cssi/SciSciGPT-SciSciNet huggingface dataset:
1.3.3 Conceptual Model for Space Mission Systems Design

Modelling tools and methodologies without concerns about human understanding may not be suitable for communicating with stakeholders, customers, or management. There are many factors that can increase understandability. Using a generic systems engineering modelling language certainly helps but is not always enough. The understandability of modelling can be improved by using better modelling techniques and strategies, which might be part of a coherent methodology with a deliberate emphasis on communicability. The paper describes the application of Systems Modeling Language (SysML) to the design of a JPL mission using the Object Oriented System Engineering Method (OOSEM). Complementary formal modelling using the Web ontology language (OWL) has also been investigated. Using only traditional means, under increased demands on productivity and decreased resources, system integration may become high risk, and lifecycle support is expensive and may result in rapidly outdated components. Model-based systems engineering (MBSE) is showing promise as a solution to this problem in addition to and enhancing more traditional approaches. The space mission systems models represent sciences and technologies including astrophysics, physics, electronics, mechanisms, hardware and software. Representations of system architecture specification, requirements, evaluation of alternative architectures and trade studies, including static simulation of the performance are grouped into views that represent different stakeholder viewpoints. The human understandability of the resulting models and how the modeling process can increase communication and understandability has also been addressed and observations are reported.
Androstenedione Effects on the Vasopressin Innervation of the Rat Brain

The steroid hormone androstenedione profoundly influences the development and expression of sexual and aggressive behavior. The neural basis of these effects are, however, poorly understood. In this study we evaluated androstenedione's ability to maintain vasopressin peptide levels in the gonadal steroid-responsive vasopressin cells of the bed nucleus of the stria terminalis and the centromedial amygdala, and their projections. Adult male rats were castrated and given testosterone, androstenedione or no hormonal treatment for five weeks. Their brains were then processed for vasopressin immunoreactivity. Androstenedione and testosterone treatment were equally effective in preventing the reduction of vasopressin immunoreactivity associated with castration. Androstenedione may therefore be able to mimic the effects of testosterone on testosterone-responsive neural systems.
Common genetic variants associated with plasma fibrin D-dimer concentration in older European- and African-American adults.

Summary. Background and Objectives: D-dimer is a hemostasis marker that reflects ongoing fibrin formation and degradation. There is significant inter-individual and inter-population variability in D-dimer concentration, but whether genetic factors underlie these differences is largely unknown. We hypothesized that common coagulation gene variants contribute to differences in circulating D-dimer concentration. Methods: The setting was European-American (EA; n = 1858) and African-American (AA; n = 327) unrelated older adults from the Cardiovascular Health Study (CHS), in which we genotyped SNPs in 42 genes related to blood coagulation and fibrinolysis. Results: Several fibrinogen gene polymorphisms, including the Thr312Ala Aα chain variant and the FGG-10034 C/T variant, were associated with ∼20% higher plasma D-dimer levels in EA (false discovery rate < 5% for covariate-adjusted model). There was also some evidence that a Pro41Leu variant of the PLAU gene encoding urinary plasminogen activator and non-coding polymorphism of the plasminogen activator inhibitor type 1 gene (SERPINE1) were associated with higher plasma D-dimer in EA. There were no significant associations between the studied coagulation or fibrinolysis gene SNPs and plasma D-dimer levels in the smaller AA sample. However, each standard deviation increase in European ancestry assessed by ancestry-informative gene markers was associated with ∼10% lower mean D-dimer levels in AA. Conclusions: Together, common coagulation/fibrinolysis gene SNPs explained only ∼2% of the variance in plasma D-dimer levels in EA. These findings suggest that the association of D-dimer with risk of vascular outcomes may be mediated largely by environmental factors, other genes, and/or genetic interactions.
The Monstered Self: Narratives of Death and Performance in Latin American Fiction

The Monstered Self: Narratives of Death and Performance in Latin American Fiction. Eduardo Gonzalez. Durham: Duke University Press, 1992. xix + 275pp. $39.50 (cloth). ISBN 0–8223–1209–3
On a conjecture of Barlow and Proschan concerning reliability bounds

Abstract This article solves an old problem about reliability bounds. It turns out that the first statement of a Barlow and Proschan conjecture about this problem is always correct and the second statement is correct under a certain assumption about the system.
A Comparative Study of the Response of Double Shearing and Hypoplastic Models

The principal objective of this paper is to compare the mechanical response of a double shearing model with that of a hypoplastic model under biaxial compression and under cyclic shear loading. As the origins and nature of these two models are completely different, it is interesting to compare the predictions of these two models. The constitutive relations of the double shearing and the hypoplastic models are implemented in the finite element program ABACUS/Explicit. It is found that the hypoplastic and the double shearing constitutive models both show strong capability in capturing the essential behavior of granular materials. In particular, under the condition of non-cyclic loading, the stress ratio and void ratio predictions of the double shearing and the hypoplastic models are relatively close, while under the condition of cyclic loading, the predictions of these models are quite different. It is important to note that in the double shearing model employed in this comparison the shear rates on the two slip systems are assumed to be equal. Hence, the conclusions derived in this comparison pertain only to this particular double shearing model. Similarly, the hypoplasticity model considered here is that proposed by Wu, et al. [30] and the conclusions reached here pertain only to this particular hypoplasticity model.Copyright © 2002 by ASME
The Financial Accounting System Viewed as a Control System

