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An attempt has been made to enhance the sensitivity of a high-sensitive surface plasmon resonance (SPR) biosensor with an aluminium-cobalt bimetallic layer covered by a tungsten disulfide-graphene heterostructure. A thin layer of cobalt coated on an aluminium layer contributed substantially to increase the sensor performance. The use of Al and Co metals instead of noble metals like Ag and Au reduced the cost of the sensor. Further, tungsten disulfide (WS2) layers were employed to improve sensitivity and protect the bimetal Al-Co from becoming oxidized, whereas graphene served as the biomolecule trapping medium. The number of WS2 and graphene layers have optimized for better sensitivity. The proposed biosensor Al-Co-WS2-graphene structure displayed an excellent sensitivity of 300°/RIU, convenient for sensing biomolecules.

Energy conservation has become crucial due to the present energy crisis in the world. To resolve such crises and reduce peak hours' electricity demand, the conservation voltage reduction (CVR) technique is frequently implemented in the power grid system. In this paper, experimental work along with simulation has been done to conserve energy by employing the CVR technique in a smart grid (SG). To verify the simulation result, an Arduino-based SG has been designed with a real-time clock (RTC) and Wi-Fi module esp8266. A program has been developed and burnt into a microcontroller integrated circuit (IC) of an Arduino board that senses day-to-day peak and/or off-peak hours of electricity consumption. The intelligent program that has been put in the system to control the switching of triode for AC (i.e., TRIAC) with an optocoupler to vary the firing angle α (0-π). At peak hours the developed system optimizes the output supplied voltage to load and it results in lesser supplied power at load. The energy consumption data is then sent to the ThingSpeak cloud for remote monitoring. Data aggregation and analytics can be done on ThingSpeak to estimate the energy consumption trend and according to the trend distribution management can notify the generation section for demand management. It has been found that the CVR technique is feasible in RTC-based SG systems which conserves 8.33 % energy by considering 2 ms as an optimized firing delay while the CVR factor = 1. The developed RTC-based SG could be useful in mitigating the present energy crisis in developing countries.

Water quality is the key of environmental concern because of its important provision of water for drinking and domestic purpose, irrigation and aquatic life including fish and fisheries. The present study was conducted to assess the surface water quality of the Shitalakhya River from January, 2017 to December, 2018. Temperature, pH, EC, TDS, TSS, BOD5, Alkalinity, Total Hardness, Calcium Hardness, Magnesium Hardness, Chloride, Dissolved Silica, Total Iron concentration and Turbidity in water samples have been found in the ranges 24 - 33°C, 6.5 - 7.6, 108 - 478 µS/cm, 54 - 245 ppm, 8 - 118 mg/l, 6 - 12 mg/l, 36.6 - 231.8 mg/l, 30 - 190 mg/l, 20 - 120 mg/l, 10 - 80 mg/l, 3.54 - 9.91 mg/l, 16 - 51 mg/l, 0.10 - 1.5 mg/l, 2.09 - 120 NTU in the year 2017 and 21 - 32.5°C, 6.7 - 7.3, 101 - 424 µS/cm, 55 - 212 ppm, 10 - 154 mg/l, 7 - 16 mg/l, 42.7 - 219.6 mg/l, 35 - 180 mg/l, 25 - 115 mg/l, 10 - 70 mg/l, 4.96 - 16.99 mg/l, 19 - 84 mg/l, 0.10 - 2.50 mg/l, 2.73 - 214 NTU in the year 2018 respectively. Obtained results of the present study area shows that most of the parameters were within the permissible limit except Turbidity, Total Suspended Solid (TSS), Dissolved Silica (SiO2) and Biological Oxygen Demand for five days (BOD5). Use of river water can pose serious problems to human health and aquatic ecosystem via biological food chain. The present research suggests special preference for better management of the river water to protect the health of aquatic ecosystem of the river.

Background Wearing masks or personal protective equipment (PPE) has become an integral part of the occupational life of physicians due to the coronavirus disease 2019 (COVID-19) pandemic. Most physicians have been developing various health hazards related to the use of different protective gears. This study aimed to determine the burden and spectrum of various health hazards associated with using masks or PPE and their associated risk factors. Methods This cross-sectional survey was conducted in Dhaka Medical College from March 01–May 30, 2021, among physicians from different public hospitals in Dhaka, Bangladesh. We analyzed the responses of 506 physicians who completed case record forms through Google forms or hard copies. Findings The mean (SD) age of the respondents was 35.4 [7.7], and 69.4% were men. Approximately 40% were using full PPE, and 55% were using N-95 masks. A total of 489 (96.6%) patients experienced at least one health hazard. The reported severe health hazards were syncope, severe dyspnea, severe chest pain, and anaphylaxis. Headache, dizziness, mood irritation, chest pain, excessive sweating, panic attack, and permanent facial disfigurement were the minor health hazards reported. Extended periods of work in the COVID-19-unit, reuse of masks, diabetes, obesity, and mental stress were risk factors for dyspnea. The risk factors for headaches were female sex, diabetes, and previous primary headaches. Furthermore, female sex and reusing masks for an extended period (> 6 h) were risk factors for facial disfigurement. The risk factors for excessive sweating were female sex and additional evening office practice for an extended period. Conclusions Healthcare workers experienced several occupational hazards after using masks and PPE. Therefore, an appropriate policy is required to reduce such risks.

