Climate change can benefit individual species, but when pest species are enhanced by warmer temperatures agricultural productivity may be placed at greater risk. We analyzed the effects of ...temperature anomaly on arrival date and infestation severity of potato leafhopper, Empoasca fabae Harris, a classic new world long distance migrant, and a significant pest in several agricultural crops. We compiled E. fabae arrival dates and infestation severity data at different states in USA from existing literature reviews and agricultural extension records from 1951-2012, and examined the influence of temperature anomalies at each target state or overwintering range on the date of arrival and severity of infestation. Average E. fabae arrival date at different states reveal a clear trend along the south-north axis, with earliest arrival closest to the overwintering range. E. fabae arrival has advanced by 10 days over the last 62 years. E. fabae arrived earlier in warmer years in relation to each target state level temperature anomaly (3.0 days / °C increase in temperature anomaly). Increased temperature had a significant and positive effect on the severity of infestation, and arrival date had a marginal negative effect on severity. These relationships suggest that continued warming could advance the time of E. fabae colonization and increase their impact on affected crops.
Egg cannibalism is a widely observed behaviour in nature that provides nutritional benefits without the costs of subduing prey. However, when egg cannibalism involves sibling eggs, the benefits ...obtained must balance inclusive fitness losses. Neonates of the Colorado potato beetle, Leptinotarsa decemlineata, readily consume other eggs within their natal clutch. To explore the fitness consequences of this behaviour, neonates were fed no, one, or two eggs upon hatching, along with their normal diet of potato foliage. Daily mass, the time to each moult, adult volume and mass, and fecundity were measured for each individual, along with mortality rates. Cannibals gained mass more quickly and reached each developmental stage 1 day earlier than noncannibals. No benefits at the adult stage (other than earlier emergence) were observed, and there were no sex differences in the benefits of cannibalism. Mortality was not reduced by cannibalism under laboratory conditions. A simulation demonstrated that when the mortality risk is high, decreased development time due to cannibalism can reduce this risk sufficiently to balance the inclusive fitness loss of eating a single half-sibling. Additional benefits of cannibalism, such as reduced competition, need to be investigated to fully explain cannibalism of multiple sibling eggs.
► Beetle neonates fed eggs gained mass more quickly than those fed only foliage. ► Cannibals reached each developmental stage at least 1 day faster than noncannibals. ► No sex differences were observed in the benefits of cannibalism. ► The observed development-time benefits compensate for the death of a half-sibling.
This study aimed to address the current limitations of the use of composite endpoints in orthopaedic trauma research by quantifying the relative importance of clinical outcomes common to orthopaedic ...trauma patients and use those values to develop a patient-centered composite endpoint weighting technique.
A Best-Worst Scaling choice experiment was administered to 396 adult surgically-treated fracture patients. Respondents were presented with ten choice sets, each consisting of three out of ten plausible clinical outcomes. Hierarchical Bayesian modeling was used to determine the utilities associated with the outcomes.
Death was the outcome of greatest importance (mean utility = - 8.91), followed by above knee amputation (- 7.66), below knee amputation (- 6.97), severe pain (- 5.90), deep surgical site infection (SSI) (- 5.69), bone healing complications (- 5.20), and moderate pain (- 4.59). Mild pain (- 3.30) and superficial SSI (- 3.29), on the other hand, were the outcomes of least importance to respondents.
This study revealed that patients' relative importance towards clinical outcomes followed a logical gradient, with distinct and quantifiable preferences for each possible component outcome. These findings were incorporated into a novel composite endpoint weighting technique.
Incremental (distance-dependent) costs and benefits of dispersal have received less attention than those that are qualitative. We present a dynamic programming model of settling behavior using ...parameters estimated from a field study of dispersal in desert isopods, Hemilepistus reaumuri, which walk up to thousands of meters before settling in new or already-established burrows each spring. The model shows that incremental costs of dispersal lead to right-skewed population dispersal patterns, in contrast to cost-free systems or those with unitary costs (i.e., a one time cost of leaving a group or patch). In the model, continuous variation in habitat quality, as opposed to discrete suitable vs. unsuitable sites, allows for trade-offs with dispersal costs that lead to shifts in the likelihood of settling in a patch of a given quality. Thus, measurement of quantitative costs and benefits of movement are needed to understand population dispersal distributions. These costs or benefits may be observable during or after movement, and we examined both pre- and postsettling incremental consequences of dispersal. The daily mortality rate of traveling isopods was 4.2% during the dispersal season, higher than that of settled individuals. Successful settlers traveled more slowly, but burrows started in midseason were most likely to succeed. More distant burrows failed more often, suggesting either an additional cost of movement or a difference in the quality of individuals traveling different distances. The predicted mean dispersal duration from the simulations matched observed values closely, but was based on an unrealistic assumption of perfect knowledge of habitat quality, suggesting some other factor favors longer times before settling. Reproductive success was much higher in re-used burrows than in new burrows, making them a possible incentive for long-distance movements.
