cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural Studies of Nonclassical Cyclobutylmethyl Cations by the ab initio Method

Ab initio calculations at the MP2/cc-pVTZ level show that the cyclobutylmethyl cation is a nonclassical sigma-delocalized species, which is distinct from the global minimum C2-symmetric cyclopentyl cation (Schleyer, P. v. R.; Carneiro, J. W. de M.; Koch, W.; Raghavachari, K. J. Am. Chem. Soc. 1989, 111, 5475). Relatively lower level DFT calculations, on the other hand, show that the primary cyclobutylmethyl cation spontaneously collapses into the cyclopentyl cation (Prakash, G. K. S.; Reddy, V. P.; Rasul, G.; Casanova, J.; Olah, G. A. J. Am. Chem. Soc. 1998, 120, 13362). The secondary 1-cyclobutylethyl cation is also a nonclassical carbocation, as shown by calculations at the MP2/cc-pVTZ level. Two structures having energy minima are identified for the latter cation on the potential energy surface. The conformer in which the methyl group is in the exo orientation is a global minimum and is favored over the corresponding endo conformer by 1.2 kcal/mol at the MP2/cc-pVTZ//MP2/cc-pVTZ +ZPE level of calculations. The tertiary 1-cyclobutyl-1-methylethyl cation, at this level of calculations, also involves substantial nonclassical sigma-delocalization, showing that the nonclassical stabilization is more important for cyclobutylmethyl cations relative to the cyclopropylmethyl cations. The 13C NMR chemical shifts obtained from GIAO-CCSD(T)/tzp/dz calculations further substantiate the nonclassical structures for these carbocations.
Regulation of atrial natriuretic factor receptors in portal hypertensive rabbits

Abstract Background/Aims: Portal hypertension is characterized by a marked splanchnic hyperemia due to a reduction in mesenteric vascular resistance. Possible mediators of this decreased resistance include an increased amount of and/or responsiveness to vasodilatory substances. Previous studies have demonstrated an enhanced hypotensive effect of exogenous atrial natriuretic factor in portal hypertension. We hypothesized that changes in the atrial natriuretic factor hormone receptor system may contribute to this response and hence underlie the marked hyperemia of portal hypertension. Methods: We used a portal-vein-ligated rabbit model of portal hypertension to study the integrity of the atrial natriuretic factor receptor system within the hyperemic vasculature. Results: There was no significant difference in the serum concentrations of sodium, potassium, atrial natriuretic factor, ANG-II, cGMP, serum osmolality, or hematocrit between normal and portal hypertensive rabbits. Superior mesenteric artery, thoracic aorta and portal vein atrial natriuretic factor receptor number and affinity were determined using [ 125 I]-rANF 99–126 binding analysis and affinity cross-linking studies. Receptor classification using specific atrial natriuretic factor-C receptor ligands, along with affinity cross-linking studies revealed two receptor subtypes present on these vessels. There was a significant decrease in the number of atrial natriuretic factor receptors in the portal vein and a significant increase in the superior mesenteric artery in portal hypertension without any significant change in affinity. Thoracic aortic atrial natriuretic factor receptors were increased with a concurrent decrease in affinity in portal hypertension. There was a concomitant increase in tissue cGMP levels within the superior mesenteric artery and thoracic aorta of portal hypertensive animals but not the portal vein. Conclusion: These data suggest the increased number of functional atrial natriuretic factor receptors may in part contribute to the hyperdynamic splanchnic circulation peculiar to portal hypertension.
Lectins and the soybean-Rhizobium symbiosis: I. Immunological investigations of soybean lines, the seeds of which have been reported to lack the 120 000 dalton soybean lectin

Seeds of six soybean lines (Glycine max (L.) Merr. cv. Columbia, D68-127, Norredo, Sooty, T-102, Wilson 5) have been reported to lack the 120 000 dalton soybean lectin. Immunodiffusion and radioimmunoassay using anti-soybean lectin immunoglobulin failed to detect the lectin in seeds of five lines, but D68-127 seeds contained as much soybean lectin as the control line, Harosoy 63. The D68-127 seed lectin could be purified by affinity chromatography on Sepharose-N-caproylgalactosamine, and was indistinguishable from the conventional soybean lectin by the following criteria: electrophoretic migration in acidic and alkaline buffers, subunit molecular weight and composition, analytical isoelectric focusing, gel filtration chromatography. Phosphate-buffered saline extracts of roots, hypocotyls, stems, and leaves of 3--66-day-old Norredo and Harosoy 63 plants lacked soybean lectin, as determined by hemagglutination and radioimmunoassay (detection limit: 1.4 micrograms soybean lectin/g dry weight tissue). Cotyledons of Harosoy 63 (but not Norredo) contained large quantities of the lectin, which diminished as the plants aged. 5-day-old roots and hypocotyls of 20 soybean lines did not contain soybean lectin. Roots of Columbia, Norredo, Sooty, T-102, Wilson 5, and Harosoy 63 (control) were nodulated by a variety of strains of Rhizobium japonicum and Rhizobium sp.
Online Knowledge Sharing Among Chinese and American Employees: Explore the Influence of National Cultural Differences

