cssi/SciSciGPT-SciSciNet huggingface dataset:
Glutathione Depletion Is Necessary for Apoptosis in Lymphoid Cells Independent of Reactive Oxygen Species Formation

Changes in the intracellular redox environment of cells have been reported to be critical for the activation of apoptotic enzymes and the progression of programmed cell death. Glutathione (GSH) depletion is an early hallmark observed in apoptosis, and we have demonstrated that GSH efflux during death receptor-mediated apoptosis occurs via a GSH transporter. We now evaluate the relationship between GSH depletion, the generation of reactive oxygen species (ROS), and the progression of apoptosis. Simultaneous single cell analysis of changes in GSH content and ROS formation by multiparametric FACS revealed that loss of intracellular GSH was paralleled by the generation of different ROS including hydrogen peroxide, superoxide anion, hydroxyl radical, and lipid peroxides. However, inhibition of ROS formation by a variety of antioxidants showed that GSH loss was independent from the generation of ROS. Furthermore, GSH depletion was observed to be necessary for ROS generation. Interestingly, high extracellular thiol concentration (GSH and N-acetyl-cysteine) inhibited apoptosis, whereas, inhibition of ROS generation by other non-thiol antioxidants was ineffective in preventing cell death. Finally, GSH depletion was shown to be a necessary for the progression of apoptosis activated by both extrinsic and intrinsic signaling pathways. These results document a necessary and critical role for GSH loss in apoptosis and clearly uncouple for the first time GSH depletion from ROS formation.
Effectiveness of systems analysis and design education: an exploratory study

This paper reports the results of an exploratory study of student perceptions of the education and experiences of the Systems Analysis and Design (SA&D) course taught in the IS programs at academic institutions. An ex-ante and post hoc empirical study of student perceptions in the SA&D courses was conducted. The results indicate that after taking the SA&D course and working with a real-life project, students' perceptions improved for the applicability of structured methodologies across industries, the importance of computer programming in systems analysis and design process, and the role of advanced technologies in SA&D. Respondents also perceived that when working as groups, SA&D team members did not do their fair share of the work. However, the importance of user involvement was recognized.
Accountability in Education: Assessing Program Outcomes:

Accountability for program quality is becoming a major thrust in higher educa tion. This article describes the process for assessing program quality currently used in a university hospitality educa...
The reaction of atomic hydrogen with the formyl radical

The addition and abstraction reaction pathways on the potential energy surface for H+HCO have been characterized by an ab initio four electron, complete active space, self-consistent field electronic structure calculation. The elimination pathway to go from the excited adduct H 2 CO * to products H 2 +CO has already been characterized by M.Dupuis, et al., [ J. Chem. Phys. 79, 6167 (1983)]. All the theoretical information is used in variational transition state theory and RRKM calculations to determine a rate constant as a function of temperature and pressure. The room temperature calculated value is inconsistent with the earliest and highest experimental value but falls within the error bars of the two other and more recent experimental measurements. The results indicate that abstraction is the more important process, followed by addition-elimination. Pressure-induced stabilization of the H 2 CO * adduct is calculated to be negligible in Air buffer gas up to 1 atm. However up to a 15% change in the room temperature rate with a pressure change of from 10 to 760 torr is predicted for more efficient buffer gases such as CH 4 . Experimental measurements to date have been too imprecise (errors of at least±20%) to detect such a pressure dependence.
Growth of the plant cell wall

Plant cells encase themselves within a complex polysaccharide wall, which constitutes the raw material that is used to manufacture textiles, paper, lumber, films, thickeners and other products. The plant cell wall is also the primary source of cellulose, the most abundant and useful biopolymer on the Earth. The cell wall not only strengthens the plant body, but also has key roles in plant growth, cell differentiation, intercellular communication, water movement and defence. Recent discoveries have uncovered how plant cells synthesize wall polysaccharides, assemble them into a strong fibrous network and regulate wall expansion during cell growth.
Aromatic halogen displacement by cyclohexyl radicals

Cyclohexyl radicals displace either halogen or hydrogen from dihalobenzenes to give mono- and di-halogenated cyclohexylbenzenes. The unusual reactivity of fluorine in the sequence, F > I > Br > Cl, shows that breaking of the carbon-halogen bond is not involved in the rate-determining step. Halogens ortho to each other are consistently more reactive toward displacement than hydrogen in the same molecule. This higher reactivity is explained by a combination of electronic and steric effects plus the ability of halogen ortho to the reaction site to stabilize a cyclohexadienyl radical, while the preference for fluorine displacement is attributed to the nucleophilic nature of the cyclohexyl radical which reacts more readily at a position of low electron density.
Global genetics: worldwide considerations.