This paper views the outputs of the accounting information system as elements of a control system. These outputs may be of a financial accounting nature as well as a managerial accounting nature. Rewards for management are often based on measures typically found in the annual reports. Managers have an interest in making sure these measures are favorable. This paper presents ways for management to deal with situations where what is good (bad) for the manager may be bad (good) for the company.
Experimental and analytical investigation of lean premixed methane/air combustion in a mesoscale counter-flow reactor

Abstract Combustion-based personal power systems have great potential for applications that demand high energy density, compact, and durable components. Through the use of heat recirculation, increased combustor firing rates and extension of flammability limits can be achieved. This study examines the combustion of lean methane/air reactant mixtures below the conventional flammability limit in a mesoscale heat-recirculating counter-flow reactor. An analytical model, previously developed for reforming in the counter-flow reactor, was adapted and applied to study lean operation. Results qualitatively describe the operating principle of the reactor and its behavior in response to changes in inlet conditions. Experiments determined the stable operating range of the reactor. Peak reactor wall temperature measurements indicate superadiabatic operation. Exhaust emissions of CO and NO x range from 35 to 143 ppm and 5 to 25 ppm, respectively, and emission indices as a function of firing rate are presented. Unburned hydrocarbons were detected at the lowest firing rates.
An Assessment of the Role Construct Repertory Test

This paper reports data on the reliability and ex ternal validity of the Construct Role Repertory Test (Rep Test). Results show that test scores were moderately internally consistent; scores exhibi...
Internal sequential innovations: How does interrelatedness affect patent renewal?

Abstract The value of patented innovations has attracted substantial research attention, especially in the context of patent renewal. However, research often assumes that a firm's patented innovations are independent from each other. We draw upon evolutionary economics and suggest that some of a firm's patents share important genealogical relationships, which we refer to as internal sequential innovations. We propose internal sequential innovations are more valuable and therefore more likely to be renewed than stand-alone innovations. We examine our hypotheses from a dataset of US pharmaceutical and biotechnology patents. The results confirm our hypotheses at both the patent and the firm levels.
Vision‐based obstacle detection for rotorcraft flight

An obstacle detection approach to rotorcraft flight is described which is based on feature tracking and recursive range estimation. Flight characteristics are taken into account. A range map derived on the basis of this approach provides an advisory display to the pilot and can serve as input to an automatic obstacle-avoidance guidance system. A NASA CH-47 Chinook helicopter was used to develop an image and rotorcraft flight data base for verification of obstacle detection concepts. The performance of the passive range estimation algorithms is demonstrated using both laboratory image and flight image data.
Improved Staging in Node-Positive Breast Cancer Patients Using Lymph Node Ratio: Results in 1,788 Patients with Long-term Follow-Up

Background Axillary lymph node status remains the most important prognostic factor in breast cancer. Established staging systems emphasize the absolute number of positive nodes, without regard for the total number of lymph nodes examined. We sought to confirm that a ratio of positive nodes to total nodes examined (LNR) has prognostic value beyond the current TNM classification for women with node-positive breast cancer. Study Design Using the Duke University Medical Center breast cancer tumor registry, we identified women diagnosed with node-positive breast cancer between 1985 and 2005 (n = 1,788). Variables analyzed for impact on disease-free survival (DFS) included the number of positive nodes, N classification, and the calculated LNR. Based on LNR, the patients were divided into low- (≤0.2), intermediate- (>0.2 and ≤0.65), and high- (>0.65) risk groups. Kaplan-Meier survival analysis was performed with groups compared by the log-rank test. Values of p Results For all patients, the 10-year actuarial DFS rates for the low-, intermediate-, and high-risk LNR groups were 69%, 60%, and 45%, respectively. The DFS curves for the 3 LNR groups were significantly different (p Conclusions Our data show that LNR has prognostic value in assessing breast cancer survival beyond the current TNM classification. This study supports the inclusion of LNR for enhanced risk stratification beyond traditional pN classification.
Interacting effects of gender and genotype on blood pressure response to hydrochlorothiazide

