Direct toxicity assessment of toxic chemicals with electrochemical method

Electrochemical measurement of respiratory chain activity is a rapid and reliable screening for the toxicity on microorganisms. Here, we investigated in-vitro effects of toxin on Escherichia coli (E. coli) that was taken as a model microorganism incubated with ferricyanide. The current signal of ferrocyanide effectively amplified by ultramicroelectrode array (UMEA), which was proven to be directly related to the toxicity. Accordingly, a direct toxicity assessment (DTA) based on chronoamperometry was proposed to detect the effect of toxic chemicals on microorganisms. The electrochemical responses to 3,5-dichlorophenol (DCP) under the incubation times revealed that the toxicity reached a stable level at 60 min, and its 50% inhibiting concentration (IC50) was estimated to be 8.0 mg L-1. At 60 min incubation, the IC50 values for KCN and As2O3 in water samples were 4.9 mg L-1 and 18.3 mg L-1, respectively. But the heavy metal ions, such as Cu2+ Pb2+ and Ni2+, showed no obvious toxicity on E. coli.

四种电化学分析仪器的研制

本报告介绍我们实验室以原有研究工作为基础，结合国家十五科技攻关课题，适应市场需要，研发的生化需氧量(BOD)快速监测仪、溶氧(DO)在线检测仪、毛细管电泳电化学发光检测仪(CE/ECL)、USB插头式超微型电化学研究系统(uECS)等四种电化学分析仪器。BOD、DO仪采用纳米、自组装等技术制作电化学探头，可实现对水体中的BOD、DO的快速、灵敏的检测，所得结果与使用传统的方法相一致，而所需时间很短，可以实时、在线监测;CE/ECL仪系结合了毛细管电泳的高分离能力和电化学发光的高灵敏度的特点开发出的整体仪器;uECS突破了原有电化学分析仪器的概念，结合了先进的USB2.0技术，整个系统体积小巧(如U盘)，通过计算机的USB接口提供电源并进行高速数据传输，具有一般研究型电化学仪的各项功能，并且具有较强的可扩展性。

生化需氧量微生物传感器的研究进展

生化需氧量 (biochemicaloxygendemanded ,BOD)是衡量水污染程度必须测定的重要指标之一。然而 ,传统的 5d法不能及时反映排放水的污染程度。因此 ,能够快速、准确测定BOD的微生物传感器近年来得到了迅速发展。本文综述了BOD微生物传感器及其商品化仪器的发展 ,并对能使BOD传感器与传统的 5d法得到更为一致的结果的方法做了总结

一种新型生化需氧量传感器的研制

目的　研制快速测定生化需氧量 (BOD)的方法。方法　应用溶胶 凝胶有机 无机杂化材料,采用包埋法固定异常汉逊酵母菌,制备微生物膜。该微生物膜与氧电极结合制成传感器。传感器测试的最佳条件为 :pH70;28℃ ;响应时间 3～12min。用该传感器测定了单纯有机物、生活污水及回收率。结果　经过对多种有机物测定表明该BOD微生物传感器可监测氨基酸类、糖类等多种有机物,适合于生活污水及某些含醇类、酚类等有机物浓度小的工业废水的测定。微生物膜可连续保存 3个月仍能保存其活性的 70 %。经测定生活污水的回收率在90%～105%之间。结论　这种微生物传感器可成功进行BOD的测定,检测速度快,操作与制备简便 ,灵敏度高,适用范围广,成本低,易保存,性能稳定,简化了传统的测定分析,具有很好的实用意义。

无机高分子混凝剂PSAFS的研制及其在造纸废水处理中的应用研究

本文是以废治废为原则，减少环境污染为目标进行的研究。选取凯里造成纸厂所排出的造纸废水为研究对象，了解该废水的特性及其对巴拉河的污染影响；利用工业固体废弃物硫铁矿烧渣、铝精液或氢氧化铝、工业用水玻璃，工业硫酸研制成功了一类新型号的工业废水处理混凝剂PSAFS（聚硅酸硫酸铝铁），造纸废水经过PSAFS处理后色度，COD、BOD等主要污染物低于国家一级排放标准；处理后废水中金属Pb、Cu、Zn、Gr、As的含量都低于国家地面水Ⅲ类标准。在相同的投加量和混凝时间下，PSAFS混凝剂对造成纸废水的混凝效果比碱式氯化铝（PCA）、硫酸铝、氯化铁的混凝效果好。

