cssi/SciSciGPT-SciSciNet huggingface dataset:
Augmenting Fractional Factorial Designs

Fractional factorial designs should often be followed by additional experimentation, either with another designed experiment or with confirmation runs. This chapter surveys the options and then discusses several particularly common situations.
Cohabitation before remarriage

This descriptive study focuses on 80 remarried families who had or had not cohabited prior to remarriage with respect to certain background variables as well as a number of perceptual measures associated with family strength and marital success. Those who had cohabited appeared to be similar in background to those who had not cohabited prior to remarriage, with the exception that the cohabitors' ages were younger and the age of the eldest child was older for the noncohabitors. Of the eight components of family strength used in this study, four were found to be significantly higher among the cohabitors. Likewise, the cohabitors judged their remarriage as more successful than the noncohabitors and perceived the support from children, relatives, friends, and the community in general as significantly higher.
Will the Early Use of Biomarkers Prevent the Development of Heart Failure

Alterations in biomarkers are associated with the development and progression of heart failure. As indicated by the study of Ergatoudes and colleagues in the current issue of this journal, biomarkers may also be the first sign of increased risk of developing heart failure. Prior studies also suggest that elevations in certain biomarkers can lead to more frequent clinical surveillance and initiation of therapeutic strategies that may prevent or delay the development of heart failure.
Environmental statistics and optimal regulation

Any organism is embedded in an environment that changes over time. The timescale for and statistics of environmental change, the precision with which the organism can detect its environment, and the costs and benefits of particular protein expression levels all will affect the suitability of different strategies–such as constitutive expression or graded response–for regulating protein levels in response to environmental inputs. We propose a general framework–here specifically applied to the enzymatic regulation of metabolism in response to changing concentrations of a basic nutrient–to predict the optimal regulatory strategy given the statistics of fluctuations in the environment and measurement apparatus, respectively, and the costs associated with enzyme production. We use this framework to address three fundamental questions: (i) when a cell should prefer thresholding to a graded response; (ii) when there is a fitness advantage to implementing a Bayesian decision rule; and (iii) when retaining memory of the past provides a selective advantage. We specifically find that: (i) relative convexity of enzyme expression cost and benefit influences the fitness of thresholding or graded responses; (ii) intermediate levels of measurement uncertainty call for a sophisticated Bayesian decision rule; and (iii) in dynamic contexts, intermediate levels of uncertainty call for retaining memory of the past. Statistical properties of the environment, such as variability and correlation times, set optimal biochemical parameters, such as thresholds and decay rates in signaling pathways. Our framework provides a theoretical basis for interpreting molecular signal processing algorithms and a classification scheme that organizes known regulatory strategies and may help conceptualize heretofore unknown ones.
Recognizing and Minimizing Artifacts at CT, MRI, US, and Molecular Imaging.

Understanding the physical principles and technical assumptions that underlie image production can help radiologists eliminate or minimize common imaging artifacts and improve diagnostic accuracy.
The Unravelling and the Glue

A pattern prediction emerges about Hayek: many knew him to be a fraud—but before this AIEE series, the evidence hasn’t been reported. From his ideological comrades (Gottfried Haberler, Terence Hutchison etc.), this is understandable (if inexcusable). While Friedman was a graduate student at the University of Chicago (1932–1934), two of his teachers, Frank Knight and Jacob Viner, examined and must have rejected Hayek’s assertion about having predicted the Great Depression: and circa 1945, Friedman explained to Hayek why he was unacceptable to the University of Chicago economics department. And why Friedman was sworn to secrecy.As George Stigler noted: ‘There was no Chicago School of Economcis when the Mont Pelerin Society first met in 1947.’ Friedman explained to Cato’s Edward Crane III: Austrians were ‘allies in our major battle,’ but with respect to the ‘scientific’ issue, the ‘weight of the evidence is against’ the ‘Hayek-Misean’ theory of the business cycle. Friedman came close to attributing blame for the Holocaust where it belonged (the ‘Hayek-Misean’ deflation that facilitated Hitler’s rise to power)—but stopped short.Less understandable is the restraint exercised by Paul Samuelson (who knew about Hayek’s Nazi family). Or by the journalist, John Gray to whom Hayek lied: ‘Hayek assured me that he had never read Spencer, and I’m sure this was the case.’ Replication is central to science—but very recently, few if any attempts have been made to replicate Hayek’s patently false assertions.Friedman promoted Amnesty International and campaigned for the release of political prisoners; while Hayek defended the ‘civilisation’ of Police State Apartheid from the American ‘fashion’ of ‘human rights’ and dismissed Amnesty International’s evidence about torture in Police State Chile as the outpourings of a ‘bunch of leftists.’ The low-born Friedman was pilloried for visiting Pinochet—and his Nobel Lecture was rudely interrupted. In contrast, the aristocratic-born, bogus-titled ‘von’ Hayek had a ‘cracker’ of a Nobel Lecture evening (according to his estranged daughter), and until very recently, has evaded critical examination. What does this reveal about the dynamics of knowledge construction and dissemination in the economics profession?
One future of clinical metagenomic sequencing for infectious diseases.

