The interaction between reproductive cost and individual quality is mediated by oceanic conditions in a long-lived bird

Environmental variability, costs of reproduction, and heterogeneity in individual quality are three important sources of the temporal and interindividual variations in vital rates of wild populations. Based on an 18-year monitoring of an endangered, recently described, long-lived seabird, Monteiro's Storm-Petrel (Oceanodroma monteiroi), we designed multistate survival models to separate the effects of the reproductive cost (breeders vs. nonbreeders) and individual quality (successful vs. unsuccessful breeders) in relation to temporally variable demographic and oceanographic properties. The analysis revealed a gradient of individual quality from nonbreeders, to unsuccessful breeders, to successful breeders. The survival rates of unsuccessful breeders (0.90 +/- 0.023, mean +/- SE) tended to decrease in years of high average breeding success and were more sensitive to oceanographic variation than those of both (high-quality) successful breeders (0.97 +/- 0.015) and (low-quality) nonbreeders (0.83 +/- 0.028). Overall, our results indicate that reproductive costs act on individuals of intermediate quality and are mediated by environmental harshness.     

Self-reported job burnout among female human service professionals

A sample of 135 female human service professionals completed the Maslach Burnout Inventory (MBI) and the Staff Burnout Scale for Health Professionals (SBS), along with measures of job satisfaction, role stress, self-esteem, alienation, and locus of control. Principal components factor analysis of this battery indicates considerable covariation of self-reported burnout with job dissatisfaction and perceived role stress, and moderate overlap with more general feelings of alienation and low self-esteem. Item factor analysis of the 22 MBI items resulted in two independent factors, one defined by the Emotional Exhaustion and Depersonalization items, the other by the Personal Accomplishment items. Item factoring of the SBS produced one large factor which was highly correlated with the MBI exhaustion-depersonalization factor. Implications of these findings for the construct validity of the MBI and SBS are discussed.     

Light and temperature requirements for growth and reproduction in gametophytes of Ecklonia maxima (Alariaceae: Laminariales)

The morphological and reproductive development of gametophytes of Ecklonia maxima (Osbeck) Papenf. has been studied in vitro under a wide range of light and temperature conditions, and the results related to the natural environment over the range of the distribution of the species. Initial vegetative growth was light saturated at 20 E m^-2 s^-1, and maximal at 17.5° and 20°C. Most rapid egg production corresponded to low cell number of female gametophytes, and this process was light saturated at 60 E m^-2 s^-1, and optimised at 15° and 17.5°C. Cell number was also low at lower temperatures, with reduced fertility rates. Sub-saturating irradiances and supraoptimal temperatures caused females to become filamentous, producing many more cells, and reducing reproductive rates. The final egg production per female was, however, greater in these sub-optimal conditions, and this phenomenon is interpreted as an ecological adaptation which improves survival prospects in conditions prevailing at the fringes of the depth and geographical distribution of the species. The optimal, and maximum (22.5°C) temperatures for reproduction are far higher than those of northern hemisphere Laminarians. E. maxima is very much a warm temperate organism, and this could have implications for marine phytogeographical studies on the west coast of southern Africa.     

Optimal growth and maximal survival temperatures of Atlantic Laminaria species (Phaeophyta) in culture

The effects of temperature on growth rate of rapidly-growing cultured macrosporophytes of 9 isolates of Atlantic Laminaria comprising 4 species have been investigated. No significant population variation was observed within species despite wide variations in temperature between the original collecting sites. L. saccharina showed a broad temperature optimum in the 10°–15°C range, whereas L. longicruris had a sharp optimum at 10°C. L. digitata and L. hyperborea grew more slowly, with only slightly sub-optimal growth over a wide temperature range, but with peaks at 10°C (L. digitata) and 15°C (L. hyperborea). The maximum survival temperatures of individual male and female vegetatively-growing gametophytes were ascertained for these species plus the Arctic L. solidungula, and were as follows: L. saccharina and L. longicruris, 23°C; L. digitata (male), 23°C; L. digitata (female), 22°C; L. hyperborea, 21°C; L. solidungula, 18°C. The lack of within-species differences demonstrates that the success of the genus in areas with different temperature regimes is brought about by phenotypic plasticity of individuals rather than the selection of temperature races or ecotypes.     

Revealing photon transmission in an ultraviolet reactor: Advanced approaches for measuring fluence rate distribution in water for model validation

Fluence rate (FR) distribution (optical field) is of great significance in the optimal design of ultraviolet (UV) reactors for disinfection or oxidation processes in water treatment. Since the 1970s, various simulation models have been developed, which can be combined with computational fluidic dynamic software to calculate the fluence delivered in a UV reactor. These models strive for experimental validation and further improvement, which is a major challenge for UV technology in water treatment. Herein, a review of the simulation models of the FR distribution in a UV reactor and the applications of the current main experimental measurement approaches including conventional flat-type UV detector, spherical actinometer, and micro-fluorescent silica detector (MFSD), is presented. Moreover, FR distributions in a UV reactor are compared between various simulation models and MFSD measurements. In addition, the main influential factors on the FR distribution, including inner-wall reflection, refraction and shadowing effects of adjacent lamps, and turbidity effect are discussed, which is helpful for improving the accuracy of the simulation models and avoiding dark regions in the reactor design. This paper provides an overview on the simulation models and measurement approaches for the FR distribution, which is helpful for the model selection in fluence calculations and gives high confidence on the optimal design of UV reactors in regard to present methods.     

