cssi/SciSciGPT-SciSciNet huggingface dataset:
Second Order Training and Sizing for the Multilayer Perceptron

An algorithm is developed for automated training of a multilayer perceptron with two nonlinear layers. The initial algorithm approximately minimizes validation error with respect to the numbers of both hidden units and training epochs. A median filtering approach is added to reduce deviations between validation and testing errors. Next, the mean-squared error objective function is modified for use with classifiers using a method similar to Ho–Kashyap. Then, both theoretical and practical reasons are provided for introducing growing steps into the algorithm. Lastly, a sigmoidal input layer is added to limit the effects of input outliers and further improve the method. Using widely available datasets, the final network’s average testing error is shown to be less than that of several other competing algorithms reported in the literature.
Bots fired: examining social bot evidence in online mass shooting conversations

Mass shootings, like other extreme events, have long garnered public curiosity and, in turn, significant media coverage. The media framing, or topic focus, of mass shooting events typically evolves over time from details of the actual shooting to discussions of potential policy changes (e.g., gun control, mental health). Such media coverage has been historically provided through traditional media sources such as print, television, and radio, but the advent of online social networks (OSNs) has introduced a new platform for accessing, producing, and distributing information about such extreme events. The ease and convenience of OSN usage for information within society’s larger growing reliance upon digital technologies introduces potential unforeseen risks. Social bots, or automated software agents, are one such risk, as they can serve to amplify or distort potential narratives associated with extreme events such as mass shootings. In this paper, we seek to determine the prevalence and relative importance of social bots participating in OSN conversations following mass shooting events using an ensemble of quantitative techniques. Specifically, we examine a corpus of more than 46 million tweets produced by 11.7 million unique Twitter accounts within OSN conversations discussing four major mass shooting events: the 2017 Las Vegas concert shooting, the 2017 Sutherland Springs church chooting, the 2018 Parkland School Shooting and the 2018 Santa Fe school shooting. This study’s results show that social bots participate in and contribute to online mass shooting conversations in a manner that is distinguishable from human contributions. Furthermore, while social bots accounted for fewer than 1% of total corpus user contributors, social network analysis centrality measures identified many bots with significant prominence in the conversation networks, densely occupying many of the highest eigenvector and out-degree centrality measure rankings, to include 82% of the top-100 eigenvector values of the Las Vegas retweet network.
Gradient diffusion in dilute suspensions of hard spheroidal particles

The renormalization method proposed by Batchelor is used to derive gradient diffusion coefficients in Brownian suspensions of hard spheroidal particles with aspect ratio in the range . The theory is based on pairwise steric and hydrodynamic interactions, and the results are therefore valid for dilute suspensions such that , where is the particle volume fraction. The driving force for gradient diffusion, i.e. the gradient in chemical potential, is larger for suspensions of spheroidal particles than for spheres at the same volume fraction. The hydrodynamic resistance also increases with aspect ratio, but the increase is weaker than that in the driving force. Consequently, at the same particle volume fraction, the increases in rates of gradient diffusion are greater for spheroidal particles than for spheres. The concentration-dependent gradient diffusion coefficient is shown to be closely approximated by , which reduces to the result for spheres when . Here, is the Stokes–Einstein diffusivity of a spherical particle with its radius equal to the longer dimension of the spheroidal particle, and is the orientation-averaged diffusivity of an isolated spheroidal particle.
The Anthropocene stinks! Odor, affect, and the entangled politics of livestock waste in a rural Iowa watershed:

Recent interventions in geography regarding the Anthropocene have demonstrated how Western logics of order and containment have produced massive geologic transformations. This paper focuses on odor...
A differential transformer-based force sensor utilizing a magnetic fluid core

A force sensor utilizing a transformer concept with a ferrofluid core was developed. A ferrofluid reservoir was machined out of Teflon and the open top of the reservoir was sealed with a thin silicone membrane. Forces applied to the silicone membrane caused the membrane to deflect, resulting in the displacement of the ferrofluid in the reservoir through an external tube. The ferrofluid in the tube acted as the core of voltage transformer. The ferrofluid core was excited by an alternating current across a wire coil wound around the tube. A secondary coil was wound around the top portion of the tube which was vertically oriented. As the ferrofluid level in the tube rose in response to applied forces, the secondary coil became engaged by the magnetized ferrofluid, resulting in a voltage induced in the secondary coil that varied with the level of the ferrofluid. The sensor was characterized by the relationship between the forces applied to the membrane and the output voltage readings across the secondary coil in loading and unloading cycles. This relationship was found to be nonlinear and following a negative second-degree polynomial relationship. The sensor was tested at three primary frequencies of 60, 100 and 120 kHz. It was found that 13% of the 5 V A/C exciting voltage applied across the primary coil at 60 kHz was induced into the secondary coil when it was fully engaged by the magnetized ferrofluid. It was determined that the sensor generates the highest sensitivity of 68.3 mV/N over the effective range of 0.1–2.5 N at 60 kHz. The sensor was analyzed for error and the characteristic error was found to be comparable to existing inductive sensors. Sources of most significant of error were identified and proposals for improvements to future designs of this sensor type are provided.
Regulation of chemoconvulsant-induced seizures by store-operated Orai1 channels.