Interacting effects of gender and genotype on blood pressure response to hydrochlorothiazide. Background Genetic factors may influence blood pressure (BP) response to diuretic therapy through their effects on activity of the renin-angiotensin-aldosterone system (RAAS). The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with variation in serum ACE activity and may influence BP in a gender-specific manner. Methods We measured the I/D polymorphism in 206 non-Hispanic women (130 blacks, 76 whites) and 170 non-Hispanic men (62 blacks, 108 whites) with essential hypertension (age 48 ± 7 years, mean ± SD) who underwent monotherapy with hydrochlorothiazide (HCTZ) 25 mg daily for four weeks. Results In both genders, serum ACE activity increased in a co-dominant fashion in association with the D-allele ( P P = 0.03; for diastolic BP response, P = 0.001). Among women, mean declines in systolic and diastolic BP were greater in II than in DD homozygotes; whereas among men, mean declines in systolic and diastolic BP were greater in DD than in II homozygotes. In models that included the effects of race, gender, age, and waist-to-hip ratio, there was also significant interaction between the effects of the ACE genotype and gender on pre-treatment urinary aldosterone excretion ( P = 0.01) and change in urinary aldosterone excretion in response to HCTZ ( P = 0.007). The genotypes that were associated with the greatest BP responses to HCTZ (II homozygotes in women and DD homozygotes in men) had the lowest pre-treatment urinary aldosterone excretion and the greatest increase in urinary aldosterone excretion in response to HCTZ. Conclusion The relationship between the ACE I/D polymorphism and antihypertensive response to a standard dose of HCTZ differs significantly between women and men. Because the D-allele was associated with significant, co-dominant increases in serum ACE activity in both genders, the gender-specific effects of the I/D polymorphism on BP response to HCTZ may be mediated subsequent to the enzymatic generation of angiotensin II.
Analysis Of Infrared Emission From Thin Adsorbates

Fuel and lubricant deposits on solid surfaces, though often of similar visual appearance, differ in composition, depending on the nature of the deposit formers and the circumstances of deposition. To help establish these relations an Infrared Emission Fourier Polarization Microspectrophotometer was constructed to record infrared spectra from the deposits on their original support. By focussing on small aggregates with a reflecting microscope objective and by discriminating against the randomly polarized blackbody radiation with a rotating polarizing filter phase-locked to an amplifier, excellent Fourier emission spectra of polarized bands could be obtained. In many instances, the microscope objective was adequate without the polarizer. The analysis was calibrated against a very thin film of polyethylene terephthalate attached to a highly reflective aluminum mirror on the sample positioner.
Myocardial calpain 2 is inhibited by monoclonal antibodies specific for the small noncatalytic subunit

Calpains (EC 3.4.22.17) are nonlysosomal intracellular proteinases which require calcium ion for activity. The calpains are heterodimers composed of a large catalytic subunit and a small subunit which may have a regulatory function during the catalytic cycle. However, whether calpains remain in the dimeric form or dissociate upon exposure to calcium is controversial. To resolve this issue, two monoclonal antibodies which specifically recognize the small calpain subunit were prepared using bovine calpain 2 heterodimer as the antigen. Both antibodies, designated P-1 and P-2, were capable of inhibiting bovine or canine calpain 2, and partially purified human erythrocyte calpain 1. However, neither could produce full inhibition. Further studies with P-1 and bovine calpain 2 indicated that the antibody decreased the calcium requirement for the proteinase. The Km for casein was increased and the Vmax was decreased. The addition of P-1 to the assay mixture several minutes after initiation of proteolytic activity resulted in a rapid inhibition. The P-1 antibody was also capable of decreasing the ability of the protein inhibitor of calpains (calpastatin) to inhibit bovine calpain 2. These studies indicate that the small subunit remains bound to the large subunit during catalysis and may influence its activity.
A brief survey of access control in Wireless Sensor Networks

In this paper, we investigate applications of access control to Wireless Sensor Networks (WSNs). Although access control was well established for traditional computer systems, it has not been studied thoroughly in WSN environments. We briefly provide the WSN specifications and then stress the constraints of the WSNs that would affect the access control implementation. We also provide a literature overview and discuss further possible solutions.
Laboratory Investigation of the Abrasive Wear Mechanism of Concrete Crosstie Rail Seat Deterioration (RSD)

Currently, there are divergent design and performance demands on railway infrastructure components due to increasing freight axle loads and cumulative gross tonnages, as well as increased investment in high-speed passenger rail development in North America. The divergence in loading and performance demands on shared infrastructure arises from the fact that while high-speed passenger trains exert lower loads at relatively high speeds, freight trains exert high loads at relatively low speeds. Improvements in infrastructure component designs are needed to achieve increased durability and tighter geometric tolerances. According to a rail industry survey administered by University of Illinois at Urbana-Champaign (UIUC) in 2008, Rail Seat Deterioration (RSD) is the principal performance problem limiting the service life of concrete crossties in North America. Rail infrastructure researchers and industry experts agree that abrasive wear may occur due to relative motion between the rail pad and concrete crosstie rail seat, potentially resulting in RSD. The complex tribological process of abrasion is further complicated and expected to be accelerated by the presence of abrasive fines and moisture, creating 3-body wear condition. Lack of understanding of the abrasion mechanism has resulted in a sub-optimal and iterative design of ties, causing reduced service life. This paper summarizes our efforts in understanding the effect of changing the mix design of concrete on the abrasion resistance of the rail seat which will eventually help us in modeling abrasive wear in RSD by constructing a mathematical relationship between the rail seat wear rate and input parameters including concrete mix design, mechanical/tribological properties of materials involved, normal load applied, presence of moisture, and abrasive fines. To simulate abrasive wear in RSD, a simple experiment is being carried out using a rotating wheel (lapping machine) capable of abrading concrete samples as a part of UIUC’s Small-Scale Abrasion Resistance Test (SSART). The objective of this research is to develop wear performance curves (e.g. wear depth versus load/time/cycles) for lab specimens developed from concrete crosstie mix designs that are currently being used in the industry, as well as for the evaluation of new mix designs. These data will help the rail industry in mechanistically designing concrete crossties by improving the understanding of materials used for concrete crosstie mix designs, with the objective of decreasing life cycle costs for the crosstie and fastening system. Preliminary SSART results are in agreement with relevant literature documenting the relationships between concrete mix designs and curing conditions and the resulting rate of abrasion.Copyright © 2012 by ASME
Teen dating relationships and outcomes of well-being: examining gender differences in nonviolent and violent dating relationships

