cssi/SciSciGPT-SciSciNet huggingface dataset:
Statistical models for longitudinal biomarkers of disease onset.

We consider the analysis of serial biomarkers to screen and monitor individuals in a given population for onset of a specific disease of interest. The biomarker readings are subject to error. We survey some of the existing literature and concentrate on two recently proposed models. The first is a fully Bayesian hierarchical structure for a mixed effects segmented regression model. Posterior estimates of the changepoint (onset time) distribution are obtained by Gibbs sampling. The second is a hidden changepoint model in which the onset time distribution is estimated by maximum likelihood using the EM algorithm. Both methods lead to a dynamic index that represents a strength of evidence that onset has occurred by the current time in an individual subject. The methods are applied to some large data sets concerning prostate specific antigen (PSA) as a serial marker for prostate cancer. Rules based on the indices are compared to standard diagnostic criteria through the use of ROC curves adapted for longitudinal data.
Further Aspects of the Theory of the Maser

The theory of the molecular transitions which are induced by the microwave field in a maser and the effects of various design parameters are examined in detail. It is shown that the theoretical minimum detectable beam intensity when the maser is used as a spectrometer for the 3-3 line of ammonia is about ${10}^{9}$ molecules/sec under typical experimental conditions. Various systematic frequency shifts and random frequency fluctuations of the maser oscillator are discussed and evaluated. The most prominent of the former are the "frequency-pulling" effect, which arises from detuning of the cavity, and the Doppler shift due to the asymmetrical coupling of the beam with the two traveling wave components of the standing waves which are set up in the cavity. These two effects may produce fractional shifts as large as one part in ${10}^{9}$. If adequate precautions are taken, however, they can be reduced to one part in ${10}^{10}$ or possibly less. The random fluctuations are shown to be of the order of one part in ${10}^{13}$ under typical operating conditions. For molecular beams in which the electric-dipole transition is used, the $T{M}_{010}$ mode is usually the most suitable for the maser; while in atomic beams in which magnetic transitions are utilized, the $T{E}_{011}$ mode is to be preferred.
Genetic algorithm-based wavelength selection for the near-infrared determination of glucose in biological matrixes: initialization strategies and effects of spectral resolution.

An improved genetic algorithm (GA)-based wavelength selection procedure is developed to optimize both the near-infrared wavelengths used and the number of latent variables employed in building partial least-squares (PLS) calibration models. This GA-based wavelength selection algorithm is applied to the determination of glucose in two different biological matrixes. With random selection of a small number of initial wavelengths, a dramatic reduction in the number of wavelengths required for building the PLS calibration models is observed. The fitness function used to guide the GA, the method of recombination used, and the effect of spectral resolution on the wavelength selection are also studied. In the resolution study, the original data with a point spacing of 2 cm-1 are deresolved to 4-, 8-, and 16-cm-1 point spacings by truncating the collected interferograms before applying the Fourier processing step. The use of lower resolution spectra is found to reduce further the number of final wavelengths select...
Cloning and Subcellular Location of an Arabidopsis Receptor-Like Protein That Shares Common Features with Protein-Sorting Receptors of Eukaryotic Cells

Many receptors involved in clathrin-mediated protein transport through the endocytic and secretory pathways of yeast and animal cells share common features. They are all type I integral membrane proteins containing cysteine-rich lumenal domains and cytoplasmic tails with tyrosine-containing sorting signals. The cysteine-rich domains are thought to be involved in ligand binding, whereas the cytoplasmic tyrosine motifs interact with clathrin-associated adaptor proteins during protein sorting along these pathways. In addition, tyrosine-containing signals are required for the retention and recycling of some of these membrane proteins to the trans-Golgi network. Here we report the characterization of an approximately 80-kD epidermal growth factor receptor-like type I integral membrane protein containing all of these functional motifs from Arabidopsis thaliana (called AtELP for A. thaliana Epidermal growth factor receptor-Like Protein). Biochemical analysis indicates that AtELP is a membrane protein found at high levels in the roots of both monocots and dicots. Subcellular fractionation studies indicate that the AtELP protein is present in two membrane fractions corresponding to a novel, undefined compartment and a fraction enriched in vesicles containing clathrin and its associated adaptor proteins. AtELP may therefore serve as a marker for compartments involved in intracellular protein trafficking in the plant cell.
Multiagent induction and maintenance therapy for patients with refractory immune thrombocytopenic purpura (ITP)

