cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational challenges in the large-scale simulations of fracture in disordered media

Computational modeling of fracture in disordered materials using discrete lattice models is often limited to small system sizes due to high computational cost associated with re-solving the governing system of equations every time a new lattice bond is broken. Previously, we proposed an efficient algorithm based on multiple-rank sparse Cholesky downdating scheme for 2D simulations, and an iterative scheme using block-circulant preconditioners for 3D simulations. Based on these algorithms, we were able to simulate large 2D lattice systems (e.g., $L = 1024$). However, despite these algorithmic advances, the largest 3D lattice system that we were able to solve was limited to a size of $L = 64$$. In this paper, we present three alternate approaches, namely, the efficient preconditioners, {\it krylov subspace recycling}, and massive parallelization of the algorithms, the combination of which promise to significantly reduce the computational cost associated with simulating large 3D lattice systems of sizes $$L = 200$. The main idea associated with krylov subspace recycling is to retain a subspace determined while solving the current system and reuse it to reduce the cost of solving the subsequent system obtained after removing the new broken bond. Preliminary numerical simulation of fracture using 3D random fuse networks of sizes $L = 64$ substantiates the efficiency of the present algorithms.
Neural networks-based control of active and reactive power of a stand-alone PEM fuel cell power plant

This paper presents a neural networks (NN)-based active and reactive power controller of a stand-alone proton exchange membrane (PEM) fuel cell power plant (FCPP). The controller modifies the inverter modulation index and the phase angle of the ac output voltage to control the active and reactive power output from an FCPP to match the terminal load. The control actions are based on feedback signals from the terminal load, output voltage and hydrogen input. The validity of the controller is verified when the FCPP model is used in conjunction with the NN controller to predict the response of the power plant to: (a) computer-simulated step changes in the load active and reactive power demand, and (b) actual active and reactive load demand of a single family residence. The response curves indicate the load following characteristics of the model and the predicted changes in the analytical parameters highlighted by the analysis.
Sodium and potassium channels in demyelinated and remyelinated mammalian nerve

Demyelination of peripheral axons initially causes failure of action potential conduction, probably because the internodal membrane lacks sodium channels1,2. However, Bostock and Sears3 showed that 3–14 days after demyelination of rat nerve with diphtheria toxin, some axons develop regenerative inward currents in the internodal membrane permitting continuous (non-saltatory) conduction. In nerves that have remyelinated or regenerated, the number of nodes per unit length of fibre characteristically increases greatly4,5. As the internodal membrane does not normally possess sodium channels1,2, both the earlier appearance of continuous conduction in the demyelinated nerve and the later presence of extra nodes in the remyelinated nerve require either a laying down of new sodium channels or a redistribution of the sodium channels in the original nodes. The present experiments examine the changes in the total number of sodium channels, measured by saxitoxin-binding capacity1, that occur in rabbit sciatic nerves which have been demyelinated in vivo with lysolecithin2,5 and then allowed to remyelinate. The results provide no evidence for the formation of new sodium channels during the early stage, when continuous conduction may develop, but show clearly that new channels are formed during remyelination.
Discovery of a Novel Compound with Anti-Venezuelan Equine Encephalitis Virus Activity That Targets the Nonstructural Protein 2

Alphaviruses present serious health threats as emerging and re-emerging viruses. Venezuelan equine encephalitis virus (VEEV), a New World alphavirus, can cause encephalitis in humans and horses, but there are no therapeutics for treatment. To date, compounds reported as anti-VEEV or anti-alphavirus inhibitors have shown moderate activity. To discover new classes of anti-VEEV inhibitors with novel viral targets, we used a high-throughput screen based on the measurement of cell protection from live VEEV TC-83-induced cytopathic effect to screen a 340,000 compound library. Of those, we identified five novel anti-VEEV compounds and chose a quinazolinone compound, CID15997213 (IC50 = 0.84 µM), for further characterization. The antiviral effect of CID15997213 was alphavirus-specific, inhibiting VEEV and Western equine encephalitis virus, but not Eastern equine encephalitis virus. In vitro assays confirmed inhibition of viral RNA, protein, and progeny synthesis. No antiviral activity was detected against a select group of RNA viruses. We found mutations conferring the resistance to the compound in the N-terminal domain of nsP2 and confirmed the target residues using a reverse genetic approach. Time of addition studies showed that the compound inhibits the middle stage of replication when viral genome replication is most active. In mice, the compound showed complete protection from lethal VEEV disease at 50 mg/kg/day. Collectively, these results reveal a potent anti-VEEV compound that uniquely targets the viral nsP2 N-terminal domain. While the function of nsP2 has yet to be characterized, our studies suggest that the protein might play a critical role in viral replication, and further, may represent an innovative opportunity to develop therapeutic interventions for alphavirus infection.
Pilot-scale operation and economic assessment of a two-stage, straw—manure fermentation system☆