Metagenomic next-generation sequencing (mNGS) allows unbiased sequencing of all or nearly all nucleic acid in a sample. As evidenced by the many excellent reviews on the topic, there is much intere...
Creative Yoga Intervention Improves Motor and Imitation Skills of Children With Autism Spectrum Disorder.

Background There is growing evidence for motor impairments in children with autism spectrum disorder (ASD), including poor gross and fine motor performance, poor balance, and incoordination. However, there is limited evidence on the effects of motor interventions for this population. Objective In the present study, the effects of a physical therapy intervention using creative yoga on the motor and imitation skills of children with ASD were evaluated. Design This study had a pretest-posttest control group design. Methods Twenty-four children with ASD aged between 5 and 13 years received 8 weeks of a physical therapist-delivered yoga or academic intervention. Children were tested before and after the intervention using a standardized motor measure, the Bruininks-Oseretsky Test of Motor Performance-2nd Edition (BOT-2). The imitation skills of children using familiar training-specific actions (ie, poses for the yoga group and building actions for the academic group) were also assessed. Results After the intervention, children in the yoga group improved gross motor performance on the BOT-2 and displayed fewer imitation/praxis errors when copying training-specific yoga poses. In contrast, children in the academic group improved their fine motor performance on the BOT-2 and performed fewer imitation errors while completing the training-specific building actions. Limitations The study limitations include small sample size and lack of long-term follow-up. Conclusions Overall, creative interventions, such as yoga, are promising tools for enhancing the motor and imitation skills of children with ASD.
Distance problems for planar hypercomplex numbers

We study the unit distance and distinct distances problems over the planar hypercomplex numbers: the dual numbers $\mathbb{D}$ and the double numbers $\mathbb{S}$. We show that the distinct distances problem in $\mathbb{S}^2$ behaves similarly to the original problem in $\mathbb{R}^2$. The other three problems behave rather differently from their real analogs. We study those three problems by introducing various notions of multiplicity of a point set. Our analysis is based on studying the geometry of the dual plane and of the double plane. We also rely on classical results from discrete geometry, such as the Szemeredi-Trotter theorem.
Feasibility and Acceptability of the Multicontext Approach for Individuals with Acquired Brain Injury in Acute Inpatient Rehabilitation

Abstract The Multicontext (MC) approach, a metacognitive intervention designed to improve awareness, strategy use, and executive functioning, may be beneficial for individuals with acquired brain injury (ABI) undergoing acute inpatient rehabilitation. The goal of this study was to provide evidence of feasibility, acceptability, and patient perceived benefit of the MC approach. A case series of eight individuals with acquired brain injury and at least mild executive functioning impairment were recruited from an acute inpatient rehabilitation unit. The MC approach— involving guided questioning and patient self-generation of strategies within everyday functional cognitive tasks—was implemented within routine occupational therapy. Outcome measures were self-report of treatment satisfaction, the Self-Regulation Skills Interview, and the Weekly Calendar Planning Activity. Participants rated the MC approach as highly satisfying and engaging. They described subjective improvements in their ability to use executive functioning strategies. The MC approach was associated with improvement in awareness, strategy use, and executive functioning at the conclusion of treatment. The MC approach may be a beneficial structured intervention for individuals with acquired brain injury and executive dysfunction undergoing acute inpatient rehabilitation. Further evaluation with larger samples in controlled trials is warranted.
A Bréguet Range Equation for Hybrid-Electric Jet Aircraft Sizing and Analysis

A Breguet Range Equation for a hybrid-electric (thrust-rated) jet aircraft was formulated by modifying the conventional Breguet Range Equation derivation to incorporate a power-rated electric motor and battery energy source. The resulting ranges for conceptual hybrid-electric aircraft were compared to a hybrid-electric flight performance simulation using publicly available aircraft data for the Embraer ERJ-175 regional jet aircraft. Various degrees of hybridization were simulated with the time-stepping flight performance model and compared to the Hybrid-Electric Breguet Range Equation (HEBRE) results. It is shown that the HEBRE and the time stepping model produce highly consistent maximum ranges across various levels of hybridization and battery specific energy values. Additionally, range values obtained by the HEBRE across a span of flight Mach numbers were consistent with those produced by conventional and fully-electric variants of the Breguet Range Equation, when simulations were conducted at the limits of zero and 100% hybridization factor. Results obtained from the time-stepping model and the HEBRE also indicated similar cruise Mach numbers for maximum range across a series of hybridization factors. These results demonstrated that, as the degree of hybridization in the power system increases, the cruise Mach number for maximum achievable range decreases.
Bond dissociation energies of transition metal oxides: CrO, MoO, RuO, and RhO.

