cssi/SciSciGPT-SciSciNet huggingface dataset:
Applying knowledge of autism to brain cancer management: what do we know?

Autism meets glioblastoma What do two seemingly unrelated disorders of the brain have in common? Autism encompasses a heterogeneous collection of neurodevelopmental dysfunctions ranging from impaired social behavior, stereotyped interests and language deficit. Diagnosed at increasingly high rates of one in 68 children (one in 42 for boys), autism spectrum disorders are a major impediment to childhood development worldwide. Current treatment options for autism are limited [1]. On the other hand, glioblastoma multiforme (GBM) is the most common and aggressive form of adult primary brain cancer with extremely poor 3-year survival rates of less than 10%. In GBM, clinical trials of drugs inhibiting the EGF receptor (EGFR) kinase, the most prominent oncogenic target, have been disappointing and as a result, patient outcomes have failed to show substantive improvement over median survival times of 12 months [2]. Thus, there is a great, unmet need for effective therapy in both disorders and innovative approaches are urgently needed. In order to identify new drug targets, we need a transdisciplinary approach that breaches the conventional boundaries confining each area of research. There is growing recognition that glioblastoma and many brain disorders share the same fundamental pathophysiological mechanisms at a cellular and molecular level. As a consequence, mutations or gene expression changes in the same gene family can underlie multiple, distinct clinical phenotypes. A compelling example is that of the SLC9A6 and SLC9A9 genes encoding endosomal Na/H exchangers NHE6 and NHE9, respectively [1]. Genome-wide association studies, gene linkage analysis, homozygosity mapping, transcription profiling and mining patient databases have linked these genes to a collection of neurological disorders, including autism, attention deficit hyperactivity disorder, epilepsy, intellectual disability, Alzheimer’s disease and other neurodegenerative disorders, and most recently and unexpectedly brain cancer [1–4]. “Meaningful future therapies are likely to require cocktails of drugs that target the proliferation/invasion of cancer and the development of chemoresistance.”
Anion exchange mechanism for transport of methotrexate in L1210 cells.

Abstract Structurally diverse anions (folate, 5-formyltetrahydrofolate, AMP, ADP, thiamine pyrophosphate, phosphate, sulfate, and chloride) that are competitive inhibitors of methotrexate influx in L1210 cells also enhance the efflux of methotrexate from these cells. The increase in efflux reaches a maximum of 2- to 4-fold depending upon the anion employed, and the anion concentrations required for half-maximal stimulation of efflux are similar to their K i values for inhibition of methotrexate influx. A competitive inhibitor of methotrexate uptake (fluorescein-diaminopentane-methotrexate) that is not transported by this system, does not increase methotrexate efflux. These results suggest that the efflux of intracellular methotrexate is coupled to the concomitant uptake of an extracellular anion.
NLO QCD corrections to W boson production with a massive b-quark jet pair at the Fermilab Tevatron pp collider

We calculate the next-to-leading order (NLO) QCD corrections to Wbb production including full bottom-quark mass effects. We study the impact of NLO QCD corrections on the total cross section and invariant mass distribution of the bottom-quark jet pair at the Fermilab Tevatron pp collider. We perform a detailed comparison with a calculation that considers massless bottom quarks. We find that neglecting bottom-quark mass effects overestimates the NLO total cross section for Wbb production at the Tevatron by about 8% independent of the choice of renormalization and factorization scale.
Prostaglandin response in the exercise conditioned rat

Abstract Thrombin- and collagen-induced thromboxane A 2 (TxA 2 ) production were significantly reduced in washed platelets from exercise-trained rats as compared to sedentary controls. No consistant differences were found in the synthesis of prostacyclin (PGI 2 ) from endogenous arachidonate in strips of aorta. Isolated hearts perfused by the “Langendorff” method respond to bolus injections of PGI2 with a decreased perfusion pressure.Hearts from exercised-trained animals were more responsive than those from sedentary animals to the vasodilating effects of PGI 2 . The increased ratio of PGI 2 TxA 2 and the increased responsiveness of the coronary vasculature to PGI 2 seen in the trained rats may provide protection from cardiovascular disease.
Confocal imaging through scattering media with a volume holographic filter

The use of a volume holographic filter as collector element in a confocal system imaging through scattering (turbid) material is described. We show that the penetration depth of the volume holographic system is de-coupled from the scatter noise discrimination properties, and is potentially more advantageous than the traditional confocal microscope. Since the volume-holographic filter is a matched-filter, the penetration depth is dependent on the mismatch of the refractive index of the sample being imaged relative to the recording conditions. We present a method to overcome this limitation based on using a pre-compensating index matching film during the recording of the volume hologram. An improvement of the penetration depth is shown experimentally.
New complexes of thriethanolamine (Tea): Novel structural features of [Y(TEA)2](ClO4)3·3C5H5N and [Cd(TEA)2](NO3)2

