cssi/SciSciGPT-SciSciNet huggingface dataset:
Dark field transmission electron microscope images of III-V quantum dot structures.

Abstract Multi-layer quantum dot structures are becoming increasingly common in order to improve the efficiency of quantum dot lasers. Each layer of dots may be influenced by the preceding dot layer, and the dot density can vary from layer to layer. Characterization of such structures relies on the reliable determination of the shape, size and density of dots in each layer. Dark field transmission electron microscopy (TEM) images using the 002 diffraction condition are frequently used, viewing the layers edge-on in a cross-section sample. A simple model is used to describe the contrast as a function of dot size and shape, specimen thickness, and the composition of the dot and surrounding materials. Good agreement with experimental results is obtained. It is found that the dot size is not accurately related to the bright region seen in such images. While 002 images can be used to determine the size and shape of dots, a density per unit area cannot be calculated in the cross section geometry without either measuring—or assuming—the specimen thickness. In multilayer structures, plan-view TEM images show the layers as overlapping, losing the information from individual layers. By tilting a cross-section specimen to allow imaging with the dark field 113 diffraction condition, the density in individual layers can be measured. Additional information, such as wetting layer thickness variations and alignment of dots due to surface roughness or substrate offcut, can also be obtained.
Intracranial V. cholerae sialidase protects against excitotoxic neurodegeneration.

Converging evidence shows that GD3 ganglioside is a critical effector in a number of apoptotic pathways, and GM1 ganglioside has neuroprotective and nootropic properties. Targeted deletion of GD3 synthase (GD3S) eliminates GD3 and increases GM1 levels. Primary neurons from GD3S−/− mice are resistant to neurotoxicity induced by amyloid-β or hyperhomocysteinemia, and when GD3S is eliminated in the APP/PSEN1 double-transgenic model of Alzheimer's disease the plaque-associated oxidative stress and inflammatory response are absent. To date, no small-molecule inhibitor of GD3S exists. In the present study we used sialidase from Vibrio cholerae (VCS) to produce a brain ganglioside profile that approximates that of GD3S deletion. VCS hydrolyzes GD1a and complex b-series gangliosides to GM1, and the apoptogenic GD3 is degraded. VCS was infused by osmotic minipump into the dorsal third ventricle in mice over a 4-week period. Sensorimotor behaviors, anxiety, and cognition were unaffected in VCS-treated mice. To determine whether VCS was neuroprotective in vivo, we injected kainic acid on the 25th day of infusion to induce status epilepticus. Kainic acid induced a robust lesion of the CA3 hippocampal subfield in aCSF-treated controls. In contrast, all hippocampal regions in VCS-treated mice were largely intact. VCS did not protect against seizures. These results demonstrate that strategic degradation of complex gangliosides and GD3 can be used to achieve neuroprotection without adversely affecting behavior.
A metal-oxide interconnection layer for polymer tandem solar cells with an inverted architecture.

[∗] C.-H. Chou , W. L. Kwan , Dr. Z. R. Hong , L.-M. Chen , Prof. Y. Yang Department of Materials Science and Engineering University of California Los Angeles, CA 90095 (USA) E-mail: yangy@ucla.edu C.-H. Chou Phosphors Research Laboratory Department of Applied Chemistry National Chiao Tung University Hsinchu 30050, Taiwan (Republic of China) In the past decade, polymer solar cells have attracted considerable interest due to their potential for low-cost, light-weight and fl exible applications. [ 1 , 2 ] As a result of effi cient exciton dissociation in polymer-fullerene blends, polymer bulk heterojunction (BHJ) solar cells with high external quantum effi ciencies (EQE, ratio of extracted charge carriers to incident photons) can be achieved by carefully controlling the morphology of the polymer blend. [ 3 , 4 ] The power conversion effi ciency (PCE) can be further improved by using low band gap polymers which absorb a broader range of photon energies that also provide a better match to the solar spectrum. [ 5–7 ] However, the ultimate achievable effi ciency of the solar cell is still limited by the low carrier mobility and narrow absorption spectra of the polymers. [ 8 ] Low mobility of the polymer material constrains the active layer thickness because a thicker fi lm will lower the extraction effi ciency of charge carriers, while a thinner fi lm will lead to insuffi cient absorption of incident photons. The limited absorption spectrum of the polymer also results in ineffi cient utilization of the solar spectrum. To overcome these challenges, it is desirable to stack individual cells with complementary absorption in a tandem structure to realize high effi ciency polymer tandem cells. [ 9–13 ] Typical polymer tandem cells consist of two diodes, head-to-tail connected via an interlayer. Conductive polymers, e.g., poly(3,4-ethylenedioxythiophene) blended with poly(styrenesulfonate) (PEDOT:PSS), and n-type metal oxides are commonly used as the interlayer. However, the acidic nature of PEDOT:PSS raises stability concerns. [ 14 ] In addition, optical loss due to absorption of the PEDOT:PSS fi lm is signifi cant, approaching 10% in the visible range, and even higher in the near infrared (NIR) region. [ 15 ] Metal oxides with higher stability and optical transparency has thus been proposed to replace PEDOT:PSS as the interfacial layer between indium tin oxide (ITO) and polymer BHJs. Furthermore, the polarity of the solar cells can be controlled by the properties of the metal oxides. [ 16 , 17 ] Devices with an inverted architecture, where the positions of the anode and cathode are reversed, have been demonstrated with better stability. This is because the reactive
From CRCs to resilient control systems: differentiating between reliability and security for the protection of cyber-physical systems

