cssi/SciSciGPT-SciSciNet huggingface dataset:
Developmental logic: establishing a relationship between developmental process and phylogenetic pattern in primitive vascular plants

Abstract Cladistic methods serve as a powerful example of the current shift in epistemology from a largely inductivist stance toward more `hypothetico-deductive' or `strong inference' approaches. However, in the area of character analysis, especially in addressing the roles of developmental and evolutionary processes influencing our understanding of homology, synapomorphy, and evolutionary pattern, it appears that little has changed. This omission has the very real potential of substantially limiting resolution and reliability of cladistic hypotheses, and points to the need for an expanded methodology that simultaneously addresses evolutionary pattern and underlying causal factors. Due to unique aspects of both plant development and evolutionary history, early vascular plants offer attractive features that make them highly suitable as a test case along these lines. Expanding on the Zimmermann's `telome theory' of a strong inference approach to developmental process is suggested by employing an analogy with logic gates and logic circuits in programming theory. Hypothesized units of developmental dynamic, termed `evolutionary developmental gates' (EDG) define a relationship between external and internal `environmental' factors, and developmental outcome, using a logical conditional. EDGs are then assembled into networks, specifying a relationship between developmental processes and resultant morphological structure, that may be tested. Testing utilizes several lines of evidence including comparing EDGs with specific developmental data, computer modelling, and evolutionary comparisons based on fossil and living taxa. To illustrate this approach, and to initiate analysis of what constitutes a set of developmental processes necessary for describing primitive vascular plant form, four developmental modules comprised of networks of EDGs are proposed. These include: (1) establishment of self-recognition at the shoot apex along with initiation of a hormone (auxin) gradient, (2) normal cell division modeled as an iterative and recursive process, (3) developmental cascades leading to tissue differentiation of epidermis, cortex, and vascular tissues, and (4) establishment of new apices either by bifurcation or de novo formation. Although clearly more detail is required to enable important evolutionary comparisons, it is anticipated that networks of EDGs can comprise a more realistic perspective with which to estimate homology in evolutionary studies.
On rank statistics : an approach via metrics on the permutation group

Abstract This paper investigates a general construction that generates many rank test statistics, for most of the standard nonparametric hypothesis testing situations. The construction uses metrics on permutations in a new way: the induced rank test statistics is a distance between two sets of permutations. These sets of permutations have group-theoretic descriptions, and the resulting rank statistic metrizes a quotient space of the permutation group. This construction is applied systematically to the two-sample and multi-sample location problems, the two-way layout problem, the one-sample location problem, the two-sample dispersion problem with equal medians, and the problem of testing for trend. The construction gives rise to many familiar rank test statistics for these six hypothesis testing situations, and also produces some plausible new test statistics. Additionally, the method enables one to ‘extend’ rank statistics to other hypothesis testing situations, in the sense that it creates families of statistics, for the six given settings, that are linked by their use of the same metric. Some connections with standard nonparametric theory are discussed. In the course of implementing the general construction, certain combinatorial and group-theoretic properties of metrics on permutations are studied, that play key roles in the computation of the induced rank statistics.
Zooplankton control in mass algal cultures

Abstract Infestations of rotifers ( Brachionus rubens ) and cladocerans ( Diaphanosoma brachyurum ) in a 0.1-ha high-rate algal pond were eliminated by temporarily raising the un-ionized (free) ammonia concentration to approximately 20 mg/l (as N) by addition of ammonium hydroxide solution. The 24-h LD 100 for Brachionus was found to be 17 mg/l free ammonia-N and that for Diaphanosoma just under 20 mg/l. Ammonium hydroxide treatments did not inhibit microalgal populations but rather promoted rapid recovery of algal densities to pre-infestation levels. Manipulation of free ammonia concentrations provides an economical and effective means of zooplankton control in mass algal cultures.
STRATEGIES FOR IMPROVING AND EXPANDING THE APPLICATION OF HEALTH STATUS MEASURES IN CLINICAL SETTINGS : A RESEARCHER-DEVELOPER VIEWPOINT

Health status instruments may be useful in clinical settings to screen for functional problems, monitor disease progression or therapeutic response, improve doctor-patient communications, assess quality of care, or provide case-mix adjustment for comparing other outcomes between patient groups. However, conceptual, practical, and attitudinal barriers have prevented their wider implementation. Aside from providing more data on how these measures influence the process and outcomes of clinical care, several strategies may help to improve and expand their application. Wider application would be promoted by training health care providers about the methods of health status assessment, their validity, and the available instruments; comparing newer functional measures and older scales with which clinicians are familiar (to make scores more meaningful); providing better data for the selection of instruments; and improving the responsiveness of these questionnaires to clinical changes. If health status measures are used in direct patient care, it is important to determine whether the goal is to screen for functional problems or to monitor patient changes over time. These different purposes may influence the selection of instruments, the types of patients targeted (e.g., based on age or diagnosis), and the frequency of patient assessment. Health status measures must be easily incorporated into the office routine, requiring that they be brief, easy to interpret, and not require complex training or scoring algorithms. In this setting, it may be helpful to provide clinicians not only with functional status scores, but with interpretations and recommendations about management or community resources to consider. The costs of health status measurement and data analysis will probably be borne by third-party payers, who must be persuaded of their utility. When health status measures are used for quality assurance, average scores for groups of patients should be adjusted for disease severity, comorbid conditions, demographic characteristics, socioeconomic status, and baseline health status. Furthermore, the sickest or most vulnerable members of a clinical population may be least able to provide valid health status information because of dementia, frailty, blindness, illiteracy, or inability to speak English. These patients may be of particular interest, and are likely to alter average health status scores for a population, so methods to assure complete ascertainment must be considered.
Structure and dynamics of a DNA-based model system for the study of electron spin-spin interactions.

