cssi/SciSciGPT-SciSciNet huggingface dataset:
Disparities in the appropriateness of medication use: Analysis of the REasons for Geographic And Racial Differences in Stroke (REGARDS) population-based cohort study.

Abstract Background Prior work has identified disparities in the quality and outcomes of healthcare across socioeconomic subgroups. Medication use may be subject to similar disparities. Objective To assess the association between demographic and socioeconomic factors (gender, age, race, income, education, and rural or urban residence) and appropriateness of medication use. Methods US adults aged ≥45 years (n = 26,798) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were included in the analyses, of which 13,623 participants aged ≥65 years (recruited 2003–2007). Potentially inappropriate medication (PIM) use in older adults and drug-drug interactions (DDIs) were identified through 2015 Beers Criteria and clinically significant drug interactions list by Ament et al., respectively as measures of medication appropriateness. Multivariable logistic regression was used to assess the association of disparity parameters with PIM use and DDIs. Interactions between race and other disparity variables were investigated. Results Approximately 87% of the participants aged ≥65 years used at least one drug listed in the Beers Criteria, and 3.8% of all participants used two or more drugs with DDIs. Significant gender-race interaction across prescription-only drug users revealed that white females compared with white males (OR = 1.33, 95% CI 1.20–1.48) and black males compared with white males (OR = 1.60, 95% CI 1.41–1.82) were more likely to receive PIM. Individuals with lower income and education also were more likely to use PIM in this sub-group. Females were less likely than males (female vs. male: OR = 0.55, 95% CI 0.48–0.63) and individuals resided in small rural areas as opposed to urban areas (small rural vs. urban: OR = 1.37, 95% CI 1.07–1.76) were more likely to have DDIs. Conclusion Demographic and socioeconomic disparities in PIM use and DDIs exist. Future studies should seek to better understand factors contributing to the disparities in order to guide development of interventions.
Putting the framework to work: An ethnographic exploration of race-based professional development

Louie F. Rodriguez’ (2012) Teachers College Record conceptual paper issues a call to “researchers, practitioners, and policy makers [to]...problematize the concept of recognition...and to introduce a conceptual framework to understand, examine, and help rectify the crisis facing [Latina/o youth]” (p. 1). Though Rodriguez has explicitly named Latina/o youth within the title of his Framework of Recognition, Rodriguez clearly states his intent to extend applications of the Framework beyond Latina/o youth to include other marginalized students, including “students with disabilities, English language learners, immigrants, gay/lesbian/bisexual youth, and students who identify with alternative forms of music, art, and culture” (p.25). Indeed, Rodriguez expresses his hope that “readers may create their own forms of recognition, build on this proposed framework, and apply it to other marginalized populations” (p.26). This study takes up the invitation and puts Rodriguez’ Framework to work as a lens through which to view race-based teacher professional development, resulting in a new Framework of Professional Recognition for Educational Equity (FPREE) which makes visible the multiple aspects that must simultaneously be in place and attended to by educators seeking to interrupt and eliminate systemic inequities for marginalized students.
Water, agriculture, and climate dynamics in central Chile’s Aconcagua River Basin

Agriculture in the Aconcagua Basin is both vital to Chile’s economy and critically dependent on water resources from snow and glaciers. Expanding croplands, a growing population, and a changing cli...
What Do MD/PhDs Do and Who Should Become One?

MD/PhD training is an extremely fulfilling option for many students interested in pursuing careers as physician-scientists. Graduates of MD/PhD training are able to pursue nearly every avenue in clinical medicine, academic research, and public health, among many other fields. This chapter articulates the specific goals of MD/PhD training and explores the career outcomes of MD/PhD graduates to demonstrate their success in a wide array of diverse fields. Moreover, the purpose of this chapter is to help applicants determine whether or not an MD/PhD program is the right fit. MD/PhD students and physician-scientists are becoming increasingly diverse and widespread. In fact, many believe that physician-scientists are the future of academic medicine. However, this career path involves lengthy training, and it is imperative that students pursue it for the right reasons.
A technique for phase-detection auto focus under near-infrared-ray incidence in a back-side illuminated CMOS image sensor pixel with selectively grown germanium on silicon

A novel phase-detection auto focus (PDAF) technique for incident 850 nm plane wave is demonstrated using Ge-on-Si layer and deep trench isolation (DTI), which are locally arranged on light receiving surface (LRS) of crystalline silicon (c-Si). No metal light shielding film (LSF) for pupil division is formed. The key concept of the present work for PDAF is to perform the pupil division by the locally arranged Geon-Si layer in a pixel according to incident angle. The present pixel is based on a back-side illuminated CMOS image sensor pixel; the pixel pitch is 1.85 μm and the thickness of c-Si is around 3 μm. The simulation, based on three-dimensional finite difference time domain (3D-FDTD) method, shows that the external quantum efficiency (EQE) of the present pixel exhibits above 44.3 % with the maximum of 76.0 % for incident angles of - 30° to + 30°, owing to the selectively arranged Ge-on-Si layer; it exhibits 3.6 times improvement in the EQE at normal incidence compared to that of current state-of-the-art pixel with half metal-shielded aperture; the EQE is 49.2 % and 13.8 %, respectively. The present technique can enhance the accuracy of AF under low-illuminated condition.
Deep Reinforcement Learning For Visual Navigation of Wheeled Mobile Robots

