cssi/SciSciGPT-SciSciNet huggingface dataset:
Subcortical White Matter Hyperintensities on MRI in Two Populations Exposed to Hypobaric Non-Hypoxic Conditions (S40.007)

Introduction: An increase in white matter hyperintensities (WMH) on high resolution fluid attenuated inversion recovery (FLAIR) MRI imaging has been demonstrated in United States Air Force high-altitude U-2 pilots (U2P) compared to matched normative controls (DOC), believed secondary to hypobaric non-hypoxic exposure. Altitude chamber physiology technicians (PHY) exposed to shorter periods of hypobaric non-hypoxic conditions has not been reported. Our hypothesis was the exposure experienced by PHY would demonstrate similar increased subcortical WMH on FLAIR imaging compared to a comparable DOC population but with no significant difference in findings between U2P and PHY. Objective: To compare a population of similar age, medical and neurological history non-exposed controls (DOC) to subjects with a history of hypobaric non-hypoxic exposure (U2P; PHY). Design/Methods: We examined 105 U2P and 83 PHY and compared these to 132 DOC. Quantitative measurement of subcortical FLAIR lesion count and volume was performed as previously described. We applied the 2-tailed nonparametric Mann Whitney statistical test, considering p<0.05 significant. Results: U2P, PHY, and DOC (respectively): subcortical WMH number: 9.67±18.26; 6.37±11.12; 2.83±3.38; subcortical WMH volume: 0.147cm 3 ±0.296; 0.126cm 3 ±0.404; 0.036cm 3 ±0.061. Significance for subcortical WMH number and volume (respectively): U2P vs. DOC p Conclusions: The total number and volume of subcortical WMH found in U2P and PHY is significantly greater than in DOC with no significant difference between U2P and PHY. This study provides further evidence that exposure to hypobaria without hypoxia leads to white matter change even in the absence of clinical symptoms. Research is ongoing examining the pathophysiology underlying these structural subcortical changes detected on MRI. Study supported by: AF Surgeon General grant (Log I-11-44). Disclosure: Dr. Robinson has nothing to disclose. Dr. Grogan has received personal compensation for activities with US Worldmeds as a speaker. Dr. Kochunov has nothing to disclose. Dr. Sherman has nothing to disclose. Dr. McGuire has nothing to disclose.
Integrating Motivational Interviewing and Self Determination Theory with Cognitive Behavioral Therapy to Prevent Suicide.

Abstract Cognitive behavioral therapy (CBT) has been found to be effective in preventing suicide-related behavior. However, it is often difficult to engage patients who are at-risk in treatment. Motivational Interviewing (MI) has been shown to increase treatment engagement and improve treatment outcomes when it is used to complement other treatments. As a general theory of human motivation that is consistent with MI, Self-Determination Theory (SDT) provides a framework for understanding how MI may be integrated with CBT to increase treatment engagement and outcome. In this paper, we use SDT to explain how MI may complement CBT to reduce suicide-related behavior, provide a case example of using MI with a suicidal patient before CBT-based treatment, and explore future directions for research.
895 ANTIBODY-INDEPENDENT CLASSICAL PATHWAY (CP)-MEDIATED OPSONOPHAGOCYTOSIS (OP) OF TYPE Ia GROUP B STREPTOCOCCI (IaGBS)

Since invasive IaGBS disease rarely occurs beyond the early neonatal period, heat-labile serum factors rather than type-specific antibody (SpAb) could be critical to host defense against la GBS. The OP requirements for prototype strain,090, and 18 fresh clinical isolates were assessed in an assay employing human PMN, serum containing endogenous complement, and 3×106 CFU/ml of IaGBS. Significant OP of 090 (>90% reduction in CFU) occurred after 40 min. incubation in 6 sera containing high levels of SpAb, while bacterial growth was noted in 25 sera with low levels. The mean OP for 090 was compared to that for 18 clinical isolates in 3 representative sera. OP was similar in serum with high SpAb levels (94% vs 97%). However, in low SpAb and agammaglobulinemic sera, respectively, OP was 94% (range, 83-98%) and 95% (range, 77-99%) for 18 clinical isolates, while 090 grew in these sera. Absorption of serum with high SpAb with Ia polysaccharide antigen (Ag) completely inhibited OP for 090, but did not effect that for clinical isolates. All strains required high SpAb levels for alternative pathway recruitment. Serum deficient in C2 and SpAb did not promote OP of clinical isolates of IaGBS until reconstituted with C2. These findings that OP of clinical isolates of IaGBS is CP-mediated in a non-SpAb dependent fashion indicate that substances other than Ia capsular Ag, such as polar glycophospholipids, may initiate CP activation in the absence of immunoglobulin G.
Evaluation of physics engines for robotic simulations with a special focus on the dynamics of walking robots

