cssi/SciSciGPT-SciSciNet huggingface dataset:
The "Sphere Dump" - A New Low-Cost High-Power Beam Dump Concept and a Catalytic Hydrogen-Oxygen Recombiner for Radioactive Water Systems

This paper reveals a new high-power beam dump concept developed at SLAC. Its principal features are relatively low production costs, simple assembly procedures, compactness, and rather high power absorption capacity. The main power absorption medium is a water-cooled bed of 1 cm diameter aluminum spheres contained in a tube. This "Sphere Beam Dump" is rated at 500 kW and its production costs are compatible with other designs at powers as low as 50 kW. The main features of the dump are discussed with emphasis on heat transfer in the bed of spheres, detection of burnout, and flow and mixing of the coolant. A prototype of such a dump was successfully tested in the electron beam at powers up to 495 kW and at an energy of 18 GeV. The experimental results are discussed and potential applications for other high-power absorbers are indicated. A catalytic hydrogen-oxygen recombiner for removal of radiolytically produced hydrogen from such a dump and other water-cooled power absorbers is described in the second part of the paper. Such topics as operational parameters, instrumentation, safety, and performance are stressed.
Extended-working-distance multiphoton micromanipulation microscope for deep-penetration imaging in live mice and tissue

We constructed a multiphoton (2-P) microscope with space to mount and operate microphysiology hardware, and still acquire high quality 2-P images of tumor cells deep within tissues of live mice. We reconfigured for nondescanned 2-P imaging, a dedicated electrophysiology microscope, the Nikon FN1. This microscope is compact, with retractable objectives, allowing more stage space. The instrument is fitted with long-working-distance objectives (2.5- to 3.5-mm WD) with a narrow bore, high NA, and efficient UV and IR light transmission. The system is driven by a powerful 3.5-W peak power pulsed Ti-sapphire laser with a broad tuning range. This 2-P system images a fluorescent standard to a depth of 750 to 800 microm, acquires images of murine pancreatic tumors in vivo, and also images fluorescently labeled T-cells inside live, externalized mouse lymph nodes. Effective imaging depths range between 100 and 500 microm. This compares favorably with the 100- to 300 microm micron depth attained by many 2-P systems, especially descanned 2-P instruments, and 40-microm-deep imaging with confocal microscopes. The greater depth penetration is attributable to the use of high-NA long-working-distance water-dipping lenses incorporated into a nondescanned instrument with carefully configured laser beam introduction and image-acquisition optics. Thus the new system not only has improved imaging capabilities, but allows micromanipulation and maintenance of tissues and organs.
Ultra-wideband radar imaging experiment for verifying super-resolution in nonlinear inverse scattering

The super-resolution phenomenon in nonlinear inverse scattering has been reported previously using numerically simulated data. What was shown was the ability of a nonlinear inverse scattering method to resolve features that are much less than half a wavelength, the criterion dictated by the Rayleigh criterion. The phenomenon has been attributed to the multiple scattering effect within an inhomogeneous body. The high spatial frequency (high resolution) information of the object is usually contained in the evanescent waves when only single scattering physics is considered. Multiple scattering converts evanescent waves into propagating waves and vice versa. Hence, in an inverse scattering experiment, even though an object is interrogated with a propagating wave, and only scattered waves corresponding to propagating waves can be measured, the scattered waves contains high resolution information about the scatterer because of the evanescent-propagating waves conversion in a multiply scattered field. Therefore, an inverse scattering method that can unravel the multiple scattering information can extract the high resolution information on a scatterer.
TASK TYPE AND REACTIVITY OF VERBAL REPORTS IN SLA: A First Look at a L2 Task Other Than Reading

Despite the frequency with which verbal reports are used in SLA to gather data on learners' cognitive processes (e.g., Bowles, 2003, 2004; Mackey, Gass, & McDonough, 2000; Rosa & Leow, 2004a, 2004b), only two studies (Bowles & Leow, 2005; Leow & Morgan-Short, 2004) have investigated verbal reports' reactivity (i.e., whether they alter cognitive processes) during second language (L2) reading. This is the first study to investigate the reactivity of verbal reports on a L2 problem-solving task. First-semester learners of Spanish were assigned to one of six experimental conditions, which differed in terms of the type of verbalization (i.e., metalinguistic, nonmetalinguistic, or silent) and the type of feedback (i.e., implicit vs. explicit). Results show that metalinguistic verbalization significantly increased time on task and also hindered participants' ability to produce exemplars of the target structure seen during the experimental task. However, neither type of verbalization significantly affected participants' ability to produce novel exemplars of the target structure, and there was no interaction between verbalization and feedback.
Increased fruit and vegetable intake has no discernible effect on weight loss: a systematic review and meta-analysis