KEY POINTS Temporal lobe epilepsy is a complex neurological disease caused by imbalance of excitation and inhibition in the brain. Growing literature implicates altered Ca2+ signalling in many aspects of epilepsy but the diversity of Ca2+ channels that regulate this syndrome are not well-understood. Here, we report that mice lacking the store-operated Ca2+ channel, Orai1, in the brain show markedly stronger seizures in response to the chemoconvulsants, kainic acid and pilocarpine. Electrophysiological analysis reveals that selective deletion of Orai1 channels in inhibitory neurons disables chemoconvulsant-induced excitation of GABAergic neurons in the CA1 hippocampus. Likewise, deletion of Orai1 in GABAergic neurons abrogates the chemoconvulsant-induced burst of spontaneous inhibitory postsynaptic currents (sIPSCs) on CA1 pyramidal neurons in the hippocampus. This loss of chemoconvulsant inhibition likely aggravates status epilepticus in Orai1 KO mice. These results identify Orai1 channels as regulators of hippocampal interneuron excitability and seizures. ABSTRACT Store-operated Orai1 channels are a major mechanism for Ca2+ entry in many cells and mediate numerous functions including gene expression, cytokine production and gliotransmitter release. Orai1 is expressed in many regions of the mammalian brain; however, its role in regulating neuronal excitability, synaptic function and brain disorders has only now begun to be investigated. To investigate a potential role of Orai1 channels in status epilepticus induced by chemoconvulsants, we examined acute seizures evoked by intraperitoneal injections of kainic acid (KA) and pilocarpine in mice with a conditional deletion of Orai1 (or its activator STIM1) in the brain. Brain-specific Orai1 and STIM1 knockout (KO) mice exhibited significantly stronger seizures (P = 0.00003 and P twofold (KA: P = 0.04; pilocarpine: P = 0.0002) which was abolished in Orai1 KO mice. Mice with selective deletion of Orai1 in GABAergic neurons alone also showed stronger seizures to KA (P = 0.001) and pilocarpine (P < 0.00001) and loss of chemoconvulsant-induced increases in sIPSC responses compared with WT controls. We conclude that Orai1 channels regulate chemoconvulsant-induced excitation in GABAergic neurons and that destabilization of the excitatory/inhibitory balance in Orai1 KO mice aggravates chemoconvulsant-mediated seizures. These results identify Orai1 channels as novel molecular regulators of hippocampal neuronal excitability and seizures.
Lethal Incompetence: Leaders, Organizations, and the U.S. Response to COVID-19

The study of voter competence has made significant contributions to our understanding of politics, but at this point there are diminishing returns to the endeavor. Voter competence is unlikely to improve dramatically enough to make much of a difference to our politics. By contrast, the competence of officials can and does vary substantially over short periods of time. To understand variations in government performance, therefore, we would do better to focus on the abilities and performance of officials, not ordinary citizens. We elaborate on this argument, emphasizing the “incompetence multiplier”: the way that the properties of hierarchies can amplify the incompetence of those in powerful positions. We illustrate our argument with an extended discussion of the U.S. response to the COVID-19 pandemic.
New Data and Collaborations at the Saccharomyces Genome Database: Updated reference genome, alleles, and the Alliance of Genome Resources

Saccharomyces cerevisiae is used to provide fundamental understanding of eukaryotic genetics, gene product function, and cellular biological processes. Saccharomyces Genome Database (SGD) has been supporting the yeast research community since 1993, serving as its de facto hub. Over the years, SGD has maintained the genetic nomenclature, chromosome maps, and functional annotation, and developed various tools and methods for analysis and curation of a variety of emerging data types. More recently, SGD and six other model organism focused knowledgebases have come together to create the Alliance of Genome Resources to develop sustainable genome information resources that promote and support the use of various model organisms to understand the genetic and genomic bases of human biology and disease. Here we describe recent activities at SGD, including the latest reference genome annotation update, the development of a curation system for mutant alleles, and new pages addressing homology across model organisms as well as the use of yeast to study human disease.
Exploring Caregivers’ Clothing Choices for Individuals With Severe Alzheimer's Disease: An Application of the Theories of Self-Complexity and Choosing for Others

The number of older Americans as well as those living with Alzheimer's is rapidly growing. Alzheimer's dementia is a disease that causes problems with memory, thinking, and behavior. The role of ca...
The Fractional Quantum Hall Effect and the Rotation Group

When a magnetic field B is applied perpendicular (z- direction) to a two dimensional surface with a current in the x-direction, j x , an electric field is induced in the y- direction, E y. This effect was discovered a century ago by Hall1−3.
Balanced Latin Hypercube Sampling for Stochastic Simulations of Spot Welds

In performing stochastic simulations using computer models, the method of sampling is important. It affects the quality and the convergence speed of the results. This paper discusses one special case: sampling of spot-weld locations from potentially thousands of spot welds on a vehicle body. This study is prompted by the need of evaluating the effect of missed spot welds on the structural integrity, identifying critical welds, and optimizing weld locations. A balanced random sampling algorithm based on the concept of Latin-Hypercube sampling is developed for this application. We also present a case study in which the efficiency of three different sampling methods is compared using a car joint stiffness example. The new method, called the Balanced Latin-Hypercube Sampling (BLHS), has shown significantly faster convergence over the other two.
A Model of Quench Layer Entrainment During Blowdown and Exhaust of the Cylinder of an Internal Combustion Engine

