cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluating the length of stay and value of time in a pediatric emergency department with two models by comparing two different albuterol delivery systems

AbstractObjective:Asthma is one of the most common childhood illnesses and accounts for a substantial amount of pediatric emergency department visits. Historically, acute exacerbations are treated with a beta agonist via nebulizer therapy (NEB). However, with the advent of the spacer, the medication can be delivered via a metered dose inhaler (MDI + S) with the same efficacy for mild-to-moderate asthma exacerbations. To date, no study has been done to evaluate emergency department (ED) length of stay (LOS) and opportunity cost between nebulized vs MDI + S. The objective of this study was to compare ED LOS and associated opportunity cost among children who present with a mild asthma exacerbation according to the delivery mode of albuterol: MDI + S vs NEB.Methods:A structured, retrospective cross-sectional study was conducted. Medical records were reviewed from children aged 1–18 years treated at an urban pediatric ED from July 2007 to June 2008 with a discharge diagnosis International Classification of Dis...
Outward Foreign Direct Investments by the BRICS

A review of “The Determinants of Chinese Outward Direct Foreign Investment” by Hinrich Voss Cheltenham, UK: Edward Elgar, 2011. xiii+209 pages. Given the rise of the Chinese and Indian economies es...
Are reports of life event stress among suicidal youth subject to cognitive bias

Severity of depressive symptoms, hopelessness, and suicidal ideation were examined to determine whether they were significantly associated with the accuracy of suicidal adolescents' ratings of stressful life events. The sample included 130 inpatient adolescents who endorsed suicide-related behaviors. Stress interviews were administered, and the severity of stressful events was rated separately by adolescents and an independent team. A residualized cognitive bias score was created by regressing adolescents' severity ratings to the independent team's severity ratings of the same events. Depressive symptoms, but not hopelessness or suicidal ideation, were significantly associated with cognitive bias scores. A negative cognitive bias in adolescents' reports of life stress may be present at higher levels of depression relative to minimal levels of depression. Further research on the relations between stress and suicide-related behaviors is encouraged to include independent ratings of stress severity.
Spatial Layout, Social Structure, and Innovation in Organizations

Research on the enabling factors of innovation has most often addressed either the social component of organizations or the spatial dimensions involved in the innovation process. Few studies have examined the link from spatial layout and social networks to innovation. Social networks play important roles in structuring communication, collaboration, access to knowledge, and knowledge transformation. These processes are both antecedent to and part of the innovation process. Spatial layout structures patterns of circulation, proximity, awareness of others, and encounter in an organization. These interrelationships become fundamental to the development of social networks, especially those networks critical to the innovation process. This research explored associations between innovation within three partner organizations and the organization's social and spatial structure. The organizations included: A nonprofit life sciences institute dedicated to translational research on cancer, the research laboratories of a multinational software corporation, and the quality control group of an automobile manufacturer. The study applied spatial analysis to map and characterize physical space in conjunction with survey data capturing social contacts among researchers at the three organizations. For one partner organization, we augmented these tools with location-tracking methods. It could be argued that sociometric surveys capture the ‘perceived’ social network. Social networks researchers have been very interested in assessing ‘real’ networks either as reliability checks on sociometric survey networks, or as stand-alone networks. Our use of an ultrawideband location system allowed us to assess networks in real time. In interpreting our results, we suggest that through exposure to moving others, locations with high metric choice may provide the opportunities for serendipitous encounters among individuals who may come from disparate parts of an organization. Whereas low mean distance to others may provide the enhanced connections necessary to mobilize the resources and attention to move innovative ideas forward. Results demonstrate the salience of both social and spatial dimensions in the processes of innovation. The research suggests two strong factors that appear to influence our results: the institutional context which characterizes or prioritizes certain innovation outcomes; the extent to which the physical facility design of organizations tends to concentrate or spatially distribute the research unit. Our findings indicate that relationships between salutary network positions and beneficial locales themselves derive from institutional contexts that shape the priorities, opportunities, goals and practices of discovery. We suggest that innovation is a process that occurs at the intersection of social and physical space, and moves toward a sociospatial science of design for innovation.
Synapse-Associated Protein 97 Regulates the Membrane Properties of Fast-Spiking Parvalbumin Interneurons in the Visual Cortex

Fast-spiking parvalbumin (PV)-positive interneurons in layers 2/3 of the visual cortex regulate gain control and tuning of visual processing. Synapse-associated protein 97 (SAP97) belongs to a family of proteins that have been implicated in regulating glutamatergic synaptic transmission at pyramidal-to-pyramidal connections in the nervous system. For PV interneurons in mouse visual cortex, the expression of SAP97 is developmentally regulated, being expressed in almost all juvenile but only a fraction, ∼40%, of adult PV interneurons. Using whole-cell patch-clamping, single-cell RT-PCR to assay endogenous expression of SAP97 and exogenous expression of SAP97, we investigated the functional significance of SAP97 in PV interneurons in layers 2/3 of the visual cortex. PV interneurons expressing SAP97, either endogenously or via exogenous expression, showed distinct membrane properties from those not expressing SAP97. This included an overall decrease in membrane excitability, as indexed by a decrease in membrane resistance and an increase in the stimulus threshold for the first action potential firing. Additionally, SAP97-expressing PV interneurons fired action potentials more frequently and, at moderate stimulus intensities, showed irregular or stuttering firing patterns. Furthermore, SAP97-expressing PV interneurons showed increased glutamatergic input and more extensive dendritic branching when compared with non-expressing PV interneurons. These differences in membrane and synaptic properties would significantly alter how PV interneurons expressing SAP97 compared with those not expressing SAP97 would function in local networks. Thus, our results indicate that the scaffolding protein SAP97 is a critical molecular factor regulating the input–output relationships of cortical PV interneurons.
Analysis of hydrocarbons and sulfur compounds in two FCC decant oils and their carbonization products

