cssi/SciSciGPT-SciSciNet huggingface dataset:
In Situ Electrode Formation in a Swiss Roll Reactor

The Swiss roll electrochemical reactor design, which is comprised of concentric spiral electrode coils, has a superior electrode packing density and reaction capacity in comparison with more conventional designs. Because platinized-titanium surfaces are mechanically unstable at low platinum loadings, use of the Swiss roll design with such electrodes requires in situ electrodeposition of platinum onto the titanium surfaces after fabrication. Methodology is described to examine the resultant Pt distribution across the width and along the length of expanded Ti mesh after in situ electrodeposition. Four major control variables, i.e., total electroplating charge, plating current density, number of pulses used to deliver the charge, and first coil to receive a current pulse, explain 86% of the experimental variance in a linear effects model. Resulting Pt distribution, when normalized for the extent of platinization, is surprisingly uniform on the entire extent of the electrode coils. The major discrepancies from uniform deposition occurred on the Ti electrode coil which acted as the counter electrode during the first electrodeposition, indicating a surface modification which affects the electrodeposition process.
An Improved Design Method for Automotive Powertrain Rubber Mounts

The objective of the powertrain mount design is to find the geometry which meets the desired stiffness and damping requirements. For the conventional rubber mount, which is composed of a rubber element bonded into a metal bracket, its stiffness can be predicted using FEA but the damping is evaluated by physical testing. This paper introduces a design method at which the damping coefficient of the rubber mount is to be predicted theoretically based on the assumption that the phase angle for a rubber compound is constant. Absence of physical test in this proposed new design process, the development time from concept to production is reduced.
2D groundwater contaminant transport modeling by using the finite volume method on an unstructured grid system

This paper introduces a finite volume unstructured algorithm for groundwater contaminant simulation. The algorithm is developed using the direct finite volume concept constructed on an unstructured grid system. The cell-centered explicit conservative scheme has been adopted in numerical simulation. An example of groundwater contaminant transport simulation on a simple geometry is presented and results are compared with an analytic solution and the solutions obtained by using a finite difference method on structured grids. The direct finite volume method applied on an arbitrary unstructured grid system is found promising for modeling groundwater contamination transport behavior.
The Accuracy of DNA Sequences: Estimating Sequence Quality

In this paper we describe a method for the statistical reconstruction of a large DNA sequence from a set of sequenced fragments. We assume that the fragments have been assembled and address the problem of determining the degree to which the reconstructed sequence is free from errors, i.e., its accuracy. A consensus distribution is derived from the assembled fragment configuration based upon the rates of sequencing errors in the individual fragments. The consensus distribution can be used to find a minimally redundant consensus sequence that meets a prespecified confidence level, either base by base or across any region of the sequence. A likelihood-based procedure for the estimation of the sequencing error rates, which utilizes an iterative EM algorithm, is described. Prior knowledge of the error rates is easily incorporated into the estimation procedure. The methods are applied to a set of assembled sequence fragments from the human G6PD locus. We close the paper with a brief discussion of the relevance and practical implications of this work.
Giant hamartoma of the ascending colon in an adult with ulcerative colitis

We report an unusual case of giant colonic hamartoma in a 50-yr-old man with ulcerative colitis. The clinical, endoscopic, and histological aspects of this case are discussed. In addition, the possible pathogenesis of colonic hamartoma is reviewed and related to our patient with ulcerative colitis.
Implementation and Evaluation of Self-Financing Highway Pricing Schemes: A Case Study

With the current and projected shortfalls in revenue vis-a-vis increasing needs, many transportation agencies are increasingly seeking alternative funding sources to supplement income from the motor fuel tax. One promising alternative, the fee for vehicle miles traveled (VMT), entails payment by drivers on the basis of their actual share of facility usage. This paper uses economic theory and travel demand and highway expenditure data from the State of Indiana as a basis to establish efficient VMT fee rates under various expenditure and funding scenarios. The authors have found that a VMT fee of 2.9 cents per mile, plus federal aid, would cover current expenditures for state-administered highways in the absence of any other revenue source, and that a fee of 2.2 cents per mile would be sufficient if revenue from vehicle registration was maintained. To cover the expenditures supported only by state-generated funds, the fee would be 1.3 cents per mile with vehicle registration revenues and 2.0 cents per mile without. This paper also establishes equitable fee structures that ensure self-finance of each facility class, as well as an alternative uniform-rate fee structure that entails cross-subsidy across facility classes. For the latter, it was found that the urban highway system would subsidize the rural system, the rural Interstate system would subsidize the rural non-Interstate system, and the urban non-Interstate system would subsidize the urban Interstate system. Different VMT fee structures could be established on the basis of desired levels of equity across the facility or user classes and of the technical feasibility of the implementation of VMT fees.
The dynamic response of isolated polybutadiene chains undergoing thermal retraction from extended conformations

