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Thomas Lilley Toni Laaksonen Otso Huitu Samuli Helle 《Behavioral ecology and sociobiology》2009,63(10):1539-1547
The ratio of second-to-fourth digit length (2D/4D) has been suggested to be a useful adult age marker of intrauterine exposure
to steroids because it should be sexually dimorphic and fixed already in utero. Numerous studies mainly on humans have supported
this conclusion, but it is yet unclear how well this applies to other vertebrates. This information would be especially valuable
to field biologists to whom measuring steroids in utero is often impossible. The non-human studies conducted so far have yielded
inconsistent results, perhaps due to the variety of different methods employed in measuring 2D/4D. We examined the age and
sex dependency and lateral asymmetry of 2D/4D in field voles (Microtus agrestis) and compared whether these effects differed between 2D/4D measurements taken from photographs and X-rays. Our results show
that 2D/4D measurements from photos had a higher measurement error and gave consistently higher 2D/4D than those from X-rays.
According to both measurement methods, the right paw showed higher 2D/4D values than the left paw (lateral asymmetry). Adult
voles had a lower 2D/4D than juveniles when measured from X-rays, but not when measured from photographs. We found no evidence
for a sex difference in 2D/4D using either of the measurement methods. Our findings thus suggest that X-rays, due to their
greater accuracy, should be preferred over photographs for measuring digit ratios in rodents. Our results also indicate that
in this species, 2D/4D is laterally asymmetric, but it may not be either fixed in utero or sexually dimorphic. In conclusion,
2D/4D appears to be a rather species- and method-specific measure and researchers should be careful when generalising its
applicability to study early hormonal effects in vertebrates. 相似文献
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Leena Korpinen Rauno Pääkkönen 《International journal of occupational safety and ergonomics》2013,19(4):385-400
The aim of this paper was to present how mental symptoms are connected to the use of desktop, portable or minicomputers (communicators and hand-held computers), mobile phones, and background information such as age and gender in the Finnish working-age population. The study was carried out as a cross-sectional study by posting a questionnaire to 15 000 working-age (18-65) Finns. The mental symptoms of 6121 respondents were analysed using the model factors age, gender, the use of computers and the use of mobile phones. In all data, the use of desktop computers was related to mental symptoms. However, the results of our data are not highly reliable, because the nonresponse rate was over 50%. Nevertheless, it may be essential to take into account in the future that working with computers can increase workers’ mental symptoms, and it is important to observe their mental health. 相似文献