Two decant oils (DO A and DO B) which produce coke with different optical textures were quantitatively analyzed before and at several stages of carbonization. The differences observed in mesophase development and sulfur incorporation in the semicokes were related to differences in the molecular composition of the two decant oils, including hydrocarbons and sulfur compounds. The analysis of the GC-amenable fractions of the decant oils showed that DO A contains an abundance of pyrene and substituted pyrenes, while DO B is dominated by high concentrations of polymethylphenanthrenes. In general, DO B has a much higher proportion of alkyl-substituted PAHs and a higher concentration of n-alkanes. The presence of more reactive hydrocarbons in DO B is considered to be responsible for the inferior texture development and rapid incorporation of sulfur in the semicoke. Extensive methylation/demethylation reactions appear to occur during the early stages of carbonization; the role of these reactions in mesophase deve...
History of atopy or autoimmunity increases risk of alopecia areata.

Background The association between a history of atopy or autoimmune diseases and risk of alopecia areata (AA) is not well established. Objective The purpose of this study was to use the National AA Registry database to further investigate the association between history of atopy or autoimmune diseases and risk of AA. Methods A total of 2613 self-registered sporadic cases (n = 2055) and controls (n = 558) were included in this analysis. Results Possessing a history of any atopic (odds ratio=2.00; 95% confidence interval 1.50-2.54) or autoimmune (odds ratio=1.73; 95% confidence interval 1.10-2.72) disease was associated with an increased risk of AA. There was no trend for possessing a history of more than one atopic or autoimmune disease and increasing risk of AA. Limitations Recall, reporting, and recruiting bias are potential sources of limitations in this analysis. Conclusion This analysis revealed that a history of atopy and autoimmune disease was associated with an increased risk of AA and that the results were consistent for both the severe subtype of AA (ie, alopecia totalis and alopecia universalis) and the localized subtype (ie, AA persistent).
Induction Proof for a General Exponential Integral Formula

-The authors' Poisson probability method for detecting stochastic randomness in three-dimensional space involved the need to evaluate an integral for which no appropriate closed-form solution could be located in standard handbooks. This resulted in a formula specifically calculated to solve this integral in closed form. In this paper the calculation is verified by the method of mathematical induction.
A single nucleotide polymorphism of the cholecystokinin-B receptor predicts risk for pancreatic cancer.

There currently are no tests available for early diagnosis or for the identification of patients at risk for development of pancreatic cancer. We report the discovery of single nucleotide polymorphism (SNP) in the cholecystokinin B receptor (CCKBR) gene predicts survival and risk of pancreatic cancer. Growth of human pancreatic cancer is stimulated by gastrin through the CCKBR and an alternatively spliced isoform of the CCKBR gene called CCKCR. One hundred and ten surgically resected benign and malignant pancreatic tissues as well as normal pancreas were prospectively evaluated for CCKBR genotype and protein expression. Analysis demonstrated the expression of the spliced isoform, CCKCR, was associated with a (SNP) (C > A) at position 32 of the intron 4 (IVS 4) of the CCKBR gene. Since the SNP is within an intron, it has not previously been identified in the GWAS studies. Only patients with the A/A or A/C genotypes, exhibited immunoreactivity to a selective CCKCR antibody. Survival among pancreatic cancer ...
Duration of keypecks in variable-interval schedules of reinforcement

An experiment was conducted to determine the duration of pigeons’ keypecks during three separate variable-interval (VI) schedules of reinforcement. Pigeons were exposed to VI 30-sec, VI 60-sec, and VI 120-sec schedules of reinforcement for 20 sessions each. Response durations were analyzed in terms of VI schedule value, location in time during the interreinforcement interval, and local patterns of short- and long-duration pecks. For three out of four birds, the mean response duration was reliably longer for the VI 30-sec schedule than for the VI 120-sec schedule. Results for the VI 60-sec condition were equivocal. Mean duration of response was constant throughout the VI interval, showing no change over time. No specific pattern of long and short pecks was detected. The results confirm the existence of a range of response durations during VI schedules of reinforcement and suggest that duration of response varies with VI schedule changes.
Larval Loss and Spawning Behavior in the Land Crab Gecarcinus Lateralis (Fréminville)

