477 research outputs found

    Influence of specialization among anglers and hikers on information needs and site attribute preferences during site selection

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    Galaxy Zoo: comparing the demographics of spiral arm number and a new method for correcting redshift bias

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    The majority of galaxies in the local Universe exhibit spiral structure with a variety of forms. Many galaxies possess two prominent spiral arms, some have more, while others display a many-armed flocculent appearance. Spiral arms are associated with enhanced gas content and star formation in the discs of low-redshift galaxies, so are important in the understanding of star formation in the local universe. As both the visual appearance of spiral structure, and the mechanisms responsible for it vary from galaxy to galaxy, a reliable method for defining spiral samples with different visual morphologies is required. In this paper, we develop a new debiasing method to reliably correct for redshift-dependent bias in Galaxy Zoo 2, and release the new set of debiased classifications. Using these, a luminosity-limited sample of ∼18 000 Sloan Digital Sky Survey spiral galaxies is defined, which are then further sub-categorized by spiral arm number. In order to explore how different spiral galaxies form, the demographics of spiral galaxies with different spiral arm numbers are compared. It is found that whilst all spiral galaxies occupy similar ranges of stellar mass and environment, many-armed galaxies display much bluer colours than their two-armed counterparts. We conclude that two-armed structure is ubiquitous in star-forming discs, whereas many-armed spiral structure appears to be a short-lived phase, associated with more recent, stochastic star-formation activity

    Geostatistical analysis of centimeter-scale hydraulic conductivity variations at the MADE site

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    This is the published version. Copyright American Geophysical Union[1] Spatial variations in hydraulic conductivity (K) provide critical controls on solute transport in the subsurface. Recently, new direct-push tools were developed for high-resolution characterization of K variations in unconsolidated settings. These tools were applied to obtain 58 profiles (vertical resolution of 1.5 cm) from the heavily studied macrodispersion experiment (MADE) site. We compare the data from these 58 profiles with those from the 67 flowmeter profiles that have served as the primary basis for characterizing the heterogeneous aquifer at the site. Overall, the patterns of variation displayed by the two data sets are quite similar, in terms of both large-scale structure and autocorrelation characteristics. The direct-push K values are, on average, roughly a factor of 5 lower than the flowmeter values. This discrepancy appears to be attributable, at least in part, to opposite biases between the two methods, with the current versions of the direct-push tools underestimating K in the highly permeable upper portions of the aquifer and the flowmeter overestimating K in the less permeable lower portions. The vertically averaged K values from a series of direct-push profiles in the vicinity of two pumping tests at the site are consistent with the K estimates from those tests, providing evidence that the direct-push estimates are of a reasonable magnitude. The results of this field demonstration show that direct-push profiling has the potential to characterize highly heterogeneous aquifers with a speed and resolution that has not previously been possible

    Early human impacts and ecosystem reorganization in southern-central Africa

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    Modern Homo sapiens engage in substantial ecosystem modification, but it is difficult to detect the origins or early consequences of these behaviors. Archaeological, geochronological, geomorphological, and paleoenvironmental data from northern Malawi document a changing relationship between forager presence, ecosystem organization, and alluvial fan formation in the Late Pleistocene. Dense concentrations of Middle Stone Age artifacts and alluvial fan systems formed after ca. 92 thousand years ago, within a paleoecological context with no analog in the preceding half-million-year record. Archaeological data and principal coordinates analysis indicate that early anthropogenic fire relaxed seasonal constraints on ignitions, influencing vegetation composition and erosion. This operated in tandem with climate-driven changes in precipitation to culminate in an ecological transition to an early, pre-agricultural anthropogenic landscape.info:eu-repo/semantics/publishedVersio

    Multiomics links global surfactant dysregulation with airflow obstruction and emphysema in COPD