A study is presented on applying deep reinforcement learning (DRL) for visual navigation of wheeled mobile robots (WMR) in dynamic and unknown environments. Two DRL algorithms, namely, value-learning deep Q-network (DQN) and policy gradient based asynchronous advantage actor critic ( $A$ 3C), have been considered. RGB (red, green and blue) and depth images have been used as inputs in implementation of both DRL algorithms to generate control commands for autonomous navigation of WMR in simulation environments. The initial DRL networks were generated and trained progressively in OpenAI Gym Gazebo based simulation environments within robot operating system (ROS) framework for a popular target WMR, Kobuki TurtleBot2. A pre-trained deep neural network ResNet50 was used after further training with regrouped objects commonly found in laboratory setting for target-driven mapless visual navigation of Turlebot2 through DRL. The performance of $A$ 3C with multiple computation threads (4, 6, and 8) was simulated on a desktop. The navigation performance of DQN and $A$ 3C networks, in terms of reward statistics and completion time, was compared in three simulation environments. As expected, $A$ 3C with multiple threads (4, 6, and 8) performed better than DQN and the performance of $A$ 3C improved with number of threads. Details of the methodology, simulation results are presented and recommendations for future work towards real-time implementation through transfer learning of the DRL models are outlined.
Help-seeking behavior of South Asian women in domestic violence: A scoping review

Domestic violence (DV) has serious implications for the welfare of South Asian (SA) women in the United States. Previous studies have identified significantly lower rates of help-seeking among SA w...
War Against Spam: A Comparative Analysis Of The US And The European Legal Approach

Unsolicited commercial mail (also known as spam and junk mail) can inconvenience tens of millions of Internet users and impose huge costs on Internet Service Providers. Realizing the need to boost competitiveness and consumer confidence, the European Union (EU) and the United States have instituted various legal frameworks and policies to regulate unsolicited commercial mail. The EU has adopted an opt-in approach to spam mail, which means e-marketers need to seek the permission of consumers before they send out commercial emails, while the US CAN SPAM Act takes an opt-out approach. The EU's opt-in regime is viewed as offering greater safeguards against spam mail. Despite the EU Directive and the US federal law, the barrage of junk e-mail continues to grow. This paper discusses the issue of spam mail and makes a comparative analysis of the two legal approaches and their implications on the industry and private citizens.
Exploring Hip-Hop Pedagogy for the Advancement of Girls of Color in Science:

Female and male students perform equally well on science standardized tests, yet there are disparities in gender in most science-related fields. There are far fewer women from underrepresented back...
Effect of Nickel Content on Processing of Ni-Rich NiTiHf High-Temperature Shape Memory Alloys

Shape memory alloys (SMAs), such as Nickel-Titanium, are an active material due to their ability to recover a designed shape upon heating. While binary NiTi SMAs are limited to a maximum austenite finish temperature of ~ 115 °C, high-temperature SMAs (HTSMAs), such as NiTiHf, have much higher transformation temperatures that can be tuned for specific applications, which make them attractive candidates for many aerospace and energy applications. NiTiHf has been found to be difficult to process due to the formation of oxides, intermetallics, and precipitates that exacerbate the already brittle nature of the material. In this study, the effect of Ni content on processability, microstructure, and hardness of Ni-rich NiTiHf HTSMAs was analyzed for three compositions. Each composition was characterized in three conditions: homogenized, 25%, and 50% thickness reduction through hot-rolling. Differential scanning calorimetry, scanning electron microscopy equipped with energy dispersive spectroscopy, Vickers hardness testing, and synchrotron radiation X-ray diffraction were utilized to characterize the resulting materials.
DEMAND ACTIVATED TRANSPORTATION FOR THE ELDERLY

A free transportation service has been established for elderly residents in the Model Neighborhood Area of Buffalo, NY. Transportation is provided on a demand activated basis, in which the rider is picked up at his door at a prearranged time, and taken to his specified destination within a designated 4-mile radius. This paper describes in detail the first five months of service (December, 1970 - April, 1971) including the nature of the organization needed to provide the service and trip records. Travel characteristics are presented in terms of daily person trips by purpose, origin-destination patterns, and time of day. The hourly trip volumes were greatest during the morning hours when 60% of all from-home trips were made. A third of these were medical trips. Days with wintry weather, in the form of blowing snow, produced a 25% decrease in daily usage.
Recognition of One tRNA by Two Classes of Aminoacyl-tRNA Synthetase

