cssi/SciSciGPT-SciSciNet huggingface dataset:
Wireless communication tradeoffs in distributed control

We present a framework to study control systems with feedback loops closed over wireless communication links. We show the choice of communication parameters can greatly affect the performance of such systems. The trade-offs of data rate, time delay and packet loss in the communication link layer design are illustrated with a numerical example of an inverted pendulum. Packet loss is shown to significantly degrade performance, which is not surprising since the controller design does not take into account random packet losses in the feedback loop. We thus propose an analog soft-decoding communication link design that does not incur any packet losses. It is shown that, for low channel gains, the control system closed over a soft-decoding communication link performs better than the same system closed over a hard-decoding communication link with optimal selection of sample period and data rate. This suggests fundamental changes in wireless link designs may be necessary to support robust distributed control systems.
Integrating graphics and visual computing topics into the CS curriculum

The Computing Curricula 2001 for Computer Science (CC2001-CS) identifies two core units for the Graphics and Visual Computing (GV) knowledge area. The suggested minimum of coverage time of three instructional hours for these two core units hardly warrants a computer graphics course. This paper offers suggestions for incorporating the core GV units into the CS curriculum without a computer graphics course.
A Review of “Wild West 2.0: How to Protect and Restore Your Online Reputation on the Untamed Social Frontier”: Fertik, Michael and Thompson, David. New York: American Management Association, 2010, 264 pp., $24.95, hard cover, ISBN 9780814415092.

While job-seekers should know to clean up their Facebook profile before they send out resumes, everyone should make it a point to know what appears when someone Googles their name. Wild West 2.0 wo...
Case study: an NTSC imaging system timing gate array design

A case study of the design of a timing generator ASIC (application-specific integrated circuit) for an NTSC-compatible imaging system is presented. The case history includes many of the classic problems in this type of design. Consideration is given to the problems of changing specifications during the design process, adding special functionality while minimizing testability enhancements, the pressure of timeliness, and the importance of thoroughly verifying every part of the design. >
Economics at the Antitrust Division 2014–2015: Comcast/Time Warner Cable and Applied Materials/Tokyo Electron

During 2014–2015, the Antitrust Division achieved enforcement successes in a wide range of matters. Many, such as the case against American Express, played out publicly in court proceedings. But two of the Division’s most significant investigations over the past year involved mergers that the parties abandoned in the face of concerns that were expressed by the Division. In each of these mergers, economic analysis played an important role in understanding their likely impact on competition. This article provides a sample of the types of issues that have been raised in recent antitrust cases that did not, ultimately, end up on the public record.
Feasibility and Use of School-Based Condom Availability Programs in Tijuana, Mexico

Condom availability programs (CAPs) may increase access to condoms and contribute to increased condom use among youth. This study describes the characteristics, degree of satisfaction, and gender differences among users of a CAP implemented in two high schools in Tijuana (Baja California, Mexico). A kiosk distributing free male condoms was set up in two high schools in Tijuana. Kiosk users (N=570) were more likely to be male, young, and/or enrolled in a lower SES school. Most kiosk users were either sexually active or planning to have sex. Females were less likely to request condoms and to continue using the kiosk, but more likely to request information on other contraceptive methods. Results demonstrate the feasibility of implementing CAPs in Mexican schools and suggest that these programs can improve adolescents’ condom access.
Collectively defining context in a mobile, networked computing environment

Mobile and wireless computers are rapidly becoming popular with the general public. In our research we design and evaluate new types of applications that take advantage of the unique characteristics of these devices in novel ways. One of these applications is Graffiti, a context-aware device designed using ideas from social navigation research. This system allows users to collectively define what's relevant and interesting about a location by posting electronic notes. Users encountered a variety of benefits and problems in using Graffiti primarily related to the reliance of the system on user contributions.
Serum levels of luteinizing hormone (LH), prolactin, estradiol, and progesterone in laying and nonlaying canvasback ducks (Aythya valisineria).

Temporal changes in the levels of serum luteinizing hormone (LH), prolactin, estradiol, and progesterone associated with the reproductive patterns of 53 wild captive canvasback ducks were measured. The reproductive endocrinology of both laying and nonlaying females was compared in this 3-year study. Females that remained sexually inactive had ovaries with small, undeveloped follicles. Nonlaying ducks also had lower serum levels of LH (P < 0.01), prolactin (P < 0.05), estradiol, and progesterone than those of laying ducks in mid-April (during prelay), mid-May (on the fourth day of egg production), and mid-June (during postlay and incubation). Prolactin levels of both layers and nonlayers increased over this time interval (P < 0.01) but levels of nonlayers were significantly lower than those of layers for the three blood-sampling dates. The low prolactin levels demonstrate that reproductive failure was not a result of inhibition by high serum prolactin levels. Intravenous injections of luteinizing hormone-releasing hormone (LHRH) in female canvasbacks resulted in significantly elevated (P < 0.01) serum LH on the prelay blood sampling date. Lack of reproduction in nonbreeding canvasbacks was thus associated with low circulating serum LH levels but with LHRH-sensitive pituitary pools. These data suggest that lack of reproduction was a result of the failure of the hypothalamus to release releasing factors. The serum hormones of laying canvasbacks varied temporally with stages of the nesting cycle. LH levels increased prior to egg laying and fluctuated during the laying period. LH levels decreased at the onset of incubation but increased after loss of clutch, with renesting activity. Serum prolactin levels of layers were low prior to egg laying and increased gradually through laying of the first clutch, the renesting period, and laying of the second clutch. The highest prolactin levels occurred in ducks incubating their eggs. Prolactin levels decreased in ducks that failed to incubate their eggs. Serum estradiol levels increased sharply between 2 and 5 weeks prior to egg laying and remained high until the second day of egg production. Estradiol levels decreased when the fourth egg was produced, and remained low through the laying of the first clutch, the renesting period, and laying of the second clutch. Progesterone fluctuated widely through the nesting cycle, showing several major peaks before laying and another during incubation.
A PEDAGOGIC NOTE ON THE DERIVATION OF THE BLACK-SCHOLES OPTION PRICING FORMULA