Algebra Llinol - Cyflwyniad

Cyfieithiad yw'r llyfr hwn o Linear Algebra - An Introduction a ymddangosodd gyntaf yn 1978 ac a gyhoeddwyd gan y cwmni Van Nostrand Reinhold. Cafwyd Ail Argraffiad yn 1982 a dros y blynyddoedd bu nifer o ail brintiadau. Yn y cyfamser cyfieithwyd y llyfr i'r Groeg a Thwrceg. Er i'r llyfr gael ei ddefnyddio dros y blynyddoedd gan nifer o fyfyrwyr yn Aberystwyth a oedd yn cyflwyno eu gwaith yn Gymraeg, nid oedd ar gael yn y Gymraeg. Dyma, o'r diwedd, ymgais i wneud rhyw fath o iawn am hynny. Er bod y llyfr wedi bod allan o brint yn y Saesneg ers rhai blynyddoedd yn awr, mae'n amlwg ei fod yn dal i gael ei gymeradwyo mewn nifer o brifysgolion. Felly, y gobaith yw y bydd o ddefnydd. Efallai mai'r peth nesaf bydd ei gyfiethu'n ?l i'r Saesneg! Mae nifer o newidiadau yn y fersiwn hwn. Mae'n siwr bod nifer o gamgymeriadau ac efallai gwelliannau posibl i'r cyfieithu - byddwn yn ddiolchgar dderbyn unrhyw awgrymiadau. Gellir eu cyflwyno hefyd drwy Dr Gwion Evans o'r Adran Fathemateg, Prifysgol Aberystwyth.

Rola systemu podatkowego przed, w trakcie i po kryzysie finansowym

Celem niniejszego artykułu jest podsumowanie najnowszych wyników badań analizujących rolę systemu podatkowego w kolejnych fazach kryzysu zapoczątkowanego w 2008 r. Przeprowadzona w opracowaniu analiza wskazuje, że jego rola ulegała istotnym zmianom: 1) przed wybuchem kryzysu stwarzał bodźce do takich zachowań podmiotów gospodarczych, które przyczyniały się do narastania nierównowagi leżącej u podstaw kryzysu; 2) po jego wybuchu wzrosło znaczenie stabilizacyjne systemu podatkowego: zarówno w obszarze oddziaływania tak zwanych automatycznych stabilizatorów, jak i dyskrecjonalnych zmian obciążeń podatkowych; 3) obecnie zmiany systemu podatkowego zmierzają w kierunku wsparcia procesu konsolidacji fiskalnej oczekiwanej w najbliższych latach w wielu gospodarkach rozwiniętych i w części krajów rozwijających się.

Fermentative production of glycine betaine and trehalose from acid whey using Actinopolyspora halophila (MTCC 263)

Acid whey has become a major concern especially in dairy industry manufacturing Greek yoghurt. Proper disposal of acid whey is essential as it not only increases the BOD of water but also increases the acidity when disposed of in landfill, rendering soil barren and unsuitable for cultivation. Effluent (acid-whey) treatment increases the cost of production. The vast quantities of acid whey that are produced by the dairy industry make the treatment and safe disposal of effluent very difficult. Hence an economical way to handle this problem is very important. Biogenic glycine betaine and trehalose have many applications in food and confectionery industry, medicine, bioprocess industry, agriculture, genetic engineering, and animal feeds (etc.), hence their production is of industrial importance. Here we used the extreme, obligate halophile Actinopolyspora halophila (MTCC 263) for fermentative production of glycine betaine and trehalose from acid whey. Maximum yields were obtained by implementation of a sequential media optimization process, identification and addition of rate-limiting enzyme cofactors via a bioinformatics approach, and manipulation of nitrogen substrate supply. The implications of using glycine as a precursor were also investigated. The core factors that affected production were identified and then optimized using orthogonal array design followed by response surface methodology. The maximum production achieved after complete optimization was 9.07 ± 0.25 g/L and 2.49 ± 0.14 g/L for glycine betaine and trehalose, respectively.

