Publications by authors named "Karp A"

Fire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density.

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Increasing atmospheric CO is changing the dynamics of tropical savanna vegetation. C trees and grasses are known to experience CO fertilization, whereas responses to CO by C grasses are more ambiguous. Here, we sample stable carbon isotope trends in herbarium collections of South African C and C grasses to reconstruct C discrimination.

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Introduction: There are currently limited effective treatments available to improve lusitropy in patients suffering from heart failure with preserved ejection fraction. The role of PDE9A in diastolic dysfunction has been well-studied over recent years, with a special focus on its association with myocardial hypertrophy. Recent insights into PDE9A inhibition have brought to light the potential for reversal of cardiac remodeling, with multiple studies showing promising results in preclinical data.

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The quantification of left ventricular ejection fraction (LVEF) has important clinical utility in the assessment of cardiac function and is vital for the diagnosis of cardiovascular diseases. A transthoracic echocardiogram serves as the most commonly used tool for LVEF assessment for several reasons, including, its noninvasive nature, great safety profile, real-time image processing ability, portability, and cost-effectiveness. However, transthoracic echocardiogram is highly dependent on the clinical skill of the sonographer and interpreting physician.

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The study of lipoprotein(a) [Lp(a)] has long been a source of interest as a possible independent risk factor for atherosclerotic cardiovascular disease (ASCVD). The results of large sample observational studies, genome-wide association studies, and Mendelian randomization studies have been strong indicators supporting the link between ASCVD and Lp(a) despite early studies, with less sensitive assays, failing to show a connection. The recommendations for the indications and frequency of testing Lp(a) levels vary between US, Canadian, and European organizations due to the uncertain role of Lp(a) in ASCVD.

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Article Synopsis
  • Polycyclic aromatic hydrocarbons (PAHs) make up about 20% of carbon in the interstellar medium and can form under various conditions, including in hot circumstellar environments and cold interstellar clouds.
  • Isotopic analysis of PAHs from asteroid Ryugu and meteorite Murchison shows that some PAHs, like naphthalene, fluoranthene, and pyrene, have higher carbon isotopic values than expected, indicating they likely formed in the interstellar medium rather than in hot environments.
  • In contrast, the PAHs phenanthrene and anthracene from Ryugu display isotopic values that suggest they were formed through higher-temperature reactions.
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Introduction: Unilateral vocal fold paralysis or paresis (UVFP) is a condition that causes significant morbidity due to dysphonia, dysphagia, and aspiration. Type I medialization thyroplasty (MT) is the current mainstay surgical treatment for UVFP. Though widely considered a safe procedure, concerns exist over possible airway complications which can lead to overnight observation.

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Cellular stress in the form of disrupted transcription, loss of organelle integrity, or damage to nucleic acids can elicit inflammatory responses by activating signaling cascades canonically tasked with controlling pathogen infections. These stressors must be kept in check to prevent unscheduled activation of interferon, which contributes to autoinflammation. This study examines the role of the transcription factor myocyte enhancing factor 2A (MEF2A) in setting the threshold of transcriptional stress responses to prevent R-loop accumulation.

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Pyogenic liver abscesses (PLAs) secondary to bacterial etiologies are rare in North America and other developed countries. The predominant etiology of PLAs is an infection extending from the hepatobiliary or intestinal system. As such, the most common pathogens isolated from PLA in the United States are and .

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Importance SARS-CoV-2 is a rapidly evolving virus with many strains. Although vaccines have proven to be effective against earlier strains of the virus, the efficacy of vaccination status against later strains is still an area of active research. Objective To determine if vaccination status was associated with symptomatology due to infection by later strains of SARS-CoV-2.

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Sleep plays a critical role in the development of adolescents. Identifying the factors influencing adolescent sleep duration is a critical public health concern. Our study was designed to look for associations that may affect sleep duration in adolescent students.

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3D printing is a growing tool in surgical education to visualize and teach complex procedures. Previous studies demonstrating the usefulness of 3D models as teaching tools for partial nephrectomy used highly detailed models costing between $250 and 1000. We aimed to create thorough, inexpensive 3D models to accelerate learning for trainees and increase health literacy in patients.

