cssi/SciSciGPT-SciSciNet huggingface dataset:
Understanding Metabolic Regulation and Its Influence on Cell Physiology

Metabolism impacts all cellular functions and plays a fundamental role in biology. In the last century, our knowledge of metabolic pathway architecture and the genomic landscape of disease has increased exponentially. Combined with these insights, advances in analytical methods for quantifying metabolites and systems approaches to analyze these data now provide powerful tools to study metabolic regulation. Here we review the diverse mechanisms cells use to adapt metabolism to specific physiological states and discuss how metabolic flux analyses can be applied to identify important regulatory nodes to understand normal and pathological cell physiology.
The use of an ROV in the study of juvenile flatfish

Abstract This study shows that some low cost remotely operated vehicles (ROV) can be used effectively to locate juvenile flatfish. Vehicles with cameras that are either close to the sediment or that can focus close to the sediment are necessary to see extremely small fish. Additionally a “tickler chain” or similar device which contacts the sediment and fish, causing the fish to move, is often necessary to see flatfish less than 100 mm in length. Identification to species is difficult for specimens less than 150 mm. Concurrent trawl samples in the area can be used to determine percent species composition. Estimates of juvenile flatfish densities by the ROV generally exceed the catch-per-unit-effort estimated from trawls. An ROV is also an excellent tool for observing small scale spatial variations in habitat type and their effects on flatfish distribution.
Plasmodium falciparum and Plasmodium coatneyi: immunogenicity of "knob-like protrusions" on infected erythrocyte membranes.

Abstract The plasma membrane of erythrocytes infected with Plasmodium falciparum and Plasmodium coatneyi develop “knob-like protrusions.” These protrusions are the sequestered erythrocytes' points of attachment to the capillary endothelium. In this study we have shown that many erythrocytes that are sequestered in monkey heart capillaries in P. coatneyi or P. falciparum infections can be released by perfusion of the isolated heart with a modified Tyrode's solution. Addition of 4 m M EDTA to the perfusion medium assisted in the release of all sequestered erythrocytes. Monkey erythrocytes infected with P. falciparum were collected by heart perfusion and used to prepare antisera in rats. After absorption with normal monkey erythrocytes, the antisera showed specific binding to the protrusions on membranes of erythrocytes infected with P. falciparum .
Analysis of the rate of wildcat drilling and deposit discovery

The rate at which petroleum deposits were discovered during a 16-yr period (1957–72) was examined in relation to changes in a suite of economic and physical variables. The study area encompasses 11,000 mi2 and is located on the eastern flank of the Powder River Basin. A two-stage multiple-regression model was used as a basis for this analysis. The variables employed in this model were: (1) the yearly wildcat drilling rate, (2) a measure of the extent of the physical exhaustion of the resource base of the region, (3) a proxy for the discovery expectation of the exploration operators active in the region, (4) an exploration price/cost ratio, and (5) the expected depths of the exploration targets sought. The rate at which wildcat wells were drilled was strongly correlated with the discovery expectation of the exploration operators. Small additional variations in the wildcat drilling rate were explained by the price/cost ratio and target-depth variables. The number of deposits discovered each year was highly dependent on the wildcat drilling rate, but the aggregate quantity of petroleum discovered each year was independent of the wildcat drilling rate. The independence between these last two variables is a consequence of the cyclical behavior of the exploration play mechanism. Although the discovery success ratio declined sharply during the initial phases of the two exploration plays which developed in the study area, a learning effect occurred whereby the discovery success ratio improved steadily with the passage of time during both exploration plays.
An observational study of social behavior in microcomputer classrooms

Abstract This study examines the effects of five variables — student grouping at the computer, keyboarding status, academic discipline, student gender, and gender of partner — on student social behavior, both verbal and affective, in microcomputer classrooms. The effect of these variables on teacher behavior was also investigated. This study provides empirical corroboration for an earlier survey and interview study exploring the impact of microcomputers within a social cognitive framework. For the present study, subjects were students in a business high school who were observed while working in varied academic classes using an observational coding system. Results indicate that student grouping (individual or paired), keyboarding status, and academic discipline are related to social behaviors in computer classrooms. Students paired at the computer as compared to students working alone demonstrated enhanced task-oriented social behaviors. In several academic disciplines, where there was varied software and lesson structure, social behaviors differed, but further investigation is needed to clarify the role of these factors in a complex learning situation.
The Stochastic Beverton-Holt Equation and the M. Neubert Conjecture

