Computational design and experimental discovery of an antiestrogenic peptide derived from alpha-fetoprotein.

Breast cancer is the most common cancer among women, and tamoxifen is the preferred drug for estrogen receptor-positive breast cancer treatment. Many of these cancers are intrinsically resistant to tamoxifen or acquire resistance during treatment. Consequently, there is an ongoing need for breast cancer drugs that have different molecular targets.

Do hydroxyl radical-water clusters, OH(H2O)n, n = 1-5, exist in the atmosphere?

It has been speculated that the presence of OH(H2O)n clusters in the troposphere could have significant effects on the solar absorption balance and the reactivity of the hydroxyl radical. We have used the G3 and G3B3 model chemistries to model the structures and predict the frequencies of hydroxyl radical/water clusters containing one to five water molecules. The reaction between hydroxyl radical clusters and methane was examined as a function of water cluster size to gain an understanding of how cluster size affects the hydroxyl radical reactivity.

Reward-related neuronal activity in the rat superior colliculus.

The activity of single units in the intermediate and deep layers of the superior colliculus was recorded while rats performed an operant conditioning task. On all trials, each animal pressed a bar and then inserted his snout into a food cup; on half of the trials, food reinforcement was available. To test for tactile sensitivity, on half of the trials the rats received a puff of air to the face when the snout entered the food cup.

Twenty-first century skills for students: hands-on learning after school builds school and life success.

At the core of the movement for twenty-first century skills are students. The growing efforts to increase programs leveraging out-of-school time are focused on giving American youth everything they need to compete in this increasingly complex world. The author is one of many students who have been well served by initiatives imparting twenty-first century skills during after-school hours.

Global search for minimum energy (H2O)n clusters, n = 3-5.

The Gaussian-3 (G3) model chemistry method has been used to calculate the relative deltaG(o) values for all possible conformers of neutral clusters of water, (H2O)n, where n = 3-5. A complete 12-fold conformational search around each hydrogen bond produced 144, 1728, and 20,736 initial starting structures of the water trimer, tetramer, and pentamer. These structures were optimized with PM3, followed by HF/6-31G* optimization, and then with the G3 model chemistry.

Comparison of model chemistry and density functional theory thermochemical predictions with experiment for formation of ionic clusters of the ammonium cation complexed with water and ammonia; atmospheric implications.

The G2, G3, CBS-QB3, and CBS-APNO model chemistry methods and the B3LYP, B3P86, mPW1PW, and PBE1PBE density functional theory (DFT) methods have been used to calculate deltaH(o) and deltaG(o) values for ionic clusters of the ammonium ion complexed with water and ammonia. Results for the clusters NH4(+) (NH3)n and NH4(+) (H2O)n, where n = 1-4, are reported in this paper and compared against experimental values. Agreement with the experimental values for deltaH(o) and deltaG(o) for formation of NH4(+) (NH3)n clusters is excellent.

Division of labor in the honey bee (Apis mellifera): the role of tyramine beta-hydroxylase.

The biogenic amine octopamine (OA) is involved in the regulation of honey bee behavioral development; brain levels are higher in foragers than bees working in the hive, especially in the antennal lobes, and treatment causes precocious foraging. We measured brain mRNA and protein activity of tyramine beta-hydroxylase (T betah), an enzyme vital for OA synthesis, in order to begin testing the hypothesis that this enzyme is responsible for the rising levels of OA during honey bee behavioral development. Brain OA levels were greater in forager bees than in bees engaged in brood care, as in previous studies, but T betah activity was not correlated with bee behavior.

Exploration of the potential energy surfaces, prediction of atmospheric concentrations, and prediction of vibrational spectra for the HO2...(H2O)n (n = 1-2) hydrogen bonded complexes.

The hydroperoxy radical (HO2) plays a critical role in Earth's atmospheric chemistry as a component of many important reactions. The self-reaction of hydroperoxy radicals in the gas phase is strongly affected by the presence of water vapor. In this work, we explore the potential energy surfaces of hydroperoxy radicals hydrogen bonded to one or two water molecules, and predict atmospheric concentrations and vibrational spectra of these complexes.

Spatial summation in the tactile sensory system: probability summation and neural integration.

Psychophysical thresholds for the detection of a 300-Hz burst of vibration applied to the thenar eminence were measured for stimuli applied to the skin through 1.5 cm2 and through 0.05 cm2 contactors.

