cssi/SciSciGPT-SciSciNet huggingface dataset:
Endothelin-1 reduces mesenteric microvascular hydraulic permeability via cyclic AMP and protein kinase A signal transduction

Abstract We have previously shown that endothelin-1 (ET-1) decreases microvascular hydraulic permeability. In this study, we tested the hypothesis that ET-1 exerts its permeability-decreasing effect through cAMP, cGMP, and protein kinase A (PKA) by determining the effect of ET-1 on venular fluid leak during inhibition of cAMP synthesis, inhibition of cGMP degredation, and inhibition of PKA. Rat mesenteric venules were cannulated to measure hydraulic permeability, L p (units × 10 −7 cm/(s cmH 2 O)). L p was measured during continuous perfusion of 80 pM ET-1 and either (1) an inhibitor of cAMP synthesis (10 μM 2′,5′ddA), (2) an inhibitor of cGMP degradation (100 μM Zaprinast), or (3) an inhibitor of PKA (10 μM H-89). Inhibition of cAMP synthesis blocked the permeability decreasing effects of ET-1. The peak L p of the cAMP inhibitor alone and with ET-1 was 4.11 ± 0.53 and 3.86 ± 0.19, respectively ( p = 0.36, n = 6). Inhibition of cGMP degradation did not block the permeability decreasing effects of ET-1. The peak L p during inhibition of cGMP degradation alone and with ET-1 was 2.26 ± 0.15 and 1.44 ± 0.09, respectively ( p n = 6). Inhibition of PKA activation blocked the permeability decreasing effects of ET-1. The peak L p of the PKA inhibitor alone and with ET-1 was 2.70 ± 0.15 and 2.59 ± 0.15, respectively ( p = 0.38, n = 6). The data support the notion that the signal transduction mechanism of ET-1 with regard to decreasing microvascular fluid leak involves cAMP production and PKA activation, but not cGMP degradation. Further understanding of intracellular mechanisms that control microvascular fluid leak could lead to the development of a pharmacologic therapy to control third space fluid loss in severely injured or septic patients.
Broad line quantitative chemical shift spectroscopy.

Proton NMRspectroscopy was applied to quantitate the measurement of total body water/fat distributions i n v i v o. A special MR protocol was developed to excite a thick slab of tissue and display the magnitude NMR spectrum of the collected response signal. Very short echo time TE (8 ms) and long repetition time TR (4000 ms) were used to minimize relaxation damping of the signal intensities. The spectrum was then decomposed into individual lines and proton densities of different species were calculated. Proton density information was converted into weight percentage data using stoichiometrical and physiological information. The technique was validated using phantoms that contained different mixtures of water/maize oil. A high‐resolution NMR spectrum of maize oil samples was used to determine the stoichiometric information. The test results showed good agreement with the known composition of the phantom within the whole range of water content (0–100%). This method is very fast since no phase encoding of data is required. Preliminary results for monkeys show promising potential in clinical applications.
Nonequilibrium steady states of some stochastic lattice gas models

Abstract We describe some recent studies of two stochastic lattice gas models. We summarize different approaches, show both analytical and computational results of the nonequilibrium steady states, and compare them with the corresponding equilibrium situations.
Potential wake encounter analysis in current and NextGen flight operation

Presents a collection of slides covering the following topics: potential wake encounter analysis; NextGen flight operation; wake turbulence; aircraft; airports; wake vortex separations; APA;TASS driven algorithm for wake prediction model; TDAWP; NASA; Monte Carlo simulation; aviation safety reporting system; ASRS and EWEM model.
Defect tolerance for nanocomputer architecture

Defect tolerant architectures will be mandatory for building economical and cheap computing systems with billions of devices of nanometer dimension because it will contain significant number of defects due to statistical variations. The basic idea behind a defect tolerant custom configurable system is to build the system out of partially perfect components, detect the defects and configure the available good resources using software. In this paper we discuss implications of defect tolerance on power, area, delay and other relevant parameters for computing architectures. The additional requirement of a scalable configuration mechanism, redundant components and detection scheme necessitates extra burden on the interconnect to sustain it. Through back-of-envelope calculations using a priori wire length estimation and intuitive arguments we will illustrate the hidden cost of supporting such an architecture.
The Use of Vascularized Grafts From the Distal Radius for the Treatment of Preiser’s Disease