Background: A common dietary recommendation for weight loss, especially in lay public outlets, is to eat more fruit and vegetables (F/Vs). Without a compensatory reduction in total energy intake, significant weight loss would be unlikely. Objective: We aimed to synthesize the best available evidence on the effectiveness of the general recommendation to eat more F/Vs for weight loss or the prevention of weight gain. Design: We searched multiple databases for human randomized controlled trials that evaluated the effect of increased F/V intake on body weight. Inclusion criteria were as follows: ≥15 subjects/ treatment arm, ≥8-wk intervention, a stated primary or secondary outcome of body weight, the stated goal of the intervention was weight or fat loss or the prevention of weight or fat gain, and food intake provided or prescribed was of a variety of F/Vs that remained minimally processed. Results: Two studies met all criteria; 5 other studies met all criteria but one. The primary analysis indicated an effect size of weight change (outcome of interest) from baseline [standardized mean difference (SMD) for studies that met all criteria] of −0.16 (95% CI: −0.78, 0.46) (P = 0.60). The SMD for 7 studies that met all or most criteria was 0.04 (95% CI: −0.10, 0.17) (P = 0.62). Conclusions: Studies to date do not support the proposition that recommendations to increase F/V intake or the home delivery or provision of F/Vs will cause weight loss. On the basis of the current evidence, recommending increased F/V consumption to treat or prevent obesity without explicitly combining this approach with efforts to reduce intake of other energy sources is unwarranted. This systematic review and meta-analysis was registered at http://www.crd.york.ac.uk/PROSPERO/ as CRD42013004688
Tumor Progression Stage and Anatomical Site Regulate Tumor-Associated Macrophage and Bone Marrow-Derived Monocyte Polarization

Tumor-associated macrophages (TAMs) encourage and coordinate neoplastic growth. In late stage human lung adenocarcinoma, TAMs exhibited mixed M1 (classical; argIlowiNOShigh) and M2 (alternative; argIhighiNOSlow) polarization based on arginine metabolism. In several murine cancer models including chemically and genetically-induced primary lung tumors, prostate tumors, colon xenografts, and lung metastases, TAMs expressed argIhighiNOSlow early during tumor formation; argIlowiNOShigh polarization also occurred during malignancy in some models. In a chemically-induced lung tumor model, macrophages expressed argIhighiNOSlow within one week after carcinogen treatment, followed by similar polarization of bone marrow–derived monocytes (BDMCs) a few days later. TAMs surrounding murine prostate tumors also expressed argIhighiNOSlow early during tumorigenesis, indicating that this polarization is not unique to neoplastic lungs. In a human colon cancer xenograft model, the primary tumor was surrounded by argIhighiNOSlow-expressing TAMs, and BDMCs also expressed argIhighiNOSlow, but pulmonary macrophages adopted argIhighiNOSlow polarization only after tumors metastasized to the lungs. Persistence of tumors is required to maintain TAM polarization. Indeed, in both conditional mutant Kras- and FGF10-driven models of lung cancer, mice expressing the transgene develop lung tumors that regress rapidly when the transgene is silenced. Furthermore, pulmonary macrophages expressed argIhighiNOSlow on tumor induction, but then returned to argIlow iNOSlow (no polarization) after tumors regressed. Manipulating TAM function or depleting TAMs may provide novel therapeutic strategies for preventing and treating many types of cancer.
Mother–Infant Person‐ and Object‐Directed Interactions in Latino Immigrant Families: A Comparative Approach

Cultural variation in durations, relations, and contingencies of mother-infant person-and object-directed behaviors were examined for 121 nonmigrant Latino mother-infant dyads in South America, Latina immigrants from South America and their infants living in the United States, and European American mother-infant dyads. Nonmigrant Latina mothers and infants engaged in person-directed behaviors longer than Latino immigrant or European American mothers and infants. Mother and infant person-directed behaviors were positively related; mother and infant object-related behaviors were related for some cultural groups but not others. Nearly all mother and infant behaviors were mutually contingent. Mothers were more responsive to infants' behaviors than infants were to mothers. Some cultural differences in responsiveness emerged. Immigrant status has a differentiated role in mother-infant interactions.
Nigrostriatal dopamine neurons: Modulation of impulse-induced activation of tyrosine hydroxylation by dopamine autoreceptors

Abstract The role of dopamine autoreceptors on nerve terminals in controlling the activity of tyrosine hydroxylase in the striatum was examined using a model involving supramaximal electrical stimulation of the nigro-neostriatal fibers and accumulation of 3,4-dihydroxyphenylalanine (DOPA) as a measure of the activity of tyrosine hydroxylase in vivo. In this way effects of drugs on impulse flow in these neurons could be negated and the effects on dopamine autoreceptors evaluated. Electrical stimulation, haloperidol, pimozide and clozapine increased the activity of tyrosine hydroxylase in vivo while trivastal, a dopamine agonist, had no significant effect. Combination of electrical stimulation with haloperidol or pimozide produced an additive effect on the activity of tryosine hydroxylase, consistent with blockade of autoreceptors on nerve terminals. The combination of stimulation with clozapine (a drug shown to have minimal blocking action on autoreceptors in this model) produced an effect equivalent to stimulation alone, consistent with a lack of effect on autoreceptors. Trivastal reduced the effect of electrical stimulation, indicating a stimulatory action on dopamine autoreceptors on nerve terminals. These data are consistent with the theory of regulation of the activity of tyrosine hydroxylase in dopaminergic nerve terminals of the striatum by means of dopamine autoreceptors.
Turbulent latent and sensible heat flux in the presence of evaporative droplets

