cssi/SciSciGPT-SciSciNet huggingface dataset:
THE DISPLAY OF LANDSAT DATA AT LARGE SCALES BY MATRIX PRINTER

Lineprinter images of digital Landsat multispectral data may be conveniently and economically displayed on standard line-printer paper by using a matrix printer. DOTPRINT images at nominal scales of 1:24,000, 1:50,000, and I:62,500 are produced. These images may be compared with maps and aerial photographs to locate terrain features within about a 1 percent scale error. Other smaller scales may be produced by averaging row-by-column pixels. More precise geometry is obtained by using control points and regression equations which permits features to be located to the nearest half-pixel over an area the size of a 15-minute quadrangle. Color infrared images and color classifications (geological maps) may be produced from several DOTPRINTs by overprinting channel- or ratio-images of different colors on the same piece of paper.
Pathogen kinetics and heat and mass transfer-based predictive model for Listeria innocua in irregular-shaped poultry products during thermal processing.

The increasing demand of ready-to-eat poultry products has led to serious concerns over product safety, and more emphasis has been placed on thorough cooking of products. In this study, processing conditions and thermal inactivation of Listeria innocua in chicken breast meats were evaluated during convection cooking in a pilot-plant scale air-steam impingement oven. A predictive model was developed by integrating heat and mass transfer models with a pathogen kinetics model to predict temperature, water content, product yield, and bacterial inactivation during air-steam impingement cooking. Skinless boneless chicken breasts were cooked at oven air temperatures of 177 and 200°C for 2 to 10 min at a humidity of 70 to 75% (moisture by volume) and an air velocity of 1 m/s at the exit of the nozzles. The reduction in Listeria in chicken breasts after 2 to 5 min of cooking was from 0.3 to 1.4 log CFU/g and from 0.8 to 1.8 log CFU/g at 177 and 200°C, respectively. After cooking for 10 min at both temperatures, no...
Identity Development and Attachment to Parents in College Students.

Previous research reveals the need to study adolescents' levels of exploration and commitment instead of overall identity categories for the purpose of identifying developmental trends in identity development. Similarly, attachment research points to the importance of considering separate measures of attachment to mother and attachment to father, as well as considering gender differences in attachment to parents. We tested the hypothesis regarding the relative levels of the identity-related constructs of commitment and exploration in relationship to adolescent males' and females' attachment to parents. The self-report data from 100 first-year college students suggests that females had significantly higher levels of exploration and commitment than the male subjects. Females' identity development was related to attachment relationships to parents, especially attachment to mother, while males' identity development was unrelated to attachment to either parent. These findings are discussed in terms of their implications for the development of university student services.
Specification and Analysis of Transactions in Real-Time Active Databases

The distinction between real-time and non real-time database systems lies in the timing constraints associated with transactions and data values in the real-time database systems. In real-time database systems, transactions have to complete before deadlines, and they have to read data values which are temporally valid because data values may become stale with the passage of time. Missing deadlines or using stale data may cause disastrous results in safety critical real-time applications. Examples of such applications include network services databases[9], autopilot systems, industrial plant control and robot navigation. The reliability of such software systems has been of much concern to designers and users. But there has been no work to formalize the properties of transactions in real-time active databases. In this paper, we attempt to address this lacuna.
Two-Dimensional Patterns in Bacterial Veils Arise from Self-generated, Three-Dimensional Fluid Flows

The behavior of collections of oceanic bacteria is controlled by metabolic (chemotaxis) and physical (fluid motion) processes. Some sulfur-oxidizing bacteria, such as Thiovulum majus, unite these two processes via a material interface produced by the bacteria and upon which the bacteria are transiently attached. This interface, termed a bacterial veil, is formed by exo-polymeric substances (EPS) produced by the bacteria. By adhering to the veil while continuing to rotate their flagella, the bacteria are able to exert force on the fluid surroundings. This behavior induces a fluid flow that, in turn, causes the bacteria to aggregate leading to the formation of a physical pattern in the veil. These striking patterns are very similar in flavor to the classic convection instability observed when a shallow fluid is heated from below. However, the physics are very different since the flow around the veil is mediated by the bacteria and affects the bacterial densities. In this study, we extend a model of a one-dimensional veil in a two-dimensional fluid to the more realistic two-dimensional veil in a three-dimensional fluid. The linear stability analysis indicates that the Peclet number serves as a bifurcation parameter, which is consistent with experimental observations. We also solve the nonlinear problem numerically and are able to obtain patterns that are similar to those observed in the experiments.
Binding of Organic Cations to a Cyclophane Host As Studied with Molecular Dynamics Simulations and Free Energy Calculations