Lysyl-tRNA synthetases are unique amongst the aminoacyl-tRNA synthetases in being composed of two unrelated families. In most bacteria and all eukarya, the known lysyl-tRNA synthetases are subclass He-type aminoacyl-tRNA synthetases whereas some archaea and bacteria have been shown to contain an unrelated class I-type lysyl-tRNA synthetase. We have now examined substrate recognition by a bacterial (from Borrelia burgdorferi) and an archaeal (from Methanococcus maripaludis) class I lysyl-tRNA synthetase. The genes encoding both enzymes were able to rescue an Escherichia coli strain deficient in lysyl-tRNA synthetase, indicating their ability to functionally substitute for class II lysyl-tRNA synthetases in vivo. In vitro characterization revealed lysine activation and recognition to be tRNA-dependent, a phenomenon previously reported for other class I aminoacyl-tRNA synthetases. More detailed examination of tRNA recognition has shown that class I lysyl-tRNA synthetases recognize the same elements in tRNALys as their class II counterparts; specifically, the discriminator base (N73) and the anticodon serve as recognition elements. The implications of these results for the evolution of Lys-tRNALys synthesis and their possible indications of a more ancient origin for tRNA then aminoacyl-tRNA synthetases will be discussed.
Tight-binding inhibitors—VII: Extended interpretation of the rate equation experimental designs and statistical methods

Abstract The previously derived rate equation for tight-binding inhibitors has been reinterpreted to accommodate: (1) the case where the reaction is not started by the addition of enzyme, and (2) two-substrate reactions. Two major types of experimental design, i.e. equilibrium studies and time course studies, are developed. For each experimental design, graphical methods (if feasible) and statistical methods have been presented. Potential sources of errors are discussed.
URINARY AND RENAL HISTOLOGICAL CHANGES IN CHILDREN WITH IMMUNODEFICIENCY SYNDROME (AIDS)

Patients with AIDS frequently develop circulating immune complexes (CIC) and elevated serum immunoglobulins which might predispose to renal disease. The latter has been recently described in >10% of adults with AIDS, but no such association has been reported in children. We studied 15 patients (x age 11 months, range 2-24) with proven AIDS (defined by an inverted T4/T8 ratio plus Kaposi's Sarcoma or unusual infections). All evidenced intermittent proteinuria (up to 55 mg/kg/day) and 7 had hematuria (up to 50 RBC's/HPF) and/or casts. Serum creatinine was normal (x 0.6 mg/dl). Elevated ESR (max. 116 mm/hr) was noted in all patients, increased CIC (ClQ and Raji) in 6 and high serum IgG (max. 4,910 mg/dl) in 10. Serum C3 and C4 were normal in all. Renal autopsy material was available in 7 patients of which 3 had abnormal findings: 1 with markedly increased mesangial matrix and nuclei, 1 with profuse electron-dense deposits in the mesangium, and 1 with immunofluorescent deposits of IgM and C3 in the mesangium. We conclude that AIDS is often associated with urinary and renal histological changes. These changes are not as severe as those in adults possibly due to the shorter duration of the disease, lack of associated complicating factors (drug addiction, etc.,) or to the renal and immune characteristics of children ; still they may carry prognostic significance.
Association of seven polymorphisms of the D2 dopamine receptor gene with brain receptor-binding characteristics.

Association of alleles at the Taql A, Taql B, intron 6, Taql D, exon 7, exon 8, and promoter-141C sites of the D2 dopamine receptor gene with D2 dopamine receptor binding characteristics in the caudate nucleus of Caucasian alcoholic and nonalcoholic subjects was determined. For the Taql D, exon 7, exon 8, and promoter-141C sites there were no significant allelic differences in Bmax (number of binding sites) or Kd (binding affinity) of the D2 dopamine receptors. However, subjects having the minor alleles at the Taql A, Taql B, and intron 6 sites had significantly lower Bmax than subjects not having them. None of these three polymorphisms had any significant effect on Kd. Highly significant linkage disequilibria were observed among the Taql A, Taql B, and intron 6 polymorphic sites, but linkage disequilibria between these three sites and each of the Taql D, exon 7, exon 8, and promoter-141C sites were of lesser or of no significance. Taken together, these findings suggest that the Taql A, Taql B, and intron 6 polymorphisms, but not the Taql D, exon 7, exon 8, and promoter-141C polymorphisms, are in linkage disequilibrium with a functional allelic variant that affects D2 dopamine receptor expression.
Enzymatic model for receptor activation of GTP-binding regulatory proteins

Abstract A model of specific membrane receptor function may be constructed based on analogies with soluble enzymes. Here we consider structural aspects of the photon receptor, rhodopsin, which may be considered as a ligand-exchange enzyme, catalysing the guanine nucleotide exchange of its G protein substrate, transducin.
Dietary n‐3 Fatty Acids Decrease Osteoclastogenesis and Loss of Bone Mass in Ovariectomized Mice

