cssi/SciSciGPT-SciSciNet huggingface dataset:
Challenges of interprofessional team training: a qualitative analysis of residents' perceptions.

Background: Simulation-based interprofessional team training is thought to improve patient care. Participating teams often consist of both experienced providers and trainees, which likely impacts team dynamics, particularly when a resident leads the team. Although similar team composition is found in real-life, debriefing after simulations puts a spotlight on team interactions and in particular on residents in the role of team leader. The goal of the current study was to explore residents' perceptions of simulation-based interprofessional team training. Methods: This was a secondary analysis of a study of residents in the pediatric residency training program at the University of California, San Francisco (United States) leading interprofessional teams in simulated resuscitations, followed by facilitated debriefing. Residents participated in individual, semi-structured, audio-recorded interviews within one month of the simulation. The original study aimed to examine residents' self-assessment of leadership skills, and during analysis we encountered numerous comments regarding the interprofessional nature of the simulation training. We therefore performed a secondary analysis of the interview transcripts. We followed an iterative process to create a coding scheme, and used interprofessional learning and practice as sensitizing concepts to extract relevant themes. Results: 16 residents participated in the study. Residents felt that simulated resuscitations were helpful but anxiety provoking, largely due to interprofessional dynamics. They embraced the interprofessional training opportunity and appreciated hearing other healthcare providers' perspectives, but questioned the value of interprofessional debriefing. They identified the need to maintain positive relationships with colleagues in light of the teams' complex hierarchy as a barrier to candid feedback. Discussion: Pediatric residents in our study appreciated the opportunity to participate in interprofessional team training but were conflicted about the value of feedback and debriefing in this setting. These data indicate that the optimal approach to such interprofessional education activities deserves further study.
Development of a framework for contextual concept learning

This paper shows how several limitations of inductive concept learning methods can be overcome by giving the learning system explicit knowledge of the context in which learning occurs, including knowledge of 1) the kind of concept to be learned, 2) the performance system to be improved by learning and 3) an underlying plan linking the learned concept with expected performance improvement.
Syntactic Complexity and Cognitive Style.

In Study 1, writing samples from secondary and post-secondary students were used to examine the underlying structures of 16 indices of syntactic complexity known to be related to good writing. Factor analysis revealed six syntactic dimensions: unbound description, coordination, unbound description-final position, embedding, elongation, and prepositions. Subscales were constructed to assess each dimension. The purpose of Study 2 was to examine correlations among the six syntactic dimensions and three measures of cognitive style: field-embeddedness, category width, and perceptual accuracy. A coincidence of significant correlations between nearly all of the syntactic subscales and measures of both field-independence and reflectivity indicated an association between syntactic complexity and an analytic cognitive style. Preferred styles of organization applied to verbal and to visual stimuli alike. The ability to analytically perceive spatial relationships is clearly associated with the ability to manipulate language effectively.
Impact of technological affordances on cognitive engagement in computer supported collaborative learning environments

Comprehending complex systems is difficult as some interactions between parts are invisible and as result, that makes them difficult to perceive (Feltovich et al., 2001). In order to strengthen their conceptual understanding of such complex phenomena, students need to have a great amount of interest, and an enhanced psychological investment in learning i.e. persistence in the face of failure or challenge, all of which are indicators of cognitive engagement. By providing ease of use, aesthetic appeal, choice, feedback, challenge, variety and interactivity, technology has great potential to engage learners. This also provides students with opportunities where they can think critically, make judgments and solve complex open ended problems. This study uses three different kinds of technologies to engage students as they study about one such complex system -the aquatic ecosystem. The purpose of this dissertation is to observe how affordances of these technologies encourage the students to remain cognitively engaged.
Coral settlement onto Halimeda opuntia : a fatal attraction to an ephemeral substrate?

Degraded reefs with a high abundance of macroalgae usually also have low densities of coral recruits. Few studies, however, have examined whether these algae affect coral larval settlement. This study demonstrates, experimentally, that larvae of the Caribbean coral Favia fragrum can settle on the green alga Halimeda opuntia even when another substrate more suitable for settlement is present. Larval settlement onto experimental substrates was quantified under three treatments: rubble only, rubble plus plastic algal mimic, and rubble plus live H. opuntia. Similar total larval settlement was observed in all treatments. No larvae settled on the algal mimic, but total settlement was similar on the rubble in the first two treatments, showing that the rubble alone offered sufficient substrate for high settlement success. About half the larvae in the live algal treatment settled on H. opuntia instead of on the rubble, showing that larvae did not reject this substrate as they did the algal mimic. This result raises the possibility that corals will settle on some macroalgae when their abundance is high. Most macroalgae, including H. opuntia, are ephemeral substrates unsuitable for post-settlement survival. Such unexpected settlement may therefore have significant consequences for coral recruitment success on algal-dominated reefs.
Studies on the mechanism of enzymatic DNA elongation by Escherichia coli DNA polymerase II.

