The influence of heavy metals on a mixed bacterial population of sewage origin in the chemostat

A reproducible mixed continuous bacterial population has been cultured in the chemostat at a low dilution rate. Four species originally isolated from activated sludge were used to provide an inoculum. The influence of cadmium, chromium, copper and lead as shock doses has been examined at concentrations of 50 mg l⁻¹ and the response of the population was found to vary for each metal. The most toxic metal was copper followed by cadmium, lead and chromium. Continuous doses of chromium and lead have been studied, the latter over a range of concentrations. It appears that concentrations of lead as low as 5 mg l⁻¹ cause modifications in the individual population sizes. Some of the species studied were found to be more resistant to heavy metal toxicity than others.     

Behaviour of persistent organochlorine micropollutants during primary sedimentation of waste water

The removal of polychlorinated biphenyls and the organochlorine insecticides gamma-HCH, aldrin, dieldrin and endrin during primary sedimentation of raw sewage has been studied using a pilot plant facility. A matrix of sixteen experiments was performed, where the pilot plant was operated at four different hydraulic loadings with four different influent suspended solids loadings. Significant removals of micropollutants into the primary sludge were observed, although no particular relationship with the removal of suspended solids was evident. It is concluded that a proportion of the organic microcontaminants present in raw sewage were associated with non-settleable solids and were also in the dissolved form. The significance of the behaviour of organochlorine micropollutants in waste water treatment processes and the hydrological cycle are discussed in the context of water re-use operations.     

Ambient air measurements of aromatic and halogenated hydrocarbons at urban,rural and motorway locations

Concern over the carcinogenic properties of certain volatile organics in air, particularly benzene, has recently been expressed. Reductions in the lead content of perol in the United Kingdom and other European countries are predicted to change the concentrations of aromatic and halogenated hydrocarbons (1,2-dichloroethane and 1,2-dibromoethane) in ambient air. In order to provide baseline air quality data, prior to progressive reductions in the lead content of petrol, this study reports the results of a monitoring survey of ambient air concentrations of aromatic and halogenated hydrocarbon concentrations at urban, rural and motorway locations. A thermal desorption/gas chromatographic method analysing Tenax GC sampling tubes was utilised. Highest concentrations for benzene (9.7 ppb) and toluene (15.5 ppb) were measured at the urban site. The average benzene concentration is comparable with a proposed ambient air quality standard in the Federal Republic of Germany. Multiple regression analysis of nonmethane hydrocarbon and carbon monoxide air quality data demonstrated the importance of meteorological variables in defining measured concentrations. The toluene/benzene ratio (w/w) provided useful information in determining the degree of vehicle-related air pollution and supported evidence obtained from dynamometer studies of dealkylation of higher aromatics to benzene in engines operating at high speed and load at the motorway site.     

In vitro and in vivo efficacy of sulfo‐carrabiose,a sugar‐based cosmetic ingredient with anti‐cellulite properties

Most of adult women exhibit cellulite on the hips, buttock and thighs. Although extracellular matrix and lymphatic system disorders can increase its appearance, cellulite basically results from an excessive fat storage in the adipose tissue which exerts considerable pressure on the surrounding skin tissue and creates a dimpled irregular appearance. Caffeine, the most widely used anti‐cellulite ingredient, favours fat break‐down by inhibiting the phosphodiesterase enzyme and encouraging a high intracellular level of cAMP. A series of studies has shown that spermine and spermidine, two ubiquitous polyamines, encouraged fat storage and slowed fat break‐down in the adipose tissue. Besides, it was shown that heparan sulfate glycosaminoglycans had a strong affinity for polyamines. To design a new cosmetic ingredient with anti‐cellulite properties, we used molecular modelling to screen several ingredients with a structure similar to that of heparan sulfate glycosaminoglycans. This way, we identified sulfo‐carrabiose as a potent molecule for trapping spermine and spermidine. These virtual results were first confirmed in tubo where sulfo‐carrabiose was shown to dose‐dependently inactivate spermine and spermidine. In vitro, adipocytes cultured with sulfo‐carrabiose exhibited a significant reduction of lipogenesis and a significant increase of lipolysis. When sulfo‐carrabiose was incorporated in a cosmetic formula, significant improvements were observed in thigh circumference, with better results than those obtained with caffeine after 28 days of use. Furthermore, a combination of caffeine and sulfo‐carrabiose led to results significantly better than those obtained with caffeine alone. As measured by fringe projection, thigh volume was also significantly reduced after sulfo‐carrabiose treatment. Finally, the appearance of cellulite assessed by clinical evaluation was also significantly reduced within 28 days.     