Through the use of resonant two-photon ionization spectroscopy, sharp predissociation thresholds have been identified in the spectra of CrO, MoO, RuO, and RhO. Similar thresholds have previously been used to measure the bond dissociation energies (BDEs) of many molecules that have a high density of vibronic states at the ground separated atom limit. A high density of states allows precise measurement of the BDE by facilitating prompt dissociation to ground state atoms when the BDE is exceeded. However, the number of states required for prompt predissociation at the thermochemical threshold is not well defined and undoubtedly varies from molecule to molecule. The ground separated atom limit generates 315 states for RuO, 252 states for RhO, and 63 states for CrO and MoO. Although comparatively few states derive from this limit for CrO and MoO, the observation of sharp predissociation thresholds for all four molecules nevertheless allows BDEs to be assigned as 4.863(3) eV (RuO), 4.121(3) eV (RhO), 4.649(5) eV (CrO), and 5.414(19) eV (MoO). Thermochemical cycles are used to derive the enthalpies of formation of the gaseous metal oxides and to obtain IE(RuO) = 8.41(5) eV, IE(RhO) = 8.56(6) eV, D0(Ru–O−) = 4.24(2) eV, D0(Cr–O−) = 4.409(8) eV, and D0(Mo–O−) = 5.243(20) eV. The mechanisms leading to prompt predissociation at threshold in the cases of CrO and MoO are discussed. Also presented is a discussion of the bonding trends for the transition metal oxides, which are compared to the previously measured transition metal sulfides.
Diagnostic yield of repeat testing for SARS-CoV-2: Experience from a large health system in Los Angeles.

Abstract Objective To determine the diagnostic yield of repeat testing for SARS-CoV-2. Methods A retrospective analysis was performed of all SARS-CoV-2 test results within the UCLA Health System between March 9th and April 29th, 2020. All patients with repeat test results were identified and those with discordant results were reviewed. Results Between March 9th and April 29th there were 10,165 SARS-CoV-2 test results, of which 630 (6.2%) were positive. Among the 904 patients with repeat test results, 808 (89.4%) were initially negative and 96 (10.6%) were initially positive. Among the 808 patients with an initial negative test, 15 (1.9%) subsequently tested positive. Eleven cases with an initial negative SARS-CoV-2 test and without a known prior positive SARS-CoV-2 test were reviewed; 6 were employed as healthcare workers and 10 were positive on the second test. Conclusions We found a low diagnostic yield of repeat testing for SARS-CoV-2 in our health system. Repeat testing might prove useful in certain clinical scenarios, such as in healthcare workers, when symptoms develop after a negative test, and in hospitalized patients with a high clinical suspicion for COVID-19.
Attenuated regimen of biweekly gemcitabine/nab-paclitaxel in patients aged 65 years or older with advanced pancreatic cancer:

Background:Treatment with gemcitabine/nab-paclitaxel confers a survival benefit over gemcitabine monotherapy in patients with advanced pancreatic cancer (APC). However, such treatment can be associ...
Formation mechanisms of Cr2AlB2, Cr3AlB4, and Fe2AlB2 MAB phases

Quenching studies of CrB-Al, CrB-Al-B and s-FeB-Al mixtures revealed that all three undergo a topotactic transformation in the presence of Al to form Cr2AlB2, Cr3AlB4, and Fe2AlB2 MAB phases, respe...
Out-of-plane buckling strength of free standing singly symmetric hollow pinned circular arches

Abstract This study deals with the out-of-plane flexural torsional buckling strength of singly symmetric free-standing circular arches with a hollow cross-section. The behavior of such arches is investigated numerically in terms of the out of plane critical elastic buckling load and ultimate load carrying capacity when such arches are subject to a radial pressure that creates uniform axial compression. Prediction methodologies proposed by other researchers for flexural torsional buckling of arches with an I-shaped cross-section, as well as American, European, and Australian code provisions for flexural buckling of compression members are slightly modified and compared with numerically obtained critical elastic buckling loads and ultimate load carrying capacities. All investigations are conducted using validated shell finite element simulations. A parametric study is conducted to evaluate the influence of arch depth, wall thickness, subtended angle, arch radius, yield strength, initial imperfections, and residual stresses on the 3D elastic-plastic behavior of such arches. It is concluded that it is not necessary to use eigenvalue buckling analysis to obtain critical elastic buckling loads for improving capacity predictions and that such loads may be obtained using existing formulations with slight modifications. Additionally, existing code provisions for flexural buckling of compression members may be used with minor modifications to predict the out-of-plane flexural torsional buckling capacity of such arches. Also, prediction methodologies proposed by other researchers for flexural torsional buckling of I-shaped arches may also be used with slight modifications and resulted in the most accurate, consistent, and design appropriate capacity predictions.
Histamine Plays a Role in Drinking Elicited by Eating in the Rat

Eating elicits the vagally-mediated1 release of histamine from endocrinelike non-mast cells2 in the gastric mucosa of the rat.3 Exogenous histamine elicits drinking in the rat.4,5 To examine whether eating elicits drinking through a histaminergic mechanism, a pharmacological probe was developed to block drinking elicited by systemic histamine in male Sprague-Dawley rats.
The use of Tween-80-permeabilized mammalian cells in studies of nucleic acid metabolism.