Detailed simulations of robotic systems, including their components and dynamics, play an increasingly important role in the development of new robotic systems and their applications. There are many physics engines with a mature development stage, but all of them suffer from fundamental inaccuracies due to the approximative character of the internal calculations. This article provides an in-detail evaluation of the physics engines Bullet, ODE and PhysX with a focus on robotics and legged locomotion. We present a variety of run-time experiments which provide an insight into these engines, their strengths and weaknesses. Our findings offer valuable information for the application-specific selection of a physics engine for robotics simulations.
A Pulmonary Hypertension Gas Exchange Severity (PH-GXS) Score to Assist With the Assessment and Monitoring of Pulmonary Arterial Hypertension

Submaximal exercise gas analysis may be a useful method to assess and track pulmonary arterial hypertension (PAH) severity. The aim of the present study was to develop an algorithm, using exercise gas exchange data, to assess and monitor PAH severity. Forty patients with PAH participated in the study, completing a range of clinical tests and a novel submaximal exercise step test, which lasted 6 minutes and incorporated rest (2 minutes), exercise (3 minutes), and recovery (1 minute) ventilatory gas analysis. Using gas exchange data, including breathing efficiency, end-tidal carbon dioxide, oxygen saturation, and oxygen pulse, a pulmonary hypertension gas exchange severity (PH-GXS) score was developed. Patients were retested after about 6 months. There was significant separation between healthy controls and patients with moderate PAH (World Health Organization [WHO] class I/II) and those with more severe PAH (WHO class III/IV) for breathing efficiency, end-tidal carbon dioxide, oxygen saturation, and oxygen pulse. The PH-GXS score was significantly correlated with WHO class (r = 0.51), 6-minute walking distance (r = −0.59), right ventricular systolic pressure (r = 0.49), log N-terminal pro–B-type natriuretic peptide (r = 0.54), and pulmonary vascular resistance (r = 0.71). The PH-GXS score remained unchanged in 22 patients retested (1.50 ± 0.92 vs 1.48 ± 0.94), as did WHO class (2.3 ± 0.8 vs 2.3 ± 0.8) and 6-minute walking distance (455 ± 120 vs 456 ± 103 m). Small individual changes were observed in the PH-GXS score, with 8 patients improving and 8 deteriorating. In conclusion, the PH-GXS score differentiated between patients with PAH and was correlated with traditional clinical measures. The PH-GXS score was unchanged in our cohort after 6 months, consistent with traditional clinical metrics, but individual differences were evident. A PH-GXS score may be a useful way to track patient responses to therapy.
The radius of an atom in covalent compounds

Abstract An empty-core pseudopotential to account for the atomic core and a linearized Fermi-Thomas equation to describe the valence electrons has been formulated previously to treat the simple metals. The covalent bond in semi-conductors is considered in the present work and the Dirac-Fermi-Thomas equation is used to describe the valence electrons. Calculations of the nearest-neighbor distance in fifteen AB covalent compounds with tetrahedral coordination were carried out and it was found that deviations from the experimental values correlate with the ionicity scale defined by Phillips.
The morphology of poly(Gly-Ala-Glu(OEt))

Abstract This paper concerns a structural and morphological investigation of poly(Gly-Ala-Glu(OEt)). Under the conditions studied, poly(Gly-Ala-Glu(OEt)) exists in one conformation whose X-ray pattern is that of a β-sheet and can be satisfactorily indexed with monoclinic or orthogonal unit cells. Electron microscopy reveals fibers or ribbons from several solvent treatments, and oriented electron diffraction reveals the molecular chain axis is normal to the fiber axis, identifying the conformation as cross β. The fold period of the fibers are of the order of 60 A and chain folding has been deduced.
Unified mechanistic concept of electrophilic aromatic nitration: convergence of computational results and experimental data.

The mechanism of electrophilic aromatic nitration was revisited. Based on the available experimental data and new high-level quantum chemical calculations, a modification of the previous reaction mechanism is proposed involving three separate intermediates on the potential energy diagram of the reaction. The first, originally considered an unoriented π-complex or electron donor acceptor complex (EDA), involves high electrostatic and charge-transfer interactions between the nitronium ion and the π-aromatics. It explains the observed low substrate selectivity in nitration with nitronium salts while maintaining high positional selectivity, as well as observed oxygen transfer reactions in the gas phase. The subsequent second intermediate originally considered an oriented “π-complex” is now best represented by an intimate radical cation−molecule pair, C6H6+•/NO2, that is, a SET complex, indicative of single-electron transfer from the aromatic π-system to NO2+. Subsequently, it collapses to afford the final σ-c...
Development of a two‐phase combination fermenter for the conversion of cellulose to methane

Cellulose degradation to methane under continuous fermentation conditions was compared using Cellulose degradation to methane under continuous fermentation conditions was compared using fully mixed, fully mixed with solids return, sludge-blanket, and fixed-film fermenters. In fully mixed fermenters, a decrease in hydraulic retention time (HRT) of two weeks or less caused the washout of anaerobes capable of converting volatile fatty acids to methane, while at increased feeding rates over 1 g/L day the rapid growth of cellulolytic anaerobes upset the balance between acid formation and its conversion to methane. Circulation of cellulose and difficulty in settling of cellulose with attached bacteria imposed problems in the use of other types of fermenters. On the basis of information obtained from this study, a fermenter which combined a fully mixed phase for cellulose degradation and a fixed-film phase with preimmobilized bacteria for converting fatty acids to methane in one vessel was devised. Using this fermenter, a mixed culture converted cellulose to methane at 4.8 g/L day ata HRT of six days as compared to 0.7 g/L day at a HRT of 28 days in the fully mixed fermenter.
A Heuristic Algorithm for Detecting Intercellular Interactions