3D food printing sectors require comprehensive knowledge on viscoelastic and mechanical properties of diverse food materials in order to effectively utilize them in rapid and customized 3D production for supply and manufacturing chains. In this work, we present mechanical and rheological properties of Agar and Konjac based edible gels at different Agar and Konjac weight ratio and discuss their 3D printing performance. Gel samples with higher Konjac content positively contributed to the viscoelastic properties of the gel samples which in return has been found viable for extrusion-based 3D printing. By choosing appropriate printing parameters, different shapes are printed to demonstrate printing resolution. We expect, this study will add potential scope for evaluating and optimizing soft-gel materials for 3D food printing sector., 3D printing, Rheology, Mechanical properties, Edible gel, Food printing

The management and treatment of healthcare waste (HCW) are of great concern owing to its potential hazard to human health and the environment, particularly in developing countries. Nowadays, various technological alternatives are gaining momentum as efficient and favorable waste management options across the world. However, selecting a suitable technology as well as an effective waste management approach for the treatment of HCW is still a challenging task for the municipal authorities. This study renders a comprehensive analysis of healthcare waste management (HCWM) practices and the technological options for its better management through a case study in Khulna, the southwestern division of Bangladesh. A number of healthcare establishments (HCEs) in the study area were selected and a questionnaire survey, as well as field investigations, was performed to find out the present status of HCWM and its limitations. An assessment of different technological alternatives was also carried out using Sustainability Assessment of Technologies (SAT) methodology which could pave the way for treating hazardous waste more efficiently in the Khulna metropolitan area. The study revealed that the overall HCW generation rate and hazardous HCW generation rate in Khulna city were 0.90 kg bed−1 day−1 and 0.18 kg bed−1 day−1, respectively. Assessment of management system revealed that 56% (n=38) of workers did not receive any form of training in the handling of hazardous waste. Around 54% (n=47) of them did not use any safety equipment or clothing. It has been found from the study that, among different technological alternatives based on the final score, incineration was the most suitable option for the treatment of hazardous waste in Khulna. Finally, some guidelines have been put forward to improve its existing management practices.

The study deals with an investigation into the impact of the relocation of tannery industry on water quality parameters of Buriganga. For this purpose, previous records have been collected from authentic data resources and for the attainment of present values, several samples were collected from three major locations of the Buriganga River during summer and winter seasons in 2018 to determine the distribution and variation of water quality parameters. Samples were collected six ft below the river water surface. Analysis indicates slightly acidic to slightly alkaline (6.8-7.49) in nature. Bio-Chemical Oxygen Demand, Total Dissolved Solids, Total Solids (TS) & Total Suspended Solids (TSS) have been found greater in summer. On the other hand, Dissolved Oxygen is found greater in rainy seasons. Relocation shows improvement in water quality parameters. Though the improvement related to relocation of tannery industry is not adequate to turn the water body to be an inhabitable place for aquatic lives.

Antibiotic-resistant bacteria can be detected in pristine environments and animals. Tetracycline (TC) is frequently used for wide areas of veterinary medicine, which selects TC-resistant bacteria. The TC resistance genes are known from natural environments, and tet(M) is the broadest host range tet gene. Here, we report that TC-resistant bacteria and the TC resistance gene tet(M) were diverse in Adelie penguin intestines, even within a single penguin colony. Total bacterial counts were as high as 107 CFU g−1, and TC-resistant bacteria ranged from 1.4 × 102 to 6.6 × 103 CFU g−1 intestinal contents, which was 0–0.54 % of the total viable count. Phylogenetic affiliation of TC-resistant bacteria revealed a variety of Gram-positive and Gram-negative bacteria. The tet(M) gene was identified in 32.3 % of TC-resistant strains, and two tet(M) genotypes were identified within one penguin colony, suggesting various contamination origins of tet(M).

