cssi/SciSciGPT-SciSciNet huggingface dataset:
Point-of-care ultrasound diagnosis of pediatric intussusception: a case series

Intussusception is an intestinal emergency caused by the telescoping of proximal bowel into an adjacent distal bowel segment. Nearly 50% of cases are missed on initial presentation leading to an increased risk of intestinal obstruction, ischemia, and perforation. The authors present two cases of pediatric intussusception whereby point-of-care ultrasound expedited the diagnosis and treatment in a non-pediatric dedicated emergency department. Given the risks of an undiagnosed intussusception and its nonspecific presentations, a prompt and precise diagnosis remains crucial to its successful management. The ubiquity and accuracy of point-of-care ultrasound make it an ideal adjunct for the diagnosis of intussusception.
Reinforcing carbonized polyacrylonitrile fibers with nanoscale graphitic interface-layers

Abstract Carbon fibers going through stabilization, carbonization, and graphitization heat-treatment stages will form continuous graphitic layers that are closely packed and preferentially aligned along the fiber axis, forming high mechanical stiffness or strength and electrical or thermal conductivity. The alignment of noncontinuous, powder-like graphene layers in polymers has been challenging due to the low bending modulus of a few- or even single-layered graphene, which causes aggregations or folding behaviors. This research demonstrates the leveraging of polymer-nanoparticle interactions to align graphene nanoplatelets (GNPs) in the polyacrylonitrile (PAN) matrix. An in-house designed spinning method produces a three-layered fiber that utilizes the interfacial interactions between each layer for graphene alignment between graphitic layers. This composite containing oriented GNPs significantly improves modulus (i.e., 42.3 to 74.6 GPa) and increases electrical conductivity for enhancing volatile organic compounds (VOCs) sensing behaviors. This research opens up a new scalable fabrication method for multilayered composites.
Temporal dynamics of base excision/single-strand break repair protein complex assembly/disassembly are modulated by the PARP/NAD+/SIRT6 axis

Assembly and disassembly of DNA repair protein complexes at DNA damage sites are essential for maintaining genomic integrity. Investigating factors coordinating assembly of the base excision repair (BER) proteins DNA polymerase β (Polβ) and XRCC1 to DNA lesion sites identifies a role for Polβ in regulating XRCC1 disassembly from DNA repair complexes and, conversely, demonstrates Polβ's dependence on XRCC1 for complex assembly. LivePAR, a genetically encoded probe for live-cell imaging of poly(ADP-ribose) (PAR), reveals that Polβ and XRCC1 require PAR for repair-complex assembly, with PARP1 and PARP2 playing unique roles in complex dynamics. Further, BER complex assembly is modulated by attenuation/augmentation of NAD+ biosynthesis. Finally, SIRT6 does not modulate PARP1 or PARP2 activation but does regulate XRCC1 recruitment, leading to diminished Polβ abundance at sites of DNA damage. These findings highlight coordinated yet independent roles for PARP1, PARP2, and SIRT6 and their regulation by NAD+ bioavailability to facilitate BER.
Dictyostelium: Chemotaxis and Aggregation

Free-living Dictyostelium amoebae must be able to find their way toward prey or, in the face of starvation, toward each other. Dictyostelium amoebae share a chemotactic capacity with leukocytes and many other motile cells, and employ many of the same mechanisms during the detection of the chemotactic molecule, the activation of signal transduction pathways, and the mobilization of the cytoskeleton (Devreotes and Zigmond, 1988; Parent et al ., 1998; Parent and Devreotes, 1999). Chemotactic molecules bind to cell-surface receptors and stimulate G protein-mediated signal transduction pathways in amoebae and in mammalian cells. Agonists are degraded to steepen gradients and to overcome the effects of adaptation. Despite evolutionary distance, the cytoskeletons of leukocytes and Dictyostelium employ similar cytoskeletal rearrangements to move in the right direction. The advantage of Dictyostelium in the study of chemotaxis, motility and aggregation is that the gene products involved in each event can be eliminated by mutation, and the contribution of each element can be studied. The biochemical advantages that stem from synchrony of development and quantities of material have also been invaluable. This is not to say that we understand completely how a cell perceives that a gradient exists or how it moves toward higher concentrations of cAMP, but we are beginning to understand how this complex process works.
A mixed IQC approach to nonlinear delay-dependent system analysis

Stability analysis techniques are presented for time-delay systems consisting of the feedback interconnection of a linear time-delay system, with a bounded and casual operator, featuring the nonlinearities, uncertainties, and/or time-varying components of the system. The delays considered are time-invariant but uncertain, residing within a bounded interval including zero. The theorem of integral quadratic constraints (IQC theorem) is employed in a novel fashion to formulate a stability criterion. In this method, the delay elements are replaced by parameter-dependent filters satisfying certain properties, while the nonlinearities are captured by IQCs. It is shown that satisfaction of the IQC analysis condition by the delay-differential system can be guaranteed by satisfaction of it by a finite-dimensional, parameter-dependent system. The KYP lemma is then applied to the latter to obtain a parameter-dependent LMI criterion.
Glutathione‐S‐transferase P1 is a critical regulator of Cdk5 kinase activity

