cssi/SciSciGPT-SciSciNet huggingface dataset:
Programmed cell death: Does it play a role in parkinson's disease?

In recent years, the possibility that programmed cell death (PCD), which is mediated by genetic programs intrinsic to the cell, may underlie the degeneration of neurons that occurs in Parkinson's disease (PD) and allied disorders has become an important hypothesis. Although PCD was originally identified in tissues as a normal developmental phenomenon, there is no question that it can also occur in neurologic disease and models thereof. The possibility that PCD could occur in dopamine neurons in degenerative disease is made plausible by the observations that natural cell death, with the morphology of apoptosis, does occur in these neurons and that this event is regulated by developmental target interactions. In addition, it has been shown that apoptotic death can be induced in these neurons in some animal models of parkinsonism. We have shown, for example, that apoptosis can be induced during development by intrastriatal injection of the neurotoxin 6-hydroxydopamine. Other investigators have shown that apoptosis can be induced in a chronic model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyride toxicity. However, investigations in human PD brains have yielded mixed results thus far, with some investigators identifying evidence of apoptotic death but others not. Further investigation of human postmortem tissue will benefit from a more complete understanding of the molecular basis of PCD in dopamine neurons, such that its molecular features can be investigated, rather than strictly relying on the morphologic markers presently available.
The role of topoisomerase I in suppressing genome instability associated with a highly transcribed guanine-rich sequence is not restricted to preventing RNA:DNA hybrid accumulation

Highly transcribed guanine-run containing sequences, in Saccharomyces cerevisiae, become unstable when topoisomerase I (Top1) is disrupted. Topological changes, such as the formation of extended RNA:DNA hybrids or R-loops or non-canonical DNA structures including G-quadruplexes has been proposed as the major underlying cause of the transcription-linked genome instability. Here, we report that R-loop accumulation at a guanine-rich sequence, which is capable of assembling into the four-stranded G4 DNA structure, is dependent on the level and the orientation of transcription. In the absence of Top1 or RNase Hs, R-loops accumulated to substantially higher extent when guanine-runs were located on the non-transcribed strand. This coincides with the orientation where higher genome instability was observed. However, we further report that there are significant differences between the disruption of RNase Hs and Top1 in regards to the orientation-specific elevation in genome instability at the guanine-rich sequence. Additionally, genome instability in Top1-deficient yeasts is not completely suppressed by removal of negative supercoils and further aggravated by expression of mutant Top1. Together, our data provide a strong support for a function of Top1 in suppressing genome instability at the guanine-run containing sequence that goes beyond preventing the transcription-associated RNA:DNA hybrid formation.
Micromethod system for identification of anaerobic bacteria.

A micromethod multitest system prepared by Analytab Products, Inc. and conventional tests employed at the Center for Disease Control for identification of anaerobes were compared. All procedures were conducted in an anaerobic glove box. A total of 104 cultures, including 18 reference strains and 86 diagnostic cultures, were examined. Ninety-one percent of the total tests performed with the two systems were in agreement. Greater than 90% agreement between the two systems was obtained with 12 of the 17 differential tests compared. The tests for nitrate reduction and H2S production gave the poorest agreement, 77.8 and 80.8%, respectively. Only 66% of the 86 diagnostic cultures could be presumptively identified with the micromethod system supplemented only with microscopy and colonial characteristics. However, when appropriate supplementary tests and gas-liquid chromatography were used with the micromethod system, 85% of the 86 strains could be identified. When Ehrlich reagent, instead of Kovac reagent, was used with the micromethod to test for indole, the agreement in identification was raised to 93%.
Distributed processing of sensory information in the leech. III. A dynamical neural network model of the local bending reflex

The subpopulation of identified interneurons in the local bending reflex receive multiple inputs from dorsal and ventral mechanoreceptors and have outputs to dorsal and ventral motor neurons. Their connections suggest a distributed processing mechanism in which withdrawal from dorsal, ventral, or lateral stimuli is controlled by a single population of approximately 40 multifunctional interneurons, but it is unclear whether additional interneurons dedicated to particular inputs are needed to account for each kind of bend. We therefore asked whether a model could be constructed that reproduced all behaviors without dedicated interneurons. Interneurons in the model were constrained to receive both dorsal and ventral inputs. Connection strengths were adjusted by gradient descent optimization until the model reproduced the amplitude and time course of motor neuron synaptic potentials in intracellular recordings of the response to many different stimuli. After optimization, the similarity between model and identified interneurons showed that additional dedicated interneurons are not necessary to produce all forms of the behavior. Successful optimization of networks with many fewer interneurons showed that the 40-interneuron network is redundant, raising the possibility that the interneurons have additional functions. Finally, optimizing networks with additional constraints produced better matches to some of the identified interneurons and showed that local bending can be produced by two populations of interneurons: one with outputs consistent with dorsal bending, the other with ventral bending. This suggests a simple model in which two principal types of interneurons produce many different behaviors and predicts the type of interneuron that remains to be identified.
Type-E pulse-forming-network theory and synthesis