Existing analytical tools enable broad-scale experimentation ("-omics") to provide a great deal of information about intracellular processes. However, extraction of information regarding intercellular interactions, particularly from separate datasets, is generally more limited, principally for lack of specialized analytical tools. In turn, few experiments are designed to examine intercellular interactions. Using the large number of previously identified interactions available in databases may provide a useful platform for analyzing these interactions. However, finding all possible interactions is a computationally intensive task and quickly becomes intractable using a naive approach on networks with hundreds of thousands of nodes and edges. A heuristic algorithm similar to the "Backtracking algorithm" is proposed to find all possible protein interactions across any two gene sets. The algorithm starts with an initial set of genes and incrementally adds a candidate to the interaction network and abandons each candidate x as soon as it is determined that x does not lead to a valid solution. An exclusion vector (EV) is used to accomplish this task and is populated at each step, maintaining a list of those nodes that need to be excluded from interactions in the future and thus restricting the size of the network. The EV also allows location awareness by using Gene Ontology (GO) cell component classifications to discard nodes that are not relevant for the network. This algorithm can be readily applied to pathway analysis and the determination of elements underlying intercellular interactions.
SU-DD-A4-02: Autosegmentation and Internal Target Volume (ITV) Generation in 4DCT Lung Imaging Using Deformable Image Registration

Purpose: To present a methodology using an improved intensity based deformable image registration algorithm (i.e. Juggler algorithm) for autosegmentation of normal anatomical structures, and algorithm generation of internal target volume (ITV). Method and Materials: The Juggler algorithm separately registers high intensity gradient and low intensity gradient features, and is particularly well suited for maintaining the topological properties of individual structures. Simulated CTimaging consisted of algorithm deformed clinical CTlungimaging. Clinical imaging, acquired from 4DCT, consisted of free breathing (FB) CT and 10 phased CT sets associated with the respiratory cycle. Manual image segmentation of normal structures was carried out on a reference CT (i.e. FB or end of exhalation phase), and the registration map between the reference and target CTs was used to autosegment the structures onto the target CT. This map was also used for automatic generation of ITV based either on “union target volume” (UTV) (i.e. the union of all the separate 3D segmentations), or “probability density function target volume” (PDFTV). Results: Based on known displacement vectors for simulated data, and difference imaging and cross‐correlation values for clinical data, Juggler yielded superior and faster registration compared to current deformable registration algorithms used in radiotherapy: demons, accelerated demons, free‐form deformation. Based on 4DCTs for 5 patients, normal anatomical structures (lung, skin, trachea, esophagus, heart) were automatically autosegmented onto target 3D CT sets within ⩽2mm accuracy based on visual agreement. The UTV computed ITV increased the FB GTV by up to 5mm. Total computation time was <3min (including deformable registration). Conclusions: The proposed methodology using an improved registration algorithm allowed for accurate autosegmentation of normal structures from initial manual segmentations, and the computation of ITV. It provides an effective treatment planning tool for 4DCT. New computer hardware could potentially reduce computation time to <30sec.
A Chemical Screen to Identify Novel Inhibitors of Fin Regeneration in Zebrafish

Abstract We performed a chemical screen to look for novel inhibitors of zebrafish caudal fin regeneration. In a pilot screen, 520 compounds were tested. Two compounds, budesonide and AGN192403, abrogated fin regeneration. One compound in particular, AGN192403, targets the imidazoline receptor, a pathway not previously linked to fin regeneration. In addition to inhibiting regeneration of the adult fin, AGN192403 also blocked regeneration of the larval fin fold. Finally, the inhibitory effect of AGN192403 on fin regeneration persisted after removal of the drug. These studies demonstrate that chemical screening is feasible in adult zebrafish and that it is a reasonable strategy to use for exploring the biology of regeneration.
Coronavirus Infection Modulates the Unfolded Protein Response and Mediates Sustained Translational Repression

During coronavirus replication, viral proteins induce the formation of endoplasmic reticulum (ER)-derived double-membrane vesicles for RNA synthesis, and viral structural proteins assemble virions at the ER-Golgi intermediate compartment. We hypothesized that the association and intense utilization of the ER during viral replication would induce the cellular unfolded protein response (UPR), a signal transduction cascade that acts to modulate translation, membrane biosynthesis, and the levels of ER chaperones. Here, we report that infection by the murine coronavirus mouse hepatitis virus (MHV) triggers the proximal UPR transducers, as revealed by monitoring the IRE1-mediated splicing of XBP-1 mRNA and the cleavage of ATF6alpha. However, we detected minimal downstream induction of UPR target genes, including ERdj4, ER degradation-enhancing alpha-mannosidase-like protein, and p58(IPK), or expression of UPR reporter constructs. Translation initiation factor eIF2alpha is highly phosphorylated during MHV infection, and translation of cellular mRNAs is attenuated. Furthermore, we found that the critical homeostasis regulator GADD34, which recruits protein phosphatase 1 to dephosphorylate eIF2alpha during the recovery phase of the UPR, is not expressed during MHV infection. These results suggest that MHV modifies the UPR by impeding the induction of UPR-responsive genes, thereby favoring a sustained shutdown of the synthesis of host cell proteins while the translation of viral proteins escalates. The role of this modified response and its potential relevance to viral mechanisms for the evasion of innate defense signaling pathways during coronavirus replication are discussed.
Biology of lung cancer