Ortho effect in the Bergman cyclization: electronic and steric effects in hydrogen abstraction by 1-substituted naphthalene 5,8-diradicals.

We present a detailed theoretical study of geometries, electronic structure, and energies of transition states and intermediates completing the full Bergman cycloaromatization pathway of ortho-substituted enediynes with a focus on polar and steric contributions to the kinetics and thermodynamics of hydrogen abstraction. This study provides a rare unambiguous example of remote substitution that affects reactivity of a neutral reactive intermediate through an sigma framework.

Prediction of accurate anharmonic experimental vibrational frequencies for water clusters, (H2O)n, n=2-5.

Accurate anharmonic experimental vibrational frequencies for water clusters consisting of 2-5 water molecules have been predicted on the basis of comparing different methods with MP2/aug-cc-pVTZ calculated and experimental anharmonic frequencies. The combination of using HF/6-31G* scaled frequencies for intramolecular modes and anharmonic frequencies for intermolecular modes gives excellent agreement with experiment for the water dimer and trimer and are as good as the expensive anharmonic MP2 calculations. The water trimer, the cyclic Ci and S4 tetramers, and the cyclic pentamer all have unique peaks in the infrared spectrum between 500 and 800 cm-1 and between 3400 and 3700 cm-1.

Perception of the tactile texture of raised-dot patterns: a multidimensional analysis.

An ALSCAL multidimensional scaling analysis in Euclidean space revealed that three orthogonal perceptual dimensions can account for the judged tactile dissimilarities of raised-dot patterns. Through magnitude estimates of various perceptual attributes, it was determined that the three dimensions consist of blur, roughness, and clarity. The only effect that selective adaptation of the Pacinian (P) channel had was to change the perceptual clarity of the raised dots against their background.

Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch.

The stability of the Antarctic ice shelves in a warming climate has long been discussed, and the recent collapse of a significant part, over 12,500 km2 in area, of the Larsen ice shelf off the Antarctic Peninsula has led to a refocus toward the implications of ice shelf decay for the stability of Antarctica's grounded ice. Some smaller Antarctic ice shelves have undergone periodic growth and decay over the past 11,000 yr (refs 7-11), but these ice shelves are at the climatic limit of ice shelf viability and are therefore expected to respond rapidly to natural climate variability at century to millennial scales. Here we use records of diatoms, detrital material and geochemical parameters from six marine sediment cores in the vicinity of the Larsen ice shelf to demonstrate that the recent collapse of the Larsen B ice shelf is unprecedented during the Holocene.

Comparison of CBS-QB3, CBS-APNO, G2, and G3 thermochemical predictions with experiment for formation of ionic clusters of hydronium and hydroxide ions complexed with water.

The GAUSSIAN 2, GAUSSIAN 3, complete basis set-QB3, and complete basis set-APNO methods have been used to calculate DeltaH( composite function) and DeltaG( composite function) values for ionic clusters of hydronium and hydroxide ions complexed with water. Results for the clusters H3O+(H2O)n and OH-(H2O)n, where n=1-4 are reported in this paper, and compared against experimental values contained in the National Institutes of Standards and Technology (NIST) database. Agreement with experiment is excellent for the three ab initio methods for formation of these clusters.

A Backscatter Suppressed Electron Detector for the Measurement of "a".

A new method of measuring the electron-antineutrino angular correlation coefficient, little "a", from neutron decay-to be performed at the National Institute of Standards and Technology-will require an electron spectrometer that strongly suppresses backscattered electrons. A prototype consisting of six trapezoidal veto detectors arranged around a plastic scintillator has been tested with an electron beam produced by a Van de Graaff accelerator. The results of this test and its implications for the little "a" measurement are discussed.

Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay.

Currently, the beta-neutrino asymmetry has the largest uncertainty (4 %) of the neutron decay angular correlations. Without requiring polarimetry this decay parameter can be used to measure λ (ga/gv ), test Cabibbo-Kobayashi-Maskawa (CKM) unitarity limit scalar and tensor currents, and search for Charged Vector Current (CVC) violation. We propose to measure the beta-neutrino asymmetry coeffcient, a, using time-of-flight for the recoil protons.

Measurement of Neutron Decay Parameters-The abBA Experiment.

