Gas properties computational procedure suitable for electronic calculators

A calculating procedure is presented, based on a least squares polynomial approximation, for duplicating existing tabular values of selected thermodynamic and transport properties of various important gases. Most of the data refer to ideal gases; however, for functions of both temperature and pressure , the pressure has been specified such that the polynomial approximations have only temperature as the independent variable. Suggested algorithms for polynomial evaluations up to the sixth degree are presented and optimized for hand-held or desk top calculators. Using the suggested polynomial fits and a suitable calculator, it is possible to duplicate existing table values for the various functions of the selected gases without interpolation of reference to the tables per se. The error of the included fits is generally less than 0.5%. With the lowest order approximation the error can be as high as 1%. (Author)The work reported herein is the outcome of a directed study course (AE 4900) in the Department of Aeronautics.http://archive.org/details/gaspropertiescom00andrNAApproved for public release; distribution is unlimited

Rasagiline Effects on Glucose Metabolism, Cognition, and Tau in Alzheimer’s Dementia

Background: A Phase II proof of concept (POC) randomized clinical trial was conducted to evaluate the effects of rasagiline, a monoamine oxidase B (MAO-B) inhibitor approved for Parkinson disease, in mild to moderate Alzheimer\u27s disease (AD). The primary objective was to determine if 1 mg of rasagiline daily for 24 weeks is associated with improved regional brain metabolism (fluorodeoxyglucose–positron emission tomography [FDG-PET]) compared to placebo. Secondary objectives included measurement of effects on tau PET and evaluation of directional consistency of clinical end points. Methods: This was a double-blind, parallel group, placebo-controlled, community-based, three-site trial of 50 participants randomized 1:1 to receive oral rasagiline or placebo (NCT02359552). FDG-PET was analyzed for the presence of an AD-like pattern as an inclusion criterion and as a longitudinal outcome using prespecified regions of interest and voxel-based analyses. Tau PET was evaluated at baseline and longitudinally. Clinical outcomes were analyzed using an intention-to-treat (ITT) model. Results: Fifty patients were randomized and 43 completed treatment. The study met its primary end point, demonstrating favorable change in FDG-PET differences in rasagiline versus placebo in middle frontal (P \u3c 0.025), anterior cingulate (P \u3c 0.041), and striatal (P \u3c 0.023) regions. Clinical measures showed benefit in quality of life (P \u3c 0.04). Digit Span, verbal fluency, and Neuropsychiatric Inventory (NPI) showed non-significant directional favoring of rasagiline; no effects were observed in Alzheimer\u27s Disease Assessment Scale-Cognitive Subscale (ADAS-cog) or activities of daily living. Rasagiline was generally well tolerated with low rates of adverse events and notably fewer neuropsychiatric symptoms in the active treatment group. Discussion: These outcomes illustrate the potential benefits of rasagiline on clinical and neuroimaging measures in patients with mild to moderate AD. Rasagiline appears to affect neuronal activity in frontostriatal pathways, with associated clinical benefit potential warranting a more fully powered trial. This study illustrated the potential benefit of therapeutic repurposing and an experimental medicine proof-of-concept design with biomarkers to characterize patient and detect treatment response

Heterochromatin Protein 1 (HP1a) Positively Regulates Euchromatic Gene Expression through RNA Transcript Association and Interaction with hnRNPs in Drosophila

Heterochromatin Protein 1 (HP1a) is a well-known conserved protein involved in heterochromatin formation and gene silencing in different species including humans. A general model has been proposed for heterochromatin formation and epigenetic gene silencing in different species that implies an essential role for HP1a. According to the model, histone methyltransferase enzymes (HMTases) methylate the histone H3 at lysine 9 (H3K9me), creating selective binding sites for itself and the chromodomain of HP1a. This complex is thought to form a higher order chromatin state that represses gene activity. It has also been found that HP1a plays a role in telomere capping. Surprisingly, recent studies have shown that HP1a is present at many euchromatic sites along polytene chromosomes of Drosophila melanogaster, including the developmental and heat-shock-induced puffs, and that this protein can be removed from these sites by in vivo RNase treatment, thus suggesting an association of HP1a with the transcripts of many active genes. To test this suggestion, we performed an extensive screening by RIP-chip assay (RNA–immunoprecipitation on microarrays), and we found that HP1a is associated with transcripts of more than one hundred euchromatic genes. An expression analysis in HP1a mutants shows that HP1a is required for positive regulation of these genes. Cytogenetic and molecular assays show that HP1a also interacts with the well known proteins DDP1, HRB87F, and PEP, which belong to different classes of heterogeneous nuclear ribonucleoproteins (hnRNPs) involved in RNA processing. Surprisingly, we found that all these hnRNP proteins also bind heterochromatin and are dominant suppressors of position effect variegation. Together, our data show novel and unexpected functions for HP1a and hnRNPs proteins. All these proteins are in fact involved both in RNA transcript processing and in heterochromatin formation. This suggests that, in general, similar epigenetic mechanisms have a significant role on both RNA and heterochromatin metabolisms