Abstract The mechanism of enzymatic elongation by Escherichia coli DNA polymerase II of a DNA primer, which is annealed to a unique position on the bacteriophage fd viral DNA, has been studied. The enzyme is found to dissociate from the substrate at specific positions on the genome which act as “barriers” to further primer extension. It is believed these are sites of secondary structure in the DNA. When the template is complexed with E. coli DNA binding protein many of these barriers are eliminated and the enzyme remains associated with the same primer-template molecule during extensive intervals of DNA synthesis. Despite the presence of E. coli DNA binding protein, at least one barrier on the fd genome remains rate-limiting to chain extension and disturbs the otherwise processive mechanism of DNA synthesis. This barrier is overcome by increasing the concentration of enzyme. In contrast, it is found that DNA polymerase I is not rate-limited by structural barriers in the template, however, it exhibits a non-processive mechanism of elongation. These findings provide a framework for understanding the necessity for participation of proteins other than a DNA polymerase in chain extension during chromosomal replication.
Dietary protein content affects the response of meadow voles, Microtus pennsylvanicus , to over-marks

The response to signals, including scent marks, from opposite-sex conspecifics can be affected by the nutritional state of both the sender and receiver of these signals. Protein content of the diet affects how meadow voles (Microtus pennsylvanicus) respond to single scent marks, but it is unknown how it affects an individual’s response to the overlapping scent marks of two donors (an over-mark). In experiment 1, we tested the hypothesis that protein content of the diet affects the amount of time voles spend investigating the marks of the top- and bottom-scent donors of an over-mark. Males and females fed a 22% protein diet spent more time investigating the scent mark of the top-scent donor than that of the bottom-scent donor; voles fed 9% and 13% protein diets spent similar amounts of time investigating the top- and bottom-scent donors. In experiment 2, we tested the hypothesis that protein content of the diet of the top- and bottom-scent donors affects the amount of time conspecifics spend investigating their scent marks. Female voles spent more time investigating the mark of the top-scent male than that of the bottom-scent male, independent of the differences in protein content of the diets of the top- and bottom-scent donors. Male voles, however, spent more time investigating the top-scent female when she was fed a diet higher in protein content than that of the bottom-scent female. Our results are discussed within the context of the natural history of voles.
Seasonal, Small-Scale Distribution of Atka Mackerel in the Aleutian Islands, Alaska, with Respect to Reproduction

Abstract We investigated the spatial distribution of Atka mackerel Pleurogrammus monopterygius with respect to maturity stage at Seguam Pass in the Aleutian Islands as well as their spawning locations within trawlable areas at three small-scale (10–20-nautical mile or 18.5–37.0-km) sites. Histological methods were used to determine maturity stages, and male maturity stages are described for the first time. Spawning areas were identified by catch per unit effort of demersal egg masses. At Seguam Pass, spawning was concentrated in the area adjacent to the east side of Amlia Island and between Amlia and Seguam islands. The observed spatial segregation of Atka mackerel by sex and maturity stage appears to interact with the boundaries of the trawl exclusion zone (TEZ) at Seguam Pass. During spawning, mature fish aggregate inside the closed area and immature fish and nonreproductively active mature males aggregate outside the TEZ in the area open to fishing. This increased the commercial catch selectivity of no...
Using Surface Plasmon Resonance Spectroscopy To Measure the Association of Detergents with Self-Assembled Monolayers of Hexadecanethiolate on Gold

This paper describes the use of surface plasmon resonance (SPR) spectroscopy to measure the rates and extents of association of four detergentssodium dodecyl sulfate (SDS), β-octyl glucoside, Triton X-100, and Tween 20to self-assembled monolayers (SAMs) of alkanethiolates on gold. SAMs presenting hexaethylene glycol groups resisted the adsorption of all four detergents. These same detergents associated with hydrophobic SAMs presenting methyl groups; the concentration of detergent molecules on the surface was 120−280 pmol/cm2. The associations of the detergents with the hydrophobic SAM were described well by the Langmuir adsorption isotherm. The dissociation constants Kd (M) for the desorption of the detergents from the surface correlated with the critical micelle concentration (cmc, M) of the detergents in solution, and followed the relationship cmc ≈ 7 (±2)Kd. The efficacy of SDS in removing the protein fibrinogen adsorbed on a hydrophobic SAM depended strongly on the concentration of detergent. SDS at a...
SU-E-T-302: Spine SBRT Planning for Patients with Spinal Hardware