A few years ago I sat on the dirt floor with a young childbearing Palestinian woman living in a refugee camp in Jordan. She was a carrier of thalassemia and spoke of the coming birth of the child she was carrying. She spoke of her fears for the child and the hope that this child would be born without the disease. Looking heavenward she said "Enshallah" ["God willing"] hoping that Divine Benevolence would assure a healthy outcome. While interviewing childbearing women in small villages in the highlands of Guatemala I noted a high incidence of cleft lip/cleft palate and neural tube defects that may be multifactorial associated with not only lack of dietary folic acid but also centuries of intermarriage in these closely knit communities. (excerpt)
Statistical Analysis of Dynamic Tracer Data

Statistical estimation theory is applied to the problem of analyzing data obtained in dynamic tracer studies in nuclear medicine. Procedures are given for the determination of the maximum likelihood (ML), maximum a posteriori probability (MAP), and minimum meansquare-error (MMSE) estimates of parameters describing the transport of the monitored tracer in tissue. Some numerical results are given for data obtained in monitoring the natural decay of strontium-85 and oxygen-15 isotopes frequently used in nuclear medicine.
Robust particle filters via sequential pairwise reparameterized Gibbs sampling

Sequential Monte Carlo (“particle filtering”) methods provide a powerful set of tools for recursive optimal Bayesian filtering in state-space models. However, these methods are based on importance sampling, which is known to be non-robust in several key scenarios, and therefore standard particle filtering methods can fail in these settings. We present a filtering method which solves the key forward recursion using a reparameterized Gibbs sampling method, thus sidestepping the need for importance sampling. In many cases the resulting filter is much more robust and efficient than standard importance-sampling particle filter implementations. We illustrate the method with an application to a nonlinear, non-Gaussian model from neuroscience.
Determination of ion exchange parameters by a genetic algorithm

Modeling the process of ion exchange in glass requires accurate knowledge of the self-diffusion coefficients of the incoming and outgoing ions. Furthermore, correlating the concentration profile of the incoming ions to a change in refractive index requires knowledge of the correlation coefficient. We present a method by which these three parameters can be quickly determined experimentally, using a genetic algorithm. Comparison with published data is presented.
TAX-LOSS SELLING, INSTITUTIONAL INVESTORS, AND THE JANUARY EFFECT: A NOTE

In this note we test the hypothesis that trading by tax-motivated individual investors is responsible for the January effect. We examine the ownership structure of a large sample of firms over a four-year period and find that the small firms that usually exhibit high January returns have low institutional ownership. After controlling for firm size, we still find that institutional ownership is significantly related to January abnormal returns. These results suggest that one reason the January effect may concentrate in small firms is because these firms are held by tax-motivated individual investors.
Analyzing powers and cross sections of p → p → pn π + near threshold

Analyzing powers for {rvec p}p{r_arrow}pn{pi}{sup +} were measured for the first time close to threshold at beam energies that yield maximum pion momentum fractions ({eta}{equivalent_to}p{sub c.m.}{sup max}/m{sub {pi}}c) of {eta}=0.22, 0.42, and 0.50, and enable a decomposition of the low order partial waves. Cross sections were measured at seven different beam energies with {eta}=0.07, 0.17, 0.22, 0.28, 0.34, 0.42, and 0.50. The analysis shows that pion s-wave channels dominate the reaction. The p-wave channel containing the {Delta} resonance contributes, at {eta}=0.22, less than one-tenth of the total cross section and less than one-third of the total cross section at {eta}=0.42 and 0.50. The nonresonant p-wave channel contributes less than 1{percent} of the cross section at these three energies. {copyright} {ital 1998} {ital The American Physical Society}
Cold denaturation of the hammerhead ribozyme.

Cold denaturation is a thermodynamic phenomenon resulting from a difference in the heat capacities, ΔCp, of the folded and unfolded states of a macromolecule. Whereas this phenomenon has been extensively studied in proteins, it has been thought not to occur in nucleic acids due to a negligible ΔCp of folding. Questioning the validity of this assumption, the low-temperature structure of the hammerhead ribozyme, a small catalytic RNA, was investigated by circular dichroism spectroscopy. In the presence of 10 mM Mg2+ at pH 5.0 and 40% methanol, a cold unfolding event likely corresponding to tertiary structure loss was observed with a Tm of −20 °C. In 500 mM NaCl at pH 6.6, and 40% methanol, large-scale unfolding of the ribozyme at both hot (Tm = 53 °C) and cold (Tm = −1 °C) temperatures occurred. Fitting of these data to a two-state model allowed determination of ΔCp = 3.4 kJ mol-1 K-1, corresponding to ≥0.18 kJ K-1 (mol base pair)-1, in good agreement with recently published calorimetric values for DNA dupl...
Acquisition and performance as a function of uncertainty and structure in serial tracking tasks

Abstract Criterion performance and response organization were evaluated in skilled tasks involving the pursuit tracking of step-function inputs. Both the structure and degree of first-order sequential dependencies among target events were manipulated in a factorial design. Tracking error was found to be a function of the degree of uncertainty and of the task structure (one vs two low-probability sequential alternatives) and the latter could not be attributed to the degree of uncertainty, per se. Furthermore, detailed analysis of continuous response records revealed differences in response strategies as a function of task structure. These differences accounted, in part, for difference in tracking performance and discrepancies between the present and prior research.
Assessing larval rootworm behaviour after contacting maize roots: impact of germplasm, rootworm species and diapause status