Abstract We report on the structure and dynamics of a model system for measuring long-range distances in biological macromolecules by saturation-recovery EPR. Four DNA duplexes that incorporate a paramagnetic dysprosium ion (Dy(III)) and a nitroxide spin–label were examined by electron paramagnetic resonance (EPR), circular dichroism (CD), and ultra-violet absorbance (UV) spectroscopy. Dy(III) is chelated by the modified base deoxythymidine-EDTA, (dT-EDTA). Electron spin–spin interactions between the Dy(III) ion and the nitroxide radical are observed at distances as great as ∼5.3 nm. A slight change in the conformation of those nucleotides lying between the EDTA(Dy(III)) complex and the nitroxide spin–label results in a “stiffening” of the DNA helix on the EPR time scale. Changes in conformation and helix dynamics are due to the binding of the EDTA(Dy(III)) complex to the phosphodiester backbone of the complementary strand. Molecular mechanics calculations indicate that binding occurs in the 5′ direction on the complementary strand, at a position 3 or 4 phosphates distant from the dT-EDTA(Dy(III)) * dA base pair.
Isolation and identification of adrenocortical steroids in human peripheral plasma. I. A naturally occurring C21 steroid acetate (11-dehydrocorticosterone acetate) and "free" tetrahydrocortisone in normal plasma.

ABSTRACT 11-Dehydrocorticosterone acetate and tetrahydrocortisone were isolated from large quantities of normal peripheral human plasma and identified by chemical group reactivity, column and paper chromatography, and ultraviolet and infrared spectroscopy. A survey of the literature indicates that this is the first time that a naturally occurring C21 steroid acetate has been isolated, and the possible significance of this finding with respect to the steroid transport mechanism is discussed. The presence of 11-dehydrocorticosterone acetate and tetrahydrocortisone in the “free” state indicates that the determination of Porter-Silber chromogens alone as an index of adrenocortical function must be accepted with caution. Estimation of the Porter-Silber chromogens includes the measurement of biologically inactive metabolites such as tetrahydrocortisone and tetrahydrocortisol while it does not measure biologically active 17-desoxycorticosteroids.
Valvular heart disease

Significant valvular heart disease is present in about 2 % of the population. The most common serious valve condition is calcific aortic stenosis (AS), with severe disease presenting in older adults with symptoms of decreased exercise tolerance or dyspnea and a systolic murmur. Valve replacement is lifesaving and is recommended regardless of patient age. Mitral stenosis is a late consequence of rheumatic heart disease and now is treated with percutaneous balloon commissurotomy in most patients. Mitral valve regurgitation often is secondary to other cardiac conditions, such as dilated cardiomyopathy and coronary disease, with treatment directed toward the underlying disease process. In patients with primary mitral regurgitation, for example, due to mitral valve prolapse, surgical repair often provides durable relief of valve dysfunction without the need for a prosthetic valve. Aortic regurgitation may be due to disease of the valve leaflets, such as a bicuspid valve, or to dilation of the aorta; treatment depends on the cause of valve dysfunction. Acute aortic or mitral regurgitation is a medical and surgical emergency with a range of causes including aortic dissection, endocarditis, and spontaneous mitral chordal rupture. Acute valve regurgitation often is misdiagnosed because a typical murmur may not be present; echocardiography should be considered in all patients with acute pulmonary decompensation. Patients with prosthetic heart valves require careful management to prevent endocarditis and to provide optimal antithrombotic therapy, as well as to monitor valve function. Endocarditis has mortality rate as high as 40 % at 1 year; management requires collaborative care by cardiologists, cardiac surgeons, and infectious disease specialists.
NZP: A New Family of Low Thermal Expansion Ceramics

The NZP family, which gets its name after the prototype composition NaZr2P3O12, has received much attention in recent times because of their very low coefficient of thermal expansion (CTE), controlled lattice thermal expansion anisotropy, fast ionic conductivity, high thermal and chemical stability and flexibility towards ionic substitutions. Such materials can find widespread applications as exhaust components in automobiles, mirror blank for optical telescope, substrate materials for electronic packaging, as well as in sulphur batteries, nuclear waste immobilization, port-liners for diesel engines, braze fixtures for aircraft engines etc. The low expansion behaviour of NZP materials has been attributed to: (i) strongly bonded 3—dimensional network structure, (ii) existence of structural holes which may absorb some of the thermal vibrations and (iii) anisotropy in the thermal expansion of the lattice. In this overview the crystal structure, synthesis, thermal expansion behaviour and possible applications...
Understanding the effect of polymer crystallinity on the electrical conductivity of exfoliated graphite nanoplatelet/polylactic acid composite films