Among other things, E. A. Guillemin is known for solving the Gibbs phenomenon relating to Fourier series components when combined to create step-function outputs. His work is frequently cited in the design of type A, B, C, D, and E pulse-forming networks (PFNs). The synthesis of type A, B and C networks is straightforward using Cauer or partial-fraction expansion techniques and the driving-point admittance or impedance functions. Types D and E are much more difficult to derive analytically. Type-E PFNs are often preferred in practice because of the single, tapped inductor and equal-value capacitors. However, the synthesis of a type-E PFN first requires the derivation of the negative inductances in a type-D PFN. What was laborious using tools of the 1940s, now, by using modern computers and especially symbolic mathematics software, the impedance and admittance functions can now be readily solved to fully synthesize these types of PFNs. This paper builds on the theory and synthesis methods developed by Guillemin and shows how to analytically derive the negative inductances in type D and then coupled inductors in type-E PFNs. Synthesis examples are given of multi-section PFNs. The validity of synthesized PFNs is verified by SPICE circuit models.
Biopotential as predictor of ablation zone size during radiofrequency tumor ablation

Abstract Biopotential is an electrochemical potential that has been shown to correlate well with the coagulation zone size during cardiac RF catheter ablation. We designed an in vivo experiment to test the hypothesis that a similar correlation exists during hepatic RF ablation. We created coagulation zones, in vivo, in porcine liver, with 17 gauge needle electrodes, using RF ablation ( n = 56 ). The power was set constant at 30 W, controlled by impedance, and applied for 60, 120 or 180 s. We measured the biopotential between the electrode and the ground pad with low-pass filtering. The diameter and volume of the coagulation zone were measured and correlated with the change in biopotential between the beginning and end of each ablation procedure. Moderate correlation between biopotential change and both coagulation zone volume ( R 2 = 0.43 ) and diameter ( R 2 = 0.31 ) was observed. The time constant of the biopotential change was not significantly different from the time constant of the ablation zone diameter (36.6 s, p = 0.93 ); the biopotential may, therefore, predict the time course of the ablation zone diameter. The biopotential can potentially be used for intraprocedural monitoring of the progression of the thermal damage zone. It may also allow termination of the procedure, if it can be confirmed that the biopotential reliably correlates with the cessation of ablation zone expansion.
Splenosis is regulated by a circulating factor

Abstract Splenic rupture may result in splenosis, the growth of splenic fragments. We used a parabiotic model to test the hypothesis that splenotic growth is governed by a circulating mediator(s). Pairs of C57B1/6 mice underwent side-to-side anastomosis. After 2 weeks, each of four groups underwent a second operation in which one or both of the partners had a sham operation or a splenectomy, or had splenic fragments transplanted into their peritoneums, or some combination thereof. Six weeks later, splenotic fragments were excised and weighed. Spleen fragments involuted when inserted into the pairs that had two intact spleens. In contrast, in pairs with one intact spleen and one set of fragments, multiple splenules developed, whose aggregate mass was approximately half (ratio, 0.53 ± 0.04 [mean ± SE]) that of the original transplanted fragments. Significantly more splenosis ( P
The specificity of family history of alcohol and drug abuse in cocaine abusers

This study addresses the issue of whether the increased rates of substance-related problems for family members of cocaine abusers are specific for each substance. The present analysis examined the prevalence of problems due to alcohol or drug use separately for mothers, fathers, sisters, and brothers using the Family History Assessment Module. The probands were 343 out-of-treatment subjects with DSM-III-R cocaine disorders who did or did not have additional alcohol and opiate disorders. After accounting for age, race, gender, and antisocial personality, family history of alcohol-related problems had an odds ratio of 1.6 (p <.05) if a participant was alcoholic in addition to abusing cocaine. Specifically, a significantly greater proportion of participants' sisters (p <.001) and brothers (p <.05) had alcohol-related problems if the participant had a history of alcoholism. Among probands who reported opiate abuse or dependence, 38% had relatives with drug-related problems, while participants without opiate abuse or dependence had less than 31% of relatives with drug-related problems (p <.05). However, this association with opiate abuse or dependence and family history of drug-related problems was non-significant after controlling for participants' age, race, gender, treatment status, and antisocial personality diagnosis (odds ratio = 1.4, 95% C.I. = 0.8-2.4). Associations between participants' alcoholism and first-degree relatives' drug-related problems (and vice versa) showed that participants' history of opiate addiction did improve prediction of first-degree relatives' alcohol-related problems, except for participants' brothers. Additional familial risks for alcoholism were seen among siblings of drug abusers who also reported abuse of or dependence on alcohol even after controlling for relatives' ages. Furthermore, parental prevalence of alcohol-related problems were greater when participants had opiate addiction in addition to cocaine addiction. This seems to indicate that opiate addiction in addition to cocaine addiction has particularly strong inheritance patterns. In contrast, parental prevalence of drug-related problems was not greater when participants had alcohol addiction in addition to cocaine addiction. Thus, the cross-substance parent-child familial risk is limited to the dually diagnosed illicit drug.
Autism Spectrum Disorders: Practical Overview for Pediatricians

