The present status of subsiding land vulnerable to roof collapse in the Jharia Coalfield,India, as obtained from shorter temporal baseline C-band DInSAR by smaller spatial subset unwrapped phase profiling

In this paper, we identified recently subsiding areas in Jharia Coalfield, Jharkhand, India from the shorter temporal baseline Radarsat-2 C-band interferometric synthetic aperture radar (InSAR) data pairs of 2012. Although shorter wavelength C-band differential InSAR (DInSAR) is more sensitive to slow deformation and better suited for higher precision land subsidence measurement, the dynamic and adverse land cover in mining areas and resulting temporal decorrelation problem poses a serious problem for DInSAR observation in mining areas. We used smaller temporal baseline data pairs and adopted InSAR coherence-guided incremental filtering with smaller moving windows to highlight the deformation fringes over temporal decorrelation noise. We identified the deformation fringes and validated them based on ground information to prepare the land subsidence map of the coalfield in 2012. Several new, previously unreported subsidence areas were detected in the present study with a total subsiding area of 6.9 km². The recent incidence of roof collapse on 15 November 2014 at Angar Patra village in Katras region of the coalfield where 45 houses collapsed and 10 people were injured is situated in a highly subsiding vulnerable area as obtained from the present study. Due to spatial discontinuities of InSAR coherence, DInSAR phase unwrapping for the entire study area in one go did not appear feasible. To avoid this problem, we performed DInSAR processing in smaller spatial subsets and unwrapping of the subset interferograms by a ‘minimum cost flow’ algorithm. Subsequently, we plotted unwrapped phase profiles across the deformation fringes and retrieved the maximum deformation phase with respect to background phase and translated them into radar line of sight (LOS) displacement rates. For obtaining the average subsidence rates, we adopted InSAR coherence-weighted LOS displacement rates taking into account the contribution of each data pair as a function of DInSAR phase quality of the fringe areas. Ground-based subsidence measurements by precision levelling were conducted in four test sites that had been undergoing active underground mining during the observation period. We compared space-borne DInSAR-based subsidence rates obtained by the adopted technique with precision levelling measurements. Overall, the results are found to agree well. In the four test sites with gentle to flat topography, land subsidence occurs at slow to moderate rates due to compression of in-filled material (resulting from sand stowing in underground mining), without any evidence of roof collapse. In such cases, the horizontal displacement component is less significant, and overall surface displacement occurs essentially in the vertical direction. However, we assessed the nature of subtle horizontal strain to infer relative shrinkage or dilation of the land surface which could be additive or subtractive to vertical displacement in DInSAR-based LOS displacement.     

Effect of iron supplementation during pregnancy on birthweight: evidence from Zimbabwe

BACKGROUND: Iron deficiency in pregnant women has been shown to reduce the oxygen supply to the fetus, cause intrauterine growth retardation, and increase the risk of premature delivery and reduced birthweight. Yet the effects of iron supplementation programs on pregnancy outcomes are not well documented for developing countries. OBJECTIVE: To examine the relation between iron supplementation of mothers during pregnancy and children's birthweight using data from a national population-based survey in Zimbabwe. METHODS: The analysis uses information on 3559 births during the five years preceding the 1999 Zimbabwe Demographic and Health Survey. The effect of iron supplementation during pregnancy on birthweight was estimated by multiple regression, controlling for potential confounding effects of prenatal care, child's sex and birth order, mother's education and nutritional status (measured by body-mass index), household living standard, smoke exposure, and other variables. RESULTS: Babies born to mothers who received iron supplementation during pregnancy were 103 g heavier (95% confidence interval, 42-164; p = .001), on average, than babies born to mothers who did not receive iron supplementation during pregnancy. The difference was 64 g (95% confidence interval, 2-125; p = .043) for children whose birthweights were taken from health cards and 163 g (95% confidence interval, 44-281; p = .008) for children whose birthweights were reported by their mothers. CONCLUSIONS: Iron supplementation during pregnancy is associated with significantly higher birthweight, independent of other pregnancy care factors, mother's nutritional status, smoke exposure, and a number of demographic and socioeconomic factors. Prenatal iron supplementation programs can improve pregnancy outcomes and promote child survival in developing countries.     

TiO2 coated urchin-like SnO2 microspheres for efficient dye-sensitized solar cells

Urchin-like SnO2 microspheres have been grown for use as photoanodes in dye-sensitized solar cells （DSSCs）. We observed that a thin layer coating of TiO2 on urchin-like SnO2 microsphere photoanodes greatly enhanced dye loading capability and light scattering ability, and achieved comparable solar cell per- formance even at half the thickness of a typical nanocrystalline TiO2 photoanode. In addition, this photoanode only required attaching -55% of the amount of dye for efficient light harvesting compared to one based on nanocrystalline TiO2. Longer decay of transient photovoltage and higher charge recombination resistance evidenced from electrochemical impedance spectroscopy of the devices based on TiO2 coated urchin-like SnO2 revealed slower recombination rates of electrons as a result of the thin blocking layer of TiO2 coated on urchin- like SnO2. TiO2 coated urchin-like SnO2 showed the highest value （76.1 ms） of electron lifetime （＇r） compared to 2.4 ms for bare urchin-like SnO2 and 14.9 ms for nanocrystalline TiO2. TiO2 coated SnO2 showed greatly enhanced open circuit voltage （Voc）, short-circuit current density （Jsc） and fill factor （FF） leading to a four-fold increase in efficiency increase compared to bare SnO2. Although TiO2 coated urchin-like SnO2 showed slightly lower cell efficiency than nanocrystalline TiO2, it only used a half thickness of photoanode and saved -45% of the amount of dye for efficient light harvesting compared to normal nanocrystalline TiO2.     