UNLABELLED The mechanisms of action of dietary fish oil (FO) on osteoporosis are not fully understood. This study showed FO decreased bone loss in ovariectomized mice because of inhibition of osteoclastogenesis. This finding supports a beneficial effect of FO on the attenuation of osteoporosis. INTRODUCTION Consumption of fish or n-3 fatty acids protects against cardiovascular and autoimmune disorders. Beneficial effects on bone mineral density have also been reported in rats and humans, but the precise mechanisms involved have not been described. METHODS Sham and ovariectomized (OVX) mice were fed diets containing either 5% corn oil (CO) or 5% fish oil (FO). Bone mineral density was analyzed by DXA. The serum lipid profile was analyzed by gas chromatography. Receptor activator of NF-kappaB ligand (RANKL) expression and cytokine production in activated T-cells were analyzed by flow cytometry and ELISA, respectively. Osteoclasts were generated by culturing bone marrow (BM) cells with 1,25(OH)2D3. NF-kappaB activation in BM macrophages was measured by an electrophoretic mobility shift assay. RESULTS AND CONCLUSION Plasma lipid C16:1n6, C20:5n3, and C22:6n3 were significantly increased and C20:4n6 and C18:2n6 decreased in FO-fed mice. Significantly increased bone mineral density loss (20% in distal left femur and 22.6% in lumbar vertebrae) was observed in OVX mice fed CO, whereas FO-fed mice showed only 10% and no change, respectively. Bone mineral density loss was correlated with increased RANKL expression in activated CD4+ T-cells from CO-fed OVX mice, but there was no change in FO-fed mice. Selected n-3 fatty acids (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) added in vitro caused a significant decrease in TRACP activity and TRACP+ multinuclear cell formation from BM cells compared with selected n-6 fatty acids (linoleic acid [LA] and arachidonic acid [AA]). DHA and EPA also inhibited BM macrophage NF-kappaB activation induced by RANKL in vitro. TNF-alpha, interleukin (IL)-2, and interferon (IFN)-gamma concentrations from both sham and OVX FO-fed mice were decreased in the culture medium of splenocytes, and interleukin-6 was decreased in sham-operated FO-fed mice. In conclusion, inhibition of osteoclast generation and activation may be one of the mechanisms by which dietary n-3 fatty acids reduce bone loss in OVX mice.
Sweet nectar of the Gaia: Lessons from Ethiopia's “Project Gaia”

Though initiated only at smaller scales so far, “Project Gaia” offers an innovative Ethiopian model for using byproducts from the sugar industry to create an ethanol fuel that can be utilized by cleaner burning cookstoves, predominately internally displaced refugees. Backed by the Shell Foundation and a collection of NGOs, Project Gaia has distributed almost 4000 ethanol combusting stoves throughout refugee camps in Ethiopia. After summarizing the research methods utilized by the authors and introducing readers to the energy situation in Ethiopia, this study describes the history, benefits, and challenges of Project Gaia. Though the number of distributed stoves is small, they have lessened the burden of collecting fuelwood for Ethiopian refugees, reduced deforestation around refugee camps, displaced greenhouse gas emissions, and improved the health of cooks and children—all for roughly one-third the cost of kerosene, the most prevalent substitute fuel for cooking. However, if Project Gaia is to continue to deliver these benefits, a pernicious set of educational, political, and logistical barriers must be overcome. The final part of the study details these barriers, and it concludes by pointing out the significance of government consistency, technological appropriateness, and the coupling of energy services with commercial enterprises for efforts like Project Gaia.
Cloning DNA restriction endonuclease fragments with protruding single-stranded ends.

Abstract A new method of in vitro recombination was employed to construct plasmids containing lac promoter fragments 64 bp and 144 bp long. The 64 bp HpaII-HhaI fragment contains the binding site for the catabolite activator protein (CAP). The HpaII-HaeIII 144 bp fragment includes the binding sites for RNA polymerase, the lac repressor and CAP. The method utilizes the ability of T4 DNA polymerase to make flush-ended DNA either by filling in a recessed 3′-end or by exonucleolytic removal of a protruding 3′-end. The treated fragments were then blunt-end ligated to the filled-in EcoRI cloning sites of the plasmids pVH51 and pBR322 using T4 ligase. In this process, the EcoRI sites were regenerated on the fragment ends thus facilitating the subsequent isolation of the fragments from their cloning vectors.
Sequential angiographic analysis in congenital heart malformations

A segmental angiographic analysis of congenital heart malformations has been developed with the intention of making evaluation of complex congenital heart anomalies as comprehensive as possible. Each vascular and cardiac segment is analysed sequentially, considering morphology, connections, and relations. Additional associated cardiovascular abnormalities such as shunts, stenoses, hypoplasias and atresias are also considered. Information analysed and presented in this way has more immediate anatomic and physiologic meaning than ambiguous terms, often with obscure embryologic implications. Disagreements regarding definitions and nomenclature will continue; however, a logical framework that allows clear communication among cardiologists, surgeons, and angiographers is absolutely necessary and is provided by the orderly analysis presented here.
Timing of PourThru Affects pH, Electrical Conductivity, and Leachate Volume*