Electrically conductive exfoliated graphite nanoplatelet (GNP) / polylactic acid (PLA) nanocomposite films were fabricated using a two-step, scalable melt compounding process. The effect of the polymer’s physical properties, such as crystallinity, on the mechanical and electrical properties of the composites were determined. The crystallization characteristics of PLA were altered significantly by altering the cooling rate during compression molding of the films. The crystallinity and crystal structure were investigated using differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and polarized optical microscopy (POM). The mechanical and electrical properties were also examined as a function of PLA’s crystallinity dictated by the cooling rate during compression molding. The electrical conductivity was examined using impedance spectroscopy. For the same GNP content, the crystallinity increases by ~40 % and electrical conductivity increases by ~3 orders of magnitude with decreased cooling rate indicating a strong correlation between polymer physical properties and electrical conductivity of the polymer composites. This mechanism can be utilized to tailor the electrical conductivity of a given filler/polymer system by tuning the physical properties of the polymer, without altering the fillers’ characteristics or the processing method, which is the common approach used.
The Learning Styles of Orthopedic Residents, Faculty, and Applicants at an Academic Program

Background To train surgeons effectively, it is important to understand how they are learning. The Kolb Learning Style Inventory (LSI) is based on the theory of experiential learning, which divides the learning cycle into 4 stages: active experimentation (AE), abstract conceptualization (AC), concrete experience, and reflective observation. The purpose of this investigation was to assess the learning styles of orthopedic residents, faculty, and applicants at an east-coast residency program. Methods A total of 90 Kolb LSI, Version 3.1 surveys, and demographic questionnaires were distributed to all residency applicants, residents, and faculty at an academic program. Data collected included age, sex, type of medical school (MD or DO), foreign medical graduate status, and either year since college graduation, postgraduate year level (residents only), or years since completion of residency (faculty only). Seventy-one completed Kolb LSI surveys (14 residents, 14 faculty members, and 43 applicants) were recorded and analyzed for statistical significance. Results The most prevalent learning style among all participants was converging (53.5%), followed by accommodating (18.3%), diverging (18.3%), and assimilating (9.9%) (p = 0.13). The applicant and resident groups demonstrated a high tendency toward AE followed by AC. The faculty group demonstrated a high tendency toward AC followed by AE. None of the 24 subjects who were 26 years or under had assimilating learning styles, in significant contrast to the 12% of 27- to 30-year-olds and 18% of 31 and older group (p Conclusions The majority of applicants, residents, and faculty in the orthopedic residency program were "convergers." The converging learning style involves problem solving and decision making, with the practical application of ideas and the use of hypothetical-deductive reasoning. Learning through AE decreased with age, whereas learning through AC increased.
Serum antibodies to GM1, GD1b, peripheral nerve myelin, and Campylobacter jejuni in patients with Guillain‐Barré syndrome and controls: Correlation and prognosis

Serum antibodies to monosialoganglioside (GM1), disialoganglioside (GD1b), and Campylobacter jejuni, measured by enzyme-linked immunosorbent assay and serum antibodies to peripheral nerve myelin, measured by the C1 fixation and transfer assay, were studied in 58 acute-phase patients with Guillain-Barre syndrome (GBS), 42 disease controls, and 29 normal controls. Anti-peripheral nerve myelin antibodies were elevated in 57 of 58 patients with GBS compared with controls, whereas only 8.6% had increased antibody titers to GM1 and 10.3% to GD1b. Only low antibody titers (GM1) or no antibodies (GD1b) were found in controls. More GBS patients (17.2%) than controls (7%) had antibodies to C jejuni. Poor recovery with inability to walk at 1 year after onset of symptoms was seen in 3 (5%) of the patients with GBS. All 3 patients had serological evidence of recent C jejuni infection but no antibodies to GM1 or GD1b. GBS patients with antibodies to GM1 or GD1b had excellent recovery. Our data indicate that antibodies to GM1 or GD1b do not necessarily mediate the extensive axonal damage seen in these severely affected patients.
Superconductivity in Nonsymmetric Epitaxial YBa2Cu3O7−δ - PrBa2Cu3O7−δ Superlattices Grown by Pulsed Laser Ablation

Pulsed KrF (248 nm) excimer laser ablation has been used to grow nonsymmetric epitaxial YBCO/PrBCO superlattices containing 1-, 2-, 3-, 4-, and 8-unit-cell-thick YBCO layers, separated by N-cell-thick insulating PrBCO layers (N = 1–16). The 1×N and 2×N structures exhibit a rapid initial decrease of Tco with increasing PrBCO layer thickness, followed by saturation of Tco at a nonzero value, as the YBCO layers' separation is increased further. The limiting Tco values for 1-, 2-, 3-, 4-, and 8-cell-thick YBCO layers isolated in a PrBCO matrix are ∼19 K, ∼54 K, ∼71 K, ∼80 K, and ∼87 K, respectively. Single-cell-thick YBCO layers are found to be superconducting even when separated by ∼19 nm in a PrBCO matrix. These results are discussed in terms of possible Josephson and/or proximity effects coupling the YBCO layers, and the possibility that PrBCO modifies the electronic structure and depresses Tco in YBCO cells that are immediately adjacent to the PrBCO layers. Finally, high-temperature postannealing studies show that these superlattice structures are stable and that little diffusion occurs along the c-axis direction of compositional modulation.
Experiments on electrostatic dispersion of air in water