In this talk I will discuss the need to establish clear differences between reliability and security for protecting cyber-physical systems (CPS).This is particularly important given the recent interest from researchers in exploring the vulnerability of a CPS when an attacker has partial control of the sensor or actuator signals, which has led to the proposal of several anomaly detection schemes for CPS by using data collected from physical sensors (as opposed to traditional network sensors). In the general setting, data obtained from normal behavior of the system is used to create a model and then any outlier is considered an anomaly and a potential failure or attack; however, this line of research is very similar to the fault-detection, and safety mechanisms that have been deployed in control systems for decades. In particular, the protection of control systems has traditionally been enforced by several safety mechanisms, which include bad data detection, protective relays, safety shutdowns, interlock systems, robust control, and fault-tolerant control; however, so far there has not been a systematic study that tries to identify how much these protection mechanisms can help against attacks (as opposed to failures or accidents), and how can they be broken by an attacker and potentially fixed by a system designer that incorporates attack models in the design of their system.In this talk I describe how current protection mechanisms are analogous to how error correcting codes are used in communications: they protect against a vast majority of random faults and accidents; however they are not secure against attacks - the way cryptographic hash functions are. As a community we need to revisit protection mechanisms available from control theory and then analyze them from a security perspective, giving new guidelines on security metrics and new ways to design attack-resilient CPS. In addition, we also need to avoid falling into the trap of proposing security mechanisms that are evaluated using similar tools from reliability.
The preoperative predictability of the short esophagus in patients with stricture or paraesophageal hernia.

Background: Esophageal shortening is a known complication of advanced gastroesophageal reflux disease that may preclude a tension-free antireflux procedure. A retrospective analysis was performed to test the accuracy of preoperative testing. Methods: From September 1993 to December 1998, 39 patients underwent esophageal mobilization with intraoperative length assessment. Patients were selected on the basis of irreducible hiatal hernia, stricture formation, or both. Patients in the upright position with a fixed hiatal hernia larger than 5 cm on an esophagram were considered to have a short esophagus. Manometric length two standard deviations below the mean for height was considered abnormally short. Results: In 31 patients, intraoperative mobilization was sufficient to allow the gastroesophageal junction to lie 2 cm below the diaphragmatic crus, so no esophageal-lengthening procedure was required. Eight patients with a short esophagus required an esophageal-lengthening procedure after complete mobilization. Two patients subsequently underwent intrathoracic migration of the gastroesophageal junction (GEJ), with recurrence of symptoms and required gastroplasty during the second surgery. An esophagram had a sensitivity of 66% and a positive predictive value of 37%, whereas manometric length had a sensitivity of 43% and a positive predictive value of 25% for the diagnosis of short esophagus. The preoperative endoscopic finding of either a stricture or Barrett's esophagus was the most sensitive test for predicting the need for a lengthening procedure. Conclusions: Manometry and esophagraphy are not reliable predictors of the short esophagus. Additional tests and/or tests combined with other parameters are needed.
THE ARTICULATION OF PROJECT WORK: AN ORGANIZATIONAL PROCESS

This article offers a theoretical framework or model for understanding how work within projects is articulated. A distinction is drawn between articulation of work and a more inclusive organizational process, termed the “articulation process.” The theoretical model includes several related concepts that pertain to numerous interlocking and sequential elements of the total work. These include work processes, types of work, and interactional processes. The model avoids assuming a tightly integrated organization of work; rather, it represents an extension of the negotiated order approach to organizations. A discussion of variations in projects revolves around two important dimensions of projects. The article closes with a discussion of extreme disruptions in project work flow, as well as some general considerations about the importance of focusing on articulation in organizations.
Altered regulatory T cell homeostasis in patients with CD4+ lymphopenia following allogeneic hematopoietic stem cell transplantation

CD4+CD25+Foxp3+ Tregs have an indispensable role in the maintenance of tolerance after allogeneic HSC transplantation (HSCT). Patients with chronic graft-versus-host disease (GVHD) have fewer circulating Tregs, but the mechanisms that lead to this deficiency of Tregs after HSCT are not known. Here, we analyzed reconstitution of Tregs and conventional CD4+ T cells (Tcons) in patients who underwent allogeneic HSCT after myeloablative conditioning. Following transplant, thymic generation of naive Tregs was markedly impaired, and reconstituting Tregs had a predominantly activated/memory phenotype. In response to CD4+ lymphopenia after HSCT, Tregs underwent higher levels of proliferation than Tcons, but Tregs undergoing homeostatic proliferation also showed increased susceptibility to Fas-mediated apoptosis. Prospective monitoring of CD4+ T cell subsets revealed that Tregs rapidly expanded and achieved normal levels by 9 months after HSCT, but Treg levels subsequently declined in patients with prolonged CD4+ lymphopenia. This resulted in a relative deficiency of Tregs, which was associated with a high incidence of extensive chronic GVHD. These studies indicate that CD4+ lymphopenia is a critical factor in Treg homeostasis and that prolonged imbalance of Treg homeostasis after HSCT can result in loss of tolerance and significant clinical disease manifestations.
Analysis of stochastic numerical schemes for the evolution equations of geophysics