Current methods of screening maize (Zea mays L.) germplasm for susceptibility or resistance to corn rootworms (Coleoptera: Chrysomelidae) rely primarily on information from large-scale field experiments. Due to labour and cost constraints associated with field trials, alternative evaluation methods are desirable. We used a previously developed behavioural bioassay to: (1) investigate the host search behaviour of rootworm larvae after contact with 14 maize genotypes, (2) compare the behaviour of non-diapausing Diabrotica virgifera virgifera LeConte, diapausing D. v. virgifera, and diapausing D. barberi Smith & Lawrence and (3) determine if this technique can be used to separate susceptible vs. resistant maize genotypes. The majority of rootworm larvae engaged in intensive (local search) behaviour after exposure to maize roots, whereas larvae continued to exhibit extensive (ranging) behaviour after contact with negative controls. Even though a transgenic hybrid with resistance to D. v. virgifera was included in analyses, quantitative path measurements were similar among genotypes and only differed between specific maize lines and controls. Notably, there were differences in host search behaviour among rootworm groups, with non-diapausing D. v. virgifera having more convoluted paths and engaging in intensive search more frequently than diapausing rootworms. Correlations between larval path measurements and historic root damage ratings were not significant, although there were weak positive correlations between historic adult emergence densities and measures of path linearity. However, due to the lack of significant behavioural differences among maize lines with a range of susceptibility levels, we concluded that this bioassay is not useful in screening maize germplasm for rootworm resistance.
Target classification using spatially flexible directed pursuits

There has been much attention given to the characterization of canonical scattering phenomena in complex synthetic aperture radar (SAR) imagery for the purpose of classification. These features are often extracted using greedy algorithms, such as Matching Pursuits, which attempt to extract a low-dimensional representation of a given SAR image using a prescribed feature dictionary. As results to date have been predominantly anecdotal in nature, it is of interest to assess the utility of these techniques in full automated target classification applications. In this investigation, we will focus on the potential incorporation of such techniques into automatic target recognition (ATR) systems. The primary issues addressed in this paper include robust feature extraction techniques and the development of effective likelihood-of-match metrics operating in feature space. A specific implementation is presented where robust feature extraction is achieved via a new technique called Directed Pursuits. Directed Pursuits constitutes a feature extraction process from a test image driven by a feature decomposition previously obtained via Matching Pursuits from a training image. Directed Pursuits additionally allows for spatial flexibility in the test extraction process, representative of natural intra-class variations exhibited by real target classes. Likelihood metrics will be motivated and described, and associated results presented and interpreted in the context of both airborne and compact range X-band SAR data.
COLLAGENOLYTIC ACTIVITY IN RAT BONE CELLS : Characteristics and Intracellular Location.

An assay system for estimating quantitatively collagenase-like activity present in bone cells has been developed as part of a more general investigation of mechanisms of bone resorption. Methods are described for preparing from bone a C14-labeled collagen which is relatively pure and highly resistant to degradation by trypsin although readily broken down by bacterial collagenase. Collagenolytic activity in homogenates of bone cells harvested from rat metaphyseal bone was measured as the number of counts per minute released in ultrafiltrable form from the C14-labeled collagen substrate after 40 minutes' incubation at 37°C and pH 7.3. Using these techniques, the presence of collagenase-like activity in whole bone cell homogenates was confirmed and the heat lability, partial cation dependence, pH optimum, and some other characteristics of the crude material were determined. Moreover, the major portion of the homogenate activity was found in a particulate fraction sedimenting in a centrifugal field between 700 and 15,000 g. The marked enhancement and solubilization of this activity by surface-active agents or freeze-thawing, together with the presence of considerable acid phosphatase activity in the same fraction and its sedimentation characteristics, suggested that it might be contained in lysosomes or similar bodies. The implications of these observations with respect to the physiology of collagen resorption in general and bone resorption in particular are discussed.
Compaction localization and fluid flow

[1] When subjected to nonhydrostatic, compressive stresses, some porous sandstones exhibit nonuniform compaction. The compaction occurs as a localization process, analogous to shear localization, but results in a thickening, tabular zone of compaction as opposed to culminating in a shear fracture. We report the results of several triaxial compression experiments done at a confining pressure of 45 MPa on Castlegate sandstone, measuring simultaneously, stress, strain, acoustic emission locations, and permeability. A major result is that compaction localization produces up to a 2 order-of-magnitude decrease in permeability. Correlation of local strain measurements and acoustic emission locations made on the same specimen show that the compaction process proceeds as a propagating front approximately 20 mm thick. A model of the compaction process was developed that incorporates the moving boundary between compacted, low-permeability regions and uncompacted, higher-permeability regions, and compaction-induced fluid injection at the boundaries. Because of the inhomogeneous nature of compaction produced by compaction localization, and its temporal evolution, a number of phenomena related to fluid flow are predicted by the model: locally increased pore pressures and spatial changes in the effective permeability. Experimental results are reported that show the evolution of effective permeability to be linear with respect to the distance the compaction fronts propagated as predicted by the model. Implications of the results for future experimentation and for reservoirs are briefly discussed; in particular, the interaction between compaction-induced fluid pressure and compaction localization should lead to a phenomenon analogous to dilatancy hardening, impeding the propagation of compaction bands.
Adenosine potentiates coronary flow and inhibits oxygen consumption during isoprenaline infusion in isolated perfused guinea pig hearts