In many chemical and environmental applications, the use of bubble column reactors is common and often essential in such processes as absorption, coal liquefaction, catalytic slurry reactions, and bioreactions. The objective of this work is to investigate bubble generation of air in water through electrified metal capillaries. Many important factors that affect the formation of bubbles, including capillary size, capillary tip configuration, electrode distance, and flow rate, are studied. It is found that the bubble size decreases with increasing applied voltage and decreasing airflow rate. A dimensional analysis of the system parameters is also pursued. The dimensionless numbers are correlated into an empirical model that can be used for the prediction of the bubble size as a function of the applied voltage and airflow rate. It is found that the bubble size decreases with decreasing Reynolds number and increasing Weber number. Three different modes of bubble formation are observed: a spraying mode obtained at low airflow rate and high applied voltage, a dripping mode observed at high flow rate and low applied voltage, and a mixed spraying-dripping mode.
A multi-layer model for mixing layer development in a double-diffusive thermohaline system heated from below

Abstract A mathematical model has been developed for determining the dynamic response of a saltstratified solution to heating from below and predictions have been compared with experimental results. All major data trends have been corroborated and good numerical agreement has been obtained for the temperature, salt concentration and thickness of the bottom mixed layer which forms in response to the heating. Underprediction of the time required for thermal effects to penetrate to the top of the solution is attributed to limitations associated with using the energy integral equation to describe conditions in the stable region. Parametric calculations have been performed to determine the effect of bottom heat flux and stabilizing salt gradient on system response.
Positive injury signals induce growth and prolong survival in Aplysia neurons

Injury to a peripheral nerve initiates changes that can lead to regeneration of the damaged axons. How information about a distant injury is communicated to the cell body is not clear. Using the nervous system of Aplysia californica, we tested the idea that some of this information is conveyed via positive injury signals-axoplasmic proteins that are activated at the injury site and transported to the cell soma. We collected these proteins by crushing pedal nerves and then placing a ligation proximal to the ligation. The contralateral nerves were ligated as controls. Twenty h later, axoplasm was extruded from the nerve segment just distal to the ligation on the crushed nerves (cr/lig) and on the control nerves (lig). The total proteins were rhodaminated and injected into the cytoplasm of neurons in vitro to look for nuclear import. Punctate fluorescence was detected in the nucleus of all seven neurons injected with the cr/lig axoplasm. Only two of five neurons injected with lig axoplasm had any fluorescence. Equal amounts of cr/lig and lig axoplasm were then injected directly into the cell bodies of neurons maintained in vitro. The cells injected with cr/lig axoplasm exhibited renewed growth and significantly longer survival: 25.9 +/- 2.1 days (mean +/- SEM: n = 22) relative to the cells injected with lig axoplasm (15.3 +/- 1.2 days; n = 14) and to those that were not injected (12.2 +/- 1.7 days; n = 24). Fractionation of the cr/lig axoplasm indicated that different factors are responsible for growth and survival.
The visual pigment and visual cycle of the lobster, Homarus

The visual pigment of the American lobster,Homarus americanus, has been studied in individual isolated rhabdoms by microspectrophotometry. Lobster rhodopsin has λmax at 515 nm and is converted by light to a stable metarhodopsin with λmax at 490 nm. These figures are in good agreement with corresponding values obtained by Wald and Hubbard (1957) in digitonin extracts. Photoregeneration of rhodopsin to metarhodopsin is also observed. The absorbance spectrum of lobster metarhodopsin is invariant with pH in the range 5.4–9, indicating that even after isomerization of the chromophore fromcis totrans, the binding site of the chromophore remains sequestered from the solvent environment. Total axial density of the lobster rhabdom to unpolarized light is about 0.7. As described for several other Crustacea, aldehyde fixation renders the metarhodopsin susceptible to photobleaching, a process that is faster at alkaline than at neutral or acid pH. Small amounts of a photoproduct with λmax at 370 nm are occasionally seen. A slower dark bleaching of lobster rhabdoms (τ1/2−2 h) also occurs, frequently through intermediates with absorption similar to metarhodopsin. The molar extinction coefficient of metarhodopsin is about 1.2 times greater than that of rhodopsin, each measured at their respective λmax. Isomerization of the chromophore fromcis totrans is accompanied by a change in the orientation of the absorption vector of about 3°. The absorption vector of metarhodopsin is either tilted more steeply into the membrane or is less tightly oriented with respect to the microvillar axes. When living lobsters are kept at room temperature, light adaptation does not result in an accumulation of metarhodopsin. At 4 °C, however, the same adapting lights cause a reduction of rhodopsin and an increase in metarhodopsin. There is thus a temperature-sensitive regeneration mechanism that supplements photoregeneration. Following 1 ms, 0.1 joule xenon flashes that convert about 70% of the rhodopsin to metarhodopsin in vivo, dark regeneration occurs in the living eye with half-times of about 25 and 55 min at 22 °C and 15 °C respectively.
DERIVATION AND VALIDATION OF A RISK MODEL TO PREDICT THE PRESENCE AND EXTENT OF CORONARY ARTERY CALCIFICATION IN ASYMPTOMATIC INDIVIDUALS