We are grateful and humbled to have the opportunity to edit this special issue of Pediatric Clinics of North America devoted to autism spectrum disorders. Because our understanding of the spectrum of autism continues to evolve, this collection of practical reviews presents the state of the knowledge at this time. We thank all the authors for sacrificing their invaluable time and sharing their passion and expertise to contribute articles for this issue. We thank the editorial and technical staff at Elsevier for their guidance, patience, and excellent work. We hope that the information presented here is of practical value for the pediatricians and other medical practitioners who take care of children and adolescents in their practice.
Rapid analysis of particles using a microprobe and a nondispersive x-ray analyzer☆

Abstract A lithium-drifted silicon diode is used as an x-ray detector on an electron microprobe to obtain rapid qualitative and quantitative results on particle samples. Results on NBS spectrographic standards are reported.
Models of morphogenesis: the mechanisms and mechanics of cell rearrangement

The directional rearrangement of cells is a key mechanism for reshaping embryos. Despite substantial recent progress in understanding the basic signal transduction pathways that allow cells to orient themselves in space, the extrinsic cues that activate these pathways are just beginning to be understood. Even less-well understood are the physical mechanisms cells use to change position, especially when those cells are epithelial, and how mechanical forces within the embryo affect those movements. Recent studies are providing clues regarding how this fundamental process occurs with such remarkable reliability.
MHC restriction in three dimensions: a view of T cell receptor/ligand interactions.

B and T lymphocytes of the immune system employ a highly effective diversity-generating machinery to ensure that their receptors, antibodies and T cell receptors (TCRs), respectively, have the capacity to recognize an enormous array of antigens. Indeed, antibodies can be raised against many kinds of molecules that are perceived as foreign to the host, including proteins, carbohydrates, small organic compounds, and nucleic acids. TCRs, on the other hand, have the seemingly peculiar property that they only recognize a foreign antigen when it is associated with a host- or “self”-encoded protein called a major histocompatibility complex (MHC) molecule. The T cell property of “MHC-restricted” recognition of antigen was discovered for cytotoxic T cells by Zinkernagel and Doherty 1974, work for which they received the 1996 Nobel Prize in Medicine.
Imitation learning with hierarchical actions

Imitation is a powerful mechanism for rapidly learning new skills through observation of a mentor. Developmental studies indicate that children often perform goal-based imitation rather than mimicking a mentor's actual action trajectories. Further, imitation, and human behavior in general, appear to be based on a hierarchy of actions, with higher-level actions composed of sequences of lower-level actions. In this paper, we propose a new model for goal-based imitation that exploits action hierarchies for fast learning of new skills. As in human imitation, learning relies only on sample trajectories of mentor states. Unlike apprenticeship or inverse reinforcement learning, the model does not require that mentor actions be given. We present results from a large-scale grid world task that is modeled after a puzzle box task used in developmental studies for investigating hierarchical imitation in children. We show that the proposed model rapidly learns to combine a given set of hierarchical actions to achieve the subgoals necessary to reach a desired goal state. Our results demonstrate that hierarchical imitation can yield significant speed-up in learning, especially in large state spaces, compared to learning without a mentor or without an action hierarchy.
Ten Faulty Notions About Teaching and Learning That Hinder the Effectiveness of Special Education

Commonly held notions about teaching and learning influence and reflect the practice of many classroom teachers. This article discusses 10 such notions that the author believes limit the effectiveness of special education by impeding the adoption of research-based instructional practices. Each notion is described, and then the author briefly discusses why or how it hinders effective instruction. Reasons why many educators subscribe to these faulty notions are suggested, and three recommendations that may increase the adoption of research-based teaching practices are offered.
Neural restoration of degraded audiovisual speech.

Abstract When speech is interrupted by noise, listeners often perceptually “fill-in” the degraded signal, giving an illusion of continuity and improving intelligibility. This phenomenon involves a neural process in which the auditory cortex (AC) response to onsets and offsets of acoustic interruptions is suppressed. Since meaningful visual cues behaviorally enhance this illusory filling-in, we hypothesized that during the illusion, lip movements congruent with acoustic speech should elicit a weaker AC response to interruptions relative to static (no movements) or incongruent visual speech. AC response to interruptions was measured as the power and inter-trial phase consistency of the auditory evoked theta band (4–8 Hz) activity of the electroencephalogram (EEG) and the N1 and P2 auditory evoked potentials (AEPs). A reduction in the N1 and P2 amplitudes and in theta phase-consistency reflected the perceptual illusion at the onset and/or offset of interruptions regardless of visual condition. These results suggest that the brain engages filling-in mechanisms throughout the interruption, which repairs degraded speech lasting up to ~ 250 ms following the onset of the degradation. Behaviorally, participants perceived speech continuity over longer interruptions for congruent compared to incongruent or static audiovisual streams. However, this specific behavioral profile was not mirrored in the neural markers of interest. We conclude that lip-reading enhances illusory perception of degraded speech not by altering the quality of the AC response, but by delaying it during degradations so that longer interruptions can be tolerated.
Simulation of nipi photovoltaic devices