Teen dating violence is a prevalent problem that increases the risk of multiple negative consequences, particularly among girls. However, evidence also indicates that teen relationships in general tend to be unstable and characterized by conflict. This study uses data from the 2008 self-administered Delaware School Survey to examine gender differences in the frequency of well-being outcomes for adolescents in nonviolent, verbally aggressive, and physically aggressive relationships. Results indicate that negative well-being outcomes are prevalent in both nonviolent and violent dating relationships, particularly for girls. Adolescents in violent relationships, notably verbally violent relationships, are more likely to experience negative outcomes than adolescents in nonviolent relationships. Furthermore, findings suggest that although gender differences exist in the impact of physical violence on well-being outcomes, the impact of verbal violence on well-being does not vary by gender. Policy implications ar...
Assessment of the peak systolic velocity of the middle cerebral artery in twin-twin transfusion syndrome. Part I: preoperative assessment

Objective We sought to assess the incidence of an elevated peak systolic velocity of the middle cerebral artery (MCA-PSV) in twin-twin transfusion syndrome prior to laser surgery and its prognostic value for intrauterine fetal demise 24 hours after surgery (IUFD-24). Study Design An elevated MCA-PSV was defined as a velocity > .5 multiples of the median by transabdominal pulsed Doppler. Gestational age, Quintero stage, and number and/or type of placental vascular anastomoses were assessed as risk factors for an elevated MCA-PSV. Risk of IUFD-24 was assessed relative to an elevated MCA-PSV. Results An elevated MCA-PSV was present in 4.2% of donors, 3.2% of recipients ( P = .5), and 1.5% of both twins in 189 patients with twin-twin transfusion syndrome. An elevated MCA-PSV was unrelated to gestational age, stage, and number or type of anastomoses. An elevated MCA-PSV in the recipient twin was associated with an increased risk of IUFD-24 of this fetus ( P = .01). Conclusions An elevated MCA-PSV is present in
Electro-generated Chemiluminescence Mechanism of Polymer Solution Light-Emitting Devices

The traditional polymer light-emitting device is a solid-state device in which the polymer thin film is sandwiched between two electrodes. Recently, we reported a different type of device: the polymer solution light-emitting device (SLED), in which the light-emitting medium is a thin layer of polymer solution sandwiched between two electrodes. In this article, we studied the light-emission mechanism of the SLEDs by cyclic voltammetry, transient electroluminescence measurement, current−light−voltage (I−L−V) measurement, and the optical microscopy observation on a surface cell SLED. The turn-on speed of the light-emission of the SLED with 1 μm gap was found to be ca. 40 ms, which is similar to that of the dye ECL cells. The voltage for charge injection of the SLED devices agrees with the potential difference between the onset potentials of the oxidation for radical cation formation and the reduction for radical anion formation. However, the light emission turns on at a higher voltage, and the turn-on volta...
Kinetics of fullerene triplet states

Studies are described whose goal is a quantitative kinetic description of fullerene triplet relaxation. The room-temperature intrinsic lifetimes of solution phase T1 C60 and C70 differ substantially, with values in toluene of 143 μs and 12 ms, respectively. These decay rates exhibit only weak temperature dependence near room temperature. The intrinsic lifetime of T1 C60 has a simple dependence on vibrational energy content up to 1000 K. Efficient triplet-triplet annihilation occurs in C60 and C70 solutions at ca. 50% of the diffusion-limited rate. In mixed solutions, rapid reversible triplet energy exchange was observed between C60 and C70, and between C60 and (CH3)2 C60. A new method for measuring relative triplet enthalpies and entropies in such mixtures has also been applied. Complex kinetics has been uncovered in C70 solutions and modeled by reversible formation of shortlived triplet excimers, accounting for the efficient self-quenching. C60 self-quenching has been found to be highly temperature dependent, but the mechanism remains unresolved.
Cost Comparison of Scleral Buckle versus Vitrectomy for Rhegmatogenous Retinal Detachment Repair