This paper demonstrates an alternative derivation of the Black-Scholes option pricing formula based on the risk neutrality arguments of previous researchers. The underlying economic and mathematical structure of the formula is discussed.
Reformulation of the Jahn‐Teller Theorem

The Jahn‐Teller theorem is reformulated on the basis of the Hellmann‐Feynman theorem. Examples are given illustrating the conceptual simplicity of the force approach as opposed to the energetics approach. Methods of calculation are outlined and an estimation of the effect is given for the borane (BH3) molecule.
Facile synthesis of a flexible tethered porphyrin dimer that preferentially complexes fullerene C70.

A simple, high yield, two-step synthesis yields a porphyrin dimer linked by a flexible dithiol tether that preferentially binds fullerene C70 over C60 in toluene solution. The complex forms stable aggregates when cast on glass.
Homozygous deletions inactivate DCC, but not MADH4/DPC4/SMAD4, in a subset of pancreatic and biliary cancers.

Loss of heterozygosity (LOH) of chromosome arm 18q is frequent in gastrointestinal cancers. Over 90% of pancreatic carcinomas have 18q LOH. Bi-allelic inactivation of the MADH4/DPC4/SMAD4 gene at 18q21.1 is seen in about half of pancreatic carcinomas with 18q LOH. In the remaining tumors with 18q LOH, MADH4 is not mutated and its expression is unaffected, and no alterations in MADH2/SMAD2, a MADH4-related gene at 18q12.3, have been found. A controversial candidate tumor-suppressor gene at 18q21.2 is DCC (deleted in colorectal carcinoma), which encodes a netrin-1 receptor component with functions in cell migration and apoptosis. Reduced or absent DCC expression has been observed in many cancers, but few somatic mutations that would clearly inactivate DCC function have been reported. We studied a panel of 115 pancreatic and 14 biliary cancers for homozygous deletions of DCC exons and flanking 18q regions. Seven homozygous deletions were seen in the region that includes the DCC gene. In two tumors, the deletions inactivate DCC but not MADH4. A physical and transcript map of the deleted regions was constructed, and DCC was the only known gene affected by all seven deletions. These data are the strongest mutational evidence presented yet in support of the hypothesis that DCC or another gene in the region distal to MADH4 is inactivated, playing a causal role in cancer development.
Effect of time-varying tropospheric models on near-regional and regional infrasound propagation as constrained by observational data

[1] The Chulwon Seismo-Acoustic Array (CHNAR) is a regional seismo-acoustic array with co-located seismometers and infrasound microphones on the Korean peninsula. Data from forty-two days over the course of a year between October 1999 and August 2000 were analyzed; 2052 infrasound-only arrivals and 23 seismo-acoustic arrivals were observed over the six week study period. A majority of the signals occur during local working hours, hour 0 to hour 9 UT and appear to be the result of cultural activity located within a 250 km radius. Atmospheric modeling is presented for four sample days during the study period, one in each of November, February, April, and August. Local meteorological data sampled at six hour intervals is needed to accurately model the observed arrivals and this data produced highly temporally variable thermal ducts that propagated infrasound signals within 250 km, matching the temporal variation in the observed arrivals. These ducts change dramatically on the order of hours, and meteorological data from the appropriate sampled time frame was necessary to interpret the observed arrivals.
Sonic hedgehog and BMP2 exert opposing actions on proliferation and differentiation of embryonic neural progenitor cells.

