cssi/SciSciGPT-SciSciNet huggingface dataset:
AN ANALYTICAL METHOD FOR AIRCRAFT COLLISION RISK ESTIMATION

Abstract Transportation system safety is difficult to assess, particularly when examining future systems that are unlike existing systems. The absence of consensus concerning safety metrics and associated mathematical techniques inhibits implementation of improvements. One method for assessing safety was recently applied to assess new air traffic control procedures. The method contains several steps, including use of a collision risk model. The model uses probability theory to assess collision risk between aircraft due to random deviations from course. Techniques that recognize human monitoring and intervention to avoid collisions must be combined with the model to obtain absolute values of risk. Examples of model application are presented, together with a discussion of model limitations and use.
Effect of sodium lack on local response of the single crustacean motor axon.

SummaryThe local or initial response of crustacean single motor axons has been recorded at the stimulating cathode. The deflections caused by a short duration shock of positive and negative polarity are asymmetrical. Normally the deflection caused by the negative pulse is considerably larger. In the absence of sodium, with either dextrose or Choline Chloride substituted, the local potential disappears. The deflections caused by positive and negative pulses become symmetrical. The effect is instantaneous and reversible. It is concluded that the sodium ion is essential for the production of the local or initial response.
Studies of non-classical shock wave phenomena

Most of our physical intuition regarding compressible flows and shock wave dynamics is based on experience with perfect gases in the context of an ideal fluid description. While this model is often a good approximation, there are some hydrodynamic systems in which shocks can exhibit behavior that lies outside of the classical phenomenology. Here, we present numerical simulations of a variety of such exotic shock wave effects, including “anomalous” behavior in so-called Bethe-Zel'dovich-Thompson fluids, shock “splitting,” the D'yakov-Kontorovich instability, and the influence of nonlinear heat transfer on shock structure in strong point explosions.
Quantitative modeling of dynamic behavior of a piezoelectric wafer actuator bonded to an elastic plate for guided wave propagation

Piezoelectric wafer actuators (piezo-actuators) have been extensively used in integrated structural health monitoring systems to generate ultrasonic guided waves (GWs) for structural damage interrogation. The big issue surrounding precise characterization of piezoelectrically excited GWs is addressing the dynamic interfacial stress between the piezo-actuator and the host structure. In this paper, an analytical actuator model is developed to quantitatively describe the dynamic load transfer between a bonded thin piezo-actuator and an isotropic plate under in-plane mechanical and electrical loading. The piezoelectrically induced GW responses are studied by coupling the actuator dynamics with the Rayleigh-Lamb equations and solving the resulting integral equations in terms of the interfacial shear stress. Typical examples are provided to show the capability of the current actuator model to capture the effects of the geometry and the loading frequency upon the load transfer. The analytical prediction of transient GW mode signals from the proposed model is compared with finite element simulation results for various excitation frequencies, and excellent agreement can be observed especially for high-frequency cases, which is a useful extension to the ultrasonic frequencies of most of existing analytical solutions for low frequency approximations.
Matching Taxpayer Funding to Population Health Needs: Not so Simple

In their critically acclaimed book Decisive , Chip and Dan Heath (from Stanford and Duke Universities) focus on the 4 most pernicious villains of decision-making.1 They are (1) narrow framing, seeing a decision as either X or Y, but not X and Y; (2) confirmation bias, paying attention to only those data that are consistent with prior beliefs; (3) reliance on short-term emotion; and (4) sticking with decisions rather than revising or reversing them if events do not turn out as predicted. The Heath brothers propose that decision-makers adopt a “WRAP” model in which they Widen their options, Reality test their assumptions, Attain distance before deciding, and Prepare to be wrong. The scientific community and the public are understandably interested in how government research sponsors make decisions. This interest has become increasingly acute as funds contract at the same time as research capacity continues to grow.2 The National Institutes of Health (NIH), as the world’s largest public sponsor of biomedical research, is under considerable scrutiny by many stakeholders,2–4 including scientists whose careers often depend on NIH monies, universities that factor NIH funding into their business models, and the public, which looks to the NIH to enable scientific discoveries that will relieve suffering from disease and disability. Many have voiced concern that the NIH should reconsider its business processes, from scientists who wonder about the value of NIH’s funding of big-science epidemiological studies, clinical trials, and research centers3; from policy makers who wonder whether the NIH’s approach to making funding decisions is outmoded2,4; and from critics like Michael Hanna who writes in this issue of Circulation Research that the NIH is failing to properly match funding to population health needs.5 Hanna argues that NIH funding allocations for disease-based research …
In-situ ultrasonic thickness measurement of underground water mains

