cssi/SciSciGPT-SciSciNet huggingface dataset:
Phytosociological analysis of aspen communities on three site classes for populus grandidentata in western Cheboygan County, Michigan

Ten 20×20 m plots were surveyed in each of three site classes (poor, medium, and good) for Populus grandidentata growth on three different podzolized soils in western Cheboygan County, Michigan, 14 miles south of the Straits of Mackinac. A phytosociological table shows that exclusive differential species distinguish communities of the poor sites from those of the good sites. In both groups some species are persistent from earlier stages of succession and others are invading species responsible for more recent succes sional change. The medium site class lacks differential species. Poor-site stands are developing toward Pinus resinosa-P. strobus forest and Quercus rubra-Pinus forest. Good-site stands are developing toward Acer-Fagus forest, a mesophytic community characteristic of the “northern hardwoods” regional climax. Medium-site stands have potentialities for development toward either the Pinus communities or the Acer-Fagus community, but predominantly in the direction of the latter.
An Abstract Framework for Approximate Solutions to Optimal Control Problems Governed by Hereditary Systems

Abstract : General projection methods for nonhomogeneous linear functional differential equations (FDE) dx/dt = L(x sub t) + f(t) are considered. It is shown that by an appropriate choice of spaces these can be treated as an equivalent abstract equation in a Banach space where the solution of the homogeneous equation generates a strongly continuous semigroup. Well-known approximation results for such semigroups (e.g., Trotter's theorem) are used to develop a general framework for obtaining approximate solutions of the original FDE. Convergence results are easily established. Applications to optimal control of linear FDE are discussed. In particular, the original infinite-dimensional problem is replaced by a 'projected' finite-dimensional problem which is more easily solved. Convergence of solutions of these finite-dimensional problems to solutions of the original problem is obtained.
Security approaches for radio frequency identification systems

In this thesis, I explore the challenges related to the security of the Electronic Product Code (EPC) class of Radio Frequency Identification (RFID) tags and associated data. RFID systems can be used to improve supply chain performance and automate asset management. However, an antagonist could use the functionality of the RFID tags and the EPC data to invade personal privacy or acquire access to unauthorized corporate information such as inventory levels. In addition, current RFID mechanisms expose secrets to the readers, which opens an avenue for exploits and information leakage. I examined the RFID security and privacy issues and designed a number of systems to improve tag authentication, privacy protection, and secure sharing of EPC data. The specific solutions I propose include TagCheck to protect tags from counterfeiting, JanusTag to allow recoverable dynamic recoding of tags, TagFolio for privacy policy enforcement, and TagDirective for secret management and access control. To prevent leakage at the application level during Object Name System (ONS) resolution, I propose the use of an anonymizing TorONS system. Lastly, to protect tags from being "mass killed", I designed two different categories of RFID tag kill-resistance mechanisms: active protection using Neighborhood Watch communities of readers and Exponential Rampup for tag self-defense. These technologies are combined under one umbrella called TinFoil, creating a comprehensive security solution that successfully protects the data in an EPC-enabled RFID system while minimizing required modifications to existing architecture. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
A Class of Rank — 2 Torsion Free Groups

This section has little to do with the main theme. I once thought that the notion to be discussed here was key to classifying finite rank torsion free groups; I still feel that it is the fundamental invariant for such groups. It seems to be in the back of the mind of averyone who studies these groups and it surfaces, more or less explicitly, in many discussions. I include it with the lope of giving it some formal standing.
A Global Middle Ages

‘‘Nowadays, national literature doesn’t mean much: the age of world literature is beginning, and everybody should contribute to hasten its advent.’’ This was Goethe . . . talking to Eckermann in 1827 . . .Not ‘‘comparative,’’ but world literature: the Chinese novel that Goethe was reading at the time . . .Well, let me put it very simply: comparative literature has not lived up to these beginnings. It’s been a much more modest intellectual enterprise, fundamentally limited to Western Europe . . . the literature around us is now unmistakably a planetary system. The question is not really what we should do – the question is how. (Moretti)
Steady crack growth in elastic-plastic work-hardening solids: near-tip fields and stress discontinuity

ABSTRACT The near-tip stress and deformation fields of a steadily growing crack are studied for an elastic-plastic solid with power-law work-hardening. It is shown that the same set of governing differential equations for the field quantities applies whether or not the plastic strain rate is assumed to be coaxial with the stress deviator, i.e, whether or not the usual plastic normality rule is used. Assuming continuous displacement and velocity fields, conditions of discontinuity are analyzed, and by means of numerical results it is shown that stress discontinuities do indeed exist when the plastic normality rule is relaxed.
Stable and metastable cosmic strings in heterotic M-theory

