Ejaculate Adjustment in Response to Sperm Competition Risk in Humans.

Previous research suggests that human males, like males of many mammalian and avian species, adjust their ejaculate quality in accordance with sperm competition risk. Men who spend less time with their regular female partner since the couple's last copulation produce ejaculates with more sperm at the couple's next copulation (Baker & Bellis, 1993). We conducted a conceptual replication of this research to investigate whether sperm competition risk predicts ejaculate adjustment in human males using additional measures of sperm competition risk (e.

Age-dependent changes in skin features and perceived facial appearance in women of five ethnic groups.

Objective: Research documents effects of skin features on assessments of age, health and attractiveness of female faces. Ethnic variation also has been reported for the impact of age-related changes in skin features on face assessments. Here, we investigate women's self-ratings across age cohorts and ethnic groups and discrepancies with (non-expert) assessor ratings of facial appearance together with age-dependent changes in skin features.

Associations between 2D:4D from direct and radiographic measurements with handgrip strength in young adult Tuvans.

Background: Digit ratio (2D:4D) - the relative lengths of the index and ring finger - is sexually dimorphic (male < female), possibly because of the sex-differentiated impact of prenatal androgenization on fetal development in the 1st trimester. The sex difference remains stable with age and has been reported in children, adolescents, and adults from industrialized and non-industrialized societies. Handgrip strength (HGS) also is sexually dimorphic (males > females) and correlates negatively with 2D:4D.

A Qualitative, Small-Sample Study of Employment Challenges for People with Disabilities in Saudi Arabia.

Many people live with disabilities and many countries worldwide are acting to provide people with disabilities opportunities to find and sustain gainful employment. Notwithstanding, people with disabilities still do not have the same access to employment as their counterparts without disabilities. Although some research has investigated these issues in Western countries, very little research has investigated these issues in the Middle East, in general, and in Saudi Arabia, in particular.

Teachers' Perceptions of Bullying in Saudi Arabian Primary Public Schools: A Small-Sample, Qualitative Case Study.

Bullying among primary school students is a serious problem that often has multiple negative effects including poor academic performance and mental health problems. The current study used qualitative methodology to determine the role of communication in creating awareness and preventing bullying in a school setting through stakeholder intervention and bullying-prevention programs. If teachers are aware of bullying, then they are likely to take adequate measures to reduce or prevent future bullying.