Abstract Direct numerical simulations of an Eulerian-based carrier phase are performed which are two-way coupled in momentum and energy to Lagrangian droplets within a Boussinesq-type incompressible formulation, where the droplets are allowed to evaporate and condense and are thus coupled to the vapor field of the carrier phase. Turbulent planar Couette flow is simulated under varying boundary forcings to understand the degree to which evaporating droplets modify vertical fluxes of energy in horizontally homogeneous systems. In particular, the separate influences on both sensible and latent heat are substantial but opposite in sign, and the local relative humidity can result in droplet-induced heat or moisture fluxes which counteract the prescribed background gradients. The influence of droplet Stokes number is also considered, where it is shown that both clustering and turbophoresis play important roles in determining the magnitude of the droplet-induced sensible and latent heat fluxes.
A Multidimensional Assessment of Teachers’ Knowledge of Algebra for Teaching: Developing an Instrument and Supporting Valid Inferences

Numerous researchers have suggested that there are multiple mathematical knowledge and skill areas needed by teachers in order for them to be effective teachers of mathematics: knowledge of the mathematics that are the goals of instruction, advanced mathematics beyond the instructional material, and mathematical knowledge that is specific to what is needed to teach students. The research reported here is about the development of a test of teachers’ knowledge in these three areas related to the teaching of algebra. The test development process is described and the results of several analyses are reported that had the goal of checking whether valid inferences can be made about the hypothesized components of teacher knowledge.
Oxidation of Magnesium: Implication for Aging and Ignition

Magnesium is widely used in pyrotechnic formulations; it is also a component of reactive alloys, e.g., Al—Mg and B—Mg, which are potential fuels for explosives and propellants. Despite its widespread applications, the kinetics of oxidation of Mg powders are not well quantified. Such kinetics are of fundamental importance for the models aimed to describe thermally induced ignition of metal powders. In addition, for Mg the issue of aging is important because its oxide, MgO, is porous. In this work, magnesium oxidation by both oxygen and steam was studied by thermo-analytical measurements for micron-sized spherical powders. Heat flow calorimetry and thermogravimetric analysis were used to quantify reaction rates for low and elevated temperature ranges, respectively. Experiments with spherical powders with different but overlapping particle size distributions were used to identify the location of the reaction interface. The reaction was found to occur at the interface of metal and the growing oxide layer for ...
Promoting Growth and Innovation Through Acquisition: A Choice Modeling Approach

While innovation and growth can be promoted internally through focus on research and development (R&D), many firms find acquisition from external sources to be a fast and attractive alternative. Despite the numerous theories of merger and acquisition in the literature, no empirical study has tackled the problem of target selection in an acquisition. This paper is the first to study the target selection criteria in an empirical setting. It quantifies the elusive concept of synergy by developing novel measures of similarity and complementarily between the acquirer and the target that are more comprehensive than the existing measures in the literature. Using an innovative application of the discrete choice model, the authors find that firms use acquisition to promote growth and innovation in areas of strategic interest. Specifically, acquirers choose targets whose product markets match their own R&D projects, and targets whose R&D projects match their own product markets. These findings provide support for the knowledge based view of the firm and lay the foundation for future research in this area.
Effect of triiodothyronine and cortisol on intracellular penetration of D-xylose.

SummaryDistribution of D-xylose in the uncut rat diaphragm was studied in vitro under a variety of conditions. It was found that epinephrine, triiodothyronine or Cortisol had no effect on distribution of this sugar when administered in vitro. Triiodothyronine or Cortisol, administered parenterally, increased the space occupied by D-xylose in absence of insulin, and in presence of insulin it resulted in comparatively small but consistent addition to the space occupied when insulin alone was used. A 24-hour starvation period was without effect on sugar distribution whereas a 56-hour period increased the xylose space in absence of insulin and was quantitatively additive in its presence.
Icing flashover characteristics of insulators of DC transmission lines

The icing flashover characteristics of various types of insulators for DC transmission lines were studied through tests in the artificial climate chamber,and the influence of artificial pollutants and natural pollutants on the flashover voltage was analyzed.The results showed that the material and structure of the insulator do not exert great influence on its icing flashover voltage,and the flashover voltage tends to decrease with the increase of ice thickness and pollutants.The relation expression of the flashover voltage U50% of the insulators and the ice thickness and pollutants was proposed,and it was pointed out that the icing flashover voltage of insulators under natural pollutants is higher than that of the insulators under artificial pollutants of the same pollution grade.
Lightning protection and insulation level of 1 000 kV UHV substation

Combined with the calculation results of overvoltage on the 1 000 kV AC UHV test and demonstration project from southeastern Shanxi province via Nanyang in Henan province to Jingmen in Hubei province of China, the method and theory of insulation coordination was discussed, and insulation level of the substation equipments for this project was recommended. The design and operation experiences of direct lightning stroke shielding of 500 kV and 750 kV substation were analyzed and summarized. Some special design problems on direct lightning stoke shielding of 1 000 kV AC UHV substation were calculated. Then the protection method for direct lightning stroke shielding of 1 000 kV substation was given. Lighting incoming wave protection of Jindongnan substation, Nanyang switching station and Jingmen substation were also be simulated to suggest the number and location of MOA in substation. For different station operating conditions, the safety operation guideline was calculated. According to the calculation results, the MOA installation schemes are put forward for ensuring safety operation of every station in 1 500 - 2 000 years.
Choosing between adaptation and prevention with an increasing probability of a pandemic