Abstract We address the question of finding stable and metastable cosmic strings in quasi-realistic heterotic M-theory compactifications with stabilized moduli and de Sitter vacua. According to Polchinski's conjecture, the only stable strings in the absence of massless fields are Aharonov–Bohm strings. Such strings could potentially be created in heterotic compactifications as bound states of open membranes, five-branes wrapped on four-cycles and solitonic strings. However, in generic compactifications, the process of moduli stabilization can conflict production of Aharonov–Bohm strings. In this case, heterotic cosmic strings will have to be unstable under breakage on monopoles. We estimate the monopole masses and find that they are big enough so that the strings can be metastable with a sufficiently long lifetime. On the other hand, if we allow one or more axions to remain massless at low energies, stable global strings can be produced.
Kinetostatic modeling of Exechon parallel kinematic machine for stiffness analysis

Exechon machines are a new type of parallel kinematic machines, which have been proven experimentally to be competitive in terms of accuracy, reliability, and operation speed. The proven performance is partially contributed by its unique layout of three prismatic legs; its kinematic structure is overconstrained. Higher accuracy is a primary goal for the use of an Exechon machine; accuracy relies on system stiffness and rigidity. However, the works on the stiffness analysis of Exechon machines has been limited to some numerical results from finite element analysis; no correlation between the motions and stiffness change has been studied systematically. To gain a thorough understanding of the impact of the overconstraints on system stiffness, the kinetostatic method is used for stiffness analysis. Jacobian matrices of kinematics have been derived, and they are used to develop the system stiffness model of the machine. The Exechon X700 model has been used as a case study to illustrate the process of stiffness analysis. The stiffness model is established and quantifiable comparison has been made between simulation and test data to verify the effectiveness of the stiffness model. The developed stiffness model can be applied to optimize machine structure or trajectory planning based on the specified task.
Indirect Method for Measurement of Pressure in Blood Capillaries

The capillary hydrostatic pressure of blood was measured indirectly. We used a microneedle to occlude exposed mesenteric capillaries in rats and frogs without trauma and then determined the motion of the trapped red blood cells that resulted from the absorption or filtration of water through the capillary wall. The trajectory of red cells was determined from enlarged timed photomicrographs that cover both sides of the occlusion. Gain or loss of water was measured by following the trajectory of two or more red cells to avoid errors due to injury and incomplete occlusion and extrapolating the motion to the instant of occlusion. Pressures were calculated from Starling's formula for fluid exchange. We assumed that the tissue parameters are an unknown constant in acute preparations; we used available values of filtration coefficients and colloidal osmotic pressures. The results show that 70 to 80% of the capillaries tested lost fluid, and therefore, their blood hydraulic pressure was higher than colloidal osmotic pressure. The pressures calculated in this way were similar to those measured by techniques requiring puncture of the capillary wall. Capillary arteriovenous pressure differences were approximately 4 mm Hg.
Bilaterally propagating waves of spontaneous activity arising from discrete pacemakers in the neonatal mouse cerebral cortex.

Spontaneous electrical activity that moves in synchronized waves across large populations of neurons plays widespread and important roles in nervous system development. The propagation patterns of such waves can encode the spatial location of neurons to their downstream targets and strengthen synaptic connections in coherent spatial patterns. Such waves can arise as an emergent property of mutually excitatory neural networks, or can be driven by a discrete pacemaker. In the mouse cerebral cortex, spontaneous synchronized activity occurs for approximately 72 h of development centered on the day of birth. It is not known whether this activity is driven by a discrete pacemaker or occurs as an emergent network property. Here we show that this activity propagates as a wave that is initiated at either of two homologous pacemakers in the temporal region, and then propagates rapidly across both sides of the brain. When these regions of origin are surgically isolated, waves do not occur. Therefore, this cortical spontaneous activity is a bilateral wave that originates from a discrete subset of pacemaker neurons. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Degeneracy in the amino acid code.

Abstract The composition of RNA codons has been estimated, using ribopolynucleotides containing a random distribution of two different bases as synthetic messengers in a cell-free system for protein synthesis. These data have been compared with base sequence determination of codons obtained by directing the binding of aminoacyl-sRNA to ribosomes with trinucleotides. Conclusions reached by the two methods are in good agreement.
From control of airway and breathing to cardiopulmonary-cerebral resuscitation

