cssi/SciSciGPT-SciSciNet huggingface dataset:
On the topology of filaments and chromospheric fibrils near sunspots

The similarity between the spiral topology of chromospheric fibrils and filaments observed in Hα near sunspots and the configuration of an axisymmetric force-free magnetic field is examined. It is suggested that some of the observed features could be interpreted in terms of the configuration of lines of force of an axisymmetric force-free chromospheric magnetic field. Implications of the results of analysis to the possible interpretations of other observed topological features near a sunspot are discussed.
Reexamining the relationship between working memory and comprehension: The role of available long-term memory

Two individual differences studies tested relationships between listening comprehension and two conceptualizations of working memory (WM) capacity. Recently, some theorists have stressed that the empirically indicated limits of rehearsal-based WM storage components are inconsistent with the amounts of information needed to accomplish complex cognitive tasks, including language comprehension. Accordingly, they have proposed models of WM that include available long-term memory (ALTM) as part of the cognitive workspace. We tested structural equation models (SEM) depicting relationships among factors representing ALTM, content specific background knowledge, listening comprehension, and conventional WM. The analyses revealed that ALTM mediated the relationships of both WM and background knowledge with listening comprehension. The incongruity posed by small-capacity, attention-controlled WM components and theoretical models of comprehension that depict the integration of text information and background knowledge can, at least in part, be resolved by the models presented here.
Ethylene perception and signaling: an evolutionary perspective

Ethylene signal transduction, as revealed by studies in Arabidopsis, provides an interesting example of how information-processing systems have evolved in plants. The ethylene signal is perceived by a family of receptors composed of structural elements that are characteristic of bacterial signaling proteins. In plants, these receptors transmit the signal by interacting with proteins that are eukaryotic in origin. The ethylene sensor domain of the receptors forms a membrane-associated structure that uses a copper cofactor to bind ethylene. This novel protein motif appears to have originated early in the evolution of photosynthetic organisms.
Determinants of the seasonal migration of the elderly to Sunbelt states.

For the first time in 1980, the U.S. Census Bureau compiled information relating to seasonal migration. More than one-half million persons were identified as nonpermanent residents of the localities in which they were living on the census day. Interpreting these data as measures of temporary migration flows, this article uses this information for the states of Arizona and Florida to investigate the nature of the seasonal migration of the elderly to Sunbelt states every winter.
Survey and evaluation of existing smoke movement models

This paper provides an independent evaluation of a variety of models which have potential use in describing the movement of smoke. Comparison of model results with experimental data from two fires yielded mixed success. Because of the nature of the models, focus is placed on the temperature and the depth of the upper hot gas layer as a function of time.
Learning and the development of habitat-specific bat echolocation

Bats use echolocation calls that are suited for foraging in particular habitats. Many generalist bats alter their call design patterns as they move between open and spatially complex areas. This plasticity probably allows them to respond to the perceptual challenges posed by different structural environments. I tested the hypothesis that bats learn to produce these habitat-specific calls. I recorded the echolocation calls and foraging success of 14 juvenile little brown bats, Myotis lucifugus, as they foraged repeatedly in a large flight arena in two habitat treatments: open space and cluttered space. Calls were plastic across habitats. Furthermore, as bats gained experience, their foraging performance improved significantly in both open and cluttered habitat treatments. These improvements were related to changes in echolocation behaviour within the open habitat, which is consistent with the hypothesis that bats learn to produce more efficient calls in the open. Although the bats changed some aspects of their calls in the cluttered treatment, their use of space in the arena was the best predictor of foraging success. Bats that foraged in the centre of the arena were more successful. When bats switched habitat treatments, performance in the open was not affected by previous experience in the cluttered treatment. Bats that had previously experienced the open treatment, however, tended to use a more ‘open-area’ call when foraging in cluttered space. This result is discussed in light of habitat selection in young M. lucifugus.
Analog computer simulation of cardiac muscle contraction.

Abstract Isometric and isotonic twitch curves for isolated heart muscle preparations are presented by a differential equation which is programed for analog computing. Computer solutions are shown to describe isotonic and isometric contractions. The technique affords a reliable method for obtaining the derivative of these curves as well as for analyzing the curves for changes produced by experimental procedures.
Acid‐proteinase activity of rat cartilage dependent on growth hormone

Cartilage slices from normal rats, incubated at pH 4 for 3 to 7 hours, on a gelatin-membrane substrate, digested the membrane, whereas cartilage from rats hypophysectomized for 21 days or more did not. Injection of 15 or 45 microgram of bovine growth hormone into hypophysectomized rats restored the lytic activity of the cartilage. It is concluded that an acid proteinase is present in cartilage of normal rats, that is lost after hypophysectomy, and that the enzyme is restored by injection of growth hormone.
Validity and responsiveness of the Minimum Data Set.

