cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational explorations of vinylcyclopropane-cyclopentene rearrangements and competing diradical stereoisomerizations

The rearrangements and stereoisomerizations of four systems, vinylcyclopropane, 4-tert-butylvinylcyclopropane, 5-methylvinylcyclopropane, and 2,5-dimethylvinylcyclopropane, as well as a variety of deuterated derivatives and 1- and 2-methyl-, methoxy-, difluoro-, and amino-substituted species, were studied by density functional theory calculations using the B3LYP functional and the 6-31G* basis set. Energies were evaluated with CASSCF(4,4)/6-31G* single point calculations. The major product is obtained by the si pathway. Structures on this path are essentially pure diradical in character. Higher energy diradical species and intermediates are responsible for the scrambling of the stereochemistry. The stereoselectivity of the reaction is increased by substituents which increase the relative energy of the species involved in competing stereoselectivities. The computed secondary kinetic isotope effects reproduce the experimental values reported in the literature.
Mouse Organ Imaging

By exploiting the dynamics of near infrared dyes in-vivo, we have shown that it is possible to significantly enhance the contrast of internal organs within mice. These dynamics also confer information about organ function.
Evidence that exposure of the telomere 3' overhang sequence induces senescence.

Normal human cells cease proliferation after a finite number of population doublings, a phenomenon termed replicative senescence. This process, first convincingly described by Hayflick and Moorhead [Hayflick, L. & Moorhead, P. S. (1961) Exp. Cell Res. 25, 595–621] for cultured human fibroblasts 40 years ago, is suggested to be a fundamental defense against cancer. Several events have been demonstrated to induce the senescent phenotype including telomere shortening, DNA damage, oxidative stress, and oncogenic stimulation. The molecular mechanisms underlying senescence are poorly understood. Here we report that a 1-week exposure to oligonucleotide homologous to the telomere 3′-overhang sequence TTAGGG (T-oligo) similarly specifically induces a senescent phenotype in cultured human fibroblasts, mimicking serial passage or ectopic expression of a dominant negative form of the telomeric repeat binding factor, TRF2DN. We propose that exposure of the 3′ overhang due to telomere loop disruption may occur with critical telomere shortening or extensive acute DNA damage and that the exposed TTAGGG tandem repeat sequence then triggers DNA-damage responses. We further demonstrate that these responses can be induced by treatment with oligonucleotides homologous to the overhang in the absence of telomere disruption, a phenomenon of potential therapeutic importance.
Regulation of α and β components of noradrenergic cyclic AMP response in cortical slices

The cyclic AMP response to catecholamines in the rat cerebral cortex is mediated by both β- and α-adrenoceptors. The β-receptors cause a direct activation of adenylate cyclase whereas the alpha α-receptors play a modulatory role and act by potentiating the response to β stimulation. The present study investigated whether the functions of these two types of cyclic AMP-linked receptors are regulated differently by various physiological factors known to affect adrenoceptor function. It was found that treatments that affect central noradrenergic neuronal function including repeated administration of desmethylimipramine or lesion of central noradrenergic pathways produced selective changes in the cAMP response to β-receptor stimulation whereas treatments that affect adrenocortical function including ACTH of corticosterone administration and hypophysectomy or adrenalectomy produced selective changes in the potentiation response to α-receptor stimulation. The change in the α potentiation effect caused by corticosterone was found to be abolished in the presence of prazosin indicating that the hormone affects α1-adrenoceptor function. The results support the hypothesis that the β response in the cortex is under the control of the noradrenergic system while the α potentiation response is under the control of the adrenocortical system.
Lagrangian transport and chaos in the near wake of the flow around an obstacle: a numerical implementation of lobe dynamics

In this paper we study Lagrangian transport in the near wake of the flow around an obstacle, which we take to be a cylinder. In this case, for the range of Reynolds numbers investigated, the flow is two-dimensional and time periodic. We use ideas and methods from transport theory in dynamical systems to describe and quantify transport in the near wake. We numerically solve the Navier-Stokes equations for the velocity field and apply these methods to the resulting numerical representation of the velocity field. We show that the method of lobe dynamics can be used in conjunction with computational fluid dynamics methods to give very detailed and quantitative information about Lagrangian transport. In particular, we show how the stable and unstable manifolds of certain saddle-type stagnation points on the cylinder, and one in the wake, can be used to divide the flow into three distinct regions, an upper wake, a lower wake, and a wake cavity. The significance of the division using stable and unstable manifolds lies in the fact that these invariant manifolds form a template on which the transport occurs. Using this, we compute fluxes from the upper and lower wakes into the wake cavity using the associated turnstile lobes. We also compute escape time distributions as well as compare transport properties for two different Reynolds numbers.
THE TEACHER INTERNSHIP EXPERIENCES OF PROSPECTIVE HIGH SCHOOL MATHEMATICS TEACHERS