We have studied the binding of two organic cations, an iminium (IM) and a guanidinium (GU), to a cyclophane host P4--4Na+, using molecular dynamics simulations and free energy calculations. A proper treatment of the long-range electrostatic forces is essential for the stability of these highly charged complexes, and a simple cutoff at 12 A results in an artifactual dissociation of the IM−P4--4Na+ complex. Since the host is highly aromatic and the guests cationic, cation−π interactions play an important role in the complex stability. In free energy calculations, using a simple additive force field, we calculate that the relative free energy of association of IM and GU binding to the host is 2.3 kcal/mol favoring IM, which is of the correct sign but 1.4 kcal/mol too small in magnitude. Differences in van der Waals interaction energies are mainly responsible for the different binding strengths, and the host adopts different shapes when accommodating IM compared to GU. To approximately estimate the contributi...
Analysis of heparin sodium by SAX/HPLC for contaminants and impurities

A chromatographic method was developed for the detection and quantification of the contaminant oversulfated chondroitin sulfate (OSCS) and the impurity dermatan sulfate in heparin active pharmaceutical ingredient (API). The HPLC analysis of heparin is carried out using a polymer-based strong anion exchange (SAX) column with gradient elution from 0.125 M sodium chloride to 2.5 M sodium chloride buffered mobile phase. The limit of detection (LOD) and limit of quantitation (LOQ) for the contaminant OSCS in heparin were determined to be 0.03% and 0.1%, respectively. The LOD and LOQ for dermatan sulfate, an impurity in heparin sulfate, were determined to be 0.1% and 0.8%, respectively. This manuscript is not a policy document and is not intended to replace either of the methods (capillary electrophoresis and NMR) currently required by the FDA.
Calcium Binding to Calmodulin Leads to an N-terminal Shift in Its Binding Site on the Ryanodine Receptor

The skeletal muscle calcium release channel, ryanodine receptor, is activated by calcium-free calmodulin and inhibited by calcium-bound calmodulin. Previous biochemical studies from our laboratory have shown that calcium-free calmodulin and calcium bound calmodulin protect sites at amino acids 3630 and 3637 from trypsin cleavage (Moore, C. P., Rodney, G., Zhang, J. Z., Santacruz-Toloza, L., Strasburg, G., and Hamilton, S. L. (1999)Biochemistry 38, 8532–8537). We now demonstrate that both calcium-free calmodulin and calcium-bound calmodulin bind with nanomolar affinity to a synthetic peptide matching amino acids 3614–3643 of the ryanodine receptor. Deletion of the last nine amino acids (3635–3643) destroys the ability of the peptide to bind calcium-free calmodulin, but not calcium-bound calmodulin. We propose a novel mechanism for calmodulin's interaction with a target protein. Our data suggest that the binding sites for calcium-free calmodulin and calcium-bound calmodulin are overlapping and, when calcium binds to calmodulin, the calmodulin molecule shifts to a more N-terminal location on the ryanodine receptor converting it from an activator to an inhibitor of the channel. This region of the ryanodine receptor has previously been identified as a site of intersubunit contact, suggesting the possibility that calmodulin regulates ryanodine receptor activity by regulating subunit-subunit interactions.
Graduate Digital Forensics Education at the Air Force Institute of Technology

The Department of Electrical and Computer Engineering (AFIT/ENG) at the Air Force Institute of Technology (AFIT), currently offers a graduate-level introductory course in digital forensics. Students are introduced and exposed to several challenges and topics in the digital forensics course. The course addresses the ethical and legal procedures as well as basic forensic science principles in only the most general manner. A larger percentage of lecture and lab time is spent discussing the technical details of incident response and media analysis. The detail into the network forensics and digital device analysis topics start to breach technical details but not to the level of attempting mastery. This course provides our students with real world digital forensics experience to prepare them for the challenges they may face in postgraduate employment
Saturated Absorption with Spatially Separated Laser Fields: Observation of Optical "Ramsey" Fringes*

We have observed Ramsey's interference fringes in the optical region using saturated-absorption techniques in a fast atomic beam. We discuss their physical origin and describe an optical configuration that guarantees fringes of high symmetry. This technique, with its high-resolution potential, should lead to dramatic improvements in spectral measurements.
Conformation of Aspartate Aminotransferase Isozymes Folding under Different Conditions Probed by Limited Proteolysis

The partially homologous mitochondrial (mAAT) and cytosolic (cAAT) aspartate aminotransferase have nearly identical three-dimensional structures but differ in their folding rates in cell-free extracts and in their affinity for binding to molecular chaperones. In its native state, each isozyme is protease-resistant. Using limited proteolysis as an index of their conformational states, we have characterized these proteins (a) during the early stages of spontaneous refolding; (b) as species trapped in stable complexes with the chaperonin GroEL; or (c) as newly translated polypeptides in cell-free extracts. Treatment of the refolding proteins with trypsin generates reproducible patterns of large proteolytic fragments that are consistent with the formation of defined folding domains soon after initiating refolding. Binding to GroEL affords considerable protection to both isozymes against proteolysis. The tryptic fragments are similar in size for both isozymes, suggesting a common distribution of compact and flexible regions in their folding intermediates. cAAT synthesized in cell-free extracts becomes protease-resistant almost instantaneously, whereas trypsin digestion of the mAAT translation product produces a pattern of fragments qualitatively akin to that observed with the protein refolding in buffer. Analysis of the large tryptic peptides obtained with the GroEL-bound proteins reveals that the cleavage sites are located in analogous regions of the N-terminal portion of each isozyme. These results suggest that (a) binding to GroEL does not cause unfolding of AAT, at least to an extent detectable by proteolysis; (b) the compact folding domains identified in AAT bound to GroEL (or in mAAT fresh translation product) are already present at the early stages of refolding of the proteins in buffer alone; and (c) the two isozymes seem to bind in a similar fashion to GroEL, with the more compact C-terminal portion completely protected and the more flexible N-terminal first 100 residues still partially accessible to proteolysis.
Flow impingement as an excitation source in control valves