Abstract We present and study the stability and convergence, and order of convergence of a numerical scheme used in geophysics, namely, the stochastic version of a deterministic “implicit leapfrog” scheme which has been developed for the approximation of the so-called barotropic vorticity model. Two other schemes which might be useful in the context of geophysical applications are also introduced and discussed.
On the Diffusivity of Au in Pb

The precipitation of Pb3Au from dilute Pb(Au) alloys and the subsequent Ostwald ripening of the precipitate phase have been studied. The Au diffusivity which limits the precipitation from Pb(500 at. ppm Au) specimens is in good agreement with Dp = 45 exp[(−20.8 kcal/mol)/RT], found previously to control the precipitation rate in Pb(900–1000 at. ppm Au) alloys (Rossolimo and Turnbull, 1973). In contrast, precipitation from Pb(100 at. ppm Au) alloys and Ostwald ripening in the Pb(500 at. ppm Au) specimens appear to be governed by the high temperature Au tracer diffusivity, DAu = 0.0041 exp[(−9.35 kcal/mol)/RT], which is about 103 times greater than Dp at the temperatures of interest, 75 to 112°C, and is attributed to the motion of a Au interstitial defect. In the 100 ppm alloys the Au is incorporated most easily at the ends of the Pb3Au crystals and a ribbon- or whisker-like morphology results. The particles which form at the grain boundaries in the 500 ppm Au alloy specimens are at least six times larger in volume than the matrix particles and ripen at their expense. The Ostwald ripening kinetics of the grain boundary particles scale with t1/2 rather than with t1/3 as is usual. The Pb3Au formed whiskers, blades, ribbons, or equiaxed particles depending upon the Au concentration and precipitation temperature. The precipitation and ripening kinetics are critically dependent on the morphology of the second phase.
Quasiparticle band structure of Zn-IV-N-2 compounds

Electronic energy-band structures of the Zn-IV-N${}_{2}$ compounds, with IV equal to Si, Ge, and Sn calculated in the quasiparticle self-consistent GW approximation and using the full-potential linearized muffin-tin orbital approach, are presented. A comparison is made with local-density approximation results. The bands near the gap are fitted to an effective Kohn-Luttinger-type Hamiltonian appropriate for the orthorhombic symmetry, and conduction-band effective masses are presented. Exciton binding energies and zero-point motion corrections to the gaps are estimated. While ZnSiN${}_{2}$ is found to be an indirect gap semiconductor, ZnGeN${}_{2}$ and ZnSnN${}_{2}$ are direct gap semiconductors. The gaps range from the orange-red to deep UV. The valence-band maximum is split in three levels of different symmetry, even in the absence of spin-orbit coupling, and should show transitions to the conduction band, each for a separate polarization. Spin-orbit effects are found to be surprisingly small, indicating almost exact compensation of the N-$2p$ and Zn-$3d$ contributions.
Comparing the photophysics of the two forms of the Orange Carotenoid Protein using 2D electronic spectroscopy

Broadband two-dimensional electronic spectroscopy is applied to investigate the photophysics of the photoactive orange carotenoid protein, which is involved in nonphotochemical quenching in cyanobacteria. Differences in dynamics between the light and dark forms arise from the different structure of the carotenoid in the protein pocket, with consequences for the biological role of the two forms.
Peripheral Ramification of the Cardiac Conducting System

The study of the peripheral distribution of the right bundle branch in bovine, dog's, goat's, lamb's, and human hearts demonstrates an anatomical basis for the production of varying degrees of right bundle-branch block on operative incision of the anterior wall of the right ventricle. The left branch of the cardiac conducting system, with its transventricular cavity conducting bundles to the papillary muscles and the ventricular wall in bovine, dog's, goat's, lamb's, and human hearts, offers an anatomical basis for varying degrees of disturbance in left ventricular conduction due to operative incision or instrumentation in the left ventricle. Comparative anatomical studies in man and animals show conducting fibers which traverse the ventricular cavities in structures previously termed pseudotendons or false chords. In man, the existence of these transventricular cavity conducting bundles has not been emphasized, probably because of the traditional methods of opening the heart at autopsy. The combined elec...
The ethics of sentencing white-collar criminals

The consistent sentencing of white collar criminals does not exist in today's judicial system. Guidelines for sentencing individuals and corporations have already been developed by the U.S. Sentencing Commission but have not yet been implemented in the courts. Pros and cons of the guidelines are given, as is the extent and form of sentencing deemed appropriate for the individual or corporation. The activities of the sentencing commission are depicted by a timeline.
Modified Atmosphere Packaging to Maintain Direct‐Set Cottage Cheese Quality

Direct-set cottage cheese packaged in barrier containers was flushed with 100% CO 2 75%, CO 2 :25% N 2 , 100% N 2 , or air, and stored at 4 o C for 28 days. Quality was assessed by sensory, microbiological, and chemical tests. No change was observed in headspace gas composition during storage. Psychrotrophic and lactic acid bacteria counts increased for air-treated samples, but counts for cottage cheese packaged under modified atmospheres remained unchanged. Product discoloration was not observed. Acidity increased over storage life, but lactic acid did not contribute towards increased acidity. Sensory characteristics of cottage cheese packaged under modified atmospheres remained satisfactory after 28 days, with 100% CO 2 best
Borrelia burgdorferi decreases hyaluronan synthesis but increases IL-6 production by fibroblasts

