cssi/SciSciGPT-SciSciNet huggingface dataset:
Role of radiation therapy and radiosurgery in the management of craniopharyngiomas.

Craniopharyngiomas are histologically benign neuroepithelial tumors that arise from the hypophyseal duct or Rathke’s pouch. They comprise 5% to 10% of pediatric brain tumors and 1% to 4% of adult brain tumors and have a bimodal distribution with peak rates at childhood (5–14 years) and older adulthood (50–74 years) [1]. Although these tumors are slow growing, well circumscribed, and encapsulated, the frequent involvement of such structures as the pituitary stalk, hypothalamus, adjacent vasculature, and optic apparatus complicate their management. A large number of treatment modalities are used, including gross total resection (GTR), limited surgery followed by radiation therapy, fractionated radiation approaches, intracavitary irradiation, and stereotactic radiosurgery. This article reviews the goals and complications of surgery and the results with conventional and modern radiation approaches.
Antithrombotic therapy in heart failure: WATCHful wondering.

Clarity regarding the role of antithrombotic treatments in patients with heart failure in the absence of atrial fibrillation remains elusive. In an era of an intensified search for personalized medicine, it is instructive to look back at the earliest evidence for a protective effect of anticoagulation, when little else had any promise to reduce morbidity and mortality in heart failure.1–3 It is now evident that those benefits were predominantly driven by effects in subsets of patients with atrial fibrillation and valvular disease. Sixty years later, the role of antithrombotic treatments in the remaining population remains uncertain. The Warfarin and Antiplatelet Therapy in Chronic Heart Failure Trial (WATCH), the results of which are published in the present issue,4 held the promise of providing clear support for one therapeutic approach above the others in reducing the incidence of adverse cardiovascular events. However, the primary WATCH findings provide no clear winner among warfarin, clopidogrel, and aspirin, with the limited statistical power preventing any clear conclusion. WATCH results do suggest that aspirin treatment increases the likelihood of heart failure hospitalization compared with the other approaches. Article p 1616 Evidence exists indicating that heart failure is often accompanied by a hypercoagulable state.5–7 Patients with reduced cardiac output may be predisposed to venous thrombosis and pulmonary embolus. In the sizable percentage of heart failure patients with ischemic heart disease, antiplatelet therapy is expected to decrease the incidence of recurrent coronary ischemic events, as it has been shown to do in the broader ischemic heart disease population.8–12 Among patients without known ischemic heart disease, there is suspicion that many adverse events, including worsening heart failure and sudden cardiac death, may be provoked by myocardial ischemia,13 raising the possibility that antithrombotic treatment may impact natural history in this population as well. On the …
A quantification of the economic value of flexible capacity

Traditional methods for the economic justification of new manufacturing technologies fail to include benefits such as better quality, greater flexibility and reduced work-in-progress. In this paper we develop a technique to quantify the economic value of long-term flexibility in capacity through the use of dynamic programming. We define the economic value of flexibility as the difference in the net present value of profits that a flexible system achieves over a less flexible system. Two examples are presented.
A study of particle-vibration multiplets in 203Tl using the 205Tl(p, t)203Tl, 208Pb(p, t)206Pb and 206Pb(p, t)204Pb reactions

Abstract The 205 Tl(p, t) 203 Tl reaction has been used at 26.2 MeV to obtain additional information on the particle-vibration multiplets in 203 Tl. Enhancement factors for the L = 0 and L = 2 transitions to the lower excited states of 203 Tl were well accounted for by using enhancement factors from the 206 Pb(p, t) 204 Pb reaction and the wave functions from the intermediate coupling calculations of Covello and Sartoris. Additional data on the 208 Pb(p, t) 206 Pb reaction at 26.2 MeV were used along with data at other energies to examine the energy dependence of the zero-range enhancement factors.
Bleomycin-induced DNA lesions at mutational hot spots: implications for the mechanism of double-strand cleavage.

Abstract Using various end-labeled, defined-sequence DNA substrates, we examined bleomycin-induced damage at several G.C base pairs which correspond to mutational hot spots. The most frequent lesions detected were single-strand breaks and single apurinic/apyrimidinic (AP) sites at the C residue, suggesting that this was the primary site of damage. Strand breaks and AP sites also occurred, but less frequently, at a secondary damage site--i.e., the directly opposed G residue in the complementary strand. However, damage at the secondary site occurred only when a strand break was present at the primary site, and AP sites at the primary site were never accompanied by closely opposed damage in the complementary strand. Thus, formation of a strand break at the primary damage site was a necessary though not sufficient condition for attack at the secondary site. Similar patterns were seen at other sequences attacked by bleomycin, although primary and secondary sites were sometimes staggered by one nucleotide position rather than directly opposed. These and other results suggest a mechanism of double-strand cleavage in which bleomycin is reactivated during formation of the first strand break, and the reactivated drug subsequently attacks the complementary strand at a specific position which is not normally a site of bleomycin-induced cleavage. Regeneration of activated bleomycin could result from a reaction between Fe(III).bleomycin and a 4'-peroxyl derivative of deoxyribose, both produced during formation of the strand break.
Management of one hundred seventy-one operative and nonoperative obstetrical birth palsies at the Louisiana State University Health Sciences Center.