Background Mosquito coil (MC) emits insecticide upon burning which provides limited protection against lethal mosquito borne diseases. However, apart from killing the insect, toxicities associated with the inhalation of these insecticides poses severe health hazards. However, the use of MC is increasing day by day in third world countries in particular but, yet to receive enough attention of both policy maker and general public. The current study was aimed to assess the MC smoke induced damage of pulmonary and hepatic tissues along with observing the alterations of several blood biochemical parameters in mice model. Methods A total of twenty four Swiss albino mice were allowed to inhale the smoke of allethrin based MC at different duration per day for 120 days. By the end of treatment period, blood sample was drawn from each mouse and blood biochemical parameters including alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen(BUN), serum total protein, cholesterol, low density lipoprotein (LDL) and triglyceride (TG) were analyzed. Intact lung and liver were collected for histological analysis using standard protocol. Results Biochemical study indicates elevated activity of two hepatic enzymes: ALT (89%), AST (85%), in comparison with the respective control. Increased level of some parameters of lipid profile including cholesterol (36%), LDL (48%) and triglyceride (30%) in smoke inhaled mice is the new finding of this study. On the contrary, the activity of serum total protein and BUN was decreased by 20% and 24%, respectively in inhaled mice. Pulmonary tissue of treated mice shows severe forms of emphysema and hyperplasia, especially in the peripheral region of lung, which is the hallmark of chronic obstructive pulmonary disease (COPD). Histological study of hepatic tissue shows apoptosis mediated damage of hepatocytes along with severe form of necrosis. Infiltration of Inflammatory cells was also observed in both of the organs. Conclusion Results from the present studies suggest that chronic exposure of allethrin based MC is responsible factor for severe health complications such as COPD due to the alterations of the key biochemical parameters of blood and histo-organization of lung and liver.

Islamic law of succession emanates from the Qur'an. This chapter aims to make an analysis of the pre-Islamic customs which seem to some extent to be prevailing in succession. In the pre-Islamic period there was no right for the spouses to inherit to each other. Islam has brought a new era by fixing apportionments for the spouses. Basically the right of inheritance for the spouses results from the capacity of the Qur'anic share. Under the pre-Islamic customs the strongest heirs were the agnatic male descendants. The pre-Islamic customs made the agnatic male ascendants entitled to inherit where there was no agnatic male descendant. Under the pre-Islamic customs the male collaterals were entitled to inherit in the absence of agnatic male descendants and agnatic male ascendants. The pre-Islamic customs gave preference to the agnatic male descendants in matters of succession of the deceased's estate. But the Qur'an has fixed entitlements for daughters.

Agar, Konjac glucomannan, Carrageenan are all used for making food gels. Agar gel has high gelling and melting point, Konjac glucomannan acts as thickener and a gelation enhancer in food-related application whereas Carrageenan is also produced from seaweed also has high strength and melting point. In this study, we tried combination of these gels and check their properties whether it is suitable for soft robotics or not. The conductivity of these mixtures is also studied. Our laboratory developed food 3D printer is used for printing these combinations to check its 3D printability. This type of edible gel and its electronics can be used to make edible actuator that will eventually lead the way of using it in biomedical and soft-robotics field.

Two genera of Bassinae (Hymenoptera: Braconidae) have been described and illustrated from Bangladesh and a key was prepared. The genera are: Agathis Latreille and Bassus Fabricius newly recorded from Bangladesh. DOI: http://dx.doi.org/10.3329/cujbs.v6i1-2.17239 The Chittagong Univ. J. B. Sci.,Vol. 6(1&2):135-146, 2011

Three genera of Microgastrinae (Hymenoptera: Braconidae) have been described and illustrated from Bangladesh and a key for the genera was prepared. The genera are Apanteles Foerster, Microplitis Foerster, and Protomicroplitis Ashmead. The genus Protomicroplitis is the new record to the fauna of Bangladesh. DOI: http://dx.doi.org/10.3329/cujbs.v6i1-2.17240 The Chittagong Univ. J. B. Sci.,Vol. 6(1&2):147-158, 2011

This prospective type of experimental study was carried out to determine the improvement of symptoms by ultrasound therapy in management of de'Quervain's disease. It was done in the department of physical medicine and rehabilitation in Dhaka medical college hospital during the period of 30th January 2008 to 30th July 2008.The diagnosis of de'Quervain's disease confirmed by history and clinical examination(Finkelstein test). 50 patients were selected and randomly divided into two groups. Group-A patients were treated with thumb splint,NSAIDS and ADL. Group-B patients were treated with thumb splint, NSAIDS, ADL and ultrasound therapy. Each patients was assessed by pain score, visual analogue scale(VAS), grading of tenderness and swelling. Mean age was 41.02 years. Female and male ratio was 7.5:1. Most patients occupation was housewife 40(80%) and had a precipitating factor as wringing of cloths 31(62%). History of recurrence was found in 7(14%). Most of the patients developed pain gradually 72%(36). Post treatment VAS score improved significantly in group B(p