Purpose To examine the outcome of vascularized bone grafts (VBGs) used for the treatment of Preiser's disease. Methods Over a 10-year period (1993–2003) 8 pedicled VBGs were performed as the primary treatment for Preiser's disease. All patients had preoperative magnetic resonance imaging (MRI) scans that confirmed the diagnosis of avascular necrosis of the scaphoid. Bone revascularization was evaluated by examining preoperative and postoperative MRIs. All patients had a reverse-flow pedicled VBG from the distal radius. The average patient age was 40 years and the mean follow-up period was 36 months. Postoperative evaluation included range of motion, grip strength, pain evaluation, and Mayo wrist scores. Results All MRIs showed evidence of revascularization, with improvement in T2 and/or T1 signal; however, a consistent finding on MRI was incomplete revascularization of the entire proximal pole. Wrist motion averaged 55% of the unaffected side after surgery. Grip strength remained stable. Seven patients had long-term improvement in pain. The average Mayo wrist score was 68, with 1 patient rated as excellent, 1 as good, 5 as fair, and 1 as poor. There was 1 reconstructive failure that resulted in a proximal row carpectomy less than 1 year after the surgery. Conclusions In this series VBGs led to reduced pain levels and preserved the radiocarpal wrist motion in most patients. Inability to revascularize the proximal pole of the scaphoid and ongoing wrist arthritis appear to persist despite revascularization attempts. VBGs for Preiser's disease should be limited to patients with early stage disease (Herbert stages I or II) without evidence of radiocarpal arthritis and no evidence of carpal instability. Type of study/level of evidence Therapeutic, Level IV.
STUDIES ON THE METABOLISM OF RADIOPROGESTERONE IN MICE AND RATS

THE synthesis of progesterone-21-C14 (Riegel and Prout 1948) has made possible the investigation of certain specific problems involving the metabolism of the hormone. The presence of C14 at the 21 position serves the dual purpose of labeling the hormone as well as providing a substance suitable for study of the metabolism of the side chain. An important objective of this investigation was to determine whether animals have the ability to oxidatively metabolize the side chain of progesterone. Radioactive carbon dioxide was detected in the expired air of rats and mice after the injection of progesterone-21-C14. This metabolic pathway for the oxidation and elimination of the C-21 carbon atom of progesterone is, therefore, established. A second important objective of this investigation was to determine the distribution of progesterone or its metabolites within the tissues of the animal organism. Various tissues of rats and mice have been shown to possess different capacities for the absorption and retention
The Reality Tour Model: Crossing Boundaries in the Movement to End Poverty

This article presents an organizing tool called a Reality Tour, which has been successfully utilized by activists in the anti-poverty movement. The authors discuss the ideology behind the Tour, exploring the concept of crossing boundaries as a way to educate individuals about social justice and economic human rights. An organizing template is provided so that readers might replicate the Tour in other communities. The authors share lessons learned as well as learning outcomes for the participants. Ongoing organizing dilemmas and areas for future work are also discussed.
Foreign Direct Investment in the United States: The State of Knowledge in Research

This article categorizes and summarizes the major writings published during the 1970s concerning foreign direct investment in the United States. It is based on the authors' analysis of more than 100 works published in the English language. In addition to analyzing what has been published, the article also suggests directions for future research.
Effects of Δ9-tetrahydrocannabinol on copulatory behavior and neuroendocrine responses of male rats to female conspecifics

Male rats exposed to sexually receptive females, exhibit a rapid increase in plasma levels of luteinizing hormone (LH) and prolactin, and concomitant increases in noradrenergic activity in the medial basal hypothalamus (MBH) and median eminence (ME) as well as in dopaminergic activity in the MBH. Delta-9-tetrahydrocannabinol (THC; 5 mg/kg b.wt., PO), the chief psychoactive constituent of marijuana, blocked the MBH and ME noradrenergic response and the dopaminergic response in the MBH in male rats exposed for 20 min to sexually receptive females, and suppressed the expected increases in plasma LH and prolactin levels. Moreover, THC treatment decreased the percentage of animals exhibiting copulatory behavior and increased the latency periods to mount and intromit. These findings indicate that THC interferes with the neuroendocrine and behavioral responses of male rats to the presence of a receptive female.
Zebrafish Zic2a and Zic2b regulate neural crest and craniofacial development.

Abstract Holoprosencephaly (HPE), the most common malformation of the human forebrain, is associated with defects of the craniofacial skeleton. ZIC2 , a zinc-finger transcription factor, is strongly linked to HPE and to a characteristic set of dysmorphic facial features in humans. We have previously identified important functions for zebrafish Zic2 in the developing forebrain. Here, we demonstrate that ZIC2 orthologs zic2a and zic2b also regulate the forming zebrafish craniofacial skeleton, including the jaw and neurocranial cartilages, and use the zebrafish to study Zic2-regulated processes that may contribute to the complex etiology of HPE. Using temporally controlled Zic2a overexpression, we show that the developing craniofacial cartilages are sensitive to Zic2 elevation prior to 24 hpf. This window of sensitivity overlaps the critical expansion and migration of the neural crest (NC) cells, which migrate from the developing neural tube to populate vertebrate craniofacial structures. We demonstrate that zic2b influences the induction of NC at the neural plate border, while both zic2a and zic2b regulate NC migratory onset and strongly contribute to chromatophore development. Both Zic2 depletion and early ectopic Zic2 expression cause moderate, incompletely penetrant mispatterning of the NC-derived jaw precursors at 24 hpf, yet by 2 dpf these changes in Zic2 expression result in profoundly mispatterned chondrogenic condensations. We attribute this discrepancy to an additional role for Zic2a and Zic2b in patterning the forebrain primordium, an important signaling source during craniofacial development. This hypothesis is supported by evidence that transplanted Zic2-deficient cells can contribute to craniofacial cartilages in a wild-type background. Collectively, these data suggest that zebrafish Zic2 plays a dual role during craniofacial development, contributing to two disparate aspects of craniofacial morphogenesis: (1) neural crest induction and migration, and (2) early patterning of tissues adjacent to craniofacial chondrogenic condensations.
Evaluation of Test Statistics for Robust Structural Equation Modeling With Nonnormal Missing Data