Nine prospective secondary mathematics teachers were interviewed about their teaching internship experience. The results of these interviews revealed that 7 of the 9 participants professed to value reform-oriented teaching and conceptual understanding in mathematics, yet all were paired with cooperating teachers who seemed to value traditional instruction and procedural understanding in mathematics. We explored the reasons that some of these student interns had positive experiences with their cooperating teachers and university supervisors while others had negative experiences. We found that the participants valued (a) critical feedback that was constructive and contained concrete recommendations for improvement, (b) freedom to use their own teaching methods, and (c) a friendly and supportive relationship with their mentors. The differing teaching philosophies of student teachers and their cooperating teachers contributed to negative experiences only when student teachers were not allowed freedom in their teaching methods.
Beam steerable semiconductor lasers with large steering range and resolvable spots

A novel method for achieving quasicontinuous broad angle beam steering, based on angling the mirror facets with a dry etching technique, is demonstrated. 80 degrees of far-field scanning with 11 diffraction limited resolvable spots, each independently addressable, is achieved. These represent a three-fold improvement over previous results. >
Multimodal activity in the parietal cortex

Goal-directed behavior can be thought of as dynamic links between sensory stimuli and motor acts. Neural correlates of many of the intermediate events of both auditory and visual goal-directed behaviors are found in the posterior parietal cortex. Here, we review studies that have focused on how neurons in the lateral intraparietal area (area LIP) differentially process auditory and visual stimuli. Together, these studies suggest that area LIP contains a modality-dependent representation that is highly dependent on behavioral context.
f-Element/crown ether complexes. 7. Low temperature (−150 °C) structure of [Y(OH2)8]Cl3·(15-crown-5)

Abstract The crystal and molecular structure of [Y(OH2)8]Cl3·(15-crown-5) has been determined by single-crystal X-ray diffraction at −150 °C. At this temperature the lattice constants (monoclinic, P21/n) are a = 9.126(2), b = 17.104(3), c = 15.237(4) A, β = 92.86(2)°, and Dcalc = 1.56 g cm−3 for Z = 4. A final R value of 0.035 was obtained via least-squares refinement using 3399 independent observed [Fo ⩾ 5σ(Fo] reflections. The [Y(OH2)8]3+ cation is a distorted dodecahedron with average YOH2 separations of 2.39(4) A (type A site) and 2.34(2) A (type B site). The crown ether and the chloride ions are hydrogen bonded to metal coordinated water molecules resulting in a polymeric network. The average HOH⋯O(crown) and HOH⋯Cl− separations are 1.80(8) and 2.15(9) A, respectively.
GAS COMPRESSION USING TEMPERATURE SWING ADSORPTION

For a manned mission to Mars, NASA is interested in providing pure carbon dioxide at close to 1 bar to react with hydrogen to form methane and water. The Martian atmosphere is approximately 95% carbon dioxide, 2.7% nitrogen, 1.6% argon, and 0.7% other compounds at a pressure of about 0.008 bar. If the carbon dioxide is adsorbed at a low temperature and then the system is closed and heated, the pressure will increase because of both desorption and expansion of the gas. Usually the pressure increase due to desorption will be significantly larger than the gas expansion. By operating adsorption systems in series, significantly higher pressures can be obtained. Several systems were designed at a conceptual level for use on Mars as reliable alternatives to a mechanical compressor. Solar energy will be used for heating. Methods to remove most of the impurities during the compression process are explored.
Hereditary Breast and Ovarian Cancer and Other Hereditary Syndromes: Using Technology to Identify Carriers

Purpose and Methods. Most patients who harbor a genetic mutation for hereditary breast cancer have not been identified, despite the availability of genetic testing. Developing an effective approach to the identification of high-risk individuals is the key to preventing and/or providing early diagnosis of cancer in this patient population. This educational review addresses these issues. Results and Discussion. Using data available on the internet, and making assumptions regarding the types and results of genetic testing, we have estimated the number of mutation carriers in the country and the number who have been tested and identified as such. Overall, our ability to fund and more effectively manage carriers is weak. A technological solution is discussed.
A Model for Material Requirements Planning Implementation

A theoretical model for MRP implementation is presented. Much has been written about MRP and its introduction into an organisation, but the low overall success rate of implementation shows the poor level of understanding and control of the implementation process itself. The basic MRP system, its derivatives and the need for a model are discussed. The results of successful implementation such as reduced inventory and improved customer service level are discussed. This model could also be applied to other organisation‐wide systems, such as Just‐in‐Time manufacturing, if modified.
Strategies in assessing the need for updating evidence-based guidelines for six clinical topics: an exploration of two search methodologies

Background: Because of the expense of updating practice guidelines, recent attention has focused on approaches that can reliably assess any updating required. Shekelle et al. (Journal of the American Medical Association 2001, 286, 1461–7) proposed using limited literature searches with expert involvement to reduce resources used in assessing whether a guideline needs updating. Objectives: This study compared Shekelle's method and the traditional systematic review method regarding comprehensiveness and effort. Methods: Two research teams translated critical key questions on screening test treatments and outcomes to Medical Subjects Headings (MeSH) and search strategies. They refined Shekelle's method over three iterations, seeking greater efficiency. Using both methods independently, teams assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services (US Preventive Services Task Force). Outcomes included completeness of study identification, importance of missed studies and effort involved. Results: The revised review approach produced fewer citations than the traditional approach and saved time, identifying fewer eligible studies than the traditional approach. None of the studies missed was rated important by the experts consulted. Conclusions: The revised review approach provides an acceptable method for judging whether a guideline requires updating. Librarians were an integral part of the research process that streamlined the searches.
Computer Generated Holograms In Medicine