Objectives: To provide a review of the biology of lung tumor development and progression, and advances in gene and antimetastatic therapies. Data sources: Review articles, research studies, and book chapters pertaining to the biology of lung cancer. Conclusion: Advances in understanding the molecular basis of lung cancer initiation, promotion, and progression will provide more effective methods of early detection and treatment of this disease. Promising new treatment methods based on tumor biology include gene therapies, antibodies against growth factors, and agents that prevent angiogenesis and tissue invasion. Implications for nursing practice: An understanding of the biology of cancer assists nurses with the development of protocols for the assessment and monitoring of patients receiving treatments based on cancer biology. Oncology nurses will assume important counseling roles with the development of genetic testing and prognostic markers.
Depletion of macro-nutrients from rhizosphere soil solution by juvenile corn, cottonwood, and switchgrass plants

In situ sampling of rhizosphere solution chemistry is an important step in improving our understanding of soil solution nutrient dynamics. Improved understanding will enhance our ability to model nutrient dynamics and on a broader scale, to develop effective buffers to minimize nutrient movement to surface waters. However, only limited attention has been focused on the spatial heterogeneity and temporal dynamics of rhizosphere solution, and still less is known about how rhizosphere solution chemistry varies among plant species. Nutrients in rhizosphere soil solution and changes in root morphology of juvenile corn (Zea mays L. cv. Stine 2250), cottonwood (Populus deltoids L.), and switchgrass (Panicum virgatum L.) were monitored using mini-rhizotron technology. Plants were grown for 10 days in a fine-silty, mixed, superactive, mesic Cumulic Hapludoll (Kennebec series). Micro-samples (100–200 μL) of rhizosphere and bulk soil solution were collected at 24-h intervals at a tension of −100 kPa and analyzed for P, K, Ca, and Mg concentration using Capillary Electrophoresis techniques. Plants were harvested at the end of the 10-day period, and tissue digests analyzed for nutrient content by Inductively Coupled Plasma Spectroscopy. Corn plants produced roots that were 1.3 times longer than those of cottonwood, and 11.7 times longer than those of switchgrass. Similar trends were observed in number of root tips and root surface area. At the end of 10 days, rhizosphere solution P and K concentrations in the immediate vicinity of the roots (<1 mm) decreased by approximating 24 and 8% for corn, and 15 and 5% for cottonwood. A rhizosphere effect was not found for switchgrass. After correction for initial plant nutrient content, corn shoot P, K, and Mg were respectively 385, 132, and 163% higher than cottonwood and 66, 37, and 10% higher than switchgrass. Cottonwood shoot Ca concentration, however, was 68 to 133% higher than that of corn or switchgrass. There was no difference in root P concentration among the three species. Nutrient accumulation efficiency (μg nutrient mm−1 root length) of cottonwood was 26 to 242% higher for P, 25 to 325% higher for Ca, and 41 to 253% higher for Mg than those of corn and switchgrass. However, K accumulation efficiency of corn was four to five times higher than that of the cottonwood and switchgrass. Nutrient utilization efficiency (mg of dry weight produced per mg nutrient uptake) of P, K, and Mg was higher in cottonwood than in corn and switchgrass. These differences are element-specific and depend on root production and morphology as well as plant nutrient status. From a practical perspective, the results of this study indicate that potentially significant differences in rhizosphere solution chemistry can develop quickly. Results also indicate that cottonwood would be an effective species to slow the loss of nutrients in buffer settings.
Influence of substrate treatments on diamond thin film nucleation

Abstract We studied the influence of different treatments on nucleation behavior for the enhanced chemical vapor deposition of diamond thin films. We patterned the surface of silicon substrates using selective etching methods to develop convex surface features and we observe that the majority of nucleation events occur at the apexes of the convex surface features. We also used conventional diamond powder abrasion surface treatments both with and without post-abrasion etching to study the influence of the residual damage on the nucleation behavior. We evaluated the relative dangling bond concentration before deposition for these two cases using electron spin resonance (ESR). We observe a significant ESR signal for the as-abraded surface, but a negligible signal after etching. However, the nucleation density is essentially the same for the two surface treatments. The results of this study indicate that dangling bonds play a minor role in enhancing nucleation, in contrast to a substantial role played by the topography of the substrate surface.
Parallel Optimal Kalman Filtering for Stochastic Systems in Multimodeling Form