Cyclin dependent kinase-5 (Cdk5) activity is deregulated in Alzheimer's disease (AD) and contributes to all three hallmarks: neurotoxic β-amyloid formation, neurofibrillary tangles, and neuronal death. However, the mechanism leading to Cdk5 deregulation remains controversial. Cdk5 deregulation in AD is usually linked to the formation of p25, a proteolysis product of Cdk5 activator p35, which leads to Cdk5 mislocalization and hyperactivation. A few studies have indeed shown increased p25 levels in AD brains; however, others have refuted this observation. These contradictory findings suggest that additional factors contribute to Cdk5 deregulation. This study identified glutathione-S-transferase pi 1 (GSTP1) as a novel Cdk5 regulatory protein. We demonstrate that it is a critical determinant of Cdk5 activity in human AD brains and various cancer and neuronal cells. Increased GSTP1 levels were consistently associated with reduced Cdk5 activity. GSTP1 directly inhibits Cdk5 by dislodging p25/p35, and indirectly by eliminating oxidative stress. Cdk5 promotes and is activated by oxidative stress, thereby engaging a feedback loop which ultimately leads to cell death. Not surprisingly, GSTP1 transduction conferred a high degree of neuroprotection under neurotoxic conditions. Given the critical role of oxidative stress in AD pathogenesis, an increase in GSTP1 level may be an alternative way to modulate Cdk5 signaling, eliminate oxidative stress, and prevent neurodegeneration.
A New Direct Anonymous Attestation Scheme from Bilinear Maps

Direct Anonymous Attestation (DAA) is a cryptographic mechanism that enables remote authentication of a user while preserving privacy under the user's control. The DAA scheme developed by Brickell, Camenisch, and Chen has been adopted by the Trust Computing Group (TCG) for remote anonymous attestation of Trusted Platform Module (TPM), a small hardware device with limited storage space and communication capability. In this paper, we propose a new DAA scheme from elliptic curve cryptography and bilinear maps. The lengths of private keys and signatures in our scheme are much shorter than the lengths in the original DAA scheme, with a similar level of security and computational complexity. Our scheme builds upon the Camenisch-Lysyanskaya signature scheme and is efficient and provably secure in the random oracle model under the LRSW (stands for Lysyanskaya, Rivest, Sahai and Wolf) assumption and the decisional Bilinear Diffie-Hellman assumption.
Locations of discontinuities as priors for improved Bayesian reconstructions from projections (emission tomography)

A Bayesian image reconstruction method from projection data using explicit discontinuity locations as priors is proposed. The algorithm seeks smooth solutions with occasional discontinuities with a special coupling term that influences the creation of discontinuities in the vicinity of the significant locations. It is shown that the reconstruction corresponds to the use of a generic piecewise smoothness constraint. The model incorporates prior knowledge of discontinuity location into a reconstruction algorithm. The results appear favorable. >
Eye pigment granules of Drosophila melanogaster: Isolation and characterization for synthesis of sepiapterin and precursors of drosopterin

Abstract A method is described for the isolation of eye pigment granules from heads of Drosophila melanogaster . These granules are characterized by electron microscopy. In these granules certain enzymes that are involved in sepiapterin and drosopterin biosynthesis are present at higher specific activity than the cytosol. When the granules were washed, the phosphatase activity was much less than that in the cytosol. Ramiopterin synthase, for example, is present in both the granules and cytosol, but has nine times greater specific activity in the former. Also, a procedure is described for preparation of a stable solution of dihydroneopterin triphosphate. We suggest that the enzymes for drosopterin synthesis are all contained in the pigment granule.
Two-Dimensional Potts Model and Annular Partitions

Using the random cluster expansion, correlations of the Potts model on a graph can be expressed as sums over partitions of the vertices where the spins are fixed. For a planar graph, only certain partitions can occur in these sums. For example, when all fixed spins lie on the boundary of one face, only noncrossing partitions contribute. In this paper we examine the partitions which occur when fixed spins lie on the boundaries of two disjoint faces. We call these the annular partitions, and we establish some of their basic properties. In particular we demonstrate a partial duality for these partitions, and show some implications for correlations of the Potts model.
Genomic substrates of neurophysiological endophenotypes: Where we've been and where we're going

This special issue of Psychophysiology is focused on an imaginative and labor-intensive examination of the genomic substrates of heritable neurophysiological endophenotypes in the Minnesota Center for Twin and Family Research (MCTFR) cohorts. The authors artfully combine the power of family-based behavioral data with the atheoretical genome-wide association study (GWAS) platform to enrich the examination of the genomic substrates of endophenotypes. Neurophysiological endophenotype deficits are found in psychiatric patients and are heritable in families of these psychiatric patients, allowing the investigators to combine the explanatory power of endophenotypes, with their known neural and functional substrates, with the otherwise agnostic identification of genes in the GWAS platform. This amplifies the power of the MCTFR endophenotype database. These well-considered studies add significantly to our understanding of normal human neurobiology and stimulate the use of these endophenotypes to expand our knowledge of the role of these measures and their genomic substrates in normal and psychopathology research.
In Situ Characterization of Degradation Behavior of Plasma-Sprayed Coatings on Orthopedic and Dental Implants