The impingement of high speed separated flows, often encountered in control valves, provides a feedback mechanism which enhances the pressure fluctuations at selected frequencies. The resulting dynamic loading and noise generation can be sufficiently high to cause structural damage or noise problems. This is demonstrated by considering two case-histories, one of a by-pass control valve and the other of a turbine control valve. In the first case, the behaviour of the frequency of oscillation has been found to be strikingly similar to that associated with self-excited oscillations of cavity flows. The elimination of impingement or the addition of spoilers at the separation location drastically reduces the intensity of the pressure fluctuations. p In the second case, the above mentioned excitation mechanism is coupled to an acoustical resonance mode within the valve chest. At the onset of resonance, the Strouhal number based on the jet thickness and that based on the impingement length are found to be in full agreement with those associated with impinging shear flows. In both cases, the excitation mechanism and means of alleviation have been investigated with the aid of model tests supported by measurements on full size valves in power plants.
A New Approach Toward Resolving The Line and Staff Dilemma

The article refers to management literature and the interdependency of line and staff members in an organization. Trends in management literature focus on the usefulness of the staff-and-line concept, the boundary-spanning aspect of the concept, and the change in attitude that is required to improve the line-staff relationship and make it more effective. The gap between theory and application has management costs such as additional noise in communication channels from unperceived differences in defining the functions and responsibilities of staff and line, as well as a dysfunctional increase in stress.
Non-reciprocal and highly nonlinear active acoustic metamaterials.

Unidirectional devices that pass acoustic energy in only one direction have numerous applications and, consequently, have recently received significant attention. However, for most practical applications that require unidirectionality at audio and low frequencies, subwavelength implementations capable of the necessary time-reversal symmetry breaking remain elusive. Here we describe a design approach based on metamaterial techniques that provides highly subwavelength and strongly non-reciprocal devices. We demonstrate this approach by designing and experimentally characterizing a non-reciprocal active acoustic metamaterial unit cell composed of a single piezoelectric membrane augmented by a nonlinear electronic circuit, and sandwiched between Helmholtz cavities tuned to different frequencies. The design is thinner than a tenth of a wavelength, yet it has an isolation factor of >10 dB. The design method generates relatively broadband unidirectional devices and is a good candidate for numerous acoustic applications. Unidirectional acoustic devices only permit the flow of energy one way, but most implementations are large compared to acoustic frequencies. Popa and Cummer use a metamaterial approach to build such devices that are only a tenth of a wavelength thick but retain high acoustic isolation.
The reliability of distance run tests for children in grades K-4

Abstract The purpose of this study was to determine test–retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/walk tests for children in Grades K—4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) complied the test–retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 < R < .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 < R < .83), but is not reliable for children in Grades K and 1 (.34 < R < .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 < R < .82). Results also indicated that reliability estimates remaine...
The C protein of measles virus inhibits the type I interferon response.

Abstract Type I interferons (IFNα/β) are an important part of innate immunity to viral infections because they induce an antiviral response and limit viral replication until the adaptive response clears the infection. Since the nonstructural proteins of several paramyxoviruses inhibit the IFNα/β response, we chose to explore the role of the C protein of measles virus (MV) in such inhibition. Previous studies have suggested that the MV C protein may serve as a virulence factor, but its role in the pathogenesis of MV remains undefined. In the present study, a recombinant MV strain that does not express the C protein (MV C−) and its parental strain (Ed Tag) were used. Growth of MV C− was restricted in human peripheral blood mononuclear cells and HeLa cells, but in the presence of neutralizing antibodies to IFNα/β, MV C− produced titers that were equivalent to those of Ed Tag. In addition, expression of the MV C protein from plasmid DNA inhibited the production of an IFNα/β responsive reporter gene and, to a lesser extent, inhibited an IFNγ responsive reporter gene. The ability of the MV C protein to suppress the IFNα/β response was confirmed using a biologic assay. After IFNβ stimulation, HeLa cells infected with Ed Tag produced five-fold less IFNα/β than cells infected with MV C−. While the mechanism of inhibition remains unclear, these data suggest that the MV C protein plays an important role in the pathogenesis of MV by inhibiting IFNα/β signaling.
Growing wastewater-born microalga Auxenochlorella protothecoides UMN280 on concentrated municipal wastewater for simultaneous nutrient removal and energy feedstock production

