77 research outputs found

    Spatial distribution and morphological responses to predation in the salt marsh periwinkle

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    The salt marsh periwinkle (Littoraria irrorata) is a common and often abundant mollusk in marshes of the Gulf and Atlantic coasts of the United States. Several studies have focused on the effects of periwinkles on Spartina alterniflora production and the effects of oil on periwinkle survivability, yet the general ecology of the snail has been underreported. In this study, we measured spatial distributions, biomass, shell repair frequency, and a suite of morphological characteristics of L. irrorata at three sites in each of five regions spanning the southeastern Louisiana Coast between the Atchafalaya and Mississippi rivers. Sampling was conducted along 50 m edge-to-interior transects in S. alterniflora-dominated marshes. We found that L. irrorata density, individual biomass, and total areal biomass significantly varied by region. Each also significantly varied with distance from the marsh edge, with the exception of total periwinkle areal biomass. We saw a general trend across most regions where periwinkle density tended to be greatest 10 m from the marsh edge and biomass tended to be greatest 20-30 m from the marsh edge; however, neither periwinkle density nor biomass was related to S. alterniflora density or stem height. The allometric relationship between shell length and biomass varied significantly between all regions, indicating that this species has differing regional growth patterns. A possible driver of these regional patterns in allometry is differences in predation pressures, with increased predation scaring at Port Fourchon sites corresponding to snails with larger shells yet less internal biomass per length compared to other regions. This study provides the first large-scale description of the spatial ecology and regional morphometry of the salt marsh periwinkle, an important organism in structuring salt marsh ecosystems, and suggests that the pressures exerted by L. irrorata on plant production found in other studies likely varies by geography and spatial location within a marsh

    The Vehicle, Spring 1981

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    Vol. 22, No. 2 Table of Contents Old Farmers at the Arcade CafeJohn Stockmanpage 4 ConfettiCathy Georgepage 6 Ode to a Corned Beef SandwichJeff Bennettpage 6 The Ice on Kirschner\u27s CreekScott Fishelpage 7 Love Poem to LindaJohn Stockmanpage 7 Grandfather\u27s PortraitJames Marshpage 8 The MassageKathleen Alakspage 9 A Driving ForceSandy Youngpage 10 King DandelionNancy Siebenpage 12 One Afternoon - Contemplating HouseworkKelli Sanderpage 13 Tent WallsAndy Sudkamppage 14 The SentinelElise Hempelpage 16 Daddy\u27s AftershaveJeff Bennettpage 16 The WeddingChris Goerlichpage 17 UntitledCarol Hansenpage 17 Treasures in the YardScott Fishelpage 18 Hitchhiker\u27s BootsAndy Sudkamppage 20 The RaffleLaura Henrypage 21 A Walk at NightJudi Jinespage 24 Morning in the DumpJeff Bennettpage 24 In Praise of Chocolate Ice CreamJohn Stockmanpage 25 Summer on the Isle of PalmsElisabeth Cristpage 26 The WaveHerbert S. Demminpage 27 RememberingJohn Kleinsteiberpage 27 PotatoJohn Stockmanpage 28 Late ShowChris Goerlichpage 30 Love in Him - JoeDebbie Klinnertpage 31 ShoeScott Fishelpage 35 The DrinkerBob Huntpage 36 The WidowGeorge Ndu Igbudupage 37 ElectricityScott Fishelpage 37 Hatchet JackB.L. Davidsonpage 39 Walking Home LateJohn Stockmanpage 41 NovemberCindy Hubbarttpage 41 On the BusLaura Henrypage 42 HaikuJames Marshpage 43 SpillwayGloria Rhoadspage 43 Art Cover design by Linda Fraembs PhotographRobin Scholzpage 3 PhotographRobin Scholzpage 5 PhotographMichelle Glassmeyerpage 15 PhotographRobert Schinaglpage 19 PhotographTom Robertspage 38 PhotographRobert Schinaglpage 44https://thekeep.eiu.edu/vehicle/1039/thumbnail.jp

    The Influence of Perceptual Training on Working Memory in Older Adults

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    Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement

    Swelling-Activated Ca2+ Channels Trigger Ca2+ Signals in Merkel Cells

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    Merkel cell-neurite complexes are highly sensitive touch receptors comprising epidermal Merkel cells and sensory afferents. Based on morphological and molecular studies, Merkel cells are proposed to be mechanosensory cells that signal afferents via neurotransmission; however, functional studies testing this hypothesis in intact skin have produced conflicting results. To test this model in a simplified system, we asked whether purified Merkel cells are directly activated by mechanical stimulation. Cell shape was manipulated with anisotonic solution changes and responses were monitored by Ca2+ imaging with fura-2. We found that hypotonic-induced cell swelling, but not hypertonic solutions, triggered cytoplasmic Ca2+ transients. Several lines of evidence indicate that these signals arise from swelling-activated Ca2+-permeable ion channels. First, transients were reversibly abolished by chelating extracellular Ca2+, demonstrating a requirement for Ca2+ influx across the plasma membrane. Second, Ca2+ transients were initially observed near the plasma membrane in cytoplasmic processes. Third, voltage-activated Ca2+ channel (VACC) antagonists reduced transients by half, suggesting that swelling-activated channels depolarize plasma membranes to activate VACCs. Finally, emptying internal Ca2+ stores attenuated transients by 80%, suggesting Ca2+ release from stores augments swelling-activated Ca2+ signals. To identify candidate mechanotransduction channels, we used RT-PCR to amplify ion-channel transcripts whose pharmacological profiles matched those of hypotonic-evoked Ca2+ signals in Merkel cells. We found 11 amplicons, including PKD1, PKD2, and TRPC1, channels previously implicated in mechanotransduction in other cells. Collectively, these results directly demonstrate that Merkel cells are activated by hypotonic-evoked swelling, identify cellular signaling mechanisms that mediate these responses, and support the hypothesis that Merkel cells contribute to touch reception in the Merkel cell-neurite complex

