cssi/SciSciGPT-SciSciNet huggingface dataset:
Determination of HF partial pressure during ex situ conversion of YBCO precursors

Abstract The importance of HF gas behavior during ex situ YBCO formation is well known, however no experimental data on the partial pressure of HF gas exists due to difficulties in measuring this fundamental quantity. The objective of this study is to measure the partial pressure of HF above TFA-MOD derived coated conductor during processing. The method used was based on a modified Knudsen cell technique. Fluorine loss from the Knudsen cell was monitored by measuring residual fluorine in quenched films. Fluorine loss showed two separate regimes corresponding to the oxidation of YF 3 and of BaF 2 . The partial pressure of HF was measured at 525, 575 and 625 °C. Partial pressures of HF measured at 575 °C were 0.16 ± 0.02 Pa for the YF 3 reaction and 0.02 ± 0.002 Pa for the BaF 2 reaction. Measured pressures gave Δ G values of the reactions, which were compared to calculated values for several possible reactions that literature suggests can occur during the processing. Experimental results indicate the most probable reaction for each step.
Cytotoxic Chemotherapy for Differentiated Thyroid Carcinoma

For patients with metastatic differentiated thyroid carcinoma that progresses despite standard therapies, systemic cytotoxic chemotherapy has traditionally been a limited option. Historically, phase II studies and small retrospective series have failed to identify highly effective drugs or regimens, in part by failing to recruit sufficient numbers of patients. Doxorubicin remains the single most effective cytotoxic chemotherapy for the treatment of metastatic disease, although complete responses are rare, partial responses limited and toxicity considerable. Newer agents, such as pemetrexed, may be of benefit and potentially better tolerated. Newer approaches to treatment as well as trial design and recruitment, emphasising the role of thyroid cancer patients in early drug trials, may yield advances in patient benefit.
Poetry: An ancillary technique in couples group therapy

Abstract The use of poetry as an ancillary technique in couples groups is examined. In noting the use of the arts in family and group therapy, poetry is suggested as an additional method of facilitating group process and breaking down resistance with couples. While the use of poetry in therapy has been described elsewhere, it has received little attention with couples and family therapy. Some techniques described in this report include the use of reactions to a poem or song; the construction of collaborative and dyadic poems; and the development of images from dialogue. An example of a short-term couples group is presented. Therapists are cautioned about the limitations of the method, such as supporting intellectualizations. Utilized as a medium, poetry can be an aid to the therapist in helping clients express feelings and examine communication patterns.
Location-based broadcasting for dense mobile ad hoc networks

We consider broadcasting protocols in mobile ad hoc networks that propagate a message from a node to all of the nodes of a network. In order to reduce the impact of mobility on protocols, instead of relying on the frequently changing communication topology, our approaches depend on a less frequently changing and more stable characteristic --- the distribution of mobile nodes. We propose two broadcasting approaches. For each approach, we provide specific constraints on distribution and mobility of mobile nodes to guarantee that all the nodes receive the broadcast data. Under these constraints, given a network with area A, our approaches achieve broadcasting in O(A/R2) steps, where R is the transmission range.
The distribution of autelectronic emission from single crystal metal points. I. Tungsten, molybdenum, nickel in the clean state

E. Muller has shown that the angular distribution of field emission from fine metal points can be related to the crystal structure of the metal. He also suggested that the modifications in the pattern from tungsten which took place when the point temperature was raised could be attributed to a movement of the surface atoms which caused local changes in the work function. Further experiments are described in this paper using tungsten, molybdenum and nickel. It is shown that this surface mobility occurs above 1170 degrees K for tungsten, 770 degrees K for molybdenum, and 370 degrees K for nickel. The changes in emission distribution, which are very much more marked for molybdenum and nickel than for tungsten, can be completely explained in terms of a change in the geometrical shape of the point. This is brought about by the action of the high external field upon the mobile surface atoms. The flash-over phenomenon in high vacuum is discussed and an explanation offered in terms of these observations. The effect of small traces of gas is illustrated, and it is shown that the gas film is removed at the relatively low temperature of 620-670 degrees K. Several possible suggestions are put forward to explain the dependence of the emission distribution on the crystal structure of the metal, but no definite conclusion can be reached with the data at present available.
Histochemical evidence of altered development of cholinergic fibers in the rat dentate gyrus following lesions: I. Time course after complete unilateral entorhinal lesion at various ages

