cssi/SciSciGPT-SciSciNet huggingface dataset:
Mitomycin C and menadione for the treatment of lung cancer: a phase II trial.

A phase II trial of menadione [2.5 gm/m2 as a continuous intravenous (iv) infusion over 48 hours] followed by mitomycin C (10–20 mg/m2 iv bolus) administered every 4 to 6 weeks was performed in 23 patients with advanced lung cancer. Menadione, a vitamin K analog which lowers intracellular pools of reduced glutathione (GSH), was combined with mitomycin C in an attempt to overcome thiol-mediated resistance to alkylating agent chemotherapy. The median age of patients entered on this trial was 62 years; performance status ranged from 60–90%. Two of the 23 patients (9%; 95% confidence interval, 1% to 28%) had objective responses lasting 3.5 months and 13 months respectively, while 4 additional patients developed short unconfirmed responses (lacking follow-up response data to estimate response duration). Median survival for all patients was 5.5 months. Treatment with mitomycin C and menadione was well tolerated except for hematologic toxicity and cardiac events of unclear relationship to the study drugs. Thirty-one percent of treatment courses were complicated by grade 3 or 4 hematologic toxicity including one episode of hemolytic anemia. One patient developed interstitial pneumonitis. Two patients developed a decrease in left ventricular ejection fraction: one patient remained asymptomatic, but the other patient developed congestive heart failure. Although only 9% of patients had confirmed objective responses, 28% (5 of 18) of the patients with non-small cell lung cancer demonstrated biological activity (tumor regressions fulfilling the criteria for objective response on a single occasion but 3 patients lacking a follow-up measurement to document response duration) to this combination of mitomycin C and menadione. We conclude that further studies of chemomodulation in non-small cell lung cancer are appropriate.
Repeated electroconvulsive shock downregulates the opioid receptors in rat brain

Abstract Ten consecutive daily electroconvulsive shocks (ECSs), which produce maximal tonic and clonic convulsions, caused reductions of μ- and θ-opioid receptor binding in the hypothalamus, hippocampus and caudate nucleus, but not in the frontal cortex and brainstem. These changes of opioid receptor binding were not observed in rats receiving a single ECS. Scatchard analysis revealed that ECS-induced reduction of μ- and δ-receptor binding was due to a decrease in the binding sites but not to a change in the binding affinity. Time course studies showed that 7 days after the end of 10 consecutive daily ECSs, both μ- and δ-receptor binding remained lower than those of sham controls. However, the effects of ECS on the opioid receptor binding disappeared in 2–3 weeks. These observations are consistent with the hypothesis that ECS treatments increase the release of opioid peptides in certain brain regions which in turn down-regulate the opioid receptors.
Population viability and species interactions : Life outside the single-species vacuum

Abstract Population viability analysis (PVA) has become a widely used set of tools for evaluating relative extinction risk and prioritizing management options among imperiled populations. While PVA is a widely sanctioned tool in conservation biology, the field of population viability is in its infancy with respect to species interactions. In this paper, I review available methods for evaluating extinction risk when species interactions contribute significantly to population viability. This review includes an evaluation of six broad categories of species interactions (predation, disease, competition, mutualism, parasitism and host-parasitoid interactions) in population viability analysis, with a particular focus on predation as a case study. I first evaluated how often species interactions are considered when PVA is applied to population data from imperiled species. I identified 378 articles in commonly cited conservation journals, of which 24 attempted a viability analysis for populations threatened by interactions with other species. Most of these PVA’s treat a putative species interaction as a constant source of mortality rather than a coupled, dynamic population process. Second, I reviewed the literature to identify the availability of time-series of abundance data for two interacting species in which at least one species was threatened or endangered. Adequate time-series data were available for both species comprising an interacting pair in only 9 out of 407 papers reviewed. Third, I used a stochastic, fully stage-structured predator prey model to create time-series data (vital rates and projection matrices) in order to quantify the efficacy of two matrix-based, single-species PVA approaches. Simple single-species PVAs confound stochastic variation with population cycles induced by species interactions (in this case predation). As a result these models provide conservatively biased forecasts of viability. Unfortunately, the data needed to construct more complex PVA’s with feedback and multi-species stochasticity are rarely collected. I close with a discussion of key advances needed to “escape the population vacuum” in a move toward more realistic estimates of extinction risk.
Micro-Machining of Copper and Aluminum Crystals

The process of chip formation in copper and aluminum single crystals has been examined with a scanning electron microscope. The morphology of the shear planes clearly illustrates that the actual deformation zone (layer or shear front) is an extremely thin and well-defined band of slip planes wherein the predominant deformation takes place. The appearance of the top or upper surface of the chip corresponds to the micro mechanisms operating during the process of machining.
Finding Z ' bosons coupled preferentially to the third family at CERN LEP and the Fermilab Tevatron

