Programmable and Modular DC-DC Converter

This project considers the design, implementation, and testing of an open-source dc-dc converter for microgrid prototyping. Unlike conventional dc-dc converters that are proprietary and require specialist knowledge, and are usually designed for a single function, the proposed dc-dc converter will comprise of a programmable MCU and a Raspberry Pi (RPi) interface to allow less-skilled consumers to monitor and modify a power converting system. We will develop an open-source library that contains voltage control, current control, maximum power point tracking, and battery charge control profiles. Each library will be easy to implement through a GUI on the Raspberry Pi and will be controlled using an Atmega328 located on the power conversion unit. C++ and the Arduino IDE will be used for testing and will retain functionality in the finished project for more knowledgeable customers to edit the pre-set profiles. Moreover, the Pi will need to communicate with multiple converters and monitor their set points in applications where more than one dc-dc converter is necessary. The supporting hardware around the microcontrollers is a dc-dc converter, while the connection with the RPi and any external hardware will be open-source and custom designed to accommodate multiple converters on a single system. As a result, the integration of our dc-dc converter will provide a way to easily set up a microgrid system without the use of proprietary voltage converting hardware

Are large randomised controlled trials in severe sepsis and septic shock statistically disadvantaged by repeated inadvertent underestimates of required sample size?

OBJECTIVES: We sought to understand why randomised controlled trials in septic shock have failed to demonstrate effectiveness in the face of improving overall outcomes for patients and seemingly promising results of early phase trials of interventions. DESIGN: We performed a retrospective analysis of large critical care trials of severe sepsis and septic shock. Data were collected from the primary trial manuscripts, prepublished statistical plans or by direct communication with corresponding authors. SETTING: Critical care randomised control trials in severe sepsis and septic shock. PARTICIPANTS: 14 619 patients randomised in 13 trials published between 2005 and 2015, enrolling greater than 500 patients and powered to a primary outcome of mortality. INTERVENTION: Multiple interventions including the evaluation of treatment strategies and novel therapeutics. PRIMARY AND SECONDARY OUTCOME MEASURES: Our primary outcome measure was the difference between the anticipated and actual control arm mortality. Secondary analysis examined the actual effect size and the anticipated effect size employed in sample size calculation. RESULTS: In this post hoc analysis of 13 trials with 14 619 patients randomised, we highlight a global tendency to overestimate control arm mortality in estimating sample size (absolute difference 9.8%, 95% CI -14.7% to -5.0%, p<0.001). When we compared anticipated and actual effect size of a treatment, there was also a substantial overestimation in proposed values (absolute difference 7.4%, 95% CI -9.0% to -5.8%, p<0.0001). CONCLUSIONS: An interpretation of our results is that trials are consistently underpowered in the planning phase by employing erroneous variables to calculate a satisfactory sample size. Our analysis cannot establish if, given a larger sample size, a trial would have had a positive result. It is disappointing so many promising phase II results have not translated into durable phase III outcomes. It is possible that our current framework has biased us towards discounting potentially life-saving treatments

Increased Fear Response to Contextual Cues in Mice Lacking the 5-HT1A Receptor

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Low- versus Mid-frequency Raman Spectroscopy for in Situ Analysis of Crystallization in Slurries

Slurry studies are useful for exhaustive polymorph and solid-state stability screening of drug compounds. Raman spectroscopy is convenient for monitoring crystallization in such slurries, as the measurements can be performed in situ even in aqueous environments. While the mid-frequency region (400-4000 cm(-1)) is dominated by intramolecular vibrations and has traditionally been used for such studies, the low-frequency spectral region (Peer reviewe

