cssi/SciSciGPT-SciSciNet huggingface dataset:
Benign and Low Grade Serous Epithelial Tumors: Recent Developments and Diagnostic Problems

This review focuses on recent advances in the area of low-grade ovarian serous neoplasia with emphasis on key diagnostic criteria, differential diagnosis, and disease classification based on current understanding of low-grade serous carcinogenesis. Despite considerable controversy surrounding serous tumors of low malignant potential (S-LMP) or borderline tumors, there have been great strides in our understanding of the serous group of borderline and malignant pelvic epithelial neoplasms in the past decade. Most S-LMP have a favorable prognosis, but recurrences and progression to carcinoma occur, sometimes following a protracted clinical course. Pathologic risk factors vary, but the extraovarian implant status is the most important predictor for progressive disease. Progression of S-LMP usually takes the form of low-grade serous carcinoma, although transformation to high-grade carcinoma is occasionally seen. A pelvic S-LMP - low-grade serous carcinoma pathway has been proposed based on global gene expression profiling, shared mutations in KRAS and/or BRAF, and in most cases, the presence of S-LMP in de novo low-grade serous carcinoma. Unlike high-grade serous carcinoma, low-grade serous carcinoma responds poorly to standard platinum-based chemotherapy. Development of more tailored therapy for S-LMP with invasive implants and low-grade serous carcinoma, ideally based on a relative risk model for disease progression, is under active clinical investigation.
Trends in soil characteristics along a recently deglaciated foreland on Anvers Island, Antarctic Peninsula

We assessed patterns in soil development at a recently deglaciated foreland on Anvers Island on the Antarctic Peninsula. Soil samples were collected along transects extending 35 m over bare ground from the edge of a receding glacier; the far end of these transects has been ice free for approximately 20 years. We also compared soils at the far end of these transects under bare ground to those under canopies of isolated individuals of Deschampsia antarctica, a caespitose grass, that had recently colonized the site (established for <6 years). In addition, we compared soils at this young foreland to those in a well-developed tundra island that has been ice free for at least several hundred years. At the foreland site, soil moisture was greatest near the glacier, consistent with proximity to meltwater, and declined with distance from the glacier. This decline in soil moisture may explain the decrease in litter decomposition rates and the greater soil nitrate (NO3 −) concentrations that we observed with distance from the glacier. The greater soil moisture near the glacier likely promoted leaching and transport of NO3 − to drier soils away from the glacier. The presence of D. antarctica at the glacier foreland had little effect on soil properties, which is not surprising considering it had only colonized sampling areas during the previous 5 years. Compared to the foreland, which contained only mineral soil, soil at the older tundra site had a 2.5- to 5-cm-thick organic horizon that had much higher concentrations of total carbon, nitrogen, and NO3 −.
Diagnostic uncertainty and costs associated with current emergency department evaluation of low risk chest pain.

Introduction: Of all stress tests done in low risk Emergency Department observation units (OU), a small, but significant number may be reported as positive or indeterminate. The objective of this study is to quantify the prevalence and costs associated with positive and indeterminate stress tests that result in negative cardiac catheterization. Methods: Retrospective observational cohort study over 9 months. All patients undergoing the chest pain protocol who got cardiac stress testing in the OU were eligible for inclusion. Cost data were derived from an institutional activity-based cost system utilizing actual costs. Chart review was completed on all patients with positive and indeterminate stress tests and a randomly chosen sample of those with negative stress tests. Results: Of the 1194 patients who met the inclusion criteria, 1084 (90.8%) had a negative stress test. Sixty-two (5.2%) had a positive stress test, and 48 (4.0%) had an indeterminate stress test. Of all 59 patients who underwent catheterization, 41 (69.5%) were negative cardiac catheterizations. The prevalence among all OU stress test patients of positive or indeterminate stress tests with subsequent negative cardiac catheterization was 41/1194 (3.4%; 95% CI 2.5%‐ 4.6%). The prevalence of significant coronary artery disease at cardiac catheterization was 18/1194 (1.5%; 95% CI 1.0%‐2.4%). Patients with a positive or indeterminate stress test who had a negative catheterization incurred increased OU costs ($1385 vs. $1,039, P 0.012), total costs ($7298 vs. $1562, P 0.001) and length of inpatient stay (1.83 days vs. 0.00 days) when compared with those who had a negative stress test. Conclusion: The probability of going to the OU and having a positive or indeterminate stress test resulting in a subsequent negative catheterization was double the probability of having a stress test result in catheterization that detected significant coronary artery disease. These patients incurred 5 times the total cost when compared with those patients with negative stress testing. Further investigation is warranted to determine alternative risk stratification methods for these low risk chest pain patients with positive stress tests.
Public Library Participation in a MedlinePlus Go Local Project: Perceptions of Georgia Librarians and Staff.

