cssi/SciSciGPT-SciSciNet huggingface dataset:
Communication: Charge-transfer rate constants in zinc-porphyrin-porphyrin-derived dyads: A Fermi golden rule first-principles-based study

We investigate photoinduced charge transfer (CT) processes within dyads consisting of porphyrin derivatives in which one ring ligates a Zn metal center and where the rings vary by their degree of conjugation. Using a first-principles approach, we show that molecular-scale means can tune CT rates through stabilization affected by the polar environment. Such means of CT tuning are important for achieving high efficiency optoelectronic applications using organic semiconducting materials. Our fully quantum mechanical scheme is necessary for reliably modeling the CT process across different regimes, in contrast to the pervading semi-classical Marcus picture that grossly underestimates transfer in the far-inverted regime.
Malignant peripheral nerve sheath tumor of the orbit

Malignant peripheral nerve sheath (MPNS) tumor is a rare neoplasm of the orbit. The authors report a 78-year-old woman with an anaplastic MPNS tumor of the orbit that arose from a pre-existing encapsulated tumor composed of cells having a low mitotic index and displaying ultrastructural features of Schwann cells. The encapsulated tumor was unusual for a schwannoma because of its greater cellularity, absence of Antoni B tissue, and rarity of nuclear palisading. This combination of morphologic findings has two possible interpretations: (1) the anaplastic portion of the tumor arose from a variant of benign schwannoma known as a cellular schwannoma, or (2) the entire tumor was an MPNS tumor with variable differerentiation and extensive growth within markedly thickened perineurium.
Privacy preserving average consensus

Average consensus is a widely used algorithm for distributed computing and control, where all the agents in the network constantly communicate and update their states in order to achieve an agreement. This approach could result in an undesirable disclosure of information on the initial state of agent i to the other agents. In this paper, we propose a privacy preserving average consensus algorithm to guarantee the privacy of the initial state and the convergence of the algorithm to the exact average of the initial values, by adding and subtracting random noises to the consensus process. We characterize the mean square convergence rate of our consensus algorithm and derive upper and lower bounds for the covariance matrix of the maximum likelihood estimate on the initial state. A numerical example is provided to illustrate the effectiveness of the proposed design.
A Beam-Steering Reconfigurable Antenna for WLAN Applications

A multifunctional reconfigurable antenna (MRA) capable of operating in nine modes corresponding to nine steerable beam directions in the semisphere space $\{-30^{\circ},0^{\circ}, 30^{\circ}\}; \phi\ \in \{0^{\circ}, 45^{\circ}, 90^{\circ}, 135^{\circ}\})$ is presented. The MRA consists of an aperture-coupled driven patch antenna with a parasitic layer placed above it. The surface of the parasitic layer has a grid of 3 $\,\times\,$ 3 electrically-small square-shaped metallic pixels. The adjacent pixels are connected by PIN diode switches with ON/OFF status to change the geometry of the parasitic surface, which in turn changes the current distribution on the antenna, thus provides reconfigurability in beam steering direction. The MRA operates in the IEEE 802.11 frequency band (2.4—2.5 GHz) in each mode of operation. The antenna has been fabricated and measured. The measured and simulated impedance and radiation pattern results agree well indicating an average of ${\sim} 6.5$ dB realized gain in all modes of operation. System level experimental performance evaluations have also been performed, where an MRA equipped WLAN platform was tested and characterized in typical indoor environments. The results confirm that the MRA equipped WLAN systems could achieve an average of 6 dB Signal to Noise Ratio (SNR) gain compared to legacy omni-directional antenna equipped systems with minimal training overhead.
T-Cell receptor BV6S1 null alleles and HLA-DR1 haplotypes in polyarticular outcome juvenile rheumatoid arthritis

Abstract JRA is a complex of disease subtypes which are normally identified by clinical features such as age of onset and extent of joint involvement both at onset and during the course of the disease. We previously identified an association between TCR BV6S1 null allele and one subgroup of early-onset pauciarticular patients positive for HLA-DQA1∗0101, an HLA haplotype predisposing to a polyarticular course of the disease. In this report we extend this observation by identifying an increased prevalence of this nonfunctional or null allele in the patients with a polyarticular disease course regardless of the mode of onset. This increase was most prominent in clinical subsets that have early onset of the disease and a polyarticular outcome. In one clinical group, stratification of patients by the HLA allele DQA1∗0101 strengthened the association considerably. This implies that there is an increased genetic load defined by specific alleles of both MHC and TCR genes.
The synthesis of 3-acetamido-2,3,5,6-tetradeoxy-5-fluoro-d,l-ribo-hexofuranose by the direct fluorination of methyl 3-acetamido-2,3,6-trideoxy-d,l-arabino-hexopyranoside (methyl N-acetyl-d,l-acosaminide)

Abstract 3-Acetamido-2,3,5,6-tetradeoxy-5-fluoro- d , l -ribo-hexofuranose was synthesized by direct, fluorinative dehydroxylation of methyl 3-acetamido-2,3,6-trideoxy- d , l -arabino-hexopyranoside with sulfur tetrafluoride-hydrogen fluoride. The furanose form and the ribo configuration, indicated by 13C- and 1H-n.m.r. spectroscopy, respectively, were confirmed by a single-crystal, X-ray diffraction study.
Spectroscopic studies of the thermochromism of N‐(2‐hydroxy‐4‐methoxybenzylidene)‐4‐nitroaniline

