Attitudes toward pre-retirement counselling: A path model

In structured interviews with 250 older male workers, respondents were asked whether they wished to participate in a proposed pre-retirement counselling programme. The effect of six independent variables on the workers' Attitude toward Pre-Retirement Counselling (dependent variable) was examined by means of a path analysis. Intention to Continue Working after Retirement had a significant negative effect on the dependent variable, indicating that a strong work orientation interfered with receptiveness to pre-retirement counselling. An unexpected relationship was observed between a favourable perception of retirement and the intention to continue working. This finding emphasized the dominance of the work orientation and workers' lack of awareness of alternative social roles. Implications for retirement planning programmes were discussed.     

Biochemical indices of aerobic and anaerobic capacity in muscle tissues of California elasmobranch fishes differing in typical activity level

Biochemical indices of aerobic and anaerobic metabolic capacity were measured in white myotomal muscle of eight marine elasmobranch fish species representing a broad range of locomotor performance, and in red myotomal muscle and heart of three of those species. The objectives were to determine if metabolic capacities vary with typical fish activity level, to compare the endothermic mako shark with ectothermic pelagic sharks, and to compare elasmobranchs with teleosts in order to test the hypothesis that elasmobranchs have lower aerobic capacities, metabolic rates, and swimming speeds. In white myotomal muscle, activities of the enzymes citrate synthase (an index of aerobic capacity), pyruvate kinase, and lactate dehydrogenase (LDH, an index of anaerobic capacity) covaried with typical activity level, and the ability to tolerate intracellular acidification (nonbicarbonate buffering capacity) corresponded with LDH activity. Enzyme activities in red muscle and heart did not show a consistent pattern with respect to fish activity. In comparison with ectothermic sharks, the mako shark had greater aerobic and anaerobic capacities in white muscle, but no significant differences were found in red muscle or heart. This pattern has also been found in teleosts. Thus, endothermic fishes elevate the temperature of red muscle, a tissue specialized for high aerobic performance, whereas white muscle biochemical characteristics are adjusted to support high rates of contraction both aerobically and anaerobically. Muscle enzymic activities of elasmobranchs and teleosts with comparable locomotor habits are similar, thus refuting the hypothesis that elasmobranchs are sluggish, with lower metabolic capacities than teleosts.     

Phthalates and their metabolites in breast milk--results from the Bavarian Monitoring of Breast Milk (BAMBI)

Phthalates have long been used as plasticizers to soften plastic products and, thus, are ubiquitous in modern life. As part of the Bavarian Monitoring of Breast Milk (BAMBI), we aimed to characterize the exposure of infants to phthalates in Germany. Overall, 15 phthalates, including di-2-ethylhexyl phthalate (DEHP), di-n-butyl phthalate (DnBP), di-isobutyl phthalate (DiBP), di-isononyl phthalate (DiNP), three primary metabolites of DEHP [mono-(2-ethylhexyl) phthalate (MEHP), mono-isobutyl phthalate (MiBP), and mono-n-butyl phthalate (MnBP)], and two secondary metabolites of DEHP were analyzed in 78 breast milk samples. We found median concentrations of 3.9 ng/g for DEHP, 0.8 ng/g for DnBP, and 1.2 ng/g for DiBP, while other parent phthalates were found in only some or none of the samples at levels above the limit of quantitation. In infant formula (n=4) we observed mean values of 19.7 ng/g (DEHP), 3.8 ng/g (DnBP), and 3.6 ng/g (DiBP). For MEHP, MiBP, and MnBP, the median values in breast milk were 2.3 μg/l, 11.8 μg/l, and 2.1 μg/l, respectively. The secondary metabolites were not detected in any samples. Using median and 95th percentile values, we estimated an "average" and "high" daily intake for an exclusively breast-fed infant of 0.6 μg/kg body weight (b.w.) and 2.1 μg/kg b.w., respectively, for DEHP, 0.1 μg/kg b.w. and 0.5 μg/kg b.w. for DnBP, and 0.2 μg/kg b.w. and 0.7 μg/kg b.w. for DiBP. For DiNP, intake values were 3.2 μg/kg b.w. and 6.4 μg/kg b.w., respectively, if all values in milk were set half of the detection limit or the detection limit. The above-mentioned "average" and "high" intake values corresponded to only about 2% to 7%, respectively, of the recommended tolerable daily intake. Thus, it is not likely that an infant's exposure to phthalates from breast milk poses any significant health risk. Nevertheless, other sources of phthalates in this vulnerable phase have to be considered. Moreover, it should be noted that for infants nourished with formula, phthalate intake is of the same magnitude or slightly higher (DEHP) than for exclusively breast-fed infants.     