The entorhinal cortex of rats was removed at various times during development, and the reaction of the cholinergic septohippocampal input to the dentate gyrus was examined by use of acetylcholinesterase histochemistry. When the ipsilateral entorhinal cortex is completely removed, the outer 70-75% of the molecular layer of the dentate gyrus is almost completely denervated. After such a lesion at 5 to 33 days of age, the acetylcholinesterase staining initially intensified throughout the denervated area, indicating that the septohippocampal fibers branched or elongated. This reaction could be detected within one day after a lesion at 11 days of age and within three or five days after lesions at earlier or later times. Whereas the initial response of the septohippocampal fibers was independent of the age at which the lesion was made, their final localization depended on the developmental state of the animal. After lesions at the age of 5 or 11 days, the reactive septohippocampal fibers became restricted to the outer one-sixth to one-third of the molecular layer within two days after appearance of their initial reaction. A similar concentration of reactive fibers was demonstrable after lesions at 16, 18 or 21 days of age, but some reaction persisted in the middle third of the molecular layer. Finally, after lesions at 26 or 33 days of age the proliferating cholinergic fibers ultimately were uniformly distributed throughout the outer 60% of the molecular layer. These results suggest that septohippocampal fibers initially extend or sprout throughout the denervated area to replace the lost perforant path fibers. However, the reactive fiber population becomes restricted to the outer edge of the molecular layer if the entorhinal lesion is made before the period of cholinergic synaptogenesis and concentrates in this same zone if it is made while cholinergic synapses are forming. We suggest that either the proliferative reaction continues in the outer part of the molecular layer and subsides in other parts of the denervated area or septohippocampal fibers move outward through the molecular layer to assume a more superficial location. After entorhinal lesions at 16 days of age or later the pale-staining zone (containing fibers that originate in hippocampus regio inferior) immediately deep to the denervated area widened. If the lesion was made earlier, this zone never developed at most septotemporal levels of the dentate gyrus. These results are probably related to the extension of regio inferior fibers into the denervated area.
The Impacts and Efficiency of Agriculture-to-Urban Water Transfer: Discussion

The paper by Colby is well written, thoughtful, and provocative. She reviews the record of water exchanges in the West, focusing on the policyinduced transactions costs (PITC) necessary to obtain state approval of proposed water rights exchanges. These costs result from considering externalities that otherwise would be ignored by water buyers and sellers negotiating in their own best interests. But I have a concern that we rec-
Oxidant-Antioxidant Balance: Some Observations from Studies of Ischemia- Reperfusion in Isolated Perfused Rat Hearts

Alteration in oxidant-antioxidant balance is a key feature of many common vascular diseases. Using an isolated perfused heart model, we found that (a) xanthine oxidase-derived oxygen radicals contributed to ischemia-reperfusion injury; (b) addition of antioxidants within or outside erythrocytes decreased injury following ischemia-reperfusion; (c) endotoxin pretreatment increased myocardial catalase activity and decreased injury following ischemia-reperfusion; (d) interleukin pretreatment increased myocardial glucose-6-phosphate activity and decreased ischemia-reperfusion injury, and (e) neutrophils mediated tolerance to a subsequent oxidative stress by causing a small oxidant stress that in turn increased antioxidant protection mechanisms.
Influence of mercaptoethanol on the isolation of mercury-binding proteins from the gills of Mytilus edulis

1. 1. Use of the reducing agent 2-mercaptoethanol during extraction and isolation of low mol. wt, mercury-binding proteins of mussel gills resulted in an appearance of significant quantities of mercury associated with substances of <3000 daltons. 2. 2. The source of this mercury was mercury originally bound to the pellet, high mol. wt proteins, and low mol. wt, mercury-binding proteins. 3. 3. This shift in mercury distribution is regarded as a procedural artifact caused by reduction of mercury-binding sites and possible association of released mercury with mercaptoethanol. 4. 4. Use of mercaptoethanol did not release significant amounts of the metal-binding proteins from the high mol. wt protein pool.
Some pitfalls and trade-offs in source parameter determination using body wave modeling and inversion

Abstract This paper investigates the problem of non-uniqueness in body wave modeling for source quantification. In particular, it examines how variations in source structure, source time function, and focal depth interact to alter synthetic body waves, and shows that solutions with different model parameters are capable of producing synthetic waveforms which all fit the observed data equally well. The problem of non-uniqueness is illustrated by comparing source mechanisms and the resulting synthetic waveforms from several East African earthquakes. The shapes of synthetic waveforms are controlled by the focal depth, source crustal structure and source time function, as well as the strike, dip and rake of the earthquake. Results show that if any one of the model parameters is invalid, the resulting solution is highly suspect. This point is particularly important to consider when interpreting published results of body wave modeling studies. Several of the examples show how S-waves, surface reflected phases, and gravity surveys can be used to help constrain various model parameters.
Three-loop free energy for pure gauge QCD.