This study investigates what are the national cultural factors that influence employeesâ€™ cross-cultural knowledge sharing in online environments and in what way. The article draws on findings from 41 in-depth interviewees conducted with 20 Chinese and 21 American employees who worked for a large multinational corporation. The rich interview data identified three national cultural differences that impacted Chinese and American participantsâ€™ knowledge sharing through an online system, namely, language, differences grounded in collectivism/individualism, and different levels of uncertainty avoidance. English created a barrier for Chinese users to post their ideas, but it did not seem to stop them from consuming knowledge. Differences grounded in collectivist/individualist values were mainly reflected in these two cultural groupsâ€™ different logic regarding the relationship between different working contexts and the necessity to share. Chinese also showed a higher level of uncertainty avoidance than Americans. Together these cultural differences could explain why Chinese shared knowledge less frequently than their American peers. Despite these reported cultural differences, findings from this research suggest that the actual cultural differences were smaller than what literature would predict. Possible explanations for fewer cultural differences are explored. Practical implications for knowledge management practitioners are also provided.
Autonomous Actors or Faithful Agents

Delegation and Agency in International Organizations. Edited by Darren G. Hawkins, David A. Lake, Daniel L. Nielson, Michael J. Tierney Cambridge: Cambridge University Press, 2006. 424 pp., $80.00 cloth (ISBN: 0-521-86209-4), $34.99 paper (ISBN: 0-521-68046-8). Darren Hawkins, David Lake, Daniel Nielson, and Michael Tierney open Delegation and Agency in International Organizations by sketching two metaphors that capture contradictory popular understandings of international organizations (IOs). For some, contemporary international organizations are “institutional Frankensteins terrorizing the global countryside” (p. 4). For others, they are little more than willing tools of their creators. This distinction frames the book, which is divided into two main sections. The first examines “when and why … states delegate to an IO and what sets of rules govern that interaction” (p. 5). The second focuses on the sources of IO behavior after they are established as well as the ability of states to anticipate potential problems and maintain control. To gain leverage over these questions, Hawkins, Lake, Nielson, Tierney and their contributors turn to principal-agent theory, arguing that it is equally relevant for international relations as it is for domestic politics. Given that principal-agent theory has been less prominent in international relations than in the study of US politics, the volume's most immediate contribution may lie in the Introduction's comprehensive and clear elaboration of the principal-agent framework. Hawkins, Lake, Nielson, and Tierney explain that “to be a principal, an actor must be able to both grant authority and rescind it” (p. 7). Furthermore, delegation involves “a conditional grant of authority from a principal to an agent ” (p. 7, italics in the original). The editors define “agency slack” (unwanted independent action by an agent) as a potential problem with any delegation. They distinguish two forms of slack: shirking (in which an agent minimizes effort) and slippage (in …
Hyperoxia and Inhaled NO: Evidence for Extracellular Matrix Damage† 1646

Inhaled nitric oxide (NO) is now established as a selective pulmonary vasodilator. Toxicity potential of NO however remains a great concern. The postulated injurious mechanisms include NO-induced activation of matrix metalloproteinases (MMP) with consequent breakdown of the alveolar extracellular matrix. Endothelin-1 (ET-1) is reportedly a marker of acute pulmonary injury. 8-Isoprostanes are lipid peroxidation products of oxyradical-induced cell membrane injury. We hypothesized that lung lavage fluid from animals exposed to hyperoxia and NO will show increased laminin and hydroxyproline contents as early markers of alveolar capillary basement membrane and matrix breakdown. Additionally, we reasoned that lung lavage fluid ET-1 and 8-isoprostane concentration will correlate with laminin and hydroxyproline concentration. To test this hypothesis, we designed the following study. Twenty-eight newborn piglets were randomized into four exposure groups to breathe for five days in a 200-liter exposure chamber. The groups were (i) room air (RA), (ii) RA+50 ppm NO, (RA+NO), (iii) hyperoxia(FiO2≥0.96) (O2), and (iv) hyperoxia + 50 ppm NO(O2+NO). Lung lavage fluid was obtained and analyzed by ELISA to quantitate laminin, ET-1, and 8-isoprostane concentrations. Lavage fluid hydroxyproline was measured by a colorimetric method. Mean hydroxyproline levels were about twenty fold higher in the O2 and O2 + NO group as compared to other groups. ET-1 concentration was higher in the O2 + NO group than in any other group (P <.02). Lung lavage fluid Laminin and 8-Isoprostane concentration did not differ significantly amongst the groups. We conclude, hyperoxia alone or in combination with 50 ppm NO increases lung lavage fluid hydroxyproline levels. This may reflect increased extracellular matrix breakdown. NO did not exacerbate nor ameliorate this effect of oxygen. Elevated ET-1 concentration may reflect inflammatory induction and airway hyperreactivity.
Chromosomes in Sphaeralcea and Related Genera

