the populations or measures investigated. We evaluated the relationship between constitutive pigmentation, EDR and MDR. There was a strong inverse correlation between constitutive pigmentation and EDR in the three samples (European Americans, R2=0.176, P < 0.001; Hispanics, R2=0.204, P=0.009; East Asians, R2=0.223, P=0.098) and a strong direct correlation between constitutive pigmentation and MDR in European Americans and Hispanics (European Americans, R2=0.094, P < 0.001; Hispanics, R2=0.164, P=0.012). In other words, persons with lower constitutive pigmentation both burn more and tan less than persons with higher pigmentation. However, after controlling for constitutive pigmentation, EDR and MDR were significantly correlated in European Americans (R2=0.041 P=0.006). Thus, the general observation that persons who burn more tan less is probable because of the common link that these two phenotypes have with constitutive skin pigmentation and, in fact, once pigmentation has been adjusted for, there is a positive correlation between tanning response and burning response in European Americans.