46 research outputs found
Contraceptive Adoption, Discontinuation, and Switching among Postpartum Women in Nairobi's Urban Slums.
Unmet need for contraception is highest within 12 months post-delivery, according to research. Using longitudinal data from the Nairobi Urban Health and Demographic Surveillance System, we assess the dynamics of contraceptive use during the postpartum period among women in Nairobi's slums. Results show that by 6 months postpartum, 83 percent of women had resumed sexual activity and 51 percent had resumed menses, yet only 49 percent had adopted a modern contraceptive method. Furthermore, almost half of women discontinued a modern method within 12 months of initiating use, with many likely to switch to another short-term method with high method-related dissatisfaction. Women who adopted a method after resumption of menses had higher discontinuation rates, though the effect was much reduced after adjusting for other variables. To reduce unmet need, effective intervention programs are essential to lower high levels of discontinuation and encourage switching to more effective methods
Method-Specific Attributes that Influence Choice of Future Contraception Among Married Women in Nairobi's Informal Settlements.
Despite an extensive evidence base on contraceptive method choice, it remains uncertain which factors are most influential in predisposing women toward certain methods and against others. This paper addresses this gap in knowledge by making use of rarely-measured perceptions about specific methods, perceived social network experience of methods, and women's own past experiences using specific methods. We draw on baseline data from the project, "Improving Measurement of Unintended Pregnancy and Unmet Need for Family Planning." Using conditional logit analysis, we ascertain which perceived method-specific attributes, including past experience of methods by women themselves and by their friends, predict preferred future contraceptive method among 317 women living in Nairobi slums who are using no method but intend to start in the next 12 months. Results show that satisfaction with past use, positive experience of use by a woman's social network, husband/partner's approval, lack of interference with menses, and perception of safety for long term use were all associated with choice of a future method
Childbearing desires and behaviour: a prospective assessment in Nairobi slums.
BACKGROUND: Advancing an understanding of childbearing desires is an important precursor to achievement of the policy goal of reducing unintended pregnancies. It has been long debated that concepts of fertility desires and planning may be particularly problematic in sub-Saharan Africa. However, examination of the utility of fertility preference measures and their link to reproductive behaviour is still rare in the region. The aim of this study is to assess the predictive validity of future childbearing desires on subsequent reproduction among women living in the highly unpredictable circumstances of Nairobi slums. METHODS: We used data from a longitudinal study (2007-2010) nested in the Nairobi Urban Health Demographic Surveillance System that is located in two slums in Nairobi, Kenya. We analysed baseline fertility desires among 4577 postpartum women. Cox proportional hazard model was employed to examine the effect of fertility desires on subsequent reproduction. RESULTS: One-third of the women wanted no more children and 37% wanted to wait for at least five years at baseline. While two-thirds of the women who wanted to have a child soon became pregnant within three years, less than one-third of those wanting no more children became pregnant. The multivariable analysis shows that the probability of becoming pregnant among women who expressed desires to stop or delay childbearing at least for five years was 50% less than among women who wanted to have a child in two to four years. In addition to prospective fertility desires, level of woman's education, residence and ethnicity exerted important influences on implementation of baseline preferences. CONCLUSIONS: Our study finds a strong link between baseline fertility desires and subsequent reproduction. A large difference in pregnancy risk was observed between those who wanted no more children and those who wanted another child. The link between a woman's stated desire to stop childbearing and subsequent childbearing is just as strong in the Nairobi slums as elsewhere. In addition, the findings revealed a pronounced gradient in pregnancy risk according to preferred spacing length, which support other evidence on the important contribution of long-term spacing or postponement to fertility decline in sub-Saharan Africa
Factors influencing the likelihood of acceptance of postpartum intrauterine devices across four countries: India, Nepal, Sri Lanka, and Tanzania.
OBJECTIVE: To examine the factors that positively influenced the likelihood of accepting provision of postpartum intrauterine devices (PPIUDs) across four countries: Sri Lanka, Nepal, Tanzania, and India. METHODS: Healthcare providers were trained across 24 facilities in counselling and insertion of PPIUDs as part of a large multicountry study. Women delivered were asked to take part in a 15-minute face-to-face structured interview conducted by in-country data collection officers prior to discharge. Univariate analysis was performed to investigate factors associated with acceptance. RESULTS: From January 2016 to November 2017, 6477 health providers were trained, 239 033 deliveries occurred, and 219 242 interviews were conducted. Of those interviewed, 68% were counselled on family planning and 56% on PPIUD, with 20% consenting to PPIUD. Multiple counselling sessions was the only factor resulting in higher consent rates (OR 1.30-1.39) across all countries. Odds ratios for women's age, parity, and cadre of provider counselling varied between countries. CONCLUSION: Consent for contraception, specifically PPIUD, is such a culturally specific topic and generalization across countries is not possible. When planning contraceptive policy changes, it is important to have an understanding of the sociocultural factors at play
FIGO postpartum intrauterine device initiative: Complication rates across six countries.