Various diagnostic and therapeutic procedures should be considerably enhanced by the presentation of the data from a CT,NMR,PET or ultrasonic scan in holographic form. Initially we demonstrated a holographic presentation using a multiplex white light hologram formed from many x-rays of a cadavre's hand. We have explored various methods of computer generating a hologram and in this paper we report on our method of calculating a Fresnel hologram produced by the superposition of the Fresnel pattern from the individual planes of the CT scan.The limitations of the computer generation of holograms with respect to present and anticipated computer power and recording techniques are presented.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
OVARIAN WEIGHT INCREASE AS AN OBJECTIVE MEASURE FOR ASSAY OF PROLAN

JUDGING BY THE NUMBER of papers on the assay of prolan, present methods have not proven entirely satisfactory. A number of workers have abandoned the assay based on ovarian hypertrophy, which is specific, for the non-specific assay based on uterine hypertrophy in which the changes in weight are of greater absolute magnitude. In an effort to evolve a more suitable assay procedure, the increase in ovarian weight produced by prolan administration is compared in this study under various conditions designed to produce a greater response in absolute weight. Data reported in the literature are compared and analysed as to the relative accuracy of the uterine and ovarian weight procedures. Errors in published ovarian assay procedures. Bischoff and Long (1), D'Amour and D'Amour (2), Chou and Liu (3), and Sealy and Sondern (4) present data for the effect of doubling the dose of prolan upon ovarian hypertrophy in approximately the same ovarian weight range.
Source attribution of personal exposure to airborne polycyclic aromatic hydrocarbon mixture using concurrent personal, indoor, and outdoor measurements.

Abstract Objectives Relative importance of multiple indoor and outdoor venues on personal exposure concentrations to pro-carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) remains poorly understood. This is particularly challenging because many c-PAHs share sources and occur as a complex mixture. Accurate and precise apportionment of personal exposure according to exposure venues could aid in the understanding of human health effects due to a given source. Here, we partitioned indoor and personal exposure concentrations to seven c-PAHs and pyrene according to the indoor- and outdoor-origins. Methods A simultaneous, integrated monitoring of personal, indoor and outdoor concentrations of nine PAHs was conducted in 75 homes for a consecutive 48-hour period across a two-year period in Krakow, Poland. Due to few known indoor sources for chrysene, we used this PAH species as a tracer for infiltration of outdoor PAHs. Personal and indoor concentrations of seven c-PAHs and pyrene were apportioned to home indoor, non-home indoor and outdoor origins. Results Using Chrysene in / Chrysene out as proxy for an infiltration factor, F inf , infiltrated PAHs of outdoor origin are overall higher in concentration than those emitted from the indoor origin. Average contribution by the outdoor sources on B[ a ]A, B[ b ]F, and B[ k ]F were 92%, 79%, and 78% across all seasons, respectively. In contrast, in homes where a household member smoked, average contributions by the outdoor sources on B[ ghi ]P, B[ a ]P, D[ ah ]A, and IP were lower (i.e., 67%, 65%, 67%, and 66%, respectively). Season-averaged contributions by the outdoor sources on personal exposure to B[ a ]A, B[ b ]F, and B[ k ]F were 92%, 74%, and 77%, respectively. On the other hand, season-averaged home indoor source contributions on personal exposure to B[ a ]A, B[ b ]F, and B[ k ]F were estimated at 6%, 15%, and 19%, respectively. Similar contributions by season-averaged home indoor sources on personal exposure were estimated at 28% for B[ ghi ]P, 31% for B[ a ]P, 25% for D[ ah ]A, and 28% for IP. Conclusion Of the seven c-PAHs, B[ a ]A, B[ b ]F, and B[ k ]F are enriched in indoor and personal exposure concentrations from the outdoor coal-combustion. B[ ghi ]P, B[ a ]P, D[ a,h ]A, and IP, PAHs with some of the highest carcinogenic and mutagenic potencies, are considerably enriched by cigarette smoke in addition to the outdoor sources.
Examining the link between salesperson networking behaviors, job satisfaction, and organizational commitment: Does gender matter?