In an effort to promote public library involvement in Georgia Health – Go Local, a National Library of Medicine initiative to link consumers to health resources in their local areas, staff at a large public library system in south Georgia were trained to enter local records into the Go Local database. Results of two follow-up focus groups indicated that participants were enthusiastic about demonstrating Go Local and MedlinePlus to library users but were not comfortable creating or maintaining Go Local records due to concerns about the relevance of the project, unease with medical terminology, varied levels of computer expertise, and worries about possible liability.
Operations that are Questionable for Control of Obesity.

At the last review of the literature, there were 43 different operations or modifications thereof used for the control of obesity. An effective operation for obesity control should produce a significant weight loss (≥25% excess weight loss) to ameliorate the associated medico-socio-psycho-economic ramifications of the obesity. The operative and postoperative significant morbidity should be less than 20% and mortality less than 1%. The weight lost should be maintained for a long period (≥5 years). The effects of the operation should be reproducible and documentable by more than two authors working independently. For the purpose of this paper, operations which do not meet these criteria are considered questionable and not recommended for general use. Based on these criteria, questionable operations for treatment of obesity include: tooth wiring, acupuncture, hypothalamic center manipulation, liposuction, balloon insertion, unbanded gastric partitioning, vagotomy, gastrogastrostomy, horizontal gastroplasty, gastric wrap, gastroclip, and any variety of gastroplasty without a reinforced stoma, intestinal bypass, duodenal bypass and biliointestinal bypass. Data to substantiate this classification will be presented and discussed. Since the surgical treatment of obesity is evolving, there is need to collect data from and make modifications to improve the effects of all operations. There is not enough data at this time to prohibit the use of any operation, but the data presented will justify limiting the use of certain operations to institutions dedicated to meticulous follow-up and research.
A numerical study of residual stress induced in machined silicon surfaces by molecular dynamics simulation

Residual stresses in machined surface are regarded as a critical factor affecting the quality and service life of components. However, little research has been conducted to reveal the formation of residual stresses as well as the relation between machining conditions and residual stresses at the nanometric scale. In this study, residual stresses in machined surfaces of monocrystalline silicon are computed based on molecular dynamics simulation. An orthogonal machining configuration is adopted, and diamond cutting tools are used. The numerical approach developed is able to reveal stress evolution during and after machining, as well as in-depth residual stress distributions. The results indicate that the material stresses are stabilized within a manageable amount of computation time, and the in-depth normal stress along the tool moving direction has a more dynamical and significant pattern compared with other stress components. Meanwhile, the effects of depth of cut and tool rake angle are investigated. It is found that the increase of depth of cut results in the decrease of maximum tensile residual stress on the machined surfaces and the increase of maximum compressive residual stress underneath the surface. Similar observations are observed when the tool rake angle changes from positive to negative. It is believed that the more negative tool rake angles or the larger depths of cut induce a more drastic phase transformation to the machined surfaces, and this makes the in-depth residual stress distributions more compressive.
Home Ranges and Habitat Use of Brown Pelicans (Pelecanus occidentalis) in the Northern Gulf of Mexico

Abstract. Little is known about movements and habitat use of Brown Pelicans (Pelecanus occidentalis) in the northern Gulf of Mexico. We attached satellite transmitters to 18 adult Brown Pelicans (nine males, nine females) that were captured on Grand Isle along the Louisiana coast during 31 August–2 September 2010. Their movements and habitat use were tracked between September 2010 and March 2012. Nine of the Brown Pelicans remained proximate to the Louisiana coast; four ranged along the coasts of Alabama, Mississippi, and Louisiana; three moved from Louisiana to Texas; and two migrated across the Gulf of Mexico to the Yucatan Peninsula. Annual 99% home range estimates varied widely ( x??? = 10,611 km2, SE = 2,370), and males had larger ranges (x??? = 15,088 km2, SE = 2,219) than females (x??? =6,133 km2, SE = 1,764). Habitats used by Brown Pelicans were primarily open water, estuarine emergent wetland, grassland, unconsolidated shore, and deep water habitat types.
Virtual Memory and the MC68010

The designers of this microprocessor used the continuation method to provide an elegant general solution to the problem of virtual memory support.
Thermal-noise-limited transduction observed in mechanosensory receptors of the inner ear.

Simultaneous recordings of the spontaneous mechanical input fluctuations and the electrical output fluctuations in hair cells that serve as biological microphones show that the Brownian motion of the mechanoceptive organelle, the hair bundle, is often strongly correlated with the fluctuations of the transmembrane voltage. This correlation stems from transduction of the spontaneous input noise and shows that these cells can almost reach the sensitivity limit imposed by the thermal noise at their input.
Enhanced mechanical pathways through nature's building blocks: amino acids

Amino acids are the core building blocks of nature's mechanically robust proteins. Their innate ability to self-assemble into well-ordered secondary structures, such as the α-helix and β-sheet, coupled with unique load-bearing characteristics, has sparked considerable interest in their use in innovative engineering materials. Biomimickry and bioinspired approaches to materials design can be utilized to facilitate the conception of these peptidic-based materials by introducing principles proven by the demanding conditions of nature. In this review, we will explore the design process of tailored mechanics through the examination of research that has employed amino acid sequences inspired by silks, elastin, and resilin to construct hybrid functional polymeric materials as well as polymeric materials exploiting non-canonical or non-native amino acids as building blocks. We foresee the next generation of nature-inspired materials finding widespread use, not only in biomedical and bioengineering applications, but also in roles that require tailored and functional coatings, films and fibers.
Acute effects of different diet compositions on skeletal muscle insulin signalling in obese individuals during caloric restriction.