Thermochromism of N-(2-hydroxy-4-methoxybenzylidene)-4-nitroaniline (HMBNA) was studied by Raman scattering and infrared absorption. HMBNA is yellow when freshly prepared and deepens to orange–red on heating above the melting point. On cooling at room temperature, the orange–red colour is retained for a few months. The change in colour is explained by the change in the molecular structure as indicated by the vibrational spectra. The spectra show that in the thermochromic coloured state the central group of HMBNA takes the cis-keto amine form.
Apoptotic and autophagic responses to photodynamic therapy in 1c1c7 murine hepatoma cells

Photodynamic therapy (PDT) is a process that can induce apoptosis, autophagy or both depending on the cell phenotype. Apoptosis is a pathway to cell death while autophagy can protect from photokilling or act as a death pathway. In a previous study, we reported a cytoprotective effect of autophagy in murine leukemia cell lines where both autophagy and apoptosis occur within minutes after irradiation of photosensitized cells. In this study, we examined the effects of mitochondrial photodamage catalyzed by low (≤1 µM) concentrations of the photosensitizing agent termed benzoporphyrin derivative (BPD, Verteporfin) on murine hepatoma 1c1c7 cells. Apoptosis was not observed until several hours after irradiation of photosensitized cells. Autophagy was clearly cytoprotective since PDT efficacy was significantly enhanced in a knockdown sub-line (KD) in which the level of a critical autophagy protein (Atg7) was markedly reduced. This result indicates that autophagy can protect from phototoxicity even when apoptosis is substantially delayed. Much higher concentrations (≥10 µM) of BPD had previously been shown to inhibit autophagosome formation. Phototoxicity studies performed with 10 µM BPD and a proportionally reduced light dose were consistent with the absence of an autophagic process in wild-type (WT) cells under these conditions.
Care processes and clinical outcomes of continuous outpatient support with inotropes (COSI) in patients with refractory endstage heart failure.

Abstract Background: This study describes the process and outcomes of continuous outpatient support with inotropes (COSI) in patients with Stage D heart failure (HF). Although Stage D HF has recently been defined as end-stage disease requiring special interventions for survival such as COSI or ventricular assist devices, concern has been raised regarding the safety, efficacy, mortality outcomes, and ethics of COSI. Methods and Results: Inotrope dependence was defined as worsening of the patient's clinical status with attempted inotrope withdrawal such that the patient was deemed unlikely to survive to permit hospital discharge. A care process for COSI was designed; baseline and outcome variables were evaluated. COSI was administered to 36 inotrope-dependent patients (age 55.4 ± 9.5 years, 24 males). Baseline characteristics (mean ± SD) were consistent with Stage D HF: left ventricular ejection fraction 19.9 ± 8.5, left ventricular end-diastolic dimension (LVEDD) 70 ± 10 mm, systolic blood pressure 97.4 ± 13.4 mm Hg, serum creatinine 1.5 ± 0.6, serum sodium 131.7 ± 5.3; 69 HF hospitalizations (mean 1.9 ± 1.8) 6 months before COSI initiation. Symptomatic hypotension, increasing dyspnea, renal dysfunction, and hypoperfusion most commonly prevented inotrope withdrawal. Despite Stage D HF, patients were discharged with COSI ambulatory, oriented, and pain free. Rehospitalizations were 46; 6 subjects accounted for 24 hospitalizations; 23 had 0 or 1 rehospitalization. Median survival was 3.4 months (range 0.2-26.3 months); and 3-, 6-, and 12-month Kaplan Meier survival was 51%, 26%, and 6%, respectively. The majority of patients died at home and chose to not undergo resuscitation attempts. Conclusion: COSI may be an acceptable treatment option for Stage D HF.
The role of the mast cell in acute inflammatory responses of copper-deficient rats

Macromolecular leakage associated with mast cell degranulation was studied in the cremaster muscle microcirculation of copper-deficient rats. Male Sprague-Dawley rats were fed a purified diet either adequate for copper (6 μg copper/gram diet) or deficient (no added copper) 4 weeks prior to experimentation. The rats were anesthetized and the cremasters (with nerve and blood supply intact) were spread in a tissue bath filled with Kreb's solution.In vivo television microscopy was used to observe the microcirculation. Intravascular fluorescein isothiocyanate conjugated to bovine serum albumin was injected and interstitial fluorescent emission intensity was used as an index of macromolecular leakage. Topical administration of the mast cell degranulator compound 48/80 (1.0 and 10.0 μg/ml) induced a significantly greater macromolecular leakage in the copper-deficient animals. The compound 48/80 leakage was blocked in both groups of rats by pretreatment with diphenhydramine which is a histamine H1 receptor blocker. Topical administration of the inflammatory mediators histamine, serotonin, and bradykinin all induced macromolecular leakage which was not significantly different between groups. These results suggest that copper deficiency increases macromolecular leakage associated with mast cell degranulation by a primary effect on the mast cell rather than on the endothelium.
Reinhold Niebuhr and Richard John Neuhaus on Religion and Democracy in the United States

Richard John Neuhaus, like Reinhold Niebuhr before him, understood the vital civic role that religion plays in democratic society. As pastors and public intellectuals, both men were committed to public or civil forms of religion that, at their best, could inform, inspire, or chasten American political thought and action. There are crucial differences, nevertheless–between Niebhur’s and Neuhaus’s historical contexts, theological outlooks, political positions, and attitudes toward the American project–that help to explain their distinctive legacies and different receptions within the academy. However much Neuhaus admired Niebuhr, these differences suggest why Neuhaus was not the Reinhold Niebuhr of his day.
A probable conformational difference between recombinant and urinary erythropoietins.