Abstract Sales professionals are embedded in an array of social interactions through their networking behaviors, yet the literature's understanding of these effects on job-based attitudes is relatively limited. Further, research suggests that men and women, not only network differently, but also often benefit in different ways from networking. This study examines the extent to which gender moderates the relationships between three forms of salesperson networking behaviors, job satisfaction, and organizational commitment. The data from a survey of 179 salespeople indicates that networking behaviors are related to job satisfaction and commitment in sales. However, the relationships vary for male and female salespeople. When analyzed separately, job satisfaction relates positively to professional networking for women, while job satisfaction relates positively to peer networking for men. In addition, peer networking directly relates to organizational commitment for women, rather than mediated by job satisfaction.
Functional outcome and the effect of cranioplasty after retromastoid craniectomy for microvascular decompression

BACKGROUND While the efficacy of retromastoid craniectomy for microvascular decompression for hyperactive cranial nerve syndromes is well established, there is no real information regarding the functional outcome of these operations. The purpose of this retrospective questionnaire study is to assess functional outcome regarding presence and duration of postoperative headache, incisional pain, and the time to return to normal activity in patients undergoing retromastoid craniectomy for microvascular decompression. The effect of closure with bone chips or cranioplasty in the defect upon these functional outcomes was studied, as was the influence of the particular nerve that was the object of decompression. METHODS Four-hundred and ninety-five consecutive patients were contacted and 320 (65%) returned questionnaires with enough information to be suitable for analysis. RESULTS The incidence of postoperative headache was initially 60.1%, dropping to 28.8% at 1 month and 16.8% at 6 months. Incisional pain likewise declined with time, noted in 25.8% at 1 month and only 13.1% at 6 months. Use of a cranioplasty made no significant difference in influencing either postoperative headache or incisional pain, nor was the nature of the procedure a significant factor. CONCLUSION Twenty-five percent of patients resumed normal activity by 3 weeks, 50% by 1 month, and 90% by 3 months. Overall, 98% of patients responding reported returning to normal activity. Therefore, although there is an incidence of postoperative headache and incisional pain, these decrease with time and do not seem to interfere with the return to normal activity, nor are they affected by placement of a cranioplasty or the nature of the operation.
Detection of nitric oxide in single cells

Nitric oxide (NO) is endogenously generated by nitric oxide synthase (NOS) enzymes and is involved in a surprisingly wide range of biological functions. As efforts are made to elucidate the regulatory mechanisms of NOS expression and function, there is increasing interest in following NOS activity directly by monitoring NO production. Additionally, spatial and temporal measurements of NO are important for understanding its function and metabolism. In this work, developments in technology enabling NO detection in biological systems are reviewed. Measuring NO at single cell levels is important as NOS is heterogeneously distributed; however, such measurements are difficult as physiological NO levels are in the low nanomolar to low micromolar range. Here, three categories of analytical techniques enabling NO detection at single cell levels are highlighted: fluorescence microscopy, capillary electrophoresis with laser induced fluorescence detection, and electrochemistry. For each, the basic principles, performance, applications, figures of merits and limitations are presented in terms of single cell NO detection.
Dynamic behavior of Li dust in NSTX

A lithium particle dropper was installed on NSTX during the 2008 campaign. Though the primary purpose of the dropper was to study the effects of Li wall conditioning, this experimental configuration also afforded a unique opportunity to study the interaction of dust of a known size and composition with a reactor grade plasma. Li powder was dropped into NSTX at a rate of ∼ 1–35 mg/sec attaining a velocity of ∼ 5 m/s at the plasma boundary. The individual particles rapidly become incandescent due to their interaction with the plasma. Two fast visible cameras, spatially separated by up to 60 degrees, simultaneously viewed the individual particles. Data from the two cameras was used to reconstruct the first detailed 3-D trajectory information of dust in a plasma with a known size, composition and velocity using a 3-D tracking code [1]. These data will be used to further constrain the comparisons to the dust transport codes such as DUSTT used to predict dust behavior in future fusion reactors. Although Li is not presently considered a reactor material, its mass and thus its behavior should be close to that of Be which is a first wall material on ITER.
Fully differential optical interconnections for high-speed digital systems

This work presents the design details and experimental results for a parallel optical link. The link is designed for connections within high-speed digital systems, specifically for board- and backplane-level interconnections. The link can contain as many fibers in parallel as technology permits. The unusual aspects of this interconnection system are that it is DC-coupled and uses fully differential inputs, two optical channels per signal, to achieve self-thresholding and noise immunity. A chip set consisting of a 2.5-Gb/s bipolar differential laser driver, a 800-Mb/s GaAs MSM (metal-semiconductor-metal) preamplifier array, a 800-Mb/s GaAs MSM preamplifier-postamplifier array, and a GaAs MSM preamplifier array in which each preamplifier has a different bandwidth varying from 300 Mb/s to 2 Gb/s has been designed, fabricated, and tested to serve as a vehicle for verifying the concept. Although the experimental testing of the entire interconnect system is not yet complete, the experimental studies presented show a bandwidth in excess of 800 MHz and excellent signal isolation between channels. >
Undercooling of Bulk High Temperature Metals in the 100 Meter Drop Tube