Abstract The synthesis and characterization of the triethanolamine (TEA) complexes Sc(TEA)2Cl3 (1), Y(TEA)2(ClO4)3·3C5H5N (2), Fe(TEA)2Cl3 (3), Ni(TEA)2Cl2 (4), Zn(TEA)2Br2 (5), Zn(TEA)2(NO3)2 (6), Cd(TEA)2Cl2 (7), Cd(TEA)2(NO3)2 (8), Pb(TEA)2(OAc)2 (9) and Bi(TEA)2Cl3 (10) are reported. The structures of 2 and 8, determined by X-ray diffraction, unexpectedly revealed eight-coordinate metals in both cases. Both structures adopt a distorted hexagonal bipyramidal configuration in which the atoms in the hexagonal plane alternately fall above and below the plane. In 2, the tree pyridines as well as the three perchlorates are involved only in hydrogen bonding to the OH groups of different TEA ligands, causing a novel distortion of the coordination sphere. Compound 8 represents an unusual example of the relatively rare coordination number eight for cadmium(II).
The Effects of a Second-Grade Social Studies Curriculum Infused with Positive Aging Concepts on Children's Attitudes towards Aging.

Abstract As the number of elderly people in our society increases, it becomes especially important for children to develop positive attitudes towards elders and towards their own aging. The American Association for Health Education has recommended the infusion of positive aging concepts in the K-12 curriculum. This qualitative study investigated the effects of a second-grade standards-based social studies curriculum infused with positive aging concepts on children's attitudes towards aging. Aging concepts were incorporated by means of two strategies: literature portraying positive images of older people, and interviews with elders. Triangulation of results from a word-association task, a brainstorming task, a discussion, and teachers' journals indicated that there was a positive change in children's perceptions of aging. Findings suggest that the teacher plays a key role in guiding discussions. In addition, children reported favorable experiences with both literature and interview activities.
Does it Pay to Deliver? An Evaluation of India’s Safe Motherhood Program

Summary The paper evaluates an Indian maternal conditional cash transfer scheme. Launched in 2005, the program gives women cash transfers for receiving maternal and child health care services. Data are drawn from India’s District Level Household Survey to evaluate the program’s impact. Results indicate that the program had a limited overall effect: relative to the broader population, the targeted population experienced a 3 percentage point increase in medically supervised births, but no increase in ante-natal or post-natal care. We do however, find evidence of heterogeneity of impact. Women without any formal education and women in rural areas experience disproportionate gains.
Why family planning matters

Family planning is one of the principle tools of human development. Ensuring that all babies are wanted and planned reduces health care and social costs. Human numbers will increase to 11 billion by the end of this century, and human activities are the leading cause of environmental change that threaten our health and happiness. Therefore, the provision of highly effective contraceptive methods represents an important priority of primary medical care. Since women and men with complicated medical problems remain interested in sex, medical and surgical specialists need to understand how contraception and pregnancy will interact with the underlying condition. This paper discusses the interaction between population growth and the environment, and reviews modern methods of contraception
Detection of internal browning in apples by light transmittance

Light transmittance in the 450 to 1050 nanometer (nm) region was evaluated as a nondestructive technique for identifying apples with internal browning. Shorter wavelengths of light ( 800 nm). A transmission difference between 720 and 810 nm was used to segregate apples with internal browning from good apples. Only 7.4% of the apples were misclassified in a training set. When applied to a larger validation set, 8.0% of the apples with internal browning were misclassified. For both sets, the only apples misclassified were those with very slight browning that was very difficult to detect visually were misclassified, but none of the apples with slight to severe browning was misclassified. For nondefective apples, 6.1% were identified as having internal browning, because bruises and internal browning had the same effect on the spectral composition.
Effects of environment and composition on degradation of guayule rubber

Bales of antioxidant-stabilized guayule rubber underwent significant losses in bulk viscosity when stored under ambient conditions at an Arizona processing facility. Previous work implicated the unsaturated fatty acid esters present in entrained resin as promoters of such degradation. Aging studies as functions of storage temperature and unsaturated acid ester content were carried out on both bulk rubber and rubber-resin solution (miscella) for cultivar AZ-101. The rate of thermooxidative degradation, determined as a function of Mooney viscosity, was increased by the addition of unsaturated ester. Anaerobic degradation was not affected in this way. The activation energy of chain thermolysis was found to be 116 ± 6 kJ/mol (28 ± 1 kcal/mol). At temperatures above 60°C, chain recombination successfully competed with chain scission in lower viscosity rubber. The rate of thermoox-idative degradation was substantially higher in a typical process miscella. A hindered amine antioxidant significantly reduces chain scission under these conditions. © 1996 John Wiley & Sons, Inc.
Genetics Driving Epigenetics

Humans vary according to a plethora of traits, such as height, hair color, behavior, and susceptibility to disease. Both genetics (nature) and environment (nurture) contribute to this variation. Recent large-scale genetic studies have identified thousands of specific DNA variations in the human population that are associated with different traits. However, these studies do not answer a key question: By what means do most DNA variants alter cellular behavior and contribute to differences in specific traits, such as height? A trio of papers in this issue by Kasowski et al. on page 750 ( 1 ), Kilpinen et al. on page 744 ( 2 ), and McVicker et al. on page 747 ( 3 ) provide a framework for exploring the mechanistic link between genetic and trait variation in the human population. Specifically, they find that DNA variants influence a layer of gene regulation called epigenetics through the sequence-specific activity of transcription factors.
Fabricating arrays of strings