${Z}^{\ensuremath{'}}$ bosons that couple preferentially to the third generation fermions can arise in models with extended weak $[\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(2)]$ or hypercharge $[\mathrm{U}(1)\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1)]$ gauge groups. We show that existing limits on quark-lepton compositeness set by the CERN LEP and Fermilab Tevatron experiments translate into lower bounds of the order of a few hundred GeV on the masses of these ${Z}^{\ensuremath{'}}$ bosons. Resonances of this mass can be directly produced at the Tevatron. Accordingly, we explore in detail the limits that can be set at Run II using the process $p\overline{p}\ensuremath{\rightarrow}{Z}^{\ensuremath{'}}\ensuremath{\rightarrow}\ensuremath{\tau}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}e\ensuremath{\mu}.$ We also comment on the possibility of using hadronically decaying taus to improve the limits.
Fast multigrid method for solving incompressible hydrodynamic problems with free surfaces

We develop of a finite-volume multigrid Euler scheme for solving three-dimensional, fully nonlinear ship wave problems. The flowfield and the a priori unknown free surface location are calculated by coupling the free surface kinematic and dynamic equations with the equations of motion for the bulk flow. The evolution of the free surface boundary condition is linked to the evolution of the bulk flow via a novel iteration strategy that allows temporary leakage through the surface before the solution is converged. The method of artificial compressibility is used to enforce the incompressibility constraint for the bulk flow. A multigrid algorithm is used to accelerate convergence to a steady state
Using neural networks in reliability prediction

It is shown that neural network reliability growth models have a significant advantage over analytic models in that they require only failure history as input and not assumptions about either the development environment or external parameters. Using the failure history, the neural-network model automatically develops its own internal model of the failure process and predicts future failures. Because it adjusts model complexity to match the complexity of the failure history, it can be more accurate than some commonly used analytic models. Results with actual testing and debugging data which suggest that neural-network models are better at endpoint predictions than analytic models are presented. >
Horseshoe kidney with a retrocaval ureter

Horseshoe kidney and retrocaval ureter are two uncommon congenital anomalies of the genitourinary system that have rarely been reported to occur in the same patient. In each case previously reported, the isthmus of the horseshoe was positioned posterior to the inferior vena cava and anterior to the aorta. In no case was the diagnosis of both anomalies made preoperatively. We report a case of simultaneous horseshoe kidney and retrocaval ureter diagnosed by preoperative imaging studies and discuss the diagnostic evaluation and surgical management of this rare entity.
Reliable polarization switching of BiFeO3

As a room temperature multi-ferroic with coexisting anti-ferromagnetic, ferroelectric and ferroelastic orders, BiFeO(3) has been extensively studied to realize magnetoelectric devices that enable manipulation of magnetic ordering by an electric field. Moreover, BiFeO(3) is a promising candidate for ferroelectric memory devices because it has the largest remanent polarization (P(r)>100 μC cm(-2)) of all ferroelectric materials. For these applications, controlling polarization switching by an electric field plays a crucial role. However, BiFeO(3) has a complex switching behaviour owing to the rhombohedral symmetry: ferroelastic (71°, 109°) and ferroelectric (180°) switching. Furthermore, the polarization is switched through a multi-step process: 180° switching occurs through three sequential 71° switching steps. By using monodomain BiFeO(3) thin-film heterostructures, we correlated such multi-step switching to the macroscopically observed reliability issues of potential devices such as retention and fatigue. We overcame the retention problem (i.e. elastic back-switching of the 71° switched area) using monodomain BiFeO(3) islands. Furthermore, we suppressed the fatigue problem of 180° switching, i.e. loss of switchable polarization with switching cycles, using a single 71° switching path. Our results provide a framework for exploring a route to reliably control multiple-order parameters coupled to ferroelastic order in other rhombohedral and lower-symmetry materials.
Accurate “doubly-occupied orbital sea” approximation for the many-electron valence bond wavefunction

Abstract A new approximation method based on the dominance of intra-pair correlations is proposed for calculating many-electron valence bond wavefunctions. This “doubly-occupied orbital sea” valence bond method (DOS VB) gives accurate orbitals as well as energies. The computation time increases with the number of electrons as N S rather than ( N +1)! as for an exact calculation. Results for BH are presented by way of illustration.
Prediction of brachial plexus stretching during shoulder dystocia using a computer simulation model

Abstract Objective The purpose was to study the impact of maternal endogenous and clinician-applied exogenous delivery forces on brachial plexus stretching during a shoulder dystocia event. Study design A computer software crash dummy model (MADYMO, version 5.4, TNO Automotive, Delft, The Netherlands) was modified on the basis of established maternal pelvis and fetal anatomic specifications. The brachial plexus was modeled as a spring, with mechanical properties that were based on previously reported experimental data. Increasing amounts of endogenous or exogenous loading forces were applied until delivery of the anterior fetal shoulder occurred. Brachial plexus deformation was assessed as percent stretch in the nerve (Change in length/Original length×100). Results With lithotomy positioning, both maternal endogenous and clinician-applied exogenous delivery forces were associated with brachial plexus stretching (15.7% vs 14.0%, respectively). McRoberts positioning reduced needed loading forces for delivery and resulted in 53% less brachial plexus stretch (6.6%). Downward lateral displacement of the fetal head was associated with a 30% increase in brachial plexus stretch (18.2%) compared with axial positioning of the head (14.0%). Conclusion Brachial plexus stretch varied as a result of the load required for delivery, the source of the applied force, pelvic orientation, and fetal head positioning. Maternally derived and clinician-applied delivery forces can both lead to brachial plexus deformation when shoulder dystocia is encountered. The McRoberts maneuver can reduce brachial plexus stretching. Management of fetal head position may also be important in reducing unnecessary brachial plexus stretch.
Chemical synthesis and biochemical characterization of a biotinylated derivative of 17β-estradiol with a long side chain covalently attached to its C-7α position

