1,954 research outputs found
An Account of the Collections Which Illustrate the Labors of Dr. Asa Fitch
Volume: 2 ; Start Page: 273 ; End Page: 27
List of Iowa Clover Insects and Observations on Some of Them
The following list of Iowa clover insects comprises those species enumerated by Profs. J. A. Lintner and C. M. Weed as clover feeders which are known to occur in the State with such additions as personal observation or accepted authority will permit. All insects listed occur in the collections of the Iowa Agricultural College, and the notes in connection with any individual insect refer only to its occurrence on clover
Amplification of wet and dry month occurrence over tropical land regions in response to global warming
Quantifying how global warming impacts the spatiotemporal distribution of precipitation represents a key scientific challenge with profound implications for human welfare. Utilizing monthly precipitation data from Coupled Model Intercomparison Project (CMIP3) climate change simulations, the results here show that the occurrence of very dry (10 mm/day) months comprises a straightforward, robust metric of anthropogenic warming on tropical land region rainfall. In particular, differencing tropics-wide precipitation frequency histograms for 25-year periods over the late 21st and 20th centuries shows increased late-21st-century occurrence of histogram extremes both in the model ensemble and across individual models. Mechanistically, such differences are consistent with the view of enhanced tropical precipitation spatial gradients. Similar diagnostics are calculated for two 15-year subperiods over 1979â2008 for the CMIP3 models and three observational precipitation products to assess whether the signature of late-21st-century warming has already emerged in response to recent warming. While both the observations and CMIP3 ensemble-mean hint at similar amplification in the warmer (1994â2008) subinterval, the changes are not robust, as substantial differences are evident among the observational products and the intraensemble spread is large. Comparing histograms computed from the warmest and coolest years of the observational period further demonstrates effects of internal variability, notably the El Niño/Southern Oscillation, which appear to oppose the impact of quasi-uniform anthropogenic warming on the wet tail of the monthly precipitation distribution. These results identify the increase of very dry and wet occurrences in monthly precipitation as a potential signature of anthropogenic global warming but also highlight the continuing dominance of internal climate variability on even bulk measures of tropical rainfall
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Scaling in Surface Hydrology: Progress and Challenges
This paper presents a review of the challenges in spatial and temporal scales in surface hydrology. Fundamental issues and gaps in our understanding of hydrologic scaling are highlighted and shown to limit predictive skill, with heterogeneities, nonlinearities, and non-local transport processes among the most significant difficulties faced in scaling. The discrepancy between the physical process scale and the measurement scale has played a major role in restricting the development of theories, for example, relating observational scales to scales of climate and weather models. Progress in our knowledge of scaling in hydrology requires systematic determination of critical scales and scale invariance of physical processes. In addition, viewing the surface hydrologic system as composed of interacting dynamical subsystems should facilitate the definition of scales observed in nature. Such an approach would inform the development of careful, resolution-dependent, physical law formulation based on mathematical techniques and physical laws
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Sensitivity of terrestrial precipitation trends to the structural evolution of sea surface temperatures
Pronounced intermodel differences in the projected response of land surface precipitation (LSP) to future anthropogenic forcing remain in the Coupled Model Intercomparison Project Phase 5 model integrations. A large fraction of the intermodel spread in projected LSP trends is demonstrated here to be associated with systematic differences in simulated sea surface temperature (SST) trends, especially the representation of changes in (i) the interhemispheric SST gradient and (ii) the tropical Pacific SSTs. By contrast, intermodel differences in global mean SST, representative of differing global climate sensitivities, exert limited systematic influence on LSP patterns. These results highlight the importance to regional terrestrial precipitation changes of properly simulating the spatial distribution of large-scale, remote changes as reflected in the SST response to increasing greenhouse gases. Moreover, they provide guidance regarding which region-specific precipitation projections may be potentially better constrained for use in climate change impact assessments
Massive Atropine Eye Drop Ingestion Treated with High-Dose Physostigmine to Avoid Intubation
Case: A 34-year-old male presented after ingesting 150 mg of atropine. He had altered mental status, sinus tachycardia, dry mucosa, flushed skin, and hyperthermia. Sequential doses of physostigmine, totaling 14 mg, were successful in reversing antimuscarinic toxicity and prevented the need to perform airway control with endotracheal intubation. At completion of treatment, heart rate and mental status had improved, and intubation was never performed. Discussion: Atropine causes anticholinergic toxicity; physostigmine reverses this by inhibiting acetylcholinesterase. Atropine eye drop ingestions are rare. The 14 mg of physostigmine administered is much higher than typical dosing. It is likely the physostigmine prevented intubation. Atropine eye drops can be dangerous, and physostigmine should be considered in treatment. [West J Emerg Med. 2012;13(1):77â79.
The idiosyncratic pattern of Russian corporate dividend policy during its formative era
© 2018 The Authors Annals of Public and Cooperative Economics © 2018 CIRIEC In general, the dividend payout pattern for Russian corporations during their formative period from 1998 to 2006 was seemingly independent of company earnings, size, growth opportunities and capital structure, as such firm policies appear not to conform to any of the main extant dividend payout theories. The only exception we find is that of utility firms, which were inclined to pay consistent dividends. Utility firms tended to be partly owned by the state and were subject to price regulation. Consequently, they may have had limited investment prospects. Our findings suggest that dividend payout policies in non-market economies may be driven by non-traditional determinants, such as the state's overall industrial strategy
High Variability of Mesenchymal Stem Cells Obtained via Bone Marrow Aspirate Concentrate Compared With Traditional Bone Marrow Aspiration Technique
Background: Bone marrow aspirate (BMA) is a common source for harvesting mesenchymal stem cells (MSCs), other progenitor
cells, and associated cytokines and growth factors to be used in the biologic treatment of various orthopaedic pathologies. The
aspirate is commonly centrifuged into a concentrated volume that can be immediately administered to a patient using commercially available kits. However, the handling and efficacy of BMA concentrate (BMAC) are still controversial.
Purpose: To characterize BMA versus BMAC for MSC quantity, potency, and cytokine profile.
Study Design: Controlled laboratory study.
Methods: From 8 participants (age, 17-68 years), 30 mL of bone marrow was aspirated by a single surgeon from either the
proximal humerus or distal femur and was separated into 2 equal samples. One sample was kept as BMA, and the other half was
centrifuged into BMAC. The 2 samples then underwent flow cytometry for detection of MSCs, cell analysis for colony-forming units
(CFUs), and cytokine profiling. A 2-tailed t test was used to detect differences between MSCs, CFUs, and cytokine density
concentrations between BMA and BMAC.
Results: The average concentration of MSCs in both BMA and BMAC was 0.001%. Average MSC events detected by flow
cytometry were significantly higher in BMA versus BMAC (15.1 and 8.1, respectively; P < .045). Expanded MSCs demonstrated
similar phenotypes, but CFUs were significantly increased in BMA compared with BMAC (104 vs 68 CFUs, respectively; P < .001).
Total protein concentration and cytokine profiling demonstrated great variability between BMA and BMAC and between patients.
Most importantly, BMAC failed to concentrate MSCs in 6 of 8 samples.
Conclusion: There is great variability in MSC concentration, total protein concentration, and cytokine profile between BMA and
BMAC.
Clinical Relevance: When studying the clinical efficacy of BMAC, one must also evaluate the sample itself to determine the
presence, concentration, and potency of MSCs if this is to be considered a cell-based therapy. Further standard operating procedures need to be investigated to ensure reproducible results and appropriate treatments
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