Abstract The time between irrigation and PourThru sampling had not been extensively examined for affects on pH, electrical conductivity (EC), and leachate volume in greenhouse production. A greenhouse study with 16.5 and 19.2 cm wide containers using Fafard 4P and Metro Mix 320 soilless substrates was implemented, and PourThru leachates were extracted and tested for pH, EC, and volume at 15, 30, 60, 120, and 240 minutes after irrigation. Substrates and pot sizes affected PourThru pH and EC; however, timing did not affect these values in this study. The elapsed time between irrigation and sampling affected leachate volumes and mass wetness of the substrates such that values decreased when 120 or 240 minutes elapsed from irrigation to sampling. Based upon the fluctuations in leachate volumes and mass wetness values, it is recommended that 60 minutes elapse from time of irrigation to PourThru sampling. Sixty minutes is sufficient time to allow for nutrient equilibration so the greenhouse crop producers can o...
The Emerging Field of Clinical Engineering and Its Accomplishments

Clinical engineering has emerged during the past 20 years as a specialty area to apply the knowledge produced by biomedical engineering research. The clinical engineer is a member of the health care team in a clinical environment and interfaces with physicians, nurses, and allied health care personnel. The role of clinical engineering also includes management, information systems, and health care delivery systems. A survey was performed, and the results of the questionnaire identified the primary contributions of clinical engineering to be as follows: provide technical advice, expertise, and educational services; provide electrical safety programs; provide consultation to resolve and investigate equipment malfunctions or failures; and provide for the centralized management and maintenance of medical instrumentation and equipment. The role of clnical engineering is expanding as the use of advanced technology increases in health care delivery.
Positively biased appraisals in everyday life: when do they benefit mental health and when do they harm it?

To promote optimal mental health, is it best to evaluate negative experiences accurately or in a positively biased manner? In an attempt to reconcile inconsistent prior research addressing this question, we predicted that the tendency to form positively biased appraisals of negative experiences may reduce the motive to address those experiences and thereby lead to poorer mental health in the context of negative experiences that are controllable and severe but lead to better mental health in the context of controllable negative experiences that are less severe by promoting positive feelings without invoking serious consequences from unaddressed problems. In 2 longitudinal studies, individuals in new marriages were interviewed separately about their ongoing stressful experiences, and their own appraisals of those experiences were compared with those of the interviewers. Across studies, spouses’ tendencies to form positively biased appraisals of their stressful experiences predicted fewer depressive symptoms over the subsequent 4 years among individuals judged to be facing relatively mild experiences but more depressive symptoms among individuals judged to be facing relatively severe experiences. Furthermore, in Study 2, these effects were mediated by changes in those experiences, such that the interaction between the tendency to form positively biased appraisals of stressful experiences and the objectively rated severity of initial levels of those experiences directly predicted changes in those experiences, which in turn accounted for changes in depressive symptoms. These findings suggest that cognitive biases are not inherently positive or negative; their implications for mental health depend on the context in which they occur.
International R&D rivalry and export market shares of unionized industries: Some evidence from the US manufacturing sector

Abstract This paper investigates how union activity that captures R&D rents alters the strategic investment behavior of internationally competitive firms. The effect of union activity in the Spencer, B.J., Brander, J.A., 1983 [International R&D rivalry and industrial strategy, Review of Economic Studies 50, 707–722] framework is to reduce the firm's strategic investment in R&D and its export market share. The empirical investigation at the industry level indicates that union activity has a significant and negative impact on R&D investment decisions in the US manufacturing sector. An important contribution of this work is its attempt to empirically distinguish between strategic and non-strategic R&D. The strategic effect of R&D on export market share in an imperfectly competitive product market is a decreasing function of the level of union activity.
On selecting a prior for the precision parameter of Dirichlet process mixture models

Abstract In hierarchical mixture models the Dirichlet process is used to specify latent patterns of heterogeneity, particularly when the distribution of latent parameters is thought to be clustered (multimodal). The parameters of a Dirichlet process include a precision parameter α and a base probability measure G 0 . In problems where α is unknown and must be estimated, inferences about the level of clustering can be sensitive to the choice of prior assumed for α . In this paper an approach is developed for computing a prior for the precision parameter α that can be used in the presence or absence of prior information about the level of clustering. This approach is illustrated in an analysis of counts of stream fishes. The results of this fully Bayesian analysis are compared with an empirical Bayes analysis of the same data and with a Bayesian analysis based on an alternative commonly used prior.
Salt Deposition in North Arm, Great Salt Lake, Utah: ABSTRACT

Construction of a semipermeable, rock-fill railroad causeway across the Great Salt Lake has caused a severe imbalance in concentrations of lake brines north and south of the causeway. Ninety percent of freshwater inflow enters the lake south of the causeway. South arm brines are becoming progressively fresher as salts are deposited on the floor of the north arm where there is no freshwater inflow other than rainfall and minor springs. The water surface of the south arm is as much as 40 cm higher than the surface of the north arm. Logging of 38 cores up to 1.5 m long drilled on a 4-mi grid shows a maximum salt thickness of about 1.5 m and an average thickness of more than 0.6 m covering 1,250 sq km of the north arm. Nearly 2 billion tons (metric) of salts have been deposited in the north arm since the causeway was completed 13 years ago; a rate of 150 million tons per year. X-ray diffraction analysis of more than 150 samples shows that the salt in the north arm is almost entirely halite. Minor amounts of sylvite are present in some samples, but it is uncertain whether it was deposited in the lake with the halite or from occluded brines partly evaporated from the core tubes during prolonged storage. Preliminary electron microprobe studies indicate that potassium occurs in local concentrations within halite crystals and not along crystal boundaries, suggesting that the sylvite may be primary. End_of_Article - Last_Page 957------------
Nonuniform extension of chain segments of a polymer coil in dilute solution

