RECENT TRENDS IN GENDER RATIO AT BIRTH IN HANGZHOU, CHINA.

INTRODUCTION: Higher than normal sex ratios at birth in China have been reported since the early 1980's. This study aimed to investigate recent trends in sex ratio at birth in Hangzhou, capital of Zhejiang Province in southeast China. METHODS: Information on selected maternal and birth-related characteristics was extracted from the Hangzhou Birth Information Database for all pregnant women who delivered live births during 2005-2014. The sex ratios at birth were calculated after excluding infants with missing data on gender and those born with ambiguous genitalia. RESULTS: A total of 478,192 male births and 430,852 female births were recorded giving an overall ratio of 111.0. The sex ratio at birth was almost constant at around 110.7 during the period 2005-2008, followed by an increase to the peak at 113.1 in 2010 and then declined back to 109.6 in 2014. CONCLUSION: The gender ratio at birth in Hangzhou remained unbalanced for the past decade.

Donation frequency and its association with demographic characteristics--a 1-year observational study.

OBJECTIVE: The aim of this study is to enhance the understanding of frequent blood donors' characteristics and devise strategies to achieve an optimal blood inventory. BACKGROUND: Apart from donor recruitment and retention, an effective way to increase blood supply is to increase the donation frequency among donors. Understanding the characteristics of frequent donors will be helpful to impact their future donation pattern, which would in turn achieve a stable and adequate blood inventory to meet the changing demands of the society. METHODS AND MATERIALS: Demographic information of blood donors for each donation in Hong Kong (HK) was routinely collected and stored in the database of Hong Kong Red Cross Blood Transfusion Service. Logistic regression models (by gender group) with interaction effects were constructed to analyse the differences in the likelihood of being frequent donors and the associations with their demographic characteristics. RESULTS: A total of 158,666 blood donors in 2010 gave 227,634 donations during the study. In general, male donors were more likely to be frequent donors. Logistic regression models further identified the characteristics of frequent donors in HK: older, blood type Rh D-ve and repeat donors, although their extent of impact was different for different gender group. CONCLUSION: To achieve an optimal blood inventory to meet the challenge of ageing in the society, donors who donate less often should be targeted to increase their donation frequency. More efforts in promotion should be made to recruit those non-donors to join the blood donation pool and motivate 'targeted' existing donors in the population to participate blood donation more regularly.

Influence diagnostics for generalized linear measurement error models.

We study influence diagnostics for generalized linear models when the true covariates are unobservable but measured with error. Based on the bias-corrected estimation of model parameters, diagnostic measures are developed to identify outlying and influential observations. The magnitude of influence is then assessed via a simulated envelope approach. The proposed diagnostic procedure is illustrated on two examples.

Kinetics of pyrophosphate induced iron release from diferric ovotransferrin.

The kinetics of pyrophosphate-induced iron release from diferric ovotransferrin were studied spectrophotometrically at 37 degrees C in 0.1 M HEPES, pH 7.0. At high pyrophosphate concentrations, the kinetics are biphasic, indicating that the rates of iron release from the two, presumably noninteracting iron-binding sites of ovotransferrin are different. The pseudo-first-order rate constants for iron release from both the fast and slow sites exhibit a hyperbolic dependence on pyrophosphate concentrations. The data suggest that pyrophosphate forms complexes with the two iron-binding sites of ovotransferrin prior to iron removal. The stability constants of the complex formed with the fast site (Keqf) and slow site (Keqs) are 8.3 M-1 and 40.4 M-1, respectively. The first-order rate constants for the dissociation of ferric-pyrophosphate from the fast site (k2f) and the slow site (k2s) are 0.062 and 0.0044 min-1, respectively. Results from urea gel electrophoresis studies suggest that iron is released at a much faster rate from the N-terminal binding site of ovotransferrin. At high pyrophosphate concentration, only C-monoferric-ovotransferrin is detected during the course of iron release. At low pyrophosphate concentration, however, a detectable amount of N-monoferric-ovotransferrin is accumulated. This result is consistent with the kinetic finding that the site with a higher k2 (0.062 min-1) has a lower affinity toward pyrophosphate (Keq = 8.3 M-1) whereas the site with a lower k2 (0.0044 min-1) has a higher affinity for pyrophosphate (Keq = 40.4 M-1).