Satoshi Sasaki

The impact of community-based outreach immunisation services on immunisation coverage with GIS network accessibility analysis in peri-urban areas, Zambia

Background Accessibility to health services is a critical determinant for health outcome. Objectives To examine the association between immunisation coverage and distance to an immunisation service as well as socio-demographic and economic factors before and after the introduction of outreach immunisation services, and to identify optimal locations for outreach immunisation service points in a peri-urban area in Zambia. Methods Repeated cross-sectional surveys were conducted for two groups of children born between 1999 and 2001, and between 2003 and 2005.The association between immunisation coverage for DPT3 and measles, and access distance, child sex, female headed households, and monthly household income were assessed using logistic regression analysis. Optimal locations for outreach service points were identified using GIS network analysis and genetic algorithms. Results Before the introduction of outreach services, longer distances to the service points were associated with lower DPT3 and measles immunisation coverage (OR=0.24, 95% CI 0.10 to 0.56, p<0.01 for DPT3; and OR=0.38, 95% CI 0.17 to 0.83, p<0.05 for measles). However, access distances were not an impediment to immunisation coverage once the outreach services were introduced. The average distance to immunisation services could be decreased from 232.3 to 168.4 metres if the current 12 outreach service points were repositioned at optimal locations. Conclusion Access distance to immunisation services was a critical determinant of immunisation coverage in a peri-urban area. Intervention via outreach services played an important role in averting the risk of missing out on immunisation. Optimal location analysis has the potential to contribute to efficient decision making regarding the delivery of immunisation services.

Access to a health facility and care-seeking for danger signs in children: before and after a community-based intervention in Lusaka, Zambia.

Objective  To assess the association of accessibility to a health facility with caregivers’ care‐seeking practices for children with danger signs before and after community‐based intervention in Lusaka, Zambia.

The impact of an immunization programme administered through the Growth Monitoring Programme Plus as an alternative way of implementing Integrated Management of Childhood Illnesses in urban-slum areas of Lusaka, Zambia

A time-lag study design was used to examine the effects of an immunization programme implemented through an integrated community-based child health approach called the Growth Monitoring Programme Plus (GMP+) in peri-urban areas of Lusaka, Zambia. The immunization coverage and sociodemographic data of eligible children and households were obtained from three repeated surveys in two intervention areas. Logistic regression analysis was performed to explore the factors affecting immunization coverage. For assessing the timeliness of immunization, a Computerised Immunization Coverage Calculation System (CICCS) was used. Full immunization coverage significantly increased in both the primary intervention (P<0.001) and lagged intervention (P = 0.011) areas after the initiation of the GMP+. Frequent attendance to GMP+ sessions played a significant role in the improvement of immunization coverage (P<0.001 for the final survey in the primary intervention area), whereas other sociodemographic characteristics of the child and caretaker were not associated with immunization coverage. Analysis of the timeliness of three doses of diphtheria, pertussis and tetanus DPT3 immunization by CICCS showed that coverage in the primary intervention area had significantly improved compared to the lagged intervention area. Our study indicated that immunization coverage was improved effectively with the intervention of the GMP+ as a model of an integrated immunization programme for child health in line with the Integrated Management of Childhood Illnesses (IMCI) and the Global Immunization Vision and Strategy (GIVS).

A modified grouping genetic algorithm to select ambulance site locations

This article describes the development and application of a modified grouping genetic algorithm (GGA) used to identify sets of optimal ambulance locations. The GGA was modified to consider a special case with only two groups, and the reproduction and mutation schemes were modified to operate more efficiently. It was applied to a case study locating ambulances from a fixed set of alternative locations. The sites were evaluated using data of emergency medical services (EMS) calls summarised over census areas and weighted by network distance. Census areas serviced by the same selected location defined ambulance catchments. The results indicated alternative sites for ambulances to be located, with average EMS response times improved by 1 min 14 s, and showed the impacts of having different numbers of ambulances in current locations and in new locations. The algorithmic developments associated with the modified GGA and the advantages of using census areas as spatial units to summarise data are discussed.

Intersexual Differences and Seasonal Changes in Gonadotropin- producing Cells in the Salamander Hynobius nigrescens

Intersexual differences and annual cytological changes in presumptive gonadotropin- producing cells (gonadotropes) were examined immunohistochemically in mid-sagittal sections of the pi- tuitary gland of adult Hynobius nigrescens by the use of a monoclonal antibody against bullfrog lutein- izing hormone P-subunit (LHP). Total immunoreactive areas for LH, and profiles of the pars distalis in the mid-sagittal plane of the gland were estimated with an image analyzer. Gonadotropes consistently were distributed in the pars distalis near the median eminence and the pars intermedia in both sexes through- out the year; an intersexual difference was found in their distribution pattern. Gonadotrope cells other than these consistent ones distributed in the peripheral region of the pars distalis frequently were ob- served in females, but not in males. The proportion of gonadotropes among all pars distalis cells, as well as the mean area and number of gonadotropes, was significantly greater in females than in males through- out the year. In males that had a typical aquatic-phase morph and actively exhibited reproductive behav- ior, both area and number of gonadotropes, as well as profile estimates of pars distalis size, were the great- est of all monthly values. In females, gonadotrope cells increased in area and number from July-January during the terrestrial phase of the nonbreeding season. This increase was concurrent with the develop- ment of ovaries. This consecutive increase and development may explain the absence of a second oogenic phase during early spring.

Nove l antenna arrangement for 4×4 LOS-MIMO systems

This paper proposes novel antenna arrangements which improve the channel capacity for 4×4 multiple-input multiple-output (MIMO) system in line-of-sight (LOS) environment. It is shown that the channel matrix is unitary matrix by the proposed antenna arrangement and the high channel capacity is obtained by the proposed antenna arrangement with directional antennas even if the multipath signals in indoor scenario are considered.