Temperature tolerances of two southern African Ecklonia species (Alariaceae: Laminariales) and of hybrids between them

The temperature tolerances in culture of Ecklonia maxima (Osbeck) Papenf., the dominant kelp in the Benguela upwelling region on the west coast of southern Africa, and the smaller E. biruncinata (Bory) Papenf., growing on the warmer south coast, have been investigated. Vegetative growth and reproduction of gametophytes show very similar patterns in the two species, although temperature optima in E. biruncinata are consistently 2 ° to 3 °C higher than those of E. maxima. Reciprocal crosses between clonal female and male gametophytes of the two species produced healthy juvenile sporophytes, indistinguishable from the parent crosses. All parents and hybrids grew well over a wide range of temperatures (8 ° to 22°C), with E. biruncinata sporophytes again having slightly higher optima than E. maxima. Both reciprocal crosses exhibited optima intermediate between the parent crosses. The results are discussed with respect to the origins and evolution of Ecklonia species in the region.     

Channel and Perennial Flow Initiation in Headwater Streams: Management Implications of Variability in Source-Area Size

Despite increasing attention to management of headwater streams as sources of water, sediment, and wood to downstream rivers, the extent of headwater channels and perennial flow remain poorly known and inaccurately depicted on topographic maps and in digital hydrographic data. This study reports field mapping of channel head and perennial flow initiation locations in forested landscapes underlain by sandstone and basalt lithologies in Washington State, USA. Contributing source areas were delineated for each feature using a digital elevation model (DEM) as well as a Global Positioning System device in the field. Systematic source area–slope relationships described in other landscapes were not evident for channel heads in either lithology. In addition, substantial variability in DEM-derived source area sizes relative to field-delineated source areas indicates that in this area, identification of an area–slope relationship, should one even exist, would be difficult. However, channel heads and stream heads, here defined as the start of perennial flow, appear to be co-located within both of the lithologies, which together with lateral expansion and contraction of surface water around channel heads on a seasonal cycle in the basalt lithology, suggest a controlling influence of bedrock springs for that location. While management strategies for determining locations of channel heads and perennial flow initiation in comparable areas could assign standard source area sizes based on limited field data collection within that landscape, field-mapped source areas that support perennial flow are much smaller than recognized by current Washington State regulations.     

Chemical contaminants in juvenile gray whales (Eschrichtius robustus) from a subsistence harvest in Arctic feeding grounds

Gray whales are coastal migratory baleen whales that are benthic feeders. Most of their feeding takes place in the northern Pacific Ocean with opportunistic feeding taking place during their migrations and residence on the breeding grounds. The concentrations of organochlorines and trace elements were determined in tissues and stomach contents of juvenile gray whales that were taken on their Arctic feeding grounds in the western Bering Sea during a Russian subsistence harvest. These concentrations were compared to previously published data for contaminants in gray whales that stranded along the west coast of the US during their northbound migration. Feeding in coastal waters during their migrations may present a risk of exposure to toxic chemicals in some regions. The mean concentration (standard error of the mean, SEM) of sigmaPCBs [1400 (130) ng/g, lipid weight] in the blubber of juvenile subsistence whales was significantly lower than the mean level [27,000 (11,000) ng/g, lipid weight] reported previously in juvenile gray whales that stranded in waters off the west coast of the US. Aluminum in stomach contents of the subsistence whales was high compared to other marine mammal species, which is consistent with the ingestion of sediment during feeding. Furthermore, the concentrations of potentially toxic chemicals in tissues were relatively low when compared to the concentrations in tissues of other marine mammals feeding at higher trophic levels. These chemical contaminant data for the subsistence gray whales substantially increase the information available for presumably healthy animals.     

A Process-Based Hierarchical Framework for Monitoring Glaciated Alpine Headwaters

Recent studies have demonstrated the geomorphic complexity and wide range of hydrologic regimes found in alpine headwater channels that provide complex habitats for aquatic taxa. These geohydrologic elements are fundamental to better understand patterns in species assemblages and indicator taxa and are necessary to aquatic monitoring protocols that aim to track changes in physical conditions. Complex physical variables shape many biological and ecological traits, including life history strategies, but these mechanisms can only be understood if critical physical variables are adequately represented within the sampling framework. To better align sampling design protocols with current geohydrologic knowledge, we present a conceptual framework that incorporates regional-scale conditions, basin-scale longitudinal profiles, valley-scale glacial macroform structure, valley segment-scale (i.e., colluvial, alluvial, and bedrock), and reach-scale channel types. At the valley segment- and reach-scales, these hierarchical levels are associated with differences in streamflow and sediment regime, water source contribution and water temperature. Examples of linked physical-ecological hypotheses placed in a landscape context and a case study using the proposed framework are presented to demonstrate the usefulness of this approach for monitoring complex temporal and spatial patterns and processes in glaciated basins. This approach is meant to aid in comparisons between mountain regions on a global scale and to improve management of potentially endangered alpine species affected by climate change and other stressors.