The chromosome number has been determined for 15 species and 15 subspecies, representing 10 of the 12 sections of the subgenus Eusphaeralcea. The basic chromosome number is 5. The occurrence of 5, 10 and 15 pairs is frequent, but only one form with 25 pairs has been found. No form having 20 pairs has been discovered as yet.Among approximately 275 plants examined, 22 were judged, from their morphological characters, to have originated as natural hybrids. Four of these apparent hybrids exhibited chromosome irregularities typical of F1 hybrids, 5 showed irregularities such as are characteristic of segregating hybrid generations, and 13 showed normal meiotic behavior.Six species and one subspecies of the related genus Malvastrum (subgenus Malacothamnus) were found to have 17 pairs of ehromosomes.Of forms usually referred to Sphaeralcea, S. rivularis (subgenus Iliamna) has 33 pairs of chromosomes and S. umbellata (subgenus Meliphlea), and S. abutiloides (subgenus Phymosia) have 17 pairs.The basic chromosome number of 5 in Eusphaeralcea is the lowest yet reported in the Malvaceae, and indicates that there is insufficient evidence that the ancestral basic number for the family is 7. The polyploid series 5, 10, 15 and 25 pairs is of exceptional interest, since it occurs in the wild and is the largest series known in the family.In Eusphaeralcea no relation is apparent between the chromosome number and the taxonomy of the group. The frequent occurrence of natural hybrids and their meiotic behavior, indicate a rather closely related group of species.The chromosome number of the subgenus Malacothamnus of Malvastrum clearly separates this group from Sphaeralcea. The chromosome numbers of S. rivularis, S. umbellata and S. abutiloides indicate that the genera Iliamna, Meliphlea and Phymosia may be well founded.
Receiver operating characteristic analysis for the detection of simulated microcalcifications on mammograms using hardcopy images.

The aim of this study was to compare mammography systems based on three different detectors—a conventional screen–film (SF) combination, an a-Si/CsI flat-panel (FP)-based detector, and a charge-coupled device (CCD)-based x-ray phosphor-based detector—for their performance in detecting simulated microcalcifications (MCs). 112–150 µm calcium carbonate grains were used to simulate MCs and were overlapped with a slab phantom of simulated 50% adipose/50% glandular breast tissue-equivalent material referred to as the uniform background. For the tissue structure background, 200–250 µm calcium carbonate grains were used and overlapped with an anthropomorphic breast phantom. All MC phantom images were acquired with and without magnification (1.8X). The hardcopy images were reviewed by five mammographers. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed, and the areas under the ROC curves (Azs) were used to compare the performances of the three mammography systems under various conditions. The results showed that, with a uniform background and contact images, the FP-based system performed significantly better than the SF and the CCD-based systems. For magnified images with a uniform background, the SF and the FP-based systems performed equally well and significantly better than the CCD-based system. With tissue structure background and contact images, the SF system performed significantly better than the FP and the CCD-based systems. With magnified images and a tissue structure background, the SF and the CCD-based systems performed equally well and significantly better than the FP-based system. In the detection of MCs in the fibroglandular and the heterogeneously dense regions, no significant differences were found except that the SF system performed significantly better than the CCD-based system in the fibroglandular regions for the contact images.
Comparing three-dimensional Bayesian segmentations for images with low signal-to-noise ratio (SNR<1) and strong attenuation

This paper examines three Bayesian statistical segmentation techniques with an innovative attenuation compensation on synthetic data and breast ultrasound medical images. All use expectation maximization for estimating the Gaussian model parameters and segment the data using a three-dimensional (3-D) Markov random field pixel neighborhood. This paper compares three Bayesian segmentation techniques: maximum a posteriori simulated annealing (MAP-SA), MAP iterated conditional modes (MAP-ICM), and maximization of posterior marginals (MPM). We conclude that because of the high speckle noise and adverse attenuation challenges of breast ultrasound, the MPM algorithm has the best performance. This is due to better localized segmentation than the other MAP techniques. We present results first with synthetic images then with breast ultrasound. Our new contributions for a 3-D breast ultrasound produce improved results using a model of the noise, in which the Gaussian mean is proportional to the image attenuation with depth, combined with a new prior probability model.
Effects of aripiprazole and terguride on dopamine synthesis in the dorsal striatum and medial prefrontal cortex of preweanling rats

The purpose of this study was to determine whether aripiprazole, a D2-like partial agonist increasingly prescribed to children, alters DA synthesis via actions at autoreceptors in the dorsal striatum and medial prefrontal cortex (mPFC) of preweanling rats. The ability of dopaminergic agents to alter DOPA accumulation in the striatum and mPFC was measured after NSD-1015 on postnatal day (PD) 20. Dopaminergic tone was manipulated by administering reserpine, gamma-butyrolactone (GBL), or through amphetamine withdrawal. Results showed that the partial agonists aripiprazole and terguride increased striatal DOPA accumulation under normosensitive conditions, but decreased DOPA accumulation in states of low dopaminergic tone. A different pattern of results was observed in the mPFC, because terguride and haloperidol, but not aripiprazole, increased DOPA accumulation under normosensitive conditions. In conclusion, the present data show that aripiprazole affects striatal synthesis modulating autoreceptors in an adult-typical manner during the late preweanling period. Unlike in adult rats, however, the mPFC of preweanling rats appears to contain transitory synthesis modulating autoreceptors that are sensitive to drug manipulation.
Eddy fluxes and sensitivity of the water cycle to spatial resolution in idealized regional aquaplanet model simulations