All-atom molecular dynamic simulations were performed on isolated polybutadiene chains to study the retraction velocity of a free end of an idealized network chain from extended conformations due to thermal collisions. We compare the snap-back velocity calculated from these simulations with experimental measurements on bulk rubber samples. Over a range of chain lengths, extension ratios and temperatures, we find that the average retraction velocity of a free end seen in the simulations is about two orders of magnitude less than the experimental value.
Prescription of teratogenic medications in United States ambulatory practices

Abstract Purpose The purpose of this study was to identify the potentially teratogenic medications most frequently prescribed to women of childbearing age and the specialty of physicians who provide ambulatory care to women who use such medications. In addition, we evaluated rates of contraceptive counseling to explore awareness of the risks associated with teratogenic medication use. Subjects and methods The prescription of teratogenic medications and provision of contraceptive counseling on 12 681 visits made by nonpregnant women, 14 to 44 years of age, to 1880 physicians in US ambulatory practice (National Ambulatory Medical Care Survey) between 1998 and 2000 was analyzed. Results Use of a potentially teratogenic, class D or X, medication by a woman of childbearing age is documented on 1 of every 13 visits made to US ambulatory practices. These include anxiolytics (4.1 million annual prescriptions), anticonvulsant medications (1.4 million annual prescriptions), antibiotics like doxycycline (1.4 million annual prescriptions), and statins (0.8 million annual prescriptions). Isotretinoin accounts for less than 5% of potentially teratogenic prescriptions (0.5 million annual prescriptions). Internists and family/general practitioners provide ambulatory care to 45% of women prescribed potentially teratogenic medications, psychiatrists provide ambulatory care to 20% of women prescribed potentially teratogenic medications, and dermatologists provide ambulatory care to 20% of women prescribed potentially teratogenic medications. Contraceptive counseling was provided on less than 20% of visits that documented use of a potential teratogen by a woman of childbearing age. Women using low-risk (class A or B) drugs received contraceptive counseling as frequently as women using potential teratogens ( P = .24). Conclusion Potentially teratogenic medications are prescribed to millions of women of childbearing age each year. Physician awareness of the teratogenic risk associated with class D or X medications seems low.
Comparison of unilateral and bilateral complex finger tapping‐related activation in premotor and primary motor cortex

Sixteen healthy right-handed subjects performed a complex finger-tapping task that broadly activates the motor and premotor regions, including primary motor (M1), ventral premotor (PMv), and dorsal premotor (PMd) cortex. This task was performed with the right hand only, left hand only and both hands simultaneously. Behavioral performance and the possibility of mirror movements were controlled through the use of MRI-compatible gloves to monitor finger movements. Using spatially normalized ROIs from the Human Motor Area Template (HMAT), comparisons were made of the spatial extent and location of activation in the left and right motor regions between all three tasks. During unilateral right and left hand tapping, ipsilateral precentral gyrus activation occurred in all subjects, mainly in the PMv and PMd. Ipsilateral M1 activation was less consistent and shifted anteriorly within M1, towards the border of M1 and premotor cortex. Regions of ipsilateral activation were also activated during contralateral and bilateral tasks. Overall, 83%/70%/58% of the ipsilaterally activated voxels in M1/PMd/PMv were also activated during contralateral and bilateral tapping. The mean percent signal change of spatially overlapping activated voxels was similar in PMv and PMd between all three tasks. However, the mean percent signal change of spatially overlapping M1 activation was significantly less during ipsilateral tapping compared with contra- or bilateral tapping. Results suggest that the ipsilateral fMRI activation in unilateral motor tasks may not be inhibitory in nature, but rather may reflect part of a bilateral network involved in the planning and/or execution of tapping in the ipsilateral hand.
Thermodynamic optimization of conduction-cooled HTS current leads

A theoretical optimization is performed for the conduction-cooling method of high Tc superconductor (HTS) current leads, which can be applied to the superconducting systems cooled directly by cryogenic refrigerators without liquid helium. The current lead is a series combination of a normal metal conductor at the warmer part and a HTS at the colder part, and is cooled by a contact with distributed or staged refrigerators instead of boil-off helium gas. An analytical method is developed to derive a mathematical expression for the required refrigerator power. By incorporating the critical characteristics of the HTS, it is demonstrated that there exist unique optimal values for the current density of HTS and the joint temperature of the two parts to minimize the total refrigerator power per unit current, for a given length of the HTS. As results of the study, the absolute minimum in the refrigerator power per unit current is presented as a thermodynamic limit and the leads cooled by a two-stage refrigerator are theoretically optimized. Some aspects in practical design are also discussed with a new and useful graphical method.
Mean-field simulation of field-induced domains and hysteretic behavior in dilute Ising antiferromagnets