Plasma-sprayed ‘HA’ coatings on commercial orthopedic and dental implants were developed to combine the strength of the metal (Ti or Ti alloy) and the bioactivity of the hydroxyapatite (HA). Several studies have shown that ‘HA’-coated implants provided greater amount of bone attachment, higher bone-implant interfacial strength and accelerated skeletal attachment. However, some reports on implant failures have been attributed to coating delamination and coating early resorption of the plasma sprayed ‘HA’ coating. This paper reviews studies on characterization and degradation of plasma-sprayed ‘HA’ coatings on orthopedic and dental implants and offers alternatives to plasma-spray method of providing calcium phosphate coating. X-ray diffraction analyses showed that plasma-sprayed HA coating consists principally of HA and amorphous calcium phosphate (ACP) with minor amounts of other resorbable calcium phosphates (α- or β-tricalcium phosphates, tetracalcium phosphate), sometimes calcium oxide. The HA/ACP ratios were found to range from 20HA/80ACP to 70HA/30ACP in coated implants from different manufacturers. In vitro initial dissolution rates in acidic buffer (pH 6, 37oC) increased with decreasing HA/ACP ratios in the coating because of the preferential dissolution of the ACP phase. These results suggest that coating with very low HA/ACP ratio may result in the premature resorption of the coating before the bone can attach to the implant thus causing loosening and eventual failure of the implant. Alternatives to plasma-sprayed ‘HA’ are implant surface modifications and low temperature calcium phosphate coatings using electrochemical deposition method or precipitation method.
Penetrative convection in porous medium bounded by a horizontal wall with hot and cold spots

Abstract This paper reports a series of numerical simulations and a scale analysis of the penetrative convection occurring along the unevenly heated horizontal wall of a semi-infinite porous medium. Modeling the problem as two-dimensional, and assuming that the horizontal wall temperature varies between alternating hot and cold spots, it is found that the natural circulation consists of a row of counter-rotating cells situated near the wall. Each cell penetrates vertically into the porous medium to a distance approximately equal to λ Ra 1 2 λ , where λ is the distance between a hot spot and the adjacent cold spot, and Ragl is the Darcymodified Rayleigh number based on λ and on the temperature difference between each spot and the porous medium situated far enough from the wall. The ability of each cell to convect heat between two adjacent spots increases with the Rayleigh number. The results of numerical simulations in the Raλ range 1–100 are found to support a number of scaling laws derived based on pure scaling arguments.
Electrocatalysis at Microelectrodes: Geometrical Considerations

The influence of the shape of individual electrocatalytically active, axisymmetric particles supported on an inactive substrate, on the current associated with heterogeneous redox reactions involvi...
The contributions to solvent uptake by skin and inhalation exposure.

Solvent exposures were assessed among 97 auto body repair workers in order to determine whether skin contact represented a significant route of exposure. Each subject's cumulative skin exposure was ranked categorically based on simple observation: 49 none, 33 incidental or low, and 15 moderate or high. The median time-weighted average air exposure to solvents was 8.4% of the American Conference of Governmental Industrial Hygienists (ACGIH) combined solvent threshold limit value (TLV) with a range of 0–62% TLV, including toluene (median 4 ppm) and xylenes (median 0.9 ppm). Urine methyl hippuric acids (MHAs, metabolites of xylenes) were low compared to the ACGIH biological exposure index (BEI) with a median of 2% and a range of 0–12% BEI but were strongly correlated with both the level of airborne xylenes and skin exposure when considered simultaneously by using analysis of covariance (R=0.91, p<0.0001). MHA excretion attributable to skin exposure for 15 min or more generally was comparable to or greater th...
A Note on a Traffic Counting Distribution

In this paper the author formulates and derives a discrete traffic counting distribution and a passing rule which lead to bunches of zero or one “fast” vehicle behind a “slow” vehicle. “Slow” vehicles are distributed in a Poisson fashion and, except for those instants at which passing occurs, the constrained or “fast” vehicles follow immediately behind a “slow” one. The counting distribution is a simple example of one in which successive inter-vehicle spacings have the Markov property.
Secretory component in human ocular tissues

Lacrimal tissue and accessory lacrimal tissue from seven autopsy cases, lacrimal tissue from three patients undergoing orbital exploration, and biopsy specimens from conjunctiva of 14 subjects were examined for the presence and distribution of secretory component by three anti-secretory-component antisera. Secretory component was present in all lacrimal and accessory lacrimal tissues but in no other ocular tissues. Over 60% of acinar cells stained for secretory component; about 5% of acinar cells stained brightly; about 30% of tubular cells stained brightly. Main and accessory lacrimal tissues appeared identical in their staining patterns. We concluded that the main sites of synthesis of secretory IgA in human ocular tissues are the lacrimal and accessory lacrimal tissues.
The Role of Peers' Gender in Children's Naturally Occurring Interest in Toys

The purpose of the present study was to examine naturalistically the role of same-sex and other-sex peers' contemporaneous and prior attention to toys in preschoolers' subsequent engagement with, and disengagement from, non-gender-typed toys. Contemporaneous peer involvement was significantly associated with children's toy adoption; cumulative peer involvement was not significantly related to attention to toys once the effects of contemporaneous peer involvement were controlled. Both the proportion and the absolute number of same-sex peers were higher when children initially became engaged with the toys than when they were close to the toys but did not attend to them. Moreover, for boys, there were more other-sex peers attending to the toys when children ceased involvement with the toys than when they initially became interested in the toy. The implications of the data for understanding the role of peer interaction in gender-stereotypic interest in toys are discussed.
The effect of an interphase on the stress and energy distribution in the embedded single fibre test

