cssi/SciSciGPT-SciSciNet huggingface dataset:
SU‐GG‐T‐122: Comprehensive Study of Parameters for Volumetric Modulated Arc Therapy (VMAT) Treatment Planning

Purpose: VMAT is a rotational IMRT technique that uses a traditional linear accelerator gantry with a dynamic MLC, variable dose rate, and variable gantry speed. The Pinnacle3 SmartArc treatment module has been implemented in our clinic for VMAT treatment planning. However, it was unclear how SmartArc planning parameters affected the overall plan quality. The purpose of this study was to systematically examine all planning parameters and quantify the effect of varying each on the quality of a baseline plan. Method and Materials: In this study, parameters were separated into two categories: commissioning parameters and planning parameters. Commissioning parameters are those that are available to the user during the machine commissioning process in Pinnacle, i.e. dose rate, gantry speed, MLC size, and MLC speed. Planning parameters are those that are available to the user during treatment planning,i.e. beam energy (6, 10 or 15 MV), collimator angle, arc length, and final gantry spacing. A baseline set of planning parameters was established that provided ±3% and ±5% dose homogeneity in the PTV of a cylindrical phantom a prostate patient, respectively. Each parameter was independently varied while keeping all other parameters set to the baseline values. The resulting plans were evaluated using dose volume histograms, dose homogeneity indices (DHI), and normal tissue dose metrics. Results: The DHI for the prostate baseline plan was 0.073. Changes to the collimator angle and the total arc length had the greatest influence on DHI, which ranged from 0.073–0.099 and 0.073–hyphen;0.390, respectively. Parameters such as MLC leaf size, gantry speed, and whether the dose rate was continuously or discretely variable had little effect. Conclusion: Most SmartArc parameters had little effect on dose homogeneity and normal tissue sparing. The most notable changes in plan quality came from varying the collimator angle and the total arc length.
Analysis of oscillatory metastable operation of an RS flip-flop

With continuing advances in VLSI technology, there is a growing interest in large-scale parallel systems with numerous high-frequency asynchronous interactions. However, these interactions may result in frequent failures due to metastable operation of flip-flops used as synchronizers or arbiters. For some flip-flops the metastable operation may be of an oscillatory nature, before finally resolving one of the stable states. An analysis of this mode of metastable operation based on a modified dynamic RS flip-flop model is presented. Analytical formulas for the frequency of the oscillatory metastable operation are derived. Good agreement is observed between the theoretical results, SPICE simulation, and experiments with two CMOS RS flip-flops. Failure rate due to oscillatory metastable operation is discussed based on the experimental results. >
How campaigns promote the legitimacy of elections

Abstract Why do people see elections as fair or unfair? In prior accounts, evaluations of the election depend on people's candidate preferences, where supporters of the winning candidate tend to call the election fair while those on the losing side feel it was unfair. I argue that perceptions of election fairness reflect not just the election outcome, but also the campaign process. Using a set of multilevel models and data from the 1996–2004 American National Election Studies, I explore the consequences of campaign experiences in shaping people's evaluations of the fairness of a presidential election. I find that as campaign competition increases, people are less likely to translate their feelings about the candidates into their evaluations of the election. Rather than alienating citizens, competitive campaigns mitigate the effects of prior preferences in a way that promotes the legitimacy of elections.
Metabolism and Translocation of N'-(4-Chloro-o-tolyl)-N, N-Dimethylformamidine (Chlorphenamidine) and Its Hydrochloride Salt In Grapefruit Seedlings

The metabolism of chlorphenamidine-14C and its hydrochloride salt was studied following topical application to the leaves of growing grapefruit seedlings. The concentration of either compound in and on leaves 20 days after treatment did not exceed 1% of the applied radioactivity. Radioactive metabolites characterized from the leaves included N' -(4-chloro- o -tolyl)- N -methylformamidine (demethylchlorphenamidine), N -formyl-4-chloro- o -toluidine, and 4-chloro- o -toluidine. Translocation studies revealed that chlorphenamidine and chlorphenamidine hydrochloride diffused extensively throughout treated leaf tissue 8 days after topical application to various sections of grapefruit leaves. Although translocation of the compounds into the leaves after stern injection was observed, there was only slight acropetal movement of chlorphenamidine hydrochloride following topical treatment of 2 basal grapefruit leaves.
Spectral evidence for a carbonaceous chondrite surface composition on Deimos

The surface compositions of Phobos and Deimos as determined by their UV-visible reflectance are compared in order to evaluate the hypothesis that the different surface morphologies of the two satellites are due to different mechanical properties. The UV-visible reflectance spectrum of Deimos is compiled from Mariner 9 UV spectrometry and Canopus star tracker photometry and ground-based colorimetry and polarimetry; the geometric albedo of Deimos is determined from Mariner 9 Canopus star tracker data. The reflectance spectra of Deimos and Phobos are found to be similar in a first approximation, exhibiting low, flat reflectivities in the visible and dropping off sharply in the UV, compatible with a probable carbonaceous chondrite nature for Deimos as well as Phobos and suggesting that their different surface morphologies are most likely due to different orbital histories.
Oncogenes and cancer.