We compute the free energy density for pure non-Abelian gauge theory at high temperature and zero chemical potential. The three-loop result to O(${\mathit{g}}^{4}$) is F=${\mathit{d}}_{\mathit{A}}$${\mathit{T}}^{4}$${\mathrm{\ensuremath{\pi}}}^{2}$/9{-1/5+(${\mathit{g}}_{\mathit{A}}$/4\ensuremath{\pi}${)}^{2}$-16/\ensuremath{\surd}3(${\mathit{g}}_{\mathit{A}}$/4\ensuremath{\pi}${)}^{3}$ -48(${\mathit{g}}_{\mathit{A}}$/4\ensuremath{\pi}${)}^{4}$ln(${\mathit{g}}_{\mathit{A}}$/2\ensuremath{\pi}\ensuremath{\surd}3) +(${\mathit{g}}_{\mathit{A}}$/4\ensuremath{\pi}${)}^{4}$[22/3ln\ensuremath{\mu}\ifmmode\bar\else\textasciimacron\fi{}/4\ensuremath{\pi}T+38/3\ensuremath{\zeta}'(-3)/\ensuremath{\zeta}(-3) -148/3\ensuremath{\zeta}'(-1)/\ensuremath{\zeta}(-1)-4${\ensuremath{\gamma}}_{\mathit{E}}$+64/5]+O(${\mathit{g}}_{\mathit{A}}^{5}$)}, where T is the temperature, \ensuremath{\zeta} is the Riemann zeta function, ${\mathit{g}}_{\mathit{A}}$==g(\ensuremath{\mu}\ifmmode\bar\else\textasciimacron\fi{})${\mathit{C}}_{\mathit{A}}^{1/2}$, \ensuremath{\mu}\ifmmode\bar\else\textasciimacron\fi{} is the MS\ifmmode\bar\else\textasciimacron\fi{} renormalization scale, g(\ensuremath{\mu}\ifmmode\bar\else\textasciimacron\fi{}) is the corresponding coupling constant, and ${\mathit{d}}_{\mathit{A}}$ and ${\mathit{C}}_{\mathit{A}}$ are the dimension and Casimir number of the adjoint representation. We examine the sensitivity of this result to the choice of renormalization scale \ensuremath{\mu}\ifmmode\bar\else\textasciimacron\fi{}. We also give a result for the free energy of scalar ${\mathrm{\ensuremath{\varphi}}}^{4}$ theory, correcting a result previously given in the literature.
Leptin response to glucocorticoid occurs at physiological doses and is abolished by fasting.

Objective: To examine the effects of graded doses of hydrocortisone (HC) on leptin secretion, and determine the effect of fasting. Research Methods and Procedures: This was a randomized, placebo-controlled, crossover study, with a 1-week “washout” period between interventions. Eight healthy subjects [age = 36 ± 2.3 years (±SE), body mass index = 31.5 ± 1.6 kg/m2] completed the dose-response study in which an intravenous infusion of saline (placebo) or HC (30 or 100 mg) was administered for 24 hours. Four healthy subjects (age = 35.2 ± 3.0 years, body mass index = 27.1 ± 2.1 kg/m2) completed the fasting study, which entailed continuous infusion of saline, HC (300 mg/24 hours) in the fed state, or HC (300 mg/24 hours) with total caloric deprivation for 24 hours. Blood sampling was performed every 1 to 2 hours for measurement of leptin, cortisol, insulin, and glucose levels. Results: Peak hyperleptinemia occurred after 16 hours of HC infusion; peak/baseline leptin levels were 129% (placebo), 140% (30 mg of HC for 24 hours, p = 0.05), and 185% (100 mg of HC for 24 hours, p < 0.01). During infusion of HC (300 mg/24 hours or placebo), the peak/baseline plasma leptin levels were 16.1 ± 5.8/12.8 ± 5.9 ng/mL (placebo with food, 126%), 14.6 ± 6.0/12.5 ± 6.5 ng/mL (HC fasting, 117%), and 32.5 ± 12.5/12.0 ± 8.4 ng/mL (HC with food, 271%, p < 0.001). Discussion: Leptin secretory responses occur at physiological doses of HC, are obliterated by fasting, and thus may be of metabolic significance.
Explaining recursion to the unsophisticated

This paper addresses the topic of explaining recursion to Beginning programmers. It briefly presents the common approaches, then describes an extension to those methods called the activation tree.
Nonlinear Magnetic Field Analysis of DC Machines Part II. Application of the Improved Treatment

Based on methods described in Part I1 of the paper, the airgap radial inductions are calculated for four different rotor positions at full load and at one rotor position at twice full load. Line over-relaxation and additive acceleration of convergence techniques are used. Convergence criteria are described. Results of experiments to find suitable over-relaxation factors and expedient line integral paths for convergence accelerations are given. A computer program is detailed and applied to a 500 hp, 750 V, 4-pole, 300/900 r/min, dc motor.
Gas-phase kinetic studies of tetralin hydrogenation on Pt/alumina

The hydrogenation of aromatic compounds is a reaction of relevance in the improvement of diesel fuel quality. In this work, the kinetics of tetralin (1,2,3,4-tetrahydronaphthalene) hydrogenation over Pt/Al2O3 catalysts have been studied in an integral fixed bed reactor at 500 psig in the temperature range 553−573 K. A semiempirical Langmuir−Hinshelwood equation has been used to model the kinetics. The values of the kinetic parameters were determined by a nonlinear fitting, while the heats of adsorption for the hydrocarbons involved (tetralin and cis- and trans-decalin) were experimentally obtained by temperature-programmed desorption. The adsorption competition between tetralin and the hydrogenated products (cis- and trans-decalin) for surface active sites can be quantitatively traced to the higher heat of adsorption of tetralin compared to those of cis- and trans-decalins. As a result, while the activation energy for the cis−trans isomerization is significantly lower than the one for tetralin hydrogenati...
α-Bungarotoxin used as a Probe for Acetylcholine Receptors of Cultured Neurones

THE snake venom protein α-bungarotoxin binds with specificity and high affinity to nicotinic acetylcholine receptors of striated muscle1–6, electric tissues7–9, and mammalian brain10. For these reasons, this toxin, as well as similar toxins from elapid snakes, has been used for labelling, purifying and assessing the physicochemical properties of cholinergic receptors.
Minimum spanning trees of weighted scale-free networks