Abstract Using wastewater to grow algae is probably the most promising route to reduce production costs associated with nutrients and water. In this study, a newly isolated facultative heterotrophic freshwater microalgae strain, Auxenochlorella protothecoides UMN280, was examined for algal growth, wastewater nutrient removal efficiency, and lipid accumulation in batch and semi-continuous cultivation with various hydraulic retention time using concentrated municipal wastewater (CMW) as cultivation media. The results of the 6 day batch cultivation showed that the maximal removal efficiencies for total nitrogen, total phosphorus, chemical oxygen demand (COD) and total organic carbon (TOC) were over 59%, 81%, 88% and 96%, respectively, with high growth rate (0.490 d −1 ), high biomass productivity (269 mg L −1 d −1 ) and high lipid productivity (78 mg L −1 d −1 ). Further fatty acid methyl ester (FAME) analysis showed that the microalgal lipids were mainly composed of C16/C18 fatty acids (accounting for over 94% of total fatty acid), which are suitable for high-quality biodiesel production. The system could be scaled up from 100 mL flasks to 25 L BIOCOIL reactors, and semi-continuously operated at hydraulic retention time of 3 days with a net biomass productivity of 1.51 g L −1 d −1 of dried algae.
A Baker’s Dozen of Problems

This article is a collection of open problems, with brief historical and bibliographical comments, somewhat in the spirit of the problem with which V. Arnold opened his famous seminar every semester and that were recently collected and published in a book form.
Investigating dissolved organic matter decomposition in northern peatlands using complimentary analytical techniques

Abstract The chemical transformations that govern storage, degradation, and loss of organic matter in northern peatlands are poorly characterized, despite the significance of these peat deposits as pivotal reservoirs in the global carbon cycle. One of the most challenging problems concerns the character of dissolved organic matter (DOM) in peat porewaters, particularly higher-molecular weight compounds that may function either as non-reactive sinks or reactive intermediates for organic byproducts of microbial decay. The complexity of these large molecules has defied attempts to characterize their molecular structure in bulk samples with a high degree of precision. We therefore determined the composition and reactivity of DOM from representative bog and fen sites in the Glacial Lake Agassiz Peatlands (GLAP) in northern Minnesota, USA. We applied four complementary techniques: electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS), proton nuclear magnetic resonance spectroscopy (1H NMR), specific UV absorbance (SUVA) and excitation–emission matrix (EEM) fluorescence spectroscopy. We observed that the vast majority (>80%) of molecular formulas that appear in the surface bog DOM are also present at 2.9 m depth, indicating that much of DOM in the bog is resistant to microbial degradation. In contrast to bog samples, a considerable number of new compounds with low O/C and high H/C elemental ratios were observed in the 3 m fen horizon relative to surface samples. These results indicate a more pronounced difference in the composition of surface and deep DOM in the fen. SUVA, determined at 254 nm, indicated significantly lower aromaticity in deep fen samples relative to deep bog samples. This trend was verified by 1H NMR. Aromatic and carbohydrate components represented up to 70% of deep bog DOM but comprised a much smaller proportion of deep fen DOM, which was dominated by functionalized and non-functionalized aliphatics. Molecular formula data determined by FT-ICR mass spectrometry were consistent with results from optical and NMR spectroscopy measurements and showed that compounds with low O/C and high H/C were generated with depth in the fen. Such compounds were absent in both surface fen and in surface and deep bog samples respectively, providing further evidence of qualitative and quantitative differences in the evolution of DOM in fens and bogs. These differences, attributed to either variations in source vegetation or environmental factors that render DOM more reactive in fen sites or less reactive in bog sites, have important implications for the response of peatlands to climate change, since climatic change leading to moister conditions may enhance the abundance of sedge-dominated fens and increase the pool of more labile soil carbon.
Interplay of Sp1 and Egr-1 in the Proximal Platelet-derived Growth Factor A-Chain Promoter in Cultured Vascular Endothelial Cells

The platelet-derived growth factor (PDGF) A-chain has been implicated in the initiation and progression of vascular occlusive lesions. The elements in the human PDGF-A promoter that mediate increased expression of the gene in vascular endothelial cells have not been identified. A potent inducer of PDGF-A expression in endothelial cells is phorbol 12-myristate 13-acetate (PMA). 5′-Deletion and transfection analysis revealed that a G+C-rich region in the proximal PDGF-A promoter is required for PMA-inducible gene expression. This region bears overlapping consensus recognition sequences for Sp1 and Egr-1. PMA induces Egr-1 mRNA expression within 1 h, whereas PDGF-A transcript levels increase after 2-4 h. Constitutive levels of Sp1 are not altered over 24 h. A specific nucleoprotein complex is formed when an oligonucleotide bearing the G+C-rich element is incubated with nuclear extracts from PMA-treated cells. The temporal appearance of this complex is consistent with the transient increase in Egr-1 transcripts. Antibodies to Egr-1 completely supershift the PMA-induced complex. Interestingly, increased nuclear levels of Egr-1 attenuate the ability of Sp1 to interact with the oligonucleotide, implicating competition between Egr-1 and Sp1 for the G+C-rich element. Binding studies with recombinant proteins demonstrate that Egr-1 can displace Sp1 from this region. Insertion of the G+C-rich element into a hybrid promoter-reporter construct confers PMA inducibility on the construct. Mutations that abolish Egr-1 binding also abrogate expression induced by PMA or overexpressed Egr-1. These findings demonstrate that PMA-induced Egr-1 displaces Sp1 from the G+C-rich element and activates expression driven by the PDGF-A proximal promoter in endothelial cells. The Sp1/Egr-1 displacement mechanism may be an important regulatory circuit in the control of inducible gene expression in vascular endothelial cells.
Otx2 Induction of the Gonadotropin-releasing Hormone Promoter Is Modulated by Direct Interactions with Grg Co-repressors