This review — the first in a series concerning the biology of cancer — is a comprehensive survey of oncogenes, tumor-suppressor genes, and microRNA genes in cancer cells. Work on the recently discovered microRNA genes in malignant cells has revealed new complexities in the regulation of oncogenes and tumor-suppressor genes and new opportunities for the treatment of cancer.
Independent learning: a self-instructional videotape approach in psychiatry.

Summary In response to the increased need to train well-rounded general practitioners within a limited time schedule, the teaching staff developed a self-instructional videotape programme devoted to suicide assessment. This tape, if successful, was to serve as a pilot for a full series of 18 tapes devoted to the assessment and treatment of normally stable patients suffering acute situational stress. In order to avoid the passivity induced by most educational tapes and films, a self-instructional format was adapted to the videotape medium and extensively tested. Students in the experimental group scored significantly higher on three of four measures of effectiveness than did the control group. Students and teachers both strongly supported the production of tapes using a similar format.
Continuous culture experiments with saccharomyces rouxii

Growth of Saccharomyces rouxii, an osmophilic yeast that produces glycerol and arabitol, was investigated using chemically defined media in continuous culture. Total polyol production increased with increasing aeration and growth rate. At very low aeration levels ethanol was produced but as aeration levels were increased ethanol could not be detected, formation of d-arabitol remained constant and formation of glycerol increased. In fully aerobic cultures with a replacement time of twelve hours, nitrogen-limited growth resulted in accumulation of glycerol in the medium. In glucose-limited growth glycerol tended to decrease. It was probably metabolized as a secondary carbon source. The optimum temperature for polyol production was 30°C while that for cell growth was 27°C.
Techniques To Measure The Spectral Reflectance Of Ice

The system described here was designed to use two commercially available scanning spectroradiometers, a desk top calculator, and software to obtain simultaneous readings of incident and reflected radiation. To use such laboratory instruments in a hostile environ-ment, it was necessary to develop support apparatus. A weatherized, portable module to house the data storage and readout apparatus; heated casings for spectroradiometers; power systems; and an over-ice instrument support boom are included. Problems with poor cosine response of the instruments were largely overcome. A process for using integrating spheres under both clear and overcast conditions is being developed. The system was specifically designed to measure the spectral reflectance of snow and ice in the Great Lakes. Similar systems can be used for any field or laboratory application where incident flux might change during the spectroradiometer scan. Data collected showed large differences in the spectral reflectances of certain types of freshwater ice. However, for some ice types under certain atmospheric conditions, such as brash ice under clear or partly cloudy skies, it is difficult to determine a unique spectral signature since spectral reflectances are not only diurnally dependent but also site specific.
Chronological changes in stone tool assemblages from Krapina (Croatia)

This study presents the results of the first recent analysis of stone tool assemblages from Krapina (Croatia). All assemblages are Pleistocene in age and many are associated with human remains, the Krapina Neandertals. The assemblages are described typologically and technologically, and subtle chronological changes in raw material selection and technology of tool blank production are observed. These changes involve increasingly sophisticated and selective use of lithic materials. Changing artefact assemblages are considered in light of variability in the hominids from Krapina, and are interpreted as reflecting behavioral change among Neandertals rather than between Neandertal and modern human populations.
Morphologies of C60 deposited on a substrate

Abstract The morphologies of deposited C 60 on a copper substrate from a C 60 -benzene solution were evaluated by using Scanning Electron Microscopy. It was found that the forms of deposited C 60 were dependent on the aggregation of C 60 in its original solution. During natural vaporization of benzene solution on a copper substrate, independent C 60 molecules in the solution assembled into crystal C 60 on the substrate, whereas the aggregates of C 60 in the solution were remained as amorphous C 60 particles on the substrate. However, if spinning was employed during vaporizing solvent, the C 60 aggregates were destroyed, leading to the formation of crystal C 60 . Furthermore, the speed of spinning a substrate can tune the size and shape of deposited C 60 .
Incremental 40Ar/39Ar ages of biotite and hornblende from the northeastern Reading Prong: Their bearing on late Proterozoic thermal and tectonic history

K-Ar and 40 Ar- 39 Ar incremental-release ages have been determined for biotite and hornblende from Grenville basement gneiss units of the northeastern Reading Prong west of the Hudson River. Biotite ages range from 768 ± 15 to 819 ± 18 m.y. (average of 790 m.y.), and those for unaltered hornblende range from 869 ± 20 to 949 ± 24 m.y. (average of 900 m.y.). Individual biotite and hornblende release spectra show negligible variations in 40 Ar/ 39 Ar ratios, and total-gas and incremental-release ages are similar. These ages are discordantly younger than zircon ages of about 1,060 m.y. from this area; however, the consistent correlation of K-Ar, total-gas, and incremental-release ages argues against the discordancy resulting from partial argon loss during a distinct post-Grenville thermal event. The correlation suggests that the ages date times during post-Grenville metamorphic cooling when temperatures dropped below those required for argon retention in the minerals. The ages place constraints on post-metamorphic cooling history and allow development of a model for the late Proterozoic uplift of this segment of the Appalachian Grenville terrane.
Determination of variables in the prediction of strontium distribution coefficients for selected sediments