OBJECTIVE: To record and analyze complication rates following postpartum intrauterine device (PPIUD) insertion in 48 hospitals in six countries: Sri Lanka, India, Nepal, Bangladesh, Tanzania, and Kenya. METHODS: Healthcare providers were trained in counselling and insertion of PPIUD via a training-the-trainer model. Data were collected on methodology, timing, cadre of staff providing care, and number of insertions. Data on complications were collected at 6-week follow-up. Statistical analysis was performed to elucidate factors associated with increased expulsion and absence of threads. RESULTS: From May 2014 to September 2017, 36 766 PPIUDs were inserted: 53% vaginal and 47% at cesarean delivery; 74% were inserted by doctors. Follow-up was attended by 52%. Expulsion and removal rates were 2.5% and 3.6%, respectively. Threads were not visible in 29%. Expulsion was less likely after cesarean insertion (aOR 0.33; 95% CI, 0.26-0.41), following vaginal insertion at between 10 minutes and 48 hours (aOR 0.59; 95% CI, 0.42-0.83), and when insertion was performed by a nurse (aOR 0.33; 95% CI, 0.22-0.50). CONCLUSION: PPIUD has low complication rates and can be safely inserted by a variety of trained health staff. Given the immediate benefit of the one-stop approach, governments should urgently consider adopting this model
MscS-like mechanosensitive channels in plants and microbes
The challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. Over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. Early electrophysiological analysis of the inner membrane of Escherichia coli identified the presence of three distinct mechanosensitive activities. The subsequent discoveries of the genes responsible for two of these activities, the mechanosensitive channels of large (MscL) and small (MscS) conductance, led to the identification of two diverse families of mechanosensitive channels. The latter of these two families, the MscS family, consists of members from bacteria, archaea, fungi, and plants. Genetic and electrophysiological analysis of these family members has provided insight into how organisms use mechanosensitive channels for osmotic regulation in response to changing environmental and developmental circumstances. Furthermore, determining the crystal structure of E. coli MscS and several homologues in several conformational states has contributed to our understanding of the gating mechanisms of these channels. Here we summarize our current knowledge of MscS homologues from all three domains of life and address their structure, proposed physiological functions, electrophysiological behaviors, and topological diversity
Origin and fate of deep-sea seeping methane bubbles at Kuroshima Knoll, Ryukyu forearc region, Japan
Seafloor seeping methane bubbles were successfully sampled on the summit area of the Kuroshima Knoll (depth of ca. 640 m) using the gas-tight sampler WHATS attached to the Shinkai 2000. To evaluate the origin of the bubbles and verify that the dissociation of methane hydrate was actually in progress, the chemical and isotopic composition of the samples were analyzed. The major component of the gas bubbles was methane (C1) with traces of CO2 (67 ± 16 ppmv) and helium (11 ± 1 ppmv; 4He/20Ne = 320) having a moderate 3He/4He ratio (0.44Ra). C1 was enriched relative to other hydrocarbons (C1/(C2+C3) > 3000). The δ13C values for C1 (-40.1‰VPDB), C2 (-28.3‰VPDB), and C5 (-28.0‰VPDB) were similar to those of hydrocarbons produced by thermal decomposition of organic matter. The contribution of the mantle-derived 3He-enriched component in coexisting helium also supports thermogenic generation. On the other hand, the other light hydrocarbons showed an unusual 13C-enrichment in C3 (-19.1‰VPDB), iso-C4 (-22.4‰VPDB), and n-C4 (-19.9‰VPDB). C3 and C4 had been fractionated both chemically and isotopically through subsequent microbial destruction during the long storage from Miocene in the gas reservoir. In addition, the anaerobic oxidation of CH4 within shallow sediments removed about 20% of CH4, until seepage into ocean water column. Regarding the contribution of gases originating from hydrate dissociation to the bubbles, observed helium amount in the bubbles suggests that methane hydrate is considered to be a minor contributor to the bubbles, at least at present. Direct leakage of gases from deep reservoirs is a more plausible for the source. Regarding the fate of the hydrocarbons in the bubbles in the water column, all rising bubbles at Kuroshima Knoll dissolved within 140 m of the seafloor. After the dissolution, the plume spreads horizontally along with the surface of equal density in the water column, while the concentrations decrease through dilution by eddy diffusion rather than by oxidation
