Field Guides for Leaving: A poetic exploration of the hyperlocal in Burlington, Vermont

In times of instability, we look to the land and our community for comfort. Field Guides for Leaving is a collection of seventeen (17) poems written through a hyperlocal lens that focuses on minute details about the poet’s natural and cultural landscape in Burlington, Vermont. The poems use poignant and succinct observations of the hyperlocal to both represent a longing for stability and create an antidote to instability. To cultivate a sense of place, the poems draw parallels between culture and nature to relate emotional landscapes with physical ones. This thesis contributes to the fields of ecopoetry and green studies in its study of the hyperlocal, intentional place-making, and interest in the relationships that we form with place and nature. The poems grapple with personal, communal, and climatic instability such as graduating from college, the COVID-19 pandemic, and climate change

Retention and adherence: global challenges for the long-term care of adolescents and young adults living with HIV

Purpose of review Adolescents living with HIV are the only age group with increasing HIV mortality at a time of global scale-up of access to antiretroviral therapy (ART). As a ‘treat all’ strategy is implemented worldwide, it is critically important to optimize retention and adherence for this vulnerable group. Recent findings Adolescents and young adults living with HIV have poorer outcomes when compared with adults at each stage of the HIV care cascade, irrespective of income setting. Rates of viral suppression are lowest for adolescents living with HIV, and adherence to ART remains an enormous challenge. High-quality studies of interventions to improve linkage to, and retention in, care on suppressive ART are starkly lacking for adolescents and young adults living with HIV across the globe. However, examples of good practice are beginning to emerge but require large-scale implementation studies with outcome data disaggregated by age, route of infection, and income setting, and include young pregnant women and key populations groups. Summary There is an urgent need for evidence-based interventions addressing gaps in the adolescent HIV care cascade, including supporting retention in care and adherence to ART

Contribution and pathways of diazotroph-derived nitrogen to zooplankton during the VAHINE mesocosm experiment in the oligotrophic New Caledonia lagoon

In oligotrophic tropical and subtropical oceans, where strong stratification can limit the replenishment of surface nitrate, dinitrogen (N-2) fixation by diazotrophs can represent a significant source of nitrogen (N) for primary production. The VAHINE (VAriability of vertical and tropHIc transfer of fixed N-2 in the south-wEst Pacific) experiment was designed to examine the fate of diazotroph-derived nitrogen (DDN) in such ecosystems. In austral summer 2013, three large ( similar to aEuro parts per thousand aEuro-50aEuro-m(3)) in situ mesocosms were deployed for 23 days in the New Caledonia lagoon, an ecosystem that typifies the low-nutrient, low-chlorophyll environment, to stimulate diazotroph production. The zooplankton component of the study aimed to measure the incorporation of DDN into zooplankton biomass, and assess the role of direct diazotroph grazing by zooplankton as a DDN uptake pathway. Inside the mesocosms, the diatom-diazotroph association (DDA) het-1 predominated during days 5-15 while the unicellular diazotrophic cyanobacteria UCYN-C predominated during days 15-23. A Trichodesmium bloom was observed in the lagoon (outside the mesocosms) towards the end of the experiment. The zooplankton community was dominated by copepods (63aEuro-% of total abundance) for the duration of the experiment. Using two-source N isotope mixing models we estimated a mean similar to aEuro parts per thousand aEuro-28aEuro-% contribution of DDN to zooplankton nitrogen biomass at the start of the experiment, indicating that the natural summer peak of N-2 fixation in the lagoon was already contributing significantly to the zooplankton. Stimulation of N-2 fixation in the mesocosms corresponded with a generally low-level enhancement of DDN contribution to zooplankton nitrogen biomass, but with a peak of similar to aEuro parts per thousand aEuro-73aEuro-% in mesocosm 1 following the UCYN-C bloom. qPCR analysis targeting four of the common diazotroph groups present in the mesocosms (Trichodesmium, het-1, het-2, UCYN-C) demonstrated that all four were ingested by copepod grazers, and that their abundance in copepod stomachs generally corresponded with their in situ abundance. N-15(2) labelled grazing experiments therefore provided evidence for direct ingestion and assimilation of UCYN-C-derived N by the zooplankton, but not for het-1 and Trichodesmium, supporting an important role of secondary pathways of DDN to the zooplankton for the latter groups, i.e. DDN contributions to the dissolved N pool and uptake by nondiazotrophs. This study appears to provide the first evidence of direct UCYN-C grazing by zooplankton, and indicates that UCYN-C-derived N contributes significantly to the zooplankton food web in the New Caledonia lagoon through a combination of direct grazing and secondary pathways