The simulation and characterization of multi-period GaAs n-type/intrinsic/p-type/intrinsic (nipi) doping structure solar cells has been demonstrated. The nipi device depends almost exclusively on drift rather than diffusion currents to collect the carriers. This architecture has been proposed to increase the radiation hardness of a device due to a decreased dependence upon diffusion length. This doping superlattice will allow photo generated carriers to be rapidly transported through the junction by drift. Converting them to majority carriers, and subsequently conducted laterally to selective contacts positioned at opposite sides of etched V-groove channels in the device. The result is a parallel connected multiperiod solar cell, which has been evaluated extensively under simulation. The nipi solar cells have been simulated, giving a greater understanding of the physical mechanisms at work in the device. Design variables such as finger spacing, doping concentration, nipi stack thickness, and the doped to intrinsic thickness ratio are varied to optimize the device. These results show the nipi device has great promise for development as a high efficiency solar cell, with the potential to be used in applications where radiation hardness is required, such as satellite power systems or radioisotope batteries.
Clinicopathologic correlates of acute ischemic heart disease syndromes

Abstract To better define the relations among acute and chronic coronary arterial lesions and different syndromes of acute ischemic heart disease, the clinicopathologic findings in 100 recent myocardial infarcts in 83 patients were reviewed and the results correlated with those of previous studies. Severe atherosclerosis (greater than 75 percent narrowing of luminal cross-sectional area) involved three or more major coronary arteries in 65 percent; two arteries in 16 percent, one artery in 15 percent, and no arteries in 4 percent of cases. The incidence rate of recent occlusive coronary arterial lesions was 61 percent, including 50 (90.2 percent) of 55 grossly apparent transmural infarcts, 9 (34.6 percent) of 26 grossly evident subendocardial infarcts and 2 (10.5 percent) of 19 multifocal microinfarcts associated with clinical episodes of acute coronary insufficiency (p From this and previous studies, it is concluded that (1) acute ischemic heart disease does not have a constant relation with the severity of chronic atherosclerosis; (2) myocardial necrosis commonly occurs in the absence of acute permanent coronary occlusion, but in this setting is usually limited to subendocardial involvement of variable extent; (3) acute coronary thrombosis frequently acts as a major factor in determining the extent and distribution of an evolving infarct, as indicated by the large incidence of occlusive coronary thrombi with regional transmural infarcts; and (4) coronary thrombus formation is not dependent on a generalized impairment of coronary perfusion, either before or after the onset of infarction.
Activities Of The American Association Of Physicists In Medicine And The American Institute Of Ultrasound In Medicine In Ultrasound Instrument Performance Evaluation

The main contributions of the AAPM and AIUM in ultrasound instrument performance evaluation are made through special sessions, individual members' presentations at the national meetings, and in publications of these two societies. Committee work is proceeding within the AAPM on a draft of recommended acceptance tests. In addition, the AAPM provides coordination for the NCI-sponsored Centers for Radiological Physics. The Centers are presenting regional workshops on ultrasound instrument performance evaluation and are developing techniques such as meaningful axial resolution measurements for gray scale scanners. These developments are summarized. Two existing ALUM standards are designed for performance evaluation of ultrasound equipment. These standards are "Standard Specification of Echoscope Sensitivity and Signal to Noise Ratio" and the "Standard 100 mm Test Object and Recommended Procedures for Its Use." The ALUM now offers a commendation to manufacturers who specify appropriate safety related instrument performance information, and recently has begun work to cooperate with the National Electrical Manufacturers Association, the AAPM and the Acoustical Society of America in helping to define standards for acoustic safety aspects of diagnostic ultrasound equipment. AIUM subcommittees also are active in ophthalmological equipment evaluation and transducer characterization standards.
Tenure and promotion: A study of practices by institutional type

Abstract A survey sent to research, doctorate-granting, comprehensive, and liberal arts institutions across the U.S. provides information on how evaluation criteria for academic librarians vary among different types of institutions. Job performance is almost universally considered; doctorate-granting and comprehensive universities are more likely to require evidence of publication than are either research or liberal arts institutions. Knowledge of the differences among institutions may help librarians in making career decisions.
Organic and inorganic nitrogen source effects on the metabolism of Clostridium acetobytulicum

The effects of organic and inorganic nitrogen combinations on cell growth, solvent production and nitrogen utilization by Clostridium acetobutylicum ATCC 824 was studied in batch fermentations. Fermentations in media with 10 mM glutamic acid, as the organic nitrogen source, and 0 mM to 10 mM ammonium chloride, as the inorganic nitrogen source had a solvent yield of 0.8 to 1.08 mmol solvent/mmol glucose used, with a slow fermentation rate (2 mmol solvent/l h-1). When media contained 20 mM or 30 mM glutamic acid as well as 2.5 to 7.5 mM ammonium chloride the fermentation rate increased (5.5 mmol/l h-1) while the solvent yield remained constant (0.86 to 0.96 mmol solvent/mmol glucose used). Total solvent production was higher in media containing 20 mM or 30 mM glutamic acid than with 10 mM glutamic acid.
Inhibition of Escherichia coli RNA polymerase by bacteriophage T7 gene 2 protein.