In North America, most of the water mains pipes have been fabricated with either cast or ductile iron. It is well known that unprotected iron water mains are prone to corrosion resulting sometimes in serious metal loss and even major water leaks. At present time, water utilities have thus to replace parts of their water distribution pipes ont he basis of their average age, the number of breaks per kilometer per year, the hydraulic efficiency and water quality. In this paper, an ultrasonic technique which will enable the in-situ measurement of the pipe wall thickness is presented as an alternative to these inaccurate criteria. Such a technique can be used to map the defects along a water main and to evaluate their severity even if a mortar lining has been used to avoid the formation of tubercles. This technique uses water as the ultrasonic couplant and will not notably disturb the flow. The novelty of the approach relies on the use of a specialized model for ultrasonic propagation in multilayers coupled with a variable gain amplifier which increases significantly the dynamic range of the ultrasonic measurement systems. This system has been successfully used to produce images of corroded or graphitized areas in cast iron pipes of 6 inches nd 8 inches in diameter. The ultrasonic images agree well with the corresponding optical images. Thickness measurements have been also performed on water mains specimens around the defects found. The results indicate that the remaining iron thickness in the corroded regions can be estimated, in most cases, after proper signal processing.
Slo1 is the principal potassium channel of human spermatozoa

Mammalian spermatozoa gain competence to fertilize an oocyte as they travel through the female reproductive tract. This process is accompanied by an elevation of sperm intracellular calcium and a membrane hyperpolarization. The latter is evoked by K(+) efflux; however, the molecular identity of the potassium channel of human spermatozoa (hKSper) is unknown. Here, we characterize hKSper, reporting that it is regulated by intracellular calcium but is insensitive to intracellular alkalinization. We also show that human KSper is inhibited by charybdotoxin, iberiotoxin, and paxilline, while mouse KSper is insensitive to these compounds. Such unique properties suggest that the Slo1 ion channel is the molecular determinant for hKSper. We show that Slo1 is localized to the sperm flagellum and is inhibited by progesterone. Inhibition of hKSper by progesterone may depolarize the spermatozoon to open the calcium channel CatSper, thus raising [Ca(2+)] to produce hyperactivation and allowing sperm to fertilize an oocyte. DOI:http://dx.doi.org/10.7554/eLife.01009.001.
A New Application for the Disposable Skin Biopsy Punch

The disposable skin biopsy punch is an excellent instrument for excisional biopsy of tarsal conjunctival lesions.
Major histocompatibility class II-mediated signal transduction is regulated by the protein-tyrosine phosphatase CD45.

Major histocompatibility complex class II molecules and the B cell antigen receptor (BCR) transduce similar signals when cross-linked by ligand. Therefore, studies were conducted to determine whether the protein tyrosine phosphatase CD45 regulates signaling via these transmembrane receptors in an analogous manner. Cross-linking of either class II molecules or the BCR on CD45-positive K46-17μmλ B lymphoma cells was observed to induce activation of the Src family protein- tyrosine kinase Lyn, tyrosine phosphorylation of Syk and phospholipase Cγ, and the production of inositol 1,4,5-trisphosphate leading to intracellular mobilization as well as extracellular influx of Ca2+. In the absence of CD45, cross-linking of either class II molecules or the BCR failed to induce activation of Lyn. Syk was inducibly phosphorylated on tyrosine in a normal manner, whereas phospholipase Cγ exhibited a high basal level of tyrosine phosphorylation that was not significantly increased upon stimulation. Nevertheless, phospholipase Cγ appeared to be functional because CD45-negative cells produced elevated levels of inositol 1,4,5-trisphosphate following stimulation through class II or the BCR. Regardless of this, CD45-negative cells exhibited Ca2+mobilization responses that were greatly diminished and transient in nature. Whereas little or no mobilization of Ca2+ was observed in response to class II cross-linking, CD45-deficient cells mobilized Ca2+ from intracellular stores but not the extracellular environment in response to BCR cross-linking. These results demonstrate that CD45 regulates both Src family kinase activation and Ca2+ mobilization associated with class II- and BCR-mediated signal transduction.
Tidal triggering of reservoir-associated earthquakes

Abstract If the effect of a reservoir is to bring a fault zone gradually to failure and trigger an earthquake, then it is reasonable that rapidly fluctuating tidal stresses may influence the time of the induced earthquakes. An examination of earthquakes from eight reservoirs shows that earthquakes at six sites occur at preferred times in the semidiurnal tidal cycle. Tidal-stress orientations and the phase within the semidiurnal tidal cycle were calculated for only the largest earthquakes occurring at each site. This insures the elimination of aftershocks and selects earthquakes which are independent of each other. Sites of a significant earthquake/tide correlation with less than a 3% chance of occurring randomly include Hebgen Lake, Mont., U.S.A.; Kariba, Rhodesia; Kerr Dam, Mont., U.S.A.; Kremasta, Greece; Lake Mead, Nev., U.S.A.; and Monteynard, France. Each data set includes from about ten to twenty earthquakes. In most of the above cases earthquake triggering seems to occur when tidal stress enhances slip, i.e., when tidal stresses are oriented to enhance the tectonic stress.
Prospective, randomized evaluation of a cuffed expanded polytetrafluoroethylene graft for hemodialysis vascular access