OBJECTIVE To determine the criterion validity and responsiveness to change over time of the Minimum Data Set (MDS). DESIGN Cross sectional analysis comparing prospectively collected research data with MDS data reported from nursing homes on identical subjects. Longitudinal follow-up of subjects allowed for calculation of responsiveness to change over time. PARTICIPANTS Subjects (n = 140) participating in epidemiological research on the natural history of Alzheimer's disease in the University of Washington Group Health Cooperative Alzheimer's Disease Patient Registry (ADPR) who entered nursing homes in Washington State from January 1990 through March 1996. MAIN OUTCOME MEASUREMENTS Spearman's correlation coefficients to compare MDS cognitive performance scale scores with Mini-Mental State Examinations (MMSE), MDS behavior domain scores with ADPR Physician Behavior checklist scores, and MDS activities of daily living (ADL) functioning scores with Dementia Rating Scale scores for ADLs. Partial correlations were used to control for the number of days between MDS and ADPR assessments, age, and function in the other two MDS ratings of ADL, cognition, or behavior. We determined responsiveness by using the mean change in an effect size (ES) calculation for each domain of interest. RESULTS MDS measures in all three domains were correlated modestly to the analogous ADPR research instruments, with correlation coefficients 0.45 for cognition, 0.50 for behavior, and 0.59 for ADL functioning. Controlling for age, time between ADPR and MDS assessments, and the MDS ratings of the other two MDS domains did not improve the correlations significantly. In a subgroup of 60 subjects followed for an average of 636 days, the Cognitive performance scale of the MDS had a slightly larger effect size (ES = 0.60) than the Folstein Mini-Mental Status Exam (ES = 0.39) used by the ADPR. However, the Dementia Rating Scale (ES = 0.77) used by the ADPR researchers reflected more change over time than the ADL domain of the MDS (ES = 0.02). The MDS behavior domain (ES = 0.058) was comparable to the research behavior checklist (ES = 0.065). CONCLUSIONS These data demonstrate reasonable criterion validity of the MDS and the MMSE, ADL, and behavior rating scales and suggest that the MDS data is of adequate validity for research purposes in these areas. The MDS was less able to capture dementia-related change in ADLs in this population of patients with dementia even though the same nursing home staff completing the MDS often supplied the information for completing the research scales. As a result, the MDS may be limited as an outcome assessment instrument.
AXENIC CULTIVATION OF THE HETEROTROPHIC DINOFLAGELLATE PFIESTERIA SHUMWAYAE AND OBSERVATIONS ON FEEDING BEHAVIOR1

Pfiesteria shumwayae Glasgow et J. M. Burkh. [=Pseudopfiesteria shumwayae (Glasgow et J. M. Burkh.) Litaker, Steid., P. L. Mason, Shields et P. A. Tester] is a heterotrophic dinoflagellate commonly found in temperate, estuarine waters. P. shumwayae can feed on other protists, fish, and invertebrates, but research on the biochemical requirements of this species has been restricted by the lack of axenic cultures. An undefined, biphasic culture medium was formulated that supported the axenic growth of two of three strains of P. shumwayae. The medium contained chicken egg yolk as a major component. Successful growth depended on the method used to sterilize the medium, and maximum cell yields (10(4) · mL(-1) ) were similar to those attained in previous research when P. shumwayae was cultured with living fish or microalgae. Additionally, P. shumwayae flagellate cells ingested particles present in the biphasic medium, allowing detailed observations of feeding behavior. This research is an initial step toward a chemically defined axenic culture medium and determination of P. shumwayae metabolic requirements.
The calculations of stability constants using a high speed digital computer

Abstract A least squares technique for calculating stability constants from potentiometric titration data is described for use with a high speed digital computer such as the I.B.M. 650.
Properties and Early-Age Cracking Potential of Blended Cement Concrete

Stress due to the temperature and moisture gradients in concrete slab often causes pavement curling and warping that may further cause concrete crack if the slab is under restraint conditions. The adding of supplementary cementitious materials (SCMs) can reduce the risk of cracking by reducing the temperature stress. However, under cold weather condition, the slower strength development due to SCMs could increase the risk. This paper reported a study result of using blended cement to reduce such a risk. In this study, the properties of ternary cement concrete, such as setting time, heat of hydration, and datum temperature, were investigated. The risk of early-age cracking for different concrete mixes under different weather conditions was evaluated by the HIPERPAV. The test results indicated that fly ash replacement generally increases the setting time; while the slag replacement reduced the setting time. Both fly ash and slag replacement reduced the generated heat. When the amount of slag increased, the datum temperature and activation energy increased. HIPERPAV analysis indicated that there was little risk of early-age cracking for binary or ternary cement concrete under average summer weather conditions due to proper strength development of the concrete. However, the risk of early-age cracking for the concrete pavement increased under spring or fall weather conditions.
Play in the classroom: a descriptive study of preschool teachers’ beliefs

The purpose of this study was to describe preschool teachers’ intervention during children's free play. A Weberian sociological framework was used to examine teachers’ beliefs and thus their decisions about play. Three preschool teachers were video filmed during free play and later interviewed about observed intervention episodes. The teachers were prompted to talk about what happened during the event, what they were thinking about, and for what reason they intervened. The teachers held differing beliefs and their actions were related to their belief systems. The teachers based their decisions upon their personal system of educational principles concerning how teachers should teach, how children learn, and early childhood curriculum. The reasons for intervention fell into one of the three Weberian constructs: cultural influences, social‐political influences, and economic influences. Cultural influences included decisions based upon the child's language development, social development, or value development...
Characterization of CNC machining centers