Objective The cellular effects of restricting fat versus carbohydrate during a low-calorie diet are unclear. The aim of this study was to examine acute effects of energy and macronutrient restriction on skeletal muscle insulin signalling in obesity. Materials/Methods Eighteen obese individuals without diabetes underwent euglycemic–hyperinsulinemic clamp and skeletal muscle biopsy after: (a) 5 days of eucaloric diet (30% fat, 50% carbohydrate), and (b) 5 days of a 30% calorie-restricted diet, either low fat/high carbohydrate (LF/HC: 20% fat, 60% carbohydrate) or high-fat/low carbohydrate (HF/LC: 50% fat, 30% carbohydrate). Results Weight, body composition, and insulin sensitivity were similar between groups after eucaloric diet. Weight loss was similar between groups after hypocaloric diet, 1.3 ± 1.3 kg (p < 0.0001 compared with eucaloric). Whole-body insulin sensitivity was unchanged after calorie restriction and similar between groups. However, ex vivo skeletal muscle insulin signalling differed depending on macronutrient composition of calorie-restricted diet. Skeletal muscle of the LF/HC group had increased insulin-stimulated tyrosine phosphorylation of IRS-1, decreased insulin-stimulated Ser307 phosphorylation of IRS-1, and increased IRS-1-associated phosphatidylinositol (PI)3-kinase activity. Conversely, insulin stimulation of tyrosine phosphorylated IRS-1 was absent and serine 307 phosphorylation of IRS-1 was increased on HF/LC, with blunting of IRS-1-associated PI3-kinase activity. Conclusion Acute caloric restriction with an LF/HC diet alters skeletal muscle insulin signalling in a way that improves insulin sensitivity, while acute caloric restriction with an HF/LC diet induces changes compatible with insulin resistance. In both cases, ex vivo changes in skeletal muscle insulin signalling appear prior to changes in whole body insulin sensitivity.
Mechanisms of cyclosporine A inhibition of antigen-presenting activity in uninvolved and lesional psoriatic epidermis

Abstract To elucidate how cyclosporine A affects antigen-presenting cell subsets and their function in human skin, we studied patients with psoriasis undergoing a therapeutic trial of cyclosporine A. Immunologic parameters abnormal in psoriatic epidermis were evaluated before and early in the course of therapy. We quantitated function and numbers of skin biopsy-derived epidermal cells with potential antigen-presenting cell (APC) activity. The antigen-presenting capacity of epidermal cells from normal-appearing skin to activate allogeneic T cells was profoundly inhibited (81% decrease) 7 d after the onset of therapy (p + Langerhans cells or epidermal cell release of detectable amounts of cyclosporine A or other soluble factors that abrogate T-cell alloreactivity. The time course and degree of inhibition of antigen-presenting capacity within involved psoriatic skin correlated best with a significant (p + leukocytes (from 3.0 ±1.2% to 1.0 ± 0.6% at day 7) (r = 0.71). Cyclosporine A therapy was associated with a rapid and complete loss of HLel-DR + keratinocytes (94% decrease at 7 d) in lesional skin despite the skin still being quite involved with psoriasis at this point and antigen-presenting cell activity being only 60% reduced. In conclusion, cyclosporine A interferes with T-cell activation by human epidermis through at least two mechanisms: 1) in uninvolved skin, rapid inhibition of Langerhans cell-mediated activation of T cells, and 2) in lesional skin, delayed inhibition of antigen-presenting activity which appears to correlate with the time course and level of reductions in non-Langerhans cell DR + leukocytes. The antigen-presenting activity of the latter cells appears to be cyclosporine A resistant. In psoriatic lesions, early and complete loss of DR expression on lesional keratinocytes during cyclosporine A therapy is likely due to decreased lesional T-cell lymphokine production critical for keratinocyte DR expression. Concomitantly, decreased recruitment and retention of infiltrating leukocytes by T-cell lymphokines may result in the depletion of non-Langerhans antigen-presenting leukocytes from lesional epidermis.
f-vectors of pure complexes and pure multicomplexes of rank three