ABSTRACT Females of the red land crab Gecarcinus lateralis (Freminville) must leave the physiological and physical protection of a terrestrial burrow to carry their developing egg masses to the surf and release the pelagic larvae. En route, both adults and eggs may encounter increased risks from predators, extremes of salinity (rain or concentrated tidepools), and wave impact. Several types of behavior by ovigerous females reduce these risks to both adult females and larvae during migration and spawning. Females migrate directly toward the shore, reducing the time required to reach the sea. They spawn synchronously. Ovigerous females actively release eggs only when the eggs are ripe, precluding premature release, but will do so in water of any salinity, whether still or agitated. Physiological adaptations of larvae would contribute little to their survival were eggs released in extreme salinities; the range of tolerance is only 50-125% sea water. The spawning females avoid standing water of any salinity, thereby preventing release of larvae in dilute or concentrated tidepools, or those without connection with the sea. Females begin migration to the nearshore zone before egg-releasing behavior develops, hence are unlikely to release eggs prematurely if inundated by rain. Spawning females approach the surf hesitantly, minimizing the risk of being swept to sea. The reliance of G. lateralis upon adult behaviors to reduce risks during migration and spawning is compared with strategies of other land crabs which appear to rely more heavily upon larval adaptations.
Risk stratification in medullary thyroid cancer: Moving beyond static anatomic staging

Summary Objectives: Much progress has been made over the last 10 years with regard to risk estimation in non-medullary differentiated thyroid cancer with risk of recurrence systems and response to therapy re-evaluation approaches being used to augment initial risk estimates obtained using standard anatomic staging systems. Furthermore, risk stratification is being increasingly viewed as an active, evolving, dynamic process that requires re-evaluation during follow-up rather than a single static risk estimate predicted by initial staging. As with differentiated thyroid cancer, multiple clinico-pathologic factors have been demonstrated to correlate with the risk of disease specific mortality, risk of death, likelihood of disease progression, likelihood of cure with initial therapy, and likelihood of cure with additional therapy in medullary thyroid cancer. Materials and Methods: In this review, we re-examine the clinically important initial risk factors in medullary thyroid cancer and then re-evaluate how some of these risk factors can be used to alter risk estimates over time as they reflect the response to therapy and the clinical course of the disease. Results and Conclusions: We demonstrate that the same response to therapy nomenclature that we have proposed and validated in differentiated thyroid cancer (excellent response, biochemical incomplete response, structural incomplete response, indeterminant response) can be easily applied to medullary cancer and used to guide on-going clinical management.
Disseminated herpes simplex infection with retinitis in a renal allograft recipient

An immunosuppressed recipient of a renal allograft developed bilateral necrotizing retinitis. Disseminated herpes simplex infection was documented by clinical findings and serologic and viral culture studies. Cultures and serologic tests for cytomegalovirus were negative. The evidence strongly favored the diagnosis of herpes simplex retinitis. Tapering of immunosuppressive drugs and administration of adenine arabinoside appeared to halt temporarily the progression of the disease in one eye and resulted in healing of the retinitis in the other eye. Subsequent progression of the more severely involved right eye resulted in an exudative retinal detachment and loss of vision prior to the patient's death from meningoencephalitis. Herpes simplex retinitis must be considered in the differential diagnosis of necrotizing retinitis in an immunosuppressed patient.
Continous Vacuum Foam-Drying of Whole Milk. VI. Iron Enrichment

Abstract With the growing interest in iron fortification of foods, particularly milk, we studied the processing and keeping qualities of vacuum foam-dried whole milk after the addition of 10.6mg per liter of iron in the form of ferric ammonium citrate. Added iron had no adverse effects on the dehydration process, initial flavor and dispersibility, or flavor and dispersibility after extended storage.
Matrix isolation infrared spectroscopic investigation of the coordination chemistry and reactivity of OVF3

Abstract The matrix isolation technique has been combined with infrared spectroscopy to identify and characterize the product of the codeposition of OVF 3 with NH 3 and with a series of nitrogen and oxygen donor bases into argon matrices at 14 K. This codeposition led to the formation of the isolated 1:1 complexes between OVF 3 and these bases. Each complex was characterized spectroscopically, including strong shifts to the V–F stretching modes, and a lesser shift to the VO stretching mode. Numerous perturbed vibrational modes of the base subunits were noted, including a strong, 230 cm −1 blue shift to the symmetric bending mode of NH 3 . The magnitudes of these shifts indicate that OVF 3 is a moderate strength Lewis acid. However, in contrast to analogous reactions with OVCl 3 , no further thermal or photochemical transformations of the complex occurred. Theoretical calculations were also carried out in support of the experimental work.
The thermal release of Hg from chondrites and their thermal histories