The 100 meter Drop Tube at NASA Marshall Space Flight Center provides an excellent opportunity to study the effects of containerless, microgravity processing in metals and alloys. In a series of experiments high melting temperature pure metals were melted in an electron beam furnace and dropped in vacuum. Sample sizes ranged from 0.175-1.2 grams. Large undercoolings on the order of 18% of the melting temperature were observed in Ti, Zr, Nb, Mo, Rh, Ta, and Pt. Undercoolings of 5-18% Tm were observed in Ru and Ir. These undercooling results are consistent, repeatable, and occur in a high percentage of experiments. The experimental technique will be presented as well as the resultant microstructures of undercooled drops. The data will be discussed with respect to nucleation theory.
Locally excitatory, globally inhibitory oscillator networks: theory and application to scene segmentation

A novel class of locally excitatory, globally inhibitory oscillator networks (LEGION) is proposed and investigated analytically and by computer simulation. The model of each oscillator corresponds to a standard relaxation oscillator with two time scales. The network exhibits a mechanism of selective gating, whereby an oscillator jumping up to its active phase rapidly recruits the oscillators stimulated by the same pattern, while preventing other oscillators from jumping up. We show analytically that with the selective gating mechanism the network rapidly achieves both synchronization within blocks of oscillators that are stimulated by connected regions and desynchronization between different blocks. Computer simulations demonstrate LEGION's promising ability for segmenting multiple input patterns in real time. This model lays a physical foundation for the oscillatory correlation theory of feature binding, and may provide an effective computational framework for scene segmentation and figure/ground segregation.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Configurable Symbol Synchronizer for Digital Systems

This paper provides a comprehensive symbol synchronization architecture for deployment in configurable digital receivers. While this is a well researched topic for static symbol rate conditions, significant work remains to be done in determining how to best implement variable data rates and training sequences while maintaining functionality. The synchronizer architecture is a modified version of the basic analog architecture for DSSS synchronizers making it applicable to both wideband and narrowband signals. A known training sequence is received and synchronized to within a half chip accuracy by delaying the generated sequence by half of a chip every sequence period and comparing the correlation to a set threshold. A delay-locked loop (DLL) uses the difference between early and late correlations to drive fine synchronization process. This process is made configurable with the knowledge of the number of samples per symbol, training sequence, sequence length, data rate, and coarse correlation threshold.
Early Maternal Withdrawal and Nonverbal Childhood IQ as Precursors for Substance Use Disorder in Young Adulthood: Results of a 20-Year Prospective Study

The relation between early mother–infant interaction and later socio-emotional development has been well established. The present study addresses the more recent interest in the impact of maternal caregiving on cognitive development and their role in decision-making in young adulthood. Using data from a prospective longitudinal study on attachment, prediction from early mother–infant interactions at age 18 months and from verbal and nonverbal cognitive skill at age 5 were examined as predictors of a substance use disorder (abuse/dependence) in young adulthood (age 20) on the Structured Clinical Interview for DSM-TV (SCID). Results reveal that the mother's withdrawal from interaction with the infant at age 18 months, coded using the AMBIANCE coding system (Atypical Maternal Behavior Instrument for Assessment and Classification), was associated with the child's lower nonverbal cognitive scores but not verbal cognitive scores at age 5. In addition, maternal withdrawal at 18 months predicted a clinical diagno...
Effect of gradation and source properties on stability and drainability of aggregate bases: a laboratory and field study

A combined laboratory and field study was undertaken to evaluate the effect of gradation on resilient modulus (M R) and falling weight deflectometre (FWD) modulus (M FWD) as measures of stability and coefficient of permeability (k) as an indicator of drainability of aggregate bases. Aggregates from three different sources in Oklahoma and three gradations consisting of M-AASHTO #57, ODOT Type A and OKAA Type M were used. M R and k tests on compacted aggregate specimens were conducted in the laboratory. Also, a 152.4-m long test section was constructed with the aforementioned gradations and FWD and in-situ falling head permeability tests were conducted periodically. Results showed that denser gradations resulted in higher M R and M FWD and lower k values, both in the laboratory and in the field. M FWD and field k values were found to increase and decrease, respectively, with time, possibly due to traffic-induced compaction. Regression models were developed to estimate M R and k in terms of gradation and sou...
AN EVALUATION OF THE RELATIVE QUALITY OF DIKE POOLS FOR BENTHIC MACROINVERTEBRATES IN THE LOWER MISSOURI RIVER, USA†

