Cortex necessary for pain — but not in sense that matters

Certain cortical regions are necessary for pain in humans in the sense that, at particular times, they play a direct role in pain. However, it is not true that they are necessary in the more important sense that pain is never possible in humans without them. There are additional details from human lesion studies concerning functional plasticity that undermine Key’s (2016) interpretation. Moreover, no one has yet identified any specific behaviors that mammalian cortical pain regions make possible that are absent in fish

Differential introgression and the maintenance of species boundaries in an advanced generation avian hybrid zone

Background: Evolutionary processes, including selection and differential fitness, shape the introgression of genetic material across a hybrid zone, resulting in the exchange of some genes but not others. Differential introgression of molecular or phenotypic markers can thus provide insight into factors contributing to reproductive isolation. We characterized patterns of genetic variation across a hybrid zone between two tidal marsh birds, Saltmarsh (Ammodramus caudacutus) and Nelson’s (A. nelsoni) sparrows (n = 286), and compared patterns of introgression among multiple genetic markers and phenotypic traits. Results: Geographic and genomic cline analyses revealed variable patterns of introgression among marker types. Most markers exhibited gradual clines and indicated that introgression exceeds the spatial extent of the previously documented hybrid zone. We found steeper clines, indicating strong selection for loci associated with traits related to tidal marsh adaptations, including for a marker linked to a gene region associated with metabolic functions, including an osmotic regulatory pathway, as well as for a marker related to melanin-based pigmentation, supporting an adaptive role of darker plumage (salt marsh melanism) in tidal marshes. Narrow clines at mitochondrial and sex-linked markers also offer support for Haldane’s rule. We detected patterns of asymmetrical introgression toward A. caudacutus, which may be driven by differences in mating strategy or differences in population density between the two species. Conclusions: Our findings offer insight into the dynamics of a hybrid zone traversing a unique environmental gradient and provide evidence for a role of ecological divergence in the maintenance of pure species boundaries despite ongoing gene flow

Differential introgression and the maintenance of species boundaries in an advanced generation avian hybrid zone

Background: Evolutionary processes, including selection and differential fitness, shape the introgression of genetic material across a hybrid zone, resulting in the exchange of some genes but not others. Differential introgression of molecular or phenotypic markers can thus provide insight into factors contributing to reproductive isolation. We characterized patterns of genetic variation across a hybrid zone between two tidal marsh birds, Saltmarsh (Ammodramus caudacutus) and Nelson’s (A. nelsoni) sparrows (n = 286), and compared patterns of introgression among multiple genetic markers and phenotypic traits. Results: Geographic and genomic cline analyses revealed variable patterns of introgression among marker types. Most markers exhibited gradual clines and indicated that introgression exceeds the spatial extent of the previously documented hybrid zone. We found steeper clines, indicating strong selection for loci associated with traits related to tidal marsh adaptations, including for a marker linked to a gene region associated with metabolic functions, including an osmotic regulatory pathway, as well as for a marker related to melanin-based pigmentation, supporting an adaptive role of darker plumage (salt marsh melanism) in tidal marshes. Narrow clines at mitochondrial and sex-linked markers also offer support for Haldane’s rule. We detected patterns of asymmetrical introgression toward A. caudacutus, which may be driven by differences in mating strategy or differences in population density between the two species. Conclusions: Our findings offer insight into the dynamics of a hybrid zone traversing a unique environmental gradient and provide evidence for a role of ecological divergence in the maintenance of pure species boundaries despite ongoing gene flow

Designing Primary Prevention for People Living with HIV

Today, there are new reasons for a sharper focus on prevention for people living with HIV. Growing numbers of people with the disease are living more healthy, sexual lives. Recent evidence suggests that risk taking among both HIV-positive and negative people is increasing. After nearly two decades of life in the shadow of AIDS, communities are growing weary of traditional prevention messages and many people are openly grappling with difficult questions of intimacy and sex. Increasingly, people living with HIV also face multiple complex economic and substance abuse challenges that complicate prevention efforts.There is an urgent need -- and sufficient expertise -- to move forward with prevention campaigns focused on helping people living with HIV and AIDS avoid passing their infection along to others. Numerous innovative interventions for people with HIV show promise, including:a social marketing campaign for gay men and a five-session group intervention for women living with HIV in Massachusetts,a chat line for positives and a group session program for Latinas/Latinos in Los Angeles,Internet chat room interventions in Atlanta,a group session for gay Asian American-Pacific Islander Americans living with HIV in San Francisco, andPrevention Case Management programs newly funded by the Centers for Disease Control

Genotype-environment associations support a mosaic hybrid zone between two tidal marsh birds

Local environmental features can shape hybrid zone dynamics when hybrids are bounded by ecotones or when patchily distributed habitat types lead to a corresponding mosaic of genotypes. We investigated the role of marsh-level characteristics in shaping a hybrid zone between two recently diverged avian taxa – Saltmarsh (Ammodramus caudacutus) and Nelson\u27s (A. nelsoni) sparrows. These species occupy different niches where allopatric, with caudacutus restricted to coastal marshes and nelsoni found in a broader array of wetland and grassland habitats and co-occur in tidal marshes in sympatry. We determined the influence of habitat types on the distribution of pure and hybrid sparrows and assessed the degree of overlap in the ecological niche of each taxon. To do this, we sampled and genotyped 305 sparrows from 34 marshes across the hybrid zone and from adjacent regions. We used linear regression to test for associations between marsh characteristics and the distribution of pure and admixed sparrows. We found a positive correlation between genotype and environmental variables with a patchy distribution of genotypes and habitats across the hybrid zone. Ecological niche models suggest that the hybrid niche was more similar to that of A. nelsoni and habitat suitability was influenced strongly by distance from coastline. Our results support a mosaic model of hybrid zone maintenance, suggesting a role for local environmental features in shaping the distribution and frequency of pure species and hybrids across space