Urinary and recombinant human erythropoietin differ with respect to ease of iodination, inactivation by iodination, second derivative and circular dichroic spectra, rate of inactivation by trypsin and glycosylation pattern. All of these differences are compatible with a significant difference in conformation of these two forms of erythropoietin. © 1997 Wiley-Liss Inc.
Kinesin 13s in Mitosis: Key Players in the Spatial and Temporal Organization of Spindle Microtubules

Dynamic microtubules are essential for the process of mitosis. Thus, elucidating when, where, and how microtubule dynamics are regulated is key to understanding this process. One important class of proteins that directly regulates microtubule dynamics is the Kinesin-13 family. Kinesin-13 proteins induce depolymerization uniquely from both ends of the microtubule. This activity coincides with their cellular localization and with their ability to regulate microtubule dynamics to control spindle assembly and kinetochore-microtubule attachments. In this review, we highlight recent findings that dissect the important actions of Kinesin-13 family members and summarize important studies on the regulation of their activity by phosphorylation and by protein-protein interactions.
THEORY REVIEW: LINE-DRIVEN INSTABILITY AND OTHER CAUSES OF STRUCTURE AND VARIABILITY IN HOT -STAR WINDS

The winds of the hot, luminous, OB stars are driven by the line-scattering of the star's continuum radiation flux. Several kinds of observational evidence indicate that such winds are highly structured and variable. This paper will review possible theoretical causes of such wind structure. For relatively small-scale, stochastic variability, I review the role of the strong intrinsic instability of the line-driving process itself. For larger scale structure, I describe recent efforts to examine how disturbances from the underlying, rotating star can be translated outward into propagating features in the wind.
Intra-4f2 two-photon transitions in Pr3+:LiYF4

The study of 3 H 4 → 3 P J (J=0, 1, 2) and 1 I 6 direct two-color two-photon transitions in Pr 3+ :LiYF 4 as a function of laser wavelength, polarization, intensity, and sample temperature leads to an identification of several energy levels which were not observed before in one-photon spectroscopic measurements
Coupled-cluster expansion applied to the electron gas: Inclusion of ring and exchange effects

The coupled-cluster expansion (or the Coester-K\"ummel-\ifmmode \check{C}\else \v{C}\fi{}i\ifmmode \check{z}\else \v{z}\fi{}ek method) is applied to the correlation problem in the uniform electron gas. Coupled nonlinear integral equations are developed for ring summations and the analytic structure of the expansion coefficients is examined. To facilitate the solution of the equations a technique is introduced to reduce the dimensionality of the problem. Numerical solution of the equations enable the evaluation of both ring and exchange effects. The direct random-phase-approximation (RPA) energy agrees with other work to the accuracy of the calculation. The screened exchange energy is evaluated for the first time and contributes about 30% of the RPA energy. The resulting correlation energy compares favorably with recent calculations using a dielectric formulation over the range of metallic electron densities.
BstYI Bound to Noncognate DNA Reveals a “Hemispecific” Complex: Implications for DNA Scanning

Summary DNA recognition by proteins is essential for specific expression of genes in a living organism. En route to a target DNA site, a protein will often sample noncognate DNA sites through nonspecific protein-DNA interactions, resulting in a variety of conformationally different binding states. We present here the crystal structure of endonuclease BstYI bound to a noncognate DNA. Surprisingly, the structure reveals the enzyme in a "hemispecific" binding state on the pathway between nonspecific and specific recognition. A single base pair change in the DNA abolishes binding of only one monomer, with the second monomer bound specifically. We show that the enzyme binds essentially as a rigid body, and that one end of the DNA is accommodated loosely in the binding cleft while the other end is held tightly. Another intriguing feature of the structure is Ser172, which has a dual role in establishing nonspecific and specific contacts. Taken together, the structure provides a snapshot of an enzyme in a "paused" intermediate state that may be part of a more general mechanism of scanning DNA.
Getting away from glucose: stop sugarcoating diabetes

Type 2 diabetes is often viewed as a disorder of glucose metabolism. But many factors come into play in this condition, with obesity a prime risk factor and cardiovascular disease a major result. In Bedside to Bench, Babak Razani and Clay Semenkovich examine the linkages between diabetes and cardiovascular disease. They call for new research approaches in the wake of clinical trials showing that lowering glucose levels does not decrease cardiovascular events in people with type 2 diabetes. In Bench to Bedside, Steven Shoelson and Allison Goldfine examine how type 2 diabetes and other disorders can stem from obesity—and its effect on inflammation. These authors take a look at two recent studies showing how obesity perturbs inflammatory gene networks.
Evaluating remotely sensed live fuel moisture estimations for fire behavior predictions in Georgia, USA