Abstract Characterization of CNC machining centers is a difficult task due to its inherent complexity and diversity. Although many different approaches have been proposed, none singularly serves as a globally accepted test procedure. This paper addresses this important issue by establishing a comprehensive characterization procedure for CNC machining centers. It is illustrated that static and dynamic characteristics as well as transient and steady state features can be extracted from seven complimentary characterization tests. Subsequent implementation of the procedure with five selected state-of-the-art CNC machining centers in its category reveals that such machines can deteriorate substantially even in an ideal environment. This demonstrates the necessity for characterization on a regular basis to assess the performance of new and existing machines.
Relations between half-space and finitely generated cones in polyhedral cone-ratio DEA models

Analytic relations between the two representations (half-space and finitely generated) of cones in polyhedral cone-ratio DEA models are derived, which, for useful classes of cases in which they are simple, can make available the advantages of both for analysis and computation. We prove that such transfers between the two may be made through, essentially, the inverse of an associated matrix available in the computation and we provide formulae connecting solutions in the two representations.
Binding affinities of CRBPI and CRBPII for 9-cis-retinoids

Abstract Background Cellular retinol binding-protein I (CRBPI) and cellular retinol binding-protein II (CRBPII) serve as intracellular retinoid chaperones that bind retinol and retinal with high affinity and facilitate substrate delivery to select enzymes that catalyze retinoic acid (RA) and retinyl ester biosynthesis. Recently, 9-cis-RA has been identified in vivo in the pancreas, where it contributes to regulating glucose-stimulated insulin secretion. In vitro, 9-cis-RA activates RXR (retinoid × receptors), which serve as therapeutic targets for treating cancer and metabolic diseases. Binding affinities and structure–function relationships have been well characterized for CRBPI and CRBPII with all-trans-retinoids, but not for 9-cis-retinoids. This study extended current knowledge by establishing binding affinities for CRBPI and CRBPII with 9-cis-retinoids. Methods We have determined apparent dissociation constants, K′d, through monitoring binding of 9-cis-retinol, 9-cis-retinal, and 9-cis-RA with CRBPI and CRBPII by fluorescence spectroscopy, and analyzing the data with non-linear regression. We compared these data to the data we obtained for all-trans- and 13-cis-retinoids under identical conditions. Results CRBPI and CRBPII, respectively, bind 9-cis-retinol (K′d, 11 nM and 68 nM) and 9-cis-retinal (K′d, 8 nM and 5 nM) with high affinity. No significant 9-cis-RA binding was observed with CRBPI or CRBPII. Conclusions CRBPI and CRBPII bind 9-cis-retinol and 9-cis-retinal with high affinities, albeit with affinities somewhat lower than for all-trans-retinol and all-trans-retinal. General significance These data provide further insight into structure–binding relationships of cellular retinol binding-proteins and are consistent with a model of 9-cis-RA biosynthesis that involves chaperoned delivery of 9-cis-retinoids to enzymes that recognize retinoid binding-proteins.
A New Technique for the Investigation of Tribological Behavior of Sliding Pairs Used in Hot Forming Processes

Hot forming of aluminum sheet is highly influenced by the tribological behavior of the interacting surfaces of sliding pairs. Here we describe a new technique to investigate tribo-pair candidates for Quick Plastic Forming (QPF) and warm forming processes. This technique represents a bench type simulation of the real forming process where the sheet and tool interact by sliding against each other in a single motion (slide/stroke).Copyright © 2008 by General Motors Corporation
Requirement of a Centrosomal Activity for Cell Cycle Progression Through G1 into S Phase

Centrosomes were microsurgically removed from BSC-1 African green monkey kidney cells before the completion of S phase. Karyoplasts (acentrosomal cells) entered and completed mitosis. However, postmitotic karyoplasts arrested before S phase, whereas adjacent control cells divided repeatedly. Postmitotic karyoplasts assembled a microtubule-organizing center containing gamma-tubulin and pericentrin, but did not regenerate centrioles. These observations reveal the existence of an activity associated with core centrosomal structures-distinct from elements of the microtubule-organizing center-that is required for the somatic cell cycle to progress through G1 into S phase. Once the cell is in S phase, these core structures are not needed for the G2-M phase transition.
Application of Vortex Invariants to Roll Up of Vortex Pairs