Despite the prevalence of clinical data on human Lyme disease, little is known about the immunopathologic effects of the causative organism on the host. We studied the effect of Borrelia burgdorferi on hyaluronan (hyaluronic acid, HYA) production and the effect on interleukin-6 (IL-6) synthesis by cultured fibroblasts. The cell line employed in this study produced an average of 1406 ng of hyaluronan/ml within 48 h. Using both a morphological staining protocol and a quantitative radiometric assay, we noted that in the presence of a low dose of Borrelia (9.4 x 10(5) cells/ml) the hyaluronan production decreased to an average of 1008 ng/ml, a significant difference (p < 0.05) from the amount of hyaluronan produced by the cells alone. The reduction was even more significant (p < 0.01) when a higher dose of Borrelia (9.4 x 10(6) cells/ml) was used giving an average hyaluronan concentration of 682 ng/ml. In contrast, we found that Borrelia stimulated the cells to produce IL-6 from a baseline of 293 pg/ml to a maximal value of 842 pg/ml (p < 0.01). The spirochetes had no significant effect on cell viability, nor were we able to demonstrate invasion of the cells by the bacteria. Both a decrease in hyaluronan and an increase in IL-6 may correlate with the pathogenicity of Lyme disease in man.
Helix-helix packing angle preferences for finite helix axes.

Recently, James Bowie addressed the question of how to normalize correctly the distribution of observed helix-helix packing angles in proteins (Bowie, Nature Struct. Biol. 4:915–917, 1997). A hitherto unrealized yet significant bias toward crossed packing angles was revealed. However, the derived random reference distribution of packing angles requires that helices have to be assumed as infinite in length. Here, we complement Bowie's analysis by consideration of the more realistic case where helices are of finite length. As a result, the statistical bias toward near perpendicular packings appears to be even stronger. Proteins 33:457–459, 1998. © 1998 Wiley-Liss, Inc.
High-performance liquid chromatography-based assays of enzyme activities

Abstract Interest in using HPLC to assay enzymatic reactions continues to grow as evidenced by the more than 100 papers published during the early 1990s. HPLC can be used for any enzymatic assay that requires separation of substrates and products before quantifying the extent of the reaction. The popularity of HPLC-based assays is due to several reasons: (1) HPLC offers unsurpassed precision, specificity, sensitivity, and reproducibility. (2) Powerful microcomputers and user-friendly software automate the running of samples and collection and processing of data. (3) Current columns, especially C 18 packings, separate a very wide variety of samples, and (4) A variety of on-line detectors provide a means to detect virtually any compound. This review surveys recent papers on the development of HPLC-based assays for enzymes that degrade or otherwise modify macromolecules. Methods for assaying enzymes involved in metabolic pathways are also reviewed. Work by the authors in developing HPLC-based assays for mitochondrial enzymes that use GTP/GDP and other nucleotides that cannot be or are not easily assayed by enzyme-coupled assays is discussed. These enzymes include nucleoside diphosphate kinase, succinate thiokinase, and GTP—AMP phospho-transferase. The assays are suitable for determining the submitochondrial compartmentation of enzyme activities. Finally, current and anticipated trends in HPLC technology, including new column packings and the trend toward smaller columns that give faster separations, are reviewed in relation to enzyme assays.
Bilateral Trigeminal Nerve Sensory Deficits and Nasal Deformity

• A nasal deformity developed in a woman with bilateral trigeminal sensory deficits. A comparison of the clinical and pathologic features of this case with those of several other cases that have been reported previously suggests a relationship between the bilateral fifth nerve lesions and the nasal damage. The aforementioned clinical combination does not appear to be pathognomonic of any specific nosologic entity. However, it probably should be accorded the status of a clinical syndrome since the nasal degeneration apparently occurs only if both fifth nerves are affected. ( Arch Otolaryngol 104:474-476, 1978)
Characterization of Cardiomyocyte-Like Cells in Thoracic Blood Vessels

Cardiomyocyte-like cells have been found in pulmonary veins (PV) of mammals, including humans. These cells are implicated as a possible origin of atrial fibrillation, yet their biological nature and physiological function remain poorly understood. We sought 1) to characterize the differentiation states of the cardiomyocyte-like cells in mouse PV during postnatal development, 2) to determine the distribution of cardiomyocyte-like cells in the vasculature, and 3) to investigate contractility of the venous cardiomyocyte-like cells in comparison with that of myocardium. Western blots using monoclonal antibodies recognizing cardiac muscle-specific proteins show that normal cardiac myofilament proteins are expressed at significant levels in PV and azygos vein. The expression of developmentally regulated isoforms of myosin and troponin is synchronized with that in heart. Transgenic mouse lines expressing β-galactosidase under the control of cardiac troponin T promoter show that the cardiomyocyte-like cells in PV reside singly and in clusters discontinuous from the atrial myocardium. Transmission electron microscopy found that the cardiomyocyte-like cells in PV have sarcomeric structures similar to that of ventricular cardiomyocytes. Isolated rat PV contracts upon electrical pacing and responds inotropically to isoproterenol, similarly to that of left atrium strips and ventricular papillary muscle. The paced contractile pattern of rat PV is distinct from the physiological contractions of vascular smooth muscle. Our data demonstrate that the cardiomyocyte-like cells in adult thoracic veins are at a highly differentiated state similar to that of cardiac myocytes in adult hearts. While the role of their excitability in the pathogenesis of atrial fibrillation remains controversial, the ectopic presence of differentiated cardiomyocyte-like cells provides a valuable model to understand the development and differentiation of cardiomyocytes.
Analytical Evaluation of the Maxwell-Boltzmann Velocity Average in Pressure-Broadened Half-Width Calculations.