Abstract Research has shown that remote sensing techniques can be used for assessing live fuel moisture content (LFMC) from space. The need for dynamic monitoring of the fire risk environment favors the use of fast, site-specific, empirical models for assessing local vegetation moisture status, albeit with some uncertainties. These uncertainties may affect the accuracy of decisions made by fire managers using remote sensing derived LFMC. Consequently, the analysis of these LFMC retrieval uncertainties and their impact on applications, such as fire spread prediction, is needed to ensure the informed use of remote sensing derived LFMC measurements by fire managers. The Okefenokee National Wildlife Refuge, one of the most fire-prone regions in the southeastern United States was chosen as our study area. Our study estimates the uncertainties associated with empirical site specific retrievals using NDWI (Normalized Difference Water Index; ( R 0.86 − R 1.24 ) / ( R 0.86 + R 1.24 )) and NDII (Normalized Difference Infrared Index; ( R 0.86 − R 1.64 ) / ( R 0.86 + R 1.64 )) that are simulated by coupled leaf and canopy radiative transfer models. In order to support the findings from those simulations, a second approach estimates uncertainties using actual MODIS derived indices over Georgia Forestry Commission stations that provide NFDRS model estimates of LFMC. Finally, we used the FARSITE surface fire behavior model to examine the sensitivity of fire spread rates to live fuel moisture content for the NFDRS high pocosin and southern rough fuel models found in Okefenokee. This allowed us to evaluate the effectiveness of satellite based LFMC estimations for use in fire behavior predictions. Sensitivity to LFMC (measured as percentage of moisture weight per unit dry weight of fuel) was analyzed in terms of no-wind no-slope spread rates as well as normalized spread rates. Normalized spread rates, defined as the ratio of spread rate at a particular LFMC to the spread rate at LFMC of 125 under similar conditions, were used in order to make the results adaptable to any wind-slope conditions. Our results show that NDWI has a stronger linear relationship to LFMC than NDII, and can consequently estimate LFMC with lesser uncertainty. Uncertainty analysis shows that 66% of NDWI based LFMC retrievals over non-sparsely vegetated regions are expected to have errors less than 32, while 90% of retrievals should be within an error margin of 56. In pocosin fuel models, under low LFMC conditions (
Magnitudes and Chemical Consequences of R3N+−C−H···OC Hydrogen Bonding

The magnitude of the stabilizing interaction between an aliphatic C−H bond attached to an ammonium nitrogen and a carbonyl oxygen was evaluated by ab initio calculations at the MP2/6-311++G** level of theory. Attractive R3N+−C−H···OC interactions play an important role in supramolecular recognition and various types of stereoselective catalysis. Our calculations show that R3N+−C−H···OC is the strongest hydrogen bond of the C−H···O type known to date. Such hydrogen bonds remain as stabilizing interactions even in water for amide acceptors.
The element effect in nucleophilic aromatic photosubstitution (SN2Ar

Photoreactions of 4-nitroanisole and the 2-halo-4-nitroanisoles (halogen = F, Cl, Br, I) with NaCN have been investigated. 4-Nitroanisole gave a novel, stable nitronate ion adduct (74%) with cyanid...
Infrared Spectroscopy of Prereactive Aluminum−, Gallium−, and Indium−HCN Entrance Channel Complexes Solvated in Helium Nanodroplets†

Prereactive metal atom−HCN entrance channel complexes [M−HCN (M = Al, Ga, In)] have been stabilized in helium nanodroplets. Rotationally resolved infrared spectra are reported for the CH stretching vibration of the linear nitrogen-bound HCN−Ga and HCN−In complexes that show significant perturbation due to spin−orbit coupling of the 2Π1/2 ground state with the 2Σ1/2 state which are degenerate at long range. Six unresolved bands are also observed and assigned to the linear hydrogen-bound isomers of Al−HCN, Ga−HCN, and In−HCN corresponding to the fundamental CH stretching vibration and a combination band involving the CH stretch plus intermolecular stretch for each isomer. A nitrogen-bound HCN−Al complex is not observed, which is attributed to reaction, even at 0.37 K. This conclusion is supported by the observation of a weakly bound complex containing two HCN's and one Al atom which, from the analysis of its rotationally resolved zero-field and Stark spectra is assigned to a weakly bound complex of a HCNAl ...
Resolution of Hepatic Encephalopathy Following Hepatic Artery Embolization in a Patient with Well-Differentiated Neuroendocrine Tumor Metastatic to the Liver

Hepatic encephalopathy is considered a contraindication to hepatic artery embolization. We describe a patient with a well-differentiated neuroendocrine tumor metastatic to the liver with refractory hepatic encephalopathy and normal liver function tests. The encephalopathy was refractory to standard medical therapy with lactulose. The patient's mental status returned to baseline after three hepatic artery embolization procedures. Arteriography and ultrasound imaging before and after embolization suggest that the encephalopathy was due to arterioportal shunting causing hepatofugal portal venous flow and portosystemic shunting. In patients with a primary or metastatic well-differentiated neuroendocrine tumor whose refractory hepatic encephalopathy is due to portosystemic shunting (rather than global hepatic dysfunction secondary to tumor burden), hepatic artery embolization can be performed safely and effectively.
Impact of a cloud thermodynamic phase parameterization based on CALIPSO observations on climate simulation