Abstract A two-stage fermentation system was evaluated. The system consisted of a high-rate fermenter (to produce methane from beef-cattle manure) and a low-rate fermenter (to produce methane from straw and slowly degrading material in the effluent from the high-rate fermenter). Three trials were completed. Results from these trials showed that methane yields of 0.25 m3 CH4/kg volatile solids (VS) straw can be achieved in less than 100 days of fermentation at 35°C, and that injection of anhydrous ammonia does not significantly increase the methane yield. Using only the effluent from the straw fermenter as make-up liquid in the system inhibited methane production. This inhibition was attributed to salt accumulation. Based on the assumptions used to design the system (40 Mg total solids (TS) per day) and in the economic analysis, a straw cost of slightly over $15/Mg TS was the break-even cost below which it was economically advantageous to add straw to manure for fermentation to methane. It was economically advantageous to compact the straw to densities between 150 and 300 kg/m3 to reduce the straw fermenter volume and cost. Economies of scale were apparent, especially at the smaller plant sizes. The discounted cash flow rate of return (DCFRR) increased rapidly up to a plant size of about 20 Mg TS/day, then increased linearly as plant size continued to increase. The plant sizes necessary to achieve a DCFRR of 15% were 6.4, 13, and 43 Mg/day for straw costs of $0, $15, and $30/Mg, respectively. Income tax bracket had only minimal effect on the DCFRR.
External Validity of the Personality Assessment Inventory (PAI) in a Clinical Sample

This study contributes to the ongoing construct validation of the personality assessment inventory (PAI; Morey, 1991 , 2007 ) by identifying nontest life-event correlates of the PAI full scales and subscales in a sample of psychiatric patients. The life-event data used in this study included education, marital status, and employment, as well as a history of suicide attempts, psychiatric hospitalizations, trauma, medical problems, hallucinations, paranoid ideation, drug abuse, alcohol abuse, and arrest. Correlations were calculated to explore the convergent and discriminant validity of the PAI scales relative to the life-event data. The results showed that the majority of the PAI scales (11 of 13) had meaningful correlations with at least 1 life-event variable. The PAI BOR scale had the greatest number of correlations and was associated with 8 life-event variables. In contrast, the PAI ANX and MAN scales had no correlations above a predetermined threshold (r ≥ .21). These findings add to the growing body of empirical correlates of the PAI and generally provide support for the construct validity of the PAI scales.
Mapping of hyperelastic deformable templates using the finite element method

In the current work we integrate well established techniques from finite deformation continuum mechanics with concepts from pattern recognition and image processing to develop a new finite element (FE) tool that combines image-based data with mechanics. Results track the deformation of material continua in the presence of unknown forces and/or material properties by using image-based data to provide the additional required information. The deformation field is determined from a variational problem that combines both the mechanics and models of the imaging sensors. A nonlinear FE approach is used to approximate the solution of the coupled problem. Results can be applied to (1) track the motion of deforming material and/or, (2) morphological warping of template images or patterns. 2D example results are provided for problems of the second type. One of the present examples was motivated primarily by a problem in medical imaging--mapping intersubject geometrical differences in human anatomical structures--with specific results given for the mapping 2D slices of the human distal femur based on X-ray computed tomographic images.
Fyke-Net and Gill-Net Size Selectivities for Yellow Perch in Green Bay, Lake Michigan

Abstract We estimated a fyke-net selectivity function for yellow perch Perca flavescens in Green Bay, Lake Michigan, by comparing length-frequency distributions of yellow perch captured in fyke nets with different mesh sizes in 1986. Using a length—girth relationship for Green Bay yellow perch, we expressed selectivity as the ratio of girth (G) to effective mesh perimeter (P), which was 5–7% less than nominal mesh perimeter. Then, fitting an existing gill-net selectivity function to the Green Bay yellow perch fishery, we found fyke-net and gill-net selectivities were similar, with similar G /P ratios, but fyke nets had smaller effective mesh perimeters and thus were more efficient at capturing smaller yellow perch for any given mesh size, The derived fyke-net selectivity function can be used to determine mesh sizes that minimize the sublegal catch of yellow perch in this fishery and could be applied to entrapment gear in other yellow perch fisheries, given data on the length–girth relationships and effect...
When the most “pertinent” document should not be retrieved—An analysis of the Swets model

Abstract Most automated information retrieval systems operate by relating a document to a request by means of a measure of pertinance, and then retrieving the most pertinent documents for their patrons. In this paper the consistency of this operating procedure with the well known Swets Model is examined. It is shown that accepting the assumptions made by Swets would result in the possible rejection of the most pertinent documents in favor of those that are less pertinent. This conclusion is a consequence of the normality assumptions of the model, while other distributions, such as the Poisson distribution, is consistent with the standard procedure. In the course of the development, the fundamentals of decision theory and signal detection theory are reviewed.
Thermodynamic Studies of the Mechanism of Metal Binding to the Escherichia coli Zinc Transporter YiiP

