cssi/SciSciGPT-SciSciNet huggingface dataset:
History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in genetics instruction; and (3) suggests a modified concept mapping assessment tool for both NOS and GCK. A quasi-experimental control group research design was utilized with pretests, posttests, and delayed posttests, combining qualitative data and quantitative data. The experimental group was taught with historical curricular lessons, while the control group was taught with non-historical curricular lessons. The results indicated that students in the experimental group developed better understanding in targeted aspects of NOS immediately after the intervention and retained their learning 2 months after the intervention. Both groups developed similar genetics knowledge in the posttest, and revealed a slight decay in their understanding in the delayed posttest.
Mixed layers in gulf stream rings

Abstract Immediately after formation, warm and cold Gulf Stream rings are visible in satellite infrared images of sea-surface temperature (SST) as pools of anomalous water. It is now well documented that the surface expressions of cold core rings quickly disappear, while warm rings, summertime excepted, remain visible to satellite infrared sensors throughout their lifetimes. From XBT data, one sees evidence of strong air-sea exchange and deep mixed layers in warm rings, but no unusual mixed layer development in cold rings. We apply a simple one-dimensional annual mixed layer model to Gulf Stream rings to explain these phenomena. The key ingredients of the model are the different atmospheric states over the Sargasso Sea and the Slope Water, the relative density structures of warm and cold rings, and the difference in mixed layer response to heating and cooling. Several features of the surface water behavior in warm and cold rings are qualitatively reflected in the model results. Quantitative comparisons between model predictions and observations are also encouraging, suggesting that the SST evolution of a ring can be attributed to local air-sea exchange.
Determination of Enzyme Activity in Single Bovine Adrenal Medullary Cells by Separation of Isotopically Labeled Catecholamines

A microcolumn liquid chromatography method for determining norepinephrine (NE), epinephrine (E), and phenylethanolamine N-methyltransferase (PNMT) enzyme activity in single bovine adrenal medullary cells is presented. Single cells were isolated and treated with excess deuterated substrate, D3-NE (0.05 mM) for enzyme reaction. After 6 h, the reaction was quenched and the product, D3-E, was quantified along with endogenous NE and E. Separation and detection of deuterated and protiated NE and E were achieved with microcolumns (110−125 cm long, 25 μm inner diameter) packed with 3 μm octadecylsilane-modified particles and operated with amperometric detection. Of the 33 cells reported, most cells containing predominantly E have enzyme activity while cells containing predominantly NE and cells containing a mixture of both NE and E show no enzyme activity. After incubation with 10 μM hydrocortisone, of the 17 cells reported, most cells containing predominantly E and cells containing a mixture of both NE and E hav...
TH-C-144-05: Distal and Lateral Dose Perturbation From Collimator Scattering in Proton Radiotherapy

Purpose: Dose perturbation from collimator scattering is not modeled by current treatment planning systems and is usually ignored in proton radiotherapy. In this work we study the dosimetric impact of collimator scattering and possible solutions. Methods: Three sets of apertures with non‐diverging edge, diverging edge and stepped edges that averaged divergence for each single piece, were milled by CURA to produce a 10cm×10cm field at isocenter. Cross‐plane profiles were measured at a shallow (2cm) and deep (7.5cm) depths with EBT3 films, delivered with the Mevion S250 system, which has a relatively shorter SAD (∼2m). Films were irradiated with a fully modulated proton beam with range of 15cm in water. In‐plane profiles were also acquired on a coronal plane along the central axis. Results: Although negligible changes in lateral penumbra were observed in all cases, collimator scattering added up to 11% extra dose near the field edge for the non‐diverging edge aperture. For diverging and stepped edge apertures, extra dose from collimator scattering were reduced to less than 5% at 2cm depth, and was negligible at 7.5cm depth. Deterioration of distal penumbra was observed in both non‐diverging and stepped edged apertures, broadened to 13mm from 8mm, which was measured for the diverging edge aperture. Conclusion: Collimator scattering from apertures not only introduce extra dose near the field edge at shallow depths, but also deteriorates the distal penumbra. A diverging‐cut aperture can eliminate both contaminations. Divergent edges should be considered in apertures when sensitive organs are lateral at shallow depths, or distal to the target. blown MC. The method can be integrated in existing TPS to enable PET‐based treatment verification in the daily clinical routine of proton therapy.
A hybridization-based approach for quantitative and low-bias single-stranded DNA ligation

Single-stranded DNA (ssDNA) ligation is a crucial step in many biochemical assays. Efficient ways of carrying out this reaction, however, are lacking. We show here that existing ssDNA ligation methods suffer from slow kinetics, poor yield, and severe nucleotide preference. To resolve these issues, we introduce a hybridization-based strategy that provides efficient and low-bias ligation of ssDNA. Our method uses a hairpin DNA to hybridize to any incoming acceptor ssDNA with low bias, with ligation of these strands mediated by T4 DNA ligase. This technique potentially can be applied in protocols that require ligation of ssDNA, including ligation-mediated polymerase chain reaction (LMPCR) and complementary DNA (cDNA) library construction.
The radiation efficiency of mass-loaded, slender, baffled beams