[1] This study examines the impact of a new cloud thermodynamic phase parameterization on climate simulation. The new parameterization is based on CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations and replaces the default parameterization in the Community Atmosphere Model version 4. It is shown that the application of the new cloud phase parameterization results in a small increase in global-mean liquid water path (LWP) and a small decrease in global-mean ice water path (IWP). Large regional increases in LWP mainly occur in tropical regions such as the western Pacific warm pool and northeastern Indian Ocean and middle latitudes, while large decreases in IWP occur in the midlatitude storm track regions. The increase in zonal-mean cloud water content occurs at temperatures between −15°C and −30°C and cloud fraction increases occur at higher altitudes near the −30°C isotherm. Two other sensitivity experiments that favor more ice-phase clouds also increase cloud fractions at the same altitudes, but decrease cloud water content at slightly lower altitudes. It is found that relative humidity increases at the same altitudes where the cloud fraction increases, caused by radiative cooling that is induced by cloud fraction increases but not changes in cloud water content. This result points to a deficiency in cloud fraction parameterizations that rely solely on ambient humidity without taking cloud water/ice content into account. Zonal-mean cloud albedo forcing is sensitive to LWP in mixed-phase clouds and the comparison with observations suggests that the CALIPSO and default parameterizations perform well in the extratropical regions.
Shape analysis of corpus callosum in phenylketonuria using a new 3D correspondence algorithm

Statistical shape analysis of brain structures has gained increasing interest from neuroimaging community because it can precisely locate shape differences between healthy and pathological structures. The most difficult and crucial problem is establishing shape correspondence among individual 3D shapes. This paper proposes a new algorithm for 3D shape correspondence. A set of landmarks are sampled on a template shape, and initial correspondence is established between the template and the target shape based on the similarity of locations and normal directions. The landmarks on the target are then refined by iterative thin plate spline. The algorithm is simple and fast, and no spherical mapping is needed. We apply our method to the statistical shape analysis of the corpus callosum (CC) in phenylketonuria (PKU), and significant local shape differences between the patients and the controls are found in the most anterior and posterior aspects of the corpus callosum.
Fünfgliedrige Ringe durch [3+2]‐Cycloaddition mit Trimethylenmethan und Syntheseäquivalenten

Die Bildung von Ringen durch Cycloaddition ist aufgrund ihres Potentials fur Chemo-, Regio-, Diastereo- und Enantioselektivitat von besonderem Wert. Trimethylenmethan (TMM) und seine Syntheseaquivalente ermoglichen es, diese Vorteile bei der Synthese funfgliedriger Ringe zu nutzen. Drei Typen von Reagentien sind aussichtsreiche Kandidaten: 1. Ausgewahlte 4-Alkyliden-4,5-dihydro-3H-pyrazole, 2. 2-[(Trimethylsilyl)methyl]allyl-ester und -halogenide sowie 3. Alkylidencyclopropane. Die Cycloaddition der Pyrazole an (elektronenarme) Olefine gelingt durch thermische, speziell intramolekulare Reaktionen. Fur die beiden anderen Vorstufen benotigt man Katalysatoren, vorzugsweise Palladium-Komplexe. Bei den 2-(Silylmethyl)allylestern fuhrt eine allgemeine chemo-, regio- und diastereoselektive Cycloaddition an typische Diels-Alder-Dienophile zu Methylencyclopentanen. Mit einem Zinn-Analogon lassen sich aus Carbonylverbindungen und Iminen mit hervorragender Diastereoselektivitat 3-Methylen-tetrahydrofurane bzw. -pyrrolidine herstellen. Die 2-(Silylmethyl)allylester ermoglichen auch die Anellierung einer Methylencyclopentan-Einheit an cyclische Enole. Solche Addukte kann man unter C3-Einschiebung oder unter kombinierter Ringverengung und Spiroanellierung umsetzen, indem man ein nucleophiles bzw. ein elektrophiles Steuerreagens anwendet. Bei Alkylidencyclopropanen, die mit elektronenreichen wie mit elektronenarmen Olefinen reagieren, ist die Regioselektivitat komplementar zu derjenigen der Silylreagentien. - Alle diese Cycloadditionen haben es ermoglicht, neue Strategien fur Naturstoffsynthesen zu entwickeln.
Beliefs and knowledge in chemistry teacher development

The primary objective of this research was to establish a link between preservice, secondary chemistry teachers' knowledge base and beliefs about teaching. The case study followed two preservice chemistry teachers through their methods course, practicum experience, and student teaching internship. Pedagogical content knowledge vignettes, following a microgenetic model, and other data sources were used to monitor participants' conceptual change over time. Participants had well‐intentioned beliefs about teaching and chemistry. The interaction of epistemologies and beliefs was determined to be synergistic, such that they remained separate epistemological ideas. The beliefs about content were not changed whereas those for teaching did change; one focused on epistemic understanding and the other on subjective realization.
Quality-of-service provisioning for multimedia services in next-generation wireless networks

Quality of Service (QoS) is an important issue in the next generation wireless networks providing multimedia services. In this paper, we address the connection-level QoS provisioning in wireless multimedia networks, measured by the connection blocking and dropping probabilities. The connection-level QoS for multimedia services are guaranteed by achieving the minimum connection blocking probability subject to the constraint on the handoff dropping probability. A dynamic call admission control scheme is proposed to provide connection-level QoS in wireless multimedia networks. This scheme adopts a novel strategy called prompt-decreasing/timer-increasing (PDTI) to dynamically adjust the threshold for handoff channel reservation. It can maintain the handoff dropping probability at a target rate predefined in the system specification, while maximizing resource utilization and minimizing the new call blocking rate. The proposed solution is a measurement-based method that is practical for real-world deployment. Simulations are carried out to prove the efficiency of the proposed PDTI scheme.
Functional analysis and mechanistic explanation