It has been shown that adenosine, a potent coronary vasodilator, is released during cardiac sympathetic stimulation and that infusion of adenosine reduces the increase in myocardial contractile force elicited by catecholamines. The purpose of our study was: 1) to examine if adenosine also attenuates the rise in O2 consumption (MVO2) induced by infusing isoprenaline; and 2) to determine whether such a fall in MVO2 occurs primarily because of a relative decrease in tissue O2 extraction or a change in coronary flow. We isolated guinea pig hearts, perfused the vasculature at constant pressure and measured coronary flow, inflow and outflow pO2, and isovolumetric left ventricular pressure (PLV) and its derivative (dP/dt). Before, during and after infusing isoprenaline, we infused adenosine at increasing rates; but both drugs were infused at rates which did not maximally increase flow. We observed that adenosine reduced the increases in PLV and +dP/dt due to isoprenaline from 52 to 24% and from 81 to 55%. Moreover, linear regression analysis showed that the rise in MVO2 by isoprenaline was antagonised as a function of adenosine. This relative fall in MVO2 resulted primarily because of a decrease in O2 extraction since coronary flow was enhanced as a function of adenosine. Thus, although adenosine enhances the increase in flow due to isoprenaline overall it attenuates tissue O2 extraction and MVO2. Our study suggests that during sympathetic cardiac stimulation, endogenously released adenosine may not only produce vasodilatation and enhance the delivery of O2, but may also attenuate cardiac muscle work and the extraction of O2 with a net inhibition of MVO2.
Oral Microbial Profile of the Marmoset

Qualitative and quantitative assessments were made of the cultivable oral microflora of adult marmosets that were given three difjerent dietary regimens. The identifiable isolates were dispersed among 12 recognized microbial families, 24 genera, and more than 40 species. Generally, marmosets that received a high sucrose diet had the highest bacterial counts.
On the absolute bias ratio of ratio estimators

Abstract The elegant Hartley—Ross inequality on the absolute bias ratio (ABR ≡ | Bias |/S.E.) of a ordinary ratio estimator is here generalized to that of a separate ratio estimator with stratified sampling. It is shown that, as long as the numerators and denominators used to form strata ratios are unbiased estimators, the absolute bias ratio of a separate ratio estimator will never exceed the square root of the sum of squares of the coefficient of variation of the denominators across strata. This provides, at design stages, a simple bound in practice to assess the limit and magnitude of the bias ratio of any separate ratio estimator that shares the same denominators. Exact expressions for biases of separate ratio estimators are also given.
A Numerical Integration Green's Function Model for Ultrasonic Field Profiles in Mildly Anisotropic Media

A numerical integration technique utilizing a point source Green's function is introduced to analyze the wave behavior in transversely isotropic-type anisotropic media allowing us to make fast and accurate computations of the acoustic field. The centrifugally cast stainless steel (CCSS) used in nuclear power plants is chosen as a sample medium because of its columnar grain character leading to material anisotropy. A representative number of field profiles are computed and plotted to illustrate the quasi-longitudinal, quasi-transverse, and horizontally-polarized shear wave propagation in a transversely-isotropic medium. Phenomena such as beam skewing, beam splitting, beam focusing, unsymmetrical beams, and other anisotropic effects, some of which are already known from earlier experimental observations, emerge as a computational result of the introduced technique.
Immobilized heparinase: In vitro reactor model

Heparinase immobilized to agarose has previously been shown to be useful in degrading heparin and thereby preventing thromboembolytic complications when this anticoagulant has been used in extracorporeal perfusions. The current study examined the kinetics of this immobilized enzyme. When heparinase is covalently bound to 8% agarose, the partition coefficient of heparin in the catalytic particle is 0.36 ± 0.048 (N = 10). The immobilized enzyme has a Km of 0.15 ± 0.03 mg/mL and an activation energy of 10.3 ± 0.57 kcal/gmol (N = 5). These values are statistically indistinguishable from the values for the free enzyme. The immobilized enzyme showed a pH activity optimum between 7.0 and 7.4, compared to the optimum pH of 6.5 for the soluble enzyme. The activity optimum of immobilized heparinase with respect to salt concentration was between 0 and 0.1M. A reactor containing immobilized heparinase recirculating internally at 1300 mL/min behaved as a continuously stirred tank reactor (CSTR) when solutions at a flow rate of 120 mL/min were passed through the device. The residence time distribution was determined using blue dextran (molecular weight 2 × 106 daltons), which is sterically excluded from the agarose catalyst. A model of the heparinase reactor based on ideal CSTR behavior and the immobilized enzyme kinetic parameters was developed. It accurately predicted experimental conversions over a range of catalyst volumes, enzyme loadings, and substrate concentrations to within 7% in most cases and with a maximum deviation of 13%.
Micromorphic theory: a gateway to nano world