A quantitative treatment and implications of isothermal and linear heating data on Hg in meteorites are given as a sequel to a more qualitative analysis of meteorite thermal histories (Reed and Jovanovic, 1968). Studies of Hg in terrestrial metamorphic rocks establish that thermal events to which meteorites were subjected fall in the same temperature range, of 400-900 C, as exists during terrestrial metamorphism. Hg diffusion parameters based on data from the linear and isothermal heating experiments are calculated. The conclusions are: (1) Meteorites experienced thermal events of the same magnitude as those measured by primarily mineralogical metamorphic indicators reviewed by Dodd (1969); (2) no correspondence with mineralogical-petrological metamorphic grade is evident; (3) Hg data for some chondrites correlate with shock facies (non-thermal) indicators (Dodd and Jarosewich, 1979); (4) small Hg activation energies (6-14 kcal/mole) require that the meteorites must have been stored in closed systems until low temperatures were attained. Hg must be presented as an involatile mineral(s) or as a substituent in a host phase at temperatures below 100 C. Consistent with this interpretation is the fact that despite diffusion times of 100-1,000,000 years at 200 K, Hg was retained in small objects over cosmic ray exposure periods of a hundred-million years.
Flavor preferences conditioned by postingestive effects of nutrients in preweanling rats

The purpose of these experiments was to determine if preweanling rats, like adults, are capable of learning to associate an arbitrary flavor with the postingestive effects of nutrients, and then demonstrate a preference for that flavor after weaning. In Experiment 1, preweanlings were trained daily from postnatal day (P) 16 through P19 with intraoral (IO) infusions of a grape or cherry flavor (CS+) mixed with 20% glucose (US), and the opposite flavor (CS-) mixed with 0.05% saccharin. After weaning, rats were given a 4-h two-bottle choice between the CS+ and CS- flavors both presented in 0.05% saccharin. Rats preferred the flavor previously paired with glucose. In Experiment 2 using similar methods, rats learned to prefer a flavor (CS+G) paired with a glucose US over a flavor (CS+S) paired with a sweeter but less nutritive sucrose US, indicating involvement of postingestive reinforcement. In Experiment 3 preweanling rats with IO and intragastric (IG) catheters were trained with a CS+ flavor paired with IG nutrient infusion, and a CS- flavor paired with no IG infusion. These rats showed no flavor preference 3 days after weaning, but did significantly prefer the CS+ flavor over the CS- flavor 10 days after weaning. Together these experiments demonstrate that neural mechanisms for flavor-nutrient associations are developed before weaning, allowing young rats to learn associations between arbitrary flavors and nutritive consequences. Thus nutrient conditioning may be one way that early experience (such as flavors from the maternal diet transmitted in milk) influences later dietary preferences.
Analysis of multiprocessor architectures for management of space-based power systems

The research project, Advanced Electrical Power Management Techniques for Space System (ADEPTS) was continued. The decomposition method for doing load-flow analysis presented in (1993) is extended to power systems of 16, 25, 34, 43, 52, 61, 70, and 79 nodes. Each of the power systems was divided into subsystems and simulated under steady-state conditions using a set of up to 13 transputers.
Detection of Selfish Manipulation of Carrier Sensing in 802.11 Networks

Recently, tuning the clear channel assessment (CCA) threshold in conjunction with power control has been considered for improving the performance of WLANs. However, we show that, CCA tuning can be exploited by selfish nodes to obtain an unfair share of the available bandwidth. Specifically, a selfish entity can manipulate the CCA threshold to ignore ongoing transmissions; this increases the probability of accessing the medium and provides the entity a higher, unfair share of the bandwidth. We experiment on our 802.11 testbed to characterize the effects of CCA tuning on both isolated links and in 802.11 WLAN configurations. We focus on AP-client(s) configurations, proposing a novel approach to detect this misbehavior. A misbehaving client is unlikely to recognize low power receptions as legitimate packets; by intelligently sending low power probe messages, an AP can efficiently detect a misbehaving node. Our key contributions are: 1) We are the first to quantify the impact of selfish CCA tuning via extensive experimentation on various 802.11 configurations. 2) We propose a lightweight scheme for detecting selfish nodes that inappropriately increase their CCAs. 3) We extensively evaluate our system on our testbed; its accuracy is 95 percent while the false positive rate is less than 5 percent.
An introduction to mathematical modeling of electrophysiological processes in the myocardium

We discuss major features of modeling cardiac electrophysiology based on the modern concept of an excitable medium such as: general physical mechanisms and energetics of excitability, discrete and continuous aspects of cardiac conduction stemming from its fibrous structure, and anisotropy as another feature of such myocardial structure. We use the propagation velocity as a certain integral measure of the medium excitability and show that the expression for its value always consists of three factors, the scaling factor built out of dimensional constants of the myocardium, and two dimensionless factors, a universal directional factor taking full account of the medium anisotropy, and a dynamical factor that represents balances of all electrical sources and sinks. We describe the minimum, two variable models of an excitable cellular membrane. We show that in the first approximation the effect of the slow inactivation/recovery processes on the propagation velocity can be neglected. The excitation wave becomes in such an approximation a trigger wave of transitions from the resting to the exciting state. Then we discuss the formation of the conduction block at nonzero propagation speed due to the effect of inhibitive (recovery) processes.
Insufficient evidence on diagnostic accuracy of radiographic methods in periapical tissues.