Publisher Summary The chapter describes the use of Tween-80 as an agent that produces a reversible permeability to nucleotides in Chinese hamster ovary (CHO) cells. Several techniques are described for rendering mammalian cells permeable to exogenous nucleoside triphosphates for the purpose of studying DNA metabolism. These include cold shock and cold shock in a hypotonic medium. The use of Tween-80 to permeabilize mammalian cells seems to have general applicability. CHO cells are reversibly permeabilized by Tween; this has obvious advantages for studies in which subsequent cell growth is important. Whether other cell types can be reversibly permeabilized probably depends on whether or not appropriate conditions for achieving it are attainable. The possibility of using this technique to introduce enzymes and other proteins into cells has not been explored, however clearly, if such could be done, the usefulness of this permeabilization process would be increased for in situ studies of cellular activities.
A Thermal Analysis System for Radioactive Materials

A thermal analysis system is described that provides simultaneous thermogravimetric, derivative thermogravimetric, and effluent gas analyses of radioactive materials. An analytical balance detects weight changes of 20 µg, and a mass spectrometer detects m/e ratios up to 200. The basic equipment is located within a compartmentalized stainless steel glove box that can safely contain gram quantities of compounds of the lower actinides and up to 100 mg of 244Cm. The system is designed for ease of operation and maintenance. Typical thermal analyses of standard and radioactive materials are presented.
Proapoptotic protein Bax heterodimerizes with Bcl-2 and homodimerizes with Bax via a novel domain (BH3) distinct from BH1 and BH2

Most members of the Bcl-2 protein family of apoptosis regulating proteins contain two evolutionarily conserved domains, termed BH1 and BH2. Both BH1 and BH2 in the Bcl-2 protein are required for its function as an inhibitor of cell death and for heterodimerization with the proapoptotic protein Bax. In this report, we mapped the region in Bax required for heterodimerization with Bcl-2 and homodimerization with Bax, using yeast two-hybrid and in vitro protein-protein interaction assays. Neither the BH1 nor the BH2 domain of Bax was required for binding to the wild-type Bcl-2 and Bax proteins. Moreover, Bax (deltaBH1) and Bax (deltaBH2) mutant proteins bound efficiently to themselves and each other, further confirming the lack of requirement for BH1 and BH2 for Bax/Bax homodimerization. Bax/Bax homodimerization was not dependent on the inclusion of the NH2-terminal 58 amino acids of the Bax protein in each dimerization partner, unlike Bcl-2/Bcl-2 homodimers which involve head-to-tail interactions between the region of Bcl-2 where BH1 and BH2 resides, and an NH2-terminal domain in Bcl-2 that contains another domain BH4 which is conserved among antiapoptotic members of the Bcl-2 family. Similarly, heterodimerization with Bcl-2 occurred without the NH2-terminal domain of either Bax or Bcl-2, suggesting a tail-to-tail interaction. The essential region in Bax required for both homodimerization with Bax and heterodimerization with Bcl-2 was mapped to residues 59-101. This region in Bax contains a stretch of 15 amino acids that is highly homologous in several members of the Bcl-2 protein family, suggesting the existence of a novel functional domain which we have termed BH3. Deletion of this 15-amino acid region abolished the ability of Bax to dimerize with itself and to heterodimerize with Bcl-2. The findings suggest that the structural features of Bax and Bcl-2 that allow them to participate in homo-and heterodimerization phenomena are markedly different, despite their amino-acid sequence similarity.
Lethal doses of irradiation for Lumbricus.

Irradiation effects in the phylum Annelida are almost entirely unknown, nor is it know why the LD/sub 50/30// for amoebae is 100 kr, whereas mammals show LD/sub 50/ doses of approximates 0.5 kr. To shed more light on comparative radiosensitivity, Lumbricus terrestris was irradiated at a rate of 1 kr/min with 250-kr x rays to total doses of 10 to l00 kr. No lethal effect occurs at 45 kr or below in Lumbricus, whereas a definite mortality occurs with 75 kr. All worms died within 2 months after 100 kr. The LD/sub 50/35//and LD/sub 100/67// are approximates 100 kr. This is in contrast to the mollusk Radix which has a for lethal effects. The annelid Enchytraeus shows no apparent effect after 90 kr. It is suggested that some feature of biological organization, which has up to the present escaped discovery, may hold a clue to the fundamental nature of radiobiological action, and may explain the extremes of radiosensitivity present within a few selected invertebrate types. (BBB)
Integration of WIP management policies with automated material handling systems

As the demand for semiconductor products are ever increasing, more and more semiconductor companies are leveraging their automation systems to improve productivity, yield and quality. To be competitive, manufacturers must maximize the return on resources (e.g. people and equipment). Intel has invested in integrated automated material handling systems (AMHS) as a key strategy for addressing these objectives. As the user or processing station must interface with the AMHS to obtain WIP, the interface or layer between the user and the AMHS becomes the logical place to guide or automate lot selection. This paper describes such intervening functionality and its ability to model dispatch policies that reflect factory WIP Management Policies.
Masses of W and Z bosons without Higgs

