Search for: All records

Climate change will increase soil drying, altering microbial communities via increasing water stress and decreasing resource availability. The responses of these microbial communities to changing environments is likely governed by physiological tradeoffs between high yield, resource acquisition, and stress tolerance (Y-A-S framework). We leveraged a unique field experiment that manipulates both drought and carbon availability across two years and three land uses, and we used both metagenomic and bioassay indicators of the three microbial community traits to test the following hypotheses: 1. Drought increases microbial allocation to stress tolerance functions, at the expense of growth and resource acquisition. 2. Because microbes are resource-limited under drought, increased carbon will enable greater expression of stress tolerance. 3. All three key life history traits described in the YAS framework will trade off, especially when resources are limited. Drought did increase microbial physiological investment in stress tolerance (measured via trehalose production), but we saw few other changes in microbial communities under drought. Carbon addition increased resource acquisition (measured via enzyme activity and resource acquisition gene abundance) and stress tolerance (trehalose assay), but did so in both drought and average rainfall environments. We found no evidence of trait tradeoffs, as we found no significant negative correlations between traits (measured via bioassay and metagenomics). In summary, we found C addition, and to a lesser extent, drought, both altered microbial community function and functional genes. However, resources did not alter drought response in a way that was consistent with theory of life history tradeoffs. 

Abstract PremiseCo‐occurring plant species that share generalist pollinators often exchange pollen. This heterospecific pollen transfer (HPT) impacts male and female reproductive success through pollen loss and reductions in seed set, respectively. The resulting fitness cost of HPT imposes selection on reproductive traits (e.g., floral color and shape), yet we currently lack strong predictors for the post‐pollination fate of heterospecific pollen, especially within community and phylogenetic contexts. MethodsWe investigated the fate of heterospecific pollen at three distinct stages of plant reproduction: (1) pollen germination on the stigma, (2) pollen tube growth in the style, and (3) fertilization of ovules. We experimentally crossed 11 naturally co‐flowering species in the subalpine meadows of the Colorado Rocky Mountains, across a spectrum of phylogenetic relatedness. Using generalized linear mixed models and generalized linear models, we evaluated the effect of parental species identity and phylogenetic relatedness on pollen tube growth at each reproductive stage. ResultsWe found that heterospecific pollen tubes can germinate and grow within pistils at each reproductive stage, even when parental species are >100 My divergent. There was no significant effect of phylogenetic distance on heterospecific pollen success, and no evidence for a mechanism that suspends heterospecific pollen germination or pollen tube growth within heterospecific stigmas or styles. ConclusionsOur results show that even in communities where HPT is common, pre‐zygotic post‐pollination mechanisms do not provide strong barriers to interspecific fertilization. HPT can result in the loss of ovules even between highly diverged plant species. 

IntroductionDespite converging evidence that people more closely associate the construct of criminality with Black people who exhibit a more African facial phenotype than Black people who express a more European phenotype, eyewitness researchers have largely ignored phenotypic bias as a potential contributor to the racial disparities in the criminal legal system. If this form of phenotypic bias extends to eyewitness identification tasks, eyewitnesses may be more likely to identify Black suspects with an African rather than European phenotype, regardless of their guilt status. Further, in cases where the witness’s description of the perpetrator does not contain phenotypic information, phenotypic mismatch between the suspect and the other lineup members may bias identification decisions toward or against the suspect. If witnesses can use elements of the lineup construction to guide their identification decisions rather than relying on their recognition memory, then the lineup should be deemed unfair due to suspect bias. The current study also investigated lineup presentation method as a procedural safeguard, predicting that that when lineups were presented simultaneously, there would be a significant two-way interaction of phenotypic bias and lineup composition, with a larger simple main effect of phenotypic bias when lineups were suspect-biased (i.e., the fillers were a phenotypic mismatch to the suspect) than when all lineup members shared the same phenotype. We expected that this interaction would be significantly smaller or non-significant for sequential lineups. MethodsParticipants watched a mock crime video that contained a Black culprit with either a more African phenotype or a less African phenotype before attempting identifications from a photo array that contained a suspect whose phenotype always matched the culprit viewed in the video, but varied in culprit-presence, phenotypic match of the suspect and fillers, and presentation method. ResultsParticipants did not identify Black suspects with Afrocentric features more often than Black suspects with Eurocentric features. However, witnesses made more identifications of suspects when the fillers did not match the suspect’s phenotype compared to when all lineup members possessed similar phenotypic features. DiscussionIn sum, phenotypic bias did not influence our participant-witnesses’ identification decisions, nor interact with lineup composition and lineup presentation type to affect identifications of suspects, suggesting that phenotypic bias may be less influential in match-to-memory tasks than other types of legal decision-making (e.g., determining guilt and sentencing). However, the suggestiveness created by failing to match fillers’ phenotypes to the suspect’s phenotype can be avoided with proper attention to fair lineup construction. 

Soil microbiomes are heterogeneous, complex microbial communities. Metagenomic analysis is generating vast amounts of data, creating immense challenges in sequence assembly and analysis. Although advances in technology have resulted in the ability to easily collect large amounts of sequence data, soil samples containing thousands of unique taxa are often poorly characterized. These challenges reduce the usefulness of genome-resolved metagenomic (GRM) analysis seen in other fields of microbiology, such as the creation of high quality metagenomic assembled genomes and the adoption of genome scale modeling approaches. The absence of these resources restricts the scale of future research, limiting hypothesis generation and the predictive modeling of microbial communities. Creating publicly available databases of soil MAGs, similar to databases produced for other microbiomes, has the potential to transform scientific insights about soil microbiomes without requiring the computational resources and domain expertise for assembly and binning. 