A study of the radiation of sound from mass-loaded, baffled beams which are either simply supported or clamped is described. The Rayleigh-Ritz method is employed to obtain approximate natural frequencies and mode shapes for the mass-loaded beams. A set of comparison functions is selected which are used with the Rayleigh integral to obtain expressions for the radiation efficiency of the mass-loaded beams. The radiation efficiency is determined for simply supported and clamped mass-loaded beams as a function of the location and magnitude of a single added mass. The radiation efficiency is evaluated numerically over a broad frequency range below coincidence. In the region well below coincidence approximate analytical expressions are developed to represent the radiation efficiency. The concept of volume velocity cancellation is used to interpret the radiation efficiency. It is shown that well below coincidence the radiation efficiency of simply supported mass-loaded beams is equivalent to the radiation efficiency produced by a series of in-phase monopoles and a series of dipoles. Two examples are used to illustrate the effect of mass addition to an otherwise uniform beam: a simply supported, mass-loaded beam vibrating in the second mode and a clamped mass-loaded beam vibrating in the third mode.
Restoration methods for abandoned roads at lower elevations in Grand Teton national park, Wyoming

Abstract Plant community development was examined in response to various cultural practices on an abandoned road in Grand Teton National Park in northwestern Wyoming. Restoration methods of increasing intensity were tested over a two‐year period. Treatments included seedbed scarification, fertilizing, seeding, topsoiling, and mulching. Plant cover was estimated and soil physical attributes (bulk density, infiltration, aggregate stability) were tested to determine the effect of soil properties on restoration efforts. Topsoil significantly increased overall plant cover, but there were no differences between topsoil depths. It appears that topsoil did not contribute nutritionally to plant growth, but improved the soil physical properties, thus enhancing water relations. Indigenous plant materials that were collected on site produced greater plant cover (23%) than the native materials (19%) purchased from a commercial supplier. These differences were significant when scarifying and topsoiling practices were c...
Cheater Detection is Modified by Social Rank: The Impact of Dominance on the Evolution of Cognitive Functions

Abstract Cheater detection plays a crucial role in biologial and psychological theories of the evolution of cooperation and reciprocity. Here it is argued that cheater detection plays a broader role in social coordination as a fundamental, primitive cognitive adaptation to dominance hierarchies. In functional terms, dominance means that certain individuals have priority of access to resources in competitive situations. In cognitive terms, dominance hierarchies constitute a set of social norms that reflect which behaviors are permitted, prohibited, or obligated given one's rank. In order to maintain priority of access to resources, dominant individuals monitor the behavior of subordinates and aggress against those who "cheat" (violate social norms). An implication of this analysis is that higher-ranking individuals should be more likely to detect cheating in lower-ranking individuals than vice versa. Two experiments are described that support this prediction. In the first experiment, people were far more likely to look for cheaters when monitoring compliance of lower-ranking individuals on a social norm reasoning task than higher- or equal-ranking individuals. In the second, the same result obtained when reasoners were required to switch perspectives: More cheater detection was observed when reasoners adopted a high-ranking than a low-ranking perspective.
Quantum oscillations of the specific heat in d -wave superconductors with loop current order

We report numerical results of quantum oscillations of the specific heat in the vortex state of a ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconductor in the presence of loop current order [C. M. Varma, Phys. Rev. B 55, 14554 (1997); Phys. Rev. Lett. 83, 3538 (1999)], which gives rise to the Fermi pockets coexisting with nodal ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconductivity. Within a lattice tight-binding model, we find that in an intermediate temperature range, the oscillations seem to approximately follow the Onsager relation with an effective charge comparable to the electric charge. However, the quasiparticle spectrum does not resemble the Landau levels. In order to understand the origin of the oscillations, we also perform the Franz-Tesanovic transformation in the presence of the loop order and find that in addition to scalar and the Berry potentials [M. Franz and Z. Te\ifmmode \check{s}\else \v{s}\fi{}anovi\ifmmode \acute{c}\else \'{c}\fi{}, Phys. Rev. Lett. 84, 554 (2000)], one component of the gauge invariant superfluid velocity couples to the low-lying Dirac particles as a component of a vector potential. The magnetic field associated with this vector potential vanishes on average but is highly nonuniform in the magnetic unit cell. We attribute the quantum oscillations to this field. We also compare the results with the model without the loop order but with the Zeeman-like coupling, which also induces the Fermi pockets in the superconducting state.
Toxicological properties of O,O,S‐trialkyl phosphorothioates

The effect of atropine, 2-pyridine aldoxime methiodide (2-PAM), and several O,O,O-trialkylphosphorothioates on poisoning of rats by a series of O,O-dimethyl and O,O-diethyl S-alkyl phosphorothioates was investigated. Atropine and 2-PAM successfully protected rats treated with O,O-diethyl S-n-propyl and S-i-propyl phosphorothioates, while the O,O,O-trialkyl phosphorothioates were effective in protecting rats treated with O,O-dimethyl S-methyl and S-ethyl phosphorothioates. O,O-Dimethyl and O,O-diethyl S-i-propyl phosphorothioates also were examined for in vitro and in vivo inhibition of rat plasma, red blood cell, and brain cholinesterase. Overall, the results indicated that two different mechanisms, cholinergic and noncholinergic, are involved in intoxication by the O,O,S-trialkyl phosphorothioates.
Afferent projections to the central nucleus of the inferior colliculus in the rat

