Sex Ratio
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2023 ◽  
Vol 83 ◽  
Author(s):  
M. G. Barbosa ◽  
S. A. Souza ◽  
T. P. P. André ◽  
A. D. S. Pontes ◽  
C. S. Teixeira ◽  
...  

Abstract The possible interference of resistant pest’s populations to insecticides in natural enemies in the action thas not been clarified yet. Thus, this study aimed to evaluate Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) performance on Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) eggs with resistance frequency to the Metaflumizone over six generations of product exposure. Egg cards (2.0 x 7.0 cm) containing eggs from two populations of S. frugiperda, (resistant to Metaflumizone and the other susceptible), were exposed to T. pretiosum females for 24 hours in free-choice and no-choice testing in three generations (G1, G4, and G6). A completely randomized experimental design was used with 25 replications, each consisting of an egg card (experimental unit) containing 20 eggs. The parameters evaluated were: parasitism (%), emergence (%), sex ratio, number of emerged parasitoids per egg and males/females longevity. ANOVA and Tukey test (P≤ 0.05) were applied on the results. Results showed a reduction in parasitism [41.0% (G1) and 28.4% (G4)], egg emergence (17.5%) and parasitoids/egg [16.2 (G4) and 17.2 (G6)] in eggs originating from the population with resistance frequency. Females emerging from G6 populations eggs without exposure to Metaflumizone had greater longevity (3.5 days more) than the resistant population. The sex ratio and male longevity were not affected. The results indicate a reduction in T. pretiosum activity if S. frugiperda populations have some frequency of resistance to Metaflumizone.


2022 ◽  
Author(s):  
Srinivas Goli ◽  
Somya Arora ◽  
Neha Jain ◽  
TV Sekher

In multi-level and multi-layered foundations of gendered approaches for understanding the kinship system, son preferences, and male-skewed child sex ratios in India; patriarchy, and patrilineality have received greater attention than patrilocality. To fill this gap, in this study, we construct a measure of patrilocality and examine its association with skewed child sex ratios. We hypothesize that households practice sex selection and daughter discrimination because of patrilocal norms that dictate the later life co-residence between parents and sons. Our findings reveal that the child sex ratio, the sex ratio at birth, and the sex ratio at last birth are positively correlated with the patrilocality rates across states and districts of India. The relationship holds across the multiple robustness checks. Findings, although not surprising, emerge from the robust empirical analyses at a time when child sex ratios continue to worsen in India, notwithstanding the country’s socio-economic progress. We conclude that in the absence of strong social security measures and lack of preference for old-age homes amidst the accepted practice of patrilocality coupled with increasing lower fertility norms, the dependency on sons will continue and further lead to the continuation of sex selection in India.


2022 ◽  
Author(s):  
Haoyu Lin ◽  
Jiajin Wang ◽  
Songkai Liao ◽  
Jiahao Huang ◽  
Ruonan Fu ◽  
...  

Eriogyna pyretorum Westwood is a notorious defoliator of Cinnamomum camphora (L.) J. Presl that causes large economic and ecological losses in planted forests. To understand the importance of suppress population of E. pyretorum on natural parasitoids, a two-years investigation was conducted in the field. Four parasitoid species were identified from E. pyretorum: Gregopimpla himalayensis (Cameron, 1899), Theronia depressa (Gupta, 1962), Xanthopimpla konowi (Krieger, 1899) and Kriechbaumerella longiscutellaris Qian et He. G. himalayensis and T. depressa were first reported parasitoid wasps within E. pyretorum. Parasitism rates were 18.76% for K. longiscutellaris, 2.10% for G. himalayensis, 7.55% for T. depressa and 0.83% for X. konowi. Longevity, offspring and sex ratio were compared in four hymenopteran species, and K. longiscutellaris was the abundant parasitoid of E. pyretorum in Fujian province of China.


Author(s):  
Dr.V.Pugazhenthi

National Family Health Survey-5 (NFHS-5) fieldwork for India was conducted in two phases, during the years between 2019 and 2021 by 17 Field Agencies and gathered information from 636,699 households, 724,115 women, and 101,839 men. Information was gathered from 27,929 households, 25,650 women, and 3,372 men from Tamil Nadu and in Thanjavur from 826 households, 687 women, and 83 men. This research paper points out the health indicators in which Thanjavur District improved over the earlier NFHS and over the State as well as Country level averages in the NFHS-5. As per The NFHS -4 the sex ratio has raised marginally to 1053 and in the NFHS-5, sharply raised to 1112. The sex ratio of the country is also remarkably high crossing 1000 mark, first time in the Indian statistical history in the NFHS-5. NFHS-5 reveals positive note that the child sex ratio restoration back to 934. It reflects the changing mindset proliferating in the district towards the female. Amidst the negative mindset towards upbringing girl children in the state of Tamil Nadu, revealed by the reduced child sex ratio of 878 in NFHS -5 from 954 in NFHS-4 in Tamil Nadu a sharp positive increase in the child sex ratio in Thanjavur is fair enough to the fair sex. On the other hand, the reason for the reduction in the child sex ratio in the rest of the state of Tamil Nadu needs an immediate attention comparing the previous NFHS. It is also to be noted here that even the country level child sex ratio also is in increasing trend as per the present NFHS comparing its earlier survey. KEYWORDS: National Family Health survey, Government sponsored health insurance schemes, health insurance, Sex ratio, child sex ratio, AB-PMJAY.


