15 research outputs found

    A proposed framework for the development and qualitative evaluation of West Nile virus models and their application to local public health decision-making

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    West Nile virus(WNV) is a globally distributed mosquito-borne virus of great public health concern. The number of WNV human cases and mosquito infection patterns vary in space and time. Many statistical models have been developed to understand and predict WNV geographic and temporal dynamics. However, these modeling efforts have been disjointed with little model comparison and inconsistent validation. In this paper, we describe a framework to unify and standardize WNV modeling efforts nationwide. WNV risk, detection, or warning models for this review were solicited from active research groups working in different regions of the United States. A total of 13 models were selected and described. The spatial and temporal scales of each model were compared to guide the timing and the locations for mosquito and virus surveillance, to support mosquito vector control decisions, and to assist in conducting public health outreach campaigns at multiple scales of decision-making. Our overarching goal is to bridge the existing gap between model development, which is usually conducted as an academic exercise, and practical model applications, which occur at state, tribal, local, or territorial public health and mosquito control agency levels. The proposed model assessment and comparison framework helps clarify the value of individual models for decision-making and identifies the appropriate temporal and spatial scope of each model. This qualitative evaluation clearly identifies gaps in linking models to applied decisions and sets the stage for a quantitative comparison of models. Specifically, whereas many coarse-grained models (county resolution or greater) have been developed, the greatest need is for fine-grained, short-term planning models (m–km, days–weeks) that remain scarce. We further recommend quantifying the value of information for each decision to identify decisions that would benefit most from model input

    Effects of winter temperatures, spring degree-day accumulation, and insect population source on phenological synchrony between forest tent caterpillar and host trees. Forest Ecology and Management

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    Global climate change has the potential to dramatically alter multiple ecosystem processes, including herbivory. The development rates of both plants and insects are highly sensitive to temperature. Although considerable work has examined the effects of temperature on spring phenologies of plants and insects individually, few studies have examined how anticipated warming will influence their phenological synchrony. We applied elevated temperatures of 1.7 and 3.4 °C in a controlled chamberless outdoor experiment in northeastern Minnesota, USA to examine the relative responses in onset of egg eclosion by forest tent caterpillar (Malacosoma disstria Hübner) and budbreak of two of its major host trees (trembling aspen, Populus tremuloides Michaux, and paper birch, Betula papyrifera Marshall). We superimposed four insect population sources and two overwintering regimes onto these treatments, and computed degree-day models. Timing of egg hatch varied among population source, overwintering location, and spring temperature regime. As expected, the development rates of plants and insects advanced under warmer conditions relative to ambient controls. However, budbreak advanced more than egg hatch. The degree of phenological synchrony between M. disstria and each host plant was differentially altered in response to warming. The interval by which birch budbreak preceded egg hatch nearly doubled from ambient to +1.7 °C. In the case of aspen, the sequence changed from egg hatch preceding, to following, budbreak at +3.4 °C. Additionally, under temperature regimes simulating future conditions, some insect populations currently south of our study sites became more synchronous with the manipulated hosts than did currently coexisting insect populations. These findings reveal how climate warming can alter insect-host plant interactions, through changes in phenological synchrony, possibly driving host shifts among tree species and genotypes. They also suggest how herbivore variability, both among populations and within individual egg masses, may provide opportunities for adaptation, especially in species that are highly mobile and polyphagous

    Effects of winter temperatures, spring degree-day accumulation, and insect population source on phenological synchrony between forest tent caterpillar and host trees

    No full text
    Global climate change has the potential to dramatically alter multiple ecosystem processes, including herbivory. The development rates of both plants and insects are highly sensitive to temperature. Although considerable work has examined the effects of temperature on spring phenologies of plants and insects individually, few studies have examined how anticipated warming will influence their phenological synchrony. We applied elevated temperatures of 1.7 and 3.4. C in a controlled chamberless outdoor experiment in northeastern Minnesota, USA to examine the relative responses in onset of egg eclosion by forest tent caterpillar (. Malacosoma disstria Hubner) and budbreak of two of its major host trees (trembling aspen, Populus tremuloides Michaux, and paper birch, Betula papyrifera Marshall). We superimposed four insect population sources and two overwintering regimes onto these treatments, and computed degree-day models. Timing of egg hatch varied among population source, overwintering location, and spring temperature regime. As expected, the development rates of plants and insects advanced under warmer conditions relative to ambient controls. However, budbreak advanced more than egg hatch. The degree of phenological synchrony between M. disstria and each host plant was differentially altered in response to warming. The interval by which birch budbreak preceded egg hatch nearly doubled from ambient to +1.7 C. In the case of aspen, the sequence changed from egg hatch preceding, to following, budbreak at +3.4 C. Additionally, under temperature regimes simulating future conditions, some insect populations currently south of our study sites became more synchronous with the manipulated hosts than did currently coexisting insect populations. These findings reveal how climate warming can alter insect-host plant interactions, through changes in phenological synchrony, possibly driving host shifts among tree species and genotypes. They also suggest how herbivore variability, both among populations and within individual egg masses, may provide opportunities for adaptation, especially in species that are highly mobile and polyphagous

    Police Use of Less Lethal Force: Does Administrative Policy Matter?

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    Scholars have long theorized that constraining police officer discretion via organizational policy improves decision-making. Empirically, prior research shows that more restrictive lethal force policies result in a reduction in the number of police shootings and in racial disparity. Yet, researchers have never examined the impact of less lethal force policies in relation to the full spectrum of less lethal force tactics. In addressing this research void, we examine 3,340 use of force incidents from three US agencies, each varying in terms of policy direction and restrictiveness. The results consistently show that officers working within the most restrictive policy framework used force less readily than officers who operated within more permissive policy environments. Hence, police administrators wishing to reduce coercion should consider the potential effect that a more restrictive policy may have on such behavior
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