Abstract The afferent projections to the inferior colliculus of the rat were studied using the method of retrograde transport of horseradish peroxidase (HRP). Following large injections of HRP into the central nucleus, cells within the cochlear nuclei, superior olivary complex and auditory cortex were stained. Within the contralateral dorsal cochlear nucleus, fusiform cells were heavily labeled. Giant cells were also labeled in deeper layers. In the contralateral ventral cochlear nucleus, virtually all major cell types were labeled, with some types being labeled in greater numbers than others. Octopus cells of posteroventral division of ventral cochlear nucleus (PVCN) were never labeled. HRP-positive cells were found in ipsilateral and contralateral lateral superior olivary nucleus (LSO), ipsilateral medial superior olivary nucleus (MSO), ipsilateral and contralateral lateral nucleus of the trapezoid body (LTB), ipsilateral ventral nucleus of the trapezoid body (VTB), and ipsilateral superior paraolivary nucleus (SPN). Pyramidal cells of layer V of auditory cortex were heavily labeled. Small injections of HRP into the central nucleus resulted in labeled cells within restricted regions of the cochlear nuclei, superior olivary complex and auditory cortex. Injections into dorsal regions of the central nucleus resulted in cells labeled in ventral regions of the dorsal and ventral cochlear nuclei, and in lateral regions of LSO. These regions contain neurons which are considered to have low best frequencies. Injections placed in more ventral regions of the central nucleus led to labeling of cells in more dorsal regions of the cochlear nuclei and more medial regions of LSO in agreement with the tonotopical progressions within these structures.
Roles for aged individuals in post-industrial societies

Cowgill and Holmes in their book, Aging and Modernization predicted an inverse relationship between industrialization and status accorded older persons. They argued that the more industrialized a country becomes the lower the status accorded older persons. A more careful examination of historical and anthropological work suggests that if we look at the status of the old over the course of history and make projections into the future an S curve is a more realistic pattern. The pattern projected would be one in which the old were accorded a low status in early nomadic tribes, a high status in settled agricultural communities, a low status in industrialized society and ultimately will receive a somewhat higher status in the post-industrial period.
Contextual Analysis of Interpretation Focused on Human-Black Bear Conflicts in Yosemite National Park

This study examined how Yosemite National Park addresses the continuing problem of human-bear interactions with its interpretive communication services. A particular focus was on the food storage behavior of overnight users in Yosemite Valley. A theory-based questionnaire was used to elicit visitors salient beliefs pertinent to proper food storage behavior, and a message inventory was conducted to analyze message content that references human-bear conflicts. Following the theory of planned behavior, results reveal beliefs that may underpin future communication intervention strategies for human behavior modification related to proper food storage by Yosemite Valley overnight users. Implications are drawn for how the Yosemite interpretive services germane to human-bear conflicts might improve with guidance from contemporary communication theory.
Psychological traits of rural entrepreneurs

Abstract This research focused on differences between rural and urban entrepreneurs. It replicates and extends a study of New England managers using data from 926 firms in rural North Florida. Probit and ordered probit models were used to analyze data. Entrepreneurial status and measures of firm performance were related to psychological traits. Type A behavior, need for achievement, ascendancy, emotional stability, and personal relations were the traits which differentiated founders and nonfounders. No major differences in psychological traits were found between rural and urban managers. Thus, psychological traits do not seem to pose constraints on expansion of entrepreneurship in rural areas.
Transmission electron microscopy for optical storage material analysis

Abstract Transmission electron microscopy is the most natural tool for investigating in detail the physical and metallurgical changes produced in optical storage media by laser writing. Examples of laser writing in bilayer media with low melting points such as Te/Se and Te/C are compared with laser-written spots in metal silicide bilayers formed by the deposition of amorphous silicon onto tellurium, rhodium or gold. Particulate gold films with and without carbon coatings are investigated as potential storage media. Simulated life tests performed by annealing are presented for some of the media.
Performance and Carcass Quality of Broilers Reared on Wire Flooring, Plastic Inserts, Wood Slats, or Plastic-Coated Expanded Metal Flooring Each with or Without Padded Roosts,

Abstract Commercial straight-run broilers were reared on raised flooring in two experiments to study the effects on broiler performance and carcass quality of padded roosts and four raised floor types – wire, wood slats, plastic inserts over wire (Experiment 1) and plastic-coated expanded metal – and added dietary zinc bacitracin (Zb) at a level of 40 g per ton (909 kg) of feed (Experiment 2). In both experiments mean body weights, feed conversion ratios, percentages of mortality, and percentages of deformed legs were not significantly different among floor types. Floor types did not affect incidence of foot pad dermatitis or percent of body fat in Experiment 1 or folliculitis in Experiment 2. Feather soilage and folliculitis were significantly greater (P
Formation of toroidal bubbles from acoustic droplet vaporization