Necessary and sufficient conditions are established for an integer vector to be the f-vector of some pure simplicial complex of rank three, and also for an integer vector to be thef-vector of some pure simplicial multicomplex of rank three. For specified numbers of sets of cardinality one and cardinality two, an upper bound on the number of sets of cardinality three is established using shifting arguments. Then techniques from combinatorial design theory are used to establish a lower bound. Then it is shown that every number of sets of cardinality three between the lower and the upper bound can be realized. This characterization is restated to determine the precise spectrum of possible numbers of sets of cardinality two for specified numbers of sets of cardinality one and three. For simplicial complexes, these spectra are not always intervals, and the gaps are determined precisely. For simplicial multicomplexes, an alternative proof is given that these spectra are always intervals.
Monte Carlo Simulations of Sterol Superlattice Mosaics in Bilayers Yield Simultaneous Agreement with Concentration and Chemical Potential Data

Multiple experiments suggest that at certain mol fractions (χsterol = Cr) sterol molecules, cholesterol (chol) and ergosterol (erg), form superlattice (SL) structures occupying particular acyl chain sites in a lipid bilayer. We have constructed a theoretical model, which we have tested successfully against our own nystatin-erg channel data and the fluorescence measurements of sterol concentration [1]. Our Monte Carlo (MC) simulations show that mosaics of SLs, with structures strongly dependent on χsterol , form in bilayers for all χsterol studied. Here we successfully test the model against the chemical potential data using Kirkwood's coupling parameter method. Holding all interaction energies (sterol/sterol, sterol/lipid) constant the model successfully predicts simultaneously the observed increase in chemical potential [2] and no marked increase in sterol concentration at χsterol = 0.4 [1].1. Chong, P.L-G., and M. Olsher. 2004. Fluorescence Studies of the Existence and Functional Importance of Regular Distributions in Liposomal Membranes. Soft Mat. 2:85-108.2. Ali, M.R., K.H. Cheng, and J. Huang. 2007. Assess the nature of cholesterol-lipid interactions through the chemical potential of cholesterol in phosphatidylcholine bilayers. PNAS 104:5372-5377.
Contact electrical resistivity between cement and carbon fiber: Its decrease with increasing bond strength and its increase during fiber pull-out

The contact electrical resistivity between carbon fiber and cement paste was found to decrease with increasing bond strength and to increase during fiber pull-out from the paste. Both effects are due to the interfacial voids, which are electrically insulating. Evidence is provided in support of the feasibility for the volume electrical resistivity increase during tensile loading of carbon fiber reinforced cement to be due to fiber pull-out.
Arterial Pressure Pulsation During Nonpulsatile Biventricular Bypass Experiments: Possible Idioperipheral Pulsation

During nonpulsatile biventricular bypass (NPBVB) experiments, regular fluctuations of arterial pressure were observed in all five long-term animals whose ventricles were fibrillated. Analysis of the characteristics of this fluctuation was performed retrospectively. The pulse pressure of this fluctuation increased gradually after the first 2 weeks. They were 6.7, 7.6, 10.2, and 12.4 mm Hg on the fortieth, sixtieth, eightieth, and ninetieth postoperative day, respectively, in the animal surviving for 99 days. Cycle rate was generally high for the first 40 days, and then decreased to approximately 40 cycles/min in calves alive for greater than 90 days. The beat rate of these arterial pressure fluctuations was lower than atrial but similar to respiratory cycle rates. However, no flow fluctuations were observed in conjunction with the arterial pressure oscillations. Therefore, neither atrial contractions nor the mechanical effects of respiration were causing the pressure pulsations. Though further investigations are necessary, it is highly suggestive that this phenomenon was derived from the vasomotor center and can be called "idioperipheral pulsation." It is conceivable that the NPBVB animals adapted to the nonpulsatile condition by adding active pulsatile components of their own to maintain adequate peripheral circulation.
Müllerian inhibiting substance in the diagnosis and management of intersex and gonadal abnormalities