A Lagrangian of electroweak interactions without Higgs is used to study the contributions of quarks and leptons to the masses of the W and the Z bosons. It is shown that the $SU(2)\times U(1)$ symmetry is broken by both fermion masses and axial-vector components of the intermediate bosons. The masses of the W and the Z bosons are obtained to be (m^{2}_{W}={1\over2}g^{2}m^{2}_{t}) and (m^{2}_{Z}=\rho m^{2}_{W}/cos^{2}\theta_{W}) with (\rho\simeq 1). Two fixed gauge fixing terms for W and Z boson fields are derived respectively. A coupling between photon and Z boson is predicted. Massive neutrinos are required.
Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thunderclouds

Electric field values measured inside thunderclouds have consistently been reported to be up to an order of magnitude lower than the value required for the conventional electrical breakdown of air. This result has made it difficult to explain how lightning frequently occurs in thunderclouds. A few different theories have been offered to explain the lightning initiation process, one of them being the theory of lightning initiation from hydrometeors. According to this theory, lightning can be initiated from electrical discharges originating around thundercloud water or ice particles in the measured thundercloud electric field. These particles, called hydrometeors, are believed to cause significant enhancement of the thundercloud electric field in their vicinity and then initiate streamers that are the precursor discharges for the hot lightning leader channel. Previously, Liu et al. (2012a) reported streamer formation from a model hydrometeor in an electric field value of half of the conventional breakdown threshold (Ek) for air. In this paper, we present modeling results for streamer formation in electric fields as low as one third of the breakdown threshold. According to our results, initiation of stable streamers from thundercloud hydrometeors in a 0.3Ek electric field is possible, only if enhanced ambient ionization levels (e.g., the ionization created by corona discharges around the same or other nearby hydrometeors) are present ahead of the streamer. The magnitude and distribution of this ambient density may be a determining factor on whether the streamer branches, recovers after the prebranching stage, or continues propagating stably. We investigate the streamer branching behavior and characteristics and test a theory that has recently been proposed to explain this phenomenon. We find that the geometry of the streamer head plays an important role in the streamer branching phenomena. The fast radial movement of the maximum streamer head curvature, combined with the slow reduction of the maximum curvature value, eventually leads the streamer head to branching. Finally, we compare our modeling results with laboratory experiments and realistic thundercloud conditions and discuss the implications of this study to lightning initiation and other lightning-related phenomena.
Fiduciary Duties of Brokers-Advisers-Financial Planners and Money Managers

Broker dealers and investment advisers form the lifeline of the financial markets. While in the past their functions were separate, and their regulation differed, throughout the years their functions were allowed to merge but their regulation remained separate. Advisers are their clients’ fiduciaries. Brokers are not, with some exceptions. It is recognized that the law has to change, and the question is how. In this Article I argue for imposing the fiduciary duty of loyalty and limiting conflict of interest all financial intermediaries, including broker dealers, and suggest a process for establishing the details of the law that should apply to them. Section One of the Article outlines the principles on which fiduciary law is based. Section Two offers a short overview of the past and current practice of broker dealers. Section Three highlights the fiduciary aspects of broker dealers and the risks posed to their clients from their conflicts of interest Section Four proposes changes in the current law and a process to achieve future changes. The law should impose principles; the financial intermediaries should seek the specificity.
The Changing Pattern of American Economic Development

The name of our discipline, economic history, suggests the use of history in reaching economic conclusions, and the use of economic principles in classifying the findings of history. Actually, both practices deserve to be employed more than they are. This is an effort to employ a simple economic principle to reinterpret our nation's economic development. The principle is that the cheaper a factor of production is, the more generously it will be used, and contrariwise, the more costly a factor of production is, the more sparingly it will be used.
Google's hybrid approach to research

By closely connecting research and development Google is able to conduct experiments on an unprecedented scale, often resulting in new capabilities for the company.
Advances in multichannel spectroscopic ellipsometry

Abstract Since the development and perfection of automatic ellipsometers, an effort that began nearly three decades ago, spectroscopic ellipsometry (SE) has increased in popularity as a non-destructive tool for characterizing the optical properties and layered structure of bulk solids and thin films. With the more recent development of multichannel ellipsometers for high-speed spectral scanning, in situ real-time SE has emerged as a very powerful tool for characterizing the time evolution of the optical properties and layered structure of materials during preparation and processing. High-speed spectral scanning has also opened up the possibility of real-time monitoring and control for complex material systems that cannot be fully characterized using well-established real-time measurements at one (or a few) wavelength(s). In this review, we will first describe the most recent developments in multichannel, multiparameter SE, in which spectroscopic information is obtained in addition to the ellipsometric parameters (ψ, Δ). Then we will discuss recent applications of multichannel SE to amorphous semiconductor film growth in order to obtain material properties in complex multilayer and graded-layer device structures. In general in this review, the focus will be on recent examples of the characterization of complex optical systems of technological interest. Practical situations will be described in which the dielectric functions of films are deposition-dependent and evolve with thickness due to particle and grain size effects and intentional compositional gradients, and in which film growth occurs on rough surfaces, leading to optical models for film growth that require interface and surface roughness layers.
Wide-Bandwidth Phased Arrays using Random Subarraying