Although Sonic Hedgehog (Shh) plays a critical role in brain development, its actions on neural progenitor cell proliferation and differentiation have not been clearly defined. Transcripts for the putative Shh-receptor genes patched (Ptc) and smoothened (Smo) are expressed by embryonic, postnatal, and adult progenitor cells, suggesting that Shh can act directly on these cells. The recombinant human amino-terminal fragment of Shh protein (Shh-N) alone did not support the survival of cultured progenitor cells, but treatment with Shh-N in the presence of bFGF increased progenitor cell proliferation. Furthermore, treatment of embryonic rat progenitor cells propagated either in primary culture or after mitogen expansion significantly increased the proportions of both β-tubulin- (neuronal marker) and O4- (oligodendroglial marker) immunoreactive cells and reduced the proportion of nestin- (uncommitted neural progenitor cell marker) immunoreactive cells. By contrast Shh-N had no effect on the elaboration of GFAP- (astroglial marker) immunoreactive cells. Cotreatment with Shh-N and bone morphogenetic protein-2 (BMP2) inhibited the anti-proliferative, astroglial-inductive, and oligodendroglial-suppressive effects of BMP2. Our observations suggest that Shh-N selectively promotes the elaboration of both neuronal and oligodendroglial lineage species and inhibits the effects of BMP2 on progenitor cell proliferation and astroglial differentiation.
Four-Way Microstrip-Based Power Combining for Microwave Outphasing Power Amplifiers

A lossless multi-way outphasing and power combining system for microwave power amplification is presented. The architecture addresses one of the primary drawbacks of Chireix outphasing; namely, the sub-optimal loading conditions for the branch power amplifiers. In the proposed system, four saturated power amplifiers interact through a lossless power combining network to produce nearly resistive load modulation over a 10:1 range of output powers. This work focuses on two microstrip-based power combiner implementations: a hybrid microstrip/discrete implementation using a combination of microstrip transmission line sections with discrete shunt elements, and an all-microstrip implementation incorporating open-circuited radial stubs. We demonstrate and compare these techniques in a 2.14 GHz power amplifier system. With the all-microstrip implementation, the system demonstrates a peak CW drain efficiency of 70% and drain efficiency of over 60% over a 6.5-dB outphasing output power range with a peak power of over 100 W. We demonstrate W-CDMA modulation with 55.6% average modulated efficiency at 14.1 W average output power for a 9.15-dB peak to average power ratio (PAPR) signal. The performance of this all-microstrip system is compared to that of the proposed hybrid microstrip/discrete version and a previously reported implementation in discrete lumped-element form.
Effects of thermal convection currents on formation of ice

Abstract A Mach-Zehnder interferometer was used to study the role of convection currents in the formation of ice. With this experimental set-up, the isotherms are obtained throughout the liquid, and from these the convection pattern can be deduced. The critical Rayleigh number for freezing from below is about 480; when this number is exceeded there is coupling between the water-ice interface and the thermal convection currents. The dendrites that initially form in the metastable, supercooled portion of the water extend to the 0°C isotherm.
Experimental studies in natural groundwater recharge dynamics: Assessment of recent advances in instrumentation

Abstract To quantify and model the natural groundwater-recharge process, two sites in south-central Kansas, U.S.A., were instrumented with various modern sensors and data microloggers. The atmospheric-boundary layer and the unsaturated and saturated soil zones were monitored as a unified regime. Data from the various sensors were collected using microloggers in combination with magnetic-cassette tape, graphical and digital recorders, analog paper-tape recorders, and direct observations to evaluate and automate data collection and processing. Atmospheric sensors included an anemometer, a tipping-bucket raingage, an air-temperature thermistor, a relative-humidity probe, a net radiometer, and a barometric-pressure transducer. Sensors in the unsaturated zone consisted of soil-temperature thermocouples, tensiometers coupled with pressure transducers and dial gages, gypsum blocks, and a neutron moisture probe operated by an observer. The saturated-zone sensors consisted of a water-level pressure transducer, a conventional float gage connected to a variable potentiometer, soil thermocouples, and a number of multiple-depth piezometers. Evaluation of the operation of these sensors and recorders indicated that certain types of equipment such as pressure transducers are very sensitive to environmental conditions. Extraordinary steps had to be taken to protect some of the equipment, whereas other equipment seemed to be reliable under all conditions. Based on such experiences, a number of suggestions aimed at improving such investigations are outlined.
Effects of S1-recurrent selection for protein yield on seven agronomic traits of oat

Three S1-recurrent selection programs (designated HG, HP, and HGP) for increasing protein yield of oat (Avena sativa L.) were conducted for five cycles of selection. The selection criteria in each program (line of descent) emphasized different components of protein yield; high grain yield in HG, both high protein concentration of the groats (caryopsis) and high grain yield in HP, and high protein yield per se in HGP. Heading date and height were restricted to no net change. The objectives of this study were to evaluate the agronomic performance of these three lines of descent and the correlated responses in agronomic traits due to selection. Thirty to sixty random S0-derived lines from each cycle and ten check lines were grown in hill-plot experiments at two locations in 1989. Grain yield increased in all three lines of descent; HG showed the greatest rate of gain followed by HGP and then HP (0.20, 0.10, and 0.07 Mg ha-1 per cycle, respectively). Test weight decreased in HGP by 2.6 kg m-3 per cycle and in HP by 4.0 kg m-3 per cycle, but remained constant in HG. Cycle 5 (C5) means for straw yield, height, and seed weight were not significantly different from the C0 means for any line of descent. Groat percent remained unchanged in HGP, increased from 70.1 to 71.7% in HG, and decreased from 69.9 to 67.6% in HP. Heading date decreased by 3 d in HG and HGP, but remained unchanged in HP. HG compares most favorably with commercial cultivars because of its high yield and acceptable agronomic traits, while HP tends to be low in test weight, seed weight, and groat percent.
Benign ulcer of the cecum

