Disposable clean delivery kits and prevention of neonatal tetanus in the presence of skilled birth attendants.

OBJECTIVE: To determine whether the use of disposable clean delivery kits (CDKs) is effective in reducing neonatal tetanus (NNT) infection, regardless of the skills of birth attendants in resource-poor settings. METHODS: A secondary analysis was conducted on data from a matched case-control study in Karachi, Pakistan, involving 140 NNT cases and 280 controls between 1998 and 2001. Conditional logistic regression was performed to assess the independent effect on NNT of CDKs and skilled birth attendants (SBAs). RESULTS: After adjustment for socioeconomic factors, both CDKs (adjusted matched odds ratio [mOR] 2.0; 95% confidence interval [CI], 1.3-3.1) and SBAs (adjusted mOR 1.7; 95% CI, 1.1-2.7) were independently associated with NNT. The association with CDKs remained significant when additionally adjusted for SBAs (mOR 2.0; 95% CI, 1.0-3.9; P=0.05). The population attributable risk for lack of CDK use was 24% in the study setting. CONCLUSION: In the context of resource-poor settings in low-income countries with poor coverage of tetanus toxoid immunization, the use of CDKs seems to be an effective strategy for reducing NNT infection, irrespective of the skill levels of birth attendants. Approximately one-quarter of NNT cases could be prevented in low-income populations with the use of CDKs

Measuring Persistence of U.S. City Prices: New Evidence from Robust Tests

This paper revisits the empirical analysis in Cecchetti, Mark and Sonora (2002) involving long-span U.S. city prices, who estimated the persistence of U.S. price differentials to be around nine years. After controlling for the structural breaks in the data, we find that U.S. city price level differentials are I(0) stationary processes with the median half-life of convergence ranged between 1.5 and 2.6 years, estimates that are in accordance with what should be expected from a highly integrated economy as the United States. Our results are also robust to a pairwise tests of price level convergence.Purchasing power parity; Price level convergence; Half-life; Multiple structural breaks; Pairwise convergence.

Price level convergence, purchasing power parity and multiple structural breaks: An application to US cities

This article provides a fresh methodological and empirical approach for assessing price level convergence and its relation to purchasing power parity (PPP) using annual price data for seventeen US cities. We suggest a new procedure that can handle a wide range of PPP concepts in the presence of multiple structural breaks using all possible pairs of real exchange rates. To deal with cross-sectional dependence, we use both cross-sectional demeaned data and a parametric bootstrap approach. In general, we find more evidence for stationarity when the parity restriction is not imposed, while imposing parity restriction provides leads toward the rejection of the panel stationarity. Our results can be embedded on the view of the Balassa-Samuelson approach, but where the slope of the time trend is allowed to change in the long-run. The median half-life point estimate are found to be lower than the consensus view regardless of the parity restriction.

Deconstructing Shocks and Persistence in OECD Real Exchange Rates

This paper analyzes the persistence of shocks that affect the real exchange rates for a panel of seventeen OECD developed countries during the post-Bretton Woods era. The adoption of a panel data framework allows us to distinguish two different sources of shocks, i.e. the idiosyncratic and the common shocks, each of which may have di¤erent persistence patterns on the real exchange rates. We first investigate the stochastic properties of the panel data set using panel stationarity tests that simultaneously consider both the presence of cross-section dependence and multiple structural breaks that have not received much attention in previous persistence analyses. Empirical results indicate that real exchange rates are non-stationary when the analysis does not account for structural breaks, although thisconclusion is reversed when they are modeled. Consequently, misspecification errors due to the non-consideration of structural breaks leads to upward biased shocks' persistence measures. The persistence measures for the idiosyncratic and common shocks have been estimated in this paper always turn out to be less than one year.