Purpose: To investigate the effects of different imaging artifact correction strategies and susceptibility to setup errors for multiple spinal SBRT planning approaches in treating a patient with titanium hardware. Methods: Two-step-IMRT, IMRT and two arc VMAT plans were created for a C-spine SBRT case with titanium hardware. The plans were normalized to the maximum point dose to the thecal sac. Density overrides for the planning CT were applied to mitigate imaging artifacts. All plans were recalculated on CTs with no density overrides and with the density of all structures set to 1g/cm^3. Setup errors up to 2mm toward the spinal cord were simulated. Results: The 2-step IMRT plans achieved a mean dose to the cord of 6.5Gy compared to 8.0 and 8.7Gy for the IMRT and VMAT plans. The PTV coverage was comparable for both the 2-step-IMRT and the IMRT plan. The VMAT plan achieved a higher mean dose, but had hot spots >130%. If no density overrides were applied for the same MUs the increase in maximum dose to the cord was 0.3, 1.2 and 0.0% for 2-step-IMRT, IMRT and VMAT plans, respectively, compared to an increase of 2.3, 2.0 and 1.0% for unit density override.An isocenter shift of 2mm toward the cord resulted in an increase in maximum dose to the cord of 10.7, 8.0 and 5.0% for the 2-step IMRT, IMRT and VMAT plan, respectively, with the absolute dose to the cord still being lowest for the 2-step-IMRT plan compared to the other plans without simulated setup errors. Conclusion: The 2-step-IMRT plan achieved the clinically most acceptable dose distribution. The plan quality was relatively insensitive to density overrides. The 2-step-IMRT plan was the most sensitive to setup errors due to the steep gradient but this was offset by the initial improvement in sparing of the cord.
Prenatal development of gonadotropin-releasing hormone receptors in the rat anterior pituitary.

The development of pituitary GnRH receptors was studied in the rat with in vitro and in vivo autoradiography. GnRH receptors were first seen in pituitary primordia of 13- day-old fetuses. The binding was specific and saturable and was abolished in the presence of 10 μM synthetic GnRH. To examine whether GnRH was available to the fetus, amnionic fluid was collected on days E 12–18. RIA analyses showed that GnRH levels in the amnionic fluid were low on days 12 and 13 (0–20 pM/ml) and rose to 225 pM/ml on day E 16 before they declined to 110 pM/ml on fetal day E 18. The highest levels of GnRH in the amnionic fluid on day E 16 coincided with the first appearance of immunoreactive LH cells, as determined by immunohistochemistry. Intravenous injection of 500 μl amnionic fluid into pentobarbital-anesthetized adult rats caused a transient 40–60% increase in circulating serum LH in the recipient animal. To show that GnRH from the amnionic fluid has access to the developing pituitary, the 125I-labeled GnRH agonist ...
Modeling nitrogen saturation in forest ecosystems in response to land use and atmospheric deposition

Abstract A generalized, lumped-parameter model of carbon (C), water, and nitrogen (N) interactions in forest ecosystems (PnET-CN) is presented. The model operates at a monthly time step and at the stand-to-watershed scale, and is validated against data on annual net primary productivity, monthly carbon and water balances, annual net N mineralization, nitrification, foliar N concentration and annual and monthly N leaching losses for two sites, Hubbard Brook (West Thornton, NH) and Harvard Forest (Petersham, MA). It is then used to predict transient responses in function resulting from changes in land use and N deposition, as well as the maximum rate of N cycling which can be sustained for any given combination of site, climate and species. Model predictions suggest a very long legacy effect of land use history on N cycling. Even with only one ‘active’ soil organic matter pool, complete recovery from three modest harvests at Hubbard Brook is predicted to require more than two centuries at current N deposition rates. Complete recovery is predicted to take even longer at the Harvard Forest where biomass removals have been more intense. PnET-CN is used to predict maximum sustainable rates of N cycling for 14 sites throughout the northeastern USA. Predicted maximum values were higher, as expected, than measured N mineralization rates for all but one site. The measured fraction of N mineralization nitrified at these 14 sites showed a general relationship with the ratio of measured to maximum net N mineralization. This latter ratio is discussed as a potentially useful indicator of the degree of nitrogen saturation in forest ecosystems. A regional map of predicted maximum N cycling rates is presented based on regressions between model predictions and summary climatic variables.
An Analysis of Frequency Modulation Circuit Using p-n Junction Varactors

Simple circuits performing oscillation-frequency modulation functions using one active device and p-n junction type varactors are studied. The performance of the common circuit is analyzed. Equations are derived to determine signal-to-frequency deviation, transducer gain, frequency deviation, input impedance, distortion, maximum signal, noise and signal sensitivity, dynamic range, and maximum resolution. The upper or lower bounds of these quantities are given as functions of the varactor parameters and circuit constants.
In Silico Polymerization: Computer Simulation of Controlled Radical Polymerization in Bulk and on Flat Surfaces

We use Monte Carlo computer simulation to study the effect of several molecular parameters on controlled/“living” radical polymerization in bulk and on flat substrates. Specifically, we investigate how the molecular weight and molecular weight distribution of grown polymers depend on the initial number of initiators, the initial number of monomers, the initiator activation probability, the initial probability of addition of a new monomer to a growing chain, the probability of terminating two “living” polymers, and the numbers of “living” polymers and their lifetime. Some observations reported here are common to both bulk- and surface-initiated polymerizations. Specifically, we demonstrate that increasing the termination probability and/or decreasing the initial probability of addition of a new monomer to a growing chain broadens the molecular weight distribution. In addition, decreasing the lifetime of the “living” radicals results in polymers with narrower molecular weight distributions. One of the goals...
U.S. Global telecommunications: The popcorn principle