The goal of this study was to quantify and demonstrate the dynamic effects of hydraulic retention time (HRT), organic carbon and various components of extracellular polymeric substances (EPS) produced by microorganisms on the performance of submersed hollow-fiber microfiltration (MF) membrane in a hybrid powdered activated carbon (PAC)-MF membrane bioreactor (MBR). The reactors were operated continuously for 45 days to treat surface (river) water before and after pretreatment using a biofiltration unit. The real-time levels of organic carbon and the major components of EPS including five different carbohydrates (D(+) glucose and D(+) mannose, D(+) galactose, N-acetyl-D-galactosamine and D-galactose, oligosaccharides and L(-) fucose), proteins, and polysaccharides were quantified in the influent water, foulants, and in the bulk phases of different reactors. The presence of PAC extended the filtration cycle and enhanced the organic carbon adsorption and removal more than two fold. Biological filtration improved the filtrate quality and decreased membrane fouling. However, HRT influenced the length of the filtration cycle and had less effect on organic carbon and EPS component removal and/or biodegradation. The abundance of carbohydrates in the foulants on MF surfaces was more than 40 times higher than in the bulk phase, which demonstrates that the accumulation of carbohydrates on membrane surfaces contributed to the increase in transmembrane pressure significantly and PAC was not a potential adsorbent of carbohydrates. The abundance of N-acetyl-d-galactosamine and d-galactose was the highest in the foulants on membranes receiving biofilter-treated river water. Most of the biological fouling compounds were produced inside the reactors due to biodegradation. PAC inside the reactor enhanced the biodegradation of polysaccharides up to 97% and that of proteins by more than 95%. This real-time extensive and novel study demonstrates that the PAC-MF hybrid MBR is a sustainable technology for treating river water.

Tetracycline (TC) and ampicillin (AMP) resistant bacteria were identified from both fresh and brackish water shrimp farming system, in Bangladesh. Among 78 isolates from freshwater samples, 14.10, 17.95 and 23.8% were found resistant to TC, AMP and TC plus AMP, respectively. On the other hand, isolates from the brackish water samples, the percentages of TC, AMP and TC plus AMP resistant isolates were 10.25, 12.82 and 15.38, respectively. In freshwater samples, the highest percentage of resistant bacteria was Bacillus sp. (38.9), Pseudomonas sp. (22.2), Staphylococcus sp. (16.7), Acinetobacter sp. (11.1), Brevibacillus sp. (5.5) and Enterobacter sp. (5.5). While in brackish water samples dominant resistant bacteria was Bacillus sp. (50) followed by Pseudomonas sp. (16.7), Acinetobacter sp. (16.7), Enterobacter sp. (8.3) and Microvirgula sp. (8.3). DOI: http://dx.doi.org/10.3329/bjb.v41i2.13449 Bangladesh J. Bot. 41 (2): 197-200, 2012 (December)

Two species of Euphorinae (Hymenoptera: Braconidae) have been described and illustrated from Bangladesh. The species are: Mateorus erratus Achterberg, 1997 and Perilitus lateropus Achterberg, 1997. These two species are new record to the fauna of Bangladesh. Mateorus erratus and Perilitus lateropus were collected from Tangail and Dhaka districts, respectively. DOI: http://dx.doi.org/10.3329/cujbs.v3i1.13405 The Chittagong Univ. J. B. Sci.,Vol. 3(1&2):45-52, 2008

Two genera of Helconinae (Hymenoptera: Braconidae) have been described and illustrated from the districts of Cox’s Bazar and Chittagong in Bangladesh and a key for the genera is given. The genera are: Helcon Nees and Eubazus Nees. The genera Helcon and Eubazus are new records to the fauna of Bangladesh. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13368 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):37-44, 2010

An anammox assay involving a ¹⁵N tracer and gas chromatography-mass spectrometry revealed that the potential anammox activity accounted for 1 to 5% of total N₂ production in a ravine paddy field, Japan. Among four 4-cm-deep layers, the top layer showed the highest activity. Clone libraries showed that the DNA in the top layer contained sequences related to those of Candidatus 'Brocadia fulgida', Ca. 'B. anammoxidans', and Ca. 'Kuenenia stuttgartiensis'. These results suggest that a specific population of anammox bacteria was present in paddy soils, although a small part of dinitrogen gas was emitted from the soil via anammox.