A habitat-based aquatic macroinvertebrate study was initiated in the Lower Missouri River to evaluate relative quality and biological condition of dike pool habitats. Water-quality and sediment-quality parameters and macroinvertebrate assemblage structure were measured from depositional substrates at 18 sites. Sediment porewater was analysed for ammonia, sulphide, pH and oxidation–reduction potential. Whole sediments were analysed for particle-size distribution, organic carbon and contaminants. Field water-quality parameters were measured at subsurface and at the sediment–water interface. Pool area adjacent and downstream from each dike was estimated from aerial photography. Macroinvertebrate biotic condition scores were determined by integrating the following indicator response metrics: % of Ephemeroptera (mayflies), % of Oligochaeta worms, Shannon Diversity Index and total taxa richness. Regression models were developed for predicting macroinvertebrate scores based on individual water-quality and sediment-quality variables and a water/sediment-quality score that integrated all variables. Macroinvertebrate scores generated significant determination coefficients with dike pool area (R2 = 0.56), oxidation–reduction potential (R2 = 0.81) and water/sediment-quality score (R2 = 0.71). Dissolved oxygen saturation, oxidation–reduction potential and total ammonia in sediment porewater were most important in explaining variation in macroinvertebrate scores. The best two-variable regression models included dike pool size + the water/sediment-quality score (R2 = 0.84) and dike pool size + oxidation–reduction potential (R2 = 0.93). Results indicate that dike pool size and chemistry of sediments and overlying water can be used to evaluate dike pool quality and identify environmental conditions necessary for optimizing diversity and productivity of important aquatic macroinvertebrates. A combination of these variables could be utilized for measuring the success of habitat enhancement activities currently being implemented in this system. Published in 2011 by John Wiley & Sons, Ltd.
Sensitivity for detecting fibrillation potentials: a comparison between concentric and monopolar needle electrodes.

The sensitivity of monopolar and concentric electrodes for detecting fibrillation potentials (FP) has never been formally compared. We studied 35 muscles with FP, sampling 20 sites each with concentric and monopolar needles. The concentric needle identified 0.88 +/- 3.44 (mean +/- standard deviation) more sites with spontaneous activity. Although statistically significant (Wilcoxon signed rank test P less than .03), this difference in sensitivity did not appreciably affect diagnostic interpretation. Subjects described the concentric needles as more painful. Needle insertions in 25 other muscles demonstrated that needle movement generated the majority of FP. We suggest that the increased tissue injury caused by concentric needles may account for both their increased sensitivity and discomfort.
Switching between microtubule- and actin-based transport systems in melanophores is controlled by cAMP levels.

Abstract Background: Intracellular transport involves the movement of organelles along microtubules (MTs) or actin filaments (AFs) by means of opposite-polarity MT motors or actin-dependent motors of the myosin family. The correct delivery of organelles to their different destinations involves a precise coordination of the two transport systems. Such coordination could occur through regulation of the densities of the two cytoskeletal systems or through regulation of the activities of the cytoskeletal motors by signaling mechanisms. Results: To investigate the mechanisms of switching between MT and AF-dependent transport, we examine the influence of the densities of the MT and AF network on pigment transport in fish melanophores. We also change signaling by using activators and inhibitors of Protein Kinase A (PKA). We find that the key parameters characterizing pigment granule transport along MTs do not depend on MT density and are not significantly altered by complete disruption of AFs. In contrast, the kinetics of changes in these parameters correlate with the kinetics of changes in the intracellular levels of cAMP and are affected by the inhibitors of PKA, suggesting the regulation of MT- and AF-dependent motors by cAMP-induced signaling. Furthermore, perturbation of cAMP levels prevents the transfer of pigment granules from MTs onto AFs. Conclusions: We conclude that the switching of pigment granules between the two major cytoskeletal systems is independent of the densities of MT or AF but is tightly controlled by signaling events.
Case report of gastric outlet obstruction from metastatic lobular breast carcinoma

The most common malignancy to cause gastric outlet obstruction is primary gastric adenocarcinoma and it is followed by carcinoma of the pancreas and gallbladder. Herein, we report a case of gastric outlet obstruction secondary to metastatic lobular breast carcinoma. Fifty-seven year old Caucasian female with recently diagnosed metastatic lobular breast carcinoma to skin was referred to gastroenterology for evaluation of dyspepsia and dysphagia. She has past medical history significant for acid reflux and Clostridium difficile colitis. Computed tomography of her abdomen showed diffused bowel wall thickening without evidence of bowel obstruction. Due to persistent abdominal pain, an upper endoscopy was performed. The upper endoscopy showed gastritis and gastric stenosis in the gastric antrum. These lesions were biopsied and dilated with a balloon dilator. The biopsy of the gastric antrum later showed a metastatic carcinoma of breast origin with typical tumor morphology and immune-phenotype. Differentiating metastatic breast carcinoma from primary gastric adenocarcinoma cannot be done using histological examination alone. Immunohistochemistry is needed to differentiate the two based on staining for estrogen and progesterone receptors. The presence of gross cystic disease fluid protein 15 is also suggestive of metastatic breast carcinoma. The stomach has a significant capacity to distend (up to 2–4 L of food) and malignant gastric outlet obstruction is often undetected clinically until a high-grade obstruction develops. Our case demonstrates valuable teaching point in terms of broadening our differentials for gastric outlet obstruction. When patients present with gastric outlet obstruction, both non-malignant and malignant causes of gastric outlet obstruction should be considered. Once adenocarcinoma has been determined to be the cause of gastric outlet obstruction, further immunohistochemistry is needed to differentiate breast carcinoma from other carcinomas.
Bacterial Quorum Sensing: Its Role in Virulence and Possibilities for Its Control