The impact of the Board of Director's composition on companies performance

The impact of the Board of Directors’ composition on companies’ performance This paper studies the impact that the board of directors’ composition has on companies’ performance in the Italian market. The research has been carried out by using a sample of 10 Italian companies, across different market sectors, over a period of 10 years (2005-2014). The characteristics of the BoD taken into consideration are the following: board size, board diversity (% of female directors), board independence and CEO duality. Results from the sample data collected concluded that these factors have a statistically significant impact on the performance of the companies that have been analysed.

Left ventricular structure in children with developmental coordination disorder

Developmental coordination disorder (p-DCD) is a neuro-developmental disorder featuring impairment in developing motor coordination. This study examined left ventricular mass (LVM) in children with p-DCD (n=63) and controls (n=63). LVM was measured using echocardiography. Body composition was determined using BOD POD and peak oxygen uptake (peak V02) was measured by a progressive exercise test. Height, weight and blood pressure were also measured. LVM was not significantly elevated in p-DCD compared to controls. Peak V02 was lower and SBP, BMI, HR, and BF(%) were significantly higher in p-DCD. They also demonstrated elevated stroke volume (SV), cardiac output (CO), end-diastolic volume, and ventricular diameter in diastole. In regression analyses, p-DCD was a significant predictor of SV and CO after accounting for height, FFM, V02FFM, and sex. These differences in children with p-DCD indicate obesity related changes in the left ventricle and may represent early stages of developing hypertrophy of the left ventricle.

Algal and protozoan response to Holocene climate change and anthropogenic impact: a case study from Sluice Pond, MA

Sluice Pond is a small (18 ha) and deep (Zmax 20.0 m) partially meromictic, pond in Lynn, Massachusetts that contains a diverse dinocyst record since the early Holocene. High dinocyst concentrations, including morphotypes not previously described, as well as the preservation of several specimens of cellulosic thecae are attributed to low dissolved oxygen (DO) in the basin. The fossil protozoan record supports the interpretation- thecamoebians were unable to colonize the basin until the middle Holocene and only became abundant when the drought-induced lowstand oxygenated the bottom waters. Protozoans tolerant of low DO became abundant through the late Holocene as water levels rose and cultural eutrophication produced a sharp increase in biochemical oxygen demand (BOD) beginning in the 17th century. Recent sediments contain a dominance of Peridinium willei, indicating cultural eutrophication and the planktonic ciliate Codonella cratera and the thecamoebian Cucurbitella tricuspis in the deep basin. Above the chemocline however, a diverse difflugiid thecamoebian assemblage is present.

Salinity Intrusion and Seasonal Water Quality Variations in the Tidal Canals of Cochin

The study conducted on the salinity intrusion and seasonal water quality variations in the tidal canals of cochin. The main objectives are, salinity intrusion profile, water quality variation of the surface water of the canals,hierarchical utility of the water bodies and to understand the non-conservative components in the water body. The parameters monitored werepH,temperature,alkalinity,conductivity,DO(dissolvedoxygen),COD(chemical oxygen demand),BOD(biochemical oxygen demand0,chloride, total hardness, calcium hardness, dissolved phosphate, nitrate, total iron, sulphate, turbidity, total coliform and SUVA at 254nm. The tidal canals of GCDA were found to be creeks extending to the interior, canals inter connecting parts of the estuary or canals with seasonally broken segments. Based on utility the canals could be classified as: canals heavely polluted and very saline,canals polluted by urban waste , canals having fresh water for most part of the year and not much polluted, fresh water bodies heavily polluted. During the rainy months carbon fixation by plankton is nonexistent,and during the dry months Chitrapuzha becomes a sink of phosphate. The study indicated abiotic subrouts for dissolved phosphate and revealed the potential pitfalls in LOICZ modeling exercise on sewage ladentidal canals. It was also found that all canals except for the canals of West cochin and chittoorpuzha have fresh water for some part of the year. The water quality index in the durable fresh water stretches was found to be of below average category.