Interactive sequencing by hybridization (ISBH) is a new approach to DNA sequencing which uses interaction to dramatically reduce the number of oligonucleotides for de novo sequencing of large DNA fragments, while preserving the parallelism which is the primary advantage of conventional SBH. Through simulations, we have established that 64kb fragments can be sequenced using approximately ten rounds of standard-sized 64K oligonucleotide arrays. This represents a potentially significant advance in sequencing large DNA fragments. The key to practical implementation of ISBH is the development of technologies for fabricating arrays of oligonucleotides which avoid substantial prefabrication costs which can only be amortized over large production runs. 20 refs., 4 figs., 4 tabs.
EFFECTIVENESS OF LOCAL VENTILATION IN REMOVING SIMULATED POLLUTION FROM POINT SOURCES

Abstract The influence of environmental conditions on the effectiveness of range hoods and window fans in removing indoor pollutants is considered. Tests were conducted in a two-room test space whose infiltration rate was less than 0.1 h −1 . Pollutants were simulated using dilute sulfur hexafluoride as a tracer gas. Range hood tests were carried out with heated and unheated tracer gas. In the former case, where the buoyancy of the tracer was fixed, removal efficiency was roughly linear over a range of flow rates from 10.3 to 60.0 L s −1 ; the highest measured efficiency was 0.77. With unheated tracer gas, effectiveness was highly dependent on free convection patterns, so that the concept of ventilation efficiency was inapplicable. Window fan tests were conducted with the source of tracer gas in each of the two rooms, the fan itself remaining fixed. The results demonstrate the difficulty of applying conventional definitions of ventilation efficiency, such as those derived from mass-balance models, to realistic situations.
Effectiveness of HIV/AIDS Interventions on Drug Use and Needle Risk Behaviors for Out-of-Treatment Injection Drug Users

Abstract-This study presents an evaluation of the effectiveness of the AIDS Community-Based Outreach/Intervention projects implemented as part of the National Institute on Drug Abuse (NIDA) Cooperative Agreement (CA), which began in 1990 and is currently ongoing. Participants in the CA were randomly assigned to one of two interventions: a NIDA/CA-developed standard intervention (SI); or the SI plus a site-specific enhanced intervention (EI). Analyses of drug use and needle-related risk behaviors were conducted among injection drug users (IDUs) in eight participating cities where follow-up rates of at least 60% were obtained (N=3,743). Results indicated that IDUs significantly reduced their needle-related risk behaviors following delivery of the interventions and that a substantial portion entered substance abuse treatment. However, there was relatively little to support the effectiveness of more expensive and involved enhanced interventions. A number of factors associated with increasing or maintaining high risk behaviors, including an HIV negative serostatus and a greater perceived chance of acquiring AIDS, were also observed. Continued outreach to drug injectors is recommended, as well as the development of new and creative interventions targeting individuals who are HIV negative and those who are aware of their high risk status but have not changed their behaviors in response to risk-reduction interventions.
The reactions of zinc, zinc chloride and zinc oxide with coal. An x‐ray diffraction study

The reactions of zinc chloride and zinc oxide with coal have been studied using X-ray diffraction to monitor the 002 graphite line. It was observed that reaction of either reagent causes this diffraction line to disappear. Furthermore, addition of zinc metal reduces the weight of zinc chloride or zinc oxide needed to remove this 002 diffraction. Experiments with magnesium compounds indicate that the results with zinc compounds and coal cannot be extended to the analogous magnesium species. Thus it appears that zinc chloride or zinc oxide are capable of breaking up some of the regularity of the coal structure. This effect is enhanced by zinc metal indicating the possibility of a reaction in which zinc is switching between the elemental and oxidized forms.
Response to open peer commentaries on "How to do research fairly in an unjust world".

The commentaries published in this issue are thoughtful and stimulating and provide an excellent contribution to the debate about fairness in research in developing countries. I cannot possibly hop...
Observations of cosmic rays at high altitudes

Direct measurements of the momenta of cosmic-ray particles at an altitude of 30,000 feet have recently been reported.
Prognostic factors in malignant mixed tumors of the salivary gland: correlation of immunohistochemical markers with histologic classification.

