An imaging gas scintillation proportional counter for the detection of subkiloelectron-volt X-rays

A large area imaging gas scintillation proportional counter (IGSPC) was constructed for use in X-ray astronomy. The IGSPC consists of a gas scintillation proportional counted (GSPC) with a micron polyprotylene window coupled to a multiwire proportional counter (MWPC) via a calcium fluoride window. Over a sensitive area of 21 cu cm the instrument has a measured energy resolution of 17.5% (FWHM) and 1.9 mm (FWHM) spatial resolution at 1.5 keV

Work and Economic Outcomes After Welfare

Using data from the 1969 to 1993 Panel Study of Income Dynamics, this article examines a number of models to determine the characteristics of AFDC recipients who fare well economically after they initially leave the welfare system. The study includes analyses of income levels, time spent employed and not employed, and time spent below the poverty line. Hypotheses regarding state welfare payments, area economic conditions, human capital and time spent receiving welfare are examined. The findings indicate that area employment conditions and the ability to quickly find work greatly affect the likelihood of faring well economically after welfare. We found that time spent receiving welfare had some small negative effects on post-welfare economic outcomes. However, former welfare recipients living in states with more generous welfare payments are as likely to work, to not use welfare, and are generally as well off as those living in states with less generous welfare payments. These results indicate that high welfare benefit levels may not be a disincentive to work. The findings also indicate that women who have little job experience, who lack education, and who have many or more children after AFDC, fare economically worse than others

The Welfare Myth: Disentangling the Long-Term Effects of Poverty and Welfare Receipt for Young Single Mothers

This study investigates the effects of receiving welfare as a young woman on long-term economic and marital outcomes. Specifically, we examine if there are differences between young, single mothers who receive welfare and young, single mothers who are poor but do not receive welfare. Using the 1968-1997 Panel Study of Income Dynamics, our findings suggest those who receive welfare for an extended period as young adults have the same pre-transfer income over a 10 to 20 year period as those who are poor but do not receive welfare as young adults. While we found some differences between the two groups in income levels and the likelihood of having relatively low income when control variables were not included in our models, once appropriate controls were used, these differences became statistically insignificant. The only statistically significant difference found between the two groups in our 10, 15, and 20 year models was the likelihood of being married in year 15. Our results indicate that it is income level as a young adult, as well as such factors as the unemployment rate in the area of residence, but not welfare receipt, that affect long-term income and marital outcomes

Choice Hygiene for “Consumer Neuroscientists”? Ethical Considerations and Proposals for Future Endeavours

Is the use of psychological and neuroscientific methods for neuromarketing research always aligned with the principles of ethical research practice? Some neuromarketing endeavours have passed from informing consumers about available options, to helping to market as many products to consumers as possible. Needs are being engineered, using knowledge about the human brain to increase consumption further, regardless of individual, societal and environmental needs and capacities. In principle, the ground ethical principle of any scientist is to further individual, societal and environmental health and well-being with their work. If their findings can be used for the opposite, this must be part of the scientist’s considerations before engaging in such research and to make sure that the risks for misuse are minimised. Against this backdrop, we provide a series of real-life examples and a non-exhaustive literature review, to discuss in what way some practices in the neuromarketing domain may violate the Helsinki Declaration of Experimentation with Human Subjects. This declaration was set out to regulate biomedical research, but has since its inception been applied internationally also to behavioural and social research. We illustrate, point by point, how these ground ethical principles should be applied also to the neuromarketing domain. Indisputably, the growth in consumption is required due to current prevalent economical models. Thus, in the final part of the paper, we discuss how alternative models may be promotable to a larger public, aided by more ethical marketing endeavours, based on neuroscientific discoveries about the human brain. We propose this as a philosophical question, a point of discussion for the future, to make neuromarketing as a discipline, fit for the future, respecting the ethical implications of this research

Nuclear magnetic resonance studies of complex materials systems: from amplification to anisotropy

This dissertation explores complex materials systems, with a special focus on developing nuclear resonance spectroscopy (NMR) techniques to decipher chemical environments at the molecular level. Chapter 1 describes the design and synthesis of a two-state materials system based on an autocatalytic, positive feedback loop that amplifies a rare input into a massive output. Chapters 2 - 4 probe nanoparticle systems with shape or functional anisotropy. Chapter 2 details new approaches to add functionality to shape-anisotropic particles. Chapter 3 establishes NMR spectroscopy as a powerful tool for interpreting the ligand shell morphology, spatial arrangement, dynamics, and distinct chemical environments that are trademarks of shape- and functionally-anisotropic particles. Chapter 4 exploits the heterogeneous reactivity of shape-anisotropic particles to fabricate sophisticated, supramolecular building blocks that can form dynamic assemblies controlled by their association constants. Chapter 5 builds on the robust NMR techniques in the preceding chapters to analyze complex nano-bio interactions that are otherwise difficult to probe

Gravitational Radiation from Pulsating White Dwarfs

Rotating white dwarfs undergoing quasi-radial oscillations can emit gravitational radiation in a frequency range from 0.1 - 0.3 Hz. Assuming that the energy source for the gravitational radiation comes from the oblateness of the white dwarf induced by the rotation, the strain amplitude is found to be \sim 10^{-27} for a white dwarf at \sim 50 pc. The galactic population of these sources is estimated to be \sim 10^7, and may produce a confusion limited foreground for proposed advanced detectors in the frequency band between space-based and ground-based interferometers. Nearby oscillating white dwarfs may provide a clear enough signal to investigate white dwarf interiors through gravitational wave asteroseismology.Comment: Accepted for Astrophysical Journal Letters. Changed value of branching ratio resulting in an order of magnitude drop in gravitational wave amplitude

Antegrade common femoral artery closure device use is associated with decreased complications.

