335 research outputs found
The Discovery of Trissolcus japonicus (Hymenoptera: Scelionidae) in Michigan
The invasive brown marmorated stink bug, Halyomorpha halys (Stål), is a pest of growing economic importance in the United States, the control of which currently relies on pesticide applications. Biological control could provide sustainable and long-term control but classical biological control agents have not yet been approved. Adventive populations of a potential biological control agents, the Samurai wasp, Trissolcus japonicus (Ashmead), have been found in the United States, first in Maryland in 2014, expanding its range west to Ohio by 2017. Trissolcus japonicus is a highly effective parasitoid of H. halys eggs, but its redistribution and augmentative releases are restricted to states where it has been detected in the wild. To assess the presence of T. japonicus in Michigan and attack rates of H. halys by native natural enemies we deployed 189 H. halys egg masses at ten sites in lower Michigan between May and October in 2018. In addition, we deployed 51 native stink bug egg masses at the same sites to evaluate potential non-target effects of T. japonicus in the field, which were shown to occur in laboratory studies. We found T. japonicus in a single H. halys egg mass, which constitutes the first record of this Asian parasitoid in Michigan. Native predators and parasitoids caused minimal mortality of H. halys eggs and we did not find evidence of non-target effects of T. japonicus on native stink bug species. These findings open the door to initiation of a classical biological control program using an efficient, coevolved parasitoid from the native range of H. halys
Impact of palliative care consultations for patients admitted to Maine Medical Center with acute exacerbations of COPD
Background and purpose:
• COPD is the 3rd leading cause of death.
• Specialty Palliative Care (PC) is underutilized in COPD patients.
•PC involvement has been shown to improve quality of life and satisfaction with overall care.
• We sought to evaluate the association of receipt of palliative medicine consultation during an admission for acute exacerbation of COPD with a documented Goals of Care conversations and/or presence of an advanced directive and/or POLST
Parental care masks a density-dependent shift from cooperation to competition among burying beetle larvae.
Studies of siblings have focused mainly on their competitive interactions and to a lesser extent on their cooperation. However, competition and cooperation are at opposite ends on a continuum of possible interactions and the nature of these interactions may be flexible with ecological factors tipping the balance toward competition in some environments and cooperation in others. Here we show that the presence of parental care and the density of larvae on the breeding carcass change the outcome of sibling interactions in burying beetle broods. With full parental care there was a strong negative relationship between larval density and larval mass, consistent with sibling competition for resources. In the absence of care, initial increases in larval density had beneficial effects on larval mass but further increases in larval density reduced larval mass. This likely reflects a density-dependent shift between cooperation and competition. In a second experiment, we manipulated larval density and removed parental care. We found that the ability of larvae to penetrate the breeding carcass increased with larval density and that feeding within the carcass resulted in heavier larvae than feeding outside the carcass. However, larval density did not influence carcass decay.The authors were supported by a Consolidator’s Grant from the European Research Council (310785 Baldwinian Beetles). Research was funded by the Natural Environment Research Council, UK (NE/H019731/1), the European Research Council, and the Department of Zoology at the University of Cambridge.This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/evo.12615/abstract
Using Experimental Evolution to Study Adaptations for Life within the Family.
Parents of many species provision their young, and the extent of parental provisioning constitutes a major component of the offspring's social environment. Thus, a change in parental provisioning can alter selection on offspring, resulting in the coevolution of parental and offspring traits. Although this reasoning is central to our evolutionary understanding of family life, there is little direct evidence that selection by parents causes evolutionary change in their offspring. Here we use experimental evolution to examine how populations of burying beetles adapt to a change in posthatching parental provisioning. We measured the performance of larvae descended from lab populations that had been maintained with and without posthatching parental care (Full Care and No Care populations). We found that adaptation to the absence of posthatching care led to rapid and consistent changes in larval survival in the absence of care. Specifically, larvae from No Care populations had higher survival in the absence of care than larvae from Full Care populations. Other measures of larval performance, such as the ability of larvae to consume a breeding carcass and larval mass at dispersal, did not differ between the Full Care and No Care populations. Nevertheless, our results show that populations can adapt rapidly to a change in the extent of parental care and that experimental evolution can be used to study such adaptation.The authors were supported by a Consolidator’s Grant from the European Research Council (310785 Baldwinian Beetles). Research was funded by the Natural Environment Research Council UK (NE/H019731/1), the European Research Council, and the Department of Zoology at the University of Cambridge.This is the author accepted manuscript. The final version is available from the University of Chicago Press via http://dx.doi.org/10.1086/68050