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Temperature dependence of gas properties in polynomial form

Based on a least-squares polynomial approximation, a procedure is introduced for calculating existing tabular values of thermodynamic and transport properties for common gases. The specific heat at constant pressure is given for 238 gases, the thermal conductivity for 55 gases, the dynamic viscocity for 58 gases, and the second and third virial coefficients for 14 gases. At sufficiently low pressures, ideal gas behavior prevails and temperature may be used as the single independent variable. The algorithm for nested multiplication is presented, optimized for hand-held or desktop electronic calculators. Using the polynomial approximations and a suitable calculator, it is possible to duplicate existing reference source tabular values directly, obviating the need for interpolation or further reference to the tables per se. The accuracy of the calculated values can be within 0.5% of the tabular values. The polynomial coefficients are given in the International System of Units (SI). Methods are presented to calculate the temperature corresponding to a given property value. Extrapolation features of the polynomials are discussedThe work presented herein is the result of an attempt to make our earlier report (NPS-57Zi7407lA) more useful. No explicit sponsorship is identifiable.http://archive.org/details/temperaturedepen00and

The development of an optically active laser Schlieren system with application to high pressure solid propellant combustion

A laser schlieren system, using an optically active single-piece quartz prism-polaroid sheet combination aperture in place of the conventional knife edge, was developed and applied to high pressure solid propellant combustion studies. Advantages and limitations of the system are discussed. Ammonium perchlorate deflagration was observed to pressures of 2500 psi. Distinct surface reaction sites were evidenced in the gas phase at high and low pressures by alternating density gradients across the surface. These sites were found to be very small or nonexistent at intermediate pressures.http://archive.org/details/developmentofopt00andrLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

The development of an optically active laser schlieren system with application to high pressure solid proellant combustion

A laser schlieren system, using an optically active quartz prism-polaroid sheet combination aperture in place of the conventional knife edge, was developed and applied to high pressure solid propellant combustion studies. Advantages and limitations of the system are discussed. Ammonium perchlorate deflagration was observed to pressures of 2200 psi. Distant surface reaction sites were evidenced at high and low pressures by alternating density gradients in the gas across the deflagrating surface. These sites were found to be very small or nonexistent at intermediate pressuresSupported by Naval Sea Systems Command, Arlington, VAhttp://archive.org/details/developmentofopti00andrNaval Sea Systems CommandN

Dissociation of Down syndrome and Alzheimer's disease effects with imaging

AbstractIntroductionDown Syndrome (DS) adults experience accumulation of Alzheimer's disease (AD)–like amyloid plaques and tangles and a high incidence of dementia and could provide an enriched population to study AD-targeted treatments. However, to evaluate effects of therapeutic intervention, it is necessary to dissociate the contributions of DS and AD from overall phenotype. Imaging biomarkers offer the potential to characterize and stratify patients who will worsen clinically but have yielded mixed findings in DS subjects.MethodsWe evaluated 18F fluorodeoxyglucose positron emission tomography (PET), florbetapir PET, and structural magnetic resonance (sMR) image data from 12 nondemented DS adults using advanced multivariate machine learning methods.ResultsOur results showed distinctive patterns of glucose metabolism and brain volume enabling dissociation of DS and AD effects. AD-like pattern expression corresponded to amyloid burden and clinical measures.DiscussionThese findings lay groundwork to enable AD clinical trials with characterization and disease-specific tracking of DS adults