In this paper we show how to completely and exactly decompose the optimal Kalman filter of stochastic systems in multimodeling form in terms of one pure-slow and two pure-fast, reduced-order, independent, Kalman filters. The reduced-order Kalman filters are all driven by the system measurements. This leads to a parallel Kalman filtering scheme and removes ill-conditioning of the original full-order singularly perturbed Kalman filter. The results obtained are valid for steady state. In that direction, the corresponding algebraic filter Riccati equation is completely decoupled and solved in terms of one pure-slow and two pure fast, reduced-order, independent, algebraic Riccati equations. A nonsingular state transformation that exactly relates the state variables in the original and new coordinates (in which the required decomposition is achieved) is also established. The eighth order model of a passenger car under road disturbances is used to demonstrate efficiency of the proposed filtering technique.
Photoinduced Reversible Charge-Transfer Processes in Transition-Metal-Doped Single-Crystal SrTi O 3 and Ti O 2

When SrTi${\mathrm{O}}_{3}$ or Ti${\mathrm{O}}_{2}$ doped with certain transition elements is irradiated with light in the region 0.39 to 0.43 \ensuremath{\mu}, broad visible absorption bands with peak absorption as high as 100 ${\mathrm{cm}}^{\ensuremath{-}1}$ are introduced. The study of optical and EPR spectra of Fe/Mo doped crystals under the influence of light and various heat treatments shows that the effect is due to a transfer of charge between Fe and Mo ions such that the nonabsorbing ${\mathrm{Fe}}^{3+}$ and ${\mathrm{Mo}}^{6+}$ ions become ${\mathrm{Fe}}^{4+}$ and ${\mathrm{Mo}}^{5+}$ with absorption bands in the visible.
Study of the acoustoelectric effect for SAW sensors

Research has recently begun on the use of ultrathin films and nanoclusters as mechanisms for sensing of gases, liquids, etc., because the basic material parameters may change because of film morphology. As films of various materials are applied to the surface of SAW devices for sensors, the conductivity of the films may have a strong acoustoelectric effect, whether desired or not. The purpose of this paper is to reexamine the theory and predictions of the acoustoelectric effect for SAW interactions with thin conducting or semi-conducting films. The paper will summarize the theory and predict the effects of thin film conductivity on SAW velocity and propagation loss versus frequency and substrate material. The theory predicts regions of conductivity which result in extremely high propagation loss, and which also correspond to the mid-point between the open and short-circuit velocities. As an example of the verification and possible usefulness of the acoustoelectric effect, recent experimental results of palladium (Pd) thin films on a YZ LiNbO3 SAW delay line have shown large changes in propagation loss, depending on the Pd film thickness, exposure to hydrogen gas, or both. By proper design, a sensitive hydrogen leak detector SAW sensor can be designed.
The effects of plasma characteristics on the melting time at the front surface of a film on a substrate: An exact solution

Plasma heating of a film on a substrate is solved by using the Laplace transform method. The plasma is composed of a collisionless presheath and sheath on an electrically negative bias film partially reflecting and secondly emitting ions and electrons. The heating of the film from the plasma accounting for the presheath and sheath is determined from the kinetic analysis. This work proposes an analytical model to calculate the melting time and heating rate of the front surface of a film on the substrate, and provides quantitative results applicable to control the temperature evolution and the melting time in the film. The predicted surface temperature of the film on the substrate as a function of time is found to agree well with experimental data. The effects of dimensionless bias voltage, reflectivities of the ions and electrons on the wall, electron-to-ion source temperature ratio at the presheath edge, ion-to-electron mass ratio, charge number, plasma flow work-to-heat conduction ratios, substrate-to-film solid thermal conductivity ratios, and film-to-substrate solid specific heat ratios on the melting time and heating rate of the front surface are obtained. The contact Biot number between the film and substrate to simulate the heat conduction into substrate is also discussed. The results show that the melting time is strongly dependent on the plasma parameters and thermal properties of the material.
Create a learning organization.

Part 2 of this 3-part AONE-sponsored series proposes retention enhancement methods that target staff autonomy and feedback.
Prescribed burn smoke impact in the Lake Tahoe Basin: model simulation and field verification

Smoke dispersion modelling based on the Fire Emission Production Simulator and the Hybrid Single Particle Lagrangian Integrated Trajectory (FEPS-HYSPLIT) model was applied to prescribed burns in the Lake Tahoe Basin (LTB) during fall 2011. This, in conjunction with measurements at sources and real-time ambient PM2.5 monitoring around LTB, served to evaluate the prescribed burning impacts on air quality. For a given combustion efficiency, in-plume measurements suggest FEPS to underestimate PM2.5 emission factors by up to six-fold, though FEPS agrees relatively well with laboratory combustion of dry fuels. Prescribed burns in LTB were mostly < 100 acres; time series analysis and model prediction (with 2 km or 12 km spatial resolution) suggest generally small effects on PM2.5 exposure of local communities due to careful selection of the burn windows. In regard to a few scenarios where significant impact (≥ 2 μg/m3 hourly) is predicted, the model with 2 km resolution shows smoke arrival times more consistent with ambient observations. However, uncertainties in the model predictions should be reduced further by acquiring more accurate burn records and measuring markers specific to biomass burning at the monitoring sites.
A center location problem with congestion