A 2-stage robust procedure as well as an R package, rsem, were recently developed for structural equation modeling with nonnormal missing data by Yuan and Zhang (2012). Several test statistics that have been used for complete data analysis are employed to evaluate model fit in the 2-stage robust method. However, properties of these statistics under robust procedures for incomplete nonnormal data analysis have never been studied. This study aims to systematically evaluate and compare 5 test statistics, including a test statistic derived from normal-distribution-based maximum likelihood, a rescaled chi-square statistic, an adjusted chi-square statistic, a corrected residual-based asymptotical distribution-free chi-square statistic, and a residual-based F statistic. These statistics are evaluated under a linear growth curve model by varying 8 factors: population distribution, missing data mechanism, missing data rate, sample size, number of measurement occasions, covariance between the latent intercept and s...
AUDIOMETRIC ASSESSMENT OF NORTHERN FUR SEALS, CALLORHINUS URSINUS

Aerial and underwater audiograms for two young female northern fur seals (Callorhinus ursinus) and one young female California sea lion (Zalophus californianus) were obtained with the same procedure and apparatus. Callorhinus hears over a larger frequency range and is more sensitive to airborne sounds than Zalophus or any other pinniped thus far tested in the frequency range of 500 Hz to 32 kHz. Sensitivity of Callorhinus to waterborne pure tones, ranging from 2 to 28 kHz, is equal or superior to all other pinnipeds tested in this same frequency range. Like Zalophus, the upper frequency limit for underwater hearing (as defined by Masterton et al. 1969) in Callorhinus is about one-half octave lower than the three phocid species thus far tested. Callorhinus' upper frequency limit in air is about 36 kHz and under water it is about 40 kHz. Comparison of air and water audiograms shows Callorhinus is no exception to previous behavioral findings demonstrating that the „pinniped ear” is more suitable for hearing in water than in air. Similar to Zalophus and Phoca vitulina, Callorhinus shows an anomalous hearing loss at 4 kHz in air. The basis for this insensitivity to airborne sounds at 4kHz and not at lower or higher frequencies is presumably caused by specialized middle ear mechanisms matching impedance for waterborne sounds. Critical ratio curves for Callorhinus are similarly shaped to ones obtained for humans but are shifted upwards in frequency. Compared to all other marine mammals thus far evaluated, the critical ratios for Callorhinus are the smallest yet reported.
Equation of state modeling of high-pressure, high-temperature hydrocarbon density data

Abstract Experimental densities are reported for n-pentane, n-octane, cyclooctane, 2,2,4-trimethylpentane, n-decane, and toluene to ∼280 MPa and ∼250 °C. These densities are in good agreement with available literature data that typically cover lower pressure and temperature ranges than those reported here. The data are modeled with the Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK) cubic equations, the temperature-dependent, volume-translated SRK equation, the temperature- and density-dependent SRK equation, and the SAFT and PC-SAFT equations. Mean absolute percentage deviation (MAPD) values between densities calculated with the PR equation and literature data are 4.55 for n-pentane, 2.91 for n-octane, 3.68 for cyclooctane, 3.98 for 2,2,4-trimethylpentane, 5.58 for n-decane, and 1.99 for toluene. With the exception of 2,2,4-trimethylpentane, these MAPD values are substantially better than those obtained with the SRK and modified SRK equations. Although both SAFT-based models have MAPD values significantly lower than those with the PR equation, the PC-SAFT equation provides the lowest MAPD values.
RNA aptamers selected against the GluR2 glutamate receptor channel.

The excessive activation of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors, a subtype of glutamate ion channels, has been implicated in various neurological diseases such as cerebral ischemeia and amyotrophic lateral sclerosis. Inhibitors of AMPA receptors are drug candidates for potential treatment of these diseases. Using the systematic evolution of ligands by exponential enrichment (SELEX), we have selected a group of RNA aptamers against the recombinant GluR2Qflip AMPA receptor transiently expressed in HEK-293 (human embryonic kidney) cells. One of the aptamers, AN58, is shown to competitively inhibit the receptor. The nanomolar affinity of AN58 rivals that of NBQX (6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione), one of the best competitive inhibitors. Like NBQX, AN58 has the highest affinity for GluR2, the selection target, among all AMPA receptor subunits. However, AN58 has a higher selectivity for the GluR4 AMPA receptor subunit and remains potent even at pH = 6.8 (i.e.,...
Mixture growth models of RAN and RAS row by row: insight into the reading system at work over time