Patients with severe immune thrombocytopenic purpura (ITP) may require an acute increase in the platelet count for surgery or ongoing hemorrhage as well as long-term maintenance treatment. Certain of these patients may be refractory to steroids, intravenous anti-D, intravenous immunoglobulin (IVIG), and splenectomy. Therefore, acute platelet increases were studied in 35 patients completely unresponsive to IVIG or high-dose steroid treatment. Because of their lack of response to either or both single agents, these patients were administered a 3- or 4-drug combination including IVIG 1 g/kg, intravenous methylprednisolone 30 mg/kg, Vinca alkaloids (VCR 0.03 mg/kg), and/or intravenous anti-D (50-75 microg/kg). Subsequent maintenance therapy with the oral combination of danazol (10-15 mg/kg) and azathioprine (2 mg/kg) was given to 18 of the 35 patients. Seventy-one percent of the patients responded to the intravenous combination treatment with acute platelet increases of at least 20 x 10(9)/L to a level greater than 30 x 10(9)/L. Two thirds of the patients given maintenance therapy achieved stable platelet counts greater than 50 x 10(9)/L without other treatments. One patient developed an ileus, but otherwise there was little toxicity of combination treatment. Combination chemotherapy is a useful approach for patients with ITP refractory to conventional treatments both for acute induction and for long-term maintenance therapy.
PTHrP regulates cerebral blood flow and is neuroprotective.

in 1925, collip and clark (the same Collip who had extracted insulin from the pancreas several years earlier) infused crude parathyroid extracts into dogs and observed a decrease in systemic blood pressure ([5][1]). Thus began an interest in the putative regulation of excitable cells by parathyroid
A Re-Examination of the Proximity Effect in Man:

A recent report indicated that the mere proximity to refined sugar could reduce human grip strength. A reexamination of this hypothesis yielded no significant effect.
Gastric Proteolysis in the Preterm Infant: Protein Digestion is Limited and Is Not Affected by Diet, Human Milk or Formula † 580

Gastric Proteolysis in the Preterm Infant: Protein Digestion is Limited and Is Not Affected by Diet, Human Milk or Formula † 580
Effectively Facilitating Gender Transition in the Workplace

Issues surrounding gender identity in the workplace are sensitive and complex. One of the more challenging scenarios for employers is facilitating the gender transition process. Effectively communicating with co-workers and clients about the change, modifying personnel documents at the appropriate time, and dealing with more mundane issues such as restroom usage and dress code represent the tip of the iceberg. This paper is a comprehensive review of the literature to help employers aptly manage the transition process, so as to retain employees’ sense of fair treatment and acceptance at work.
Stylistic variability of stemmed obsidian tools (mata'a), frequency seriation, and the scale of social interaction on Rapa Nui (Easter Island)

Abstract Easter Island, or Rapa Nui, has been the focus of much research and speculation, particularly with reference to the island’s hundreds of giant, enigmatic statues and the set of conditions that supported their construction and transportation. In this paper, we analyze an abundant class of lithic artifacts, mata’a , to study of patterns of cultural transmission with implications for the evolution of groups, competition, and scale of socio-political organization among this island population. While these kinds of studies often draw upon assemblages of decorated ceramics, here we show how analysis of variability unconstrained by performance allows us to measure aspects of inheritance related to the manufacture of these artifacts. In the case of mata’a from Rapa Nui, we demonstrate that it is possible to reach falsifiable conclusions about the evolutionary dynamics that shaped the remarkable archaeological record on Rapa Nui.
Inhibition and breaking of advanced glycation end-products (AGEs) with bis-2-aminoimidazole derivatives

Advanced glycation end-products (AGEs), unregulated modifications to host macromolecules that occur as a result of metabolic dysregulation, play a role in many diabetes related complications, inflammation and aging, and may lead to increased cardiovascular risk. Small molecules that have the ability to inhibit AGE formation, and even break preformed AGEs have enormous therapeutic potential in the treatment of these disease states. We report the screening of a series of 2-aminoimidazloles for anti-AGE activity, and the identification of a bis-2-aminoimidazole lead compound that possesses superior AGE inhibition and breaking activity compared to the known AGE inhibitor aminoguanidine.
Comparing five modelling techniques for predicting forest characteristics

Broad-scale maps of forest characteristics are needed throughout the United States for a wide variety of forest land management applications. Inexpensive maps can be produced by modelling forest class and structure variables collected in nationwide forest inventories as functions of satellite-based information. But little work has been directed at comparing modelling techniques to determine which tools are best suited to mapping tasks given multiple objectives and logistical constraints. Consequently, five modelling techniques were compared for mapping forest characteristics in the Interior Western United States. The modelling techniques included linear models (LMs), generalized additive models (GAMs), classification and regression trees (CARTs), multivariate adaptive regression splines (MARS), and artificial neural networks (ANNs). Models were built for two discrete and four continuous forest response variables using a variety of satellite-based predictor variables within each of five ecologically different regions. All techniques proved themselves workable in an automated environment. When their potential mapping ability was explored through simulations, tremendous advantages were seen in use of MARS and ANN for prediction over LMs, GAMs, and CART. However, much smaller differences were seen when using real data. In some instances, a simple linear approach worked virtually as well as the more complex models, while small gains were seen using more complex models in other instances. In real data runs, MARS and GAMS performed (marginally) best for prediction of forest characteristics.
Real-time autonomous disturbance detection and monitoring system with L-band UAVSAR