An aerodynamic model of the entrainment of the head wall quench layer during blowdown and exhaust of an internal combustion engine was developed. The model may be used to calculate the time resolved concentration and mass flowrate of hydrocarbons (HC) in the exhaust, from a knowledge of engine geometry and operating conditions. It predicts that the area A/sub s/ from which HC are swept will be proportional to the cube root of the ratio of the quench layer thickness delta/sub q/ to the thickness of the viscous boundary layer delta/sub v/. Since the mass of HC emitted is proportional to the product of the HC density rho/sub HC/, the area A/sub s/ and the thickness delta/sub q/, the HC emissions will be proportional to the product rho/sub HC/ delta/sub q//sup 4/3/ and this is the most important factor determining the emissions. The model also predicts that the time dependence of the HC mass flowrate will depend relatively strongly on the pressure ratio p/sub 4//p/sub e/ across the exhaust valve when it opens: in an unthrottled engine virtually all the head wall HC exit during blowdown; in a heavily throttled engine the HC are emitted more or less uniformly during themore » exhaust stroke.« less
Plutonium-244 dating

Re-examination of all known xenon isotopic data for ordinary chondrites reveals that244Pu fission xenon can be resolved in about one-fourth of the meteorites of this class. The amounts of244Pu fission xenon found in these meteorites range from ca. 1–2 up to 6–8·10−12 ccSTP/g. These meteorites started to retain their xenon some 200–500 million years later than did the carbonaceous chondrites Allende, Groznaya, Mokoia, Murchison, Murray, and Renazzo which began to retain their xenon over 4800 million years ago.
Base of the Pyramid Markets: Culture Insights and Marketing Implications

Most of the world's population is poor and lives on less than $1–2 a day in developing countries. Known as the “base of the pyramid” (BOP), this population represents a largely untapped market for global businesses. Till recently, global businesses were content to pursue the middle and the top of the pyramid segments, which are open to and have the means to buy a wide assortment of goods and services. However, as growth of these markets has slowed down, businesses are now seeking new customers and sales. The BOP is perhaps the largest remaining global market frontier. Though the BOP market presents enormous opportunities, it also poses unrivaled challenges given its immense scale and deep deprivations. A chief need is knowledge of the market's culture, so that firms can develop effective and beneficial marketing approaches. This article explores the complex and dynamic BOP culture, elaborating how it is characterized by shared values and limited opportunities, a paradox of scarcity and abundance, embeddedness in layers of cultural influences, and heterogeneous meanings in its response to other cultures. On the basis of these insights, marketing insights are arrived at for firms to meet successfully the needs of the BOP consumers, who have historically been excluded from the global marketplace. Keywords: base of the pyramid (BOP); subsistence markets; developing countries; culture; marketing
The diagnosis and management of adult intussusception.

Abstract Background While intussusception is relatively common in children, it is a rare clinical entity in adults, where the condition is almost always secondary to a definable lesion. Data sources Thirteen cases of intussusception occurring in individuals older than 16 were encountered at our institute between 1981 and 1994. Results Presenting signs/symptoms included recurrent bowel obstruction, intermittent pain, and red blood per rectum. Correct preoperative diagnosis was made in six patients using colonoscopy, flexible sigmoidoscopy, upper gastrointestinal (GI) series and computed tomography (CT). At surgery the lead point was identified in the small intestine in eight cases, in the colon in four cases, and one small intestinal intussusception was considered idiopathic. Twelve patients underwent laparotomy and one patient was both diagnosed and treated by colonoscopy alone. Conclusions Adult intussusception is an unusual cause of bowel obstruction. The likelihood of neoplasia, particularly in the colon as a cause, is high. Operative management is thus almost always necessary.
USArray design implications for wavefield imaging in the lithosphere and upper mantle

Although seismic tomography is currently the mainstay of global seismic imaging, the large-scale deployment of portable instruments to be conducted as the USArray component of Earthscope over the next decade will allow much higher resolution imaging of the solid earth using migration/inversion methods similar to those used in petroleum exploration. Direct wavefield imaging in solid earth structural seismology has been uncommon in comparison to practices in exploration seismology, generally due to the large separation between seismic stations. With the development of portable observatory quality broadband (0.01–20 Hz) seismographs and acquisition of modest numbers of them for the PASSCAL instrument pool over the past decade, a number of academic field programs have had receiver spacing dense enough for wavefield back-projection and imaging. Recordings from these experiments have been used in several different imaging schemes, all of which are outgrowths of and bear resemblance to either post- or prestack d...
Evidence for itinerant 3d-electron spin density oscillations surrounding solute atoms in Fe alloys

Abstract Hyperfine field and saturation magnetization data are analyzed to obtain solute transition element moments and Fe moment perturbations in dilute Fe alloys. A direct comparison of these results is made with the neutron scattering data. The host moment perturbations show simple oscillatory behavior which is interpreted as arising from the polarization of itinerant d electrons by localized d moments through mainly Coulomb exchange interactions. The behavior of Ni-based alloys can also be understood within this model.
Three-dimensional axial next-nearest-neighbor Ising model: A series investigation