Mullerian inhibiting substance (MIS), a gonadal hormone important in sexual differentiation, is high (10 to 70 ng/mL) in human male serum postnatally for several years before declining during the peripubertal period, but is undetectable in female serum until the onset of puberty. The sexually dimorphic secretion of MIS suggested possibilities for its use in several clinical settings. Thirty-one patients with intersex and gonadal anomalies from 17 institutions were therefore evaluated between 1989 and 1992 with an MIS enzyme-linked immunosorbent assay (ELISA). Serum MIS levels correlated with the presence of testicular tissue in two patients with suspected anorchia, five patients with male pseudohermaphroditism, and eight other intersex patients with undescended testes, dysgenetic gonads, or ovotestes. In these latter patients, serial MIS values were also helpful to confirm complete removal of gonadal tissue postoperatively. MIS may be a more sensitive marker for the presence of testicular tissue than serum testosterone levels, both before and after the neonatal androgen surge, and, consequently, may obviate the need for human chorionic gonadotropin stimulation in the evaluation of certain intersex disorders. In values were useful in differentiating the underlying etiology of the disorder. Four patients with undetectable levels have presumptive MIS gene mutations, while 7 others with MIS values of 2 to 45 ng/mL may have bioinactive hormone of MIS receptor defects. Finally, two young girls with ovarian granulosa cell tumors had elevated MIS values that fell from 18 to 2 ng/mL and from 6.5 to 1 ng/mL during postoperative follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale (nanoparticles). Nanoparticles can be engineered in a precise fashion where their size, composition and surface chemistry can be carefully controlled. This enables unprecedented freedom to modify some of the fundamental properties of their cargo, such as solubility, diffusivity, biodistribution, release characteristics and immunogenicity. Since their inception, nanoparticles have been utilized in many areas of science and medicine, including drug delivery, imaging, and cell biology1-4. However, it has not been fully utilized outside of "nanotechnology laboratories" due to perceived technical barrier. In this article, we describe a simple method to synthesize a polymer based nanoparticle platform that has a wide range of potential applications. The first step is to synthesize a diblock co-polymer that has both a hydrophobic domain and hydrophilic domain. Using PLGA and PEG as model polymers, we described a conjugation reaction using EDC/NHS chemistry5 (Fig 1). We also discuss the polymer purification process. The synthesized diblock co-polymer can self-assemble into nanoparticles in the nanoprecipitation process through hydrophobic-hydrophilic interactions. The described polymer nanoparticle is very versatile. The hydrophobic core of the nanoparticle can be utilized to carry poorly soluble drugs for drug delivery experiments6. Furthermore, the nanoparticles can overcome the problem of toxic solvents for poorly soluble molecular biology reagents, such as wortmannin, which requires a solvent like DMSO. However, DMSO can be toxic to cells and interfere with the experiment. These poorly soluble drugs and reagents can be effectively delivered using polymer nanoparticles with minimal toxicity. Polymer nanoparticles can also be loaded with fluorescent dye and utilized for intracellular trafficking studies. Lastly, these polymer nanoparticles can be conjugated to targeting ligands through surface PEG. Such targeted nanoparticles can be utilized to label specific epitopes on or in cells7-10.
Serous effusion cytology in gynecologic malignant mixed müllerian tumors

We reviewed 51 serous effusions (50 peritoneal/one pleural) from 38 patients with uterine (30 cases) and ovarian (eight cases) malignant mixed Mullerian tumors (MMMT). There were 16 patients (42%) with positive effusion cytology specimens; 13 cases (81%) were diagnosed as adenocarcinoma with three cases (19%) interpreted as having a sarcomatous component. Eight of 16 positive effusion specimens had cell block material available for immunoperoxidase (IP) study that included cytokeratin (AE1/3), vimentin, muscle specific actin (HHF) and S-100 protein to determine if unsuspected mesenchymal components were present in the cases originally diagnosed as carcinoma (six cases), or sarcomas (two cases). In the six cases originally interpreted as carcinoma, three were diagnosed as adenocarcinoma and three as poorly differentiated carcinoma. All three of the cases considered adenocarcinoma and two of those diagnosed as poorly differentiated carcinoma reacted only with AE1/3 and vimentin. The remaining case, considered a poorly differentiated carcinoma, stained only with vimentin. In the two cases having cell blocks interpreted as having a sarcomatous component, only vimentin was positive in one while AE1/3, vimentin, HHF, and S-100 were positive in the other. The case where all immunohistochemical stains were reactive contained both carcinomatous and sarcomatous components. In the three cases considered sarcomatous, the cytomorphologic features helpful in the recognition of a mesenchymal component included a dissociated smear pattern of pleomorphic round to oval cells and/or spindle cells. In retrospect, the IP stains did not alter any of the original diagnoses.(ABSTRACT TRUNCATED AT 250 WORDS)
Term-by-term bosonization method

We propose here a new method, called a term-by-term bosonization method, to be used to construct the boson expansion theory. It is trivial to justify it mathematically. Its use makes the whole procedure of the bosonization very easy and transparent.
Tricuspid insufficiency in pulmonary embolism.

Abstract Experimental evidence has been presented to show that electrocardiographic changes associated with large pulmonary embolism are caused by an immobile and tense right ventricle. If tricuspid insufficiency develops from the embolism, the ventricle becomes mobile and the ECG pattern does not occur. Thus, when one suspects a major pulmonary embolism in the absence of a typical electrocardiogram, tricuspid insufficiency should be carefully searched for by studying the venous pressure patterns.
An improved evolvable oscillator for all flight mode control of an insect-scale flapping-wing micro air vehicle

In previous work, we presented an adaptive evolvable oscillator that enables online, in-flight, adaptation of a rigorous controller for hovering in an insect-scale flapping-wing micro air vehicle based on the Harvard RoboFly. That particular evolvable hardware oscillator, however, was a proof-of-concept prototype and is incapable of supporting the types of signal adaptation necessary to support on-line correction for other flight modes (E.G. roll, pitch, forward translation, etc.). This paper introduces a new oscillator design capable of supporting signal adaptation for all possible flight modes of the vehicle. It will also present preliminary experimental results demonstrating the adaptive oscillator to be capable of correcting for vehicle faults in a two degree of freedom (2DOF) control task requiring simultaneous regulation of vehicle altitude and roll. The paper will conclude with discussion of application of this adaptive, evolvable oscillator to full vehicle control.
Tax policy and the demand for health insurance

Estimates of the price and income elasticities of demand for health insurance are derived from econometric estimates of the parameters of a discrete choice model of health insurance demand using data from a survey of plan choices among a sample of federal government employees. The estimated income elasticity (+0.01) is similar to most previous estimates. The estimated price elasticity (-0.16) is in absolute value much less than the earlier previous estimates and somewhat less than the more recent previous estimates. Possible causes of these differences in price elasticity estimates are discussed.
Answering the question: "Doctor, if this were your child, what would you do?".