Hormonal communication between the hypothalamus, pituitary, and gonads orchestrates the development and regulation of mammalian reproductive function. In mice, gonadotropin-releasing hormone (GnRH) expression is limited to ∼1000 neurons that originate in the olfactory placode then migrate to specific positions scattered throughout the hypothalamus. Coordination of the hypothalamic-pituitary-gonadal axis is dependent upon correct migration of GnRH neurons into the hypothalamus followed by the appropriate synthesis and pulsatile secretion of GnRH. Defects in any one of these processes can cause infertility. Recently, substantial progress has been made in identifying transcription factors, and their cofactors, that regulate not only adult expression of GnRH, but also the maturation of GnRH neurons. Here, we show that expression of Otx2, a homeodomain protein required for the formation of the forebrain, is dramatically up-regulated during GnRH neuronal maturation and that overexpression of Otx2 increases GnRH promoter activity in GnRH neuronal cell lines. Furthermore, Otx2 transcriptional activity is modulated by Grg4, a member of the Groucho-related-gene (Grg) family. Using mutational analysis, we show that a WRPW peptide motif within the Otx2 protein is required for physical interaction between Otx2 and Grg4. Without this physical interaction, Grg4 cannot repress Otx2-dependent activation of GnRH gene transcription. Taken together, these data show that Otx2 is important for GnRH expression and that direct interaction between Otx2 and Grg co-repressors regulates GnRH gene expression in hypothalamic neurons.
Predicting cross‐sex first‐date sexual expectations and involvement: Contextual and individual difference factors

This study investigates how individual difference variables (gender and self-monitoring) and contextual factors (gender of the date-initiator and alcohol consumption) influence sexual expectations for, and sexual involvement on, a first date. College students reported on their most recent male- or female-initiated first date. Alcohol and gender were the strongest determinants of both sexual expectations and involvement. Binge drinkers engaged in more sexual involvement than did nonbinge drinkers who, in turn, engaged in greater sexual involvement than nondrinkers. Men reported more intimate sexual expectations and involvement than women. Individual difference and contextual variables explained more of the variance in males' (when compared to females') sexual expectations and involvement.
On the orbital implementation of the kinetic theory of stopping

The relationship of the orbital implementation of the kinetic theory of stopping to more conventional descriptions of stopping is discussed. It is argued that, provided that the Bethe logarithm is used for the scatterer zero velocity stopping number, the orbital kinetic theory (using individual orbital Ik's) and conventional Bethe theory (using a single target I) are identical in the limit of large projectile velocity. The identity is fulfilled if ln I = Σk (ωk/Z2) ln Ik, where the ωk are the orbital weights.
IRF4 Is a Key Thermogenic Transcriptional Partner of PGC-1α

Brown fat can reduce obesity through the dissipation of calories as heat. Control of thermogenic gene expression occurs via the induction of various coactivators, most notably PGC-1α. In contrast, the transcription factor partner(s) of these cofactors are poorly described. Here, we identify interferon regulatory factor 4 (IRF4) as a dominant transcriptional effector of thermogenesis. IRF4 is induced by cold and cAMP in adipocytes and is sufficient to promote increased thermogenic gene expression, energy expenditure, and cold tolerance. Conversely, knockout of IRF4 in UCP1(+) cells causes reduced thermogenic gene expression and energy expenditure, obesity, and cold intolerance. IRF4 also induces the expression of PGC-1α and PRDM16 and interacts with PGC-1α, driving Ucp1 expression. Finally, cold, β-agonists, or forced expression of PGC-1α are unable to cause thermogenic gene expression in the absence of IRF4. These studies establish IRF4 as a transcriptional driver of a program of thermogenic gene expression and energy expenditure.
Regulation of the sarcoplasmic reticulum calcium permeability by sulfhydryl oxidation and reduction

Abstract The release of Ca 2+ from an intracellular membrane system, the sarcoplasmic reticulum, is known to cause muscle contraction in both skeletal and cardiac muscle. The molecular mechanism by which Ca 2+ release is triggered remains unknown. We report that Ca 2+ release from the sarcoplasmic reticulum can be triggered by either binding of various heavy metals to a sulfhydryl group on the release protein or by catalyzing the oxidation of this critical sulfhydryl group to its disulfide form. The possible physiological significance of these findings is discussed. We propose that the open versus closed state of the Ca 2+ release channel in vivo may be controlled by the oxidation and reduction of this critical sulfhydryl group.
Nitrogenase. IV. Simple method of purification to homogeneity of nitrogenase components from Azotobacter vinelandii.