A method developed by Betz for the rolled-up structure of vortices shed by isolated wing tips is extended to vortex pairs (two vortical regions of opposite sign), which are shed by wings of finite span. The present analysis again uses the invariants for the two-dimensional time-dependent motion of vortex systems, but the extension made here to vortex pairs depends primarily on the invariant for kinetic energy. It is found that the total energy in the flowfield can be separated into a part that governs the structure of each vortical region and a part that governs the spanwise distance between the centroids of the vortical regions. As a consequence, the rules for the rolled-up structure of vortical regions are the same as the one derived by Betz. Because the analysis does not apply a constraint that forces the circular contours of constant circulation to coincide with streamline paths, the solution is labeled first order. A method that can be used to obtain second- and higher-order approximations is described. Application of the first-order method to the vortex wake of an elliptically loaded wing indicates that a first-order solution for vortex pairs is adequate for many engineering purposes. The method derived here for single vortex pairs also justifies the superposition of axially symmetric vortical cores to simulate complex vortex wakes.
PERSONAL TRAVEL ASSISTANTS AND THE WORLD WIDE WEB

To be successful, handheld computers known as Personal Travel Assistants (PTAs) must be connected to external information sources. The viability of using the Internet and the world wide web (www) as such sources is explored. Considerations include whether www is flexible and robust enough to support various travel applications, whether to use a simulated passenger transportation terminal, and whether existing Internet protocols would be appropriate for PTAs.
Con: I would not perform another ESI in this patient.

In a perfect world, this patient would receive an ESI, return to work, and stop her opioids. ESIs are relatively safe procedures, containing lower risks than opioid therapy [1,2]. However, the world we live in is not perfect, and the decisions we make need to consider factors such as perceptions from peers and patients, long-term financial implications, and unintended consequences. After weighing the potential risks and benefits in this patient, I would opt not to proceed with another ESI. The patient described previously has multiple risk factors for failing ESI, including disability, depression, opioid use, absence of …
Climatic Control of the Geography of Clay Minerals Genesis

Abstract Concentrations of secondary clay minerals (mica, vermiculite, montmorillonite, chlorite, and kaolinite) in the A horizon of 99 U.S. soils were used in a stepwise regression with climate, parent material, and soil property variables to develop models of the occurrence and abundance of each clay mineral species. Climate–especially water balance estimates of soil water surplus, water deficit, and indicators of seasonality–were especially useful variables. These models correctly predicted the dominant (most abundant) clay minerals for 80 of the 99 sites even though the R 2 values for individual clays were modest. Maps of predicted and actual clay dominance are in good agreement. In addition, the models may be used to devise a weathering sequence of clay minerals from least to most stable (i.e., mica < montmorillonite < vermiculite < kaolinite). Weathering sequences based on existing models place vermiculite before montmorillonite. The models in this study suggest that vermiculite with aluminum as the...
Using Student Paraprofessionals in the Treatment of Eating Disorders

A rationale for adjunctive treatment in responding to eating disorder clients at a university counseling center is presented. The program described provides a highly structured internship experience for paraprofessional psychology trainees who serve as therapeutic aides and peer counselors to eating disorder clients. This collaborative Counseling Center and Psychology Department model emphasizes intern training, close supervision, and professional-paraprofessional cotreatment of anorexic and bulimic clients. Program evaluation methods and therapy outcome data are presented. Advantages of this treatment-training program for all participants are discussed.
Chronic pain in persons with neuromuscular disease.

Abstract Jensen MP, Abresch RT, Carter GT, McDonald CM. Chronic pain in persons with neuromuscular disease. Arch Phys Med Rehabil 2005;86:1155–63. Objective To examine the nature and scope of pain in persons with neuromuscular disorder (NMD). Design Survey study. Setting University-based rehabilitation research programs. Participants Adults with NMD (N=193). Interventions Not applicable. Main Outcome Measures Pain presence or absence, pain severity, pain quality (Neuropathic Pain Scale), pain interference (Brief Pain Inventory), pain site, quality of life (Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]), and pain treatment. Results Seventy-three percent of the sample reported pain, with 27% of these reporting that this pain was severe (≥7 on a 0–10 scale), on average. "Deep," "tiring," "sharp," and "dull" were the words used most frequently to describe NMD pain. Patients with amyotrophic lateral sclerosis and myotonic muscular dystrophies reported the greatest pain interference, and patients with Charcot-Marie-Tooth the least, among all NMD diagnoses. The most frequent pain site, overall, was back (49%), followed by leg (47%), shoulder (43%), neck (40%), buttock and hip(s) (37%), feet (36%), arm(s) (36%), and hand(s) (35%). The study participants reported significantly greater dysfunction than subjects in the SF-36 normative sample (persons without health problems) on a number of the SF-36 scales. However, we found no significant differences between the study participants and the US norms on the SF-36 role-emotional or mental health scales. A number of pain treatments were used by the study sample, but no treatment appeared to be effective for all participants, and some of the treatments reported as most effective (eg, chiropractic care) were used by very few participants. Conclusions Pain is a common problem among patients with NMDs. There are many similarities, but also some important differences, between NMD diagnostic groups on the nature and scope of pain and its impact. More research is needed to identify and test effective treatments for NMD-related pain.
A Recursive Hybrid Time-Stepping Scheme for Intermittent Contact in Multi-Rigid-Body Dynamics