A multi-scale moisture budget analysis is used to identify the mechanisms responsible for the sensitivity of the water cycle to spatial resolution using idealized regional aquaplanet simulations. In the higher resolution simulations, moisture transport by eddy fluxes dry the boundary layer enhancing evaporation and precipitation. This effect of eddies, which is underestimated by the physics parameterizations in the low-resolution simulations, is found to be responsible for the sensitivity of the water cycle both directly, and through its upscale effects on the transport of mean moisture by the mean circulation. Correlations among moisture transport by eddies at adjacent ranges of scales provides a potential for reducing this sensitivity by representing the unresolved eddies by their marginally resolved counterparts.
Evaluation of an automated on-line method for generating calibration curves in inductively coupled plasma atomic emission spectrometry

A high-performance liquid chromatography pump (HPLC) is used for the computer-controlled on-line generation of calibration standards in inductively coupled plasma-atomic emission spectrometry. Such a pump, employed as a solution-delivery device, is well suited for feeding a nebulizer, since it is capable of delivering a range of constant flows and of mixing selected stock solutions or solvents automatically; this capability translates into the capacity to dilute stock or sample solutions and to introduce the resulting mixtures at constant flow into any of a number of nebulizers. Further, the range of useful nebulizers is broadened, since the mixture is supplied under high pressure. This feature makes the method especially useful for devices such as the jet-impact nebulizer (JIN), which requires a pressurized, constant feed. At present, the principal limitation of the new approach is the flow resolution of available HPLC pumps. Although this limitation does not ordinarily cause difficulties in schemes for automatic dilution or calibration, it can be a serious shortcoming if the apparatus is to be used for automated standard-additions analysis.
Ranges and Straggling Coefficients of Alpha-Particles

A review and evaluation of the analytical and graphical methods customarily applied in range determinations reveals several types of errors that frequently have been overlooked. Of particular importance are the area and error effects. The extrapolated range is shown to be subject to other errors and it is concluded, therefore, that the mean range is much the best measure of range. A method of analysis which takes into account these errors is developed and applied to a set of polonium data. The experimental straggling coefficient is only 13 percent greater than the Bethe-Williams theoretical value and 20 percent greater than the Bohr value.
Two-Dimensional Circulation in Straits

A two-dimensional model for a stratified strait of constant width and variable depth is developed. The model describes the density distribution and the longitudinal gravitational circulation maintained by imposed density differences between adjacent seas, by surface slope and by tangential wind stress. The effects of vertical mixing and longitudinal advection for mass and momentum are included in the model. A similarity solution requiring power law dependence for the bottom slope and for longitudinal variations of all functions is obtained. The theoretical calculations are in reasonable agreement with observations in the Bosphorus and other straits. The model shows that, due to the vertical entrainment processes, the water masses become thinner while approaching the downstream ends.
On the width-amplitude inequality of electron phase space holes

[1] Electron phase space holes are analyzed in terms of solitary-wave solutions to the nonlinear Vlasov-Poisson equations in a collisionless plasma. Width-amplitude relations for one-dimensional and three-dimensional electron holes are derived to be inequalities that allow existence of the holes in regions to one side of a bound. The theoretical origin of the width-amplitude inequality is elucidated to show that the inequality nature is independent of specific functional forms of the solitary potential and ambient plasma distribution functions. Ion dynamics and effects of finite hole velocity and finite perpendicular size are subsequently included. Finally, we show that the electron holes reported by Franz et al. (2005) populate an allowed region in the solution space that is significantly away from the bounding curve. These electron holes evidence the accessibility of electron holes whose widths and amplitudes are only loosely constrained and open up the possibility of spontaneous generation of phase-space holes in turbulent fluctuations.
Multiple exposure to activity anorexia in rats: effects on eating, weight loss, and wheel running.

Abstract Animals were given five cycles of an activity anorexia (AA) procedure in order to determine the effect of additional experience on eating, running, and weight loss. Female Sprague–Dawley rats were given a 1 h meal and allowed access to a running wheel for the remainder of each day. Upon reaching 75% of free-feeding body weight, each animal was denied wheel access and given ad libitum food until it regained the lost weight. Then, food was again restricted and wheel access provided. Sedentary control animals were placed on the restricted feeding schedule for the median number of days experimental animals required to reach weight loss criterion. Experimental animals showed adaptation by increasing food consumption and decreasing the rate of weight loss despite an increase in running across cycles. Additionally, the distribution of running shifted gradually so that during the later cycles, much of the running occurred in the hours just before feeding. The results support the hypothesis that running interferes with adaptation to the restricted feeding schedule and also that the marked increase in anticipatory behavior during the later cycles is primarily responsible for the maintenance of AA.
Quantitative cerebral perfusion using dynamic susceptibility contrast MRI: evaluation of reproducibility and age- and gender-dependence with fully automatic image postprocessing algorithm.

