Cuticular hydrocarbons correlate with fertility, not dominance, in a paper wasp, Polistes dominulus

Cuticular hydrocarbons (CHCs) are information-rich signals in social insects that coordinate behaviors within nests. However, in some taxa, the precise information conveyed by CHCs is poorly understood. In particular, there is a debate over whether CHCs convey information about their bearer's dominance or fertility. Distinguishing between dominance and fertility signaling is difficult because fertility and rank are frequently correlated within social insect colonies. This study disentangles those relationships by examining CHCs of Polistes dominulus paper wasps during the early nest-founding stage before dominance and fertility become correlated. First, we confirm that dominance and fertility are not associated in early spring foundresses. Then we show that CHCs are more strongly associated with fertility than dominance. There was no relationship between cuticular hydrocarbon profiles and a wasp’s ability to dominate rivals through aggression, suggesting that CHCs are unlikely to provide information about dominance. However, there was a significant correlation between ovarian development and the CHC profile, suggesting that CHCs could convey valuable information about their bearer's fertility. Furthermore, our data provide a potential mechanism for chemical signaling of fecundity, as there is a relationship between endogenous juvenile hormone titer (a gonadotropin), degree of ovarian development, and the CHC profile. Hormonal regulation of CHC profile expression offers a physiological mechanism to coordinate behavior, physical state, and signal expression.     

Are white-crowned sparrow badges reliable signals?

Status badges, such as crown plumage, mediate intraspecific interactions. The reliability of crown morphology as a status badge in male mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) is uncertain. We examined morphological and physiological correlates of the proportion of crown that was white (“crown-white”) in 178 male mountain white-crowned sparrows during the 2008–2009 breeding seasons. Using a paired experimental design, we presented territory-holding males with white-enhanced and white-reduced decoys and recorded aggressive behaviors. To assess physiological constraints on signal bluffing, a subsample of birds was captured and released after manipulating natural crowns to simulate bluffed white-enhanced or white-reduced crowns; corticosterone concentrations were assayed from blood drawn upon recapture and after a restraint-induced stressor. We found a significant positive association between crown-white and a measure of body size—tarsus length—which is an established indicator of resource-holding potential. In the decoy challenge, males responded more aggressively toward white-enhanced than white-reduced decoys. In the hormone experiment, white-enhanced birds had higher baseline corticosterone levels, whereas white-reduced birds had similar concentrations to controls. Furthermore, white-enhanced birds had an attenuated restraint-induced corticosterone response, while white-reduced birds mounted a significantly larger increase in corticosterone than controls. Taken together, these findings indicate that crown-white is a reliable status badge of resource-holding potential in male mountain white-crowned sparrows during the breeding season.     

SWATmodel: A Multi‐Operating System,Multi‐Platform SWAT Model Package in R

The Soil and Water Assessment Tool (SWAT) model (Arnold et al., 1998) is a popular watershed management tool. Currently, the SWAT model, actively supported by the U.S. Department of Agriculture and Texas A&M, operates only on Microsoft^® Windows, which hinders modelers that use other operating systems (OS). This technical note introduces the Comprehensive R Archive Network (CRAN) distributed “SWATmodel” package which allows SWAT 2005 and 2012 to be widely distributed and run as a linear model‐like function on multiple OS and processor platforms. This allows researchers anywhere in the world using virtually any OS to run SWAT. In addition to simplifying the use of SWAT across computational platforms, the SWATmodel package allows SWAT modelers to utilize the analytical capabilities, statistical libraries, modeling tools, and programming flexibility inherent to R. The software allows watershed modelers to develop a simple hydrological watershed model conceptualization of the SWAT model and to obtain a first approximation of the minimum expected results a more complicated model should deliver. As a proof of concept, we test the SWAT model by initializing and calibrating 314 U.S. Geological Survey stream gages in the Chesapeake Bay watershed and present the results.     

Value of information analysis: the state of application

The value of information (VoI) is a decision analytic method for quantifying the potential benefit of additional information in the face of uncertainty. This paper reviews the prevalence of VoI applications reported in the peer-reviewed literature from the years 1990–2011. We categorize papers’ applications across the types of uncertainties considered, modeling choices, and contexts of social importance (such as health care and environmental science). We obtain and analyze statistics on the range of applications and identify trends and patterns in them, and conclude with an interpretation of what these mean for researchers and practitioners as they pursue new efforts. Key results include a substantial increase over the last 20 years in published papers utilizing VoI, particularly in the medical field. Nineteen trends in VoI applications from the period of 1990–2000 to 2001–2011 were found to be at least weakly significant. Beyond simple trends, some characteristics of VoI usage depend on the area of application, and in some cases, certain sets of characteristics tend to be found together.     

