494 research outputs found

    Food Web Impacts of the Invasive New Zealand Mudsnail in an Estuarine System

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    Non-indigenous species (hereafter NIS) have long been recognized as adversely affecting habitats they invade. While many of their documented ecological impacts have been to specific species, namely prey, they may impact whole food webs. Both vertebrate and invertebrate NIS have been present in the Columbia River since the mid 1800’s. The New Zealand mudsnail, (Potamopyrgus antipodarum, hereafter NZMS) was first reported in the Columbia River Estuary in 1995. This typically freshwater NIS invaded Youngs Bay, a shallow embayment within the Columbia River estuary system, and has proliferated within this benthic community. To date, there have been no inquiries into the impact of NZMS on the food web in a brackish water estuary within the United States. To identify community-level impacts by the invasive NZMS, an ecological census of the benthic communities of Youngs and Cathlamet Bays (reference site) was conducted, including comprehensive sampling of vertebrates and benthic invertebrates from these two brackish water systems. Stable isotope analysis (SIA) from these two systems is being utilized to identify trophic level food web relationships. 50% of one common estuarine fish, the Pacific staghorn sculpin (Leptocottus armatus) were found to contain NZMS in their guts. Furthermore, I have found densities reaching 15,711 snails/m² sampled. These results indicate NZMS in Youngs Bay may affect higher trophic levels. Faculty Mentors: Valance Brenneis and Catherine deRiver

    Examining the impacts of elevated, variable pCO2 on larval Pacific razor clams (Siliqua patula) in Alaska

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    An increase in anthropogenic carbon dioxide is driving oceanic chemical shifts resulting in a long-term global decrease in ocean pH, colloquially termed ocean acidification (OA). Previous studies have demonstrated that OA can have negative physiological consequences for calcifying organisms, especially during early life-history stages. However, much of the previous research has focused on static exposure to future OA conditions, rather than variable exposure to elevated pCO2, which is more ecologically relevant for nearshore species. This study examines the effects of OA on embryonic and larval Pacific razor clams (Siliqua patula), a bivalve that produces a concretion during early shell development. Larvae were spawned and cultured over 28 days under three pCO2 treatments: a static high pCO2 of 867 μatm, a variable, diel pCO2 of 357 to 867 μatm, and an ambient pCO2 of 357 μatm. Our results indicate that the calcium carbonate polymorphism of the concretion phase of S. patula was amorphous calcium carbonate which transitioned to vaterite during the advanced D-veliger stage, with a final polymorphic shift to aragonite in adults, suggesting an increased vulnerability to dissolution under OA. However, exposure to elevated pCO2 appeared to accelerate the transition of larval S. patula from the concretion stage of shell development to complete calcification. There was no significant impact of OA exposure to elevated or variable pCO2 conditions on S. patula growth or HSP70 and calmodulin gene expression. This is the first experimental study examining the response of a concretion producing bivalve to future predicted OA conditions and has important implications for experimentation on larval mollusks and bivalve management

    Hemorrhagic stroke outcomes of KApSR patients with co-morbid diabetes and Alzheimer’s disease

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    Background: Vascular risk factors, such as diabetes mellitus (DM), are associated with poorer outcomes following many neurodegenerative diseases, including hemorrhagic stroke and Alzheimer’s disease (AD). Combined AD and DM co-morbidities are associated with an increased risk of hemorrhagic stroke and increased Medicare costs. Therefore, we hypothesized that patients with DM in combination with AD, termed DM/AD, would have increased hemorrhagic stroke severity. Methods: Kentucky Appalachian Stroke Registry (KApSR) is a database of demographic and clinical data from patients that live in Appalachia, a distinct region with increased health disparities and stroke severity. Inpatients with a primary indication of hemorrhagic stroke were selected from KApSR for retrospective analysis and were separated into four groups: DM only, AD only, neither, or both. Results: Hemorrhagic stroke patients (2,071 total) presented with either intracerebral hemorrhage (ICH), n=1,448, or subarachnoid hemorrhage (SAH), n=623. When examining all four groups, subjects with AD were significantly older (AD+, 80.9±6.6 yrs) (DM+/AD+, 77.4±10.0 yrs) than non AD subjects (DM-/AD-, 61.3±16.5 yrs) and (DM+, 66.0±12.5 yrs). A higher percentage of females were among the AD+ group and a higher percentage of males among the DM+/AD+ group. Interestingly, after adjusting for multiple comparison, DM+/AD+ subjects were ten times as likely to suffer a moderate to severe stroke based on a National Institute of Health Stroke (NIHSS) upon admission [odds ratio (95% CI)] compared to DM-/AD- [0.1 (0.02–0.55)], DM+ [0.11 (0.02–0.59)], and AD+ [0.09(0.01–0.63)]. The odds of DM+/AD+ subjects having an unfavorable discharge destination (death, hospice, long-term care) was significant (P Conclusions: In our retrospective analysis utilizing KApSR, regardless of adjusting for age, sex, and comorbidities, DM+/AD+ patients were significantly more likely to have had a moderate or severe stroke leading to an unfavorable outcome following hemorrhagic stroke