Idaho State University and the US Geological Survey, in cooperation with the US Department of Energy, conducted a study to determine and evaluate strontium distribution coefficients (Kds) of subsurface materials at the Idaho National Engineering and Environmental Laboratory (INEEL). The Kds were determined to aid in assessing the variability of strontium Kds and their effects on chemical transport of strontium-90 in the Snake River Plain aquifer system. Data from batch experiments done to determine strontium Kds of five sediment-infill samples and six standard reference material samples were analyzed by using multiple linear regression analysis and the stepwise variable-selection method in the statistical program, Statistical Product and Service Solutions, to derive an equation of variables that can be used to predict strontium Kds of sediment-infill samples. The sediment-infill samples were from basalt vesicles and fractures from a selected core at the INEEL; strontium Kds ranged from ~201 to 356 ml g–1. The standard material samples consisted of clay minerals and calcite. The statistical analyses of the batch-experiment results showed that the amount of strontium in the initial solution, the amount of manganese oxide in the sample material, and the amount of potassium in the initial solution are the most important variables in predicting strontium Kds of sediment-infill samples.
A survey of behavioral science contributions to laboratory management

The results of a survey of the behavioral science literature pertinent to the performance of scientists and engineers are presented. The manager desiring to make use of existing behavioral science findings to achieve specific results within his organization is provided with a guide to those items in the literature which provide relevant information.
Attractors and recurrence for dendrite-critical polynomials

We call a rational map f dendrite-critical if all its recurrent critical points either belong to an invariant dendrite D or have minimal limit sets. We prove that if f is a dendrite-critical polynomial, then for any conformal measure μ either for almost every point its limit set coincides with the Julia set of f, or for almost every point its limit set coincides with the limit set of a critical point c of f. Moreover, if μ is non-atomic, then c can be chosen to be recurrent. A corollary is that for a dendrite-critical polynomial and a non-atomic conformal measure the limit set of almost every point contains a critical point.
Suppressor T cells and suppressor macrophages induced by Corynebacterium parvum.

Abstract Corynebacterium parvum, injected intravenously into C57B1/6 mice (H-2 b ) previously alloimmunized with P815 (H-2 d ) mastocytoma cells, generated splenic suppressor cells that inhibited the development of primary cytotoxic lymphocytes in vitro . These suppressor cells differed from those generated by intravenous C. parvum injection of naive C57B1/6 mice. The former suppressor cells were effectively induced by administration of 700 μg of C. parvum whereas the latter suppressor cells were dependent upon higher doses (1400 μg) of adjuvant for their activation. Furthermore, suppressor cells generated in alloimmunized mice could only suppress C57B1/6 anti-P815 in vitro cytotoxic responses whereas suppressor cells generated in naive mice could suppress C57B1/6 anti-CBA (H-2 k ) responses as well. Suppressor cells were not H-2 restricted in their action. Fractionation of spleens from alloimmunized, C. parvum -treated mice revealed the presence of suppressor T cells and suppressor macrophages. We were unable, however, to determine which cell was responsible for “antigen specificity” of suppression since the fractionation procedures seemed to trigger both suppressor cell types prior to adding them to the primary culture.
The impact of regional government structure on the concentration and supply of affordable housing

Abstract Public choice theory provides a basis for predicting that a fragmented regional government structure encourages municipalities to limit affordable housing for low‐income households, an action that in turn has consequences for the region's overall supply and distribution of such units. This research tests two hypotheses: First, greater fragmentation in a metropolitan region is expected to be associated with increased segregation of affordable rental housing. Second, greater fragmentation is expected to be associated with a smaller supply of affordable rental units relative to the need. Contrary to these hypotheses, the results show that greater fragmentation is associated with a greater relative supply of affordable housing for extremely low and very low income households, but does not affect its distribution. These findings suggest that a unified government structure may reduce the supply of, rather than the barriers to, affordable housing for low‐income households.
The impact of forced joint exercise on lubricin biosynthesis from articular cartilage following ACL transection and intra-articular lubricin's effect in exercised joints following ACL transection

Summary Objective To evaluate the impact of forced joint exercise following acute knee injury on lubricin metabolism and its relationship to cartilage degeneration and to assess chondroprotection of a single-dose purified human lubricin injection in exercised injured joints. Methods Anterior cruciate ligament transection (ACLT) was performed in rats with six experimental groups; 3-week post-ACLT, 3-week post-ACLT + exercise, 5-week post-ACLT, 5-week post-ACLT + exercise, and 5-week post-ACLT + exercise treated with intra-articular phosphate buffered saline (PBS) or lubricin. Joint exercise was achieved using a rotating cylinder at a speed of 6 rpm for 30 min daily, 5 days a week starting 1 week following surgery. Cartilage lubricin expression in injured joints was determined. Histological analyses included Safranin O/Fast Green, activated caspase-3, and lubricin mRNA in-situ hybridization. Assessment of cartilage damage was performed by osteoarthritis research society international (OARSI) modified Mankin scoring and urinary CTXII (uCTXII) levels. Results At 3 weeks, lubricin expression in exercised ACLT joints was significantly ( P P P P Conclusion Joint exercise resulted in decreased lubricin cartilage expression, increased cartilage degeneration and reduced superficial zone chondrocyte viability in the ACLT joint. Intra-articular lubricin administration ameliorated cartilage damage due to exercise and preserved superficial zone chondrocytes' viability.
Vibration-Based Bending Fatigue of a Hybrid Insert-Plate System