Acoustic droplet vaporization (ADV) is the selective vaporization of liquid microdroplets using ultrasound to produce stable gas bubbles. ADV is the primary mechanism in an ultrasound based cancer therapy, called gas embolotherapy, where the resulting bubbles are used to create localized occlusions leading to tumor necrosis. In this investigation, early time scale events including phase change are directly visualized using ultra-high speed imaging. Modulating elevated acoustic pressure or pulse length resulted in toroidal bubbles. For sufficiently short pulses (4 cycles at 7.5 MHz), toroidal bubble formation could be avoided, regardless of acoustic pressures tested.
Lack of correlation between diarrhea and weight loss in HIV-positive outpatients in Houston, Texas

To determine the prevalence of diarrhea and weight loss among human immunodeficiency virus (HIV)-positive patients, we reviewed the records of all patients attending the Harris County HIV Clinic during a 4-month time period. Diarrhea was considered persistent if it had been present for > 14 days or on two or more consecutive clinic visits. Weight loss was defined as moderate (5-10% reduction in weight) or severe (> 10% reduction) when the present weight was compared with the weight found at the initial clinic visit. Records were reviewed for 1,370 patients, of whom 12.2% complained of diarrhea (7.7% acute and 4.5% persistent). Diarrhea was more common among patients with a history of male-to-male sexual contact than in patients with other HIV risk factors (p < 0.003 for acute and p < 0.006 for persistent). The mean CD4 cell count was not significantly different in patients with or without persistent diarrhea (176 versus 212) or acute diarrhea (215 versus 212). Weight loss was reported in 25.2% of subjects (12.8% moderate and 12.4% severe). It did not correlate with CD4 count. Persistent diarrhea also was not associated with weight loss. Acute and persistent diarrhea were common among ambulatory HIV-positive patients, particularly in homosexual men. We did not identify a correlation among diarrhea, weight loss, and CD4 count. Thus, factors other than chronic diarrhea and immunosuppression appear to be responsible for weight loss in HIV-infected patients.
The role of computer science in digital production arts

Special effects production is a rapidly expanding field in the film, television, and gaming industries. The educational goals and requirements for digital artists in these fields vary widely, and tend to change dramatically over short spans of time. Several years ago, we began a new graduate program at Clemson University to train students in this field. Though the impetus to develop the program originated in the computer science department, the department was not suited to cover all of the topics necessary, even with the addition of several new courses. Accordingly, the program was established as interdisciplinary, with major components in computer science and art. The computer science portion of the curriculum emphasizes basic computing concepts, especially programming. The program has evolved from a somewhat disparate collection of courses into a tighter, more integrated, educational experience, with a high graduate placement in the industry each year.
Acquisition of operant behavior in rats with delayed reinforcement: A retractable-lever procedure.

Abstract Experimentally naive rats acquired lever pressing with delayed reinforcement when the immediate programmed consequence for lever pressing was the simultaneous retraction of two identical levers. Presses on one lever also produced access to sweetened condensed milk after a delay of 10 s following retraction. Presses on the second lever resulted in retraction only. Lever retraction prevented the possibility of adventitious reinforcement of contacting the operanda during the reinforcement delays. Several measures indicated that the delayed reinforcers strengthened behavior. The majority of responses for all rats were on the lever that initiated reinforcer delivery. Responding for seven out of eight rats decreased during a subsequent extinction phase in which retraction was the only consequence arranged for lever pressing. Responding recovered rapidly when food reinforcement was available again. Furthermore, when contingencies on the two levers were switched, rats allocated their behavior accordingly, showing control by the delayed reinforcers.
Electrical and material characteristics of the sub 5 nm hafnium doped tantalum oxide high k film

Ultra-thin films (less than 5 nm) of hafnium doped tantalum oxide (Hf-doped TaO/sub x/) high-k dielectric films were deposited by reactive sputtering as alternative gate dielectric materials for future CMOS devices. A film with an equivalent oxide thickness (EOT) of 13 /spl Aring/ and a leakage current density of 7/spl times/10/sup -3/ A/cm/sup 2/ at -1 V relative to the flat-band voltage has been obtained. The Hf-doped TaO/sub x/ film is composed of HfO/sub x/ and TaO/sub x/. The binding energy of Ta 4f in the film shifts to a lower value with the inclusion of the Hf in the film due to charge transfer among elements. The Hf-doped film remains amorphous after 700/spl deg/C N/sub 2/ or O/sub 2/ annealing. The N/sub 2/ annealed film has a lower EOT, a thinner interfacial layer, and a higher leakage current than the O/sub 2/ annealed film.
Subsampling Inference with K Populations and a Non-standard Behrens–Fisher Problem