We developed an autonomous disturbance detection and monitoring system with imaging radar that combines the unique capabilities of imaging radar with high throughput onboard processing technology and onboard automated response capability based on specific science algorithms. This smart sensor development leverages off recently developed technologies in real-time onboard synthetic aperture radar (SAR) processor and onboard automated response software as well as science algorithms previously developed for radar remote sensing applications. In this project, we use a high rate data interface to ingest NASApsilas UAVSAR data and compute SAR imagery in real-time complete with motion compensation and antenna beam steering capabilities. NASApsilas UAVSAR is a compact, L-band 80 MHz bandwidth, fully polarimetric radar. It is designed for repeat-pass InSAR and has had engineering flights in 2007 and successful science data collections in 2008. The fidelity of the onboard SAR processor is tuned by implementing polarimetric calibration capabilities. Science algorithms are implemented for detecting and monitoring fire disturbances over the US forests. We additionally developed artificial intelligence for decision-making, and adapted existing onboard activity re-planning and execution software to interface with the UAVSAR radar controller. The product of this development is a prototype closed loop smart sensor.
Modeling the electrical resistivity of deformation processed metal–metal composites

Abstract Deformation processed metal–metal (matrix–reinforcement) composites (DMMCs) are high-strength, high-conductivity in situ composites produced by severe plastic deformation. The electrical resistivity of DMMCs is rarely investigated mechanistically and tends to be slightly higher than the rule-of-mixtures prediction. In this paper, we analyze several possible physical mechanisms (i.e. phonons, interfaces, mutual solution, grain boundaries, dislocations) responsible for the electrical resistivity of DMMC systems and how these mechanisms could be affected by processing conditions (i.e. temperature, deformation processing). As an innovation, we identified and assembled the major scattering mechanisms for specific DMMC systems and modeled their electrical resistivity in combination. From this analysis, it appears that filament coarsening rather than dislocation annihilation is primarily responsible for the resistivity drop observed in these materials after annealing and that grain boundary scattering contributes to the resistivity at least at the same magnitude as does interface scattering.
Temporal signaling and differential expression of Bordetella iron transport systems: the role of ferrimones and positive regulators

The bacterial respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica employ multiple alternative iron acquisition pathways to adapt to changes in the mammalian host environment during infection. The alcaligin, enterobactin, and heme utilization pathways are differentially expressed in response to the cognate iron source availability by a mechanism involving substrate-inducible positive regulators. As inducers, the iron sources function as chemical signals termed ferrimones. Ferrimone-sensing allows the pathogen to adapt and exploit early and late events in the infection process.
Growth in transitional countries: The long-term impact of under-nutrition on health

Context: Despite significant economic development in many parts of the world, upwards of 150 million children are short for their age. Epidemiologic and clinical data suggest that stunting increases the risk for nutrition-related chronic diseases (NRCD), a particular problem for transitional countries as dietary and environmental shifts that accompany development are also reported to increase the risk for NRCD. Objective and methods: This paper reviews studies on the causes and long-term effects of poor nutrition as well as data from clinical studies of growth retardation and metabolism and body composition that may explain the link between poor growth and later risk for NRCD. Results: Growth retardation is the physical outcome of a complex interaction of socio- economic factors during key periods of development. Growth-retarded children may present with metabolic or body fat distribution profiles that predispose them to NRCD, a risk factor that may be compounded by consuming a diet consistent with the ‘n...
Strategic Alliances: What Can We Learn When They Fail?

Purpose. The purpose of this research is to develop a theory-based model of alliance failure with a specific focus on alliance lifecycle phases that have, for the most part, been ignored in extant ...
Assessment of morbidity following insertion of fixed preoperative orthopedic appliance in infants with complete cleft lip and palate

Objective To examine physiologic and behavioral indicators of pain within the first 24 hours following insertion of the fixed presurgical orthopedic appliance (FPOA) under general anesthesia in infants with unilateral and bilateral complete cleft lip and palate. Methods The study sample included 109 infants who had either a dentomaxillary appliance (DMA) or an elastomeric chain premaxillary retraction (ECPR) appliance. Vital signs and FLACC (Face, Legs, Activity, Cry, Consolability) scores were used to measure the outcomes. Results There was an initial postoperative increase in the median heart rate. Heart rate returned to the median baseline level by 8 hours. The median systolic blood pressure increased postoperatively and remained elevated throughout the time of evaluation. The median respiratory rate remained below that at baseline throughout the study period. The highest mean change in FLACC measurements was observed approximately 2 hours postoperatively. By 3 hours postoperatively, the scores decreased. Conclusions Although there was a large individual variability, the FLACC scores became reduced after 3 hours following surgical insertion of the DMA and the ECPR appliance.
Medical Error Reporting System Design: Multiple User Considerations and their Implications:

The purpose of this paper is to examine the differences between the preferences of physicians and clinical assistants for the design of a statewide medical error reporting system. The study employed a series of separate focus groups composed of physicians and clinical assistants. The focus groups covered a wide range of relevant topics based on the previous literature on error reporting both in and outside of healthcare. Focus group transcripts were subject to a content analysis resulting in a total of 86 major and minor themes. While physicians and clinical assistants shared similar preferences and beliefs surrounding error reporting such as its educational potential and fear of punitive repercussions, they differed as well. Some of the differences uncovered included the rules and regulations governing the use of the system, the medium of reporting, and aspects of the organization that may affect reporting levels. The design implications for considering these issues are discussed.
Bile acids induce ileal damage during experimental necrotizing enterocolitis.