A hybrid bending specimen system was developed to reduce material waste when using the vibration-based fatigue method to gather high cycle fatigue (HCF) data. In the vibration-based fatigue method, a base-excited plate specimen is driven into a high frequency resonant mode until failure. Compared to the axial testing methods, vibration-based failure better represents the conditions and surface-initiated cracks experienced by structural components subject to high frequency vibrations, like blades and vanes in gas turbine engines. In addition, the method produces data over 40 times faster than conventional axial testing methods. Only a small portion of the vibration-based bending specimen is needed to determine crack initiation failure. In order to reduce material waste, a hybrid bending system was designed to test a small specimen held in a reusable carrier plate, thereby reducing material costs to gather HCF data. The final optimized design, the Bruns-Zearley plate specimen, produced fatigue data using 95 % less material. The results are comparable tofatigue data acquired from standard vibration-based plate specimen methods within a 95 % confidence interval.
Transport Powder and Liquid Samples by Surface Acoustic Waves

Sample transport is an important requirement for In-situ analysis of samples in NASA planetary exploration missions. Tests have shown that powders or liquid drops on a surface can be transported by surface acoustic waves (SAW) that are generated on the surface using interdigital transducers. The phenomena were investigated experimentally and to generate SAWs interdigital electrodes were deposited on wafers of 128 deg rotated Y-cut LiNbO?. Transporting capability of the SAW device was tested using particles of various sizes and drops of various viscosities liquids. Because of different interaction mechanisms with the SAWs, the powders and the liquid drops were observed to move in opposite directions. In the preliminary tests, a speed of 180 mm/s was achieved for powder transportation. The detailed experimental setup and results are presented in this paper. The transporting mechanism can potentially be applied to miniaturize sample analysis system or " lab-on-chip" devices.
Patient advocacy in the USA: Key communication role functions

Researchers have long documented the importance of patient advocacy programs as a means of providing customer service in health-care organizations. Yet, while effective communication is often acknowledged as key to effective patient advocacy, knowledge of the specific communication role functions enacted by patient advocates remains limited, as does our understanding of the function of patient advocacy at the organizational level. This qualitative investigation not only provides a typology of communication roles enacted by patient advocates while solving problems on behalf of patients and their family members, but also integrates scholarly research on "boundary-spanning" as a means of theoretically contextualizing the advocacy role at the organizational level.
Quaternary volcanic and tectonic segmentation of Central America

Central America is divided into seven segments based on differences in the strikes and positions of volcanic lineaments in the historically active volcanic chain. This block-like pattern is also seen in the contrasting volcano morphology, recent fault patterns and the distribution of shallow earthquakes. Discontinuities in the deep seismic zone can be identified at some segment margins. The boundary areas between the segments are characterized by faulting transverse to the volcanic lineaments, frequently accompanied by basalt cinder cone fields, by concentrations of shallow earthquakes and by catastrophic historic eruptions. This volcanological, structural and seismological data can be explained by a segmented converging plate margin. At shallow depths the underthrust lithosphere is broken along tear faults into 100 to 300 km long segments. The separate segments descend into the mantle with different strikes and dips and give the geology its segmented character. Evidence for similar segmented converging plate margins is found in Mexico and in other parts of the circumpacific and alpine belts.
The institutional expansion of human rights, 1863–2003: A comprehensive dataset of international instruments:

This article summarizes the results of a recently completed, comprehensive coding of 779 human rights instruments from 1863 to 2003. As such, it offers an extensive portrayal of how, and to what degree, this powerful doctrine has been formally institutionalized over time. Following a brief overview of the data collection process, selected results from this study are presented that highlight how many human rights instruments have been drafted, what kind of violations have been most prominent, the number of rights that have been specified over time, and the ultimate aspirations that are linked to the realization of human rights. Next, potential applications of this dataset are discussed regarding both human rights and peace research scholarship. Specifically, the results shed new light on the historical development of human rights by highlighting key periods of instrument growth in the late 19th century, the interwar years, and the post-World War II period. In addition, the data can effectively augment recent quantitative studies that measure the effect of treaty ratification on internal state violence by helping to generate more extensive ratification information, develop better measures of state compliance, and construct new measures that assess how human rights principles get translated into national practice and potentially mitigate state violence over time.
Carolyn Abbate and Roger Parker, A History of Opera