Quorum sensing is a process of cell-cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly. This process enables bacteria to express energetically expensive processes as a collective only when the impact of those processes on the environment or on a host will be maximized. Among the many traits controlled by quorum sensing is the expression of virulence factors by pathogenic bacteria. Here we review the quorum-sensing circuits of Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Vibrio cholerae. We outline these canonical quorum-sensing mechanisms and how each uniquely controls virulence factor production. Additionally, we examine recent efforts to inhibit quorum sensing in these pathogens with the goal of designing novel antimicrobial therapeutics.
Spirochetes in atrophic skin lesions accompanied by minimal host response in a child with Lyme disease

Acrodermatitis chronica atrophicans, which has rarely been observed in the United States, is a late skin manifestation of Lyme borreliosis. A 12-year-old girl who spent summers on Cape Cod presented with a 2-year history of hyperpigmentation and atrophy of the skin on the hands, wrists, and ankles. The skin biopsy specimen of an affected area showed mild dermal fibrosis, a few inflammatory cells, and spirochetes morphologically compatible with Borrelia burgdorferi . An IgG antibody response to B. burgdorferi could be elicited by immunoblotting, but not by enzyme-linked immunosorbent assay. We conclude that this patient had chronic Lyme borreliosis manifested only by indolent infection of the skin.
Perspectives on Self-Care

Self-care for clinicians is much needed. To discover ways to implement self-care into our lives, we (four therapists) tried different self-care methods over a span of one to two weeks. After using practices that explored self-care through mindfulness meditation, autohypnosis, music, and spirituality, we wrote about the outcome of these experiences on our personal lives and our interactions with clients. From a personal perspective, we discussed the need to guard against burnout. Our experiences produced concrete ways to focus on our own needs in the midst of complex and demanding lives. Finally, we discussed how our methods could be applied to clinical work and the need for future research on self-care for clinicians.
Hierarchical and variational geometric modeling with wavelets

This paper discusses how wavelet techniques may be applied to a variety of geometric modeling tools. In particular, wavelet decompositions are shown to be useful for hierarchical control point or least squares editing. In addition, direct curve and surface manipulation methods using an underlying geometric variational principle can be solved more efficiently by using a wavelet basis. Because the wavelet basis is hierarchical, iterative solution methods converge rapidly. Also, since the wavelet coefficients indicate the degree of detail in the solution, the number of basis functions needed to express the variational minimum can be reduced, avoiding unnecessary computation. An implementation of a curve and surface modeler based on these ideas is discussed and experimental results are reported.
BROWN‐HEADED COWBIRD BEHAVIOR AND MOVEMENTS IN RELATION TO LIVESTOCK GRAZING

The Brown-headed Cowbird (Molothrus ater) is a widespread brood parasite which often engages in a commensalistic feeding relationship with domestic livestock. We studied the behavior of female cowbirds breeding in pinyon–juniper woodlands in New Mexico, USA, on two adjacent sites, one an active cattle ranch, and the other a site that was not grazed by domestic livestock throughout the songbird breeding season. In 1994, we conducted morning and afternoon surveys of cowbird abundance in pinyon–juniper and prairie habitats; from 1995 to 1997 we used radio telemetry to monitor daily and seasonal movement and behavioral patterns of female cowbirds. Our objectives were to measure how closely cowbird feeding behavior was linked to livestock grazing, and how the presence or absence of active livestock grazing within a female's breeding range influenced diurnal patterns of behavior. During morning surveys, we detected cowbirds primarily in pinyon–juniper habitat, but in similar numbers in the ungrazed and actively...
A comparison of two spectral wave models in the Southern California Bight

Abstract Two models, a spectral refraction model (Longuet-Higgins) and a parabolic equation method (PEM) refraction-diffraction model (Kirby), are used to simulate the propagation of surface gravity waves across the Southern California Bight. The Bight contains numerous offshore islands and shoals and is significantly larger (≈ 300 km by 300 km) than regions typically studied with these models. The effects of complex bathymetry on the transformation of incident wave directional spectra, S0(f,θ0), which are very narrow in both frequency and direction are difficult to model accurately. As S0(f,θ0) becomes broader in both dimensions, agreement between the models improves and the spectra predicted at coastal sites become less sensitive to errors in the bathymetry grid, to tidal changes in the mean water depth, and to uncertainty in S0(f,θ0) itself. The smoothing associated with even relatively narrow (0.01 Hz-5° bandwidth) S0(f,θ0) is usually sufficient to bring the model predictions of shallow water energy into at least qualitative agreement. However, neither model is accurate at highly sheltered sites. The importance of diffraction degrades the predictions of the refraction model, and a positive bias [O (10%) of the deep ocean energy] in the refraction-diffraction model estimates, believed to stem from numerical “noise” (Kirby), may be comparable to the low wave energy. The best agreement between the predicted spectra generally occurs at moderately exposed locations in deeper waters within the Bight, away from shallow water diffractive effects and in the far-field of the islands. In these cases, the differences between the models are small, comparable to the errors caused by tidal fluctuations in water depth as waves propagate across the Bight. The accuracy of predicted energies at these sites is likely to be limited by the uncertainty in specifying S0(f,θ0).
Integrated video interface technology