Benign cecal lesions, although not frequently encountered, are often difficult to differentiate from carcinomas. With the general availability of colonoscopy, cecal lesions can be visualized and a biopsy can be done. If the biopsy specimen reveals inflammatory changes only, the patient should be managed nonoperatively and colonoscoped again in four weeks.
CHARACTERIZATION OF THE MOLECULAR DEFECT IN THE VASOPRESSIN-NEUROPHYSIN II GENE IN A FAMILY WITH AUTOSOMAL DOMINANT NEUROHYPOPHYSEAL DIABETES INSIPIDUS

Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a rare familial form of vasopressin-deficient DI. In previous studies, we have shown genetic linkage between ADNDI and the argmine vasopressin-neurophysin II (AVP-NP II) gene locus. This gene contains 3 exons that encode AVP, its carrier protein NP II, and a small glycoprotein. We obtained genomic DNA from a 25 yr old woman with longstanding DI, her 2 year old affected daughter, and her husband and unaffected daughter. Each of the three exons of the AVP-NP II genes of these individuals was amplified by polymerase chain reaction and sequenced by thermocycle sequencing. In the affected individuals, a single nucleotide mutation (C T) was detected in exon II of the AVP-NP II gene. The nucleotide sequence of exons I and III were completely normal. These affected individuals also have one normal allele of the AVP-NP II gene. The mutation encodes a Pro Leu substitution in the NP II protein. This mutation also destroys an Apa I restriction enzyme recognition site and creates a Dde I site. To ensure that this mutation is not a common, genetically silent polymorphism in the sequence of the AVP-NP II gene, we amplified exon II of 50 control individuals representing 100 AVP-NP II genes to screen for the presence of this nucleotide change. Neither absence of the Apa I restriction site nor presence of the Dde 1 site was detected in control individuals, suggesting that this mutation is the cause of ADNDI in the affected family. The mechanism by which vasopressin deficiency results from a mutation in one of a person's two NP II-encoding sequences is under investigation.
Through a different lens: Examining professional women's interrole coping by focus and mode

An alternative method for classifying women's interrole coping efforts is proposed based upon current stress and coping theory. This coping classification method is then used to examine the coping responses and reported satisfaction of a sample of 135 professional women employed full-time as college faculty. Distinctive patterns of coping response use emerged for this group of women when the coping response strategy was expanded to include whether the response was problem focused or emotion focused and active or passive. The women report greater use of problem-focused than emotion-focused coping responses across several different types of work role conflict situations. Differences in rated satisfaction were reported, with the highest satisfaction reported when active coping responses that involved others were used.
AB initio calculations of the electronic properties of polyethylene

Abstract Previous studies of simple polymers have produced energy bands and densities of states which are not in good agreement with each other. We present here an accurate non-parametric method for determining the electronic energy levels of simple polymers, and apply this method to several simple polymers, both with and without impurity side groups.
Male-male interactions and mating kinetics in Drosophila.

Male-male interaction (K) has been estimated from data on the attrition rate of virgin females per minute in a study of the mating kinetics inDrosophila. K is expressed as the time males expend on other males relative to that expended while searching for, courling, and copulating with females. The value of K in these studies ranged from 0 (approximately) to. 695; it was affected both by strain (sepia orebony D. melanogaster and wild-typeD. simulans) and by size of the mating chamber. Host-parasitoid models of ecologists appear to be appropriate for examining mating kinetics inDrosophila.
New protein kinase inhibitors in breast cancer: afatinib and neratinib.

Introduction: Human epidermal growth factor receptor (HER) 2 is overexpressed in 20 – 25% of breast cancers, and has historically been a poor prognostic marker. The introduction of trastuzumab, the first fully humanized monoclonal antibody targeting HER2, has drastically changed the outcomes of metastatic breast cancers. However, despite initial response, most patients develop resistance. Recent data suggest that strategies targeting more than one member of HER family may circumvent trastuzumab resistance and confer synergistic effects. Areas covered: Following a literature search on PubMed, national meetings and clinicaltrials.gov using ‘afatinib’, ‘neratinib’, ‘HER2’ and ‘breast cancer’ as keywords, we critically analyzed the different HER2-targeted therapies for their drug development and evidence-based therapeutic strategies. Afatinib and neratinib, two second-generation tyrosine kinase inhibitors (TKIs) that irreversibly inhibit more than one HER family member, are being actively investigated in clin...
Performance analysis of slotted ALOHA with periodic server vacations for energy-efficient medium access

Slotted ALOHA is one of the earliest proposed contention-based medium access solutions for wireless networks and it remains a common approach in literature. In this paper, we present the throughput and delay performance analysis for a slotted ALOHA system with periodic server vacations. By this, we mean that the service is governed by a fixed cycle composed of alternating active and inactive periods, representative of an energy-efficient medium access solution that implements sleep cycles. To our knowledge, ours is the first work to fully develop this analysis.
Size- and support-dependent electronic and catalytic properties of Au0/Au3+ nanoparticles synthesized from block copolymer micelles.