Tommy* was only 2 years old when he was admitted to our ICU. He was a bright toddler, full of joy and laughter. His parents loved him dearly, and they cared for him with great affection. Tommy's family did not have a pool, but they did have a small fishpond in the backyard. No one ever thought about putting a fence around the fishpond; how dangerous could such a small pond be? Well, it seems it was quite dangerous, and one morning Tommy's mother found him face down in it. She called 911, and Tommy's heart began beating after prolonged cardiopulmonary resuscitation. He was admitted to our ICU unconscious and unresponsive. Two days went by, and Tommy showed no sign of neurologic recovery. Although his other organ systems improved, he had no purposeful movements. I had been meeting with the parents every day in anticipation of our discussion that day. I explained to Tommy's parents that without some recovery by 48 hours, there was no hope of meaningful recovery after such an event. I explained that we had 2 options: discontinue support, and he would likely die relatively quickly, or continue the ventilator, and his brainstem would regain enough function that he would continue to breathe but would surely remain in a vegetative or minimally conscious state for the rest of his life. Then it came—the question: “Doctor, if he were your child, what would you do?” In 1999, Truog1 wrote a thought-provoking essay in which he distinguished differences between giving advice based on medical facts and giving value-laden advice. Truog also drew our attention to the “gray zone” between these extremes. He argued that although it is appropriate for physicians to give strictly medical advice, it may be less advisable to give advice that is based on … Address correspondence to Alexander A. Kon, MD, Pediatrics and Bioethics, University of California at Davis, 2516 Stockton Blvd, Sacramento, CA 95817. E-mail: aakon{at}ucdavis.edu
Synthesis of PGE2, Collagenase and Tissue Factor by Fibroblast Substrains: Substrains are Differentially Activated for Different Metabolic Products

Abstract Metabolic heterogeneity has previously been demonstrated for cloned fibroblast populations. It is unclear whether a "high producer" or "activated" phenotype for one cell product reflects general metabolic activation or whether activated phenotypes for different metabolic markers segregate independently among cloned populations. We examined human foreskin fibroblast substrains, isolated by limiting dilution cloning, for heterogeneity in biosynthesis of PGE2 and collagenase (stimulated by Interleukin 1-containing mononclear cell supernates), and tissue factor. Synthesis of these products varied 5- to 10-fold among 16 substrains isolated from two parent lines (AT and WB). Metabolic phenotypes (high versus low levels of synthesis) were stable for the substrains over multiple weeks of culture. In neither group of substrains was there a correlation between levels of stimulated PGE synthesis and stimulated collagenase synthesis (r= -0.24 and 0.29 for AT and WB substrains, respectively). Similarly, tissue factor generation did not correlate with either PGE production (r= 0.12 and -0.38 for AT and WB substrains, respectively) or collagenase synthesis (r= 0.17 and 0.21 for AT and WB substrains, respectively). The discordance between high producer phenotypes for the different products was observed even when all three products were measured in the same culture. Activated phenotypes for different metabolic markers thus appear to segregate among cells independently. The process of connective tissue activation by immune cell-derived mediators may depend on the constituent makeup of the responding connective tissue cell population.
Microbiological changes in the uneviscerated bird hung at 10 degrees C with particular reference to the pheasant.

Synopsis Thirty pheasants which had been reared in captivity for 19 weeks were killed by dislocating the neck and hung for up to 15 d at 10 °C. Microbiological, sensory and chemical assessments were made at 0, 3, 6, 8, 10, 13 and 13 d and this paper reports the microbiological results. Examination of the duodenum, small intestine and caecum showed very little multiplication of coli‐aerogenes bacteria during hanging, although there was some increase in the numbers of faecal streptococci. Psychrophilic clostridia, mainly Clostridium putrefaciens, were found in the small intestine after 8 d and these organisms increased in number up to the 15th d. The muscle remained relatively free from bacteria for most of the hanging period, but at 15 d Cl. putrefaciens was found in two out of three muscle samples at io3 and io4 per g. No signs of spoilage due to greening were observed. Twelve 16½>‐week‐old chickens were also killed by dislocating the neck and hung without plucking for 12 d at 10 °C with the pheasants. Al...
The eating patterns of non‐purging bulimic subjects