Abstract High-affinity biotinylated derivatives of 17β-estradiol (E2) are of value for isolation of various estrogen-binding proteins (including estrogen receptors) and also for studying protein–protein interactions involving these proteins. In this study, we developed a simplified route for the chemical synthesis of a biotinylated derivative of E2 (compound 7) with a side chain attached to its C-7α position. Compound 7, i.e., 7α-{7-[8-(biotinamido)-octanamido]-heptyl}-estradiol, could be readily synthesized from 6-keto-estradiol-3,17β-di-tetrahydropyranyl ether (compound 2, which can be prepared from E2), with a final yield of 36%. In vitro receptor-binding assay confirmed that the synthesized affinity ligand has a high binding affinity for both human estrogen receptor α and β. When the affinity ligand (compound 7) was immobilized with avidin on an affinity column, it effectively bound human estrogen receptor α, and the receptor protein could be selectively eluted with a biotin-containing buffer. Using the same affinity ligand, prolyl 4-hydroxylase β-subunit (also known as protein disulfide isomerase) was identified as one of the high-affinity E2-binding proteins in the whole cytosolic protein mixture prepared from MCF-7 human breast cancer cells. Computational molecular modeling analysis showed that compound 7 can bind to human estrogen receptor α in a similar manner as ICI-182,780 and raloxifene, and their binding energy values are also similar.
Reactions to DRL schedule change in rats with septal damage

Normal rats and rats with septal lesions were given 45 days of DRL training on one of three different schedule sequences: DRL 10-20-10, 20-30-20, and 30-40-30, with 15 days of training on each schedule value. Interpolated training on a DRL schedule having a 10-sec longer delay requirement than the initial schedule did not result in further response suppression than that generated by the initial schedule in the case of rats with septal lesions. However, normal rats showed lower responding on the second exposure of DRL 10 and DRL 20 but not on DRL 30. In general, increasing the DRL delay requirement by 10 sec resulted in decreased responding. However, the magnitude of the decrease was a function of the relative difference in schedule requirement only in the case of rats with septal damage. Decreasing the delay by 10 sec led to increased responding in both normal and operated rats, with the magnitude of the increase being a function of the relative difference in delay requirement.
Scanning Electron Microscopic Studies of Antennal Receptors of the Worker Honey Bee, including Sensilla Campaniformia

The sensory receptors of the flagellum of worker honey bees were studied with the scanning electron microscope. The various types of sensilla present on the flagellum are illustrated. The sensillum campaniform , not previously reported to be present on the antennal flagella of honey bees is illustrated and discussed. The presence of this sense organ on at least 9 of the 10 segments of the flagellum suggests that its function is not olfactory, because it is known that olfaction is lost upon amputation of the 8 distal segments. Also campaniform sensilla, in general, are considered to be mechanoreceptors. The possibility that the campaniform sensilla are sensitive to temperature, CO2, humidity, or a combination of these factors is discussed. Comparative studies of the sensory receptors of Apis mellifera ligustica (Spinola) and Apis mellifera adansonii (Latreille) revealed very few, if any, differences.
Family portraits: past and present representations of parents in special education text books

This paper analyses the descriptions of families of children with disabilities as contained in introductory special education texts over the last 50 years. These text books are typically used in pr...
Epidemiology, outcomes, and mortality predictors of invasive mold infections among transplant recipients: a 10-year, single-center experience.

Background The epidemiology of invasive mold infections (IMI) in transplant recipients differs, based on geography, hosts, preventative strategies, and methods of diagnosis.
Burn-in test reduction for the Digital Micromirror Device (DMD)

Burn-in test has long been used in the semiconductor industry to screen out manufacturing defects. MEMS technologies, such as the DMD, can also use burn-in test to eliminate infant mortality failures. Burn-in test and test systems are among the most costly however, and it is always under review to shorten time or increase efficiency without reducing effectiveness. Detailed failure mode analysis from many thousands of device test logs resulted in the development of a novel application of an observed stress factor. Burn-in test time was reduced 55% on high volume DMD products with increased test efficiency and effectiveness.
Effect of hypoxic hypoxia on taurine concentrations in ventricles of mouse hearts.