    Longitudinal Bioluminescence Imaging of Primary Versus Abdominal Metastatic Tumor Growth in Orthotopic Pancreatic Tumor Models in NSG Mice

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    Objectives: The purpose of the present study was to develop and validate noninvasive bioluminescence imaging methods for differentially monitoring primary and abdominal metastatic tumor growth in mouse orthotopic models of pancreatic cancer. Methods: A semiautomated maximum entropy segmentation method was implemented for the primary tumor region of interest, and a rule-based method for manually drawing a region of interest for the abdominal metastatic region was developed for monitoring tumor growth in orthotopic models of pancreatic cancer. The 2 region-of-interest methods were validated by having 2 observers independently segment Panc-1 tumors, and the results were compared with the number of mesenteric lymph node nodules and histopathologic assessment of liver metastases. The findings were extended to orthotopic tumors of the more metastatic MIA PaCa-2 and AsPC-1 cells where separate groups of animals were implanted with different numbers of cells. Results: The results demonstrated that the segmentation methods were highly reliable, reproducible, and robust and allowed statistically significant discrimination in the growth rates of primary and abdominal metastatic tumors of different cell lines implanted with different numbers of cells. Conclusions: The present results demonstrate that primary tumors and abdominal metastatic foci in orthotopic pancreatic cancer models can be reliably quantified separately and noninvasively over time with bioluminescence imaging

    The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group HI–Halo Mass Relation

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    We present a four-step group-finding algorithm for the Gas in Galaxy Groups (G3) initiative, a spin-off of the z ∼ 0 REsolved Spectroscopy Of a Local VolumE (RESOLVE) and Environmental COntext (ECO) surveys. In preparation for future comparisons to intermediate redshift (e.g., the LADUMA survey), we design the group finder to adapt to incomplete, shallow, or nonuniform data. We use mock catalogs to optimize the group finder’s performance. Compared to friends-of-friends (with false-pair splitting), the G3 algorithm offers improved completeness and halo-mass recovery with minimal loss of purity. Combining it with the volume-limited H I census data for RESOLVE and ECO, we examine the H I content of galaxy groups as a function of group halo mass. Group-integrated H I mass M rises monotonically over halo masses M ∼ 10–10 M, pivoting in slope at M ∼ 10M, the gas-richness threshold scale. We present the first measurement of the scatter in this relation, which has a median of ∼0.3 dex and is asymmetric toward lower M I,grp. We discuss interesting tensions with theoretical predictions and prior measurements of the M–M relation. In an appendix, we release RESOLVE DR4 and ECO DR3, including updates to survey redshifts, photometry, and group catalogs, as well as a major expansion of the ECO H I inventory with value-added data products. © 2023. The Author(s). Published by the American Astronomical SocietyWe are grateful to the anonymous referee, whose feedback has improved the quality of this work. We also thank Adrienne Erickcek, Andrew Mann, Mugdha Polimera, Matthew Bershady, Joshua Oppor, Jeremy Darling, Hayley Roberts, and Amir Kazemi-Moridani for valuable feedback at varying stages of the project. Z.L.H., S.J.K., and E.R.C. acknowledge support for this research from National Science Foundation (NSF) grant AST-1814486. Z.L.H. and D.S.C. are also supported through a North Carolina Space Grant Graduate Research Fellowship. S.J.K. and D.S.C. acknowledge support from NSF grant AST-2007351. A.J.B. acknowledges support from NSF grant AST-1814421. K.M.H. acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the "Center of Excellence Severo Ocho" awarded to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), via participation in SKA-SPAIN, funded by the Ministry of Science and Innovation (MCIN), and financial support from grant RTI2018-096228-B-C31 (MCIU/AEI/FEDER,UE)

    Impact of shortened crop rotation of oilseed rape on soil and rhizosphere microbial diversity in relation to yield decline

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    Oilseed rape (OSR) grown in monoculture shows a decline in yield relative to virgin OSR of up to 25%, but the mechanisms responsible are unknown. A long term field experiment of OSR grown in a range of rotations with wheat was used to determine whether shifts in fungal and bacterial populations of the rhizosphere and bulk soil were associated with the development of OSR yield decline. The communities of fungi and bacteria in the rhizosphere and bulk soil from the field experiment were profiled using terminal restriction fragment length polymorphism (TRFLP) and sequencing of cloned internal transcribed spacer regions and 16S rRNA genes, respectively. OSR cropping frequency had no effect on rhizosphere bacterial communities. However, the rhizosphere fungal communities from continuously grown OSR were significantly different to those from other rotations. This was due primarily to an increase in abundance of two fungi which showed 100% and 95% DNA identity to the plant pathogens Olpidium brassicae and Pyrenochaeta lycopersici, respectively. Real-time PCR confirmed that there was significantly more of these fungi in the continuously grown OSR than the other rotations. These two fungi were isolated from the field and used to inoculate OSR and Brassica oleracea grown under controlled conditions in a glasshouse to determine their effect on yield. At high doses, Olpidium brassicae reduced top growth and root biomass in seedlings and reduced branching and subsequent pod and seed production. Pyrenochaeta sp. formed lesions on the roots of seedlings, and at high doses delayed flowering and had a negative impact on seed quantity and quality