The current study was undertaken to provide descriptive data regarding the eating patterns of non-purging bulimic subjects and to determine whether these patterns are reflected in the DSM-III-R criteria. The self-monitored food records of 22 non-purging women seeking treatment for binge eating were analyzed. Subjects consumed an average of 602 kcal during their eating binges and the mean duration of binges was 38 minutes. There was large variability both in binge size and duration suggesting that a perception of loss of control during eating is preferable to the present D5M-III-R criterion that binges necessarily consist of the rapid consumption of a large amount of food in a discrete period of time. Consumption during binge episodes consisted of significantly less protein and fiber than consumption of non-binge days. There was no significant difference, however, between fat or carbohydrate consumption. Subjects' intake averaged approximately 2400 kcal/day on binge days compared with 1500 kcal on binge-free days. Thus, non-purging bulimic subjects meet the DSM-III-R criterion that binge episodes alternate with periods of restrictive dieting. An interesting additional finding was that subjects' recall of days during which binge eating occurred seems to be more accurate than their recall of the specific number of binge eating episodes.
Effects of d-amphetamine and cocaine on strained ratio behavior in a repeated-acquisition task.

Abstract Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of four colors. When the fixed-ratio requirement for food presentation was five completions of the chain, d-amphetamine and cocaine disrupted the behavior. As the dose of each drug was increased, the overall response rate decreased, the overall accuracy was impaired (i,e., percent errors increased), and there was less within-session error reduction (acquisition). In contrast, when the fixed-ratio requirement was either 20 or 50 completions of the chain, certain doses of both drugs produced large increases in the overall response rate by eliminating the extended pausing (ratio strain) that was characteristic of the control sessions. These rate-increasing effects were accompanied by error-decreasing effects, both during acquisition and after the response chain had been acquired. Taken together, the results show that the effects of d-amphetamine and cocaine on behavior in a repeated-acquisition task can be modulated by manipulating the value of the fixed-ratio schedule maintaining the behavior.
Hall Effect in Impurity Conduction

The existence of a nonvanishing Hall effect in the "impurity conduction" regime of a semiconductor is demonstrated. In this regime (prevalent at low temperatures and at low impurity concentrations) the dominant electron transport mechanism is the phonon-induced hopping of charge carriers from occupied to unoccupied majority sites. The basic element of the theory is the existence of a (magnetic) field-dependent contribution to the jump probability between two sites. This contribution is computed and is shown to arise from the interference between the amplitude for a direct transition between the initial and final sites and the amplitude for an indirect, second-order transition, involving intermediate occupancy of a third site.
The melting behavior of polybutadienes

The melting temperatures of five emulsion polymerized polybutadienes containing varying amounts of trans-1,4 units were determined. Since slow heating rates were used subsequent to the initial crystallization, melting temperatures were observed that were appreciably higher than previously indicated. The data were analyzed according to the theory of the melting point depression of copolymers, and a lower limit for the heat of fusion per 1,4-trans unit of 18.5 cal./g. was obtained. This value is larger than that for natural rubber and explains why calorimetric measurements of the heat of fusion apparently give abnormally high values. The index of refraction and densities of the amorphous polymers were determined at 25°C. and the specific refractivities found to be constant and independent of polymer constitution in the composition range studied.
Do natural killer cells participate in a killer vascular disease

The article reporting on the exacerbated atherosclerosis in the double mutant, Lystbeige, LDL receptor (LDLR) knockout is important in drawing attention to the possible involvement of natural killer (NK) cells in atherogenesis.1 It is appropriate that NK cells come into focus: a recent review on immune mechanisms in atherosclerosis made scant mention of NK cells,2 and they are important cytolytic cells of the innate immune system. The Lyst beige mutation results in a defect in the cytolytic function of NK cells, and this was demonstrated in the double mutant after consumption of a high-fat diet for 16 weeks. See page 1341 So the authors asked whether the impaired cytolytic activity of NK cells in beige mice may account for the increased atherosclerosis they observed in these mice. To test this, they generated a second complex knockout mouse, one lacking both the LDLR and the perforin gene involved in the cytolytic activity of both cytotoxic T cells, NK T cells, and NK cells. The absence of the perforin gene had no effect on atherosclerosis, even though the total serum cholesterol was increased in these double knockout mice at 16 weeks of diet treatment. Thus the cytolytic defect of NK cells in the Lyst beige LDLR−/− strain does not by itself seem to account for the increased atherosclerosis in this strain. NK cells are important components of the innate immune system. To ascertain whether the adaptive immune system might be implicated in the pro-atherogenic influence of the beige mutation, these experiments were repeated in the absence of an adaptive immune system, ie, with a defective Rag (recombinase activating) gene. A comparison was made of the LDLR−/− RAG1−/− strain with the triple knockout including the Lyst beige mutation. In this context too, the addition of the beige mutation resulted …
Views on exercise and physical activity among rural-dwelling senior citizens.