Malignant mixed tumor of salivary glands is a rare tumor whose variable behavior and prognosis are related for the most part to the clinical stage and histologic grade of the carcinomatous component. The purpose of this study is to predict prognosis by comparing the histologic grading and subclassification of the carcinomatous component with the immunohistochemical reactivity for E-cadherin, P53 mutation protein, and cellular proliferation (Ki67). Stains were performed on formalin-fixed paraffin-embedded tissue sections from 18 cases of malignant mixed tumor. Clinical follow-up was obtained for each patient. Regional lymph node and distant organ metastases were the criteria for poor prognosis. Of seven cases with lymph nodes metastasis, five were high-grade tumors (with one subsequent death from brain metastasis) and two were low-grade. Of the eight high-grade tumors, positivity for Ki67, p53, and E-cadherin were noted in six, four, and two cases, respectively. In contrast, of the 10 low-grade tumors, two stained with Ki67, five with p53, and none with E-cadherin. Most notably, all seven metastatic cases (as opposed to only one of 11 nonmetastatic tumors) had Ki67 reactivity of more than 10%. We conclude that malignant mixed tumor represents a spectrum of malignancies in which the clinical behavior is closely related to the carcinomatous element. In addition to histologic grading, Ki67 is a useful prognostic marker in the evaluation of malignant mixed tumor while p53 and E-cadherin appear to be of limited value.
6A5 - Possibility of self-focusing due to intensity dependent anomalous dispersion

Close to an atomic resonance, the dependence of the real part of the susceptibility on power level (i.e., saturation effects) can be sizeable and therefore lead to self-trapping or self-focusing. It is shown here under what conditions this effect can occur. Order of magnitude estimates are given for the intensity dependent index change and the diameter of the trapped beam for some laser materials.
2.5 GB/s germanium gate photoMOSFET integrated to silicon photonics

We demonstrate a monocrystalline 1×8 μm germanium gate photoMOSFET integrated with silicon photonic waveguides and grating coupler operating at over 2.5 GB/s at 1550nm.
Multi-Agent System Dynamics: Bifurcation and Behavior of Animal Groups

Abstract Systematic design of decentralized feedback for coordinated control of multi-agent systems has much to gain from the rigorous examination of the nonlinear dynamics of collective animal behavior. Animals in groups, from bird flocks to fish schools, employ decentralized strategies and have limitations on sensing, computation, and actuation. Yet, at the level of the group, they are known to manage a variety of challenging tasks quickly, accurately, robustly and adaptively in an uncertain and changing environment. In this paper we review recent work on models and methods for studying the mechanisms of collective migration and collective decision-making in high-performing animal groups. Through bifurcation analyses we prove systematically how behavior depends on parameters that model the system and the environment. These connections lay the foundations for proving systematic control design methodologies that endow engineered multi-agent systems with the remarkable features of animal group dynamics.
The Influence of Union Instability and Union Quality on Children’s Aggressive Behavior

We investigate whether mother’s poor union quality attenuates the association between union instability and young children’s behavioral adjustment. Using data from three waves of the Fragile Families and Child Well-being Study to consider children born to married or cohabiting mothers (N = 1730), we determine that children who have experienced poor union quality between mothers and their partners have higher predicted aggressive behavior scores at age 3, regardless of whether they have experienced union transitions, compared to children who have experienced high-quality, stable unions. Children who have experienced instability in the context of higher-quality unions and relatively less acrimonious dissolutions are similar to children raised in high-quality stable unions in terms of predicted aggressive behavior scores.
Phase dynamics of wavy vortex flow.

The phase dynamics of wavy vortex flow is studied by applying a forced modulation to the upper boundary of a large-aspect-ratio concentric cylinders system. The experimental results are consistent with a model based on coupled phase equations. We find that the perturbations propagate as traveling waves parallel with the axis of the system when there is a strong coupling between the axial and azimuthal phase variables, and diffusively for weak coupling. The propagating wave speed is measured for a range of Reynolds numbers.
Neighborhoods, families, and children: Implications for policy and practice

Recent global and national trends have put a growing number of families and children living in the United States at risk for adverse health and developmental outcomes. Policies and programs designed to address these problems have too often focused on the characteristics of individuals as the root cause and have failed to address significantly core problems. The research reported here suggests that researchers, program planners, and policy makers should go beyond the focus on individuals to incorporate and target larger structural issues such as increasing poverty, growing economic inequalities between rich and poor, and eroding public social programs. This research demonstrates the importance of larger social structures for individuals' health. It also has implications for policy, namely: Neighborhoods are an important target for intervention; policy makers must take a multi-issue approach to addressing problems of the inner city; programs should look at building on community resources and infrastructure, as well as address the needs of individual community residents; and a “one-size-fits-all” mentality is not appropriate when designing programs to serve neighborhoods. © 1999 John Wiley & Sons, Inc.
Preschool children's understanding of the desire and knowledge constraints on intended action

In two experiments, 3-, 4- and 5-year-olds were tested on their ability to distinguish between intended and unintended actions on the basis of the agent's desire (wanting vs. not wanting the outcome) and/or the agent's knowledge state (having vs. not having the relevant knowledge to intend the outcome). Whereas all age groups had little difficulty imputing intention on the basis of desire, only about one-half of 3- and 4-year-olds were able to impute intention on the basis of knowledge; mastery of this latter aspect of intention understanding was not in place until after the age of 5 years. Within-subjects analyses confirmed these findings fully, and also showed that children were able to attribute ignorance and false beliefs on the basis of a lack of perceptual access before they were able to make judgments of intent on the basis of an agent's knowledge state. The relative lag in young children's appreciation of the knowledge constraints on intended actions is discussed in terms of cognitive, linguistic and social factors.
Noise analysis of ion channels in non-space-clamped cables: Estimates of channel parameters in olfactory cilia