Finding Rare AGN: X-ray Number Counts of Chandra Sources in Stripe 82

We present the first results of a wide area X-ray survey within the Sloan Digital Sky Survey (SDSS) Stripe 82, a 300 deg$^2$ region of the sky with a substantial investment in multi-wavelength coverage. We analyzed archival {\it Chandra} observations that cover 7.5 deg$^2$ within Stripe 82 ("Stripe 82 ACX"), reaching 4.5$\sigma$ flux limits of 7.9$\times10^{-16}$, 3.4$\times10^{-15}$ and 1.8$\times10^{-15}$ erg s$^{-1}$ cm$^{-2}$ in the soft (0.5-2 keV), hard (2-7 keV) and full (0.5-7 keV) bands, to find 774, 239 and 1118 X-ray sources, respectively. Three hundred twenty-one sources are detected only in the full band and 9 sources are detected solely in the soft band. Utilizing data products from the {\it Chandra} Source Catalog, we construct independent Log$N$-Log$S$ relationships, detailing the number density of X-ray sources as a function of flux, which show general agreement with previous {\it Chandra} surveys. We compare the luminosity distribution of Stripe 82 ACX with the smaller, deeper CDF-S + E-CDFS surveys and with {\it Chandra}-COSMOS, illustrating the benefit of wide-area surveys in locating high luminosity AGN. We also investigate the differences and similarities of X-ray and optical selection to uncover obscured AGN in the local Universe. Finally, we estimate the population of AGN we expect to find with increased coverage of 100 deg$^2$ or 300 deg$^2$, which will provide unprecedented insight into the high redshift, high luminosity regime of black hole growth currently under-represented in X-ray surveys.Comment: Accepted for publication in MNRAS, 15 pages, 6 Figures, 2 Table

Quantification of white matter cellularity and damage in preclinical and early symptomatic Alzheimer\u27s disease

Interest in understanding the roles of white matter (WM) inflammation and damage in the pathophysiology of Alzheimer disease (AD) has been growing significantly in recent years. However, in vivo magnetic resonance imaging (MRI) techniques for imaging inflammation are still lacking. An advanced diffusion-based MRI method, neuro-inflammation imaging (NII), has been developed to clinically image and quantify WM inflammation and damage in AD. Here, we employed NII measures in conjunction with cerebrospinal fluid (CSF) biomarker classification (for β-amyloid (Aβ) and neurodegeneration) to evaluate 200 participants in an ongoing study of memory and aging. Elevated NII-derived cellular diffusivity was observed in both preclinical and early symptomatic phases of AD, while disruption of WM integrity, as detected by decreased fractional anisotropy (FA) and increased radial diffusivity (RD), was only observed in the symptomatic phase of AD. This may suggest that WM inflammation occurs earlier than WM damage following abnormal Aβ accumulation in AD. The negative correlation between NII-derived cellular diffusivity and CSF Aβ42 level (a marker of amyloidosis) may indicate that WM inflammation is associated with increasing Aβ burden. NII-derived FA also negatively correlated with CSF t-tau level (a marker of neurodegeneration), suggesting that disruption of WM integrity is associated with increasing neurodegeneration. Our findings demonstrated the capability of NII to simultaneously image and quantify WM cellularity changes and damage in preclinical and early symptomatic AD. NII may serve as a clinically feasible imaging tool to study the individual and composite roles of WM inflammation and damage in AD. Keywords: Inflammation, White matter damage, Diffusion basis spectrum imaging, Neuro-inflammation imaging, Cerebrospinal fluid, Preclinical Alzheimer disease, Early symptomatic Alzheimer disease, Magnetic resonance imagin

The Partisan Politics of New Social Risks in Advanced Postindustrial Democracies: Social Protection for Labor Market Outsiders

Advanced postindustrialization generates numerous challenges for the European social model. Central among these challenges is declining income, unstable employment, and inadequate training of semi- and unskilled workers. In this chapter, I assess the partisan basis of support for social policies that address the needs of these marginalized workers. I specifically consider the impacts of postindustrial cleavages among core constituencies of social democratic parties on the capacity of these parties to pursue inclusive social policies. I argue – and find support for in empirical analyses – that encompassing labor organization is the most important factor in strengthening the ability of left parties to build successful coalitions in support of outsider-friendly policies. I go beyond existing work on the topic by considering the full array of postindustrial cleavages facing left parties, by more fully elaborating why encompassing labor organization is crucial, and by considering a more complete set of measures of outsider policies than extant work. I compare my arguments and findings to important new work that stresses coalition building and partisan politics but minimizes the role of class organization

Core-Shell Hydrogel Microcapsules for Improved Islets Encapsulation

Islets microencapsulation holds great promise to treat type 1 diabetes. Currently used alginate microcapsules often have islets protruding outside capsules, leading to inadequate immuno-protection. A novel design of microcapsules with core–shell structures using a two-fluid co-axial electro-jetting is reported. Improved encapsulation and diabetes correction is achieved in a single step by simply confining the islets in the core region of the capsules.Juvenile Diabetes Research Foundation International (grant 17-2007-1063)National Institutes of Health (U.S.) (Postdoctoral Fellowship F32 EB011580- 01)Tayebati Family Foundatio