ObjectiveAntegrade femoral artery access is often used for ipsilateral infrainguinal peripheral vascular intervention. However, the use of closure devices (CD) for antegrade access (AA) is still considered outside the instructions for use for most devices. We hypothesized that CD use for antegrade femoral access would not be associated with an increased odds of access site complications.MethodsThe Vascular Quality Initiative was queried from 2010 to 2019 for infrainguinal peripheral vascular interventions performed via femoral AA. Patients who had a cutdown or multiple access sites were excluded. Cases were then stratified into whether a CD was used or not. Hierarchical multivariable logistic regressions controlling for hospital-level variation were used to examine the independent association between CD use and access site complications. A sensitivity analysis using coarsened exact matching was performed using factors different between treatment groups to reduce imbalance between the groups.ResultsOverall, 11,562 cases were identified and 5693 (49.2%) used a CD. Patients treated with a CD were less likely to be white (74.1% vs 75.2%), have coronary artery disease (29.7% vs 33.4%), use aspirin (68.7% vs 72.4%), and have heparin reversal with protamine (15.5% vs 25.6%; all P < .05). CD patients were more likely to be obese (31.6% vs 27.0%), have an elective operation (82.6% vs 80.1%), ultrasound-guided access (75.5% vs 60.6%), and a larger access sheath (6.0 ± 1.0 F vs 5.5 ± 1.0 F; P < .05 for all). CD cases were less likely to develop any access site hematoma (2.55% vs 3.53%; P < .01) or a hematoma requiring reintervention (0.63% vs 1.26%; P < .01) and had no difference in access site stenosis or occlusion (0.30% vs 0.22%; P = .47) compared with no CD. On multivariable analysis, CD cases had significantly decreased odds of developing any access site hematoma (odds ratio, 0.75; 95% confidence interval, 0.59-0.95) and a hematoma requiring intervention (odds ratio, 0.56; 95% confidence interval, 0.38-0.81). A sensitivity analysis after coarsened exact matching confirmed these findings.ConclusionsIn this nationally representative sample, CD use for AA was associated with a lower odds of hematoma in selected patients. Extending the instructions for use indications for CDs to include femoral AA may decrease the incidence of access site complications, patient exposure to reintervention, and costs to the health care system

Quantitative Chemically-Specific Coherent Diffractive Imaging of Buried Interfaces using a Tabletop EUV Nanoscope

Characterizing buried layers and interfaces is critical for a host of applications in nanoscience and nano-manufacturing. Here we demonstrate non-invasive, non-destructive imaging of buried interfaces using a tabletop, extreme ultraviolet (EUV), coherent diffractive imaging (CDI) nanoscope. Copper nanostructures inlaid in SiO2 are coated with 100 nm of aluminum, which is opaque to visible light and thick enough that neither optical microscopy nor atomic force microscopy can image the buried interfaces. Short wavelength (29 nm) high harmonic light can penetrate the aluminum layer, yielding high-contrast images of the buried structures. Moreover, differences in the absolute reflectivity of the interfaces before and after coating reveal the formation of interstitial diffusion and oxidation layers at the Al-Cu and Al-SiO2 boundaries. Finally, we show that EUV CDI provides a unique capability for quantitative, chemically-specific imaging of buried structures, and the material evolution that occurs at these buried interfaces, compared with all other approaches.Comment: 12 pages, 8 figure

Clostridium perfringens Epsilon Toxin Compromises the Blood-Brain Barrier in a Humanized Zebrafish Model

This is the final version. Available on open access from Elsevier vis the DOI in this recordClostridium perfringens epsilon toxin (ETX) is hypothesized to mediate blood-brain barrier (BBB) permeability by binding to the myelin and lymphocyte protein (MAL) on the luminal surface of endothelial cells (ECs). However, the kinetics of this interaction and a general understanding of ETX's behavior in a live organism have yet to be appreciated. Here we investigate ETX binding and BBB breakdown in living Danio rerio (zebrafish). Wild-type zebrafish ECs do not bind ETX. When zebrafish ECs are engineered to express human MAL (hMAL), proETX binding occurs in a time-dependent manner. Injection of activated toxin in hMAL zebrafish initiates BBB leakage, hMAL downregulation, blood vessel stenosis, perivascular edema, and blood stasis. We propose a kinetic model of MAL-dependent ETX binding and neurovascular pathology. By generating a humanized zebrafish BBB model, this study contributes to our understanding of ETX-induced BBB permeability and strengthens the proposal that MAL is the ETX receptor.National Institute of Neurological Disorders and StrokeWilma S. and Laurence A. Tisch Foundatio