Physical Conditions of Accreting Gas in T Tauri Star Systems

We present results from a low resolution (R~300) near-infrared spectroscopic variability survey of actively accreting T Tauri stars (TTS) in the Taurus-Auriga star forming region. Paschen and Brackett series H I recombination lines were detected in 73 spectra of 15 classical T Tauri systems. The values of the Pan/PaB, Brn/BrG, and BrG/Pan H I line ratios for all observations exhibit a scatter of < 20% about the weighted mean, not only from source to source, but also for epoch-to-epoch variations in the same source. A representative or `global' value was determined for each ratio in both the Paschen and Brackett series as well as the BrG/Pan line ratios. A comparison of observed line ratio values was made to those predicted by the temperature and electron density dependent models of Case B hydrogen recombination line theory. The measured line ratios are statistically well-fit by a tightly constrained range of temperatures (T < 2000 K) and electron densities 1e9 < n_e < 1e10 cm^-3. A comparison of the observed line ratio values to the values predicted by the optically thick and thin local thermodynamic equilibrium cases rules out these conditions for the emitting H I gas. Therefore, the emission is consistent with having an origin in a non-LTE recombining gas. While the range of electron densities is consistent with the gas densities predicted by existing magnetospheric accretion models, the temperature range constrained by the Case B comparison is considerably lower than that expected for accreting gas. The cooler gas temperatures will require a non-thermal excitation process (e.g., coronal/accretion-related X-rays and UV photons) to power the observed line emission.Comment: 12 pages, emulateapj format, Accepted for publication in Ap

Relationships between changes in sustained fronto-striatal connectivity and positive affect with antidepressant treatment in major depression

Objective: Deficits in positive affect and their neural bases have been associated with major depression. However, whether reductions in positive affect result solely from an overall reduction in nucleus accumbens activity and fronto-striatal connectivity or the additional inability to sustain engagement of this network over time is unknown. The authors sought to determine whether treatment-induced changes in the ability to sustain nucleus accumbens activity and fronto-striatal connectivity during the regulation of positive affect are associated with gains in positive affect. Method: Using fMRI, the authors assessed the ability to sustain activity in reward-related networks when attempting to increase positive emotion during per- formance of an emotion regulation para- digm in 21 depressed patients before and after 2 months of antidepressant treat- ment. Over the same interval, 14 healthy comparison subjects underwent scanning as well. Results: After 2 months of treatment, self-reported positive affect increased. The patients who demonstrated the largest increases in sustained nucleus accumbens activity over the 2 months were those who demonstrated the largest increases in positive affect. In addition, the patients who demonstrated the largest increases in sustained fronto-striatal connectivity were also those who demonstrated the largest increases in positive affect when control- ling for negative affect. None of these associations were observed in healthy comparison subjects. Conclusions: Treatment-induced change in the sustained engagement of fronto- striatal circuitry tracks the experience of positive emotion in daily life. Studies examining reduced positive affect in a va- riety of psychiatric disorders might benefit from examining the temporal dynamics of brain activity when attempting to under- stand changes in daily positive affect

How Do We Combat Bogus Medicines in the Age of the COVID-19 Pandemic?

The COVID-19 pandemic has brought concurrent challenges. The increased incidence of fake and falsified product distribution is one of these problems with tremendous impact, especially in low- and middle-income countries. Up to a tenth of medicines including antibiotics and antimalarial drugs in the African market are considered falsified. Pandemics make this worse by creating an ecosystem of confusion, distraction, and vulnerability stemming from the pandemic as health systems become more stressed and the workload of individuals increased. These environments create opportunities for substandard and falsified medicines to be more easily introduced into the marketplace by unscrupulous operators. In this work, we discussed some of the challenges with fake or falsified product distribution in the context of COVID-19 and proposed strategies to best manage this problem

Family history of cancer and head and neck cancer survival

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/1/lary26524_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/2/lary26524.pd

Stability of methylation markers in head and neck squamous cell carcinoma

BackgroundAs cancer progresses, methylation patterns change to promote the tumorigenic phenotype. However, stability of methylation markers over time and the extent that biopsy samples are representative of larger tumor specimens are unknown. This information is critical for clinical use of such biomarkers.MethodsNinety‐eight patients with tumor specimens from 2 timepoints were measured for DNA methylation in the promoter regions across 4 genes.ResultsThere were no significant differences in overall methylation of CCNA1 (cyclin A1), NDN (necdin), deleted in colorectal carcinoma (DCC), and cluster of differentiation 1a (CD1A) within paired specimens (p values = .56, .17, .66, and .58, respectively). All genes showed strong correlations between paired specimens across time. Methylation was most consistent for CCNA1 and NDN over time.ConclusionThis report provides the first evidence that methylation markers measured in biopsy samples are representative of gene methylation in later specimens and suggests that biopsy markers could be representative biomarkers for use in defining personalized treatment utilizing epigenetic changes. © 2015 Wiley Periodicals, Head Neck 38: E1325–E1331, 2016Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/1/hed24223.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/2/hed24223_am.pd

The status of paediatric medicines initiatives around the world-what has happened and what has not?