The oilseed Brassica rapa flowers and matures earlier than B. oleracea, as well as their amphidiploid B. napus. Therefore, earliness of B.rapa has been investigated as a source of variation for earliness in B. napus breeding programs. Variation for days to flower exists in B. oleracea; however, its earliest flowering variant B. alboglabra flowers 2–3 weeks later than B. napus. We hypothesized that the C genome of B. alboglabra carries alleles for early flowering which are different from the C-genome alleles of B. napus; and these alleles can be used for the improvement of B. napus. To test this, we examined flowering time in pedigree and DH populations from two B. napus × B. alboglabra crosses. A B. napus line with about a week earlier flowering than the B. napus parent was achieved through reconstitution of its C genome following pedigree selection. Introgression of the B. alboglabra allele in the early flowering pedigree lines is also evident from the presence of B. alboglabra-specific SSR alleles in this line. However, application of doubled haploidy failed to generate any line that flowered earlier than the B. napus parent, which is probably due to the difficulty of obtaining large numbers of euploid B. napus DH lines from this interspecific cross. Thus, we demonstrate that a trait of the diploid species, which apparently looks undesirable, might in fact be highly valuable for the improvement of amphidiploids; and knowledge from this research can also be applied for other traits.

aBs TRacT ThewinterandspringtypesofoilseedBrassica napusL.� belongtodistinctlydifferentgenetic� groups.� Hence,� itshouldbepossibletouse� wintertypesfortheimprovementofspringtype� B. napus.� Weinvestigatedtheeffectofintro- gressionofallelesfromwintertypeintoopen- pollinatedCanadianspringB. napuscultivars.� CrossesweremadebetweentwoEuropean� winterrapeseedcultivars,� AvisoandTequila,� aCanadianspringdoubled-haploid� (DH)� line,� A03-3NR,� andtwoDHpopulationsdeveloped� fromF 2 �plants.�Atotalof�134�simplesequence� repeat� (SSR)� markersfrom� 19� linkagegroups� wereevaluatedonthethreeparents,� ofwhich� 84�markerswerepolymorphic.�Basedonthese� markers,�geneticsimilaritybetweenthetwowin- terparentswasestimatedtobe�0.49,�whereas� itwasonly�0.27�betweenthespringandthetwo� winterparents.� Thirty-sevenselectedpolymor- phicmarkersweretestedonthetwoDHpop- ulations,� whichdetectedatotalof� 94� alleles.� Occurrenceoftheallelesfromthewinterparent� rangedfrom�17.0�to�59.9%�inDHpopulationof� Aviso��A03-3NR,�whereasinthepopulationof� Tequila��A03-3NRitrangedfrom�13.8�to�50.0%.�

The structure of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) solutions with a number of common deuterated organic solvents was studied by means of 1H NMR spectroscopy. The resonance bands of the polymer backbone protons appear at much lower frequencies in CDCl3 compared to their positions in aromatic solvents. This has been attributed to the π-π self-stacking interaction of the polymer segments in the aliphatic solvent, which is replaced by a polymer-solvent π-π interaction in the aromatic solvents. In mixed solvent systems with an aliphatic solvent component and an aromatic one, the intensities of the polymer resonances pass through a maximum at intermediate solvent compositions. This has been attributed to the minimum aggregation tendency of the polymer at these solvent compositions. The results suggest that a mixed solvent system constituting an aliphatic component and an aromatic component might be a choice for casting films of hairy-rod type conjugated polymers if minimization of aggregate domains in the films is desired.

We present preparation, characterization, and 3D printing of electrically conductive Acrylonitrile butadiene styrene (ABS) polymer. The electrically conducting ABS was prepared by doping carbon fibers (150μm in length, acquired from Nippon Graphite Corporation), at 200 ̊C by using a thermo-plasto mill, with different weight percentages (wt%) of carbon fibers in ABS polymer matrix. Electrical conductivity of samples with following weight percentages (10, 15, 25, 50 and 60 wt% carbon fibers in ABS polymer matrix) were measured using 4-point probe method [1, 2], with a result that percolation threshold occurs at 25wt%, as shown in Fig 1. SEM analysis (Fig. 2) shows uniform dispersion of carbon fibers in ABS polymer matrix, when compared to previously reported methods [3, 4]. Electrical conductivity of 1.013S/m is observed at 50 wt %. We employed melt extrusion technique in order to fabricate cylindrical filament with a diameter of 1.75 mm. A standard Fused Deposition Modeling (FDM) type printer (Makerbot) was used to print the developed filament (Fig. 3). The developed ABS electrically conductive composite is being applied in applications, such as 3D printing of wires, circuits, sensors, resistors, heaters, robotics, MEMS and microfluidics devices. References: Khosla, A. (2011). Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications(Doctoral dissertation, Applied Science: School of Engineering Science). http://summit.sfu.ca/item/12017 Khosla, A. (2012). Nanoparticle-doped electrically-conducting polymers for flexible nano-micro Systems. The Electrochemical Society Interface, 21(3-4), 67-70. doi: 10.1149/2.F04123-4if Gray, B. L., & Khosla, A. (2010). Microfabrication and applications of nanoparticle doped conductive polymers. Nanoelectronics: Nanowires, Molecular Electronics, and Nanodevices, 227. Khosla, A., & Gray, B. L. (2010, March). Fabrication of multiwalled carbon nanotube polydimethylsiloxne nanocomposite polymer flexible microelectrodes for microfluidics and MEMS. In Proc. SPIE (Vol. 7642, p. 76421V). doi: 10.1117/12.847292 Figure 1

