cssi/SciSciGPT-SciSciNet huggingface dataset:
Virtual reality for small colleges

The popularity of Virtual Reality (VR) display systems has increased dramatically in recent years. VR applications are characterized by a virtual world into which users are immersed, providing interactivity and sensory feedback [1]. These superior sensory environments make virtual reality a popular medium for many types of applications, ranging from exploration of severe thunderstorm and tornado data [2], to architecture from ancient times [5]. Proponents of virtual reality feel that the VR experience enhances learning, since participants utilize more of their senses than with typical computer applications. VR systems generally provide displays to users in stereo projection that give a sense of 3D viewing. Traditionally, the cost of implementing virtual reality environment has been very high, limiting VR to only those institutions with large research budgets. However, with recent advances in commodity hardware capabilities and the reduction in cost of typical LCD projectors, a low cost VR system can now be constructed at any institution, even those with significant budget restrictions. This paper discusses our experiences with the construction of a stereo projection display environment at Hanover College, and some projects my students and I have done with this system. Several potential research projects in virtual reality, which could be done with little funding, are also proposed.
Asserting the Power of the Purse: Institutional Conflict and Regulatory Authority

This study seeks to answer a crucial and unexplored question about American regulatory law and policy: How does Congress use its spending power to circumvent intra-branch conflict and judicial constraints against regulating by finding alternate avenues to assert its regulatory authority over states and private actors? This study provides the first empirical evidence of congressional use of the spending power to assert implementation authority in the face of constraints against more direct legislating. It is through this process of conditioning funds upon regulatory compliance that Congress is able to work toward ideal policy outcomes without inciting institutional conflict with the other branches or from the opposing party. I base my conditional spending analysis on data on statutory specificity and congressional delegation from the 80th to the 110th Congresses provided by Sean Farhang, and include additional measures of institutional conflict. The above argument is supported by the empirical analysis.
Ageing diminishes endothelium-dependent vasodilatation and tetrahydrobiopterin content in rat skeletal muscle arterioles.

Ageing reduces endothelium-dependent vasodilatation through an endothelial nitric oxide synthase (NOS) signalling pathway. The purpose of this study was to determine whether arginase activity diminishes endothelium-dependent vasodilatation in skeletal muscle arterioles from old rats, and whether NOS substrate (l-arginine) and cofactor (tetrahydrobiopterin; BH4) concentrations are reduced. First-order arterioles were isolated from the soleus muscle of young (6 months old) and old (24 months old) male Fischer 344 rats. In vitro changes in luminal diameter in response to stepwise increases in flow were determined in the presence of the NOS inhibitor NG-nitro-l-arginine methyl ester (l-NAME, 10−5 mol l−1), the arginase inhibitor Nω-hydroxy-nor-l-arginine (NOHA, 5 × 10−4 mol l−1), exogenous l-arginine (3 × 10−3 mol l−1) or the precursor for BH4 synthesis sepiapterin (1 μmol l−1). Arteriolar l-arginine and BH4 content were determined via HPLC. Ageing decreased flow-mediated vasodilatation by 52%, and this difference was abolished with NOS inhibition. Neither inhibition of arginase activity nor addition of exogenous l-arginine had any effect on flow-mediated vasodilatation; arteriolar l-arginine content was also not different between age groups. BH4 content was lower in arterioles from old rats (94 ± 8 fmol (mg tissue)−1) relative to controls (234 ± 21 fmol (mg tissue)−1), and sepiapterin elevated flow-mediated vasodilatation in arterioles from old rats. These results demonstrate that the impairment of endothelium-dependent vasodilatation induced by old age is due to an altered nitric oxide signalling mechanism in skeletal muscle arterioles, but is not the result of increased arginase activity and limited l-arginine substrate. Rather, the age-related deficit in flow-mediated vasodilatation appears to be the result, in part, of limited BH4 bioavailability.
The Discovery of the Mechanisms of Enzyme Action, 1947–1963

Publisher Summary The application of the concepts of physical organic chemistry to the understanding of mechanisms of enzyme action constitutes one of the major triumphs of our science. Many important discoveries in two diverse fields laid the foundation for the understanding of the mechanisms of enzyme action. The application of reaction kinetics, of the spectroscopic identification of intermediates; the trapping of intermediates; the understanding of acid and base catalysis, of metal–ion catalysis; the use of isotopes as tracers; and for the determination of kinetic isotope effects, and much more, provided the intellectual armament needed to solve problems in enzymology. The chapter explores that mechanistic enzymology has developed at a rapid pace since 1963 and the artificial catalysts in 1902 appear within the realm of possibility. Enzymologists have reasonable notions of mechanism and of the factors needed to achieve rapid rates and specificity. The chapter also reviews that the foundations for mechanism and to some extent for an understanding of the factors relevant to enzymology were laid down in the years 1947–1963. By the end of that time, enzymology had become incorporated into physical organic chemistry.
Results of a National Survey on Technology in Academic Advising