Resume Nous passons en revue la methodologie et le developpement historique des methodes de sous-echantillonnage, et explorons en detail leur utilisation dans le cadre des problemes de tests d'hypotheses, ou ces methodes ont eteetonnamment peu prises en consideration. Nous explorons, en particulier, le cas tres general d'un modele aKechantillons faisant intervenir un parametre de grande dimension. Nous mettons en evidence le role important que joue le centrage de la loi de sous-echantillonnage, et montrons que ce centrage augmente la puissance des tests consideres. Nous montrons egalement comment les methodes de sous-echantillonnage permettent de traiter une forme non standard du probleme de Behrens-Fisher dans laquelle les populations dont on desire comparer les moyennes ne different pas seulement par leurs variances (qui peuvent eventuellement etre infinies), mais peuvent presenter des lois completement heterogenes. Notre formulation est tres generale, et s'applique meme a des observations de nature fonctionnelle. Enfin, nous developpons une theorie pour les statistiques-U permettant d'etablir, dans le cadre tres general de Kechantillons, la validite asymptotique des intervalles de confiance et des tests fondes sur le sous-echantillonnage. Summary We revisit the methodology and historical development of subsampling, and then explore in detail its use in hypothesis testing, an area which has received surprisingly modest attention. In particular, the general set-up of a possibly high-dimensional parameter with data fromKpopulations is explored. The role of centring the subsampling distribution is highlighted, and it is shown that hypothesis testing with a data-centred subsampling distribution is more powerful. In addition we demonstrate subsampling’s ability to handle a non-standard Behrens–Fisher problem, i.e., a comparison of the means of two or more populations which may possess not only different and possibly infinite variances, but may also possess different distributions. However, our formulation is general, permitting even functional data and/or statistics. Finally, we provide theory forK-sampleU-statistics that helps establish the asymptotic validity of subsampling confidence intervals and tests in this very general setting.
Analysis and simulation of multiconductor transmission lines for high-speed interconnect and package design

The authors present a novel approach to the crosstalk analysis of high-speed interconnects which are modeled as multiconductor transmission lines. The method is applicable to the general problem of N coupled lossy and/or dispersive interconnects with arbitrary linear source/load impedances. Closed-form formulas for determining the voltage and current transfer functions are derived using the spectral domain modal analysis technique. The transfer function is expanded to its Taylor series form, and the inverse Fourier transform is applied to the significant terms in the series. As a result, analytical expressions of time-domain signal waveforms are obtained. Besides providing valuable insight into the coupling phenomenon, the formulas facilitate analytical computation of noise and waveform distortion due to crosstalk. >
Creating a Bureau-Adhocracy: Integrating Standardized and Innovative Services in a Professional Work Group

This paper explores the organizing dilemmas of professionals who work in small organizations that attempt to provide standardized and innovative services with the same staff. Mintzberg (1979) suggested that the bureau-adhocracy would be the most appropriate form for coping with such conditions but did not elaborate on how it might develop or be maintained over time. The longitudinal the case study reported here supports this claim and goes further in two fundamental areas with respect to the smaller professional enterprise: First, it describes some of the learning processes involved in the creation of this hybrid, and second, it suggests the existence of two definable stages in the form's development, i.e., naive and mature.
Wolff-Parkinson-White–type ventricular preexcitation mimicking left ventricular hypertrophy and an inferoposterior myocardial infarct

The electrocardiogram (Figure) meets at least two commonly used criteria for left ventricular enlargement: the R wave in V5 or V6 > 2.6 mV, i.e., >26 mm with the usual standardization of 1.0 mV = 10 mm (here RV5 is 35 mm); and SV1 + RV5 or RV6 > 3.5 mV, i.e., >35 mm (here SV1 + RV5 = 57 mm). Broad and deep Q waves in leads II, III, and aVF with broad and tall R waves in leads V1 and V2 are consistent with an infer posterior myocardial infarct of indeterminate age. The patient's age of 19 years, however, extends the limits of normal for SV1 + RV5 voltage to 60 mm (1) and makes myocardial infarction highly unlikely. Even more importantly, the electrocardiogram is typical of Wolf-Parkinson-White–type ventricular preexcitation, with a short P-R interval of 0.11 seconds, a long QRS duration of 0.12 seconds, and a delta wave visible in every lead except aVR and V6. Delta waves are responsible for the Q waves in leads II, III, and aVF and the R waves in leads V1 and V2. Figure Electrocardiogram obtained during hospitalization for trauma. See text for explication. Wolf-Parkinson-White–type ventricular preexcitation is a notorious mimicker and can imitate right or left ventricular enlargement, right or left bundle branch block, and an infarct of various segments of the ventricular myocardium, in each instance dependent on the location of the accessory pathway (2). This patient probably has a posteroseptal accessory pathway (3, 4). Although repolarization is nearly normal in this patient, in many of those with Wolf-Parkinson-White–type preexcitation the QRS abnormalities are accompanied by repolarization changes that may be mistaken for ischemia. In addition, false-positive exercise tests have been reported (2). Finally, when the atrioventricular reciprocating tachycardia that often occurs in these patients is antidromic, i.e., antegrade over the accessory pathway and retrograde via the atrioventricular conduction system, the arrhythmia is often misdiagnosed as ventricular tachycardia. The electrocardiographic abnormality in this patient was an incidental finding. He was admitted to the hospital because of being struck by an automobile, which resulted in a comminuted fracture of his right femur, a laceration of his right superficial femoral artery, and extensive soft tissue damage. He underwent multiple operations without cardiac difficulty, and at no time was a history of cardiac disease obtained.
Transcriptional Regulation by Ferric Uptake Regulator (Fur) in Pathogenic Bacteria