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35S rRNA transcripts include a 5'-external transcribed spacer followed by rRNAs of the small and large ribosomal subunits. Their processing yields massive precursors that include dozens of assembly factor proteins. In Saccharomyces cerevisiae, nucleolar assembly factors form 2 coaxial layers/volumes around ribosomal DNA.

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Objective: To understand the impact of pediatric multiple sclerosis (MS), health-related quality of life (HRQL) measures have been used. However, specific areas of concern of youths with MS are not known. The objective of this study was to contribute content for inclusion in a new condition-specific measure of the life impact of MS for children and adolescents.

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Fire activity varies substantially at global scales because of the influence of climate, but at broad spatiotemporal scales, the possible effects of herbivory on fire activity are unknown. Here, we used late Quaternary large-bodied herbivore extinctions as a global exclusion experiment to examine the responses of grassy ecosystem paleofire activity (through charcoal proxies) to continental differences in extinction severity. Grassy ecosystem fire activity increased in response to herbivore extinction, with larger increases on continents that suffered the largest losses of grazers; browser declines had no such effect.

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An asteroid impact in the Yucatán Peninsula set off a sequence of events that led to the Cretaceous-Paleogene (K-Pg) mass extinction of 76% species, including the nonavian dinosaurs. The impact hit a carbonate platform and released sulfate aerosols and dust into Earth's upper atmosphere, which cooled and darkened the planet-a scenario known as an impact winter. Organic burn markers are observed in K-Pg boundary records globally, but their source is debated.

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That fire facilitated the late Miocene C grassland expansion is widely suspected but poorly documented. Fire potentially tied global climate to this profound biosphere transition by serving as a regional-to-local driver of vegetation change. In modern environments, seasonal extremes in moisture amplify the occurrence of fire, disturbing forest ecosystems to create niche space for flammable grasses, which in turn provide fuel for frequent fires.

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Background: Ofatumumab is a humanized anti-CD20 monoclonal antibody that has recently garnered interest as a potential therapeutic agent for nephrotic syndrome. We report our center's experience in administering ofatumumab to five pediatric patients with idiopathic nephrotic syndrome.

Methods: Between March 2015 and November 2016, five patients were treated with ofatumumab.

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Suggestions that novel, non-food, dedicated biomass crops used to produce bioenergy may provide opportunities to diversify and reinstate biodiversity in intensively managed farmland have not yet been fully tested at the landscape scale. Using two of the largest, currently available landscape-scale biodiversity data sets from arable and biomass bioenergy crops, we take a taxonomic and functional trait approach to quantify and contrast the consequences for biodiversity indicators of adopting dedicated biomass crops on land previously cultivated under annual, rotational arable cropping. The abundance and community compositions of biodiversity indicators in fields of break and cereal crops changed when planted with the dedicated biomass crops, miscanthus and short rotation coppiced (SRC) willow.

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Willow species () are important as short-rotation biomass crops for bioenergy, which creates a demand for faster genetic improvement and breeding through deployment of molecular marker-assisted selection (MAS). To find markers associated with important adaptive traits, such as growth and phenology, for use in MAS, we genetically dissected the trait variation of a (L.) population of 323 accessions.

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The pathogenesis of childhood-onset nephrotic syndrome (NS), disparity in incidence of NS among races, and variable responses to therapies in children with NS have defied explanation to date. In the last 20 years over 50 genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, and at least two disease loci for two pathologic variants of SRNS (focal segmental glomerulosclerosis and membranous nephropathy) have been defined. However, the genetic causes and risk loci for steroid-sensitive nephrotic syndrome (SSNS) remain elusive, partly because SSNS is relatively rare and also because cases of SSNS vary widely in phenotypic expression over time.

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Identifying key performance traits is essential for elucidating crop growth processes and breeding. In Salix spp., genotypic diversity is being exploited to tailor new varieties to overcome environmental yield constraints.

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Willows ( spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes.

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Older adults with asthma face numerous barriers to effective self-management and asthma control, and experience worse outcomes than younger asthmatics. Yet, there have been no controlled trials of interventions specifically designed to improve their care and outcomes. Through a multi-stakeholder collaboration (patients, academia, community-based organizations, a state department of health, and an advocacy organization) we developed a multi-component asthma self-management support intervention to address the myriad psychosocial, functional, health status, and cognitive barriers to effective asthma self-management in adults ages 60 and older.

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