Abstract The risk of pandemics is increasing, driven by changes in human behavior and climate, both of which are difficult for policymakers to control. There are two main strategies available for reacting to these changes. This paper considers the decision to invest in either adaptation (domestic) capital or prevention (foreign) capital before a pandemic in an interval of time when pandemic risk is increasing. This paper demonstrates how relatively small investments in the two strategies can provide large savings through smaller expected future damages. The technical relationships between adaptation, prevention and risk also determine the optimal mixture of investment over time. As risk increases, the technical relationships between these three stocks causes the optimal mixture of strategies to change over time.
Visual Agenda-Setting, Emotion, and the BP Oil Disaster

This study seeks to identify the most memorable visual imagery of the Deepwater Horizon Oil Spill by comparing a content analysis of television images and a survey of the most-remembered images. The study compared visuals from weeks 1 and 6 of the disaster to a survey conducted a year later that asked respondents to freely recall the most memorable images of the disaster. The comparison showed respondents did indeed choose as the most memorable images the visuals coded with greatest frequency in the content analysis. However, the emotions evoked by the oil-soaked animals elevated that set of images to the most memorable—chosen by almost half of respondents. This set of images was number one with the respondents yet number eight in frequency in the content analysis. This study shows a visual agenda-setting effect heightened by emotion.
How Eighteen-Year-Olds Got the Vote

Recent legal challenges to state voter ID laws have raised pressing questions about the correct interpretation of the constitutional amendment that guarantees eighteen-year-olds the right to vote. The Twenty-sixth Amendment, which was ratified in 1971, lowered the minimum voting age from twenty-one to eighteen. This Article offers a new, urgently needed comprehensive political history of the amendment's origins. Drawing on exhaustive primary source research, the piece traces the story of eighteen-year-old voting from World War II to the present and demonstrates that the story of eighteen-year-old voting is far more complicated that is commonly thought. This Article argues that the motives and rationales both for and against eighteen-year-old voting shifted over time and were always deeply embedded in their particular historical moments. As such, the history of the Twenty-sixth Amendment poses a challenge to those who would look to original intent to interpret it.
Defining A Disaster

Disasters are highly complex events resulting in immediate medical problems, as well as longer-term public health consequences. They are generally considered "low probability–high impact" events. As such they are not defined by a specific number of casualties but rather by the event itself and the venue in which it occurs. The definition of disaster is variable and usually reflects the nature and focus of the organization or individuals defining it. The World Health Organization (WHO) defines a disaster as a sudden ecological phenomenon of sufficient magnitude to require external assistance. This broad definition may exclude some events that result in mass casualties. A more focused definition generally accepted by the specialty of emergency medicine is: when the number of patients presenting within a given time period are such that the emergency department cannot provide care for them without assistance. This definition excludes events that result in mass death but place little or no stress on the medical system. At the community level, disasters can be defined operationally as any emergency that seriously affects people's lives and property and exceeds the capacity of the community to respond effectively to that emergency. Disasters affect a community in numerous ways. Roads, telephone lines, and other transportation and communication lines are often destroyed; public utilities and energy supplies are often disrupted. Many victims are often rendered homeless. The community's industrial or economic base may be damaged or destroyed. Casualties may require urgent or emergent medical care. Damage to water and sanitation systems, food sources and utilities may create public health threats. Each disaster follows a general pattern in its development. This pattern is often repeated and is illustrated in Figure 1. While the divisions are artificial as one phase merges with another, this simplified disaster cycle model is useful to help understand and plan for these complex events. Initially, a quiescent level or interdisaster period is seen during which the combination of events that will lead to a disaster are occurring but not readily apparent. A prodrome or warning phase develops next and lasts a variable length of time. The warning period represents a time during which a particular event (e.g. a hurricane, 1
Multi-photon microfabrication of three-dimensional capillary-scale vascular networks

Biomimetic models of microvasculature could enable assays of complex cellular behavior at the capillary-level, and enable efficient nutrient perfusion for the maintenance of tissues. However, existing three-dimensional printing methods for generating perfusable microvasculature with have insufficient resolution to recapitulate the microscale geometry of capillaries. Here, we present a collection of multiphoton microfabrication methods that enable the production of precise, three-dimensional, branched microvascular networks in collagen. When endothelial cells are added to the channels, they form perfusable lumens with diameters as small as 10 μm. Using a similar photochemistry, we also demonstrate the micropatterning of proteins embedded in microfabricated collagen scaffolds, producing hybrid scaffolds with both defined microarchitecture with integrated gradients of chemical cues. We provide examples for how these hybrid microfabricated scaffolds could be used in angiogenesis and cell homing assays. Finally, we describe a new method for increasing the micropatterning speed by synchronous laser and stage scanning. Using these technologies, we are working towards large-scale (>1 cm), high resolution (~1 μm) scaffolds with both microarchitecture and embedded protein cues, with applications in three-dimensional assays of cellular behavior.
Freedom versus Standardization: Structured Data Generation in a Peer Production Community