A lively chronicle of opera’s greatest hits and great men, A History of Opera is unlike previous histories of opera. Keenly aware of the difficulty of writing about opera’s history and of doing so ...
Preparing Women for Baptist Church Leadership: Mentoring Impact on Beliefs and Practices of Female Ministers

Effective leadership is important in all organizations, and the Baptist church is no exception. Strong spiritual leaders can make a difference in the life of the institution and its members. Today, a growing number of African American women are answering the call to the Baptist church ministry; but the preparation, training, and mentoring are often insufficient. Ten African American women were interviewed to learn about their backgrounds, education, support, and roles as Baptist ministers in the church to discover perceptions of themselves as teachers, preachers, counselors, and leaders in the church and how they were trained and prepared to assume their leadership roles. Feminist and “servant leadership” theory provided the underpinning of this study. Research questions for study were: (1) In what ways did being mentored, or not, affect African American women ministers' perceptions of their effectiveness in ministry? (2) What relationship/role, if any, do mentors have in preparing these ministers to adva...
Inductively coupled NMR probe for versatile dynamic nuclear polarization operation at 7 T: Observation of 61 ± 2% 1H polarization at 4 K

Abstract We have performed dynamic nuclear polarization (DNP) experiments at liquid helium temperatures using a low-power ( 1 H NMR signal at 300 MHz, as such coils are well suited for higher frequency NMR detection. The Alderman–Grant coil is inductively coupled to the rest of the radiofrequency (rf) circuit, whose design allows probe components to be placed away from the sample area, and also enables easy switching of coils with different diameters and resonance frequencies. We have tested our DNP instrument on a frozen nitroxide model system consisting of 4-Amino TEMPO dissolved in a glycerol:water mixture. The largest nuclear spin polarization observed was 61 ± 2% with a sample containing 20 mM 4-Amino TEMPO dissolved in deuterated glycerol (d-glycerol):D 2 O:H 2 O (50:40:10), amounting to record polarization measured to date at an easily amenable temperature of 4 K.
Cellulose and lignin degradation in forest soils: Response to moisture, temperature, and acidity

The concentration of lignin in plant tissue is a major factor controlling organic matter degradation rates in forest ecosystems. Microbial biomass and lignin and cellulose decomposition were measured for six weeks in forest soil microcosms in order to determine the influence of pH, moisture, and temperature on organic matter decomposition. Microbial biomass was determined by chloroform fumigation; lignin and cellulose decomposition were measured radiometrically. The experiment was designed as a Latin square with soils of pH of 4.5, 5.5, and 6.5 adjusted to 20, 40, or 60% moisture content, and incubated at temperatures of 4, 12, or 24°C. Microbial biomass and lignin and cellulose decomposition were not significantly affected by soil acidity. Microbial biomass was greater at higher soil moisture contents. Lignin and cellulose decomposition significantly increased at higher soil temperatures and moisture contents. Soil moisture was more important in affecting microbial biomass than either soil temperature or soil pH.
Further studies on tryptophan hydroxylase in rat brainstem and beef pineal.

Abstract Soluble tryptophan hydroxylating enzymes have been obtained from both the beef pineal gland and rat brainstem. The enzymes have a pH optimum of 7.5 and appear to be typical aromatic ring hydroxylases. Although aniron requirement of the enzymes can be demonstrated by iron chelators, exogenous iron is not absolutely required for activity. Tetrahydrobiopterin was more effective than 2-amino-4-hydroxy-6,7-dimethyl-5,6,7,8 tetrahydropteridine as a cofactor for the enzymes. The beef pineal enzyme hydroxylates phenylalanine at approximately the same rate as it does tryptophan, whereas the brain enzyme showed no detectable activity toward phenylalanine. Finally, catechol compounds are effective inhibitors of the enzymes, presumably because of their ability to chelate iron.
Folic acid intake of young women.

Objective To investigate the folic acid intake of young women ages 18–24. Design Nonexperimental, descriptive survey. Setting Small private college in western North Carolina. Participants A convenience sample of 42 female college students ages 18–24. Main Outcome Measures Survey of demographics, folic acid intake, knowledge of folic acid, and pregnancy contemplation. Results All participants were found to have an inadequate diet and an inadequate intake of folic acid. Only 33.3% reported taking daily multivitamins. These findings may be attributed to the participants' lack of knowledge about folic acid and the birth defects it helps to prevent. Conclusion Inadequate folic acid intake is common in young women ages 18–24. These young women frequently have poor nutritional habits and are usually noncontemplators of pregnancy.
The History of Expertise in Security Management Practice and Litigation

Security has been necessary from time immemorial for the development and flourishing of societies. In modern times, security has aided the functioning of modern corporations, non-government organizations, and government itself. Yet only in the past few generations has the concept of security ‘expertise’ been a distinctive feature of organizations. And, for even a lesser period of time, security knowledge and concepts have been significant in civil and criminal litigation. What are the fundamental bases for these practices, and how substantial are they? What is the context for assertions from security experts? And what implications have they for the present and future of the American legal process?
A controlled study of flumazenil-precipitated withdrawal in chronic low- dose benzodiazepine users

