A paradox of the ciliates? High ciliate diversity in a resource-poor environment

Ecological theory predicts that low productivity systems should have low biodiversity. However, despite the oligotrophic status of the Gulf of Aqaba (Northern Red Sea) ciliate species richness was unexpectedly high. In addition, phytoplankton, as main ciliate prey, was made up by only few genera, indicating a significant niche overlap among the grazers. Up to 97% of the ciliates were from the same taxonomic group and of the same size range, implying very similar food niches. Ciliate diversity was highest at times of lowest chlorophyll concentrations, during the period of stable abiotic conditions, but relatively high genetic diversity within the ciliate prey, notably among the cyanobacteria Synechococcus and Prochlorococcus. In the absence of disturbance and with little predation pressure, the alternate explanations for the observed ciliate diversity are either very fine niche partitioning by the ciliates, or their competitive equivalence resulting in a random assortment of species immigrating from a larger metacommunity, in accordance with Hubbell’s, (The unified neutral theory of biodiversity and biogeography. Princeton University Press, Princeton, 2001) neutral model. While the use of species abundance distributions (SAD’s) is far from definitive, the theoretical SAD’s that best fit the Gulf of Aqaba ciliate data was most often not that expected by neutral theory.     

The persistence of insecticidal chemicals in soils treated with granular formulations of aldicarb and their uptake by potato plants

Abstract

Potatoes were grown in Plainfield sand and muck treated, in furrow, with aldicarb (Temik 15G, 3.36 kg Al/ha). .Soils were contained in 2 m^z field plots and had not been treated previously with pesticides. Soil, seed pieces, foliage and tubers were analyzed for the insecticide and its sulfoxide and sulfone metabolites during the 12 wk following planting. The disappearance of aldicarb from the soil was accompanied by partial conversion to the sulfoxide and sulfone. After increasing rapidly during the first 2 wk, the aldicarb concentration in the seed piece declined and a similar concentration of aldicarb sulfoxide accumulated which subsequently slowly disappeared. Aldicarb sulfoxide was the major insecticidal material in the new foliage. High initial concentrations, observed at 3–4 wk, declined by about 90% after 6 wk. Aldicarb sulfoxide residues of 2–4 ppm in the first new tubers at 6 wk declined by 90% by 12 wk. Potatoes were also grown under greenhouse conditions in Plainfield sand treated with Temik 10G at rates equivalent to 1.68, 3.36 and 6.72 kg Al/ha. Maximum aldicarb sulfoxide concentrations in soil, seed piece and foliage increased with application rate. The sulfoxide was much more persistent in the soil and foliage than in the field experiment indicating the importance of environmental factors to its behaviour in both soil and potato plants.     

A Methodology for Assessing Blast Protection in Explosive Ordnance Disposal Bomb Suits

To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax.

A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn.     

Biomechanical Assessment of Three Rebar Tying Techniques

The National Institute for Occupational Safety and Health (NIOSH) conducted a study of ironworkers to evaluate their risk for developing back and hand injuries from hand-tying reinforcing steel bar and to investigate whether power tying tools can be an effective intervention for the prevention of work-related musculoskeletal disorders. A field investigation of biomechanical loading when using 3 techniques to tie together rebar was conducted. Researchers measured employees ‘ wrist and forearm movement with goniometers and videotaped and analyzed trunk postures. Manually tying rebar at ground level involved sustained deep trunk bending and rapid, repetitive, and forceful hand-wrist and forearm movements. Using a power tier significantly reduced the hand-wrist and forearm movements and allowed the ironworkers to use one free hand to support their trunk posture while tying. Adding an extension handle to the power tier allowed the ironworkers to tie rebar while standing erect, minimizing sustained trunk flexion.     

Explaining task performance and creativity from perceived organizational support theory: Which mechanisms are more important?

Perceived organizational support (POS) theory specifies three mechanisms—felt obligation, group identification, and outcome expectancy—to explain the effects of organizational support on employee work outcomes. These mechanisms have usually been examined in isolation so that it is not possible to assess their relative explanatory power. The present study aims to remedy this problem by examining the three mechanisms simultaneously using structural equation modeling. On the basis of a sample of 206 bank employees in China, we focus on two types of employee performance—task performance and creativity—as dependent variables. Drawing on self‐determination theory and characteristics of the research context, we propose that task performance is more strongly predicted by felt obligation than by the other two mechanisms, whereas identification and expectancy more strongly predict creativity than felt obligation. We conclude by discussing our contribution to POS and creativity research, and highlight some important implications of our findings. Copyright © 2012 John Wiley & Sons, Ltd.     