The 64 amino acid residue product of bacteriophage T7 gene 2 (gp2) binds the Escherichia coli RNA polymerase and inhibits transcription. We localized the gp2 binding site to within 53 amino acid residues in the functionally dispensable region of the RNA polymerase beta' subunit. We investigated the effect of gp2 on transcription at a -10/-35 promoter and at an "extended -10" promoter. Our results indicate that binding of gp2 to the sigma70holoenzyme (Esigma70) prevents promoter recognition at -10/-35 promoters. Once open promoter complexes are formed, however, Esigma70transcription is resistant to gp2, since gp2 can no longer bind RNA polymerase. Surprisingly, transcription inhibition by gp2 is both sigma and promoter-specific. gp2 has little effect on Esigma70transcription from an extended -10 promoter, which does not depend on sigma70region 4 interactions with the -35 promoter box for its activity. gp55-dependent phage T4 late promoter transcription is also resistant to gp2. From these results, we conclude that the interaction of the sigma70region 4 with the -35 consensus promoter element is the primary target of gp2 inhibition.
Effect of silica on the proliferative behavior of human lung fibroblasts

We show that silica enhances the proliferation of some but not all lung derived fibroblastlike cells (FLC) of fetal and adult origin. Cultures were obtained from lung biopsy and lavage of normal individuals and patients with interstitial lung disease. The responses of these cell lines were heterogenous; some cultures were stimulated to proliferate in the presence of silica and others were not stimulated. There was no apparent correlation between source of the cell lines and the effects of silica. The proliferative capacity of the cells appeared to be an important determinant of the effect of silica on the growth of the cultures.
Judgment Difficulty and the Moral Intensity of Unethical Acts: A Cognitive Response Analysis of Dual Process Ethical Judgment Formation

This study analyzes cognitive responses to explore a dual processing perspective of ethical judgment formation. Specifically, the study investigates how two factors, judgment task difficulty and moral intensity, influence the extent of deontological and teleological processing and their effects on ethical judgments. A single experiment on 110 undergraduate research participants found that judgment task difficulty affected the extent of deontological and teleological processing. Although moral intensity affected ethical judgments, it did not produce effects on either deontological or teleological cognitive responses. Results did not support the hypotheses that deontological and teleological cognitive responses would mediate the relationships between the experimental factors and ethical judgments. Overall, the results support continued research of factors that affect the nature of information processing in ethical decision situations and the use of cognitive response analysis as a tool for conducting this r...
Developmental patterns of intestinal transport mechanisms in the chick

Abstract o 1. The intestinal absorption of a variety of nutrients has been studied by an in vitro tissue-accumulation technique in the chick. 2. Day-old chick epithelium absorbed 3-O-methyl glucose, methionine, glutamic acid, thiamine, choline, lysine, but not sucrose, in both the jejunum and ileum, and that the rates for each substrate, respectively, appeared to be similar in both regions. β -Alanine, however, was transported more rapidly in the ileum. 3. Transport of 3-O-methyl glucose was repressed in the ileum of 8-week old chicks. 4. The essential amino acids and choline, which is a dietary requirement, showed similar activities, respectively, in both regions of the older birds. 5. Jejunal transport of thiamine, on the other hand, was repressed, while that of β -alanine was strongly intensified in the older birds. 6. Sucrose uptake was uniformly induced (or derepressed) in both regions in the older birds.
TRANSVERSELY ISOTROPIC THERMOELASTIC PROBLEM OF UNIFORM HEAT FLOW DISTURBED BY A PENNY-SHAPED CRACK

Abstract A solution for an antisymmetrical problem of uniform heat flow disturbed by a penny-shaped crack in a transversely isotropic medium is obtained using the techniques of Hankel transforms and multiple integrations. The thermal stresses and displacements in the crack plane are obtained in closed forms. The stress intensity factor is shown to be dependent upon the material properties.
The Organizational Dynamics of Adjustment Lending