A mean-field free-energy surface of a dilute Ising antiferromagnet on two-, three-, and four-dimensional lattices is studied numerically as a function of temperature and an applied magnetic field. In the presence of the field parallel to spins, the dilute Ising antiferromagnet is believed to map onto the random-field Ising model providing a convenient experimental realization. From the hysteretic behavior we identify three temperature regions: (1) a high-temperature equilibrium region above the hysteresis boundary ${T}_{H}$ where an accessed state is independent of the sample history; (2) a low-temperature region below ${T}_{c}$ where the antiferromagnetic state has the lowest free energy; (3) an intermediate-temperature region ${T}_{c}lTl{T}_{H}$ where the accessed state depends on the sample history, but the domain state has a lower free energy than the antiferromagnetic state. When the sample is cooled in a finite field, the domains are formed and stabilized below ${T}_{H}$. Thus the antiferromagnetic state is inaccessible in our simulation. In contrast, once the antiferromagnetic order is prepared at low temperatures and the temperature is raised in the finite field, the sample remains in the antiferromagnetic state until ${T}_{c}$ and then the domains nucleate above ${T}_{c}$, and finally the sample recovers the high-temperature equilibrium state at ${T}_{H}$. In recent neutron scattering experiments on three-dimensional (3D) Ising antiferromagnets, the analogous behavior is observed. Using the simulation results, we argue that strong domain-wall pinning prevents long-range order from occurring in 3D samples when cooled with $H\ensuremath{\ne}0$, despite the theoretical consensus that the lower critical dimension in equilibrium is 2 for the random-field Ising model.
Decision processes during sentence comprehension: Effects of surf ace structure on decision times

Sentence comprehension is considered to be a set of decisions concerning the identification of entities at the various linguistic “levels.” Such decisions utilize overlapping fixed capacity psychological mechanisms. To the extent that one decision is difficult, others should take longer. This framework received support in two studies in which Ss’ reaction times (RT) to the presence of a phoneme in a sentence were measured. When surface structure syntax was difficult, as in self-embedded sentences, RT was longer (given that S comprehended the sentence) than when surface structure syntax was relatively easy. Additionally, the presence in surface structure of a putative cue for underlying structure did not affect RT, though comprehension was significantly inferior.
The alloying study of CeAl3

Abstract We have studied low temperature properties of CeAl3 as a function of both negative (La) and positive (Y) chemical lattice pressure. The changes of the lattice constants due to positive chemical pressure are strongly anisotropic and similar to those caused by the application of hydrostatic pressure. We have shown that the evolution of the low temperature anomaly cannot be explained by the changes of lattice constants nor by atomic disorder alone. We have suggested a new non-Fermi liquid tuning mechanism.
An experimental test of a stochastic model of intrapersonal conflict in a two-person situation

Abstract This paper describes a stochastic model for a type of intrapersonal conflict that arises in two-person interactions when an individual's perceived goal-approach response is incompatible with a compliant response to another person's influence attempt. The conflict model is an extension of a class of learning models for the response continuum. Results from a two-person laboratory experiment show that with one interactive reinforcement schedule (termed “convergent”) influence communication between close friends results in a lower frequency of correct outcomes for such pairs than does influence communication between strangers; the reverse occurs with a second interactive schedule (termed “divergent”). These and other findings are interpreted in terms of certain parameters of the conflict model that are assumed to be related to the existing social relationship. Also examined are the functions relating a subject's change in response from Trial n to n + 1 to (i) the distance to his goal on Trial n, and (ii) his partner's influence attempt on Trial n. With one exception, the observed functions are in accord with the model.
Research on the Recognition Technology of Letter String on Label

A letters recognition method based on a small area of the feature matching is proposed, in which the unqualified letter in the string were recognized based on its geometric feature. In this method, firstly confirm label’s position by the extracted straight line characters. Then, rotate and zoom image according to the prior knowledge of label. Acquire the position of the string on the label and cut them out. And then single letters are segmented out using the projection method in the area of the string. Finally, compare geometrical characteristics of the extracted letters with its template to recognize and eliminate unqualified labels. The matching process proceeded only in the small region with letters and there is no need to search the irrelevant information. For this algorithm, so much time has been saved compared with traditional letter recognition method and projection method which is used for single character segmentation is very quick also. Theory analysis and experiment showed that the method can segment unqualified characters robustly and quickly.
The Effect of SFAS 142 on the Ability of Goodwill to Predict Future Cash Flow

This study examines the effect of Statement of Financial Accounting Standards No.142 (SFAS 142) on the ability of goodwill to predict future cash flows. SFAS 142 allows substantial managerial discretion and leads to a significant magnitude of economic impact on financial statements, resulting in critical debates over the consequence of its adoption. I find that the ability of goodwill to predict future cash flows has improved since the Financial Accounting Standards Board (FASB) adopted SFAS 142. Furthermore, sub-sample analyses fail to reveal compelling evidence that reporting discretion induced by SFAS 142 is used opportunistically or informatively, contrasting with the pervasive view based on the opportunistic reporting hypothesis. Overall, contrary to the position of critics of SFAS 142, the results support the view taken by the FASB and proponents of SFAS 142: eliminating systematic amortization and adopting fair value estimates improve representational faithfulness of goodwill reporting.
13C NMR spectral studies of some methoxycoumarin derivatives. A re‐assignment for citropten (limettin) and an examination of Peri‐proximity effects for the methyl‐methoxy and methoxy‐methyl couples