Rationale: Preclinical studies of the benzodiazepine antagonist flumazenil (Romazicon®) have contributed to the understanding of the physical dependence associated with chronic benzodiazepine use; when administered to animals chronically pretreated with benzodiazepines, flumazenil precipitates a withdrawal syndrome. However, few controlled clinical studies have been conducted. Objectives: The objective was to characterize the effects of flumazenil in long-term users of therapeutic doses of benzodiazepines. Methods: The acute physiological, participant-rated, and observer-rated effects of intravenously administered flumazenil (1 mg/70 kg) and caffeine (300 mg/70 kg; active drug control) were evaluated in an experimental group of 13 long-term users (mean 4.6 years) of low therapeutic doses (mean 11.2 mg/day diazepam equivalent) relative to a matched group of 13 volunteers without prior exposure to benzodiazepines in a double-blind, placebo-controlled, mixed design. Results: Whereas the experimental group did not differ from the control group with respect to the effects of placebo, and both groups showed some changes in response to caffeine (e.g., increased blood pressure and anxiety scores), only the experimental group showed considerable changes in physiological measures, participant ratings (e.g., increased ratings of dizziness, blurred vision, heart pounding, feelings of unreality, pins and needles, nausea, sweatiness, noises louder than usual, jitteriness, things moving, sensitivity to touch), and observer ratings in response to flumazenil; in addition, four participants developed panic attacks. Conclusions: This study clearly demonstrates that flumazenil can precipitate symptoms commonly associated with benzodiazepine withdrawal in chronic low-dose benzodiazepine users.
Complex Education: Depth psychology as a mode of ethical pedagogy

This essay applies the material developed in The Wounded Researcher to education. The core issue in that book is the necessity to make a place for the complex unconscious in research in order to lay a foundation for an ethics that is based in deep subjectivity. The therapy room has characteristically been the place where this kind of work has occurred, and in this regard therapy has been a form of education. The boundaries of the therapy room have, however, exploded and, given the awesome powers of technology to develop and communicate information, how do we make a place for the unconscious in our educational practices? Drawing upon the work of Carl Jung this essay addresses the following questions: How does one make a place for the unconscious in the classroom, without turning teaching into therapy?; How does a teacher make a place for the unconscious dynamics in the complex interactive field among himself/herself, the students, and the material without overwhelming students?; What are the limits and dan...
Simplified Physical Model of Spray Combustion in a Gas Turbine Engine

Abstract Heterogeneous processes have been identified as important in determining levels of exhaust emissions from liquid-fueled gas turbine engines. From correlations of NO and CO emissions indices with differential fuel injection pressure, a simplified physical model of the spray combustion process in a turbine combustor has been developed. This model not only is consistent with previous experimental data obtained in this laboratory, but also assists in understanding the successes and failures of analytical combustor models available in the open literature.
Structural states of dictyostelium myosin

Myosin purified from Dictyostelium amoebae has approximately 10% by weight of RNA associated with it, unless specific steps (DEAE cellulose chromatography or RNase digestion) are taken to remove it. This RNA has significant effects on the structural states formed by the myosin at low ionic strength in the presence of Mg2+. Rapid precipitation of RNA-free myosin by dilution generates bipolar thick filaments (540 nm long, 33 nm thick), often with a bare zone and a 15-nm transverse repeat. Rapid precipitation of myosin with copurified RNA yields linear aggregates of bipolar filaments, showing some lateral association. Slow precipitation of RNA-free myosin by dialysis yields very long filaments or ribbons (greater than 5 micrometer, 30--60 nm wide) in which the myosin may be packed diagonally across the filament, similar to the "side-polar" aggregates formed by other nonmuscle myosins and by smooth muscle myosin (Craig R, Megerman J: J Cell Biol 75:990, 1977; Hinssen H, D'Haese J, Small JV, Sobieszek A: J Ultrastruct Res 64:282, 1978). Slow precipitation of myosin with copurified RNA generates linear filaments with repeat intervals of 290 and 650 nm. Other polyanions were tested for their effects on myosin aggregation. Total RNA and ribosomal RNA from Dictyostelium, when added to RNA-free myosin, also induced the extensive linear aggregation seen with the copurified RNA/myosin complex, although higher concentrations of RNA were required to obtain quantitatively the same effect. DNA and heparin were also effective inducers of linear aggregation, whereas homopolymers of nucleotides and of acidic or basic amino acids were poorly effective.
Prestorage leucoreduction improves several in vitro red cell storage parameters following gamma irradiation.