The structures of an amphiphilic conjugated graft copolymer, poly(2,3-diphenyl-5-(trimethylene-heptadeca(oxyethylene)-methoxy-phenylene vinylene) (denoted as PVEO17) composing of a conjugated DPPPV backbone and PEO side chains, in bulk and solutions with tetrahydrofuran (THF) and water have been investigated by small-angle X-ray scattering (SAXS). In bulk state, the DP-PPV main chains in PVEO17 stacked to form flat disk microdomains dispersed in the PEO side-chain matrix. The corresponding wide angle X-ray scattering pattern revealed the existence of crystallinity of the PEO side chains. The structure of the polymer in solution was affected by the solvent quality and the polymer concentration. PVEO17 chains were relatively well dispersed in THF. In aqueous solutions, however, the amphiphilic PVEO17 chains aggregated significantly over the concentration range of 1–8 wt%, where the polymer was found to self-organize to form cylindrical micelles with the aggregation number increasing with the increase of concentration. The photophysical properties characterized by UV–Vis and photoluminescence spectroscopy were strongly affected by the aggregation state of the polymer.

Arsenic contamination in the shallow aquifers has created the crisis and hence 4.73 million tubewells out of a total of 8.61 million have been tested for arsenic contamination and 29% of these tested tubewells have been found to be contaminated with arsenic beyond the safe limit of Bangladesh standards. Around 81% of the inhabitants of our total villages are now affected with this poison where 27% of those are beyond the Bangladesh standards and which is responsible for the health suffering of 50 million people. This paper examines this arsenic crisis and critically identifies treatment methods and technologies used for mitigation against this crisis. The common technologies that are used to treat arsenic-contaminated water are using oxidizing agents followed by flocculation and precipitation. Research groups have used this technology and finally they have developed their own methods to suit the local environment using locally available materials. Again, alternative water supply options like deep tubewells, very shallow tubewells, pond sand filters, solar disinfection, rainwater harvesting and, in many situations, surface water treatment options are very useful to mitigate this arsenic crisis in some areas. Deep tubewells, which have been widely accepted by the communities during the past few decades in Bangladesh, emerge to be a more suitable alternative option for mitigation.

Root exudates from strawberry plants are known to cause autotoxicity and benzoic acid (BA), a potent growth inhibitor, was found in the exudate. BA (400 μm) was easily decomposed by electrodegradation (ED) treatment at 10.0 V and 2.0 A after the addition of BA into nutrient solution. The growth of strawberry plantlets in nutrient solution containing BA (400 μm) or in control nutrient solution varied significantly depending on the use of ED treatment. The growth inhibition of plantlets in the BA-containing nutrient solution or in nutrient solution used for strawberry culture was significantly ameliorated by ED treatment. This growth recovery resulting from ED treatment was most pronounced in terms of the yield of strawberry fruit. These results suggest that ED treatment of the culture nutrient solution could result in the decomposition of toxic root exudates, including BA from strawberry plants, and mitigates the autotoxicity observed in closed hydroponic culture. In addition, the supplementation of Fe-EDTA is recommended after ED treatment as a result of the rapid decomposition of Fe-EDTA by ED.

Supramolecular comb-coil block copolymers formed by the stoichiometric complexation of two amphiphilic surfactants, dodecylbenzenesulfonic acid (DBSA) and 3-pentadecylphenol (PDP), with the poly(4-vinylpyridine) (P4VP) blocks in a linear PS-b-P4VP and a nonlinear AnBn-type heteroarm star PS-P4VP copolymer have been investigated. All linear and heteroarm star systems under study exhibited lamellae-within-lamellae morphology even at high PS volume fraction, at which the previously studied systems showed lamellae-within-cylinder or lamellae-within-sphere morphology. The interlamellar distances of the larger-scale copolymer microdomains were found to be much larger in all heteroarm complexes than those in their linear counterparts. This was attributed to the chain crowding effect coupled with the different types of arrangement of comb blocks forming the smaller-scale lamellar mesophase. Moreover, the order−disorder transition temperatures of both the larger- and smaller-scale structures in the heteroarm star ...