Abstract For the first time the half-width within the complex Robert–Bonamy (CRB) formalism is calculated without making the mean relative thermal velocity approximation. The application is to the nitrogen-broadened half-width of the 500.4-GHz transition (34 2 32 ←34 1 33 ) of the ground vibrational state of ozone. For each state of the perturber, the optical cross sections are determined at a number of velocities with the intermolecular potential taken as a sum of electrostatic contributions and Lennard–Jones (6–12) atom–atom components. The dynamics of the collision process are correct to second order in time. Using a nonlinear least-squares fitting method, the optical cross sections are fit to a double power law, which allows the velocity integral for the half-width to be done analytically. The results are compared with the mean relative thermal velocity complex Robert–Bonamy calculations and with measurement. The temperature dependence of the half-width, which is necessary for reduction of remotely sensed data, is determined from both methods and compared with experiment.
Late results of two hundred seventeen femoropopliteal bypasses to isolated popliteal artery segments.

Abstract A 10-year-experience of 217 femoropopliteal bypasses to isolated popliteal artery segments in 207 patients is reported. Thirty-three femoropopliteal bypasses (15%) were performed with reversed saphenous vein and 184 (85%) with polytetrafluoroethylene grafts. Operative indications were gangrene in 121 (56%), nonhealing ulceration in 40 (18%), ischemic rest pain in 51 (24%), and claudication in 5 (2%) cases. The 5-year primary graft patency rate of these bypasses was 59% (reversed saphenous vein, 74%; polytetrafluoroethylene, 55%; p p
Bortezomib Inhibits PKR-Like Endoplasmic Reticulum (ER) Kinase and Induces Apoptosis via ER Stress in Human Pancreatic Cancer Cells

Bortezomib (Velcade, formerly known as PS-341) is a boronic acid dipeptide derivative that is a selective and potent inhibitor of the proteasome. We hypothesized that proteasome inhibition would lead to an accumulation of misfolded proteins in the cell resulting in endoplasmic reticulum (ER) stress. The ability of bortezomib to induce ER stress and the unfolded protein response was investigated in a human pancreatic cancer cell line, L3.6pl. Bortezomib increased expression of ER stress markers, CHOP and BiP, but inhibited PKR-like ER kinase and subsequent phosphorylation of eukaryotic initiation factor 2α (eif2α), both of which are key events in translational suppression. These effects resulted in an accumulation of ubiquitylated proteins leading to protein aggregation and proteotoxicity. Peptide inhibitor or small interfering RNA targeting ER-resident caspase-4 blocked DNA fragmentation, establishing a central role for caspase-4 in bortezomib-induced cell death. The translation inhibitor cycloheximide abrogated bortezomib-induced protein aggregation, caspase-4 processing, and all other characteristics of apoptosis. Because malignant cells have higher protein synthesis rates than normal cells, they may be more prone to protein aggregation and proteotoxicity and possess increased sensitivity to bortezomib-induced apoptosis. Taken together, the results show that bortezomib induces a unique type of ER stress compared with other ER stress agents characterized by an absence of eif2α phosphorylation, ubiquitylated protein accumulation, and proteotoxicity. (Cancer Res 2005; 65(24): 11510-9)
Design and implementation of MPI on Puma portals

As the successor to SUNMOS, the Puma operating system provides a flexible, lightweight, high performance message passing environment for massively parallel computers. Message passing in Puma is accomplished through the use of a new mechanism known as a portal. Puma is currently running on the Intel Paragon and is being developed for the Intel TeraFLOPS machine. We discuss issues regarding the development of the Argonne National Laboratory/Mississippi State University implementation of the Message Passing Interface standard on top of portals. Included is a description of the design and implementation for both MPI point-to-point and collective communications, and MPI-2 one-sided communications.
Identification of Tyr residues that enhance folate substrate binding and constrain oscillation of the proton-coupled folate transporter (PCFT-SLC46A1)

The proton-coupled folate transporter (PCFT) mediates intestinal folate absorption and transport of folates across the choroid plexus. This study focuses on the role of Tyr residues in PCFT functio...
Recruit It or Lose It! Training Students to Recruit Positive Teacher Attention