This paper describes a novel method for the modeling of intermittent contact in multi-rigid-body problems. We use a complementarity based time-stepping scheme in Featherstone’s Divide and Conquer framework to efficiently model the unilateral and bilateral constraints in the system. The time-stepping scheme relies on impulse-based equations and does not require explicit collision detection. A set of complementarity conditions is used to model the interpenetration constraint and a linearized friction cone is used to yield a linear complementarity problem. The Divide and Conquer framework ensures that the size of the resulting mixed linear complementarity problem is independent of the number of bilateral constraints in the system. This makes the proposed method especially efficient for systems where the number of bilateral constraints are much greater than the number of unilateral constraints. The method is demonstrated by applying it to a falling 3D double pendulum.Copyright © 2009 by ASME
Prostaglandin F2α Receptors in Bovine Corpora Lutea Throughout Pregnancy

These studies were undertaken to examine whether or not receptors for prostaglandin PGF2a were present in bovine corpora lutea throughout pregnancy. The results show that cell membranes prepared from corpora lutea throughout pregnancy bind H-PGF2 o reflecting the availability of its receptors. Variations in the receptor numbers rather than in the receptor affinities appear to account for the variations in 3H-PGF3s binding throughout pregnancy. The fact that PGF2n receptors are present in corpora lutea throughout pregnancy and yet luteolysis occurs only at the end of pregnancy suggests that PGF3o receptor availability is not a limiting factor in the onset of luteolysis.
Synthesis and characterization of substituted cyclopentadienide ligands that may form chelates or metal dimers

Abstract Nine different substituted cyclopentadienyl ligands, which have substituents that may either chelate or bridge to second metal center, have been prepared from nucleophilic substitution reactions of esters or alkyl halides with NaCp. The sodium or thallium salts of these ligands were isolated as solids and characterized by 1 H NMR. The alkyl halide and NaCp reaction proved to yield the purer salts of the ligands because of the milder reaction conditions. These salts were reacted futher with Mn(CO) 5 Br to form the corresponding manganese tricarbonyl derivatives (i.e. (C 5 H 4 R)Mn(CO) 3 ; where R = C(O)CH 2 OCH 3 , C(O)CH 2 SCH 3 , C(O)CH 2 CH 2 SCH 3 , CH 2 CO 2 CH 3 , CH 2 CO 2 CH 2 CH 3 , CH 2 CH 2 CO 2 CH 3 , CH 2 CH 2 CO 2 CH 2 CH 3 , CH 2 CH 2 O 2 CCH 3 , and CH 2 CH 2 OCH 3 ) and Na(C 5 H 4 C(O)CH 2 OCH 3 ) was reacted with Co 2 (CO) 8 to form (C 5 H 4 C(O)CH 2 OCH 3 )Co(CO) 2 . The manganese and cobalt compounds were characterized by elemental analysis, IR, 1 H, and 13 C NMR spectra.
Accessibility, security, and accuracy in statistical databases: the case for the multiplicative fixed data perturbation approach

Organizations store data regarding their operations, employees, consumers, and suppliers in their databases. Some of the data are considered confidential, and by law, the organization is required to provide appropriate security measures in order to preserve privacy. Yet a number of companies have little or no security measures. The reason for this lack of security may, at least in part, be attributed to a lack of awareness and empirical evidence about the relative effectiveness of security mechanisms. This study investigates the effectiveness of different security mechanisms for protecting numerical database attributes. The trade-off between security, accessibility, and accuracy are examined. A comparison of different security mechanisms reveals that fixed data perturbation is preferred because it maximizes both security and accessibility. An investigation of the different approaches to fixed data perturbation indicates that multiplicative method best meets these criteria.
Functional and molecular responses of suckling rat pups and human intestinal Caco-2 cells to copper treatment

Ctr1 and Atp7A are copper (Cu) transporters that may play a role in the regulation of intestinal Cu absorption; however, intestinal regulation of these transporters by Cu in vivo has not been well defined. In this study, we hypothesized that Cu supplementation would alter the expression of intestine Ctr1 and Atp7A in vivo and further documented effects of Cu exposure on Cu transport, Ctr1 and Atp7A levels and localization in enterocyte-like Caco-2 cells. Suckling rat pups were supplemented with Cu (0 and 25 microg Cu/day) for 10 days and small intestine Cu concentration, Ctr1, Atp7A and metallothionein (MT) gene expression were measured by Northern blot analysis. Caco-2 cells were treated with basal medium, or medium supplemented with 3 and 94 microM CuSO4 and 67Cu transport, Ctr1 and Atp7A levels and localization were determined. In rat pups, Cu supplementation increased intestinal Cu, Ctr1 and MT gene expression; however, Atp7A gene expression was not significantly affected. Caco-2 cells treated with 94 microM Cu had lower cellular Cu uptake and export compared to untreated cells. While Ctr1 and Atp7A gene and protein levels were unaffected, confocal microscopy indicated that Ctr1 was endocytosed and co-localized with transferrin in Cu treated cells. This study demonstrates the functional response of intestinal cells to Cu treatment and suggests that both Ctr1 and Atp7A may regulate Cu absorption.
Synthesis of the nonconserved dihydroorotase domain of the multifunctional hamster CAD protein in Escherichia coli.