    Decision-making in cancer care for people living with dementia

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    Objective: Increasing numbers of people are expected to live with comorbid cancer and dementia. Cancer treatment decision-making for these individuals is complex, particularly for those lacking capacity, requiring support across the cancer care pathway. There is little research to inform practice in this area. This ethnographic study reports on the cancer decision-making experiences of people with cancer and dementia, their families, and healthcare staff. Methods: Participant observations, informal conversations, semi-structured interviews, and medical note review, in two NHS trusts. Seventeen people with dementia and cancer, 22 relatives and 19 staff members participated. Results: Decision-making raised complex ethical dilemmas and challenges and raised concerns for families and staff around whether correct decisions had been made. Whose decision it was and to what extent a person with dementia and cancer was able to make decisions was complex, requiring careful and ongoing consultation and close involvement of relatives. The potential impact dementia might have on treatment understanding and toleration required additional consideration by clinicians when evaluating treatment options. Conclusions: Cancer treatment decision-making for people with dementia is challenging, should be an ongoing process and has emotional impacts for the individual, relatives, and staff. Longer, flexible, and additional appointments may be required to support decision-making by people with cancer and dementia. Evidence-based decision-making guidance on how dementia impacts cancer prognosis, treatment adherence and efficacy is required

    Prospective Association of Daily Steps with Cardiovascular Disease: A Harmonized Meta-Analysis

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    Background: Taking fewer than the widely promoted “10 000 steps per day” has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the dose–response relationship between steps per day and CVD can help inform clinical and public health guidelines. Methods: Eight prospective studies (20 152 adults [ie, ≥18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional hazards regression analyses were completed using study-specific quartiles and hazard ratios (HR) and 95% CI were meta-analyzed with inverse-variance–weighted random effects models. Results: The mean age of participants was 63.2±12.4 years and 52% were women. The mean follow-up was 6.2 years (123 209 person-years), with a total of 1523 CVD events (12.4 per 1000 participant-years) reported. There was a significant difference in the association of steps per day and CVD between older (ie, ≥60 years of age) and younger adults (ie, <60 years of age). For older adults, the HR for quartile 2 was 0.80 (95% CI, 0.69 to 0.93), 0.62 for quartile 3 (95% CI, 0.52 to 0.74), and 0.51 for quartile 4 (95% CI, 0.41 to 0.63) compared with the lowest quartile. For younger adults, the HR for quartile 2 was 0.79 (95% CI, 0.46 to 1.35), 0.90 for quartile 3 (95% CI, 0.64 to 1.25), and 0.95 for quartile 4 (95% CI, 0.61 to 1.48) compared with the lowest quartile. Restricted cubic splines demonstrated a nonlinear association whereby more steps were associated with decreased risk of CVD among older adults. Conclusions: For older adults, taking more daily steps was associated with a progressively decreased risk of CVD. Monitoring and promoting steps per day is a simple metric for clinician–patient communication and population health to reduce the risk of CVD

    The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group H i –Halo Mass Relation

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    We present a four-step group-finding algorithm for the Gas in Galaxy Groups (G3) initiative, a spin-off of the z ∼ 0 REsolved Spectroscopy Of a Local VolumE (RESOLVE) and Environmental COntext (ECO) surveys. In preparation for future comparisons to intermediate redshift (e.g., the LADUMA survey), we design the group finder to adapt to incomplete, shallow, or nonuniform data. We use mock catalogs to optimize the group finder’s performance. Compared to friends-of-friends (with false-pair splitting), the G3 algorithm offers improved completeness and halo-mass recovery with minimal loss of purity. Combining it with the volume-limited H i census data for RESOLVE and ECO, we examine the H i content of galaxy groups as a function of group halo mass. Group-integrated H i mass M H I,grp rises monotonically over halo masses M halo ∼ 1011–1014.5 M ⊙, pivoting in slope at M halo ∼ 1011.4 M ⊙, the gas-richness threshold scale. We present the first measurement of the scatter in this relation, which has a median of ∼0.3 dex and is asymmetric toward lower M H I,grp. We discuss interesting tensions with theoretical predictions and prior measurements of the M H I,grp–M halo relation. In an appendix, we release RESOLVE DR4 and ECO DR3, including updates to survey redshifts, photometry, and group catalogs, as well as a major expansion of the ECO H i inventory with value-added data products
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