Purpose To estimate and compare the costs of scleral buckle (SB) and pars plana vitrectomy (PPV) for treatment of rhegmatogenous retinal detachment (RRD). Design Cost analysis based on published prospective data comparing SB and PPV for RRD repair. Methods The costs of initial surgery, postoperative retina-affecting procedures, and eventual cataract extraction resulting from SB and PPV for RRD repair were estimated for both phakic and pseudophakic or aphakic patients and then were compared. A univariate sensitivity analysis also was performed to examine the sensitivity of our estimations. Results When considering all costs, SB was 10.7% less expensive than PPV for RRD repair in phakic patients, whereas PPV was 12% less expensive than SB for RRD repair in pseudophakic or aphakic patients. These conclusions were robust in the sensitivity analysis. Conclusions SB seems to offer a modest cost savings over PPV for repair of RRD in phakic patients. However, in pseudophakic and aphakic patients, PPV seems to be less expensive than SB.
Factors influencing the likelihood of customer defection: The role of consumer knowledge

Customer satisfaction is the predominant metric firms use for detecting and managing customers' likelihood to defect. But while satisfaction and defection are related, satisfaction is only a weak predictor of whether a customer will defect. This article suggests that for repurchase decisions that involve an information-based evaluation of alternatives to the incumbent, likelihood of defection will be influenced by “how much” customers know about those alternatives. The relationship between level of knowledge about alternatives and defection is examined in the context of actual health insurance choices. Results suggest that the level of objective and subjective knowledge about alternatives has a direct effect on likelihood of defection—above and beyond satisfaction level. The view of defection forwarded in this article suggests that managers may be able to gain additional control over customer defection through actions aimed at influencing how much customers know (or come to know) about alternative vendors.
Role of prostaglandins in the regulation of intestinal electrolyte transport.

Abstract The E prostaglandins (and to a lesser extent PGF 2α ) stimulate active electrolyte secretion in mammalian small intestine and colon. They do so by stimulating intestinal mucosal adenylate cyclase and thereby increasing cAMP concentration. The diarrheagenic action of the prostaglandins is seen as a side effect of their therapeutic use, in certain hormone-secreting tumors, and in inflammatory lesions of the bowel in which leukocyte infiltrates are the probable sources of prostaglandin excess. Prostaglandins are also normally synthesized by intestinal epithelial cells and appear to play an important role in the physiologic regulation of intestinal fluid transport. In recent in vitro studies, we have shown that addition of arachidonic acid ( K 1 2 ⋍ 10 −6 M ) also stimulates secretion, cAMP accumulation, and PGE 2 production in rabbit ileal mucosa. In the continued presence of arachidonate, tachyphylaxis develops: both secretory and cAMP responses have a half-life of about twenty minutes and subsequent additions of arachidonate produce little or no further response. In contrast, PGE 2 production continues undiminished. Similar tachyphylaxis develops when PGE 2 itself is added. Resensitization following removal of PGE 2 is rapid, 50% of the initial sensitivity being restored in 6–7 min. Prostaglandin desensitization has been noted in other cell systems and appears to be exerted on adenylate cyclase.
When is the Deuteron Six Quarks?—Possible Evidence Against Dimensional Scaling

Recent data on high-energy elastic and threshold inelastic electron scattering are shown to provide a sensitive test of the constituent nature of the target. Present evidence seems to support a quark description at these energies but mitigates against a naive dimensional-scaling argument. (AIP)
Yeast culture supplementation prevented milk fat depression by a short-term dietary challenge with fermentable starch

Effects of yeast culture on responses to a fermentable starch challenge were evaluated in an experiment with a crossover arrangement of treatments for yeast culture supplementation with 28-d periods and a fermentable starch challenge on the last 2 d of each 28-d period as a split plot within period. Eight ruminally cannulated, midlactation, multiparous Holstein cows (96 +/- 14 d in milk) were randomly assigned to treatment sequence. Treatments were yeast culture or control (mix of dry ground corn and soybean meal), top-dressed at 56 g per head per day throughout each period. Diets containing dry ground corn grain were fed from d 1 through 26 of each period. On the last 2 d of each period, the dry ground corn was replaced by finely ground high-moisture corn grain on an equivalent dry matter basis to abruptly increase ruminal fermentability of dietary starch. Response variables were averaged for d 25 and 26 for the dry corn treatment and for d 27 and 28 for the high-moisture corn treatment each period. The fermentable starch challenge decreased dry matter intake by 1.9 kg/d and tended to increase milk yield compared with the dry corn diet. However, effects of the fermentable starch challenge on yield of milk fat varied for the yeast culture and control diets; yield of milk fat decreased from 1.42 to 1.30 kg/d for the control treatment but increased from 1.40 to 1.47 kg/d for the yeast culture treatment. Milk fat concentration tended to decrease from 3.34 to 3.03% during the dietary challenge compared with the base diet for the control treatment but was not affected (mean = 3.32%) by the dietary challenge for the yeast culture treatment. An interaction of treatments was also detected for fat-corrected milk, which increased from 41.0 to 43.0 kg/d for the yeast culture treatment but decreased from 41.6 to 39.8 kg/d for the control diet with the fermentable starch challenge. Frequency of ruminating bouts was decreased by yeast culture compared with control (12.8 vs. 15.7 bouts/d) but not the fermentable starch challenge. No treatment interactions were observed for any measure of ruminal pH, total or individual volatile fatty acid concentration in ruminal fluid, acetate:propionate ratio, or individual fatty acid isomers in milk fat. Yeast culture supplementation may help prevent depression in milk fat during transition to a diet with highly fermentable starch, but the mechanism responsible remains to be elucidated.
Calibration of magnetic field probes at relevant magnitudes