The results of a fall 2002 national survey conducted by the National Academic Advising Association (NACADA) in cooperation with the NACADA Technology in Advising Commission concerning the uses of t...
The Mixed Mode I and II Interface Crack in Piezoelectromagneto–Elastic Anisotropic Bimaterials

Taking the electric-magnetic field inside the interface crack into account, the interface crack problem of dissimilar piezoelectromagneto (PEMO)-elastic anisotropic bimaterials under in-plane deformation is investigated. The conditions to decouple the in-plane and anti-plane deformation is presented for PEMO-elastic biaterials with a symmetry plane. Using the extended Stroh's dislocation theory of two-dimensional space and the analytic continuition principle of complex analysis, the interface crack problem is turned into a nonhomogeneous Hilbert equation in matrix notation. Four possible eigenvalues as well as four eigenvectors for the fundamental solution to the corresponding homogeneous Hilbert equation are found, so are four modes of singularities for the fields around the interface crack tip. These singularities are shown to have forms of r -(1/2)±i∈ 1 and r- (1/2)±i∈ 2, in which the bimaterial constants ∈ 1 and ∈ 2 are proven to be real numbers for practical dissimilar PEMO-elastic bimaterials. Compared with the solution for the interface crack of dissimilar elastic bimaterials without electro-magnetic properties, two new additional singularities are discovered for the interface crack in the PEMO-elastic bimaterial media. The electric-magnetic field inside the crack is solved by employing the "energy method, " which is based on finding the stationary point of the saddle surface of the energy release rate with respect to the electro-magnetic field inside the crack. Closed form expressions for the extended crack tip stress fields and crack open displacements are formulated, so are some other fracture characteristic parameters, such as the extended stress intensity factors and energy release rate (G) for dissimilar PEMO-elastic bimaterial solids. Finally, fundamental results and some conclusions are presented, which could have applications in the failure of piezoelectro /magneto-elastic devices.
Increasing web accessibility by automatically judging alternative text quality

The lack of appropriate alternative text for web images remains a problem for blind users and others accessing the web with non-visual interfaces. The content contained within web images is vital for understanding many web sites but the majority are assigned either inaccurate alternative text or none at all. The capability to automatically judge the quality of alternative text has the promise to dramatically improve the accessibility of the web by bringing intelligence to three categories of interfaces: tools that help web authors verify that they have provided adequate alternative text for web images, systems that automatically produce and insert alternative text for web images, and screen reading software. In this paper we describe a classifier capable of measuring the quality of alternative text given only a few labeled training examples by automatically considering the image context.
NOTIFYING INDIVIDUAL STUDENTS OF A DEATH LOSS: PRACTICAL RECOMMENDATIONS FOR SCHOOLSAND SCHOOL COUNSELORS

Although there is a growing body of literature focused on child and adolescent grief, surprisingly little information addresses the needs of school communities with regard to death. The emerging literature has focused primarily on crisis management when someone within the school community dies. Neglect has been the more common occurrence in which an individual child must be notified of the death of someone close. This article provides practical recommendations for schools and school counselors regarding preparation and follow-up associated with individual death notification situations, as well as specific suggestions pertaining to the who, when, where, and how of notification. Recommendations offered are based on a synthesis of relevant research and literature (e.g., children and death, general death notification, school culture), the clinical experience of the authors, and the collective wisdom of a sample of school counselors currently working in the field.
A hands-on microwave laboratory course using microstrip circuits

The microwave region of the electromagnetic spectrum provides an excellent vehicle for introducing electromagnetic concepts. Unfortunately, the relatively high cost of microwave experiments make it difficult to reinforce lecture material with laboratory exercise. A discussion is presented as to how a CAD program and a nonconventional fabrication procedure have been used in a two-semester microwave course at Cornell University, Ithaca, NY to design and build a variety of low-cost microstrip circuits. >
Cancer gene and oncolytic virus therapy.

Abstract By far, cancer accounts for the majority of gene therapy trials that are being carried out worldwide. Seventy percent of the gene therapy protocols that have been reviewed by the National Institutes of Health Recombinant DNA Advisory Committee (NIH RAC) are for the treatment of cancer. Of these, two thirds involve immunotherapy, with transfer of genes for cytokines, immune accessory molecules, or tumor antigens into a variety of cellular targets. Other clinical protocols include chemoprotection, prodrug activation, or tumorsuppressor gene replacement. Either local or distal bystander effects may mediate antitumor effects. These bystander mechanisms may help to overcome poor transduction efficiencies by currently available vectors. Replicating oncolytic viruses entering the clinic include herpes virus, Newcastle disease virus, reovirus, and others. These viruses have been shown to replicate selectively in cancer cells, albeit by different mechanisms. Reovirus, for example, requires the presence of an activated Ras signaling pathway in order to replicate and destroy cells. Tumor selectivity can be achieved by placing an essential viral gene under the control of a tumor-specific promoter. The tumoricidal effects of replicating viruses may be enhanced by genetic modification—for example, by the insertion of a cytokine gene to elicit antitumor immunity. Clearly, much work needs to be done both in the laboratory and in the clinic in order to exploit the full potential of these novel gene and viral therapies.
Tillage effect on seasonal nitrogen availability in corn supplied with legume green manures