Influence of organic and inorganic soil amendments on corn root growth and soil chemical properties

One of the main constraints to corn production on a highly weathered acid soil is aluminum (Al) toxicity. High Al concentration in acid soils restricts root growth by inhibiting cell elongation and cell division. The objective of this study was to determine the effects of inorganic arid organic soil amendments on corn root growth and soil chemical properties A laboratory experiment was conducted using Bungor series soil (Typic Paleudult) surface sampled (0 - 20 cm) from Puchong farm. Aliquot of the soil (600 g) was treated with legume residues (1% w/w), chicken manure (1% w/w), GML (4 t had), gypsum (4 t ha-1) and control The treated soils were moistened at field capacity (0 25 kg H20 kg-1 soil) and allowed to react for 7 days. Corn seeds (Zea mays L.) were sown and after 5 days root length was measured The results showed that soils amended with GML or chicken manure gave relatively high root length compared to other treatments. The GML and chicken manure treatments increased soil pH and decreased both the soil exchangeable Al and Al-saturation Chicken manure had an additional ameliorative effect over lime in that it increased soil exchangeable Ca, Mg and K

Local Exchangeability

Exchangeability---in which the distribution of an infinite sequence is invariant to reorderings of its elements---implies the existence of a simple conditional independence structure that may be leveraged in the design of probabilistic models, efficient inference algorithms, and randomization-based testing procedures. In practice, however, this assumption is too strong an idealization; the distribution typically fails to be exactly invariant to permutations and de Finetti's representation theory does not apply. Thus there is the need for a distributional assumption that is both weak enough to hold in practice, and strong enough to guarantee a useful underlying representation. We introduce a relaxed notion of local exchangeability---where swapping data associated with nearby covariates causes a bounded change in the distribution. We prove that locally exchangeable processes correspond to independent observations from an underlying measure-valued stochastic process. We thereby show that de Finetti's theorem is robust to perturbation and provide further justification for the Bayesian modelling approach. Using this probabilistic result, we develop three novel statistical procedures for (1) estimating the underlying process via local empirical measures, (2) testing via local randomization, and (3) estimating the canonical premetric of local exchangeability. These three procedures extend the applicability of previous exchangeability-based methods without sacrificing rigorous statistical guarantees. The paper concludes with examples of popular statistical models that exhibit local exchangeability

Doppler-free approach to optical pumping dynamics in the 6S1/2−5D5/26S_{1/2}- 5D_{5/2} electric quadrupole transition of Cesium vapor

The $6S_{1/2}-5D_{5/2}$ electric quadrupole transition is investigated in Cesium vapor at room temperature via nonlinear Doppler-free 6P-6S-5D three-level spectroscopy. Frequency-resolved studies of individual E2 hyperfine lines allow one to analyze optical pumping dynamics, polarization selection rules and line intensities. It opens the way to studies of transfer of light orbital angular momentum to atoms, and the influence of metamaterials on E2 line spectra.Comment: 4 pages, 5 figures, minor updates from previous versio

An evaluation of cation exchange capacity methods for acid tropical soils

The cation exchange capacity (GEC) of soil is an important criteria for assessing soil fertility beside its use in soil classification. Seven methods, namely, (1) BaCl2 - triethanolamine of BaCl2 - TEA (PH 8.2), (2) NH40Ac (PH 7.0) - leaching, (3) NH40Ac (PH 7.0) - shaking, (4) compulsive exchange method of Gillman (1979) (GECcd, (5) modified compulsive exchange method of Gillman (1986) (CEC3, (6) Summation of Ca from method 5 with 1 M NH4 NO3 exchangeable Al (CECtotal and (7) summation of NH40Ac (PH 7.0) exchangeable bases with 1 M KCl exchangeable Al (CECsum) were used to determine and compare the CEC values of five acid tropical soils. All methods gave different CEC values which followed the order BaCl2 - TEA> NH40Ac shaking = NH40Ac leaching> CECsum = CECto tal > CECCE = CECB• Methods with pH conditions close to field situations gave much lower CEC values than the buffered methods. The buffered methods generate charge on the variable-charge colloids, thus resulting in inflated CEC values, while the unbuffered methods do not. There is a high correlation between BaCl2 - TEA and NH40Ac (PH 7. 0) leaching method; CECCE and CECsum; and, CECB and CECtotal Amongst the methods evaluated, the NH40Ac (PH 7.0) leaching is recommended in routine soil analyses for classification purposes while CECsum is recommended for agronomic evaluation