The Globalizers: The IMF, the World Bank and Their Borrowers. By Ngaire Woods. Ithaca: Cornell University Press, 2006. 264 pp., $29.95 (ISBN: 0-8014-4424-1). Perhaps mirroring public debate on the issue, scholarship on the role of the International Monetary Fund (IMF) and the World Bank in economic development has often treated these institutions as mere conduits of US interests. In The Globalizers , Ngaire Woods seeks to amend this perception, offering a rich account of their activities that emphasizes the inner workings of these institutions and their negotiations with policymakers in developing countries. As such, The Globalizers provides a valuable inside look at the processes that shape the IMF and World Bank's role in the global economy. The Globalizers explains the design and implementation of conditional lending agreements by the IMF and the World Bank. In the design phase, pressures from powerful member governments are mediated through these two organizations, whose staffs work under bureaucratic incentive structures favoring uniform and simple solutions. “Sympathetic interlocutors” within the borrowing government give the lending institutions willing partners in negotiations over the terms of their loans (that is, the conditionality terms). These technocrats possess the policy competence to understand the necessary reforms. They also have the ideological commitment to enact the reforms and the bureaucratic autonomy to avoid competing demands from domestic interests. Thus, if the borrowers follow through on their commitments, the success of the program depends on external …
Perfect extensions of regular double Stone algebras

In 1951 Jonsson and Tarski showed that every Boolean algebra with operators could be embedded in a perfect (or canonical) extension. We obtain a similar result for regular double Stone algebras with operators. As a corollary we obtain another proof that every regular double Stone algebra can be represented as an algebra of rough subsets of an approximation space.
Language-related Cntnap2 gene is differentially expressed in sexually dimorphic song nuclei essential for vocal learning in songbirds

Multiple studies, involving distinct clinical populations, implicate contactin associated protein-like 2 (CNTNAP2) in aspects of language development and performance. While CNTNAP2 is broadly distributed in developing rodent brain, it shows a striking gradient of frontal cortical enrichment in developing human brain, consistent with a role in patterning circuits that subserve higher cognition and language. To test the hypothesis that CNTNAP2 may be important for learned vocal communication in additional species, we employed in situ hybridization to characterize transcript distribution in the zebra finch, an experimentally tractable songbird for which the neural substrate of this behavior is well established. Consistent with an important role in learned vocalization, Cntnap2 was enriched or diminished in key song control nuclei relative to adjacent brain tissue. Importantly, this punctuated expression was observed in males, but not females, in accord with the sexual dimorphism of neural circuitry and vocal learning in this species. Ongoing functional work will provide important insights into the relationship between Cntnap2 and vocal communication in songbirds and thereby clarify mechanisms at play in disorders of human cognition and language.
Flower Classification for a Citizen Science Mobile App

This work describes an efficient approach for flower classification that is suitable for deployment in mobile devices, allowing its use in a citizen science application for biodiversity monitoring. In the proposed system, geo-located images are uploaded by the user and segmented semi-automatically. We propose a classification method based on histogram comparison of color, shape and texture cues, using metric learning for feature weighting. Our method is tested on the Oxford Flower Dataset and we are able to achieve state-of-the-art accuracy, while proposing an approach that can run efficiently in mobile devices.
Direct Observations of the Strain-Limited Island Growth of Sn-Doped GaAs(100)

We have used scanning tunneling microscopy (STM) in ultrahigh vacuum and atomic force microscopy (AFM) in air to investigate the microscopic mechanisms of Sn surface segregation during the molecular beam epitaxial growth of GaAs and AlAs(100). Submonolayer amounts of Sn segregate to the surface during growth and strongly modify the growth kinetics. This is indicated by both extra-ordinary reflection high energy electron diffraction (RHEED) measurements, and the STM and AFM images of rapidly quenched growth fronts. At the high surface coverages of 0.1–0.6 monolayers of Sn, studied in this work, neither step bunching nor three-dimensional (3D) growth of GaAs(100), was observed. Instead, STM and RHEED measurements indicated a significantly enhanced layer-by-layer growth of GaAs with increasing surface coverage of Sn. STM snapshots of the initial stages of GaAs growth revealed 2D islands which contained a higher-than-equilibrium bulk concentration of Sn, in Ga-substitutional sites, of up to 50%. Other directly observed Sn effects which are presented in this work include the removal of GaAs(100) island growth anisotropy and the formation of 2D islands with a relatively narrow distribution of size and separation. The completion of the top layers is shown to proceed by the coalescence of these islands before any significant nucleation of the next layer islands. This effect is used to explain the Sn enhancement of the layer-by-layer growth which was indicated in our RHEED and scanning probe observations. A model is presented for Sn segregation which explains these results based on an island-size-dependent, strain-driven, oscillatory Sn occupation of Ga-substitutional sites and surface interstitial sites on top GaAs(100) layers during growth. This model, which introduces a strain-limiting mechanism for the size and shape of the 2D islands, can also explain the observed enhancement of postgrowth surface recovery, as well as a delayed onset in increasing adatom surface diffusion length with increasing Sn coverage. The main conclusion is that, if impurity incorporation results in significant strain, then in addition to step climbing by surface impurities, the exchange of incorporated impurities with native species in top layers can be an important path for impurity segregation during expitaxial growth.
Heterochromatin assembly: A new twist on an old model

