Acidogenic fermentation of blended food‐waste in combination with primary sludge for the production of volatile fatty acids

The performance of a laboratory‐scale anaerobic acidogenic fermenter fed with a mixture of blended kitchen food‐waste and primary sludge from a sewage treatment plant was investigated for the production of volatile fatty acids (VFA). The operating variables for acidogenic fermentation were kitchen food‐waste content (10 and 25 wt %), hydraulic retention time (HRT: 1, 3 and 5 days), temperature (ambient: 18 ± 2 °C, and mesophilic: 35 ± 2 °C) and pH (varied from 5.2 to 6.7). The experimental results indicated that effluent VFA concentrations and VFA production rates were higher at ambient temperature than at mesophilic conditions. The net amount of VFA with 10 wt % food‐waste increased up to 920 mg dm^?3 with an increase of HRT, but contrasting results (a decrease of 2610 mg dm^?3) were found due to the conversion of VFA into biogas in the case of 25 wt % food‐waste, which increased significantly at HRT of 3–5 days. In terms of biogas composition (CO₂ and CH₄), the organic matter was converted into CO₂ through the oxidative pathway by facultative species at low temperature while mesophilic temperature and optimum pH (6.3–7.8) played a pivotal role in increasing rate of conversion of VFA into biogas by methanogenesis. Rates of VFA production and their conversion are dependent on the food‐waste content in the mixture. Yet, the higher concentration of food‐waste (25% compared with 10%) did not produce VFA proportionally due to the increased rate of conversion of VFA into gaseous products. The maximum VFA production rate (0.318 g VFA_produced g^?1 VS_fed day^?1) was achieved in the 10 wt % food‐waste at ambient temperature and at a 5‐day HRT. Copyright © 2005 Society of Chemical Industry     

Work-site smoking policies: their population impact in Washington State

This article presents data from a population-based, random-digit dialing telephone survey of 1228 employed adults in Washington State, conducted 1989 through 1990. Eighty-one percent of men and 91% of women reported work-site smoking restrictions. Employees in work sites with no-smoking policies were less likely to be current smokers; men in work sites with policies restricting smoking smoked fewer cigarettes on both workdays and nonworkdays. Forty-eight percent of male and 53% of female smokers reported reduced smoking as a result of work-site policy. Work-site smoking policies, intended to protect against smoke exposure, may also reduce employee smoking.     

Imported measles. A potential control problem

From Dec 23, 1978, through Jan 31, 1979, an outbreak of five laboratory-confirmed cases and four clinical cases of measles occurred in a Vietnamese refugee population living in a single housing complex in Albuquerque, NM. The index cases were in two refugee siblings in whom measles was incubating on arrival in the United States. Despite spread through three subsequent generations of disease transmission within the Vietnamese population, there was no additional spread into the general Albuquerque population. Responsible factors included the age distribution of susceptible persons, the social isolation of the refugee population, and the physical structure of the housing complex. There is a need to identify the problem of imported measles in "ethnic islands" in need of vaccination.     

The effects of sulphur fertilisers on the content of sulpho-amino acids in seeds of cowpea (Vigna unguiculata)

Seed meals of three cowpea (Vigna unguiculata) cultivars, grown in pots containing sulphur-deficient soil supplemented with 0, 0.2, 0.6, 1.8, 5, 15 and 45 parts/10⁶ sulphate-S levels in the soil solution, were examined for total nitrogen, total sulphur and sulpho-amino acid contents. The sulphur content and the ratio of sulphur to nitrogen were found to increase with the increasing level of sulphate-S fertilisation up to ca 5 parts/10⁶. Compared with the control the sulpho-amino acid content in seeds of cowpea TVu 76 increased with S-supplementation up to 5 parts/10⁶ and that of cowpea Sitao Pole increased with S up to 1.8 parts/10⁶. Similar levels (7 and 2 parts/10⁶ respectively) of sulphate-S were required in the soil solution to obtain 95% of the maximum yields of cowpea seeds. The content of sulpho-amino acids in the seeds from 5 parts/10⁶ treatments were similar to those reported for cowpeas grown under field conditions at IITA and elsewhere with adequate levels of soil sulphur for maximum yield.     