It has been shown that legume green manures have great potential for replacing a substantial amount of the N fertilizer required for corn (Zea mays L.) production. An experiment was conducted in central Pennsylvania (USA) to study seasonal fluctuation of nitrogen (N) availability in corn with conventional tillage (CT) and no-till (NT) following red clover (Trifolium pratense L.) and hairy vetch (Vicia villosa Roth) green manures double-cropped with winter wheat (Triticum aestivum L.). Samples of corn, weeds, and soil were taken periodically and analyzed for total N content in plant tissue and soil nitrate-N content. The sum of plant N (corn plus weed) and soil nitrate-N in the upper 45 cm profile was used as an indicator of total available N. Under CT, total available N increased rapidly upon legume incorporation and reached 80% of the maximum within 4 weeks. Under NT, total available N increased steadily after the legumes were killed with herbicides and reached a maximum within 7 to 8 weeks. Seasonal corn N accumulations with the legume N source were similar to those where corn followed fallow with 200 kg N ha−1 fertilizer with CT, but were less than those in the same fallow 200 kg N ha−1 treatment with no-till. Dry weather conditions together with weed competition reduced N availability to the no-till corn compared to the CT treatments. The seasonal fluctuations of total available N and corn N uptake suggest good synchronization between N availability from the legume green manures and N accumulation by corn plants in both tillage systems under the conditions of this study.
Artificial superlattices grown by MBE: Could we design novel superconductors?

Abstract We review briefly the technique of atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) that allows us to deposit atomically smooth single-crystal thin films of cuprate superconductors and various other complex oxides. We give a couple of examples showing how this technique has been used to synthesize ‘artificial’ high- T c superconductors – metastable high- n members of known cuprate families or superlattices of various known (natural, stable) compounds. We also report briefly on the present status of our state-of-the-art ALL-MBE system, and suggest that this technique could be useful in search for new natural or artificial superconducting materials.
The mechanism of radiation-induced segregation in ferritic–martensitic alloys

Abstract The mechanism of radiation-induced segregation in Fe–Cr alloys was modeled using the inverse Kirkendall mechanism and compared to experimental measurements over a range of temperatures, bulk Cr compositions, and irradiation dose. The model showed that over a large temperature range chromium was enriched at sinks by interstitial migration, and at very high temperatures it was depleted by diffusing opposite to the vacancy flux. Experimental results and model predictions were in good qualitative and quantitative agreement with regard to the temperature dependence of segregation and the crossover from Cr enrichment to Cr depletion. The inverse Kirkendall mechanism was also in agreement with experimental findings that observed a decreasing amount of Cr enrichment with increasing bulk Cr composition. The effects of solute drag were modeled within the inverse Kirkendall framework, but were unable to account for either the crossover from Cr enrichment to Cr depletion or the magnitudes of segregation measured in experiments.
Current Status of Ti PM: Progress, Opportunities and Challenges

Utilization of titanium components made by powder metallurgy methods has had limited acceptance largely due to the high cost of titanium (Ti) powder. There has been renewed interest in lower cost economical powders and several Ti reduction methods that produce a particulate product show promise. This talk summarizes work done at Oak Ridge National Laboratory to consolidate these economical powders into mill products. Press and sinter consolidation, hot isostatic pressing (HIP) and direct roll consolidation to make sheet have been explored. The characteristics of the consolidated products will be described as a function of the consolidation parameters.
Evaluation of Hox11L1 in the fmc/fmc rat model of chronic intestinal pseudo-obstruction.

Abstract Background/Purpose The spontaneous rat mutation, familial megacecum and colon ( fmc ), is responsible for an autosomal recessive phenotype similar to intestinal pseudo-obstruction observed in Hox11L1 −/− mice. We hypothesized that fmc is a mutant allele of the rat Hox11L1 gene and tested this hypothesis by direct sequencing. Methods DNA was extracted from fmc/fmc rats and wild-type littermates. All exons, introns, and DNA 5′ to the transcriptional start site of rat Hox11L1 were directly sequenced, and data from the mutant and wild-type animals were compared with each other and corresponding genomic data from humans and mice. Results Alignment of sequences obtained from rat, human, and mouse indicates that putative regulatory elements of the Hox11L1 gene are conserved in rat, mice, and humans. No mutations were identified in the Hox11L1 allele of fmc/fmc rats. Conclusions Despite the phenotypic similarities between fmc/fmc rats and Hox11L1 −/− mice, fmc does not appear to be a mutant allele of the Hox11L1 gene.
The relationship between demographic variables and intent to stay in the military: medical personnel in a U.S. Air Force hospital

This study tested empirically the relationships between eleven demographic variables and intent to stay in the U.S. Air Force, used as a proxy for turnover. The research reported here was conducted...
Option pricing under a normal mixture distribution derived from the Markov tree model

Abstract We examine a Markov tree (MT) model for option pricing in which the dynamics of the underlying asset are modeled by a non-IID process. We show that the discrete probability mass function of log returns generated by the tree is closely approximated by a continuous mixture of two normal distributions. Using this normal mixture distribution and risk-neutral pricing, we derive a closed-form expression for European call option prices. We also suggest a regression tree-based method for estimating three volatility parameters σ, σ+, and σ− required to apply the MT model. We apply the MT model to price call options on 89 non-dividend paying stocks from the S&P 500 index. For each stock symbol on a given day, we use the same parameters to price options across all strikes and expires. Comparing against the Black–Scholes model, we find that the MT model’s prices are closer to market prices.
Early spring leaf out enhances growth and survival of saplings in a temperate deciduous forest.