Pain, the most common symptom reported among patients in the primary care setting, is complex to manage. Opioids are among the most potent analgesics agents for managing pain. Since the mid-1990s, ...the number of opioid prescriptions for the management of chronic non-cancer pain (CNCP) has increased by more than 400%, and this increased availability has significantly contributed to opioid diversion, overdose, tolerance, dependence, and addiction. Despite the questionable effectiveness of opioids in managing CNCP and their high rates of side effects, the absence of available alternative medications and their clinical limitations and slower onset of action has led to an overreliance on opioids. Conolidine is an indole alkaloid derived from the bark of the tropical flowering shrub
used in traditional Chinese, Ayurvedic, and Thai medicine. Conolidine could represent the beginning of a new era of chronic pain management. It is now being investigated for its effects on the atypical chemokine receptor (ACK3). In a rat model, it was found that a competitor molecule binding to ACKR3 resulted in inhibition of ACKR3's inhibitory activity, causing an overall increase in opiate receptor activity. Although the identification of conolidine as a potential novel analgesic agent provides an additional avenue to address the opioid crisis and manage CNCP, further studies are necessary to understand its mechanism of action and utility and efficacy in managing CNCP.
Dispersal is a fundamental but poorly understood process in ecology, evolution and conservation. Natal dispersal patterns are a major determinant of population kin structure and thus may play a key ...role in social evolution. We studied natal dispersal in the cooperatively breeding long-tailed tit Aegithalos caudatus, a non-territorial species that does not exhibit delayed dispersal. We investigated the factors associated with local recruitment and dispersal distance using 11 years of data, and generated dispersal distance distributions (DDDs) before and after correcting for sampling bias. We also examined how dispersal direction varied between and within nests, using a novel randomisation method to correct for bias. Recruitment was male-biased and increased with nestling weight, and there were significant nest and year effects. Neither sex nor weight had a significant effect on dispersal distance, but distance increased with brood size and there was a significant nest effect. The observed DDD was right-skewed but the corrected DDD was almost symmetrical, and this correction more than doubled estimates of mean dispersal distance and fledgling recruitment rate. There was no tendency across nests for birds to disperse in a particular direction, but siblings dispersed in similar directions. These results provide a detailed description of natal dispersal in long-tailed tits with minimal bias. They also demonstrate the importance of studying the different aspects of dispersal in combination, and show that direction is an important component of dispersal that is usually overlooked. The pattern of natal dispersal is consistent with the nature of helping behaviour in long-tailed tits, and may play an important role in the evolution and maintenance of cooperation despite the absence of delayed dispersal.
Reduced fitness among resistant versus susceptible individuals slows resistance evolution and makes it easier to manage. A loss of resistance costs could indicate novel adaptations or mutations ...contributing to resistance. We measured costs of resistance to imidacloprid in a Massachusetts resistant population compared with a Massachusetts susceptible population in 1999 in terms of fecundity, hatching success, egg development time, and sprint speed. Resistance was additive and seemed to be polygenic with high heritability. The fecundity cost appeared overdominant in 1999, and the hatch rate cost was partly recessive in 1999, but neither was significantly different from dominant or recessive. In 2004, we repeated our measures of resistance costs in Massachusetts in terms of fecundity and hatching success, and we added a new resistant population from Maine. In 2005, we compared development time of Maine resistant and the laboratory susceptible colony eggs. Significant fecundity costs of resistance were found in both population in both 1999 and 2004, and significant egg developmental time costs were found in 1999 and 2005. However, the hatching success costs of resistance were significant in 1999 and not apparent in 2004, suggesting some modification or replacement of the resistance genes in the intervening time.
Eastern New York State is frequently the site of Colorado potato beetle (Leptinotarsa decemlineata, Say) populations with the highest observed levels of insecticide resistance to a range of active ...ingredients. The dominance of a resistant phenotype will affect its rate of increase and the potential for management. On organic farms on Long Island, L. decemlineata evolved high levels of resistance to spinosad in a short period of time and that resistance has spread across the eastern part of the Island. Resistance has also emerged in other parts of the country as well. To clarify the level of dominance or recessiveness of spinosad resistance in different parts of the United States and how resistance differs in separate beetle populations, we sampled in 2010 beetle populations from Maine, Michigan, and Long Island. In addition, a highly resistant Long Island population was assessed in 2012. All populations were hybridized with a laboratory-susceptible strain to determine dominance. None of the populations sampled in 2010 were significantly different from additive resistance, but the Long Island population sampled in 2012 was not significantly different from fully recessive. Recessive inheritance of high-level resistance may help manage its increase.
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