Difficulty driving large currents through an inductive load at high frequency typically results in field magnitudes of a few microTesla or less. The calibration factor is then necessarily assumed linear, even though the magnetic field of the primary experiment is several orders of magnitude larger than the field magnitude used to calibrate the probe. In this work calibration factors of two differential configuration magnetic field probes are presented as functions of frequency and field magnitude. Calibration factors are determined experimentally using a 80.4 mm radius Helmholtz coil in two separate configurations. A conventional low-magnitude calibration using a network analyzer with field magnitude of 158 nT yielded calibration factors of 15,107±233 and 4,899±180 T/V-s at 457 kHz for the surface mounted inductor and hand-wound probe, respectively. A relevant-magnitude calibration using a pulsed-power setup with field magnitude of 43.5 to 83.0 mT yielded calibration factors of 14,541±41.8 and 4,484±15.8 T/V-s at 457 kHz for the surface mounted inductor and hand-wound probe, respectively. The uncertainty reported is one standard deviation of the repeated calibration measurement. Low-magnitude calibration always resulted in a larger calibration factor, with a maximum difference of 18.5%. Comparison of the pulsed-power Helmholtz coil current waveform with the magnetic field waveform measured with the magnetic probes showed differences of 1.4% and 0.7% in the waveform extrema at 457 kHz for the surface mounted inductor and hand-wound probe, respectively.
The Democratic Corporation: A Radical Prescription for Recreating Corporate America and Rediscovering Success

The article presents a review of the book ‘The Democratic Corporation: A Radical Prescription for Recreating Corporate America and Rediscovering Success,' by Russell L. Ackoff.
The mentor in graduate education

ABSTRACT The study examined the presence of mentors in and some of their effects on doctoral student education. It was hypothesised that males would be mentored at a significantly higher rate than females; and that a positive overall evaluation of one's graduate experiences at the doctoral level would be positively related to having a mentor. Data were gathered using a survey questionnaire completed by doctoral students. No evidence was found that males are more likely to be mentored than females. It is clear that doctoral students who had experienced a close working relationship with a faculty member had a fuller education than their counterparts who had not.
Film and pore diffusion studies with immobilized glucose oxidase

Quantitative studies are reported of external film and internal pore diffusion effects for glucose oxidase immobilized on porous glass in a continuous, tubular, packed bed reactor. The McCune and Wilhelm model for external film diffusion is shown to describe these data over a particle Reynolds number range from 0.2 to 25. The Thiele analysis provides a good description of internal pore diffusion resistances. It appears that immobilized enzymes free of internal diffusional restrictions generally require the use of supports with pore sizes larger than those currently available in porous glass.
Computer-Assisted Scheduling and Dispatching Systems for Paratransit Brokerage and Coordination: State Strategies for Implementation

In times of increasingly selective federal and state funding possibilities, paratransit providers need to consider whatever efficiencies can be gained through operational improvements and coordination with other providers. Both objectives can be facilitated through the implementation of computer-assisted scheduling and dispatching (CASD) systems. However, the level of realized positive impacts depends on the specifics of each implementation plan and overall deployment strategy. Moreover, with increasing numbers of local CASD system implementations, state departments of transportation have only recently realized the need for statewide strategies regarding future deployments of such systems. Potential strategies and results from a survey of states that have attempted statewide CASD system implementations are discussed.
The intact nephron hypothesis: the concept and its implications for phosphate management in CKD-related mineral and bone disorder

Mechanistic understanding of secondary hyperparathyroidism, vascular calcification, and regulation of phosphate metabolism in chronic kidney disease (CKD) has advanced significantly in the past five decades. In 1960, Bricker developed the ‘intact nephron hypothesis', opening the door for hundreds of investigations. He emphasized that ‘as the number of functioning nephrons decreases, each remaining nephron must perform a greater fraction of total renal excretion'. Phosphate per se , independent of Ca 2+ and calcitriol, directly affects the development of parathyroid gland hyperplasia and secondary hyperparathyroidism. Vitamin D receptor, Ca 2+ sensing receptor, and Klotho–fibroblast growth factor (FGF) receptor-1 complex are all significantly decreased in the parathyroid glands of patients with CKD. Duodenal instillation of phosphate rapidly decreases parathyroid hormone release without changes in calcium or calcitriol. The same procedure also rapidly increases renal phosphate excretion independently of FGF-23, suggesting the possibility of an ‘intestinal phosphatonin'. These observations suggest a possible ‘phosphate sensor' in the parathyroid glands and gastrointestinal tract, although as yet there is no proof for the existence of such a sensor. Evidence shows that phosphate has a key role in parathyroid hyperplasia by activating the transforming growth factor-α–epidermal growth factor receptor complex. Thus, control of serum phosphorus early in the course of CKD will significantly ameliorate the pathological manifestations observed during progressive deterioration of renal function.
Multicomponent mass transfer in fixed-bed carbon adsorption columns