Saplings of many canopy tree species in winter deciduous forests receive the major portion of their light budget for their growing season prior to canopy closure in the spring. This period of high light may be critical for achieving a positive carbon (C) gain, thus contributing strongly to their growth and survival. This study of saplings of Aesculus glabra and Acer saccharum in Trelease Woods, Illinois, USA, tested this hypothesis experimentally by placing tents of shade cloth over saplings during their spring period of high light prior to canopy closure in three consecutive years. Leaf senescence began 16 days (year 0) and 60 days (year 1) earlier for shaded A. glabra saplings than control saplings. No change in senescence occurred for A. saccharum. The annual absolute growth in stem diameter of both species was negligible or negative for shaded saplings, but positive for control saplings. Only 7% of the shaded A. glabra saplings were alive after 2 years, while all control saplings survived for 3 years; only 20% of the shaded A. saccharum saplings survived for 3 years, while 73% of control saplings were alive after the same period. Early spring leaf out is a critical mechanism that allows the long-term persistence of saplings of these species in this winter deciduous forest. Studies and models of C gain, growth, and survival of saplings in deciduous forests may need to take into account their spring phenology because saplings of many species are actually “sun” individuals in the spring prior to their longer period in the summer shade.
Insulin Levels, Physical Activity, and Urinary Catecholamine Excretion of Obese and Non‐Obese Rhesus Monkeys

The hypothesis that spontaneous obesity in rhesus monkeys is associated with abnormalities in energy expenditure was tested. Obese (n=7) and non-obese (n=5) monkeys were described in terms of body size and composition, food intake, and physical activity. Additionally, the relationships among fasting and stimulated insulin levels in serum, C-peptide levels in serum and urine, and urinary catecholamines were examined. Obese animals had primarily abdominal deposition of excess body fat, as indicated by markedly elevated abdominal circumferences and skin-fold thicknesses. Food intake did not differ between groups. Physical activity was much lower in the obese group. Obese monkeys had markedly higher serum insulin and C-peptide levels in the fasted state and in response to an intravenous glucose challenge. Urinary excretion of C-peptide and catecholamines was measured during successive 2-day periods of ad libitum feeding, food deprivation, and refeeding in order to examine potential differences between groups in sympathoadrenal activity and their relationship to insulin secretion. C-peptide excretion was greater for obese and decreased for both groups during food deprivation. Urinary dopamine (DA), norepinephrine (NE), and epinephrine (E) levels were significantly greater for obese animals in all conditions. DA excretion was lowest during deprivation and E excretion was lowest during refeeding, whereas NE excretion was relatively unaffected by feeding condition. The overall patterns of C-peptide and catecholamine excretion were qualitatively similar for both groups, and there were no reliable differences between obese and non-obese in their responses to the feeding manipulation. The results suggest that hyperinsulinemia associated with obesity in rhesus monkeys is linked to increased catecholamine secretion and a resistance to cate-cholaminergic action.
Origin of the “lost cause” argument: Analysis of civil war letters

Analysis of letters sent home by Confederate soldiers reveals three dominant rhetorical themes: Love of hone, region, and God. Similar visions were created in post‐Civil War southern oratory.
Studies on methylene chloride-induced fatty liver.

Abstract The fatty liver induced by methylene chloride inhalation in the guinea pig was investigated by studying the effects of this solvent on several pathways of hepatic lipid metabolism. Inhalation of 5200 ppm (18,000 mg/m3) methylene chloride for 6 hr resulted in a 2.5-fold increase in hepatic triglyceride. Electron microscopy revealed the hepatocytes following exposure to be of normal appearance except for the presence of numerous lipid droplets in the cell periphery. No changes were evident by light microscopy. Serum free fatty acid levels were unaffected by exposure. The incorporation of palmitic acid into triglyceride by liver slices was also unchanged by methylene chloride. These results suggest that increased triglyceride synthesis rates were not responsible for the fatty liver. Exposure resulted in a 63% decrease in serum triglyceride, suggesting a defect in triglyceride secretion as a cause of the fatty liver. This defect does not appear to be due to decreased hepatic protein synthesis, in as much as incorporation of [1-14C]leucine into hepatic proteins was unaltered, or by decreased availability of phospholipids, because hepatic phospholipids actually increased with triglyceride. Liver slices from exposed animals incubated with control guinea pig serum containing [1-14C]palmitic acid were able to incorporate [14C] into triglyceride and then secrete triglyceride into the medium at control rates. In toto, the results may suggest that methylene chloride inhalation leads to the depletion or alteration of some component present in serum necessary for the maintenence of normal hepatic triglyceride secretion.
The Improvement about the Reliability of Sampling Based on Process Bus in Smart Substation