The organization of eukaryotic genomes requires a harmony between efficient compaction and accessibility. This is achieved through its packaging into chromatin. Chromatin can be subdivided into two general structural and functional compartments: euchromatin and heterochromatin. Euchromatin comprises most of the expressed genome, while heterochromatin participates intimately in the production of structures such as centromeres and telomeres essential for chromosome function. Studies in the fission yeast Schizosaccharomyces pombe have begun to highlight the genetic pathways critical for the assembly and epigenetic maintenance of heterochromatin, including key roles played by the RNAi machinery, H3 lysine 9 methylation and heterochromatin protein 1 (HP1). Recent studies have also identified a novel E3 ubiquitin ligase universally required for H3 K9 methylation. Here we outline these studies and propose several models for the role of this E3 ligase in heterochromatin assembly.
The Direct Effect of Personal Relevance on Attitudes

The personal relevance of several academic and public policy proposals was manipulated, in the absence of any persuasive message, in two studies using a survey methodology and in two laboratory studies. Results generally showed that high personal relevance attitudes differed from low personal relevance attitudes. These results seem to indicate that a high-relevance version of a policy proposal is not the same attitude object as the low-relevance version of the same proposal. In expectancy-value terms, relevance manipulations may affect the valued consequences of a policy that come to mind. Framing a question in high-versus low-relevance terms can increase the accessibility of different object attributes. Implications for interpreting personal relevance findings in persuasion research are also discussed.
Nutrition and reproduction in euglena

1. There are three distinct methods of nutrition ineuglena: 2. Cultures develop most rapidly at room temperature, if sufficient food is present. 3. Acidity and alkalinity are controlling factors in reproduction, nutrition and life of cultures. 4. Lack of food and presence of chlorophyll are conducive to encystment, while the lack of both food and chlorophyll occasions death. 5. In the free active phase the saprophytic method of nutrition plays the most important role, while the holozoic method contributes but little. 6. The holophytic method predominates in the encysted forms. 7. Lack of food or slight acidity causes theeuglena to migrate downward to the interior or bottom of the culture. 8. Transverse division occurs in the active and encysted forms. Reproduction by longitudinal division plays the greatest role in the free swimming and encysted forms. 9. Temporary encystment without reproduction occurs inE. gracilis.
A laser-based technique for measuring accuracy and distortion in judgments of linear dimensions

A new technique is described that permits precise measurement of accuracy and distortion in judgments of linear dimensions based on either perception or memory. This technique involves the use of a single laser beam and a reference line placed on a projection surface. By rotating a laser device, the distance between the reference line and the point created by the beam may be continuously varied. This procedure avoids unintentional distortion from misjudgment of standard metrics, while the semicircular movement required by this technique eliminates body-referenced estimation and some other potential confounds. Potential applications to research in visual perception, spatial memory, and body image are discussed.
A phenomenological description of ENDOR in solution; example: The tri-t-butyl phenoxyl radical

Abstract The ENDOR spectrum of the tri- t -butyl phenoxyl radical is interpreted and precise values of the coupling constants reported. The relative intensities of the lines are reported under various conditions of microwave power, rf power, temperature, viscosity, and the Zeeman modulation, and a phenomenological theory beginning with the Bloch equations is developed to explain each effect. The optimization of each parameter for solution ENDOR is discussed.
Al-awādi al-ğāmia: A Contemporary Account of the Mongol Conquest of Baghdad, 656/1258

This article contains a translation (Arabic-English) with introduction and commentary of the events of years 655/1257 and 656/1258 of al-awādi al-gāmia including two qaīdas, written by an Iraqi anonymous author. It deals with the conquest of Baghdad by the Mongols and the death of the last Abbasid caliph al-Mustaim. al-awādi al-gāmia is a very interesting local Iraqi chronicle of the VIIth/XIIIth century and provides an abundance of detail that is not to be found elsewhere. Historiography of the period can often be divided along Arabic-Mamluk and Persian-Mongol lines; however, this chronicle cannot really be situated on either side. Translations of other primary sources of this event, both Arabic and Persian, have been made available; this translation not only complements them, but also adds a local perspective to the evaluation of the events.
Geographic and clonal variation in the milkweed- oleander aphid, Aphis nerii (Homoptera: Aphididae), for winged morph production, life history, and morphology in relation to host plant permanence