Comparison of Clinical Outcomes, Resource Utilization, and Injury Patterns between Hospitalized Obese and Non-Obese Pediatric Patients with Traumatic Injuries
Background: Children within the US are experiencing very high rates of obesity. Currently almost 31.9% of children have BMI’s that exceed the 85th percentile and 16.3% of children are greater than the 95th percentile in BMI’s. There have been several studies which indicate that obese children receive differences in care both surgically and medically from their non-obese counterparts. Other literature suggests that obese adults require more resources and have worse outcomes after traumatic injuries than non-obese adults. Most studies fail to look at the differences that occur in children who have been admitted to a hospital due to a traumatic injury. Objectives: The goal of the study was to conduct a retrospective chart review/analysis of admitted pediatric trauma patients to St. Christopher’s Hospital for Children looking for variations in complications, resources, and injury patterns that may exist between obese and non-obese patients.Methods: Records for all admitted trauma patients between January 1st 2003 and December 31st 2008 were obtained and analyzed for eligibility in the study. A total of 175 records were included in the study. Specific data regarding the patients were then input into Excel and SPSS for statistical analysis. Patients were placed into one of four separate BMI percentile categories. The data was then cross analyzed using SPSS to explore for variations among groups.Results: For all of the variables that were analyzed among BMI percentiles there were no statistical differences. All p-values were greater than 0.05. There were no differences with respects to outcomes, lengths of stay, resources such as labs and radiological exams, or injury patterns after statistical analysis among study groups. Marginal significance was observed in patient complications (p=0.07).Conclusions: The statistics in this study suggest no difference among the groups, however due to the small sample size and the wide variation in injury severity score (ISS) as well as injury type it is not possible to conclude indefinitely on the status of the aforementioned problem. The potentiality for there to be differences exists pending on the completion of a larger study with more patients and a narrower bracket of injury severity scores.M.P.H., Public Health -- Drexel University, 201
Retention of low-fitness genotypes over six decades of admixture between native and introduced tiger salamanders
<p>Abstract</p> <p>Background</p> <p>Introductions of non-native tiger salamanders into the range of California tiger salamanders have provided a rare opportunity to study the early stages of secondary contact and hybridization. We produced first- and second-generation hybrid salamanders in the lab and measured viability among these early-generation hybrid crosses to determine the strength of the initial barrier to gene exchange. We also created contemporary-generation hybrids in the lab and evaluated the extent to which selection has affected fitness over approximately 20 generations of admixture. Additionally, we examined the inheritance of quantitative phenotypic variation to better understand how evolution has progressed since secondary contact.</p> <p>Results</p> <p>We found significant variation in the fitness of hybrids, with non-native backcrosses experiencing the highest survival and F2 hybrids the lowest. Contemporary-generation hybrids had similar survival to that of F2 families, contrary to our expectation that 20 generations of selection in the wild would eliminate unfit genotypes and increase survival. Hybrid survival clearly exhibited effects of epistasis, whereas size and growth showed mostly additive genetic variance, and time to metamorphosis showed substantial dominance.</p> <p>Conclusions</p> <p>Based on first- and second- generation cross types, our results suggest that the initial barrier to gene flow between these two species was relatively weak, and subsequent evolution has been generally slow. The persistence of low-viability recombinant hybrid genotypes in some contemporary populations illustrates that while hybridization can provide a potent source of genetic variation upon which natural selection can act, the sorting of fit from unfit gene combinations might be inefficient in highly admixed populations. Spatio-temporal fluctuation in selection or complex genetics has perhaps stalled adaptive evolution in this system despite selection for admixed genotypes within generations.</p
Recommended from our members
The role of parents in Evolution
In this thesis, I investigated the role of parental care in evolution. Parents provide the environment in which offspring develop and therefore have a large influence on their offspring's phenotypes, and so are in prime position to influence evolutionary processes. I used an experimental approach, and focused on the burying beetle, . The burying beetle is a perfect system for this question: they exhibit elaborate biparental care which is correlated with rapid speciation in the genus.
I started with a thorough exploration of burying beetle ecology and how the guild structure and interspecific competition in local populations can shape phenotypic evolution of my focal species, . Interspecific competition shapes how the carrion niche is partitioned, which feeds back onto the evolution of body size within reducing competition. The evolution of parental care in this genus likely facilitated its adaptive radiation, as parental care is linked with body size, both within and across species.
But to what extent does the ecology shape the production and maintenance of phenotypic and genetic variation? I then use a quantitative genetic approach to show that body size and development time of shows no additive genetic variation. Evolution of these fitness related traits can only occur through maternal effects or sibling effects.