Abstract Extracts of Azotobacter vinelandii have been fractionated by simple techniques to obtain highly purified components of nitrogenase. The yield of each component is greater than 60%. Purified Component I has a specific activity of 1638 nmoles ethylene formed/min per mg protein. The spectrum of Component I exhibits a broad absorption between 300 and 600 nm, with no distinctive peaks or shoulders. Addition of sodium dithionite or exposure to air has no effect on the absorption spectrum. Component I, examined at 4.2 °K has EPR signals at g = 4.2, 3.65 and 2.01. Addition of sodium dithionite does not produce additional resonances nor does it alter the signals already present. Crystals of Component I are dark brown and needle-shaped. Purified Component II has a specific activity of 1815 nmoles ethylene formed/min per mg protein. The absorption spectrum has no peaks or shoulders between 390 and 650 nm. Upon exposure of Component II to air, absorption increases between 400 and 650 nm. Treatment of oxidized Component II with dithionite causes this absorption to fall below that of the native Component II. EPR spectra of Component II has signals at g values of 2.05, 1.94, and 1.88. Upon inactivation by O2, these signals disappear. Neither component by itself has detectable acetylene-reducing or N2-fixing activity. The ratio of acetylene reduced to N2 fixed is 3.86 with different ratios of the components. Both components form aggregated species upon exposure to air. Dithionite does not reverse this effect.
Temperature and modulation dependence of spectral linewidth in distributed Bragg reflector laser diodes

The paper investigates the dependence of spectral linewidth for temperature and modulation in distributed Bragg reflector laser diodes. The spectral linewidth was measured by the delayed self-heterodyne method. It is proven that a rise in temperature and modulation frequency and modulation depth enhance the spectral linewidth. It is confirmed that there is a close relationship between environmental change and spectral linewidth. The variation of normalized spectral linewidth (NSL) was 2.0 MHz*mW/deg at 25 C.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Radiative Recombination of Electron-Hole Pairs Generated by Two-Photon Absorption in Indium Antimonide

The radiative-recombination coefficient $r$ of electron-hole pairs in InSb generated by irradiation with a C${\mathrm{O}}_{2}$ laser is calculated and compared with measurements at liquid-He and -${\mathrm{N}}_{2}$ temperatures. To obtain the theoretical $r$, the spontaneous transition rate is calculated using Kane's wave functions with the assumption of parabolic energy bands. Thermal equilibrium, within each band and between the two valence bands, is also assumed. Measurements of the decay of excess conductivity yield $r\ensuremath{\approx}1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ ${\mathrm{cm}}^{3}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ at both 2 and 4 \ifmmode^\circ\else\textdegree\fi{}K. No value for $r$ could be measured at 77 \ifmmode^\circ\else\textdegree\fi{}K since the decay is dominated by a monomolecular recombination process at this temperature. The experimental values of $r$ are between one and two orders of magnitude smaller than the theoretical values. This large discrepancy is caused by the nonparabolicity of the heavy-hole band. The possibility of acquiring accurate information about the shape of the warped valence band by measuring the decay of excess-carrier densities at liquid-He temperatures is discussed.
A meta-analysis of plant physiological and growth responses to temperature and elevated CO2

Atmospheric carbon dioxide (CO2) and global mean temperature are expected to be significantly higher by the end of the 21st century. Elevated CO2 (eCO2) and higher temperature each affect plant physiology and growth, but their interactive effects have not been reviewed statistically with respect to higher chronic mean temperatures and abrupt heat stress. In this meta-analysis, we examined the effect of CO2 on the physiology and growth of plants subjected to different temperature treatments. The CO2 treatments were categorized into ambient ( 560 ppm) levels, while temperature treatments were categorized into ambient temperature (AT), elevated temperature (ET; AT + 1.4–6°C), or heat stress (HS; AT + >8°C). Plant species were grouped according to photosynthetic pathways (C3, C4), functional types (legumes, non-legumes), growth forms (herbaceous, woody), and economic purposes (crop, non-crop). eCO2 enhanced net photosynthesis at AT, ET, and HS in C3 species (especially at the HS level), but in C4 species, it had no effect at AT, a positive effect at ET, and a negative effect at HS. The positive effect of eCO2 on net photosynthesis was greater for legumes than for non-legumes at HS, for non-crops than crops at ET, and for woody than herbaceous species at ET and HS. Total (W T) and above- (W AG) and below-ground (W BG) biomass were increased by eCO2 for most species groups at all temperatures, except for C4 species and W BG of legumes at HS. Hence, eCO2 × heat effects on growth were often not explained by effects on net photosynthesis. Overall, the results show that eCO2 effects on plant physiology and growth vary under different temperature regimes, among functional groups and photosynthetic pathways, and among response variables. These findings have important implications for biomass accumulation and ecosystem functioning in the future when the CO2 level is higher and climate extremes, such as heat waves, become more frequent.
Holmium:YAG laser: effect on pulpal tissues and root surfaces