Abstract The finite element method is used to study the behaviour of an E-glass/epoxy system containing an interphase tested by the embedded single fibre test. The effect of mechanical properties and thickness of an interphase on the stress distribution after fibre breakage is examined. Energy distribution within the composite and elastic energy released during propagation of an interfacial crack are evaluated. These results are used to develop a strain history for this system.
Determination of Antimycin-A in Water by Liquid Chromatographic/Mass Spectrometry: Single-Laboratory Validation

An LC/MS method was developed and validated for the quantitative determination and confirmation of antimycin-A (ANT-A) in water from lakes or streams. Three different water sample volumes (25, 50, and 250 mL) were evaluated. ANT-A was stabilized in the field by immediately extracting it from water into anhydrous acetone using SPE. The stabilized concentrated samples were then transported to a laboratory and analyzed by LC/MS using negative electrospray ionization. The method was determined to have adequate accuracy (78 to 113% recovery), precision (0.77 to 7.5% RSD with samples > or = 500 ng/L and 4.8 to 17% RSD with samples < or = 100 ng/L), linearity, and robustness over an LOQ range from 8 to 51 600 ng/L.
Quantifying a Statistical Aspect of Segmented Selection/Quota Systems

Abstract We consider the problem of filling n positions from a pool of N applicants. We assume that there exists an objective measure of each applicant's ability—the applicant's “score.” Letting Q be the mean score of the n accepted applicants, we study the difference in Q as the N applicants are stratified into K subsets, a certain number of the n accepted applicants necessarily coming from each subset. Clearly, any accepted group other than the top n out of N will result in a lower Q. We consider how the decrease in average score, Q, varies with various parameters and proportion allocations. There is no question that the issue of segmented selection (essentially, quota systems) can be controversial. Many argue for and many argue against using segmented selection, under such names as veteran's preference, affirmative action, and others. We take no “stand” on this controversy. We consider solely this one statistical/quantitative aspect of the segmented selection/quota system question. We believe that the ...
A role for MEK kinase 1 in TGF-β/activin-induced epithelium movement and embryonic eyelid closure

MEKK1-deficient mice show an eye open at birth phenotype caused by impairment in embryonic eyelid closure. MEK kinase 1 (MEKK1) is highly expressed in the growing tip of the eyelid epithelium, which displays loose cell–cell contacts and prominent F-actin fibers in wild-type mice, but compact cell contacts, lack of polymerized actin and a concomitant impairment in c-Jun N-terminal phosphorylation in MEKK1-deficient mice. In cultured keratinocytes, MEKK1 is essential for JNK activation by TGF-β and activin, but not by TGF-α. MEKK1-driven JNK activation is required for actin stress fiber formation, c-Jun phosphorylation and cell migration. However, MEKK1 ablation does not impair other TGF-β/activin functions, such as nuclear translocation of Smad4. These results establish a specific role for the MEKK1–JNK cascade in transmission of TGF-β and activin signals that control epithelial cell movement, providing the mechanistic basis for the regulation of eyelid closure by MEKK1. This study also suggests that the signaling mechanisms that control eyelid closure in mammals and dorsal closure in Drosophila are evolutionarily conserved.
Efficient purely-dynamic information flow analysis (abstract only)

We present a novel approach for efficiently tracking information flow in a dynamically-typed language such as JavaScript. Our approach is purely dynamic, and it detects problems with implicit paths via a dynamic check that avoids the need for an approximate static analyses while still guaranteeing non-interference. We incorporate this check into an efficient evaluation strategy based on sparse information labeling that leaves information flow labels implicit whenever possible, and introduces explicit labels only for values that migrate between security domains. We present experimental results showing that, on a range of small benchmark programs, sparse labeling provides a substantial (30%--50%) speed-up over universal labeling.
Mars Rover Sample Return mission

To gain a detailed understanding of the character of the planet Mars, it is necessary to send vehicle to the surface and return selected samples for intensive study in earth laboratories. Toward that end, studies have been underway for several years to determine the technically feasible means for exploring the surface and returning selected samples. This paper describes several MRSR mission concepts that have emerged from the most recent studies.
Perturbation theory for toroidal plasma

Abstract The self magnetic field of an axially symmetric toroidal plasma is shown to contain positive powers of the aspect ratio and a logarithmic function of this quantity. The limit of large aspect ratio is finite.
Extracellular ATP in activity-dependent remodeling of the neuromuscular junction