In addition to encyclopedia articles and software, peer production communities produce structured data, e.g., Wikidata and OpenStreetMap's metadata. Structured data from peer production communities has become increasingly important due to its use by computational applications, such as CartoCSS, MapBox, and Wikipedia infoboxes. However, this structured data is usable by applications only if it follows standards. We did an interview study focused on OpenStreetMap's knowledge production processes to investigate how -- and how successfully -- this community creates and applies its data standards. Our study revealed a fundamental tension between the need to produce structured data in a standardized way and OpenStreetMap's tradition of contributor freedom. We extracted six themes that manifested this tension and three overarching concepts, correctness, community, and code, which help make sense of and synthesize the themes. We also offered suggestions for improving OpenStreetMap's knowledge production processes, including new data models, sociotechnical tools, and community practices (e.g. stronger leadership).
Synthesis of 2,6-Hexa-tert-butylterphenyl Derivatives, 2,6-(2,4,6-t-Bu3C6H2)2C6H3X, where X = I, Li, OH, SH, N3, or NH2

A “double benzyne” reaction between 1,3-dichloro-2-iodobenzene and 2,4,6-t-Bu3C6H2MgBr followed by the addition of iodine led to 2,6-(2,4,6-t-Bu3C6H2)2C6H3I (HTBTI) in 65% yield. Lithiation of HTBTI with Li-t-Bu gave Li(Et2O)2HTBT from which HTBTSH, HTBTN3, HTBTNH2, and HTBTOH were prepared. An X-ray structure of W(OHTBT)2Cl4 shows that the two HTBTO ligands are trans to one another with the t-Bu3C6H2 groups on one HTBTO interdigitated with the t-Bu3C6H2 groups on the other HTBTO.
Hardware-based on-line intrusion detection via system call routine fingerprinting

We introduce a hardware-based methodology for performing on-line intrusion detection in microprocessors. The proposed method extracts fingerprints from the basic blocks of the routine executed in response to a system call and examines their validity using a Bloom filter. Implementation in hardware renders spoofing attacks, to which operating system or hypervisor-level intrusion detection methods are vulnerable, ineffective. The proposed method is evaluated using kernel rootkits which covertly modify the system call service routines of a Linux operating system running on a 32-bit x86 architecture, implemented in the Simics simulation environment, while hardware overhead is evaluated using a predictive 45nm PDK.
DIAGONALIZATION OF THE INTEGRAL EQUATION FOR MULTIPERIPHERAL DYNAMICS AT VANISHING VALUES OF THE MOMENTUM TRANSFER.

Abstract The elegant equation written down by Chew and De Tar, for multiperipheral dynamics at zero-momentum transfer, is diagonalized using the expansion theorems for the amplitude in terms of the SO(3, 1) and SO(2, 1) groups, respectively. Extensive use is made of the techniques developed by M. Toller.
Geographic Variation in Use of Ambulance Transport to the Emergency Department

Study objective Evidence on variability in emergency medical services use is limited. We obtain national evidence on geographic variation in the use of ambulance transport to the emergency department (ED) among Medicare enrollees and assess the role of health status, socioeconomic status, and provider availability. Methods We used 2010 Medicare claims data for a random sample of 999,999 enrollees aged 66 years and older, and identified ambulance transport and ED use. The main outcome measures were number of ambulance transports to the ED per 100 person-years (ambulance transport rate) and proportion (percentage) of ED visits by ambulance transport by hospital referral regions. Results The national ambulance transport rate was 22.2 and the overall proportion of ED visits by ambulance was 36.7%. Relative to hospital referral regions in the lowest rate quartile, those in the highest quartile had a 75% higher ambulance transport rate (incidence rate ratio [IRR] 1.75; 95% confidence interval [CI] 1.69 to 1.81) and a 15.5% higher proportion of ED visits by ambulance (IRR 1.155; 95% CI 1.146 to 1.164). Adjusting for health status, socioeconomic status, and provider availability reduced quartile 1 versus quartile 4 difference in ambulance transport rate by 43% (IRR 1.43; 95% CI 1.38 to 1.48) and proportion of ED visits by ambulance by 7% (IRR 1.145; 95% CI 1.135 to 1.155). Among the 3 covariate domains, health status was associated with the largest variability in ambulance transport rate (30.1%), followed by socioeconomic status (12.8%) and provider availability (2.9%). Conclusion Geographic variability in ambulance use is large and associated with variation in patient health status and socioeconomic status.
The Future of Formal Thought Research: The Study of Analogy and Metaphor

It is time to move research based upon Piaget’s stage of formal thought into new territory. Recent critics of this stage point out weaknesses in various aspects of the combinatorial system and the four-group (INRC) postulated as the structural foundation for a qualitatively different mode of thinking at the time of adolescence. Specifically, one camp in the old territory concentrates on the weaknesses in Piaget’s use of propositional logic (for example, Brainerd, 1975; Bynum, Thomas, & Weitz, 1972; Ennis, 1975a,b). Some of the confusion in this area may be attributed to misinterpretations of the aim of Piaget’s structuralism: to study children and adolescents not so much as logicians, but as scientists who invent and construct their own understandings (Falmagne, 1975; Stone, 1976).
TeamWATCH: Visualizing development activities using a 3-D city metaphor to improve conflict detection and team awareness