Laboratory evaluation of 3-(5-tetrazolyl) penam, a new semisynthetic beta-lactam antibacterial agent with extended broad-spectrum activity

In the new agent 3-(5-tetrazolyl)penam, hereafter referred to as CP-35,587, the carboxyl function at C3 in the penicillin nucleus has been replaced with the 5-tetrazolyl moiety. Marked changes in spectrum and resistance to gram-negative beta-lactamases, particularly with regard to Klebsiella pneumoniae isolates, were conferred by this modification. The anti-Klebsiella activity clearly distinguishes the antibacterial spectrum of CP-35,587 from any known broad-spectrum penicillin. Compared to orally active cephalosporins, the spectrum advantage of CP-35,587 encompasses Enterobacter, Serratia marcescens, Citrobacter, Providencia, Haemophilus influenzae, and Streptococcus faecalis, both in vitro and in murine infections produced by many of the above-named microorganisms. Thus, CP-35,587 combines and extends the antibacterial activity of broad-spectrum penicillins and orally active cephalosporins.     

Early unconjugated hyperbilirubinaemia after paracetamol overdosage

A rapid increase of predominantly unconjugated bilirubin in the blood -- which was not due to haemolysis -- was observed in 38 of 60 patients who had taken an overdose of paracetamol. Studies in the rat given an overdose of the drug showed that within 24 hours there was a striking reduction in the activity of bilirubin glucuronyl-transferase and the content of cytochrome P.450 in the liver. It is suggested that such early damage of the hepatic endoplasmic reticulum contributes to the hyperbilirubinaemia of paracetamol poisoning.     

Intersubject variation of warfarin binding to protein in serum of normal subjects

The protein binding of warfarin was determined in the serum of 18 normal adult subjects (8 males and 10 females). A statistically significant negative correlation between free fraction of warfarin and albumin concentration was found. The free fraction of warfarin in the serum of women was significantly larger than that in the serum of men, apparently due to the lower albumin concentration in the serum of women.     

Endogenous oncornaviral DNA sequences: evidence for two classes of viral DNA sequences in guinea pig cells

The nature of the endogenous viral DNA sequences in guinea pig cells was studied by hybridization. A segment of the viral RNA (r-VRNA) hybridizing to abundant (or reiterated) DNA sequences (R-VDNA) was isolated by recycling to a Cot of 300. The hybridization of the recycled VRNA, as well as the total VRNA, was followed by determining their kinetics and by Wetmur-Davidson analysis. The kinetics of hybridization of total VRNA were complex, did not follow a second-order kinetics, and revealed two slopes by Wetmur-Davidson analysis. The recycled RNA, on the other hand, had a second-order reaction rate expected of the hybridization between a single species of RNA and DNA sequences and yielded a single straight line in a Wetmur-Davidson plot. The Cot1/2 and slope of the recycled r-VRNA was almost identical to that of the abundant VDNA sequences obtained from the hybridization data of the total VRNA. Guinea pig 28S rRNA with or without recycling was used in monitoring hybridization rate. The kinetics of hybridization of 28S RNA followed a second-order reaction and produced a single straight line by Wetmur-Davidson plot, with a second-order reassociation rate constant of 9.6 x 10(-3) liters/mol-s, a Cot1/2 of 104 mol-s/liter, and reiteration frequency of 146. There was no difference in the kinetics of hybridization of 28S RNA before and after recycling. These experiments showed that guinea pig cells contain two classes of VDNA sequences. (i) R-VDNA sequences with a second-order reassociation rate constant of 8.2 x 10(-4) liters/mol-s, a Cot1/2 of 1,219 mol-s/liter, and a reiteration frequency of 12 represent 37.5% of the viral genome. (ii) Unique VDNA sequences with a second-order reassociation rate constant of 1.2 x 10(-4) liters/mol-s, a Cot1/2 of 7,692 mol-s/liter, and a reiteration frequency of 2 represent 62.5% of the viral genome.