OBJECTIVE: The management of obstetrical brachial plexus injury, often called birth palsy, remains one of the most controversial topics in pediatric neurosurgery. Most birth palsies have acceptable spontaneous recoveries, whereas only a minority require surgical intervention. A selective approach for surgery was used in this Louisiana State University Health Sciences Center (LSUHSC) series, for which the operative rate was 9%. At LSUHSC, the patient with obstetrical brachial plexus injury is followed for 6 to 9 months before surgery, which is performed if there is no satisfactory biceps and/or shoulder function. METHODS: This is a retrospective analysis of 169 patients with 171 palsies referred to LSUHSC for possible surgery. There were 76 patients with 77 birth palsies managed operatively and nonoperatively at LSUHSC between 1975 and 1991. An additional 93 patients with 94 palsies who were managed between 1992 and 2003 were included in this analysis. The results of initial and follow-up examinations using Eng's criteria for impairment ratings (IRs) were available for 151 of 171 (88%) nonoperative and operative obstetrical brachial plexus injuries managed between 1975 and 2001. RESULTS: Fifty-two percent of the nonoperative patients evaluated at an initial visit had an IR of 4 or 5, which represents very poor function by comparison to IR of 1 in the Eng scale, which represents almost no abnormality. The percentage of patients in this category (4-5) improved to 30% after follow-up visits. For the 16 operative cases, the initial and follow-up percentages of patients with IRs of 4 or 5 were 67% and 22%, respectively. Ultimately, 47% of the nonoperative patients achieved a grade 2 IR after follow-up compared with 17% of the operative patients. CONCLUSION: Using this selective approach at LSUHSC, in which the operative rate was 9%, acceptable outcomes were obtained both in patients not having surgery and also in those having surgical intervention.
MBAs' changing attitudes toward marketing dilemmas: 1981–1987

This study investigates the reactions of 561 MBA students to ethical marketing dilemmas. An analysis is conducted across time to determine how MBA students' attitudes about ethical marketing issues have been changing over the course of the 1980s. The findings show some support for the notion that MBA students in the late 1980s are somewhat less likely to use moral idealism when resolving an ethical dilemma and more likely to justify the decision in terms of its outcomes as compared with their counterparts at the start of the decade.
The effect of tetracycline on skeletal development in the larval sand dollar (Echinarachnius parma)

Abstract Developing larvae of E. parma responded adversely to sea water to which tetracycline was added. Low concentrations of tetracycline produced delay in development; somewhat higher concentrations resulted in inhibition of skeletal formation; still higher concentrations completely inhibited larval development. At concentrations which permitted skeletal development, tetracycline became incorporated into the growing skeleton. This tissue exhibited a very pronounced avidity for and retention of tetracycline. Concentrations which inhibited skeletal formation were found to exert their effect specifically at the onset of skeletal differentiation.
Building Capacity: Challenges and Opportunities in Large Class Pedagogy (LCP) in Sub-Saharan Africa.

Over the past 20 years most countries, particularly developing countries, have seen a large increase in the number of students seeking higher education. A consequence of this growth is increasing pressure on teaching staff and institutions, usually resulting in, among other effects, increased class size. Large classes of between 300 and 1,000, and even more, at the undergraduate level are not uncommon in a number of countries (Mulryan-Kyne in Teach High Educ 15(2):175-185, 2010). Large classes are often per- ceived as one of the major obstacles to the attainment of quality education. Despite the difficulties associated with teaching and learning in large classes, they remain a reality in many countries affecting learners across all levels of the education system and are often the only perceived option available to meet growing demand for higher education in Sub- Saharan Africa (Mohamedbhai in The effects of massification on higher education in Africa. Report from the Working Group on Higher Education of the Association for the Development of Education in Africa, 2008). We contend that the challenges of delivering large classes can be confronted, and in many ways diminished, through the use of current and emerging technologies and enhanced faculty development. In this expository paper, we present findings from project activities focused on higher education faculty development and capacity building. The findings include both formative and summative development activities, as well as data collected in faculty professional development workshops and the results of two surveys. We use these data to lay out issues, challenges (e.g., skills, resources, logistics—including poor campus infrastructure), and opportunities (e.g., mobile capacity, distance tools such as Moodle) of large class pedagogy using a design-based research framework.
Prediction of Peak Serum Vancomycin Levels from Trough Values in Neonates 1438

The high incidence of infections with coagulase-negative staphylococcus has resulted in a very frequent use of vancomycin (V) in the NICU. Levels of V should be at least adequate to kill bacteria with intermediate resistance(IR), which are increasing in prevalence. In adults, peak V levels can be accurately predicted from trough values, so that measuring trough levels may be sufficient in patients with normal renal function. In neonates, however, we expected that high variability of pharmacokinetics of V and renal function would limit the predictability of peak levels from trough values. We administered V according to the protocol described in NeoFax, which is based on the volume of distribution (Vd) and glomerular filtration rate that are expected for gestational age (GA) and postconceptional age (PCA). We obtained a steady state trough level at the fourth dose and a peak level one hour after the end of a 1-hour infusion. We assumed a single compartment distribution, first order kinetics and completion of V distribution at the time of peak level. We measured V levels by Syva EMIT reaction and plasma serum creatinine concentrations (Pcr) by kinetic Jaffe method using a Hitachi 914 or a Delta CX3. We have obtained 100 paired V levels in 72 patients with a GA of 29.4±4.7 weeks (mean ±SD) and a PCA of 32.9 ±4.5 weeks. Six patients had a high peak and a low trough or vice-versa. The agreement between peak and trough was poor (Cohen Kappa 0.18, p<0.014, 95% CI 0.03-0.33). If trough alone had been obtained, adjusting the interval but not the dose, would have led to peak levels that would have been toxic in 6 patients, and subtherapeutic for IR organisms in 4 patients. Peak level was best predicted(r=0.71, p<0.001, n=78) from dose, trough and PCA using the formula: Peak(μg/ml) = 19.02 + 1.07 dose (mg/kg) + 1.05 trough (μg/ml) - 0.47 PCA(wk). The standard error of the estimate was high (6.8), leading to a 95% CI that was twice the width of the normal range for peak values. The clearance, half-life and the Vd of V had an inter-individual coefficient of variance greater than 50%. The prediction of peak V level did not improve by using Pcr, possibly because of the low precision of Pcr measurements by kinetic Jaffe in neonates, especially for levels <1 mg/dl (Clermont et al, 1986).Within the limits of the methods, peak V levels cannot be reliably predicted from trough values in neonates.
Analysis of a Ladyzhenskaya model for incompressible viscous flow

Abstract In this paper we analyze a model for the motion of incompressible viscous flows proposed by Ladyzhenskaya. We establish a new a priori estimate for the nonstationary model and then obtain more general existence and uniqueness results. We also present some uniqueness results for the stationary model. The relationship between fluid motion governed by the Ladyzhenskaya model and that governed by the Navier-Stokes equations is addressed.
Real-time background suppression during frequency domain lifetime measurements.

Abstract We describe real time background suppression of autofluorescence from biological samples during frequency domain or phase modulation measurements of intensity decays. For these measurements the samples were excited with a train of light pulses with widths below 1 ps. The detector was gated off for a short time period of 10 to 40 ns during and shortly after the excitation pulse. The reference signal needed for the frequency domain measurement was provided by a long-lifetime reference fluorophore which continues to emit following the off-gating pulse. Both the sample and the reference were measured under identical optical and electronic conditions avoiding the need for correction of the photomultiplier tube signal for the gating sequence. We demonstrate frequency domain background suppression using a mixture of short- and long-lifetime probes and for a long-lifetime probe in human plasma with significant autofluorescence.
Trial Lawyers and Testosterone: Blue-Collar Talent in a White-Collar World1

Three studies considered whether trial lawyers, in their hormones and their language, might be regarded as blue-collar workers of the legal system. Study 1 found that lawyers as a group had testosterone levels similar to other white-collar workers and lower than blue-collar workers. Study 2 found that male and female trial lawyers had testosterone levels higher than nontrial lawyers of the same gender; the difference between lawyer types was approximately the same as the difference between blue- and white-collar workers. Study 3 found that trial lawyers used fewer cognitive mechanisms than did appellate lawyers in oral arguments before the Supreme Court. High levels of testosterone are associated with energy, dominance, persistence, combativeness, and focused attention, qualities that are useful both in trial lawyering and blue-collar work.
War and reconciliation

Many scholarly disciplines as well as popular opinion recognize reconciliation as a powerful force in restoring social order following conflict. Reconciliation between countries following a war or a series of wars has attracted little attention from international relations scholars, however. This paper uses four international events datasets developed by others and a reconciliation events dataset assembled by the authors to determine whether reconciliation events lead to a discernable decrease in the level of conflict between former belligerents. The results suggest that reconciliation events signal a change towards more cooperative and less conflictual bilateral relations in a number of cases. The impact of reconciliation is hardly uniformly positive, however, and limitations of the data constrain what can be asserted. The paper concludes with thoughts on continuing this inquiry to determine the forces that give rise to reconciliation and the factors that might explain the variance in the dependent varia...
Improved outcomes with radiation for prostate cancer.

Radiation has been widely used to treat prostate cancer for almost 100 years. Early results were suboptimal, but a series of important technical improvements in the 1980s and 1990s allowed substantial dose escalation for external beam and brachytherapy radiation. The technical improvements were significant advances associated with increased evidence of higher cure rates and acceptable complication rates.
Gene-environment factors that contribute to alcoholic pancreatitis in humans

Alcohol-associated acute and chronic pancreatitis occur in a minority of alcohol users, suggesting that most drinkers are protected from pancreatic diseases while a subset is susceptible. Ongoing studies suggest that the pathophysiology is complex and can involve multiple genetic and environmental pathways and stochastic events. Both rat models and human genetic epidemiology studies have been used to understand susceptibility and modifying factors in humans. Rat studies suggest that different types of altered pancreatic physiology occur depending on dose, they occur rapidly and that alcohol changes the immune response to recurrent pancreatic injury. Human studies suggest that PRSS1 and SPINK1 mutation increase the pancreas' susceptibility to alcohol-associated pancreatitis, and that tobacco smoking, and some factors, affect disease progression.
Transgenic Analysis of Signaling Pathways Required for Xenopus Tadpole Spinal Cord and Muscle Regeneration

The Xenopus tadpole has the capacity fully to regenerate its tail after amputation. Previously, we have established that this regeneration process requires the operation of several signaling pathways including the bone morphogenic protein, Wnt, and Fgf pathways. Here, we have addressed the signaling requirements for spinal cord and muscle regeneration in a tissue-specific manner. Two methods were used namely grafts of transgenic spinal cord to a wild type host, and the use of the Tet-on conditional transgenic system to express inhibitors in the individual tissues. For the grafting experiments, the tail was amputated through the graft, which contained a temperature inducible inhibitor of the Wnt-β-catenin pathway. For the Tet-on experiments, treatment with doxycycline was used to induce cell autonomous inhibitors of the Wnt-β-catenin or the Fgf pathway in either spinal cord or muscle. The results show that both spinal cord and muscle regeneration depend on both the Wnt-β-catenin and the Fgf pathways. This experimental design also enables us to observe the effect of inhibition of regeneration of one tissue on the regeneration of the others. Regardless of the method of inhibition, we find that reduction of spinal cord regeneration reduces regeneration of other parts of the tail, including the myotomal muscles. In contrast, reduction of muscle regeneration has no effect on the regeneration of the spinal cord. In common with other regeneration systems, this indicates that soluble factors from the spinal cord are needed to promote the regeneration of the other tissues in the tail.
Large-orbital-degeneracy expansion for the lattice Anderson model

We study the low-temperature Anderson lattice Hamiltonian via an ``auxiliary-boson'' 1/N expansion that generalizes to a lattice an approach previously used to study one Anderson impurity. We set up the formalism needed and show that infrared divergences cancel in physical quantities. We show that as far as low-energy excitations are concerned the model behaves like a ``heavy'' Fermi liquid with a Fermi temperature determined essentially by the one-impurity Kondo temperature. We compute thermodynamic quantities including the Wilson ratio, we study the electron wave functions in the ground state of the lattice and compare them with the wave functions in the ground state of the one-impurity problem, we discuss the question of which physical quantities involve the ``mass enhancement'' present in the thermodynamics, we compute the spin-spin and density-density correlation functions, and we discuss the frequency- and temperature-dependent conductivity, obtaining results in qualitative agreement with experiment.
Development and Reproduction of Ladybeetles (Coleoptera: Coccinellidae) on the Citrus Aphids Aphis spiraecola Patch and Toxoptera citricida (Kirkaldy) (Homoptera: Aphididae)

Abstract Seven species of Coccinellidae inhabiting citrus groves in Florida were evaluated for ability to develop and reproduce on the citrus aphids Toxoptera citricida (Kirkaldy) and Aphis spiraecola Patch. Choice tests performed with adults and larvae indicated that both aphid species were generally acceptable prey. Coccinella septempunctata L., Coleomegilla maculata fuscilabris (Mulsant), Coelophora inaequalis F., and Olla v-nigrum Mulsant were unable to complete development on either aphid. Hippodamia convergens Guerin larvae completed development on A. spiraecola with 68% survival; none survived on T. citricida. Only Cycloneda sanguinea (L.) and Harmonia axyridis Pallas completed development on both A. spiraecola (60 and 70% survival, respectively) and T. citricida (100 and 95% survival, respectively). Larval developmental time was shorter on T. citricida than on A. spiraecola, and resulting adults were heavier, differences being more pronounced in H. axyridis. Females of C. septempunctata, C. inaequalis, and O. v-nigrum produced viable eggs on T. citricida. O. v-nigrum did not produce eggs on A. spiraecola. Females of C. m. fuscilabris and H. axyridis produced no eggs on A. spiraecola and mostly infertile eggs on T. citricida. Female H. convergens laid twice as many eggs feeding on T. citricida as on A. spiraecola and egg viability was similar. C. sanguinea females laid similar numbers of eggs on both aphids, but eggs produced on A. spiraecola had higher fertility. Pollen added to the T. citricida diet temporarily improved the fertility of H. axyridis females, but not that of C. sanguinea females. C. sanguinea was judged the best candidate for augmentative biocontrol of T. citricida, the primary vector of citrus tristeza virus.
Synthesis and properties of imide-aryl ether 1,2,4-triazole random copolymers

New imide-aryl ether copolymers containing a 1,2,4-triazole heterocyclic unit were prepared by reaction of new 1,2,4-triazole diamines with 4,4'-oxydianilines and pyromellitic dianhydride. Curing of the resulting poly(amic acid)s at 350°C yielded films with good mechanical properties. The polyimides have decomposition temperatures in the range of 425-490°C
Mixed-mode singularity and temperature effects on dislocation nucleation in strained interconnects

Dislocations can be nucleated from sharp geometric features in strained interconnects due to the thermal expansion coefficient mismatch, lattice mismatch, or stresses that arise during material processing. The asymptotic stress fields near the edge root can be described by mixed-mode singularities, which depend on the dihedral angle and material properties, and a transverse T-stress, which depends on how residual stress is realized in the interconnects. The critical condition for stress nucleation can be determined when an appropriate measure of the stress intensity factors (SIFs) reaches a critical value. This method, however, does not offer an explicit picture of the dislocation nucleation process so that it has difficulties in studying complicated structures, mode mixity effects, and more importantly the temperature effects. Using the Peierls concept, a dislocation can be described by a continuous slip field, and the dislocation nucleation occurs when the total potential energy reaches a stationary state. Through implementing this ad hoc interface model into a finite element framework, it is found that dislocation nucleation becomes more difficult with the increase of mode mixity, or the decrease of the T-stress, or the decrease of the length-to-height ratio of the surface pad, while the shape of the surface pad, being a square or a long line, plays a less important role. The Peierls dislocation model also allows us to determine the activation energy, which is the energy needed for the thermally activated, mechanically assisted dislocation nucleation when the applied load is lower than the athermal critical value. The calculated saddle point configuration agrees well with the molecular simulations in literature. Suggestions on making immortal strained interconnects are made.
Simulation-based experimental design and statistical modeling for lead time quotation

In a produce-to-order environment, it is of substantial interest to be able to quote a tight and reliable lead time for a new job (or order) upon its arrival to a manufacturing system. This work developed a simulation-based statistical approach to provide responsive and high-quality prediction of a new job's flow time through the system, which renders the capability of accurately quoting lead times in real time. The approach integrates analytical queueing analysis, design of experiments, and statistical modeling to quantify the dependence of a new job's flow time distribution upon the shop status “seen” by that job. To the best of our knowledge, this is the first attempt to design simulation experiments in the space spanned by a complete set of shop status factors for the thorough investigation of the possible impacts those factors may have on the distribution of a new job's flow time. The method has been applied on a scaled-down semiconductor manufacturing system, and the quality of the quoted lead time has been evaluated based on a large and well-designed validation data set in terms of the six commonly used performance criteria.
Isolation and Partial Characterization of Plasmalemma from Quiescent Schwann Cells in Denervated Cat Sciatic Nerve

: Fractions enriched in plasma membranes have been obtained from peripheral nerves enriched 89% in quiescent Schwann cells. Fractions were prepared from the intrafascicular tissue of desheathed distal stumps of cat sciatic nerve 8–10 weeks after transection and suture in the upper thigh. Tissue enriched in Schwann cells was minced, homogenized, and centrifuged to remove nuclei and undispersed tissue. Centrifugation of the resulting supernatant produced a pellet that was osmotically shocked, layered over a discontinuous sucrose gradient, and recentrifuged. Fractions enriched in plasma membrane (PM) markers were pooled, osmotically shocked for 16 h, layered over a second discontinuous sucrose density gradient, and recentrifuged. Membrane fractions (0.6 M:0.85 M and 0.85 M: 1.0 M interfaces) contained a homogeneous population of unilamellar vesicles free of myelin. The 0.85 M fraction was enriched in 5′-nucleotidase, 2′,3′-cyclic nucleotide 3′-phosphohydrolase, and specific [3H]ouabain binding, 4.8–, 3.0–, and 5.7–fold over the crude homogenate, respectively. These fractions also demonstrated low enzyme activities for succinate de-hydrogenase, lactate dehydrogenase, and glucose-6–phos-phatase (9, 13, and 15% of control values, respectively). Protein yield of the PM fraction (0.85 M) was approximately 0.6 mg/g of denervated nerve. This preparation should be suitable to characterize the surface properties of Schwann cells free of neuronal regulation.
Organizational Size and Job Satisfaction

The article tests the hypothesis that organizational size is inversely related to job satisfaction in the context of several studies which examined the relations between the two. The hypothesis has...
Therapy insight: Potential of statins for cancer chemoprevention and therapy.

Statins are commonly prescribed to treat dyslipidemia and to prevent coronary artery disease, but studies also indicate their potential for cancer prevention. Preclinical data suggest pleiotropic antineoplastic effects of statins, but clinical data assessing cancer risk associated with statin use are conflicting. This review critically discusses the existing evidence highlighting the role of statins for cancer chemoprevention. The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, are commonly prescribed medications that lower serum cholesterol and decrease cardiac morbidity and mortality. These agents inhibit the rate-limiting step of the mevalonate pathway, an effect that influences cholesterol homeostasis and other diverse cellular functions. Preclinical data suggest statins have pleiotropic antineoplastic effects in a variety of tumors, but clinical studies have provided conflicting data regarding whether statins may increase or decrease the risk of cancer. Abnormal cholesterol metabolism in cancer is poorly understood but should be considered when evaluating the antineoplastic effects of statins. Emerging evidence suggests that atherosclerosis and cancer have similar underlying molecular mechanisms, both having lipid abnormalities and a pro-inflammatory phenotype. Like nonsteroidal anti-inflammatory agents, statins target lipid metabolism, have significant anti-inflammatory effects, and can influence cardiovascular mortality. Recent studies show that statins may have chemopreventive effects and may complement cytotoxic chemotherapy or radiotherapy as a biologic response modifier in established cancer, but current data do not support their use as monotherapy. The preclinical data supporting anticancer activity, their additional health benefits, and the safety and relative low cost of statins compared to other 'targeted' agents currently under development all favor conducting prospective clinical trials of these drugs in cancer chemoprevention and therapy.
A high precision goniometer for charged particle spectroscopy

Abstract A high precision goniometer capable of positioning Ge(Li) charged particle detectors with a precision of ±0.02° has been built. This device consists of a 4 ft radius, detector support which rotates outside of a central target vacuum chamber. The main features of the system are described and a summary of the tests to verify its operational capabilities is presented. A description is also given of the installation of the unit on the beam line, illustrating the precautions which were taken to insure alignment. The performance of this apparatus in studying Ni(p,p′) reactions at 40 MeV is discussed.
Economic & commercial viability of hydrogen fuel cell vehicles from an automotive manufacturer perspective

Abstract Ford Motor Company's experience with Fuel Cell Vehicle (FCV) technology began over ten years ago with the P2000 concept. Development of this vehicle demonstrated technological feasibility of, and revealed a number of challenges to, automotive fuel cell commercialization. By 2005, Ford launched the Focus FCV fleet in partnership with the U.S. Department of Energy, Fuel Cells Canada (now Hydrogen and Fuel Cells Canada), and the Clean Energy Partnership (CEP). This fleet was tested to Federal Motor Vehicle Safety Standards (FMVSS) and was placed in service for general on-road usage. Following the Focus fleet, Ford introduced the Fuel Cell Explorer (2005), the Hydrogen 999 (2007), and the HySeries Edge (2007). With each of these new vehicles, more forward looking technologies were implemented for on-road demonstration and testing. To-date the Company's fuel cell powertrains have logged over 1 million miles, accumulated over 30,000 h of operation, propelled an FCV in excess of 207 mph, and achieved significant milestones for cold start, cost reduction, and thermodynamic efficiency. Other achievements include the implementation of new automotive requirements and test procedures, as well as service and architectural standards unique to hydrogen/fuel cell powered vehicles. A discussion is presented here that outlines the above and other key successes in the development of Ford's automotive fuel cell technology. Additionally, inhibitors to the development path are outlined. The state of the technology suggests that recent predictions of major market penetration in the 2010–2035 time period are optimistic. Without disruptive technological change, material availability considerations alone will prevent this. Unfortunately a great deal of unwarranted hype in the popular press, industry, and academia has led to the perception that widespread automotive application of fuel cell technology is a near-term certainty. The magnitude of the technological, economic, and other challenges make this (popular) outlook unlikely. Nevertheless, Ford successes to-date lead it to remain committed to the long-term development path that it began well over a decade ago. Ford believes that fuel cell vehicles will become economically viable, and an important contributor to the resolution of global warming and air quality issues.
Comparative Cost-effectiveness of the Baerveldt Implant, Trabeculectomy With Mitomycin, and Medical Treatment

Importance The Tube vs Trabeculectomy Trial (TVT) found that the 350-mm 2 Baerveldt implant (tube) and trabeculectomy with mitomycin may be similarly effective in lowering intraocular pressure in primary open-angle glaucoma. However, to date, there are no published long-term clinical data on the cost-effectiveness of trabeculectomy with mitomycin vs tube insertion. Objective To assess the cost-effectiveness of these procedures compared with maximal medical treatment. Design, Setting, and Participants We used the Markov cohort model with a 5-year time horizon to study a hypothetical cohort of 100 000 patients who required glaucoma surgery. Main Outcomes and Measures Quality-adjusted life-years (QALYs) gained, costs from the societal perspective, and the incremental cost-effectiveness ratio of medical treatment, trabeculectomy, and tube insertion. Costs were identified from Medicare Current Procedural Terminology and Ambulatory Payment Classification reimbursement codes and Red Book medication costs. The QALYs were based on visual field and visual acuity outcomes. The hypothetical societal limit to resources was included using a willingness-to-pay threshold of $50 000 per QALY. Costs and utilities were discounted at 3% per year. Uncertainty was assessed using deterministic sensitivity analyses. Results The mean costs for medical treatment, trabeculectomy, and tube insertion were $6172, $7872 and $10 075, respectively; these amounts resulted in a cost difference of $1700 (95% CI, $1644-$1770) for medical treatment vs trabeculectomy, $3904 (95% CI, $3858-$3953) for medical treatment vs tube insertion, and $2203 (95% CI, $2121-$2261) for trabeculectomy vs tube insertion. The mean 5-year probability of blindness was 4% for both surgical procedures and 15% for medical treatment. The utility gained after medical treatment, trabeculectomy, and tube insertion was 3.10, 3.30, and 3.38 QALYs, respectively. The incremental cost-effectiveness ratio was $8289 per QALY for trabeculectomy vs medical treatment, $13 896 per QALY for tube insertion vs medical treatment, and $29 055 per QALY for tube insertion vs trabeculectomy. The cost-effectiveness of each surgical procedure was most sensitive to early and late surgical failure rates and was minimally affected by adverse events, rates of visual field progression, or medication costs. Conclusions and Relevance Assuming a willingness to pay of $50 000 per QALY, trabeculectomy and tube insertion are cost-effective compared with medical treatment alone. Trabeculectomy, however, is cost-effective at a substantially lower cost per QALY compared with tube insertion. More research is necessary to reliably account for patient preferences between the 2 operations.
Inequalities for the parallel connection of resistive n-port networks

Abstract Inequalities are derived relating the impedance and admittance matrices of parallel connections without ideal transformers to the matrices of parallel connections with ideal transformers; necessary and sufficient conditions for equality are given. Equivalent conditions for equality, but not the inequalities themselves, were previously obtained in the invertible case by Lempel and Cederbaum and by Murti and Thulasiraman.
Image-guided brachytherapy for cervical cancer: Analysis of D2 cc hot spot in three-dimensional and anatomic factors affecting D2 cc hot spot in organs at risk

Abstract Purpose To analyze the D2 cc hot spot in three-dimensional CT and anatomic factors affecting the D2 cc hot spot in organs at risk (OARs). Methods and Materials Thirty-one patients underwent pelvic CT scan after insertion of the applicator. High-dose-rate treatment planning was performed with standard loading patterns. The D2 cc structures in OARs were generated in three dimensional if the total equivalent dose in 2 Gy exceeded our defined dose limits (hot spot). The location of D2 cc hot spot was defined as the center of the largest D2 cc fragment. The relationship between the hot spot and the applicator position was reported in Digital Imaging and Communication in Medicine coordinates. Results The location of sigmoid, small bowel, and bladder D2 cc hot spots was around the endocervix: The mean location of sigmoid hot spot for lateral view was 1.6 cm posteriorly and 2.3 cm superiorly (Y, 1.6 and Z, 2.3), small bowel was 1.6 cm anteriorly and 2.7 cm superiorly (Y, −1.6 and Z, 2.7). The mean location of bladder hot spot was 1.6 cm anteriorly and 1.6 cm superiorly (Y, −1.6 and Z, 1.6). These hot spots were near the plane of Point A (X, 2.0 or −2.0; Y, 0; and Z, 2.0). The mean location of rectal hot spot was 1.6 cm posteriorly and 1.9 cm inferiorly (Y, 1.6 and Z, −1.9). D2 cc hot spot was affected by uterine wall thickness, uterine tandem position, fibroids, bladder fullness, bowel gas, and vaginal packing. Conclusions Because of the location of the D2 cc hot spots, larger tumors present a challenge for adequate tumor coverage with a conventional brachytherapy applicator without an interstitial implant. Additionally, anatomic factors were identified which affect the D2 cc hot spot in OARs.
Malignant melanoma with a myxoid stroma: a diagnostic pitfall on fine-needle aspiration biopsy.

Malignant melanoma (MM), both primary and metastatic, may be associated with a prominent myxoid stromal reaction causing diagnostic confusion on fine-needle aspiration biopsy (FNAB), most often with sarcomas that demonstrate a myxoid stroma, particularly malignant peripheral nerve sheath tumor (MPNST). We present a case of a 32-yr-old man with no past medical history who presented with a unilateral neck mass clinically suspicious for lymphoma. FNAB produced a specimen composed of large sheets of anaplastic cells encased in a myxoid stroma that was S100 and vimentin-positive but HMB-45-negative. A diagnosis of MPNST was made. Excision demonstrated a metastatic MM of unknown primary, with a prominent myxoid stromal reaction. A repeat HMB-45 was again negative. Electron microscopy demonstrated intracytoplasmic melanasomes and cisternae of rough endoplasmic reticulum with intracisternal parallel tubules, confirming the diagnosis. Although HMB-45 is typically negative in both tumors, S100 should be strongly positive in myxoid MM and only focal in MPNST.
Excitation energy dependent photochemistry near the carbon K edge in polymer films

Ion desorption from solid films of polystyrene and polyethylene is used to monitor chemistry following excitation by monochromatic soft X-rays. The chemical relaxation depends upon the nature of the state created in the excitation process. Excitation of ..pi.. resonances in polystyrene does not produce ion desorption unlike nearby resonances. Possible explanations are suggested. 14 references, 1 figure.
Learning of boundary patterns to recognize the gradually changed patterns within the boundary

If the binary image pattern, e.g., the edge-detected boundary of an object, is varying in real time among several extreme boundaries, then learning just the extreme boundaries by an OLNN (one-layered neural network) will allow the OLNN to recognize any unlearned, time-varying patterns of the object varying among these extreme boundaries. This is possible because of the unique property of CONVEX LEARNING existing in the OLNN. This paper will first derive this property from mathematical point of view, and then verify it with some simple experiments. The main advantage of this neural network is that it can recognize very similar objects not only from the static patterns it learns but also from the ways how these objects vary in real time even these varying patterns are NOT learned one by one at each time. Consequently the recognition is much more accurate than just learning the static patterns alone.
Analysis of Intestinal Microvascular Permeability Associated with Cardiopulmonary Bypass

Abstract Background.Cardiopulmonary bypass (CPB) is associated with a generalized inflammatory response and splanchnic edema formation that are thought to be related to microvascular barrier injury. In particular, intestinal edema and dysfunction have been associated with sepsis and post-CPB complications. The purpose of this study was to measure the forces determining fluid flux induced by CPB across the intestinal microvascular barrier. Materials and methods.An anesthetized canine model was used for this study (n= 12). To determine mesenteric microvascular permeability, a mesenteric lymphatic was cannulated and mesenteric venous pressure was elevated to 33 ± 1 mm Hg to reach a minimal lymph protein concentration (CL). With simultaneous measurement of plasma protein concentrations (CP), the reflection coefficient, ς, was calculated using the formula: ς = 1 −CL/CP. Capillary pressures (PC), lymph flow (QL), lymph protein flux, transvascular protein flux, and intestinal tissue water were all measured using standard techniques. Normothermic cardiopulmonary bypass with flows of 75–80 ml/kg/min was initiated after a steady state was achieved, and CPB was continued for 2 h and then discontinued. Measurements were repeated 30 min after CPB was discontinued. A second group (n= 5) was studied without mesenteric venous pressure elevation to evaluate the role of capillary pressure on the increased fluid flux seen with the initiation of CPB. Results.Initiation of CPB was associated with an increase in intestinal microvascular permeability. ς decreased from 0.77 ± 0.01 to 0.68 ± 0.01 (P Conclusions.Initiation of CPB results in a moderate increase in intestinal microvascular permeability to protein and an increase in intestinal tissue water. The increases in tissue water are not due to increased capillary pressure. A better understanding of the microvascular changes associated with extracorporeal circulation will facilitate the search for clinical interventions to minimize the impact of CPB.
PERIODIC OPERATION OF CHEMICAL REACTOR SYSTEMS: ARE GLOBAL IMPROVEMENTS ATTAINABLE?

Application of forced oscillations to chemical reactor systems is investigated for three systems based on: (1)a homogeneous/heterogeneous reaction mechanism proposed by Horn and Bailey (1968) (2)amine and alcohol reactions on oxide catalysts and (3)cobalt catalyzed CO methanation. Previous analyses of these systems have demonstrated experimentally and/or theoretically, significant enhancements in reactor performance upon periodic operation. For the three cases investigated, computer-simulated modelling confirms great improvements in reactor performance upon periodic concentration forcing: (1)30% enhancement in selectivity, (2)50 fold increase in reaction rate and (3)13 fold improvement in conversion, respectively. However, it is also observed that yield improvements in these systems do not exceed or even match the performance obtained under optimal steady state conditions.
Conversion of glucose into levulinic acid with solid metal(IV) phosphate catalysts

Abstract We have prepared a series of well-characterized solid acid metal(IV) phosphate catalysts and tested them for the two-step dehydration/rehydration reaction to produce levulinic acid from glucose. The catalysts include zirconium (ZrP) and tin (SnP) phosphates with varying ratios of phosphorus to metal(IV). The structural, surface and bulk properties have been investigated using XRD, BET, XPS and 31P solid-state MAS NMR spectroscopy. ZrP is distinguished by a high concentration of polyphosphate species in the bulk phase, as well as increased hydroxyl groups on the surface. ZrP also shows a higher concentration of total acid sites and Bronsted acid sites compared to SnP, as determined by TPD measurements using gas-phase NH3 and isopropylamine. The catalyst selectivity is a function of the Bronsted to Lewis acid site ratio using either heterogeneous or homogeneous catalysts. Catalytic activity increases with increased Lewis acid sites. The Lewis sites mainly produce fructose via isomerization reactions and undesired degradation products (humins). HMF is produced on both Bronsted and Lewis sites, whereas levulinic acid is exclusively produced on Bronsted sites. Zirconium phosphate with a P/Zr molar ratio of 2 is favorable for levulinic acid production due to its inherently high surface area and enhanced Bronsted acidity. This study lays the grounds for further design of improved solid acid catalysts for aqueous phase production of HMF and levulinic from carbohydrates.
Investigating the Effect of Complexity Factors in Stoichiometry Problems Using Logistic Regression and Eye Tracking

This paper includes two experiments, one investigating complexity factors in stoichiometry word problems, and the other identifying students' problem-solving protocols by using eye-tracking technology. The word problems used in this study had five different complexity factors, which were randomly assigned by a Web-based tool that we developed. The logistic regression analysis in the first experiment of this study showed that the ability of a student to achieve a correct answer was dependent on three complexity factors: number format, unit, and chemical equation. This was followed by an eye-tracking experiment, which reaffirmed that eye fixation durations were different between students at different levels of success when they solved chemistry word problems. The online tool in this study provides a general instrument to design chemistry word problems with various complexities, as well as a method to quantitatively assess problem difficulty and students' cognitive load. This can be applied in constructing curricula and examinations with desired difficulties in chemistry courses.