Ion channels in the cilia of olfactory neurons are part of the transduction machinery of olfaction. Odorant stimuli have been shown to induce a biphasic current response, consisting of a cAMP-activated current and a Ca(2+)-activated Cl- current. We have developed a noise analysis method to study ion channels in leaky cables, such as the olfactory cilium, under non-space-clamp conditions. We performed steady-state noise analysis on ligand-induced currents in excised cilia, voltage-clamped at input and internally perfused with cAMP or Ca2+. The cAMP-activated channels analyzed by this method gave results similar to those of single-channel recordings (gamma = 8.3 pS). Single-channel currents have not yet been recorded for the Ca(2+)-activated Cl- channels. Using our noise analysis method, we estimate a unit conductance, gamma = 0.8 pS, for these channels. The density of channels was found to be approximately 70 channels/micron2 for both channel species.
Treatment of patients with asymmetries using asymmetric mechanics

The orthodontic correction of dental asymmetries is often considered a difficult and challenging process, primarily because of misdiagnosis and poorly planned treatment mechanics. A careful differential diagnosis together with a thorough treatment plan can ensure successful treatment outcomes in the management of these malocclusions. In this article, key elements of differential diagnosis and treatment planning are reviewed. Different treatment strategies, including an analysis of the side effects associated with the use of these appliance systems, are described. This approach will help the clinician to best adapt treatment mechanics to a given malocclusion.
Protein kinase C-β as a therapeutic target in breast cancer

Combining existing breast cancer therapies with novel agents that interfere with major signaling pathways is a promising approach. Targeting protein kinase C (PKC)-beta may serve as an attractive candidate in this regard for the following reasons: first, PKC-beta II (a splice variant of PKC-beta) has been implicated in tumorigenesis in human and rodent models. Second, PKC-beta, mainly PKC-betaII, is the predominant mediator of vascular endothelial growth factor-induced endothelial cell proliferation, which is a well-known stimulator of tumor angiogenesis and growth in breast cancer. There is increasing evidence that PKC-beta-selective inhibitors are effective in both preclinical and clinical trials. Enzastaurin, a potent inhibitor of PKC-beta, suppresses both tumor growth and tumor-induced angiogenesis in human tumor xenografts. Phase II trials of enzastaurin in recurrent high-grade gliomas and lymphomas have shown promising results. A similar compound, ruboxistaurin, is also under investigation in clinical trials for diabetic complications. This review focuses on the rationale for using PKC-beta as a therapeutic target at both the preclinical and clinical levels in breast cancer.
Teaching science through designing technology

This paper is a review of the literature related to teaching science through designing technology. The premise of this method is that designing technology presents the students with the context through which they can apply the science concepts they learned and thus enhancing their understanding of these concepts. Despite the promise of this method, teachers attempting it were faced by many challenges such as: (1) teachers did not have a grasp of the complex relationship between science and technology and assumed that technology was simply applied science, (2) the students were not able to transfer their learning of science to designing technology, (3) teachers did not have a deep understanding of the design process and tried to teach it as a linear, context-free process without regard to the context of the problem. The purpose of this paper is to extract from the literature a better understanding of teaching science through designing technology and the elements that teachers need to satisfy in order to increase their chances of successfully implementing this method in the classroom.
Finite state Markov chain model for wind generation forecast: A data-driven spatiotemporal approach

Integrating a large amount of wind energy into the bulk power grid has put forth great challenges for operations planning and system reliability. In particular, a complication that arises is that wind generation is highly variable (stochastic) and non-dispatchable, thus making it difficult to guarantee that the load and generation remain balanced at each instant. This uncertainty of wind generation impacts decision making at various system levels, and mischaracterizing the uncertainty can lead to spilt generation. In this work, the supply-side uncertainty is investigated by developing a realistic Markov chain model for wind generation forecasting. Specifically, using extensive measurement data obtained from an actual wind farm, a spatiotemporal analysis of the aggregate wind generation output from the farm is performed. One critical observation from empirical data is that the wind power output from the turbines are not necessarily equal even if they are identical and colocated. Using tools from graph theory and time-series analysis, a systematic procedure to characterize the statistical distribution of the aggregate wind power output from the farm is constructed. The procedure developed is amenable to the case when the farm has turbines from multiple classes, e.g., when they belong to multiple manufacturers or when they are deployed with different hub heights. The temporal dynamics of the aggregate wind power is characterized using auto-regression analysis, while taking into account the diurnal non-stationarity and the seasonality. Building on these spatial and temporal characterizations, a realistic, finite state Markov chain model for forecasting the aggregate wind power in a rigorous optimization framework is developed.
Mean Lives of Excited Levels in O i–O vi*

Ion beam-foil produced oxygen spectra in wavelength range between 450 and 2200 A, determining mean radiative lives of O I - O VI excitation levels
Biochemical effects of the geneg on the development of the axolotlAmbystoma mexicanum