Abstract An isolated, flexible polymer chain in dilute solution assumes a random configuration. In reality such a polymer coil is not completely random, because an excluded volume effect requires a modification from randomness. In addition, the coil placed in a better solvent is more expanded than that in a poor solvent. In other words, the polymer chain segments in a better solvent are more extended, compared to those in a neutral solvent. In the present study we have discovered an indication that the chain segments lying on the periphery of the coil are more extended than those in the interior. This discovery has been made in the course of relating intrinsic viscosity to thermodynamic interaction between polymer and solvent. The resulting relationship provides a means of evaluating the thermodynamic interaction parameter from the measured value of intrinsic viscosity, if the molecular weight of the polymer, its intrinsic viscosity in a neutral solvent, and the degree of excess extension of chain segment...
Direct and Fluorescence Excitation of the K-Level in Thick Targets of Copper

The ratio $P$ of the probability of exciting the $K$ shell of copper by direct cathode-ray impact to the probability of exciting the same shell by fluorescence in a thick target, is measured with normally emergent rays over a range of voltages extending from 2 to 17.4 times the $K$ excitation voltage. $P$ is found to vary from 6.63 at $U=2 \mathrm{to} 7.2$ at $U=17.4$, where $U$ is the ratio of tube voltage to $K$ excitation voltage. The ratio $Q$ of the probability of a cathode ray ionizing the $K$ shell directly to the probability of a cathode ray exciting a continuous quantum of frequency greater than the $K$-limit frequency is found to be very nearly constant at 3.5 for the same voltage range. The variation of $P$ with $Z$ is examined theoretically and compared with experiment showing a lack of good agreement.
Statistical mechanics and its application to physical-chemical problems

BARTOL RESEARCH (I) Introduction.-At the end of the last FOUNDATION lecture we concluded that it seemed reasonable Communica*ion No. 12. to take a microcanonical ensemble of systems distributed uniformly in the phase space with energies between E and E + dE, as giving a fair representation of the successive states of a single system left to itself with energy in that range. This principle provides the basis for nearly all the results of statistical mechanics which have practical application to systems of molecules, and in the present lecture I wish to describe to you some of the results which we obtain in this manner for systems of molecules that are in a steady condition of equilibrium. The results are so numerous and the time ,available so short that I shall have to omit a great many, and even then I am afraid that my lecture may sound too much like a page of equations read out from a handbook of mathematics. (2) Tt%e Maxzuell-Boltzwzamz Distribution La-w.-The first result of statistical mechanics to which I wish to call your attention is the well-known Maxwell-Boltzmann distribution law. Consider a gas containing N molecules, and let the condition of each molecule be specifiable by giving the values of n generalized ‘coordinates and the corresponding momenta q1 . . . p,. Three of these coordinates, say ql, q2, and q3, could be taken as the three coordinates x, y, and z which give the position of the centre of gravity of the molecule and the corresponding momenta, p,, p,, and p, would then be the linear momenta 112 (dx/dt), m( dy/dt) and uz (dz/dt), where wz is the mass of the molecule. The remaining co6rdinates q4 . . . qn could then be used to specify the angular orientation of the molecule and the positions of its internal parts, and the corresponding momenta p, . . . p, deter* Delivered in the lecture hall of the Institute, Friday afternoon, November rg, rgz6.
Accelerated gene evolution through replication-transcription conflicts

Several mechanisms that increase the rate of mutagenesis across the entire genome have been identified; however, how the rate of evolution might be promoted in individual genes is unclear. Most genes in bacteria are encoded on the leading strand of replication. This presumably avoids the potentially detrimental head-on collisions that occur between the replication and transcription machineries when genes are encoded on the lagging strand. Here we identify the ubiquitous (core) genes in Bacillus subtilis and determine that 17% of them are on the lagging strand. We find a higher rate of point mutations in the core genes on the lagging strand compared with those on the leading strand, with this difference being primarily in the amino-acid-changing (nonsynonymous) mutations. We determine that, overall, the genes under strong negative selection against amino-acid-changing mutations tend to be on the leading strand, co-oriented with replication. In contrast, on the basis of the rate of convergent mutations, genes under positive selection for amino-acid-changing mutations are more commonly found on the lagging strand, indicating faster adaptive evolution in many genes in the head-on orientation. Increased gene length and gene expression amounts are positively correlated with the rate of accumulation of nonsynonymous mutations in the head-on genes, suggesting that the conflict between replication and transcription could be a driving force behind these mutations. Indeed, using reversion assays, we show that the difference in the rate of mutagenesis of genes in the two orientations is transcription dependent. Altogether, our findings indicate that head-on replication-transcription conflicts are more mutagenic than co-directional conflicts and that these encounters can significantly increase adaptive structural variation in the coded proteins. We propose that bacteria, and potentially other organisms, promote faster evolution of specific genes through orientation-dependent encounters between DNA replication and transcription.
Directed Differentiation of Induced Pluripotent Stem Cells towards T Lymphocytes