The 13C chemical shifts and 13C1H coupling constants of some methoxycoumarins are reported. Some earlier spectral assignments, including those for citropten (limettin), require revision. Methoxy substituent effects on longrange 13C1H couplings in coumarins are highlighted. Peri-proximity effects for the methyl-methoxy and methoxy-methyl couples are derived, and the value of these effects in the assignment of peri-substituted compounds is illustrated.
The expected dimension of a sum of vector subspaces

Let W be an n −dimensional vector space over a field F . It is shown that the expected dimension of a vector subspace of W is n /2. If F is infinite, the expected dimension of a sum of a pair of subspaces of W is ( n + 1)/2 if n > 1; and 3/4 if n = 1. If F is finite, with q elements, the expected dimension of a sum of subspaces of W depends on q and n . For fixed n , the limiting value of this expectation as q → ∞ is n if n is even; and n − 1/4 if n is odd. Moreover, if F is finite and n > 1, the expected dimension of a sum of three (not necessarily distinct) subspaces of W has limit n as q → ∞.
Phase-flip bifurcation in a coupled Josephson junction neuron system

Abstract Aiming to understand group behaviors and dynamics of neural networks, we have previously proposed the Josephson junction neuron (JJ neuron) as a fast analog model that mimics a biological neuron using superconducting Josephson junctions. In this study, we further analyze the dynamics of the JJ neuron numerically by coupling one JJ neuron to another. In this coupled system we observe a phase-flip bifurcation, where the neurons synchronize out-of-phase at weak coupling and in-phase at strong coupling. We verify this by simulation of the circuit equations and construct a bifurcation diagram for varying coupling strength using the phase response curve and spike phase difference map. The phase-flip bifurcation could be observed experimentally using standard digital superconducting circuitry.
Bias in Counselor Hypothesis Testing: Testing the Robustness of Counselor Confirmatory Bias

Explored the issue of confirmatory bias in counselors' clinical hypothesis testing. Recent research suggests that counselors are subject to a confirmatory bias when using information to test a client hypothesis. The current research tested the robustness of this finding by adding realism and accountability to the experimental situation. Two experiments examined the facts that experienced counselors recalled (a) about a coached client in a naturalistic situation, and (b) when they selected information from a client narrative when told that they would later be held accountable for their selection. In Experiment I, experienced counselors recalled more confirmatory than disconfirmatory information from a coached client's live presentation of factors. In Experiment 2, counselors-in-training selected more confirmatoty than disconfirmatory information from a case history despite the accountability implied by the experimental instructions. The authors concluded (a) that the confirmatory bias is a robust one that may be a natural part of any judgment situation and (b) that counselor education should explicitly train counselors to avoid this confirmatory bias.
Synthesis of organically templated nanoporous Tin(II/IV) phosphate for radionuclide and metal sequestration.

Nanoporous tin (II/IV) phosphate materials, with spherical morphology, have been synthesized using cetyltrimethylammonium chloride (CH3(CH2)15N(CH3)3Cl) as the surfactant. The structure of the material is stable at 500°C; however, partial oxidation of the material occurs with redox conversion of Sn2+ to Sn4+, resulting in a mixed Sn(II)/ Sn(IV) material. Preliminary batch contact studies were conducted to assess the effectiveness of nanoporous tin phosphate, NP-SnPO, in sequestering redox sensitive metals and radionuclides, technetium(VII), neptunium(V), thorium(IV), and a toxic metal, chromium(VI), from aqueous matrices. Results indicate tin (II) phosphate removed > 95% of all contaminants investigated from solution.
The Roles of Context and Word Morphology in Learning New Kanji Words

This study explores quantitative and qualitative differences between context and word morphology as determinants of students' guesses of the meanings of novel kanji compounds (i.e., words consisting of two or more Chinese characters). In this study, 74 Japanese language learners interpreted unknown compounds consisting of familiar characters under three conditions (i.e., words in isolation, contextual clues only, and both). When the students' guesses were compared against the actual meanings, context and word morphology were equally effective. However, the combined effect of both sources was the best, suggesting that the 2 sources provide information that does not overlap. Students expressed higher confidence in their context-based guesses than in their words-in-isolation guesses. Furthermore, contextual clues generated more syntactically related guesses than did kanji clues, whereas kanji clues yielded more semantically related guesses than did context. In general, the strength of contextual support and morphological transparency worked additively when combined but sometimes affected each other negatively. These findings suggest that context and word morphology play different roles in word inference.
Regulatory perspectives and research activities at the FDA on the use of phantoms with in vivo diagnostic devices