Micromorphic theory (MMT) envisions a material body as a continuous collection of deformable particles; each possesses finite size and inner structure. It is considered as the most successful top-down formulation of a two-level continuum model, in which the deformation is expressed as a sum of macroscopic continuous deformation and internal microscopic deformation of the inner structure. In this work, the kinematics including the objective Eringen tensors is introduced. Balance laws are derived by requiring the energy equation to be form-invariant under the generalized Galilean transformation. The concept of material force and the balance law of pseudomomentum are generalized for MMT. An axiomatic approach is demonstrated in the formulation of constitutive equations for a generalized micromorphic thermoviscoelastic solid, generalized micromorphic fluid, micromorphic plasticity, and micromorphic electromagnetic–thermoelastic solid. Applications of MMT in micro/nanoscale are discussed.
Aztec State Making: Ecology, Structure, and the Origin of the State

It has become increasingly difficult to account for state formation solely in terms of ecological variables. It is suggested that consideration of prestate political structure and the interplay of ecological variables and political dynamics (political ecology) would enhance our understanding of why and how states emerge. The Aztecs provide a case for examination. [Aztecs, ecology, political competition, state origins] THE STATE IS A POWERFUL, COMPLEX, PERMANENTLY INSTITUTED SYSTEM Of centralized political administration. It exercises sovereignty in carrying out basic political functions (maintaining territorial rights, maintaining internal order, making and executing decisions regarding group action), and its authority in these matters is buttressed by sovereignty in the use of force within its jurisdiction (Keesing 1976:348; Sahlins 1968:4-7; Yoffee 1979:14-17). States are characterized by administrative complexity; administrative personnel are hierarchically ordered and specialized by administrative tasks (Johnson 1973:1-4; Wright 1978:49-68). The numerous attempts to explain why states emerge in some times and places but not others have been dominated by two contrasting approaches: the ecological and the structural. The first, based on the work of Julian Steward, relates state formation to the problems and/or opportunities presented to a human population by its environmental setting. In this approach, population growth and its resulting pressures provide the dynamic for state formation, and at least the initial stages are said to be promoted by the ecological benefits that the state confers on its general population. The second approach, growing out of the Marx-Engels tradition, regards state formation as a process generated by particular sociocultural orders. Certain types of societies (stratified societies, for example) are said to possess an internal dynamic that exerts pressure for state formation even when the relationship between the human population and its environment is stable. In this approach, the focus is less on a human population as a whole and more on social components and their interactions. Of these two approaches, the first has received a greater share of attention and has been elaborated more fully. As a result, some of its difficulties are now evident. The structural approach has been less thoroughly explored. This paper has three objectives: to discuss the strengths and weaknesses of the ecological approach to state formation in its current form; to suggest how a greater em
Structural instabilities of excited phases

The structural stability of various elemental metals (Ti, Sc, Al, Mo, and Nb), ordered compounds (PtTi and PtV), and disordered Ni-Cr alloys along distortion paths linking high-symmetry structures are investigated. A number of high-symmetry nonequilibrium structures are found to be mechanically unstable for these deformation paths, even for structures that occur at high temperature. For Ti, the electronic entropy is found to stabilize of the bcc phase at high temperatures, but without vibrational effects the hcp\ensuremath{\leftrightarrows}bcc transition would occur at much higher temperatures than observed. To treat disordered alloys along the Bain distortion path, the cluster expansion method is applied to the body-centered-tetragonal lattice, with particular choices of clusters in order to guarantee that the effective cluster interactions comply with the symmetry conditions of the cubic lattices. For disordered Ni-Cr alloys, the range of composition where the bcc and fcc phases are mechanically stable is determined.
A Mencian Version of Limited Democracy

The compatibility between Western democracy and other cultures, and the desirability of democracy, are two important problems in democratic theory. Following an insight from John Rawls’s later philosophy, and using some key passages in Mencius, I will show the compatibility between a ‘thin’ version of liberal democracy and Confucianism. Moreover, elaborating on Mencius’s ideas of the responsibility of government for the physical and moral well-being of the people, the respectability of the government and the ruling elite, and the competence-based limited political participation, I shall explore the Mencian criticisms of some ‘thick’ democratic ideas. Through the discussion in this paper, I hope to show the relevance of Confucianism to contemporary political philosophy and society.
Study of the reduction of airborne222Rn through chemical stabilization of226Ra in uranium mill tailings

In an attempt to decrease the emanating power of uranium and radium mill tailings, the tailings226Ra+2 were incorporated onto/into an alkaline earth sulfate crystal lattice. The difference in emanating power of aged and fresh crystals spiked with226Ra+2 solution to be adsorbed and incorporated into the sulfate crystal lattice was compared. The tailings were treated in three different slurries. The results indicate that treatment of tailings (by slurry) with BaSO4 is an effective method for reducing the emanating power of mill tailings when either deionized or HNO3 is used for a transfer medium of226Ra+2.
Influence of fertilization and atmospheric CO2 enrichment on ecosystem CO2 and H2O exchanges in single- and multiple-species grassland microcosms