The effects of hypoxic hypoxia on the concentration of taurine in right ventricles was studied in the hearts of male CF1 mice caged individually and maintained for 16 hr per day in a hypobaric chamber evacuated to an air pressure of 307 mm Hg. After 23 days hearts were excised and right and left ventricles were separated and lyophilized. Hematocrits in chamber animals were 77-82%, compared to 45-49% for control mice. Mean weights of right ventricles of animals from the chamber were 11.2 +/- 0.9, compared to control values of 7.0 +/- 0.4, mg dry weight. The mean dry weights of left ventricles in both groups of animals were the same. There were no significant differences in the nmoles taurine per mg day tissue in either heart chamber, with mean values +/- S.E.M. of 124.0 +/- 4.6 and 135.0 +/- 4.5 in right ventricles and 128.0 +/- 4.3 and 110.9 +/- 15.3 in left ventricles of experimental and control animals respectively. Thus, hypertrophy which results from hypoxia is not accompanied by increased concentrations of taurine in right ventricles.
Permeability of human dental enamel to acriflavine and potassium fluoride.

Abstract Permeability of human dental enamel was studied by following the penetration of acriflavine and potassium fluoride when applied to the surface of the teeth either in vitro or in vivo. Using ultraviolet microscopy to follow the penetration of acriflavine, and the increased resistance to acid etching to follow fluoride penetration, the results indicate that the prism boundary is the permeable structure of enamel. Acriflavine diffuses more rapidly into enamel than potassium fluoride, and both diffuse more rapidly in vivo than in vitro. Application of a concentrated fluoride solution to the surface of the enamel in vivo produced an acid-resistant layer that was similar in etching pattern to a natural maturation. This finding may have clinical application in caries prevention.
Pore structural effects in catalytic gasification of coal chars

The effect of pore structure on the gasification of two chars impregnated with potassium carbonate catalyst is investigated. Well-characterized char samples were reacted with carbon dioxide, water vapor, and oxygen. The effects of catalyst on the magnitude of the gasification rate as well as on the entire rate vs. conversion pattern are reported. Reactivity and structural data are analyzed to obtain a meaningful comparison of the gasification behavior for all char-gas pairs. Initial intra-particle catalyst dispersion was strongly influenced by the pore structure of the chars. During gasification with carbon dioxide and water, the catalyst appeared to redistribute itself in accordance to the accepted reaction mechanism, leading to superior catalytic activity. The reported measurements indicate that both the pore structure of the chars and the chemistry of a particular reaction are key factors in determining the overall catalytic performance.
Comparison of the Roles of Insulin and Insulin-Like Growth Factor I in Casein Gene Expression and in the Development of α-Lactalbumin and Glucose Transport Activities in the Mouse Mammary Epithelial Cell

The concentration-activity profiles for insulin and insulin-like growth factor I (IGF-I; in the presence of hydrocortisone and PRL) have been compared in terms of the accumulation of β-casein mRNA, total casein synthesis, and α-lactalbumin and basal carrier-mediated glucose transport activities in mammary epithelial cells from midpregnant mice. For the accumulation of the casein mRNA and the induction of casein synthesis and α-lactalbumin activity, the insulin ED50 is 1–2 ng/ml, while that for IGF-I is 10- to 20-fold greater. The effects of insulin and IGF-I are not additive in these instances. For the induction of basal carrier-mediated glucose transport, the insulin ED50 is 8 ng/ml, and that for IGF-I is 16 ng/ml. Either factor can induce transport activity up to the level present in the cells from 2-day lactating mice. In this instance the effects are additive; insulin and IGF-I together can induce the transport up to the 10-day lactating level. (Endocrinology 120: 1411–1416, 1987)
Differencing of the diffusion equation in Lagrangian hydrodynamic codes

Abstract The general problem of finite differencing the diffusion equation on a two-dimensional Lagrangian hydrodynamic mesh is discussed and a set of general criteria is developed. A detailed description is given of a particular difference scheme satisfying these criteria. A numerical test case is presented.
A cerebroprotective dose of intravenous citrate/sorbitol-stabilized dehydroascorbic acid is correlated with increased cerebral ascorbic acid and inhibited lipid peroxidation after murine reperfused stroke.

OBJECTIVE: Oxidative damage has been implicated in the pathogenesis of cerebral ischemia. We previously demonstrated that exogenously supplied dehydroascorbic acid (DHA), an oxidized, blood-brain barrier transportable form of the antioxidant ascorbic acid (AA), improves outcome after experimental stroke. METHODS: To investigate the neuroprotective effect of DHA therapy, we measured cerebral AA levels using a novel assay, quantified markers of lipid peroxidation, and evaluated infarct volume after reperfused stroke in a murine model. All experiments were performed using a new citrate/sorbitol-stabilized DHA formulation to improve the stability of the compound. RESULTS: Intraparenchymal AA levels declined after cerebral ischemia/reperfusion and were repleted in a dose-dependent fashion by postischemic administration of intravenous DHA (P < 0.01). Repletion of these levels was associated with reductions in cerebral malondialdehyde levels (P < 0.05), which were also elevated after reperfused stroke. DHA repletion of interstitial AA levels and reduction in cerebral lipid peroxidation was associated with dose-dependent reductions in infarct volume (P < 0.05). CONCLUSION: Together, these results indicate that an intravenous cerebroprotective dose of citrate/sorbitol-stabilized DHA is correlated with increased brain ascorbate levels and a suppression of excessive oxidative metabolism.
Proton NMR studies of the biologically active 1–34 fragment of bovine parathyroid hormone: Examination of a structural model