Supported Au nanoclusters synthesized from diblock copolymer micelles can be reliably prepared with well-controlled sizes and dispersions. For particles with diameters between approximately 1 and 6 nm, the particle size and the support were found to strongly influence the oxygen reactivity, the formation and stabilization of a metal-oxide, and the catalytic activity for electrooxidation of carbon monoxide. The smallest particles studied (1.5 nm) were the most active for electrooxidation of CO and had the largest fraction of oxygen associated with gold at the surface as measured by the Au3+/Au0 X-ray photoemission intensities. Conducting and semiconducting substrates, ITO-coated glass and TiO2, respectively, were associated with greater stabilization of Au3+ oxide as compared to insulating, SiO2, substrates.
Quantifying the Gurken morphogen gradient in Drosophila oogenesis

Quantitative information about the distribution of morphogens is crucial for understanding their effects on cell-fate determination, yet it is difficult to obtain through direct measurements. We have developed a parameter estimation approach for quantifying the spatial distribution of Gurken, a TGFα-like EGFR ligand that acts as a morphogen in Drosophila oogenesis. Modeling of Gurken/EGFR system shows that the shape of the Gurken gradient is controlled by a single dimensionless parameter, the Thiele modulus, which reflects the relative importance of ligand diffusion and degradation. By combining the model with genetic alterations of EGFR levels, we have estimated the value of the Thiele modulus in the wild-type egg chamber. This provides a direct characterization of the shape of the Gurken gradient and demonstrates how parameter estimation techniques can be used to quantify morphogen gradients in development.
Post-Combustion In-Cylinder Vaporization During Cranking and Startup in a Port-Fuel–Injected Spark Ignition Engine

During port-fuel-injected (PFI) spark-ignition (S1) engine startup and warm-up fuel accounting continues to be a challenge. Excess fuel must be injected for a near stoichiometric combustion charge. The "extra" fuel that does not contribute to the combustion process may stay in the intake port or as liquid films on the combustion chamber walls. Some of this combustion chamber wall liquid fuel is transported to the engine's oil sump and some of this liquid fuel escapes combustion and evolves during the expansion and exhaust strokes. Experiments were performed to investigate and quantify this emerging in-cylinder fuel vapor post-combustion cycle by cycle during engine startup. It is believed that this fuel vapor is evaporating from cylinder surfaces and emerging from cylinder crevices. A fast in-cylinder diagnostic, the fast flame ionization detector, was used to measure this behavior. Substantial post-combustion fuel vapor was measured during engine startup. The amount of post-combustion fuel vapor that develops relative to the in-cylinder precombustion fuel charge is on the order of one for cold starting (0 °C) and decreases to ∼ ) 1/3 for hot starting engine cycles. Fuel accounting suggests that the intake port puddle forms quickly, over the first few engine cranking cycles. Analysis suggests that sufficient charge temperature and crevice oxygen exists to at least partially oxidize the majority of this post-combustion fuel vapor such that engine out hydrocarbons are not excessive.
Response strength of young children in operant audiometry.

An operant conditioning discrimination paradigm was evaluated in terms of relationships between response behavior of young children and two stimulus components of the paradigm, the discriminative s...
Carbon sequestration in wetland soils of the northern Gulf of Mexico coastal region

Coastal wetlands play an important but complex role in the global carbon cycle, contributing to the ecosystem service of greenhouse gas regulation through carbon sequestration. Although coastal wetlands occupy a small percent of the total US land area, their potential for carbon storage, especially in soils, often exceeds that of other terrestrial ecosystems. More than half of the coastal wetlands in the US are located in the northern Gulf of Mexico, yet these wetlands continue to be degraded at an alarming rate, resulting in a significant loss of stored carbon and reduction in capacity for carbon sequestration. We provide estimates of surface soil carbon densities for wetlands in the northern Gulf of Mexico coastal region, calculated from field measurements of bulk density and soil carbon content in the upper 10–15 cm of soil. We combined these estimates with soil accretion rates derived from the literature and wetland area estimates to calculate surface soil carbon pools and accumulation rates. Wetlands in the northern Gulf of Mexico coastal region potentially store 34–47 Mg C ha−1 and could potentially accumulate 11,517 Gg C year−1. These estimates provide important information that can be used to incorporate the value of wetlands in the northern Gulf of Mexico coastal region in future wetland management decisions related to global climate change. Estimates of carbon sequestration potential should be considered along with estimates of other ecosystem services provided by wetlands in the northern Gulf of Mexico coastal region to strengthen and enhance the conservation, sustainable management, and restoration of these important natural resources.
Evaluation of the 11CO2 Positron Emission Tomographic Method for Measuring Brain pH. I. pH Changes Measured in States of Altered PCO2

The 11CO2 method for measuring local brain pH with positron emission tomography (PET) has been experimentally evaluated, testing the adequacy of the kinetic model and the ability of the method to measure changes in brain pH. Plasma and tissue time/activity curves measured during and following continuous inhalation of 11CO2 were fit with a kinetic model that includes effects of tissue pH, blood flow, and fixation of CO2 into compounds other than dissolved gas and bicarbonate ions. For each of ten dogs, brain pH was measured with PET at two values of PaCO2 (range 21–67 mm Hg). The kinetic model fit the data well during both inhalation and washout of the label, with residual root mean square (RMS) deviations of the model from the measurements consistent with the statistical quality of the PET data. Brain pH calculated from the PET data shows a linear variation with log(PaCO2). These results were in good agreement with previously reported measurements of brain pH, both in absolute value and in variation with ...
Semi-Classical Quantization, Adiabatic Invariants and Classical Chaos

