Study on arsenic level in public water supply of Delhi using hydride generator accessory coupled with atomic absorption spectrophotometer

Exposure to arsenic has been associated with several health hazards. Worldwide the main reason for chronic human intoxication with arsenic is intake of contaminated drinking water. Air acetylene type of atomic absorption spectrophotometer in combination with hydride generator accessory was used to analyze arsenic level in 25 water samples collected from 25 booster pumping stations and 313 water samples collected from tap water supply of 62 areas of Delhi. Results were analyzed using SPSS and Barlett’s Chi Square Test. Mean arsenic level detected in water samples collected from booster pumping stations was 0.00976 ppm (Range 0.000–0.017 ppm, Standard Deviation 0.006 and Standard error of Mean 0.00118). Maximum arsenic level (0.017 ppm) was found in water samples of booster pumping stations of Mehrauli, Punjabi Bagh and Ramjas Road. Mean arsenic level detected in samples collected from tap water supply was 0.013 ppm (Range 0–0.0430 ppm, Standard Deviation 0.00911 and Standard error of Mean 0.000515). In water samples of 42 areas arsenic level detected was exceeding WHO/EPA permissible limit of 0.01 ppm (10 ppb). The mean arsenic level detected in water samples of booster pumping station was within WHO/EPA permissible limit while mean arsenic level detected in tap water samples was marginally higher. Mixing of ground water and contamination through broken or leaking channel could be the possible reason of higher arsenic level in tap water. Continuous monitoring of quality of drinking water is required particularly in view of water contamination caused by industrial waste and uncontrolled ground water extraction.     

Maddy and Mathematics: Naturalism or Not

Penelope Maddy advances a purportedly naturalistic account ofmathematical methodology which might be taken to answer thequestion `What justifies axioms of set theory?' I argue thather account fails both to adequately answer this question andto be naturalistic. Further, the way in which it fails to answerthe question deprives it of an analog to one of the chief attractionsof naturalism. Naturalism is attractive to naturalists andnonnaturalists alike because it explains the reliability ofscientific practice. Maddy's account, on the other hand, appearsto be unable to similarly explain the reliability of mathematicalpractice without violating one of its central tenets.

1 Introduction

2 Mathematical Naturalism

3 Desiderata and the attractionof naturalism

4 Assessment: Naturalism and names

4.1 Taking‘naturalism’seriously

4.2 Second philosophy (orwhat's in a name)

5 A way out?

6 Or out of the way?

     

Seawater desalination by reverse osmosis

Until comparatively recently the purification of sea or brackish water depended largely on some form of distillation. In recent years, however, a number of industrial concerns have directed increasing attention to processes depending on reverse osmosis. A number of large plants have been installed and this article reviews the present state of reverse osmosis technology and the factors determining its efficiency. Its advantages include its relatively low fuel consumption, and in this respect further substantial savings are in prospect.     

Chips,tags and scanners: Ethical challenges for radio frequency identification

Radio Frequency Identification (RFID) systems identify and track objects, animals and, in principle, people. The ability to gather information obtained by tracking consumer goods, government documents, monetary transactions and human beings raises a number of interesting and important privacy issues. Moreover, RFID systems pose an ensemble of other ethical challenges related to appropriate uses and users of such systems. This paper reviews a number of RFID applications with the intention of identifying the technology’s benefits and possible misuses. We offer an overview and discussion of the most important ethical issues concerning RFID, and describes and examine some methods of protecting privacy. Norman G. Einspruch serves as a consultant to several high-technology companies, one of which is in the RFID components and systems business.     

Rights of animals, perceptions of science, and political activism: profile of American animal rights activities

This article reports original research examining characteristics of the active followers of the American animal rights movement. Typical respondents were Caucasian, highly educated urban professional women approximately thirty years old with a median income of $33,000 (1989). Most activists think of themselves as Democrats or as Independents, and have moderate to liberal political views. They were often suspicious of science and made no distinction between basic and applied science, or public versus private animal-based research. The research suggests that animal rights activism is part of a symbolic manifestation of egalitarian social and political views concerning scientific and technological change.     

Feminising and masculinising primary teaching: a critical examination of the interpretive frameworks of male primary school principals in Hong Kong

Over the past two decades, the feminisation of primary school teaching has been identified by the media and government officials in Western countries as an important contributing factor to boys' academic problems. This panic, which has been criticised by feminists as a backlash and a form of recuperative politics, has promoted the development of research into gender and education, particularly studies related to the gendered culture of primary schools and on the masculinities of male teachers. However, male primary principals remain relatively under-researched in the literature, despite the importance of their structural position and increasing concern over the masculinisation of school leadership. This paper aims to contribute to the discussion by critically analysing the interpretive frameworks of 12 male primary school principals. The findings reveal not only the complex, contradictory and at times culturally specific gendered discourses that some male principals employ, but also their feminising and masculinising effects on the school workplace and leadership.     

Mechanism-based causal reasoning in young children

The hypothesis that children develop an understanding of causal mechanisms was tested across 3 experiments. In Experiment 1 (N = 48), preschoolers had to choose as efficacious either a cause that had worked in the past, but was now disconnected from its effect, or a cause that had failed to work previously, but was now connected. Four-year-olds chose the now-connected cause more often than 3-year-olds. Experiment 2 (N = 16) showed 4-year-olds responded appropriately to an irrelevant modification in the same causal system. Experiment 3 (N = 24) demonstrated when the mechanism was batteries rather than connection, 3-year-olds could properly distinguish between relevant and irrelevant modifications. Together, these data suggest that understanding of specific causal mechanisms develops at different ages.     

Double jeopardy: poorer social-emotional outcomes for children in the NICHD SECCYD experiencing home and child-care environments that confer risk

Using data from the National Institute of Child Health and Human Development Early Child Care Research Network (NICHD SECCYD), the authors examined whether interactions between home and child-care quality affect children's social-emotional adjustment at 24, 36, and 54 months (N = 771). Triadic splits on quality of home and child care were used to examine children in specific ecological niches, with a focus on those who experience the double jeopardy of poor quality home and child-care environments. Children in this niche exhibited the highest levels of mother-reported problem behavior and the lowest levels of prosocial behavior. However, there was evidence that children from lower quality home environments were able to benefit from the compensatory influence of high-quality child care. These results suggest policies aimed at the cross-context influences of protective and risky settings.     

Maternal employment, work schedules, and children's body mass index

Previous work has shown that mothers' employment is associated with increases in children's body mass index (BMI), a measure of weight for height. Nonstandard work (working evenings or nights, weekends, or an irregular shift) may also be associated with children's BMI. This article examines the association between maternal work and children's BMI and considers the influence of mothers' nonstandard work schedules. Using data from school-age children (approximately 8 to 12 years) in the NICHD's Study of Early Child Care and Youth Development (N = 990), this study found that an increase in the total time a mother is employed is associated with an increase in her child's BMI; additionally, the association between maternal employment and children's weight is much stronger at 6th grade relative to younger ages. There was no evidence that maternal or home characteristics or children's time use mediated these associations, nor was there any evidence that nonstandard work was associated with children's BMI. Implications for policy and future research are discussed.