Electrical activity during early development affects the development and maintenance of synapses (Spitzer [2006]: Nature 4447:707-712), but the intercellular signals regulating maintenance of synapses are not well identified. At the neuromuscular junction, adenosine 5-triphosphate (ATP) is coreleased with acetylcholine at activated nerve terminals to modulate synaptic function. Here we use cocultured mouse motor neurons and muscle cells in a three-compartment cell culture chamber to test whether endogenously released ATP plays a role in activity-dependent maintenance of neuromuscular synapses. The results suggest that ATP release at the synapse counters the negative effect of electrical activity, thus stabilizing activated synapses. Confirming our previous work (Li et al. [2001]: Nat Neurosci 4:871-872), we found that in doubly innervated muscles, electrical stimulation induced heterosynaptic downregulation of the nonstimulated convergent input to the muscle fiber with no or little change of the stimulated inputs. However, in preparations that were stimulated in the presence of apyrase, an enzyme that degrades extracellular ATP, synapse downregulation of stimulated inputs was substantial and significant, and end plate potentials were reduced. Apyrase treatment for 20 h in the absence of stimulation did result in moderate diminution, but this was prevented by blocking spontaneous neural activity with tetrodotoxin. The P2 receptor blocker, suramin, also induced activity-dependent synapse diminution. The decrease in synaptic efficacy produced by prolonged stimulation in the presence of apyrase persisted for greater than 20 h, consistent with a developmental time-course and distinct from the rapid neuromodulatory actions of ATP that have been demonstrated by others. We conclude that extracellular ATP promotes stabilization of the neuromuscular junction and may play a role in activity-dependent synaptic modification during development.
Functional interdependence among ribosomal elements as revealed by genetic analysis.

Escherichia coli strains with preexisting ribosomal mutations were used in order to isolate further ribosomal mutations. The ribosomal mutations used were resistance to erythromycin, spectinomycin, streptomycin or kasugamycin. These mutations cause alteration of specific ribosomal elements, L4, S5, S12 proteins and 16S rRNA respectively. Mutations have been introduced into strains carrying one, two or three of these mutations. Strains with all possible combinations of these four mutations were constructed. The phenotypes of all isolated mutants were tested, and frequently the strains lost one or more of their pre-existing resistances.
Induction of specific immunity to human colon carcinoma by anti‐idiotypic antibodies to monoclonal antibody CO17‐1A

Anti-idiotypic antibodies (Ab2) to murine monoclonal antibody (mAb) CO17-1A (Ab1), which defines an antigen associated with human colon carcinoma, were produced in goats. The Ab2 inhibited binding of Ab1 to colon carcinoma cells, and purified tumor antigen inhibited binding of Ab1 to Ab2. The Ab2 elicited in rabbits anti-anti-idiotypic antibodies (Ab3) that bound to cultured human cells of various tissue origins with a binding pattern identical to that of Ab1. Moreover, both Ab1 and Ab3 bound to the isolated tumor antigen, and the Ab3 lysed human colon carcinoma cells in culture in the presence of rabbit complement. Thus, Ab2 raised to mAb CO17-1A are candidates for use in immunotherapy trials in cancer patients.
Active pixel sensor array as a detector for electron microscopy.

Abstract A new high-resolution recording device for transmission electron microscopy (TEM) is urgently needed. Neither film nor CCD cameras are systems that allow for efficient 3-D high-resolution particle reconstruction. We tested an active pixel sensor (APS) array as a replacement device at 200, 300, and 400 keV using a JEOL JEM-2000 FX II and a JEM-4000 EX electron microscope. For this experiment, we used an APS prototype with an area of 64×64 pixels of 20 μm×20 μm pixel pitch. Single-electron events were measured by using very low beam intensity. The histogram of the incident electron energy deposited in the sensor shows a Landau distribution at low energies, as well as unexpected events at higher absorbed energies. After careful study, we concluded that backscattering in the silicon substrate and re-entering the sensitive epitaxial layer a second time with much lower speed caused the unexpected events. Exhaustive simulation experiments confirmed the existence of these back-scattered electrons. For the APS to be usable, the back-scattered electron events must be eliminated, perhaps by thinning the substrate to less than 30 μm. By using experimental data taken with an APS chip with a standard silicon substrate (300 μm) and adjusting the results to take into account the effect of a thinned silicon substrate (30 μm), we found an estimate of the signal-to-noise ratio for a back-thinned detector in the energy range of 200–400 keV was about 10:1 and an estimate for the spatial resolution was about 10 μm.
Giga-pixel fluorescent imaging over an ultra-large field-of-view using a flatbed scanner.

We demonstrate a new fluorescent imaging technique that can screen for fluorescent micro-objects over an ultra-wide field-of-view (FOV) of ∼532 cm2, i.e., 19 cm × 28 cm, reaching a space-bandwidth product of more than 2 billion. For achieving such a large FOV, we modified the hardware and software of a commercially available flatbed scanner, and added a custom-designed absorbing fluorescent filter, a two-dimensional array of external light sources for computer-controlled and high-angle fluorescent excitation. We also re-programmed the driver of the scanner to take full control of the scanner hardware and achieve the highest possible exposure time, gain and sensitivity for detection of fluorescent micro-objects through the gradient index self-focusing lens array that is positioned in front of the scanner sensor chip. For example, this large FOV of our imaging platform allows us to screen more than 2.2 mL of undiluted whole blood for detection of fluorescent micro-objects within <5 minutes. This high-throughput fluorescent imaging platform could be useful for rare cell research and cytometry applications by enabling rapid screening of large volumes of optically dense media. Our results constitute the first time that a flatbed scanner has been converted to a fluorescent imaging system, achieving a record large FOV.
Interdisciplinary Studies and Management Faculty Involvement

Abstract An innovative approach to course development is introduced that may facilitate the learning process and better prepare students to satisfy the changing needs of their future employers. The uniqueness of this method lies in the refocusing of basic business concepts. For years, functional area emphasis has been construed as the most efficient method to teach introductory business concepts to all business majors. This article suggests that a stakeholder approach could assist learning while meeting goals proposed by accrediting agencies and the general public.
Virus and virus-like particle-based immunogens for Alzheimer's disease induce antibody responses against amyloid-β without concomitant T cell responses