Beam steering with phased arrays requires the use of true-time-delay devices when communicating a wideband signal. In many applications, this requirement cannot be met, due to size and cost limitations, and the array is divided into subarrays: each element is implemented with a phase shifter (frequency independent phase-shifting device) and each subarray is fed through a single true time delay. The common implementation is with identical contiguous subarrays, which, due to periodicity, cause high sidelobes and grating lobes. We suggest to design divided arrays by trying random sizes of subarrays, with random locations of their centers, in order to avoid periodicity. We develop closed-form expressions for the average array factor, the average power pattern and its variance.
Role of methane clathrates in past and future climates

Methane clathrates are stable at depths greater than about 200 m in permafrost regions and in ocean sediments at water depths greater than about 250 m, provided bottom waters are sufficiently cold. The thickness of the clathrate stability zone depends on surface temperature and geothermal gradient. Average stability zone thickness is about 400 m in cold regions where average surface temperatures are below freezing, 500 m in ocean sediments, and up to 1,500 m in regions of very cold surface temperature (<-15 °C) or in the deep ocean. The concentration of methane relative to water within the zone of stability determines whether or not clathrate will actually occur. The geologic setting of clathrate occurrences, the isotopic composition of the methane, and the methane to ethane plus propane ratio in both the clathrates and the associated pore fluids indicate that methane in clathrates is produced chiefly by anaerobic bacteria. Methane occurrences and the organic carbon content of sediments are the bases used to estimate the amount of carbon currently stored as clathrates. The estimate of about 11,000 Gt of carbon for ocean sediments, and about 400 Gt for sediments under permafrost regions is in rough accord with an independent estimate by Kvenvolden of 10,000 Gt. The shallowness of the clathrate zone of stability makes clathrates vulnerable to surface disturbances. Warming by ocean flooding of exposed continental shelf, and changes in pressure at depth, caused, for example, by sea-level drop, destabilize clathrates under the ocean, while ice-cap growth stabilizes clathrates under the ice cap. The time scale for thermal destabilization is set by the thermal properties of sediments and is on the order of thousands of years. The time required to fix methane in clathrates as a result of surface cooling is much longer, requiring several tens of thousands of years. The sensitivity of clathrates to surface change, the time scales involved, and the large quantities of carbon stored as clathrate indicate that clathrates may have played a significant role in modifying the composition of the atmosphere during the ice ages. The release of methane and its subsequent oxidation to carbon dioxide may be responsible for the observed swings in atmospheric methane and carbon dioxide concentrations during glacial times. Because methane and carbon dioxide are strong infrared absorbers, the release and trapping of methane by clathrates contribute strong feedback mechanisms to the radiative forcing of climate that results from earth's orbital variations.
Atomic carbon as a terminal ligand: studies of a carbidomolybdenum anion featuring solid-state (13)C NMR data and proton-transfer self-exchange kinetics.

Anion [CMo(N[R]Ar)_3]- (R = C(CD3)_2CH_3 or tBu, Ar = 3,5-C_6H_3Me_2) containing one-coordinate carbon as a terminal substituent and related molecules have been studied by single-crystal X-ray crystallography, solution and solid-state ^(13)C NMR spectroscopy, and density functional theory (DFT) calculations. Chemical reactivity patterns for [CMo(N[R]Ar)_3]- have been investigated, including the kinetics of proton-transfer self-exchange involving HCMo(N[R]Ar)_3, the carbidomolybdenum anion's conjugate acid. While the Mo⋮C bond lengths in [K(benzo-15-crown-5)_2][CMo(N[R]Ar)_3] and the parent methylidyne, HCMo(N[R]Ar)_3, are statistically identical, the carbide chemical shift of δ 501 ppm is much larger than the δ 282 ppm shift for the methylidyne. Solid-state ^(13)C NMR studies show the carbide to have a much larger chemical shift anisotropy (CSA, 806 ppm) and smaller 95Mo−13C coupling constant (60 Hz) than the methylidyne (CSA = 447 ppm, 1J_MoC = 130 Hz). DFT calculations on model compounds indicate also that there is an increasing MoC overlap population on going from the methylidyne to the terminal carbide. The pKa of methylidyne HCMo(N[R]Ar)_3 is approximately 30 in THF solution. Methylidyne HCMo(N[R]Ar)3 and carbide [CMo(N[R]Ar)3]- undergo extremely rapid proton-transfer self-exchange reactions in THF, with k = 7 × 10^6 M^(-1) s^(-1). Besides being a strong reducing agent, carbide [CMo(N[R]Ar)_3]- reacts as a nucleophile with elemental chalcogens to form carbon−chalcogen bonds and likewise reacts with PCl_3 to furnish a carbon−phosphorus bond.
Ethanol fermentation of red oak acid prehydrolysate by the yeast Pichia stipitis CBS 5776