Background: For respiratory resuscitation without devices, the author hypothesized that providing upper airway patency requires lifting the base of the tongue off the posterior pharyngeal wall and that artificial ventilation with intermittent positive pressure using exhaled air, i.e., direct mouth-to-mouth ventilation (MMV), is more effective than back or chest pressure with or without arm lift. MMV leaves the operator's hands free for backward tilt of the head, forward displacement of the mandible, or both. Methods: The author studied 25 sedated, nonintubated adult human volunteers under neuromuscular blockade with succinylcholine for 1-3 h each. One hundred sixty-seven untrained lay persons performed various direct MMV methods after one demonstration. Eighteen trained ambulance rescuers performed back or chest pressure arm-lift methods. Ventilation volumes were recorded during MMV from a calibrated pneumograph and during the manual methods from a taped face mask on a spirometer. Arterial oxygen saturation was monitored by an ear oximeter, and end-tidal carbon dioxide was measured by an infrared analyzer. Results: With the head in the mid position or flexed, airway obstruction occurred in all volunteers, equally in the supine or prone position. With the head tilted backward and the mouth held open, one half to two thirds of the volunteers had an open airway; the remaining volunteers required additional forward displacement of the mandible or a pharyngeal tube. Ninety percent of the lay persons performed MMV effectively. Moderate hyperventilation by the operator achieved normoxemia and normocapnia in the volunteer and moderate hypocapnia in the operator. Apnea-induced moderate hypoxemia was reversed with 5-9 MMVs. In the majority of volunteers, the manual methods caused no ventilation (mostly because of neck flexion), and in others, it caused progressive airway obstruction. In some volunteers, there was valve-like nasopharyngeal obstruction. Conclusions: In coma without a tracheal tube, direct MMV is effective because of the ability of the rescuer to support the head and jaw for upper airway patency and because of controllable high inflation pressures and volumes, whereas manual methods frequently fail to ventilate, mainly because of upper airway obstruction. The author recommends that backward tilt of the head plus exhaled air inflation methods be taught for general use in adults and children.
Spectral-Function Sum Rules with Symmetry Breaking

The symmetry breaking based on Okubo's ansatz is considered to modify Weinberg's spectral-function sum rules (particularly the second). We then apply the modified sum rules to the chiral $U(3)\ifmmode\times\else\texttimes\fi{}U(3)$ and obtain physically interesting results for the mass relation and mixing angles of the vector mesons, a nonet assignment of the axial-vector mesons, and the decay constants of the pseudoscalar mesons.
Generational evolution and the future of pediatrics.

Abstract The opinions expressed herein by the author(s) do not necessarily reflect the official endorsement of The Association of Medical School Pediatric Department Chairs, Inc.
Nonisothermal Compressor Station Optimization

A detailed mathematical model of compressor stations and pipes is essential for optimizing the performance of the gas pipeline system. Most of the available literature on compressor station modeling is based on isothermal solutions for pipe flow, which is inadequate for our purposes. In the present work, the pipe flow is treated as nonisothermal unsteady one-dimensional compressible flow. This is accomplished by treating the compressibility factor as a function of pressure and temperature, and the friction factor as a function of Reynolds number. The solution method is the fully implicit finite difference method that provides solution stability, even for relatively large time steps. The compressors within the compressor station are modeled using centrifugal compressor map-based polynomial equations. This modeling technique permits the designation of different models of compressors in the compressor station. The method can be easily extended to include other types of compressors. Using this mathematical model as a basis, a nonlinear programing problem (NLP) is set up wherein the design variables are the compressor speeds and the objective function to be minimized is the total fuel consumption. The minimum acceptable throughput is imposed as a constraint. This NLP is solved numerically by a sequential unconstrained minimization technique, using the mathematical model of the system for the required function evaluations. The results show that this approach is very effective in reducing fuel consumption. An application of this methodology for selecting the number of compressors to be shut down for the most fuel-efficient operation is also presented. Our results further indicate that station-level optimization produces results comparable to those obtained by network-level optimization. This is very significant because it implies that the optimization can be done locally at the station level, which is computationally much easier.
Overview of: “Short‐ and Long‐Term Outcome Results from a Multisite Evaluation of the G.R.E.A.T. Program”

This article presents results from a randomized control trial of the Gang Resistance Education and Training (G.R.E.A.T.) program; 3,820 students enrolled in 195 classrooms in 31 schools in seven cities were surveyed six times over 5 years (pretests and posttests in Year 1 and four annual follow-up surveys). The results indicate that during the 4 years posttreatment, students who received the program had lower odds of gang membership compared with the control group. The treatment group also reported more prosocial attitudes on several program-specific outcomes. In addition to examining the effectiveness for the full sample, we also report analyses that examine program effects by (a) site and (b) initial levels of risk for gang membership. Policy Implications Effective youth violence-prevention programs continue to be few in number; effective youth gang-prevention programs are even rarer. Various rating systems exist (e.g., University of Colorado's Blueprint Model, Helping America's Youth, OJJDP Model Program Guide, and NIJ's Crime Solutions), but even application of the least rigorous standards fails to identify many promising or effective programs. Based on results reported in this article, the Gang Resistance Education and Training (G.R.E.A.T.) program holds promise as a universal gang-prevention program. KEYWORDS: Juvenile justice; Juvenile delinquency Language: en
Pedestrian flows and non-classical shocks

We present a model for the o w of pedestrians that describes features typical of this o w, such as the fall due to panic in the outo w of people through a door. The mathematical techniques essentially depend on the use of nonclassical shocks in scalar conservation laws. 2000 Mathematics Subject Classic ation: 35L65, 90B20.
The effect of age and diet on the cellular protein synthesis of liver of male mice