Children (n = 122) and adults (n = 200) with dyslexia completed rapid automatic naming (RAN) letters, rapid automatic switching (RAS) letters and numbers, executive function (inhibition, verbal fluency), and phonological working memory tasks. Typically developing 3rd (n = 117) and 5th (n = 103) graders completed the RAS task. Instead of analyzing RAN/RAS results the usual way (total time), growth mixture modeling assessed trajectories of successive times for naming 10 symbols in each of five rows. For all three samples and both RAN and RAS, two latent classes were identified. The “faster” class performed slowly on the first row and increased time by small increments on subsequent rows. The “slower” latent class performed more slowly on the first row, and children, but not adults, increased time by larger increments on subsequent rows. For children, both the initial row (automaticity index) and slope (sustained controlled processing index) of the trajectory differentiated the classes. For adults, only the initial row separated the classes. The longest time was on row 3 for RAN and row 4 for RAS. For the typically developing 5th graders, close in age to the children with dyslexia, the trajectories were flatter than for children with dyslexia and only the slower class (4%) showed the peak on row 4. For children with dyslexia, inhibition predicted RAN slope within the slower latent class and phonological working memory predicted RAS slope for both latent classes. For adults with dyslexia, inhibition and phonological working memory differentiated both latent classes on RAN intercept and RAS slope. Taken together, RAN, which may assess the phonological loop of working memory, and RAS, which may assess the central executive in working memory, may explain the timing deficit in dyslexia in sustaining coordinated orthographic-phonological processing over time.
Differential reward conditioning: S− contrast as a function of the magnitude of S+

Forty-two rats received 19, 10, or 1 pellets of food reward in one (S+) of two runways of different brightness. In the other runway (S−) all Ss received 1 pellet. In the initial segments of the response chain speeds in S− were an inverse function of reward magnitude in S+. Response speeds in S+ did not differ significantly.
First report of bacterial fruit blotch of watermelon caused by Acidovorax avenae subsp. citrulli in Illinois.

In August 2001, symptomatic mature fruit of watermelon (Citrullus lanatus) cvs. Crimson Sweet and Royal Sweet were collected from six fields (48 ha) in Iroquois, Kankakee, and Mason counties in Illinois. The fruit surface had dark green, water-soaked lesions, and the rind's epidermis was cracked. Sections of infected rind were examined with a light microscope, and bacterial streaming was observed. Rind tissue was disinfested by rubbing the fruit surface with a paper towel moistened with 70% ethanol. Pieces of rind from the margins of lesions were placed in a test tube containing sterile-distilled water. The tube was shaken, and the suspension was streaked on King's medium B agar in petri plates. The plates were incubated at 26°C for 3 days. A nonfluorescent, gramnegative, anaerobic, oxidase-positive, rod-shaped bacterium was isolated that produced creamy white colonies on nutrient agar. The bacterium was identified as Acidovorax avenae subsp. citrulli based on an enzyme-linked immunosorbent assay test specific for A. avenae subsp. citrulli (kit PSA 14,800; Agdia Inc., Elkhart, IN). The disease was diagnosed as bacterial fruit blotch (1,2). The occurrence of bacterial fruit blotch of watermelon in Illinois is important because (i) watermelon is widely grown in Illinois, (ii) the pathogen also infects melons and pumpkins, and (iii) Illinois grows approximately 1,000 ha of melons and 8,000 ha of pumpkins. References: (1) R. X. Latin. Bacterial fruit blotch. Pages 34-35 in: Compendium of Cucurbit Diseases. The American Phytopathological Society, St. Paul, MN,1996. (2) G. S. Somodi et al. Plant Dis. 75:1053, 1991.
Potato quality XX: After-Cooking darkening in potatoes as related to the distribution of radioiron

Radiotracer techniques were used to correlate the distribution of iron with the distribution of after-cooking darkening in cooked potatoes. Autoradiographs of cooked tubers showed that while radioiron was found throughout the tuber, the greatest concentration was found in the stem end and around lateral buds. A visual comparison of photographs of tubers showing after-cooking darkening with autoradiographs of the same tubers showed that the areas of radioiron concentrations corresponded closely to the darkened areas of the tuber. No after-cooking darkening or areas of iron concentration were found at the apical ends of cooked potato tubers. Regardless of the other constituents which affect the discoloration reaction, after-cooking darkening occurs only in areas of the potato tuber where iron is concentrated.
Resolution of Headache and Papilledema in Idiopathic Intracranial Hypertension Associated With Inhibition of Na+-K+-2Cl- Cotransport:

Medical treatment of idiopathic intracranial hypertension is often ineffective. Cerebrospinal fluid diversion or optic nerve sheath fenestration is employed when medical therapy fails. Here, we describe a case of a 13-year-old girl with idiopathic intracranial hypertension refractory to long-term trials of acetazolamide and furosemide at maximally tolerated doses. After declining surgical intervention despite progression of her visual symptoms, a trial of bumetanide (0.25 mg daily) monotherapy was successful in resolution of the patient’s symptoms. These results suggest bumetanide could be effective in the treatment of idiopathic intracranial hypertension, perhaps by restoring the balance between cerebrospinal fluid formation and absorption and/or by altering the volume or ionic composition of the brain’s extracellular fluid compartment.
ON-THE-FLY CUSTOMIZATION OF AUTOMATED ESSAY SCORING