Prenatal Exposure of the Ovine Fetus to Androgens Sexually Differentiates the Steroid Feedback Mechanisms That Control Gonadotropin Releasing Hormone Secretion and Disrupts Ovarian Cycles

Exposure of the female sheep fetus to exogenous testosterone in early pregnancy permanently masculinizes the reproductive neuroendocrine axis. Specifically, in utero androgens given to female lambs from day 30 to 90 of a 147 day pregnancy dramatically altered the response of the gonadotropin releasing hormone (GnRH) neuronal network in the hypothalamus to both estrogen (E) and progesterone (P) feedback. Elevated concentrations of estrogen stimulated a massive release of GnRH in gonadectomized female sheep; however, male and androgenized female lambs were unable to respond to high E concentrations by producing this preovulatory-like “surge” of GnRH. Further, the inhibitory actions of progesterone (P) were also sexually differentiated and adult males and androgenized females were much less responsive to P-negative feedback than normal ewes. The consequences of these abnormal steroid feedback mechanisms were reflected in the fact that only 72% of ovary-intact androgenized ewes exhibited normal estrous cycles in their first breeding season whereas none had a single estrous cycle during the second breeding season. In contrast, 100% of the control animals exhibited repeated reproductive cycles in both seasons. These data indicate that a relatively short exposure to male hormones during in utero life permanently alters the neural mechanisms that control reproduction and leads progressively to a state of infertility.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44102/1/10508_2004_Article_365183.pd

Risk of acute myeloid leukemia and myelodysplastic syndrome among older women receiving anthracycline-based adjuvant chemotherapy for breast cancer on Modern Cooperative Group Trials (Alliance A151511)

We examined acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) events among 9679 women treated for breast cancer on four adjuvant Alliance for Clinical Trials in Oncology trials with >90 months of follow-up in order to better characterize the risk for AML/MDS in older patients receiving anthracyclines

Targeted Nasal Vaccination Provides Antibody-Independent Protection Against Staphylococcus aureus

Despite showing promise in preclinical models, anti-Staphylococcus aureus vaccines have failed in clinical trials. To date, approaches have focused on neutralizing/opsonizing antibodies; however, vaccines exclusively inducing cellular immunity have not been studied to formally test whether a cellular-only response can protect against infection. We demonstrate that nasal vaccination with targeted nanoparticles loaded with Staphylococcus aureus antigen protects against acute systemic S. aureus infection in the absence of any antigen-specific antibodies. These findings can help inform future developments in staphylococcal vaccine development and studies into the requirements for protective immunity against S. aureu

Accounting for variability when resurrecting dormant propagules substantiates their use in eco-evolutionary studies

There has been a steady rise in the use of dormant propagules to study biotic responses to environmental change over time. This is particularly important for organisms that strongly mediate ecosystem processes, as changes in their traits over time can provide a unique snapshot into the structure and function of ecosystems from decades to millennia in the past. Understanding sources of bias and variation is a challenge in the field of resurrection ecology, including those that arise because often-used measurements like seed germination success are imperfect indicators of propagule viability. Using a Bayesian statistical framework, we evaluated sources of variability and tested for zero-inflation and overdispersion in data from 13 germination trials of soil-stored seeds of Schoenoplectus americanus, an ecosystem engineer in coastal salt marshes in the Chesapeake Bay. We hypothesized that these two model structures align with an ecological understanding of dormancy and revival: zero-inflation could arise due to failed germinations resulting from inviability or failed attempts to break dormancy, and overdispersion could arise by failing to measure important seed traits. A model that accounted for overdispersion, but not zero-inflation, was the best fit to our data. Tetrazolium viability tests corroborated this result: most seeds that failed to germinate did so because they were inviable, not because experimental methods failed to break their dormancy. Seed viability declined exponentially with seed age and was mediated by seed provenance and experimental conditions. Our results provide a framework for accounting for and explaining variability when estimating propagule viability from soil-stored natural archives which is a key aspect of using dormant propagules in eco-evolutionary studies

Txikispora philomaios n. sp., n. g., a micro-eukaryotic pathogen of amphipods, reveals parasitism and hidden diversity in Class Filasterea