Background & Aims: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of premature infants. While the effect of bile acids (BAs) on intestinal mucosal injury is known, we investigated the contribution of BAs during the development of NEC in neonatal rats. Methods: Premature rats were fed with cow's milk–based formula and subjected to asphyxia and cold stress to develop NEC. Jejunal and ileal luminal BAs, portal blood BAs, and messenger RNA and protein for the apical sodium-dependent bile acid transporter, the ileal bile acid binding protein, and the heteromeric organic solute transporter (Ostα/Ostβ)were evaluated. Results: Ileal luminal BAs levels were increased significantly during disease development and the removal of ileal BAs significantly decreased the incidence and severity of disease. Furthermore, when NEC was reduced via treatment with epidermal growth factor (EGF), BA levels were reduced significantly. Jejunal luminal BA levels were similar between animals with NEC and controls, but portal/ileal luminal BA ratios were decreased significantly in animals with NEC. The apical sodium-dependent bile acid transporter was up-regulated at the site of injury in animals with NEC and decreased after EGF treatment; however, the ileal bile acid binding protein was up-regulated only in the NEC and EGF group. Ostα/Ostβ expression was low in all groups, and only slightly increased in the NEC group. Conclusions: These data strongly suggest that BAs play a role in the development of ileal damage in experimental NEC and that alterations in BA transport in the neonatal ileum may contribute to disease development.
Mesophase and pyrolytic carbon formation in aircraft fuel lines

Exposure of jet fuel to high temperatures in aircraft fuel lines triggers pyrolysis reactions which eventually lead to deposition of carbonaceous solids on metal surfaces. This is a particularly important problem for advanced future aircraft which may expose fuel to very high temperatures. Different optical textures were observed in samples of deposits formed in different sections of aircraft fuel systems. Deposits from a burner fuel line consist only of pyrolytic carbon, indicating that gas phase reactions were responsible for solid formation. Afterburner line deposits, on the other hand, contain both pyrolytic carbon and carbonaceous mesophase structures, implicating also liquid phase carbonization reactions. The FTIR data shows that solids containing mesophase consist of polynuclear aromatic hydrocarbons with a low degree of condensation and alkyl substitution. In contrast, solids with pyrolytic carbon structure are composed of highly condensed, large polyaromatic species. It is clear that jet fuels go through extensive cracking, aromatization, and aromatic polymerization reactions before solid deposition takes place in the fuel lines.
Sleep problems and substance use in adolescence

Longitudinal studies of adults have reported finding insomnia to significantly predict onset of substance abuse. This study estimated the association between sleep problems and substance use among adolescents in the context of psychiatric problems. Data come from the US National Household Survey on Drug Abuse 1994-1996 that included 13,831 adolescents. Use of cigarettes, alcohol and any illicit drug were each associated with adolescents' reports of having frequent sleep problems, adjusting for age, sex, race and family income (odds ratios ranging from 1.5 to 3.8). Adjusting for internalizing (e.g. depression and anxiety) and externalizing (e.g. deviance and aggression) problems reduced the associations between sleep problems and use of these substances, suggesting that part of the association is attributable to psychiatric problems. The part of the association not attributable to psychiatric problems was limited to the associations between sleep problems and use of illicit drugs. These results suggest that the relationship between sleep problems and drug use/abuse must be viewed in the context of psychiatric problems. Longitudinal research that employs more specific measures of sleep problems is indicated. Such research may provide information on the relationship of sleep problems to the immediate health and well being of adolescents, as well as their trajectories into adulthood.
Effect of leucogenenol, a thymothyroid hormone, on the enzymes and several other constituents of the serum

It has been found that rats treated with the thymothyroid hormone, leucogenenol, have significantly elevated levels of alkaline phosphatase and lactate dehydrogenase in their serum 8 hrs. later. These levels remain elevated for 24 hrs. and 12 hrs., respectively. The concentrations of creatine phosphokinase and aspartate aminotransferase as well as total protein, albumin, calcium, inorganic phosphorus, glucose, urea nitrogen, uric acid and creatinine in the serum are not affected by treatment with leucogenenol. These results are in agreement with the previously reported findings that treatment with leucogenenol increases the rate of development of blood cells of the bone marrow, increases the rate of recovery from immunosuppression and enhances the immune response.
Cold-sensitive regulatory mutants of simian virus 40☆