The awareness of others' activities has been widely recognized as essential in facilitating coordination in a team among Computer-Supported Cooperative Work communities. Several field studies of software developers in large software companies such as Microsoft have shown that coworker and artifact awareness are the most common information needs for software developers; however, they are also two of the seven most frequently unsatisfied information needs. To address this problem, we built a workspace awareness tool named TeamWATCH to visualize developer activities using a 3-D city metaphor. In this paper, we discuss the importance of awareness in software development, review existing workspace awareness tools, present the design and implementation of TeamWATCH, and evaluate how it could help detect and resolve conflicts earlier and better maintain group awareness via a controlled experiment. The experimental results showed that the subjects using TeamWATCH performed significantly better with respect to early conflict detection and resolution.
Scaled experiment investigating sonomechanically enhanced inert gas sparging mass transfer

Abstract One of the leading advanced reactor concepts is the fluoride salt high temperature reactor (FHR) currently under investigation. This design utilizes a fluoride molten salt, flibe ( 2 LiF / BeF 2 ) , as the primary coolant. One challenge of employing flibe as a coolant is the production and release of tritium. The FHR community is currently investigating various techniques to solve this tritium management challenge. One of the methods investigated is inert gas sparging which has been investigated during the Molten Salt Reactor Experiment (MSRE) in the 1960’s and 1970’s. To enhance the efficiency of this technique, high power ultrasonics can be employed to sonomechanically enhance the mass transfer performance. Initial experimental studies coupling ultrasonics and inert gas sparging have been performed in the scaled ultrasonic mass transfer (SUMATRA) experiment. The scaling was done by matching the Sc between a water/glycerol mixture and flibe at FHR temperatures. The SUMATRA experiment evaluated the performance of inert gas sparging with and without ultrasonic enhancement. The results show a significant performance enhancement due to the sonomechanical effect which is contributed to an increase in the diffusive mass transfer contribution due to bubble breakup and the subsequent increase interfacial area.
Rapid microwave synthesis and optical activity of highly crystalline platinum nanocubes

We have developed a novel, facile, and reproducible synthesis of highly crystalline oleylamine-capped colloidal platinum nanocubes by microwave (MW) heating. Use of MW heating decreases reaction times, eliminates the need for dangerous reagents [e.g., Fe(CO)5], and gives efficient production of monodispersed 8 nm Pt nanocubes [MW-nanoparticles (NPs)]. We also present a study of the optical properties of these NPs, which to our knowledge has not been previously reported. Absorbance spectra of the MW-NPs show a distinct localized surface plasmon resonance band at 213 nm. This observation could be significant for developments in plasmonic photocatalysis and advanced catalytic materials.
Defining Tip-Frenulum Length for Ankyloglossia and Its Impact on Breastfeeding: A Prospective Cohort Study.

Abstract Objective: The purpose of this study was to investigate the normal lingual frenulum anatomy in newborns and to evaluate tip–frenulum distance as an objective diagnostic tool for identifying newborns at risk for anterior and posterior tongue tie and breastfeeding difficulty. Materials and Methods: The distance from the tongue tip to the insertion of the lingual frenulum was measured in a group of 100 healthy newborns to establish normative data. The presence of a visible or palpable cord was noted. Inter-rater reliability was assessed. Breastfeeding surveys including a maternal pain scale and Infant Breastfeeding Assessment Tool (IBFAT) were administered on days of life 2 and 14 to determine whether these findings predict breastfeeding difficulty. Results: Mean tip–frenulum length was 9.07 mm. Intraclass correlation coefficient between observers for tip–frenulum length was 0.82. A visible cord was identified in 21 subjects (21%). A palpable cord was identified in 59 subjects (59%). Unweighted κ co...
Hintikka’s Ontology

The philosophical community is far from unanimous in its attitude toward possible-worlds semantics. One faction, with Jaakko Hintikka as its most creative and prolific spokesman, regards the possible-worlds apparatus as helpful for achieving clarification, illumination, and perhaps solution to various traditional problems — problems associated with modality, psychological attitudes and the objects of such attitudes, identity and individuation, and the relationships among various “kinds” of entities. Yet there is an opposing sentiment, one which is skeptical that anything philosophically valuable can be achieved with the aid of such metaphysically suspicious items as are employed by the possible-worlds theorist. Completeness results and formally adequate truth theories for intensional languages are one thing; but perennial problems are not to be illuminated by supplanting them with even greater problems.
SOME PROBLEMS OF REACTION-DIFFUSION EQUATIONS

Publisher Summary This chapter explores some problems of reaction–diffusion equations. It presents a simple model governing the combustion of the material and a simple model describing populations that are diffusing and interacting with each other. No model of the given form can be relied on to be in quantitative agreement with real world systems. Differential equations are, at best, only rough approximations of actual ecological systems. They would apply only to animals without age or memory, which eat all the food they encounter and immediately convert it into offspring. System is worth studying as it might offer better qualitative understanding of real-world problems and as such study might help in constructing and analyzing more complex models. The chapter presents the comparison results including the notion of quasi-solutions.
A book review of “Brave, Strong, True: The Modern Warrior’s battle for Balance”