In the Beverton-Holt difference equation of population biology with intrinsic growth parameter above its critical value, any initial non-zero population will approach an asymptotically stable fixed point, the carrying capacity of the environment. When this carrying capacity is allowed to vary periodically it is known that there is a globally asymptotically stable periodic solution and the average of the state variable along this solution is strictly less than the average of the carrying capacities, i.e. the varying environment has a deleterious effect on the state average. In this work we consider the case of a randomly varying environment and show that there is a unique invariant density to which all other density distributions on the state variable converge. Further, for every initial non-zero state variable and almost all random sequences of carrying capacities, the averages of the state variable along an orbit and the carrying capacities exist and the former is strictly less than the latter.
The transverse optical mode anharmonic self-energy of NaCl from measurements by dispersive Fourier-transform spectroscopy

The complex dielectric response associated with the q ≈ 0 transverse-optical mode in NaCl at 105 and 300 K is reported from measurements using dispersive Fourier-transform spectroscopy, and is used to discuss the frequency dependence of the mode anharmonic self-energy.
Cognitive performance of super-experts on computer program modification tasks

Abstract The present research attempts to identify factors which account for cognitive skill acquisition beyond the experienced worker standard, and understand differences between expert (E) and super-expert (SE) skill levels on the cognitive-oriented task of computer program modification. The current literature identifies automatization, problem representation, learning mechanisms, and cognitive abilities as factors affecting skill acquisition. In an effort to test these approaches, five SE programmers (rated among the top 95th percentile in their field) and five E programmers (70th to 80th percentile) were asked to enhance a fairly standard database program. A variety of performance and behavioural variables were collected from the analysis of verbal reports on the program modification session. Results indicate the SE subjects utilized a global search strategy to obtain abstract information while experts used a minimal ‘directed’ search to obtain task specific information. No differences in the level of...
QUANTUM THEORY OF SUPERFLUID VORTICES. I. LIQUID HELIUM II.

A Hamiltonian formulation is constructed for the classical dynamical equations of slightly deformed rectilinear vortices. The system is then quantized by interpreting the conjugate variables as quantum-mechanical operators that obey canonical commutation relations. A linear canonical transformation diagonalizes the Hamiltonian in terms of operators that create and destroy single quanta of vortex vibrations. The theory is applied to two distinct configurations in He II: a single vortex and a rotating vortex lattice. The specific heat associated with the vortex waves varies approximately as ${T}^{\frac{1}{2}}$ at low temperatures. Quantum-mechanical and thermal fluctuations produce a finite mean-square displacement of the vortex core, which is studied both at $T=0$ and at $Tg0$.
Coding and reimbursement: the lifeline of the urologist's office.

Coding rules and regulations change constantly, and this issue of Urologic Clinics of North America is not intended to be a coding and reimbursement course. Hopefully, all readers of this issue periodically send their staff (physicians and coders) to courses to learn the latest wrinkles in coding. Accurate coding depends on the information sources that the coding staff has available. A valuable and comprehensive compilation of information resources is included at the end of this article.
Empirical Hospital and Professional Charges for Patient Care Associated with Out of Hospital Cardiac Arrest Before and After Implementation of Therapeutic Hypothermia for Comatose Survivors

Abstract Objective The objectives of this study are to characterize the total hospital and professional charges for patients with out of hospital cardiac arrest both with and without therapeutic hypothermia treatment. Methods Retrospective cohort study of all adult patients with non-traumatic out of hospital cardiac arrest brought to the ED of a single tertiary care hospital over 20 months preceding and 20 months following implementation of therapeutic hypothermia for comatose survivors. Billing and clinical data were obtained from administrative databases and the electronic medical record using explicit audited abstraction. Demographic, payer characteristics, median charges and reimbursements with interquartile ranges are described before and after implementation, stratified by patient outcome. Results Two hundred and twenty-three patients met study criteria. The median charge was $3,112 among the 135 patients (60.5%) that did not survive to admission and $94,916 among the 88 (39.5%) that did. Median charges before and after implementation of therapeutic hypothermia were $6,324 and $15,537 respectively. Medicare was the most frequent payer. Good neurological outcome occurred in 11/115 patients (9.6%) prior to implementation and 22/108 patients (20.4%) after. Among 23 patients treated with hypothermia, good neurological outcome occurred in 11 patients (47.8%). Good neurological outcome and treatment with hypothermia were associated with increased procedure utilization and higher charges. Conclusion Empirical patient level data confirm that charges for patients with out of hospital cardiac arrest are substantial, even among patients that do not survive to hospital admission. Treatment with therapeutic hypothermia is associated with better outcomes, more procedures, and higher charges.
Burr cells: classification and effect of splenectomy.