Abstract The telecommunications policies of the United States have mostly been spearheaded through the “Free Market Philosophy.” The Federal Communications Commission has been most influential in leading this effort. This philosophy has permeated U.S. international telecommunications, and its effects are producing interesting results worldwide.
Stream Scheduling: A Framework to Manage Bulk Operations in a Memory Hierarchy

Summary form only given. Recently, streaming architectures such as Imagine, Merrimac and cell were demonstrated to achieve significantly higher performance and efficiency over traditional architectures by introducing an explicitly managed on-chip storage in the memory hierarchy. This software managed memory serves as a staging area for bulk amounts of data, making all functional unit references short and predictable, while data is asynchronously transferred from external memory. The decoupling of computation from memory accesses allows the software to statically optimize the execution pipeline, transferring the onus of latency tolerance from hardware to software.
Hyperfine Structures, Isotope Shifts, and Nuclear Moments of Hg 195 , Hg 195 m, and Hg 194 †

The hyperfine structures of five lines in the optical spectra of Hg195, Hg195m, and Hg194 have been investigated under high resolution. The nuclear moments, calculated from ratios of hyperfine splittings, are μ(195m) = −1.060 ± 0.01 nm, Q(195m) = 1.5 ± 1 b, and μ(195) = +0.526 ± 0.005 nm. Isotope shifts measured relative to Hg196 were found to be Δ(195–196) = +77.2 ± 5 mK, Δ(195m–196) = +92.6 ± 5 mK, and Δ(194–196) = +143 ± 10 mK. The last result is not in agreement with published measurements. Further investigation is required before a theory can be considered applicable.
Amino-acid substitution in haemoglobin I (Texas variant).

AN electrophoretically fast genetic variant of adult haemoglobin was described in six members of a Negro family living in Texas by Thompson et al. in 1963 (ref. 1). Fingerprints of the purified haemoglobin established the identity of this variant with haemoglobin I previously described by Murayama and Ingram2, in which the third tryptic peptide from the N-terminus of the α chain contained an amino-acid alteration responsible for the rapid electrophoretic migration of the intact haemoglobin. Lysine, which is the sixteenth residue, had been replaced in haemoglobin I by an acidic amino-acid. The substitution was described in both I variants from Texas1 and Philadelphia3 as being lysine to aspartic acid; however, recent elucidation of the genetic code has eliminated the substitution lys→asp from the class of mutations which could result from alteration of a single nucleotide base in the triplet code4. A nucleotide triplet coding for lysine (AAA or AAG) could not be altered in a single base so that it would specify aspartic acid (GAU or GAC). This led Beale and Lehmann5 to re-examine the I variant from Philadelphia. Their findings established the substitution to be lys→glu, which is in agreement with an alteration in a single nucleotide (AAA or AAG to GAA or GAG).
Microbial C-hydroxylation and β-4-O-methylglucosidation of methyl-benzamide 7-azanorbornane ethers with Beauveria bassiana

Abstract N -Substituted 7-azanorbornanes were prepared by acylation of easily accessible 7-azanorbornane hydrochloride. Derivatives possessing an electron-withdrawing docking/protecting group and bearing an aryl methylether were subjected to biotransformation with the fungus Beauveria bassiana ATCC 7159. O -Demethylation and β-4- O -methylglucosidation reactions were observed for the major metabolite in this biotransformation (isolation yields: 6 , 30%; 11a , 44%; 11b , 47%; 11c , 14%). C -Hydroxylation on an unfunctionalized carbon was also observed in most of the cases.
Colonic manifestations of PTEN hamartoma tumor syndrome: case series and systematic review.

AIM: To investigate our clinical experience with the colonic manifestations of phosphatase and tensin homolog on chromosome ten (PTEN) hamartoma tumor syndrome (PHTS) and to perform a systematic literature review regarding the same. METHODS: This study was approved by the appropriate institutional review board prior to initiation. A clinical genetics database was searched for patients with PHTS or a component syndrome that received gastrointestinal endoscopy or pathology interpretation at our center. These patient’s records were retrospectively reviewed for clinical characteristics (including family history and genetic testing), endoscopy results and pathology findings. We also performed a systematic review of the literature for case series of PHTS or component syndromes that reported gastrointestinal manifestations and investigations published after consensus diagnostic criteria were established in 1996. These results were compiled and reported. RESULTS: Eight patients from our institution met initial inclusion criteria. Of these, 5 patients underwent 4.2 colonoscopies at mean age 45.8 ± 10.8 years. All were found to have colon polyps during their clinical course and polyp histology included adenoma, hyperplastic, ganglioneuroma and juvenile. No malignant lesions were identified. Two had multiple histologic types. One patient underwent colectomy due to innumerable polyps and concern for future malignant potential. Systematic literature review of PHTS patients undergoing endoscopy revealed 107 patients receiving colonoscopy at mean age 37.4 years. Colon polyps were noted in 92.5% and multiple colon polyp histologies were reported in 53.6%. Common polyp histologies included hyperplastic (43.6%), adenoma (40.4%), hamartoma (38.3%), ganglioneuroma (33%) and inflammatory (24.5%) polyps. Twelve (11.2%) patients had colorectal cancer at mean age 46.7 years (range 35-62). Clinical outcomes secondary to colon polyposis and malignancy were not commonly reported. CONCLUSION: PHTS has a high prevalence of colon polyposis with multiple histologic types. It should be considered a mixed polyposis syndrome. Systematic review found an increased prevalence of colorectal cancer and we recommend initiating colonoscopy for colorectal cancer surveillance at age 35 years.
Light transmittance across smoke plumes downwind from point sources of aerosol emissions