Sequence homology of the Escherichia coli YiiP places it within the family of cation diffusion facilitators, a family of membrane transporters that play a central role in regulating cellular zinc homeostasis. Here we describe the first thermodynamic and mechanistic studies of metal binding to a cation diffusion facilitator. Isothermal titration calorimetric analyses of the purified YiiP and binding competitions among Zn2+, Cd2+, and Hg2+ revealed a mutually competitive binding site common to three metal ions and a set of noncompetitive binding sites, including one Cd2+ site, one Hg2+ site, and at least one Zn2+ site, to which the binding of Zn2+ exhibited partial inhibitions of both Cd2+ and Hg2+ bindings. Lowering the pH from 7.0 to 5.5 inhibited binding of Zn2+ and Cd2+ to the common site. Further, the enthalpy change of the Cd2+ binding to the common site was found to be related linearly to the ionization enthalpy of the pH buffer with a slope corresponding to the release of 1.23 H+ for each Cd2+ binding. These H+ effects are consistent with a coupled deprotonation process upon binding of Zn2+ and Cd2+. Modification of histidine residues by diethyl pyrocarbonate specifically inhibited Zn2+ binding to the common binding site, indicating that the mechanism of binding-deprotonation coupling involves a histidine residue(s).
Jones Fracture Fixation A Biomechanical Comparison of Partially Threaded Screws Versus Tapered Variable Pitch Screws

Background: Stabilization of fifth metatarsal Jones fractures with intramedullary screw fixation is the most common method for surgical fixation when operative treatment is indicated. Conventional partially threaded screws of various diameters are routinely used for Jones fracture fixation. Recently, the use of tapered variable pitch screws has become popular, but information regarding their performance in Jones fracture fixation is limited. No previous studies have compared conventional and tapered variable pitch screws in Jones fracture fixation under physiologic cyclic loading conditions.Purpose: To determine whether biomechanical differences exist between appropriately sized conventional partially threaded screws and tapered variable pitch screws under physiologic cyclic loading conditions with regard to Jones fracture fixation.Study Design: Controlled laboratory study.Methods: Simulated Jones fractures were created in 23 matched pairs of fresh-frozen fifth metatarsals. One bone from each pair was sta...
Renal handling of 2'-deoxyadenosine and adenosine in humans and mice.

In a child lacking adenosine deaminase and in patients treated with deoxycoformycin (a potent inhibitor of the enzyme), apparent renal secretion of 2′-deoxyadenosine (dAdo) and reabsorption of adenosine (Ado) were observed. The renal clearance of dAdo in humans was approximately five-fold that of creatinine, whereas the renal clearance of Ado was only one-fifth that of creatinine. In mice treated with deoxycoformycin, a similar paradigm was observed. Specifically, plasma levels of Ado and dAdo were elevated to detectable levels and apparent renal secretion and reabsorption of these purine nucleosides became manifest. Thus, the mouse may serve as a suitable model to study the renal handling of these two compounds. The active renal secretion of dAdo may occur because the compound has not been appreciably synthesized by mouse kidney in situ, and ‘ion-trapping’ of dAdo in acid urine could not explain the net secretion. The differential transport of these similar purine nucleosides suggests a very selective transport system in mammalian kidney. Although carrier-mediated, facilitated diffusion of purine nucleosides across cell membranes is a well-known phenomenon, the present data indicate the existence of (an) active transport sysem(s) for the transepithelial secretion of dAdo, and possibly for the reabsorption of Ado.
Analytical evaluation and comparison of Dupont aca® lactate dehydrogenase-1 (LD1) isoenzyme assay diagnostic efficiency for acute myocardial infarction detection with other LD1 methods and aca® CK-MB : a two-site study

The purpose of this study was to examine the analytical characteristics of a rapid new assay for lactate dehydrogenase 1 (LD1) isoenzyme on the Dupont aca analyzer and the diagnostic efficiency of LD1 for detection of acute myocardial infarction (AMI) when used alone and with creatine kinase MB (CKMB). Total aca LD1 assay precision, with percent coefficients of variation (%CVs) of less than 3.2% from 56 U/L to 469 U/L LD1, across fifty assay days was excellent. Linearity was confirmed from 0 to 332 U/L and no detectable calibration drift was noted from 5 to 489 U/L over a ninety-day period. The aca LD1 results compared well with Roche Isomune-LD1, Abbott Spectrum A-Gent, Helena electrophoresis, and Beckman electrophoresis LD1 methods, giving r's from 0.987 to 0.994, slopes from 0.94 to 1.65, and y-intercepts from -2.95 to 6.94 U/L. Examination of 450 ambulatory subjects, about equally distributed by sex, yielded a 43 +/- 14 U/L aca LD1 patient reference interval. Serum samples from 159 consecutive patients at the University of Tennessee Memorial Hospital and 96 patients at Allentown Hospital, submitted for AMI detection assistance, were assayed in a single-blind study for LD1 and ion-exchange CKMB by Dupont aca methods, which provide automated results in ten minutes whenever needed. The aca LD1 assay yielded a clinical sensitivity of 89% and specificity of 95% for AMI with a decision threshold of 120 U/L. The diagnostic efficiency of the aca LD1 assay was 94% at 120 U/L, which equaled or exceeded that of the three comparative LD1 methods. The predictive value of positive (PV+) and negative (PV-) results on the first sample collected were 80% and 85% for aca LD1, 65% and 90% for aca ion-exchange CKMB, and 83% and 90% when both tests were combined. Significantly, the PV+ and PV- results when two or more samples were assayed was improved to 88% and 95% for aca LD1, relatively constant at 65% and 97% for aca ion-exchange CKMB, and dramatically improved to 95% and 100% when both CKMB and LD1 tests were combined. The results from these two medical centers show that the aca LD1 assay provides useful clinical information for AMI diagnosis when employed alone or in combination with aca CKMB. These results also suggest that LD1 should be included in biochemical evaluations for AMI to attain optimal predictive values of results.
Tbx1, a DiGeorge syndrome candidate gene, is regulated by sonic hedgehog during pharyngeal arch development