In the ancient anaerobic environment, ferrous iron (Fe2+) was one of the first metal cofactors. Oxygenation of the ancient world challenged bacteria to acquire the insoluble ferric iron (Fe3+) and later to defend against reactive oxygen species (ROS) generated by the Fenton chemistry. To acquire Fe3+, bacteria produce low-molecular weight compounds, known as siderophores, which have extremely high affinity for Fe3+. However, during infection the host restricts iron from pathogens by producing iron- and siderophore-chelating proteins, by exporting iron from intracellular pathogen-containing compartments, and by limiting absorption of dietary iron. Ferric Uptake Regulator (Fur) is a transcription factor which utilizes Fe2+ as a corepressor and represses siderophore synthesis in pathogens. Fur, directly or indirectly, controls expression of enzymes that protect against ROS damage. Thus, the challenges of iron homeostasis and defense against ROS are addressed via Fur. Although the role of Fur as a repressor is well documented, emerging evidence demonstrates that Fur can function as an activator. Fur activation can occur through three distinct mechanisms 1) indirectly via small RNAs, 2) binding at cis regulatory elements that enhance recruitment of the RNA polymerase holoenzyme (RNAP), and 3) functioning as an antirepressor by removing or blocking DNA binding of a repressor of transcription. In addition, Fur homologs control defense against peroxide stress (PerR) and control uptake of other metals such as zinc (Zur) and manganese (Mur) in pathogenic bacteria. Fur family members are important for virulence within bacterial pathogens since mutants of fur, perR, or zur exhibit reduced virulence within numerous animal and plant models of infection. This review focuses on the breadth of Fur regulation in pathogenic bacteria.
The Ratchet Effect

Everyone agrees that “sustainable” management of our farms, forests, and rangelands is desirable, but it is hard to find a definition of sustainability upon which everyone agrees. An extreme view is that the only kind of resource harvesting that is sustainable is that of aboriginal hunter-gatherers in the rain forest. They live in a closed ecosystem. Nothing is artificially imported into the ecosystem, so there is no pollution. Nothing is transported out of the ecosystem, so there is no depletion. Everything is recycled, and natural soil erosion is so slow that losses are replaced by natural soilforming processes.
Democratic Integration: Self-Organized Integration of Adaptive Cues

Sensory integration or sensor fusion - the integration of information from different modalities, cues, or sensors - is among the most fundamental problems of perception in biological and artificial systems. We propose a new architecture for adaptively integrating different cues in a self-organized manner. In Democratic Integration different cues agree on a result, and each cue adapts toward the result agreed on. In particular, discordant cues are quickly suppressed and recalibrated, while cues having been consistent with the result in the recent past are given a higher weight in the future. The architecture is tested in a face tracking scenario. Experiments show its robustness with respect to sudden changes in the environment as long as the changes disrupt only a minority of cues at the same time, although all cues may be disrupted at one time or another.
Emergency communications for NASA's deep space missions

The ability to communicate with spacecraft during emergencies is a vital service that NASA's Deep Space Network (DSN) provides to all deep space missions. Emergency communications is characterized by low data rates (typically ∼10 bps) with the spacecraft using either a low-gain antenna (LGA, including omnidirectional antennas) or, in some cases, a medium-gain antenna (MGA). Because of the use of LGAs/MGAs for emergency communications, the transmitted power requirements both on the spacecraft and on the ground are substantially greater than those required for normal operations on the high-gain antenna (HGA) despite the lower data rates. In this paper, we look at current and future emergency communications capabilities available to NASA's deep-space missions and discuss their limitations in the context of emergency mode operations requirements. These discussions include the use of the DSN 70-m diameter antennas, the use of the 34-m diameter antennas either alone or arrayed both for the uplink (Earth-to-spacecraft) and the downlink (spacecraft-to-Earth), upgrades to the ground transmitters, and spacecraft power requirements both with unity gain (0 dB) LGAs and with antennas with directivity (> 0 dB gain, either LGA or MGA, depending on the gain). Also discussed are the requirements for forward-error-correcting codes for both the uplink and the downlink. In additional, we introduce a methodology for proper selection of a directional LGA/MGA for emergency communications
Human soluble epoxide hydrolase: Structural basis of inhibition by 4-(3-cyclohexylureido)-carboxylic acids

X-ray crystal structures of human soluble epoxide hydrolase (sEH) complexed with four different dialkylurea inhibitors bearing pendant carboxylate “tails” of varying length have been determined at 2.3–3.0 A resolution. Similarities among inhibitor binding modes reinforce the proposed roles of Y381 and/or Y465 as general acids that protonate the epoxide ring of the substrate in concert with nucleophilic attack of D333 at the electrophilic epoxide carbon. Additionally, the binding of these inhibitors allows us to model the binding mode of the endogenous substrate 14,15-epoxyeicosatrienoic acid. Contrasts among inhibitor binding modes include opposite orientations of inhibitor binding in the active-site hydrophobic tunnel. Alternative binding orientations observed for this series of inhibitors to human sEH, as well as the binding of certain dialkylurea inhibitors to human sEH and murine sEH, complicate the structure-based design of human sEH inhibitors with potential pharmaceutical applications in the treatment of hypertension. Thus, with regard to the optimization of inhibitor designs targeting human sEH, it is critical that human sEH and not murine sEH be utilized for inhibitor screening, and it is critical that structures of human sEH-inhibitor complexes be determined to verify inhibitor binding orientations that correlate with measured affinities.
Ontogeny and Differentiation of Murine Natural Killer Cells and Their Receptors