Abstract Xylose, the dominant sugar in red oak acid prehydrolysate, was fermented to ethanol. In batch cultures of xylose concentrations ranging from 10 to 100 g l −1 , Pichia stipitis CBS 5776 yielded 0.50–0.40 g ethanol per g xylose consumed. Model compounds of inhibitors generated in the acid prehydrolysis of red oak hemicelluloses, lignin and extractives, hindered the fermentation. Recycled yeasts and treatments with molecular sieve or mixed bed ionresins facilitated the ethanol fermentation of red oak acid prehydrolysate. A maximal ethanol concentration of 9.9 g l −1 was obtained from an acid prehydrolysate containing 21.7 g l −1 of xylose. Fermentation inhibitors derived from red oak lignin and extractives were identified.
A novel broadband fractal metamaterial unit cell

A fractal inspired metamaterial structure based on the electricLCresonator (ELC) described in (1) is presented. The proposed unit cell was built with a larger physical size to shift the frequency of operation to lower frequencies, and a partial repetition of the basic I-shape was inserted in each capacitive gap. The resulting structure was simulated in HFSS, and the relative permittivity and permeability values were extracted from the simulations. The structure was found to have negative per- mittivity over the range 1.3 GHz - 1.75 GHz, which corresponds to a percent bandwidth of 29.5% with a unit cell that is smaller than /10. I. INTRODUCTION Metamaterials have been the focus of significant research in recent years because of the promise of such lofty notions as cloaking, faster than light travel, and flat lenses. To realize these technologies, negative values of relative permittivity are necessary, and some metamaterial structures have given enticing glimpses of achieving this goal with typically narrow band performance. Thus, one significant goal of research in this area is to achieve wideband performance. This paper begins with the electricLCresonator (ELC) first described by Liu et. al. (1). The original unit cell geometry was designed to provide negative permittivity across the band 10.8 GHz - 13 GHz to achieve 18.5% bandwidth; the unit cell that achieved this response required an electric length of approximately 7.6 at midband. The proposed geometry exploits fractal notions to modify the ELC structure with additional features in the vertical direction to achieve increased bandwidth and decreased electrical size.
Bluetooth: The invisible connector. Short-range wireless technology for the contemporary orthodontic practice

Although it sounds like a nonvital tooth, Bluetooth is actually one of technology's hottest trends. It is an industrial specification for wireless personal area networks, but for a busy orthodontic practice, it translates to freedom from cables and cords. Despite its enigmatic name, Bluetooth-based devices and the wireless technology that these gadgets work with are here to stay. They promise to make life easier for the electronic-device users of all stripes, and orthodontists are no exception. The purpose of this article is to orient orthodontists, office staff, and auxiliary personnel to this universal wireless technology that is slowly becoming an integral part of every office.
Formulating Retail Location Strategy in a Changing Environment

To design successful strategies retailers must take into account not only the marketing environment confronting them today but also anticipate possible competitive and demographic changes. This art...
Operating room assist: surgical mentorship and operating room experience for preclerkship medical students.

Background Despite the importance of preclerkship experiences, surgical education has essentially remained confined to the third-year operating room experience. According to experience-based learning theory, the acquisition of new clinical knowledge is a dynamic process of social enculturation and professional identity development that requires active participation, clinical applicability, and direct interaction with doctors and other members of the medical team. In conjunction with a previously described surgical skills elective, we created a new clinical elective in which preclerkship medical students were assigned a surgical mentor and invited into the operating room to assist in surgeries. Methods The elective paired 36 first-year students with 24 surgeons and instructed students to participate in at least 2 surgeries over the 3-month elective period. Students, surgeons, and operating room nurses filled out questionnaires after each surgery. Results Although 6 students failed to enter the operating room, 30 students scrubbed and gowned for a total of 62 procedures during the elective period. Although most students reported the operating room to be a comfortable learning environment in which they were actively included, students consistently underrated their performance and contribution to the surgical team compared with the surgeons' and nurses' ratings. With 75% of students who reported using a previously learned surgical skill during each surgery, this elective succeeded in allowing preclerkship medical students the opportunity to participate actively in the operating room. Conclusions Early surgical exposure is critical for attracting student interest in careers in surgery. We believe that these early clinical experiences, combined with strong mentorship from the surgical faculty, will eventually lead to greater success during clerkships and greater interest in surgery as a career.
The Congruency Effect in the Posterior Medial Frontal Cortex Is More Consistent with Time on Task than with Response Conflict

The posterior medial frontal cortex (pMFC) is thought to play a pivotal role in enabling the control of attention during periods of distraction. In line with this view, pMFC activity is ubiquitously greater in incongruent trials of response-interference (e.g., Stroop) tasks than in congruent trials. Nonetheless, the process underlying this congruency effect remains highly controversial. We therefore sought to distinguish between two competing accounts of the congruency effect. The conflict monitoring account posits the effect indexes a process that detects conflict between competing response alternatives, which is indexed by trial-specific reaction time (RT). The time on task account posits the effect indexes a process whose recruitment increases with time on task independent of response conflict (e.g., sustained attention, arousal, effort, etc.). To distinguish between these accounts, we used functional MRI to record brain activity in twenty-four healthy adults while they performed two tasks: a response-interference task and a simple RT task with only one possible response. We reasoned that demands on a process that detects response conflict should increase with RT in the response-interference task but not in the simple RT task. In contrast, demands on a process whose recruitment increases with time on task independent of response conflict should increase with RT in both tasks. Trial-by-trial analyses revealed that pMFC activity increased with RT in both tasks. Moreover, pMFC activity increased with RT in the simple RT task enough to fully account for the congruency effect in the response-interference task. These findings appear more consistent with the time on task account of the congruency effect than with the conflict monitoring account.
Substitution Is in the Variance: Resources and Foreign Policy Choice