Summary The recessive lethal geneg affects the late embryonic development of the axolotl,Ambystoma mexicanum. Mutant embryos show abnormal gills, slow yolk metabolism, and excessive xanthophore and melanophore pigmentation; they die, usually within 1 week after hatching. The biochemical abnormalities of mutant embryos were studied to discover the basis of the mutant syndrome. Thein vitro activity of esterases ofgg embryos and the electrophoretic properties of their isolated esterases are normal. However, theirin vivo activity is reduced, probably as a result of the defective attachment to membranes of at least one of the esterases. Other membrane bound enzymes may be affected similarly. Mutant embryos usually show an abnormally highin vitro andin vivo activity of the pentose shunt, and an abnormal accumulation of pteridines, suggesting a dependence upon “soluble” enzymes for energy. The plasma membranes of axolotl embryos are of two density classes. Mutant embryos have a large proportion of low density membrane material and little high density membrane material. Normal embryos have little low density membrane material and a large proportion of high density material. Less protein is detachable by electrophoresis from plasma membranes ofgg embryos than from the plasma membranes of normal embryos. The results support the hypothesis that the product of the normal allele is a membrane component or some other protein necessary for the attachment of proteins to membranes.
Reactive Path Planning in a Dynamic Environment

This paper deals with the problem of path planning in a dynamic environment, where the workspace is cluttered with unpredictably moving objects. The concept of the virtual plane is introduced and used to create reactive kinematic-based navigation laws. A virtual plane is an invertible transformation equivalent to the workspace, which is constructed by using a local observer. This results in important simplifications of the collision detection process. Based on the virtual plane, it is possible to determine the intervals of the linear velocity and the paths that lead to collisions with moving obstacles and then derive a dynamic window for the velocity and the orientation to navigate the robot safely. The speed of the robot and the orientation angle are controlled independently using simple collision cones and collision windows constructed from the virtual plane. The robot's path is controlled using kinematic-based navigation laws that depend on navigation parameters. These parameters are tuned in real time to adjust the path of the robot. Simulation is used to illustrate collision detection and path planning.
Rheology of hydrophobically modified polymers with spherical and rod-like surfactant micelles

Abstract Rheological measurements are used to probe the interactions between hydrophobically modified polymers and surfactant micelles. Hydrophobically modified hydroxyethylcellulose (hmHEC) with substitution levels of C12 and C16 hydrophobes between 0.9 and 7.3 mol% and hydrophobically modified polyacrylamide (hmPAM) with a sulfonated C12 hydrophobe at 1 mol% show the effects of hydrophobe type and content on interactions. Sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and cetyldimethylamine oxide (CDMAO) surfactants show the effect of anionic, cationic, and nonionic surfactant interactions, respectively. Two patterns of association are observed: strong cooperative interaction and non-cooperative interaction. For the systems displaying cooperativity (e.g. SDS/hmHEC and CTAB/hmPAM), a large increase in viscosity is seen as a function of surfactant concentration, and the increase begins about a decade in concentration below the critical micelle concentration (cmc). For the non-cooperative interactions, the viscosity maximum occurs at concentrations higher than the cmc. For CTAB the addition of KBr and for CDMAO the addition of hexanol induce a sphere-to-rod transition in the surfactant phase. Whereas, the polymer-surfactant interaction is completely masked at high surfactant concentrations for spherical micelles, in the case of rod-like micelles high viscosity levels are maintained at high surfactant concentrations.
Bright emissive core-shell spherical microparticles for shock compression spectroscopy

Experiments were performed to study the response to shock compression of rhodamine 6G (R6G) dye encapsulated in 1.25 μm diameter silica microspheres. When R6G was encapsulated in microspheres, the emission intensity under steady-state irradiation (the brightness) was 3.4 times greater than the same dye in solution (the free dye). At least part of the brightness improvement was caused by an enhanced radiative rate. When the microspheres were embedded in poly-methylmethacrylate subjected to planar shocks in the 3–8.4 GPa range by laser-driven flyer plates, the dye emission redshifted and lost intensity. The dye emission redshift represents an instantaneous response to changes in the local density. In free dye samples, the shock-induced intensity loss had considerably slower rise times and fall times than the redshift. When dye was encapsulated in microspheres, the time dependence of the intensity loss matched the redshift almost exactly over a range of shock pressures and durations. The faster response to shock of dye in silica microspheres was explained by dye photophysics. The microsphere environment decreased the singlet state lifetime, which decreased the rise time, and it also decreased the triplet state lifetime, which decreased the fall time. Since it is much easier and more convenient to make measurements of intensity rather than spectral shift, these microspheres represent a substantial improvement in optical sensors to monitor shock compression of microstructured materials.
Induction of neuroblastoma maturation by a new chemotherapy protocol.