The sampling based on process bus is not widely used in smart substation because there are still some technical problems on synchronization, the design of network architecture and sampling data receiving and processing areas. There are some researches about the problems are carried out, but they only focus on part of them and cannot give the whole solution. In order to improve the reliability of network sampling, a new system method which includes all the segments of the sampling based on process such as the synchronization of data acquisition, data transmission, network optimization and data processing are presented. In the data acquisition segment, the synchronization based on IEEE1588 is provided, In the data transmission segment, a new hardware architecture which is based on FPGA+DSP+VxWorks is described, in the segment of network optimization, the topology structure and virtual LAN are suggested. At last, the automatic resampling is proposed in the data receiving and processing segment. It will be useful to improve the reliability of sampling based on process bus in smart substation.
A mouse mutant p53 product recognized by CD4+ and CD8+ T cells.

Abstract The T-cell response to mutated and normal p53 products of BALB/c-derived Meth A sarcoma was analyzed. Meth A p53 is known to have three missense point mutations in codons 132, 168, and 234, and 24 peptides containing wild-type or mutated sequences at the three mutation sites were constructed. Spleen cells from BALB/c or (BALB/c x C57BL/6)F1 mice immunized with p53 peptides were sensitized in vitro with the corresponding peptides. Because Meth A is resistant to cytotoxic T cells, the sensitive P1-HTR cell line, which expresses a low level of p53 lacking the Meth A p53 mutations, was chosen as a target, either pulse-labeled with p53 peptides or transfected with plasmids containing coding sequences from Meth A p53. One peptide, a nonamer containing the codon 234 mutation (234CM), induced CD8+ cytotoxic T cells that lysed 234CM-pulsed P1-HTR cells in an H-2Kd-restricted fashion. P1-HTR cells pulsed with the corresponding wild-type peptide were only weakly lysed by 234CM-reactive cytotoxic T cells. P1-HTR cells pulsed with other wild-type or mutated p53 peptides were not lysed by 234CM-reactive cytotoxic T cells, nor could these peptides, including 234CW (the wild-type counterpart to 234CM), elicit cytotoxic cells. P1-HTR cells transfected with plasmids coding for the 234CM sequence and expressing high p53 levels were weakly lysed by 234CM-reactive cytotoxic T cells. However, lysis of one of the transfectants was significantly increased by pretreatment with interferon gamma. A proliferative response of CD4+ T cells was elicited by immunization with 234CM and 234CW, but not with other p53-related peptides. The specificity of 234CM-induced CD4+ T cells for 234-region peptides was broader than the reactivity of 234CM-reactive cytotoxic T cells. Mice immunized with 234CM in incomplete Freund's adjuvant showed heightened resistance to Meth A challenge.
Stationary phase effects on retention behavior of phenols in micellar liquid chromatography: perfluorooctane vs. C18

Abstract The usefulness of fluorinated bonded stationary phases is further examined in micellar liquid chromatography (MLC) using cationic micellar eluents. The retention behavior of substituted phenols was investigated in MLC with both a Perfluorooctane (FO) column and a C18 column. It has been found that phenols with electron withdrawing groups (e.g., -CN, -NO2, and -COR) have longer retention on the FO column than that on the C18 column. This might be due to the larger specific polar interactions between the solutes and the FO column. The functional group selectivity (τ) values of these polar substituents were significantly increased on the FO column. However, phenols with substituted hydrocarbons show shorter retention on the FO column than that on the C18 column. This may be due to the smaller hydrophobic interactions between hydrocarbon substituents and fluorocarbon stationary phase. The simultaneous enhancement of solvent strength and selectivity that has been reported in the SDS hybrid system was also observed in the C14TAB hybrid system. This is due to the existence of the competing partitioning equilibria in MLC and because of the interactive nature of the two eluent parameters, micelle concentration and the volume fraction of organic solvents; both of which influence solvent strength and selectivity. The iterative regression startegy was used to optimize these two mobile phase parameters for a group of phenols using the FO column with the cationic micellar eluents. Excellent agreement was obtained between the observed and the predicated optimum chromatograms using only five initial experiments. This indicates that the easily predictable and highly reproducible retention behavior that has been reported in MLC systems with the alkyl bonded phases is also observed with fluorocarbon bonded phases and cationic micellar eluents.
Framework for statistical analysis of homogeneous multicore power grid networks

In this paper, we propose a framework to analyze the large-scaled multicore power grid network statistically by first building a simplified multicore power supply distribution model. We then apply the Modified Nodal Analysis (MNA) method on a simplified power gird circuit. Under such a framework, most statistical approaches, including Monte Carlo (MC), Importance Sampling, and Stochastic Spectrum Analysis, can be applied to analyze the process-induced variation of homogeneous multicore power grid networks. In the experiment, we focus on the subthreshold leakage current variations, which are modeled as lognormal distribution random variables, by using MC approach as an example to demonstrate the feasibility of such a framework.1
Advice to White allies: insights from faculty of Color