But it was different in Mr. Patterson's room. Jessica would only be on the third or fourth problem when first Clifton, then Gloria, and then two or three other students would call out, “Finished!” or, “I'm all done, Mr. Patterson.” That's when Jessica would usually stop working; she still had so many more problems left.“Jessica's always quiet and well behaved. She doesn't cause any trouble.” Fourth-grade teacher Mr. Patterson was talking with Ms. Marino, the special educator who works with Jessica. “She just never finishes her seatwork.”Ms. Marino was disappointed. For several weeks now she and Jessica had been working in the resource room on just that problem. Each day Ms. Marino would give Jessica several opportunities to see how many worksheet problems she could complete in 1 minute. Jessica would try to beat her score each time, and she and Ms. Marino marked each day's best total on a colorful chart. It was fun, and Jessica was learning to be a good worker in the resource room. She'd start her seatwor...
ANALYSIS OF BIOLOGICAL SELECTIONS FOR HIGH-EFFICIENCY GENE TARGETING

A two-marker selection system that allows the efficient isolation of diploid gene knockouts by two sequential rounds of targeted homologous recombination has been developed. A systematic evaluation of the biological parameters that govern the selection process showed that a successful strategy must match the expression level of the target gene, the efficacy of the marker, and the selection stringency. An enrichment ratio of 5,000- to 10,000-fold, which resulted in a 30% targeting efficiency of the c-myc gene in a fibroblast cell line, has been achieved. Such efficiency brings the difficulty of gene targeting effectively down to the level of simple transfections, since only 10 to 20 drug-resistant clones need to be screened to recover several homologous hits. The general utility of the targeting strategy is of interest to investigators studying gene function in a large variety of mammalian tissue culture systems.
Electric field and Charged Molecules Mediated Self-Assembly for Electronic Devices

In this paper we present techniques, utilizing dielectrophoresis and electrohydrodynamics, which can possibly be used for assembling devices suspended in a solution onto a binding site on a substrate. We explored the concepts using micro-scale negatively charged polystyrene beads and rectangular silicon blocks. Dielectrophoretic forces on devices in buffer solutions were examined as a function of frequency of the applied AC signal. The observed results can be explained by taking in account electro-thermal and AC electroosmotic effects. The study described in the paper can be used for placing and assembling micro and nano-electronic devices and objects at specific sites on various substrates, in combination with bio-inspired biological binding techniques such as DNA hybridization, antigen-antibody interactions, and ligand-receptor (avidin-biotin) interactions.
Speaker normalization based on subglottal resonances

Speaker normalization typically focuses on variabilities of the supra-glottal (vocal tract) resonances, which constitute a major cause of spectral mismatch. Recent studies show that the subglottal airways also affect spectral properties of speech sounds. This paper presents a speaker normalization method based on estimating the second and third subglottal resonances. Since the subglottal airways do not change for a specific speaker, the subglottal resonances are independent of the sound type (i.e., vowel, consonant, etc.) and remain constant for a given speaker. This context-free property makes the proposed method suitable for limited data speaker adaptation. This method is computationally more efficient than maximum-likelihood based VTLN, with performance better than VTLN especially for limited adaptation data. Experimental results confirm that this method performs well in a variety of testing conditions and tasks.
Hydrogen Peroxide Decreases pHi in Human Aortic Endothelial Cells by Inhibiting Na+/H+ Exchange

Postischemic endothelial dysfunction may occur as a result of the effects of endogenous oxidants like hydrogen peroxide. Since endothelium-dependent vasodilator function may be affected by pHi, the effect of hydrogen peroxide on endothelial pHi was examined. Hydrogen peroxide (100 micromol/L for 10 minutes) decreased pHi from 7.24+/-0.01 to 7.02+/-0.02 and inhibited recovery from an ammonium chloride-induced intracellular acid load in carboxy SNARF 1 (c-SNARF 1)-loaded human aortic endothelial cells in bicarbonate-free solution. Prior inhibition of Na+/H+ exchange with 5-(N-ethyl-N-isopropyl)amiloride (10 micromol/L), by removal of extracellular Na+, or by glycolytic inhibition with iodoacetic acid blocked the subsequent effect of hydrogen peroxide on pHi. A 2-minute exposure to 100 micromol/L H2O2 decreased intracellular ATP levels by approximately 40%; this was prevented by 3-aminobenzamide and nicotinamide (1 mmol/L each), inhibitors of the DNA repair enzyme poly(ADP-ribose) polymerase. Both 3-aminobenzamide and nicotinamide significantly inhibited the hydrogen peroxide-induced intracellular acidification and the effect of hydrogen peroxide on recovery from an intracellular acid load. Hydrogen peroxide decreases pHi in human endothelial cells by inhibiting Na+/H+ exchange. This appears to be mediated by activation of the DNA repair enzyme poly(ADP-ribose) polymerase and subsequent depletion of intracellular ATP. Since a decrease in pHi in this range may alter the activity of NO synthase or affect the synthesis of vasodilator prostaglandins, the effect of hydrogen peroxide on the endothelial Na+/H+ exchanger may be important in the pathogenesis of postischemic endothelial dysfunction.
Extracellular Matrix Molecules and Formation of CNS Synapses