A complete characterization of real networks requires us to understand the consequences of the uneven interaction strengths between a system's components. Here we use minimum spanning trees (MSTs) to explore the effect of correlations between link weights and network topology on scale-free networks. Solely by changing the nature of the correlations between weights and network topology, the structure of the MSTs can change from scale-free to exponential. Additionally, for some choices of weight correlations, the efficiency of the MSTs increases with increasing network size, a result with potential implications for the design and scalability of communication networks.
FOSTERING SUCCESS AMONG TRADITIONALLY UNDERREPRESENTED STUDENT GROUPS: HARTNELL COLLEGE'S APPROACH TO IMPLEMENTATION OF THE MATH, ENGINEERING, AND SCIENCE ACHIEVEMENT (MESA) PROGRAM

Hartnell College is an accredited California Community College serving Salinas and the Salinas Valley, a vast 1,000 square mile agricultural region. The district is characterized by large numbers o...
Chromosome-bound mitotic factors: release by endonucleases

Additional evidence is presented to support our recently reported conclusion that the mitotic factors of mammalian cells, which induce germinal vesicle breakdown and chromosome condensation when injected into fully grown Xenopus laevis oocytes, are localized on metaphase chromosomes. Chromosomes isolated from mitotic HeLa cells were further purified on sucrose gradients and digested for varying periods with either the micrococcal nuclease or DNase II. At each time point of digestion the amount of mitotic factors released was determined by injecting a supernatant of these fractions, obtained by high-speed centrifugation, into oocytes. The amount of DNA rendered acid soluble under the conditions of digestion used was 3% ot 5% of the total chromosomal DNA. The extent of release of mitotic factors with both nucleases was estimated to be about 30% to 40% as evidenced by the reextraction of the undigested chromosomal pellet with 0.2 M NaC1. Similar results were obtained when nuclei from G2 cells were digested under identical conditions. The release of these chromosome-bound mitotic factors by mild digestion with these nucleases though only partial, clearly demonstrates that a significant proportion of these factors are localized on metaphase chromosomes.
The accuracy of visual estimation of body weight in the ED

Abstract Preventable medical errors may be due to incorrect drug dosage based on poor weight estimation. This study was to examine the accuracy of patient weight estimations in an emergency medical setting. This prospective study enrolled a convenience sample of medically stable adults. The patient’s attending physician, resident physician, nurse, a paramedic, and the patient estimated the patient’s weight. Of 394 patients enrolled, patients erred in the estimation of their weight by greater than 20% only 1.5% of the time. The group values were 14.7% for attending physicians, 13.4% for resident physicians, 15.9% for nurses, and 17.4% for paramedics. Our study suggests that emergency department staff estimation of a patient’s weight is often inaccurate. When available, the patient’s own estimate can be used as their actual weight. When the patient is incapacitated, measurement of the patient’s weight is the proven method to avoid this type of dosage error.
The Design and Analysis of Hospital Utilization Studies

The reports of hospital utilization review (UR) studies that appear in this issue employ a range of design strategies, and much of the variation seems accidental—arising because there are many acceptable strategies—rather than functional. This paper is about general design strategy: the value of explicit protocols for sampling and data collection, of analyses appropriate to the sampling, of generating reports managers can use. More coordination is strongly encouraged, to reduce unnecessary variation and to facilitate comparisons across studies. While individual groups may still opt for different strategies, techniques for increasing the comparability of reported findings are discussed. This will increase the value of each study, individually, as well as the value of the collective effort.
Mathematical Models of Cancer Stem Cells

Human cancers are thought to be sustained in their growth by a pathologic counterpart of normal adult stem cells: cancer stem cells. This concept was first developed in human myeloid leukemias and is today being extended to solid tumors such as breast and brain cancers. A quantitative understanding of cancer stem cells requires a mathematical framework to describe the dynamics of cancer initiation and progression, the response to treatment, and the evolution of resistance. In this review, I use chronic myeloid leukemia as an example to discuss how mathematical and computational techniques have been used to gain insights into the biology of cancer stem cells.
Self-Excitation of Capacitor Motors [includes discussion]

In this paper a method is presented for calculating the limits of self-excitation in capacitor induction motors when the motors are disconnected from the power source and operating at constant speed. Practical means are suggested for the suppression of self-excitation and test data are given which confirm the soundness of the conclusions.
On Ricci flat 3-fold

In this paper we study a sub-class of compact Ricci flat manifolds from certain standard constructions.
Noise signal pickup in coaxial cables

Abstract Three mechanisms by which undesired signals may appear across a load at the end of a coaxial cable are identified and discussed. These three mechanisms extend beyond the normal shielding action of the outer conductor against electric and magnetic fields, and account for a large fraction of the pickup problems encountered in the use of coaxial cables. The first mechanism involves the flow of an externally-induced unbalance current through the outer conductor, and the resulting response across the load. The second and third mechanisms involve and effects which occur in the sending and receiving-end circuite beyond the extent of the coaxial structure. Experimental methods are presented for the measurement of the noise signal components from each of the three mechanisms. Techniques for minimizing the magnitudes of the pickup signals are also suggested.
Sensitivity of quantitative metrics derived from DCE MRI and a pharmacokinetic model to image quality and acquisition parameters.