The rates of cellular protein synthesis were estimated in liver by determining: 1) the half lives of proteins by the rate of disappearance of radioactivity following the intraperitoneal injection of C14 labeled sodium bicarbonate, and 2) the cellular protein levels estimated by the concentration of proteins and DNA of the tissue. The age studies were carded out on C57BL/6J mice, aged 12, 18, 24, and 32–34 months, fed the NIH Open Formula Mouse Diet. Dietary studies were carried out on 9 month old B6D2F1 mice fed purified diets which contained crude casein. The animals were offered one of the following regimens. One group was fed a 24% protein diet ad libitum. Another group was fed a 4% protein diet ad libitum. The third and fourth groups were fed the 24% protein diet ad libitum for twenty-four hours on Monday and Wednesday, and for eight hours on Friday. The third group was sacrificed following a 24 hour feeding period, while the fourth group wee sacrificed following a 24 hour fasting period. The rates of disappearance of radioactivity from the liver proteins of mice were not statistically significantly affected by age or dietary regimens. However, there was a 27% progressive decrease in the cellular protein synthesis of liver between the ages of 12 and 32–34 months. Feeding a low protein diet ad libitum resulted in a 28% decrement. In addition, during the 24 hour period of starvation during intermittent feeding, there is a 30% decrease in cellular protein synthesis which returns to normal levels during the 24 hour feeding period.
Synthesis of [4′‐13C] pyridoxol

5-Cyano-3-hydroxy-2-methylpyridine-l-oxide, after O-methylation with dimethylsulfate, was reacted regiospecifically with sodium [13C] cyanide to give [4′-13C] 4,5-dicyano-3-hydroxy-2-methylpyridine. The latter compound was successively transformed to [4′-13C] pyridoxol and [4′-13C] pyridoxal phosphate.
Chemosensory elements of courtship in normal and mutant, olfaction-deficient Drosophila melanogaster

Male-female courtship interactions inDrosophila melanogaster are mediated in part by chemical cues. A comparison of the courtship behaviors of normal and genetically olfaction-deficient (olfD) flies lends strong support to this hypothesis and leads to the following inferences regarding the importance of chemical interchange during courtship. Virgin females respond to male courtship by slowing and finally stopping their movements, which appears to enhance the probability of copulation; (olfD) females are defective in this stopping response and in their receptivity to mating. Males can be stimulated to court by airborne cues from virgin females which are effective over a distance of ca. 5 mm. By comparison, the chemical courtship-stimulating cues from immature flies have little airborne efficacy; immature males appear to stimulate courtship only by contact chemoreception. The genetic upset or removal from courtship interactions of olfactory, visual, and auditory cues (thus leaving contact chemoreception as the probable major means of male-female interaction) results in virtual behavioral sterility.
Automated Finite Element Model Mesh Updating Scheme Applicable to Mistuning Analysis

Advancement of optical geometric measurement hardware has enabled the construction of accurate 3D tessellated models for a wide range of turbomachinery components. These tessellated models can be reverse-engineered into computer-aided design (CAD) models and input into grid generation software for finite element analyses. However, generating a CAD model from scan data is a time consuming and cumbersome process requiring significant user-involvement for even a single model. While it is possible to generate finite element models (FEMs) directly from tessellated data, current direct-grid methods produce unstructured grids that can introduce fictitious, numerical mistuning in these models, obscuring geometric mistuning. Nonetheless, as-measured scan data captured in a structured grid is essential for accurate geometric mistuning analyses, provided the tessellated scan data can be rapidly and accurately transformed into a FEM. This paper outlines and demonstrates an approach for rapidly generating structured FEMs for a population of integrally bladed rotors (IBRs) without requiring the arduous task of generating a CAD model for each as-measured IBR. This is accomplished by morphing the structured mesh of a nominal model to the tessellated data set collected from an optical scanner. It is shown that the fidelity and structure of these FEMs can be utilized for accurate mistuning analyses.© 2014 ASME
Nanoparticle Self‐Assembly Directed by Antagonistic Kinase and Phosphatase Activities

Reversible self-assembly is ubiquitous in Nature. The ability to dynamically control the assembly and disassembly of biomolecular complexes is essential to higher-order biological processes, including the control of intracellular communication, gene expression, and platelet aggregation upon injury. To date, assembly or disassembly of nanoparticles (NPs) has been exploited to improve sensitivity for detection of single biomolecular targets, including DNA, small molecules, proteins, and pH changes in vitro; however, mechanisms of sensing that allow multiple, opposing stimuli to dynamically assemble and dis-assemble NPs have not been described. Development of inorganic nanoparticles that respond to multiple, antagonistic biological signals could facilitate sensing of the physiologic balance between opposing effectors of cellular and tissue function. Herein, we introduce a nanoparticle (NP) system where self-assembly is dynamically coupled to the balance between the classic antagonistic enzymes: tyrosine kinase and phosphatase. In vivo, these enzymes regulate cellular communication, gene expression, and ultimately cell life and death through the phosphorylation and dephosphorylation of tyrosine residues on other proteins Their dysregulation contributes significantly to the development of cancer and other inflammatory diseases. Here, kinase-induced superparamagnetic nanoassemblies enhance the T2 relaxation of hydrogen atoms at picomolar enzyme concentrations and are shown to be fully reversible by introducing excess phosphatase activity. In the future, these nanomaterials may be optimized to report the balance between these cytosolic enzyme activities and may facilitate new screens for inhibitors in vitro and in vivo. Additionally, extensions of this design logic may be synthesized to probe the dynamics of a diversity of antagonistic biologic processes. To construct a system of NPs that could coalesce in the presence of kinase activity and re-disperse in the presence of phosphatase activity, two NP populations were synthesized (Scheme 1). The first population was modified with peptide substrates that may be phosphorylated by Abl tyrosine kinase and dephosphorylated by a phosphatase. The second popula-
Application of new diagnostic techniques to combustion studies in engines