Interspecific hybrids were produced from reciprocal crosses between Brassica napus (2n = 38, AACC) and B. oleracea var. alboglabra (2n = 18, CC) to introgress the zero-erucic acid alleles from B. napus into B. oleracea. The ovule culture embryo rescue technique was applied for production of F1 plants. The effects of silique age, as measured by days after pollination (DAP), and growth condition (temperature) on the efficiency of this technique was investigated. The greatest numbers of hybrids per pollination were produced under 20°/15°C (day/night) at 16 DAP for B. oleracea (♀) × B. napus crosses, while under 15°/10°C at 14 DAP for B. napus (♀) × B. oleracea crosses. Application of the ovule culture technique also increased the efficiency of BC1 (F1 × B. oleracea) hybrid production by 10-fold over in vivo seed set. The segregation of erucic acid alleles in the self-pollinated backcross generation, i.e. in BC1S1 seeds, revealed that the gametes of the F1 and BC1 plants carrying a greater number of A-genome chromosomes were more viable. This resulted in a significantly greater number of intermediate and a smaller number of high-erucic acid BC1S1 seeds.

The structure of poly(9,9-dioctylfluorene-2,7-diyl) (PF8) in deuterated toluene solutions at concentrations ranging from 0.60% to 7.0% (w/v) has been investigated by means of small-angle neutron scattering (SANS) and nuclear magnetic resonance (NMR) spectroscopy. PF8 chains exhibited aggregation above 1.0%, where the corresponding SANS profiles were characterized by the superposition of an aggregate component and a dynamic component associated with the transient network formed by interchain overlap. The 1H NMR resonance lines for both the polymer as well as for the residual protons in the solvent showed large upfield shift at higher concentrations, indicating strong polymer−solvent interaction. At a higher concentration (4.5%) an additional resonance line was observed in the aromatic regions of both the 1H and the 2H spectra that has been attributed to a residual anisotropic chemical shift of the solvent molecules. The later phenomenon is suggestive of the existence of magnetically anisotropic aggregate d...

Fish, like mammals, have several stages of wound healing, including inflammation, reepithelialization, proliferation, organization, and differentiation. However, little is known about the molecular mechanisms of fish skin wound healing. In the present study, 23 polymerase chain reaction (PCR) bands were identified which appeared to be specifically expressed during wound healing by a simple differential display (DD) method. Sequences of cDNAs from these 14 bands were highly homologous to known genes. However, reverse transcriptase PCR (RT-PCR) analyses of these 14 bands revealed that only one of them, the gene for matrix metalloproteinase 9 (MMP-9), was significantly expressed in wounded skin, and that the others were probably false positives. MMPs are known to have gelatinolytic activity, and film in situ zymography detected strong gelatinolytic activity in the surface and dermis of wounded skin of flounder.

The segregation and linkage between glufosinate (transgenes ‘Rf3’ and ‘T177’) and blackleg resistance genes in canola (Brassica napus L.) were assessed using F1 microspore-derived doubled haploid (DH) populations from four crosses including reciprocals, two involving the transgene ‘Rf3’ and the other two involving the transgene ‘T177’. To relax the assumption of no segregation distortion required for the conventional analysis of segregation and linkage, we employed Bailey's analysis that allows detecting segregation distortion at linked loci. The significant departures from the 1:1 segregation were detected in the crosses involving the transgene ‘T177’ but not in the crosses involving the transgene ‘Rf3’. The apparent deficit of the herbicide tolerant DH lines in the crosses with the transgene ‘T177’ is likely due to differential selection against the gametes carrying ‘T177’ during microspore culture. The linkage was strong between blackleg resistance and the transgene ‘Rf3’ but weak or absent between blackleg resistance and the transgene ‘T177’, suggesting that the two transgenes are probably inserted into distant regions of the genome. The observed linkage offers an opportunity to develop new canola cultivars with both glufosinate tolerance conferred by transgene ‘Rf3’ and blackleg resistance.

One of the worst health hazards in Bangladesh is arsenic contamination of drinking water, which demands immediate and urgent remedial measures. The common strategy to control environmental health problems is to erect interventions at three levels: control at source, avoid ingestion and provide heath care The source of arsenic contamination is absolutely geological and almost any method can be applied to control it at source. There is little proven treatment for acute arsenic toxicity, but drinking water free of arsenic can aid the affected people at their initial stage of illness to get rid of the symptoms of arsenic toxicity. Hence, provision of safe drinking water is the foremost element of the arsenic mitigation plan. Identification of affected people and the population at risk of toxicity from arsenic, establishment of a standard value for the presence of arsenic in drinking water, provision of medical and health care and establishment of appropriate research work and study programmes are important elements of the plan. Finally, international, interdisciplinary and inter-organizational co-operation and collaboration have been highly emphasized in the mitigation plan.