For a number of years, phantoms have been used to optimize device parameters and validate performance in the primary medical imaging modalities (CT, MRI, PET/SPECT, ultrasound). Furthermore, the FDA under the Mammography Quality Standards Act (MQSA) requires image quality evaluation of mammography systems using FDA-approved phantoms. The oldest quantitative optical diagnostic technology, pulse oximetry, also benefits from the use of active phantoms known as patient simulators to validate certain performance characteristics under different clinically-relevant conditions. As such, guidance provided by the FDA to its staff and to industry on the contents of pre-market notification and approval submissions includes suggestions on how to incorporate the appropriate phantoms in establishing device effectiveness. Research at the FDA supports regulatory statements on the use of phantoms by investigating how phantoms can be designed, characterized, and utilized to determine critical device performance characteristics. These examples provide a model for how novel techniques in the rapidly growing field of optical diagnostics can use phantoms during pre- and post-market regulatory testing.
Steady-state photomodulation mechanisms in CdSxe1−x doped glass

Abstract We compare low-power steady-state photoinduced transmission modulation, photoluminescence and electromodulation measurements on a series of glasses with well-characterized CdS x Se 1− x crystalline inclusions. We propose that the photomodulation effect is dominated by coulombic interaction of trapped carriers with the lowest lying quantized exciton state for small ( A ) particles. We also propose that a combination of state-filling and coulombic interaction is responsible for the observed photomodulation effect in larger (≈100 A ) crystallites.
Petroleum Geology Of Baltimore Canyon Trough

Significant shows of natural gas have been reported from 3 out of 14 completed wildcat wells. The combined initial flow rates were about 2 million m/sup 3/ per day (68.5 million ft/sup 3/ per day) from Upper Jurassic sandstone beds at depths of about 4000 m. In the Baltimore Canyon trough, analysis indicates that shelf sediments have a relatively low potential for the generation of liquid hydrocarbons, but indications are favorable that natural gas could have been generated below a depth of 3000 m. However, sandstone porosities deteriorate below 3000 m, and at these depths, the Jurassic sandstone beds may lack lateral continuity. 28 refs.
Low-temperature ion exchange of dried gels for potential waveguide fabrication in glasses

Dried sol-gel silicate materials containing metal ions (2Th02-2M20-96Si02; where M = Na, K, or Cs) were ion-exchanged at 25 °C in selected regions using microelectronic masking methods and ionic solutions. After heat densification, the compositions and properties of the exchanged and unexchanged regions of the gel were investigated by microscopy, SEM-EDAX, and micro- Raman spectroscopy. Comparison of the spectra with those of melt-quench glasses of the same stoichiometries, exchanged identically, shows the effectiveness of the gel exchange.
Obesity, regardless of comorbidity, influences outcomes after colorectal surgery-time to rethink the pay-for-performance metrics?

An elevated body mass index (BMI) is associated with increased morbidity and mortality after colorectal surgery. While coexistent comorbid conditions are captured in some determinations of case-severity, BMI itself is not factored into pay for performance (P4P) initiatives. From the National Surgical Quality Improvement Program database 2006–2011, obese (BMI ≥30 kg/m2) and nonobese (BMI <30 kg/m2) patients with and without comorbidity undergoing colorectal resection were identified. Pre- and intraoperative factors as well as postoperative outcomes were compared. Of 130,415 patients, 31.3 % were obese. 80.4 % of obese and 72.9 % of nonobese patients had comorbid conditions. Among obese patients, overall rates of surgical site infection (SSI), wound dehiscence, and various medical complications were significantly higher for those with comorbidity compared to those without (p < 0.001 for all). Obese patients with comorbidity overall had greater risk of renal failure and urinary tract infection than nonobese patients. Regardless of comorbidity, obese patients more commonly had pulmonary embolism, failure to wean from the ventilator, overall SSI, and wound dehiscence. Comorbid factors associated with obesity influence outcomes; however, obesity itself in their absence is associated with worse outcomes. This supports inclusion of obesity as an independent determinant of case-severity, quality, and reimbursement after colorectal surgery.
Robust amplification in adaptive signal transduction networks

Abstract Amplification of small changes in input signals is an essential feature of many biological signal transduction systems. An important problem is how sensitivity amplification can be reconciled with wide dynamic range of response. Here a general molecular mechanism is proposed, in which both high amplification and wide dynamic range of a sensory system is obtained, and this without fine-tuning of biochemical parameters. The amplification mechanism is based on inhibition of the enzymatic activity of the sensory complex. As an example, we show how this ‘inhibition-driven amplification’ mechanism might function in the bacterial chemotaxis network, where it could explain several intriguing experimental observations connected with the existence of high gain, wide dynamic range and robust adaptation.
Laser induced breakdown spectroscopy for in situ heavy metal analysis of ocean sediments