A novel approach for quantifying cerebral blood flow (CBF) is proposed that combines the bookend technique of calculating cerebral perfusion with an automatic postprocessing algorithm. The reproducibility of the quantitative CBF (qCBF) measurement in healthy controls (N = 8) showed a higher intraclass correlation coefficient (ICC) and lower coefficient of variation (COV) when calculated with automatic analysis (ICC/COV = 0.90/0.09) than when compared to conventional manual analysis (ICC/COV = 0.58/0.19). Also, the reproducibility in patients (N = 25) was successfully evaluated with the automatic analysis (ICC/COV = 0.81/0.14). In 175 consecutive clinical scans, we found 3.0% and 7.4% of qCBF decrease per decade in white matter (WM) (21.5 ± 6.66 ml/100 g-min) and gray matter (GM) (49.6 ± 16.2 ml/100 g-min), respectively. Cerebral blood volume (CBV) showed a significant 3.7% decrease per decade in GM (3.00 ± 0.94 ml/100 g) but not in WM (1.69 ± 0.40 ml/100 g). Mean transit time (MTT) increased by 1.9% and 3.8% per decade in WM (5.04 ± 0.88 s) and GM (4.14 ± 0.80 s), respectively. qCBF and MTT values between males (N = 85) and females (N = 90) were significantly different in GM. Women showed 11% higher qCBF as well as a higher decrease in qCBF with increasing age than men in the whole brain (WB). Our results supported the notion that population average empirical quantification of cerebral perfusion is subject to individual variation as well as age- and gender-dependent variability. Magn Reson Med, 2007. © 2007 Wiley-Liss, Inc.
Signal processing considerations in power management applications

Abstract As with many other applications, power management systems are improving due to the use of ASICs containing DSP circuits. The ICs used in these applications contain sufficient computing power to determine high current conditions and measure power as well as perform other functions of interest. The programmability and flexibility of these ICs have caused them to be widely used since the same IC can serve an entire product line of power management products. At the heart of these devices are signal processing methods which allow them to be technically and economically feasible. From the Δ−Σ A/D converters, which allow devices to be fabricated in an inexpensive CMOS process, to the complex digital signal processing used in power metering, signal processing plays a significant role in realizing these devices.
Pediatrician or Professional Athlete? Gender, Ethnicity, and Occupational Aspirations of Urban Adolescents

This study compared the occupational aspirations of beginning high school students by gender and ethnicity, and examined the relationship between the educational demands of the occupations desired by students and their academic performance before and after entering high school. Desired occupations were obtained from 662 entering 9th-grade students in a large urban district, and linked to General Educational Demand ratings and to student grades. Young women were more likely than young men to aspire to professional occupations and to occupations requiring more education. The educational demands associated with students' aspirations accounted for about 3% of variance in grades. Educational demands of desired jobs were highest across all groups for Latina young women and lowest for Latino young men. Forty-one percent of African American young men aspired to be professional athletes, but this aspiration was not associated with grade point average before or after entering high school.
7115 A multidisciplinary overview of colitis.

Inflammation of the colon can be caused by a variety of diseases. While the clinical presentation may suggest colitis, further evaluation by radiology, endoscopy and surgical pathology is usually necessary to make a specific diagnosis. BACKGROUND: For the past nine years, the authors have participated in a weekly multidisciplinary digestive disease conference. To preserve the teaching value from these cases and to increase the number of people who benefit from these efforts, we have begun to compile this information into educational videotapes. METHODS: Clinical cases of colitis from 1990 to 1999 were reviewed. Characteristic features of the clinical presentation, radiology, colonoscopy and surgical pathology from various cases were selected. A detailed script was created and revised according to the ASGE guidelines. The illustrative case histories, radiographs, video sequences, histology and pertinent teaching points were then formatted to match the script and edited onto a videotape. RESULTS: Eight conditions are presented in a sequential, multidisciplinary fashion: the normal colon, ulcerative colitis, Crohn's colitis, ischemic colitis, colonic mucosal prolapse syndrome, collagenous & lymphocytic colitis, acute hemorrhagic colitis and pseudomembranous colitis. CONCLUSION: This videotape reviews the charateristic features of several common forms of colitis in a multidisciplinary fashion.
Over-the-air performance results of a dynamic spectrum management Wi-Fi system in TVWS

A Dynamic Spectrum Management (DSM) Wi-Fi Prototype Platform is described in this paper. The platform hosts a modified 802.11n waveform that operates in TV White Space (TVWS), receives channel lists from a TVWS database, evaluates channel quality, and selects and aggregates data transmitted across up to four noncontiguous channels. The over-the-air (OTA) performance results collected in the Melville, New York lab are described. The results include data throughput, received signal strength indicator (RSSI), interference sensing and signal-to-noise plus interference (SNIR). The results are analyzed, including the advantages and efficiency of channel aggregation; indicate issues that were uncovered during testing and present possible solutions.
Attitudes, cognitive structures and emotional reactivity to sex and security: sex differences.

An attempt was made to determine if sex differences existed for attitudes, cognitive structures, and emotional reactivity for concepts of sex and security and for stimuli. It was hypothesized that for males, the concept of sex and/or sexual stimuli will be ranked higher, elicit a stronger physiological response, elicit a greater number of responses in a free-association task, and be more prevalent in compositions written about love, and that for females, the concept of security and/or security stimuli will be greater on the above measures. The data (with the exception of the paragraph written about love) were interpreted as supporting the sex differences along the sex and security dimensions.
Rapid transneuronal degeneration and death of cortical neurons following removal of the olfactory bulb in adult rats.