Abstract Proton NMR spectra of the biologically active 1–34 fragment of bovine parathyroid hormone (bPTH) were studied as a function of pH over the range of pH 4 to 10, in buffer and in 6 m guanidine DC1. One of the histidine C-2 peaks titrated normally, with a p K a value of 6.8, but the other two histidines in this peptide had p K a values of 6.3. Denatured PTH showed only one histidine C-2 peak with a p K a of 6.7. An aliphatic peak identified as due to either a methionine or a glutamine residue also shifted with pH, and the p K a for this shift was 6.3. Finally, small but significant upfield shifts in the methyl and methylene resonances were observed as a function of pH, and when compared to the denatured peptide. These results indicate that the N-terminal domain of native PTH has considerable structure in solution, and are consistent with a theoretical model for the folding of this peptide (10).
Influence of temperature and water potential on root growth of white oak

Root growth of white oak (Quercus alba L.) was observed under field conditions using a rhizotron. The effects of temperature, soil water potential, and leaf water potential were evaluated on three measures of root growth and development: root elongation rate, number of growing roots, and root growth intensity (sum of projected root area compared to the total root viewing area). Root elongation rate was linearly related to changes in soil temperature and soil water potential. At soil temperatures less than 17deg;C, temperature was the dominant factor affecting rate of growth, bat at temperatures greater than 17°C soil water potential became the important factor. Unlike root elongation rate, the number of growing roots and root growth intensity increased at cold soil temperatures (8°C) and at soil water potentials of-0.3 to -0.8 MPa. At high soil water potentials (-0.1 MPa) root elongation rate reached a maximum while the number of growing roots and root growth intensity were low. These differences showed that root growth and development were not exclusively affected by the soil environment. In addition, the relationship between root growth and predawn leaf water potential suggested that root growth was a contributing factor to the drought resistance of white oak.
mother or mistress but never a monk: Buddhist notions of female gender in rural Thailand

Notions of gender, like those of space, time, and especially person, constitute fundamental ideas in an Aristotelian sense (Durkheim 1965[1915]:21-22, 488ff.), serving to orient people in their relationships with others. While gender notions never determine behavior, they are evoked-sometimes explicitly, more often implicitly-in making sense of the self as an actor in the world. In most societies, such notions have a givenness, an unproblematic character, because they are rooted in unquestioned understandings of the underlying meaning of reality. Insofar as the world view remains unchallenged, deviations as well as conformance to cultural norms derived from gender ideas are understood with reference to
A theoretical analysis of the influence of wheelchair seat position on upper extremity demand

article i nfo Background: The high physical demands placed on the upper extremity during manual wheelchair propulsion can lead to pain and overuse injuries that further reduce user independence and quality of life. Seat position is an adjustable parameter that can influence the mechanical loads placed on the upper extremity. The pur- pose of this study was to use a musculoskeletal model and forward dynamics simulations of wheelchair propulsion to identify the optimal seat position that minimizes various measures of upper extremity demand including muscle stress, co-contraction and metabolic cost. Methods: Forward dynamics simulations of wheelchair propulsion were generated across a range of feasible seat positions by minimizing the change in handrim forces and muscle-produced joint moments. Resulting muscle stress, co-contraction and metabolic cost were examined to determine the optimal seat position that minimized these values. Findings: Musclestressandmetaboliccostwerenearminimalvaluesatsuperior/inferiorpositionscorresponding to top-dead-center elbow angles between 110 and 120° while at an anterior/posterior position with a hub- shoulder angle between −10 and −2.5°. This coincided with a reduction in the level of muscle co-contraction, primarily at the glenohumeral joint.
Limited social learning of a novel technical problem by spotted hyenas.

Social learning can have profound evolutionary consequences because it drives the diffusion of novel behaviours among individuals and promotes the maintenance of traditions within populations. We inquired whether spotted hyenas (Crocuta crocuta), generalist carnivores living in complex, primate-like societies, acquire information from conspecifics about a novel problem-solving task. Previously, we presented wild hyenas with a food-access puzzle and found that social learning opportunities did not affect problem-solving success among observers, but did reduce observers’ neophobia. However, we had little control over which individuals observed conspecifics solve the problem, and few wild hyenas were successful. Therefore, we conducted an experiment in captivity where we controlled observer access to two demonstration styles. Again, social learning opportunities did not affect problem-solving success, but tended to reduce neophobia among captive observers. Social learning opportunities also influenced problem-solving style. Captive hyenas showed limited evidence for directed social learning; low-ranking individuals paid closer attention to demonstrators than high-ranking individuals, although this greater attention did not result in greater success. We conclude that wild and captive hyenas exploit social learning opportunities similarly, and that the limited social learning shown by hyenas on this task is likely based on localized stimulus enhancement.
From Homodimer to Heterodimer and Back: Elucidating the TonB Energy Transduction Cycle