Development of bioreactors for nitrifying sewage

Nitrification is the biological oxidation of ammonium, first to nitrite and then to nitrate by two groups of aerobic, chemolithotrophic bacteria belonging to the family Nitrobacteriaceae. The biological nitrification in municipal wastewater treatment is important in those cases were ammonia removal requirement specially exist. In a trickling filter or in an activated sludge system nitrification is rate limiting and thus necessitates longer detention time. The combined carbon oxidation-nitrification processes generally have low population of nitrifiers due to a high ratio of BOD to total nitrogen in the effluent. This necessitates, separate carbon and nitrogen oxidation processes, which thus minimizes wash out ofthe nitrifiers. Therefore, a separate stage nitrification has become essential to achieve faster and efficient removal of ammonia from the wastewater. The present work deals with the development of bio reactor for nitrifying of sewage as the tertiary process so that the treated wastewater can be used for irrigation, algal culture or fish culture

Microbial Treatment Of Rubber Latex Centrifugation Effluent

Many of the existing methods for the treatment of rubber latex centrifugation eflluent are not only unsatisfactory in their efliciency to effect near perfect treatment in bringing down the COD to optimum level, but also time consuming and need a large landspace. As the rate of effluent generation is extremely high (20 litres for kilogram of rubber) there is a need for development of efficient system,capable of rapid reduction of COD and BOD. Though the organic load of the rubber efiluent is very high, it does not contain much processed chemicals and therefore it can be considered as a ‘biological eflluent’. Further, the ratio of the Chemical Oxygen Demand to Biological Oxygen Demand (COD/BOD) of this effluent remain almost as a constant value. According to Montgomery (1967), estimation of BOD is not ideally suited for studies on process design, treatability, control of treatment plants, setting standards for treated effluents and assessing the effect of polluting discharges on the oxygen resources of receiving waters. Hence in the present study COD was measured to determine the impact of treatment system on the effluent. In the present study, attempts were made to evaluate the efficiencies of certain methods such as packed bed reactor using immobilized microbial cells, rotating biological contactor (RBC) and activated sludge process, for rapid and efficient treatment of natural rubber latex centrifugation effluent. In addition, studies were also carn'ed out to develop a suitable bioprocess for the coagulation of skim latex, as an alternative to the presently used acid coagulation process towards reducing the pollution load, besides recovering quality rubber

Activated packed bed bioreactor for rapid nitrification in brackish water hatchery systems

A packed bed bioreactor (PBBR) was developed for rapid establishment of nitrification in brackish water hatchery systems in the tropics. The reactors were activated by immobilizing ammonia-oxidizing (AMONPCU- 1) and nitrite-oxidizing (NIONPCU-1) bacterial consortia on polystyrene and low-density polyethylene beads, respectively. Fluorescence in situ hybridization demonstrated the presence of autotrophic nitrifiers belong to Nitrosococcus mobilis, lineage of b ammonia oxidizers and nitrite oxidizer Nitrobacter sp. in the consortia. The activated reactors upon integration to the hatchery system resulted in significant ammonia removal (P\0.01) culminating to its undetectable levels. Consequently, a significantly higher percent survival of larvae was observed in the larval production systems. With spent water the reactors could establish nitrification with high percentage removal of ammonia (78%), nitrite (79%) and BOD (56%) within 7 days of initiation of the process. PBBR is configured in such a way to minimize the energy requirements for continuous operation by limiting the energy inputs to a single stage pumping of water and aeration to the aeration cells. The PBBR shall enable hatchery systems to operate under closed recirculating mode and pave the way for better water management in the aquaculture industry.