The effects of the Holmium:YAG irradiation on the pulpal tissues and surface topography on root surface dentin in human teeth in vivo were studied. The exposed root surfaces of seventeen pre-immediate denture patients were scaled and root planed with a Gracey 3 - 4 curette apical to the dentinoenamel junction until smooth and hard. The prepared root surfaces of two teeth per patient were exposed with Holmium:YAG laser energy after an application of nonfilled resin/fluoride mixture. The laser exposed areas were below the dentinoenamel junction around one-half of each root surface. The opposing sides of each of the teeth received resin/fluoride but no laser energy. A third tooth was identified as a nontreated control. The HO:YAG at 2.12 microns wavelength with a defocused beam size of 3 mm was used. The amount of laser energy delivered per 3 X 5 mm area was 0.450 (+/- .05) joules with a fluence of 2.66 - 3.30 J/cm2. The teeth were extracted after periods of 45 - 120 days. The specimens were fixed in formalin and prepared for histological examination using hematoxylin and eosin stains. Microscopic evaluation of room surfaces showed increased smoothness on the laser treated sites compared to their opposing non-lased sides. Histological examination of the pulpal tissues exhibited no abnormal changes. No clinical symptoms of pulpal pathology were produced. HO:YAG laser energy proved safe for treating room surfaces of human teeth in vivo under conditions presented in this study.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Splendid Isolation: Patterns of Geographic Range Collapse in Endangered Mammals

Population densities of terrestrial animals tend to be higher and less variable near the center versus along the periphery of a species' geographic range. If extinctions are tied to local population dynamics, geographic ranges of endangered species should collapse inward, with remnant populations persisting near the center of a species' historic range. Geographic-Information-System analysis of range collapse in nonvolant, terrestrial mammals reveals, however, that extant populations of 23 of 31 species were located along the periphery, not the center, of their historic range. In addition, range collapse appears to be independent of fragment area and has a directional bias from east to west. Persistence of endangered populations also appears to be greater on islands than on continents. These results contradict conventional wisdom in biogeography and macroecology and have important implications for conserving biodiversity. Because of their relative isolation from central populations and from a suite of anthropogenic disturbances, islands and other sites along the periphery of a species' historic range represent critical refugia for many endangered species.
LIGHT‐INDUCED SHIFTS IN THE ABSORPTION SPECTRUM OF CAROTENOIDS IN RED AND BROWN ALGAE

— Changes in light absorption in the region 450–540 nm were observed upon illumination of the red algae Iridaea splendens, Schizymenia pacifica and Porphyra perforata and the brown alga Pheostrophion irregulare. The difference spectra of these changes in Iridaea and Schizymenia showed maxima and minima at about 465, 480, 495, 515 nm. The spectra were similar to difference spectra earlier observed in photosynthetic bacteria, and the location of the maxima and minima suggested a shift towards longer wavelength of a compound with absorption maxima at about 440, 470, and 500 nm, probably a carotenoid. Similar, but more distorted difference spectra were observed in the other algae. Time courses and size of the signals induced by light of different wavelengths suggest that excitation of both photosynthetic pigment systems causes a shift in carotenoid absorption, with kinetics which appear to be similar to those of the well-known change at 515 nm in green plants.
School-Age Child Care: The Community Leadership Role of Educators

(1989). School-Age Child Care: The Community Leadership Role of Educators. Childhood Education: Vol. 66, No. 2, pp. 78-82.
Characteristics of mammalian Rh glycoproteins (SLC42 transporters) and their role in acid-base transport.

The mammalian Rh glycoproteins belong to the solute transporter family SLC42 and include RhAG, present in red blood cells, and two non-erythroid members RhBG and RhCG that are expressed in various tissues, including kidney, liver, skin and the GI tract. The Rh proteins in the red blood cell form an “Rh complex” made up of one D-subunit, one CE-subunit and two RhAG subunits. The Rh complex has a well-known antigenic effect but also contributes to the stability of the red cell membrane. RhBG and RhCG are related to the NH4+ transporters of the yeast and bacteria but their exact function is yet to be determined. This review describes the expression and molecular properties of these membrane proteins and their potential role as NH3/NH4+ and CO2 transporters. The likelihood that these proteins transport gases such as CO2 or NH3 is novel and significant. The review also describes the physiological importance of these proteins and their relevance to human disease.
The Role of Psychosomatic Medicine in Global Health Care