Adoptive cell transfer (ACT) of antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) is a promising treatment for a variety of malignancies 1. CTLs can recognize malignant cells by interacting tumor antigens with the T cell receptors (TCR), and release cytotoxins as well as cytokines to kill malignant cells. It is known that less-differentiated and central-memory-like (termed highly reactive) CTLs are the optimal population for ACT-based immunotherapy, because these CTLs have a high proliferative potential, are less prone to apoptosis than more differentiated cells and have a higher ability to respond to homeostatic cytokines 2-7. However, due to difficulties in obtaining a high number of such CTLs from patients, there is an urgent need to find a new approach to generate highly reactive Ag-specific CTLs for successful ACT-based therapies. TCR transduction of the self-renewable stem cells for immune reconstitution has a therapeutic potential for the treatment of diseases 8-10. However, the approach to obtain embryonic stem cells (ESCs) from patients is not feasible. Although the use of hematopoietic stem cells (HSCs) for therapeutic purposes has been widely applied in clinic 11-13, HSCs have reduced differentiation and proliferative capacities, and HSCs are difficult to expand in in vitro cell culture 14-16. Recent iPS cell technology and the development of an in vitro system for gene delivery are capable of generating iPS cells from patients without any surgical approach. In addition, like ESCs, iPS cells possess indefinite proliferative capacity in vitro, and have been shown to differentiate into hematopoietic cells. Thus, iPS cells have greater potential to be used in ACT-based immunotherapy compared to ESCs or HSCs. Here, we present methods for the generation of T lymphocytes from iPS cells in vitro, and in vivo programming of antigen-specific CTLs from iPS cells for promoting cancer immune surveillance. Stimulation in vitro with a Notch ligand drives T cell differentiation from iPS cells, and TCR gene transduction results in iPS cells differentiating into antigen-specific T cells in vivo, which prevents tumor growth. Thus, we demonstrate antigen-specific T cell differentiation from iPS cells. Our studies provide a potentially more efficient approach for generating antigen-specific CTLs for ACT-based therapies and facilitate the development of therapeutic strategies for diseases.
Pressure induced transition from spin glass-like behavior to a metamagnet exhibiting weak ferromagnetism observed for decamethylferrocenium hexacyanobutadienide, [FeCp*2]˙+ [HCBD]˙-.

The magnetic properties of [FeIIICp*2]˙+[HCBD]˙− (Cp* = pentamethylcyclopentadienide; HCBD = hexacyanobutadienide, C4(CN)6) and [FeIIICp*2]˙+[DDQ]˙− (DDQ = 2,3-dichloro-5,6-dicyanoquinonide) were measured at ambient and applied hydrostatic pressures up to 11.4 and 9.2 kbar, respectively. At ambient pressure [FeCp*2][HCBD] exhibits spin glass-like behavior with a freezing temperature, Tf, of 2.93 K from the peak in χ′(T) at 10 Hz, but magnetic ordering is not evident due to the lack of a remnant magnetization, bifurcation temperature, and hysteresis. Above 3.1 kbar, [FeCp*2][HCBD] magnetically orders as a metamagnet with an antiferromagnetic ground state with an ordering temperature, Tc, of 2.46 K determined from the Fisher specific heat, which increases linearly to 4.80 K at 11.4 kbar at a rate of 0.28 K kbar−1. Upon application of pressure metamagnetic-like behavior with hysteresis indicative of a weak ferromagnet (canted antiferromagnet) was observed at and above 3.1 kbar, with a coercive field, Hcr, of 65 Oe, which increases exponentially to 795 Oe at 11.4 kbar. [FeCp*2]˙+[DDQ]˙− did not magnetically order above 2 K, and magnetic order was not observed up to 9.2 kbar. The pressure dependencies are reversible.
Use of neural network analysis to classify electroencephalographic patterns against depth of midazolam sedation in intensive care unit patients.