We have derived a twelfth-order, high-temperature series for the axial next-nearest-neighbor Ising (ANNNI) models on the fcc and the sc lattices, and we present detailed results for one of the fcc models. We have determined the phase boundaries of these models and located the Lifshitz point from the intersection of the phase boundary with the ``disorder'' line, where the maximum in the susceptibility \ensuremath{\chi}(q) begins to occur at nonzero q signaling the onset of modulated correlations. As expected, the Lifshitz point appears to be an inflection point of the phase boundary. The effective susceptibility index shows the predicted universal values for definite regions of the parameter space, e.g., XY-like in the midrange modulated regime, with the expected smooth crossover near the multicritical points. Throughout the modulated regime from the Lifshitz point to the decoupling point, the variation in the critical wave vector shows only small deviations from mean-field predictions. Our best estimates for the Lifshitz-point indices, ${\ensuremath{\gamma}}_{\mathit{l}}$=1.62\ifmmode\pm\else\textpm\fi{}0.12, 4${\ensuremath{\nu}}_{\mathit{l}4}$=1.63\ifmmode\pm\else\textpm\fi{}0.10, and ${\mathrm{\ensuremath{\alpha}}}_{\mathit{l}}$=0.20\ifmmode\pm\else\textpm\fi{}0.15, differ from previous estimates. We are confident that our estimates are more reliable not only because we have longer series for a close-packed lattice but also primarily because we have analyzed our series along the appropriate scaling direction.
The Reagan dollar

In a recent editorial (cf. INTERECONOMICS, No. 3/1984, p. 101) Professor Armin Gutowski commented on the surprising increase of the external value of the US dollar which seems to defy traditional explanations of exchange rate determination. The following article presents an American economist’s view of the same subject.
Curare as a Neuromuscular Blocking Agent in Insects

Topical application of curare produced no effects on electrical activity in single flight-muscle fibers of the fly Sarcophaga. However, the intraabdominal injection of curare induced a neuromuscular block similar to that described for vertebrates. The general refractoriness of some insects to chemical agents may well be due to the method of application.
Wound complications associated with incision enlargement for foldable intraocular lens implantation during cataract surgery.

Abstract Purpose To ascertain whether enlarging the incision for implantation of MA60 intraocular lenses (IOLs) causes increased wound instability and compare the incidence of wound-related complications with that after SI-40NB IOL implantation through an unenlarged incision. Methods This retrospective study comprised operative and postoperative notes of consecutive patients who had implantation of an Allergan SI-40NB IOL using the Unfolder or an Alcon MA60 AcrySof IOL from April 30, 1999, and before. The operative reports were used to determine whether there were any wound problems, particularly the need to suture the wound. Records from the first postoperative day were reviewed for evidence of wound leak or other wound-related complications. Results Of the 200 eyes receiving an SI-40NB IOL, 3 (1.5%) required the placement of a suture during surgery to secure the wound. None had a wound leak 1 day postoperatively. Of the 200 eyes receiving an MA60 IOL, 12 (6.0%) required the placement of a suture during surgery to secure the wound. One eye had a wound leak 1 day postoperatively. The difference in the number of wound-related complications between the 2 IOL groups was significant ( P = .01). Conclusions Significantly more wound-related complications occurred after incision enlargement for implantation of MA60 IOLs than after implantation of SI-40NB IOLs through unenlarged incisions.
True digestibility of amino acids and protein in pigs with 13C as a label to determine endogenous amino acid excretion

The objective of this study was to determine whether differential labeling of 13 C occurs in pigs fed diets with different 13 C abundances and, if so, to use 13 C as a label to determine true amino acid digestibility. Forty-eight pigs averaging 10.5 kg BW were fed dietary treatments consisting of a corn-corn gluten meal-crystalline amino acid diet (C-CGM) and a wheat-soybean meal diet (W-SBM). The 13 C abundance of the amino acid fraction (AAF) of the C-CGM and W-SBM diets averaged delta 13 C -14.19 and -26.36‰, respectively. Three pigs/treatment group were killed when groups averaged 10.5 (initial), 22.9, and 46.6 kg BW, and AAF of organs were analyzed for 13 C abundance. Carbon 13 in empty body AAF increased (-18.14, -13.98, and -12.66‰) with increasing body weight in pigs fed the C-CGM diet and decreased (-18.06, -22.78, and -24.76‰) in pigs fed the W-SBM diet. Liver, small intestine, and longissimus muscle tissues showed similar trends. Each tissue had dietary treatment effects (P<.001) and dietary treatment x weight group (P<.001) interactions. Ten pigs averaging 55.0 kg BW from each treatment group were assigned to metabolism cages and fed at 0700 and 1900. Six of these pigs from each treatment group were implanted with T-cannulas in the ileum and given a 17-d recovery period. At 1900 on d 0 of the collection phase, pigs were switched to the opposite diet that contained chromic oxide. Digesta were collected from 1000 to 1400 and 2200 to 0200 on d 1, 2, and 9, and feces were collected on d 7 and 8. Additionally, the four pigs from each treatment group that were not implanted with cannulas were fed similarly and a pig was killed at 1200 and 2400 on d 1 and at 1200 and 2400 on d 2, and AAF of organs were analyzed for 13 C abundance. By using 13 C abundance of small intestine AAF as a index of endogenous protein label, ileal protein was partitioned into endogenous and undigested protein. True and apparent amino acid digestibilities for W-SBM were as follows: Lys 79.9, 73.7; Thr 79.2, 70.6; Ile 86.1, 81.6; and Phe 86.6, 82.4, respectively. True and apparent amino acid digestibilities for the C-CGM were as follows: Lys 85.0, 81.5; Thr 74.6, 66.7; Ile 90.8, 88.2; and Phe 89.4, 86.5, respectively. In summary, pig tissue protein was labeled with 13 C according to diet, and 13 C can be used to determine true amino acid digestibility
Exploring the Role of the Active Site Cysteine in Human Muscle Creatine Kinase