A variety of experimental diagnostic techniques are being developed to investigate the physical and chemical processes that occur in internal combustion engines. These optical diagnostics have been applied to critical problems arising in the development of direct-injection stratified-charge, diesel, and lean-homogeneous charge engines. The results presented illustrate (1) the application of laser velocimetry to measure fluid flow, (2) spontaneous Raman scattering to measure time- and space-resolved temperature and species concentration, (3) optical techniques for spatially mapping temperature and soot concentration, and (4) various flow visualization schemes.
Patterns of food intake in the monkey during free or restricted feeding and in response to 2-DG or insulin injection.

Abstract When given free access to food, the restrained macaque monkey establishes a pattern of ingestion characterized by frequent meals and a stable caloric intake of 26–33 g/kg/day. When the availability of food is restricted to eight hours per day, the number of meals decreases but the mean daily intake as well as the first meal size increases. No consistent correlation is found between meal size and either the pre- or post-meal interval. A subcutaneous injection of 300 mg/kg 2-deoxy-D-glucose (2-DG) causes a 100% increase in the size of the monkey's first meal but a reduction in the number of meals eaten with no change in its daily food intake. This compensatory adjustment to the large first meal is made through a decrease in the number of meals eaten with the insertion of one extremely long post-meal interval. Insulin (1.0 or 5.0 U/kg) similarly injected evokes an increase in both the size of the first meal and the monkey's daily food intake; however, this occurs only in the female macaque. The failure to regulate caloric intake accurately in this case is due to an increase in the magnitude of at least two meals. Thus, although both insulin and 2-DG do augment the size of the following meal, only insulin enhances the total daily intake of food. The differential patterning of food intake after an injection of either 2-DG or insulin suggests that a meal eaten under the influence of 2-DG results in a greater satiation than normal, whereas a meal consumed during insulin-induced hypoglycemia could be less satiating.
Inhibition of the Action of Phytochrome by the Herbicide CIPC

CIPC, (Chlorpropham) isopropyl N-(3S-chlorophenyl) carbamate, and its analogues are inhibitors of protein synthesis in excised segments of seedling plants1. Investigation suggested that this inhibition is actually exercised on the synthesis or release of messenger RNA (ref. 2, and in preparation by Mann, Cota, Robles, Moretti and Yung). Thus it was of interest to determine whether this particular inhibitor could prevent the effect of light in stimulating germination of Grand Rapids lettuce seeds.
Grain Boundary Sliding in the Presence of Grain Boundary Precipitates during Transient Creep.

A constitutive rate equation for grain boundary sliding (GBS), in the presence of grain boundary precipitates, is developed. Langdon’s GBS model is modified by incorporating physically de-fined back stresses opposing dislocation glide and climb and by modifying the grain size de-pendence of creep rate. The rate equation accurately predicts the stress dependence of minimum creep rate and change in activation energy occurring as a result of changing the grain boundary precipitate distribution in complex Ni-base superalloys. The rate equation, along with the math-ematical formulations for internal stresses, is used to derive a transient creep model, where the transient is regarded as the combination of primary and secondary stages of creep in constant load creep tests. The transient creep model predicts that the transient creep strain is dependent on stress and independent of test temperature. It is predicted that a true steady-state creep will only be observed after an infinitely long time. However, tertiary creep mechanisms are expected to intervene and lead to an acceleration in creep rate long before the onset of a true steady state. The model accurately predicts the strain vs time relationships for transient creep in IN738LC Ni-base superalloy, containing different grain boundary carbide distributions, over a range of temperatures.
Clinical outcome and incidence of pregnancy after bipolar and total hip arthroplasty in young women

Abstract Female patients under 45 years of age (average, 32.5; range, 14–44) at the time of primary bipolar or total hip arthroplasty (THA) were surveyed an average 10.5 years (range, 1.7 to 20.3 years) after the index procedure. Most patients were satisfied with the pain relief and functional abilities. Of the 109 respondents (137 hips), 37 (34%) had undergone 50 additional hip procedures. Thirteen women (12%) had 19 children at an average of 3 years after hip arthroplasty. Seven women had 1 child each; 6 had 2 children; and 1 had dizygotic twins. Eleven infants were delivered vaginally and 8 by cesarean section (5 planned, 3 unplanned). Two pregnancies were considered high risk unrelated to the hip arthroplasty. Pregnancy-related complications for these patients did not differ from those in the general population.
Facile cleavage of a phenyl group from SbPh3 by dirhenium carbonyl complexes

