436 research outputs found
Radio Regulation Revisited: Coase, the FCC, and the Public Interest
It is now more than forty years since Ronald Coaseâs seminal article on the Federal Communications Commission first appeared in the pages of the Journal of Law and Economics.1 The article remains important for a number of reasons, not least of which is that it offered his first articulation of the Coase Theorem.2 Of even greater importance for our purposes, the article literally redefined the terms of debate over American broadcast regulation, in both historical and contemporary treatments of the subject. Focusing particularly on the development of radio regulation, Coase rejected the prevailing notion that the establishment of the Federal Communications Commission (FCC) served the public interest. Rather, he concluded that its creation had been a mistake, the product of faulty economic reasoning. The complex regulatory apparatus developed under the Federal Radio Act of 1927 and recodified in the Federal Communications Act of 1934 was built on the flawed assumption that scarce resourcesâin this case the radio spectrumâhad to be allocated by government fiat. A more efficient solution, Coase maintained, would have been to allocate the spectrum like any other scarce resource, on the basis of well-defined property rights and a free market guided by the price mechanism. Indeed, this is why he suggested that the spectrum ought to be cut up and sold at auction rather than regulated by the federal government.
Promoting Vulgarity by Teaching Slang in the Classroom
Mark Twain once said, "Indecency, vulgarity, obscenity -- these are strictly confined to man; he invented them. Among the higher animals there is no trace of them." I would like to suggest that we, as language teachers, need to be a little more open to the vulgar vernacular. I use "vulgar" in its original sense -- "common, ordinary" -- from the Latin vulgaris, "of or pertaining to the common people." Essentially, then, I wish to argue that we need to teach our students the use more vulgarity in their speech
A framework for experimental-data-driven assessment of Magnetized Liner Inertial Fusion stagnation image metrics
A variety of spherical crystal x-ray imager (SCXI) diagnostics have been
developed and fielded on Magnetized Liner Inertial Fusion (MagLIF) experiments
at the Sandia National Laboratories Z-facility. These different imaging
modalities provide detailed insight into different physical phenomena such as
mix of liner material into the hot fuel, cold liner emission, or reduce impact
of liner opacity. However, several practical considerations ranging from the
lack of a consistent spatial fiducial for registration to different
point-spread-functions and tuning crystals or using filters to highlight
specific spectral regions make it difficult to develop broadly applicable
metrics to compare experiments across our stagnation image database without
making significant unverified assumptions. We leverage experimental data for a
model-free assessment of sensitivities to instrumentation-based features for
any specified image metric. In particular, we utilize a database of historical
and recent MagLIF data including image plate scans
gathered across different experiments to assess the
impact of a variety of features in the experimental observations arising from
uncertainties in registration as well as discrepancies in signal-to-noise ratio
and instrument resolution. We choose a wavelet-based image metric known as the
Mallat Scattering Transform for the study and highlight how alternate metric
choices could also be studied. In particular, we demonstrate a capability to
understand and mitigate the impact of signal-to-noise, image registration, and
resolution difference between images. This is achieved by utilizing multiple
scans of the same image plate, sampling random translations and rotations, and
applying instrument specific point-spread-functions found by ray tracing to
high-resolution datasets, augmenting our data in an effectively model-free
fashion.Comment: 17 pages, 14 figure
Not lesser but Greater fractional anisotropy in adolescents with alcohol use disorders
AbstractObjectiveThe objective of this study is to examine white matter microstructure using diffusion tensor imaging (DTI) in a sample of adolescents with alcohol use disorders (AUD) and no psychiatric or substance co-morbidity.MethodsFifty adolescents with AUD and fifty non-alcohol abusing controls matched on gender and age were studied with DTI, neurocognitive testing, and a clinical assessment that included measures of alcohol use and childhood trauma. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were computed, registered to a common template, and voxel-wise statistical analysis used to assess group differences. Associations between regions of altered WM microstructure and clinical or neurocognitive measures were also assessed.ResultsCompared with controls, adolescent drinkers without co-morbid substance abuse or externalizing disorder, showed 1) no regions of significantly lower FA, 2) increased FA in WM tracts of the limbic system; 3) no MD differences; and 4) within the region of higher FA in AUD, there were no associations between FA and alcohol use, cognition, or trauma.DiscussionThe most important observation of this study is our failure to observe significantly smaller FA in this relatively large alcohol abuse/dependent adolescent sample. Greater FA in the limbic regions observed in this study may index a risk for adolescent AUD instead of a consequence of drinking. Drinking behavior may be reinforced in those with higher FA and perhaps greater myelination in these brain regions involved in reward and reinforcement
Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice
BACKGROUND: The worldwide appearance of drug-resistant strains of H. pylori motivates a search for new agents with therapeutic potential against this family of bacteria that colonizes the stomach, and is associated with adenocarcinoma development. This study was designed to assess in vitro the anti-H. pylori potential of cathelicidin LL-37 peptide, which is naturally present in gastric juice, its optimized synthetic analog WLBU2, and the non-peptide antibacterial agent ceragenin CSA-13. RESULTS: In agreement with previous studies, increased expression of hCAP-18/LL-37 was observed in gastric mucosa obtained from H. pylori infected subjects. MBC (minimum bactericidal concentration) values determined in nutrient-containing media range from 100-800 ÎŒg/ml for LL-37, 17.8-142 ÎŒg/ml for WLBU2 and 0.275-8.9 ÎŒg/ml for ceragenin CSA-13. These data indicate substantial, but widely differing antibacterial activities against clinical isolates of H. pylori. After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity. Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins. CONCLUSION: These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains
What is the Brightest Source for Dilepton Emissions at RHIC?