The electroencephalographic (EEG) analog signal is complex and cannot easily be described by univariate variables. Clear visual changes in the EEG power spectrum can be present with little or no change in univariate variable values. A method that could produce a single value based on the total data available in the EEG power spectrum would be very useful in monitoring EEG changes. Neural network analysis is a technique that can take multiple inputs and produce a single output value using complicated processing patterns that require training to establish. We examined the usefulness of a series of neural network models to classify 63 EEG patterns against sedation level in 26 mechanically ventilated patients requiring midazolam for long-term sedation. During a stable period of sedation, a 4- to 60-minute period of EEG data was obtained concurrently with a sedation level from 1 (follows commands) to 7 (no or gag response to suctioning of the endotracheal tubc). The EEG power spectrum was divided into equal frequency bands, and the log absolute powers in each of these bands were used as inputs for a series of neural network models. The output target was the sedation level associated with each set of EEG data. Networks were trained on a subset of EEG power/sedation score data pairs, and the ability to classify the remaining data pairs was tested. Using at-test comparison with a random set of sedation levels, we found that trained neural network models classified EEG patterns against sedation level successfully (p<0.001). Fifty to sixty percent of EEG patterns were classified to within a sedation level, as oposed to 30% by chance alone, depending on the network model. Correlation coefficients between actual and predicted sedation levels ranged from 0.1 to 0.5. The best efficiency, as measured by training time and classification success, was obtained when the EEG power spectrum was divided into 2-Hz bands. We conclude that (1) neural network analysis can be used to successfully classify EEG patterns against sedation level when long-term midazolam infusions are used; and (2) a trained neural network may be useful as an on-line monitor of EEG changes, producing a single-output value based on the total EEG data set.
Spindle Cell Lesions—Neoplastic or Non-Neoplastic?: Spindle Cell Carcinoma and Other Atypical Spindle Cell Lesions of the Head and Neck

One challenging feature of head and neck pathology is that a dizzying array of spindle cell lesions occur here ranging all the way from reactive to malignant and very aggressive. This makes accurate diagnosis critical. At mucosal sites, the most important of these is spindle cell carcinoma (SpCC). Most SpCC are overtly malignant, and the differential diagnosis then includes a number of different malignant spindle cell neoplasms. However, there are several benign or even non-neoplastic lesions that can sometimes be difficult to discern from SpCC. The pathologic and clinical features can resolve this differential diagnosis. This review will focus on the clinical and diagnostic features of SpCC and the select non-neoplastic or benign lesions which are occasionally hard to distinguish from it.
Lead exposure potentiates predatory attack behavior in the cat.

Epidemiologic studies have demonstrated that environmental lead exposure is associated with aggressive behavior in children; however, numerous confounding variables limit the ability of these studies to establish a causal relationship. The study of aggressive behavior using a validated animal model was used to test the hypothesis that there is a causal relationship between lead exposure and aggression in the absence of confounding variables. We studied the effects of lead exposure on a feline model of aggression: predatory (quiet biting) attack of an anesthetized rat. Five cats were stimulated with a precisely controlled electrical current via electrodes inserted into the lateral hypothalamus. The response measure was the predatory attack threshold current (i.e., the current required to elicit an attack response on 50% of the trials). Blocks of trials were administered in which predatory attack threshold currents were measured three times a week for a total of 6-10 weeks, including before, during, and after lead exposure. Lead was incorporated into cat food "treats" at doses of 50-150 mg/kg/day. Two of the five cats received a second period of lead exposure. Blood lead concentrations were measured twice a week and were <1, 21-77, and <20 micro g/dL prior to, during, and after lead exposure, respectively. The predatory attack threshold decreased significantly during initial lead exposure in three of five cats and increased after the cessation of lead exposure in four of the five cats (P<0.01). The predatory attack thresholds and blood lead concentrations for each cat were inversely correlated (r=-0.35 to -0.74). A random-effects mixed model demonstrated a significant (P=0.0019) negative association between threshold current and blood lead concentration. The data of this study demonstrate that lead exposure enhances predatory aggression in the cat and provide experimental support for a causal relationship between lead exposure and aggressive behavior in humans.
The NBS radon-water standard generator

Abstract NBS has completed the development of a transfer standard for radon-in-water measurements. This standard can be used to generate and accurately dispense radium-free 222 Rn solutions of known concentration. It is based on an earlier and previously described prototype. The standard consist of a polyethylene-encapsulated 226 Ra solution source in a small-volume accumulation chamber and an ancillary mixing and dispensing system which is partially automated with motor-driven syringes. The revised source configuration is more stable than the original prototype; and the mixing and dispensing system is more compact, rugged, and convenient. The standard generator was calibrated and certified in terms of the 222 Rn concentration or total activity in an aliquot dispensed from the generator when a detailed operation procedure is adequately followed. The overall uncertainty of the calibration was estimated to be approximately ± 4%.
The Effects of Nuclear Radiation on High Temperature Thermistors

High temperature thermistors, 100°C to 600°C, were tested before, during, and after irradiation in the Ground Test Reactor at The Nuclear Aerospace Research Facility, General Dynamics/Fort Worth. The radiation environment was held constant at 2.2 × 1010 nf/cm2-sec (nf = fast neutrons with energy> 2.9 Mev) and 4.2 × 108 ergs/ gm(C) hr ? for a period of 91 hours. Resistance as a function of temperature was measured for high, medium, and low resistance type thermistors. No permanent damage was observed, but transient effects were severe at high resistance values. The transient effects were due to ionization of the air and the thermistor material by the nuclear environment. The ionic conduction in the thermistor material was highly temperature dependent.