Populations of the milkweed-oleander aphid,Aphis nerii, were sampled in California, Iowa and Puerto Rico. Among these localities the aphid's host plants differ greatly in permanence. I compared populations for migratory potential, measured as the proportion of winged offspring produced in response to being crowded, and for life history and morphometric traits of the subsequent adult winged aphids. I predicted a negative correlation between degree of host plant permanence and migratory potential. As predicted, aphids from Iowa, where migration on to temporary hosts must occur each year, produce a greater proportion of winged offspring (37.7%) than those from California (25.7%) or Puerto Rico (31.6%) where hosts are more permanent. However, hosts in Puerto Rico appear to be more permanent than those in California, yet the difference between populations for migratory potential was opposite to that predicted. Within California the prediction again held: aphids collected from the most impermanent sites produce the greatest proportion of winged offspring. There were no population differences for any life history or morphometric traits of winged aphids that are important contributors to fitness or migratory ability such as time to reproductive maturity, fecundity or wing length. Nor did any traits covary with migratory potential. Thus, there does not appear to be an association of life history and morphology with migratory potential that could enhance the colonizing ability of migrant aphids. I was unable to detect population differentiation for life history and morphology even though there is ample genetic variation within populations on which selection could act and an absence of constraints arising from genetic correlations that could prevent appropriate evolution of traits within populations. The exploitation of temporary host plants therefore occurs by an increase in the number of colonists produced and not by change in life history or morphology of those colonists.
The "manganese(III)-containing" purple acid phosphatase from sweet potatoes is an iron enzyme.

Abstract An improved purification of the purple acid phosphatase from sweet potatoes has been developed, and the properties of the enzyme have been reexamined. Contrary to previous reports, (e.g., Y. Sugiura, et al., J. Biol. Chem. , 256 , 10664–10670 (1981)), the enzyme contains two moles of iron and insignificant amounts of manganese. The specific activity of the iron-containing preparations is ca . 14 times higher than that reported previously for the purported “Mn(III)” enzyme. The sweet potato purple acid phosphatase does indeed bind manganese, but it can be removed by dialysis with no changes in specific activity or spectral properties.
Pancreas and islet transplants for patients with diabetes: taking positions and making decisions.

Objective: To help endocrinologists develop a position and then make decisions about the applicability of pancreas and islet transplantations for treatment of patients with diabetes. Methods: An ov...
Crankshaft motions of the polypeptide backbone in molecular dynamics simulations of human type-α transforming growth factor

Order parameters for the backbone N−H and Cα−H bond vectors have been calculated from a 150 ps molecular dynamics (MD) simulation of human type-α transforming growth factor in H2O solvent. Two kinds of ‘crankshaft motions’ of the polypeptide backbone are observed in this MD trajectory. The first involves small-amplitude rocking of the rigid peptide bond due to correlated changes in the backbone dihedral angles ψi−1 and φi. These high-frequency ‘librational crankshaft’ motions are correlated with systematically smaller values of motional order parameters for backbone N−H bond vectors compared to Cα−H bond vectors. In addition, infrequent ‘crankshaft flips’ of the peptide bond from one local minimum to another are observed for several amino acid residues. These MD simulations demonstrate that comparisons of N−H and Cα−H order parameters provide a useful approach for identifying crank-shaft librational motions in proteins.
Mass Loading and Fate of Perfluoroalkyl Surfactants in Wastewater Treatment Plants

Wastewater treatment plants have recently been identified as a significant pathway for the introduction of perfluoroalkyl surfactants (PASs) to natural waters. In this study, we measured concentrations and fate of several PASs in six wastewater treatment plants (WWTPs) in New York State. We also monitored and measured matrix effects (ionization suppression and enhancement) by postcolumn infusion and standard additions. Concentrations of perfluorooctanoate (PFOA) in effluents of the six WWTPs ranged from 58 to 1050 ng/L. Perfluorooctanesulfonate (PFOS) was also ubiquitous in effluents of these WWTPs, albeit at much lower concentrations (3-68 ng/L). Two of these WWTPs employed identical treatment processes, with similar hydraulic retentions, but differed only in that Plant B treated domestic and commercial waste, whereas Plant A had an additional industrial influence. We found that this industrial influence resulted in significantly greater mass flows of all of the PASs analyzed. Primary treatment was found to have no effect on the mass flows of PASs. Secondary treatment by activated sludge in Plant A significantly increased (p < 0.05) the mass flows of PFOS, PFOA, perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA). However, in Plant B, only the mass flow of PFOA was significantly increased. The observed increase in mass flow of several PASs may have resulted from biodegradation of precursor compounds such as fluorotelomer alcohols, which is supported by significant correlations in the mass flow of PFOA/PFNA and PFDA/PFUnDA. Furthermore, the masses of PFDA and PFUnDA were significantly correlated only after the secondary treatment. In Plant A, concentrations of odd-number PFCAs were greater than those of even-number PFCAs, and concentration decreased with increasing chain length (from C8 to C12). A different pattern was observed in sludge samples, in which the dominance of PFOA decreased, and PFDA and PFUnDA increased, suggesting preferential partitioning of longer-chain PFCAs to sludge.
R68-23 The Greenblatt Chess Program

For more than fifteen years, people have been talking and writing about the possibility of chess playing programs. Previous "successful" programs have played a scaled-down game, parts of the game, or a weak overall game. This paper describes the first chess program to play a creditable amateur tournament game; it won the class D trophy in a Massachusetts State Chess Association Amateur Tournament. The paper is a well-written case study in artificial intelligence.