Cellular immunology was actively investigated during the 1960s, stimulated in large part by the development of plaque assays for antibody-forming cells (Jerne and Nordin 1963) and the assay for cytotoxic cells (Rosenau and Moon 1964). The discovery that the thymus and bursa of Fabricius are necessary for the development of T and B cells (Miller and Mitchell 1969; Glick and Whatley 1967; Cooper et al. 1965) led to the concept of “central lymphoid organs.” Subsequently it appeared that the effector cell responsible for rejection of bone marrow allografts following large doses of total-body irradiation is not a T or a B cell, but is eliminated by destruction of bone marrow with the bone-seeking isotope 89Sr (Cudkowlcz and Bennett 1971; Bennett 1973). Thus these effector cells were termed “marrow-dependent” or M cells, based on the analogy with the thymus and bursa-dependent T and B cell. Later studies revealed that M cells are identical to natural killer (NK) cells.
Carbon-based primary productivity modeling with vertically resolved photoacclimation

[1] Net primary production (NPP) is commonly modeled as a function of chlorophyll concentration (Chl), even though it has been long recognized that variability in intracellular chlorophyll content from light acclimation and nutrient stress confounds the relationship between Chl and phytoplankton biomass. It was suggested previously that satellite estimates of backscattering can be related to phytoplankton carbon biomass (C) under conditions of a conserved particle size distribution or a relatively stable relationship between C and total particulate organic carbon. Together, C and Chl can be used to describe physiological state (through variations in Chl:C ratios) and NPP. Here, we fully develop the carbon-based productivity model (CbPM) to include information on the subsurface light field and nitracline depths to parameterize photoacclimation and nutrient stress throughout the water column. This depth-resolved approach produces profiles of biological properties (Chl, C, NPP) that are broadly consistent with observations. The CbPM is validated using regional in situ data sets of irradiance-derived products, phytoplankton chlorophyll:carbon ratios, and measured NPP rates. CbPM-based distributions of global NPP are significantly different in both space and time from previous Chl-based estimates because of the distinction between biomass and physiological influences on global Chl fields. The new model yields annual, areally integrated water column production of ∼52 Pg C a−1 for the global oceans.
Bis[dihydrobis(1-pyrazolyl)borate]cadmium(II): a monomeric, severely distorted tetrahedral complex of cadmium(II)☆

Abstract The crystal structure of the complex [H 2 B(pz) 2 ] 2 Cd has been determined: orthorhombic, Pbca, a = 16.052(3), b = 13.935(3), c = 14.974(4) A , V = 3349.4(13) A 3 , Z = 8, R(F) = 3.61% . It is the first structurally characterized non-porphyrin CdN 4 complex. It is monomeric in the solid state with a pseudotetrahedral geometry about the cadmium atom. The NCdN angles are distorted by the approximate 93° bite angle of the ligand; the interligand NCdN angles also are distorted, ranging from 106.9 to 131.7°. These distortions are the result of intermolecular packing forces and are facilitated by the spherical set of valence orbitals for Cd 2+ .
Syntaxin and 25-kDa synaptosomal-associated protein: Differential effects of botulinum neurotoxins C1 and A on neuronal survival

The Clostridium botulinum neurotoxins (BoNTs) A and C1 cleave specific proteins required for neuroexocytosis. We demonstrated that, in intact neurons, BoNT A cleaves 25-kDa synaptosomal-associated protein (SNAP-25), and BoNT C1 cleaves both syntaxin and SNAP-25 (Williamson et al.: Mol Biol Cell 6:61a, 1995; J Biol Chem 271:7694–7699, 1996). Here, we compare the actions of BoNT A and BoNT C1 on mature and developing mouse spinal cord neurons in cell culture and demonstrate that BoNT C1 is severely neurotoxic. In mature cultures, synaptic terminals become enlarged shortly after BoNT C1 exposure, and, subsequently, axons, dendrites, and cell bodies degenerate. Electron microscopy confirms that early degenerative changes occur in synaptic terminals when the somatic cytoplasm appears normal. In newly plated cultures, few neurons survive exposure to BoNT C1. Whereas both BoNT A and BoNT C1 cleave SNAP-25, BoNT A has no adverse effect on neurite outgrowth, synaptogenesis, or neuron survival. This cytotoxicity is unique to BoNT C1, is specific to neurons, and is initiated at the synaptic terminal, suggesting either a novel role for syntaxin or additional actions of BoNT C1. The neurodegeneration induced by BoNT C1 may be significant in terms of its efficacy for the clinical treatment of dystonia and spasticity. J. Neurosci. Res. 52:569–583, 1998. Published 1998 Wiley-Liss, Inc.1
Evaluation of fracture resistance in aqueous environment of four restorative systems for posterior applications. Part 1.