Abstract A new calculation procedure for theoretically predicting the magnitude of light transmittance across a smoke plume downwind of its emission source is presented. The calculation procedure is based on a combination of Mie light scattering theory and the Gaussian (Pasquill-Gifford) plume diffusion equations. Source information needed to estimate the light transmittance through the plume at a given downwind include the meteorological conditions, stack height, gas exhaust temperature and velocity, aerosol emission mass flowrate, size distribution, and refractive index. Graphs of the horizontal plume light transmittance dispersion parameter and the horizontal average extinction coefficient dispersion parameter are presented as a function of the downwind distance. A sample calculation is included to illustrate the procedure and use of the various parameters.
Some theoretical and practical considerations for multivariate statistical cell classification useful in autologous stem cell transplantation and tumor cell purging.

Background: As flow cytometric data becomes more complex, it becomes increasingly difficult to classify cells using conventional flow cytometry data techniques based on visual classification of the data by user-drawn regions. This paper shows some simple applications of multivariate statistical classification to classify flow cytometric data. Methods: Discriminant Function Analysis (DFA) and Logistic Regression (LR) analysis techniques were evaluated with respect to their potential utility in the problem of detecting human breast cancer cells within normal bone marrow cells. Data sets having defined properties were employed to evaluate the potential utility of these statistical classification techniques whose performance was measured by ROC analysis. Results: Two extreme but reasonable situations are presented: (1) data where the separation of cells was obvious by visual inspection and (2) data where major overlaps in the values of the individual FCM parameters made intuitive classification improbable. Both DFA and LR analysis were able to classify the cells of each type with acceptable accuracy and yield. Conclusions: The excellent empirical performance of both DFA and LR techniques, suggests that they offer promising approaches for classifying multiparameter FCM data using objective rules that may represent an improvement over commonly employed ad hoc approaches. Cytometry 36:60‐70, 1999. r 1999 Wiley-Liss, Inc.
Aldehyde oxidase activity during development in Musca domestica

Abstract 1. 1. Polyacrylamide gel electrophoresis was used to demonstrate several bands of aldehyde oxidase activity in homogenates of Musca domestica eggs, larvae, pupae, and adults. Isoelectric points of these bands were within the range of 4.4–5.3. 2. 2. Homogenates of late pupae and early adult flies exhibited the greatest aldehyde oxidase specific activities. 3. 3. Larval gut homogenate contained the greatest specific activity while Malpighian tubules and fat body homogenates, respectively, exhibited lesser aldehyde oxidase specific activities. 4. 4. Thermostability of aldehyde oxidase activity was examined by heating homogenates of larvae, pupae, and adults at 60°C for varying times. In larval and pupal homogenates approx. 70% of the aldehyde oxidase specific activity remained after heating for 1 hr whereas 80% of the adult aldehyde oxidase activity was lost after 10 min of heating.
Living Beyond Our “Means”: New Methods for Comparing Distributions

This paper introduces the projection methods for describing and testing the differences between pairs of continuous distributions. These methods include the projection plot, the projection spline, and the iter-1 test. The projection plot displays the difference between corresponding quantiles against the average of the corresponding quantiles. It is analogous to an empirical quantile-quantile plot that has been rotated 45 degrees. The projection spline is a knotted linear spline iteratively fit to the projection plot so that all knots are associated with significant changes in slope. It summarizes nonrandom deviations from linearity on the projection plot, allowing classification of the highest level of difference between two distributions as a difference in shape, in spread, or in location. The iter-1 test compares the first iteration of the projection spline with the line y = 0, providing a global test of difference between two distributions that is more powerful in simulations than either the chi-square test of independence or the Kolmogorov-Smirnov test. These methods will enhance epidemiologic practice by making the comparison of full distributions an accessible tool for routine data analysis.
Graduate studies in acoustics at Northwestern University

