Modeling and inference of animal movement using artificial neural networks

Movement of animals in relation to objects in their environment is important in many areas of ecology and wildlife conservation. Tools for analysis of movement data, however, still remain rather limited. In previous work, we developed nonlinear regression models for movement in relation to a single landscape feature. Here we greatly expand these previous models by using artificial neural networks. The new models add substantial flexibility and capabilities, including the ability to incorporate multiple factors and covariates. We devise a likelihood-based model fitting procedure that utilizes genetic algorithms and demonstrate the approach with movement data for red diamond rattlesnakes. The proposed methodology can be useful for global positioning system tracking data that are becoming more common in studies of animal movement behavior.     

Cyber first aid: proactive risk management and decision-making

Public and private organizations need a robust approach to prepare, respond, and recover from cyber-attacks. This perspective article will refer to such an approach as Cyber First AID—adaptable, integrated, and deliberate. Adaptable describes that one size does not fit all; Integrated means the effort is throughout the organization; and Deliberate describes plans that are reviewed periodically and practiced, in which all members of the organization know their respective roles and responsibilities. The article outlines a decision-making process for how to minimize the impacts of cyber threats, maintain stakeholder and customer confidence, and help organizations to adaptively manage and respond to cyber threats in rapidly changing cyber environments.     

The influence of age on the morbidity and mortality of pedestrian victims

OBJECTIVES: The present study examined the influence of age on the morbidity and mortality of pedestrian victims while controlling for confounding factors. METHODS: The Pedestrian Crash Data Study (PCDS) database was used for a cross-sectional study to compare the outcome of senior (age >or=60 years) and adult (age 19 to 50 years) pedestrian victims. The outcome measures were the Injury Severity Score (ISS), Maximum Abbreviated Injury Score (MAIS), Abbreviated Injury Scale (AIS), and Mortality. Logistic regression models were used to estimate age-associated risks while controlling for confounders such as vehicle type, impact speed, and pedestrian height, weight, and gender. RESULTS: Compared to the adult victims, the seniors had a higher average ISS (23 vs. 16, p = 0.018) and higher mortality (30 percent vs. 11 percent, p or=9 (odds ratio = 2.72; 95 percent CI: 1.31-5.68) and to die (odds ratio = 6.68; 95 percent CI: 2.37-19.88). The seniors were approximately twice as likely to have higher AIS scores to almost every body region. CONCLUSIONS: The adjusted age-dependent risks indicated by the current study should be considered when calculating or projecting pedestrian morbidity and mortality. Adjustment in statistical models is essential to achieve precise risk estimates and in turn to appropriately allocate public health rescores.     

Soil uptake of carbon monoxide emitted in the exhaust of a gasoline-powered engine

Carbon monoxide (CO) poses dangers to both human and environmental health, sickening thousands of people annually in the United States and decreasing the capacity of the atmosphere to oxidize greenhouse gases. Globally, soil ecosystems with their populations of bacteria, fungi, and algae are estimated to remove 9-36% of total CO emissions, which makes them the second largest CO sink after hydroxyl oxidation. Our aim was determine whether soil ecosystems could remove CO from an atmosphere mixed with gasoline-powered engine exhaust. Sealed microcosms containing no soil (NoSoil), nonvegetated soil (Soil), or vegetated soil (Soil+Veg), were exposed to 800, 100, and 50 ppm of CO for 1 hr. The uptake rate of CO was found to be higher at the 800 ppm level suggesting first-order rate kinetics. Soil+Veg exhibited a significantly higher CO uptake rate than either Soil or NoSoil (P<0.05), and Soil exhibited significantly higher uptake than NoSoil (P<0.05). As a free ecosystem service, the uptake of CO by soil ecosystems needs to be properly valued and ecologically engineered into the urban traffic network in a manner analogous to how wetlands, vegetated swales, and other ecologically based storm water treatment systems have improved urban runoff.     

Combined effect of iron and zinc on micronutrient levels in wheat (Triticum aestivum L.)

A nutrient solution experiment was conducted to investigate the effect of Fe and Zn supply on Fe, Zn, Cu, and Mn concentrations in wheat plants. The experiment used a factorial combination of two Fe levels (0 and 5 mg l(-1)) and three Zn levels (0, 0.1 and 10 mg I(-1)). The supply of Fe (5 mg l(-1)) and Zn (0.1 mg l(-1)) increased plant dry weight and leaf chlorophyll content compared to the Fe or Zn deficient (0 mg 11) treatments. However, excess Zn supply (10 mg l(-1)) reduced plant dry weights and leaf chlorophyll content. Iron supply (5 mg l(-1)) reduced wheat Zn concentrations by 49%, Cu concentrations by 34%, and Mn by 56% respectively. Zinc supply (10 mg l(-1)) reduced wheat Fe concentrations by an average of 8%, but had no significant effect on Cu and Mn concentrations. Stepwise regression analyses indicated that Zn, Cu, and Mn concentrations were negatively correlated with root- and leaf-Fe concentrations, but positively correlated with stem-Fe concentrations. Leaf-Mn concentrations were negatively correlated with root-, stem- and leaf-Zn concentrations.     

Effects of chytrid fungus and a glyphosate-based herbicide on survival and growth of wood frogs (Lithobates sylvaticus)

Anthropogenic-derived stressors in the environment, such as contaminants, are increasingly considered important cofactors that may decrease the immune response of amphibians to pathogens. Few studies, however, have integrated amphibian disease and contaminants to test this multiple-stressor hypothesis for amphibian declines. We examined whether exposure to sublethal concentrations of a glyphosate-based herbicide and two strains of the pathogenic chytrid fungus, Batrachochrytrium dendrobatidis (Bd) could: (1) sublethally affect wood frogs (Lithobates sylvaticus) by altering the time to and size at metamorphosis, and (2) directly affect survivability of wood frogs after metamorphosis. Neither Bd strain nor herbicide exposure alone significantly altered growth or time to metamorphosis. The two Bd strains did not differ in their pathogenicity, and both caused mortality in post-metamorphic wood frogs. There was no evidence of an interaction between treatments, indicating a lack of herbicide-induced susceptibility to Bd. However, the trends in our data suggest that exposure of wood frogs to a high concentration of glyphosate-based herbicide may reduce Bd-caused mortality compared to animals exposed to Bd alone. These results exemplify the complexities inherent when populations are coping with multiple stressors. In this case, the perceived stressor, glyphosate-based herbicide, appeared to affect the pathogen more than the host's immune system, relieving the host from disease-caused effects. This suggests caution when invoking multiple stressors as a cause for increased disease susceptibility and indicates that the effects of multiple stressors on disease outcome depend on the interrelationships of stressors to both the pathogen and the host.