Book review of Brave, Strong, True: The Modern Warrior's battle for Balance by Dr. Kate Hendricks Thomas.
Attitudes Regarding Enrollment in a Genetic Research Project: An Informed Consent Simulation Study Comparing Views of People With Depression, Diabetes, and Neither Condition:

In this study, participants with a self-reported history of depression, diabetes, or no illness underwent a simulated informed consent process for a hypothetical genetic study related to depression...
Temporal trends of inpatient C. difficile infections within the Veterans Health Administration hospitals: An analysis of the effect of molecular testing, time to testing, and mandatory reporting

Background:Clostridium difficile infection (CDI) is a reportable hospital metric associated with significant healthcare expenditures. The epidemiology of CDI is pivotal to the implementation of preventative measures.Objective:To portray temporal CDI trends in Veterans Health Administration (VA) hospitals.Design:A retrospective analysis of veterans who had stool testing for C. difficile.Setting:VA acute-care hospitals within the continental United States.Methods:Data were mined from the VA’s Corporate Data Warehouse. CDI is reported per 10,000 patient days.Results:From 2006 to 2016, 472,346 patients had C. difficile testing. Overall, decreases in incidence of total CDI (16.81 to 13.66) and hospital-onset healthcare facility-associated (HO-HCFA) CDI (10.87 to 6.41) were observed. Temporal increases in the incidence of total and HO-HCFA CDI were associated with the increased use of molecular testing (P < .0001). Decreased use of fluoroquinolones (P < .0001), clindamycin (P = .0006), and third-generation cephalosporins (P = .0002) correlated with decreased rates of CDI, but VA mandatory reporting did not influence CDI rates (P = .24). The overall crude 30-day mortality of patients with CDI decreased from 2.17 deaths per 10,000 patient days in 2006 to 1.41 in 2016. The frequency of International Classification of Disease, Ninth/Tenth Revision (ICD-9/10) discharge diagnosis for CDI was 73.3%.Conclusion:Molecular testing was associated with increased incidence of CDI. Controlling CDI is likely multifactorial. Although the VA initiative to report cases of hospital-acquired CDI was not significant in our model, the advent of stewardship programs throughout the VA and reductions in the use of third-generation cephalosporins, fluoroquinolones, and clindamycin were significantly associated with reduced rates of CDI.
Heat Treatment Design to Modify the Martensite Misorientation and Obtain Superior Strength–Toughness Combinations

A heat treatment methodology is described for obtaining ultra-high strength (> 1700 MPa) and increased − 40 °C toughness (> 45 J/cm2) in a steel. Thermodynamic approach to design heat treatments is demonstrated and utilized to produce refinement of the prior austenite grain size leading to superior properties. The cleavage energy was shown to correlate to both prior austenite grain size, according to an inverse root relationship, as well as the density of high-angle martensite lath boundaries.
Transient hot-carrier dynamics and intrinsic velocity saturation in monolayer Mo S 2

Drift velocity saturation (at some characteristic value, ${v}_{d}^{\mathrm{sat}}$) is a critical process that limits the ultimate current-carrying capacity of semiconductors at high electric fields $(\ensuremath{\sim}{10}^{4}\phantom{\rule{0.16em}{0ex}}\mathrm{V}/\mathrm{cm})$ . With the recent emergence of two-dimensional (2D) semiconductors, there is a need to understand the manner in which velocity saturation is impacted when materials are thinned to the monolayer scale. Efforts to determine ${v}_{d}^{\mathrm{sat}}$ are typically hampered, however, by self-heating effects that arise from undesirable energy loss from the active 2D layer to the dielectric substrate that supports it. In this work, we explore this problem for an important 2D semiconductor, namely monolayer molybdenum disulfide ($\mathrm{Mo}{\mathrm{S}}_{2}$). By applying a strategy of rapid (nanosecond duration), single-shot, pulsing, we are able to probe the true hot-carrier dynamics in this material, free of the influence of self-heating of its $\mathrm{Si}{\mathrm{O}}_{2}$ substrate. Our approach allows us to realize high current densities $(\ensuremath{\sim}\mathrm{mA}/\ensuremath{\mu}\mathrm{m})$ in the $\mathrm{Mo}{\mathrm{S}}_{2}$ layers, representing a significant enhancement over prior studies. We similarly infer values for the saturated drift velocity $({v}_{d}^{sat\phantom{\rule{4pt}{0ex}}}\ensuremath{\sim}5\ensuremath{-}7\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{0.16em}{0ex}}\mathrm{cm}{\mathrm{s}}^{\ensuremath{-}1})$ that are higher than those reported in earlier works, in which the influence of self-heating (and carrier injection into oxide traps) could not be excluded. In fact, our estimates for ${v}_{d}^{\mathrm{sat}}$ are somewhat close to the ideal velocity expected for normal (parabolic) semiconductors. Since a proper knowledge of this parameter is essential to the design of active electronic and optoelectronic devices, the insight into velocity saturation provided here should provide useful guidance for such efforts.
Motoric Cognitive Risk Syndrome in Polypharmacy.