Purpose The goals of this study were to: (1) establish a range of the performance of four restorative systems for posterior single-tooth crowns under single load to fracture submerged in an aqueous environment, (2) identify restorative system(s) of interest to be examined in the second study phase under sliding contact step-stress fatigue as full-contour anatomically appropriate single posterior tooth restoration(s), (3) establish a range for loading/testing for phase 2. Materials and Methods Forty specimens (n = 10/group) of 2 mm uniform thickness were tested. Group 1: monolithic lithium disilicate IPS e.max Press; group 2: IPS e.max ZirPress, 0.8 mm zirconia core with 1.2 mm pressed veneering porcelain; group 3: IPS e.max ZirPress, 0.4 mm zirconia core with 1.6 mm pressed veneering porcelain; group 4: IPS InLine PoM. Specimens were bonded to a block of polycast acrylic resin on a 30° sloped surface with resin cement. Specimens were axially single loaded to failure while submerged under water. Results There was a statistically significant difference (p < 0.001) in failure load among the four restorative systems. Lithium disilicate showed a mean failure load similar to mean maximum posterior bite forces (743.1 ± 114.3 N). IPS e.max Zirpress with a 0.4 mm zirconia core exhibited the lowest mean failure load (371.4 ± 123.0 N). Conclusion Fracture resistance of monolithic lithium disilicate in an aqueous environment is promising and requires second phase testing to evaluate the potential of various thicknesses appropriate for posterior single tooth applications. Doubling the IPS e.max Zirpress zirconia core from 0.4 mm to 0.8 mm increased the fracture resistance of this restorative system threefold.
STEREO and Wind observations of intense cyclotron harmonic waves at the Earth's bow shock and inside the magnetosheath

We present the first observations of electron cyclotron harmonic waves at the Earth's bow shock from STEREO and Wind burst waveform captures. These waves are observed at magnetic field gradients at a variety of shock geometries ranging from quasi-parallel to nearly perpendicular along with whistler mode waves, ion acoustic waves, and electrostatic solitary waves. Large amplitude cyclotron harmonic waveforms are also observed in the magnetosheath in association with magnetic field gradients convected past the bow shock. Amplitudes of the cyclotron harmonic waves range from a few tens to more than 500 millivolts/meter peak-peak. A comparison between the short (15 meters) and long (100 meters) Wind spin plane antennas shows a similar response at low harmonics and a stronger response on the short antenna at higher harmonics. This indicates that wavelengths are not significantly larger than 100 meters, consistent with the electron cyclotron radius. Waveforms are broadband and polarizations are distinctively comma-shaped with significant power both perpendicular and parallel to the magnetic field. Harmonics tend to be more prominent in the perpendicular directions. These observations indicate that the waves consist of a combination of perpendicular Bernstein waves and field-aligned waves without harmonics. A likely source is the electron cyclotron drift instability which is a coupling between Bernstein and ion acoustic waves. These waves are the most common type of high-frequency wave seen by STEREO during bow shock crossings and magnetosheath traversals and our observations suggest that they are an important component of the high-frequency turbulent spectrum in these regions.
Web services for genre vocabularies

This paper presents an approach for providing terminology Web services for controlled vocabulary terms. Services are implemented within a service oriented framework. Aset of experimental services for genre vocabularies are provided through the MS Office Research pane, a built-in feature of Internet Explorer (IE) when users have loaded MS Office 2003. Web browsers, such as Mozilla Firefox and Opera, also provide side-bars which could be used to deliver loosely-coupled Web services.
Radiofrequency ablation of renal tumours with clinical, radiographical and pathological results

What's known on the subject? and What does the study add? Radiological imaging is heavily relied on for follow up after renal ablative therapy. We show that while this is largely reliable, there are quantifiable false negative and false positive findings. A non-involuting zone of ablation should be considered for multisite-directed core biopsies even in the absence of detectable enhancement. Objective To evaluate our experience with radiofrequency ablation (RFA) for renal masses and to report on clinical, radiological and post-RFA biopsy results. Patients and Methods The study collected clinical, radiological and pathological data from 150 consecutive patients who were treated with RFA of a renal mass between 2002 and 2008 at a tertiary referral centre. Post-ablation biopsies were performed in patients with non-involuting lesions or suspicion of recurrence on imaging. Comparisons were performed using the Mann–Whitney U-test. Survival was estimated using the Kaplan–Meier method. Results Renal malignancy was found in 72.1% of patients based on the initial diagnostic biopsy. Median tumour size was 2.6 cm, 22.7% of patients had a solitary kidney, and most were central tumours. The mean follow-up period was 40.1 month. There was no recurrence in 96.7% of the entire cohort. Cancer-specific survival for 106 patients with sporadic, localized, biopsy proven renal malignancy was 100% at 38.5 months. Biopsies were obtained in 43 patients for a median of 21 months after RFA. Among 38 patients who had biopsy for non-involuting, non-enhancing zones of ablation, three (7.9%) were positive. Conclusions Short-term cancer-specific survival after RFA remains excellent and most cases are successful based on a combination of imaging and post-ablation biopsies performed almost 2 years after treatment. There were four out of 150 (2.7%) patients who had recurrences with tissue confirmation; one of these patients was detected on imaging and three (2%) were radiologically occult. The absence of enhancement in the setting of non-involuting lesions is not always a guarantee of a successful ablation.