Appropriate interactions between the epithelium and adjacent neural crest-derived mesenchyme are necessary for normal pharyngeal arch development. Disruption of pharyngeal arch development in humans underlies many of the craniofacial defects observed in the 22q11.2 deletion syndrome (del22q11), but the genes responsible remain unknown. Tbx1 is a T-box transcription factor that lies in the 22q11.2 locus. Tbx1 transcripts were found to be localized to the pharyngeal endoderm and the mesodermal core of the pharyngeal arches, but were not present in the neural crest-derived mesenchyme of the pharyngeal arches. Sonic hedgehog (Shh) is also expressed in the pharyngeal arches and is necessary for normal craniofacial development. We found that Tbx1 expression was dependent upon Shh signaling in mouse embryos, consistent with their overlapping expression in the pharyngeal arches. Furthermore, Shh was sufficient to induce Tbx1 expression when misexpressed in selected regions of chick embryos. These studies reveal a Shh-mediated pathway that regulates Tbx1 during pharyngeal arch development.
THE IMPOSSIBILITY OF CONSISTENT DISCRIMINATION BETWEEN I(0) AND I(1) PROCESSES

An I(0) process is commonly defined as a process that satisfies a functional central limit theorem, i.e., whose scaled partial sums converge weakly to a Wiener process, and an I(1) process as a process whose first differences are I(0). This paper establishes that with this definition, it is impossible to consistently discriminate between I(0) and I(1) processes. At the same time, on a more constructive note, there exist consistent unit root tests and also nontrivial inconsistent stationarity tests with correct asymptotic size.
Brain-derived neurotrophic factor expression in the substantia nigra does not change after lesions of dopaminergic neurons.

Progressive and irreversible loss of specific neuronal cell populations is commonly seen in chronic neurodegenerative diseases such as Parkinson s disease (PD). Evidence is accumulating that a poptosis is a crucial cellular event responsible for the dysfunction and death of neurons in this disease. Thus, limiting apoptosis may prevent disease pathogenesis. Key to reducing apoptosis is the discovery of neuroprotective compounds that can be given to patients to minimize neuronal damage. In this manuscript, we reviewed the rationale of using an experimental strategy to provide neurotrophic support to injured neurons. Such rationale includes the increase of endogenous production of brain-derived neurotrophic factor (BDNF). BDNF is a potent inhibitor of apoptosis-mediated cell death and neurotoxin-induced degeneration of dopaminergic neurons. However, availability of BDNF may be reduced when dopaminergic neurons degenerate. Therefore, in this work, we have used two well-established neurotoxins for dopaminergic neurons, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and the HIV protein gp120, to examine whether degenration of nigrostriatal fibers alters BDNF expression. Our data show that these neurotoxins do not decrease the levels of BDNF in the substantia nigra, suggesting that up-regulation of BDNF synthesis by pharmacological means may be a viable therapy to slow down the progress of PD and other neurodegenerative diseases.
Defining the role of the bladder-neck sling in the surgical treatment of urinary incontinence in children with neurogenic incontinence.

Patient selection for the creation of a fascial sling procedure to increase outlet resistance has been somewhat controversial. We review our experience with the fascial sling technique and report our patient selection process. Since 1991, 30 patients, including 6 males and 24 females aged 4–20 years (mean 10 years), underwent a rectus fascial sling procedure as part of their reconstructive efforts for continence. The underlying cause of incontinence was neurogenic in 28 patients. All males were prepubertal. Videourodynamics were performed in all patients preoperatively. Criteria for enhancement of bladder-outlet resistance included a detrusor leak-point pressure (LPPd) of <50 cmH2O; a stress leak-point pressure (LPPs) of <100 cmH2O; an open bladder neck, irrespective of LPP; and clinical evidence of stress incontinence, irrespective of videourodynamic parameters. Technical aspects of the procedure are discussed. Augmentation cystoplasty was performed in 29 patients with poor bladder compliance. In 18 patients a catheterizable stoma was also created. The period of follow-up currently ranges from 2 to 70 (mean 37) months. In all, 28 patients (93%) became continent and 2 female patients remain incontinent with a low LPP. All patients are on clean intermittent catheterization (CIC); 12 patients (40%) are catheterizing per urethra without difficulty. All prepubertal males are completely dry. The fascial sling repair has many advantages over other methods for increasing outlet resistance, including simplicity of technique, effectiveness, minimal likelihood of erosion, and low cost.
Fractional topological insulators in three dimensions.