Abstract Background. A cuffed expanded polytetrafluoroethylene (ePTFE) hemodialysis graft was developed to address the problem of recurrent stenosis at the graft-vein anastomosis. The purpose of this study was to compare graft patency and blood flow rates of cuffed and noncuffed (standard) ePTFE grafts placed for hemodialysis access. Methods. Forty-eight patients were prospectively randomized and followed for up to 24 months after placement of a cuffed or standard ePTFE graft for hemodialysis access. Study end points included time to graft failure and blood flow rates on hemodialysis. Results. Risk factors for graft failure were similar in both groups. However, the overall incidence of graft failure was significantly lower in the cuffed ePTFE graft group (P =.039). Graft patency rates in the cuffed versus standard groups were 64% versus 32% at 12 months (P =.037) and 58% versus 21% at 24 months (P =.0213). No cuffed ePTFE graft failed as a result of venous outflow stenosis. Average graft flow rates were similar when first measured 3 months postoperatively (845 mL/min, cuffed vs 715 mL/min, standard; P =.51) but declined more rapidly in the standard group (12 months, 623 vs 253 mL/min [P =.037]; 24 months, 531 vs 121 mL/min [P =.012]). Conclusions. The cuffed ePTFE graft was associated with increased blood flow rates during hemodialysis and improved graft patency compared with a standard ePTFE graft. Our results suggest a beneficial effect of the cuffed venous geometry for hemodialysis vascular access. (Surgery 2002;132:135-40.)
Rectangular distribution whose width is not exactly known: isocurvilinear trapezoidal distribution

After the Gaussian distribution, the probability distribution most commonly used in evaluation of uncertainty in measurement is the rectangular distribution. If the half-width of a rectangular distribution is specified, the mid-point is uncertain, and the probability distribution of the mid-point may be represented by another (narrower) rectangular distribution then the resulting distribution is an isosceles trapezoidal distribution. However, in metrological applications, it is more common that the mid-point is specified but the half-width is uncertain. If the probability distribution of the half-width may be represented by another (narrower) rectangular distribution, then the resulting distribution looks like an isosceles trapezoid whose sloping sides are curved. We can refer to such a probability distribution as an isocurvilinear trapezoidal distribution. We describe the main characteristics of an isocurvilinear trapezoidal distribution which arises when the half-width is uncertain. When the uncertainty in specification of the half-width is not excessive, the isocurvilinear trapezoidal distribution can be approximated by an isosceles trapezoidal distribution.
Optical and electrical properties of a-Si:H films grown by remote plasma enhanced chemical vapor deposition (RPECVD)

Abstract We have deposited a-Si:H films by RPECVD (substrate temperatures, Ts = 38 to 400°C) and have studied the IR and optical absorbance, and other electrical and optical properties. The RPECVD films differ from glow discharge (GD) and sputtered films most notably in the Ts dependence of the hydrogen bonding environments (SiH, SiH2, etc.), and the photoconductivity. RPECVD films produced with Ts = 235°C have properties comparable to ‘device grade’ GD films.
Implementing learning‐science research in university settings: New research opportunities

This chapter highlights some specific differences encountered between K–12 and higher education settings as a way to provide context for several research studies under way in engineering education. Specifically, this chapter highlights differences in three aspects of an academic learning environment: faculty, students, and subject matter.
A numerical study of silane combustion

A kinetic model of the mechanism of silane combustion has been developed, using a system of 70 elementary reaction steps and 25 chemical species. The model was used to examine silane ignition at ordinary pressures under both shock tube conditions and low-temperature constant-volume conditions. The agreement between model predictions and experimental data is very good, both with respect to shock tube ignition delay times and to the pronounced, nonlinear variation of autoignition time with initial pressure at near-ambient temperatures. The model also reproduces observed trends in H 2 /H 2 O product yield as a function of the initial SiH 4 /O 2 ratio. One key to this mechanism is competition between thermal stabilization and chain-branching decomposition reactions of an excited-state silylperoxy radical, and a second key is the reaction of water vapor with the intermediate species SiH 2 =O.
Learning about a fish from an ANT: actor network theory and science education in the postgenomic era

This article uses actor network theory (ANT) to develop a more appropriate model of scientific literacy for students, teachers, and citizens in a society increasingly populated with biotechnological and bioscientific nonhumans. In so doing, I take the recent debate surrounding the first genetically engineered animal food product under review by the FDA, AquaBounty Technologies’ AquAdvantage® salmon, as a vehicle for exploring the ways in which the biosciences have fundamentally altered the boundary between nature and culture and thus the way the public understands both. In response to the new challenges of a postgenomic society, I outline three frameworks for using ANT literacies in classroom settings. Each frame, I argue, is foundational to the development of a scientific literacy that can trace and map actors involved in controversies such as the AquAdvantage® salmon. In examining these frames I follow the actor of a salmon through an environmental history lens, the technoscientific literacy operating in AquaBounty’s FDA application and the National Academies new science education framework, and finally to a model of democracy rooted in an ethic of the common. The ultimate claim of this article is that until science education (and education in general) can begin to include nonhumans such as the AquAdvantage® salmon as part of a common political framework, students, educators, and community members will continue to be at the mercy of experts and corporate stakeholders for defining the terms in which people heal, feed, and educate themselves now and in the future.
Synthesis and characterization of gold(I) N-heterocyclic carbene complexes bearing biologically compatible moieties