The complex Re 2 (CO) 8 [μ-η 2 -C(H) C(H)Bu n ](μ-H) ( 1 ) reacts with SbPh 3 at 68 °C to yield the new σ-phenyl dirhenium complex Re 2 (CO) 8 (SbPh 3 )(Ph)(μ-SbPh 2 ) ( 4 ) in 72% yield. Compound 4 contains two rhenium atoms held together by a bridging SbPh 2 ligand. One rhenium atom contains a σ-phenyl group. The other rhenium atom contains a SbPh 3 ligand. Compound 4 was also obtained in 34% yield from the reaction of Re 2 (CO) 10 with SbPh 3 in the presence of UV–Vis irradiation together with some monorhenium products: HRe(CO) 4 SbPh 3 ( 5 ), Re(Ph)(CO) 4 SbPh 3 ( 6 ) and fac -Re(Ph)(CO) 3 (SbPh 3 ) 2 ( 7 ) in low yields. Complex 4 is split by reaction with an additional quantity of SbPh 3 to yield the monorhenium SbPh 3 complexes 6 , 7 and mer -Re(Ph)(CO) 3 (SbPh 3 ) 2 ( 8 ) that contain a σ-phenyl ligand. When 4 was treated with hydrogen, the phenyl ligand was eliminated as benzene and the dirhenium complexes Re 2 (CO) 8 (μ-SbPh 2 )(μ-H) ( 10 ), and Re 2 (CO) 7 (SbPh 3 )(μ-SbPh 2 )(μ-H) ( 11 ), were formed that contain a bridging hydrido ligand. The doubly SbPh 2 -bridged dirhenium complex Re 2 (CO) 7 (SbPh 3 )(μ-SbPh 2 ) 2 ( 9 ) that has no metal–metal bond was also formed in these two reactions.
Spatiotemporal transfer function of human accommodation.

We have investigated the spatiotemporal transfer function of human “reflex” accommodation. An accommodative mechanism that is sensitive to an intermediate temporal rate of retinal image contrast change is proposed as the basis of the fine focus control hypothesis. To test the proposed mechanism accommodative responses were monitored by a dynamic infrared optometer while the subject focused on sinusoidal gratings (0.98–10.5 c/deg) which were moving sinusoidally at temporal frequencies in the range of 0.05–0.80 Hz over a 0.50 or 2.00 D peak-to-peak amplitude. The accommodative responses were best at 3 and 5 c/deg at both amplitudes of target motion. This result does not support the proposed mechanism or the fine focus control hypothesis for “reflex” accommodation. Fitting the data with first-order response functions showed little evidence of prediction. In addition, a second experiment found that the profile of the accommodative gain function is not altered by instruction at spatial frequencies above 5 c/deg in this type of dynamic accommodation experiment. The use of sinusoidally moving accommodative blur targets, particularly with careful instruction, seems to discourage voluntary accommodation in investigations of “reflex” control mechanisms of accommodation.
Visibility of Rectangular Targets as a Function of Length and Width

The human threshold contrast of circular targets has been thoroughly studied by Blackwell and his data has been used in a number of visibility prediction models. These models either assumed the difference in visibility between circular and non-circular targets to be negligible or they used some form of a target shape conversion method. The present research is an effort to quantify the effects of the target aspect-ratio (shorter dimension to longer dimension) on the human threshold contrast. Threshold contrast data from two published target detection studies were combined with data from a small laboratory experiment conducted at Ohio University using a regression model (adjusted R2=0.991). The results clearly suggest that small aspect-ratios should be used if, for a given target area, the rectangular target visibility must be maximized. Applications of this research may include retro-reflective conspicuity markings used for improved nighttime visibility of pedestrians and vehicles or reflectorized posts of...
Practitioner Research on Critical Multicultural Pedagogy: Challenging Heterosexism in a Public School

How do students who do not identify as gay interrupt the institutionalized silence pervading the issue of heterosexism in public schools? Drawing on data from practitioner research conducted with high school students, I illustrate one such journey where students with situated privilege chose to challenge heterosexism. Analysis of field notes, interviews, and students' journals illuminates how using a critical multicultural pedagogy and critical literacy strategies can help to interrupt institutionalized silence, deepen students' awareness of the power of language and support their development as allies, as well some of the challenges involved in such work.
FREEMAN'S K MODELS AS RESERVOIR COMPUTING ARCHITECTURES