DATA SOURCES The Cochrane Central register of controlled trials, Medline and Embase databases were searched. STUDY SELECTION Clinical studies that compared methods against a reference standard were included. Studies also needed to have sensitivity, specificity, likelihood ratio, odds ratio or receiver operator curve (ROC) data or data reported so this could be calculated. DATA EXTRACTION AND SYNTHESIS Two reviewers independently assessed abstracts and full text articles. Study quality was assessed using the GRADE criteria (www.gradeworkinggroup.org/). A qualitative summary was conducted. RESULTS Twenty-six studies were included, none was considered to be of high quality, 11 were of moderate quality. There was insufficient evidence that the digital intraoral radiographic technique is diagnostically as accurate as the conventional film technique. The same applies to Cone beam computed tomography (CBCT). CONCLUSIONS No conclusions can be drawn regarding the accuracy of radiological examination in identifying various forms of periapical bone tissue changes or about the pulpal condition.
Assessment of Introductory Transportation Engineering Course and General Transportation Engineering Curriculum

Transportation engineering is a critical subdiscipline of the civil engineering profession as indicated by its inclusion on the Fundamentals of Engineering Examination and overlap with other specialty areas of civil engineering and as recognized by TRB, ITE, and ASCE. With increasing transportation workforce needs, low numbers of students entering the pipeline, and limited hours within undergraduate civil engineering programs, it is important to ensure that civil engineering students receive adequate preparation and exposure to career opportunities in the transportation engineering field. Thus, investigations into the status of transportation engineering within civil engineering programs and specifically the introductory transportation engineering course are essential for understanding implications to the profession. Relevant literature and findings from a new survey of civil engineering programs accredited by the Accreditation Board for Engineering and Technology is reviewed; that survey yielded 84 respo...
Linking linear threshold units with quadratic models of motion perception

Behavioral experiments on insects (Hassenstein and Reichardt 1956; Poggio and Reichardt 1976) as well as psychophysical evidence from human studies (Van Santen and Sperling 1985; Adelson and Bergen 1985; Watson and Ahumada 1985) support the notion that short-range motion perception is mediated by a system with a quadratic type of nonlinearity, as in correlation (Hassenstein and Reichardt 1956), multiplication (Torre and Poggio 1978), or squaring (Adelson and Bergen 1985). However, there is little physiological evidence for quadratic nonlinearities in directionally selective cells. For instance, the response of cortical simple cells to a moving sine grating is half-wave instead of full-wave rectified as it should be for a quadratic nonlinearity (Movshon ef al. 1978; Holub and Morton-Gibson 1981) and is linear for low contrast (Holub and Morton-Gibson 1981). Complex cells have full-wave rectified responses, but are also linear in contrast. Moreover, a detailed theoretical analysis of possible biophysical mechanisms underlying direction selectivity concludes that most do not have quadratic properties except under very limited conditions (Grzywacz and Koch 1987). Thus, it is presently mysterious how a system can show quadratic properties while its individual components do not. We briefly discuss here a simple population encoding scheme offering a possible solution to this problem.
Vicious-circle behavior in the Y maze

Abstract Laboratory rats were given escape training in both arms of a Y maze followed by extinction in one of four conditions: regular (no shock), punished (both arms containing a shock mid-segment), choice, or forced (one arm containing a shock mid-segment, one arm shock free). Subjects in the punished and forced conditions required more extinction trials than those in the regular extinction condition. The choice condition was intermediate and not significantly different from the others. Choice subjects avoided the shock by choosing the safe alley early and consistently during extinction, but some continued to run for many trials without further punishment. It was suggested that the number of punished trials early in extinction is related to persistence of running, and the results were discussed in relation to the Mowrer-Brown and the discrimination hypotheses.
Factors Affecting the Impact of Social Interaction Skills Interventions in Early Childhood Special Education

As a group, preschool children with disabilities are at risk for problems in the development of social interaction skills and related behaviors. This article highlights the need for effective social skills interventions for these children and reviews available intervention procedures and packages. In addition, factors affecting the current impact of social skills interventions in early childhood special education are discussed, and research efforts to increase the impact of these interventions are reviewed. Specifically, research efforts aimed at documenting intervention integrity and confirming the link between intervention integrity and intervention effectiveness are addressed.
Vestibular evoked myogenic potential testing for the diagnosis of conductive hearing loss: Survey of pediatric otolaryngologists' knowledge and beliefs

Abstract Objectives To assess physicians’ knowledge and beliefs regarding vestibular evoked myogenic potential (VEMP) testing in children. Methods A survey was delivered via email in html format to 1069 members of the American Academy of Otolaryngology – Head and Neck Surgery who identified as pediatric otolaryngologists. Study data were collected and managed using the Research Electronic Data Capture (REDCap) tools. Results 443 (41.4%) physicians opened the email. 190 (42.9% of opens) initiated the survey, of which 117 (61.9%) fully completed the survey of the physicians who responded to a question regarding knowledge of VEMP, 16% of respondents had never heard of the test. 16% of participants would use it in the setting of diagnosing pediatric conductive hearing loss. Responses regarding the youngest age at which VEMP is possible ranged from younger than 6 months through greater than 13 years of age. Beliefs regarding utility and reliability of VEMP varied, with ‘unsure’ as the most frequent response. Additionally, only 26% of pediatric otolaryngologists indicated some access to the test. Conclusion The knowledge and availability of VEMP testing in the pediatric otolaryngology community varies widely.
Theoretical Study of Alternative Pathways for the Heck Reaction through Dipalladium and “Ligand-Free” Palladium Intermediates