We introduce a group of facility location problems whose objective involves both congestion and covering effects. For the Stochastic Queue Center problem, a single facility is to be located on a network to minimize expected response time (travel time plus expected queue delay) to the furthest demand point. We demonstrate certain convexity properties of the objective function on a general network, and show how the optimal location can be found using a finite-step algorithm. On a tree network, we characterize the optimal location trajectory as a function of the customer call rate. We compare this problem to the median, center, and Stochastic Queue Median problems. We then consider several different extensions which incorporate probabilistic travel times and/or distribution of demands.
Six years in orbit: the MCP detectors aboard the Extreme Ultraviolet Explorer Satellite

The Extreme UV Explorer satellite (EUVE) was launched on June 7, 1992 with seven microchannel plate detectors behind four telescopes. All seven detectors have been operating continuously since then, cycling the high voltage bias to half voltage during the daylight portions of the orbit as well as during passage through the South Atlantic Anomaly. This paper will present the time history of the detector performance characteristics, including spatial and spectral response, gain, and flat fields. We will also discuss our experiences with the thin-film filters used to define the detector EUV bandpasses including spatial and spectral response, gain, and flat fields. We will also discuss our experiences with the thin-film filters used to define the detector EUV bandpasses including the development of 'micro' pinholes in the Al/Ti/C filters. We then illustrate specific examples of detector problems and their solutions, such as 'dithering' the spacecraft pointing to average out the small scale image distortions and off-axis pointing to avoid an on-axis 'deadspot'.
Experimental ecology of Dryas octopetala ecotypes. V. Field photosynthesis of reciprocal transplants

The response of photosynthesis to reciprocal transplanting was measured in 1980, 1981, and 1986 in two genetically-distinct populations of Dryas octopetala, a circumpolar dwarf shrub. Contrary to expectation, photosynthetic rates were lowest in “home” environments and highest in “foreign” sites. Also, “native” plants had lower photosynthetic rates than “alien” plants. A “rapid-transplant” experiment showed that the observed pattern was not caused by environmental differences between sites at the time of measurement, but rather by the long-term response of transplants to the environment. These results, in combination with the results of an analysis of the fitness response to transplanting (published elsewhere), caution against assuming that a positive relationship always exists between photosynthetic rate and fitness. Integrated measures of carbon gain may be more appropriate as measures of plant performance.
Trends and Challenges in Investor-State Arbitration

THE PAST several years have seen a number of significant developments in investor-state arbitration. In this article, I offer a few observations on the trends and challenges in investor-state arbitration, from the perspective of counsel for a large, democratic government that has been a repeat player in these cases. Perhaps the most striking trend is the steady increase in the number of investor-state arbitrations over the past several years. The docket of ICSID provides a useful general barometer, because the only arbitrations ICSID handles are the investor-state variety. In 1999, ICSID registered 10 new cases, which figure nearly doubled to 19 cases in 2002 (a number of these cases are based on state contracts rather than investment treaties, but investment treaties more and more make up the bulk of ICSID's docket). The docket of investor-state cases under the NAFTA also continues to increase. In 1999, there were nine cases pending under NAFTA's investment chapter. As of today, there are 12. I should note, however, that this increase has not been due to a change in the rate of new cases filed per year: that rate has remained fairly steady. Essentially what we are seeing is a slow accretion of cases resulting from the fact that it takes several years, on average, to dispose of these cases. The ICSID and NAFTA dockets are perhaps the most visible indicators of activity in investor-state arbitration, but they do no not reflect all of the activity. A number of investment treaty arbitrations are held under UNCITRAL and other arbitration rules which do not provide for a public registry like that for ICSID and the NAFTA. While there is no way accurately to survey the number of investment treaty arbitrations under those rules, anecdotal evidence suggests that it too is on the rise. In my …
Serum IGF-1 Affects Skeletal Acquisition in a Temporal and Compartment-Specific Manner

Insulin-like growth factor-1 (IGF-1) plays a critical role in the development of the growing skeleton by establishing both longitudinal and transverse bone accrual. IGF-1 has also been implicated in the maintenance of bone mass during late adulthood and aging, as decreases in serum IGF-1 levels appear to correlate with decreases in bone mineral density (BMD). Although informative, mouse models to date have been unable to separate the temporal effects of IGF-1 depletion on skeletal development. To address this problem, we performed a skeletal characterization of the inducible LID mouse (iLID), in which serum IGF-1 levels are depleted at selected ages. We found that depletion of serum IGF-1 in male iLID mice prior to adulthood (4 weeks) decreased trabecular bone architecture and significantly reduced transverse cortical bone properties (Ct.Ar, Ct.Th) by 16 weeks (adulthood). Likewise, depletion of serum IGF-1 in iLID males at 8 weeks of age, resulted in significantly reduced transverse cortical bone properties (Ct.Ar, Ct.Th) by 32 weeks (late adulthood), but had no effect on trabecular bone architecture. In contrast, depletion of serum IGF-1 after peak bone acquisition (at 16 weeks) resulted in enhancement of trabecular bone architecture, but no significant changes in cortical bone properties by 32 weeks as compared to controls. These results indicate that while serum IGF-1 is essential for bone accrual during the postnatal growth phase, depletion of IGF-1 after peak bone acquisition (16 weeks) is compartment-specific and does not have a detrimental effect on cortical bone mass in the older adult mouse.
Characterization of insulin signaling pathway in calnexin knockout cells