Abstract A series of conditionally or partially defective simian virus 40 mutants has been constructed with lesions within the regulatory segment of the viral genome near the Bgl I cleavage site which includes the origin of replication of viral DNA. A single-stranded gap was positioned in this region by controlled, approximately synchronous nick translation from the Bgl I site with DNA polymerase I, followed by enzymatic extension of the nick into a small gap. The gapped DNA was either deaminated with sodium bisulfite or converted into linear form by digestion with nuclease S 1 . After infection of cell monolayers with the modified DNA, viable mutants containing deletions or base substitutions within the regulatory segment were isolated with high efficiency, and their mutational sites were mapped by restriction analysis and nucleotide sequencing. One set of mutants had overlapping deletions extending from the start of the T antigen coding sequence to within 32 base-pairs of the Bgl I site. Most of these mutants were cold-sensitive, i.e. formed small plaques at 32 °C relative to wild-type virus, as were several mutants with base substitutions in the same region. Other mutants formed small plaques at all temperatures tested. A second series of deletion and base substitution mutations has been mapped to the late side of the Bgl I site. The late deletion closest to the replication origin diverged from the wild-type sequence 33 base-pairs from the Bgl I site, and formed wild-type plaques; however, a mutant with base substitutions in the same region was cold-sensitive. Since all the detectable mutational alterations map outside known protein-coding sequences, we infer that these mutants are probably defective in DNA replication, transcription, RNA processing, and/or translation. The frequency of cold-sensitive mutants suggests that this phenotype may reflect changes in protein-nucleic acid interactions involved in regulatory phenomena.
Purchase and Consumption Habits: Not Necessarily What You Intend

Purchase and consumption behaviors in daily life often are repetitive and performed in customary places, leading consumers to develop habits. When habits have formed, environmental cues can activate the practiced responses in the absence of conscious decision making. This research tested these ideas using a longitudinal design. We predicted that regardless of their explicit intentions, consumers would repeat habits to purchase fast food, watch TV news, and take the bus. The results yielded the anticipated pattern in which participants repeated habitual behaviors even if they reported intentions to do otherwise. Intentions only guided behavior in the absence of strong habits. This study ruled out a number of artifactual accounts for these findings including that they arise from the level of abstraction at which intentions are identified, the certainty with which participants held intentions, a restriction of range in the measures, and the strategy participants used to estimate frequency of past performance.
Mitochondrial DNA Variation and Phylogeography of the Ferruginous Pygmy-Owl (Glaucidium brasilianum)

Sequences from the mitochondrial cytochrome b gene were used to examine patterns of variation within and among populations of the ferruginous pygmy-owl (Glaucidium brasilianum) from both North America (including populations from Mexico) and South America. As currently conceived, G. brasilianum is paraphyletic, with North American and South American clades representing two distinct groups that should be recognized as the distinct species G. ridgwayi and G. brasilianum, respectively. Within the G. ridgwayi clade, populations from Arizona, Sonora, and Sinaloa are genetically distinct and share no mitochondrial haplotypes with populations occurring in Texas and other regions of Mexico. According to nested clade analysis this separation may be the consequence of past fragmentation that predates the origin of the Sonora desert. In addition, gene flow between the Arizona/Sonora/Sinaloa populations and the Texas/other Mexico populations is practically nonexistent, with estimates being approximately one individual every 10 generations. Collectively, these data suggest that the Arizona/Sonora/Sinaloa clade should be recognized as either a distinct subspecies or phylospecies from the group containing populations in Texas and the remainder of Mexico. These data should be used as guidelines for pygmy-owl recovery and conservation, as they meet the recommendations of task 3 of the pygmy-owl recovery plan that lists genetic data as essential information for pygmy-owl management.
Exchange Bias in Bulk Ni $_{50}$ Mn $_{35}$ In $_{15 - {\rm x}}$ Si $_{\rm x}$ Heusler Alloys

We have studied the effects of partial substitution of In by Si on the magnetic and exchange bias properties of bulk Ni 50Mn 35In 15 Heusler alloys through magnetization measurements. Zero-field and field-cooled magnetization measurements were performed in fields up to 5 T. It was observed that an increase in the Si concentration strongly affects the ground state of the martensitic phase and the magnetic properties of compounds. It was found that exchange bias increases with increasing conduction electron concentration, and the maximum bias field was found to be ap 0.017 T at 5 K for a cooling field of H=5 T.
Proteoglycans synthesized by gingival fibroblasts derived from human donors of different ages