2022 ◽  
Vol 5 (1) ◽  
pp. 01-07
Author(s):  
K.C. Bhuyan

The paper was to throw some light on the risk factors for diabetes disability among Bangladeshi adults of 18 years and above residing in both urban and rural areas. In investigating the adults, it was decided to cover 50.1% males and 49.9% females to maintain the national level of sex ratio in the sample. The respondents were interviewed when they were visiting some diagnostic centres in urban and semi-urban areas. The percentage of diabetic respondents included in the sample was 67% and 25.5% of them were suffering for 10 years and above, 6.4% were disable against 4.8% total disable respondents in the sample, and obese adults were 30.2%. Diabetic disable adults in the sample were 4.3%. The most responsible variable for diabetes disability was obesity followed by longer duration of diabetes, sedentary activity, smoking habit, being housewife, being married, etc. These variables were identified on the basis of risk ratio and correlation coefficients of variables and discriminant function scores. Beside these variables, rural people, Muslims, adults of ages 40 – 50 years, illiterate people had more risk of facing the problem of diabetes disability.


Author(s):  
Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He

Animals can adjust reproductive strategies in favour of corporation or competition in response to local population size and density, the two key factors of social environments. However, previous studies usually focus on either population size or density but ignore their interactions. Using a haplodiploid spider mite, Tetranychus ludeni Zacher, we carried out a factorial experiment in the laboratory to examine how ovipositing females adjust their fecundity and offspring sex ratio during their early reproductive life under various population size and density. We reveal that females laid significantly more eggs with increasing population size and significantly fewer eggs with increasing population density. This suggests that large populations favour cooperation between individuals and dense populations increase competition. We demonstrate a significant negative interaction of population size and density that resulted in significantly fewer eggs laid in the large and dense populations. Furthermore, we show that females significantly skewed the offspring sex ratio towards female-biased in small populations to reduce the local mate competition among their sons. However, population density incurred no significant impact on offspring sex ratio, while the significant positive interaction of population size and density significantly increased the proportion of female offspring in the large and dense populations, which will minimise food or space competition as females usually disperse after mating at crowded conditions. These results also suggest that population density affecting sex allocation in T. ludeni is intercorrelated with population size. This study provides evidence that animals can manipulate their reproductive output and adjust offspring sex ratio in response to various social environments, and the interactions of different socio-environmental factors may play significant roles.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Andreas Filser ◽  
Sven Stadtmüller ◽  
Robert Lipp ◽  
Richard Preetz

Abstract Background School injuries are an important adolescent health problem. Previous research suggests that relevant risk behaviors for school injuries, risk-taking and aggression, are highly susceptible to peer effects. Specifically, evidence suggests that the ratio of men and women in peer groups (sex ratio) affects individuals’ propensity for aggression and risk-taking. However, potential associations of classroom sex ratios with adolescent school injury risks have not been studied so far. The purpose of this paper is to investigate the association of classroom sex compositions with adolescent school injuries. Methods We investigate the association of classroom sex ratios with school injuries in a longitudinal survey dataset containing 13,131 observations from 9,204 adolescent students (ages 13-16) from secondary schools in Germany. The data also allow us to identify injuries due to aggressive behavior and analyze these injuries in detail. We use multilevel logistic regression models to analyze risks of both overall and aggression-related school injuries. Results Adolescent students’ risk for school injuries is significantly and positively associated with male-skewed classroom sex ratios (OR = 1.012, p=0.012). Specifically, the risk of sustaining a school injury increases by 33.5 percent when moving from the 10th to the 90th classroom sex ratio percentile. Moreover, we find an even stronger positive association between male-dominated classrooms and aggression-related injury risks (OR = 1.022, p=0.010). Compared to classroom sex ratios at the 10th percentile, the risk of an aggression-related injury is 78 percent higher in classrooms with a sex ratio at the 90th percentile. Finally, we find that both boys’ and girls’ injury risks equally increase with a higher proportion of male students in their classroom. Conclusions Our findings indicate that sex composition of classrooms is an important contextual factor for adolescent school injuries, in particular school injuries resulting from aggression. These findings illustrate the need to integrate a contextual perspective on school injuries among adolescent students both into research and into intervention planning.


2022 ◽  
Vol 24 (1) ◽  
Author(s):  
N. R. RANGARE ◽  
MANISH BHAN ◽  
S. K. PANDEY

A two-year field experiment was initiated in 2017-18 and 2018-19 years simultaneously to assess temperature on flower morphogenesis stages, flower sex ratio (hermaphrodite/staminate male flower) and fruit set in monoembryonic Langra and Amrapali varieties. Different dates of flower phenological stages viz., bud, panicle, bloom and flower initiation, pea, marble, egg, and maturity of fruits were recorded. The Langra variety exhibited bud initiation after mid December whereas Amrapali variety by the end of December. The range of mean maximum / minimum temperature as 26-31/10-12 °C promoted hermaphrodite flowers per panicle by 74 per cent in Langra variety, whereas range of 27-29/11-13 °C favored by 35 per cent in Amrapali variety. A positive and significant correlation between total number of flower / panicle and flower sex ratio in both the varieties suggested that higher temperature during initial flower phenologies improved number of hermaphrodite flowers. A mean minimum temperature for producing more number of hermaphrodite flower  exhibited a range of 11-14 °C under central Indian conditions.  Fruit set was maximum during pea stage and decline afterwards in marble and fruit maturity stages due to sudden rise in temperature at marble stage that caused in drop down of humidity thereby resulted in fruit drop in both the varieties.


Author(s):  
Greg G. Sass ◽  
Stephanie L. Shaw ◽  
Jeremiah A. Gorne ◽  
Danielle Godard ◽  
Nicole Nietlisbach ◽  
...  

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