Einstein-Brillouin-Keller (E.B.K.) quantization of multidimensional non-separable classical hamiltonian dynamics is expeditiously carried out with classical adiabatic switching as hoped for in the early days of the old quantum theory by Ehrenfest, and reintroduced rather recently by Solov'ev. The method is briefly described along with a critique relating to the fact that the method seems to assume that invariant tori exist as a continuous one - parameter function of the coupling constant, although they do not. None the less, the method not only appears to work well for the types of systems envisaged by Ehrenfest, and Solov'ev, but continues to provide a useful asymptotic method following the onset of chaos. After distinguishing between adiabatic and geometric invariants, an analysis of adiabatic switching for the standard map is presented, with results given in the perturbative and strong coupling regimes. In the latter, a key phenomenological result is that principal non-adiabaticities can be understood in terms of the Farey organization of rationals spanning the relevant range of winding numbers. Finally the self-similar geometry of adiabatically generated `pseudoinvariant' curves is shown from the map of Siegal and Henon.
Teachers' social validity ratings of social skills: Comparisons between mildly handicapped and nonhandicapped children

Teachers have certain expectations or standards for children's social behavior in mainstream classrooms. The purpose of the present study was to document regular education teachers' social behavior...
Synthetic, structural, chemical, and electrochemical studies of the metallatricarbadecaboranyl analogues of ferrocene, ruthenocene, and osmocene and the observation of a reversible η6-η4 tricarbadecaboranyl coordination that is analogous to the η5-η3 cyclopentadienyl ring-slippage process

The tricarbadecaboranyl anions, 6-R-nido-5,6,9-C3B7H9- (R = CH3 or C6H5), have been employed to produce a series of metallatricarbadecaboranyl analogues of the group VIII metallocenes, (η5-C5H5)2M,...
Pathologic fractures of the mandible following invasive oral carcinomas

Invasive and metastatic oral carcinomas can and often do result in pathologic fractures of the facial bones. Three cases of invasive oral carcinomas resulting in fractures of the mandible have been reported. It was only after multiple-view radiographs that pathologic fractures could be identified. It is mandatory that dental practitioners avail themselves of the radiographic views which assist in establishing a diagnosis. In addition, the role of the dental profession in diagnosing primary and secondary oral carcinomas cannot be overemphasized.
Polarization weighting of Fano-type transmission through bi-dimensional metallic gratings

We demonstrate an approach allowing isolating effects of surface plasmon polariton mediated resonant transmission in a periodic grating by means of polarization rotation. The grating comprises a square array of cylindrical holes in an optically thick metallic film. Transmittance data for the co- and cross-polarized cases are described accurately with Fano-type and pure Lorentzian-type line shapes, respectively. This polarization control allows for changing the relative weights of resonant and non-resonant transmission mechanisms, thus controlling the shape and symmetry of the observed Fano-type line shapes.
Lower-Hybrid Current Drive in the PLT Tokamak

Order of magnitude improvements in the level and duration of current driven by lower hybrid waves have been achieved in the PLT tokamak. Steady currents up to 175 kA have been maintained for three seconds and 400 kA for 0.3 sec by the rf power alone. The principal current carrier appears to be a high energy (approx. 100 keV) electron component, concentrated in the central 20 to 40 cm diameter core of the 80 cm PLT discharge.
Possible spin-liquid state at large S for the frustrated square Heisenberg lattice.

We present conventional spin-wave calculations for a frustrated antiferromagnetic Hamiltonian on a square lattice. We find that quantum fluctuations can destabilize the classical ordered ground state, even at large $S$, for large enough values of frustration. This instability is likely to generate a spin liquid, providing the first example of a resonating-valence-bond ground state in two dimensions.
Comprehensive Evaluation of the Contribution of X Chromosome Genes to Platinum Sensitivity

Using a genome-wide gene expression data set generated from Affymetrix GeneChip Human Exon 1.0ST array, we comprehensively surveyed the role of 322 X chromosome gene expression traits on cellular sensitivity to cisplatin and carboplatin. We identified 31 and 17 X chromosome genes whose expression levels are significantly correlated (after multiple testing correction) with sensitivity to carboplatin and cisplatin, respectively, in the combined HapMap CEU (Utah residents with ancestry from northern and western Europe) and YRI (Yoruba in Ibahan, Nigeria) populations (false discovery rate, FDR < 0.05). Of those, 14 overlap for both cisplatin and carboplatin. Using an independent gene expression quantification method, the Illumina Sentrix Human-6 Expression BeadChip, measured on the same HapMap cell lines, we found that 4 and 2 of these genes are significantly associated with carboplatin and cisplatin sensitivity, respectively, in both analyses. Two genes, CTPS2 and DLG3 , were identified by both genome-wide gene expression analyses as correlated with cellular sensitivity to both platinating agents. The expression of DLG3 gene was also found to correlate with cellular sensitivity to platinating agents in NCI-60 cancer cell lines. In addition, we evaluated whether the expression of X chromosome genes contributed to the observed differences in sensitivity to the platinums between CEU and YRI-derived cell lines. Of the 34 distinct genes significantly correlated with either carboplatin or cisplatin sensitivity, 14 are differentially expressed (defined as P < 0.05) between CEU and YRI. Thus, sex chromosome genes play a role in cellular sensitivity to platinating agents and differences in the expression level of these genes are an important source of variation that should be included in comprehensive pharmacogenomic studies. Mol Cancer Ther; 10(3); 472–80. ©2011 AACR .
Intermediates in the transformation of phosphonates to phosphate by bacteria