Because there is no commonly accepted view of what makes for good writing, automated essay scoring (AES) ideally should be able to accommodate different theoretical positions, certainly at the level of state standards but also perhaps among teachers at the classroom level. This paper presents a practical approach and an interactive computer program for judgment-based customization. This approach is based on the AES system, e-rater®. Through this new approach, a user can gain easy accessibility to system components, flexibility in adjusting scoring parameters, and procedures for making scoring adjustments that can be based on only a few benchmark essays. The interactive prototype program that implements this approach allows the user to customize e-rater and watch the effect on benchmark essay scores as well as on score distributions for a reference testing program of the user's choice. The paper presents results for the use of this approach in customizing e-rater to the standards of different assessments.
Sink or swim: lipid rafts in parasite pathogenesis

Lipid rafts, sterol- and sphingolipid-rich membrane microdomains, have been extensively studied in mammalian cells. Recently, lipid rafts have been shown to control virulence in a variety of parasites including Entamoeba histolytica, Giardia intestinalis, Leishmania spp., Plasmodium spp., Toxoplasma gondii, and Trypanosoma spp. Parasite rafts regulate adhesion to host and invasion, and parasite adhesion molecules often localize to rafts. Parasite rafts also control vesicle trafficking, motility, and cell signaling. Parasites disrupt host cell rafts; the dysregulation of host membrane function facilitates the establishment of infection and evasion of the host immune system. Discerning the mechanism by which lipid rafts regulate parasite pathogenesis is essential to our understanding of virulence. Such insight may guide the development of new drugs for disease management.
Interactions between the environmental pathogen Listeria monocytogenes and a free‐living protozoan (Acanthamoeba castellanii)

Summary Listeria monocytogenes can cause severe disease in animal hosts, but it has no recognized animal host reservoir. We tested the hypothesis that L. monocytogenes retains virulence traits to survive predation by amoebae and that listeriolysin O plays a crucial role in this process. Co-culturing of L. monocytogenes and Acanthamoeba castellanii demonstrated that L. monocytogenes does not actively kill amoebae, but in the presence of amoebae, high bacterial population densities can be maintained over a period of at least 96 h. A gentamicin protection assay demonstrated that there is no significant difference in the ability to survive predation between serovars (4b versus 1/2a and 1/2c; P = 0.08) and between five species of Listeria (P = 0.14). Three of these species do not harbour the hly gene responsible for listeriolysin O production. A hly knockout strain had poorer survival compared with the parental strain (P = 0.04 at 24 h; P = 0.04 at 48 h; P = 0.02 at 72 h) and electron microscopy was consistent with a wild-type strain being able to escape the phagosome whereas the hly knockout strain did not appear to have this ability. Thus, while there is weak evidence that listeriolysin O can contribute to improved survival after ingestion by amoebae, listeriolysin O does not appear to provide a significant selective advantage under the conditions of this study.
Determinants of Peak V.o2 in Peripheral Arterial Occlusive Disease Patients

Peripheral arterial occlusive disease (PAOD) patients with intermittent claudication are functionally limited and deconditioned. This study examined whether peak aerobic capacity (V(O2) peak) was associated with PAOD severity, muscle mass, and comorbidities in 109 PAOD patients (93 men and 16 women) aged 48-86 years. The V(O2) peak (1.12+/-0.34 L/min), percentage body fat (30.6+/-8.3%), lean tissue mass of the total body (51.4+/-8.4 kg), lean tissue mass of the legs (16.6+/-3.0 kg), and appendicular skeletal mass (22.8+/-4.2 kg) were determined. The lean tissue mass of the total body (r = .44), lean tissue of the legs (r = .43) and resting ankle/brachial systolic pressure index (ABI; r = .41) correlated with peak V(O2) (all p < .001). None of the comorbidity variables (obesity, arthritis, coronary artery disease, hypertension, diabetes, and smoking history) were significantly associated with peak V(O2) except smoking status. The final model for the prediction of peak V(O2) included lean tissue mass of the legs, resting ABI, smoking status, and ABI x smoking status (r2 = .37,p < .001). In older patients with intermittent claudication, lean tissue mass is an important determinant of physical performance independent of PAOD severity and smoking status. Prevention of muscle atrophy may preserve ambulatory function and peak exercise capacity in older PAOD patients.
Web-based instruction in China: Cultural and pedagogical implications and challenges

The Internet, the Web, and WBI are vital for learners all over the world to gather and exchange information, to communicate and interact, and to learn. Since the open-door policy was implemented in China more than 20 years ago, advocates of the Internet have continuously urged the Chinese government to adopt a less restricted policy for Internet use. However, the Internet is characteristically Western and may convey an unwanted Western bias. Strategies that will help prevent the negative influence from using the Westernized Internet are needed. It is recommended that the Chinese government reform the current test-driven educational system, provide better technological training for teachers and students, have appropriate technological resources for students in the less-developed areas, and implement more quality WBI that is conducive to constructivist learning.
Non-tryptophan fluorescence associated with human lens protein; apparent complexity and isolation of bityrosine and anthranilic acid.