Background: Calnexin is a lectin-like chaperone in the endoplasmic reticulum (ER) lumen, which along with calreticulin are involved in folding, maturation and trafficking of many glycoproteins. Insulin receptor and glucose transporters are among some of the proteins which are synthesized and folded in the ER. Previously, calreticulin was reported to play a role in the folding of GLUT-4 transporter as well as its stability. Furthermore, our lab reported that loss of calreticulin function results in increased insulin receptor synthesis, increased phosphorylation of Akt upon stimulation by insulin and increased glucose uptake. To date no data are available on the changes in insulin receptor pathway upon loss of calnexin chaperone. Objectives: The aim of this study is to examine changes in insulin receptor expression and insulin-mediated phosphorylation of Akt upon loss of calnexin function. Methods: Mouse embryonic fibroblast cells were serum starved overnight, then stimulated with insulin for 10 mins at 37°...
An Image Slicer Integral Field Unit with Diffraction-limited Performance for Three-Dimensional Imaging Spectroscopy

We have designed and constructed an advanced image slicer (AIS) integral field unit (IFU). The IFU employs an all-mirror design and will be installed in the Penn State near-IR Imager and Spectrograph (PIRIS) for three-dimensional integral field spectroscopy at various astronomical telescopes. Using the AIS technique, the slicer IFU can preserve the telescope's focal ratio and pupil (both position and size) while maximizing the packing efficiency for three-dimensional data on the detector. Compared to other existing AIS IFU designs, our design, which uses monolithic optical components for both pupil and field mirror arrays, provides a convenient engineering solution for manufacturing, using the state-of-the-art diamond-turning machines and alignment of the IFU optics. Our slicer mirror array was also manufactured by diamond turning, with all the mirrors simultaneously machined, which also simplifies the procedure for the manufacture and the assembly of the mirrors. We present the IFU optical description, component test results, and overall IFU system performance. We also discuss possible science applications using the IFU.
Complete reduction of fermion-antifermion Bethe-Salpeter equation with static kernel. II☆

Abstract Recent work with the Bethe-Salpeter (BS) equation for a spin - 1 2 fermion-antifermion system is developed further and extended in a number of ways. Static kernels are considered, as previously, but in the present case, the structure of the kernels serves to suppress completely all pair terms. The reduction of the 16 coupled integro-differential equations involving the BS bispinor wavefunctions can be carried out much more simply than before. The effective Hamiltonians of the eigenvalue equations which result for single scalar and vector wavefunctions are not only in formally closed operator form, correct to all orders in the coupling constant and v c , but have an explicit and simple structure. They depend at most linearly on the static potential, and also on powers of momentum and simple functions of the relativistic free-particle energies. Previous work is further generalized by the consideration of static four-vector interactions (vector gluons or photons) in an arbitrary “gauge” for equal mass particles and antiparticles on the one hand, and the fourth (scalar) component of a vector potential for unequal mass particle and antiparticle on the other hand, the latter in order to study the mass dependence of the effective interactions and of the wavefunctions. Spin-orbit, spin-spin, and tensor interactions are expected to arise from the Breit-like four-vector interactions in conventional v c expansions, but the present results are correct to all orders in v c . Furthermore, such types of interactions also arise, as previously, for the case of a Coulomb-like potential, for which they are not, at first guess, expected. In the unequal mass case, an interesting new type of effective tensor interaction is also generated which serves to mix triplet and singlet states. Various special “gauges” are considered in the equal mass case. The general structure of the BS amplitude is also discussed, and specifically developed in some detail in perturbation theory for the ground state of positronium. While the current work should be considered as a general examination of the properties of a large class of BS equations of the Coulomb-Dirac or Breit-type, two areas for specific applications immediately come to mind: the calculation of positronium energy levels to very high order and the study of quark-antiquark binding involving both like and unlike quarks.
Organizational learning and transformational leadership in the library environment

Purpose – This paper aims to provide librarians with an in‐depth review of transformational management and its relation to organizational learning and adaptation.Design/methodology/approach – The paper broadens the library literature related to management style, organizational learning and transformation, with concepts derived from the relevant management literature.Findings – Librarians are experimenting with organizational learning and new management styles in an attempt to cope with rapid change. Transformational management styles can be learned and applied by library administrators. The extent to which library administrators are using transformational management techniques to cope with change remains obscured by the fact that appropriate surveys have not been conducted.Research limitations/implications – The self‐assessment tool is based on an adaptation of the multifactor leadership questionnaire (MLQ), developed by Bass and Avolio to study leadership styles in business, industry and the military. Re...
The Career Concept Scale: An Assessment of Career Judgment