Phosphorus is an essential element for all known forms of life. In living systems, phosphorus is an integral component of nucleic acids, carbohydrates and phospholipids, where it is incorporated as a derivative of phosphate. However, most Gram-negative bacteria have the capability to use phosphonates as a nutritional source of phosphorus under conditions of phosphate starvation. In these organisms, methylphosphonate is converted to phosphate and methane. In a formal sense, this transformation is a hydrolytic cleavage of a carbon-phosphorus (C-P) bond, but a general enzymatic mechanism for the activation and conversion of alkylphosphonates to phosphate and an alkane has not been elucidated despite much effort for more than two decades. The actual mechanism for C-P bond cleavage is likely to be a radical-based transformation. In Escherichia coli, the catalytic machinery for the C-P lyase reaction has been localized to the phn gene cluster. This operon consists of the 14 genes phnC, phnD, …, phnP. Genetic and biochemical experiments have demonstrated that the genes phnG, phnH, …, phnM encode proteins that are essential for the conversion of phosphonates to phosphate and that the proteins encoded by the other genes in the operon have auxiliary functions. There are no functional annotations for any of the seven proteins considered essential for C-P bond cleavage. Here we show that methylphosphonate reacts with MgATP to form α-D-ribose-1-methylphosphonate-5-triphosphate (RPnTP) and adenine. The triphosphate moiety of RPnTP is hydrolysed to pyrophosphate and α-D-ribose-1-methylphosphonate-5-phosphate (PRPn). The C-P bond of PRPn is subsequently cleaved in a radical-based reaction producing α-D-ribose-1,2-cyclic-phosphate-5-phosphate and methane in the presence of S-adenosyl-L-methionine. Substantial quantities of phosphonates are produced worldwide for industrial processes, detergents, herbicides and pharmaceuticals. Our elucidation of the chemical steps for the biodegradation of alkylphosphonates shows how these compounds can be metabolized and recycled to phosphate.
Assessment of lamellar level properties in mouse bone utilizing a novel spherical nanoindentation data analysis method

In this work, we demonstrate the viability of using our recently developed data analysis procedures for spherical nanoindentation in conjunction with Raman spectroscopy for studying lamellar-level correlations between the local composition and local mechanical properties in mouse bone. Our methodologies allow us to convert the raw load-displacement datasets to much more meaningful indentation stress–strain curves that accurately capture the loading and unloading elastic moduli, the indentation yield points, as well as the post-yield characteristics in the tested samples. Using samples of two different inbred mouse strains, A/J and C57BL/6J (B6), we successfully demonstrate the correlations between the mechanical information obtained from spherical nanoindentation measurements to the local composition measured using Raman spectroscopy. In particular, we observe that a higher mineral-to-matrix ratio correlated well with a higher local modulus and yield strength in all samples. Thus, new bone regions exhibited lower moduli and yield strengths compared to more mature bone. The B6 mice were also found to exhibit lower modulus and yield strength values compared to the more mineralized A/J strain.
Collision frequencies of fractal bacterial aggregates with small particles in a sheared fluid

Bacteria were aggregated in a paddle mixer, producing highly amorphous aggregates of 3−300 μm diameter with an average fractal dimension of D = 2.52. To determine the rate that these types of biological flocs could coagulate with other particles, collision frequencies of these aggregates with small (0.49 μm diameter) fluorescent yellow green (YG) latex microspheres were measured in a paddle mixer at a mean shear rate of 17 s-1. As the aggregate sizes (<5 μm) approached that of the small YG microspheres, measured collision rates converged to values similar to those predicted by two conventional coagulation models (rectilinear and curvilinear) developed for collisions between spherical particles. Collision frequencies between larger bacterial aggregates (La ∼100 μm) and YG microspheres were found to be as much as 2 orders of magnitude smaller than values predicted using a rectilinear coagulation model but 5 orders of magnitude higher than predicted using the curvilinear model. Similar but slightly larger co...
A Micro-Scale Liquid Bridge Between Two Elastic Spheres: Deformation and Stability