Two new gold(I) complexes bearing the bulky N-heterocyclic carbene IPr (IPr = bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and respectively 2,3,4,6-tetra-O-acetyl-1-thio-β-d-pyranosatothiolato [(IPr)AuTgt (1)] and a saccharin ligand [(IPr)AuSac (2)] have been synthesized in good yield and are fully characterized by NMR spectroscopy and by inert-atmosphere MALDI-TOF. These complexes are well-behaved compounds analogous to gold drugs such as Auranofin and Solganol.
Automated material handling systems: a simulation-based design framework for automated material handling systems in 300mm fabrication facilities

This paper describes a methodology to tackle the problem of designing Automated Material Handling Systems (AMHS) for 300mm wafer fabrication facilities. The proposed framework divides the design process into two levels: architectural and elaborative. Prior to the design, fab data are preprocessed using simulation of manufacturing operations. The output data and fab requirements data are then profiled to aid in design decision making at the architectural level. Once architectural design decisions are made, lower-level design decisions are made and analyzed using a simulation model that incorporates the AMHS. Due to the potential number of alternatives and time constraints on the design process, we are exploring rapid model generation methods. In this paper, we describe our progress to date in creating this methodology.
The Second‐Best Level of a Public Good: An Approach Based on the Marginal Excess Burden

This paper studies the second-best level of public goods, a topic first addressed formally by Atkinson and Stern (1974, Review of Economic Studies, 41, 119–128). It goes beyond the existing literature on this “level problem” by identifying the marginal excess burden as a key underlying force behind level comparisons. The propositions in this paper include previous results as special cases. The paper also relates the marginal excess burden condition to consumer behavior and to the complementarity or substitutability between the public good and the taxed private good.
Improved sandwich enzyme-linked immunosorbent assays for transforming growth factor β1

Transforming growth factor beta s (TGF-beta s), a highly homologous family of 25 kDa dimers, function as both paracrine and autocrine growth modulators which relay a broad spectrum of critical biological functions. Although sensitive bioassays for TGF-beta s have been described, their interference by other growth modulators have limited their application. We have previously described a highly sensitive (20-50 pg/ml) and specific sandwich enzyme-linked immunosorbent assay (SELISA) for TGF-beta 1, based on use of rabbit anti-TGF-beta 1 as the capture antibody. Widespread use of this assay was limited by the availability of this rather low-titer antibody. This report describes improved TGF-beta 1 SELISAs with comparable sensitivities to the above assay based on available sources of commercial monoclonal and polyclonal antibodies. These newly developed SELISAs are the most sensitive, specific, precise and convenient methods for the quantitation of TGF-beta 1 in complex biological fluids.
High Vacuum Portable Pumping Station Suitable for Accelerator Use

The need for a Portable Pump Station for Ultra High Vacuum use became apparent when the ''Isabelle'' collider was first being designed. A Portable Pump Station had to be developed which contained the following features: maneuverability, compact size, rugged, self protected against various failures, capable of running unattended, and capable of reaching 10/sup -9/ torr. The Pump Station that was developed and other variations are the subject of this paper. Emphasis will be on the Isabelle and HITL versions. 1 ref., 2 figs., 1 tab.
Hepatic angiography in patients undergoing damage control laparotomy

Objective: Patients undergoing damage control (DC) laparotomy require intensive and aggressive resuscitation, and may require additional maneuvers to control parenchymal bleeding. Those patients suffering significant liver injury are at high risk for arterial bleeding deep within the liver, and many require hepatic angiography in addition to hepatic packing. We reviewed our experience with hepatic angiography, and sought to determine its safety in the DC population of penetrating and blunt trauma patients. Methods: A 3-year (June 1997-May 2000) retrospective review generated 37 DC patients. Patients sustaining hepatic trauma constituted the study group. Patients undergoing angiography in addition to DC laparotomy were compared with the group of patients not undergoing angiography. Data regarding mechanism of injury, patient demographics, extent of hepatic injury, and presence of associated injuries were collected. Physiologic parameters including vital signs at admission, lowest pH and base excess in the operating room, and lactate levels in the intensive care unit, as well as volumes of fluid resuscitation throughout all phases of DC were examined. Complications including death, intra-abdominal processes, acute respiratory distress syndrome and/or multiple organ dysfunction syndrome, and acute renal failure were reviewed. Results: Nineteen patients (51%) had hepatic trauma and underwent perihepatic packing as a part of DC laparotomy. Eleven had sustained penetrating injury and 8 had blunt injury. There was I American Association for the Surgery of Trauma grade I, 5 grade II, 3 grade III, and 10 grade IV injuries. Nine patients in the study population underwent angiography, and eight of these were hepatic artery angiograms. One hepatic angiogram was obtained before operation and seven were obtained in the immediate postoperative period. Six underwent embolization of bleeding hepatic vessels, for a therapeutic liver angiography rate of 75%. There was no statistical difference in physiologic parameters or fluid requirements between the patients who underwent angiography and those who did not. There were no mishaps or complications from angiography or while in the angiography suite. Conclusion: Hepatic angiography is a safe adjunct to the principles of damage control. It has a high therapeutic ratio, with no significant untoward effect in this small study population.
Eat Local? Constructions of Place in Alternative Food Politics