Abstract This paper reports on measurements of net CO 2 and H 2 O exchange from single- and multiple-species microcosms composed of California annual grassland species grown at either ambient or elevated (ambient+36 Pa) CO 2 . Microcosms consisted of grassland species grown in PVC tubes (∼0.95 m deep×0.2 m diameter) containing ∼45 kg of either serpentine or sandstone derived soil or parent material in open-top enclosures under ambient meteorological conditions. Half of the microcosms were left unfertilized (low nutrient) while the other half received an intermediate level of a slow-release (N,P,K) fertilizer (high nutrient). Gas exchange was performed by sealing individual microcosms within a transparent chamber (on clear sunny days) and coupling this to an open gas-exchange system. In fertilized single-species microcosms, elevated CO 2 consistently enhanced net `ecosystem' CO 2 exchange (NCE) on a ground area basis in both early and late spring. Among unfertilized single-species microcosms, no significant trends or differences were observed in NCE between those grown at ambient versus elevated CO 2 . The NCE in sandstone and serpentine multiple-species microcosms was monitored seasonally over a majority of the 1993–1994 growing season. Rates were largely unaffected by growth CO 2 or fertilization until after mid-February, 1994. Water-use efficiency (WUE=NCE/evapotranspiration (ET)) was generally enhanced by elevated CO 2 , but this was primarily a result of enhancements in NCE as opposed to decreases in ET. Enhancements in NCE by elevated CO 2 in fertilized single-species microcosms at the growth-CO 2 concentration were partially explained by higher above-ground biomass in elevated CO 2 microcosms. However, ecosystem-level `acclimation' occurred such that microcosms grown at elevated CO 2 consistently had lower NCE than ambient CO 2 treatments at a single measurement CO 2 concentration (ambient or elevated). The reduction in apparent ecosystem-level photosynthetic capacity in elevated CO 2 microcosms was accompanied by decreases in foliar Rubisco activity, such that NCE measured at ambient CO 2 was highly correlated ( r =0.98) with foliar Rubisco activity across the three single-species microcosms in which it was measured.
Fitting a logarithmic spiral to the shoreline of a headland-bay beach

Abstract In some geographic areas, for example northeastern Venezuela, the beach shorelines which develop in the lee of a headland generally approximate a logarithmic spiral in plan view. A logarithmic spiral. r = exp( φ cot χ ), is written in polar coordinates and the search for the best-fitting polar-coordinate is a nonlinear minimization problem. A Macintosh TM Pascal program is described to determine the best origin and fit of a logarithmic spiral by least-squares regression. The logarithmic spiral is superimposed on a graph of the shoreline. Both curves are plotted as cubic splines. The area between the beach and fitted spiral is measured to evaluate the goodness-of-fit
Medicaid Eligibility Policies for People with AIDS

Although Medicaid is the primary prayer for health services provided to people with AIDS, Medicaid eligibility policies can be restrictive. This study presents Medicaid eligibility policies in each state for people with AIDS or HIV infection, including the categorical and medically needy classifications. The study documents that medically needy coverage is an important route to Medicaid coverage for people with AIDS. Because of the importance of this medically needy coverage, extending presumptive disability to any person with HIV and allowing them to spend down would provide a health financing safety net for people infected with HIV.
Ronald Reagan as Presidential Symbol Maker: The Federal Bureaucrat as Loafer, Incompetent Buffoon, Good Ole Boy, and Tyrant

Federal bureaucrat bashing has a long history in this country. In recent years Ronald Reagan, in particular, played on the public's resentment of the federal bureaucracy. For Reagan and his devoted audiences the federal bureaucrat was a symbol represent ing many of the qualities that are wrong with present-day society. Four dominant images of the federal bureaucrat emerge from Ronald Reagan's Public Papers. Reagan depicted the federal bureaucrat primarily as a loafer, incompetent buffoon, good ole boy, and tyrant. It is possible that these images were so well-received by much of the public because of widespread ambivalence about our organizational society.
Surface polaritons on uniaxial antiferromagnets

We investigate the properties of surface polaritons on uniaxial antiferromagnets. In zero applied field we find that surface polaritons may exist in a band of frequencies forbidden to bulk polaritons and that propagation is reciprocal, i.e., if the mode has frequency $\ensuremath{\omega}$ and wave vector ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}_{\ensuremath{\parallel}}$, then $\ensuremath{\omega}(+{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}_{\ensuremath{\parallel}})=\ensuremath{\omega}(\ensuremath{-}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}_{\ensuremath{\parallel}})$. When a field is applied parallel to the surface, along the anisotropy axis, surface and bulk polaritons may exist in the same frequency range, and the dispersion relation of the surface polaritons is no longer reciprocal. We show that surface polaritons may be easily detected through a standard attenuated total reflection measurement. The case of an antiferromagnetic metal is also discussed, since the negative dielectric constant of the metal influences the dispersion relation in a qualitative manner.
Effect of pressure on spin-orbit splitting in germanium

Abstract Using the OPW method we have evaluated the change in spin-orbit splitting of the strong optical reflectivity peak near 2.2 eV in Ge under hydrostatic pressure.
Separation of chiral furan derivatives by liquid chromatography using cyclodextrin-based chiral stationary phases.

