Potential of <Emphasis Type="Italic">Micranthemum umbrosum</Emphasis> for phytofiltration of organic arsenic species from oxic water environment

Arsenic (As) is a toxic and carcinogenic metalloid that causes various hazards to human health. Phytofiltration is a more eco-friendly and green approach than chemoremediation, or other traditional technologies, for removing As from aquatic environments. Recently, Micranthemum umbrosum was shown as a promising candidate for phytofiltration of inorganic As species. This work examines the potential application of M. umbrosum to phytofiltration of organic As species, such as monomethylarsonic acid (MMAA, CH₅AsO₃) and dimethylarsinic acid (DMAA, C₂H₇AsO₂), from oxic water environments. M. umbrosum plants were grown in two test concentrations of MMAA and DMAA, or a control, in a hydroponic experiment. After seven days, leaves accumulated 90 ± 3.2 and 48 ± 1.6 µg As g^?1 (oven dry basis) from 1 µg As mL^?1 of water added from MMAA and DMAA, respectively. Bioconcentration factor values and translocation factor values were always greater than 1.0, indicating that M. umbrosum was a good As accumulator and that leaves accumulated significantly higher amounts of As than stems and roots. Analysis of macro- and micronutrient data showed that M. umbrosum had higher resistance to organic As treatments than the control. These results confirm the potential application of M. umbrosum for phytofiltration of organic As from contaminated oxic water environments.     

Millimetric properties of gamma-ray burst host galaxies

We present millimetre (mm) and submillimetre (submm) photometry of a sample of five host galaxies of gamma-ray bursts (GRBs), obtained using the Max Planck Millimetre Bolometer (MAMBO2) array and Submillimetre Common-User Bolometer Array (SCUBA). These observations were obtained as part of an ongoing project to investigate the status of GRBs as indicators of star formation. Our targets include two of the most unusual GRB host galaxies, selected as likely candidate submm galaxies: the extremely red  ( R − K ≈ 5)  host of GRB 030115, and the extremely faint  ( R > 29.5)  host of GRB 020124. Neither of these galaxies is detected, but the deep upper limits for GRB 030115 impose constraints on its spectral energy distribution, requiring a warmer dust temperature than is commonly adopted for submillimetre galaxies (SMGs).
As a framework for interpreting these data, and for predicting the results of forthcoming submm surveys of Swift -derived host samples, we model the expected flux and redshift distributions based on luminosity functions of both submm galaxies and GRBs, assuming a direct proportionality between the GRB rate density and the global star formation rate density. We derive the effects of possible sources of uncertainty in these assumptions, including (1) introducing an anticorrelation between GRB rate and the global average metallicity, and (2) varying the dust temperature.     

Floating wetland mesocosm assessment of nutrient removal to reduce ecotoxicity in stormwater ponds

A grouped mesocosm study was conducted with different water holding capacities and conditions to determine nutrient removal efficiency using floating wetland macrophytes. Different scenarios were created by changing water depth, littoral vegetation, sorption media and area coverage to observe how they affect nutrient removal efficiencies. Plant species were screened and selected based on the literature, local availability and previously performed microcosm studies. Sorption media were warped using geotextile filter fostering microbial colonization in the rhizospheric zone to enhance denitrification and plant growth. Water quality parameters included total nitrogen, total phosphorus, orthophosphate, nitrate?Cnitrogen and ammonia?Cnitrogen in addition to in situ parameters such as pH, dissolved oxygen, temperature and chlorophyll-a. Composite samples across several locations were collected periodically to understand the spatial distribution or aggregation of nutrients. After 3?months of water quality monitoring, plants were analyzed for tissue nutrient concentrations, and the average uptake rate was calculated as 36.39 and 1.48?mg?m^?2?day^?1 for nitrogen and phosphorus, respectively, by the floating treatment wetland system. Finally, considering the higher nutrient aggregation in the rhizospheric zone, the removal rate with 5?% area coverage and water quality improvement by littoral zone, the optimized design, placement and maintenance of the whole system were recommended.     

Analyzing the occurrence of floods and droughts in connection with climate change in Punjab province,Pakistan

Natural Hazards - Frequency and intensity of extreme weather events are immensely changing throughout the world. This study aims to give insight into the changing climatic patterns leading to...     

Near surface lithology and spatial variation of arsenic in the shallow groundwater: southeastern Bangladesh

This study investigated the relationship between near-surface lithology and the spatial variability of As concentrations using sediment grain-size analysis and electromagnetic induction survey in the southeast Bangladesh. It has been observed that the aquifers overlain by finer sediments have higher concentrations of As in groundwater, whereas As concentrations are remarkably low in aquifers having permeable sandy materials or thinner silt/clay layer at the surface. The near-surface lithology acts as a controlling factor for spatial distributions of groundwater As within the very shallow depths (<15 m). Shallow alluvial aquifers can provide low-As drinking water in many areas of the country when tube wells are properly installed after investigation of the overlying near-surface sediment attributes and hydraulic properties.     

Socio-economic determinants of women’s livelihood time use in rural Bangladesh

Achieving gender well-being and equality is one of the 17 Sustainable Development Goals of the United Nations. A close examination of female livelihood time allocation can reveal gender inequality in livelihood choices between males and females. Using the feminist political ecology framework, this paper examines how gendered knowledge, roles, and responsibilities influence female livelihood time use in a patriarchal society like Bangladesh. We use a nationally representative household survey data to create Multiple Linear Regression Model to understand the association between economic, cultural, and environmental shocks with the total time allocation toward livelihood activities by women. Our results suggest that use of ‘Purdah’ by Muslim women acts as a negative detrimental factor towards their livelihood time allocation, thus affirming the complex role of culture and gendered economic activities. Women also allocate less time toward livelihood activities during pregnancy and/or breastfeeding. We find that female livelihood time use also depends on their ability to speak in public, their autonomy in livelihood decision processes, and their ownership in business enterprises. This research suggests creating more robust and gender sensitive policies in Bangladesh that can help achieve the United Nation’s goals of Sustainable Development.

     

沉积岩数据库:计算机的应用

岩石学数据在许多地质统计分析中是相当有用的。为了得出焦伊布尔哈德地区的焦因蒂亚布尔区和锡尔赫特地区焦伊布尔哈德灰岩区的构造、地层和沉积作用情况，已作了大量的详细的野外工作和室内分析。已对锡尔赫特地区和焦伊布尔哈德地区的灰岩作了化学分析，且对Ｔｉｐａｍ砂岩作了矿物分析。所获取数据可应用于ＳＥＤＢＡ。用于ＳＥＤＢＡ的参数必须是精确的和沉积成因的。