Asrac Caegor: 2. Chroic CAD/Sale Ischemic Hear Disease: Cliicalreseaio umer: 1205-394Auhors: Herman Feringa, Michael Blaha, Ron Blankstein, Juan Rivera, Matthew Budoff, Leslee Shaw, Paolo Raggi, Daniel Berman, Tracy Callister, Arthur Agatston, Roger Blumenthal, Harlan Krumholz, Khurram Nasir, Yale School of Medicine, New Haven, CT, USA, Johns Hopkins School of Medicine, Baltimore, MD, USAIntroduction: I is uo if a ris moel ca preic he presece a ee of coroar arer calcium (CAC) i asmpomaic suecs ihou o CAD.Methods: I a 3-ceer oservaioal su, 44,052 cosecuive asmpomaic suecs free of o CAD, referre for cariac CT, ere raoml ivie io a erivaio (=22,098) a valiaio (=21,954) cohor. Saar self-repore cariac ris facors ere collece. Logisic regressio ieiie preicors of CAC i he erivaio cohor. Weighe pois ere assige o each preicor muliplig he ʼ-coeficie 10. C-saisics ere use for moel iscrimiaio i oh erivaio a valiaio cohor.Results: The prevalece of CAC=0, 1-100, 101-400, a >400 as 45%, 32%, 13% a 10%. respecivel. The ris moel (+ pois) iclue: Age>50 (0), age 50-59 (+8), age 60-69 (+14), age 70-79 (+20), age>79 (+29), iaees (+8), hperesio (+4), smoig (+3), slipiemia (+3), a male (+1). Base o hese scores, paies ere sraiie io 5 ris groups. The os of havig CAC icrease ih higher scores (Tale). The umer eee o sca o eec oe posiive es (S+) a oe egaive es (S-) ecrease a icrease, respecivel, ih higher scores (Tale). C-saisics ere similar i oh cohors: 0.70 for preicio of CAC>0, 0.76 for CAC>100, a 0.79 for CAC>400.Conclusion: A ris moel o preic he presece a ee of CAC is largel rive age a has moerae poeial i preicig paies ih CAC. Score OR 95% CI CAC score S+ S-Lo 0-1 ref 22 ± 1.2 3.2 1.5Lo-iermeiae 2-8 1.62 1.48-1.76 51 ± 1.9 2.3 1.7Iermeiae 9-12 2.82 2.58-3.01 105 ± 3.1 1.8 2.3Iermeiae-high 13-17 4.20 3.84-4.57 175 ± 4.5 1.5 3.0High >17 8.16 7.41-8.98 402 ± 7.4 1.3 5.0
Avoiding Tree Saturation in the Face of Many Hotspots with Few Buffers

In a multistage network, hotspots induce tree saturation. The known solutions employ a variety of techniques, including combining (which works only for certain kinds of messages), feedback damping (which appears to provide low utilization in the absence of hot spots), and large numbers of buffers. In practice, the approach used today is to provide large numbers of buffers: in a P-processor system, the rule of thumb appears to be to provide 10P buffers, but 10P buffers maybe too expensive for systems containing 105 or more processors. Even employing Omega(P) buffers does not appear to provide any guarantees, however. We show that by organizing the switches so that the messages addressed to a particular processor can use only certain of the buffers, many hotspots can be tolerated with few buffers. For example, a switch with O(log P) buffers can tolerate a single hotspot with probability 1, and allows the first few hotspots to have a large number of buffers before being declared a hotspot. A switch with B buffers can be organized so that it blocks a particular non-hotspot message with probability less than O(1/s) if there are O(B/log s) hotspots, and can handle a factor of O(B (log log s)/log s) more hotspots before the probability becomes a constant. A similar approach can also be used to improve caching behavior in a multithreaded system in which one of the threads tries to consume all of the cache.
Binding of an endosperm-specific nuclear protein to a maize beta-zein gene correlates with zein transcriptional activity