An assessment scale of career concepts found to be reliably related with vocational sophistication is developed. With the renewed emphasis in CETA programs for youth-employment counseling efforts, the relative prevocational maturity of those seeking our services can be an element in deriving baseline data from which the efficacy of vocational counseling services can be judged.
Optical sum frequency studies of adsorption and laser-induced desorption of CO on W(110)

Abstract The adsorption and laser-induced desorption behavior of CO on W(110) has been studied using sum frequency generation (SFG) and thermal desorption spectroscopy (TDS). The temperature and coverage dependence of the CO-stretch SFG-signal was measured. Laser irradiation of CO on the surface showed CO desorption and almost no dissociation of CO by visible laser pulses of 15–45 mJ/cm 2 without damaging the surface. Simulations of the surface reactions are in agreement with these measurements. Furthermore, it was observed that the non-resonant SFG-intensity change caused by CO or O adsorption is correlated to the work function change.
Outpatient management of pilonidal disease

Abstract Outpatient management of pilonidal disease is appropriate for abscesses and chronic sinuses. An abscess is drained but several options are available for treatment of a sinus. Our practice's preference is unroofing with healing by secondary intention. Its advantages include immediate treatment, minimal pain, and a quick return to normal activities. Our experience with outpatient management of pilonidal disease is presented. From 1998 to 2002, 75 patients presented with pilonidal disease. Presentation, treatment, healing, and recurrences were reviewed. All were managed as outpatient. Abscesses were present in 34 and drained. Eighty-two percent healed and 12% developed a recurrence. All recurrences healed after undergoing unroofing. Chronic symptoms from a sinus were managed by incision/excision with secondary healing, primary closure, or a Bascom procedure. Unroofing was performed in 73%. Eighty-three percent healed and 24% developed a recurrence. Seventy-two percent of these healed for an overall rate of 77%. Pilonidal disease can be treated as an outpatient. An abscess should be drained. A chronic sinus can be managed with unroofing and healing by secondary intention, which allows patients to return to normal activities immediately after treatment.
The 70kilodalton heat shock protein is an inhibitor of apoptosis in prostate cancer

The 70 kD heat shock protein (HSP70) plays essential cellular roles in mediating intracellular protein folding and protecting cells from proteotoxic stress. This study has examined the role of HSP70 in the expression of apoptosis in prostate carcinoma cells. Apoptosis was negatively correlated with HSP70 expression in PC-3 cells heat shocked in vivo. Further experiments carried out on an in vitro reconstituted system with isolated nuclei and cytoplasm from PC-3 cells showed that purified HSP70 directly inhibits apoptosis in a dose-dependant manner. Therefore, the potential role of depletion of intracellular HSP70 was examined as a means of inducing apoptosis in PC-3 cancer cells. Depletion of HSP70 by two independent strategies, either with anti-sense oligonucleotides directed against HSP70 mRNA or with the bioflavinoid drug quercetin, led to apoptosis in the absence of stress. In addition, quercetin pre-treatment synergistically enhanced apoptosis in combination with heat shock. Thus, HSP70 plays a physiological role in tumour cells as an inhibitor of apoptosis occurring both spontaneously and after stress and is a potential target for apoptosis-based cancer therapy.
Differential theory of learning for efficient neural network pattern recognition

We describe a new theory of differential learning by which a broad family of pattern classifiers (including many well-known neural network paradigms) can learn stochastic concepts efficiently. We describe the relationship between a classifier's ability to generalize well to unseen test examples and the efficiency of the strategy by which it learns. We list a series of proofs that differential learning is efficient in its information and computational resource requirements, whereas traditional probabilistic learning strategies are not. The proofs are illustrated by a simple example that lends itself to closed-form analysis. We conclude with an optical character recognition task for which three different types of differentially generated classifiers generalize significantly better than their probabilistically generated counterparts.
Culture, Literacy, and L2 Reading

This article examines the relationship between cultural membership and individual language learning behavior, a relationship that has so far been addressed chiefly through questionnaire research aimed at documenting the learning styles of different cultural groups. Because such an approach does not illuminate the mechanisms by which culture influences learning, this article suggests an alternative approach that focuses on a narrower range of behavior—namely, L2 reading strategies—and a defined set of cultural practices having to do with literacy. The article reviews briefly the research on these two areas and then presents data on the strategies for English academic reading tasks used by two quite different groups of students: secondary school students in northern Nigeria and university graduates in China. The strategies that the two groups of students used were strikingly difference whereas the Nigerian students showed a marked preference for top-down methods of solving comprehension problems, the Chinese students reported a strong tendency to use bottom-up ones. These differing strategies are then related to the different language backgrounds of the two groups of students and to their different experiences of literacy. The article concludes that cultural background is an important factor in the formation of individual reading strategies but that this fact should not lead to a simple cultural determinism; individual variation must always be acknowledged, and so must the fact that both individuals and cultures may change in the very process of L2 learning.