Rationale and Objectives This study aims to investigate the sensitivity of quantitative metrics derived from dynamic contrast-enhanced (DCE) magnetic resonance imaging and a pharmacokinetic (PK) model to image quality and acquisition parameters. Materials and Methods A computer-synthesized DCE model that consisted of a large range of values of K trans (transfer constant of a paramagnetic contrast agent from blood to tissue), v p (fractional plasma volume), and k ep (back flux rate) was created to test the reliability of quantitative metrics derived from a standard PK model. Effects of the contrast-to-noise ratio (CNR), total acquisition time, and sampling interval on the stability and bias of the derived metrics were investigated. Results The instability and bias of the estimated K trans , v p , and k ep values increased with sampling interval and decreased with increasing CNR. Total acquisition times had limited influence on the estimations of K trans and v p values, but increasing the total acquisition time improved the stability of the estimation of k ep values. However, for small k ep values, the stability was still poor even with a total acquisition time of 8 minutes. Also, the stability and bias of the estimated values of K trans , v p , and k ep are interrelated. Conclusions Our synthesized DCE model represents perfectly reproduced data except for the presence of Gaussian-distributed random noise. Our analysis suggests minimum changes that may be considered potentially significant in longitudinal therapy assessment studies. Our data are complementary to experimental data from human subjects and phantoms, and provide guidance for the design of image acquisition strategies.
Correlates of eating related difficulties among college students: A preliminary investigation

In this preliminary correlational study, sex, dieting, and rigorous eating were compared to three types of eating related difficulties (binge eating, general symptoms of anorexia nervosa, and more specific obsessions about food and weight). As predicted, significant correlations were obtained between being female, dieting, and more rigorous styles of eating and scoring higher on measures of these eating related difficulties. In addition, there were significant correlations between predictor variables. Females reported more dieting and more rigorous eating. Dieting and rigorous eating also were somewhat related. When extent of dieting and rigorous eating was controlled, the association between being female and scoring higher on these measures was somewhat reduced. The association between being female and binge eating no longer retained significance.
Brain abnormalities in human obesity: A voxel-based morphometric study

Obesity is accompanied by damage to several tissues. Overweight is a risk factor for Alzheimer's disease and other neurodegenerative disorders. Whether structural abnormalities associated with excess body fat may also occur in the brain is unknown. We sought to determine to what extent excess body fat is associated with regional alterations in brain structure using voxel-based morphometry (VBM), a whole-brain unbiased technique based upon high-definition 3D magnetic resonance imaging (MRI) scans normalized into a common standard space and allowing for an objective assessment of neuroanatomical differences throughout the brain. We studied 24 obese (11 male, 13 female; age: 32 +/- 8 years; body mass index [BMI]: 39.4 +/- 4.7 kg/m2) and 36 lean (25 male, 11 female; mean age: 33 +/- 9 years; BMI: 22.7 +/- 2.2 kg/m2) non-diabetic Caucasians. In comparison with the group of lean subjects, the group of obese individuals had significantly lower gray matter density in the post-central gyrus, frontal operculum, putamen, and middle frontal gyrus (P < 0.01 after adjustment for sex, age, handedness, global tissue density, and multiple comparisons). BMI was negatively associated with GM density of the left post-central gyrus in obese but not lean subjects. This study identified structural brain differences in human obesity in several brain areas previously involved in the regulation of taste, reward, and behavioral control. These alterations may either precede obesity, representing a neural marker of increased propensity to gaining weight, or occur as a consequence of obesity, indicating that also the brain is affected by increased adiposity.
Relationship of sex, social class and rural/urban locale to preschoolers' AML scores.

Analysis of effects of sex, race, socioeconomic status, and rural/urban locale on AML scores (Aggressive, Moody, Learning Problems) of preschoolers showed that 345 boys evidenced more aggression, learning problems, and adjustment problems than 334 girls. An interaction of race by social status suggested that middle-status blacks showed more aggression, moodiness, and adjustment problems than middle-status whites, low-status blacks, and low-status whites. Discussion focused on the needs for use of separate cut-off scores by sex, and the use of our data and Carberry and Handal's 1980 data as preliminary norms.
Bovine aorta ribonuclease

Abstract 1. 1. A ribonuclease from bovine aorta has been partially purified. 2. 2. The purification procedure involved ethanol fractionation and gel filtration on polyacrylamide and Sephadex. 3. 3. The enzyme is free of deoxyribonuclease, phosphomonoesterase, and cyclic phosphatase activity (under the conditions employed). It exhibited a small amount of diesterase activity using bis ( p- nitrophenyl ) phosphate as substrate. 4. 4. A comparison of the action of the enzyme on poly (C), poly (A), poly (U), poly (I) and RNA with the action of bovine pancreatic ribonuclease is presented. 5. 5. The optimum temperature for activity was about 50° and optimum pH about 7.0.
Reduction of carcinogenic chromium(vi) on the skin of living rats