Carbon and oxygen isotopes of cool-water bryozoans from the Great Australian Bight and their paleoenvironmental significance
The carbon and oxygen isotopic compositions of selected bryozoan skeletons from upper Pleistocene bryozoan mounds in the Great Australian Bight (Ocean Drilling Program Leg 182; Holes 1129C, 1131A, and 1132B) were determined. Cyclostome bryozoans, Idmidronea spp. and Nevianipora sp., have low to intermediate magnesian calcite skeletons (1.5-10.0 and 0.9-6.4 molar percentage [mol%] MgCO₃, respectively), but a considerable number include marine cements. The cheilostome Adeonellopsis spp. are biminerallic, principally aragonite, with some high magnesian calcite (HMC) (6.6-12.1 mol% MgCO₃). The HMC fraction of Adeonellopsis has lower δ¹³C and similar δ¹⁸O values compared with the aragonite fraction. Reexamination of modern bryozoan isotopic composition shows that skeletons of Adeonellopsis spp. and Nevianipora sp. form close to oxygen isotopic equilibrium with their ambient water. Therefore, changes in glacial-interglacial oceanographic conditions are preserved in the oxygen isotopic profiles. The bryozoan oxygen isotopic profiles are correlated well with marine isotope Stages 1-8 in Holes 1129C and 1132B and to Stages 1-4(?) in Hole 1131A. The horizons of the bryozoan mounds that yield skeletons with heavier oxygen isotopic values can be correlated with isotope Stages 2, 4(?), 6, and 8 in Hole 1129C; Stages 2 and 4(?) in Hole 1131A; and Stages 2, 4, 6, and 8 in Hole 1132B. These results provide supporting evidence for a model for bryozoan mound formation, in which the mounds were formed during intensified upwelling and increased trophic resources during glacial periods.Hideaki Machiyama, Tsutomu Yamada, Naotomo Kaneko, Yasufumi Iryu, Kei Odawara, Ryuji Asami, Hiroki Matsuda, Shunsuke F. Mawatari, Yvonne Bone, and Noel P. Jame
Origin of late Pleistocene bryozoan reef mounds; Great Australian Bight
Bryozoan-rich biogenic mounds grew periodically on the prograding carbonate slope of the central Great Australian Bight throughout Pliocene-Pleistocene time. Cores from three ODP Leg 182 drill sites provide a record of mound growth during the last 300,000 years over a stratigraphic thickness of ∼ 150 m. These mounds, the first such structures described from the modern ocean, grew between paleodepths of 100 and 240 m; we infer that the upper limit of growth was established by swell wave base, and the lower boundary was fixed by an oligotrophic water mass. Detailed chronostratigraphy, based on radiometric and U-series dating, benthic foraminifer stable-isotope stratigraphy, and planktonic foraminifer abundance ratios, confirms that buildups flourished during glacial lowstands (even-numbered marine isotope stages) but were largely moribund during interglacial highstands and are not extant today. Mound floatstones are compositionally a mixture of in situ bryozoans comprising 96 genera and characterized by fenestrate, flat robust branching, encrusting, nodular-arborescent, and delicate branching growth forms. The packstone matrix comprises autochthonous and allochthonous sand-size bryozoans, benthic and planktonic foraminifers, serpulids, coralline algae, sponge spicules, peloids, and variable glauconite and quartz grains, together with mud-size ostracods, tunicate spicules, bioeroded sponge chips, and coccoliths. Intermound, allochthonous packstone and local grainstone contain similar particles, but they are conspicuously worn, abraded, blackened, and bioeroded. An integrated model of mound accretion during sea-level lowstands begins with delicate branching bryozoan floatstone that increases in bryozoan abundance and diversity upward over a thickness of 5-10 m, culminating in thin intervals of grainstone characterized by reduced diversity and locally abraded fossils. Mound accumulation was relatively rapid (30-67 cm/ky) and locally punctuated by rudstones and firmgrounds. Intermound highstand deposition was comparatively slow (17-25 cm/ky) and typified by meter-scale, fining-upward packages of packstone and grainstone or burrowed packstone, with local firmgrounds overlain by characteristically abraded particles. Mound growth during glacial periods is interpreted to have resulted from increased nutrient supply and enhanced primary productivity. Such elevated trophic resources were both regional and local, and thought to be focused in this area by cessation of Leeuwin Current flow, together with northward movement of the subtropical convergence and related dynamic mixing. © 2004, SEPM (Society for Sedimentary Geology)