Topological insulators can be generally defined by a topological field theory with an axion angle $\ensuremath{\theta}$ of 0 or $\ensuremath{\pi}$. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal $T$ invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization ${P}_{3}$, and a ``halved'' fractional quantum Hall effect on the surface with Hall conductance of the form ${\ensuremath{\sigma}}_{H}=\frac{p}{q}\frac{{e}^{2}}{2h}$ with $p$, $q$ odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged ``quarks'' coupled to a deconfined non-Abelian $SU(3)$ ``color'' gauge field, where the fractional charge of the quarks changes the quantization condition of ${P}_{3}$ and allows fractional values consistent with $T$ invariance.
A physics-based gap-flow model for potential flow solvers

Gap/clearance flows (also known as tip gap flows) affect the hydrodynamic forces, flow structure, and cavitation in both turbomachines and hydrofoils. Computational Fluid Dynamics (CFD) solvers permit high-fidelity, viscous simulations of gap-flow, but the computational expense often prohibits their use for fully exploring design spaces. Conventional potential flow solvers, on the other hand, cannot capture the viscosity-dominated gap-flow dynamics. In the present study, a physics-based gap-flow model is presented to capture the critical effects of gap-flow using general potential flow solvers. This is accomplished by re-casting a lift-retention model as a corrected boundary condition. A simple lifting-line formulation is used to demonstrate the applicability of the gap-flow model. Results from the lifting-line analysis, modified by the gap-flow model, are compared with experimental measurements and high-fidelity CFD simulations over a range of gap sizes for two confined-wing arrangements with different geometries and flow conditions. The modified lifting-line analysis improves significantly upon the circulation, downwash, and drag predictions, compared to a standard lifting-line formulation without the gap-flow model. A viscosity-corrected expression for tip-vortex strength is proposed. Using the viscous correction, qualitatively-correct trends are predicted for vortex strength and tip vortex minimum pressure coefficients across a range of foil aspect-ratios, gap sizes, and angles of attack.
The estimation of melanophore responses in a pleuronectid fish

A description is given of a simple method of estimating physiological responses of epidermal and dermal melanophores in a pleuronectid fish.
Understanding Patients' Agendas

Volumes of research support the contention that in most outpatient clinic encounters there are two diagnoses to be made. We know now that the chief complaint is often not the reason for the visit, unless the symptoms are intolerable; rather symptoms and request act together to prompt visits. Symptoms act as cues, but patients initiate visits when they have a request in mind that they think can best be fulfilled by a professional. This is particularly true for the kinds of presenting complaints described as “signal behavior.”
Promoting collaborative interdisciplinary research at the Duke Center for Systems Biology

Systems biology is the science of how interactions between biological components – genes, pathways, cells, and so forth – give rise to complex biological systems. The systems biology approach is an iterative interplay between experimentation and computational analysis that strives to explain the data in terms of these interactions. The comprehensive nature of systems biology requires not only integration of data from a variety of approaches and sources, but also integration of scientists from diverse experimental, computational, and theoretical disciplines. In the Duke Center for Systems Biology (DCSB) we have strived to create an academic culture of free and open discussions across scientific disciplines, which has generated synergy on multiple levels. Beyond the obvious value of collaborations between experimentalists and theorists, the Center has been an incubator for cross-pollination of ideas between experimentalists working on different systems and between modelers approaching problems from different perspectives. Productive interactions have been formed between scientists at all levels of training, from undergraduate students to faculty. These interactions have led to research that never would have occurred without the DCSB. Our goal in this article is to share some insights into the development of a Center, and moreover of a collaborative culture, that continues to stimulate interdisciplinary science.
The effects of supplemental sericea lespedeza pellets in lambs and kids on growth rate

Sericea lespedeza (SL; Lespedeza cuneata), a condensed tannin rich plant, has been used in recent years to aid in the control of gastrointestinal nematodes (GIN) in sheep and goats. Grazing or feeding dried SL leads to a reduction in egg production by GIN and reduces coccidiosis. Growth rates in lambs and kids when fed SL for more than 56 d has not been well characterized. The objective was to determine the effects of feeding SL leaf meal pellets on growth rate in lambs and kids. Lambs or kids weaned between 86 and 108 days of age (day 0) were supplemented with up to 900 g of a control supplement (CO) or SL leaf meal pellets for 56–112 days while grazing grass pastures at the USDA, Agricultural Research Service (ARS) in Booneville, AR or Louisiana State University (LSU), Baton Rouge, LA in 2010 (ARS lambs only), 2011 (lambs only), 2012, and 2013 (kids only). Animals were weighed every 28 days for up to 112 days of supplemental feeding. Data were analyzed using GLM [average daily gain (ADG)], mixed models using repeated measures, or regression. Between days 0 and 56, ADG was greater in 2012 (P=0.01) or tended to be greater in 2010 (P=0.07) in SL than CO lambs at ARS, but lower in SL than CO ARS lambs (P<0.001) and kids in 2012 (P=0.02) and 2013 (P<0.001), and similar in LSU lambs. During the latter growth phase, ADG was reduced in SL compared with CO fed lambs and kids (P<0.01, all), except for LSU lambs in 2011 which were similar between groups. Additional studies are necessary to understand changes in growth rate of SL supplemented lambs and kids. It may be necessary to restrict the period of supplementation to less than 56 days to maximize weight gains in lambs and kids.
Determinants of Laplacians