A recent study showed that for a liquid bridge of volume Vo interposed between two half-spaces and originally separated by uniform gap H, the interface stability was determined by a single dimensionless parameter. When the parameter exceeds a certain value, the interface loses stability and the solid surfaces come into contact. Further, once contact is made, the contact zone will continue to spread without bound. In the present work, the interaction between two curved elastic bodies coupled via a small liquid bridge is investigated. The equilibrium configurations are determined by minimizing the total free energy stored in the interface among all provisional equilibrium configurations; i.e., those configurations consistent with the equations of elasticity and capillarity. In the case of curved bodies, the stability of the interface is governed by the above parameter as well as by a dimensionless ratio involving the liquid volume (Vo), the composite radius (R) and the original (undeformed) minimum sphere–sphere separation (H). When the interface becomes unstable, solid–solid separation cannot be sustained and contact ensues. The resulting solid–solid contact radius is found to depend on the above parameters as well as on the ratio of solid–liquid and liquid–air surface energies. Based on the numerical calculations, simple relations are found between the contact radius and the other relevant parameters.
The gaugephobic Higgs

We present a class of models that contains Randall-Sundrum and Higgsless models as limiting cases. Over a wide range of the parameter space WW scattering is mainly unitarized by Kaluza-Klein partners of the W and Z, and the Higgs particle has suppressed couplings to the gauge bosons. Such a gaugephobic Higgs can be significantly lighter than the 114 GeV LEP bound for a standard Higgs, or heavier than the theoretical upper bound. These models predict a suppressed single top production rate and unconventional Higgs phenomenology at the LHC: the Higgs production rates will be suppressed and the Higgs branching fractions modified. However, the more difficult the Higgs search at the LHC is, the easier the search for other light resonances (like Z',W',t', exotic fermions) will be.
Reactivity of Fe0 Atoms and Clusters with D2O over FeO(111)

The interaction of Fe0 atoms with D2O layers on FeO(111) has been investigated using the “atom-dropping” preparation technique and a combination of temperature-programmed desorption, X-ray photoele...
Gamma Rays from Neutron Inelastic Scattering

A NaI scintillation counter has been used to observe gamma rays from neutron inelastic scattering in ${\mathrm{B}}^{10}$, C, N, O, F, Mg, Al, S, Ca, Fe, Ni, Cu, Ta, Pb, and Bi. In most cases these gamma rays can be fitted into known level schemes of the target nuclides; however, a few gamma rays require the existence of previously undetected levels. In addition, several gamma rays have been observed from ($n, {p}^{\ensuremath{'}}\ensuremath{\gamma}$) and ($n, {\ensuremath{\alpha}}^{\ensuremath{'}}\ensuremath{\gamma}$) reactions. The problems involved in measuring absolute cross sections for the production of gamma rays are considered in detail. The usefulness of neutron inelastic scattering in nuclear spectroscopy is illustrated in several cases.
Association between responsiveness to phenobarbital induction of CYP2B1/2 and 3A1 in rat hepatic hyperplastic nodules and their zonal origin.

To explore further the mechanism underlying the alteration in expression of P450 enzymes in hepatic preneoplastic lesions, expression of CYP2B1/2 and 3A1 in individual hepatic hyperplastic nodules ...
Design considerations for an infrared flying-spot telescope.

This device combines the image-forming capability of a passive-ir line-scanning radiometer with motion sensing. The main purpose is to enhance image interpretability by adding motion information to the picture. Selection of wavelength and other salient features is discussed. The 10.6-μ wavelength has unique advantages and is the preferred choice, mainly due to the existence of high power, high efficiency cw lasers at this wavelength, coherent receiver techniques, and haze/fog penetration capability. A simplified method of estimating laser power is given, based on area scan rate as the dominant factor.
Control of Supersonic Boundary Layers Using Steady Suction

Control of supersonic boundary layers using steady suction through a series of very small two-dimensional strips is numerically investigated at a free stream Mach number of 1.8. The mean flow induced by rows of suction holes is also computed. Both the steady and unsteady solutions are obtained by solving the full Navier-Stokes equations using the 5th-order accurate weighted essentially non-oscillatory (WENO) scheme for space discretization and using third-order total-variationdiminishing (TVD) Runge-Kutta scheme for time integration. Computations for the two-dimensional cases are performed at suction coefficients 0.001 and 0.002 to investigate the stabilizing effects of suction. The simulation showed that a series of shock waves are generated at the slots. The stability results showed that the total amplification is reduced up to the end of the computational domain. However, the growth rates become larger at downstream distances away from the suction region. The computations for the suction holes showed the generation of Mach waves from each hole and the formation of longitudinal vortices.
Maurice Ravel and Alzheimer's Disease

To the Editor.— Dalessio's 1 recent editorial about Maurice Ravel effectively portrays the tragic final years of that influential 20th-century composer. However, I must take exception to his description of Ravel's amusia. I base these comments on the published testimony of Ravel's neurologist, Theophile Alajouanine, whose article, "Aphasia and Artistic Realization," 2 should be read by any physician with an interest in the creative arts. Assisted by one of Ravel's favored pupils and by a neurology colleague who was also an accomplished musician, Alajouanine made a detailed study of his celebrated patient's musical abilities. What he found was that Ravel's capacity to appreciate music and evaluate it critically was unimpaired. For example, when some of his own piano music was played for him with even minor errors in rhythm or melody, he could immediately identify the errors, and, in his halting speech, he could specify what was incorrect. Also, his