418 research outputs found
Hasse-Schmidt Derivations and Coefficient Fields in Positive Characteristics
We show how to express any Hasse-Schmidt derivation of an algebra in terms of
a finite number of them under natural hypothesis. As an application, we obtain
coefficient fields of the completion of a regular local ring of positive
characteristic in terms of Hasse-Schmidt derivationsComment: 14 pages; A gap in the statement of Proposition (2.7) has been fixed
and the proof of Theorem (3.14) has been adapte
SIGGMA: A Survey of Ionized Gas in the Galaxy, Made with the Arecibo Telescope
A Survey of Ionized Gas in the Galaxy, made with the Arecibo telescope
(SIGGMA) uses the Arecibo L-band Feed Array (ALFA) to fully sample the Galactic
plane (30 < l < 75 and -2 < b < 2; 175 < l < 207 and -2 < b < 1) observable
with the telescope in radio recombination lines (RRLs). Processed data sets are
being produced in the form of data cubes of 2 degree (along l) x 4 degree
(along b) x 151 (number of channels), archived and made public. The 151
channels cover a velocity range of 600 km/s and the velocity resolution of the
survey changes from 4.2 km/s to 5.1 km/s from the lowest frequency channel to
the highest frequency channel, respectively.RRL maps with 3.4 arcmin resolution
and line flux density sensitivity of 0.5 mJy will enable us to identify new HII
regions, measure their electron temperatures, study the physics of
photodissociation regions (PDRs) with carbon RRLs, and investigate the origin
of the extended low density medium (ELDM). Twelve Hn{\alpha} lines fall within
the 300 MHz bandpass of ALFA; they are resampled to a common velocity
resolution to improve the signal-to-noise ratio (SN) by a factor of 3 or more
and preserve the line width. SIGGMA will produce the most sensitive fully
sampled RRL survey to date. Here we discuss the observing and data reduction
techniques in detail. A test observation toward the HII region complex
S255/S257 has detected Hn{\alpha} and Cn{\alpha} lines with SN>10
There is a low rate of major adverse cardiovascular events in chest pain patients with a moderate risk heart score referred from urgent care for expedited outpatient cardiology evaluation: a multi-center study
Background The HEART score is an effective method of risk stratifying emergency department (ED) patients with chest pain. The rate of major adverse cardiovascular events (MACE) in patients with moderate HEART score referred from an urgent care (UC) for an expedited outpatient cardiology evaluation for 11 months was described in 133 patients in a previous study. This is a follow-up study with 18 months of data and 206 patients.Aim. The primary outcome was to examine the rate of MACE when patients with moderate HEART score were referred for an expedited outpatient cardiology follow-up after evaluation in urgent care. The secondary outcome was to determine if there is a decrease in rate of ED transfer after this protocol was introduced.Methods. A cross-sectional study was conducted by a multispecialty group in Las Vegas, Nevada, which included 206 patients with a HEART score of 4 to 6 (i.e.: moderate risk) who presented to one of five UC centers with chest pain or an anginal equivalent. A streamlined evaluation protocol to assess each HEART score component was adopted by all UC providers to facilitate an expedited outpatient cardiology follow-up, as an alternative to referral to the emergency department. Data was collected from February 14, 2019 through August 13, 2020. The population was followed for 6 weeks with a primary endpoint of MACE determined by electronic medical record review and direct phone contact with patients. Outcomes were confirmed in 98% of patients. Chest pain transfer data was compared between 12 months prior to implementing HEART protocol and 18 months of data analysis while using the new protocol.Results. Over the course of 18 months, 206 patients with a moderate risk HEART score were referred to outpatient cardiology in an expedited manner. The average age was 65 with 53% female and 47% male patients. 150 patients (73% of the 206) were seen within 3 days, 114 (55%) underwent stress testing, 6 (3%) had coronary computed tomography angiogram, and 6 (3%) received an invasive coronary angiogram. Five patients were found to have MACE: one patient who had a non-ST-elevation myocardial infarction and subsequent coronary stent, two patients were found to have obstructive disease after coronary angiography with subsequent coronary artery bypass graft, one patient had an abnormal stress test and subsequent coronary stent, and one patient had critical mitral stenosis, multi-vessel coronary artery disease and underwent coronary artery bypass graft with mitral valve replacement with complications of renal failure and COVID-19 and expired. The emergency department referral rate declined by 21%.Conclusion. Patients with a moderate risk HEART score referred from UC for an expedited outpatient cardiology evaluation had a low rate of MACE and no deaths due to delay of care. There was also a significant decrease in the rate of ED referrals.Background. The HEART score is an effective method of risk stratifying emergency department (ED) patients with chest pain. The rate of major adverse cardiovascular events (MACE) in patients with moderate HEART score referred from an urgent care (UC) for an expedited outpatient cardiology evaluation for 11 months was described in 133 patients in a previous study. This is a follow-up study with 18 months of data and 206 patients.Aim. The primary outcome was to examine the rate of MACE when patients with moderate HEART score were referred for an expedited outpatient cardiology follow-up after evaluation in urgent care. The secondary outcome was to determine if there is a decrease in rate of ED transfer