Following olfactory bulb removal in young and adult rats, many neurons in the primary olfactory cortex become markedly argyrophilic in silver impregnated preparations. Although argyrophilic neurons are found scattered throughout the pyramidal and multiform cell layers, the heaviest concentration is seen in the superficial part of the pyramidal layer. Electron microscopic analysis reveals that argyrophilic neurons are undergoing rapid degeneration. The degenerative changes are similar in all affected cells, although some cells begin to disintegrate within 24 hours following bulbectomy, whereas others are just beginning to show pathological changes at three or four days. The first clear signs of cellular degeneration occur in the cytoplasm of the perikaryon and involve swelling of mitochondria and polysome disaggregation. An increase in the electron density of the cytoplasm follows and this is accompanied by the appearance of enlarged cisternae and disruption of the nuclear membrane. Degenerative changes in the nucleus usually are detected at a slightly later stage than in the cytoplasm. Nuclear changes are characterized by the proliferation of local aggregations of condensed chromatin, and the replacement of the nucleolus with large homogenous islands of electron dense material. In advanced stages of degeneration ribosomes are increased in density and become uniformly dispersed throughout the cytoplasm. Remnants of necrotic organelles are visible only at the cellular periphery, and phagocytosis of dying neurons by astrocytes and microglia follows quickly. Evidence from HRP-studies indicates that cells in the olfactory cortex, which project directly to the bulb do not correspond to those which show fulminant necrosis following olfactory bulb removal. The majority of those which degenerate are located superficially, whereas the cells of origin of the centrifugal projection lie more deeply. Based on this dissociation, it is proposed that rapid cell death in the olfactory cortex is not caused by retrograde factors involving axotomy, but is due instead to transneuronal deafferentation that results from a sudden massive loss of input from the olfactory bulb.
Extending Prolog with nonmonotonic reasoning

Nonmonotonic reasoning has been developed to capture common sense inferences. This paper considers nonmonotonic reasoning in logic programs with negation, specifically its implementation using Prolog and its integration with Prolog execution. Even within logic programming frameworks, a variety of inferencing methods, model-theoretic semantics, and language features have been proposed for different forms of nonmonotonic reasoning. A challenging problem is to incorporate them into an integrated system. This paper describes an implementation of such a system in Prolog and different reasoning capabilities that are supported. By combining Prolog technology with various mechanisms of nonmonotonic reasoning, the resulting system offers a more realistic testbed for applications of common sense reasoning.
Voltage-Gated Ion Channels and Electrical Excitability

Our original research has been generously supported over many years by National Institutes of Health grants NS08174 and NS12547.
Temperature‐dependent magneto‐photoluminescence spectroscopy of carbon nanotubes: evidence for dark excitons

We review recent experimental and theoretical stud- ies on the radiative properties of excitons in single-walled car- bon nanotubes (SWNTs) as a function of magnetic field and temperature. These studies not only provide new insight into the fundamental properties of excitons in the ultimate one- dimensional (1D) limit but also reveal new phenomena associ- ated with the unique crystal and electronic structure of SWNTs. During the past several years, SWNTs have emerged as one of the most ideal systems available for the systematic study of 1D excitons, which are predicted to possess a set of prop- erties that are distinctly different from excitons in higher di- mensions. In addition, their tubular nature allows them to ex- hibit non-intuitive quantum phenomena when subjected to a parallel magnetic field, which breaks time reversal symmetry and adds an Aharonov-Bohm phase to the electronic wave- function. In particular, a series of recent experiments demon- strate that such a symmetry-breaking magnetic field can dra- matically "brighten" an optically-inactive, or dark, exciton state at low temperature (see the title figure on the right). We show that this phenomenon, magnetic brightening, can be understood as a consequence of interplay between the strong intervalley Coulomb mixing and field-induced lifting of valley degeneracy. Detailed temperature-dependent photoluminescence studies of excitons in SWNTs in a varying magnetic field have thus pro- vided one of the most critical tests for recently proposed theo- ries of 1D excitons taking into account the strong 1D Coulomb interactions and unique band structure on an equal footing. Fur- thermore, results of these studies suggest the intriguing possi- bility of manipulating the optical properties of SWNTs by ju- dicious symmetry control, which can lead to novel devices and applications in lasers and optoelectronics.
Assignment of the oxidation states of Zr and Co in a highly reactive heterobimetallic Zr/Co complex using X-ray absorption spectroscopy (XANES).

The reduced heterobimetallic complex (THF)Zr(MesNPiPr2)3CoN2 (1) has been examined along with a series of structurally similar reference compounds using X-ray absorption near edge structure (XANES) spectroscopy. Complex 1 has been shown to be highly reactive, often via one-electron pathways that might be expected for a d1 ZrIII complex. However, the presence of two strongly interacting metals in complex 1 renders the assignment of oxidation states ambiguous. Both Zr and Co K-edge XANES spectra reveal that the most accurate description of complex 1 is that of a ZrIV/Co−I zwitterion. Electronic structure calculations support this assignment.
Mathematics Belongs in a Liberal Education.