Piccinini and Craver (Synthese 183:283–311, 2011) argue for the surprising view that psychological explanation, properly understood, is a species of mechanistic explanation. This contrasts with the ‘received view’ (due, primarily, to Cummins and Fodor) which maintains a sharp distinction between psychological explanation and mechanistic explanation. The former is typically construed as functional analysis, the analysis of some psychological capacity into an organized series of subcapacities without specifying any of the structural features that underlie the explanandum capacity. The latter idea, of course, sees explanation as a matter of describing structures that maintain (or produce) the explanandum capacity. In this paper, I defend the received view by criticizing Piccinini and Craver’s argument for the claim that psychological explanation is not distinct from mechanistic explanation, and by showing how psychological explanations can possess explanatory force even when nothing is known about the underlying neurological details. I conclude with a few brief criticisms about the enterprise of mechanistic explanation in general.
Urban general equilibrium models and simplicial search algorithms

Abstract This paper describes how simplicial search algorithms work, and discusses how they may be used to solve static theoretical urban models. If such algorithms are to be used, land must be treated as consisting of a number of discrete sections. It is argued that this is not a serious disadvantage, and that for many purposes such discrete models have significant advantages over models in which land is treated as continuous. In particular, it is possible to deal with several groups of people having different tastes and incomes. Several related models are described, and some interesting qualitative results are presented.
Targeting anticancer drugs to the brain: II. Physiological pharmacokinetic model of oxantrazole following intraarterial administration to rat glioma-2 (RG-2) bearing rats

The disposition of the anticancer drug oxantrazole (OX) was characterized in rats bearing the rat glioma-2 (RG-2) brain tumor. Following intraarterial administration of 3 mg/kg of OX, serial sacrifices were completed from 5 min to 5 hr after administration. Blood and tissue samples collected at the time of sacrifice were processed and measured for OX concentrations by HPLC. The kidney had the greatest affinity for OX with the Cmaxbeing 40.6 μg/mlat 15 min after administration. OX concentrations in brain tumor were higher than in normal right and left brain hemispheres, and consistent with enhanced drug blood-tumor barrier (BTB) permeability seen in experimental models for brain tumors. Observed heart, liver, lung, and spleen OX concentrations were similar, ranging from approximately 2 μg/mlto 20 μg/ml. A unique technique was used to develop a global physiological pharmacokinetic model for OX. A hybrid or forcing function method was used to estimate individual tissue compartment biochemical parameters (i.e., partition and mass transfer coefficients). A log likelihood optimization scheme was used to determine the best model structure and parameter sets for each tissue. Most tissues required a 3-subcompartment structure to adequately describe the observed data. The global model was then reconstructed with an arterial blood and rest of body compartments that provided predicted OX concentrations in agreement with the data. The model development strategy provides a systematic approach to physiological pharmacokinetic model development.
Melting and Heat Capacity of Gel-Spun, Ultra-High-Molar-Mass Polyethylene Fibers

Abstract The melting behaviors of gel-spun, ultra-high molar mass polyethylene fibers have been investigated using standard differential scanning calorimetry and wide-angle X-ray diffraction. For laterally constrained fibers the standard DSC exhibits the usually reported two melting peaks (one at about 415 K and one at about 423 K), a glass transition (at about 275 K) and an unusually large and reversible heat capacity as one approaches the melting peaks (starting at about 350–370 K). Earlier observations that sometimes only the lower melting endotherm is retained, are proven to be of fibers free of longitudinal and lateral constraints. Up to the beginning of major melting, all fibers are mainly orthorhombic. The orthorhombic–hexagonal transition is proven to occur only for the constrained fibers, implying that the hexagonal phase is a non-equilibrium phase, usually not present in the initial fibers. An oriented, intermediate phase, discovered by solid state NMR and full-pattern X-ray analysis, gives rise to a substantially broadened glass transition that reaches to about 300 K, compared to the glass transition of the amorphous polyethylene with a midpoint at 237 K and end at 250 K.
Cell-specific modulation of drug resistance in acute myeloid leukemic blasts by diphtheria fusion toxin, DT388-GMCSF

Radiochemotherapy-resistant blasts commonly cause treatment failure in acute myeloid leukemia (AML), and their resistance is due, in part, to overexpression of multidrug resistance (mdr) proteins. We reasoned that targeted delivery of protein synthesis inactivating toxins to leukemic blasts would reduce the cellular concentrations of relatively short half-life resistance proteins and sensitize the cells to cytotoxic drugs. To test this hypothesis, we employed human granulocyte-macrophage colony-stimulating factor fused to truncated diphtheria toxin (DT388-GMCSF). The human AML cell line HL60 and its vincristine-resistant sublines, HL60Vinc and HL60VCR, were incubated in vitro for 24 h with varying concentrations of toxin. Doxorubicin was added for an additional 24 h, and cell cytotoxicity was assayed by thymidine incorporation and colony formation in semisolid medium. DT388-GMCSF sensitized HL60Vinc and HL60VCR but not HL60 to doxorubicin. Combination indices for three log cell kill varied from 0.2 to 0.3. In contrast, pretreatment with doxorubicin followed by toxins failed to show synergy. At least in the case of the vincristine-resistant cell lines, modulation of drug resistance correlated with reduction in membrane P-glycoprotein concentrations based on immunoblots with C219 antibody, flow cytometry with MRK16 antibody, and cell uptake of doxorubicin. These observations suggest clinical trials of combination therapy may be warranted in patients with refractory AML. Further, targeted toxins may represent a novel class of cell-specific modulators of drug resistance for a number of malignancies.
Advances in variable selection methods I: Causal selection methods versus stepwise regression and principal component analysis on data of known and unknown functional relationships