after this protocol was introduced.Methods. A cross-sectional study was conducted by a multispecialty group in Las Vegas, Nevada, which included 206 patients with a HEART score of 4 to 6 (i.e.: moderate risk) who presented to one of five UC centers with chest pain or an anginal equivalent. A streamlined evaluation protocol to assess each HEART score component was adopted by all UC providers to facilitate an expedited outpatient cardiology follow-up, as an alternative to referral to the emergency department. Data was collected from February 14, 2019 through August 13, 2020. The population was followed for 6 weeks with a primary endpoint of MACE determined by electronic medical record review and direct phone contact with patients. Outcomes were confirmed in 98% of patients. Chest pain transfer data was compared between 12 months prior to implementing HEART protocol and 18 months of data analysis while using the new protocol.Results. Over the course of 18 months, 206 patients with a moderate risk HEART score were referred to outpatient cardiology in an expedited manner. The average age was 65 with 53% female and 47% male patients. 150 patients (73% of the 206) were seen within 3 days, 114 (55%) underwent stress testing, 6 (3%) had coronary computed tomography angiogram, and 6 (3%) received an invasive coronary angiogram. Five patients were found to have MACE: one patient who had a non-ST-elevation myocardial infarction and subsequent coronary stent, two patients were found to have obstructive disease after coronary angiography with subsequent coronary artery bypass graft, one patient had an abnormal stress test and subsequent coronary stent, and one patient had critical mitral stenosis, multi-vessel coronary artery disease and underwent coronary artery bypass graft with mitral valve replacement with complications of renal failure and COVID-19 and expired. The emergency department referral rate declined by 21%.Conclusion. Patients with a moderate risk HEART score referred from UC for an expedited outpatient cardiology evaluation had a low rate of MACE and no deaths due to delay of care. There was also a significant decrease in the rate of ED referrals
Characterization of Trypsin-like activity from Pyloric Caeca of the Red Hind Grouper, Epinephelus guttatus: considerations of use as an environmental indicator
Sustained striatal ciliary neurotrophic factor expression negatively affects behavior and gene expression in normal and R6/1 mice
Huntington's disease (HD) is a neurodegenerative disorder caused by an elongation of CAG repeats in the HD gene, which encodes a mutant copy of huntingtin with an expanded polyglutatmine repeat. Individuals who are affected by the disease suffer from motor, cognitive, and emotional impairments. Levels of certain striatal-enriched mRNAs decrease in both HD patients and transgenic HD mice prior to the development of motor symptoms and neuronal cell death. Ciliary neurotrophic factor (CNTF) has been shown to protect neurons against chemically induced toxic insults in vitro and in vivo. To test the hypothesis that CNTF might protect neurons from the negative effects of the mutant huntingtin protein in vivo, CNTF was continuously expressed following transduction of the striatum by recombinant adeno-associated viral vectors (rAAV2). Wild-type and R6/1 HD transgenic (R6/1) mice that received bilateral or unilateral intrastriatal injections of rAAV2-CNTF experienced weight loss. The CNTF-treated R6/1 HD transgenic mice experienced motor impairments at an earlier age than expected compared with age-matched control R6/1 HD transgenic animals. CNTF also caused abnormal behavior in WT mice. In addition to behavioral impairments, in situ hybridization showed that, in both WT and R6/1 mice, CNTF expression caused a significant decrease in the levels of striatal-enriched transcripts. Overall, continuous expression of striatal CNTF at the dose mediated by the expression cassette used in this study was detrimental to HD and wild-type mice. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58641/1/21636_ftp.pd
The Arecibo Arp 220 Spectral Census I: Discovery of the Pre-Biotic Molecule Methanimine and New Cm-wavelength Transitions of Other Molecules
An on-going Arecibo line search between 1.1 and 10 GHz of the prototypical
starburst/megamaser galaxy, Arp 220, has revealed a spectrum rich in molecular
transitions. These include the ``pre-biotic'' molecules: methanimine
(CHNH) in emission, three direct l-type absorption lines of
HCN, and an absorption feature likely to be from either OH or formic
acid (HCOOH). In addition, we report the detection of two, possibly three,
transitions of 4-cm excited OH not previously detected in Arp~220
which are seen in absorption, and a possible absorption feature from the
6.668-GHz line of methanol. This marks the first distant extragalactic
detection of methanimine, a pre-biotic molecule. Also, if confirmed, the
possible methanol absorption line presented here would represent the first
extragalactic detection of methanol at a distance further than 10 Mpc. In
addition, the strong, previously undetected, cm-wave HCN direct
l-type lines will aid the study of dense molecular gas and active star-forming
regions in this starburst galaxy.Comment: 25 pages, 10 figures. Accepted for publication in A
Binding of DNA by a dinitro-diester calix[4]arene: denaturation and condensation of DNA