Abstract In order to characterize the age-related protein bound fluorescent compounds of human cataractous lenses, the insoluble yellow protein component was proteolytically digested and then fractionated using ion-exchange, gel filtration and high pressure liquid chromatography. A complex and heterogeneous mixture of fluorescent components was found to be associated with these lens proteins. In the course of this study 3,3′-bityrosine and anthranilic acid were structurally identified as constituents of the proteolytic hydrolysate. The latter compound appears to be a degradation product of an unstable precursor.
Mapping and monitoring conifer mortality using remote sensing in the Lake Tahoe Basin

Abstract A prolonged drought in the western United States has resulted in alarming levels of mortality in conifer forests. Satellite remote sensing holds the potential for mapping and monitoring the effects of such environmental changes over large geographic areas in a timely manner. Results from the application of a forest canopy reflectance model using multitemporal Landsat TM imagery and field measurements, indicate conifer mortality can be effectively mapped and inventoried. The test area for this project is the Lake Tahoe Basin Management Unit in the Sierra Nevada of California. The Landsat TM images are from the summers of 1988 and 1991. The Li-Strahler canopy model estimates several forest stand parameters, including tree size and canopy cover for each conifer stand, from reflectance values in satellite imagery. The difference in cover estimates between the dates forms the basis for stratifying stands into mortality classes, which are used as both themes in a map and the basis of the field sampling design. Field measurements from 61 stands collected in the summer of 1992 indicate 15 % of the original timber volume in the true fir zone died between 1988 and 1992. The resulting low standard error of 11 % for this estimate indicates the utility of these mortality classes for detecting areas of high mortality. Also, the patterns in the estimated mean timber volume loss for each class follow the expected trends. The results of this project are immediately useful for fire hazard management, by providing both estimates of the degree of overall mortality and maps showing its location. They also indicate current remote sensing technology may be useful for monitoring the changes in vegetation that are expected to result from climate change.
Growth and survival of Escherichia coli and enterococci populations in the macro-alga Cladophora (Chlorophyta)

The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4°C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g−1 in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.
Experimental demonstration of an acousto-optic system for two-dimensional phased-array antenna scanning

A novel in-line interferometric acousto-optic architecture for two-dimensional beam scanning of planar phased arrays is demonstrated experimentally for a 330-MHz carrier. The required modulo-2π phase control along the two orthogonal antenna-array directions is achieved by using two independent control frequencies f1 and f2 with frequency variations of 0–170 and 0–210 kHz, respectively. A processor output carrier signal-to-noise ratio of 48 dB at +1-MHz offset is measured in an analyzer bandwidth of 300 kHz, with a carrier tuning range of 90 MHz.
Design, implementation, and evaluation of a Revision Control System

The Revision Control System (RCS) is a software tool that helps in managing multiple revisions of text. RCS automates the storing, retrieval, logging, identification, and merging of revisions, and provides access control. It is useful for text that is revised frequently, for example programs and documentation.This paper presents the design and implementation of RCS. Both design and implementation are evaluated by contrasting RCS with SCCS, a similar system. SCCS is implemented with forward, merged deltas, while RCS uses reverse, separate deltas. (Deltas are the differences between successive revisions.) It is shown that the latter technique improves run-time efficiency, while requiring almost no extra space.
The effect of H2O gas on volatilities of planet-forming major elements: I. Experimental determination of thermodynamic properties of Ca-, Al-, and Si-hydroxide gas molecules and its application to the solar nebula

The vapor pressures of Ca(OH)2(g), Al(OH)3(g), and Si(OH)4(g) molecules in equilibrium with solid calcium-, aluminum, and silicon-oxides, respectively, were determined, and were used to derive the heats of formation and entropies of these species, which are expected to be abundant under the currently postulated physical conditions in the primordial solar nebula. These data, in conjunction with thermodynamic data from literature, were used to calculate the relative abundances of M, MO(x), and M(OH)n gas species and relative volatilities of Fe, Mg, Si, Ca, and Al for ranges of temperature, total pressure, and H/O abundance ratio corresponding to the plausible ranges of physical conditions in the solar nebula. The results are used to explain how Ca and Al could have evaporated from Ca,Al-rich inclusions in carbonaceous chondrites, while Si, Mg, and Fe condensed onto them during the preaccretion alteration of CAIs.
Indium transients in the growth of InGaAs by metal-organic chemical vapor deposition

Abstract A study of indium transients in the growth of InGaAs-AlGaAs and InGaAs-GaAs heterostructures is described for samples grown by atmospheric-pressure metal-organic chemical vapor deposition (MOCVD) using trimethylindium (TMIn) and an interrupted growth process. No evidence of large compositional transients and rapid decays in the indium signal are observed in analysis of secondary ion mass spectrometry (SIMS) and sputtered neutral mass spectrometry (SNMS) data taken at the interfaces of both InGaAs-GaAs strained-layer superlattice structures and InGaAs-AlGaAs laser structures.
The optical activity of polypeptides

The present status of the theory of the optical properties of polypeptides is discussed in a general way. Arguments are presented that indicate that the interaction of exciton bands in helices will occur in a tensorial way with the parallel polarized bands normally having stronger interactions than the perpendicular polarized bands, with only small cross-interactions. The net result is an anisotropy of the hyperchromism of the ππ* band and an imbalance of the rotatory strengths of the parallel and perpendicular components. According to the evidence of Mandel and Holzwarth [(1973) Biopolymers13, 655–674], this is, in fact, the origin of the strongly nonconservative CD bands of polyproline II and related structures. The implications of anisotropic hyperchromicity on the interpretation of the linear dichroism of crystals is discussed.
Identification and characterization of a cDNA encoding cytochrome P450 3A from the fresh water teleost medaka (Oryzias latipes).