Hydrological predictions at a watershed scale are commonly based on extrapolation and upscaling of hydrological behavior at plot and hillslope scales. Yet, dominant hydrological drivers at a hillslope may not be as dominant at the watershed scale because of the heterogeneity of watershed characteristics. With the availability of quantifiable watershed data (watershed descriptors and streamflow indices), variable selection can provide insight into the dominant watershed descriptors that drive different streamflow regimes. Stepwise regression and principal components analysis have long been used to select descriptive variables for relating runoff to climate and watershed descriptors. Questions have remained regarding the robustness of the selected descriptors. This paper evaluates five new approaches: Grow-Shrink, GS; a variant of Incremental Association Markov Boundary, interIAMBnPC; Local Causal Discovery, LCD2; HITON Markov Blanket, HITON-MB; and First-Order Utility, FOU. We demonstrate their performance by quantifying their accuracy, consistency and predictive potential compared to stepwise regression and principal component analysis on two known functional relationships. The results show that the variables selected by HITON-MB and the first-order utility are the most accurate while variables selected by Stepwise regression, although not accurate have a high predictive potential. Therefore, a model with high predictive power may not necessary represent the underlying hydrological processes of a watershed system.
Benzyl and naphthalene methylphosphonic acid inhibitors of autotaxin with anti-invasive and anti-metastatic activity

Autotaxin (ATX, NPP2) is a member of the nucleotide pyrophosphate phosphodiesterase enzyme family. ATX catalyzes the hydrolytic cleavage of lysophosphatidylcholine (LPC) by lysophospholipase D activity, which leads to generation of the growth-factor-like lipid mediator lysophosphatidic acid (LPA). ATX is highly upregulated in metastatic and chemotherapy-resistant carcinomas and represents a potential target to mediate cancer invasion and metastasis. Herein we report the synthesis and pharmacological characterization of ATX inhibitors based on the 4-tetradecanoylaminobenzylphosphonic acid scaffold, which was previously found to lack sufficient stability in cellular systems. The new 4-substituted benzylphosphonic acid and 6-substituted naphthalen-2-ylmethylphosphonic acid analogues block ATX activity with K(i) values in the low micromolar to nanomolar range against FS3, LPC, and nucleotide substrates through a mixed-mode inhibition mechanism. None of the compounds tested inhibit the activity of related enzymes (NPP6 and NPP7). In addition, the compounds were evaluated as agonists or antagonists of seven LPA receptor (LPAR) subtypes. Analogues 22 and 30 b, the two most potent ATX inhibitors, inhibit the invasion of MM1 hepatoma cells across murine mesothelial and human vascular endothelial monolayers in vitro in a dose-dependent manner. The average terminal half-life for compound 22 is 10+/-5.4 h and it causes a long-lasting decrease in plasma LPA levels. Compounds 22 and 30 b significantly decrease lung metastasis of B16-F10 syngeneic mouse melanoma in a post-inoculation treatment paradigm. The 4-substituted benzylphosphonic acids and 6-substituted naphthalen-2-ylmethylphosphonic acids described herein represent new lead compounds that effectively inhibit the ATX-LPA-LPAR axis both in vitro and in vivo.
Noninvasive detection of pulmonary hypertension

Plain chest x-rays, twelve-lead electrocardiograms, and M-mode echocardiograms were analyzed in 50 control patients and 79 consecutive patients with pulmonary hypertension documented at cardiac catheter-ization in order to determine the relative values of these noninvasive techniques as screening tests in detecting pulmonary hypertension. The sensitivity and specificity of selected findings previously described as being associated with pulmonary hypertension were calculated for each test. All test results were found to have sensitivities too low to function as satisfactory noninvasive screening techniques. Most findings were highly specific for pulmonary hypertension when present. Patients with pulmonary vascular disease were detected more frequently than those with pulmonary hypertension due to pulmonary venous congestion.
Hydrolytic cleavage of peptides by palladium(II) complexes is enhanced as coordination of peptide nitrogen to palladium(II) is suppressed

Abstract We report on the kinetics and mechanism of regioselective hydrolysis of amide bonds in various dipeptides and tripeptides after these substrates react with [Pd(H2O)3(OH)]+ and cis-[Pd(en)(H2O)2]2+. Peptides devoid of coordinating side chains form mononuclear palladium(II) complexes and hydrolyze slowly, over weeks. Peptides containing thio ether side chains (of methionine and S-methylcysteine) as anchors form binuclear palladium(II) complexes and hydrolyze rapidly, with half-lives that are measured in minutes. The ethylenediamine ligand stabilizes the initial complex but is released prior to hydrolysis, so that the two mononuclear complexes form similar binuclear promoter complexes with anchoring peptides. Hydrolysis requires acidic solutions, but this reaction is not catalyzed by acid; the palladium(II) promoter is required. Binding of the sulfur-anchored palladium(II) atom to the deprotonated nitrogen atom in the amide bond inhibits hydrolysis. Methylation of the amide nitrogen atom suppresses binding of palladium(II) to it and enhances the hydrolysis rate constant as much as 300-fold.
Cadaver Use and Coping Mechanisms in a Biomechanics Laboratory