The determinant of the Laplacian on spinor fields on a Riemann surface is evaluated in terms of the value of the Selberg zeta function at the middle of the critical strip. A key role in deriving this relation is played by the Barnes double gamma function.
Cardiac Arrhythmias During Performance of the Flow-Volume Loop

The purpose of our study was to determine the frequency of cardiac ectopy during the performance of flow-volume loops. The performance of an adequate flow-volume loop entails significant shifts in intrathoracic pressure and oxyhemoglobin saturation that could heighten myocardial arrhythmogenicity and lead to increased cardiac ectopy. Forty-two male patients referred for performance of flow-volume loops were studied with an ambulatory cardiac monitor and an arterial oxyhemoglobin saturation monitor during the performance of three flow-volume loops before and after administration of an aerosolized, selective beta 2-agonist. For comparison, the 60 min prior to and after completion of the loop testing was monitored with the continuous cardiac monitor. The frequency of cardiac ectopy was determined in four patient populations delineated by the presence or absence of cardiac, pulmonary, or cardiopulmonary disease. Each group was further divided based on the occurrence of arterial oxyhemoglobin desaturation during the performance of the flow-volume loop. We found that, despite the presence or absence of underlying cardiopulmonary disease or the occurrence of oxyhemoglobin desaturation during flow-volume loop performance, the number of cardiac ectopies diminished significantly during loop performance when compared with the 60-min study period prior to testing. This is in contrast to what had been reported previously. We conclude that the flow-volume loop is safe to perform in the general population, including those individuals with an increased risk of arrhythmias such as those with cardiac or pulmonary disease.
The elements of electrocardiographic theory

A survey of some of the more important theoretical ideas of electrocardiography is presented for the consumption of the electrical engineer. The development, importance, and objectives of electrocardiography are discussed briefly, followed by a description of the electrical activity of the human heart and the potentials it produces at the surface of the body. Standard connections used in electrocardiography are described. A simplified theory is developed based upon a homogeneous, spherical conducting model containing a current dipole at its center, and the weakness of the assumptions on which it is based is pointed out. The concept and use of the heart vector is treated and methods of portraying heart-vector functions, similar to impedance functions, are illustrated. A limited description is given of the new field of vectorcardiography.
On Wave Equation Vector-Matrices and Their Spurs

If a system of tensor (or spinor) equations may also be written in the matrix form $p\ensuremath{\psi}={\ensuremath{\psi}}^{\ensuremath{'}}$ where the column matrices $\ensuremath{\psi}$ and ${\ensuremath{\psi}}^{\ensuremath{'}}$ undergo the same transformation under a change of coordinates, then the square matrix $P$ is termed a vectrix. General considerations indicate that $P$ should obey invariant matrix identities. Of course, the matrix $P$ merely images an operation implicitly defined in the original system of equations in terms of a set of tensor parameters $p$. A natural method to seek identities is to iterate this operation in the original system with different values ascribed to the parameters. Of especial interest are the vectrices defined by wave equation systems such as those of Dirac and Proca. Here $p$ is to be interpreted as the four-vector of momentum and energy. By carrying out the iteration process, various identities are found. In particular, formulas are obtained for the spur of the product of an arbitrary number of Proca vectrices.
Experiments on sound radiation from a duct with a circumferentially varying liner

The radiation of sound from an asymmetrically lined duct is experimentally studied for various hard-walled standing mode sources. Measurements were made of the directivity of the radiated field and amplitude reflection coefficients in the hard-walled source section. These measurements are compared with baseline hard-wall and uniformly lined duct data. The dependence of these characteristics on mode number and angular location of the source is investigated. A comparison between previous theoretical calculations and the experimentally measured results is made and, in general, good agreement is obtained. For the several cases presented, an asymmetry in the liner impedance distribution was found to produce related asymmetries in the radiated acoustic field. a c / k krn kmn m, n p Pmn r R t x 6 Nomenclature duct radius, m speed of sound, m/s free wavenumber, w/c, m"1 radial wavenumber, m ~ 1 axial wavenumber, k2mn = k2 — ( krn ) 2, m ~ 1 length of lined section, m mode number, (0,0) is plane wave acoustic pressure, N/m2 pressure amplitude, N/m2 radial cylindrical coordinate, m amplitude reflection coefficient, nondimensional time, s axial cylindrical coordinate, m angular cylindrical coordinate, rad $ = phase, deg \l/ — radiation angle, deg w = frequency, rad/s
On the Study of National Character