Abstract The technique based upon the constant pattern model was extended to evaluate mass transfer coefficients for multicomponent (binary) adsorption by carbons. The mass transfer coefficient of the lesser adsorbed component was essentially the same for both single component and binary systems. The mass transfer coefficient of the more strongly adsorbed component was significantly lower in the binary case, indicating interference between components. The mass transfer coefficients obtained were used in a computer simulation of fixed bed adsorption columns, and experimental data were successfully predicted.
Medial collateral ligament replacement with a partially absorbable tissue scaffold

The medial collateral ligaments and medial capsular structures of canines were resected and replaced with a carbon fiber-polylactic acid polymer tissue scaffold or allowed simply to "scar-in." After 4, 8, 12, and 26 weeks in vivo, the stability of the knees was quantitatively evaluated and the mechanical properties of the regrown structures determined. Histological sections of the re grown structures were examined after 26 weeks in vivo.At all time periods, the knees receiving tissue scaffold ligaments were signifiicantly more stable than those knees allowed to stabilize with scar tissue. Initial strength, rapid ingrowth, and benign tissue reaction suggest this new composite material may be useful in the treatment of joint instability.
Mixing of Cartesian squares of positive operators

LetT be a power bounded positive operator inL 1(X, Σ, m)of a probability space, given by a transition measureP (x, A). The Cartesian squareS is the operator onL 1 (X × X, Σ × Σ, m × m) induced by the transition measure Q((x, y), A × B)=P(x, A)P(y, B).T iscompletely mixing if ∝u e dm=0 impliesT n u→0 weakly (where 0≦e ∈L ∞ withT * e=e).Theorem. IfT has no fixed points, thenT is completely mixing if and only ifS is completely mixing.
Tetrahydroaminoacridine facilitates passive avoidance learning in rats with nucleus basalts magnocellularis lesions

Abstract The effect of bilateral ibotenic acid lesions of the nucleus basalis magnocellularis (NBM) on performance in a step-through passive avoidance task and the ability of tetrahydroaminoacridine (THA) to enhance learning were evaluated. Fischer 344 rats were used in a passive avoidance task in which footshock was replaced by ultrasound (30–62 K Hz, 125 dB) as the aversive training stimulus. THA was given immediately after each single daily training trial and retention was tested 24 hr later for 10 consecutive days. Although NBM lesions alone did not impair passive avoidance learning, THA at 5 mg/kg (1.p.), but not 1 mg/kg, significantly facilitated latency performance in NBM-lesloned rats.
Anterior brain electrical asymmetries in response to reward and punishment.

Abstract A variety of recent research indicates that when subjects are induced to experience certain negative emotions, there is greater suppression of alpha power in the right than left frontal region, while during the experience of positive emotion, alpha power asymmetry in this region shows the opposite pattern. We have conceptualized this assymetry as reflecting specialization for approach and withdrawal processes in the left and right frontal regions, respectively. In this experiment, reward and punishment contingencies were directly manipulated to produce approach and withdrawal response motional states. In addition, subjects responded to imperative stimuli using either an approach response (finger press) or a withdrawal response (finger lift). EEG was recorded from multiple scalp locations. During the foreperiod prior to the response to the imperative stimuli, the EEG was extracted, Fourier-transformed and power computed in the theta, alpha and beta frequency bands. In addition, the contingent negative variation (CNV) was derived from the identical epoch. Reward trials were associated with greater left frontal alpha power suppression than punishment trials, while during the latter trials, there was greater right-sided frontal alpha power suppression than during reward trials. There was also some evidence to indicate that withdrawal responses were associated with greater right-sided alpha power suppression in the temporo-parietal region compared with approach responses. Power in the theta and beta bands did not systematically vary with condition. The CNV was larger during trials on which subjects responded quickly compared with slow trials, but did not differentiate between reward and punishment contingencies. The findings support the hypothesis that approach-related processes can be differentiated from withdrawal-related processes on the basis of asymmetrical shifts in alpha power in the frontal region. They also indicate that the CNV and spectral power estimates from the identical epochs reflect different neural processes.
Nutritional regulation of the glucose-6-phosphate dehydrogenase gene is mediated by a nuclear posttranscriptional mechanism.