Purpose: This review was conducted to examine the current status of paediatric medicines initiatives across the globe. Methods: The authors made a non-systematic descriptive review of current world situation. Results: Two regions, the United States (US) and the European Union (EU), and the World Health Organization (WHO) have introduced strong paediatric initiatives to improve children's health through improving access to better paediatric medicines. The experience from the US initiative indicates that it is possible to stimulate development and study of paediatric medicines and provide important new information for improvement of paediatric therapy. The early results from the EU initiative are similarly encouraging. In Canada, Japan, Australia and other developed countries, specific paediatric medicines initiatives have been less extensive and weaker, with modest results. Disappointingly, current evidence suggests that results from clinical trials outside the US often do not benefit children in the country in which the trials were largely conducted. Pharmaceutical companies that have derived a financial benefit commensurate with the cost of doing the paediatric trials in one country do not seem to be making the results of these trials available to all countries if there is no financial incentive to the company. The WHO campaign 'make medicines child size' has produced substantive accomplishments in building improved foundations to improve mechanisms that will enhance children's access to critical medicines in resource-limited settings. However, practically all of this work has been performed using an amalgamation of short-term funding from a variety of sources as opposed to a sustained, programmatic commitment. Conclusions: Although much still needs to be done, it's clear that with concerted efforts and appropriate resources, change is possible but slow. Retaining and fostering public and political interest in paediatric medicines is challenging, but pivotal for success.Fil: Hoppu, Kalle. Helsinki University Central Hospital; FinlandiaFil: Anabwani, Gabriel. Botswana-Baylor Children’s Clinical Centre of Excellence; BotsuanaFil: Garcia Bournissen, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Gazarian, Madlen. University of New South Wales; Australia. Sydney Children’s Hospital; AustraliaFil: Kearns, Gregory L.. The Children’s Mercy Hospital; Estados Unidos. University of Missouri; Estados UnidosFil: Nakamura, Hidefumi. National Center for Child Health and Development; JapónFil: Peterson, Robert G.. University of British Columbia; CanadáFil: Sri Ranganathan, Shalini. University Of Colombo. Faculty Of Medicine; Sri LankaFil: De Wildt, Saskia N.. Sophia Children’s Hospital; Países Bajo

A simulation-calibrated limit on the H i power spectrum from the GMRT Epoch of Reionization experiment

The Giant Metrewave Radio Telescope Epoch of Reionization experiment is an ongoing effort to measure the power spectrum from neutral hydrogen at high redshift. We have previously reported an upper limit of (70 mK)^2 at wavenumbers of k ≈ 0.65 h Mpc^(−1) using a basic piecewise-linear foreground subtraction. In this paper, we explore the use of a singular value decomposition to remove foregrounds with fewer assumptions about the foreground structure. Using this method, we also quantify, for the first time, the signal loss due to the foreground filter and present new power spectra adjusted for this loss, providing a revised measurement of a 2σ upper limit at (248 mK)^2 for k = 0.50 h Mpc^(−1). While this revised limit is larger than previously reported, we believe it to be more robust and still represents the best current constraint on reionization at z ≈ 8.6

The Properties of X-ray Luminous Young Stellar Objects in the NGC 1333 and Serpens Embedded Clusters

We present Chandra X-ray data of the NGC 1333 embedded cluster, combining these data with existing Chandra data, Sptizer photometry and ground based spectroscopy of both the NGC 1333 & Serpens North clusters to perform a detailed study of the X-ray properties of two of the nearest embedded clusters to the Sun. In NGC 1333, a total of 95 cluster members are detected in X-rays, of which 54 were previously identified with Spitzer. Of the Spitzer sources, we detect 23% of the Class I protostars, 53% of the Flat Spectrum sources, 52% of the Class II, and 50% of the Transition Disk YSOs. Forty-one Class III members of the cluster are identified, bringing the total identified YSO population to 178. The X-ray Luminosity Functions (XLFs) of the NGC 1333 and Serpens clusters are compared to each other and the Orion Nebula Cluster. Based on this comparison, we obtain a new distance for the Serpens cluster of 360+22/-13 pc. The X-ray luminosity was found to depend on the bolometric luminosity as in previous studies of other clusters, and that Lx depends primarily on the stellar surface area. In the NGC 1333 cluster, the Class III sources have a somewhat higher X-ray luminosity for a given surface area. We also find evidence in NGC 1333 for a jump in the X-ray luminosity between spectral types of M0 and K7, we speculate that this may result from the presence of radiative zones in the K-stars. The gas column density vs. extinction in the NGC 1333 was found to be N_H = 0.89 +/- 0.13 x 10^22 A_K, this is lower than expected of the standard ISM but similar to that found previously in the Serpens Cloud Core.Comment: 58 pages, 14 figures, accepted by A