The pathways for the Heck reaction, in particular, carbon−carbon bond formation between ethylene and phenyl bromide, catalyzed by dipalladium intermediates and substrate-bound palladium complexes, were investigated by density functional calculation. For the sterically hindered phosphine ligand, PtBu3, the free energy barrier for phenyl bromide oxidative addition to Pd2(PtBu3)2 is significantly higher than that to Pd(PtBu3) due to the higher steric interaction. However, for the PMe3 ligand, phenyl bromide oxidative addition by Pd2(PMe3)2 has a lower free energy barrier than that by Pd(PMe3). Although the dipalladium is less likely to be active when coordinated by two sterically hindered phosphines, such as PtBu3, it could serve as the active catalyst when less sterically encumbered. For Pd2(PMe3)2, the free energy profile for the complete Heck reaction cycle shows that, like the monopalladium pathway, oxidative addition of phenyl bromide is the rate-limiting step. Substrate-bound palladium complexes were a...
Thyroid transcription factor-1 (TTF-1/Nkx2.1/TITF1) gene regulation in the lung

TTF-1 [thyroid transcription factor-1; also known as Nkx2.1, T/EBP (thyroid-specific-enhancer-binding protein) or TITF1] is a homeodomain-containing transcription factor essential for the morphogenesis and differentiation of the thyroid, lung and ventral forebrain. TTF-1 controls the expression of select genes in the thyroid, lung and the central nervous system. In the lung, TTF-1 controls the expression of surfactant proteins that are essential for lung stability and lung host defence. Human TTF-1 is encoded by a single gene located on chromosome 14 and is organized into two/three exons and one/two introns. Multiple transcription start sites and alternative splicing produce mRNAs with heterogeneity at the 5' end. The 3' end of the TTF-1 mRNA is characterized by a rather long untranslated region. The amino acid sequences of TTF-1 from human, rat, mouse and other species are very similar, indicating a high degree of sequence conservation. TTF-1 promoter activity is maintained by the combinatorial or co-operative actions of HNF-3 [hepatocyte nuclear factor-3; also known as FOXA (forkhead box A)], Sp (specificity protein) 1, Sp3, GATA-6 and HOXB3 (homeobox B3) transcription factors. There is limited information on the regulation of TTF-1 gene expression by hormones, cytokines and other biological agents. Glucocorticoids, cAMP and TGF-beta (transforming growth factor-beta) have stimulatory effects on TTF-1 expression, whereas TNF-alpha (tumour necrosis factor-alpha) and ceramide have inhibitory effects on TTF-1 DNA-binding activity in lung cells. Haplo-insufficiency of TTF-1 in humans causes hypothyroidism, respiratory dysfunction and recurring pulmonary infections, underlining the importance of optimal TTF-1 levels for the maintenance of thyroid and lung function. Recent studies have implicated TTF-1 as a lineage-specific proto-oncogene for lung cancer.
Galton’s number

Galton posed the following question: What is the number of accessible autobiographical episodes in memory? The answer to this question implicates a number of issues in the psychophysics of time and memory. We had found (Crovitz & Schiffman, 1974) a surprisingly fertile equation (log f = log b –; a log t) relating the number (f) of episodes accessible at any given time (t) ago. We discuss this log-log law of memory; we differentiate it, exposing a form of Weber’s law in the time domain; and we integrate this equation, which allows us to answer Galton’s question and make other empirical predictions.
Spin diffusion between inequivalent quadrupolar nuclei by double-quantum flip-flops

Abstract A new mechanism for spin diffusion between quadrupolar nuclei whose NMR lines do not overlap is proposed. For spin-1 nuclei, double-quantum flip-flop transitions allow the diffusion of Zeeman order, but not quadrupolar order, without requiring an extraneous energy reservoir. The flip-flop rate is sensitive to the relative signs of the quadrupolar splittings.
The relationship between self-reported cardiovascular disease and periodontitis and carotid calcification assessed from panoramic radiographs is not clear

Summary Subjects Of 1084 persons sampled, 1064 had panoramic radiographs0689 (PMX); 485 of the subjects (46%) were male; the mean age was 67 years. Recruitment was from Seattle (65%) and Vancouver (35%). Forty-seven percent were Caucasian, 31% Asian, 10% East Indian (mainly Sikh), 8% African American, and 3% other races. All the East Indians were recruited from Vancouver. Dates of data collection were not given. Exposure The exposure was alveolar bone height assessed by using0689 an ordinal index of 4 categories. No further details were provided. Carotid calcification was said to be present if a radiopaque mass or 2 vertical radiopaque lines were present at the lower margin of the third cervical vertebra (C3). In Seattle all radiographs were taken at 1 center, whereas in Vancouver radiographs were taken at multiple centers. Main outcome measure Histories were obtained by interviews. All non-native0689 English-speaking participants had translators. Main results The authors observed a statistically significant association 0689 between cardiovascular disease (CVD) and periodontitis, CVD and carotid calcification, and carotid calcification and periodontitis. However, the results were not significant after adjustment for smoking (Table 1; Fig 1).
How to determine the compatibility of undirected character state trees