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    RATIONALE: Pulmonary surfactant is vital for lung homeostasis as it reduces surface tension to prevent alveolar collapse and provides essential immune-regulatory and antipathogenic functions. Previous studies demonstrated dysregulation of some individual surfactant components in COPD. We investigated relationships between COPD disease measures and dysregulation of surfactant components to gain new insights into potential disease mechanisms. METHODS: Bronchoalveolar lavage proteome and lipidome were characterised in ex-smoking mild/moderate COPD subjects (n=26) and healthy ex-smoking (n=20) and never-smoking (n=16) controls using mass spectrometry. Serum surfactant protein analysis was performed. RESULTS: Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, surfactant protein (SP)-B, SP-A and SP-D concentrations were lower in COPD versus controls (log2 fold change (log2FC) -2.0, -2.2, -1.5, -0.5, -0.7 and -0.5 (adjusted p<0.02), respectively) and correlated with lung function. Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, SP-A, SP-B, SP-D, napsin A and CD44 inversely correlated with computed tomography small airways disease measures (expiratory to inspiratory mean lung density) (r= -0.56, r= -0.58, r= -0.45, r= -0.36, r= -0.44, r= -0.37, r= -0.40 and r= -0.39 (adjusted p<0.05)). Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, SP-A, SP-B, SP-D and NAPSA inversely correlated with emphysema (% low-attenuation areas): r= -0.55, r= -0.61, r= -0.48, r= -0.51, r= -0.41, r= -0.31 and r= -0.34, respectively (adjusted p<0.05). Neutrophil elastase, known to degrade SP-A and SP-D, was elevated in COPD versus controls (log2FC 0.40, adjusted p=0.0390), and inversely correlated with SP-A and SP-D. Serum SP-D was increased in COPD versus healthy ex-smoking volunteers, and predicted COPD status (area under the curve 0.85). CONCLUSIONS: Using a multiomics approach, we demonstrate, for the first time, global surfactant dysregulation in COPD that was associated with emphysema, giving new insights into potential mechanisms underlying the cause or consequence of disease

    Telemedicine Evaluations in Neuro-Ophthalmology During the COVID19 Pandemic: Patient and Physician Surveys

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    Background: The novel coronavirus 2019 (COVID-19) pandemic has transformed healthcare. With the need to limit COVID-19 exposures, telemedicine has become an increasingly important format for clinical care. Compared to other fields, neuro-ophthalmology faces unique challenges given its dependence on physical examination signs that are difficult to elicit outside the office setting. As such, it is imperative to understand both patient and provider experiences in order to continue to adapt the technology and tailor its application. The purpose of this study is to analyze both neuro-ophthalmology physician and patient satisfaction with virtual health visits during the time of the COVID-19 pandemic. Methods: Across three institutions (NYU Langone Health, Indiana University Health, and Columbia University Medical Center), telemedicine surveys were administered to 159 patients. Neuro-ophthalmologists completed 157 surveys; each of these were linked to a single patient visit. Patient surveys consisted of five questions regarding visit preparation, satisfaction, challenges, and comfort. The physician survey included four questions that focused on ability to gather specific clinical information by history and examination. Results: Among 159 patients, 104 (65.4%) reported that they were satisfied with the visit, and 149 (93.7%) indicated that they were comfortable asking questions. Sixty-eight (73.9%) patients found the instructions provided prior to the visit easy to understand. Potential areas for improvement noted by patients included more detailed preparation instructions and better technology (phone positioning, internet connection, software). Over 87% (137/157) of neuroophthalmologists surveyed reported having performed an examination that provided enough information for medical decision-making. Some areas of the neuro-ophthalmologic exam were reported to be easy to conduct (range of eye movements, visual acuity, Amsler grids, Ishihara color plates, and pupillary exam). Other components were more difficult (saccades, red desaturation, visual fields, convergence, oscillations, ocular alignment, and smooth pursuit); some were especially challenging (vestibulo-ocular reflex [VOR], VOR suppression, and optokinetic nystagmus). Clinicians noted that virtual health visits were limited by patient preparation, inability to perform certain parts of the examination (funduscopy and pupils), and technological issues. Conclusions: Among virtual neuro-ophthalmology visits evaluated, most offer patients with appointments that satisfy their needs. The majority of physicians in this cohort obtained adequate clinical information for decision-making. Even better technology and instructions may help improve aspects of virtual health visits
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