I tested this prediction by mimicking the radiation of the burying beetles by imposing my own selection on body size when parents could care for their offspring and when they could not. The presence of post-hatching parental care dramatically changed how populations responded to selection, through a combination of cooperation between parents and offspring, and cooperation between offspring.
As well as shaping the evolutionary potential of populations, an experimental change in parental care can induce new selective forces, favouring adaptive novelties for the new social environment. Larvae evolving without parental care evolved disproportionately larger mandibles when small to better adapt them to a life without care.
Much is known about the evolution of parental care across the animal kingdom, but what happens next: are the burying beetles a "one-off"? I compiled data across the arthropods comparing clades that exhibit post-hatching parental care with their sister clades and show that clades with care are more species rich. While the mechanism may not be the same as with , I discussed other potential mechanisms that may be at play in the role of parents in evolution.I was funded by the European Research Council (310785_Baldwinian_Beetles to Prof. Rebecca M. Kilner)
Recommended from our members
An evolutionary switch from sibling rivalry to sibling cooperation, caused by a sustained loss of parental care.
Sibling rivalry is commonplace within animal families, yet offspring can also work together to promote each other's fitness. Here we show that the extent of parental care can determine whether siblings evolve to compete or to cooperate. Our experiments focus on the burying beetle Nicrophorus vespilloides, which naturally provides variable levels of care to its larvae. We evolved replicate populations of burying beetles under two different regimes of parental care: Some populations were allowed to supply posthatching care to their young (Full Care), while others were not (No Care). After 22 generations of experimental evolution, we found that No Care larvae had evolved to be more cooperative, whereas Full Care larvae were more competitive. Greater levels of cooperation among larvae compensated for the fitness costs caused by parental absence, whereas parental care fully compensated for the fitness costs of sibling rivalry. We dissected the evolutionary mechanisms underlying these responses by measuring indirect genetic effects (IGEs) that occur when different sibling social environments induce the expression of more cooperative (or more competitive) behavior in focal larvae. We found that indirect genetic effects create a tipping point in the evolution of larval social behavior. Once the majority of offspring in a brood start to express cooperative (or competitive) behavior, they induce greater levels of cooperation (or competition) in their siblings. The resulting positive feedback loops rapidly lock larvae into evolving greater levels of cooperation in the absence of parental care and greater levels of rivalry when parents provide care
The Discovery of Trissolcus japonicus (Hymenoptera: Scelionidae) in Michigan
The invasive brown marmorated stink bug, Halyomorpha halys (Stål), is a pest of growing economic importance in the United States, the control of which currently relies on pesticide applications. Biological control could provide sustainable and long-term control but classical biological control agents have not yet been approved. Adventive populations of a potential biological control agents, the Samurai wasp, Trissolcus japonicus (Ashmead), have been found in the United States, first in Maryland in 2014, expanding its range west to Ohio by 2017. Trissolcus japonicus is a highly effective parasitoid of H. halys eggs, but its redistribution and augmentative releases are restricted to states where it has been detected in the wild. To assess the presence of T. japonicus in Michigan and attack rates of H. halys by native natural enemies we deployed 189 H. halys egg masses at ten sites in lower Michigan between May and October in 2018. In addition, we deployed 51 native stink bug egg masses at the same sites to evaluate potential non-target effects of T. japonicus in the field, which were shown to occur in laboratory studies. We found T. japonicus in a single H. halys egg mass, which constitutes the first record of this Asian parasitoid in Michigan. Native predators and parasitoids caused minimal mortality of H. halys eggs and we did not find evidence of non-target effects of T. japonicus on native stink bug species. These findings open the door to initiation of a classical biological control program using an efficient, coevolved parasitoid from the native range of H. halys
Larval environmental conditions influence plasticity in resource use by adults in the burying beetle, Nicrophorus vespilloides.
Recent studies have shown that intraspecific patterns of phenotypic plasticity can mirror patterns of evolutionary diversification among species. This appears to be the case in Nicrophorus beetles. Within species, body size is positively correlated with the size of carrion used to provision larvae and parental performance. Likewise, among species, variation in body size influences whether species exploit smaller or larger carrion and the extent to which larvae depend on parental care. However, it is unclear whether developmental plasticity in response to carcass size, parental care, or both underlie transitions to new carcass niches. We examined this by testing whether variation in the conditions experienced by Nicrophorus vespilloides larvae influenced their ability to breed efficiently upon differently sized carcasses as adults. We found that the conditions experienced by larvae during development played a critical role in determining their ability to use large carcasses effectively as adults. Specifically, individuals that developed with parental care and on large carcasses were best able to convert the resources on a large carcass into offspring when breeding themselves. Our results suggest that parentally induced plasticity can be important in the initial stages of niche expansion
- …