Seasonal water demand in Benin's agriculture

This paper describes and analyzes agricultural water demands for Benin, West Africa. Official statistical data regarding water quantities as well as knowledge on factors influencing the demand for water are extremely rare and often reveal national trends without considering regional or local differences. Thus policy makers usually work with this estimated and aggregated data, which make it very difficult to adequately address regional and local development goals. In the framework of an interdisciplinary analysis the following paper provides insight into water quantification and detects water problems under seasonal aspects for agriculture according to regional differences. Following the definition of the Food and Agriculture Organization [FAO, 1995. Water Report 7. Irrigation in Africa in Figures. Rome] agriculture is divided into irrigation and livestock watering, which were analyzed using different field methods. The study reveals that although water supply in absolute terms seems to be sufficient in Benin, seasonal water problems occur both in irrigation and in livestock management. Thus arising seasonal water problems are not the consequence of general water scarcity but more linked to three major problems. These problems emerge from difficulties in technical equipment and financial means of farmers, from the specific local conditions influencing the access to water sources and the extraction of groundwater, and third from the overall low organizational structure of water management. Therefore regional differences as well as a general improvement of knowledge on better management structures, technical know how, and access to credits for farmers need to be considered in national strategies in order to improve the agricultural water usage in Benin.     

Frost drought in conifers at the alpine timberline: xylem dysfunction and adaptations

Drought stress can cause xylem embolism in trees when the water potential (psi) in the xylem falls below specific vulnerability thresholds. At the alpine timberline, frost drought is known to cause excessive winter embolism unless xylem vulnerability or transpiration is sufficiently reduced to avoid critical psi. We compared annual courses of psi and embolism in Picea abies, Pinus cembra, Pinus mugo, Larix decidua, and Juniperus communis growing at the timberline vs. low altitude. In addition, vulnerability properties and related anatomical parameters as well as wood density (D(t)) and wall reinforcement (wall thickness related to conduit diameter) were studied. This allowed an estimate of stress intensities as well as a detection of adaptations that reduce embolism formation. At the alpine timberline, psi was lowest during winter with corresponding embolism rates of up to 100% in three of the conifers studied. Only Pinus cembra and Larix decidua avoided winter embolism due to moderate psi. Minor embolism was observed at low altitude where the water potentials of all species remained within a narrow range throughout the year. Within species, differences in psi50 (psi at 50% loss of conductivity) at high vs. low altitude were less than 1 MPa. In Picea abies and Pinus cembra, psi50 was more negative at the timberline while, in the other conifer species, psi50 was more negative at low altitude. Juniperus communis exhibited the lowest (-6.4 +/- 0.04 MPa; mean +/- SE) and Pinus mugo the highest psi50 (-3.34 +/- 0.03 MPa). In some cases, D(t) and tracheid wall reinforcement were higher than in previously established relationships of these parameters with psi50, possibly because of mechanical demands associated with the specific growing conditions. Conifers growing at the alpine timberline were exposed to higher drought stress intensities than individuals at low altitude. Frost drought during winter caused high embolism rates which were probably amplified by freeze-thaw stress. Although frost drought had a large effect on plant water transport, adaptations in hydraulic safety and related anatomical parameters were observed in only a few of the conifer species studied.     