ABSTRACT The TonB system actively transports large, scarce, and important nutrients through outer membrane (OM) transporters of Gram-negative bacteria using the proton gradient of the cytoplasmic membrane (CM). In Escherichia coli, the CM proteins ExbB and ExbD harness and transfer proton motive force energy to the CM protein TonB, which spans the periplasmic space and cyclically binds OM transporters. TonB has two activity domains: the amino-terminal transmembrane domain with residue H20 and the periplasmic carboxy terminus, through which it binds to OM transporters. TonB is inactivated by all substitutions at residue H20 except H20N. Here, we show that while TonB trapped as a homodimer through its amino-terminal domain retained full activity, trapping TonB through its carboxy terminus inactivated it by preventing conformational changes needed for interaction with OM transporters. Surprisingly, inactive TonB H20A had little effect on homodimerization through the amino terminus and instead decreased TonB carboxy-terminal homodimer formation prior to reinitiation of an energy transduction cycle. That result suggested that the TonB carboxy terminus ultimately interacts with OM transporters as a monomer. Our findings also suggested the existence of a separate equimolar pool of ExbD homodimers that are not in contact with TonB. A model is proposed where interaction of TonB homodimers with ExbD homodimers initiates the energy transduction cycle, and, ultimately, the ExbD carboxy terminus modulates interactions of a monomeric TonB carboxy terminus with OM transporters. After TonB exchanges its interaction with ExbD for interaction with a transporter, ExbD homodimers undergo a separate cycle needed to re-energize them. IMPORTANCE Canonical mechanisms of active transport across cytoplasmic membranes employ ion gradients or hydrolysis of ATP for energy. Gram-negative bacterial outer membranes lack these resources. The TonB system embodies a novel means of active transport across the outer membrane for nutrients that are too large, too scarce, or too important for diffusion-limited transport. A proton gradient across the cytoplasmic membrane is converted by a multiprotein complex into mechanical energy that drives high-affinity active transport across the outer membrane. This system is also of interest since one of its uses in pathogenic bacteria is for competition with the host for the essential element iron. Understanding the mechanism of the TonB system will allow design of antibiotics targeting iron acquisition.
Epithelial biology in the gastrointestinal system: insights into normal physiology and disease pathogenesis.

The gastrointestinal system comprises a multifaceted collection of organs whose coordinated functions are essential for life. The gut, and the organs that drain into it, subserve the dual imperative of digesting and absorbing nutrients while preventing the uptake of toxins and pathogens. These functions were critical to the development of multicellular life-forms. Much of the physiology of the gastrointestinal system revolves around the biology of the columnar epithelia that line its hollow organs. The intestinal epithelium, in particular, represents a massive contiguous interface with the outside world that, in an adult human, exceeds the surface area of a tennis court. Thus, there is substantial reserve capacity for the digestion and absorption of dietary components but also a vast surface that must be defended against potential invaders, as well as surplus capacity for fluid and electrolyte transport that can contribute to life-threatening dehydration in certain severe diarrhoeal diseases. Indeed, many digestive diseases are common, and the pathogenesis of several can be traced, at least in part, to epithelial dysfunction.
Secretory avocado idioblast oil cells: evidence of their defensive role against a non-adapted insect herbivore

We tested the hypothesis that avocado idioblast oil cells play a defensive role against herbivorous insects. Toxicities of the intact avocado idioblast oil cells and the extracted idioblast oil were compared for three insect herbivores. Spodoptera exigua (Hubner) larvae are generalists that do not feed on avocados. By contrast, Sabulodes aegrotata (Guenee) and Pseudoplusia includens (Walker) larvae are generalist herbivores that readily feed on avocados. All bioassays were performed at a naturally occurring concentration of idioblast oil cells (2% w/w). Choice experiments showed that S. exigua larvae avoided diet treated with avocado idioblast oil cells and consume more control than treated diet. In contrast, idioblast oil cells had no significant antifeedant effects on the adapted S. aegrotata and P. includens larvae. Subsequent experiments designed to assess resistance mechanisms separated pre-ingestive (behavioral) and post-ingestive (physiological) effects of the avocado idioblast oil cells, and the extracted idioblast oil, on the two adapted herbivores. Post-ingestive adaptation was the mechanism that allows feeding. Because the impact of the avocado idioblast oil cells was greatest on the performance of non-adapted S. exigua, additional experiments determined that larvae fed diet containing the oil cells had higher mortality and reduced larval growth compared to controls. Developmental times were significantly prolonged for the survivors. Thus, increased mortality, reduced developmental rates, and antifeedant activity in the non-adapted insect indicate that defense against non-adapted herbivores may be an important function of idioblast cells in avocados.
Image distance functions for manifold learning