The reduction of chromate (Cr(VI)) on the skin of living rats was investigated using the technique of in vivo electron paramagnetic resonance (EPR) spectroscopy with a surface coil resonator. Topical application of aqueous solution of Cr(VI) on the skin of rats generated the transient species, Cr(V). Partial removal of the stratum corneum increased the rates of formation and decay of Cr(V), as well as Cr(V) signal intensity. The results demonstrate that skin represents one route for chromium to enter into animals and humans. The generation of reactive Cr(V) species in the reduction of Cr(VI) by the skin may play an important role in the mechanism of Cr(VI)-induced skin cancer. These findings indicate the potential for in vivo EPR spectroscopy for studying the metabolism of paramagnetic reactive species in chemical and biochemical reactions occurring in/on the skin of both small and large animals, and possibly humans.
Phonon propagation with isotope scattering and spontaneous anharmonic decay

Calculations of the propagation of high-energy phonons introduced into a crystal at {ital T}=0 K are presented. The phonons are assumed to undergo elastic scattering and anharmonic decay processes. We show that in addition to the quasidiffusion'' component to the phonon propagation (discussed previously by Levinson and co-workers) there is also a contribution that arrives at close to the time expected for ballistic propagation. This latter mode of propagation continues to be of substantial importance even when the elastic scattering is much stronger than the anharmonic processes.
Using split capabilities for access control

The fundamental problem of access control is to limit what a process can do to an object and when that process can do if. For example, any access control mechanism must know whether to honor a request to read or write a particular file. Unfortunately, the access control mechanisms we use when sharing resources over the Internet were designed in the days when networking computers was a rarity. Many security breakdowns currently occurring come from the resulting mismatch between today's realities and the assumptions made in designing those mechanisms. We developed split capabilities to make the system scalable. If we used conventional capabilities, we would need a capability for every combination of access rights. That's not a problem in some systems where a capability is a single word. However, our design required over 100 bytes per resource. This fact presented us with a problem because of two of our design principles, "every thing is a resource" and "no special cases." Split capabilities allow us to define a single resource that can represent an arbitrary set of access rights to a large set of resources.
Micromethod for zinc protoporphyrin in erythrocytes: Including new data on the absorptivity of zinc protoporphyrin and new observations in neonates and sickle cell disease☆

Abstract Millimolar absorptivity of ZnPROTO in pyridine, 221, and acetone containing 8.2% of 0.5-mole aqueous acetic acid per liter, 211, has been determined on a sample characterized by chromatography, fluorescence spectroscopy, nuclear magnetic resonance spectroscopy, and elemental analysis. These values are substantially higher than previously reported values. A quantitative fluorometric micromethod specific for ZnPROTO in blood is reported. This method gives results equivalent to an FEP method when ZnPROTO is the only species of porphyrin present. If PROTO is also present, the FEP method which measures both, gives a high result. The fraction of PROTO may be calculated from the difference between the FEP and ZnPROTO. In healthy young children with ZnPROTO only, PbB ⪯ 26 and hematocrit ⪰ 36%, the following average values were found: ZnPROTO, 1.28 μ m per liter of erythrocytes; FEP, 1.24 μ m per liter of erythrocytes. Observations in patients show that protoporphyrin is not the only condition in which the concentration of PROTO in erythrocytes is elevated. Increase in PROTO has been found in sickle cell (SS) disease, cord blood from newborns, and in anemic iron deficient children with and without increased lead absorption. Density gradient studies in human cord blood show that PROTO is found in the reticulocyte-rich fraction, as has been reported by others in studies of patients with iron deficiency anemia. The quantitative micromethod for ZnPROTO described here, if used in conjunction with both a standard FEP method and spectrophoto-fluorometry, may prove useful in exploring the significance of elevations in PROTO in these varied clinical conditions.
Temporal databases status and research directions

It seems somehow fitting to begin this paper on databases that store historical information with a chronology, touching briefly on all work that I am aware of in this area. I discuss in some detail what I consider to be the ten most important papers and events in terms of their impact on the discipline of temporal databases. These are emphatically not meant to detract from the other excellent papers in temporal databases. My goal is to characterize the evolution of this field, as an introduction to the approximately 350 papers specifically relating time to databases that have appeared thus far. I then identify and discuss areas where more work is needed.
Factors guiding regenerating retinotectal fibres in the frog Xenopus laevis

I have examined the pathways of retinotectal fibres regenerating back to the contralateral tectum, and also to innervated and ‘virgin’ ipsilateral tecta in postmetamorphic Xenopus . The fibres were visualized by HRP labelling of either the whole optic nerve, or a selected quadrant of the retina. Most fibres grow into either the ipsilateral or contralateral optic tract, although a small proportion go down the outside of the contralateral optic nerve. In the tracts, many fibres grow superficially, close beneath the pia, but a variable proportion runs more deeply. Axonal growth is not, therefore, restricted absolutely to the subpial region in the postmetamorphic Xenopus brain. Fibres growing onto the contralateral, or a ‘virgin’ tectum mostly grow straight onto the rostral margin of the tectal lobe, without growing around its margin in the form of a medial or lateral brachium. Most of these fibres grow through the deeper part of the tectal layer which normally contains optic neuropil, but a proportion of them grow immediately deep to the pia. Fibres regenerating to an innervated ipsilateral tectum mostly enter either the medial or lateral brachium of the optic tract, and only leave this close to their site of termination. In the brachia the fibres run superficially under the pia, but when they leave the brachia they mostly run through the deeper retinorecipient layers. These observations provide further evidence that ingrowing optic fibres have their pathways influenced by the axons which have preceded them.
Therapeutic potential of genetically modified adult stem cells for osteopenia.