In recent years those seeking alternatives to industrialized and globalized food systems have looked beyond organic production to develop a range of alternative food networks (AFNs). Alongside these developments in sustainable food and agriculture activism, a body of literature has emerged in rural sociology, agri-food studies and human geography exploring the development of alternative food networks. This article explores some potential synergies between this literature and geographical theory surrounding space and place. Place has been identified as central to AFN discourse and efforts to localize food systems, and while the benefits of localized food systems can be accepted uncritically by activist communities and the media, important questions have been raised about the reflexivity of local food activism. This article argues that a closer engagement with place theory would help avoid the fetishized constructions of the local often present in alternative food politics. Drawing on geographical debates about place, this article demonstrates the ways in which geographical place theory could inform and develop literatures examining alternative food politics.
Experimental Flight Characterization of Asymmetric and Maneuvering Projectiles from Elevated Gun Firings

Instrumented flight experiments were conducted to quantify flight behavior for two precision munitions programs.These projectileswere of different shapes and calibers but each featured roll-inducing tailfins and canards as their maneuver mechanisms. In this effort, aerodynamic terms for asymmetries, side moments, and control mechanisms were estimated from onboard sensor data acquired during elevated gun firings. Additionally, these experiments uncovered an in-flight reversal in coning direction of the projectile and the reasons for this behavior are described in a flight stability analysis.
Chronic prostatitis/chronic pelvic pain syndrome: role of alpha blocker therapy.

Introduction: This article reviews the rationale and data supporting alpha blocker therapy for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), the most common and diffic
Weak radiative hyperon decays

Abstract A summary is given of recent experimental and theoretical developments in weak radiative hyperon decays. As an example, data and new results are presented from Brookhaven experiment E811, the first high statistics measurement of the branching ratio for the Λ weak radiative decay, Λ → n + γ .
Two-dimensional theory of free-electron lasers

The two-dimensional dispersion relation for the free-electron laser is derived in the cold-beam limit. It is found that the forward wave has the largest growth rate, but the backward wave has the greatest spatial amplification rate. For $\frac{{k}_{0}v}{{\ensuremath{\omega}}_{p}}g{\ensuremath{\gamma}}^{\frac{\ensuremath{-}3}{2}}+{\ensuremath{\gamma}}^{\frac{\ensuremath{-}1}{2}}$, the free-electron laser is unstable at all angles with the low-frequency waves being absolutely unstable.
Experimental method for characterizing CVOC removal from fractured clays during boiling

Abstract Conventional remediation methods that rely on contact with contaminants can be ineffective in fractured media, but thermal methods of remediation involving CVOC stripping at boiling temperature show promise. However, limited experimental data are available to characterize thermal remediation because of challenges associated with high temperature. This research reports an experimental method using uniformly contaminated clay packed into two types of experimental cells, a rigid-wall stainless steel tube and a flexible-wall Teflon tube in a pressurized chamber. Both tubes are 5 cm in diameter and approximately 25 cm long. This laboratory apparatus was developed as a 1D physical model for contaminant transport in a cylindrical matrix towards a fracture, which is represented by one end of the cylinder and serves as the outlet of vapor and contaminant. The clay was contaminated with dissolved 1,2-dichloroethane (DCA) and bromide, and the columns were heated to more than 100 °C and then the top end was depressurized to atmospheric pressure to induce boiling. The outflow was condensed and analyzed for contaminant mass. The flexible-wall cell was confined to 100 kPa (gage), allowing equilibrium boiling temperatures of approximately 120 °C to be maintained. The clay was sampled before and after heating and extracted to determine the DCA distribution along the length of the column. During a typical test in the rigid-wall cell, internal temperatures and pressures along the column during heating reached the saturated vapor pressure curve. DCA concentrations in the recovered condensate were up to 12 times of the initial pore concentration in the clay. Less than 5% of non-volatile bromide was recovered. Significant removal of DCA and water occurred along the entire length of the clay column. This suggests that boiling was occurring in the clay matrix.
Functioning of nanovalves on polymer coated mesoporous silica Nanoparticles

Nanomachines activated by a pH change can be combined with polymer coatings on mesoporous silica nanoparticles to produce a new generation of nanoparticles for drug delivery that exhibits properties of both components. The nanovalves can trap cargos inside the mesoporous silica nanoparticles without premature release and only respond to specific stimuli, resulting in a high local concentration of drugs at the site of release. The polymer surface coatings can increase the cellular uptake, avoid the reticuloendothelial uptake, provide protected space for storing siRNA, and enhance the biodistribution of nanoparticles. Two nanovalve-polymer systems are designed and their successful assembly is confirmed by solid state NMR and thermogravimetric analysis. The fluorescence spectroscopy results demonstrate that the controlled release functions of the nanomachines in both of the systems are not hindered by the polymer surface coatings. These new multifunctional nanoparticles combining stimulated molecule release together with the functionality provided by the polymers produce enhanced biological properties and multi-task drug delivery applications.
The ARS Culture Collection: present status and new directions