Promoter regions of alpha- and beta-zein genes were analyzed for binding of nuclear proteins from developing endosperm and seedling tissue of maize. Using a band-shift assay, we identified two distinct protein factors, alpha-1 and beta-1, that interacted specifically with alpha- and beta-zein gene promoter regions, respectively. Alpha-1 was present in nuclei from both endosperm and seedling tissue, whereas beta-1 was found only in nuclei from developing endosperm tissue. Mixing of nuclear extracts demonstrated that seedling tissue contained undetectable amounts of beta-1, rather than having an inhibitor for formation of the beta-1/DNA complex. Chemical footprinting analysis localized the beta-1 recognition site to a 22 bp sequence flanked by CCAT and TATA boxes. The apparent molecular mass of beta-1 was determined to be 29 kDa by southwestern blotting. Based onin vitro binding assays, the greatest concentration of the beta-1 in endosperm nuclei is at 16 days after pollination, which coincides with the time of highest transcriptional activity of the beta-zein gene. These results suggest that beta-1 may act as a tissue-specific,trans-acting regulator of the expression of the beta-zein gene in developing maize endosperm.
Ligand-specific deactivation time course of GluN1/GluN2D NMDA receptors

N-methyl-D-aspartate (NMDA) receptors belong to the family of ionotropic glutamate receptors that mediate a majority of excitatory synaptic transmission. One unique property of GluN1/GluN2D NMDA receptors is an unusually prolonged deactivation time course following the removal of L-glutamate. Here we show, using x-ray crystallography and electrophysiology, that the deactivation time course of GluN1/GluN2D receptors is influenced by the conformational variability of the ligand-binding domain (LBD) as well as the structure of the activating ligand. L-glutamate and L-CCG-IV induce significantly slower deactivation time courses compared with other agonists. Crystal structures of the isolated GluN2D LBD in complex with various ligands reveal that the binding of L-glutamate induces a unique conformation at the backside of the ligand-binding site in proximity to the region at which the transmembrane domain would be located in the intact receptors. These data suggest that the activity of the GluN1/GluN2D NMDA receptor is controlled distinctively by the endogenous neurotransmitter L-glutamate.
Pioneer Venus 1978 multiprobe spacecraft simulator

A test which duplicates the signals of the four probes to be deployed by the PV 78 multiprobe spacecraft was developed. It will be used for receiver operator training prior to the mission. This article describes the operation and characteristics of the test set.
SEARCH STRATEGIES FOR LANDSCAPE-LEVEL INTERPATCH MOVEMENTS

Ecologists need a better understanding of how animals make decisions about moving across landscapes. To this end, we developed computer simulations that contrast the effectiveness of various search strategies at finding habitat patches in idealized land- scapes (uniform, random, or clumped patches), where searchers have different energy re- serves and face different mortality risks. Nearly straight correlated random walks always produced better dispersal success than relatively uncorrelated random walks. However, increasing patch density decreased the degree of correlation that maximized dispersal suc- cess. Only under high mortality and low energy reserves in a uniform landscape did ab- solutely straight-line search perform better than any random walk. With low mortality risks and high energy reserves, exhaustive systematic search was superior to the best correlated random walk; an increase in the perceptual range of the searcher (i.e., patch delectability) also favored exhaustive search over relatively straight random walks. For all conditions examined, the "average distance rule," a hybrid search rule incorporating both straight- line and systematic search, was best. Overall, however, our results suggest that a simple and effective search rule for many landscape-explicit models would involve straight or nearly straight movements.
Fiber deposition in the tracheobronchial region: experimental measurements.

Fiber deposition efficiency in the tracheobronchial region was studied by using two human airway replicas. Carbon fibers with a monodisperse diameter of 3.66 μ were delivered into lung casts at the flow rates of 15, 45, and 60 L/min. Deposition efficiencies in each airway bifurcation were obtained individually. Even though the data shows large variability among the bifurcations within the same generation, there is a general trend for the data obtained in these two replicas. Our results show that fiber deposition for carbon fibers increases with the Stokes number, indicating that inertial impaction is the dominant mechanism. Also, fiber deposition in the tracheobronchial region is lower than that of spherical particles at a given Stokes number, and is similar to the deposition found in the nasal and oral airways as reported previously. This finding implies that it is easier for fibers to penetrate the upper respiratory tract and to reach the lower airways as compared to spherical particles. Our measurement...
Advanced Visualization Technology for Terascale Particle Accelerator Simulations

This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of next-generation accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphics cards to achieve perceptually effective visualization of the very dense and complex electromagnetic fields produced from the modeling of reflection and transmission properties of open structures in an accelerator design. Because of the collaborative nature of the overall accelerator modeling project, the visualization technology developed is for both desktop and remote visualization settings. We have tested the techniques using both time-varying particle data sets containing up to one billion particles per time step and electromagnetic field data sets with millions of mesh elements.
The Streptococcus pneumoniae Competence Regulatory System Influences Respiratory Tract Colonization