In higher education today, mathematics has been marginalized: except to a tiny elite, it is either taught as a tool required for the study of other sciences or it is entirely absent. Yet mathematics has been and is an essential ingredient in our understanding and mastery of the physical world, our economic life, our information technology and, increasingly, the workings of biology. Its key insights belong in the toolkit of all educated people. Unfortunately, present-day school instruction isolates mathematics from the tangible things that were its historical roots: the geometry and physics of the world, data and commerce, chance and randomness. We will look at the history of mathematics in western culture, the nature of the present-day alienation of our society from mathematics and suggest some ideas for bridging this gap.
Effects of smoking status on content of caloric intake and energy expenditure

The present study compared daily caloric and nutrient intake, participation in leisure time activities, and resting metabolic rate (RMR) following overnight smoking abstinence between male smokers (n=29) and nonsmokers (n=21), with groups equated on age, body weight, and fitness
Variation of Vitamin Concentration and Retention in Canned Snap Beans from Three Processing Plants During Two Years

A statistical evaluation of vitamin status during canning was obtained from samplings of raw, blanched and canned snap beans. With the exception of folic acid retention, it was not possible to distinguish the separate plants. This leads to the expectation that the season averages of vitamins from processing plants obtaining material from the same area would be similar. Retention percentages were lower for thiamin, folic acid and B6 than for ascorbic, which was lower than for carotene. Raw material was a source of variation. Average concentrations in drained canned beans, dry weight basis were: ascorbic acid, 116 mg/100g; carotene, 22 μg/g; thiamin, 3.4 μg; B6, 5.3 μg/g; and folic acid, 7.3 μg/g.
Cp∗Ru(NO) (catecholate) compounds. Synthesis, redox behavior, extended Hückel molecular orbital calculations, and X-ray diffraction structure of the pentamethylcyclopentadienylruthenium complex Cp∗Ru(NO) (2,3-naphthalenediolate)·CH2Cl2

Abstract Eight new catecholate- and naphthalenediolate-substituted pentamethylcyclopentadienylruthenium, compounds have been prepared from the reaction between Cp ∗ Ru(NO)Cl 2 and the appropriate aromatic diol in methanolic KOH. Each new compound has been isolated and fully characterized in solution by IR and NMR ( 1 H and 13 C) spectroscopy, in addition to X-ray diffraction analysis which has established the solid-state structure of the naphthalenediolate compound Cp ∗ Ru(NO)(2,3-O 2 C 10 H 6 ). Cp ∗ Ru(NO)(2,3-O 2 C 10 H 6 ) crystallizes, as the CH 2 Cl 2 solvate, in the monoclinic space group P 2 1 / n with a = 11.0176(8), b = 16.041(2), c = 13.0504(9) A , β = 112.024(6)° , V = 2138.1(3) A 3 and Z =4. Full-matrix least-squares refinement yielded R =0.0376 for 1893 ( l .3 ϱ ( l )) reflections. Cyclic voltammetric studies have been carried out, and two redox responses were observed, assignable to the 0/1− and 0/1+ redox couples. Whereas the reduction wave in each of the compounds is essentially independent of the nature of the ancillary diolate ligand, the stability of the oxidation couple is modulated by the electronic properties of the diolate ligand. The molecular orbital properties of several model CpRu(NO)(diolate) compounds were explored by extended Huckel calculations. The calculated HOMO and LUMO energies of each compound displayed good agreement with the cyclic voltammetry data, allowing for generalizations to be made concerning the site of electron addition to and electron removal from the new Cp ∗ Ru(NO)(diolate) compounds.
Fundraising Efforts in Hospital Libraries

Abstract Being a support service means that the hospital library is always looking for ways to supplement an already shrinking budget. This article describes strategies the author has successfully used for obtaining funding beyond the library budget.
Cortical slow potentials and the occipital EEG in congenital blindness

Abstract In a group of 7 congenitally blind adults, electroencephalographic occipital alpha rhythms were absent, but slow negative cortical potentials (CNV) were recorded over the visual cortex and were similar to those of normally sighted controls. Frontal and central CNV amplitudes, but not auditory evoked potentials or reaction times, were decreased significantly in the blind. The results confirm the presence of a developmental EEG abnormality following early blindness, and demonstrate the independance of slow potential generation from rhythmic 8–12 c/sec EEG activity in deafferented visual cortex. Non-sensory specific, event-related potentials such as the Contingent Negative Variation may prove to be useful psychophysiological probes of residual cortical function in brain regions which are deprived of primary sensory input.
Polymer-Supported Palladacycles: Efficient Reagents for Synthesis of Benzopyrans with Palladium Recovery. Relationship among Resin Loading, Pd:P Ratio, and Reactivity of Immobilized Palladacycles

Oxapalladacycles were immobilized on polystyrene−divinylbenzene supports and treated with 3-aryl-2-propynoates or 1-alkyl-1,2-propadienes to afford 2H-1-benzopyrans in yields superior to those for solution-phase experiments. Isolation of benzopyrans was facilitated, and 71−80% of the palladium was recovered. Effects of resin loading with phosphorus and palladium were studied, and the optimum immobilized palladacycles featuring a medium loading with P (1.35 mmol P/g) and a high loading with Pd (Pd:P ratio 1:1.7) were identified. Resins with higher swelling capacities were more reactive.
The effect of ‘allergenic’ and ‘nonallergenic’ antibiotics on dog keratinocyte viability in vitro