ON THE STUDY OF NATIONAL CHARACTER By DAVID G. MANDELBAUM IKE other human institutions, scientific meetings serve a variety of func­ tions and the ostensible reason for their existence is not always nor for everyone the prime purpose for attending. But it cannot be gainsaid that ideas may be exchanged, modified, developed at such occasions, especially at so notable an occasion for anthropologists as the International Symposium of 1952 arranged under the auspices of the Wenner-Gren Foundation. This paper is one example of such interchange of ideas. It was the author's assignment to comment at one of the Symposium sessions on the inventory paper written by Dr. Margaret Mead on the subject of national character studies. Much of Mead's survey was found straightway to be useful, stimulat­ ing and unexceptionable. But on three points of practical and theoretical moment, I took exception. They had to do with the relation of national char­ acter studies to applied anthropology, to psychological theory and to sampling techniques and theory. These three matters were discussed by Mead and myself briefly before the relevant session of the Symposium and again at the session. Since they seemed of some importance, I drafted an amplification of my comments at the Sym­ posium and sent it to Mead. Our discussion and correspondence, together with Mead's revision of the wording of several statements in her original paper (1953), clarified my understanding of these statements. This clarification on the subjects of applied anthropology and psychological theory made unnecessary some parts of my previous comment, although other parts' are included here to present certain emphases which I believe are necessary. On the subject of sam­ pling, divergence of opinion apparently still exists and my original observations stand much as first given. Since these three subjects are dealt with in various parts of the inventory paper, interspersed among others, it is well for purposes of clarity to sketch first those aspects of national character studies on which there is agreement and then discuss the three topics on which there has been something less than agreement. I L The people studied in national character analyses are socially demarcated as members of a political grouping, a state or nation. They are thus subject to at least some common institutional influence which justifies the common cultural implications of the term nation, and by any test, a modern state is a real, a viable, social unit, not to say a crucial one at times. People do act as members of a particular nation, not necessarily in the whole round of their lives, not always consistently, but frequently and consistently enough to make
MÖSSBAUER EFFECT STUDIES OF FINE ARTS

In an effort to demonstrate the application of Mossbauer Effect Spectroscopy in the field of Fine Arts, a survey of iron-bearing pigments was undertaken, a back-scattering detector was designed and constructed, and terra-cotta statuary was studied. These results show that there is great potential for classifying artists' pigments that contain iron oxides as an aid to identification, that spectra can be obtained on works of art efficiently and harmlessly, and that certain types of problems can be solved regarding differences in terra-cotta statues.
Etching processes of transparent carbon nanotube thin films using laser technologies

Carbon nanotubes (CNTs) have potential as a transparent conductive material with good mechanical and electrical properties. However, carbon nanotube thin film deposition and etching processes are very difficult to pattern the electrode. In this study, transparent CNT film with a binder is coated on a PET flexible substrate. The transmittance and sheet resistance of carbon nanotube film are 84% and 1000 Ω/□, respectively. The etching process of carbon nanotube film on flexible substrates was investigated using 355 nm and 1064 nm laser sources. Experimental results show that carbon nanotube film can be ablated using laser technology. With the 355 nm UV laser, the minimum etched line width was 20 μm with a low amount of recast material of the ablated sections. The optimal conditions of laser ablation were determined for carbon nanotube film.
The vasorelaxant effects of acetate: Role of adenosine, glycolysis, lyotropism, and pHi and Cai2+

The mechanism of acetate vasorelaxation is unknown. In the rat caudal artery, acetate has a vasorelaxant effect and also increases cyclic AMP. Here we evaluate the role of adenosine, of possible glycolysis inhibition by acetate, of the lyotropic properties of acetate and other anions, and of intracellular calcium and pH. Adenosine per se did not relax the caudal artery in the range of 10(-8) to 10(-2) M. Preincubation with adenosine deaminase (ADA, 5.0 U/ml) or with 8-phenyltheophylline (8-PT, 10(-6) to 10(-4) M) increased, rather than blocked the vasorelaxant effect of acetate. Oxypurinol (10(-3) M) or the nucleoside transport inhibitor NBMPR (10(-4) M) had no effect on acetate relaxation. Whereas acetate increased tissue cyclic AMP content, 10(-3) M adenosine or 10(-6) M PIA had no effect. In strips studied under conditions of inhibited glycolysis (no glucose, with 11 mM 2-deoxyglucose, 1.0 mM pyruvate, and 0.5 mM 5-iodoacetate), acetate-induced relaxation, as well as acetate-induced cyclic AMP generation, tended to be reduced but not significantly so. Other anions relaxed vascular strips in relation to their lyotropic number, but only at higher doses, and they did not stimulate cyclic AMP formation. Acetate (10 mM) caused a transient fall in Ca2+i followed by a slight, sustained rise. A concomitant decrease in pHi was seen. DIDS, which blocks the relaxant and cyclic AMP effects of acetate, had no effect on the pHi decrease, but did decrease the rate of pHi recovery.(ABSTRACT TRUNCATED AT 250 WORDS)
Thermal stresses in an elastic solid weakened by two coplanar circular cracks

Abstract Some linear thermoelastic problems are studied for the thermal stress and displacement fields in an infinite elastic medium weakened by cracks occupying the space interior to two coplanar circular regions with equal radii. The thermal stresses are caused by the uniform heating or heat flow disturbed by the presence of the coplanar cracks. The problem is reduced to the determination of the solution of infinite sets of Fredholm integral equations. Attention is given to the case when the plane occupying the space external to the cracks is insulated from uniform heat flow. The sets of integral equations are solved iteratively by assuming the spacing between the center of the cracks is large as compared to the radii. Physical quantity of interest such as crack-opening displacement is investigated.
Argentation Thin-Layer Chromatography of the p-Nitrobenzyl Esters of Gibberellins and Their Precursors