Adult stem cells have therapeutic potential because of their intrinsic capacity for self-renewal, especially for bone regeneration. The present study shows the utility of ex vivo modified mesenchymal stem cells (MSC) to enhance bone density in an immunocompetent mouse model of osteopenia. MSC were transduced ex vivo with a recombinant adeno-associated virus 2 (rAAV2) expressing bone morphogenetic protein 2 (BMP2) under the transcriptional control of collagen type-1α promoter. To enrich bone homing in vivo, we further modified the cells to transiently express the mouse α4 integrin. The modified MSC were systemically administered to ovariectomized, female C57BL/6 mice. Effects of the therapy were determined by dual-energy X-ray absorptiometry, 3D micro-CT, histology and immunohistochemistry for up to 6 months. Results indicated that mice transplanted with MSC expressing BMP2 showed significant increase in bone mineral density and bone mineral content (P<0.001) with relatively better proliferative capabilities of bone marrow stromal cells and higher osteocompetent pool of cells compared to control animals. Micro-CT analysis of femora and other bone histomorphometric analyses indicated more trabecular bone following MSC-BMP2 therapy. Results obtained by transplanting genetically modified MSC from green fluorescent protein transgenic mouse suggested that production of BMP2 from transplanted MSC also influenced the mobilization of endogenous progenitors for new bone formation.
Fast Gas Chromatography Analysis of N-Carbamates with Cold On-Column Injection

Direct gas chromatographic (GC) analysis of thermally labile N-carbamates is studied by using fast GC with cold on-column injection. With the greatly reduced injection temperature, short column lengths, high flow rate, and fast temperature-programming rate, the exposure of carbamates to high temperature is reduced and degradation can be avoided. Nine N-carbamates in EPA Method 531 are eluted without thermal decomposition. The relative standard deviation percentage for peak areas average 1.9% for all of the carbamates analyzed. A conventional GC instrument is employed to simplify the experiments. GC-mass spectrometry is used to monitor the decomposition peaks.
Aquatic insects as umbrella species for ecosystem protection in Death Valley National Park

Under the United States Endangered Species Act (ESA), critical habitat for listed species is also protected. Many aquatic insects protected under the ESA are habitat-restricted, mainly to springs. Some of these species do not co-occur with ostensibly more charismatic vertebrates, and have the potential to act as umbrella species for aquatic ecosystems. We suggest that the flightless creeping water bug Ambrysus funebris La Rivers (Insecta: Heteroptera: Naucoridae) has the potential to be such a species. Endemic to a spring system in Death Valley National Park, it co-occurs with eight other endemic aquatic invertebrate species, but with no vertebrates. Therefore, its protection would facilitate protection of this desert oasis. Ambrysus funebris is a candidate for protection under the ESA because of its endemicity, a decline in abundance, and habitat degradation. To facilitate its use as an umbrella species, we report the first illustrated descriptions of the five nymphal instars of Ambrysus funebris La Rivers. Recommendations on its conservation and role as an umbrella species for conserving its habitat are presented. A synopsis of aquatic insect species protected or listed as candidates under the ESA indicates that spring-endemics predominate. We also present a list of potentially threatened and unprotected aquatic heteropterans in the western United States.
Naïve theories of price: A developmental model

A model of the development of naive theories of price is presented and tested. The criterion used to account for price variations within a product category is product features at age five, product features and quality at age ten, product quality and buyer utility at age thirteen, and a combination of supply considerations and buyer utility/demand in adulthood. Five-year-olds do not justify their use of product features as a price criterion; however, older respondents all justify their price criterion by referring to a source of value. At age ten, variation in the amount of manufacturing inputs is the source of value which justifies the use of product features as a price criterion; at age thirteen, variations in the quality of manufacturing inputs justify the use of product quality as a price criterion; and in adulthood, relative scarcity and buyer preferences justify the use of cost and demand as price criteria.
Benefits of Required Counseling for Counseling Students

Graduate students experience mental health distress. The authors investigated the benefits of required counseling services at a training clinic for students enrolled in counseling courses. Results indicated that after receiving services, students (N = 55) reported decreases in overall problems, depressive symptoms, and anxiety symptoms. Implications for counselor educators are discussed.
PEROXISOMES IN INNER ADRENOCORTICAL CELLS OF FETAL AND ADULT GUINEA PIGS

Abundant membrane-bounded granules, 0.1–0.45 µm in diameter, occur among the elements of the smooth-surfaced endoplasmic reticulum in zona fasciculata and zona reticularis adrenocortical cells of guinea pigs. Acid phosphatase cannot be cytochemically demonstrated in them, and they are therefore distinct from lysosomes. Incubation in medium containing 3,3'-diaminobenzidine results in dense staining of the granules, identifying them as peroxisomes. These small peroxisomes increase in number as fetal adrenocortical cells differentiate, and they appear to arise from dilated regions of endoplasmic reticulum. They maintain interconnections with the smooth endoplasmic reticulum and with one another.
Web site redesign: the University of Washington Libraries' experience

