410 research outputs found
Adolescents with Idiopathic Scoliosis are Not Osteoporotic
In the past, prior studies have associated adolescent idiopathic scoliosis (AIS) to abnormalities in bone mineral density (BMD) such as osteoporosis\u27 or \u27osteopenia\u27 based on their adult definitions, but in reality very few AIS patients have clinically abnormal BMD. Fracture risk has not been correlated to Z-scores in pediatric populations, so the terms \u27osteoporosis\u27 and \u27osteopenia\u27 can not be applied to AIS. Our study examined adolescents with and without scoliosis of varying weights to better understand the relationship of BMD to body mass index (BMI). This cross-sectional retrospective study compared the dual photon X-ray absorptiometry (DXA) scans of hips and distal femora of 49 adolescents with idiopathic scoliosis and 40 normal control adolescents. Z-scores were compared using student\u27s t-test or simple linear regression procedures to discover correlations between Z-scores and clinical and demographic variables. In both populations, there was a strong correlation with z-scores and BMI (p\u3c.001). Scoliosis had the effect of lowering the Z-score as if the individual had \u27lost\u27 3.4 BMI units. Essentially, thin subjects had lower BMD and heavy subjects had higher BMD. The impact of scoliosis reducing BMI scores by 3.4 units puts thin subjects in the \u27low for age\u27 level while the effect is negligible in heavier subjects. There were no subjects in either group that met the International Society of Clinical Densitometry (ICSD) definition for \u27osteoporosis.\u27\u2
Reliable Location-Based Services from Radio Navigation Systems
Loran is a radio-based navigation system originally designed for naval applications. We show that Loran-C’s high-power and high repeatable accuracy are fantastic for security applications. First, we show how to derive a precise location tag—with a sensitivity of about 20 meters—that is difficult to project to an exact location. A device can use our location tag to block or allow certain actions, without knowing its precise location. To ensure that our tag is reproducible we make use of fuzzy extractors, a mechanism originally designed for biometric authentication. We build a fuzzy extractor specifically designed for radio-type errors and give experimental evidence to show its effectiveness. Second, we show that our location tag is difficult to predict from a distance. For example, an observer cannot predict the location tag inside a guarded data center from a few hundreds of meters away. As an application, consider a location-aware disk drive that will only work inside the data center. An attacker who steals the device and is capable of spoofing Loran-C signals, still cannot make the device work since he does not know what location tag to spoof. We provide experimental data supporting our unpredictability claim
A qualitative study of overdose responses among Chicago IDUs
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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Repurposing the GNAT Fold in the Initiation of Polyketide Biosynthesis.
Natural product biosynthetic pathways are replete with enzymes repurposed for new catalytic functions. In some modular polyketide synthase (PKS)Â pathways, a GCN5-related N-acetyltransferase (GNAT)-like enzyme with an additional decarboxylation function initiates biosynthesis. Here, we probe two PKS GNAT-like domains for the dual activities of S-acyl transfer from coenzyme A (CoA) to an acyl carrier protein (ACP) and decarboxylation. The GphF and CurA GNAT-like domains selectively decarboxylate substrates that yield the anticipated pathway starter units. The GphF enzyme lacks detectable acyl transfer activity, and a crystal structure with an isobutyryl-CoA product analog reveals a partially occluded acyltransfer acceptor site. Further analysis indicates that the CurA GNAT-like domain also catalyzes only decarboxylation, and the initial acyl transfer is catalyzed by an unidentified enzyme. Thus, PKS GNAT-like domains are re-classified as GNAT-like decarboxylases. Two other decarboxylases, malonyl-CoA decarboxylase and EryM, reside on distant nodes of the superfamily, illustrating the adaptability of the GNAT fold
Preliminary statewide projections of county-level water demands in Illinois: Draft project completion report
Illinois State Water Survey and Southern Illinois University CarbondaleOpe
Outcomes of multimodal therapy in a large series of patients with anaplastic thyroid cancer
