Thermal stress and physiological strain of children exposed to hot environments in a glass bangle factory

A group of 19 male children (mean age 12.1 years SEM 1.6 years) occupationally exposed to an excessively hot environment for an average duration of 2.5 years SEM 1.7 years in the glass bangle factory in Firozabad, India, were studied to evaluate the physiological strain induced by the thermal radiation (mean radiant temperature 46.2 degrees SEM 5.1 degrees C) and high ambient temperature (38.2 degrees SEM 3.4 degrees C) prevailing in the factory. Over a work-shift the mean increase in oral temperature was 0.90 degrees C in the exposed children, in comparison with the 0.40 degrees C increase recorded in the control children (p less than 0.05). The maximum increase in oral temperature was recorded in 'gulliwalas' (0.90 degrees C) and the minimum in 'battiwalas' (0.80 degrees C). The mean peak value of oral temperature (37.5 degrees C) was observed at 1600 hours. A significant increase in the pulse rate (25.9 beats.min-1) during the work-shift was observed in the exposed children in comparison with a mean increase of 9.4 beats.min-1 in the control group. Ventilatory studies showed pulmonary hyperventilation in the exposed workers. The increase in pulmonary ventilation was in the form of an increase in tidal volume and respiratory frequency induced by high environmental temperatures and thermal radiation. The cardio-respiratory responses showed physiological strain induced by the high ambient temperature and radiant heat prevailing in the glass bangle factory.     

The association of acrylamide with proteins. The interpretation of fluorescence quenching experiments

The association properties of acrylamide with a number of proteins in aqueous solution have been investigated by a fluorescence-quenching method previously used in micelles and lipid bilayers (Blatt, E., Chatelier, R.C. and Sawyer, W.H. (1984) Chem. Phys. Lett. 108, 397-400). At pH 7.0, acrylamide partitions between the bulk aqueous phase and the proteins, human serum albumin, monellin and ovalbumin. Comparison with an earlier method of analysis (Sikaris, K.A., Thulborn, K.A. and Sawyer, W.H. (1981) Chem. Phys. Lipids 29, 23-36) confirms the data quantitatively. For human serum albumin at pH 2.2, acrylamide associates according to both partition and binding processes. Equilibrium dialysis experiments performed for the latter system verify that acrylamide associates with proteins.     

Flavonoids of Tinospora malabarica

A dibenzoylethane and an allyloxyflavone isolated from Tinospora malabarica have been assigned the structures 1-(2′,4′-dimethoxyphenyl)-3-(3″     

Growth condition controls on G-93 parameters of isoprene emission from tropical trees

Despite its major role in global isoprene emission, information on the environmental control of isoprene emission from tropical trees has remained scarce. Thus, in this study, we examined the relationship between parameters of G-93 isoprene emission formula (C_T1, C_T2, and α), growth temperature and light intensity, photosynthesis (?, P_max), isoprene synthase (IspS) level, and 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway metabolites using sunlit and shaded leaves of four tropical trees. The results showed that the temperature dependence of isoprene emission from shaded leaves did not differ significantly from sunlit leaves. In contrast, there was a lower saturation irradiance in shaded leaves than in sunlit leaves, the same as temperate plants. The photosynthesis rate of shaded leaves showed lower saturation irradiance, similar to the light dependence of isoprene emission. In most cases, the concentration of MEP pathway metabolites was of lower tendency in shaded leaves versus in sunlit leaves, whereas no significant difference was noted in IspS level between sunlit and shaded leaves. Correlation analysis between these parameters found that C_T1 of the G-93 parameter was positively correlated with the concentration of DXP and DMADP, whereas C_T2 correlated with the concentration of MEP and the average air temperature for the past 48 h. Similarly, α closely associated with the initial slope (?) of photosynthesis rate, and the basal emission factor is also linked to the photon flux of past days. These results suggest that growth conditions may control the temperature dependence of isoprene emission from tropical trees via the changes in the profiles of MEP pathway metabolites, causing alteration in the parameters of the isoprene emission formula.

     

Evolutionary and Functional Relationships of the dha Regulon by Genomic Context Analysis

3-hydroxypropionaldehyde (3-HPA) and 1,3-propanediol (1,3-PD) are subproducts of glycerol degradation and of economical interest as they are used for polymers synthesis, such as polyesters and polyurethanes. Some few characterized bacterial species (mostly from Firmicutes and Gamma-proteobacteria groups) are able to catabolize these monomers from glycerol using the gene products from the dha regulon. To expand our knowledge and direct further experimental studies on the regulon and related genes for the anaerobic glycerol metabolism, an extensive genomic screening was performed to identify the presence of the dha genes in fully sequenced prokaryotic genomes. Interestingly, this work shows that although only few bacteria species are known to produce 3-HPA or 1,3-PD, the incomplete regulon is found in more than 100 prokaryotic genomes. However, the complete pathway is found only in a few dozen species belonging to five different taxonomic groups, including one Archaea species, Halalkalicoccus jeotgali. Phylogenetic analysis and conservation of both gene synteny and primary sequence similarity reinforce the idea that these genes have a common origin and were possibly acquired by lateral gene transfer (LGT). Besides the evolutionary aspect, the identification of homologs from several different organisms may predict potential alternative targets for faster or more efficient biological synthesis of 3-HPA or 1,3-PD.