Purpose – The purpose of this paper is to make a case study of a large academic library's web site redesign, undertaken during the 2003‐2004 academic year.Design/methodology/approach – During the redesign process, numerous methods of eliciting user feedback were used; this included an online survey, focus groups with each of the Libraries' primary user populations, parallel design process to generate the first round of prototypes, low‐fidelity prototyping, card sorting, high‐fidelity prototyping, and three rounds of usability testing. The results of each type of feedback session were analyzed carefully in order to determine the most important areas for improvement and to provide valuable information regarding how users used the web site.Findings – The design teams spent nine months developing a web site that was grounded in user‐centered design methodologies and employed appropriate usability standards. Feedback from users was sought at every step in the process and in very different ways. From each inter...
Antimicrobial peptides in the female reproductive tract: a critical component of the mucosal immune barrier with physiological and clinical implications

Background At the interface of the external environment and the mucosal surface of the female reproductive tract (FRT) lies a first-line defense against pathogen invasion that includes antimicrobial peptides (AMP). Comprised of a unique class of multifunctional, amphipathic molecules, AMP employ a wide range of functions to limit microbial invasion and replication within host cells as well as independently modulate the immune system, dampen inflammation and maintain tissue homeostasis. The role of AMP in barrier defense at the level of the skin and gut has received much attention as of late. Given the far reaching implications for women's health, maternal and fetal morbidity and mortality, and sexually transmissible and polymicrobial diseases, we herein review the distribution and function of key AMP throughout the female reproductive mucosa and assess their role as an essential immunological barrier to microbial invasion throughout the reproductive cycle of a woman's lifetime. Methods A comprehensive search in PubMed/Medline was conducted related to AMP general structure, function, signaling, expression, distribution and barrier function of AMP in the FRT, hormone regulation of AMP, the microbiome of the FRT, and AMP in relation to implantation, pregnancy, fertility, pelvic inflammatory disease, complications of pregnancy and assisted reproductive technology. Results AMP are amphipathic peptides that target microbes for destruction and have been conserved throughout all living organisms. In the FRT, several major classes of AMP are expressed constitutively and others are inducible at the mucosal epithelium and by immune cells. AMP expression is also under the influence of sex hormones, varying throughout the menstrual cycle, and dependent on the vaginal microbiome. AMP can prevent infection with sexually transmissible and opportunistic pathogens of the female reproductive tissues, although emerging understanding of vaginal dysbiosis suggests induction of a unique AMP profile with increased susceptibility to these pathogens. During pregnancy, AMP are key immune effectors of the fetal membranes and placenta and are dysregulated in states of intrauterine infection and other complications of pregnancy. Conclusions At the level of the FRT, AMP serve to inhibit infection by sexually and vertically transmissible as well as by opportunistic bacteria, fungi, viruses, and protozoa and must do so throughout the hormone flux of menses and pregnancy. Guarding the exclusive site of reproduction, AMP modulate the vaginal microbiome of the lower FRT to aid in preventing ascending microbes into the upper FRT. Evolving in parallel with, and in response to, pathogenic insults, AMP are relatively immune to the resistance mechanisms employed by rapidly evolving pathogens and play a key role in barrier function and host defense throughout the FRT.
Regulation of DNA replication by the S-phase DNA damage checkpoint

Cells slow replication in response to DNA damage. This slowing was the first DNA damage checkpoint response discovered and its study led to the discovery of the central checkpoint kinase, Ataxia Telangiectasia Mutated (ATM). Nonetheless, the manner by which the S-phase DNA damage checkpoint slows replication is still unclear. The checkpoint could slow bulk replication by inhibiting replication origin firing or slowing replication fork progression, and both mechanisms appear to be used. However, assays in various systems using different DNA damaging agents have produced conflicting results as to the relative importance of the two mechanisms. Furthermore, although progress has been made in elucidating the mechanism of origin regulation in vertebrates, the mechanism by which forks are slowed remains unknown. We review both past and present efforts towards determining how cells slow replication in response to damage and try to resolve apparent conflicts and discrepancies within the field. We propose that inhibition of origin firing is a global checkpoint mechanism that reduces overall DNA synthesis whenever the checkpoint is activated, whereas slowing of fork progression reflects a local checkpoint mechanism that only affects replisomes as they encounter DNA damage and therefore only affects overall replication rates in cases of high lesion density.
THE COLUMBIA CRISIS: CAMPUS, VIETNAM, AND THE GHETTO

A survey of student and faculty attitudes and behavior at Columbia University following widespread demonstrations and disorders in the Spring of 1968 found that students and faculty divided in roughly equal proportions on the major issues. Only a small minority favored the sit-in tactics of the demonstrators, but majorities favored some of their major stated goals. Police action that ended the sit-ins slightly increased acceptance of the demonstrators' tactics, but did not change attitudes on issues very much. Attitudes toward the crisis were strongly related to over-all satisfaction with the University and to attitudes toward the ghetto and the Vietnam war. The author is Director of the Bureau of Applied Social Research at Columbia University. This survey was made possible by the support of the Russell Sage Foundation.