This article reviews the principles and skills involved with psychosomatic medicine and their potential ability to improve global health care. New awareness of the escalating global public health impact of noncommunicable diseases, including chronic medical conditions and mental disorders, has stimulated interest in determining how best to organize health services. Home to the biopsychosocial model, the field of psychosomatic medicine is well-suited to inform such efforts by virtue of its emphasis on cross-disciplinary collaboration and specialized knowledge at the interface of medicine and psychiatry that takes into account individual and contextual influences on health. Consistent with the principles of psychosomatic medicine, promising strategies to improve global health care include integrating mental health care into primary care, applying the chronic care model in programs aimed at enhancing disease self-management, and using innovative models such as Internet-based therapy and telemedicine to increase access to quality care.
TECTONIC-MAGMATIC STAGES OF SHIELD EVOLUTION: THE PAN-AFRICAN BELT IN NORTHEASTERN EGYPT

Abstract The Arabian-Nubian shield illustrates an example of plate tectonics during the Pan-African orogenic event (ca. 950-550 Ma); it is considered one of the most remarkable Proterozoic shield areas yet known. Although there is now a general agreement that the shield has evolved by a series of magmatic arcs and terrain accretion, the evolution of its northernmost part exposed in northeastern Egypt remains controversial. Two contrasting tectonic models have been proposed for the evolution of this region: regional crustal extension and magmatic-arc regimes. There is no convincing evidence of older (Archean) sialic materials within the region, although the region is flanked by Archean crust. The Neoproterozoic crustal components exposed in northeastern Egypt preserve a record for its evolution. A large gabbro-diorite-tonalite complex (GDT, 881 Ma) emplaced during the early stage of the Pan-African orogeny is geochemically primitive, exhibits a low initial 87 Sr 86 Sr ratio (0.704) and shows trace-element characteristics of oceanic-arc-related lavas. The GDT complex was produced (by fractionation) from a mantle-derived tholeiitic magma formed within an island-arc tectonic environment. A synorogenic stage characterized by extensive volcanism that produced the Dokhan volcanic suite (DVS, 620 Ma) forms a continuous basalt to rhyolitic ignimbrite calc-alkaline magma series, exhibiting features of arc-related volcanism, with REE profiles similar overall to Andean andesites and ignimbrites. The Dokhan suite was produced in a continental-arc setting. A granodiorite-adamellite-leucogranite composite batholith (552 Ma) emplaced during the late stage of the Pan-African orogeny exhibits typical features of I-type complexes, trace element traits of volcanic-arc granites, and is also interpreted to have been formed in an Andean-type setting. A trondhjemite pluton was also formed at this late orogenic stage, by partial melting of GDT host rocks at depth. Cooling and relaxation of the newly formed Pan-African crust caused extensive fracturing, which was followed by intrusion of NE-SW- and NNW-SSE-trending dyke swarms at 493 Ma. This episode marks a fundamental inversion from orogenic compressional to anorogenic extensional processes around the Neoproterozoic-Paleozoic boundary. Anorogenic magmatism was locally associated with such extension-induced structures. The Mount Gharib peralkaline granite (476 Ma), for example, exhibits trace element traits of A-type, within-plate granites, and a high initial 87 Sr 86 Sr ratio (0.711), and was formed in a rift environment. Thus, the region is characterized by lengthy episodes of discontinuous subduction (∼ 880-550 Ma), during which it evolved to form a primitive crust by early Pan-African island arcs and late Pan-African continental arcs. This was followed by an even longer period of crustal extension (∼ 550-90 Ma) that produced localized anorogenic magmatism.
Analysis of the Polymerization Kinetics of Homodimeric EIAV p51/51 Reverse Transcriptase Implies the Formation of a Polymerase Active Site Identical to Heterodimeric EIAV p66/51 Reverse Transcriptase†

Homodimeric EIAV p51/51 and heterodimeric EIAV p66/51 reverse transcriptase were purified in order to compare the different modes of DNA synthesis supported by the enzymes. Analysis of the dimerization behavior of the EIAV enzymes indicates that the dimer stability of EIAV reverse transcriptase enzymes is higher than that of their HIV-1 reverse transcriptase counterparts. EIAV p51/51 polymerizes DNA distributively whereas DNA synthesis by EIAV p66/51 is processive. Steady-state and pre-steady-state kinetic analyses of primer/template binding and nucleotide incorporation were performed with both enzymes to determine the reasons for the different polymerization behavior. Equilibrium fluorescence titrations demonstrated that the Kd values of EIAV p51/51 for binding of DNA/DNA and DNA/RNA substrates are increased 10-fold and 28-fold, respectively, as compared to EIAV p66/51. Stopped-flow measurements with DNA/DNA show that the increase in the Kd is in part due to a 17. 4-fold higher dissociation rate constant (k-1) for EIAV p51/51. Additionally, with EIAV p51/51, kdiss is increased 7-fold for DNA/DNA and 14-fold for DNA/RNA primer/template substrates, respectively. The lack of the RNase H domain in EIAV p51/51 leads to differences in the pre-steady-state kinetics of nucleotide incorporation on DNA/DNA and DNA/RNA templates. The burst of both enzymes is composed of two phases for both substrates, and the values for the corresponding pre-steady-state burst rates, kpol1 and kpol2, are similar for both enzymes, implying the formation of identical polymerase active sites. However, the amplitudes of the two phases differ with DNA/DNA templates, indicating a different distribution between two states varying greatly in their kinetic competence.