Abstract Methods for cladistic character compatibility analysis have required a priori estimates of the direction of evolutionary trends among the states of a character, in order to ensure consistency. Results are presented here that can enable comparative biologists, if they choose, to proceed with cladistic character analysis without a priori estimates of the direction of evolutionary trends. Specifying only undirected character state trees is sufficient to ensure the compatibility of a collection of characters each pair of which is compatible. The results have been implemented in a computer program, for which a FORTRAN source deck is available.
Lattice super-Yang-Mills using domain wall fermions in the chiral limit

Lattice N=1 super-Yang-Mills formulated using Ginsparg-Wilson fermions provides a rigorous nonperturbative definition of the continuum theory that requires no fine-tuning as the lattice spacing is reduced to zero. Domain wall fermions are one explicit scheme for achieving this and using them we have performed large-scale Monte Carlo simulations of the theory for gauge group SU(2). We have measured the gaugino condensate, static potential, Creutz ratios, and residual mass for several values of the domain wall separation L{sub s}, four-dimensional lattice volume, and two values of the bare gauge coupling. With this data we are able to extrapolate the gaugino condensate to the chiral limit, to express it in physical units, and to establish important benchmarks for future studies of super-Yang-Mills on the lattice.
MINOS detectors for neutrino interactions

Abstract The MINOS experiment will explore neutrino oscillations in the range of parameter space suggested by measurements with atmospheric neutrinos. The two magnetized toroidal tracking calorimeters, 1 kton at Fermilab and 5.4 kton in the Soudan Mine, will be constructed out of 2.54 cm iron plates interspersed with scintillator strips made in the extrusion process and will use wavelength shifting and clear fibers read out by multi-anode photomultipliers.
Effects of axial dispersion on the optimal design of the activated sludge process

Abstract The axial dispersion (longitudinal mixing) which occurs in the aeration chamber of the activated sludge system is investigated to determine the effects of axial dispersion on system performance. In this investigation, the so-called diffusion model is employed to characterize the flow in the aeration chamber. A pattern search technique is used to determine the optimum detention time in the aerator and the optimum return sludge flow rate. Two economic models, the overall size (total volume) of the aeration chamber and clarifier, and the total construction cost based on Smith's correlation for unit costs of subunits of the activated sludge process, are optimized and the results are compared. This analysis shows that the Peclet number, which indicates the extent of longitudinal fluid mixing or dispersion in the aeration chamber, and the feed concentration of organic sewage are two important parameters which affect the optimum design of activated sludge systems. Based on the models used in this work, longitudinal mixing appears to be undesirable, especially when the feed concentration of organic sewage is large.
Exploitation of Peasants: A Reply to Dunn

Danilova, L. V. 1971 Controversial Problems of the Theory of Precapitalist Societies. Soviet Anthropology and Archeology 9(4):269-328. 1973 Krestianstvo (Peasantry). In Bolshaia Sovetskaia Entsiklopediia. Vol. 14, cols. 1215-1223. Moscow: Publishing House of the Great Soviet Encyclopedia. Dunn, Stephen P. 1972 The Fall and Rise of the Asiatic Mode of Production. Paper presented at the Western Slavic Association Conference, Portland. Freeman, Susan T. 1970 Neighbors: The Social Contract in a Castilian Hamlet. Chicago: University of Chicago Press. Mandel, William M. 1969 Soviet Marxism and Social Science. In Social Thought in the Soviet Union. A. Simirenko, ed. Pp. 21-76. Chicago: Quadrangle Books. Martin, William 1966 Histoire de la Suisse: Essai sur la
Reversal of repolarization gradient does not reverse the chirality of shock-induced reentry in the rabbit heart.

Chirality and Repolarization. Introduction: Two hypotheses have been proposed to explain the mechanisms of vulnerability and related failure of defibrillation therapy: the cross-field-induced critical point hypothesis and the virtual electrode-induced phase singularity hypothesis. These two hypotheses predict the opposite effect of preshock repolarization on the chirality (direction of rotation) of shock-induced reentry. The former suggests its reversal upon reversal of repolarization, whereas the latter suggests its preservation. The aim of this study was to determine, by reversing the repolarization sequence, which of the mechanisms is responsible for internal shock-induced arrhythmia in the Langendorff-perfused rabbit heart. Methods and Results: We used high-resolution optical mapping to assess the chirality of postshock reentry in 11 hearts. Hearts were paced at a coupling interval of 300 msec at various sites around the field of view (13.5 × 13.5 to 16.5 × 16.5 mm). Cathodal monophasic implantable cardioverter defibrillator shocks (-100 V, 8 msec) were applied during the T wave from a 10-mm coil electrode placed into the right ventricular cavity. We used 3.5 ± 0.8 different pacing sites per heart. Change in direction of repolarization did not result in change of chirality. Chirality was constant in all 11 hearts despite the complete reversal of activation and repolarization patterns. However, the position of resulting vortices depended on transmembrane polarization gradient δVm and amplitude of negative polarization Vm (deexcitation). Stronger gradients and deexcitation produced earlier epicardial break excitation (P = 0.04 and P < 0.0001, respectively). Conclusion: Virtual electrode-induced phase singularity mechanism underlies internal shock-induced arrhythmia in this model.
An agent-based approach to the problem of evil