Five patients, 1.5 to 9 years old, were treated at M.D. Anderson Hospital for Stage III of IV neuroblastoma. Each was entered into a chemotherapy protocol which included cyclophosphamide, vincristine, 5-trifluoromethyl-2'-deoxyuridine (F3TdR), and papaverine, and each responded with marked reduction in size of the abdominal tumor mass. All patients then underwent exploratory laparotomy and resection or biopsy of residual tumor. In three cases, histological examination of the treated tumor showed ganglioneuroblastoma with predominance of mature cells; one patient had a mature ganglioneuroma, whereas only necrotic tissue was obtained from the fifth patient. These findings support the hypothesis that this chemotherapy protocol can induce neuroblastoma maturation.
Symmetry breaking leads to forward flapping flight

Flapping flight is ubiquitous in Nature, yet cilia and flagella, not wings, prevail in the world of micro-organisms. This paper addresses this dichotomy. We investigate experimentally the dynamics of a wing, flapped up and down and free to move horizontally. The wing begins to move forward spontaneously as a critical frequency is exceeded, indicating that ‘flapping flight’ occurs as a symmetry-breaking bifurcation from a pure flapping state with no horizontal motion. A dimensionless parameter, the Reynolds number based on the flapping frequency, characterizes the point of bifurcation. Above this bifurcation, we observe that the forward speed increases linearly with the flapping frequency. Visualization of the flow field around the heaving and plunging foil shows a symmetric pattern below transition. Above threshold, an inverted von Karman vortex street is observed in the wake of the wing. The results of our model experiment, namely the critical Reynolds number and the behaviour above threshold, are consistent with observations of the flapping-based locomotion of swimming and flying animals.
Dexamethasone acutely down-regulates genes involved in steroidogenesis in stallion testes

In rodents, livestock and primate species, a single dose of the synthetic glucocorticoid dexamethasone acutely lowers testosterone biosynthesis. To determine the mechanism of decreased testosterone biosynthesis, stallions were treated with 0.1mg/kg dexamethasone 12h prior to castration. Dexamethasone decreased serum concentrations of testosterone by 60% compared to saline-treated control stallions. Transcriptome analyses (microarrays, northern blots and quantitative PCR) of testes discovered that dexamethasone treatment decreased concentrations of glucocorticoid receptor alpha (NR3C1), alpha actinin 4 (ACTN4), luteinizing hormone receptor (LHCGR), squalene epoxidase (SQLE), 24-dehydrocholesterol reductase (DHCR24), glutathione S-transferase A3 (GSTA3) and aromatase (CYP19A1) mRNAs. Dexamethasone increased concentrations of NFkB inhibitor A (NFKBIA) mRNA in testes. SQLE, DHCR24 and GSTA3 mRNAs were predominantly expressed by Leydig cells. In man and livestock, the GSTA3 protein provides a major 3-ketosteroid isomerase activity: conversion of Δ(5)-androstenedione to Δ(4)-androstenedione, the immediate precursor of testosterone. Consistent with the decrease in GSTA3 mRNA, dexamethasone decreased the 3-ketosteroid isomerase activity in testicular extracts. In conclusion, dexamethasone acutely decreased the expression of genes involved in hormone signaling (NR3C1, ACTN4 and LHCGR), cholesterol synthesis (SQLE and DHCR24) and steroidogenesis (GSTA3 and CYP19A1) along with testosterone production. This is the first report of dexamethasone down-regulating expression of the GSTA3 gene and a very late step in testosterone biosynthesis. Elucidation of the molecular mechanisms involved may lead to new approaches to modulate androgen regulation of the physiology of humans and livestock in health and disease.
Single axioms for groups

We study equations of the form (α=x) which are single axioms for group theory. Earlier examples of such were found by Neumann and McCune. We prove some lower bounds on the complexity of these α, showing that McCune's examples are the shortest possible. We also show that no such α can have only two distinct variables. We do produce an α with only three distinct variables, refuting a conjecture of Neumann. Automated reasoning techniques are used both positively (searching for and verifying single axioms) and negatively (proving that various candidate (α=x) hold in some nongroup and are, hence, not single axioms).
Money Demand in Guyana

This paper analyzes broad money demand (M2) in Guyana from January 1990 to September 1999; a period marked by deep transformations aimed at shifting Guyana from a centralized to a market economy. The paper develops a stable error-correction model based on a long-run cointegrating vector of money demand. The latter establishes that real money demand is determined in the long run by real income, interest rates, and the exchange rate. The results also show the existence of strong exchange rate-induced inflation anticipations that are typical to Guyana.
Frequency of uterine contractions and the risk of spontaneous preterm delivery.

Background The measurement of the frequency of uterine contractions has not been useful for reducing the rate of preterm delivery in randomized trials. Nonetheless, ambulatory monitoring of contractions continues to be used in clinical practice. Methods We assessed the frequency of uterine contractions as a predictor of the risk of spontaneous preterm delivery before 35 weeks of gestation. We enrolled women with singleton pregnancies between 22 and 24 weeks of gestation. The women used a contraction monitor at home to record contraction frequency twice daily on 2 or more days per week from enrollment to delivery or 37 weeks of gestation. Results We obtained 34,908 hours of successful monitoring recordings from 306 women. Although more contractions were recorded from women who delivered before 35 weeks than from women who delivered at 35 weeks or later, we could identify no threshold frequency that effectively identified women who delivered preterm infants. The sensitivity and positive predictive value of ...
Seasonal abundance of Lutzomyia shannoni (Diptera: Psychodidae) on Ossabaw Island, Georgia.