The enantiomeric separation of a set of 30 new chiral furan derivatives has been achieved on native and derivatized β-cyclodextrin stationary phases using high performance liquid chromatography (HPLC). The hydroxypropyl-β-cyclodextrin (Cyclobond RSP), the 2,3-dimethyl-β-cyclodextrin (Cyclobond DM), and the acetyl-β-cyclodextrin (Cyclobond AC) stationary phases are the most effective chiral stationary phases (CSPs) for the separation of these racemates in the reverse phase mode. No enantioseparations have been observed on the native β-cyclodextrin chiral stationary phase (Cyclobond I 2000) and only a few separations have been attained on the S-naphthylethyl carbamate β-cyclodextrin (Cyclobond SN) and 3,5-dimethylphenyl carbamate β-cyclodextrin (Cyclobond DMP) chiral stationary phases in the reverse phase mode. The polar organic and the normal phase mode on these CSPs are not effective for separation of these compounds. The characteristics of the analytes, including steric bulk, hydrogen bonding ability, and geometry, play an important role in the chiral recognition process. The pH affects the enantioseparation of compounds with ionizable groups and the addition of 0.5% methyl tert-butyl ether to the mobile phase significantly enhances the separation efficiency for some highly retained compounds.
Effect of load conductance on the selectivity of notch filters

It has been found that notch filters using hyperbolically shaped RC lines have less fluctuations in selectivity due to load than those using exponentially shaped lines; the latter, in turn, fluctuate less than those using trigonometric lines. The longer a hyperbolic line is, the less it is affected by the load.
Low- and high-affinity phorbol ester and diglyceride interactions with protein kinase C: 1-O-alkyl-2-acyl-sn-glycerol enhances phorbol ester- and diacylglycerol-induced activity but alone does not induce activity.

Phorbol ester-induced conventional protein kinase C (PKCα, -βΙ/ΙΙ, and -γ) isozyme activities are potentiated by 1,2-diacyl-sn-glycerol. This has been attributed to a “cooperative” interaction of the two activators with two discrete sites termed the low- and high-affinity phorbol ester binding sites, respectively [Slater, S. J., Milano, S. K., Stagliano, B. A., Gergich, K. J., Ho, C., Mazurek, A., Taddeo, F. J., Kelly, M. B., Yeager, M. D., and Stubbs, C. D. (1999) Biochemistry 38, 3804−3815]. Here, we report that the 1-O-alkyl ether diglyceride, 1-O-hexadecyl-2-acetyl-sn-glycerol (HAG), like its 1,2-diacyl counterpart, 1-oleoyl-2-acetyl-sn-glycerol (OAG), also potentiated PKCα, -βI/II, and -γ activities induced by the phorbol ester 4β-12-O-tetradecanoylphorbol-13-acetate (TPA). Similar to OAG, HAG was found to bind to the low-affinity phorbol ester binding site and to enhance high-affinity phorbol ester binding, and to decrease the level of Ca2+ required for phorbol ester-induced activity, while being wi...
Studies of DNA dumbbells VIII. Melting analysis of DNA dumbbells with dinucleotide repeat stem sequences.

Melting curves and circular dichroism spectra were measured for a number of DNA dumbbell and linear molecules containing dinucleotide repeat sequences of different lengths. To study effects of different sequences on the melting and spectroscopic properties, six DNA dumbbells whose stems contain the central sequences (AA)10, (AC)10, (AG)10, (AT)10, (GC)10, and (GG)10 were prepared. These represent the minimal set of 10 possible dinucleotide repeats. To study effects of dinucleotide repeat length, dumbbells with the central sequences (AG)n, n = 5 and 20, were prepared. Control molecules, dumbbells with a random central sequence, (RN)n, n = 5, 10, and 20, were also prepared. The central sequence of each dumbbell was flanked on both sides by the same 12 base pairs and T4 end-loops. Melting curves were measured by optical absorbance and differential scanning calorimetry in solvents containing 25, 55, 85, and 115 mM Na+. CD spectra were collected from 20 to 45°C and [Na+] from 25 to 115 mM. The spectral database did not reveal any apparent temperature dependence in the pretransition region. Analysis of the melting thermodynamics evaluated as a function of Na+ provided a means for quantitatively estimating the counterion release with melting for the different sequences. Results show a very definite sequence dependence, indicating the salt-dependent properties of duplex DNA are also sequence dependent. Linear DNA molecules containing the (AG)n and (RN)n, sequences, n = 5, 10, 20, and 30, were also prepared and studied. The linear DNA molecules had the exact sequences of the dumbbell stems. That is, the central repeat sequence in each linear duplex was flanked on both sides by the same 12-bp sequence. Melting and CD studies were also performed on the linear DNA molecules. Comparison of results obtained for the same sequences in dumbbell and linear molecular environments reveals several interesting features of the interplay between sequence-dependent structural variability, sequence length, and the unconstrained (linear) or constrained (dumbbell) molecular environments. © 2005 Wiley Periodicals, Inc. Biopolymers 82: 199–221, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Basic rectangle of the mandible.