Genotype-environment associations support a mosaic hybrid zone between two tidal marsh birds

Local environmental features can shape hybrid zone dynamics when hybrids are bounded by ecotones or when patchily distributed habitat types lead to a corresponding mosaic of genotypes. We investigated the role of marsh-level characteristics in shaping a hybrid zone between two recently diverged avian taxa – Saltmarsh (Ammodramus caudacutus) and Nelson\u27s (A. nelsoni) sparrows. These species occupy different niches where allopatric, with caudacutus restricted to coastal marshes and nelsoni found in a broader array of wetland and grassland habitats and co-occur in tidal marshes in sympatry. We determined the influence of habitat types on the distribution of pure and hybrid sparrows and assessed the degree of overlap in the ecological niche of each taxon. To do this, we sampled and genotyped 305 sparrows from 34 marshes across the hybrid zone and from adjacent regions. We used linear regression to test for associations between marsh characteristics and the distribution of pure and admixed sparrows. We found a positive correlation between genotype and environmental variables with a patchy distribution of genotypes and habitats across the hybrid zone. Ecological niche models suggest that the hybrid niche was more similar to that of A. nelsoni and habitat suitability was influenced strongly by distance from coastline. Our results support a mosaic model of hybrid zone maintenance, suggesting a role for local environmental features in shaping the distribution and frequency of pure species and hybrids across space

Relationship of phenotypic variation and genetic admixture in the Saltmarsh–Nelson\u27s sparrow hybrid zone

Hybridization is influential in shaping species\u27 dynamics and has many evolutionary and conservation implications. Identification of hybrid individuals typically relies on morphological data, but the assumption that hybrids express intermediate traits is not always valid, because of complex patterns of introgression and selection. We characterized phenotypic and genotypic variation across a hybrid zone between 2 tidal-marsh birds, the Saltmarsh Sparrow (Ammodramus caudacutus) and Nelson\u27s Sparrow (A. nelsoni) (n = 290), and we sought to identify morphological traits that could be used to classify admixed individuals. Sparrows were sampled from a total of 34 marshes, including 23 sympatric and 11 putatively allopatric marshes. Each individual was scored at 13 plumage traits, and standard morphometric data were collected. We used genotyping analysis at 24 microsatellite loci to categorize individuals into genotypic classes of pure, F1–F2, or backcrossed. Genetic data revealed that 52% of individuals sampled along the geographic transect were of mixed ancestry, and the majority of these were backcrossed. Traits related to the definition of plumage features (streaking, crown, and face) showed less overlap between genotypic classes than traits related to the amount or color of plumage features. Although morphological data performed well in distinguishing between the 2 taxa, pure and backcrossed individuals of each parental type could not be distinguished because of substantial overlap in plumage and morphology. We conclude that the discrimination of pure and hybrid individuals is not possible in the absence of genetic data. Our results have implications for conservation of pure populations, as extensive backcrossing throughout the hybrid zone may present challenges for monitoring pure species identified by morphology alone

Broadening the Focus

Over the past dozen or so years neuroethics has become a rich and dynamic field that has brought together individuals from a variety of disciplines and interests to consider issues that lie at the intersection of ethics and neuroscience. During this period there has been a significant amount of important empirical and philosophical work on a range of topics at this intersection; however, there has been comparatively little work on this intersection as it applies to nonhuman animals. In fact, it is fair to say that neuroethics has had a distinct and almost exclusive “humanistic focus.” Our hope with this special section is to broaden this focus and to provoke and encourage discussion of nonhuman animals within neuroethics. There are a number of explanations for neuroethics’ humanistic focus

Effect of Deer Density on Breeding Birds in Delaware

Previous research has suggested that high deer densities negatively impact bird communities. Most of this research was conducted using a very high deer density compared to no deer. Our research investigated deer impacts across a density gradient to determine an appropriate density for deer management efforts. Using Breeding Bird Survey (BBS) data from 2005- 2006 and Delaware Department of Natural Resources and Environmental Control (DNREC) deer density data for the same time period, we compared avian richness and relative abundance for BBS points to deer density in Delaware. We divided deer densities into 3 categories: low (\u3c12 deer/km2), medium (12-23 deer/km2) and high (\u3e23 deer/km2). We placed birds into the following deer-sensitive guilds: interior obligates, forest ground nesters, shrub nesters, ground gleaners, low canopy foragers, and tropical migrants. The species richness of ground gleaners was higher in high deer densities (F1.36 = 17.05, P = 0.0002). No other guilds\u27 species richness was affected. The relative abundances of ground gleaners (F1.36 = 25.60, P = \u3c0.0001) and tropical migrants (F1.36 = 4.11, P = 0.0501) were lowest in low deer densities. Relative abundance of wood thrush (Hylocichla mustelina) was also lowest in low deer densities (F1.36 = 21.60, P = \u3c0.0001). Richness and abundance of all guilds were positively influenced by the percent forest cover within a 50 m buffer. The effects of deer density on these bird communities were generally opposite of what past literature has suggested. In order to better understand this trend I have also conducted 618 of my own point counts and corresponding vegetation surveys throughout Delaware. This data was collected from May- August 2008 and will be repeated in the summer of 2009