Residential Care in Los Angeles: evaluating the spatial distribution of facilities and neighbourhood access to care among older adults

ABSTRACT

Residential care has increased in number of facilities and has grown in density in urban areas, yet it is disproportionately dispersed in cities and only beginning to meet the current long-term care need of older adults as an alternative to institutional and in-home care. California State Department of Social Services residential care facility data were linked with Los Angeles County census tract data to examine the spatial distribution of facilities through hot spot analysis of clusters of small and large facilities and zero-inflated negative binomial regression of census tract facility counts on older age and race groups, older disabled adults, and older adults in poverty in the area. The results show clusters of large facilities west of downtown Los Angeles and clusters of small facilities in the northern suburbs of the city in the San Fernando Valley. Increases in pre- and early-retired adults and older Hispanics in census tracts are associated with the greatest decreases in facility tract capacity in the area, whereas increases in the oldest old and older disabled adults are associated with the greatest increases. Understanding spatial disparities in residential care can help local agencies and developers plan and partner in more intentional and equitable development of facilities. The greatest opportunity for such development may lie in institutional tools for eldercare facility development such as the eldercare facility ordinance of Los Angeles and development of board and care facilities in residential zones of Los Angeles and other cities.     

Exploring the perceptions of Malaysian Gen Z towards the impact of COVID-19 on sustainable development

Environmental Science and Pollution Research - COVID-19 has affected the pursuit of sustainable development in multifaceted ways; this study investigates Malaysian Gen Z perceptions of the COVID-19...     

Predictors of conviction and sentencing of DWI offenders in a New Mexico County

OBJECTIVE: To analyze predictors of conviction and dismissal of individuals charged with DWI, and predictors of the sentences of those who are convicted. METHODS: Data come from the Citation Tracking System of the State of New Mexico's Motor Vehicle Division and includes information on all individuals who were arrested for DWI in San Juan County between August 1994 and December 2000. Independent variables were: age, gender, race/ethnicity, waiver of right to an attorney, court of arraignment, year of arrest, BAC, and number of prior DWI arrests. Dependent variables were: (1) conviction or dismissal, (2) jail or no jail, (3) incarceration/treatment or not, (4) fine or no fine, (5) length of jail sentence, (6) waived right of attorney, and (7) magnitude of fine. Multiple linear and logistic regression was used in the analyses. RESULTS: Use of an attorney is associated with reduced likelihood of conviction and, if convicted, in reduced likelihood of jail sentence and reduced jail time, but greater likelihood and magnitude of a fine. Native Americans were more likely than Hispanics and non-Hispanic whites to waive their right to an attorney. Native Americans were most likely to be sentenced to the detention/treatment program. BAC and number of prior arrests were each positively associated with increased likelihood of conviction and more severe sentences. There is also substantial variability in severity of sentencing among courts. CONCLUSION: Likelihood of conviction and severity of sentences are both determined by extra-legal factors, resulting in inconsistent application of the law. This may in turn contribute to a lack of compliance with laws related to DWI.     

The invasibility of marine algal assemblages: role of functional diversity and identity

The emergence of the biodiversity-ecosystem functioning debate in the last decade has renewed interest in understanding why some communities are more easily invaded than others and how the impact of invasion on recipient communities and ecosystems varies. To date most of the research on invasibility has focused on taxonomic diversity, i.e., species richness. However, functional diversity of the communities should be more relevant for the resistance of the community to invasions, as the extent of functional differences among the species in an assemblage is a major determinant of ecosystem processes. Although coastal marine habitats are among the most heavily invaded ecosystems, studies on community invasibility and vulnerability in these habitats are scarce. We carried out a manipulative field experiment in tide pools of the rocky intertidal to test the hypothesis that increasing functional richness reduces the susceptibility of macroalgal communities to invasion. We selected a priori four functional groups on the basis of previous knowledge of local species characteristics: encrusting, turf, subcanopy, and canopy species. Synthetic assemblages containing one, two, three, or four different functional groups of seaweeds were created, and invasion by native species was monitored over an eight-month period. Cover and resource availability in the assemblages with only one functional group showed different patterns in the use of space and light, confirming true functional differences among our groups. Experimental results showed that the identity of functional groups was more important than functional richness in determining the ability of macroalgal communities to resist invasion and that resistance to invasion was resource-mediated.     

Predicting extinctions as a result of climate change

Widespread extinction is a predicted ecological consequence of global warming. Extinction risk under climate change scenarios is a function of distribution breadth. Focusing on trees and birds of the eastern United States, we used joint climate and environment models to examine fit and climate change vulnerability as a function of distribution breadth. We found that extinction vulnerability increases with decreasing distribution size. We also found that model fit decreases with decreasing distribution size, resulting in high prediction uncertainty among narrowly distributed species. High prediction uncertainty creates a conservation dilemma in that excluding these species under-predicts extinction risk and favors mistaken inaction on global warming. By contrast, including narrow endemics results in over-predicting extinction risk and promotes mistaken inaction on behalf of individual species prematurely considered doomed to extinction.