Increased numbers of burr cells appear following splenectomy especially in those patients splenectomized for idiopathic thrombocytopenic purpura. However, all splenectomized children demonstrate this phenomenon regardless of the basic disorder. The varieties of burr cells and fragmented red cells are discussed with reference to their morphologic appearance and the pathologic states in which they occur.
A Guided Tour of Mathematical Methods for the Physical Sciences

After reading A Guided Tour of Mathematical Methods for the Physical Sciences, not only will you be able to impress your friends with a back-of-the-envelope scaling analysis to debunk the myth that a bathtub drains in different directions in both hemispheres. You will also know whether life is possible in a five-dimensional world. In fact, you will understand a lot of mathematical methods and know how to apply them to real physical problems. This unique textbook presents all of its material in the form of problems that invite the reader to participate in the development of the theory Guided by Roel Sneider's textbook, learning mathematical methods can be fun.
Juvenile temporal arteritis

Juvenile temporal arteritis (JTA) is a nongranulomatous inflammation of the temporal artery with fragmentation of the internal elastic lamina and no concurrent systemic manifestations. It is a rare clinicopathologic entity with fewer than 20 reported cases, most of which represent localized disease with no recurrence or systemic symptoms at follow-up of up to 2 years. Histopathologic features can include lymphoeosinophilic infiltrate and endothelial proliferation. As the histology may resemble angiolymphoid hyperplasia with eosinophilia or Kimura disease, whether JTA is a discrete localized disease or a manifestation of these systemic conditions has been debated. We present a case of a 36-year-old Jamaican woman with a painful forehead nodule that showed histologic features of JTA, including intimal hyperplasia, lymphoeosinophilic inflammation of the vessel wall, and disruption of the internal elastic lamina; distinctive signet ringlike cytomorphologic alterations of the endothelial cells were noted as well. The lesion also showed extensive subcutaneous lymphoeosinophilic infiltrates and neovascularization with extension into the underlying muscle consistent with angiolymphoid hyperplasia with eosinophilia or Kimura disease. As the connection between JTA and angiolymphoid hyperplasia with eosinophilia and Kimura disease is currently debated and most reported cases of JTA have had only brief follow-up, the long-term sequelae of JTA are not known and careful patient monitoring may be necessary.
Mutual Mentoring: Co-Narrating an Educative Friendship Between an Education Professor and an Urban Youth

An education professor and a high school student tell the story of their mentoring relationship, focusing on the academic journey of the protege. The narrative attempts to give voice to both mentor and protege as it relates an authentic “win–win” situation for both participants and their families. The narrative is theoretically grounded in the literature describing co-mentoring and network mentoring arrangements that are less unilateral and authoritative, and more bi-directional and relationally-based than traditional mentoring arrangements. The authors contend that since educational achievement and attainment determine to a significant degree one’s participation in the “American Dream,” academic assistance and guidance provide a logical area of emphasis for mentoring our youth. Important recent developments in the youth mentoring movement are also discussed.
Spatio-temporal growth of broken spiral and concentric ringed spherulites in blends of poly(vinylidene fluoride) and ethylene-vinylacetate copolymers

Melting and crystallization behavior in mixtures of poly(vinylidene fluoride) (PVDF) and several ethylene-vinyl acetate copolymers (EVAc) with various ethylene contents have been investigated by means of differential scanning calorimetry, atomic force microscope, and optical microscopy. PVDF/EVAc-80 exhibits the melting point depression of PVDF crystals, suggestive of a miscible character of the pair. Crystallization behavior and morphology development in blends of PVDF/EVAc-80 have been investigated with an emphasis on the spherulitic growth demonstrating the spiral and concentric ringed (or target) patterns. Of particular interest is the break-up of the spiral or concentric ringed patterns at very shallow supercoolings, which may be attributed to instabilities driven by the exclusion of amorphous PVDF and EVAc chains into the emerging inter- and intra-spiral (or target) lamellar regions.
The Magnetic Properties and Structure of the Hemochromogens and Related Substances

In the course of a general study of the structure of hemoglobin and its derivatives we have investigated the magnetic properties of ferriheme, ferroheme, several hemochromogens and nickel protoporphyrin. The results of this investigation and their structural interpretation are discussed in the following paragraphs.
Application of neurally adjusted ventilatory assist in neonates

Neurally adjusted ventilatory assist (NAVA) uses the electrical activity of the diaphragm (Edi) as a neural trigger to synchronize mechanical ventilatory breaths with the patient's neural respiratory drive. Using this signal enables the ventilator to proportionally support the patient's instantaneous drive on a breath-by-breath basis. Synchrony can be achieved even in the presence of significant air leaks, which make this an attractive choice for invasive and non-invasive ventilation of the neonate. This paper describes the Edi signal, neuroventilatory coupling, and patient-ventilator synchrony including the functional concept of NAVA. Safety features, NAVA terminology, and clinical application of NAVA to unload respiratory musculature are presented. The use of the Edi signal as a respiratory vital sign for conventional ventilation is discussed. The results of animal and adult studies are briefly summarized and detailed descriptions of all NAVA-related research in pediatric and neonatal patients are provided. Further studies are needed to determine whether NAVA will have significant impact on the overall outcomes of neonates.
SUSCEPTIBILITY OF SEVENTY SPECIES OF FLOWERING PLANTS TO X-RADIATION.