Abstract The ARS Culture Collection (NRRL) is one of the world's largest microbial culture collections. The strains maintained are primarily of agricultural and industrial importance and have been the focus of research on penicillin and other antibiotics, riboflavin, organic acids, xanthan and dextran gums and more recently on food fermentations, mycotoxins and biomass conversions. The collection is also internationally recognized as a depository for patent cultures. The history, policies and research programmes of the collection are discussed.
High resolution spectroscopic imaging of GABA at 3 Tesla

A spin echo-based MRSI sequence was developed to acquire edited spectra of γ-aminobutyric acid in an entire slice. Water and lipid signals were suppressed by a dual-band presaturation sequence, which included integrated outer volume suppression pulses for additional lipid suppression. Experiments in three normal volunteers were performed at 3 T using a 32-channel head coil. High signal-to-noise ratio spectra and metabolic images of γ-aminobutyric acid were acquired from nominal 4.5 cm3 voxels (estimated actual voxel size 7.0 cm3) in a scan time of 17 min. The sequence is also expected to co-edit homocarnosine and macromolecules, giving a composite γ-aminobutyric acid+ resonance. The γ-aminobutyric acid+ to water ratio was measured using a companion water MRSI scan and was found to correlate linearly with the % gray matter (GM) of each voxel (γ-aminobutyric acid+/water=(1.5×GM+3.2)×10(-5), R=0.27), with higher γ-aminobutyric acid+ levels in gray matter compared with white. In conclusion, high signal-to-noise ratio γ-aminobutyric acid-MRSI is possible at 3 T within clinically feasible scan times.
DENSE AND DILUTE INSTANTON - ANTI-INSTANTON PAIR CONFIGURATIONS

We present a Yang-Mills gauge field configuration which for large values of a separation parameter is an instanton--anti-instanton pair. At a minimum finite separation the field is a pure gauge. The interaction is calculated for large and small separations. According to an approximation algorithm the configuration is the most important quantum fluctuation about the exact solutions.
Desiccation and Germination of Grain Sorghum as Affected by Glufosinate

Preharvest desiccants are needed to reduce moisture content of grain sorghum [Sorghum bicolor (L.) Moench] for earlier harvest to preserve seed quality and quantity. Objectives of this study were (i) to examine the desiccant activity of glufosinate [2-amino-4-(hydroxy-methylphosphinyl)butanoic acid] applied at several rates to grain sorghum at different seed moisture levels in contrasting environments and (ii) to determine the effect of glufosinate on germination and seedling growth of the treated crop. The soil at College Station (east-central Texas), was a Ships clay (very-fine, mixed, active, thermic, Chromic Hapludert); at Mayaguez, PR, a Coto clay (very-fine, kaolinitic, isohyperthermic Typic Hapludox). Glufosinate was evaluated because of its contact herbicidal properties and limited systemic activity. In both Texas and Puerto Rico, glufosinate was applied at 0, 0.56, 1.1, or 2.2 kg ha -1 to grain sorghum. Leaves and seed were sampled at 0, 1, 2, and 3 wk after treatment (WAT) for grain and leaf moisture. Seed was collected at 2 and 3 WAT for germination and growth studies. Glufosinate at all three treatment rates dried seed of the grain sorghum hybrid ATx638/Tx2783 in Texas from >350 g kg -1 grain moisture at application to a storable moisture of <120 g kg -1 at 2 WAT, at which time untreated grain moisture was 150 g kg -1 . Glufosinate rate did not affect grain moisture except at the high glufosinate rate at 1 WAT. Leaf moisture reduction was glufosinate rate-dependent, but all treatments significantly reduced leaf moisture content at 1 WAT. Germination and seedling growth were not affected by glufosinate treatment. Grain desiccation rate under a tropical environment (Puerto Rico) was slightly slower than in Texas, but leaf moisture reduction was rapid and reached <300 g kg -1 by I WAT from initial leaf moisture contents of 500 or 770 g kg 1 . Germination was not adversely affected by glufosinate.
Dental caries and levels of treatment for school children by geographical region, socioeconomic status, race, and size of community.

The data supplied by the two investigators from a study of a large sample of children in this country may have considerable significance if a program of National Health Insurance should be initiated by the Federal Government to begin with preschool children.
Conformational Changes in BAK, a Pore-forming Proapoptotic Bcl-2 Family Member, upon Membrane Insertion and Direct Evidence for the Existence of BH3-BH3 Contact Interface in BAK Homo-oligomers