Abstract Expression of the glucose-6-phosphate dehydrogenase (G6PD) gene is inhibited by addition of polyunsaturated fat to a high-carbohydrate diet and stimulated by feeding a high-carbohydrate diet to starved mice. The mechanism of this regulation is posttranscriptional. To define the regulated step, we measured the abundance of G6PD mRNA both in the nucleus and in total RNA. Feeding mice a high-fat diet results in a 70% or greater inhibition of nuclear precursor mRNA (pre-mRNA) and mature mRNA abundance. Amounts of both pre-mRNA and mature mRNA for G6PD are stimulated 13-fold or more by refeeding starved mice. Changes in amount of pre-mRNA for G6PD are of a similar magnitude and precede the changes in amount of mature mRNA for G6PD in total RNA. These changes in pre-mRNA abundance occur in the absence of observable changes in the rate of transport of mRNA from the nucleus to the cytoplasm, splicing of the pre-mRNA, or degradation at the 3′-end of the transcript. Despite large changes in pre-mRNA amount in mice fed a low-fat diet relative to mice fed a high-fat diet, the rate of change in the amount of pre-mRNA during the diurnal feeding cycle is not altered. Thus, expression of G6PD is regulated at an early step after transcription of the pre-mRNA. We suggest that pre-mRNA which enters the processing pathway is stable and can be processed and transported to the cytoplasm where it is translated.
Oscillation of MPF is accompanied by periodic association between cdc25 and cdc2-cyclin B

Activation of maturation-promoting factor at the onset of mitosis requires the tyrosine dephosphorylation of one of its components, the cdc2 protein kinase. cdc25 is the specific tyrosine phosphatase that activates cdc2. We find that Xenopus oocytes contain a relative of cdc25, p72. In Xenopus embryos the abundance of p72 does not oscillate during the cell cycle. However, p72 directly associates with cdc2-cyclin B in a cell cycle-dependent manner, reaching a peak at M phase. The M phase kinase that associates with p72 is catalytically active. These results suggest that the mechanism by which cdc25 triggers cdc2 activation involves a periodic physical association between cdc25 and the cyclin B-cdc2 complex and also that mitotic control can be affected by mechanisms other than transcriptional regulation of the cdc25 gene.
On the equivalence problem for regular Thue systems

Abstract A decision procedure is presented for the equivalence problem for regular almost-confluent Thue systems. On the other hand, the equivalence problem for regular preperfect systems is shown to be undecidable.
Dehydration-induced conformational transitions in proteins and their inhibition by stabilizers

Dehydration of proteins results in significant, measurable conformational changes as observed using Fourier-transform infrared spectroscopy and resolution-enhancement techniques. For several proteins these conformational changes are at least partially irreversible, since, upon rehydration, denaturation and aggregation are observed. The presence of certain stabilizers inhibited these dehydration-induced transitions; the native structure was preserved in the dried state and upon reconstitution. Conformational transitions were also observed in a model polypeptide, poly-L-lysine, after lyophilization and were inhibited with the addition of stabilizing cosolutes. The ability of a particular additive to preserve the aqueous structure of dehydrated proteins and poly-L-lysine upon dehydration correlates directly with its ability to preserve the activity of lactate dehydrogenase, a labile enzyme, during drying.
Production of low molecular weight esters using vegetable oils or butter oil as reaction media

Corn oil, peanut oil, sunflower oil, soybean oil, canola oil, olive oil and butter oil were tested as replacements for nonaqueous solvents in the lipase mediated biosynthesis of ethyl butyrate, butyl butyrate, isoamyl butyrate and isoamyl acetate. The most effective oils tested were butter oil, soybean oil, peanut oil and olive oil (yield = 50–60% after 16 h incubation at 25°C) while corn oil was least effective (yield = 38%). Higher yields were obtained, for all ester syntheses, at a reaction temperature of 50°C. Drying agents were shown to have no effect or to inhibit the synthesis. Of the four enzymes tested, Candida cylindracea lipase was the most effective enzyme for ethyl butyrate synthesis.
What, after all, was Heidegger about?

The premise is that Heidegger remained a phenomenologist from beginning to end and that phenomenology is exclusively about meaning and its source. The essay presents Heidegger’s interpretation of the being (Sein) of things as their meaningful presence (Anwesen) and his tracing of such meaningful presence back to its source in the clearing, which is thrown-open or appropriated ex-sistence (das ereignete/geworfene Da-sein). The essay argues five theses: (1) Being is the meaningful presence of things to man. (2) Such meaningful presence is the Befragtes of Heidegger’s question, not the Erfragtes. (3) Being and Time’s goal was to articulate the openness that allows for all meaningfulness. (4) Ereignis—the appropriation of ex-sistence to sustaining the clearing—is the later Heidegger’s reinscription of thrown-openness, der geworfene Entwurf. (5) Appropriated thrown-openness, as the clearing, is intrinsically hidden, i.e., unknowable. Some preliminaries
Histochemical differentiation of anterior pituitary cell types by contrasting azo-coupling and mucoprotein stains.

Azo compounds couple with aromatic amino-acid nuclei in the cytoplasmic proteins of human anterior pituitary acidophile and basophile cells. In acidophile cells the reaction appears to be due primarily to tyrosine, but also in part to histidine. Procedures are given for the use of naphthanil diazo blue B (tetrazotized di-ortho-anisidine), with or without a second coupling agent (H acid; 8-amino-1-naphthol-3, 6-disulfonic acid), to demonstrate acidophile cells, in contrast to mucoprotein stains (periodic acid oxidation followed by leukofuchsin or leukothionin) for the cytoplasm of basophile cells. Evans blue can also be used to give a contrasting color to basophile cells.