Abstract CAD is the multifunctional protein of higher eukaryotes which catalyzes the first three steps of pyrimidine biosynthesis. Its enzymatic activities exist as independent domains in the order: N terminus-carbamylphosphate synthetase II(CPSase)-dihydroorotase(DHOase)-aspartate transcarbamylase(ATCase)-C terminus. To functionally define the minimum hamster cDNA region required to encode an active DHOase, expression constructs were generated. Many such constructs complement Escherichia coli mutants defective not only in DHOase but also in ATCase. Constructs deleted for most of the sequence encoding the ATCase domain continue to complement E. coli mutants defective in DHOase. All of these smaller constructs also lack the region encoding CPSase. Therefore, a ‘genetic cassette’, containing information for neither the CPSase nor the ATCase domain, can direct the synthesis of a polypeptide with DHOase activity. Interestingly, inclusion of a portion of the DHOase-ATCase interdomain bridge appears to be required for optimum activity.
Sol–Gel Processing of Tetramethylammonium Silicate

A new sol–gel silica material based on tetramethylammonium silicate (TMAS) is reported here. Both xerogels and aerogels were produced by gelling a solution of 18.7 wt% TMAS using a series of esters. The gelation kinetics was controlled by varying the type and concentration of the ester. The supercritically dried TMAS aerogel was seen to have a larger pore size distribution with high porosity (>90%). In contrast, the conventionally dried gel showed a narrow distribution of mesopores, indicating its potential as a host matrix for protein encapsulations and catalysts.
Bis(naphthalene diimide) derivatives with mono- and dicarbonyl-fused tricyclic heterocyclic bridges as electron-transport materials

A series of triads in which two naphthalene diimide (NDI) units are bridged through their 2-positions by cyclopenta[2,1-b; 3,4-b′]dithiophene-4-one, cyclopenta[2,1-b;3,4-b′]dithiazole-4-one, benzo[1,2-b:6,5-b′]dithiophene-4,5-dione, and benzo[1, 2-b:6,5-b′]dithiazole-4,5-dione was synthesised, characterised by cyclic voltammetry and UV–vis absorption spectroscopy, modelled using density functional theory (DFT) calculations, and examined as solution-processed films in n-channel OFETs. The influence of the electron affinity and ionisation potential of the bridging fused heterocycle and of the length and position of alkyl chains in the triads on the electronic properties of the materials in solution and electrical properties in the thin film was explored. The nature of the bridge has a strong effect on the optical and electrochemical properties of materials. Use of increasingly electron-poor bridging groups led to hypsochromic shifts of the low-energy visible absorption (assigned to a transition from a bridg...
Lesion detectability in diagnostic ultrasound with short-lag spatial coherence imaging.

We demonstrate a novel imaging technique, named short-lag spatial coherence (SLSC) imaging, which uses short distance (or lag) values of the coherence function of backscattered ultrasound to create images. Simulations using Field II are used to demonstrate the detection of lesions of varying sizes and contrasts with and without acoustical clutter in the backscattered data. B-mode and SLSC imaging are shown to be nearly equivalent in lesion detection, based on the contrast-to-noise ratio (CNR) of the lesion, in noise-free conditions. The CNR of the SLSC image, however, can be adjusted to achieve an optimal value at the expense of image smoothness and resolution. In the presence of acoustic clutter, SLSC imaging yields significantly higher CNR than B-mode imaging and maintains higher image quality than B-mode with increasing noise. Compression of SLSC images is shown to be required under high-noise conditions but is unnecessary under no- and low-noise conditions. SLSC imaging is applied to in vivo imaging o...
Angiotensin I-converting enzyme localization on cultured fibroblasts by immunofluorescence

Angiotensin I-converting enzyme is responsible for the activation of angiotensin I and the inactivation of bradykinin. It has been localized by immunofluorescence on the endothelium of a variety of tissues and has been considered to be a specific marker for endothelial cells in culture. The present paper demonstrates, by immunofluorescence, the presence of angiotensin I-converting enzyme in monolayer cultures of fibroblasts derived from adult rat lung, bovine calf pulmonary artery, and human foreskin (CF-3 cells). Fluorescent localization of angiotensin I-converting enzyme was observed over the cytoplasm of adult rat lung and bovine calf pulmonary artery fibroblasts and as distinct areas overlying the nuclei of human foreskin fibroblasts. Determination of angiotensin I-converting enzyme activity by fluorimetric assay in parallel studies confirmed the presence of angiotensin I-converting enzyme activity in cultured fibroblasts. Immunofluorescent studies with antibody to Factor VIII demonstrated the presence of Factor VIII on cultured endothelial cells but not on fibroblasts. These results indicate that angiotensin I-converting enzyme is not confined to endothelial cells, and thus may not serve as a specific marker for endothelial cells in culture. Factor VIII may be a more specific marker for these cells.
Evaluation of a novel FSO receiver for mitigating alignment errors