Abstract Thirteen p-nitrobenzyl esters of gibberellins and their precursors have been separated by thin-layer chromatography on silver nitrate-impregnated silica gel. The fluorescence produced by sulfuric acid was used for their detection.
A micromechanical hyperelastic modeling of brain white matter under large deformation

A finite element based micromechanical model has been developed for analyzing and characterizing the microstructural as well as homogenized mechanical response of brain tissue under large deformation. The model takes well-organized soft tissue as a fiber-reinforced composite with nonlinear and anisotropic behavior assumption for the fiber as well as the matrix of composite matter. The procedure provides a link between the macroscopic scale and microscopic scale as brain tissue undergoes deformation. It can be used to better understand how macroscopic stresses are transferred to the microstructure or cellular structure of the brain. A repeating unit cell (RUC) is created to stand as a representative volume element (RVE) of the hyperelastic material with known properties of the constituents. The model imposes periodicity constraints on the RUC. The RUC is loaded kinematically by imposing displacements on it to create the appropriate normal and shear stresses. The homogenized response of the composite, the average stresses carried within each of the constituents, and the maximum local stresses are all obtained. For each of the normal and shear loading scenarios, the impact of geometrical variables such as the axonal fiber volume fraction and undulation of the axons are evaluated. It was found that axon undulation has significant impact on the stiffness and on how stresses were distributed between the axon and the matrix. As axon undulation increased, the maximum stress and stress in the matrix increased while the stress in the axons decreased. The axon volume fraction was found to have an impact on the tissue stiffness as higher axon volume fractions lead to higher stresses both in the composite and in the constituents. The direction of loading clearly has a large impact on how stresses are distributed amongst the constituents. This micromechanics tool provides the detailed micromechanics stresses and deformations, as well as the average homogenized behavior of the RUC, which can be efficiently used in mechanical characterization of brain tissue.
MOTION OF AND MASS TRANSFER FROM AN ASSEMBLAGE OF SOLID SPHERES MOVING IN A NON-NEWTONIAN FLUID AT HIGH REYNOLDS NUMBERS

Abstract An approximate solution for the motion of an assemblage of solid spheres moving in a power-law fluid in the high Reynolds number region is obtained using a combination of Happel's free-surface cell model and the boundary layer theory. It is theoretically predicted that the drag coefficient will decrease with the increase of the shear-thinning anomaly. The results of the present analysis are in reasonably good agreement with the available experimental data for fixed and fluidized beds. The influence of the non-Newtonian behavior on the mass transfer rate from an assemblage of solid spheres is also discussed.
CONTIGUOUS APPROACH CONDITIONING: A MODEL FOR SIDMAN AVOIDANCE LEARNING

The study sought to extend M. R. Denny's contiguous approach conditioning model of instrumental reinforcement effects to account for Sidman avoidance conditioning. Experimental subjects (rats) received a 15-sec. duration light which was paired, independently of the subject's behavior, with the nonoccurrence of regularly scheduled 1-ma. shocks. Controls received light and shock unpaired. All subjects were then tested in a simple T-maze for approach to the light. Groups did not differ significantly in the direction of their initial response (approach or nonapproach to the light) but did differ in latency of approach to the light. Further, a significantly higher proportion of experimental subjects than control subjects approached the light within the 15 sec. that had been the “safety” period during pairing. While these findings are largely consistent with Denny's theory, they might also be taken to support expectancy or informational interpretations of Sidman avoidance.
927 A phase I and bioavailability study of oral topotecan

Topotecan (T) is an inhibitor of topoisomerase I undergoing clinical development. The oral bioavailability (F) of T in dogs is 36%, however, bioequivalent toxicity is closer to 100%. The objectives of this study were to determine the MTD (part 1) and absolute F (part 2) of T. All patients (pts) fasted 4 hours prior to and 2 hours after treatment with oralT Pharmacokinetic analysis was performed by HPLC. In part 1, 12 pts (median age 63, median PS 1, 6 M/6 F) received a total of 51 courses of therapy. The initial starting dose of 17.5 mg/m 2 was well tolerated IV but was accompanied by grade 4 neutropenia and thrombocytopenia when given orally. The oral dose was reduced to 14.0 mg/m 2 where 1/6 patients developed grade 4 neutropenia. Non-hematologic toxicities were mild ( 2 oral T on cycle 1 and 17.5 mg/m 2 IV on cycle 2 or visa versa. T demonstrated 44% F with rapid oral absorption (peak 0.74 hr) and peak lactone cone. (50 ± 22) 10 × less than IV (493 ± 221 ng/ml). There was no difference in clearance or Vdss. The AUC achieved PO (275 ± 113) is 2.8 × lower than IV (776 ± 167 ngxhr/ml). APR in a pt with H&N cancer and a MR in a pt with melanoma were observed. Even with lower peak cone and AUC's, oral T maintains it's biologic activity.