During apoptosis, the pro-apoptotic Bcl-2 family proteins BAK and BAX form large oligomeric pores in the mitochondrial outer membrane. Apoptotic factors, including cytochrome c, are released through these pores from the mitochondrial intermembrane space into the cytoplasm where they initiate the cascade of events leading to cell death. To better understand this pivotal step toward apoptosis, a method was developed to induce membrane permeabilization by BAK in the membrane without using the full-length protein. Using a soluble form of BAK with a hexahistidine tag at the C terminus and a liposomal system containing the Ni2+-nitrilotriacetic acid lipid analog that can bind hexahistidine-tagged proteins, BAK oligomers were formed in the presence of the activator protein p7/p15Bid. In this system, we determined the conformational changes in BAK upon membrane insertion by applying the site-directed spin labeling method of EPR to 13 different amino acid locations. Upon membrane insertion, the BH3 domains were reorganized, and the α5-α6 helical hairpin structure was partially exposed to the membrane environment. The monomer-monomer interface in the oligomeric structure was also mapped by measuring the distance-dependent spin-spin interactions for each residue location. Spin labels attached in the BH3 domain were juxtaposed within 5–10 Å distance in the oligomeric form in the membrane. These results are consistent with the current hypothesis that BAK or BAX forms homodimers, and these homodimers assemble into a higher order oligomeric pore. Detailed analyses of the data provide new insights into the structure of the BAX or BAK homodimer.
Functions of thymic stromal lymphopoietin in immunity and disease

Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine expressed mainly by epithelial cells. Current studies provide compelling evidence that TSLP is capable of activating dendritic cells to promote T helper (Th) 2 immune responses. TSLP has also been shown to directly promote Th2 differentiation of naive CD4+ T cell and activate natural killer T cells, basophils and other innate immune cells at the initial stage of inflammation. In addition, TSLP affects B cell maturation and activation and can also influence regulatory T (Treg) cell differentiation and development. TSLP-induced Th2 responses are associated with the pathogenesis of allergic inflammatory diseases, including atopic dermatitis, asthma, and rhinitis. Based on recent findings in humans and mouse models, TSLP might also be involved in the pathogenesis of inflammatory bowel disease and progression of cancer. In this review, we will summarize our current understanding of the biology of TSLP and highlight the important issues for future investigations.
Metabolism of 14C-DDT in the mouse and hamster.

1. When 1,1-bis(P-chloro[14C]phenyl)-2,2,2-trichloroethane (DDT) was fed to CF-1 mice and Syrian golden hamsters, conjugates of bis(p-chlorophenyl)-acetic acid (DDA) were the major urinary metabolites. As well as DDA-glycine, DDA-alanine and DDA-glucuronic acid previously identified, a new conjugate with serine is reported.2. Small amounts of non-polar metabolites were detected in urine. Mouse urine contained DDE, whereas this was never detected in hamster urine. The relevance of this finding to the tumorigenicity of DDT in mice, compared with its inactivity in this respect in hamsters, is discussed.
Overexpression of noggin inhibits BMP-mediated growth of osteolytic prostate cancer lesions.

Abstract Introduction Although a majority of metastatic prostate cancer lesions are osteoblastic in nature, some are mixed or lytic; and, osteoblastic lesions require osteolytic activity in order to progress. The role of BMPs in the formation of prostate cancer metastases to bone remains unknown. We hypothesized that BMPs influence the development and progression of osteolytic prostate cancer lesions. Methods RT-PCR and Western blot analysis were used to determine BMP receptor expression on the osteolytic prostate cancer cell line PC-3. Migration, invasion, and cellular proliferation assays were performed on PC-3 cells to quantify the effects of BMP-2, -4, and -7. In vivo, PC-3 cells were injected alone, with an empty retroviral vector, or with a retroviral vector overexpressing noggin, into the tibias of SCID mice. The animals were followed for 8 weeks, and histologic and radiographic analysis were performed at 2, 4, 6, and 8 weeks. Results BMP receptors are expressed on PC-3 cells, suggesting that they would be responsive to host BMP secretion. BMP-2, and to a lesser extent, BMP-4, stimulated PC-3 cell migration and invasion in a dose-dependent fashion. Noggin inhibited cellular migration and invasion of BMP-2 and -4 stimulated PC-3 cells. BMP-2 alone stimulated PC-3 cell proliferation, but BMP-4 had no effect. BMP-7 had no effect on proliferation, migration, or invasion. PC-3 cells implanted into SCID mouse tibias formed osteolytic lesions as early as 2 weeks and completely destroyed the proximal tibia by 8 weeks. Overexpression of noggin in PC-3 cells inhibited the expansion of the lesion in vivo. Conclusions BMPs influence the formation of the osteolytic prostate cancer metastases, and treatment modalities that inhibit BMP activity may limit the progression of the lytic component of prostate cancer metastases.
Application of position encoding to a complex joint transform correlator

Because a joint transform correlator can be used as a general optical signal processor, complex-impulse-response implementations in the spatial domain are often requested. We introduce a position-encoding technique with which complex-valued references for the joint transform correlator can be obtained with an amplitude-modulated spatial light modulator. A proof-of-concept experiment is also provided.
Betti numbers of congruence groups

It is shown that, for certain congruence families of Galois coverings of a manifold, the individual Betti numbers are polynomial periodic functions of the level. Similar results are proved for the dimensions of other spaces of automorphic forms.
Development and analytical applications of multispectral imaging techniques: An overview