Gamma irradiation (GI) can prevent transfusion-associated graft-vs.-host disease, result in a small decrement in 24-h in vivo red blood cell (RBC) recovery and in a minor loss of maintenance of several in vitro parameters during routine storage. Results from studies by Davey et al. (Transfusion 1995, 35, 55S) demonstrated that the decrement in 24-h recovery was not observed if units were first leucoreduced (LR), suggesting that RBC damage on leucocytes from GI was secondary to the effects of irradiation . In this study, we further investigated how leucoreduction affected eight in vitro storage parameters of gamma-irradiated units by using a matched sample study design. Leucoreduction significantly reduced (P > 0.5) the enhanced potassium release associated with GI. Some, but not all, the observed RBC damage caused by GI appears to be secondary to the effect of irradiation on leucocytes. Based on the in vivo survival studies of Davey et al. and the results of this study, there is justification to consider performing additional survival studies to support extended storage of LR gamma-irradiated RBC.
Three Regions of Dielectric Breakdown

In a previous paper, the writers published results on the dielectric strength of various glasses and concluded that for ordinary thicknesses there were three distinct types of breakdown. The present paper emphasizes the fact that this is true not only for glass but also for fused quartz and for celluloid. By the elimination of edge-effect the following breakdown gradients were obtained: For celluloid, 2,500,000 volts/cm.; for glass, 3,100,000 to 5,000,000 volts/cm.; and for mica, 10,600,000 volts/cm. The various methods of eliminating edge-effect are discussed and compared and an attempt is made to correlate the electrical properties of the glasses with their chemical composition.
Effects of E-Mail on the Organization

Abstract The objective of this article is to enable managers better to understand the current nature and future potential of e-mail communication in organizations and some of the associated social processes. Following a review, William Lucas examines the direct and secondary benefits of e-mail on organizational efficiency, which are enhanced as more and more employees are given e-mail capability. His analysis combines research literature, case studies and survey data, and a major conclusion highlights managerial compromises which may be necessary when e-mail communication encourages the flow of information in organizations outside formally-authorized channels.
Structure-based design of an intramolecular proton transfer site in murine carbonic anhydrase V.

Carbonic anhydrase V (CA V) is a mitochondrial enzyme that catalyzes the hydration of CO2 to produce bicarbonate and a proton. The catalytic properties of wild-type murine CA V suggest the presence of a proton shuttle residue having pKa = 9.2, the role of which is to transfer a proton from zinc-bound water to solution in the hydration direction to regenerate the zinc hydroxide form of the enzyme. Two likely candidates for shuttle residues are the tyrosines at positions 64 and 131 in the active site cavity. The crystal structure of wild-type carbonic anhydrase V [Boriack-Sjodin et al. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 10949-10953] shows that the side chain of Tyr 64 is forced into an orientation pointing away from the zinc by Phe 65, although Tyr 131 is oriented toward the zinc. We have prepared mutants of murine CA V replacing both Tyr 64 and Tyr 131 with His and Ala and investigated the proton shuttle mechanism using stopped-flow spectrophotometry and the depletion of 18O from CO2 measured by mass spectrometry. Experiments with both single and double mutations showed that neither position 64 nor position 131 was a prominent site for proton transfer. However, a double mutant of CA V containing the two replacements, Tyr 64-->His and Phe 65-->Ala, demonstrated enhanced proton transfer with an apparent pKa of 6.8 and maximal contribution to kcat of 2.2 x 10(5) s-1. In addition to the altered catalytic properties, the crystal structure of the His 64/Ala 65 double mutant strongly suggested proton transfer by His 64 after removal of the steric hindrance of Phe 65. This is the first structure-based design of an efficient proton transfer site in an enzyme.
Development of Ultrasound-Switchable Fluorescence Imaging Contrast Agents Based on Thermosensitive Polymers and Nanoparticles

In this paper, we first introduced a recently developed high-resolution, deep-tissue imaging technique, ultrasound-switchable fluorescence (USF). The imaging principles based on two types of USF contrast agents were reviewed. To improve USF imaging techniques further, excellent USF contrast agents were developed based on high-performance thermoresponsive polymers and environment-sensitive fluorophores. Herein, such contrast agents were synthesized and characterized with five key parameters: 1) peak excitation and emission wavelengths (λex and λem); 2) the fluorescence intensity ratio between on- and off-states (IOn/IOff); 3) the fluorescence lifetime ratio between on- and off-states (τOn/τOff); 4) the temperature threshold to switch on fluorophores (Tth); and 5) the temperature transition bandwidth (TBW). We mainly investigated fluorescence intensity and lifetime changes of four environment-sensitive dyes [7-(2-Aminoethylamino)-N,N-dimethyl-4-benzofurazansulfonamide (DBD-ED), St633, Sq660, and St700] as a function of temperature, while the dye was attached to poly(N-isopropylacrylamide) linear polymers or encapsulated in nanoparticles. Six fluorescence resonance energy transfer systems were invented in which both the donor (DBD-ED or ST425) and the acceptor (Sq660) were adopted. Our results indicate that three Forster resonance energy transfer systems, where both IOn/IOff and τOn/τOff are larger than 2.5, are promising for application in future surface tissue bioimaging by the USF technique.
Brief report: Affluence and college alcohol problems: The relevance of parent- and child-reported indicators of socioeconomic status

A mediational model predicting alcohol problems was tested in a sample of college students (n = 130) and their parents (n = 115). The indirect effect of substance-use coping and the age of onset of alcohol use were examined in the relationship between socioeconomic status (SES) and alcohol problems. Findings indicated that parent-reported SES was associated with increased alcohol problems; the age of onset of alcohol use partially mediated this relationship. Substance-use coping was not a significant mediator in the model. Student-reported SES was not associated with alcohol problems. Implications for examining social status in relation to college drinking behaviors are discussed.
Mechanical hyperalgesia in rats with chronic perfusion of lumbar dorsal root ganglion with hyperglycemic solution.