In order to track, acquire and maintain a free-space optical link between mobile platforms experiencing misalignment due to movement and atmospheric turbulence requires a different approach than traditional free-space optical transceivers. Recently, an investigation of alternative receiver configurations found that a small focal length lens combined with larger core fibers significantly expanded the range of angular and translational misalignments tolerated by the receiver. The trade-off for this increased misalignment tolerance was a smaller receiving area, typical of short focal length lenses, which limited the collected power. This paper investigates a novel approach using a lens array coupled to an array of large-core fibers in an effort to maximize both misalignment tolerance and optical power collected. The approach is evaluated on the key parameters of maximum allowable lateral, allowable angular misalignment, and collected power for both collimated and divergent beams. Both experimental and theoretical analyses of the system are presented to characterize the system performance. The investigation finds that the lens array provides superior performance over a single lens combined with a fiber bundle.
U.S. environmental laws and their impact on American steel

Arthur D. Little casts an authoritative eye on the real effect of government regulation on the competitive position of the U.S. steel industry.
The formation and alkylation of α-ketoamide dianions

Abstract Alpha ketoamides may be deprotonated twice with strong base. The dianions so formed react with alkyl halides to yield α-amido tertiary alcohols.
The Use of the Semi‐Markov Model in the Study of the Development of Sleep‐Wake States in Infants

Employing a semi-Markov model, all-night sleep-wake patterns of 68 full-term, normal infants, 32 at 2 mos and 36 at 9 mos of age, were analyzed. The results are compared to the changes in proportional relationships of sleep-wake states with age and to the time series method of binary autocorrelation. Simulated nights of sleep were also computed using parameters derived from the semi-Markov model. We conclude that the sleep process in infants meets the assumptions of a semi-Markov model and that using such a model provides information about the maturation of transition and sequencing mechanisms of sleep-wake states. Simulating sleep patterns offers an opportunity to model hypothetical disturbances of sleep and assess the effectiveness of potential interventions.
A design and implementation methodology for real time control of mechanical systems

Real time software forms the core of mechatronic systems. It provides the medium for implementation of far more complex decision making than had been possible with previous technologies. This paper describes a methodology for the design of real time software for control and for its portable implementation. In addition to automated generation of engineering documentation, the method provides for production of diagnostic audit trail information and a means for comparative performance evaluation.
An analysis of CAF-1 interacting proteins reveals dynamic and direct interactions with the ku complex and 14-3-3 proteins

CAF-1 is essential in human cells for the de novo deposition of histones H3 and H4 at the DNA replication fork. Depletion of CAF-1 from various cell lines causes replication fork arrest, activation of the intra-S phase checkpoint, and global defects in chromatin structure. CAF-1 is also involved in coordinating inheritance of states of gene expression and in chromatin assembly following DNA repair. In this study, we generated cell lines expressing RNAi-resistant versions of CAF-1 and showed that the N-terminal 296 amino acids are dispensable for essential CAF-1 function in vivo. N-terminally truncated CAF-1 p150 was deficient in proliferating cell nuclear antigen (PCNA) binding, reinforcing the existence of two PCNA binding sites in human CAF-1, but the defect in PCNA binding had no effect on the recruitment of CAF-1 to chromatin after DNA damage or to resistance to DNA-damaging agents. Tandem affinity purification of CAF-1-interacting proteins under mild conditions revealed that CAF-1 was directly associated with the KU70/80 complex, part of the DNA-dependent protein kinase, and the phosphoserine/threonine-binding protein 14-3-3 ζ. CAF-1 was a substrate for DNA-dependent protein kinase, and the 14-3-3 interaction in vitro is dependent on DNA-dependent protein kinase phosphorylation. These results highlight that CAF-1 has prominent interactions with the DNA repair machinery but that the N terminus is dispensable for the role of CAF-1 in DNA replication- and repair-coupled chromatin assembly.
Carbamate-stabilized anions of 2-azabicyclo[2.1.1]hexanes

Abstract The regiochemical outcomes for s -BuLi/TMEDA deprotonations of N -Boc-2-azabicyclo[2.1.1]hexanes had been shown to be temperature dependent. Computational methods have been applied to advance understanding of the complexes that the reagents form, the character of the deprotonations, and hence the experimentally observed regiochemical biases. The tertiary anion is formed more readily than the secondary anion and is also the more stable anion. Computations for the enthalpy of proton abstraction from the analogous N -methoxycarbonyl structure also indicate greater stability for the tertiary carbamate anion.
Grids: A new program structuring mechanism based on layered graphs

Abstract : The structure of a computer program and the extent to which that structure is visible dramatically affect the clarity of the program. Programming languages therefore contain structuring mechanisms to provide a framework within which to structure programs. This thesis describes a new program structuring mechanism, called the grid. The grid mechanism was designed to specify, represent, document and enforce the structure of large programs having a layered organisation. Layered programs arise whenever levels of abstraction, layers of protection or multiple views of objects are used, yet they are not handled adequately by other structuring mechanisms. The structure of layered program is conveniently modeled by a layered graph consisting of interacting layers, each of which is directed graph of program parts. The grid mechanism is based on this model. A grid specification identifies the layers explicitly, and specifies program structure in terms of them. Similarities between layers are exploited to simplify a specification. Differences between layers, as well as any structural irregularities or relaxation of access restrictions, are highlighted. The grid mechanism emphasises human readability. It uses some novel techniques to specify layered graph structures in a clear and concise manner, including specification of irregular structures as regular structures with explicit deviations, omission of unnecessary detail, and localisation of information. The gird can specify multiple relationships between program parts. It also serves as a structured repository for information about a program, such as documentation or the information required by source management or version control systems.
Results from a new reticle defect inspection platform