Agreement between clinical examination and parental morbidity histories for children in Nepal

Traumatic diaphragmatic hernia is rare, but is of utmost importance due to its high morbidity and mortality. It is markedly important in patients with blunt abdominal trauma, and diagnosis is difficult because of the numerous associated injuries. A patient with few symptoms of chronic traumatic diaphragmatic hernia is described, who underwent surgery due to a gastric volvulus. Laparoscopic surgery permits repair of these injuries through an abdominal approach, avoiding a thoracic incision or selective intubation.     

Resident Involvement and Participation in Urban Tourism Development: A Comparative Study in Maun and Gaborone,Botswana

This paper reports a comparative study of urban tourism development in two areas, Maun and Gaborone, located in northern and southeastern Botswana. More specifically, the study evaluated residents’ tourism awareness and its importance in their lives; assessed economic benefits and employment derived from tourism; and examined impacts of tourism and development issues as perceived by the residents. Data were collected via household surveys and key informant interviews between June 2003 and April 2004. Findings indicate that both study sites bear some similarities in terms of infrastructural development and rapid population growth. The study also found that only a small proportion of the local population is employed within the tourism sector and that the vast majority of tourism-related enterprises are foreign-owned. Various recommendations are outlined to increase citizen participation in urban tourism development, most notably in cultural heritage tourism.

Smallholders’ access to agricultural credit in Pakistan

The Government of Pakistan has implemented a policy of food security for smallholders by making provision of credit needed for purchasing inputs such as farm machinery, fertilizer and seed. This study analyzed access to and adequacy of credit for smallholders with landholdings up to 5 acres (= 2 ha), using primary data collected through a survey of 208 households, focus-group discussions and unstructured interviews. The findings revealed a partial success of the national credit policy in terms of the proportion of households having access to formal credit but appeared less successful when this was compared with the total amount of credit demanded and obtained. Among the three types of smallholders compared, i.e. lower-smallholders (≤1.0 acre), middle-smallholders (1.01–2.50 acres) and upper-smallholders (2.51–5.00 acres), the lower-smallholders obtained least benefit from the policy as reflected in the formal credit accounting for 12% of the total credit obtained and only 6% of the total credit demanded. The other two types of smallholders had relatively better access to formal credit. Due to a lack of access to adequate formal credit, informal sources have continued to play a major role in the credit market. The causes for this are explained and relevant policy recommendations are made for improving smallholders’ access to credit in the study area and elsewhere in Pakistan. It is hoped that the findings of this study will make a useful contribution to the understanding and remedying of the difficulties that smallholders experience in obtaining credit which may be of value not only in Pakistan but in other developing countries.     

Performance of IEEE 802.11 under Jamming

We study the performance of the IEEE 802.11 MAC protocol under a range of jammers that covers both channel-oblivious and channel-aware jamming. We consider two channel-oblivious jammers: a periodic jammer that jams deterministically at a specified rate, and a memoryless jammer whose interfering signals arrive according to a Poisson process. We also develop new models for channel-aware jamming, including a reactive jammer that only jams non-colliding transmissions and an omniscient jammer that optimally adjusts its strategy according to current states of the participating nodes. Our study comprises of a theoretical analysis of the saturation throughput of 802.11 under jamming, an extensive simulation study, and a testbed to conduct real world experimentation of jamming IEEE 802.11 using a software defined radio (GNU Radio combined with USRP boards). In our theoretical analysis, we use a discrete-time Markov chain analysis to derive formula for the saturation throughput of 802.11 under memoryless, reactive and omniscient jamming. One of our key results is a characterization of optimal omniscient jamming that establishes a lower bound on the saturation throughput of 802.11 under arbitrary jammer attacks. We validate the theoretical analysis by means of Qualnet simulations. Finally, we measure the real-world performance of periodic, memoryless and reactive jammers using our GNURadio/ USRP aided experimentation testbed.     

Decursinol Angelate Mitigates Sepsis Induced by Methicillin-Resistant Staphylococcus aureus Infection by Modulating the Inflammatory Responses of Macrophages

The herbal plant Angelica gigas (A. gigas) has been used in traditional medicine in East Asian countries, and its chemical components are reported to have many pharmacological effects. In this study, we showed that a bioactive ingredient of A. gigas modulates the functional activity of macrophages and investigated its effect on inflammation using a sepsis model. Among 12 different compounds derived from A. gigas, decursinol angelate (DA) was identified as the most effective in suppressing the induction of TNF-α and IL-6 in murine macrophages. When mice were infected with a lethal dose of methicillin-resistant Staphylococcus aureus (MRSA), DA treatment improved the mortality and bacteremia, and attenuated the cytokine storm, which was associated with decreased CD38⁺ macrophage populations in the blood and liver. In vitro studies revealed that DA inhibited the functional activation of macrophages in the expression of pro-inflammatory mediators in response to microbial infection, while promoting the bacterial killing ability with an increased production of reactive oxygen species. Mechanistically, DA treatment attenuated the NF-κB and Akt signaling pathways. Intriguingly, ectopic expression of an active mutant of IKK2 released the inhibition of TNF-α production by the DA treatment, whereas the inhibition of Akt resulted in enhanced ROS production. Taken together, our experimental evidence demonstrated that DA modulates the functional activities of pro-inflammatory macrophages and that DA could be a potential therapeutic agent in the management of sepsis.