Technology finally permits high-end consumer systems to accept, store, and display broadcast-quality signals cost-effectively. Mixed-signal design challenges include low-noise preprocessing and clean reconstruction of the video signal, plus real-time visual evaluation of image artifacts. This paper reviews the design, architecture and performance of a video input/output chipset which can digitize, decompose, mix, and synthesize NTSC and PAL television signals.
Narrow-Band Synchrotron Radiation Excitation of Soft X-Ray Emission Spectra,

Monochromatized synchrotron radiation has been employed as the excitation source for soft x-ray emission spectroscopy. In the present paper changes in the emission spectra that occur as the excitation energy is varied near the core-absorption threshold are discussed. In the case of crystalline silicon, strong variations are seen in the L2,3 emission for excitation energies up to 30 eV above threshold. These variations are shown to be dependent on the crystalline order of the material and can be interpreted in terms of restrictions on the crystal momentum that arise in an inelastic scattering description of the combined absorption and emission. On the other hand this description is less relevant to the excitation-energy dependence of ionic insulators, in which strong phonon coupling removes these restrictions on crystal momentum. In the insulators B2O3 and BN strong variations in the emission are observed at threshold, upon creation of a core exciton: the exciton affects the emission through its influence on the phonon coupling as well as on the initial and final-state screening.
Applications of truncated QR methods to sinusoidal frequency estimation

Three truncated QR methods are proposed for sinusoidal frequency estimation: (1) truncated QR without column pivoting (TQR); (2) truncated QR with pre-ordered columns, (TQRR); and (3) truncated QR with column pivoting (TQRP). It is demonstrated that the benefit of truncated singular value decomposition (TSVD) for high-frequency resolution is achievable under the truncated QR approach with much lower computational cost. Other attractive features of these methods include the ease of updating, which is difficult for the SVD method, and numerical stability. Thus, the TQR methods offer efficient ways for identifying sinusoidals closely clustered in frequencies under stationary and nonstationary conditions. Based on the forward-backward linear prediction model, computer simulations and comparisons are provided for different truncation methods under various signal-to-noise ratios. >
Women More than Men Attend to Indicators of Good Character: Two Experimental Demonstrations

Past research implicates adaptations in women to assess men's willingness to invest in offspring (La Cerra, 1995). In two new studies, women's evaluations of an opposite-sex target as a long-term p...
EEG maturation and stability of cerebral oxygen extraction in very low birth weight infants

Fractional cerebral tissue oxygen extraction (FTOE) can be continuously monitored by simultaneous near-infrared spectroscopy (NIRS) and pulse oximetry. The objective of this study is to test the hypothesis that in very low birth weight (VLBW) infants, the more mature EEG activity is, the less variable FTOE is. A prospective study was conducted on VLBW infants (<1500 g and ⩽34 weeks gestation) without significant brain injury. Simultaneous continuous two-channel electroencephalography (EEG), NIRS and pulse oximetry were recorded. Absolute and relative powers of EEG in the delta, theta, alpha, beta and total frequency bands have been calculated. FTOE variability was calculated on two scales: short scales (3 to 20 s) and long scales (20 to 150 s). FTOE variability was examined against changes in relative spectral power of different EEG bands. We evaluated 67 studies performed on 46 VLBW infants. Average study duration was 21.3±5.5 h. Relative power of delta band positively correlated with FTOE short- and long-scale variability (r=0.45, P<0.001; r=0.44, P<0.001, respectively). Relative power of alpha bands negatively correlated with FTOE short- and long-scale variability (r=−0.38, P=0.002; r=−0.42, P<0.001, respectively). These correlations continued to be significant when controlling for sex, small for gestational age, postmenstrual age, being on respiratory support, hemoglobin concentration, systemic oxygen saturation and transcutaneous carbon dioxide tension. Increased maturation of EEG activity is associated with decreased variability in cerebral oxygen extraction. The implications of increased variability in FTOE on brain injury in premature infants need further exploration.
Early development of the Drosophila mushroom body: the roles of eyeless and dachshund.

The mushroom body (MB) is a uniquely identifiable brain structure present in most arthropods. Functional studies have established its role in learning and memory. Here we describe the early embryonic origin of the four neuroblasts that give rise to the mushroom body and follow its morphogenesis through later embryonic stages. In the late embryo, axons of MB neurons lay down a characteristic pattern of pathways. eyeless (ey) and dachshund (dac) are expressed in the progenitor cells and neurons of the MB in the embryo and larva. In the larval brains of the hypomorphic ey(R) strain, we find that beside an overall reduction of MB neurons, one MB pathway, the medial lobe, is malformed or missing. Overexpression of eyeless in MBs under the control of an MB-specific promoter results in a converse type of axon pathway abnormality, i.e. malformation or loss of the dorsal lobe. In contrast, loss of dachshund results in deformation of the dorsal lobe, whereas no lobe abnormalities can be detected following dachshund overexpression. These results indicate that ey and dachshund may have a role in axon pathway selection during embryogenesis.