A new DUV high-resolution reticle defect inspection platform has been developed to meet the sub-90nm node 248/193nm lithography reticle qualification requirements of the IC industry. This advanced lithography process typically includes COG layers, EPSM layers, and AltPSM layers; aggressive OPC is typically used which includes jogs, serifs, and SRAF (sub-resolution assist features). The architecture and performance of the new reticle defect inspection platform is described. Die-to-die inspection results on standard programmed defect test reticles are presented showing typically 50nm edge placement defect sensitivity, 80nm point defect sensitivity, 5.5% flux defect sensitivity, and 100nm quartz phase defect sensitivity. Low false detection results are also shown on 90nm node and below product reticles. Direct comparisons with UV wavelength inspections show measurable sensitivity improvement and a reduction in false detections. New lithography oriented defect detectors are discussed and data shown.
We're Going to Need a Bigger Room: Advice Workshops Are the Hit of Career Center

Advice workshops proved to be the most well-attended Career Center events at this year's Fall Meeting, with a total of roughly 700 people participating. Topics included how to avoid mistakes when applying for and working on a post doctoral position, finding hidden job opportunities by networking, negotiation strategies, and tips for taking control of your career.
The hydrolysis of amines to alcohols: Clues from chorismate processing enzymes

Abstract Two examples in nature of enzyme-catalyzed hydrolysis of cyclohexenylamines to cyclohexenols have no known counterpart in the literature of organic chemistry. Conditions which lead to the observed equilibrium are discussed.
Control in time and space: Tramtrack69 cooperates with Notch and Ecdysone to repress ectopic fate and shape changes during Drosophila egg chamber maturation.

Organ morphogenesis requires cooperation between cells, which determine their course of action based upon location within a tissue. Just as important, cells must synchronize their activities, which requires awareness of developmental time. To understand how cells coordinate behaviors in time and space, we analyzed Drosophila egg chamber development. We found that the transcription factor Tramtrack69 (TTK69) controls the fates and shapes of all columnar follicle cells by integrating temporal and spatial information, restricting characteristic changes in morphology and expression that occur at stage 10B to appropriate domains. TTK69 is required again later in oogenesis: it controls the volume of the dorsal-appendage (DA) tubes by promoting apical re-expansion and lateral shortening of DA-forming follicle cells. We show that TTK69 and Notch compete to repress each other9s expression and that a local Ecdysone signal is required to shift the balance in favor of TTK69. We hypothesize that TTK69 then cooperates with spatially restricted co-factors to define appropriate responses to a globally available (but as yet unidentified) temporal signal that initiates the S10B transformations.
Perceptual context effects on line discriminations by monkeys as measured by choice response accuracy and eye movements

Stumptailed monkeys (Macaca arctoides) were given two two-choice line-discrimination problems in which the lines were presented either alone or embedded in a patterned context that was the same in all cases. When the stimuli were a left- and a right-tilting line, the addition of the context significantly improved performance, as measured by frequency of correct choice responses. It also decreased choice response latency, duration of visual fixations, and frequency of scanning back and forth between the two stimuli. When the stimuli were a horizontal and a vertical line, the addition of the context had the opposite effect on all the performance measures. These results are very similar to those found with adult and infant humans when given the same stimuli. They suggest that the pattern perception of monkeys, like that of humans, involves top-down or holistic processing of incoming visual information.
The effect of a non-Maxwellian electron distribution on oxygen and iron ionization balances in the solar corona

Analytic expressions are derived for ionization and recombination rates in a parameterized non-Maxwellian electron velocity distribution with an enhanced high-energy tail. These expressions are then used in investigating the effect of such an enhancement in the high-energy tail of the coronal electron velocity distribution on the oxygen and iron ionization balances, O(+6) - O(+7) and Fe(+11) - Fe(+12). Relative to a Maxwellian of the same mean electron energy, the degree of ionization allowed by such a distribution is found to be either unchanged or slightly decreased for iron but often substantially increased for oxygen. The greater sensitivity of oxygen ionization balance to the high-energy distribution tail derives from the higher oxygen ionization threshold energy. It is noted that the electron temperature inferred from a measurement of the oxygen ionization ratio, O(+6)/O(+7), could indeed overestimate the actual coronal electron temperature by nearly 10 to the 6th K if the coronal electron distribution is incorrectly assumed to be Maxwellian.
A study of acidulated fluoride solutions—II: The caries inhibiting effect of single annual topical applications of an acidic fluoride and phosphate solution. A two year experience

Abstract One hundred and fifteen children who received single topical applications of an acidic fluoride and phosphate solution once a year for two years had approximately 70 per cent fewer carious surfaces than the 113 children who served as controls at the end of both first and second year.