Ten years of study of the effects of x-rays on different species of flowering plants has resulted in a grouping according to ray susceptibility which should be of value, since many investigators are engaged in studying the various ways in which radiation influences living organisms. When sufficient data concerning the morphological and physiological action of x-rays have been collected, it should be possible to give reasons for the ray resistance of some families as compared with the ray susceptibility of others. This paper deals particularly with the morphological effects produced on the above-ground parts of seventy different species distributed in thirty -five families ; another paper (11) will discuss the action of the rays on undergroiind stems or roots of twenty-two species. The susceptibility of species of Helianthus, Solanum, Lycopersicum, Vicia, Atriplex, Linum, Nemophila, and Zinnia have been treated elsewhere (5, 6, 7, 8, 9, 10, 12) .
Neural stem cells: mechanisms and modeling.

In the adult brain, neural stem cells have been found in two major niches: the hippocampus and the olfactory bulb. Neurons derived from these stem cells contribute to learning, memory, and the autonomous repair of the brain under pathological conditions. Hence, the physiology of adult neural stem cells has become a significant component of research on synaptic plasticity and neuronal disorders. In addition, the recently developed induced pluripotent stem cell technique provides a powerful tool for researchers engaged in the pathological and pharmacological study of neuronal disorders. In this review, we briefly summarize the research progress in neural stem cells in the adult brain and in the neuropathological application of the induced pluripotent stem cell technique.
The current role of laparoscopic surgery for gastroesophageal reflux disease in infants and children

Background The benefits of surgery for gastroesophageal reflux disease (GERD) in infants and children have been questioned in the recent literature. The goal of this review was to determine the best current practice for the diagnosis and management of this disease.
Introduction to the Alpha-proteobacteria: Wolbachia and Bartonella, Rickettsia, Brucella, Ehrlichia, and Anaplasma

Wolbachia is an obligate intracellular endosymbiont and likely mutualist living within the heartworm Dirofilaria immitis and a number of other filarial nematodes in the family Onchocercidae. The bacterial infection is passed from worm to worm transovarially; the organisms are in ovarian cells, the developing microfilariae, and multiply and persist in all later developmental stages through the mosquito and into the next host. Besides being present in the ovaries of the adult worms, they also are present in large numbers within the hypodermal tissues of the nematode. It is now know that these bacteria that were first observed in heartworms more than 30 years ago are actually related to similar Wolbachia bacteria that are found in arthropods. Wolbachia is an alpha-proteobacteria, and this group includes a number of important arthropod-transmitted bacterial agents of dogs and cats: Rickettsia rickettsii , R. felis , Anaplasma platys , Ehrlichia canis , E. chaffeensis , and E. ewingii . Alpha-proteobacteria are also important as obligate intracellular mutualists in plants in which they are responsible for nitrogen fixation. Recent work on the treatment of heartworms in dogs with doxycycline stems from related work with the human filarial nematode Onchocerca volvulus that causes river blindness in people.
STRATEGY AND APPLICATION OF DATA-DRIVEN TESTING OF AN OCEAN TURBINE DRIVETRAIN

An ocean turbine generator will be subject to variations in water current velocity at one end and resistive load at the other. Measurements acquired during bench testing of the turbine's drivetrain can be used to predict the effect of these variables on the turbine during deployment. This paper outlines an ongoing series of tests involving vibration data captured at various velocities and loads. This data is analyzed to detect the machine's state using two approaches. In the first approach, machine learning techniques are used to discern between states given adjacent values for velocity or load. The purpose of that approach is to assess a learner's ability to draw the fine distinctions needed for subsequent fault identification. The second approach computes a power spectrum for each velocity and load combination over enough trials as to construct an operating envelope. The purpose of that approach is to identify as abnormal, incoming data having parts of its spectrum that fall outside that envelope. A case study applies each approach to baseline data and data for a deterioration scenario. The rationale behind each approach, their assumptions, and their limitations are also discussed.
Numerical algorithms for eigenvalue assignment problem via observer matrix equations

A unified approach to the development of several algorithms for the well-known eigenvalue and canonical form assignment problems is presented via observer matrix equations. Furthermore, a relationship between these algorithms and the Q-R factorization method is explicitly stated. This relationship allows the algorithms to be implemented in a more numerically robust way. The algorithms are discussed, and several research problems are outlined. >
Numerical solution of free surface, porous flow problems

An inexpensive, finite difference numerical method is developed for the approximate solution of general, free surface, porous flow problems. The method is so designed that the required numerical boundary conditions coincide exactly with the required physical boundary conditions. In the present paper, application is made to prototype, steady state, dam flow problems.
Inhibition during early adolescence predicts alcohol and marijuana use by late adolescence.