A new member of the CYP3A gene family has been cloned from the teleost fish medaka (Oryzias latipes) by reverse-transcriptase polymerase chain reaction (RT-PCR). Degenerate primers homologous to highly conserved regions of known CYP3A sequences were used for initial RT-PCRs. Individual PCR products were cloned, sequenced, and identified as those belonging to the cytochrome P450 superfamily based on amino acid sequence similarity and the presence of the highly conserved heme-binding region. PCR products were subsequently used as probes to screen a complementary DNA library. A full-length cDNA clone was identified containing a 1758-base-pair (bp) insert with an open reading frame encoding a single peptide of 500 amino acids. Comparisons of the deduced amino acid sequence to other known cytochrome P450 sequences indicate that this gene product is most similar to the CYP3A gene family and has been designated as CYP3A38 by the cytochrome P450 nomenclature committee. Northern blot analysis identified two abundant CYP3A related transcripts in liver of both male and female adults and demonstrated quantitative differences in abundance according to gender. Similarly, Western blot analysis demonstrated the presence of two abundant cytochrome P450 related proteins in liver of both male and female adults. These results suggests that O. latipes contains multiple forms of CYP3A. Heterologous expression of CYP3A38 cDNA in HEK 293 cells produced a single protein that was reactive with anti-scup P450A (CYP3A) polyclonal antibody. Microsomes of HEK 293 cells expressing recombinant CYP3A38 protein actively catalyzed the hydroxylation of testosterone.
The nonexistence of almost continuous surjections between certain continua

Abstract Theorems about the nonexistence of continuous surjections between continua and related results are extended to almost continuous surjections. Several questions are posed.
Two-dimensional vibratory impact with chaos

Abstract Two-dimensional vibratory impact is investigated analytically. A sphere, idealized as a point mass, bounces on a massive flat horizontal surface, all points of which translate with circular motion in a vertical plane. The sphere is constrained to move in a plane of oscillation. The impact is modeled using two parameters, the traditional coefficient of restitution and the impulse ratio. The latter is determined by the kinematics and the coefficient of friction. Between impacts the sphere follows a parabolic trajectory under the influence of gravity. Regions of periodic and chaotic responses are observed. Higher order periodic motions are achieved through period-doubling bifurcations. Even though the normal and tangential components of the trajectory are coupled through the impact model, changes in the friction coefficient have no effect on the normal motions. Frictionless periodic motions remain periodic and of the same order in the presence of friction. Transition to chaos is also unaffected by friction. When normal motion is periodic, tangential motion is periodic, and when normal motion is chaotic, tangentical motion is also chaotic.
Use of visible and infrared reflectance and luminescence imaging spectroscopy to study illuminated manuscripts: pigment identification and visualization of underdrawings

Site specific, in situ techniques such as X-ray fluorescence (XRF) and Raman spectroscopy are commonly used to identify pigments on illuminated manuscripts. With both techniques, spectra are usually acquired on visually identified sites thought to be representative of the pigments and mixtures used for the illumination. Such visual inspection may not always ensure an adequate representation of the pigment diversity. Here we report on the application of multispectral (MSI) visible/infrared reflectance and luminescence imaging spectroscopy, along with fiber optics reflectance spectroscopy (FORS) to help determine and map the primary pigments in a late 14th century miniature on vellum, attributed to Niccolo da Bologna and representing the birth of John the Baptist. XRF analyses of visually selected sites found elements consistent with azurite, ultramarine, vermillion, lead white, "mosaic gold" and yellow earth pigments. Visible/infrared FORS analyses confirmed these assignments and showed evidence for the use of organic dyes. The spectral analysis of the MSI-reflectance images gave distribution maps for these pigments (i.e., regions of azurite, ultramarine, vermillion) along with some indication of pigment layering not identified visually. The luminescence image gave a probable map of the organic dye(s). Images acquired in the near- and shortwave-infrared (NIR and SWIR, 750 to 2400 nm) revealed preparatory sketches and illumination techniques. These results show, like those of a prior study carried out on another 14th century Italian miniature, that the combination of low light multi-spectral imaging spectroscopy with FORS provides improved in situ mapping and identification of pigments on illuminated manuscripts.
Effects of dominant-negative lac repressor mutations on operator specificity and protein stability

