337 research outputs found
Cold Harbor Syndrome: Balanced, Compelling Study\u27 Examines Grant\u27s Overland Miscalculations
Ulysses S. Grant\u27s offensive against Robert E. Lee\u27s entrenched Army of Northern Virginia at Cold Harbor on June 3, 1864, summons powerful images. Northern assaults that day stand alongside Ambrose E. Burnside\u27s attacks at Fredericksburg and John Bell Hood\u27s at Franklin as examples of seemingly poin...
An Analysis of Milk Assembly Costs in the Greater Ohio Area: A Multi-Output Approach
A non-traditional multi-output cost function for milk haulers is estimated. Hauling firm outputs are (i) assembly miles, (ii) transport miles, and (iii) volume of milk hauled. Data were provided by 40 firms. The estimated cost function is shown to exhibit substantial economies of scale for all three joint outputs
Crucible of the Civil War: Virginia from Secession to Commemoration
Crucible of the Civil War offers an illuminating portrait of the state’s wartime economic, political, and social institutions. Weighing in on contentious issues within established scholarship while also breaking ground in areas long neglected by scholars, the contributors examine such concerns as the war’s effect on slavery in the state, the wartime intersection of race and religion, and the development of Confederate social networks. They also shed light on topics long disputed by historians, such as Virginia’s decision to secede from the Union, the development of Confederate nationalism, and how Virginians chose to remember the war after its close.https://scholarship.richmond.edu/bookshelf/1258/thumbnail.jp
Nerve conduction studies are safe in patients with central venous catheters
IntroductionIt is unknown if central venous catheters bypass the skin’s electrical resistance and engender a risk of nerve conduction study‐induced cardiac arrhythmia. The objective of this study is to determine if nerve conduction studies affect cardiac conduction and rhythm in patients with central venous catheters.MethodsUnder continuous 12‐lead electrocardiogram monitoring, subjects with and without central venous catheters underwent a series of upper extremity nerve conduction studies. A cardiologist reviewed the electrocardiogram tracings for evidence of cardiac conduction abnormality or arrhythmia.ResultsTen control subjects and 10 subjects with central venous catheters underwent the nerve conduction study protocol. No malignant arrhythmias or conduction abnormalities were noted in either group.ConclusionsNerve conduction studies of the upper extremities, including both proximal stimulation and repetitive stimulation, do not appear to confer increased risk of cardiac conduction abnormality in those patients with central venous catheters who are not critically ill or have a prior history of arrhythmia. Muscle Nerve 56: 321–323, 2017Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137740/1/mus25497.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137740/2/mus25497_am.pd
Observations and simulations of nova Vul 1984 no. 2: A nova with ejecta rich in oxygen, neon, and magnesium
Nova Vul 1984 no. 2 was observed with IUE from Dec. 1984 through Nov. 1987. The spectra are characterized by strong lines from Mg, Ne, C, Si, O, N, and other elements. Data obtained in the ultraviolet, infrared, and optical show that this nova is ejecting material rich in oxygen, neon, and magnesium
The Aspergillus fumigatus Protein GliK Protects against Oxidative Stress and Is Essential for Gliotoxin Biosynthesis
The function of a number of genes in the gliotoxin biosynthetic cluster (gli) in Aspergillus fumigatus remains unknown. Here, we
demonstrate that gliK deletion from two strains of A. fumigatus completely abolished gliotoxin biosynthesis. Furthermore,
exogenous H2O2 (1 mM), but not gliotoxin, significantly induced A. fumigatus gliK expression (P 0.0101). While both mutants
exhibited significant sensitivity to both exogenous gliotoxin (P<0.001) and H2O2 (P<0.01), unexpectedly, exogenous
gliotoxin relieved H2O2-induced growth inhibition in a dose-dependent manner (0 to 10 g/ml). Gliotoxin-containing organic
extracts derived from A. fumigatus ATCC 26933 significantly inhibited (P<0.05) the growth of the gliK26933 deletion mutant.
The A. fumigatus gliK26933 mutant secreted metabolites, devoid of disulfide linkages or free thiols, that were detectable by reverse-
phase high-performance liquid chromatography and liquid chromatography-mass spectrometry with m/z 394 to 396.