The Streptococcus pneumoniae ComDE two-component signaling system controls the development of genetic competence in the bacterium and affects virulence in models of pneumonia and bacteremia. We have investigated the impact of the competence pathway during colonization of the nasopharynx, the principal ecological niche of the pneumococcus. Previous work showed that deletion of the pneumococcal CiaRH signaling system inhibited colonization and increased expression of genes required for competence. We anticipated that signaling by the competence pathway might similarly reduce carriage. Consistent with this expectation, a comE deletion that blocked transformation increased colonization fitness such that the mutant outcompeted the wild type in an infant rat model of asymptomatic carriage. Deletion of comD-immediately upstream of comE and likewise required for competence-similarly increased colonization fitness if the orientation of the antibiotic resistance cassette inserted into the comD locus was such that it reduced transcription of comE. However, an alternative comD deletion mutation that caused an increase in comE transcription impaired colonization instead. Activation of the competence system through a comE(D143Y) mutation did not affect colonization, but an inability to secrete the competence-stimulating peptide due to deletion of comAB produced a density-dependent reduction in colonization fitness. These results suggest a model in which signaling by the unactivated form of ComE reduces colonization fitness compared to that of bacteria in which it is either activated or absent entirely, with the most substantial fitness gain accompanying deletion of comE. This observation demonstrates that the pneumococcus incurs a substantial fitness cost in order to retain a functional competence regulatory system.
INTERACTIONS OF THE COMPLEMENT SYSTEM WITH ENDOTOXIC LIPOPOLYSACCHARIDE : GENERATION OF A FACTOR CHEMOTACTIC FOR POLYMORPHONUCLEAR LEUKOCYTES

Endotoxic lipopolysaccharide has recently been shown to fix large amounts of the complement components related to the biologic activities mediated by that system. The present study sought to determine whether the generation of chemotactic factor by endotoxin in serum was dependent upon complement system activation. Preheating serum, incubating at 0°C, or incubating in the presence of EDTA, all prevented chemotactic factor generation as well as complement fixation by endotoxin. "Endotoxoids" deficient in complement-firing activity were also deficient in chemotactic factor generation. Chemotactic factor could not be generated by endotoxin in sera of mice congenitally deficient in the C'S component of complement, while chemotactic factor was generated by endotoxin in the sera of coisogenic mice with normal complement levels for that species. The chemotactic factor induced by endotoxin was heat stable and nondialyzable. Molecular sieve chromatography and sucrose density gradient ultracentrifugation demonstrated that the chemotactic factor was a relatively low molecular weight product (15,000–30,000) and as such different from previously scribed C' system-derived chemotactic factors. These experiments demonstrate that generation of chemotactic factor by endotoxin in serum is dependent upon C' system activation involving at least C'5. Furthermore, the relatively low molecular weight of this factor suggests that it might be derived from activation of a single complement component rather than from complexing of multiple complement components.
Topological origin of Planck’s constant

We show that the limiting velocityc and Planck's constanth can be considered to be topological quantities associated with the local tangent space of space-time and its local invariance group of four-dimensional rotations.h is associated withH3[SO(3, 1)], whereH3 is the third homotopy group. As a side benefit, the quantization of spin emerges from the topological characterization without recourse to quantum-mechanical formalism.
Laser Measurements of Fly Ash Rebound Parameters for Use in Trajectory Calculations

This paper describes an experimental method used to find particle restitution coefficients. The equations that govern the motion of solid particles suspended by a compressible gas flow through a turbomachine depend on the restitution coefficients. Analysis of the data obtained by a laser-Doppler velocimeter (LDV) system of the collision phenomenon gives the restitution ratios as a function of the incidence angle. From these ratios, the particle velocity components after collision are computed and used as the initial conditions to the solution of the governing equations of motion for particle trajectories. The erosion of metals impacted by small dust particles can be calculated by knowing the restitution coefficients. The alloy used in this investigation was 410 stainless steel.
ROCC: A Communication Overlay Abstraction for Wireless Users

As wireless devices become more popular, the potential for new collaborative applications has emerged. For example, a group of coworkers can opportunistically come together and share project documents and other data. Such applications are characterized by the fact that information needs to be distributed among all members of a group. Supporting such coordination currently requires using low-level multicast protocols that are complex and resource intensive to initialize and maintain without the support of an infrastructure. In this paper, we introduce the ring overlay for collaborative coordination (ROCC), which offers a fair, reliable coordination service for wireless environments. ROCC specifically addresses wireless application situations requiring group coordination. ROCC is influenced by traditional token ring and overlay communication protocols but leverages unique properties of the broadcast nature of the wireless environment to improve performance. The result is a minimal, fair, dynamic group coordination service. This paper introduces the ROCC abstraction and demonstrates its potential through analysis.
ELECTRON-ASSISTED DEPOSITION OF CUBIC BORON NITRIDE BY R.F. MAGNETRON SPUTTERING

Abstract Cubic boron nitride (cBN) has been deposited on silicon (100) substrates by means of radio frequency (r.f.) magnetron sputtering in nitrogen using a hexagonal boron nitride target with the assistance of a simultaneous electron bombardment of the growing surface. Unlike most thin-film deposition processes for cBN, intentional bombardment of the growing surface by ion beams within specific ranges in energy and flux is not required for this process to achieve high-purity cBN films. Fourier transform infra-red (FTIR) spectra of cBN films show a strong absorption band around 1070 cm −1 . With electrons bombarding the growing surface at a current density of 140 mA cm −2 or higher, pure (according to FTIR spectra) cBN films are deposited on silicon substrates at temperatures above 750°C. The effects of electron current density and nitrogen gas pressure on the synthesis of cBN films will be discussed.
A Randomized Controlled Trial of Massage Therapy in Children with Sickle Cell Disease