After long-term aging, surfactant-mediated colloidal aggregates of sulfonated polyaniline (S-PANI) and poly(vinylidene fluoride) (PVF 2 ) converted into three-dimensional polymer networks, whereas colloidal crystals prepared from pure PVF 2 remained unaltered. A model, where the surfactant tails anchored from the colloidal particles interdigitate with time resulting in coalescence of the particles to form the network morphology, has been proposed. X-ray photoelectron spectroscopy (XPS) revealed higher relative abundances of carbon atoms on the surface of the polymer networks than those of the colloidal aggregates, which adequately supports the proposed model.

The melting of isothermally crystallized poly(vinylidene fluoride) (PVF 2 ) , produced in the intercrystalline spaces of poly(ethylene terephthalate) (PET) from its blends, showed a unique behavior: the melting temperature decreased with the increasing crystallinity of PVF 2 (i.e., with increasing crystallization time) for PVF 2 volume fractions of 0.64 and 0.51. The melting temperature of already crystallized PET also decreased as the PVF 2 crystallization progressed and the isothermal crystallization temperature of PVF 2 increased. Separate reasons were proposed to account for these behaviors. The equilibrium melting temperatures of PVF 2 in the blends, measured by the Hoffman-Weeks extrapolation procedure, were used to calculate the polymer-polymer interaction parameter (χ 21 ); only the noncrystallized portion of PET contributing to the mixed amorphous phase was considered. The χ 21 value (-1.75) was lower than χ 12 (-0.14), calculated from the melting temperature depression of PET. However, when they were normalized to the unit volumes of the respective components, the two values were found to be the same. The crystallization rate of PVF 2 decreased with an increasing volume fraction of PET in the blend. The Avrami exponent increased for the volume fraction of PVF 2 (0.77) and then progressively decreased with an increasing volume fraction of PET. A gradual change in the nature of the regime transition from regime II/regime I to regime III/regime II with increasing PET concentration was observed. The value of the chain-extension factor of PVF 2 significantly increased with an increase in the PET concentration in the blends.

Blends of poly(vinylidene fluoride) (PVF 2 ) and dodecyl benzene sulfonic acid (DBSA) were found to phase separate in the melt state from hot-stage polarizing optical microscopy and differential scanning calorimetry (DSC). Both these studies also indicated the formation of a reversible mesomorphic order in the DBSA-rich phase of the blends. Scanning electron microscopy (SEM) showed a fibrillar network morphology of the DBSA-rich phase. Wide-angle X-ray diffraction (WAXD) revealed the formation of a lamellar structure in the blends corresponding to a long period of 26 A. The mesomorphic nature of the blends is believed to arise from the supramolecular organization of the surfactant molecules within the lamella. Thermal study indicated that the supramolecularly organized complex is the VF 2 monomer unit:DBSA ≈ 4:1, and the enthalpy of complexation is ~723 J mol −1 .

A gradual change in morphology of poly(vinylidene fluoride)-camphor sulfonic acid (PVF 2 -CSA) blend from compact spherulites of PVF 2 to open spherulites and finally to giant spherulites with increasing CSA concentration in the blend is observed when viewed in optical microscopy. An X-ray study indicates the presence of two types of lamella, viz., (i) supramolecularly organized lamella of the PVF 2 -CSA system and (ii) lamella of pure PVF 2 crystal in the blends. A differential scanning calorimetry study reveals that the crystallization of the supramolecular organized structure is a slow process Supramolecular organization of PVF 2 -CSA blends produces giant spherulites at CSA-rich compositions. The giant spherulites contain a fibrillar network structure with the piezoelectric form of PVF 2 and may find application as a sensor material.

Stable layers of nearly monodisperse spheres of β-polymorphic poly(vinylidene fluoride) with iridescent properties are prepared. The colloidal crystalline arrays (CCAs) were characterized by optical microscopy, differential scanning calorimetry (DSC), and FT-IR spectroscopy. FT-IR spectroscopic and wide-angle X-ray scattering (WAXS) studies revealed a β-polymorphic PVF 2 structure, the DSC study showed that the level of crystallinity in the CCA was much higher than that in the melt-crystallized sample, and UV-visible spectroscopy showed extinction peaks at 323 and 510 nm in the CCAs. The β-polymorphic PVF 2 structure, along with the optical extinction properties of these CCAs, raises the prospect of their application in optical filters and/or piezoelectric sensors.

Bacterial coldwater disease is considered to be one of the most serious diseases in ayu Plecoglossus altivelis in Japan. We evaluated the efficacy of three highly water-soluble adjuvants (Montanidae IMS-1311, IMS-1312 and IMS-2212) combined with formalin-killed bacterin of Flavobacterium psychrophilum (FKB) in ayu, in comparison with a minimally water-soluble adjuvant (Montanidae ISA-763A). The retention period and toxicity of these adjuvants in ayu were also examined. Experimental challenge 4 wk after vaccination showed that FKB adjuvanted with IMS-1311 and IMS-1312 had higher potency than FKB alone and significantly (p