THE arrangement of teeth in the lower jaw of man (Hominidae) may be distinguished from that of apes (Pongidae) by means of the “basic rectangle of the mandible”1. Leakey defined the rectangle and suggested that, in the Pongidae, the sides “are nearly twice as long as the upper and lower ends”; whereas in the Hominidae “the basic rectangle is seen to be nearly a square”1. Leakey presented several illustrative diagrams but he did not otherwise quantify his measurements.
ENDOSCOPIC URETEROURETEROSTOMY: LONG-TERM FOLLOWUP USING A NEW TECHNIQUE

Purpose: We describe a new technique using a single ureteroscope and fluoroscopy for reestablishing ureteral continuity.Materials and Methods: Nine patients with obliterated ureteral segments (1 bilateral) were referred for treatment, of whom 3 had concurrent ureterovaginal fistulas. Mechanism of injury included open pelvic surgery in 9 ureteral segments and ureteroscopy in 1. Ureteral continuity was reestablished using a technique combining ureteroscopy and a fluoroscopically guided antegrade snare. The affected ureteral segment was then dilated and stented using a 14/7 reversed endopyelotomy stent.Results: Ureteral continuity was reestablished in all 10 consecutive attempts with this technique. At a mean followup of 16 months (range 6 to 33) all patients were stent-free without radiological evidence of obstruction. All 3 patients with fistulas were dry. In 3 patients ureteral strictures developed and required balloon dilation. Balloon dilation failed in 1 case and ultimately ureteral reimplantation was ...
Rapid identification and speciation of Haemophilus bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Several species of the genus Haemophilus are well known etiological agents of pneumonia, meningitis, conjunctivitis, epiglottitis and chancroid. However, identification and speciation of Haemophilus is both time consuming and labor intensive. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF-MS) has been used by several investigators to profile proteins from intact and disrupted bacteria; consequently, MALDI/TOF-MS has emerged as a powerful tool in diagnostic bacteriology. This paper reports the use of MALDI/TOF-MS as a technique for the rapid identification and speciation of Haemophilus. This technique was used to not only identify the pathogen, H. ducreyi, but also to determine strain differences from different isolates. Mass spectral ‘fingerprints’ were obtained which permitted the rapid speciation of not only pathogenic forms of Haemophilus, but also those bacteria which are normally regarded as non-pathogenic and members of the normal flora. MALDI/TOF mass spectra can be acquired in 10 min, allowing the identification of Haemophilus spp. within 24 h rather than the 48 h or more needed for traditional bacteriological methods. In addition, these are the first mass spectral fingerprints available in the literature for many of these organisms. © 1998 John Wiley & Sons, Ltd.
CHEMICAL EFFECTS OF SMOKE-PROCESSING ON FRANKFURTER MANUFACTURE AND STORAGE CHARACTERISTICS

Frankfurters were made by standard commercial practices except for the smoke treatment which involved four different methods: solid smoke-aerosol, liquid smoke-aerosol, liquid smoke-external dip, and liquid smoke-internal mix. For control purposes, frankfurters were prepared without any smoke treatment. All frankfurters were packaged and stored at 5°C with samples removed for analyses weekly for 3 wk. Method of smoke application did affect the processed weight of the frankfurters. Liquid smoke-aerosol treatment produced the heaviest franks; the liquid smoke-internal mix application produced franks lighter in weight than the other treatments including the nonsmoked control. Smoke treatment had no significant effect on the fat or total volatile nitrogen (expressed on a fat-free basis) content of the franks. However, it did affect the amounts of moisture, phenol, FFA and TVN as well as the pH and TBA values. The use of the liquid smoke-external dip significantly lowered the nitrite content of the franks when compared to all other treatments which were not different from each other. As the phenol content increased, pH decreased. Generally, storage had no effect on the frankfurter properties evaluated in these studies. However, pH was seen to drop then rise again whereas the amount of FFAs rose then fell during the 3-wk period.
Unique cell wall abnormalities in the putative phosphoinositide phosphatase mutant AtSAC9

SAC9 is a putative phosphoinositide phosphatase in Arabidopsis thaliana involved in phosphoinositide signaling. sac9-1 plants have a constitutively stressed phenotype with shorter roots which notably accumulate phosphatidylinositol 4,5-bisphosphate and its hydrolysis product inositol trisphosphate. We investigated the primary roots of sac9-1 seedlings at the cytological and ultrastructural level to determine the structural basis for this altered growth. Despite the normal appearance of organelles and cytoplasmic elements, our studies reveal extreme abnormalities of cell wall and membrane structures in sac9-1 primary root cells, regardless of cell type, position within the meristematic area, and plane of section. Cell wall material was deposited locally and in a range of abnormal shapes, sometimes completely fragmenting the cell. Simple protuberances, broad flanges, diffuse patches, elaborate folds, irregular loops and other complex three-dimensional structures were found to extend randomly from the pre-existing cell wall. Abundant vesicles and excessive membrane material were associated with these irregular wall structures. We argue that a perturbed phosphoinositide metabolism most likely induces these observed abnormalities and hypothesize that a disorganized cytoskeleton and excessive membrane trafficking mediate the cell wall defects.