Population dynamics of Lutzomyia shannoni were monitored from April 1986 through December 1987 on Ossabaw Island, Ga. Most (99%) of the 19,788 adult sand flies were collected in light traps supplemented with dry ice; ≤l% were aspirated from diurnal resting sites. Adult sand flies first appeared in April and were followed by peaks of abundance during May 1986, and May and July 1987. Numbers of adults captured fell rapidly in October and November 1986 and in September and October 1987. No specimens were collected in December 1986 or in March, November, and December 1987. Light trap catch was affected positively by mean nightly air temperature and negatively by rainfall 14 d before collection, but not by wind speed or moon phase. Vesicular stomatitis viral activity, as measured by antibodies in feral and domestic swine, roughly corresponded to the seasonal appearance of adult L. shannoni during 1986 and 1987. Significantly more adults (72%) were collected in light traps at ground level (0.5 m) than at heights of 4 and 8 m. Most resting adults were collected from dark, moist tree holes and cavities of various hardwoods.
Bereavement, stress, and social support in members of a self-help group.

The relationship between demographic characteristics, social support, network orientation, and the stress response to the death of a family member was studied. Participants were members of a national self-help group for the bereaved, The Compassionate Friends (sample n =158), who completed a demographic questionnaire, and measures of stress response, social support, and orientation toward the helpfulness of others. Results indicated that time since the death was the strongest determinant of the severity of the stress response, followed by orientation toward the helpfulness of others. Satisfaction with social support was directly related to the number of people in the support network and participants' orientation toward others' helpfulness. Help-seeking behavior was directly related to number of people in the support network. These results are discussed relative to counseling practice and grief awareness.
An Evaluation of the Large-Eddy Simulation Option of the Regional Atmospheric Modeling System in Simulating a Convective Boundary Layer: A FIFE Case Study

Abstract A large-eddy simulation (LES) model was used to simulate the convective boundary layer (CBL) that developed on 1 July 1987, over the domain of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). Three simulations were produced using different boundary conditions at the ground surface, namely, (i) spatial distribution of topography and spatial distribution of surface heat fluxes; (ii) spatial distribution of topography but mean surface heat fluxes; and (iii) no topography and mean surface heat fluxes. The diurnal variation of mean surface fluxes and their spatial distribution were derived from the FIFE network of observations. In all cases, the model was initialized with the atmospheric sounding observed in this domain at 0700, and run until 1500 local time. The resulting mean profiles of temperature and specific humidity were compared to those observed with atmospheric soundings at 0900, 1030, and 1230 local time. The simulated structure of turbulence was q...
Retrospectives: The Origins of the Representative Agent

This paper examines Alfred Marshall's invention of the representative firm. Marshall first used the representative firm in order to describe an industry supply curve for an industry with heterogeneous firms. Despite Marshall's limited use of the notion, the representative agent was extensively criticized as an ephemeral, useless construct that was unable to account for economic growth and that ignored important heterogeneities. The criticisms succeeded in banishing the representative agent from economics. These initial criticisms are also shown to apply to modern uses of the representative agent as well.
Human evolution: Those feet in ancient times

A fossil foot found in Ethiopia suggests that human ancestors that walked on two feet and also ably climbed trees existed until 3.4 million years ago, adding evidence for locomotor diversity during early human evolution. See Article p.565 A 3.4-million-year-old partial skeleton of a hominin foot unearthed in Ethiopia offers an intriguing riddle. The only hominin previously known from that date was Australopithecus afarensis (to which 'Lucy' belonged), which was fully bipedal, and had essentially modern feet. The latest specimen, however, shows evidence for an opposable big toe, more like that seen in modern apes or in the hominin Ardipithecus ramidus, which lived one million years earlier. The new find suggests the coexistence of more than one hominin species in the Pliocene epoch, three to four million years ago, each with its own way of getting around.
Free energy methods in molecular simulation

An overview is given of methods for calculating free energies by molecular simulation. Techniques may be categorized as density-of-states methods and work-based methods. Emphasis is given to the latter, with particular focus on issues of performance and accuracy. Two points of view are provided for understanding these issues. One is based on the distribution of work values observed in the calculation, and the other considers the relationship of the important regions of phase space for the systems. We present a metric that brings together the two viewpoints, and provide a demonstration that connects to the accuracy of a calculation as a function of sampling length. We also discuss staging methods and their appropriate formulation in consideration of phase-space relations.
Can computed tomography score predict outcome of adenoidectomy for chronic rhinosinusitis in children.

BackgroundChronic adenoiditis (CA) and chronic rhinosinusitis (CRS) in children are difficult to distinguish based on symptoms alone. A computed tomography (CT) scan is one way to distinguish betwe...