An Assessment of Risk of Iodine Deficiency Among Pregnant Women in Sarawak, Malaysia

Previous findings from a state-wide Iodine Deficiency Disorders (IDD) study among pregnant women (PW) in Sarawak indicated that PW are at risk of IDD and further assessment is needed. This paper describes the methodology used in conducting this study for an assessment of risk of iodine deficiency among pregnant women in Sarawak, Malaysia. A total of 30 maternal child health care clinics (MCHCs) were selected using probability proportional to population size (PPS) sampling technique. The PW sample size was calculated based on 95% confidence interval (CI), relative precision of 5%, design effect of 2, anticipated IDD prevalence of 65.0% and non-response rate of 20%. Thus, the total sample size required was 750 (25 respondents per selected MCHC). The WHO Expanded Programme on Immunization (EPI) surveys approach was used to randomly select the first respondent and subsequent respondents were chosen until the required number of PW was met. The required data were obtained through: face-to-face interviews (socio-demographic and food frequency questionnaire), clinical assessments (thyroid size, and hyper/hypothyroidism) and biochemical analysis (urine and blood serum). A total of 677 PW responded in the study with a response rate of 90.2%. Majority of the PW were at second gravida, aged 25-29 years old and of Malay ethnicity. The methodology used in this study was based on International guidelines which may provide state's estimates. All the necessary steps were taken into consideration to ensure valid and reliable findings on current iodine status among PW

Sedimentological characteristics of sediments of the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam waters

Surficial investigation of bottom sediments was conducted within the waters off the coast of Sabah, Sarawak and Brunei Darussalam. Two sampling of bottom sediments were conducted, one before (September 1996) and one after (April 1997) the Northeast monsoon period, which normally lasts from November to February annually. During the pre-monsoon cruise, fifty-one samples were collected while 52 samples were collected during the post-monsoon exercise. The collected samples were analysed for their sedimentological characteristics of mean, sorting, skewness and kurtosis. Analyses revealed that the post-monsoon sediments are finer, better sorted in arrangement, more symmetrical and less peaked than the pre-monsoon sediments. Deeper water sediment shows the same characteristics as described above when compared to shallow water sediments. In general, the near-shore sediments are coarsest, more poorly sorted, more positively skewed and most peaked in characteristics when compared to the mid-shore and off-shore sediments

Detection of large-scale synchrotron radiation from the molecular envelope of the Sgr B cloud complex at the Galactic center

We present highly sensitive measurements taken with MeerKAT at 1280 MHz as well as archival GBT, MWA and VLA images at 333, 88 and 74 MHz. We report the detection of synchrotron radio emission from the infrared dark cloud (IRDC) associated with the halo of the Sgr B complex on a scale of ~60 pc. A strong spatial correlation between low-frequency radio continuum emission and dense molecular gas, combined with spectral index measurements, indicates enhanced synchrotron emission by cosmic-ray electrons. Correlation of the FeI 6.4 keV Kalpha line and synchrotron emission provides compelling evidence that the low energy cosmic-ray electrons are responsible for producing the Kalpha line emission. The observed synchrotron emission within the halo of the Sgr B cloud complex has mean spectral index alpha -1+/-1 gives the magnetic field strength ~100 muG for cloud densities nH = 10^4-10^5 cm-3 and estimate cosmic-ray ionization rates between 10^-13 and 10^-14 s^-1. Furthermore, the energy spectrum of primary cosmic-ray electrons is constrained to be E^-3 +/-1 for typical energies of few hundred MeV. The extrapolation of this spectrum to higher energies is consistent with X-ray and gamma-ray emission detected from this cloud. These measurements have important implications on the role that high cosmic-ray electron fluxes at the Galactic center play in production of radio synchrotron emission, the FeI Kalpha line emission at 6.4 keV and ~GeV gamma-ray emission throughout the central molecular zone (CMZ).Comment: 10 pages, 4 figures, MN (in press

Sedimentological characteristics of the sediments of the South China Sea, Area I: Gulf of Thailand and east coast of Peninsular Malaysia