OBJECTIVE: Adolescent substance use has been associated with poorer neuropsychological functioning, but it is unclear if deficits predate or follow the onset of use. The goal of this prospective study was to understand how neuropsychological functioning during early adolescence could predict substance use by late adolescence. METHOD: At baseline, participants were 175 substance-use-naive healthy 12- to 14-year-olds (41% female) recruited from local schools. Participants completed extensive interviews and neuropsychological tests. Each year, participants' substance use was assessed. By late adolescence (ages 17 to 18), 105 participants transitioned into substance use and 75 remained substance-naive. Hierarchical linear regressions examined how baseline cognitive performance predicted subsequent substance use, controlling for common substance use risk factors (i.e., family history, externalizing behaviors, gender, pubertal development, and age). RESULTS: Poorer baseline performance on tests of cognitive inhibition-interference predicted higher follow-up peak drinks on an occasion (β = -.15; p .05). CONCLUSIONS: Compromised inhibitory functioning during early adolescence prior to the onset of substance use was related to more frequent and intense alcohol and marijuana use by late adolescence. Inhibition performance could help identify teens at risk for initiating heavy substance use during adolescence, and potentially could be modified to improve outcome. (PsycINFO Database Record (c) 2014 APA, all rights reserved). Language: en
Driving the Gravity-Mode Pulsations in γ Doradus Variables

The γ Doradus stars are a newly discovered class of gravity-mode pulsators that lie just at or beyond the red edge of the δ Scuti instability strip. We present the results of calculations that the predict pulsation instability of high-order g-modes with periods between 0.4 and 3 days, as observed in these stars. The pulsations are driven by the modulation of the radiative flux by convection at the base of a deep envelope convection zone. Pulsation instability is predicted only for models with temperatures at the convection zone base between ~200,000 and ~480,000 K. The estimated shear dissipation that is due to turbulent viscosity within the convection zone or in an overshoot region below the convection zone can be comparable to or even exceed the predicted driving and is likely to reduce the number of unstable modes or possibly quench the instability. Additional refinements in the pulsation modeling are required to determine the outcome. At least one γ Doradus star has been observed that also pulsates in δ Scuti-type p-modes, and others have been identified as chemically peculiar. Since our calculated driving region is relatively deep, γ Doradus pulsations are not necessarily incompatible with surface abundance peculiarities or with δ Scuti p-mode pulsations driven by the H and He ionization κ-effect. Such stars will provide useful observational constraints on the proposed γ Doradus pulsation mechanism.
A central California coastal ocean modeling study: 2. Adjoint sensitivities to local and remote forcing mechanisms

[1] The sensitivity of particular features within the California Current System to remote and local forcing is numerically investigated using the adjoint model version of the Regional Ocean Modeling System. We define three integral measures of nearshore surface temperature, cross-shore transport, and sea surface height as metrics that characterize important aspects of the coastal circulation. We determine the metrics' relative sensitivity to different components of the surface external forcing and model initial condition fields. Calculations are performed for 14-d intervals over the 5-year period from 2000 to 2004. Sensitivities are ranked in terms of their relative importance in the annual average, and their seasonal cycle is examined. Contributions from different portions of the domain are identified to determine the importance of local versus remote forcing. Local forcing, particularly wind stress and, at times, heat flux, are the dominant forcing contributors to temperature and transport sensitivities, although model initial conditions can contribute quantitatively on the same order as surface fluxes. The sea surface height metric reveals important nonlocal effects, particularly along the open boundary of this regional simulation.
MO-D-BRB-09: Treatment Delivery QA for Online Adaptive Radiation Therapy Based on Dynamic Machine Information (DMI): A Feasibility Study.

Purpose: To implement a quality assurance (QA) system for the treatmentdelivery of online adaptive radiation therapy utilizing Dynamic Machine Information (DMI).Materials and Methods: DMI provides the expected/actual MLC leaf‐positions, delivered MU, and beam‐on status every 50ms during delivery. In this study a stream of DMI inputs is simulated by playing back Dynalog information recorded while delivering a test fluence map (FM). Based on these DMI inputs, the QA system performs three levels of monitoring/verification on the plan delivery process: (1) Following each input, actual and expected FMs delivered up to the current MLC position is dynamically updated using corresponding MLC positions in the DMI. The magnitude and frequency of pixel‐by‐pixel fluence differences between these two FMs are calculated and visualized in histograms.(2) At each control point, actual MLC positions are verified against the treatment plan for potential errors in data transfer between the treatment planning system (TPS) and the MLC controller.(3) Both (1) and (2) can signal beam‐hold with a user‐specified error tolerance.(4) After treatment,delivereddose is reconstructed in TPS based on DMI data during delivery, and compared to planned dose.Results: (1) Efficiency: Average latency from DMI input to the completion of fluence difference calculation is <1ms.(2) Efficacy: For test FM, transient error in leaf positions is (−0.07±0.28)mm; cumulative errors in delivered fluence is (0.003±0.183)% of the maximal fluence. The system can also identify data transfer errors between TPS and MLC controller. Off‐line dose reconstruction and evaluation show <0.5% dosimetric discrepancy from planned dose distribution for the test FM.Conclusion: This QA system is capable of identifying MLC position/fluence errors in near real‐time, and assessing dosimetricimpact of the treatmentdelivery process. It is thus a valuable tool for clinical implementation of online adaptive radiation therapy. (Research partially supported by Varian) Research partially supported by Varian Medical Systems
Testing of a sub-hypothesis in linear regression models with long memory errors and deterministic design