Walter Freeman in his classic 1975 book "Mass Activation of the Nervous System" presented a hierarchy of dynamical computational models based on studies and measurements done in real brains, which has been known as the Freeman's K model (FKM). Much more recently, liquid state machine (LSM) and echo state network (ESN) have been proposed as universal approximators in the class of functionals with exponential decaying memory. In this paper, we briefly review these models and show that the restricted K set architecture of KI and KII networks share the same properties of LSM/ESNs and is therefore one more member of the reservoir computing family. In the reservoir computing perspective, the states of the FKM are a representation space that stores in its spatio-temporal dynamics a short-term history of the input patterns. Then at any time, with a simple instantaneous read-out made up of a KI, information related to the input history can be accessed and read out. This work provides two important contributions. First, it emphasizes the need for optimal readouts, and shows how to adaptively design them. Second, it shows that the Freeman model is able to process continuous signals with temporal structure. We will provide theoretical results for the conditions on the system parameters of FKM satisfying the echo state property. Experimental results are presented to illustrate the validity of the proposed approach.
Graphene quantum capacitance varactors for wireless sensing applications

The low density of states in graphene makes it possible for the quantum capacitance to be of the same order of magnitude as the oxide capacitance for experimentally achievable gate dielectric thicknesses [1]. This property, combined with the fact that the density of states varies as a function of energy, means that the capacitance in a metal-oxide-graphene capacitor can be tuned by varying the carrier concentration [2]. The very high mobility and zero band gap in graphene also allow it to remain conductive throughout the entire tuning range, making graphene an idea material to realize a high quality factor (Q) variable capacitor (varactor). If combined with an on-chip inductor to form an LC oscillator circuit, graphene varactors could enable a new class of ultra-compact sensors with wireless readout capability. Compared to MEMS-based varactors [3], the extremely-large capacitance per unit area of graphene varactors should allow orders-of-magnitude improvement in scalability, a vital feature for numerous applications including in vivo sensing where small size is critical. In this abstract, the device concept is described and simulated performance projections are provided. The main findings in this study are that wide frequency tuning ratios (> 50%) and high Q (> 40 at 1 GHz) are possible using realistic assumptions for the graphene properties, device dimensions and parasitic resistances.
Suppression of Epithelial Ion Transport Transcripts during Pneumococcal Acute Otitis Media in the Rat

Until recently, it was not feasible to conduct genome-wide screening for gene transcript variations that play key roles in the pathogenesis of otitis media. In this study microarray technology was used to profile differential gene expression patterns from rat middle ear mucosa at 12 and 48 h after Streptococcus pneumoniae challenge. Real-time polymerase chain reaction was performed for independent verification of the microarray results. Three ion transport mRNAs were simultaneously suppressed more than 4-fold at 12 h in bacteria-challenged ears, including Na,K-ATPase alpha 1 subunit (SPATPa1), sodium channel beta 2 subunit (SCNB2) and sodium -hydrogen exchange protein isoform 2 subunit (NHE2). At 48 h after infection, the mRNA levels of SCNB2 and NHE2 had decreased 7- and 10-fold, respectively, whereas the relatively abundant SPATPa1 transcript showed recovery. The downregulation of Na + -transporting transcripts suggests a reduced number of epithelial cells and transporting proteins and/or the dysfunctio...
Utilization of echocardiography by internists and cardiologists: A comparative study

Objective To compare the utilization of echocardiography as a diagnostic tool by internists and cardiologists. Design Retrospective study. Setting Tertiary care university hospital. Methods Indications and clinical utility of echocardiographic studies ordered by cardiologists (group A, n=301) and internists (group B, n=297) were compared by chart review. The two groups of patients were analyzed to determine if the studies detected new cardiac pathology and/or altered patient management. Results The proportion of studies with abnormal results were similar in both groups (19% versus 14%, P >0.05). The results of echocardiography, however, led to a change in management more often when the study was ordered by cardiologists (16% versus 10%, P P P >0.05). However, diagnostic yield was very poor when the study was performed in patients with suspected mitral valve prolapse in both groups. Cardiologists utilized echocardiography more often for evaluation of left ventricular function (35% versus 18%, P P Conclusion Diagnostic yield of echocardiography is similar when ordered by internists and cardiologists. With the information obtained, management is altered in a slightly greater proportion of cases involving a cardiologist. This may be due to utilization of echocardiography more often for estimating left ventricular function and for detecting wall motion abnormalities by cardiologists.
Review: Environmental exposure to mercury and its toxicopathologic implications for public health

Mercury is a toxic and hazardous metal that occurs naturally in the earth's crust. Natural phenomena such as erosion and volcanic eruptions, and anthropogenic activities like metal smelting and industrial production and use may lead to substantial contamination of the environment with mercury. Through consumption of mercury in food, the populations of many areas, particularly in the developing world, have been confronted with catastrophic outbreaks of mercury-induced diseases and mortality. Countries such as Japan, Iraq, Ghana, the Seychelles, and the Faroe Islands have faced such epidemics, which have unraveled the insidious and debilitating nature of mercury poisoning. Its creeping neurotoxicity is highly devastating, particularly in the central and peripheral nervous systems of children. Central nervous system defects and erethism as well as arrythmias, cardiomyopathies, and kidney damage have been associated with mercury exposure. Necrotizing bronchitis and pneumonitis arising from inhalation of mercury vapor can result in respiratory failure. Mercury is also considered a potent immunostimulant and -suppressant, depending on exposure dose and individual susceptibility, producing a number of pathologic sequelae including lymphoproliferation, hypergammaglobulinemia, and total systemic hyper- and hyporeactivities. In this review we discuss the sources of mercury and the potential for human exposure; its biogeochemical cycling in the environment; its systemic, immunotoxic, genotoxic/carcinogenic, and teratogenic health effects; and the dietary influences on its toxicity; as well as the important considerations in risk assessment and management of mercury poisoning.
A Teacher-Developed Process For Collaborative Professional Reflection