All known guanidino kinases contain a conserved cysteine residue that interacts with the non-nucleophilic eta1-nitrogen of the guanidino substrate. Site-directed mutagenesis studies have shown that this cysteine is important, but not essential for activity. In human muscle creatine kinase (HMCK) this residue, Cys283, forms part of a conserved cysteine-proline-serine (CPS) motif and has a pKa about 3 pH units below that of a regular cysteine residue. Here we employ a computational approach to predict the contribution of residues in this motif to the unusually low cysteine pKa. We calculate that hydrogen bonds to the hydroxyl and to the backbone amide of Ser285 would both contribute approximately 1 pH unit, while the presence of Pro284 in the motif lowers the pKa of Cys283 by a further 1.2 pH units. Using UV difference spectroscopy the pKa of the active site cysteine in WT HMCK and in the P284A, S285A, and C283S/S285C mutants was determined experimentally. The pKa values, although consistently about 0.5 pH unit lower, were in broad agreement with those predicted. The effect of each of these mutations on the pH-rate profile was also examined. The results show conclusively that, contrary to a previous report (Wang et al. (2001) Biochemistry 40, 11698-11705), Cys283 is not responsible for the pKa of 5.4 observed in the WT V/K(creatine) pH profile. Finally we use molecular dynamics simulations to demonstrate that, in order to maintain the linear alignment necessary for associative inline transfer of a phosphoryl group, Cys283 needs to be ionized.
Malfunction diagnosis using quantitative models with non‐boolean reasoning in expert systems

An approach to chemical plant fault diagnosis is presented that utilizes patterns of violation and satisfaction of the quantitative constraints governing the process. Process knowledge consists of a list of the operational constraints on the plant together with sufficient conditions for violation of each constraint. Interpretation of the pattern of constraint violations is treated by Boolean and non-Boolean techniques. It is shown that non-Boolean reasoning techniques increase the stability and sensitivity of the diagnosis in the presence of noise. The techniques introduced in this paper are easily implemented in rule-based expert systems using certainty factors.
Learning to detect malicious URLs

Malicious Web sites are a cornerstone of Internet criminal activities. The dangers of these sites have created a demand for safeguards that protect end-users from visiting them. This article explores how to detect malicious Web sites from the lexical and host-based features of their URLs. We show that this problem lends itself naturally to modern algorithms for online learning. Online algorithms not only process large numbers of URLs more efficiently than batch algorithms, they also adapt more quickly to new features in the continuously evolving distribution of malicious URLs. We develop a real-time system for gathering URL features and pair it with a real-time feed of labeled URLs from a large Web mail provider. From these features and labels, we are able to train an online classifier that detects malicious Web sites with 99p accuracy over a balanced dataset.
Effect of high-current stimulation in patients with sustained ventricular tachycardia rendered noninducible by antiarrhythmic drugs.

Abstract Successful antiarrhythmic drug therapy for sustained ventricular tachycardia (VT) is presumed to be related to effects on myocardium within the reentrant circuit. To test the hypothesis that prevention of VT induction may be related to effects on myocardium other than that directly involved in the tachycardia circuit, high-current stimulation was used to achieve shorter coupling intervals in 22 patients with sustained uniform VT that was rendered noninducible by antiarrhythmic agents during stimulation at twice threshold. Sustained uniform VT was induced in 10 patients in response to high-current stimulation (group 1), including 4 tachycardias with the same morphology observed in the baseline study. There were no inducible arrhythmias in 12 patients (group 2). Patients were receiving several different antiarrhythmic regimens, but there was no particular drug associated with the induction of VT using high-current stimulation. There was no statistically significant difference between groups 1 and 2 in baseline VT cycle length (247 ± 41 vs 253 ± 44 ms), drug-induced increase in effective refractory period (20 ± 15 vs 16 ± 7%), QRS duration (25 ± 10 vs 20 ± 17%) or maximal current strength delivered (10.9 ± 5.3 vs 9.3 ± 4.0 mA). There was no significant difference in local activation with high-current stimulation between groups 1 and 2. In conclusion, sustained uniform VT was induced in 45% (10 of 22) of patients whose arrhythmias were rendered noninducible by antiarrhythmic agents during programmed stimulation at twice threshold. This suggests that prolongation of refractoriness at the site of stimulation or slowing in conduction time of extrastimuli to the presumed reentrant circuit, or both, may be one mechanism by which antiarrhythmic drugs prevent induction of VT during programmed stimulation.
Bicinchoninic Acid Protein Assay in the Determination of Adriamycin Cytotoxicity Modulated by the MDR Glycoprotein