Highly contaminated sediments exist in harbors and coastal environments due to shipping, poor management of waste, and anthropogenic inputs. Contaminated sediment is detrimental to fisheries, shell fishing, benthic communities, and human health. Measurement of heavy metals in sediments is of interest for identifying areas with elevated levels that should be targeted for remediation and for monitoring levels during and after remediation efforts. Developing in situ sensors capable of measuring heavy metals in sediments would enable rapid analysis and large spatial observations. Here we investigate the use of Laser induced-breakdown spectroscopy (LIBS), a type of atomic emission spectroscopy that can be used for elemental analysis of samples, for heavy metal analysis of sediments. We present our laboratory-based investigation that to date has demonstrated the ability of LIBS to measure cadmium, nickel, zinc, lead, and copper and to measure zinc underwater.
Studies on the conformations and interactions of elastin. Proton magnetic resonance of the repeating tetramer

Proton magnetic resonance studies at 220 MHz were carried out on synthetic polymers of the repeating tetrapeptide of elastin. Temperature dependence and solvent-mixture dependence of peptide proton chemical shifts were determined for both linear polymers, N-formyl-(Val-Pro-Gly1-Gly2)n-Val OMe where n ≃ 8 and 40, and for cyclic polymers (Val-Pro-Gly1-Gly2)n, where n = 3 and 4. The Gly2 NH was found to be solvent shielded. In addition, by studying the polymers Boc-Val-Pro-Gly1-Gly2-OH, H-Pro-Gly1-Gly2-Val OMe, H(Pro-Gly1-Gly2-Val)3OH, and others, it was demonstrated that the Val C–O immediately preceding the Gly2 NH in the sequence was required for solvent shielding. Also the Gly2 NH resonance is found at higher field than the Gly1 NH resonance. This provides the basis for proposing a β turn in which the Pro and Gly1 residues form the corners, i.e., residues i + 1 and i + 2, and in which the Gly2 NH, residue i + 3 hydrogen bonds to the carbonyl of residue i, the Val residue. Studies on methanol–water solvent systems indicated retention of the β turn as a significant conformational feature. This suggests that the β turn occurs in the elastic fiber, which contains about 60% water but which utilizes association of hydrophobic groups as a primary force in fibrogenesis.
Assessment of oxidative stress due to exposure to pesticides in plasma and urine of traditional limited-resource farm workers: formation of the DNA-adduct 8-hydroxy-2-deoxy-guanosine (8-OHdG).

The objective of this study was to assess the risk of genotoxicity caused due to oxidative stress using plasma and urinary levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) in farm workers for six months during a growing season. Blood and urine samples were collected once a month for six months (June to November 2003) from farm workers (n = 15) and urban unexposed controls (n = 10). Plasma and urinary levels of 8-OHdG were evaluated by Enzyme Linked Immunosorbent Assay (ELISA) technique. There was no significant difference in the urinary levels of 8-OHdG between the farm workers and the control group, but there was an approximately four-fold increase in mean values of plasma 8-OHdG levels in the farm worker group (P ≤ 0.05).
Pediatric demyelinating diseases.

Purpose of ReviewIn the past decade, the number of studies related to demyelinating diseases in children has exponentially increased. Demyelinating disease in children may be monophasic or chronic. Typical monophasic disorders in children are acute disseminated encephalomyelitis and clinically isola
Effect of stem cell factor (c-kit ligand), granulocyte-macrophage colony stimulating factor and interleukin 3 on hematopoietic progenitors in human long-term bone marrow cultures

In this paper we attempt to improve upon the methods of hematopoietic stem cell expansion. We evaluate the effects of recombinant human stem cell factor (SCF or c-kit ligand) alone and also in combination with recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3), on cell proliferation and differentiation in human long term bone marrow cultures (LTBMC). Weekly addition of 5 ng/ml of SCF with 25% serum containing media resulted in increased recovery of total nonadherent cells, granulocyte-macrophage colony forming units (CFU-GM), and burst-forming units erythroid (BFU-E) at week 1, but the number of bone marrow (BM) progenitor cells fell below the level of untreated control cultures at weeks 3 (BFU-E) and 4 (CFU-GM). At week 8, when the cultures were terminated, the CFU-GM recovery was markedly reduced in flasks supplemented with SCF compared with the controls (p < 0.002). Moreover, SCF treatment induced the early disappearance of BFU-E. When LTBMC were supplemented with the combination of SCF plus GM-CSF (100 U/ml) and IL-3 (5 ng/ml), synergistic activity of the CSFs was observed at week 1. The number of BM colony forming cells (CFC) rapidly declined below the level of growth factor-free controls, leading to the early exhaustion of the culture when SCF was combined with GM-CSF. By comparison, GM-CSF and IL-3 alone induced a statistically significant increase above the controls (no growth factor) in the number of nonadherent cell colonies of CFU-GM and BFU-E. Analysis of adherent layer cells from cultures supplemented with SCF showed increased cellularity, no adipogenesis, and early disappearance of myeloid progenitors while the percentage of CFU-GM in S phase, assessed by cytosine arabinoside (Ara-C) suicide assay, was 9.2 +/- 5% SD versus 27.7 +/- 10% SD in control (no growth factor) samples (p < 0.01). SCF increased the number of fibroblast colony forming units (CFU-F) and also showed a synergistic activity (9.6-fold increase) when combined with IL-3. These findings suggest that SCF, GM-CSF and IL-3 exert their activity on different cell populations within the hematopoietic system. Further investigations are needed to optimize the use of SCF in supporting hematopoiesis.
Atrazine, Deethylatrazine, and Deisopropylatrazine Persistence Measured in Groundwater in Situ under Low-Oxygen Conditions.