The proteoglycans synthesized by fibroblasts derived from human donors of ages ranging from 12 years to 68 years have been studied. In addition, the in vitro proliferation rates of the various cell strains were studied and demonstrated that increasing donor age correlated with a decrease in proliferative activity. The incorporation of [35S]-sulfate into proteoglycans decreased with increasing donor age with cells from the oldest donor demonstrating a 50% reduction compared with cells from the youngest donor. Analysis on Sepharose CL-4B of isolated [35S]-labeled proteoglycans for molecular size distribution revealed few differences between the cell-layer-associated proteoglycans of all cell strains studied. However, analysis of the medium-associated [35S]-labeled proteoglycans demonstrated an increase in the amount of small molecular size proteoglycans with increasing age. More specific analysis of the glycosaminoglycan composition revealed an increase in heparan sulfate from 52% to 73% in the cell-layer-associated proteoglycans of cells from the youngest and oldest donors, respectively. Accompanying this increase was a relative decrease in dermatan and chondroitin sulfate content from 24% to 13% and 25% to 16%, respectively, with increasing donor age. Additionally, the degree of N-sulfation of cell layer heparan sulfate increased with age. Heparan sulfate levels increased in the medium as well with increasing age, with a concomitant decrease in chondroitin sulfate. The quantity of medium-derived dermatan sulfate remained relatively evenly distributed throughout the various ages studied. The various differences noted are considered to reflect the general metabolic changes associated with aging. In particular the increase in heparan sulfate content with age is considered to be related to the decreased proliferative activity of the fibroblasts with increasing age.
A biomechanical study of the human cricoarytenoid joint

Objectives/Hypothesis: To develop a model to investigate the biomechanics of the cricoarytenoid joint and establish stiffness, laxity, and range of motion of the cricoarytenoid joint in adult human larynges. Study Design: Laboratory investigation of freshly frozen larynges from adult humans, measuring the stiffness, laxity, and range of motion in intact and injured cricoarytenoid joints. Methods: Eight normal-appearing frozen cadaver larynges from adult humans were studied. The cricoid cartilage was fixed to a load cell sensitive to forces in three dimensions. A probe was rigidly fixed to the arytenoid cartilage and attached to a frame to allow active rotation, rocking, and gliding of the arytenoid. A computer program simultaneously recorded forces generated by these motions and tracked the motion of the arytenoid in three dimensions. The joint was studied before and after injury to the posterior cricoarytenoid ligament, and the joint surfaces were digitized after completion of these studies. Results: A successful method of evaluating the biomechanical properties of the cricoarytenoid joint was developed. Comparing intact and injured joints confirmed that laxity and range of motion increased during rocking, gliding, and rotational motion when the cricoarytenoid ligament had been divided. Stiffness measurements for rocking, rotation, and gliding also were documented. Conclusions: The model of study introduced in this report provides a significant and unique method of investigating the biomechanics of the cricoarytenoid joint, allowing insight into the basic joint characteristics and alteration in joint biomechanics related to injuries and surgical procedures. Dividing the cricoarytenoid ligament increases laxity and range of motion in sagittal rocking, gliding, and axial rotation. Secondary constraints on the joint provide significant stiffness of greater degrees of displacement. Further studies should provide insight into the significant secondary elements supporting the joint and into the mechanisms of cricoarytenoid injuries, as well as the effect of surgical procedures on the cricoarytenoid joint. Laryngoscope, 108:1704–1711, 1998
Evaluation of four soil test extractants for Zimbabwe soils

Abstract The objective of this research was to compare the results from anion exchange Resin extraction of P, and the acidified ammonium acetate (AA) extraction of K and Mg with the results obtained using two single extraction procedures, Mehlich 1 (M‐l) and Mehlich 3 (M‐3). Phosphorus extracted from 72 Zimbabwe soils using M‐l and M‐3 was comparable to Resin extracted P in about 80% of the soils. Mehlich 1 extracted about half the amount of P as the Resin method, and M‐3 extracted about one and one‐half times as much. Phosphorus by M‐3 was highly correlated, (r — 0.846), with Resin extracted P from soils having 0.01M CaCl2 pH values of equal to or greater than 5.9. On soils less than pH 5.9, the r value was 0.502, and for all soils, the r value for M‐3 vs Resin P was 0.615. Mehlich 1 extracted P vs Resin P had a r value of 0.298. Acidified ammonium acetate (AA) extraction of K and Mg was comparable to M‐l and M‐3 extraction of K and Mg in 92% or more of the 72 soils. The K correlation coefficient (r) for...
Optimal H/sub 2//l/sub 1/ control via duality theory

In this paper we consider the problem of minimizing the H/sub 2/-norm of the closed-loop map while maintaining its l/sub 1/-norm at a prescribed level. The problem is analyzed in the case of discrete-time, SISO closed-loop maps. Utilizing duality theory, it is shown that the optimal solution is unique, and, in the nontrivial case where the l/sub 1/ constraint is active, the optimal solution has a finite impulse response. A finite step procedure is given for the construction of the exact solution. This procedure consists of solving a finite number of quadratic programming problems which can be performed using standard methods. Finally, continuity properties of the optimal solution with respect to changes in the l/sub 1/-constraint are established. >
Are Drug Experimenters Better Adjusted Than Abstainers and Users?: A Longitudinal Study of Adolescent Marijuana Use