Many natural image sets are samples of a low-dimensional manifold in the space of all possible images. When the image data set is not a linear combination of a small number of basis images, linear dimensionality reduction techniques such as PCA and ICA fail and non-linear dimensionality reduction techniques are required to automatically determine the intrinsic structure of the image set. Recent techniques such as ISOMAP and LLE provide a mapping between the images and a low-dimensional parameterization of the images. This paper specializes general manifold learning by considering a small set of image distance measures that correspond to key transformation groups observed in natural images. This results in more meaningful embeddings for a variety of applications.
Effect of Physical Form and Amount of Citrus Pulp on Utilization of Complete Feeds for Dairy Cattle

Abstract Experiment 1 tested effects of conventional pulp on rumen fermentation in five groups of fistulated steers. All rations were 1 3 hay and 2 3 ; concentrates with 0 to 60% citrus pulp. Acetate/propionate ratios were over 4 in all cases, and no significant difference resulted from percent of citrus pulp. Digestibilities of energy, dry matter, and protein were unaffected by portion of citrus pulp. The second experiment was similar to the first, but the controlled variable was the portion of pellets in a constant (33%) citrus pulp. Rumen volatile fatty acids data were similar to those of experiment 1 in that all were normal and no differences were significant. The average acetate/propionate ratio was about 4. Experiment 3 involved two separate switchback trials in which the comparison was pelleted with conventional citrus pulp. The criterion was milk composition of fat, solids not fat, protein, titratable acidity, and chloride. All observations were normal, and no treatment effects occurred.
Contractualism on saving the many

Imagine three boats, the position of each being equidistant from the other two. You are in the largest boat, alone, and your boat is in excellent condition. The other two boats are rapidly sinking; one contains two people (B&C), the other only one person (A). You only have time to reach one of the boats and save its passengers, before both boats sink beneath the surface, each taking all its remaining passengers with it. As far as common-sense morality is concerned, one's duty as rescuer, under the circumstances, is a straightforward matter: one ought to save the greater number. For some non-consequentialist characterizations of moral reasoning, however, the question of how this claim is to be justified if, in fact, it is justifiable is anything but an obvious matter. T. M. Scanlon's contractualism is a case in point. It excludes appeals to either the aggregate value of outcomes, or to the combined force of individual claims, from valid moral reasoning about the justification of the principles governing the duties we owe one another, which constitute much of what is normally appealed to as 'common-sense morality'. That such appeals are debarred by contractualism from playing any kind of fundamental role in moral reasoning is one of the central features of the view that mark it as a distinctively non-consequentialist characterization of common-sense moral reasoning. The exclusion of appeals to aggregate considerations, or claims on behalf of groups, from valid moral reasoning may lead one to doubt whether a plausible rationale, on contractualist terms, for the duty to save the greater number is even available. For how is a duty to save the many to be justified if one cannot appeal to the force of considerations like 'the claim of the many'? Some kind of aggregation of claims, one might think, has to be allowed to play a role in valid moral reasoning if the duty to save the many, rather than the one, is to prove to be morally defensible.' This suggests that a plausible rationale for the duty to save the many cannot be developed in contractualist terms, a conclusion that is certainly damaging for contractualism's claim to provide an illuminating characterization of common-sense moral reasoning about the kinds of duties we owe one another.
Motion and shape signatures for object-based indexing of MPEG-4 compressed video

The emerging MPEG-4 standard enables direct access to individual objects in the video stream, along with boundary/shape, texture, and motion information about each object. This paper proposes an object-based video indexing method that is directly applicable to the MPEG-4 compressed video bitstreams. The method aims to provide object-based content-interactivity; thus, defines the audio-visual object as the indexing unit. The scheme involves object-based temporal segmentation of the video bit-stream, selection of key-frames and key-video-object-planes, and characterization of the motion and/or shape of each video object including the background object. We also propose syntax and semantics for an indexing field to meet the content-based access requirement of MPEG-4. Experimental results are shown on two MPEG-4 test sequences.
Community Service Project Planning for ASCE Student Chapters/Clubs

Community service projects are key components of successful ASCE student chapters or clubs. Community service projects allow chapter members to serve the community, develop leadership skills, interact with professional civil engineers, and hone their own engineering skills on real-world projects. This paper presents a proven plan for student chapters and clubs to develop and run successful community service projects.
Taxonomy of Leitneria (Simaroubaceae) Resolved by ISSR, ITS, and Morphometric Characterization

Abstract A new species, Leitneria pilosa, and a new subspecies, L. pilosa subsp. ozarkana, are described based on leaf morphology, ISSR polymorphisms, ITS sequence character, and geographical isolation. Our infrageneric assessment of populations of Leitneria showed that L. pilosa, which occurs as western disjunct populations in Missouri, Arkansas, and Texas, has undergone species-level divergence from plants of Leitneria floridana indigenous to Florida and Georgia. Leitneria pilosa differs from L. floridana in the presence of dense trichomes on both abaxial and adaxial leaf surfaces, while trichomes are sparse to absent on the leaf surfaces of L. floridana. Leaves of L. pilosa are smaller, about half the length, and have a lower length ∶ width ratio than leaves of L. floridana. Within L. pilosa, subsp. ozarkana indigenous to Arkansas and Missouri differs from subsp. pilosa indigenous to Texas by its consistently larger, elliptic to slightly oblanceolate or obovate leaves with longer petioles. Leaves of L....
CENTRAL MOMENTS AND PROBABILITY DISTRIBUTIONS OF THREE MEASURES OF PHYLOGENETIC TREE IMBALANCE