Decision framework for evaluating the macroeconomic risks and policy impacts of cyber attacks

Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape.     

A meta‐analytic evaluation of diversity training outcomes

The purpose of this meta‐analysis was to use theory and research on diversity, attitudes, and training to examine potential differential effects on affective‐based, cognitive‐based, and skill‐based outcomes, to examine potential moderators of those effects with a focus on affective‐based outcomes, and finally, to provide quantitative estimates of these posited relationships. Results from 65 studies (N = 8465) revealed sizable effects on affective‐based, cognitive‐based, and skill‐based outcomes as well as interesting boundary conditions for these effects on affective‐based outcomes. This study provides practical value to human resources managers and trainers wishing to implement diversity training within organizations as well as interesting theoretical advances for researchers. Practitioners have quantitative evidence that diversity training changes affective‐based, cognitive‐based, and skill‐based trainee outcomes. This study also supports and addresses future research needs. Copyright © 2012 John Wiley & Sons, Ltd.     

Fertilizer source effect on ground and surface water quality in drainage from turfgrass

Nutrients in surface and ground water can affect human and aquatic organisms that rely on water for consumption and habitat. A mass-balance field study was conducted over two years (July 2000-May 2001) to determine the effect of nutrient source on turfgrass runoff and leachate. Treatments were arranged in an incomplete randomized block design on a slope of 7 to 9% of Arkport sandy loam (coarseloamy, mixed, active, mesic Lamellic Hapludalf) and seeded with Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.). Three natural organic (dairy and swine compost and a biosolid) and two synthetic organic nutrient sources (readily available urea and controlled-release N source sulfur-coated urea) were applied at rates of 50 and 100 kg N ha(-1) per application (200 kg ha(-1) yr(-1)). Runoff water collected from 33 storms and composite monthly leachate samples collected with ion exchange resins were analyzed for nitrate (NO3- -N), phosphate (PO4(3-) -P), and ammonium (NH4+ -N). Nutrient concentrations and losses in both runoff and leachate were highest for the 20-wk period following turfgrass seeding. The NO3- -N and NH4+ -N losses declined significantly once turfgrass cover was established, but PO4(3-) -P levels increased in Year 2. Turf's ability to reduce nutrient runoff and leachate was related to overall plant growth and shoot density. The use of natural organics resulted in greater P loss on a percent applied P basis, while the more soluble synthetic organics resulted in greater N loss.     

First-trimester biochemical and molecular diagnoses using chorionic villi: High accuracy in the U.S. collaborative study

The accuracy of biochemical and molecular prenatal diagnoses using chorionic villi as the fetal source was assessed by seven centres participating in the NICHD collaborative study on the safety and accuracy of chorionic villus sampling (CVS) and amniocentesis. Of 601 pregnancies studied, biochemical methods were used to determine the diagnosis in 283 fetuses at risk for 35 different metabolic disorders. Fifteen different lysosomal storage diseases accounted for 81 per cent of the biochemical prenatal diagnoses performed, with 57 per cent of these pregnancies at risk for Tay-Sachs disease. No errors were made in the biochemical diagnoses that predicted affected or unaffected fetuses. However, the diagnoses of certain disorders (e.g., mucopolysacchariodosis type IH, metachromatic leukodystrophy, and Krabbe disease) occasionally required confirmatory studies in cultured amniocytes because the enzyme results were inconclusive in direct and/or cultured villi or due to the presence of a pseudodeficiency allele. Of these, only the diagnosis of a fetus at risk for Krabbe disease remained inconclusive after special studies to discriminate between mutant and pseudodeficiency alleles. Recombinant DNA techniques were used to predict the diagnosis of 318 fetuses at risk for 16 different disorders in which the defective disease gene could be detected either directly or by linkage analysis to a nearby polymorphic marker. Of these, 32 per cent were for haemoglobinopathies, 25 per cent for cystic fibrosis, 24 per cent for Duchenne or Becker muscular dystrophy, and 7 per cent for haemophilias. Pregnancies at risk for known disorders with specific molecular lesions (e.g., sickle cell disease) were accurately diagnosed in direct and/or cultured villi. Diagnoses requiring analyses with closely linked polymorphic markers were occasionally uninformative or inconclusive. Maternal contamination was not reported in any biochemical or molecular-based diagnosis. These studies document the high accuracy and rapidity of both biochemical and mutation-specific prenatal diagnoses with direct and cultured chorionic villi.