The development of simultaneous resistance to structurally unrelated drugs in cancer cells is a major obstacle to effective cancer chemotherapy. This multidrug-resistance (MDR) phenomenon is largely attributed to overexpression of a 170 kD glycoprotein, which serves as a transmembrane efflux pump in extruding a variety of natural anticancer drugs such as vinblastine, doxorubicin, and taxol from cancer cells. It is desirable, therefore, to discover compounds that can block the efflux mechanism and thus reverse drug resistance. The bicinchoninic acid protein assay has been adapted for use in a microtiter plate, into an easy, indirect method for screening MDR efflux blockers in plant extracts. This spectrophotometric assay is used to determine the enhancement of adriamycin cytotoxicity against resistant cancer cells by plant extracts or pure compounds indirectly. We have shown that the optical density measured (amount of cellular protein present) correlates with the number of viable cells and that fluorescence of Adriamycin associated with the cell correlates with the concentrations of Adriamycin added to the media. In addition, the relative efficacy of MDR reversal by various alkaloids has been determined.
Exploiting the Good Guys: Th1 Antiviral & Antitumor Human & Mouse NKT Cells

Toll-like receptor 2 (TLR2) signaling from TLR2/1 or TLR2/ 6 complexes, in response to peptidoglycan (PGN)-embedded lipoproteins and glycopolymers, is a primary step in the activation of adaptive responses against Staphylococcus aureus and other Gram-positive bacteria. Recent studies from our laboratory have shown that PGN from S. aureus can also down-regulate human T cell activation through a TLR2dependent, IL-10-mediated mechanism (Chau et al, Nature Medicine 2009; 15: 641). The molecular basis of the plasticity of TLR2-dependent signaling is unknown. Here we show that the down-regulatory effect of TLR2 signaling on adaptive T cell responses is operational when human monocytes and monocyte-derived macrophages (MΦ), but not monocytederived dendritic cells (DCs), are the primary antigenpresenting cells (APCs). Such a modulatory capacity of MΦs correlated with significantly higher levels of surface TLR2 on MΦs than on DCs, with surface levels of TLR1 and TLR6 being similar in these APCs. Differential availability of TLR2 signaling complexes correlated with functional polarization of these APCs into IL-10-producing or IL-12-producing cells in response to staphylococcal PGN. The IL-10 response triggered by TLR2/1 and TLR2/6 agonists did not require the TLR accessory molecules CD14 and CD36, and was dependent on the activation of the PI3K/Akt pathway. Our results illustrate that S. aureus can exploit an inherent plasticity of TLR2dependent signaling to modulate the host response. This may explain the different outcomes of the interaction between S. aureus and humans, which range from commensalism to pathogenicity (i.e., local infection, sepsis, toxic shock).
Prospective assessment of coronary heart disease risk factors: the NHANES I epidemiologic follow-up study (NHEFS) 16-year follow-up.

Objective: Our specific aim in the 16 year prospective NHANES I epidemiologic follow-up study (NHEFS) was to assess the important roles of modifiable dietary and behavioral factors in causation and prevention of deaths and hospitalizations for coronary heart disease (CHD).Methods: Using NHEFS 16 year follow-up data (1971 to 1987), we studied 5811 subjects, 1958 with and 3853 without CHD events, using logistic regression.Results: In age groups 40 to 49, 50 to 59, 60 to 69, and 70 to 74 years (at study entry in 1971–4), the numbers of men and women were respectively 597 and 1019, 570 and 619, 932 and 1042, and 486 and 546. The following factors were independently positively associated (p<.05) with CHD: age, serum cholesterol, body mass index, cigarette use, and region (Midwest, Northeast). The following factors were independently negatively associated (p<.05) with CHD: gender (female), race (black), fish intake, alcohol, high school education, moderate exercise, and moderate and heavy habitual physical acti...
Socially augmented hierarchical reinforcement learning for reducing complexity in cooperative multi-agent systems

This paper addresses the inherent complexity in coordinating learned behavioral strategies of multiple agents working towards a common goal. Because of the interactions among the agents, a primary challenge of policy learning is escalating computational complexity with increasing number of agents and the size of the task space (including action choices and world states). We employ an approach that incorporates social constructs based on analogs from biological systems of high functioning mammals in order to constrain state-action choices in reinforcement learning. Additionally, we use state-space abstraction and a hierarchical learning structure to improve learning efficiency. Theoretical results bound the reduction in computational complexity due to state abstraction, hierarchical learning, and socially-constrained action selection in learning problems that can be described as decentralized Markov decision processes. Simulation results show that these theoretical bounds hold and that satisficing multi-agent coordination policies emerge, which reduce task completion time, computational cost, and memory resources compared to learning with no social knowledge.
Use of Glutaraldehyde as a Poultry Processing Equipment Sanitizer