Le probleme logique du mal repose sur l'affirmation selon laquelle les etres bons sont motives par l'elimination du mal et la production du bien. L'A. affirme qu'une ethique de la vertu porte atteinte a cette affirmation pour des raisons qui n'ont rien a voir avec le probleme du mal ou des considerations theologiques. Il y a de bonnes raisons d'accepter une ethique fondee sur la notion d'agent a la fois dans l'experience et dans la theorie. L'A. plaide pour une theorie ethique fondee sur la notion d'agent associee a une conception chretienne traditionnelle de la nature de Dieu
Satellite accretion on to massive galaxies with central black holes

Minor mergers of galaxies are expected to be common in a hierarchical cosmology such as A cold dark matter. Though less disruptive than major mergers, minor mergers are more frequent and thus have the potential to affect galactic structure significantly. In this paper, we dissect the case-by-case outcome from a set of numerical simulations of a single satellite elliptical galaxy accreting on to a massive elliptical galaxy. We take care to explore cosmologically relevant orbital parameters and to set up realistic initial galaxy models that include all three relevant dynamical components: dark matter haloes, stellar bulges, and central massive black holes (BHs). The effects of several different parameters are considered, including orbital energy and angular momentum, satellite density and inner density profile, satellite-to-host mass ratio, and presence of a BH at the centre of the host. BHs play a crucial role in protecting the shallow stellar cores of the hosts, as satellites merging on to a host with a central BH are more strongly disrupted than those merging on to hosts without BHs. Orbital parameters play an important role in determining the degree of disruption: satellites on less-bound or more-eccentric orbits are more easily destroyed than those on more-bound or more-circular orbits as a result of an increased number of pericentric passages and greater cumulative effects of gravitational shocking and tidal stripping. In addition, satellites with densities typical of faint elliptical galaxies are disrupted relatively easily, while denser satellites can survive much better in the tidal field of the host. Over the range of parameters explored, we find that the accretion of a single satellite elliptical galaxy can result in a broad variety of changes, in both signs, in the surface brightness profile and colour of the central part of an elliptical galaxy. Our results show that detailed properties of the stellar components of merging satellites can strongly affect the properties of the remnants.
Modeling of the Amorphous Phase of Poly-CO with He and N

Density functional theory (DFT) and variational density functional perturbation theory (DFPT) simulations of amorphous poly-CO structures were performed to understand the stability of the polymerized structure at low pressures and to study the mechanism of destruction of the extended network at low pressures. Charge population analyses accompanied the search of the “weakest link” in the covalently bonded network. IR and Raman spectra of amorphous p-CO, calculated at 15 and 5.02 GPa, show significant contributions of CO molecules, carbonyl groups fragments decorating chains, and lactones of amorphous p-CO structures. DFT simulations of formation of amorphous polymeric structures were also done with the addition (as a result of replacement of CO molecules) of N or He atoms to the crystalline delta phase of CO. For the CO-N mixtures, the concentration of N was varied in the range from 6.25 % to 50% with different distribution patterns of N atoms in the unit cell. For all studied CO-N concentrations, isotropic compression led to CO polymerization beginning at a pressure of 11 GPa; the N was incorporated in the random network in low concentration. In CO-He mixtures He atoms appear to facilitate complete formation of the random structure which is almost completely polymerized at a pressure of 18 GPa. He atoms also help stabilize the structure at low pressures.
Morphometric variation and the classification of Pennisetum section Brevivalvula (Gramineae) in tropical Africa

Morphological data for 15 reproductive characters were compiled for 177 African collections of Penniseturn section Brevivalvula (Gramineae). Principal component analyses of the resulting data set revealed the presence of three phenetically distinct groups which are here treated as species. Although extensive morphological variation exists within two of these species, this variation is essentially continuous and is recognized here at the subspecific level.
Atmospheric compensation of extreme off-nadir hyperspectral imagery from Hyperion

Compared to nadir viewing, off-nadir viewing of the ground from a high-altitude platform provides opportunities to increase area coverage and to reduce revisit times, although at the expense of spatial resolution. In this study, the ability to atmospherically compensate off-nadir hyperspectral imagery taken from a space platform was evaluated for a worst-case viewing geometry, using EO-1 Hyperion data collected with an off-nadir angle of 63° at the sensor, corresponding to six air masses along the line of sight. Reasonable reflectance spectra were obtained using both first-principles (FLAASH) and empirical (QUAC) atmospheric-compensation methods. Some refinements to FLAASH that enable visibility retrievals with highly off-nadir imagery, and also improve accuracy in nadir viewing, were developed and are described.