Context: This study was conducted with senior citizens in the 2 rural communities of Ada and Lindsay, Oklahoma. These communities are both predominantly white, with the largest minority population being American Indian. Both communities are more than 60 miles from a metropolitan area and have a history of farming and ranching. Purpose: The purpose of this study was to explore contextual factors related to physical activity among senior citizens living in rural communities. Methods: Two focus groups were conducted. The groups were conducted in mixed-sex sessions and were audiotaped and transcribed verbatim for the purpose of analysis. Findings: Themes from the focus groups included the following: (1) the types of daily activities engaged in by seniors; (2) the meaning and connotation of the words exercise and physical activity, with physical activity connoting for some the negative imagery of physical labor; and (3) the availability and suitability of settings for physical activity. For seniors living in rural settings in Oklahoma, the lack of indoor facilities and the sometimes extreme climatic conditions serve as significant barriers to physical activity. Conclusion: This study suggests that programs seeking to encourage physical activity among seniors in rural areas could benefit from an assessment of resources and settings for physical activity and the avoidance of language that may have negative connotations for this population.
A theoretically rigorous solution for fundamentally eliminating the low-frequency breakdown problem in finite-element-based full-wave analysis

It has been observed that a full-wave based solution of Maxwell's equations breaks down at low frequencies. Such a problem is especially severe in VLSI circuit applications because the breakdown frequency is in the range of circuit operating frequencies. To eliminate the low-frequency breakdown problem, first, one has to know the exact solution of Maxwell's equations at low frequencies. However, such a benchmark solution does not exist yet because full-wave solvers break down at low frequencies whereas static solvers involve theoretical approximations. The theoretical approximation involved in static solvers is the assumption that E and H are decoupled at low frequencies. Such an assumption is not rigorous because in Maxwell's equations, E and H are always coupled as long as frequency is not zero. Existing solutions to overcoming the low-frequency breakdown problem, in general, rely on static approximations, and hence are not theoretically rigorous. For example, the loop-tree and loop-star basis functions were used to achieve a natural Helmholtz decomposition of the current to overcome the low-frequency breakdown problem in integral-equation-based methods [1]. As another example, the tree-cotree splitting [2–3] was used to provide an approximate Helmholtz decomposition for edge elements in finite-element-based methods. In addition, even by using static approximations, the low-frequency breakdown problem has not been fundamentally solved.
Using Target RCS when Tracking Multiple Rayleigh Targets

Closely-spaced (but resolved) targets pose a challenge for measurement-to-track data association algorithms. Since the Mahalanobis distances between measurements collected on closely-spaced targets and tracks are similar, several elements of the corresponding kinematic measurement-to-track assignment cost matrix are also similar. Lacking any other information upon which to base assignments, it is not surprising that data association algorithms make mistakes. Given this problem many in the target tracking community have speculated that measurement-to-track data association could be improved through the use of features. Since the radar cross section (RCS) naturally occurs with the detection and kinematic measurement and does not require use of high-energy/high-resolution waveforms, it is typically a favored feature for radar systems. To gain insight into its impact on measurement-to-track data association, the benefits of RCS-assisted tracking are analytically assessed in several simple cases. Both the rigorous hypothesis probability approach and several less rigorous ad hoc approaches (which are commonly used in practice) are treated. Results vary between the approaches, but the conclusion is that the benefit of RCS-assisted tracking is limited. In fact applying it blindly in every dwell can actually degrade measurement-to-track data association. For this reason the steps required to incorporate RCS-assisted tracking in a beneficial manner are also identified.
Achilles in Vietnam: Combat Trauma and the Undoing of Character

Dr. Shay has spent the past several years treating Vietnam-combat veterans afflicted with post-traumatic stress disorder. He has come to see an overwhelming and undeniable similarity to the experience of soldiers in Homer's Iliad, including Achilles' shrinking moral and social world and his feelings of betrayal and being "already dead".
A virtual PNNI network testbed

We describe our experiences designing and implementing a virtual PNNI network testbed. The network elements and signaling protocols modeled are consistent with the ATM Forum PNNI draft specifications. The models will serve as a high-fidelity testbed of the transport and network layers for simulation-based studies of the scalability and perforrnance of PNNI protocols. Our models are written in the new network description language TED which offers two advantages. First, the testbed design is transparent; the model descriptions are developed separately from, and are independent of, the simulation-specific code. Second, TED is compiled to run with the GTW (Georgia Tech Time Warp) simulation engine which is supported on shared-memory multiprocessors. Therefore, we directly obtain the advantages of parallel simulation. This is the first complex test of the TED modeling and simulation software system. The feedback from our experiences resulted in some significant improvements to the simulation software. The resulting PNNI models are truly transparent and the performance of the simulations is encouraging. We give results from preliminary simulations of call admission, set-up and tear-down in sample PNNI networks consisting of two hundred nodes and over three hundred edges. The time to simulate ten thousand call requests decreases significantly with the number of processors; we observe a speedup factor of 5.3 when 8 processors are employed compared to a single processor. Our initial implementations demonstrate the advantages of TED for parallel simulations of largescale networks.