Abstract Purpose Experimentation with substance use is normative during adolescence and prior research suggests that adolescents who refrain from experimentation may be psychologically maladjusted. This longitudinal study compared lifetime marijuana abstainers (n = 1177), experimenters (n = 873), and frequent users (n = 205) at grade 12 on psychosocial functioning during late adolescence and young adulthood. Methods Participants were recruited from middle schools in 1985 (grade 7) and assessed repeatedly, including in 1990 (grade 12) and 1995 (age 23). Self-report surveys assessed lifetime substance use at grade 12, and psychosocial functioning at grade 12 and age 23. Group differences after controlling for key demographics were estimated using multivariate logistic regression and analysis of covariance. Results Adolescent abstainers from marijuana often fared better (and in no case worse) than experimenters and frequent users both concurrently and later in life on school engagement, family and peer relations, mental health, and deviant behavior. Similar results were found in ancillary analyses using a definition of adolescent “abstainer” that also accounted for cigarette and alcohol use. Conclusions Results refute the idea that adolescents who abstain from substance use are maladjusted, and suggest instead that they function better than experimenters later in life, during the transition to young adulthood.
Model collaboration for advancing student-centered engineering education

The University of Texas at El Paso (UTEP) and the Franklin W. Olin College of Engineering (Olin) are establishing a student-centered hands-on interactive approach to engineering education (similar to Olin's) at UTEP, where it will reside in UTEP's innovative B.S. in Leadership Engineering (LE) program. The goal of the proposed collaboration is to catalyze UTEP's educational innovation through a cross-campus collaboration between the two institutions by incorporating the Olin educational process, both design and features, into the first offerings of the Bachelor of Science in Leadership Engineering (BSLE) program. Specifically, the collaboration includes faculty exchanges between the two institutions; a series of retreats for planning and assessment; curriculum development; and student recruitment practices. The 21st century workplace demands a new engineer - one who effectively contributes to solving problems using innovation, creativity, and strategic foresight. Graduates of the Olin-UTEP developed Bachelor of Science in Leadership Engineering (LE) program will possess these attributes through the program's rigorous yet flexible major in engineering, and in-depth study of leadership and its effect upon technology and society. In this panel we will share the context for our innovative approach, key features of the partnership to date, and acclaim the value of inter-institutional sharing.
Adhesion of epoxy to hydrotalcite conversion coatings: II. Surface modification with ionic surfactants

Abstract Hydrotalcites (HT) are naturally occurring compounds being developed as environmentally benign conversion coatings for aluminum aerospace alloys. A successful conversion coating should provide corrosion resistance and act as a base for adhesion with subsequent organic layers. In the first paper of this series, the effect of interlayer anion substitution on the adhesion of epoxy primer was investigated. Interfacial tension and electrostatic interactions were found to influence adhesion between epoxy and conversion coatings. It was believed that increased adhesion could be attained by modification of these properties. This investigation examines the effect of ionic surfactants on the corrosion resistance and epoxy adhesion for HT-based conversion coatings. Post-treatment of a NO 3 HT conversion coating with a trialkyl ammonium surfactant (Adogen®-464) increased the pull-off tensile strength (POTS) of an epoxy coating by 55%. However, treatment with a linear anionic surfactant, sodium lauryl sulfate (SLS); a linear cationic surfactant, cetyltrimethylammonium bromide (CTAB); or a divalent cation (Ca 2+ ) had no effect on the epoxy POTS. Electrophoresis and the rising height method were employed to investigate the effect of the Adogen on electrostatic interactions and interfacial tension, respectively. Adogen decreased the isoelectric point (IEP) of NO 3 HT powders from 11.3 to 10.5. This was attributed to a shift in the Outer Helmholtz Plane (OHP) by the Adogen. A model epoxy molecule, N -methylethanolamine (NMEA), was used for contact angle measurements on conversion coating powders by the rising height method. The contact angle data was found to correlate with the epoxy dry adhesion rankings reported in Part 1 of this series. Adogen adsorption on NO 3 HT powders decreased the NMEA contact angle from 67.9 to 24.1°. Fourier Transform Infrared (FTIR) spectroscopy did not indicate primary bonding between NO 3 HT and Adogen. However, covalent bonding between NO 3 HT and NMEA (and, thus, epoxy) was suggested by FTIR. The improvement of epoxy adhesion on NO 3 HT by Adogen is believed to be due to the increased wettability of the HT.
Treatment of high-risk, non-muscle-invasive bladder cancer

For patients with high-risk superficial bladder cancer, accurate identification of tumor grade and stage, and appropriate treatment are paramount to achieving durable disease control and long-term survival. In this article, the author highlights the important issues relating to the management of this disease.
An easily-diagnosable fault-tolerant binary tree architecture

Abstract Tree structure has been widely used in the design of distributed systems. In this paper, we present a new fault-tolerant modular architecture for binary trees. The number of nodes in each module can be adjusted to compromise between area overhead and reliability (or yield). Since each module is constructed by clustering nodes at the same level, it can be used for non-homogeneous trees where each level of the tree is made up of homogeneous nodes. The structure can be layed out using H-tree method. A fault diagnosis algorithm utilizing the topological property of the modular tree architecture is also proposed. The structure is inherently useful in implementing a concurrent fault detection/location scheme. A dictionary machine is used to illustrate the fault location scheme.
Products of reaction of OH radicals with α‐pinene