Two batches of eighty sediment samples were cut from the first centimeter of sediment cores collected during September 1995, representing the pre-monsoon period, and April 1996, representing the post-monsoon period, at the same location. The samples were collected within the waters of the Gulf of Thailand and the eastern board of Peninsular Malaysia. The sediment samples were analyzed for their sedimentological characteristics using the techniques of sieving and laser diffraction. In general the sediments of the Gulf of Thailand are finer, better sorted, more peaked than that of the Malaysian waters. Skewness of sediments from Thailand waters was more positively skewed than the Malaysian sediments for the pre-monsoon period but tended to be more negatively skewed for the post-monsoon period. It is also interesting to note that in general, the sediments collected during the post-monsoon period are finer, better sorted, more positively skewed and less peaked than the sediments collected during the pre-monsoon period. This is true for both the sediments collected from the Gulf of Thailand and the Malaysian waters. Near-shore sediments were also found to be the coarsest, followed by the off-shore sediments

Quality of life satisfaction among converted Kelantan Chinese Muslims

This article investigates the quality of life of the Kelantan Chinese Muslim community before and after conversion to Islam, focusing on their level of satisfaction in term of economic aspect. This research was carried out using the sequential explanatory mixed method design involving 75 respondents selected for quantitative and five respondents for qualitative. The sampling method adopted was convenience and snowball samplings. The research data was collected using questionnaires and semi-structured interviews. The results revealed that respondents were moderately satisfied before conversion and satisfied after conversion. Besides that, there is no significant difference of quality of life before and after conversion to Islam (F = 0.868, p = 0.355) and it was not influenced by the period of conversion to Islam (F = 0.832, p = 0.589). This analysis indicates numerous respondents are still moderately satisfied in their quality of life even though the average data shows they are satisfied after conversion

Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal

Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix imposes highly alkaline pH conditions (10 < pH < 11). The screening of a range of anaerobic denitrifying bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these extreme conditions of pH. The denitrifying activity of Halomonas desiderata was quantified in batch bioreactor in the presence of solid matrices and / or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement matrix (< 100 hours) and 2 to 3 times slower in the presence of bituminous matrix. Overall, the presence of solid cement promoted the kinetics of denitrification. The observation of solid surfaces at the end of the experiment revealed the presence of a biofilm of Halomonas desiderata on the cement paste surface. These attached bacteria showed a denitrifying activity comparable to planktonic bacterial culture. On the other side, no colonization of bitumen could be highlighted as either by SEM or epifluorescence microscopy. Now, we are currently developing a continuous experimental bioreactor which should allow us a more rational understanding of the bitumen-cement-microbe interactions

Canonical Particle Acceleration in FRI Radio Galaxies

Matched resolution multi-frequency VLA observations of four radio galaxies are used to derive the asymptotic low energy slope of the relativistic electron distribution. Where available, low energy slopes are also determined for other sources in the literature. They provide information on the acceleration physics independent of radiative and other losses, which confuse measurements of the synchrotron spectra in most radio, optical and X-ray studies. We find a narrow range of inferred low energy electron energy slopes, n(E)=const*E^-2.1 for the currently small sample of lower luminosity sources classified as FRI (not classical doubles). This distribution is close to, but apparently inconsistent with, the test particle limit of n(E)=const*E^-2.0 expected from strong diffusive shock acceleration in the non-relativistic limit. Relativistic shocks or those modified by the back-pressure of efficiently accelerated cosmic rays are two alternatives to produce somewhat steeper spectra. We note for further study the possiblity of acceleration through shocks, turbulence or shear in the flaring/brightening regions in FRI jets as they move away from the nucleus. Jets on pc scales and the collimated jets and hot spots of FRII (classical double) sources would be governed by different acceleration sites and mechanisms; they appear to show a much wider range of spectra than for FRI sources.Comment: 16 figures, including 5 color. Accepted to Astrophysical Journa

Radio emission from Supernova Remnants

The explosion of a supernova releases almost instantaneously about 10^51 ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from a SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critical discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analyzing the prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure