cssi/SciSciGPT-SciSciNet huggingface dataset:
An Algorithmic Answer to the Ore-Type Version of Dirac’s Question on Disjoint Cycles

Corradi and Hajnal in 1963 proved the following theorem on the NP-complete problem on the existence of k disjoint cycles in an n-vertex graph G: For all k ≥ 1 and n ≥ 3k, every (simple) n-vertex graph G with minimum degree δ(G) ≥ 2k contains k disjoint cycles. The same year, Dirac described the 3-connected multigraphs not containing two disjoint cycles and asked the more general question: Which (2k − 1)-connected multigraphs do not contain k disjoint cycles? Recently, Kierstead, Kostochka, and Yeager resolved this question. In this paper, we sharpen this result by presenting a description that can be checked in polynomial time of all multigraphs G with no k disjoint cycles for which the underlying simple graph \( \underline {G}\) satisfies the following Ore-type condition: \(d_{ \underline {G}}(v)+d_{ \underline {G}}(u)\geq 4k-3\) for all nonadjacent u, v ∈ V (G).
Equivalent Outcomes With Retransplantation and Primary Liver Transplantation in the Direct-acting Antiviral Era.

BACKGROUND The present multicenter study investigated whether equivalent outcomes to primary liver transplant (LT) could be achieved with liver retransplant (reLT) and whether improvements in outcomes have taken place over time, particularly in the direct-acting antiviral era. METHODS All reLT performed at Mayo Clinic Florida, Mayo Clinic Rochester, and Mayo Clinic Arizona were divided into era 1 (2002-2007), era 2 (2008-2012), and era 3 (2013-2017) based on the date of reLT. RESULTS Improvement in graft survival (GS) after reLT was seen over the 3 eras (P < 0.001). In era 1, GS after reLT was inferior to primary LT (P < 0.001), whereas no difference was seen between reLT and primary LT in era 2 (P = 0.68) or era 3 (P = 0.36). A significantly higher proportion of patients achieved sustained viral response (SVR) within the first year after reLT in each subsequent era (era 1: 10.3%, era 2: 22.5%, and era 3: 100%) (P < 0.001). Graft survival was superior in patients undergoing reLT for recurrent hepatitis C virus who achieved SVR after reLT compared with those who did not (P = 0.03). CONCLUSIONS Results similar to primary LT were achieved in era 3. These improvements coincide with the availability of direct-acting antivirals, which resulted in a 100% SVR rate in era 3 and a decrease in the number of patients undergoing reLT for recurrent hepatitis C virus. The historic dogma that reLT results in inferior outcomes should be revisited.
A Comprehensive Rethinking of Equal Protection Post-Obergefell: A Plea for Substantivity in Law

Obergefell v. Hodges, the case holding that same-sex marriage is a fundamental right that states cannot deny, is widely regarded by progressives as a civil rights milestone. Lochner v. New York, on the other hand, is nearly uniformly considered by constitutional scholars, progressive or not, as a virtual epithet—one of the worst blunders in Supreme Court history. In this Article, drawing together years of my ideas and scholarship written to link substantive equality outcomes with the practice of law, I argue, from a pro-gay rights perspective, that Obergefell and Lochner are actually cut from the same cloth and ultimately that substantive due process, the engine of both decisions, will never successfully vindicate the rights of gay Americans or of other marginalized classes. I contend that, under Justice Kennedy's leadership, the Court's continued subsumption of equal protection into the due process clause actually perpetuates inequality, even when the outcome (like access to marriage) appears to promote equality. The culmination of this analysis is my proffering of a theory of equal protection that is substantive in its own right.
Transparent Boundary Conditions for the Time-Dependent Schr\"odinger Equation with a Vector Potential

We consider the problem of constructing transparent boundary conditions for the time-dependent Schrodinger equation with a compactly supported binding potential and, if desired, a spatially uniform, time-dependent electromagnetic vector potential. Such conditions prevent nonphysical boundary effects from corrupting a numerical solution in a bounded computational domain. We use ideas from potential theory to build exact nonlocal conditions for arbitrary piecewise-smooth domains. These generalize the standard Dirichlet-to-Neumann and Neumann-to-Dirichlet maps known for the equation in one dimension without a vector potential. When the vector potential is included, the condition becomes non-convolutional in time. For the one-dimensional problem, we propose a simple discretization scheme and a fast algorithm to accelerate the evaluation of the boundary condition.
1992 National Clinical Pharmacy Services Study.

Study Objective. To determine the extent of hospital-based clinical pharmacy services in 1992. Design. National survey with trend comparison to 1989. Setting. All 1597 United States acute care, general medical-surgical and pediatric hospitals with 50 or more licensed beds and one or more full-time pharmacists (43% of all U.S. hospitals). Measurements and Main Results. Fourteen clinical pharmacy services, carefully defined to indicate pharmacist proactive or concurrent patient care provision, were assessed to determine pharmacists' specific patient care responsibilities. The percentage of hospitals offering each of the services increased from 1989 to 1992, with greatest growth in management of adverse drug reactions (22% increase), pharmacokinetic consultations (14%), and drug therapy protocols (12%). The mean percentage of patients actually receiving clinical pharmacy services ranged from 0.2% for pharmacist participation on the cardiac arrest team to 36.1% for daily monitoring of drug therapy. Pharmacists conducted clinical research in 13% of all hospitals, averaging 3.9 ± 4.3 protocols per year with a total budget of $79,765 ± $128,641. Conclusions. Clinical pharmacy services continue to expand; however, even the most common direct patient care service is provided to a small number of inpatients.
Securing Large-scale Data Transfers in Campus Networks: Experiences, Issues, and Challenges

Increasingly, campus networks manage a multitude of large-scale data transfers. Big data plays a pivotal role in university research and impacts domains such as engineering, agriculture, natural sciences, and humanities. Over the years, numerous solutions have been proposed to manage and secure large-scale data transfers efficiently. Examples consist of the inclusion of security policies at the network edge, optimized middlebox management, and the Science Demilitarized Zone (Science DMZ). These solutions either severely degrade data transfer performance or result in data flows completely bypassing the campus network security controls. In this paper, we present our experience with the design, development, and management of large-scale data transfers using software defined networking (SDN) and network functions virtualization (NFV). We also discuss the issues and challenges associated with securing large-scale data transfers in campus networks.
Use of 3D-Printed and 2D-Illustrated International Frontal Sinus Anatomy Classification Anatomic Models for Resident Education:

ObjectiveTo examine the impact of 2-dimensional (2D) illustrations and 3-dimensonal (3D)–printed anatomic models of the frontal sinuses according to the International Frontal Sinus Anatomy Classifi...
Grandmothers raising their transgender grandchildren: An exploratory study

This exploratory study builds upon previous research relating to grandparents of transgender and gender-diverse (TGD) youth by investigating the experiences of 2 affirming grandmothers raising thei...
RELATIVISTIC HEAVY IONS — Workshop I

A brief review is presented of our present understanding of reactions induced by relativistic heavy ions.
Getting Incentives Right in Payment Reform: Thinking Beyond Financial Risk

Successful payment reform requires strong incentives for provider organizations to limit health care spending. Often overlooked in the debate over how to strengthen global budget models is that inc...
Computer Architecture Simulators for Different Instruction Formats

Several simple computer architecture simulators are developed and implemented for different instruction formats, including stack-based, accumulator-based, two-address, and three-address machines. These simulators can be used to assemble and run assembly language programs on the above computer architectures. Several simple applications are used to illustrate how to develop assembly language programs to deal with arrays, subroutines, and recursions on these different computer architectures. Students will have a better understanding of computer architectures by using these simulators on their assembly language programming assignments. In addition, students can also modify these simulators to add more instructions, debugging functions, and etc.
Necrotizing and exfoliative diseases of the skin

Diseases of the skin are a common problem seen in burn units internationally. These common disorders can be generally classified into two categories: necrotizing soft tissue disorders and exfoliative soft tissue disorders. Oftentimes patients present initially to primary medical centers but ultimately require transfer to tertiary burn centers due to the physiologic derangements associated with the large amount of total body surface area (TBSA) involved as well as for complex dressing care and wound management. As is the case with extensive thermal injuries, patients presenting with exfoliative and necrotizing diseases of the skin present unique challenges to the burn surgeon This chapter will address the relevant pathophysiology, as well as how to promptly diagnose and adequately treat each disease process.
Reconstituting Stratified Epithelial Branching Morphogenesis by Engineering Cell Adhesion

Abstract During embryogenesis, many organs undergo branching morphogenesis to form tree-like hierarchical structures. However, it remains unclear what drives branching in stratified epithelia, such as in embryonic salivary gland and pancreas. Here, we performed live-organ imaging of mouse embryonic salivary glands at single-cell resolution to reveal branching driven by expansion and folding of an epithelial surface cell sheet characterized by strong cell-matrix adhesion and weak cell-cell adhesion. We successfully reconstituted this early developmental process by experimentally suppressing E-cadherin expression and inducing basement membrane formation in 3D spheroid cultures of engineered cells. Reconstituted branching required integrin-mediated cell-matrix adhesions and was promoted by elevating cell-matrix adhesion strength. Thus, stratified epithelial branching is driven by the combination of strong cell-matrix adhesion and weak cell-cell adhesion of peripheral epithelial cells.
Genesis 2:24 as Basis for Monogamous Christian Marriage: Illustrations from Nigeria

The issue of monogamy versus polygamy has been a matter of constant debate within Christendom, particularly in Africa. There are several passages used to support monogamy as the biblical standard, but this article focuses on Genesis 2:24. Citing illustrations from Nigeria, the aim of this article is to examine the claim that Genesis 2:24 serves as a basis for monogamous Christian marriage. This article employs the descriptive and exegetical methods. It discovers that Genesis 2:24 is an aetiology, which means that it is descriptive rather than prescriptive. The essay concludes that the passage is silent on the form of marriage, whether monogamous or polygamous. The monogamy interpretation fails to take cognisance of the fact that the text is an aetiology, and therefore descriptive, having reference to marriage only as it was practised at the time of writing. The monogamy view also loses sight of the Mosaic laws that regulated the practice of polygamy. Finally, since the passage has no reference for monogamy or polygamy originally, it is incorrect to say that Jesus’ or Paul’s allusion to it supports monogamy.
La concepción de la comprensión en dos modelos de seguimiento de movimientos oculares: Just y Carpenter (1980) y Rayner y Pollatsek (1989)

Previous research on language comprehension has generally focused on the eye tracking method, as it allows us to account for reading processes and lexical access in real time. This method aims to observe the comprehension processes of the entire text contents. The contribution of these studies is undeniable, though visual processing of words is not a guarantee of its comprehension. For this reason, in this work I compare how comprehension is conceived in two models used in eye-tracking studies on language processing during reading: Just and Carpenter’s model (1980) and Rayner and Pollatsek’s model (1989), as they offer an interesting insight on text comprehension. This article mainly focuses on similarities and differences between both models and the extent to which the term processing could be used alternatively to refer to comprehension.
Expanded Use of Preloaded Branched and Fenestrated Endografts for Endovascular Repair of Complex Aortic Aneurysms.

Objective The aim of this study was to report the expanded use of preloaded catheters and wires of fenestrations and directional branches to facilitate access to renal and mesenteric target arteries during endovascular repair of complex aortic aneurysms. Methods This was an observational retrospective cohort multicentre study. Prospectively collected data from six physician sponsored investigational device exemption studies at US centres were analysed. Patients were treated with fenestrated and branched aortic endografts for pararenal and thoraco-abdominal aortic aneurysms (TAAAs) between 2012 and 2017. Technical success was defined as successful intra-operative catheterisation and stenting of all intended target visceral arteries. Univariable and stratified analyses were performed to identify differences in outcomes between repairs using preloaded and standard devices. Results There were 564 patients (73% men, mean age 73 ± 8 years) treated for 168 pararenal aortic aneurysms (29.8%), 216 type IV TAAAs (38.3%), and 180 type I – III TAAAs (31.9%). Preloaded grafts (PGs) were used in 387 (68.6%) patients and standard grafts (SGs) in 177 (31.4%). PGs were used preferentially for type IV TAAAs (45% vs. 24%; p Conclusion Endovascular repair of complex aortic aneurysms is safe and effective. The expanded use of preloaded catheters and wires of fenestrations and directional branches for target artery incorporation is associated with a high technical success and low early mortality.
Disability and the Surgical Career

If anything, surgery is a career of ability. So, what happens when a person with a disability tries to become a surgeon? In this chapter, I consider barriers to becoming a surgeon for people with disabilities and wonder what surgery would be like were we to lower those barriers.
Conference Summary: AGN Physics with the Sloan Digital Sky Survey

The ``AGN Physics with the Sloan Digital Sky Survey'' conference was held at Princeton University in July 2003 to bring together groups working inside and outside of the SDSS collaboration at radio through X-ray wavelengths to discuss the common goal of better understanding the physics of Active Galactic Nuclei (AGN). Although we still do not have a full understanding of AGN, much progress has been made in recent years. In this conference summary, we concentrate on those topics discussed at the meeting where we believe that there has been significant change or where there is a new standard of comparison, as well as on important new trends in AGN research.
Gravitational wave heating of stars and accretion discs

We investigate the electromagnetic (EM) counterpart of gravitational waves (GWs) emitted by a supermassive black hole binary (SMBHB) through the viscous dissipation of the GW energy in an accretion disk and stars surrounding the SMBHB. We account for the suppression of the heating rate if the forcing period is shorter than the turnover time of the largest turbulent eddies. We find that the viscous heating luminosity in 0.1M⊙ stars can be significantly higher than their intrinsic luminosity, but still too low to be detected for extragalactic sources. The relative brightening is small for accretion disks.
Multiphysics investigations for efficient contactless ultrasound acoustic energy transfer in fluid

Ultrasound acoustic energy transfer (UAET) is a transformative contactless energy transfer (CET) technology that outperforms conventional electromagnetic based CET techniques to recharge and communicate with low-power implanted medical devices which eliminates the need for invasive surgery. The limited modeling and proof-of-concept experiments on AET were performed in the linear range with several assumptions by neglecting the nonlinear wave propagation and the electroelastic nonlinearities of transmitter and receiver that become significant at higher source strengths and influence energy transfer characteristics. We present a series of experiments and experimentally-validated multiphysics models that we considered to address the knowledge gaps in UAET.
Problem framing and cognitive style: Impacts on design ideation perceptions

Designers' engagement in ideation is impacted by their perceptions of the parameters of the design task. Whereas expert designers actively interrogate and reframe given problems, novice designers tend to solve them as given. We investigated novice designers' perceptions of their ideas relative to problem frames and their cognitive styles. We found that innovative styles and framings corresponded to higher perceptions of idea diversity and creativity, whereas adaptive framings corresponded to lower perceptions of idea creativity and perceptions of greater difficulty generating ideas. Novice designers may hold implicit theories of creativity that undervalue adaptive creativity. However, problem frames that misalign with a novice's preferred cognitive style can impact their ideation, and so hold promise for challenging their initial interpretations and approaches.
Nano- and microplastics in the workplace.

The on-going COVID-19 pandemic has resulted in a dramatic increase in the use of N95 respirators, barrier face coverings, disposable gloves, gowns, and other measures to control the spread of SARS-...
Adolescent Dopamine Neurons Represent Reward Differently during Action and State Guided Learning.

Neuronal underpinning of learning cause-and-effect associations in the adolescent brain remains poorly understood. Two fundamental forms of associative learning are Pavlovian (classical) conditioning, where a stimulus is followed by an outcome, and operant (instrumental) conditioning, where outcome is contingent on action execution. Both forms of learning, when associated with a rewarding outcome, rely on midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra (SN). We find that, in adolescent male rats, reward-guided associative learning is encoded differently by midbrain dopamine neurons in each conditioning paradigm. Whereas simultaneously recorded VTA and SN adult neurons have a similar phasic response to reward delivery during both forms of conditioning, adolescent neurons display a muted reward response during operant but a profoundly larger reward response during Pavlovian conditioning. These results suggest that adolescent neurons assign a different value to reward when it is not gated by action. The learning rate of adolescents and adults during both forms of conditioning was similar, supporting the notion that differences in reward response in each paradigm may be because of differences in motivation and independent of state versus action value learning. Static characteristics of dopamine neurons, such as dopamine cell number and size, were similar in the VTA and SN of both ages, but there were age-related differences in stimulated dopamine release and correlated spike activity, suggesting that differences in reward responsiveness by adolescent dopamine neurons are not because of differences in intrinsic properties of these neurons but engagement of different dopaminergic networks. SIGNIFICANCE STATEMENT Reckless behavior and impulsive decision-making by adolescents suggest that motivated behavioral states are encoded differently by the adolescent brain. Motivated behavior, which is dependent on the function of the dopamine system, follows learning of cause-and-effect associations in the environment. We find that dopamine neurons in adolescents encode reward differently depending on the cause-and-effect relationship of the means to receive that reward. Compared with adults, reward contingent on action led to a muted response, whereas reward that followed a cue but was not gated by action produced an augmented phasic response. These data demonstrate an age-related difference in dopamine neuron response to reward that is not uniform and is guided by processes that differentiate between state and action values.
The Absolute Dimensions and Masses of IQ Persei

High signal-to-noise ratio spectrometric observations of the large light-ratio eclipsing binary IQ Per (B7 + A2) have been obtained with the coude Reticon spectrograph of the 2.7 m reflector at McDonald Observatory. Absorption lines of the secondary are seen at the 4481 A MgII line and the 4549 A TiII + FeII blend. Radial velocities of both components have been measured by cross-correlation techniques and spectroscopic orbits have been computed. The fitted orbits have an eccentricity (0.075 ± 0.007) that is consistent with the photometric orbit of Hall, Gertken and Burke (1970). Young’s (1975) “provisional” estimate of K2 is about 14% too small. Absolute dimensions and masses have been computed from Hall et al.’s (1970) photometric orbit and the new spectroscopic orbit. Additionally, V-R photometric observations obtained by M. Frueh at McDonald Obs. have been analysed by Popper with light curve synthesis techniques (WINK and EB0P). The relative radii of the new photometric orbits differ by less than 2% from the previous orbits, and the other orbital elements also show excellent agreement. The absolute dimensions and masses are (3.51 ± 0.04\( {{\text{M}}_ \odot }\), 2.46 ± 0.04 \( {{\text{R}}_ \odot }\)) for the primary and (1.73 ± 0.02\( {{\text{M}}_ \odot }\), 1.50 ± 0.03 \( {{\text{R}}_ \odot }\))) for the secondary. Both stars are near the zero-age main sequence. The value of ω has changed significantly between the epoch of Hall, Gertken, and Burke’s (1970) observations and my own due to apsidal motion. The apsidal motion period is estimated to be in the interval 90 ≤ τ ≤ 180 yr.
Normalized specifications for identifying reusable software

An approach to retrieving reusable software components by means of module specifications is described. The approach depends on normalizing specifications to reduce the variations in the representation of software concepts. The concept is illustrated in terms of both formal and informal approaches to component specifications.
Applications of Electron Linear Induction Accelerators

Linear Induction Accelerators (LIAs) can readily produce intense electron beams. For example, the ATA accelerator produced a 500 GW beam and the LIU-30 a 4 TW beam (see Chap. 2). Since the induction accelerator concept was proposed in the late 1950s [1, 2], there have been many proposed schemes to convert the beam power to other forms. Categories of applications that have been demonstrated for electron LIAs include:
Retroactive Application of "New Rules" and the Antiterrorism and Effective Death Penalty Act

For three decades, the retroactive application of United States Supreme Court criminal procedure decisions has confused the Court's habeas corpus jurisprudence. In 1999, the Court's decision in Williams v. Taylor might have resolved the ambiguous relationship between the pre-1996 habeas corpus retroactivity decisions - the most significant of which was Teague v. Lane - and the habeas corpus reform provisions of the Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA). Unfortunately, the Williams decision has only engendered further confusion. Two decades before Teague, the second Justice Harlan proposed an approach to retroactivity questions, arguing that a decision that announced a new rule of criminal procedure should not apply in federal habeas corpus proceedings reviewing criminal convictions that had become final before the new rule's announcement. The Teague Court expressly adopted Justice Harlan's suggestion, but the post-Teague opinions that addressed the subsidiary question of whether particular Supreme Court rulings constituted new rules greatly complicated the issue. In numerous decisions during the 1990s, a fragile majority of the Court employed such an expansive definition of the term new rule that the Justices effectively converted Justice Harlan's retroactivity system into a deferential standard of review for state court decisions, even as to questions of federal law. The 1996 overlay of AEDPA's ambiguous habeas corpus reform provisions aggravated the confusion created by the case law in the early 1990s. This Article seeks to clarify habeas corpus jurisprudence by advancing the counterintuitive claim that AEDPA, properly understood, compels the Court to revisit and narrow substantially its definition of new rules to honor the Act's command that federal courts review pure questions of law de novo. The Article also articulates a standard for determining when a Supreme Court decision announces a new rule that better effectuates both AEDPA and Justice Harlan's position on retroactivity.
Necrotising herpetic retinopathies: a review and progressive outer retinal necrosis case report

Necrotising retinopathies can be visually devastating. Most often associated with the viral family Herpesviridae and seen in both immune-competent and immunocompromised hosts, possible complications of necrotising retinopathies include progressive retinal necrosis with or without macular involvement, optic neuropathy and ultimately, secondary retinal detachment. Examples include progressive outer retinal necrosis, acute retinal necrosis and cytomegaloviral retinitis. If diagnosed early and treated aggressively, visual complications can be prevented; however, there is no current consensus on the most appropriate antiviral regimen for each of the different varieties of necrotising herpetic retinopathy. This paper reviews aspects of varieties of necrotising herpetic retinopathy, including pathophysiology, treatment and diagnostic testing.
Development of human gene reporter cell lines using rAAV mediated homologous recombination

Understanding mechanisms of gene regulation has broad therapeutic implications for human disease. Here we describe a novel method for generating human cell lines that serve as reporters of transcriptional activity. This method exploits the ability of recombinant adeno-associated virus to mediate the insertion of exogenous DNA sequences into specific genomic loci through homologous recombination. To overcome the severe size limitation of the rAAV for carrying exogenous DNA, an enhanced green fluorescent protein (EGFP)-Luciferase fusion gene was used as both a selectable marker and gene expression reporter. EGFP was used for selection of correctly targeted alleles by taking advantage of known regulatory conditions that activate transcription of specific genes. Using this method, we describe the generation of primary human fibroblasts that express EGFP-Luciferase under the control of the c-Myc oncogene.
Passivity validation for numerically-generated electromagnetic macromodels

The issue of passivity in the macromodeling of electromagnetic components and subsystems is examined. In particular, the way loss of passivity may occur during the numerical characterization of the component/subsystem is investigated in the context of discrete modeling methods. In addition, the way various types of model order reduction techniques impact the passivity of the generated macromodel is considered. Finally, ways to ensure passivity during the numerical modeling and macromodel generation of an electromagnetic subsystem are identified.
Phosphoinositide binding by the Toll adaptor dMyD88 controls antibacterial responses in Drosophila.

Summary The cell biological principles that govern innate immune responses in Drosophila are unknown. Here, we report that Toll signaling in flies was dictated by the subcellular localization of the adaptor protein dMyD88. dMyD88 was located at the plasma membrane by a process dependent on a C-terminal phosphoinositide-binding domain. In vivo analysis revealed that lipid binding by dMyD88 was necessary for its antimicrobial and developmental functions as well as for the recruitment of the downstream cytosolic adaptor Tube to the cell surface. These data are reminiscent of the interactions between the mammalian Toll adaptors MyD88 and TIRAP with one major exception. In the mammalian system, MyD88 is the cytosolic adaptor that depends on the phosphoinositide-binding protein TIRAP for its recruitment to the cell surface. We therefore propose that dMyD88 is the functional homolog of TIRAP and that both proteins function as sorting adaptors to recruit downstream signaling adaptors to activated receptors.
Synthesis and Properties of Segmented Block Copolymers of Functionalised Polybenzimidazoles for High‐Temperature PEM Fuel Cells

A series of novel segmented block copolymers of sulphonated polybenzimidazole (PBI) (s-PBI) and p-PBI were prepared with various polymer ratios (10–90 mol% s-PBI; 90-10 mol% p-PBI). A two-step synthesis of oligomeric species, followed by combination and further polymerisation was used via the polyphosphoric acid (PPA) process. The membranes showed improved high-temperature proton conductivities and fuel cell performance over previous literature reports, with moderate incorporation of s-PBI into the copolymer showing the best results. The non-humidified fuel cell performance was extensively studied with various fuels and oxidants and showed excellent properties. Block copolymers that incorporated 40, 50 or 60 mol% s-PBI and the corresponding 60, 50 or 40 mol% p-PBI, at 0.2 A cm–2 and 160 °C, had hydrogen–air performances of 0.661–0.666 V, depending on composition. The performance was improved using hydrogen–oxygen, with voltages between 0.734 and 0.742 V at 0.2 A cm–2 and 160 °C. Fuel cells operating on a reformed hydrocarbon gas showed decreased performance (0.622–0.627 V, same conditions), especially at lower temperatures, but was significantly improved over previous literature reports of sulphonated PBI membranes operating at high temperatures.
Mean-Value Analysis of Closed Multichain Queuing Networks

It is shown that mean queue sizes, mean waiting times, and throughputs in closed multiple-chain queuing networks which have product-form solution can be computed recursively without computing product terms and normalization constants. The resulting computational procedures have improved properties (avoidance of numerical problems and, in some cases, fewer operations) compared to previous algorithms. Furthermore, the new algorithms have a physically meaningful interpretation which provides the basis for heuristic extensions that allow the approximate solution of networks with a very large number of closed chains, and which is shown to be asymptotically valid for large chain populations.
Deficient attention is hard to find: applying the perceptual load model of selective attention to attention deficit hyperactivity disorder subtypes

Background: Whether selective attention is a primary deficit in childhood Attention Deficit Hyperactivity Disorder (ADHD) remains in active debate. Methods: We used the perceptual load paradigm to examine both early and late selective attention in children with the Primarily Inattentive (ADHD-I) and Combined subtypes (ADHD-C) of ADHD. Results: No evidence emerged for selective attention deficits in either of the subtypes, but sluggish cognitive tempo was associated with abnormal early selection. Conclusions: At least some, and possibly most, children with DSM-IV ADHD have normal selective attention. Results support the move away from theories of attention dysfunction as primary in ADHD-C. In ADHD-I, this was one of the first formal tests of posterior attention network dysfunction, and results did not support that theory. However, ADHD children with sluggish cognitive tempo (SCT) warrant more study for possible early selective attention deficits.
Metastable singlet NF: reactivity and energy storage

A flow reactor using the 2F + HN 3 reaction to generate NF(a 1 Δ) has been used to systematically study the reactions of NF(a 1 Δ) at 300K. The biomolecular self-removal rate constant for NF(a 1 Δ) was assigned as 5 +/- 2 x 10 -12 cm 3 s -1 . Quenching rate constants by stable molecules span a wide range of values; those for diatomic molecules, with the notable exception of the halogens, generally are less than 1 x 10 -14 cm 3 s -1 , but more reactive molecules, such as C 2 H 4 , NH 3 and P(CH 3 ) 3 , have rate constants of l x 10 -11 cm 3 s -1 . For those polyatomic molecules which can act as Lewis bases, a correlation exists between the magnitude of the quenching rate constant and the base strength. The rate constants for the halogens increase dramatically with molecular weight and the rate constant for I 2 is (1.5+/-1.0) x 10 -10 cm 3 s -1 . The rate constants for open shell atoms and molecules tend to be smaller than expected; values for NO 2 , N0, F, N, 0 and C are 0.65 x l0 -14 , 0.10 x 10 -14 , 4 x 10 -13 , 5 x 10 -13 , 6 x 10 -12 and 2.7 x 10 -11 cm 3 s -1 , respectively. In general, the NF(a 1 Δ) quenching rate constants are not so large as to preclue the utilization of complex schemes to extract the stored energy of NF(a 1 Δ).
Cortisol is necessary for seawater tolerance in larvae of a marine teleost the summer flounder

Abstract Larval-stage summer flounder ( Paralichthys dentatus ) were immersed in the corticosteroid-receptor blocker RU486 to test the effects of cortisol deficiency on salinity tolerance. Premetamorphic larvae held at 10 (near isosmotic) or 30 (hyperosmotic) parts per thousand (‰) seawater survived well over 5 d in 0, 0.012, or 0.12 μM RU486. However, at concentrations of 1.2 or 3.6 μM RU486, mortality was significantly greater for larvae in 30‰ compared to larvae in 10‰. In a separate experiment, the ability of RU486 to inhibit tolerance to hyperosmotic medium (30‰) was confirmed; immersion at 1.2 μM RU486 induced mortality of larvae in the metamorphic climax stage held at 30‰, but not 0 or 10‰. Mortality due to RU486 in pre- or prometamorphic stage larvae was prevented by concurrent immersion in cortisol at concentrations approximately 10–200 times greater than RU486, indicating that the action of RU486 was specific to antagonism of cortisol. The efficacy of 1.2 μM RU486 in reducing survival in 30‰ was found to be stage-dependent and exhibited the following hierarchy for fastest time to 50% mortality: prometamorphosis > metamorphic climax > premetamorphosis. In a 5-d pretreatment of pre- or prometamorphic larvae by immersion in 20 μM cortisol and/or 0.12 μM RU486 at 30‰, only RU486 had a limited effect on decreasing survival when larvae were challenged with abrupt exposure to 50‰. In total, the results evidence for the first time a necessary role for cortisol in seawater tolerance of a larval marine teleost.
Doppler assessment of prosthetic valve orifice area. An in vitro study.

BACKGROUND Although Doppler echocardiography has been shown to be accurate in assessing stenotic orifice areas in native valves, its accuracy in evaluating the prosthetic valve orifice area remains undetermined. METHODS AND RESULTS Doppler-estimated valve areas were studied for their agreement with catheter-derived Gorlin effective orifice areas and their flow dependence in five sizes (19/20-27 mm) of St. Jude, Medtronic-Hall, and Hancock aortic valves using a pulsatile flow model. Doppler areas were calculated three ways: using the standard continuity equation; using its simplified modification (peak flow/peak velocity); and using the Gorlin equation with Doppler pressure gradients. The results were compared with Gorlin effective orifice areas derived from direct flow and catheter pressure measurements. Excellent correlation between Gorlin effective orifice areas and the three Doppler approaches was found in all three valve types (r = 0.93-0.99, SEE = 0.07-0.11 cm2). In Medtronic-Hall and Hancock valves, there was only slight underestimation by Doppler (mean difference, 0.003-0.25 cm2). In St. Jude valves, however, all three Doppler methods significantly underestimated effective orifice areas derived from direct flow and pressure measurements (mean difference, 0.40-0.57 cm2) with differences as great as 1.6 cm2. In general, the modified continuity equation calculated the largest Doppler areas. When orifice areas were calculated from the valve geometry using the area determined from the inner valve diameter reduced by the projected area of the opened leaflets, Gorlin effective orifice areas were much closer to the geometric orifice areas than Doppler areas (mean difference, 0.40 +/- 0.31 versus 1.04 +/- 0.20 cm2). In St. Jude and Medtronic-Hall valves, areas calculated by either technique did not show a consistent or clinically significant flow dependence. In Hancock valves, however, areas calculated by both the continuity equation and the Gorlin equation decreased significantly (p less than 0.001) with low flow rates. CONCLUSIONS Doppler echocardiography using either the continuity equation or Gorlin formula allows in vitro calculation of Medtronic-Hall and Hancock effective valve orifice areas but underestimates valve areas in St. Jude valves. This phenomenon is due to localized high velocities in St. Jude valves, which do not reflect the mean velocity distribution across the orifice. Valve areas are flow independent in St. Jude and Medtronic-Hall prostheses but decrease significantly with low flow in Hancock valves, suggesting that bioprosthetic leaflets may not open fully at low flow rates.
Enkephalin systems in diencephalon and brainstem of the rat

The immunocytochemical distribution of [Leu]enkephalin and an adrenal enkephalin precursor fragment (BAM-22P) immunoreactivity was investigated in the diencephalon and brainstem of rats pretreated with relatively high doses of colchicine (300-400 micrograms/10 microliters intracerebroventricularly). The higher ranges of colchicine pretreatment allowed the visualization of extensive enkephalin-containing systems in these brain regions, some of which are reported for the first time. Immunoreactive perikarya were found in many hypothalamic and thalamic nuclei, interpeduncular nucleus, substantia nigra, the colliculi, periaqueductal gray, parabrachial nuclei, trigeminal motor and spinal nuclei, nucleus raphe magnus and other raphe nuclei, nucleus reticularis paragigantocellularis, vestibular nuclei, several noradrenergic cell groups, nucleus tractus solitarius, as well as in the spinal cord dorsal horn. In addition to the above regions, immunoreactive fibers were also noted in the habenular nuclei, trigeminal sensory nuclei, locus coeruleus, motor facial nucleus, cochlear nuclei, dorsal motor nucleus of the vagus, and hypoglossal nucleus. When adjacent sections of those stained for [Leu]enkephalin were processed for BAM-22P immunoreactivity, it was found that these two immunoreactivities were distributed identically at almost all anatomical locations. BAM-22P immunoreactivity was generally less pronounced and ws preferentially localized to neuronal perikarya. The results of the present as well as the preceding studies (Khachaturian et al., '83) strongly suggest substantial structural similarity between the adrenal proenkephalin precursor and that which occurs in the brain. Also discussed are some differences and parallels between the distribution of [Leu]enkephalin and dynorphin immunoreactivities.
Overexpression of Cyclooxygenase 2 in Hamartomatous Polyps of Peutz-Jeghers Syndrome

OBJECTIVE: Peutz-Jeghers syndrome (PJS) is an autosomal-dominant hamartomatous polyposis syndrome. Affected individuals are at risk for intestinal and extraintestinal malignancies. Prostaglandins and polyamines are small molecules believed to be important in tumor formation and growth. Cyclooxygenase (COX) and ornithine decarboxylase (ODC) are key enzymes in the prostaglandin and polyamine biosynthetic pathways, respectively. The aim of this study was to measure and compare COX-1 and COX-2 expression in normal and hamartomatous tissue of PJS patients. METHODS: We measured COX-1 and COX-2 protein expression in normal and hamartomatous GI tissues from affected PJS individuals and compared it with that in normal controls. COX-2 RNA in these tissues was also measured and compared by reverse transcription polymerase chain reaction (PCR). In addition, COX-2 expression was detected in tissue slides by immunostaining. ODC activity was measured between normal and hamartomatous tissues of PJS compared with control tissues. RESULTS: COX-1 expression was similar in normal and control GI tissues. In contrast, COX-2 overexpression was noted in hamartomatous polyp tissue from PJS patients compared with normal control and PJS tissue. COX-2 expression by reverse transcription PCR was 10-fold greater in a hamartoma compared with other tissues. COX-2 expression was noted in the epithelial cells of hamartomatous polyps, and also coursing throughout the stromal tissue of the lamina propria, including muscle cells. ODC activity was similar in the tissues studied. CONCLUSIONS: Selective COX-2 overexpression was noted in hamartomatous polyp tissue from PJS individuals. The results of the study provide an avenue for possible effective chemoprevention of polyp formation and growth in PJS.
Low-pH disc electrophoresis of spinal fluid; changes in multiple sclerosis.

Abstract A method for low pH acrylamide disc electrophoresis of unconcentrated cerebrospinal fluid is described. Evidence for the reduction or absence of a specific, slowly migrating protein in the spinal fluid of multiple sclerosis patients is presented.
Selection without harm: drug resistance gene therapy hits the big time

Comment on Neff et al, page [997][1] In this issue, Neff and colleagues provide an important advance in the field of hematopoietic stem cell gene therapy: the ability to select for transduced progenitor cells over time in a large animal. The drug selection gene used is methylguanine-DNA
Postoperative Propionibacterium Endophdiahnitis: Treatment Strategies and Long-term Results

Purpose: Postoperative Propionibacterium endophthalmitis is a condition characterized by exacerbations and remissions that has often been accompanied by recurrence after treatment. The purpose of this study is to evaluate the efficacy of initial therapies in preventing recurrent endophthalmitis and to assess the safety of intraocular lens (IOL) exchange performed during treatment of active endophthalmitis. Methods: The records of 22 patients with culture-proven Propionibacterium endophthalmitis treated at one facility were retrospectively reviewed. Results: Two patients presented acutely, were treated with intraocular antibiotic injection alone, and experienced no recurrent inflammation. Twenty patients presented with chronic, delayed-onset pseudophakic endophthalmitis. Eight of these were treated initially with intraocular antibiotic injection alone, and recurrent endophthalmitis developed in seven. Twelve patients with chronic endophthalmitis were initially managed surgically with either pars plana vitrectomy or IOL exchange. Four of the 12 experienced recurrent endophthalmitis. Patients undergoing capsulectomy as part of initial management experienced the lowest rate of recurrent endophthalmitis. Eight patients eventually underwent total capsulectomy and IOL explantation, seven of whom had IOL exchange. None of these eight patients had recurrent endophthalmitis. In seven of the eight, persistent bacterial colonization of the lens capsular remnants was demonstrated. Conclusions: These data suggest that recurrent Propionibacterium endophthalmitis is due to persistence of viable organisms sequestered within lens capsular remnants, and that initial therapy directed toward surgical removal of these sequestered organisms results in a reduced frequency of recurrent endophthalmitis. Intraocular lens exchange with complete capsular removal during active endophthalmitis was not associated with recurrent or persistent endophthalmitis.
Experimental searches for strange quark matter in cosmic rays

Abstract The results of various cosmic ray experiments are reviewed in order to set limits on the possibility of a cosmic flux of small lumps of strange quark matter (SQM). Large-area detectors, both balloon-borne and space-based, that have been flown to measure elemental abundances of cosmic rays, would be sensitive to relativistic SQM with charge in the atomic range (Z > 6). The absence of cosmic rays with Z/β > 100 leads to good limits on the flux of relativistic and subrelativistic SQM in this range, as there have been several large experiments flown in space that have failed to detect any relativistic particle of such large Z. At lower charge, a few possible candidate events have been seen, and these results will also be reviewed. Finally, various experiments, including space-based, ground-based, and underground detectors, can be used to set limits on the abundance of nuclearites (lumps of SQM that have typical galactic virial velocities ∼ 250 km/sec).
Laryngotracheoplasty for subglottic stenosis in Down Syndrome children: The Cincinnati experience

Previous studies from our institution have noted difficulties in the surgical repair of subglottic stenosis (SGS) in children with Down Syndrome. The objectives of this paper were to update our 15 year experience in the Down Syndrome patient population, compare our results with our overall series of laryngotracheoplasty for SGS, and to report on the increased incidence of posterior glottic stenosis (PGS) within this group of patients. Medical records of all children with SGS and Down Syndrome evaluated between 1982 and 1997 were reviewed for history of prior intubation, tracheotomy, gastroesophageal reflux disease (GERD), pre-operative SGS grade, and decannulation. From this review several conclusions have been drawn. First, the risk factors for SGS appear to be the same in the Down Syndrome group as the general population. Second, SGS continues to be more prevalent among children with Down Syndrome than among children in the general population. Third, we have now found a higher rate of PGS within these patients when compared to our overall series. Finally, it now seems that our decannulation rates in Down Syndrome children are approaching our overall series results.
Investigation of recombination and trapping processes in 3As2Se32Sb2Se3 amorphous films by photoconductivity method

Abstract Photoconductivity experiment has been performed on high resistivity ( π ≅ 10 9 Ω- cm ) 3As2Se32Sb2Se3 amorphous films in the temperature range from 278°K to 308°K, as a function of light intensity, I0. The results are that at intermediate light levels the photocurrent varies as I00.7 and at high light levels the photocurrent is directly proportional to I0. A simple recombination and trapping model is developed to interpret the observed photoconductivity data. From the temperature dependence of the photocurrent, an effective trap level located 0.3 eV below the band edge is deduced.