A vaccine targeting the amyloid-beta (Abeta) peptide is a promising potential immunotherapy for Alzheimer's disease patients. However, experience from a recent clinical trial of a candidate Abeta vaccine has suggested that it is important to develop techniques to induce high titer antibodies against Abeta associated with vaccine efficacy while reducing the T cell responses against Abeta that were potentially responsible for serious side effects. We have previously demonstrated that immunization with self- and foreign antigens arrayed in a repetitive fashion on the surface of virus-like particles (VLPs) induces high titer antibody responses at low doses and in the absence of potentially inflammatory adjuvants. In this study, we examined the antibody and T cell responses upon immunization with human papillomavirus VLP- and Qbeta bacteriophage-based Abeta vaccines. Immunization with Abeta conjugated to VLPs or Qbeta elicited anti-Abeta antibody responses at low doses and without the use of adjuvants. The flexibility of these virus-based display systems allowed us to link and induce antibodies against short Abeta-derived peptides from the amino- and carboxyl-termini of the peptide. Immunization of mice with Abeta peptide in combination with Freund's adjuvant elicited predominantly IgG2c antibodies and strong T cell proliferative responses against Abeta. In contrast, VLP-conjugated Abeta peptides elicited more balanced isotype responses, dominated by IgG1. Both VLP and Qbeta-based Abeta vaccines induced weak or negligible T cell responses against Abeta. T cell responses were largely directed against linked viral epitopes. Taken together, virus-based vaccines that allow the presentation of Abeta in a repetitive dense array are new and potentially more effective vaccine candidates for Alzheimer's disease.
Catalytic cleavage of an RNA target by 2-5A antisense and RNase L.

Abstract 2-5A antisense (2-5A-AS) molecules are chimeric oligonucleotides that cause 2-5A-dependent RNase (RNase L) to catalyze the selective cleavage of RNA in human cells. These composite nucleic acids consist of a 5′-monophosphorylated, 2′,5′-linked oligoadenylate known as 2-5A (an activator of RNase L) covalently attached to antisense 3′,5′-oligodeoxyribonucleotides. Here, we characterize the targeted cleavage of the double-stranded RNA-dependent protein kinase (PKR) mRNA by purified, recombinant human RNase L. A 2-5A-AS chimera, which contains complementary sequence to PKR mRNA, and unmodified 2-5A, which causes general RNA decay, were about 20- and 40-fold more active, respectively, than 2-5A-AS chimeras in which the DNA domains are not complementary to sequences in PKR mRNA. Directed cleavage was efficient because each 2-5A-AS chimera targeted many RNA molecules. Moreover, RNase L caused the catalytic cleavage of the RNA target (kcat of approximately 7 s−1). The precise sites of PKR mRNA cleavage caused by 2-5A-AS were mapped, using a primer extension assay, to phosphodiester bonds adjacent to the 3′ terminus of the chimera binding site (5′ on the RNA target) as well as within the chimera's oligonucleotide binding site itself. The selectivity of this approach is shown to be provided by the antisense arm of the chimera, which places the RNA target in close proximity to the RNase.
The impact of social capital on the earnings of puerto rican migrants

There is a paucity of studies examining the relationship between Puerto Ricans' social capital and their earnings. I utilized data from the Latin American Migration Project (collected in 1998 and 1...
Comparison of Seasat scatterometer winds with tropical Pacific observations

The Seasat-A satellite scatterometer (SASS) observed near-surface vector winds over the world ocean from an 800-km orbit by measuring radar backscatter from the wind-roughened surface. To increase the geographical range of SASS and in situ comparison experiments, data from nine islands in the tropical Pacific and contemporaneous scatterometer winds were compared. The SASS-2 algorithm due to Wentz provides clearly better agreement in wind speed than the earlier SASS-1 algorithm. SASS-1 speeds tend to be higher than the island measurements by about 1 m/s, while daily mean SASS-2 minus island wind speed differences average -0.07 m/s. The rms differences between SASS-2 and the daily mean island data average 1.7 m/s, the SASS-1 rms differences average 2.2 m/s.
Permeation of alkylbenzene isomers of molecular weight 120 through nitrile gloves

Factors determining the permeation of eight alkylbenzene isomers of molecular weight 120.19 (three ethyl toluenes, three trimethylbenzenes, and two propl benzenes) were investigated for a lined nitrile industrial type glove using an ASTM-type cell, liquid collection, and gas chromatography/mass spectrometry. The initial permeation rate Pi correlated inversely with the logarithm of the lag time tl. The logarithm of the steady-state permeation rate Ps correlated inversely with the logarithm of the breakthrough time tb. Ps/Pi for a given compound correlated directly with Ps and with tl/tb. Pi depended directly on the logarithm of the entropy of fusion divided by the square of the refractive index and divided by the solubility parameter. The tb was inversely correlated to the logarithm of the water solubility. The logarithm of tl was most directly correlated to the entropy of vaporization. High Ps for 1,2,4-trimethylbenzene, m-ethyltoluene, and p-ethyl toluene was linked to a common structural similarity to 1,2,4-trimethylbenzene relative to the unhindered geometry of the methyl group in the ethyl side chain. The existence of optimum radii of gyration for enhanced Ps and for long tb suggested that the protective properties of nitrile followed discontinuous relationships rather than continuous ones and so are not explainable by correlative relationships of continuous functions. © 1996 John Wiley & Sons, Inc.
Presence and Measurement of Imidazoleacetic Acid, a γ-Aminobutyric Acid Agonist, in Rat Brain and Human Cerebrospinal Fluid