The degradation of atrazine [2-chloro-4-(ethylamino)-6-isopropylamino-1,3,5-triazine], deethylatrazine [DEA; 2-amino-4-chloro-6-(isopropylamino)-1,3,5-triazine], and deisopropylatrazine [DIA; 2-amino-4-chloro-6-(ethylamino)-1,3,5-triazine] was assessed under limited oxygen conditions using in situ microcosms. Denitrification was induced in a shallow sand and gravel aquifer to measure the potential for degradation of atrazine, DEA, and DIA under low-O2 conditions. The dissolved oxygen content decreased from 7-8 mg/L to e1 mg/L within 4 days and remained j3 mg/L for the remainder of the 45-day experiment. Atrazine, DEA, and DIA concentrations (normalized to the bromide concentration at each sampling time to account for dilution) did not show a significant decrease with time, indicating that these compounds are relatively stable under the low-O2conditions induced in the aquifer. Although removal of one alkyl group has been proposed as the rate-limiting step in atrazine degradation, no transformation of either monodealkylated metabolite (DEA or DIA) was observed in this study.
A large-to-fine-scale shape prior for probabilistic segmentations using a deformable m-rep

Training a shape prior has been potent scheme for anatomical object segmentations, especially for images with noisy or weak intensity patterns. When the shape representation lives in a high dimensional space, principal component analysis is often used to calculate a low dimensional variation subspace from frequently limited number of training samples. However, the eigenmodes of the sub-space tend to keep the large-scale variation of the shape only, losing the detailed localized variability which is crucial to accurate segmentations. In this paper, we propose a large-to-fine-scale shape prior for probabilistic segmentation to enable local refinement, using a deformable medial representation, called the m-rep. Tests on the goodness of the shape prior are carried out on large simulated data sets of (a) 1000 deformed ellipsoids with mixed global deformations and local perturbation; (b) 500 simulated hippocampus models. The predictability of the shape priors are evaluated and compared by a squared correlations metric and the volume overlap measurement against different training sample sizes. The improved robustness achieved by the large-to-fine-scale strategy is demonstrated, especially for low sample size applications. Finally, posterior 3D segmentations of the bladder from CT images from multiple patients in day-to-day adaptive radiation therapy demonstrate that the local residual statistics introduced by this method improve the segmentation accuracy.
Efficient distributed scheduling in cognitive radio networks in the many-channel regime

The design of efficient and distributed scheduling algorithms is essential to garner the full potential of cognitive radio networks. In this paper, we propose a distributed OFDM-based scheduling algorithm, named collision-queue-regulated algorithm, which aims to limit the collision rate to a level imposed by primary users of a cognitive radio network. Via a novel equivalent-queue-system analysis, we prove that the proposed algorithm can achieve at least a constant fraction of the asymptotic capacity region in the many-channel regime. Our numerical studies indicate that the proposed distributed collision-queue-regulated algorithm achieves a throughput very close to that achievable by a centralized throughput-optimal back-pressure-based scheduling algorithm.
The contribution of hope to the quality of life among aging African Americans: 1980-1992

This study examined age differences between 1979–80 and 1992 in the quality of life of African Americans using panel data from the National Survey of Black Americans. Of particular interest was the role of the hope dimension of personal efficacy in accounting for variance in general well-being, beyond that contributed by social demographic and economic indicators. Hierarchical regression analyses revealed that hope and family satisfaction in 1980 consistently accounted for significant amounts of variance in general life satisfaction in the 1992 fourth wave of data among all three cohorts. For older respondents, increased frequency of contact with friends and family help were the most important contributors to high satisfaction. Across waves in all age cohorts family satisfaction and contact with friends were most important in contributing to life satisfaction. Implications for further research on well-being among African Americans were discussed.
A context-sensitive search mechanism

