The transition of a line plume to round plume

Environmental Fluid Mechanics - Buoyant turbulent plumes are often categorized by their geometry and described as either round plumes, issuing from a point source, or line/planar plumes, issuing...     

Sex-specific inhibition and stimulation of worker-reproductive transition in a termite

In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.     

Building safety in humanitarian programmes that support post-disaster shelter self-recovery: an evidence review

The humanitarian sector is increasingly aware of the role that good quality evidence plays in the underpinning of effective and accountable practice. This review addresses the need for reliable evidence by evaluating current knowledge about the intersection of two key outcome targets of post-disaster shelter response: supporting shelter self-recovery and building back safer. Evidence about post-disaster shelter programmes that aim to improve hazard resistance while supporting shelter self-recovery has been systematically analysed and evaluated. Technical support, especially training in safer construction techniques, was found to be a central programme feature, but the impact of this and other programme attributes on building safety was largely not ascertainable. Programme reports and studies lack sufficient detail, especially on the hazard resistance of repaired houses. Accounts of shelter programmes need to include more reliable reporting of key activities and assessment of outcomes, in order to contribute to the growing evidence base in this field.     

Underaddressed animal-welfare issues in conservation

Much progress has been made toward assessing and improving animal welfare in conservation. However, several glaring knowledge gaps remain where animal-welfare concerns exist but animal-welfare studies have not been performed in politically sensitive contexts. Based on contemporary issues in Australia, we identified 4 topics that require more research: animal-welfare oversight for operations designated as management (as opposed to research); animal-welfare impacts of biological agents used to control invasive animals; welfare of animals hunted recreationally; and animal-welfare impacts associated with indigenous wildlife use. Animal-welfare science may be applied to these sensitive topics through simple quantitative studies (e.g., quantifying the frequency of adverse animal-welfare events). Several such studies have effectively addressed animal-welfare concerns in similarly contentious contexts, including feral camel (Camelus dromedarius) culling in Australia, recreational hunting in Scandinavia, and indigenous whale hunting in the United States. For discussions of animal welfare in conservation to be evidence-based, courageous research is required in the 4 key areas we identified.     

A critique on neuroscientific methodologies in organizational behavior and management studies

Organizational neuroscience continues to flourish in organizational behavior and management studies as indicated by the growing number of publications. However, with a few exceptions, substantive critiques of organizational neuroscience are conspicuous by their absence. In this point–counterpoint article, we aim to redress this imbalance. We do so by asking two significant yet neglected questions: (i) how strong is the science behind this domain, and (ii) why are we doing this type of research (the so what? question)? Our analysis shows that the science behind organizational neuroscience is far less rigorous than currently advocated (due to low statistical power of some neuroimaging studies plus an inability to locate mental phenomena precisely in the brain). In terms of the so what? question, we encourage researchers to move away from general statements and become more specific about the phenomena they research. We contend that the practical implications of this research, as well as inferences of the link to behavioral changes, are currently overstated. We also underscore the importance for these studies to become contextually sensitive in order for the researchers to capture important events in the workplace. Finally, we offer some suggestions for future research. Copyright © 2014 John Wiley & Sons, Ltd.     

The influence of system complexity on bacterial transport in saturated porous media

A series of miscible-displacement column experiments were conducted under saturated flow conditions to systematically investigate the influence of physical and biological complexity on bacterial activity and fate in the presence and absence of a non-sorbing growth substrate, salicylate. Bacterial elution was monitored for three different systems; System I--a sterilized, inoculated, well-sorted sand, System II--a sterilized, inoculated, heterogeneous loamy sand (Hayhook), and System III--two different unsterilized loamy sands (Hayhook and Vinton) each with their associated indigenous microbial community. Results show that System I behaved ideally with respect to both cell and substrate transport, wherein: (1) growth occurred in response to substrate addition, (2) cell elution increased in response to the substrate pulse, and (3) breakthrough curves were reproducible for both substrate and cell elution. In contrast, System II showed ideal behavior with respect to substrate transport but showed variable behavior for cell transport. Further, there was no measurable growth in response to substrate addition and no increase in cell elution during the salicylate pulse. System III exhibited non-ideal behavior for both substrate and cell transport. Of particular interest is the fact that the indigenous communities of the two soils behaved differently. Specifically, for the Hayhook soil, an increased elution response was observed for the heterotrophic population while the salicylate-degrading community was preferentially retained in the column. In contrast for the Vinton soil, the substrate pulse did not elicit an elution response from either the heterotrophic or salicylate-degrading community from the culturable, indigenous Vinton microorganisms. For Systems II and III, the observed variability appears to be associated with the biological component of the system, since sterile controls were reproducible. This type of systematic study is critical for understanding cell and substrate transport behavior in complex, heterogeneous systems, and illustrates the potential uncertainty associated with measurements in such systems.