Imidazoleacetic acid (IAA) was unequivocally demonstrated in rat brain, human CSF, and human plasma by a gas chromatographic-mass spectrometric method that can reliably quantify as little as 8 pmol, i.e., 1 ng. Owing to tautomerism of the imidazole ring, IAA and [15N, 15N]IAA, the internal standard, each formed two chromatographically distinct isomers after derivatization of the ring nitrogens with either ethyl chloroformate or methyl chloroformate. The isomers of n-butyl(N-ethoxycarbonyl)imidazole acetate and n-butyl(N-methoxycarbonyl)imidazole acetate were identified by analysis with methane chemical ionization and electron impact ionization of molecular and fragment ions. The levels (mean +/- SEM) of free IAA were 140 +/- 14 pmol/g and 2.7 +/- 0.2 pmol/ml in brains of untreated rats and human lumbar CSF, respectively. Mean levels of IAA in brains of anesthetized rats, perfused free of blood, did not differ significantly from mean levels of anesthetized, nonperfused controls or from untreated rats. The source or sources of IAA in brain and CSF are unknown. Because IAA is a potent agonist at gamma-aminobutyrate receptors, it merits examination as a regulator in brain.
Sealant Effectiveness for Children Receiving a Combination of Preventive Methods in a Fluoridated Community: Two-Year Results

A series of preventive methods in combination have been used to reduce dental caries in children including dental health education, prophylaxes, pit and fissure sealants, topical application of fluoride and restorative care. Prophylaxes, sealant, and fluoride procedures are repeated every six months. Two-year results show reductions of occlusal caries increments of 74.3% for first graders and 77.1% for sixth graders. Sealant loss, as defined in this study, varied from 33% to 90% with the highest loss occurring in the newly erupted permanent molars during the first six months of the project. These high sealant loss rates are thought to be related to the age of the population which was designed to include children at the ages of peak eruption of permanent molar teeth (ages six and twelve). These teeth were often only minimally erupted and maintaining the dry field required for sealant retention was extremely difficult. However, in spite of these high rates of sealant loss, caries reduction on occlusal surfaces was highly significant in comparision to that of children who did not receive sealants.
Field-Induced Droplet Ionization Mass Spectrometry

A neutral droplet elongates along the axis of a strong electric field, ejecting opposing jets of positively and negatively charged progeny droplets. Images of droplets from a vibrating orifice aerosol generator illustrate this phenomenon, and mass spectrometric sampling of the progeny droplets demonstrates that they are a viable source of desolvated gas-phase ions. Field-induced droplet ionization (FIDI) mass spectra are presented for several species, including tetraheptylammonium cation, deprotonated benzene tetracarboxylic acid anion, and multiply protonated cytochrome c.
Absence of (1,0) supersymmetry anomaly in world-sheet gauge theories: A purely cohomological proof.

A purely cohomological proof is given for the absence of the (1,0) supersymmetry anomaly in gauge theories on a world sheet. In particular, it is shown that generalized cohomological approaches to anomalies in supersymmetric gauge theory, either formulated in whole superconnection space or only in the Wess-Zumino-gauge surface, yield results which agree with those obtained by noncohomological field-theoretical methods. We argue that the success of the cohomological arguments implies that there should be a generalization of (family) index theorem in the supersymmetric cases.
GENERALIZED LIPODYSTROPHY: EFFECT OF CEREBRAL DOPAMINERGIC BLOCKING AGENT (PIMOZIDE)

Generalized lipodystrophy (GLD), characterized by loss of subcutaneous and other fat, skeletal/muscle overgrowth, neutral fat hepatomegaly, genital enlargement, gonadal failure, hyper-pigmentation, acanthosis nigricans, hyperlipidemia, hyperglycemia, and hyperinsulinism, is associated with detectable hypothalamic regulatory hormones in plasma (J Pediat 82:625, 1973). Reasoning that GLD is a disorder of hypothalamic dysfunction dependent on catecholaminergic mechanisms, and using our earlier experience with chlorpromazine, we administered Pimozide to a 7-year-old girl with GLD (8 mg/day for 16 mo). Pimozide (a diphenylbutylpiperidine used as a neuroleptic) is a selective inhibitor of cerebral dopaminergic receptors. Effects over 16-months were: a) immediate and sustained diminution of luteinizing releasing hormone and corticotropin releasing hormone to zero or trace plasma levels, b) return of normal response to intravenous ACTH (Acta Endocr 73:437, 1973), c) return of liver function and size to normal or near normal with abatement of abdominal pain, d) reversal of skin and hair changes, e) return of subcutaneous fat to face and back as shown by appearance and biopsy (0.5 cm thick). These results 1) support the concept of diencephalic involvement in GLD, 2) indicate that Pimozide impairs the synthesis/release of hypothalamic regulatory hormones, and 3) suggest that GLD is amenable to meaningful treatment.
The long-range retarded interaction between two hydrogen atoms