Intracellular scaffolding proteins play important roles in synaptogenesis by linking major components of pre- and postsynaptic machineries with pre- and postsynaptic cell adhesion molecules. Molecules of the extracellular matrix (ECM), secreted from neurons and glial cells, also form scaffolds, although in the extracellular space. These scaffolds are involved in recruitment and stabilization of synaptic components. For instance, ECM molecules may cluster postsynaptic glutamate receptors via direct interactions with the extracellular domains of these receptors in a synapse-specific manner, or accumulate presynaptic Ca2+ channels and growth factors. Furthermore, binding of ECM molecules to cell surface receptors, such as integrins and apolipoprotein E receptor 2, may trigger intracellular signaling cascades resulting in maturation and plasticity of synapses. Additionally, thrombospondins (TSPs) and tenascin-R have prominent effects on formation of synapses via not-yet-identified mechanisms. In this chapter we review available data on synaptogenic activities of ECM molecules, suggesting that these molecules are important for many aspects of synaptic function in the central nervous system (CNS).
Fire Regime of an Ozark Wilderness Area, Arkansas

Abstract Many of the present day issues associated with fire management in wilderness areas are addressed by studying past interactions among fire, humans, vegetation and climate. In this paper we describe three centuries of the fire regime in the Lower Buffalo River Wilderness Area, Arkansas, USA. We reconstructed fire events from 159 tree-ring dated fire scars on 26 shortleaf pine (Pinus echinata Mill.) remnants and live trees. During the late-17th Century and early 18th Century the mean fire return interval (MFI) was 7.7 y. Fire frequency increased abruptly circa 1820 with fires burning every 2 y on average until 1920. The number of fires decreased during the 1900s as cultural values changed to favor fire suppression over multiple-use burning. Analyses of the influence of human ignitions and drought on the fire regime resulted in two important findings: (1) that fire frequency was positively correlated to human population density up to 1920 and (2) the influence of drought seemed to be masked by freque...
The Causal Implications of Mechanistic Thinking: Identification Using Directed Acyclic Graphs (DAGs)

In analyzing causal claims, the most common evidentiary strategy is to use an experimental or quasi-experimental framework; holding all else constant, a treatment is varied and its effect on the outcome is determined. However, a second, quite distinct strategy is gaining prominence within the social sciences. Rather than mimic an experiment, researchers can identify causal relations by finding evidence for mechanisms that link cause and effect. In this chapter, we use Directed Acyclic Graphs (DAGs) to illustrate the power of using mechanisms. We show how mechanisms can aid in causal analysis by bringing additional variation to bear in instances where causal effects would otherwise not be identified. Specifically, we examine five generic situations where a focus on mechanisms using DAGs allows an analyst to warrant causal claims.
Conducting the Redesigned Experiment: Putting the Question asking Aspect of Design Cognition under the Microscope

The second part of the third empirical step of this research involves conducting the redesigned version of the experiment and analyzing the data. After redesigning the exercise and improving the experimental methodology by reflecting on the pilot experiments. I conducted the final version of the exercise with twelve design teams. I then analyzed the data in order to test the four hypotheses.
Firearm Ownership and Safety Practices: A Random-Digit Dial Survey of San Diego

A random-digit dialing procedure was used to identify correlates of gun ownership and storage for a defined population. Of subjects contacted, 525 (64.7%) completed the survey. Subjects were generally representative of the population with slight underrepresentation of minority groups (16% were non-Caucasian). Of respondents, 129 (25.2%) reported owning a gun. Of these, 72.6% owned a handgun, 55% kept firearms for protection, 27.7% kept gun(s) loaded and ready to shoot, 66.4% kept gun(s) locked, and 46.2% carried gun(s) in the car some of the time. The strongest correlates of ownership were formal training (odds ratio [OR] = 3.52; 95% confidence intervals [CI] = 2.18, 5.67) and having been shot at (OR = 2.15; 95% CI = .97, 4.75). The strongest correlates of loaded gun status were children in the home (OR = 6.46; 95% CI = 1.18, 35.42), formal training (OR = 4.65; 95% CI = 1.04, 20.77), and keeping a gun for protection (OR = 8.82; 95% CI = .87, 89.83). Having been shot at was negatively correlated with keeping one's gun(s) locked (OR = .26; 95% CI = .07, 1.01). The strongest correlates of keeping a gun in the car were handgun ownership (OR = 11.44; 95% CI = 1.02, 128.65), keeping one's gun(s) loaded (OR = 3.79; 95% CI = 1.00, 14.43), and formal training (OR = 3.34; 95% CI = .82, 13.65). The data suggest that leaving firearms loaded and unlocked is common. Results may provide guidance in the design of interventions to decrease firearm-related morbidity and mortality.
Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH4/Air and CH4/O2/CO2 Flames

Premixed CH4/O2/CO2 flames (oxy-flames) and CH4/air flames (air-flames) were experimentally studied in a swirl-stabilized combustor. For comparing oxy and air flames, the same equivalence ratio and adiabatic flame temperature were used. CO2 dilution was adjusted to attain the same adiabatic temperature for the oxy-flame and the corresponding air-flame while keeping the equivalence ratio and Reynolds number (=20,000) the same. For high equivalence ratios, we observed flames stabilized along the inner and outer shear layers of the swirling flow and sudden expansion, respectively, in both flames. However, one notable difference between the two flames appears as the equivalence ratio reaches 0.60. At this point, the outer shear layer flame disappears in the air-flame while it persists in the oxy-flame, despite the lower burning velocity of the oxy-flame. Prior PIV measurements (Ref. 9) showed that the strains along the outer shear layer are higher than along the inner shear layer. Therefore, the extinction strain rates in both flames were calculated using a counter-flow premixed twin flame configuration. Calculations at the equivalence ratio of 0.60 show that the extinction strain rate is higher in the oxy than in the air flame, which help explain why it persists on the outer shear layer with higher strain rate. It is likely that extinction strain rates contribute to the oxy-flame stabilization when air flame extinguish in the outer shear layer. However, the trend reverses at higher equivalence ratio, and the cross point of the extinction strain rate appears at equivalence ratio of 0.64.Copyright © 2015 by ASME
Aging Effect on Post-recovery Hypofusion and Mortality Following Cardiac Arrest and Resuscitation in Rats.