We calculate the dilepton emissions as the decay product of the charm and
bottom quarks produced in heavy-ion collisions at RHIC energy. We take into
account the next-to-leading-order radiative corrections in perturbative QCD to
the heavy quark production from both an initial hard parton-parton scattering
and an ideal quark-gluon plasma. We find that the thermal charm decay dominates
the dilepton production in the low dilepton mass region ( GeV), while the
heavy quark production from the initial scattering takes over the intermediate
and high mass regions ( GeV). Our result also indicates the importance of
the bottom quark in the high mass region ( GeV ) due to its large mass and
cascade decay. If the initial scattering produced charm suffers a significant
energy loss due to the secondary interaction, the bottom decay constitutes the
major background for the thermal dileptons.Comment: 12 pages in RevTeX, 3 epsf figures embedde
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Single cell analysis reveals human cytomegalovirus drives latently infected cells towards an anergic-like monocyte state
Human cytomegalovirus (HCMV) causes a lifelong infection through establishment of latency. Although reactivation from latency can cause life-threatening disease, our molecular understanding of HCMV latency is incomplete. Here we use single cell RNA-seq analysis to characterize latency in monocytes and hematopoietic stem and progenitor cells (HSPCs). In monocytes, we identify host cell surface markers that enable enrichment of latent cells harboring higher viral transcript levels, which can reactivate more efficiently, and are characterized by reduced intrinsic immune response that is important for viral gene expression. Significantly, in latent HSPCs, viral transcripts could be detected only in monocyte progenitors and were also associated with reduced immune-response. Overall, our work indicates that regardless of the developmental stage in which HCMV infects, HCMV drives hematopoietic cells towards a weaker immune-responsive monocyte state and that this anergic-like state is crucial for the virus ability to express its transcripts and to eventually reactivate
Prognosis of Differentiated Thyroid Cancer in Relation to Serum Thyrotropin and Thyroglobulin Antibody Status at Time of Diagnosis
BACKGROUND: Serum thyrotropin (TSH) concentration and thyroid autoimmunity may be of prognostic importance in differentiated thyroid cancer (DTC). Preoperative serum TSH level has been associated with higher DTC stage in cross-sectional studies; data are contradictory on the significance of thyroid autoimmunity at the time of diagnosis.
OBJECTIVE: We sought to assess whether preoperative serum TSH and perioperative antithyroglobulin antibodies (TgAb) were associated with thyroid cancer stage and outcome in DTC patients followed by the National Thyroid Cancer Treatment Cooperative Study, a large multicenter thyroid cancer registry.
METHODS: Patients registered after 1996 with available preoperative serum TSH (n=617; the TSH cohort) or perioperative TgAb status (n=1770; the TgAb cohort) were analyzed for tumor stage, persistent disease, recurrence, and overall survival (OS; median follow-up, 5.5 years). Parametric tests assessed log-transformed TSH, and categorical variables were tested with chi square. Disease-free survival (DFS) and OS was assessed with Cox models.
RESULTS: Geometric mean serum TSH levels were higher in patients with higher-stage disease (Stage III/IV=1.48 vs. 1.02âmU/L for Stages I/II; p=0.006). The relationship persisted in those aged â„45 years after adjusting for sex (p=0.01). Gross extrathyroidal extension (p=0.03) and presence of cervical lymph node metastases (p=0.003) were also significantly associated with higher serum TSH. Disease recurrence and all-cause mortality occurred in 37 and 38 TSH cohort patients respectively, which limited the power for survival analysis. Positive TgAb was associated with lower stage on univariate analysis (positive TgAb in 23.4% vs. 17.8% of Stage I/II vs. III/IV patients, respectively; p=0.01), although the relationship lost significance when adjusting for age and sex (p=0.34). Perioperative TgAb was not an independent predictor of DFS (hazard ratio=1.12 [95% confidence interval=0.74-1.69]) or OS (hazard ratio=0.98 [95% confidence interval=0.56-1.72]).
CONCLUSIONS: Preoperative serum TSH level is associated with higher DTC stage, gross extrathyroidal extension, and neck node metastases. Perioperative TgAb is not an independent predictor of DTC prognosis. A larger cohort is required to assess whether preoperative serum TSH level predicts recurrence or mortality
Prognostic significance of T-cellâinflamed gene expression profile and PD-L1 expression in patients with esophageal cancer
PURPOSE: The ability of the Tâcellâinflamed gene expression profile (GEP) to predict clinical outcome in esophageal cancer (EC) is unknown. This retrospective observational study assessed the prognostic value of GEP and programmed death ligand 1 (PDâL1) expression in patients with EC treated in routine clinical practice. METHODS: Tumor samples of 294 patients from three centers in Denmark, South Korea, and the United States, collected between 2005 and 2017, were included. Tâcellâinflamed GEP score was defined as nonâlow or low using a cutoff of â1.54. A combined positive score (CPS) â„10 was defined as PDâL1 expression positivity. Associations between overall survival (OS) and GEP status and PDâL1 expression were explored by Cox proportional hazards models adjusting for age, sex, histology, stage, and performance status. RESULTS: Median age was 65 years; 63% of patients had adenocarcinoma (AC) and 37% had squamous cell carcinoma (SCC). Thirtyâsix percent of tumors were GEP nonâlow, with higher prevalence in AC (46%) than SCC (18%). Twentyâone percent were PDâL1âpositive: 32% in South Korean samples versus 16% in nonâAsian samples and 26% in SCC versus 18% in AC. GEP scores and PDâL1 CPS were weakly correlated (Spearmanâs RÂ =Â 0.363). OS was not significantly associated with GEP status (nonâlow vs low; adjusted hazard ratio, 0.91 [95% CI, 0.69â1.19]) or PDâL1 expression status. CONCLUSION: Neither GEP nor PDâL1 expression was a prognostic marker in Asian and nonâAsian patients with EC
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