In diabetes, chronic systemic hyperglycemia is associated with pain and other symptoms of peripheral neuropathy. Evaluation of mechanisms causing these symptoms is complicated because of the overlap between the systemic effects of hyperglycemia and its toxic effects within the peripheral nervous system. To address this problem we developed a technique for chronic local in vivo perfusion of rat lumbar dorsal root ganglion (DRG) with a hyperglycemic solution. Osmotic pumps were filled with 30 mM glucose in physiological buffer and implanted in normal adult rats. The output of the catheter attached to the pump was positioned in a hole drilled through the right transverse process of the L5 vertebrae to perfuse the corresponding DRG. Repetitive tests of foot withdrawal to mechanical stimuli have shown that chronic hyperglycemia localized to the L5 DRG causes hyperalgesia in the hind limb innervated by perfused ganglion but not in the contralateral limb. Control experiments (DRG perfusion with 5 mM glucose or 5 mM glucose+25 mM mannitol solution) have shown that hyperglycemia-induced hyperalgesia can not be attributed to surgery-related injury or hyperosmolality of the ganglion-perfusing solution. These data demonstrate direct functional toxicity of hyperglycemia in the peripheral nervous system. This technique provides a new approach for in vivo study of chronic effects of physiologically active factors on DRG neuron function.
The impact of race on survival in nasopharyngeal carcinoma: a matched analysis.

Abstract Objective To determine if nasopharyngeal carcinoma (NPC) exhibits significant prognostic differences in Chinese versus white patients. Methods From the Surveillance, Epidemiology, and End Results database for the time period 1988 to 2000, all cases of NPC were extracted and staging variables computed. To each case of NPC diagnosed in a Chinese patient, a case of NPC in a white patient was randomly matched for age at diagnosis, gender, grade, stage, and treatment modality. Kaplan-Meier survival analysis was then conducted for the matched groups comparing overall survival and disease-specific survival both for the overall matched cohort and stage stratified cohorts. Results Among 1,520 cases of NPC, 338 were identified in Chinese patients with staging information. Of these, 171 were successfully matched to white patients. Average age at presentation was 51.5 years with a 3:1 male predominance. Overall survival was substantially better for Chinese patients (mean survival, 94 months; median survival, 95 months) than for white patients (81 months and 64 months, P = .037). Stratified for stage, overall survival was better for Chinese patients for stage 3 but not stage 4 disease (P = .012 and P = .447, respectively). Disease-specific survival was not substantially different between Chinese patients (mean survival, 116 months) and white patients (mean survival 117 months, P = .99). No differences in disease-specific survival were identified for race when stratified by stage (all P > .05). Conclusions Although overall survival is better for Chinese patients with NPC compared with white patients, disease-specific survival is similar between these racial groups. These data suggest that the biological behavior of NPC is relatively independent of race.
H2A.Z-dependent regulation of cohesin dynamics on chromosome arms.

Structural maintenance of chromosomes (SMC) complexes and DNA topoisomerases are major determinants of chromosome structure and dynamics. The cohesin complex embraces sister chromatids throughout interphase, but during mitosis most cohesin is stripped from chromosome arms by early prophase, while the remaining cohesin at kinetochores is cleaved at anaphase. This two-step removal of cohesin is required for sister chromatids to separate. The cohesin-related Smc5/6 complex has been studied mostly as a determinant of DNA repair via homologous recombination. However, chromosome segregation fails in Smc5/6 null mutants or cells treated with small interfering RNAs. This also occurs in Smc5/6 hypomorphs in the fission yeast Schizosaccharomyces pombe following genotoxic and replication stress, or topoisomerase II dysfunction, and these mitotic defects are due to the postanaphase retention of cohesin on chromosome arms. Here we show that mitotic and repair roles for Smc5/6 are genetically separable in S. pombe. Further, we identified the histone variant H2A.Z as a critical factor to modulate cohesin dynamics, and cells lacking H2A.Z suppress the mitotic defects conferred by Smc5/6 dysfunction. Together, H2A.Z and the SMC complexes ensure genome integrity through accurate chromosome segregation.
Numerical simulations of cardiac dynamics. What can we learn from simple and complex models

Modeling the electrical activity of the heart, and the complex signaling patterns that underlay dangerous arrhythmias such as tachycardia and fibrillation, requires a quantitative model of action potential propagation. At present, there exist detailed ionic models of the Hodgkin-Huxley form that accurately reproduce dynamical features of the action potential at a single cell level. However, such models are very time consuming in computer simulations. The authors show how simplified models can help on the study of cardiac arrhythmias. In particular, how breakup of spiral waves, believed as the dynamics underlying the transition from tachycardia to fibrillation, can occur as function of tissue size and shape. The authors also discuss some of the limitations in these models and some differences in dynamics between simple and complex models.