Objective This randomized controlled trial investigated the short-term effects of massage therapy on youth with SCD and their parents. Methods Thirty-four children and adolescents, and their parents were assigned to a massage therapy or an attention control group. Parents were trained in massage in their homes once a week for 4 weeks, with instructions to provide nightly massages. Families in the control group were visited weekly by a research assistant. Participants completed measures of depression and anxiety, functional status, pain intensity, medication use, and service utilization. Results Parents in the massage therapy group reported higher levels of depression and anxiety following the intervention. Youth in this group showed higher levels of functional status, and lower levels of depression, anxiety, and pain. Health service utilization rates were unchanged from pre- to post-intervention. Conclusions These results offer preliminary support for parent-delivered massage therapy as an intervention for SCD pain.
Molecules and morphology: comparative developmental genetics of the Brassicaceae

For approximately 20 years Arabidopsis has been a model system to investigate developmental and physiological questions in plant biology, leading to the identification of genes and genetic systems involved in many processes. Extending ideas arising from knowledge of developmental genetic systems in Arabidopsis to other species of the Brassicaceae will require the application of genomics technologies developed in Arabidopsis and the establishment of additional genetic systems and resources in other species. Morphological variation in all plant organs, as well as in growth habit, mating systems, and physiology are represented in the breadth of Brassicaceae species offering ample opportunity to investigate the molecular basis of morphological evolution in this family. In addition, the frequent recent hybridization events in Brassica and Arabidopsis facilitate study of this pervasive force in the evolution of all plants.
Spin transfer effect in magnetic tunnel junction with a nano-current-channel Layer in free layer

The current-induced magnetization switching (spin transfer effect) in a low resistance-area (RA) product magnetic tunnel junction (MTJ) device with critical current density of 1.4/spl times/10/sup 7/ A/cm/sup 2/ was demonstrated. The RA product of the MTJ is 4.2 /spl Omega//spl mu/m/sup 2/ and the magnetoresistance (MR) ratio induced by current is up to 16%. An MTJ structure with a novel nano-current-channel (NCC) layer inserted into the free layer for the current-induced magnetization switching by lower current density was proposed and prototyped. By using the current confined effect, the local current density in the integrated free layer was sufficiently high to switch the magnetization locally. Such local magnetization reversal helped to reverse the magnetic moments around together with the polarized current and spread out the switching of the entire free layer through the superparamagnetic nano-channels. The critical current density was reduced to 4.2/spl times/10/sup 6/ A/cm/sup 2/, which is only one quarter of that for a pure MTJ structure.
Manipulating ordering transitions in interfacially modified block copolymers

We report a synthetic strategy that allows us to manipulate the interfacial region between blocks and control ordering transitions in poly(isoprene-b-styrene) [P(I-S)] block copolymers. This interfacial modification is accomplished by combining a semi-batch feed with anionic polymerization techniques. Using this approach, we are able to control the segmental composition and molecular interactions in our phase-separated block copolymers, independent of molecular weight and block constituents. A library of copolymers is prepared with various interfacial modifications to examine the effect of interfacial composition on copolymer self-assembly. The morphological characteristics of the self-assembled structures are investigated using small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and dynamic mechanical analysis (DMA). Normal and inverse tapered block copolymers, containing approximately 15–35 vol% tapered material, show a measurable decrease in the order–disorder transition temperature (TODT) relative to the corresponding non-tapered diblock copolymers, with the inverse tapered materials showing the greatest deviation in TODT. Additionally, TODT was inversely related to the volume fraction of the tapered region in both normal and inverse tapered copolymer materials.
Design and modeling of a 17 GHz photocathode RF gun

The performance of a high-frequency (17-GHz), high accelerating gradient (250 MV/m) photocathode RF gun is studied with the particle-in-cell code MAGIC. For the parameter regime of interest, i.e., bunch charge smaller than 1 nC and bunch length shorter than 2 ps, space-charge forces and finite-bunch-length effects are less significant in determining the beam quality than nonlinear RF forces are. The cavity geometry, RF phase for photoemission, cathode size, and current density are being optimized to obtain high-quality beams. Preliminary results are presented. >
New Borrelia burgdorferi antigenic variant isolated from Ixodes dammini from upstate New York.

A previously undescribed Borrelia burgdorferi antigenic variant was isolated from each of four Ixodes dammini larvae removed from white-footed mice, Peromyscus leucopus, captured in Millbrook, N.Y. This site is in the northern range of the known distribution of the tick in the northeastern United States. The molecular weights of approximately 32,500 and 35,500 for outer surface A and outer surface B proteins, respectively, were distinctly higher than those for previously characterized isolates from North American ticks, humans, and wild mammals. A prominent low-molecular-weight protein of about 23,500 was also present. All four isolates infected Syrian hamsters and retained their antigenicity after passage through these rodent hosts. Serum samples from patients with Lyme disease tended to have immunoglobulin M, immunoglobulin G, and immunoglobulin antibodies to Connecticut B. burgdorferi 2591 at titers slightly higher than or equal to those recorded for an antigenically different strain of B. burgdorferi from Millbrook, N.Y. Images