This article interweaves discussions of successes and tensions surrounding cross-racial collaborative social justice efforts in teacher education. It addresses frustrations that often occur for faculty of Color when working with White allies in P-12 settings and schools of education at Predominantly White Institutions. Advice is offered with the larger goal of helping White allies think about ways to shift the gaze from educators’ politics to the wellbeing of culturally and linguistically diverse students. Suggestions for how White allies can better support faculty of Color are presented.
Cardiovascular and Catecholamine Responses to Head‐Up Tilt in the Diagnosis of Recurrent Unexplained Syncope in Elderly Patients

To increase understanding of the mechanisms causing syncope in patients over the age of 60, hemodynamic and hormonal responses to 60 minutes of 60 degree head-up tilt were examined in 10 patients with recurrent syncope of unknown origin and five controls with no history of syncope. Nine of 10 patients and all five controls experienced orthostatic intolerance on the tilt table. Syncope or pre-syncope occurred later in controls than in those syncope patients who had exact reproduction of their clinical symptoms (median time 52 versus 22 minutes, P = 0.05). Three different mechanisms of orthostatic intolerance were identified in the 14 subjects: (1) vasovagal syncope, n = 9 (sudden hypotension ± bradycardia); (2) dysautonomic syncope, n = 3 (immediate and gradual parallel declines in both systolic and diastolic pressures with blunted increase in heart rate); (3) psychogenic or vestibular reaction, n = 2 (orthostatic intolerance without hemodynamic changes). Vasovagal syncope patients showed a significant increase in plasma norepinephrine from baseline to maximum level during tilt (100 ± 39% increase, P = 0.03) and a subsequent decrease at the time of syncope (30 ± 5% decrease, P = 0.01), while plasma epinephrine increased markedly from baseline to the time of syncope (827 ± 154% increase, P = 0.0003). Dysautonomy syncope patients had lower supine levels of norepinephrine compared to vasovagal syncope patients (182 ± 30 versus 614 ± 146 pg/mL, P = 0.008) and no significant change in norepinephrine over time; epinephrine levels increased significantly less than in vasovagal patients (net change 38 ± 8 versus 189 ± 56 pg/mL, P = 0.008). Psychogenic and vestibular reactions were distinguished by rising levels of norepinephrine at the time of symptoms. The 50% (5 of 10) prevalence of vasovagal reactions found in the syncope patients suggests that vasovagal syncope may be more common among the elderly than previously recognized.
Structural evolution in Nb3Sn during mechanical attrition

Abstract Amorphization by mechanical attrition was observed for the Nb3Sn alloy composition on milling of Nb + Sn, Nb + NbSn2 or Nb3Sn crystalline powders. Mechanical alloying occurred first for Nb + Sn or Nb + NbSn2 powder mixtures such that the A15 structure Nb3Sn phase was synthesized. With continued milling, this phase transformed to the amorphous structure. Complete disordering of the ordered A15 Nb3Sn phase was found at milling times (about 1 h) well before amorphization was first observed (5–6 h). The estimated energy differences between the crystalline and amorphous Nb3Sn phases suggest that the driving force for the crystalline-to-amorphous transformation comes from a sum of the disordering energy and the grain boundary energy of the nanocrystalline grain structure that develops during milling. The hardness of hard brittle A15 Nb3Sn increases by about 20% before amorphization occurs. This hardness increase can be attributed to the refinement of the grain structure, and the data fit a Hall-Petch relationship. That plastic deformation can occur in nominally brittle Nb3Sn must be the result of a large hydrostatic component of the stress state in the powders during ball milling.
Thermodynamic Modeling of the Succinonitrile-Water System

Succinonitrile-water (SCN-H2O) system is a widely used transparent metallic alloy system due to its analog solidification behavior to metals. In the present work, Gibbs energy of pure succinonitrile was derived utilizing temperature as well as enthalpy of transformations, and temperature dependencies of heat capacity available in the literature. The phase diagram for the binary SCN-H2O system was assessed via the CALPHAD approach using phase equilibrium data available in the literature. Self-consistent thermodynamic parameters were obtained. A good agreement between the experimental and calculated data for the phase diagram has been achieved. The present work contributes to the development of the thermodynamic database of the SCN-H2O system that can be incorporated into thermodynamic and kinetic codes for computational simulations.
Basal forebrain cholinergic cell attachment and neurite outgrowth on organotypic slice cultures of hippocampal formation