    The experience of stigma in inflammatory bowel disease: an interpretive (hermeneutic) phenomenological study

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    Aim: To explore experiences of stigma in people with inflammatory bowel disease Background: Diarrhoea, urgency and incontinence are common symptoms in inflammatory bowel disease. Social rules stipulate full control of bodily functions in adulthood: poor control may lead to stigmatisation, affecting patients’ adjustment to disease. Disease-related stigma is associated with poorer clinical outcomes but qualitative evidence is minimal. Design: An interpretive (hermeneutic) phenomenological study of the lived experience of stigma in inflammatory bowel disease. Methods: Forty community-dwelling adults with a self-reported diagnosis of inflammatory bowel disease were recruited purposively. Participants reported feeling stigmatised or not and experiencing faecal incontinence or not. Unstructured interviews took place in participants’ homes in the United Kingdom (September 2012 – May 2013). Data were analysed using Diekelmann’s interpretive method. Findings: Three constitutive patterns - Being in and out of control, Relationships and social Support and Mastery and mediation - reveal the experience of disease-related stigma, occurring regardless of continence status and because of name and type of disease. Stigma recedes when mastery over disease is achieved through development of resilience - influenced by humour, perspective, mental wellbeing and upbringing (childhood socialisation about bodily functions). People travel in and out of stigma, dependent on social relationships with others including clinicians and tend to feel less stigmatised over time. Conclusion: Emotional control, social support and mastery over disease are key to stigma reduction. By identifying less resilient patients, clinicians can offer appropriate support, accelerating the patient’s path towards disease acceptance and stigma reduction

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

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    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Modern English in action

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    AN ANALYSIS OF ORGANIZATIONAL CLIMATE AND PRINCIPAL LEADER BEHAVIOR IN CLASS III SECONDARY SCHOOLS OF NEBRASKA.

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    Abstract not availabl

    A Rare Soft Tissue Tumor Masquerading as a Parathyroid Adenoma in a Patient with Birt-Hogg-Dubé Syndrome and Multiple Cervical Endocrinopathies

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    Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant disorder that presents with renal tumors, pulmonary cysts with spontaneous pneumothoraces, and skin hamartomas. We present a case of a 67-year-old female with multiple endocrinopathies and a history of BHD syndrome. In 2011, a thyroidectomy with a four-gland parathyroidectomy was performed for toxic multinodular goiter (TMNG) and parathyroid hyperplasia. On frozen section, a tumor was identified next to a hypercellular parathyroid. After being worked up, this tumor was determined to be an adult rhabdomyoma. This represents the first time that both TMNG and parathyroid hyperplasia have been present in a BHD patient. Additionally, this is the first adult rhabdomyoma reported in a patient with BHD syndrome. Adult rhabdomyomas have no reported associations; however, potential colocation of the mutation in BHD syndrome and translocation in adult rhabdomyomas on chromosome 17p suggests a possible connection. Further work is needed to better understand this connection

    A model for classification of invasive fungal rhinosinusitis by computed tomography

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    Abstract Our purpose was to classify acute invasive fungal rhinosinusitis (AIFR) caused by Mucor versus Aspergillus species by evaluating computed tomography radiological findings. Two blinded readers retrospectively graded radiological abnormalities of the craniofacial region observed on craniofacial CT examinations obtained during initial evaluation of 38 patients with eventually pathology-proven AIFR (13:25, Mucor:Aspergillus). Binomial logistic regression was used to analyze correlation between variables and type of fungi. Score-based models were implemented for analyzing differences in laterality of findings, including the ‘unilateral presence’ and ‘bilateral mean’ models. Binary logistic regression was used, with Score as the only predictor and Group (Mucor vs Aspergillus) as the only outcome. Specificity, sensitivity, positive predictive value, negative predictive value and accuracy were determined for the evaluated models. Given the low predictive value of any single evaluated anatomical site, a ‘bilateral mean’ score-based model including the nasal cavity, maxillary sinuses, ethmoid air cells, sphenoid sinus and frontal sinuses yielded the highest prediction accuracy, with Mucor induced AIFR correlating with higher prevalence of bilateral findings. The odds ratio for the model while integrating the above anatomical sites was 12.3 (p < 0.001). PPV, NPV, sensitivity, specificity and accuracy were 0.85, 0.82, 0.92, 0.69 and 0.84 respectively. The abnormal radiological findings on craniofacial CT scans of Mucor and Aspergillus induced AIFR could be differentiated based on laterality, with Mucor induced AIFR associated with higher prevalence of bilateral findings
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