Collaborative help systems are a widely used type of information systems. Users seeking information, post questions on a collaborative help system, which are answered by other users who possess the requested information. Collaborative help systems often contain domains of information that are significantly disparate. There may exist several questions in a collaborative help system, which have similar wording but dissimilar context and therefore each one of them has completely different answers. When searching the collaborative help system for a certain question, it is quite possible that a regular-search mechanism would return some question that is not in the context that the user wanted. A search mechanism that is sensitive to context, however, would produce the correct result. In this paper we present our context-sensitive search mechanism. The mechanism uses the recent activity of a user as the context of their questions and searches. The mechanism has been implemented in our collaborative help system called knowledge exchange.
Lessons learned writing digital forensics tools and managing a 30TB digital evidence corpus

Writing digital forensics (DF) tools is difficult because of the diversity of data types that needs to be processed, the need for high performance, the skill set of most users, and the requirement that the software run without crashing. Developing this software is dramatically easier when one possesses a few hundred disks of other people’s data for testing purposes. This paper presents some of the lessons learned by the author over the past 14 years developing DF tools and maintaining several research corpora that currently total roughly 30TB. Published by Elsevier Ltd.
Following the Molecular Pathways toward an Understanding of the Pathogenesis of Systemic Sclerosis

This review discusses the clinical and physiologic principles of systemic sclerosis, a disease of unknown origin characterized by excessive deposition of collagen and other connective tissue macrom...
Solubilization and purification of xanthine oxidase from bovine milk fat globule membrane.

Abstract Bovine milk xanthine oxidase (XO) was isolated and purified from milk fat globule membrane (MFGM). The method included the following steps: solubilization of XO from MFGM in 200 mM dithiothreitol (DTT) at pH 8.0, fractionation of solubilized proteins with ammonium sulfate, chromatography on DEAE–Sepharose with gradient elution, and rechromatography of the XO fraction for final purification. The method is highly reproducible, is comparatively simple, and provides highly pure enzyme. Purified XO, analyzed by (8%) SDS–PAGE, had only one band of 140–150 kDa. XO showed a high specific activity of 2.5 units/mg of protein and an A 280 : A 450 ratio of 4.8.
Optimal Web cache sizing: scalable methods for exact solutions

This paper describes two approaches to the problem of determining exact optimal storage capacity for Web caches based on expected workload and the monetary costs of memory and bandwidth. The first approach considers memory/bandwidth tradeoffs in an idealized model. It assumes that workload consists of independent references drawn from a known distribution (e.g. Zipf) and caches employ a ''Perfect LFU'' removal policy. We derive conditions under which a shared higher-level ''parent'' cache serving several lower-level ''child'' caches is economically viable. We also characterize circumstances under which globally optimal storage capacities in such a hierarchy can be determined through a decentralized computation in which caches individually minimize local monetary expenditures. The second approach is applicable if the workload at a single cache is represented by an explicit request sequence and the cache employs any one of a large family of removal policies that includes LRU. The miss costs associated with individual requests may be completely arbitrary, and the cost of cache storage need only be monotonic. We use an efficient single-pass simulation algorithm to compute aggregate miss cost as a function of cache size in O(MlogM) time and O(M) memory, where M is the number of requests in the workload. Because it allows us to compute arbitrarily weighted hit rates at all cache sizes with modest computational resources, this algorithm permits us to measure cache performance with no loss of precision. The same basic algorithm also permits us to compute complete stack distance transformations in O(MlogN) time and O(N) memory, where N is the number of unique items referenced. Experiments on very large reference streams show that our algorithm computes stack distances more quickly than several alternative approaches, demonstrating that it is a useful tool for measuring temporal locality in cache workloads.
A UPC runtime system based on MPI and POSIX threads

MuPC is a portable runtime system for Unified Parallel C (UPC). A modified version of the EDG C/C++ front end translates the user's UPC program into C and turns UPC-specific language features into calls to MuPC runtime functions. MuPC implements each UPC thread (process) as two Pthreads, one for the user program and private memory accesses, and the other for remote memory accesses. Remote memory is accessed by two-sided MPI message passing. MuPC performance features include a runtime software cache for remote accesses and low latency access to shared memory with affinity to the issuing thread. MuPC is a useful platform for experimenting with current and future UPC language features and investigating UPC performance. This paper describes the internal design of MuPC and compares its performance to several other available platforms.
Heterodox macro after the crisis

Macroeconomics is in crisis and this creates openings for alternative perspectives. The dominant heterodox traditions, however, have shortcomings that need to be addressed, both to improve our understanding of the real world and to take advantage of the opportunities offered by the irrelevance of most mainstream macro. This paper discusses three examples of areas that need attention: (i) investment functions (where popular specifications lack behavioral and empirical support), (ii) income distribution (where key developments have received little attention) and (iii) the relation between income inequality and financial markets (where extensions of existing models may help explain financial instability).