Several recent studies have included attempts to use the balance of phylogenetic trees, i.e., the extent to which sister groups within a tree tend to be the same size, to test hypotheses about the macroevolutionary processes that produced them. Such tests require measures of bal- ance or imbalance and the moments or probability distributions of these measures under some null models. In earlier work, I developed recursion equations for the mean, variance, skewness, and complete probability distribution of Colless's coefficient of imbalance (2) (Rogers, 1994, Evo- lution 48:2026-2036). In this paper, I report the extension of these techniques to two additional imbalance measures, the number of unbalanced nodes on a tree (/) and Sackin's index (K), under both the equal-rates Markov (ERM) model and the equal probability (EP) model. I also show how to find the correlations and joint probability distributions of all pairs of these three coefficients. / and K are so highly correlated for trees of all sizes that K contains little additional information about tree balance that is not conveyed by /. The correlation of / and /, however, decreases rapidly with increasing tree size, indicating that the testing of macroevolutionary hypotheses may be refined by employing the joint distribution of these two coefficients. The results of two simulation studies of non-ERM speciation processes are used to illustrate how the joint distribution of / and / may be used. (Phylogenetic trees; macroevolutionary processes; speciation; tree imbalance co- efficients; probability distributions.)
Ss-DNA functionalized array of ALN Contour-Mode NEMS Resonant Sensors with single CMOS multiplexed oscillator for sub-ppb detection of volatile organic chemicals

This paper reports on the design and experimental verification of the first prototype of a resonant sensing platform based on nanoscaled aluminum nitride Contour-Mode Resonant Sensors (CMR-S) for selective detection of sub-ppb levels of volatile organic chemicals (VOCs). For the first time arrays of 8 nano-CMR-S were fabricated on the same chip and functionalized with two different thiol-terminated ss-DNA sequences. A low noise and low power (as low as 224 µW) CMOS circuit read-out capable of monitoring the responses of each NEMS sensor in a time-multiplexed mode was used. A ss-DNA sequence dependant adsorption of two vapors, such as DNT and DMMP, was recorded. Concentrations of DMMP and DNT as low as 700 part per billion (ppb) and 700 part per trillion (ppt), respectively, were experimentally detected. A limit of detection to mass per unit area as low as ∼60 zg/µm2 was extracted by noise characterization of the sensor array.
Culturally Responsive Performance-based Assessment: Conceptual and Psychometric Considerations

This article provides a rationalefor advocating the development of culturally responsive performance-based assessments as a means of achieving equity for students of color. It first addresses the argumentsfor and against these types of assessments, noting important psychometric concerns. It then discusses their potential for effectuating culturally responsive instructional approaches. Last, it recommends that existing test development procedures be modified to emphasize the meaningful participation of individuals who are not only experts in the content area being assessed but have deep understandings of the cultural contexts of students of color based on substantial teaching experience in those contexts.
Process differences and individual differences in some cognitive tasks

This study is based on three distinct elementary cognitive tasks (ECTs) using chronometric techniques: (a) the S. Sternberg memory scan task, (b) a visual scan task which is perfectly analogous to the memory scan, except that the target digit is presented first and the subject must then scan a set of digits and indicate the presence or absence of the target digit in the set, and (c) the Hick paradigm, which involves responding to a visual stimulus (a light going “on”) when the stimulus is one among sets of either 1, 2, 4, or 8 equally probable alternatives. Certain parameters of all three tasks, such as intercept and slope of RT as a function of set size, from which different cognitive processes are inferred, are compared experimentally and correlationally. Subjects were 48 university students, tested and retested on the three tasks in a counterbalanced design on two separate days to obtain the retest reliabilities needed to correct all correlations for attenuation. Subjects were also given Raven's Advanced Progressive Matrices as a measure of psychometric g. Parameters of the ECTs are significantly and, in some cases, quite substantially correlated with g. Virtually all of this correlation is due to the general factor of the various ECTs, rather than to specific processing components (independent of the general factor). The results also indicate that different ECT paradigms (e.g., visual search and memory search tasks) may yield markedly different values in terms of the group means of analogous parameters, indicating different processes, and yet not show independence of the parameters in terms of individual differences; that is, measurements of the different parameters in individuals are perfectly correlated (i.e., disattenuated correlations do not differ significantly from r = 1). This is found for the intercept parameter of visual and memory search. The reverse condition is also found for the other parameters (e.g., slope); that is, their mean values are nearly identical, suggesting the same processes, yet disattenuated correlations between individual differences are relatively low, or even negative, indicating different processes. Although the general factor clearly predominates, it does not completely overwhelm individual differences in various component processes that are distinct from the general factor.