We are developing an experiment to measure the correlations a, A, and B, and the Fierz interference term b in neutron decay, with a precision of approximately 10(-4). The experiment uses an electromagnetic spectrometer in combination with two large-area segmented silicon detectors to detect the proton and electron from the decay in coincidence, with 4π acceptance for both particles. For the neutron-polarization-dependent observables A and B, precision neutron polarimetry is achieved through the combination of a pulsed neutron beam, under construction at the SNS, and a polarized (3)He neutron polarizer.

Polarized (3) He Spin Filters for Slow Neutron Physics.

Polarized (3)He spin filters are needed for a variety of experiments with slow neutrons. Their demonstrated utility for highly accurate determination of neutron polarization are critical to the next generation of betadecay correlation coefficient measurements. In addition, they are broadband devices that can polarize large area and high divergence neutron beams with little gamma-ray background, and allow for an additional spin-flip for systematic tests.

Commissioning of the NPDGamma Detector Array: Counting Statistics in Current Mode Operation and Parity Violation in the Capture of Cold Neutrons on B 4 C and (27) Al.

The NPDGamma γ-ray detector has been built to measure, with high accuracy, the size of the small parity-violating asymmetry in the angular distribution of gamma rays from the capture of polarized cold neutrons by protons. The high cold neutron flux at the Los Alamos Neutron Scattering Center (LANSCE) spallation neutron source and control of systematic errors require the use of current mode detection with vacuum photodiodes and low-noise solid-state preamplifiers. We show that the detector array operates at counting statistics and that the asymmetries due to B4C and (27)Al are zero to with- in 2 × 10(-6) and 7 × 10(-7), respectively.

Measurement of Parity Violation in np Capture: the NPDGamma Experiment.

The NPDGamma experiment will measure the parity-violating directional gamma ray asymmetry A γ in the reaction [Formula: see text]. Ultimately, this will constitute the first measurement in the neutron-proton system that is sensitive enough to challenge modern theories of nuclear parity violation, providing a theoretically clean determination of the weak pion-nucleon coupling. A new beam-line at the Los Alamos Neutron Science Center (LANSCE) delivers pulsed cold neutrons to the apparatus, where they are polarized by transmission through a large volume polarized (3)He spin filter and captured in a liquid para-hydrogen target.

Instructors' practices in and attitudes toward teaching ethics in the genetics classroom.

There is strong consensus among educators that training in the ethical and social consequences of science is necessary for the development of students into the science professionals and well-rounded citizens needed in the future. However, this part of the curriculum is not a major focus of most science departments and it is not clear if, or how, students receive this training. To determine the current status of bioethics education of undergraduate biology students in the United States, we surveyed instructors of introductory genetics.

The relation between parental coping styles and parent-child interactions before and after treatment for children with ADHD and oppositional behavior.

This study examined the relation between parental coping styles, discipline, and child behavior before and after participating in a parent training program for parents of children with Attention-Deficit/Hyperactivity Disorder (ADHD) and oppositional behavior. For mothers, use of more maladaptive and less adaptive coping styles was related to more self-reported lax and overreactive discipline, more observed coercive parenting, and more observed child misbehavior prior to parent training. No significant relations were found for mothers following parent training after controlling for pretreatment variables.

Thermodynamics of forming water clusters at various temperatures and pressures by Gaussian-2, Gaussian-3, complete basis set-QB3, and complete basis set-APNO model chemistries; implications for atmospheric chemistry.

The Gaussian-2, Gaussian-3, complete basis set- (CBS-) QB3, and CBS-APNO methods have been used to calculate Delta H degrees and Delta G degrees values for neutral clusters of water, (H(2)O)(n), where n = 2-6. The structures are similar to those determined from experiment and from previous high-level calculations. The thermodynamic calculations by the G2, G3, and CBS-APNO methods compare well against the estimated MP2(CBS) limit.

Yeast Agp2p and Agp3p function as amino acid permeases in poor nutrient conditions.

The gene AGP2 and the ORF YFL055w (here named AGP3) are classified as members of the yeast amino acid permease gene family. Analysis of the growth of multiply-mutant strains in which these genes are disrupted shows that both encode permeases capable of supplying branched chain, and other, amino acids as nitrogen source. Both Agp2p and Agp3p are low affinity permeases for leucine (Kmapp 0.