In Spring 2000, a group of five elementary school teachers met to investigate the nature of professional reflection and develop a process of collaborative reflection as productive professional development. These teachers' beliefs that reflection is both necessary and valuable, coupled with their recommendation that it be collaborative, served as the basis of the process for collaborative reflection developed by the group and described in this paper. While designing the process, these teachers felt very strongly about how it should look and thus, they included many perceived requirements or ‘shoulds’ in their design. Interestingly, when the viability of these ‘shoulds’ were tested, the testing teachers wrestled with the process as designed, finding their naturally emerging reflection process to be more holistic than sequential. Yet, as these teachers struggled with the order of the designed process, they engaged in the tasks themselves, which propelled them through effective reflections.
Intracellular injection of a Ca2+ chelator inhibits spike repolarization in hippocampal neurons.

Abstract The Ca-dependence of spike repolarization and afterhyperpolarizations (AHPs) in CA 1 pyramidal cells, was tested with intracellular electrodes containing the Ca buffers EGTA or 1,2-bis(σ-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA). EGTA blocked only the slow AHP; but the fast-acting Ca chelator BAPTA also inhibited spike repolarization and the fast AHP. This supports the hypothesis that a fast Ca-activated K-current contributes to spike repolarization.
Solar abundance determination from ultraviolet emission lines.

Relative solar abundance for O, Si and Fe determined from intensities of far UV emission lines of solar corona
A SASR macro for the multivariate extension of the Kruskal-Wallis test including multiple comparisons: Randomization and ϰ2 criteria

Abstract In a multi-group experimental design where interest is in a univariate response, the nonparametric Kruskal-Wallis test [Kruskal and Wallis (1952)] provides a potentially more powerful alternative to the parametric one-way analysis of variance when the assumptions of normality are in question. For multivariate response, Puri and Sen (1966) proposed a generalization of the Kruskal-Wallis test that is a nonparametric analog of the one-way multivariate analysis of variance and can be used when multivariate response data are measured on at least an ordinal scale. Large sample theory suggests that the multivariate Kruskal-Wallis statistic is approximately distributed as chi-square, but in small samples the behavior of the statistic warrants conditioning on the observed data and using randomization theory to tabulate the exact distribution. We have written a SAS [SAS Institute, Inc. (1985)] macro that computes the probability values and tabulates the exact distribution for the univariate and multivariate Kruskal-Wallis test that will be useful to applied statisticians.
The cell surface of mouse dendritic cells: FACS analyses of dendritic cells from different tissues including thymus

The surface of dendritic cells from mouse spleen, thymus, and epidermis has been compared with a panel of monoclonal antibodies and the FACS. A method was first developed to isolate populations of large, adherent, thymic dendritic cells that were greater than 90% pure. These were released by collagenase digestion and separated from adherent macrophages after overnight culture. Enrichment was based on the facts that most macrophages remained plastic adherent and rosetted strongly with antibody-coated erythrocytes. As in spleen, thymic dendritic cells were stellate in shape, had abundant class I and II MHC products, lacked many standard macrophage and lymphocyte markers, and actively stimulated the mixed leukocyte reaction. Most spleen and thymic dendritic cells could be lysed by the 7D4 mAb, to the low-affinity IL-2 receptor, and complement but the levels of 7D4 by FACS were low and sometimes not above background. Differences among dendritic cells from different tissues were noted with other mAb. Adherent dendritic cells from thymus all expressed the J11d "B cell" antigen and the NL145 interdigitating cell marker, but lacked the 33D1 spleen dendritic cell antigen. Eighty to ninety percent of spleen dendritic cells were J11d-, NL145-, 33D1+ but the remainder expressed the J11d+, NL145+, 33D1- thymic phenotype. The latter phenotype also was identical to that of epidermal Langerhans' cells. We postulate that the major 33D1+ cell in spleen represents a migratory stage in which dendritic cells are moving from tissues to lymphoid organs.
Skeletal growth in a medieval population from Sudanese Nubia

Long bone growth is analyzed for 180 children from a Medieval population at Kulubnarti in Sudanese Nubia (550–1450 A.D.). A regional interpopulation comparison is made with growth data from Wadi Halfa in Lower Nubia, and an intrapopulation analysis is undertaken to assess diachronic changes in growth at Kulubnarti. Changes in growth patterns are interpreted in the context of mortality and morbidity profiles and relationships between the three variables are discussed. It is suggested that changes in the sociopolitical environment may have been responsible in part for altering levels of biological stress and impacting growth.