Northwestern University has a vibrant and highly interdisciplinary community of acousticians. Of the 13 ASA technical areas, three have strong representation at Northwestern: Speech Communication, Psychological and Physiological Acoustics, and Musical Acoustics. Sound-related work is conducted across a wide range of departments including Linguistics (in the Weinberg College of Arts and Sciences), Communication Sciences & Disorders, and Radio/Television/Film (both in the School of Communication), Electrical Engineering & Computer Science (in the McCormick School of Engineering), Music Theory & Cognition (in the Bienen School of Music), and Otolaryngology (in the Feinberg School of Medicine). In addition, The Knowles Hearing Center involves researchers and labs across the university dedicated to the prevention, diagnosis and treatment of hearing disorders. Specific acoustics research topics across the university range from speech perception and production across the lifespan and across languages, dialect an...
Carbon−Fluorine Bond Activation Coupled with Carbon−Hydrogen Bond Formation α to Iridium: Kinetics, Mechanism, and Diastereoselectivity

Reactions of iridium(fluoroalkyl)hydride complexes Cp*Ir(PMe3)(CF2RF)Y (RF = F, CF3; Y = H, D) with LutHX (Lut = 2,6-dimethylpyridine; X = Cl, I) results in C−F activation coupled with hydride migration to give Cp*Ir(PMe3)(CYFRF)X as variable mixtures of diastereomers. Solution conformations and relative diastereomer configurations of the products have been determined by 19F{1H}HOESY NMR to be (SC, SIr)(RC, RIr) for the kinetic diastereomer and (RC, SIr)(SC, RIr) for its thermodynamic counterpart. Isotope labeling experiments using LutDCl/Cp*Ir(PMe3)(CF2RF)H and Cp*Ir(PMe3)(CF2RF)D/LutHCl) showed that, unlike a previously studied system, H/D exchange is faster than protonation of the α-CF bond, giving an identical mixture of product isotopologues from both reaction mixtures. The kinetic rate law shows a first-order dependence on the concentration of iridium substrate, but a half-order dependence on that of LutHCl; this is interpreted to mean that LutHCl dissociates to give HCl as the active protic source ...
The impact of experience on individual performance and workload differences using object-oriented and process-oriented systems analysis techniques

Interest in object oriented analysis (OOA) and object oriented design (OOD) has increased over the last several years. Proponents of OOA and OOD have called the shift to these methods "revolutionary" and have cited a number of impressive claims with respect to their use. However, empirical research investigating these claims remains in its infancy. This research study was conducted to test theoretical hypotheses designed to better understand the findings of previous research. The paper presents the results of an empirical study which examined both experienced and novice systems analysts using both procedural and object oriented techniques. This research examined whether experience in using procedural methods helped or hindered performance using OOA and compared procedural and OOA methods on the subjective mental workload induced. A cognitive processing model adapted from DeSanctis (1984) and Huchins, Hollan, and Norman (1985) provided the theoretical framework for this study. Dependent variables include subjective mental workload time to perform task, and attitudinal measures. While some of these dependent variables have been used in past research, we believe this is the first time that subjective mental workload (SMW) has been examined in an IS context. Our results indicate that both novice and experienced subjects demonstrate higher SMW when using OOA. However as a group, novices prefer object oriented techniques and find these techniques easier as compared to experienced subjects.
COMPARISON OF FORELIMB AND HINDLIMB MOTOR DEFICITS FOLLOWING DORSAL COLUMN SECTION IN MONKEYS

Macaca speciosa monkeys were trained to acquire food reinforcement with motor responses that were defined by 4 different tasks. The effects of dorsal column lesions on the speed of these responses were compared for the forelimbs vs. the hindlimbs. Enduring impairments were not seen for any limb when the animal was required to accurately project a limb to different points in space, even with exclusion of visual guidance and with random variation of the start and stop points for each movement. Similarly, when the task required that the animals emit rapid response sequences, the forelimbs were impaired temporarily, but no long-term deficits were seen for the forelimbs or the hindlimbs. Although these impositions of spatial and temporal demands did not reveal striking disruptions of whole-limb movements, hindlimb grasp responses were shown to be impaired over long periods of postoperative testing. This corroborates previous findings for the forelimb and indicates that facility of distal extremity movement depends crucially on dorsal column-lemniscal input.
Residual bounds for varieties of modules

In [3] and also in [4], Freese and McKenzie prove that a finitely generated congruence modular variety is residually small if and only if it is residually less than n for some n < ~o. In fact, they showed that ifA generates a residually small congruence modular variety and [A] = m, then "//(A) is residually less than the bound l! + m where l = m .... 3. They obtained this result by associating to ~'(A) a finite ring with unit, R = R(~(A), m), and relating the size of the subdirectly irreducible algebras in "f/"(A) to the size of subdirectly irreducible R-modules. Their final bound is based on two estimates. First they estimate that tR[ < / = m m'~ ~. Then they show that ifR is a ring of cardinality l, the subdirectly irreducible R-modules are bounded by l!. Using these estimates and applying modular commutator theory leads them to their result. In [1], we asked whether there is a function f such that for any residually small variety f~ with the CEP that is generated by an algebra of cardinality m, one has that ~ is residually less than f(m). This question was answered affimatively by E. Kiss in [2]. His proof does not produce a suitable function and no choice for f is known. We will show that, if R is finite, no subdirectly irreducible R-module can have larger cardinality than IR]. This has the effect of removing the factorial sign in Freese and McKenzie's result. It has a second consequence of providing a tight bound on the size of subdirectly irreducibles in finitely generated, congruence modular varieties with the CEP.
Experimental studies of Cl-atom reactions at high temperatures: Cl+H2→HCl+H from 291 to 1283 K