In this study we investigated the effect of aging on brain blood flow following transient global ischemia. Male Fisher rats (6 and 24 months old) underwent cardiac arrest (15 min) and resuscitation. Regional brain (cortex, hippocampus, brainstem and cerebellum) blood flow was measured in non-arrested rats and 1-h recovery rats using [14C] iodoantipyrene (IAP) autoradiography; the 4-day survival rate was determined in the two age groups. The pre-arrest baseline blood flows were similar in cortex, brainstem and cerebellum between the 6-month and the 24-month old rats; however, the baseline blood flow in hippocampus was significantly lower in the 24-month old group. At 1 h following cardiac arrest and resuscitation, both 6-month and 24-month groups had significantly lower blood flows in all regions than the pre-arrest baseline values; compared to the 6-month old group, the blood flow was significantly lower (about 40 % lower) in all regions in the 24-month old group. The 4-day survival rate for the 6-month old rats was 50 % (3/6) whereas none of the 24-month old rats (0/10) survived for 4 days. The data suggest that there is an increased vulnerability to brain ischemic-reperfusion injury in the aged rats; the degree of post-recovery hypoperfusion may contribute to the high mortality in the aged rats following cardiac arrest and resuscitation.
Location of the estrogen effect on uterine glucose metabolism.

SummaryMeasurements of incorporation of 14C from differentially labelled glucose and pyruvate into uterine lipid and CO2 were used to evaluate early metabolic changes produced by estradiol in immature rat uterus. Tissue was incubated with the isotopes in vitro after hormone treatment in vivo. With pyruvate-3-14C as substrate, substantially more 14CO2 is produced than with glucose-1-14C or glu-cose-6-14C as substrates. Also, 14CO2 output from glucose-1-14C is about double that from glucose-6-14C. Estradiol treatment causes a similar increase of 14C incorporation into lipid with either of the glucose substrates or with pyruvate. This suggests that the estradiol effect on lipid synthesis is beyond pyruvate. A differential effect on 14CO2 production from glucose and pyruvate, however, locates an estradiol effect between these substrates. Furthermore, the estradiol acceleration of 14CO2 production from glucose-1-14C and glucose-6-14C is equal. This suggests that the site of estrogen stimulation of uterine gluc...
Allogeneic peripheral blood stem cell transplantation following CD34 + enrichment by density gradient separation

GVHD is a significant cause of morbidity and mortality following allogeneic peripheral blood stem cell transplantation (AlloPBSC). CD34+ cell selection could reduce GVHD by negative selection of T cells. In an attempt to reduce the T cell content of alloPBSC we carried out a trial in which 11 patients with hematologic malignancies received alloPBSC from HLA-matched siblings following density gradient separation using an isotonic colloidal silica solution (BDS 60; Dendreon Corporation). Cyclosporine and methylprednisone were used for GVHD prophylaxis. The mean yield of CD34+ cells was 69 ± 15.6% with a purity of 2.9 ± 1.7%. The mean number of CD3+ cells infused was 1.0 ± 1.2 × 107/kg, representing a 1.3 log depletion. A high risk of acute GVHD was observed: grade II–IV in 7/11 (64%) and grade III–IV GVHD in 5/11 (45%) patients. Nine of the 11 (82%) patients died with a median survival of 68 days. Cytokine expression in PBSC was compared pre and post processing. Interferon-gamma was detected only following density gradient separation while IL-8 expression increased 3- to 6-fold post processing. Therefore, processing with this device may augment production of pro-inflammatory cytokines. Bone Marrow Transplantation (2000) 25, 1223–1228.
On the History of Determinants

(1930). On the History of Determinants. The American Mathematical Monthly: Vol. 37, No. 5, pp. 216-219.
Boerhaave's Syndrome: A Pediatric Case

Background The term Boerhaave's syndrome refers to esophageal rupture after a sudden increase in intraluminal pressure. This syndrome is most common among alcoholic adult men. This case report is that of a pediatric patient with a similar pathologic process. Study A 6-month-old Hispanic boy with acute lymphoblastic leukemia on chemotherapy arrested 3 weeks into his induction therapy. Diagnostic and therapeutic procedures revealed a hydropneumothorax, which was managed with chest tube drainage. The underlying etiology was revealed 10 days later when feeds were introduced and found exiting the chest tube. A contrast study confirmed esophageal perforation, which was surgically repaired. Conclusion A nontraumatic hydropneumothorax should raise the possibility of Boerhaave's syndrome (spontaneous esophageal rupture), even in pediatric patients. Such a finding warrants a contrast study to facilitate early diagnosis.