A multispectral imaging spectrometer is an instrument that can simultaneously record spectral and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. By synergistic use of an acousto-optic tunable filter and a progressive scan camera capable of snap shot recording it was possible to develop a novel imaging spectrometer with a spatial resolution of a few microns and which can record, grab and store up to 33 images per second (at a function of time) or 16 images per second (as a function of wavelength). This overview article summarizes the instrumentation development of various imaging spectrometers and their applications including its use as the detector for the determination of identity and sequences of peptides synthesized by the combinatorial solid phase method.
Use of small stand-alone Internet nodes as a distributed control system

Abstract For several years, the standard model for accelerator control systems has been workstation consoles connected to VME local stations by a Local Area Network with analog and digital data being accessed via a field bus to custom I/O interface electronics. Commercially available hardware has now made it possible to implement a small stand-alone data acquisition station that combines the LAN connection, the computer, and the analog and digital I/O interface on a single board. This eliminates the complexity of a field bus and the associated proprietary I/O hardware. A minimum control system is one data acquisition station and a Macintosh or workstation console, both connected to the network; larger systems have more consoles and nodes. An implementation of this architecture is described along with performance and operational experience.
Multi-contrast high spatial resolution black blood inner volume three-dimensional fast spin echo MR imaging in peripheral vein bypass grafts

The purpose of this study is to primarily evaluate the lumen area and secondarily evaluate wall area measurements of in vivo lower extremity peripheral vein bypass grafts patients using high spatial resolution, limited field of view, cardiac gated, black blood inner volume three-dimensional fast spin echo MRI. Fifteen LE-PVBG patients prospectively underwent ultrasound followed by T1-weighted and T2-weighted magnetic resonance (MR) imaging. Lumen and vessel wall areas were measured by direct planimetry. For graft lumen areas, T1- and T2-weighted measurements were compared with ultrasound. For vessel wall areas, differences between T1- and T2-weighted measurements were evaluated. There was no significant difference between ultrasound and MR lumen measurements, reflecting minimal MR blood suppression artifact. Graft wall area measured from T1-weighted images was significantly larger than that measured from T2-weighted images (P < 0.001). The mean of the ratio of T1- versus T2-weighted vessel wall areas was 1.59 (95% CI: 1.48-1.69). The larger wall area measured on T1-weighted images was due to a significantly larger outer vessel wall boundary. Very high spatial resolution LE-PVBG vessel wall MR imaging can be performed in vivo, enabling accurate measurements of lumen and vessel wall areas and discerning differences in those measures between different tissue contrast weightings. Vessel wall area differences suggest that LE-PVBG vessel wall tissues produce distinct signal characteristics under T1 and T2 MR contrast weightings.
Aqueous lanthanide shift reagents. 9. Evaluation of a model for the separation of contact and dipolar shift contributions: Effects of magnetic asymmetry

Abstract A useful model for the analysis of lanthanide-induced shifts (LIS) in terms of contact and dipolar contributions is critically examined by applying it to data sets for the ligands methoxyacetate, sarcosine (N-methylaminoacetic acid), alanine (2-aminopropanoic acid), and (3-indoyl)acetate. The model assumes isostructurality of the complexes and constancy of the electron-nuclear hyperfine coupling constant along the lanthanide series and axial symmetry for the magnetic susceptibility of the central ion. In practice these conditions are fulfilled for the LIS of some but not of all the nuclei within the same ligand. Magnetic asymmetry is suggested as a major source of departures from the model. Effective axial symmetry is likely to result from the averaging effect of intramolecular rotational motions or rearrangements. The dipolar shifts in the asymmetric case contain the contributions of axial and nonaxial terms. The relative coefficients of the latter for the different lanthanides are evaluated from magnetic susceptibility data. The results of the analyses of the LIS data for the four ligands indicate that along the lanthanide series the complexes are isostructural and that the hyperfine coupling constant is invariant.
Site-directed mutagenesis of the heme axial ligands in the hemoflavoenzyme cellobiose dehydrogenase.

Abstract Cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium is an extracellular 90-kDa hemoflavoenzyme, organized into an N-terminal heme domain and a C-terminal flavin domain. The amino acid residues Met65 and His114 or His163 were suggested to be heme iron ligands. Mutations of these residues were made and mutant proteins were characterized. H114A mutant cultures produce a stable hemoflavoenzyme with spectral and kinetic characteristics similar to those of wild-type CDH. The M65A and H163A transformants secrete a 90-kDa hemoflavoenzyme, which oxidizes cellobiose in the presence of 2,6-dichlorophenol–indophenol (DCPIP), but is unable to reduce cytochrome c. The heme domains of the M65A and H163A CDH variants are, however, unstable and susceptible to degradation, both yielding a 70-kDa cellobiose–oxidizing flavoenzyme. The spectral and kinetic characteristics of these truncated variants suggest that they contain only their respective flavin domains. The yield of the 90-kDa proteins was low and the proteins could not be purified to homogeneity; however, absorption spectra indicate that the 90-kDa proteins do contain the heme domain. Like the truncated flavoenzymes, the 90-kDa variants reduce DCPIP but are unable to transfer electrons to cytochrome c, in contrast to wild-type CDH. These findings suggest that H163 and M65 are the axial heme ligands and that both ligands are required for the reactivity and structural integrity of the heme domain.