A method is presented for producing Cl atoms for kinetic experiments above 750 K. Combined with alow temperature Cl-atom production technique, rate coefficients for the title reaction have been obtained over a wide temperature range. The Cl atoms were generated by flash photolysis of CCl 4 for the lowtemperature measurements and by pulsed laser photolysis of NaCl for the high-temperature measurements. The relative Cl-atom concentrations were monitored by time-resolved resonance fluorescence. The data are well fitted by the expression k 1 (291–1283 K)=4.4×10 −11 exp(−2568 K/ T ) cm 3 molecule −1 s −1 , with 2σ precision limits of ±9 to ±16%, depending on temperature, and corresponding 2σ accuracy limits of about ±26%. There is good agreement between the rate coefficients measured here and those from previous low-temperature studies, leading to the recommendation k 1 (200–1283 K)=2.3×10 −16 ( T /K) 1.63 exp(−1592 K/ T ) cm 3 molecule −1 s −1 , with a suggested 2σ accuracy limit of ±28% for the combined data. A transition state theory calculation based on a semiempirical London-Eyring-Polanyi-Sato (LEPS) potential energy surface gives excellent agreement with the combined experimental results. Extension of our previous recommendation for the reverse reaction to lower temperatures leads to k 2 (200–1200 K)=6.6×10 −16 ( T /K) 1.44 exp(−1241 K/ T ) cm 3 molecule −1 s −1 , with 2σ accuracy limits within ±25%. There is excellent agreement between the present data and the predicted expression from that reaction and equilibrium data.
Dependence of speed of sound on salinity and temperature in concentrated NaCl solutions

Abstract An ultrasonic velocimeter for salinity measurements in a solar pond has been developed and tested. Calibration of the probe is accomplished by comparing speed of sound measurements in distilled water with accepted values. Speed of sound in NaCl solutions with salinities from 0%–21% by weight has been measured over a temperature range of 7°–88°C. An equation has been developed to compute salinity from the measured speed of sound and the temperature for NaCl solutions. Accuracies better than 0.2% by weight have been demonstrated. The method shows good potential for in situ salinity measurements in salt-gradient solar ponds.
A Re-Evaluation of Raven's Standard Progressive Matrices

Summary The utility of Raven's Standard Progressive Matrices (RPM) as a measure of intelligence (IQ) was studied. RPM was administered to 380 Vocational Rehabilitation applicants and correlated with selected variables and IQ measures. The results indicate that use of RPM 1948 British norms on U. S. Vocational Rehabilitation and general populations is a viable procedure where there is no need for IQ accuracy over 120. RPM did show a ceiling of about IQ 120. Construct validity was reinforced by correlations of RPM with other standard IQ measures. RPM shows the same race effect as is found regularly—the white mean is higher than the black mean—and is related to number of years education.
Performance of longitudinal-mode KD*P Pockels cells with transparent conductive coatings

Transparent conductive coatings of indium tin oxide have been deposited onto KD*P crystals using an ion-assisted deposition process. Three devices have been fabricated with gold rings for electrical contacting. The devices have been tested optically and electrically, and the damage thresholds of the coatings have been measured. A device was used as the Q-switch in a pulsed Nd:YLF laser.
Enzymatic deglycosylation of thyroid-stimulating hormone with peptide N-glycosidase F and endo-β-N-acetylglucosaminidase F

We investigated the ability of two enzymes, peptide N-glycosidase F (PNGase F) and endo-beta-N-acetylglucosaminidase F (Endo F), to deglycosylate microgram quantities of bovine TSH and its subunits under nondenaturing conditions. One oligosaccharide chain could be selectively removed from the alpha subunit by PNGase F, and all the oligosaccharide chains from both subunits could be removed by Endo F. These methods of enzymatic deglycosylation should permit study of the functional role of each N-linked carbohydrate chain of various glycoprotein hormones.
Challenges in building large-scale information retrieval systems: invited talk

Building and operating large-scale information retrieval systems used by hundreds of millions of people around the world provides a number of interesting challenges. Designing such systems requires making complex design tradeoffs in a number of dimensions, including (a) the number of user queries that must be handled per second and the response latency to these requests, (b) the number and size of various corpora that are searched, (c) the latency and frequency with which documents are updated or added to the corpora, and (d) the quality and cost of the ranking algorithms that are used for retrieval. In this talk I will discuss the evolution of Google's hardware infrastructure and information retrieval systems and some of the design challenges that arise from ever-increasing demands in all of these dimensions. I will also describe how we use various pieces of distributed systems infrastructure when building these retrieval systems. Finally, I will describe some future challenges and open research problems in this area.
Hybrid Feature Tracking and User Interaction for Markerless Augmented Reality