Background The role of radiotherapy (RT) in the treatment of patients with anaplastic thyroid cancer (ATC) for local tumor control is critical because mortality often is secondary to complications of tumor volume rather than metastatic disease. Herein, the authors report the long-term outcomes of RT for patients with ATC. Methods A total of 104 patients with histologically confirmed ATC were identified who presented to the study institution between 1984 and 2017 and who received curative-intent or postoperative RT. Locoregional progression-free survival (LPFS), overall survival (OS), and distant metastasis-free survival were assessed. Results The median age of the patients was 63.5 years. The median follow-up was 5.9 months (interquartile range, 2.7-17.0 months) for the entire cohort and 10.6 months (interquartile range, 5.3-40.0 months) for surviving patients. Thirty-one patients (29.8%) had metastatic disease prior to the initiation of RT. Concurrent chemoradiation was administered in 99 patients (95.2%) and 53 patients (51.0%) received trimodal therapy. Systemic therapy included doxorubicin (73.7%), paclitaxel with or without pazopanib (24.3%), and other systemic agents (2.0%). The 1-year OS and LPFS rates were 34.4% and 74.4%, respectively. On multivariate analysis, RT >= 60 Gy was associated with improved LPFS (hazard ratio [HR], 0.135; P = .001) and improved OS (HR, 0.487; P = .004), and trimodal therapy was associated with improved LPFS (HR, 0.060; P = .017). The most commonly observed acute grade 3 adverse events included dermatitis (20%) and mucositis (13%), with no grade 4 subacute or late adverse events noted (adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). Conclusions RT appears to demonstrate a dose-dependent, persistent LPFS and OS benefit in patients with locally advanced ATC with an acceptable toxicity profile. Aggressive RT should be strongly considered for the treatment of patients with ATC as part of a trimodal treatment approach
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Sometimes it does hurt to ask: The constructive role of articulating impressions
Decisions can sometimes have a constructive role, so that the act of, for example, choosing one option over another creates a preference for that option (e.g., Ariely and Norton, 2008, Payne et al., 1993, Sharot et al., 2010 and Sherman, 1980). In this work we explore the constructive role of just articulating an impression, for a presented visual stimulus, as opposed to making a choice (specifically, the judgments we employ are affective evaluations). Using quantum probability theory, we outline a cognitive model formalizing such a constructive process. We predict a simple interaction, in relation to how a second image is evaluated, following the presentation of a first image, depending on whether there is a rating for the first image or not. The interaction predicted by the quantum model was confirmed across three experiments and a variety of control manipulations. The advantages of using quantum probability theory to model the present results, compared with existing models of sequence order effects in judgment (e.g., Hogarth & Einhorn, 1992) or other theories of constructive processes when a choice is made (e.g., Festinger, 1957 and Sharot et al., 2010) are discussed
Single Nucleotide Polymorphisms That Increase Expression of the Guanosine Triphosphatase RAC1 Are Associated With Ulcerative Colitis
BACKGROUND & AIMS: RAC1 is a GTPase that has an evolutionarily conserved role in coordinating immune defenses, from plants to mammals. Chronic inflammatory bowel diseases (IBD) are associated with dysregulation of immune defenses. We studied the role of RAC1 in IBD using human genetic and functional studies and animal models of colitis. METHODS: We used a candidate gene approach to HapMap-Tag single nucleotide polymorphisms (SNPs) in a discovery cohort; findings were confirmed in 2 additional cohorts. RAC1 mRNA expression was examined from peripheral blood cells of patients. Colitis was induced in mice with conditional disruption of Rac1 in phagocytes by administration of dextran sulphate sodium (DSS). RESULTS: We observed a genetic association between RAC1 with ulcerative colitis (UC) in a discovery cohort, 2 independent replication cohorts, and in combined analysis for the SNPs rs10951982 (Pcombined UC = 3.3 × 10–8, odds ratio [OR]=1.43 [1.26–1.63]) and rs4720672 (Pcombined UC=4.7 × 10–6, OR=1.36 [1.19–1.58]). Patients with IBD who had the rs10951982 risk allele had increased expression of RAC1, compared to those without this allele. Conditional disruption of Rac1 in macrophage and neutrophils of mice protected them against DSS-induced colitis. CONCLUSION: Studies of human tissue samples and knockout mice demonstrated a role for the GTPase RAC1 in the development of UC; increased expression of RAC1 was associated with susceptibility to colitis
Demonstration of a timescale based on a stable optical carrier
We report on the first timescale based entirely on optical technology. Existing timescales, including those incorporating optical frequency standards, rely exclusively on microwave local oscillators owing to the lack of an optical oscillator with the required frequency predictability and stability for reliable steering. We combine a cryogenic silicon cavity exhibiting improved long-term stability and an accurate
87
Sr
lattice clock to form a timescale that outperforms them all. Our timescale accumulates an estimated time error of only
48
±
94
 
 
ps
over 34 days of operation. Our analysis indicates that this timescale is capable of reaching a stability below
1
×
10
−
17
after a few months of averaging, making timekeeping at the
10
−
18
level a realistic prospect
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