Although many studies have focused on emotional anxiety related to cadaver use in medical school gross anatomy laboratories and disaster relief settings, this study breaks new ground by investigating coping mechanisms employed by members of a research laboratory where cadaver use is common. This setting differs from those of other studies insofar as cadaver use is a common occurrence over an extended period of time, the laboratory is composed of engineers and computer programmers as well as medically trained individuals, and cadaver parts, rather than whole cadavers, are used in the studies. In this article, coping mechanisms are qualitatively described and then related to differences between this laboratory setting and the settings of previous studies on coping mechanisms related to cadaver use.
Natural Variants of C. elegans Demonstrate Defects in Both Sperm Function and Oogenesis at Elevated Temperatures

The temperature sensitivity of the germ line is conserved from nematodes to mammals. Previous studies in C. briggsae and Drosophila showed that isolates originating from temperate latitudes lose fertility at a lower temperature than strains originating from tropical latitudes. In order to investigate these relationships in C. elegans, analysis of the fertility of 22 different wild-type isolates of C. elegans isolated from equatorial, tropical and temperate regions was undertaken. It was found that there are significant temperature, genotype and temperature × genotype effects on fertility but region of isolation showed no significant effect on differences in fertility. For most isolates 100% of the population maintained fertility from 20°C to 26°C, but there was a precipitous drop in the percentage of fertile hermaphrodites at 27°C. In contrast, all isolates show a progressive decrease in brood size as temperature increases from 20°C to 26°C, followed by a brood size near zero at 27°C. Temperature shift experiments were performed to better understand the causes of high temperature loss of fertility. Males up-shifted to high temperature maintained fertility, while males raised at high temperature lost fertility. Down-shifting males raised at high temperature generally did not restore fertility. This result differs from that observed in Drosophila and suggested that in C. elegans spermatogenesis or sperm function is irreversibly impaired in males that develop at high temperature. Mating and down-shifting experiments with hermaphrodites were performed to investigate the relative contributions of spermatogenic and oogenic defects to high temperature loss of fertility. It was found that the hermaphrodites of all isolates demonstrated loss in both spermatogenic and oogenic germ lines that differed in their relative contribution by isolate. These studies uncovered unexpectedly high variation in both the loss of fertility and problems with oocyte function in natural variants of C. elegans at high temperature.
Protective efficacy of a tandemly linked, multi-subunit recombinant leishmanial vaccine (Leish-111f) formulated in MPL adjuvant.

Abstract Three immunodominant leishmanial antigens (TSA, LmSTI1 and LeIF) previously identified in the context of host response to infection in infected donors and BALB/c mice, as well as their ability to elicit at least partial protection against Leishmania major infection in the BALB/c mouse model, were selected for inclusion into a subunit based vaccine. This is based on the premise that an effective vaccine against leishmaniasis (a complex parasitic infection) would require a multivalent cocktail of several antigens containing a broader range of protective epitopes that would cover a wide range of MHC types in a heterogeneous population. For practical considerations of vaccine development, we report on the generation of a single recombinant polyprotein comprising the sequences of all three open reading frames genetically linked in tandem. The resulting molecule, Leish-111f, comprises an open reading frame that codes for a 111 kDa polypeptide. Evaluation of the immunogenicity and protective efficacy of Leish-111f formulated with IL-12 revealed that the immune responses to the individual components were maintained and as well, rLeish-111f protected BALB/c mice against L. major infection to a magnitude equal or superior to those seen with any of the individual components of the vaccine construct or SLA, a soluble Leishmania lysate. But because rIL-12 is expensive and difficult to manufacture and its efficacy and safety as an adjuvant for human use is questionable, we screened for other adjuvants that could potentially substitute for IL-12. We report that monophosphoryl lipid A (MPL) plus squalene (MPL–SE) formulated with rLeish-111f elicited protective immunity against L. major infection. The demonstrated feasibility to manufacture a single recombinant vaccine comprising multiple protective open reading frames and the potential use of MPL–SE as a substitute for IL-12, takes us closer to the realization of an affordable and safe Leishmania vaccine.
Simulating the effects of poverty on the race disparity in postneonatal mortality.

The U.S. postneonatal mortality rate has declined from over 60 postneonatal deaths per 1,000 live births at the turn of the century to below 4 deaths in 1987. It is generally accepted that this impressive decline is due to improvements in the general standard of living throughout the twentieth century. However, efforts to reduce the race differential in postneonatal mortality have been less successful. Black postneonatal mortality rates have been roughly double the white rate since race-specific data has been collected. This paper examines the degree to which the substantial race disparities in postneonatal mortality are a function of race disparities in the prevalence of poverty. The analysis specifies a race-specific model of postneonatal mortality. The model is then manipulated to allow for a simulation of the impact of reducing black poverty on the postneonatal mortality race disparity. It is concluded that racial postneonatal mortality differentials may be addressed by remedies which need not be explicitly medical intervention (e.g. effective policy that reduces disparities in socioeconomic status).