Abstract The leading term in the long-range relativistic interaction energy of two non-degenerate atoms is expressed in terms of functions appearing in the calculation of dynamic polarizabilities. This term is found in closed form for two ls hydrogen atoms.
Safety, Efficacy, and Patient Acceptability of the Copper T-380A Intrauterine Contraceptive Device

The ParaGard Copper T 380A intrauterine device (CuT380A) provides reversible contraception that is as effective as sterilization for up to 20 years. The CuT380A is a mainstream, first-line contraceptive option for most healthy women, including nulligravid women, as well as many women who have serious medical problems. Because it is the most cost-effective method of birth control, the CuT380A is the preferred IUD, except for women who desire lighter or no menstrual blood loss. Surveys reveal that 95% of US CuT380A users are “very” or “somewhat” satisfied with their method. This article describes current candidates for IUD use, discusses the mechanisms of action of the CuT380A, provides guidance to reduce barriers to IUD access, suggests counseling points for patients, and outlines techniques to reduce the risks and side effects that can be associated with use of the CuT380A.
The use of picolinyl esters for the characterization of microbial lipids: application to the unsaturated and cyclopropane fatty acids of campylobacter species

Picolinyl esters have been recently introduced for the mass spectrometric structure determination of unsaturated and cyclopropane fatty acids. We have used these derivatives to characterize the unsaturated and cyclopropane acids of Campylobacter species. The principle unsaturated acids were shown to be 11-octadecenoic acid, with smaller amounts of 9-hexadecenoic acid, 9-octadecenoic acid and 9, 11-octadecadienoic acid. The only cyclopropane acid present was cis 11, 12-methylene octadecanoic acid. There was no interspecific variation in the position of unsatu-ration or methylene bridges, even in the recently discovered gastric Campylobacter like organisms (GCLO) or the urease positive thermophilic Campylobacters (UPTC), the fatty acid profiles of which were consistent with their inclusion in the genus Campylobacter.
The mechanisms of the gas phase reactions of HO− with oxirane and HS− with thiirane. An ab initio study

Abstract Ab initio calculations at the MP2/6-311+G*//HF/6-31+G* level are used to characterize the mechanisms of the gas phase reactions of HO− with oxirane (I) and HS− with thiirane (II). The SN2 reaction of HO− with I has a negative activation barrier (−5.1 kcal mol−1) and produces HOCH2CH20− with 47.2 kcal mol−1 of excess internal energy. This ion is capable of an intramolecular proton transfer and can decompose by loss of H2 to give −OCH2C(O)H. The transition state for H2 loss is 17 kcal mol−1 more stable than the reactants. The ring-opening reaction of HS− + thiirane has a small barrier (+ 0.6 kcal mol−1) and produces HSCH2CH2S− with 23.5 kcal mol−1 of excess internal energy. There is virtually no barrier to intramolecular proton transfer within this thiolate; however, there is a large barrier to H2 loss — the transition state is 18.4 kcal mol−1 less stable than the reactants. In both systems, the effects of ring strain relief are almost fully realized in the SN2 transition state. Reaction profiles are presented and the theoretical studies are compared with relevant gas phase experiments. The proton affinities of −OCH2C(O)H and −SCH2C(S)H are calculated to be 358.8 and 334.6 kcal mol−1 respectively.
A neural net model for escape learning.

An escape learning situation is discussed in terms of a neural model in which a stimulus can result in a conditioned excitement and a specific conditioned response. By using the simplest relations between the strengths of conditioning and the number of reinforcements and by introducing a distribution of fluctuations occurring regularly in time, one can calculate the probabilities of various responses, as well as the various latencies, in successive trials. The results are in moderately satisfactory agreement with the data of R. L. Solomon and L. C. Wynne (Psychol. Monogr.,67, No. 4, 1953). Consequences of the model for various experimental situations are discussed.
Modeling the Weather with a Data Flow Supercomputer

Data flow computers promise efficient parallel computation limited in speed only by data dependencies in the calculation being performed. At the Massachusetts Institute of Technology Laboratory for Computer Science, the Computation Structures Group is working to design practical data flow computers that can outperform conventional supercomputers. Since data flow computers differ radically in structure from conventional (sequential) computers, the projection of their performance must be done through analysis of specific computations. The performance improvement that data flow computers offer is shown for a NASA benchmark program that implements a global weather model. We present the structure of the weather code as expressed in VAL, a functional programming language designed by the Computation Structures Group, and develop the corresponding machine-level program structures for efficient execution on a data flow supercomputer. On the basis of this analysis, we specify the capacities of hardware units and the number of each type of unit required to achieve a twenty-fold improvement in performance for the weather simulation application.
Preventing Parkinson's pathology

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopaminergic neurons in the substantia nigra pars compacta of the midbrain. The impaired production and secretion of dopamine causes a variety of symptoms, including bradykinesia, tremor, rigidity, and other
Integrating Soft Skills Through Active Learning In The Management Classroom

This article discusses how active learning can be used to develop soft skills required by managers of contemporary organizations. Findings from course materials developed in response to business and industry demand for increased focus on soft skills are examined using an emerging population, first generation college students in institutions of higher education.