Distributions of somata and neurites of cholinergic neurons were studied after seeding dissociated cells onto organotypic slice cultures. Slice cultures were made from hippocampal formation and adjacent cortical regions from rats or mice. Dissociated cell suspensions of basal forebrain tissue from rat or mouse fetuses were seeded onto the slice cultures. Combined cultures were maintained for 1-21 days in vitro. Cultures processed for acetylcholinesterase (AChE) histochemistry demonstrated non-random patterns of cholinergic cells and their neurites. Labeled cells appeared most frequently in the molecular layer of the dentate gyrus, and in the deeper layers of cortical regions adjacent to the hippocampus. Neurites extending from these labeled cells appeared to target the dentate molecular layer and the cortical subplate layer. By 4 days in vitro, AChE-positive basal forebrain cells display several short and thick neurites that appear to be dendrites, and one long process that appears to be an axon. By 5 days in vitro, dendrites are well developed; by 7 days the presumed axon has extended widely over the cortical target zone. These neurites are maintained through 3 weeks in culture. Distributions of cells varied with the age of the slice. AChE-labeled cells were not seen overlying hippocampal tissue when dissociated cells were seeded on slice cultures made from day 0 rats, but a few labeled cells were seen when seeded on slices from day 2 rats. Clear non-random patterns of labeled cells and neurite outgrowth were seen on slice cultures from day 5 or older pups. The non-random distribution seen with AChE-positive neurons was not seen using other techniques that labeled all cells (non-selective fluorescent labels) or all neurons; these techniques resulted in labeled cells scattered apparently homogenously across the slice culture.These studies demonstrate a non-random pattern of attachment or differentiation of basal forebrain cholinergic neurons when these cells are seeded onto cultured cortical slices; this pattern mimics the normal patterns of basal forebrain cholinergic projections to these cortical regions. These data suggest that the factors that normally guide basal forebrain-derived cholinergic axons to their target cells in vivo are present and detectable in this model system.
REDUCTION OF MICROSOMAL CYTOCHROMES BY PYRIDINE NUCLEOTIDES.

Summary 1. Reduction of microsomal cytochromes by TPNH and DPNH in whole microsomes and in a solubilized fraction has been studied. 2. Difference spectra, and kinetic analysis of the cycle of reduction of cytochrome b 5 by DPNH and TPNH and reoxidation by air, show that reduction of this cytochrome by DPNH is more rapid than by TPNH. The rate of reoxidation of reduced cytochrome b 5 is relatively independent of which nucleotide serves as reductant. Aerobic disappearance of DPNH is more rapid than that of TPNH; TPNH oxidation is inhibited by TPN + . 3. A “solubilized preparation” from lipase (EC 3.1.1.3)-treated microsomes 10 catalyzes reduction of its endogenous cytochrome b 5 by TPNH or DPNH, but TPNH-cytochrome b6 reductase activity has been disproportionately lost as compared to TPNH-cytochrome c reductase (EC 1.6.2.3) activity. TPNH cannot reduce externally-added purified cytochrome b 5 , while DPNH can reduce it partially. 4. Carbon monoxide partially inhibits cytochrome bs reduction by TPNH in the “solubilized fraction”; little effect on DPNH reduction of this cytochrome was observed. 5. Menadione stimulates TPNH disappearance catalyzed by both “solubilized preparation” and purified TPNH-cytochrome c reductase. In addition, reoxidation of reduced cytochrome b 5 is stimulated by this quinone; this oxidation may be due to peroxide formation. 6. Possible relationships between TPNH-cytochrome c reductase, cytochrome b 5 , the carbon-monoxide binding cytochrome, and microsomal hydroxylation reactions are discussed in the light of present findings and those of other laboratories.
Statistical Models for Intercepted Data

Abstract Consider a population of replaceable items of different ages, and suppose that for each item there is a certain measurable attribute that is a monotone function (perhaps random) of the item's age. To fix ideas, we refer to this attribute as deterioration and we assume that as items age their level of deterioration increases. We further assume that as the level of deterioration hits a certain threshold value (perhaps unknown), the item dies and disappears from the population, so it is not available for sampling any more. Since items that deteriorate at a slower rate live longer, any sample obtained over a short period of time would overrepresent slowly deteriorating items. Consequently, under such circumstances longitudinal studies are often needed to statistically study deterioration as a function of age. This article presents a statistical model that enables us to study the deterioration function, from a single cross-section “snapshot” of the population or some random parts of it. Specifically, ...
Martingale properties of an information- feedback loop

This paper generalizes some aspects of an information feedback system studied previously by the authors. While in the previous model the feedback information was required to be categorical, in the present paper this restriction is removed. Estimated average utility scores associated with each possible course of action are shown to be uniformly integrable martingale sequences. Strong convergence properties of these sequences are demonstrated. A fairly detailed example illustrates the results.
A statistical evaluation of animal and nutritional factors influencing concentrations of milk urea nitrogen