[1] Products of the gas-phase reaction of α-pinene with OH radicals in the presence of NO have been investigated using gas chromatography with flame ionization detection to quantify pinonaldehyde and in situ atmospheric pressure ionization mass spectrometry in the negative ion mode to quantify selected other products as their NO2− adducts by utilizing C6-dihydroxycarbonyls and C6-hydroxynitrates formed in situ from the reaction of OH radicals with 1-hexene as an internal standard. The products quantified, and their molar formation yields, were: pinonaldehyde, 28 ± 5%; molecular weight 184 product (dihydroxycarbonyl), 19% (with an estimated uncertainty of a factor of ∼2); molecular weight 200 product, 11% (with an estimated uncertainty of a factor of ∼2). Together with a very approximate yield from our API-MS analyses for the formation of organic nitrates (∼1%) and literature data for acetone (plus coproducts), ∼65–70% of the reaction products and pathways are accounted for.
A Finite Element Formulation for Fluid-Structure Interaction in Three-Dimensional Space

The safety evaluation of fast reactors often involves the modeling of various types of structural components which interact with surrounding fluid in three-dimensional space. In this paper, several key areas for performing three-dimensional fluid-structure interaction calculations are discussed. A new development is presented for a three-dimensional hexahedral hydrodynamic finite-element based upon a Quasi-Eulerian approach. By using trilinear shape functions and assuming a constant pressure field within the element, simple relations are obtained for internal nodal forces. The forms developed are easily coded and computationally efficient. Because the formulation is based upon a rate approach it is applicable to problems involving large displacements. Only adiabatic processes are considered. The difficult tasks (1) of input data preparation and checking and (2) the displaying of computed results are discussed. The use of automatic mesh generators, input data error analysis, and graphical display of the finite element meshes used to model reactor components are shown to ease the input task. In the final section, the formulation is applied to the three-dimensional fluid-structure interactions involved in a current reactor safety problem.
On the Riemann Hypothesis for the CharacteristicpZeta Function

. (1.1)This is a well defined element in 0. A polynomial f is said to be monic iff(t) is of the form 1+tg(t). The constant 1 is the only monic polynomialof degree zero. By convention, the constant 1 is not an irreducible polyno-mial. The characteristic p zeta function in the theory of Drinfeld modulesis then‘(A, s)=11&1x‘
Computational identification of the Spo0A‐phosphate regulon that is essential for the cellular differentiation and development in Gram‐positive spore‐forming bacteria

Spo0A-phosphate is essential for the initiation of cellular differentiation and developmental processes in Gram-positive spore-forming bacteria. Here we combined comparative genomics with analyses of microarray expression profiles to identify the Spo0A-phosphate regulon in Bacillus subtilis. The consensus Spo0A-phosphate DNA-binding motif identified from the training set based on different computational algorithms is an 8 bp sequence, TTGTCGAA. The same motif was identified by aligning the upstream regulatory sequences of spo0A-dependent genes obtained from the expression profile of Sad67 (a constitutively active form of Spo0A) and their orthologs. After the transcription units (TUs) having putative Spo0A-phosphate binding sites were obtained, conservation of regulons among the genomes of B.subtilis, Bacillus halodurans and Bacillus anthracis, and expression profiles were employed to identify the most confident predictions. Besides genes already known to be directly under the control of Spo0A-phosphate, 276 novel members (organized in 109 TUs) of the Spo0A-phosphate regulon in B.subtilis are predicted in this study. The sensitivity and specificity of our predictions are estimated based on known sites and combinations of different types of evidence. Further characterization of the novel candidates will provide information towards understanding the role of Spo0A-phosphate in the sporulation process, as well as the entire genetic network governing cellular differentiation and developmental processes in B.subtilis.
Applications of the Theory of Impulsive Parametric Excitation and New Treatments of General Parametric Excitation Problems

In this paper the stability theory of impulsive parametric excitation developed in [1] is first applied to three mechanical systems. Explicit and exact stability conditions are easily found and some typical stability charts are presented. Also presented in the paper is the use of this theory and a parallel theory involving step functions as approximate methods for treating periodic parametric excitations of more general nature. Exploratory studies along this line have led us to believe that these approximate methods have promise to be very powerful and practical tools for dealing with the stability of general high-order periodic systems.
Teacher education students' views on class discussion: Implications for fostering critical reflection

Abstract In an attempt to understand what factors motivate teacher education students to participate in class discussions, questionnaires were administered to students from two teacher education programs in the U.S.A. In addition, 30 students were interviewed. Findings point to the estimation of the worth of one's ideas as a key issue in class discussions. Men and older students believed that their ideas made important contributions more often than other students. Findings revealed that the topic, the classroom climate, and advance preparation are central factors influencing students' participation. The importance of fostering students' reflection about, as well as through, discussion is emphasized.