Monitoring of effluent DOM biodegradation using fluorescence, UV and DOC measurements

The potential of effluent DOM to undergo microbial degradation was assessed in batch experiments. Effluent samples from Haifa wastewater treatment plant and Qishon reservoir (Greater Haifa wastewater reclamation complex, Israel) were incubated either with effluent or soil microorganisms for a period of 2-4 months and were characterized by dissolved organic carbon contents (DOC), UV(254) absorbance and by fluorescence excitation-emission matrices. Three main fluorescence peaks were identified that can be attributed to humic/fulvic components and "protein-like" structures. During biodegradation, specific fluorescences (F/DOC) of the three peaks were increased at various extents, suggesting selective degradation of non-fluorescing constituents. In some cases increase in the effluent fluorescence (F) was observed thus proposing (i) the formation of new fluorescing material associated with DOM biodegradation and/or (ii) degradation of certain organic components capable of quenching DOM fluorescence. Based on the ratio between fluorescence intensity and UV(254), different biodegradation dynamics for fluorescent DOM constituents as compared with other UV-absorbing molecules was delineated. Overall, about 50% of the total DOM was found to be readily degradable such that residual resistant DOC levels were between 8 and 10 mg l(-1). Enhanced levels of residual DOM in effluent-irrigated soils may contribute to the DOM pool capable of carrying pollutants to groundwater.     

Maternal nutrition affects offspring performance via maternal care in a subsocial spider

Provisioning of nutrients to the young during parental care is one of the mechanisms by which parents can affect growth and survival of their young and thus their reproductive success. We examined the hypothesis that food quality, i.e., ratio of macronutrients, provided to the young via maternal care affects their performance and the female’s reproductive success. The subsocial spider Stegodyphus lineatus exhibits intensive maternal care behaviors, including feeding the young and matriphagy (consumption of the mother). Our results showed that a protein-enriched diet resulted in larger females at maturation and higher survival of young, relative to intermediate or lipid-enriched diets. However, fecundity was not affected by female diet. We suggest that most of the nutrients are provided to the young during maternal care rather than deposited in the eggs, allowing females to economize on limited nutritional reserves. Females before maternal care showed a low protein and high lipid content relative to females before maturation and oviposition, suggesting a change in the nutritional requirement of females before maternal care. This change in macronutrient composition may be adaptive for the success of the young in the wild and shows a novel approach to animals’ ability to increase their reproductive success. Field-collected females showed a similar macronutrient composition as that of protein-enriched females in the lab, suggesting a high reproductive success of females in the wild. To our knowledge, this is the first time the importance of different macronutrients to females’ reproductive success is examined during reproduction.     

Odorants and malodors associated with land application of biosolids stabilized with lime and coal fly ash

Malodor emissions limit public acceptance of using municipal biosolids as natural organic resources in agricultural production. We aimed to identify major odorants and to evaluate odor concentrations associated with land application of anaerobically digested sewage sludges (Class B) and their alkaline (lime and coal fly ash)-stabilized products (Class A). These two types of biosolids were applied at 12.6 tonnes ha(-1) (dry weight) to microplots of very fine clayey Vertisol in the Jezreel Valley, northern Israel. The volatile organic compounds (VOCs) emitted from the biosolids before and during alkaline stabilization and after incorporation into the soil were analyzed by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Odor concentrations at the plots were evaluated on site with a Nasal Ranger field olfactometer that sniffed over a defined land surface area through a static chamber. The odors emitted by anaerobically digested sewage sludges from three activated sludge water treatment plants had one characteristic chemical fingerprint. Alkaline stabilization emitted substantial odors associated with high concentrations of ammonia and release of nitrogen-containing VOCs and did not effectively reduce the potential odor annoyance. Odorous VOCs could be generated within the soil after biosolids incorporation, presumably because of anaerobic conditions within soil-biosolids aggregates. We propose that dimethyl disulfide and dimethyl trisulfide, which seem to be most related to the odor concentrations of biosolids-treated soil, be used as potential chemical markers for the odor annoyance associated with incorporation of anaerobically digested sewage sludges.