Abstract Laboratory studies were conducted to determine the efficacy of glutaraldehyde (1,5 pentanedial) as a sanitizer for poultry processing equipment when used in soaking or spraying applications. Sections of conveyor belts were artificially contaminated with organic matter and then soaked in varying concentrations (20 to 800 ppm) of glutaraldehyde and chlorine for up to 4 hr. Glutaraldehyde was consistently more effective than chlorine in reducing bacterial numbers. For example, after the belts were soaked for 30 min in 200 ppm solutions, 99.9% of the bacteria were destroyed by glutaraldehyde, whereas 90% were destroyed by chlorine. Lower bacterial counts were achieved by increasing the soaking time and/or the concentrations of sanitizer. Concentrations of 10 ppm to 7000 ppm of glutaraldehyde were used in spraying applications to determine an effective range. Concentrations of 100 ppm and less were ineffective in reducing bacterial numbers. When comparable concentrations of glutaraldehyde and chlorine were used in spraying applications, chlorine consistently destroyed more bacteria than glutaraldehyde.
Immunohistochemical evidence for reorganization of tau in the plaques and tangles in Alzheimer's disease.

Cytochemical and biochemical techniques have been used to assess the relationship of epitopes on the microtubuleassociated protein, tau, to the cytoskeletal pathology of Alzheimer's disease. The main probes were Tau-1 and Alz-50, two monoclonal antibodies which recognize tau and a potentially related 68kDa protein. Sequential treatment of tissue slices with combinations of the antibodies showed that each blocked the binding of the other to neurofibrillary tangles and neuritic plaques but not to normal axons. Western blot analysis of tau proteins isolated from Alzheimer's disease brains did not reveal such blocking patterns. The issue of steric hindrance affecting antibody binding in tissue sections was addressed by using Alz-50 in combination with Tau-2, another monoclonal antibody recognizing tau on blots and in Alzheimer's disease pathology. Neither antibody blocked the binding of the other to neurofibrillary tangles and neuritic plaques. These data suggest that the Alz-50 and Tau-1 epitopes are selectively organized in the tangles and plaques to be in close proximity which supports the hypothesis that in Alzheimer's disease pathology, tau is modified.
Stereoselective synthesis of stable isotope-labeled L-α-amino acids: Chemomicrobiological synthesis of 13C- and 2H-labeled L-cysteine

Tryptophan synthase catalyzes the nucleophilic replacement of the hydroxyl group at C-3 of L-serine. This enzyme can use benzyl mercaptan as a nucleophile in the conversion of serine to S-benzyl-L-cysteine which is deblocked by treatment with sodium in liquid ammonia to yield L-cysteine. A strain of E. coli engineered to overproduce tryptophan synthase was used in the conversion of L-serine to L-cysteine. Labeled serine was prepared biosynthetically as described previously.
Quantitative thin-layer spectrodensitometric determination of the components of polyene macrolide antibiotic complexes

Abstract A direct spectrodensitometric method for quantitating the components of polyene macrolide complexes after separation by thin-layer chromatography is described. Resolution of the components of the candidin and candihexin complexes was good up to 2.5 and 10 μg/spot, respectively. The peak areas were linear with the amount spotted up to the same levels. Maximum peak areas for the components of the candidin and candihexin complexes were obtained using light wavelengths of 360 and 340 nm, respectively. Spotting errors rather than instrumental parameters were responsible for the variance of repeated determinations. Minimal relative standard deviation values were found at intermediate concentration levels in the linear range.
Assessment of the impact of pattern of cocaine dosing schedule during conditioning and reconditioning on magnitude of cocaine CPP, extinction, and reinstatement.

We sought to examine the impact of differing cocaine administration schedules and dosing on the magnitude of cocaine conditioned place preference (CPP), extinction, and stress- and cocaine-induced reinstatement of CPP. First, in C57Bl/6J mice, we investigated whether total cocaine administration or pattern of drug exposure could influence the magnitude of cocaine CPP by conditioning mice with a fixed-low dose (FL; 7.5 mg/kg; total of 30 mg/kg), a fixed-high dose (FH; 16 mg/kg; total of 64 mg/kg), or an ascending dosing schedule (Asc; 2, 4, 8, and 16 mg/kg; total of 30 mg/kg). Next, we investigated if cocaine or saline is more effective at extinguishing preference by reconditioning mice with either a descending dosing schedule (Desc; 8, 4, 2, and 1 mg/kg) or saline. Finally, we examined if prior conditioning and reconditioning history alters stress (~2–3-min forced swim test) or cocaine-induced (3.5 mg/kg) reinstatement. We replicated and extended findings by Itzhak and Anderson (Addict. Biol. 17(4): 706–16, 2011) demonstrating that Asc conditioning produces a greater CPP than either the FL or FH conditioning schedules. The magnitude of extinction expressed was similar in the Desc reconditioned and saline groups. Moreover, only the saline, and not the Desc reconditioned mice, showed stress and cocaine-induced reinstatement of CPP. Our results suggest that the schedule of cocaine administration during conditioning and reconditioning can have a significant influence on the magnitude of CPP and extinction of preference and the ability of cocaine or a stressor to reinstate CPP.
Electrode Surface Area Is An Important Variable for Defibrillation