Objectives Risk factors for motoric cognitive risk syndrome (MCR), a predementia syndrome characterized by slow gait and cognitive complaints, have been identified, but few are reversible. Polypharmacy is a potentially reversible risk factor for cognitive decline, but the relationship between MCR and polypharmacy has not been examined. Our aim was to compare the epidemiology of MCR and polypharmacy. Design Cross-sectional. Setting Community-based Health and Retirement Study cohort. Participants A total of 1119 adults 65 years and older (mean age = 74.7 ± 7.0 y; 59% female). Measurements Polypharmacy is defined as the use of five or more regularly scheduled medications. MCR is defined as cognitive complaints and slow gait in an individual without dementia. Results The prevalence of MCR among 417 participants with polypharmacy was 10%; it was 6% among 702 participants without polypharmacy. The odds of meeting MCR criteria in those with polypharmacy was 1.8 (confidence interval = 1.0-3.0; P = .035) compared with those without polypharmacy, even after adjusting for high-risk medication use. Conclusion Our results show the coexistence of MCR and polypharmacy in older adults, suggesting a potentially modifiable risk factor for dementia. J Am Geriatr Soc 68:1072-1077, 2020.
The Heritage Language Learner in Study Abroad Programs: Challenges to Achieving Intercultural Competence

This article investigates the intercultural competence and identities of undergraduate heritage language learners (HLLs) studying abroad under the auspices of the U.S. Flagship Program. Based on su...
An At-Scale Tailless Flapping-Wing Hummingbird Robot. I. Design, Optimization, and Experimental Validation

Designing a hummingbird-inspired, at-scale, tail-less flapping-wing micro aerial vehicle (FWMAV) is a challenging task in order to achieve animallike flight performance under the constraints of size, weight, power, and actuation limitations. It is even more challenging to design such a vehicle with a pair of independently controlled wings equipped with a total of only two actuators. This article details a systematic solution for the design optimization and prototyping of such FWMAVs. The proposed solution covers the complete system models and analysis of wing-actuation dynamics, control authorities, body dynamics, mechanical limitations, and electrical constraints. Each subsystem, as well as the overall system, is experimentally validated. This comprehensive approach can facilitate the design of such FWMAVs with different optimization goals. To demonstrate the effectiveness of the proposed approach, in this article, we conduct three different design optimization tasks, which yield three different prototype systems: optimizing the lift-to-weight ratio, optimizing control bandwidth, and optimizing control authority. We first construct a vehicle with an optimized lift-to-weight ratio. Based on it, the other two platforms with different design optimization goals are presented for better flight performance. Flight tests were performed on each prototype to validate their flight performance and design goals. Compared to optimized control bandwidth, we demonstrate that the vehicle with optimized control authorities is significantly more capable in terms of flight performance. It shows sustained stable flight in both hovering and heavy load carrying (more than 60% of the vehicle's total weight), which is hard for the other two platforms to achieve.
Kinematic Analysis of Pitch Angle for the Platform of a Shrimp Rover in an Unstructured Terrain

In this paper, a kinematic model for the platform pitch angle of a shrimp rover is presented with in-built passive adaptability and ability to move in unstructured environments. With the rhombus configuration of the shrimp rover, platform pitch angle was determined over different types of terrains. The kinematic model of the shrimp rover was established and the rotation angles and the Pitch angle for the Platform of the Front Fork, Boogies and rear Wheel were analyzed. The Kinematic analysis and the Simulations were performed using MATLAB, Solid Works.
Adverse Events Among Young Adults Following a Third Dose of Measles-Mumps-Rubella Vaccine.

BACKGROUND A third measles-mumps-rubella vaccine (MMR) dose (MMR3) is recommended in the United States for persons at increased risk for mumps during outbreaks. MMR3 is also likely given to persons who might have received 2 doses of MMR but lack documentation. Since MMR3 safety data are limited, we describe adverse events in persons receiving MMR3 in a nonoutbreak setting. METHODS Young adults with 2 documented MMR doses were administered MMR3. From 2 weeks before until 4 weeks after MMR3 receipt, participants reported daily on 11 solicited, common symptoms potentially associated with MMR. Weekly rate differences in post- vs prevaccination (baseline) were evaluated by Poisson regression. Baseline rates were subtracted from postvaccination rates of significantly different symptoms to estimate the number and percentage of participants with excess risk for symptoms post-MMR3. Descriptive analyses were performed for 3 postvaccination injection-site symptoms. RESULTS The 662 participants were aged 18-28 years (median = 20 years); 56% were women. Headache, joint problems, diarrhea, and lymphadenopathy rates were significantly higher postvaccination vs baseline. We estimate that 119 participants (18%) reported more symptoms after MMR3 than prevaccination. By symptom, 13%, 10%, 8%, and 6% experienced increased symptoms of headache, joint problems, diarrhea, and lymphadenopathy, respectively, after MMR3. The median onset was Days 3-6 postvaccination; the median duration was 1-2 days. One healthcare visit for a potential vaccination-related symptom (urticaria) was reported. Injection-site symptoms were reported by 163 participants (25%); the median duration was 1-2 days. CONCLUSIONS Reported systemic and local events were mild and transient. MMR3 is safe and tolerable among young adults.