Data from 35 trials with 482 lactating cows fed 106 diets were used to study the effects of animal and dietary factors on the relationship between milk and blood urea N and the value of milk urea N in the assessment of protein status. In two trials, urea N in whole blood and in blood plasma were closely related (r2 = 0.952); the slope was not significantly different from 1.0, and the intercept was not significantly different from 0. Regression of milk urea N on blood urea N with a mixed effects model using all 2231 observations yielded the equation: milk urea N (milligrams of N per deciliter) = 0.620 x blood urea N (milligrams of N per deciliter) + 4.75 (r2 = 0.842); this model accounted for a significant interaction of cow and blood urea N. Single factors that yielded significant regressions on milk urea N with the mixed effects models were dietary crude protein (CP) (percentage of dry matter; r2 = 0.839), dietary CP per megacalorie of net energy for lactation (NEL) (r2 = 0.833), excess N intake (r2 = 0.772), N efficiency (r2 = 0.626), and ruminal NH3 (r2 = 0.574). When all factors were analyzed at once, 12 were significant in a mixed effects model. Blood urea N, body weight, yield of fat-corrected milk, dietary CP content, excess N intake, dry matter intake, and days in milk were positively related to milk urea N, and parity, milk and fat yield, dietary CP per unit of NEL content, and NEL intake were negatively related to milk urea N. In one trial, the mean urea concentration was 35 times greater in urine than in milk; lower proportions of total urea excretion in milk were observed in the a.m. sampling (1.8%) than in the p.m. sampling (3.3%). Measuring urea N in a composite milk sample from the whole day substantially improved reliability of data. The number of cows fed a specific diet that must be sampled to determine mean milk urea N within 95% confidence intervals with half widths of 1.0 and 2.0 mg of N/dl was estimated to be 16 and 4, respectively.
Expression of cold-tolerant pyruvate, orthophosphate dikinase cDNA, and heterotetramer formation in transgenic maize plants

Maize is a typical C4 plant of the NADP-malic enzyme type, and its high productivity is supported by the C4 photosynthetic cycle, which concentrates atmospheric CO2 in the leaves. The plant exhibits superior photosynthetic ability under high light and high temperature, but under cold conditions the photosynthetic rate is significantly reduced. Pyruvate orthophosphate dikinase (PPDK), a key enzyme of the C4 pathway in maize, loses its activity below about 12 °C by dissociation of the tetramer and it is considered as one possible cause of the reduction in the photosynthetic rate of maize at low temperatures. To improve the cold stability of the enzyme, we introduced a cold-tolerant PPDK cDNA isolated from Flaveriabrownii into maize by Agrobacterium-mediated transformation. We obtained higher levels of expression by using a double intron cassette and a chimeric cDNA made from F. bidentis and F. brownii with a maximum content of 1 mg/g fresh weight. In leaves of transgenic maize, PPDK molecules produced from the transgene were detected in cold-tolerant homotetramers or in heterotetramers of intermediate cold susceptibility formed with the internal PPDK. Simultaneous introduction of an antisense gene for maize PPDK generated plants in which the ratio of heterolologous and endogenous PPDK was greatly improved. Arrhenius plot analysis of the enzyme extracted from one such plant revealed that the break point was shifted about 3 °C lower than that of the wild type.
The glomerular mesangium in diabetes mellitus

The glomerular mesangium in diabetes mellitus. Like the renal glomerular mesangium in patients with diabetic nephropathy, glomerular mesangial cell cultures grown in 30 mM glucose accumulate increased amounts of the extracellular matrix (ECM) proteins fibronectin, laminin, and type IV collagen. This is due to increased ECM protein synthesis and mRNA levels. Similar to other cells types that are affected by the diabetic state (such as, vascular cells and peripheral nerve), mesangial cells transport glucose by an insulin-independent, facilitated diffusion transport system. Kinetic studies reveal that intracellular glucose levels may reach the ambient glucose concentrations achieved in diabetes. Growth studies reveal that glucose does not exert its effect on mesangial cell ECM accumulation by affecting cell growth, but rather it causes an increase in diacylglycerol (DAG) mass and activates protein kinase C. Agents such as phorbol myristate acetate (PMA) and the cell permeable DAG analogue, oleoyl acetyl glycerol (OAG) which activate protein kinase C also increase ECM mRNAs. These results implicate protein kinase C activation in the increased ECM accumulation observed in mesangial cell cultures grown in high glucose.
Transcription-Modulating Drugs A New Frontier in the Treatment of Essential Hypertension

While the promises of gene therapy may be years away from realization, the therapeutic use of drugs that act by modifying gene transcription is a well-established practice in clinical medicine. Although transcription-modulating drugs are frequently used in many different specialties, the deliberate development and use of these agents in cardiovascular medicine has been comparatively limited. However, research advances in the area of gene transcription and in the molecular genetic regulation of blood pressure, insulin resistance, lipid metabolism, and cell growth are providing new opportunities for controlling the expression of genes that are relevant to the pathogenesis of cardiovascular disease and essential hypertension. These research advances are beginning to converge in the development of transcription-modulating drugs with the potential to attack genetically determined risk factors that often cluster in patients with essential hypertension. Ligand-activated transcription factors that serve as receptors for small lipophilic compounds such as the thiazolidinediones and retinoids represent examples of potential therapeutic targets with direct effects on the expression of genes relevant to the pathogenesis of essential hypertension and its complications. Mounting evidence suggesting that the superior cardiorenal protective properties of converting enzyme inhibitors are related in part to their ability to indirectly modify the expression of genes in the heart and vasculature provides provisional support for the clinical value of this therapeutic approach. Given the success of transcription-modulating drugs in the treatment of type II diabetes and many other clinical disorders, it is anticipated that these agents will be developed as tools for the prevention and treatment of hypertension and cardiovascular disease in the not too distant future.