Previous studies have established efficacy of transseptal defibrillation. The purpose of the present study was to evaluate the role of transvenous electrode surface area for defibrillation. Sixteen dogs were randomized to 8 French and 5 French EnGuard™ electrodes; 8 dogs in each group. The length of the defibrillation coils was identical for both, but the surface area was different due to differences in the electrode diameters. Defibrillation threshold (DFT) testing was performed using a biphasic shock waveform, 6 msec+/2 msec-. Logistic regression analysis was used to determine if the probability of defibrillation adjusted for voltage, current, and energy was different for 8 French electrodes. Logistic regression analysis found significant differences between 8 French and 5 French electrodes, with less voltage (P < 0.005), current (P < 0.03), and energy (P < 0.001) required at any level of probability to defibrillate for 8 French electrodes. These results support the conclusion that the surface area for endocardial electrodes is a significant factor for defibrillation. Therefore, when designing endocardial electrodes a desirable objective of reducing the electrode size should be weighed against the need to minimize DFTs.
Carinamide as an adjunct in Staphylococcus albus septicemia with cavernous sinus thrombosis and meningitis.

Summary 1. The Staph. albus, although usually regarded as nonpathogenic, was recovered repeatedly from the blood stream, the cerebrospinal fluid, and a septic lesion in a moribund child. 2. Septicemia, meningitis, cavernous sinus thrombosis with cranial nerve paralysis, and possibly endocarditis were all manifestations of this Staph. albus infection. 3. The usual sources of cavernous sinus thrombosis, i.e., infections of the nose, face, and mouth, were not present. 4. The enhancing effect of carinamide was followed by recovery without sequelae.
Item-Level RFID Tag Location Sensing Utilizing Reader Antenna Spatial Diversity

A robust estimation procedure for sensing the locations of passive UHF radio frequency identification (RFID) tags is introduced based on spatial deployment of the reader antennas for maximum signal diversity. A signal model is developed for the received signal strength indicator seen by each reader antenna and incorporated into a mean-square error testing function. The error function is minimized at each test point in the interrogation zone to find the point with the minimum mean-square error. The minimization is independent of the tag type and orientation, making the proposed method very robust compared with other methods that are based on reference tags and radio maps. Experimental results are presented for a realistic retail scenario with multiple tagged items achieving an estimation accuracy of 35 cm. The location sensing system uses conventional UHF RFID readers, antennas, and passive tags, providing additional capability to existing item-level RFID systems. This added value will help to offset the high cost of large-scale RFID infrastructure development.
Practical Codes for Collaborative Estimation

In collaborative estimation a network of nodes, each indirectly observing an underlying source, communicate with each other to form improved estimates of the underlying source. This paper derives an efficient collaborative estimation algorithm achieving high performance estimates with low communication and complexity utilizing tools from multiterminal source coding theory and modern practical coding theory. Relevant theoretical limits based on achievability from multiterminal source coding are first presented in order to characterize efficient tradeoffs between communication and estimation performance and inspire the architecture of the collaborative estimation code. Next low complexity tools from modern practical coding theory are utilized to get a practical collaborative estimation algorithm approaching these performance limits. The developed algorithm utilizes successively refined trellis coded quantization (SR-TCQ) to provide necessary diverse descriptions of the source, and low-density parity-check (LDPC) codes to provide an efficient means of compressing these descriptions for low complexity belief propagation decoding with side information. Comparing the communication versus estimate quality tradeoff performance attained by the developed low complexity scheme with that obtainable with an inner bound, an average distortion gap of only 1.0 and 1.6 dB at average rates of 3.32 and 2.33 b/s, respectively, is observed.
Public policy issues affecting the health care delivery system of adolescents

Policymakers are at an important crossroad in pursuing viable solutions to the dilemma of preventing and treating adolescent health problems. A variety of coordinated and comprehensive approaches will be needed to resolve these complex and often entrenched problems. In the absence of a national policy for children and youth, it is important that those concerned with these issues join efforts at the community, local, state, and national levels to move the policy agenda forward. As an interim step, it is necessary to work on building and evaluating model programs that will influence the development of new policy directions. Both efforts are needed to address the complex array of problems facing adolescents today. The future of adolescent health will be determined by a variety of factors, including public policy. Of particular importance in shaping public policy are four factors: (1) the American character, including ideas and attitudes that are the basis of politics and policy; (2) the pluralism that characterizes the process, including the relationship between government and the private sector and the dominant role of the private sector; (3) the federal system that distributes authority among various levels of government (federalism); and (4) incrementalism, which is the step-by-step process that characterizes the development of policies. Of particular importance in terms of adolescent health are the ideas and attitudes about adolescence and adolescents; the basic ideas that affect policies broadly; and the concepts of federalism, pluralism, and the role of the private sector in dealing with domestic social issues. Although the field of adolescent health continues to advance, many complex problems that have their origin in biological, behavioral, and sociocultural factors remain. Of particular importance are problems associated with lower socioeconomic status. The problems will not yield to the single-issue, categorical approach of the past but will require comprehensive strategies involving the health, education, income maintenance, job training, employment, and social service sectors. Public policies must support these integrated, coordinated approaches, and health providers concerned with adolescent health can and must play a vital role in this process.