Vicious cycle during chemical degradation of sulfonated aromatic proton exchange membranes in the fuel cell application

Weak phase separation and vulnerable linking groups between aromatic units are common setbacks of sulfonated aromatic proton exchange membranes (PEMs) from durability point of view. In this study, sulfonated poly(ether ether ketone) (SPEEK) membranes were exposed to Fenton's solution for a specific time, ranging from 10 to 60 minutes. Chemical structure and morphology evolution, decay in mechanical and thermal stability, and H₂ permeability of SPEEK membranes were evaluated during the chemical degradation. Less-entangled polymeric chains with lower average molecular weight of degraded SPEEK samples diminished mechanical rigidity. In addition, reduction of aromatic rings in each repeat unit led to higher thermal decomposition rate. Furthermore, randomly distributed micro-defects in the SPEEK morphology and an increase in water sorption can reduce the fatigue strength of membranes in the wet-dry cycles. Eventually, hydrogen cross-over rate was gradually increased, and henceforth, accelerated destructive radical formation and degradation can be predicted.     

A method for improving global pyranometer measurements by modeling responsivity functions

Accurate global solar radiation measurements are crucial to climate change research and the development of solar energy technologies. Pyranometers produce an electrical signal proportional to global irradiance. The signal-to-irradiance ratio is the responsivity (RS) of the instrument (RS = signal/irradiance = microvolts/(W/m²)). Most engineering measurements are made using a constant RS. It is known that RS varies with day of year, zenith angle, and net infrared radiation. This study proposes a method to find an RS function to model a pyranometer’s changing RS. Using a reference irradiance calculated from direct and diffuse instruments, we found instantaneous RS for two global pyranometers over 31 sunny days in a two-year period. We performed successive independent regressions of the error between the constant and instantaneous RS with respect to zenith angle, day of year, and net infrared to obtain an RS function. An alternative method replaced the infrared regression with an independently developed technique to account for thermal offset. Results show improved uncertainties with the function method than with the single-calibration value. Lower uncertainties also occur using a black-and-white (8-48), rather than all-black (PSP), shaded pyranometer as the diffuse reference instrument. We conclude that the function method is extremely effective in reducing uncertainty in the irradiance measurements for global PSP pyranometers if they are calibrated at the deployment site. Furthermore, it was found that the function method accounts for the pyranometer’s thermal offset, rendering further corrections unnecessary. The improvements in irradiance data achieved in this study will serve to increase the accuracy of solar energy assessments and atmospheric research.     

Theory-based research for understanding the process of dynamic psychotherapy.

Research is reviewed on 6 theoretical propositions central to psychodynamic psychotherapy: (1) The establishment of an alliance is important to successful outcome; (2) the patient displays a central relationship theme (transference); (3) transference interpretations are helpful; (4) the therapist aims at accurate interpretations of the transference; (5) the patient gains understanding of self and the relationship pattern; and (6) the patient's improvement is reflected in changes in the relationship pattern, although the pattern is still evident. We suggest concepts that are in need of research development: internalization, resistance, working through, self-understanding and insight, and the therapist's adherence to recommended techniques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficacy of self-administered treatment programs: Meta-analytic review.

Using meta-analysis, we examined the efficacy of self-administered treatments. Self-administered treatments were compared with no treatment and with therapist-administered treatments. Results indicated that self-administered treatments were reliably more effective than no treatment and that differences between self-administered and therapist-administered treatments were nonsignificant. Effect sizes for type of target problem (e.g., phobias, affective disturbances) were comparable. These results suggest that self-administered treatments in general are effective in comparison with no treatment. The limitations of this review are noted, including those that preclude the conclusion that self-administered treatments are as effective as therapist-administered programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)