This study provides a morphological, ultrastructural, and phylogenetic characterization of a novel micro-eukaryotic parasite (2.3–2.6 µm) infecting amphipod genera Echinogammarus and Orchestia. Longitudinal studies across two years revealed that infection prevalence peaked in late April and May, reaching 64% in Echinogammarus sp. and 15% in Orchestia sp., but was seldom detected during the rest of the year. The parasite infected predominantly hemolymph, connective tissue, tegument, and gonad, although hepatopancreas and nervous tissue were affected in heavier infections, eliciting melanization and granuloma formation. Cell division occurred inside walled parasitic cysts, often within host hemocytes, resulting in hemolymph congestion. Small subunit (18S) rRNA gene phylogenies including related environmental sequences placed the novel parasite as a highly divergent lineage within Class Filasterea, which together with Choanoflagellatea represent the closest protistan relatives of Metazoa. We describe the new parasite as Txikispora philomaios n. sp. n. g., the first confirmed parasitic filasterean lineage, which otherwise comprises four free-living flagellates and a rarely observed endosymbiont of snails. Lineage-specific PCR probing of other hosts and surrounding environments only detected T. philomaios in the platyhelminth Procerodes sp. We expand the known diversity of Filasterea by targeted searches of metagenomic datasets, resulting in 13 previously unknown lineages from environmental samples.Ministerio de Economía y Competitividad, Grant/Award Number: BFU2017- 90114- P; Horizon 2020 Framework Programme, Grant/Award Number: 747789; Department for Environment, Food and Rural Affairs, UK Government, Grant/Award Number: FB002A and FC1214; Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza, Grant/Award Number: PRE_2016_2_0124; Agencia Estatal de Investigación (AEI); Fondo Europeo de Desarrollo Regional (FEDER); Ayuda Juan de la Cierva—Incorporación, Grant/Award Number: IJC2018- 036657-

First observations of Weddell seals foraging in sponges in Erebus Bay, Antarctica

Attaching cameras to marine mammals allows for first-hand observation of underwater behaviours that may otherwise go unseen. While studying the foraging behaviour of 26 lactating Weddell seals (Leptonychotes weddellii) in Erebus Bay during the austral spring of 2018 and 2019, we witnessed three adults and one pup investigating the cavities of Rossellidae glass sponges, with one seal visibly chewing when she removed her head from the sponge. To our knowledge, this is the first report of such behaviour. While the prey item was not identifiable, some Trematomus fish (a known Weddell seal prey) use glass sponges for shelter and in which to lay their eggs. Three of the four sponge foraging observations occurred around 13:00 (NZDT). Two of the three sponge foraging adults had higher-than-average reproductive rates, and the greatest number of previous pups of any seal in our study population, each having ten pups in 12 years. This is far higher than the study population average of three previous pups (± 2.6 SD). This novel foraging strategy may have evolved in response to changes in prey availability, and could offer an evolutionary advantage to some individuals that exploit prey resources that others may not. Our observations offer new insight into the foraging behaviours of one of the world’s most studied marine mammals. Further research on the social aspects of Weddell seal behaviour may increase our understanding of the extent and mechanisms of behavioural transfer between conspecifics. Research into the specific foraging behaviour of especially successful or experienced breeders is also warranted

ANKRD24 organizes TRIOBP to reinforce stereocilia insertion points

The stereocilia rootlet is a key structure in vertebrate hair cells, anchoring stereocilia firmly into the cell’s cuticular plate and protecting them from overstimulation. Using superresolution microscopy, we show that the ankyrin-repeat protein ANKRD24 concentrates at the stereocilia insertion point, forming a ring at the junction between the lower and upper rootlets. Annular ANKRD24 continues into the lower rootlet, where it surrounds and binds TRIOBP-5, which itself bundles rootlet F-actin. TRIOBP-5 is mislocalized in Ankrd24KO/KO hair cells, and ANKRD24 no longer localizes with rootlets in mice lacking TRIOBP-5; exogenous DsRed–TRIOBP-5 restores endogenous ANKRD24 to rootlets in these mice. Ankrd24KO/KO mice show progressive hearing loss and diminished recovery of auditory function after noise damage, as well as increased susceptibility to overstimulation of the hair bundle. We propose that ANKRD24 bridges the apical plasma membrane with the lower rootlet, maintaining a normal distribution of TRIOBP-5. Together with TRIOBP-5, ANKRD24 organizes rootlets to enable hearing with long-term resilience