Abstract This paper considers the problem of testing a sub-hypothesis in homoscedastic linear regression models where errors form long memory moving average processes and designs are non-random. Unlike in the random design case, asymptotic null distribution of the likelihood ratio type test based on the Whittle quadratic form is shown to be non-standard and non-chi-square. Moreover, the rate of consistency of the minimum Whittle dispersion estimator of the slope parameter vector is shown to be n - ( 1 - α ) / 2 , different from the rate n - 1 / 2 obtained in the random design case, where α is the rate at which the error spectral density explodes at the origin. The proposed test is shown to be consistent against fixed alternatives and has non-trivial asymptotic power against local alternatives that converge to null hypothesis at the rate n - ( 1 - α ) / 2 .
Cognitive consequences and central nervous system injury following treatment for childhood leukemia.

Objectives: To determine the relationship between membrane damage and intellectual and academic abilities in children with acute lymphoblastic leukemia (ALL) and pilot test a math intervention for children with ALL who were affected. Data Sources: Research studies and review articles. Conclusions: Despite the prophylactic central nervous system (CNS) treatment for long-term disease-free survival, many children with ALL subsequently experience declines in intellectual and academic skills. Implications for Nursing Practice: Improving academic abilities in children who have received CNS treatment is of high priority and may have longlasting implications on quality of life.
In Vitro Transcription Amplification and Labeling Methods Contribute to the Variability of Gene Expression Profiling with DNA Microarrays

The effect of different amplification and labeling methods on DNA microarray expression results has not been previously delineated. To analyze the variation associated with widely accepted T7-based RNA amplification and labeling methods, aliquots of the Stratagene Human Universal Reference RNA were labeled using three eukaryotic target preparation methods followed by uniform replicate array hybridization (Affymetrix U95Av2). Method-dependent variability was observed in the yield and size distribution of labeled products, as well as in the gene expression results. A significant increase in short transcripts, when compared to unamplified mRNA, was observed in methods with long in vitro transcription reactions. Intramethod reproducibility showed correlation coefficients >0.99, whereas intermethod comparisons showed coefficients ranging from 0.94 to 0.98 and a nearly twofold increase in coefficient of variation. Fold amplification for each method positively correlated with the number of genes present. Our experiments uncovered two factors that introduced significant bias in gene expression data: the number of labeled nucleotides, which introduces sequence-dependent bias, and the length of the in vitro transcription reaction, which introduces transcript size-dependent bias. This study provides evidence that variability in expression data may be caused, in part, by differences in amplification and labeling protocols.
Importance of diet and nutrition in evaluating the safety of drugs

The current emphasis on the real or potential inf luence of diet and nutr i t ion on human carcinogenesis has served to focus the attention of the general public and scientific community on the importance Of nutrients and total calories in shaping the responses of individuals to disease. The concern about the influence of nutrition on susceptibility to spontaneous or chemically induced tumors goes back more than 40 years. A surge of interest on this aspect of experimental carcinogenesis occurred in the late 1930s and 1940s, but enthusiasm waned and investigators tu rned their at tention to other seemingly more promising and rewarding areas of biological research. The changes in the food and drug laws in 1958 sharply increased requirements for the use of laboratory animals in safety assessment, as well as for fundamental biological investigations. The increased emphasis on human safety and demands for a reduction or elimination of risk in the mid-1960s have continued to the present. Today, millions of laboratory animals are used each year in attempts to demonstrate no more than minimal risk for drugs that promise therapeutic relief from human disease. Virtually all of the safety evaluations for drugs, developed by the pharmaceutical industry, are conducted in animals. The test animals are placed in cages, fed a commercially prepared diet, and allowed free access to the generally nutritious diet for a major portion of their lifespan. Not only are the animals allowed to eat all they want on a continuing basis, but they get no exercise and are maintained under nearideal environmental conditions (lighting, temperature, humidity, and all other conditions). We should not be surprised that under these conditions, the animals are overnourished and often become obese. This experimental animal, treated in this manner, is quite different from the human being to which the animal serves as a putative surrogate for developing safe drugs. Nor should we be surprised that overnourished rats and mice react to the stress of expo-
Adrenal Cells in Tissue Culture. X. On the Mechanism of the Stimulation of Steroidogenesis by Cyclic Cytidine Monophosphates12