This article argues that foreign policy substitution arises as a result of the costs of foreign policies relative to state resources. States with few resources are constrained in foreign policy choice compared to states with an abundance of resources. As a result, states with few resources will, on average, select, lower-cost policies than will resource-rich states. Resource-rich states, by virtue of their abundant resources, have greater discretion over policy choice and thus behave less uniformly than do resource-poor states. Our empirical results provide evidence of this and support the argument that substitution is in the variance.
Role of the Insulin-Regulated Aminopeptidase IRAP in Insulin Action and Diabetes

The insulin-regulated aminopeptidase (IRAP) is a member of the family of zinc-dependent membrane aminopeptidases. It is the homolog of the human placental leucine aminopeptidase (P-LAP). IRAP is expressed in different cell types but has been best characterized in two major insulin target cells, muscle and fat. In these cells IRAP localizes to intracellular membrane compartments under basal conditions. In response to insulin IRAP redistributes to the cell surface. IRAP shares this behavior with the insulin-responsive glucose transporter GLUT4. It is established that insulin's dramatic effect on glucose disposal is mediated through its action on GLUT4. The role IRAP plays in insulin action is unknown. IRAP cleaves several peptide hormones in vitro. In insulin-treated cells, concomitant with the appearance of IRAP at the cell surface, aminopeptidase activity toward extracellular substrates increases. Thus, insulin, by bringing IRAP to the cell surface, could increase the processing of extracellular peptide hormones and thereby change their activities. Investigations are underway to determine the in vivo substrates for IRAP and to measure the effect of insulin on the cleavage of identified substrates. In individuals with type 2 diabetes the insulin-stimulated translocation of IRAP to the cell surface of muscle and fat cells is impaired. This defect may lead to decreased cleavage and consequently increased action of peptide hormones that are substrates for IRAP. Impaired IRAP action may thus play a role in the development of complications in type 2 diabetes. The findings of decreased expression of GLUT4 and increased heart size in mice in which IRAP was deleted support this hypothesis.
Binary H2SO4-H2O homogeneous nucleation based on kinetic quasi-unary nucleation model: Look-up tables

[1] Recently, we have shown that the binary homogeneous nucleation (BHN) of H2SO4 and H2O can be treated as a quasi-unary nucleation (QUN) of H2SO4 in the equilibrium with H2O vapor and have developed a kinetic H2SO4-H2O nucleation model, which simulates the dynamic evolutions of cluster distributions explicitly. In this paper we present improved and updated version of the QUN model, which has been modified through the incorporation of more rigorous thermodynamics of the cluster formation and the effect of the surface area of preexisting particles on nucleation rates. The difference in the model predictions of the improved and original QUN models is not dramatic; however, the improved QUN model is more consistent thermodynamically. The predicted BHN rates based on the QUN model are in good agreement with existing observations within the range of uncertainties. We also study the dependence of kinetic BHN rates on key input parameters and discuss the conditions in which the H2SO4-H2O homogeneous nucleation in the atmosphere may become significant. The nucleation rates look-up tables derived from the QUN model, which can be readily used to find the nucleation rates at given conditions, are presented. The look-up tables cover a wide range of key parameters that can be found in the ambient atmosphere, in the laboratory studies, and in the exhaust plumes. These look-up tables can be easily incorporated in multidimensional models to predict BHN rates, and they can be utilized directly for the analysis and interpretation of the observed nucleation events.
Multi-rater feedback with gap analysis: an innovative means to assess communication skill and self-insight.

Abstract Objective Multi-rater assessment with gap analysis is a powerful method for assessing communication skills and self-insight, and enhancing self-reflection. We demonstrate the use of this methodology. Methods The Program for the Approach to Complex Encounters (PACE) is an interdisciplinary simulation-based communication skills program. Encounters are assessed using an expanded Kalamazoo Consensus Statement Essential Elements Checklist adapted for multi-rater feedback and gap analysis. Data from a representative conversation were analyzed. Results Likert and forced-choice data with gap analysis are used to assess performance. Participants were strong in Demonstrating Empathy and Providing Closure, and needed to improve Relationship Building, Gathering Information, and understanding the Patient's/Family's Perspective. Participants under-appraised their abilities in Relationship Building, Providing Closure, and Demonstrating Empathy, as well as their overall performance. The conversion of these results into verbal feedback is discussed. Conclusions We describe an evaluation methodology using multi-rater assessment with gap analysis to assess communication skills and self-insight. This methodology enables faculty to identify undervalued skills and perceptual blind spots, provide comprehensive, data driven, feedback, and encourage reflection. Practice implications Implementation of graphical feedback forms coupled with one-on-one discussion using the above methodology has the potential to enhance trainee self-awareness and reflection, improving the impact of educational programs.