BACKGROUND Immune-mediated adverse drug reactions (drug hypersensitivity) are relatively common in veterinary medicine, but their pathogenesis is not well understood. For an unknown reason, delayed drug hypersensitivity often targets the skin. Antibiotics, especially β-lactams and sulfonamides, are commonly associated with these adverse events. The 'danger theory' hypothesizes that 'danger' signals, such as drug-induced cell death, might be part of the pathogenesis of drug hypersensitivity reactions. HYPOTHESIS/OBJECTIVES The goal of this study was to determine whether antibiotics that are commonly associated with cutaneous drug hypersensitivity (allergenic) decrease canine keratinocyte viability in vitro more than antibiotics that rarely cause such reactions (nonallergenic). METHODS Immortalized canine keratinocytes (CPEK cells) were exposed to a therapeutic range of drug concentrations of four 'allergenic' antibiotics (two β-lactams, i.e. amoxicillin and cefalexin, and two sulfonamides, i.e. sulfamethoxazole and sulfadimethoxine) or two 'nonallergenic' antibiotics (enrofloxacin and amikacin) over 48 h (2, 4, 8, 24 and 48 h). The reactive nitroso metabolite of sulfamethoxazole was also tested. RESULTS Cefalexin (2 mmol/L) significantly decreased cell viability after 48 h (28 ± 7%; P = 0.035). The nitroso metabolite of sulfamethoxazole (100 μmol/L) decreased cell viability after 2 h (21 ± 7%; P = 0.049), but cell numbers were increased after 8 h (22 ± 6%; P = 0.018). In addition, enrofloxacin (500 μmol/L) also significantly decreased cell viability by 37% (±6%; P = 0.0035) at 24 h and by 70% (±8%; P < 0.001) at 48 h. CONCLUSION It appears that the effect of drugs on the in vitro viability of dog keratinocytes is not a good predictor of the 'allergenic' potential of an antibiotic. Further work is required to investigate other drug-induced 'danger' signals in dog keratinocytes exposed to 'allergenic' antibiotics in vitro.
Prediction of polyp histology on CT colonography using content-based image retrieval

Predicting the malignancy of colonic polyps is a difficult problem and in general requires an invasive polypectomy procedure. We present a less-invasive and automated method to predict the histology of colonic polyps under computed tomographic colonography (CTC) using the content-based image retrieval (CBIR) paradigm. For the purpose of simplification, polyps annotated as hyperplastic or "other benign" were classified as benign polyps (BP) and the rest (adenomas and cancers) were classified as malignant polyps (MP). The CBIR uses numerical feature vectors generated from our CTC computer aided detection (CTC-CAD) system to describe the polyps. These features relate to physical and visual characteristics of the polyp. A representative database of CTC-CAD polyp images is created. Query polyps are matched with those in the database and the results are ranked based on the similarity to the query. Polyps with a majority of representative MPs in their result set are predicted to be malignant and similarly those with a majority of BPs in their results are benign. For evaluation, the system is compared to the typical optical colonoscopy (OC) size based classification. Using receiver operating curve (ROC) analysis, we show our system is sufficiently better than the OC size method.
Co-payment restructuring and its impact on resources at the US Department of Veterans Affairs

The US Department of Veterans Affairs (VA) healthcare co-payment policies, governed by multiple legislations, were incoherent. In particular, the outpatient visit co-payment rate was too high compared with non-VA sectors. In early 1999, VA initiated a legislative proposal to restructure its co-payment policies and, later, the Millennium Act provided VA with the authority to set co-payment rates for outpatient care, long-term care and pharmacy. Co-payment reduction inevitably affects the congressionally appropriated VA healthcare budget; consequently, an assessment of the impact was critically needed. This paper describes the actual decision making process of co-payment redesign and presents the evaluation strategy, i.e., the combination of an enhanced two-part model and the dynamics of VA eligibility means test status. This method effectively evaluated the impact of a $38.80 reduction in outpatient co-payment, which is intractable by conventional techniques. The results of this study provided essential information for the decision makers in designing outpatient co-payment policy.
Intravenous basic fibroblast growth factor produces a persistent reduction in infarct volume following permanent focal ischemia in rats.

Abstract Basic fibroblast growth factor (bFGF) is a polypeptide with potent survival-promoting and protective effects on brain cells. In previous studies, we showed that intravenous administration of bFGF reduced infarct volume in models of focal cerebral ischemia in rats, mice, and cats. In these previous studies, infarct volume was measured within 1–7 days of the onset of ischemia. The current study was undertaken to determine whether the reduction in infarct volume by bFGF was persistent beyond the first week after stroke. Mature male Sprague–Dawley rats received an intravenous infusion of bFGF (50 μg/kg per h) or vehicle during 0.5–3.5 h after permanent proximal middle cerebral artery occlusion. We found a 27% reduction in infarct volume in bFGF- compared to vehicle-treated animals at three months after infarction ( P