These metabolites (m/z 394 to 396) were present at significantly higher levels in the culture supernatants of the A. fumigatus
gliK26933 mutant than in those of the wild type (P0.0024 [fold difference, 24] and P0.0003 [fold difference, 9.6], respectively)
and were absent from A. fumigatus gliG. Significantly elevated levels of ergothioneine were present in aqueous mycelial
extracts of the A. fumigatus gliK26933 mutant compared to the wild type (P<0.001). Determination of the gliotoxin uptake rate
revealed a significant difference (P0.0045) between that of A. fumigatus ATCC 46645 (9.3 pg/mg mycelium/min) and the
gliK46645 mutant (31.4 pg/mg mycelium/min), strongly suggesting that gliK absence and the presence of elevated ergothioneine
levels impede exogenously added gliotoxin efflux. Our results confirm a role for gliK in gliotoxin biosynthesis and reveal new
insights into gliotoxin functionality in A. fumigatus
Aging modulates the effects of ischemic injury upon mesenchymal cells within the renal interstitium and microvasculature
Abstract The renal mesenchyme contains heterogeneous cells, including interstitial fibroblasts and pericytes, with key roles in wound healing. Although healing is impaired in aged kidneys, the effect of age and injury on the mesenchyme remains poorly understood. We characterized renal mesenchymal cell heterogeneity in young vs old animals and after ischemia‐reperfusion‐injury (IRI) using multiplex immunolabeling and single cell transcriptomics. Expression patterns of perivascular cell markers (α‐SMA, CD146, NG2, PDGFR‐α, and PDGFR‐β) correlated with their interstitial location. PDGFR‐α and PDGFR‐β co‐expression labeled renal myofibroblasts more efficiently than the current standard marker α‐SMA, and CD146 was a superior murine renal pericyte marker. Three renal mesenchymal subtypes; pericytes, fibroblasts, and myofibroblasts, were recapitulated with data from two independently performed single cell transcriptomic analyzes of murine kidneys, the first dataset an aging cohort and the second dataset injured kidneys following IRI. Mesenchymal cells segregated into subtypes with distinct patterns of expression with aging and following injury. Baseline uninjured old kidneys resembled post‐ischemic young kidneys, with this phenotype further exaggerated following IRI. These studies demonstrate that age modulates renal perivascular/interstitial cell marker expression and transcriptome at baseline and in response to injury and provide tools for the histological and transcriptomic analysis of renal mesenchymal cells, paving the way for more accurate classification of renal mesenchymal cell heterogeneity and identification of age‐specific pathways and targets
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Aircraft and ground measurements of dust aerosols over the west African coast in summer 2015 during ICE-D and AER-D
During the summertime, dust from the Sahara can be efficiently transported westwards within the Saharan air layer (SAL). This can lead to high aerosol loadings being observed above a relatively clean marine boundary layer (MBL) in the tropical Atlantic Ocean. These dust layers can impart significant radiative effects through strong visible and IR light absorption and scattering, and can also have indirect impacts by altering cloud properties. The processing of the dust aerosol can result in changes in both direct and indirect radiative effects, leading to significant uncertainty in climate prediction in this region. During August 2015, measurements of aerosol and cloud properties were conducted off the coast of west Africa as part of the Ice in Cloud Experiment - Dust (ICE-D) and AERosol properties - Dust (AER-D) campaigns. Observations were obtained over a 4-week period using the UK Facility for Atmospheric Airborne Measurements (FAAM) BAe 146 aircraft based on Santiago Island, Cabo Verde. Ground-based observations were collected from Praia (14∘57′ N, 23∘29′ W; 100 m a.s.l.), also located on Santiago Island. The dust in the SAL was mostly sampled in situ at altitudes of 2-4 km, and the potential dust age was estimated by backward trajectory analysis. The particle mass concentration (at diameter d = 0.1-20 µm) decreased with transport time. Mean effective diameter (Deff) for supermicron SAL dust (d = 1-20 µm) was found to be 5-6 µm regardless of dust age, whereas submicron Deff (d = 0.1-1 µm) showed a decreasing trend with longer transport. For the first time, an airborne laser-induced incandescence instrument (the single particle soot photometer - SP2) was deployed to measure the hematite content of dust. For the Sahel-influenced dust in the SAL, the observed hematite mass fraction of dust (FHm) was found to be anti-correlated with the single scattering albedo (SSA, λ = 550 nm, for particles d < 2.5 µm); as potential dust age increased from 2 to 7 days, FHm increased from 2.5 to 4.5 %, SSA decreased from 0.97 to 0.93 and the derived imaginary part (k) of the refractive index at 550 nm increased from 0.0015 to 0.0035. However, the optical properties of Sahara-influenced plumes (not influenced by the Sahel) were independent of dust age and hematite content with SSA ∼ 0.95 and k ∼ 0.0028. This indicates that the absorbing component of dust may be source dependent, or that gravitational settling of larger particles may lead to a higher fraction of more absorbing clay-iron aggregates at smaller sizes. Mie calculation using the measured size distribution and size-resolved refractive indices of the absorbing components (black carbon and hematite) reproduces the measured SSA to within ±0.02 for SAL dust by assuming a goethite ∕ hematite mass ratio of 2. Overall, hematite and goethite constituted 40-80 % of the absorption for particles d < 2.5 µm, and black carbon (BC) contributed 10-37 %. This highlights the importance of size-dependent composition in determining the optical properties of dust and also the contribution from BC within dust plumes
The Evolution of Sunspot Magnetic Fields Associated with a Solar Flare
Solar flares occur due to the sudden release of energy stored in
active-region magnetic fields. To date, the pre-cursors to flaring are still
not fully understood, although there is evidence that flaring is related to
changes in the topology or complexity of an active region's magnetic field.
Here, the evolution of the magnetic field in active region NOAA 10953 was
examined using Hinode/SOT-SP data, over a period of 12 hours leading up to and
after a GOES B1.0 flare. A number of magnetic-field properties and low-order
aspects of magnetic-field topology were extracted from two flux regions that
exhibited increased Ca II H emission during the flare. Pre-flare increases in
vertical field strength, vertical current density, and inclination angle of ~
8degrees towards the vertical were observed in flux elements surrounding the
primary sunspot. The vertical field strength and current density subsequently
decreased in the post-flare state, with the inclination becoming more
horizontal by ~7degrees. This behaviour of the field vector may provide a
physical basis for future flare forecasting efforts.Comment: Accepted for Publication in Solar Physics. 16 pages, 4 figure
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