A study of a dinitro-diester calix[4]arene (5,17-(3-nitrobenzylideneamino)-11,23-di-tert-butyl- 25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene) interaction with calf-thymus DNA was carried out using several techniques. The measurements were done at various molar ratios X=[calixarene]/[DNA]. Results show diverse changes in the DNA conformation depending on the X value. Thus, at low macrocycle concentration, the calixarene binds to the polynucleotide. This interaction, mainly in groove mode, weakens the hydrogen bonds between the base pairs of the helix inducing the denaturation of the double strands, as well as the condensation of the macromolecule, from an extended coil state to a globular state. An opposite effect is observed at X molar ratios higher than 0.07. The de-condensation of DNA happens, that is, the transition from a compact state to a more extended conformation, probably due to the stacking of calixarene molecules in the solution. Results also show the importance of making a proper choice of the system under consideration
In-Situ TEM-STM Observations of SWCNT Ropes/Tubular Transformations
Single-walled carbon nanotubes (SWCNTs) prepared by the HiPco process were purified using a modified gas phase purification technique. A TEM-STM holder was used to study the morphological changes of SWCNT ropes as a function of applied voltage. Kink formation, buckling behavior, tubular transformation and eventual breakdown of the system were observed. The tubular formation was attributed to a transformation from SWCNT ropes to multi-walled carbon nanotube (MWCNT) structures. It is likely mediated by the patching and tearing mechanism which is promoted primarily by the mobile vacancies generated due to current-induced heating and, to some extent, by electron irradiation
Scope to predict soil properties at within-field scale from small samples using proximally sensed γ-ray spectrometer and EM induction data
Spatial predictions of soil properties are needed for various purposes. However, the costs associated with soil sampling and laboratory analysis are substantial. One way to improve efficiencies is to combine measurement of soil properties with collection of cheaper-to-measure ancillary data. There are two possible approaches. The first is the formation of classes from ancillary data. A second is the use of a simple predictive linear model of the target soil property on the ancillary variables. Here, results are presented and compared where proximally sensed gamma-ray (γ-ray) spectrometry and electromagnetic induction (EMI) data are used to predict the variation in topsoil properties (e.g. clay content and pH). In the first instance, the proximal data is numerically clustered using a fuzzy k-means (FKM) clustering algorithm, to identify contiguous classes. The resultant digital soil maps (i.e. k = 2–10 classes) are consistent with a soil series map generated using traditional soil profile description, classification and mapping methods at a highly variable site near the township of Shelford, Nottinghamshire UK. In terms of prediction, the calculated expected value of mean squared prediction error (i.e. σ2p,C) indicated that values of k = 7 and 8 were ideal for predicting clay and pH. Secondly, a linear mixed model (LMM) is fitted in which the proximal data are fixed effects but the residuals are treated as a combination of a spatially correlated random effect and an independent and identically distributed error. In terms of prediction, the expected value of the mean squared prediction error from a regression (σ2p,R) suggested that the regression models were able to predict clay content, better than FKM clustering. The reverse was true with respect to pH, however. We conclude that both methods have merit. In the case of the clustering the approach is able to account for soil properties which have non-linearity's with the ancillary data (i.e. pH), whereas the LMM approach is best when there is a strong linear relationship (i.e. clay)
Evaluation of mesofauna communities as soil quality indicators in a national-level monitoring programme
Mesofauna underpin many ecosystem functions in soils. However, mesofauna communities are often overlooked when discussing these functions on large scales. They have been proposed as bioindicators of soil quality and ecosystem health. This study aimed to evaluate differences amongst mesofauna communities, particularly Acari and Collembola, across multiple habitat and soil types, as well as organic matter levels, and their relationships with soil characteristics, on a national-scale. Soil cores were collected from 685 locations as part of a nationwide soil monitoring programme of Wales. Plant community composition, soil type, as well as physical and chemical variables, including pH, total C and N, were measured at these locations. Mesofauna were extracted from soil cores and identified using a Tullgren funnel technique. Acari were sorted to Order; Collembola were sorted according to Super-family. Abundances of mesofauna were consistently lowest in arable sites and highest in lowland woodlands, except for Mesostigmata. Differences between similar habitat types (e.g. Fertile and Infertile grasslands) were not detected using the national-level dataset and differences in mesofauna communities amongst soil types were unclear. Relationships between mesofauna groups and soil organic matter class, however, were much more informative. Oribatid abundances were lowest in mineral soils and correlated with all soil properties except moisture content. Collembola and Mesostigmata abundances were likely negatively influenced by increased moisture levels in upland peat habitats where their abundances were lowest. These groups also had low abundances in heathlands and this was reflected in low diversity values. Together, these findings show that this national-level soil survey can effectively identify differences in mesofauna community structure and correlations with soil properties. Identification of mesofauna at high taxonomic levels in national-level soil monitoring is encouraged to better understand the ecological context of changes in soil properties
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