In monolayer cultures of mouse adrenal cortex cells, cyclic cytidine monophosphate (cyclic CMP) and cyclic AMP are comparably steroidogenic. Cyclic CMP induces the same morphological changes in the cells as cyclic AMP and ACTH. The stimulatory effects of cyclic CMP are not associated with increases in intracellular cyclic AMP. Cyclic AMP levels were measured by the binding assay of Gilman and by measuring the levels of 14C-cyclic AMP in cells previously labeled with 14C-(ul)-adenine. ACTH increased cyclic AMP at least 4-fold by both these methods. Cyclic CMP is capable of displacing cyclic AMP from cyclic AMP-binding proteins in the cytosol of adrenal cell extracts. A 100-fold higher concentration of cyclic CMP than cyclic AMP is required. Cyclic GMP, which is not steroidogenic in these cells binds with the same affinity as cyclic CMP. Protein kinase activity is also increased by cyclic CMP and cyclic GMP at 100-fold higher concentrations than cyclic AMP. Stimulation of protein kinase is greater with both...
Cloud-Free Line-of-Sight Calculations.

Abstract A method for computing the probability of a cloud-free line-of-sight (CFLOS) between a given point in the atmosphere and a given point on the earth, was developed. The method is based on 3-hr synoptic weather reports of clouds, and whole-sky photographs taken during daylight hours over a period of three years at Columbia, Mo. The computational procedure is an effort to eliminate an apparent oversimplification in previously published methods that results from the use of mean cloud cover, an unsatisfactory vertical cloud distribution, and sunshine data. Present results are at variance with those earlier estimates, but compatible with recent observations actually taken from aircraft. Although the CFLOS estimates obtained are, by nature, uncertain, the range of uncertainty was estimated by using published empirical data and a quantitative error analysis.
Processing of meteoritic organic materials as a possible analog of early molecular evolution in planetary environments

The composition of the Sutter’s Mill meteorite insoluble organic material was studied both in toto by solid-state NMR spectroscopy of the powders and by gas chromatography–mass spectrometry analyses of compounds released upon their hydrothermal treatment. Results were compared with those obtained for other meteorites of diverse classifications (Murray, GRA 95229, Murchison, Orgueil, and Tagish Lake) and found to be so far unique in regard to the molecular species released. These include, in addition to O-containing aromatic compounds, complex polyether- and ester-containing alkyl molecules of prebiotic appeal and never detected in meteorites before. The Sutter’s Mill fragments we analyzed had likely been altered by heat, and the hydrothermal conditions of the experiments realistically mimic early Earth settings, such as near volcanic activity or impact craters. On this basis, the data suggest a far larger availability of meteoritic organic materials for planetary environments than previously assumed and that molecular evolution on the early Earth could have benefited from accretion of carbonaceous meteorites both directly with soluble compounds and, for a more protracted time, through alteration, processing, and release from their insoluble organic materials.
Global city region governance and multicentered development: a North American perspective:

The impact of governance on multicentered development is examined by surveying the political responses of two leading North American global city regions (GCRs): New York and Toronto. Although both GCRs have experienced very similar policy tensions during recent decades, their process of economic restructuring is strongly mediated by four systemic features in regional governance: concentration of political authority, prevailing social cleavages, civic group resources, and intergovernmental coordination. Differences in these characteristics are found to influence collective action to manage tensions in three major policy areas. Their impact is not entirely cumulative, however. Even though there is evidence that having more of certain governing attributes enhances the possibilities for joint intervention on a regional scale, interaction among system components affects forms of intergovernmental collaboration. Further, the impact of governance systems on collective action also varies with policy area.
Optical constants of soot in hydrocarbon flames

A dispersion model for the optical constants of soot in hydrocarbon flames has been established on the basis of a more rigorous consideration of the electronic band structure and the dispersion constants. The dispersion constants of hydrocarbon soot have been determined from this model in conjunction with the in-situ flame transmission data in the visible and infrared ranges, thus truly reflecting soot in flames. It is shown that the soot optical properties are rather insensitive to temperature changes at elevated temperatures but the room temperature values representative of soot in smoke do exhibit appreciable deviation. The results also indicate these properties to be relatively independent of the fuel hydrogen/carbon ratio.
Visualization of planar drug intercalations in B-DNA