The specific binding of dominant-negative (I-d) lactose (lac) repressors to wild-type (wt) as well as mutant (Oc) lac operators has been examined to explore the sequence-specific interaction of the lac repressor with its target. Mutant lacI genes encoding substitutions in the N-terminal 60 amino acids (aa) were cloned in a derivative of plasmid pBR322. Twelve of these lacI-d missense mutations were transferred from F'lac episomes using general genetic recombination and molecular cloning, and nine lacI missense mutations were recloned from M13-lacI phages [Mott et al., Nucl. Acids Res. 12 (1984) 4139-4152]. The mutant repressors were examined for polypeptide size and stability, for binding the inducer isopropyl-beta-D-thiogalactoside (IPTG), as well as binding to wt operator. The mutant repressors' affinities for wt operator ranged from undetectable to about 1% that of wt repressor, and the mutant repressors varied in transdominance against repressor expressed from a chromosomal lacIq gene. Six of the I-d repressors were partially degraded in vivo. All repressors bound IPTG with approximately the affinity of wt repressor. Repressors having significant affinity for wt operator or with substitutions in the presumed operator recognition helix (aa 17-25) were examined in vivo for their affinities for a series of single site Oc operators. Whereas the Gly-18-, Ser-18- and Leu-18-substituted repressors showed altered specificity for position 7 of the operator [Ebright, Proc. Natl. Acad. Sci. USA 83 (1986) 303-307], the His-18 repressor did not affect specificity. This result may be related to the greater side-chain length of histidine compared to the other amino acid substitutions.
A high stability optical frequency reference based on thermal calcium atoms

Here we report an imprecision below 10−14 with a simple, compact optical frequency standard based upon thermal calcium atoms. Using a Ramsey-Borde spectrometer we excite features with linewidths 0 -3P 1 intercombination line at 657 nm. We have measured a fractional frequency instability below 6 × 10−15 at 1 s, with good prospects for still quieter performance. The key remaining issue for this standard is how well first- and second-order Doppler drifts can be suppressed. Due to its experimental simplicity such a system could find application as a less accurate, but high stability reference for commercial applications.
The effects of vascular smooth muscle caldesmon on force production by ‘desensitised’ skeletal muscle fibres

Smooth muscle caldesmon inhibits actomyosin MgATPase in the absence of Ca2+ and is the key regulatory component of Ca2+-regulated thin filaments. We now show that caldesmon can affect contractility as well. Glycerinated skeletal muscle fibres were treated so as to produce substantial contractions without Ca2+ as an activator. Addition of caldesmon caused reductions in force in a concentration- and time-dependent manner. Perfusion with caldesmon concentrations for < 5 min gave up to 48% reduction in isometric tension with a half-maximal effect at 1.5 μm caldesmon. Perfusion with 15 μM caldesmon for 30 min gave an irreversible tension drop.
PUBLIC EDUCATION UNDER CRITICISM by Scott and Hill. Prentice Hall. 404 pp. $4.75

(1955). PUBLIC EDUCATION UNDER CRITICISM by Scott and Hill. Prentice Hall. 404 pp. $4.75. The Educational Forum: Vol. 19, No. 3, pp. 375-375.
Molecular diversity of voltage-sensitive Na channels.

In a wide variety of electrically excitable cells, voltage-sensitive Na channels are responsible for propagation of the action potential. They conduct the inward depolarizing Na+ currents and are regulated by steeply voltage­ dependent gating mechanisms. Their biophysical behavior, pharmacology and, more recently, biochemical properties have been intensively studied. However, it is primarily because of direct structural information derived from molecular cloning studies that our attention has been drawn to an unexpected molecular diversity among Na channels, both between different species and within a single organism. This brief review emphasizes new findings on variations in Na channel structure derived from molecular biological data. Considered in light of structural models, each variant represents, in effect, a naturally occurring mutation, providing clues about what may be essential and nonessential for channel function. We discuss implications of "divergence" of channels from different species and "diversity" of channels within a species. While some pharmacological and biochemical findings are presented, these topics are more comprehensively reviewed elsewhere (1, 6, 12, 13, 25, 71).
Associations of alleles of the esterase 1 locus with gene arrangements of the left arm of the second chromosome in Drosophila robusta

Evidence of strong associations of Est-1 alleles with the 2L, 2L1 and 2L3 gene arrangements of the left arm of the second chromosome in D. robusta is presented. Each gene arrangement is polymorphic for three to four Est-1 alleles. The allele frequencies differ in the 2L3 and 2L arrangements; the allele Est-1.92 is 8% in the 2L3 arrangement (n=203)—this allele is 82% in the 2L arrangement (n=203); the allele Est-11.0 is 66% and 14.8% in the 2L3 and 2L arrangements, respectively. There are no differences in allele frequencies in 2L3 arrangements from any of the widely separated seven different populations; similarly the allele frequencies in the 2L arrangement are alike in all five widely separated populations studied. The allele frequencies in the 2L1 arrangement are intermediate to those observed in the 2L3 and the 2L arrangements and show north-south clinal change. These associations between Est-1 alleles and gene arrangements of the left arm of the second chromosome are due to natural selection favoring different allele frequencies in different gene arrangements, as a result of epistatic interactions between the Est-1 locus and the loci on the gene arrangements. As expected, we observe that the proportion of heterozygotes is greater in the inversion heterokaryotypes than in the homokaryotypes.