This article uses a comparative analysis of immigrant rights movements in Mississippi and Alabama to examine racial formation as a cultural consequence of mobilization. Drawing on archival, media, and interview data, we demonstrate that the Mississippi movement fueled shifts in public racial discourse beyond the movement itself; however, the Alabama movement engendered no such changes, despite its efforts. These outcomes emerged despite the movements’ common origins and the states’ similar political and racial contexts. We trace these outcomes to the guiding racial orientations of each movement. While Mississippi organizers embraced an interracialist organizing approach, Alabama organizers grounded their work in an assimilationist approach. These orientations led the movements to develop different racial framings and different networks, creating pathways of broader cultural influence for the Mississippi movement and closing off pathways in Alabama. These findings speak to enduring questions about movements’ cultural impacts and about the mechanisms driving racial formation. 

In this article, we investigate the role that pro-immigrant organizations play in immigrant racialization. Drawing on a critical case study from the longest standing immigrant rights organization in North Carolina, we demonstrate how immigrant rights organizations can racialize new Latinx arrivals even as they advocate for them. We interrogate the organization’s multi-year, state-wide campaign to counteract mounting public characterizations of Latinx immigrants as drunk drivers. Analyzing a critical juncture in this campaign, we demonstrate how El Pueblo, in their effort to contest the mainstream racialization of Latinxs, unintentionally doubled down on that same racialization, buying into respectability politics and reinforcing derogatory stereotypes of Latinxs. We outline three central maneuvers that grounded this particular respectability politics campaign and demonstrate the utility of respectability politics as a framework for understanding organizational racialization processes. These findings suggest the need to shift focus toward community organizations as key sites of immigrant racialization and highlight the need for inquiry into the racialized assumptions of pro-immigrant forces. 

Growing season drought can be devastating to crop yields. Soil microbial communities have the potential to buffer yield loss under drought through increasing plant drought tolerance and soil water retention. Microbial inoculation on agricultural fields has been shown to increase plant growth, but few studies have examined the impact of microbial inoculation on plant and soil microbial drought tolerance. We conducted a rainout shelter experiment and subsequent greenhouse experiment to explore 3 objectives. First, we evaluated the performance of a large rainout shelter design for studying drought in agricultural fields. Second, we tested how crop (corn vs. soybean) and microbial inoculation alter the response of soil microbial composition, diversity, and biomass to drought. Third, we tested whether field inoculation treatments and drought exposure altered microbial communities in ways that promote plant drought tolerance in future generations. In our field experiment, the effects of drought on soil bacterial composition depended on crop type, while drought decreased bacterial diversity in corn plots and drought decreased microbial biomass carbon in soybean plots. Microbial inoculation did not alter overall microbial community composition, plant growth, or drought tolerance despite our efforts to address common barriers to inoculation success. Still, a history of inoculation affected growth of future plant generations in the greenhouse. Our study demonstrates the importance of plant species in shaping microbial community responses to drought and the importance of legacy effects of microbial inoculation. 

After Hurricane Katrina decimated the Gulf Coast in 2005, thousands of Latinx immigrants arrived in the region to work in reconstruction, one case of the growing and global phenomenon of disaster migration. Drawing on newspaper content analysis, in-depth interviews with immigrant service providers, and archival materials from Mississippi for the years surrounding Hurricane Katrina (2003-2009), we ask what reception these disaster migrants encountered upon arrival and how that reception changed as they settled permanently in the state. We find that public discourse about immigrants became markedly more positive when disaster migrants arrived en masse, with the media and public characterizing immigrants as valuable, hard workers. Negative characterizations shifted to portray immigrants as drains on public resources. However, these changes were temporary. By 2009, public debate about immigrants reverted to pre-disaster trends with only one exception. Across our study period, we find a steady rise in claims that immigrants faced racism and discrimination. Our findings suggest that disasters may briefly transform the social and cultural bases of material inequalities but are unlikely to produce lasting change. 

Abstract The temperate United States has experienced increasing incidence of mosquito-borne diseases. Recent studies conducted in Baltimore, MD have demonstrated a negative relationship between abundances of Aedes albopictus (Skuse) and Culex mosquitoes and mean neighborhood income level, but have not looked at the presence of pathogens. Mosquitoes collected from five socioeconomically variable neighborhoods were tested for infection by West Nile, chikungunya, and Zika viruses in 2015 and 2016, and again from four of the neighborhoods in 2017. Minimum infection rates of pooled samples were compared among neighborhoods for each year, as well as among individual blocks in 2017. West Nile virus was detected in both Ae. albopictus and Culex pools from all neighborhoods sampled in 2015 and 2017. No infected pools were detected in any year for chikungunya or Zika viruses, and none of the target viruses were detected in 2016. Infection rates were consistently higher for Culex than for Ae. albopictus. Minimum infection rate was negatively associated with mean neighborhood income for both species in 2015. Although earlier work has shown a positive association between block-level abandonment and mosquito abundance, no association was detected in this study. Still, we demonstrate that viral infection in mosquito pools can differ substantially across adjacent urban neighborhoods that vary by income. Though trap security and accessibility often inform city sampling locations, detecting and managing arboviral risk requires surveillance across neighborhoods that vary in socioeconomics, including lower income areas that may be less accessible and secure but have higher infection rates.