A computerized linked-atom modeling system was developed to examine the stereochemical requirements for intercalation of planar drugs into DNA. All classes of conformational possibilities for extending the polynucleotide backbone were examined for their ability to accommodate insertion of a drug into a base-paired region of DNA compatible with adjacent regions of B-DNA while stacking interactions, steric strain and non-bonded interatomic contacts were optimised. One conformation was found which proved superior to all others in ability to satisfy these criteria: an extension of the backbone by characteristic changes in two torsion angles to trans values, plus a change in one sugar puckering to C3'-endo to relieve strain in an adjacent residue. The turn angle distributed over three polynucleotides for this most general mode of intercalation is 90 degrees, equivalent to a helical unwinding of -18 degrees for B-DNA.
Dephosphorylation of inner arm 1 is associated with ciliary reversals in Tetrahymena thermophila

In many organisms, depolarizing stimuli cause an increase in intraciliary Ca2+, which results in reversal of ciliary beat direction and backward swimming. The mechanism by which an increase in intraciliary Ca2+ causes ciliary reversal is not known. Here we show that Tetrahymena cells treated with okadaic acid or cantharidin to inhibit protein phosphatases do not swim backwards in response to depolarizing stimuli. We also show that both okadaic acid and cantharidin inhibit backward swimming in reactivated, extracted cell models treated with Ca2+. In contrast, treatment of whole cells or extracted cell models with protein kinase inhibitors has no effect on backward swimming. These results suggest that a component of the axonemal machinery is dephosphorylated during ciliary reversal. The phosphorylation state of inner arm dynein 1 (I1) was determined before and after cells were exposed to depolarizing conditions that induce ciliary reversal. An I1 intermediate chain is phosphorylated in forward swimming cells but is dephosphorylated in cells treated with a depolarizing stimulus. Our results suggest that dephosphorylation of Tetrahymena inner arm dynein 1 may be an essential part of the mechanism of ciliary reversal in response to increased intraciliary Ca2+.
Coastal Transport and Dispersion Modelling

The coastal ocean, where land, air and sea meet, is a region of very high physical energy and biological diversity that is heavily exploited by man. Nearly 60% of the world’s population live within 60 km from coastline and use the coastal resources directly or indirectly for their livelihood. The multifarious demands on the coastal zone has already resulted in overexploitation of many marine resources and marked degradation of the quality of coastal habitats and environment. Industrial and urban pollution including sewage, solid waste and chemical discharges combined with unplanned construction activities, land reclamation and human manipulation of the hydrological cycle have resulted in appreciable and measurable changes to coastal environments in many countries. Such changes pose problems for environmental management in both developed and developing countries. Besides, natural calamities including floods, storms, and other episodic events affect society’s use of the resources and complicate the management problem. In addition to the current problems of coastal pollution, habitat degradation, coastal erosion, harmful algal blooms and unplanned water management must now be added to the threat of global climatic change. Coastal pollution can have readily apparent and immediate impacts, such as oil spills, the closure of beaches, or fish kills due to toxic contaminants. This type of pollution can be very serious but it is usually short term.
Delayed-Neutron Activation Determination Of Uranium in Thirteen French Rock Reference Samples

The uranium contents of thirteen rock reference samples from the Centre de Recherches Petrographiques et Geochimiques, Nancy, France, were determined by delayed-neutron activation analysis. Four others from the same laboratory were found to have uranium concentrations below our limit of detection. Meaningful comparison of our data with other workers is presently not possible (i) because of the paucity of uranium data and (ii) because of the disparity of uranium data on the samples for which uranium data exist.
Astrocyte Leptin Receptor (ObR) and Leptin Transport in Adult-Onset Obese Mice

The agouti viable yellow (A vy) spontaneous mutation generates an unusual mouse phenotype of agouti-colored coat and adult-onset obesity with metabolic syndrome. Persistent production of agouti signaling protein in A vy mice antagonizes melanocortin receptors in the hypothalamus. To determine how this disruption of neuroendocrine circuits affects leptin transport across the blood-brain barrier (BBB), we measured leptin influx in A vy and B6 control mice after the development of obesity, hyperleptinemia, and increased adiposity. After iv bolus injection, (125)I-leptin crossed the BBB significantly faster in young (2 month old) B6 mice than in young A vy mice or in older (8 month old) mice of either strain. This difference was not observed by in situ brain perfusion studies, indicating the cause being circulating factors, such as elevated leptin levels or soluble receptors. Thus, A vy mice showed peripheral leptin resistance. ObRa, the main transporting receptor for leptin at the BBB, showed no change in mRNA expression in the cerebral microvessels between the age-matched (2 month old) A vy and B6 mice. Higher ObRb mRNA was seen in the A vy microvasculature with unknown significance. Immunofluorescent staining unexpectedly revealed that many of the ObR(+) cells were astrocytes and that the A vy mice showed significantly more ObR(+) astrocytes in the hypothalamus than the B6 mice. Although leptin permeation from the circulation was slower in the A vy mice, the increased ObR expression in astrocytes and increased ObRb mRNA in microvessels suggest the possibility of heightened central nervous system sensitivity to circulating leptin.