We describe a novel markerless camera tracking approach and user interaction methodology for augmented reality (AR) on unprepared tabletop environments. We propose a real-time system architecture that combines two types of feature tracking methods. Distinctive image features of the scene are detected and tracked frame- to-frame by computing optical flow. In order to achieve real-time performance, multiple operations are processed in a multi-threaded manner for capturing a video frame, tracking features using optical flow, detecting distinctive invariant features, and rendering an output frame. We also introduce a user interaction for establishing a global coordinate system and for locating virtual objects in the AR environment. A user's bare hand is used for the user interface by estimating a camera pose relative to the user's outstretched hand. We evaluate the speed and accuracy of our hybrid feature tracking approach, and demonstrate a proof-of-concept application for enabling AR in unprepared tabletop environments using hands for interaction.
Multiplex architecture for 3 x 3 coupler based fiber optic sensors

This paper presents a frequency division multiplexing (FDM) design that is compatible with 3 X 3 coupler terminated Mach-Zehnder interferometric sensors. Unlike the FDM technique that is presently used with phase generated carrier (PGC) demodulation schemes, this technique does not require modulation of the wavelength of the laser source or the introduction of optical path differences (OPD) in the interferometer in order to generate a phase carrier modulation in the interferometer. The technique described in this paper relies simply on amplitude modulation (AM) of the light intensity and uses the three outputs of an interferometer to unambiguously recover the phase modulation in the interferometer.
Collapsing binary data for algebraic multidimensional representation

Abstract Much recent work has been focused on non-probabilistic multidimentional scaling techniques for binary data. A paradigm to which many of these methods apply involves interpreting the data matrix as defining a binary relation R from the set A of subjects to the set M of response items. Generally assumptions are made which permit the task of determining the minimum number of dimensions mediating response with which the data are consistent to be recast into the problem of finding as small as possible a family Γ of relations of a particular type such that ⋂Γ = R (⋃ Γ = R) Typically the latter task turns out to be NP-hard. Consequently, the practicability of a given algebraic representation method depends in large part on the degree to which the relation to be represented can be collapsed prior to processing. We define for any relation R , a couple of distinguished restrictions, the ∩- core and the ∪- core of R such that 1. (i) the cardinalities of these restrictions are often substantially smaller than that of R ; 2. (ii) they may be constructed at polynomial expense; 3. (iii) for an important subclass of algebraic representation techniques the task of obtaining a minimal family Γ satisfying (∗) is polynomially reducible to the same task with respect to the ∩-core (or ∪-core) of R . The collapsing methods developed are applied to a body of data drawn from S.A. Stouffer, L. Guttman, E. A. Schuman, P. Lazarsfeld, S. A. Star, and J. A. Clausen (1950, Measurement and prediction , Princeton, NJ: Princeton Univ. Press) in the construction of a representation reflecting the underlying dimensions of combat-readiness of World War II GI's.
The economics of brood raiding and nest consolidation during ant colony founding

The most dangerous time for an ant colony is during the founding stage when the small colony is vulnerable to predation and competition. Colonies can grow more rapidly when multiple queens cooperate in raising the first worker brood (pleometrosis) or by raiding other incipient colonies for their brood. This brood raiding has been proposed to be the primary force selecting for pleometrosis, i.e. multiple-queen colonies may have a considerable advantage in destroying neighbours by aggressively stealing their brood. An alternative hypothesis is that incipient nests are part of a larger, interconnected population structure and that brood raiding reflects cooperative pleometrosis with subdivided colonies. A simple mathematical model supports the second hypothesis: workers of incipient colonies are especially favoured to peaceably abandon their nest and join with other colonies if the queens are related or queens from raided colonies can infiltrate the raiding colony. The latter condition is often met in ant species that brood raid and particularly exemplified in fire ants (Solenopsis invicta), where brood raiding involves little mortal combat and combines with pleometrosis to rapidly increase colony size. It is proposed that the term nest consolidation should replace brood raiding to more accurately reflect the relatively non-aggressive and potentially apparently cooperative nature of interactions between incipient ant colonies.
Intestinal metabolism of cholesterol: evidence against side-chain oxidation by mammalian intestinal mucosa.

SummaryPreparations of intestinal mucosal scrapings, homogenates, and mitochondria from normal rats and guinea pigs, and mucosal scrapings and everted intestinal segments from bile-fistula rate, failed to oxidize cholesterol-26-14C to 14CO2. It is concluded that oxidation of side-chain in the intestinal mucosal cell is not a quantitatively significant metabolic fate of cholesterol.
Use of a solid-state detector for the analysis of x-rays excited in silicate rocks by alpha-particle bombardment.

The analysis of alpha-excited X-rays has been studied as a possible addition to the alpha-scattering technique used on the Surveyor spacecraft for the first in situ chemical analyses of the lunar surface.