Laser-plasma coupling for enhanced ablation of GaAs with combined femtosecond and nanosecond pulses.

The laser-plasma interactions that occur during the ablation of solid materials by a femtosecond filament superimposed with a lower-intensity nanosecond pulse are investigated. Pulses of 50 fs duration with intensities of ∼10 W/cm centered at 800 nm are combined with 8 ns pulses at 1064 nm with ∼10 W/cm intensity with delays of ±40 ns on crystalline GaAs targets in air. For each delay, the volume of material removed by a single femtosecond-nanosecond dual-pulse is compared to the laser-plasma interactions that are captured with ultrafast shadowgraph imaging of the plasma and shockwave generated by each pulse.

The Role of Executive Function and Theory of Mind in Pragmatic Computations.

In sentences such as "Some dogs are mammals," the literal semantic meaning ("Some and possibly all dogs are mammals") conflicts with the pragmatic meaning ("Not all dogs are mammals," known as a scalar implicature). Prior work has shown that adults vary widely in the extent to which they adopt the semantic or pragmatic meaning of such utterances, yet the underlying reason for this variation is unknown. Drawing on theoretical models of scalar implicature derivation, we explore the hypothesis that the cognitive abilities of executive function (EF) and theory of mind (ToM) contribute to this observed variation.

Filament conductivity enhancement through nonlinear beam interaction.

Laser filament applications relying on filament plasma conductivity are limited by their low electron densities and corresponding short lifetimes. Filament plasma formation, an intensity-dependent process, is limited by the clamping of the filament core intensity. Consequently, increasing initial beam energy results in the breakup of the beam into multiple filaments rather than the enhancement of the electron density and conductivity of an individual filament.

Pragmatics and social meaning: Understanding under-informativeness in native and non-native speakers.

Foreign-accented non-native speakers sometimes face negative biases compared to native speakers. Here we report an advantage in how comprehenders process the speech of non-native compared to native speakers. In a series of four experiments, we find that under-informative sentences are interpreted differently when attributed to non-native compared to native speakers.

Direct wavefront measurements of filaments in the assisted-collapse regime.

Wavefront measurements are used to characterize the process of filament formation in air under assisted-collapse conditions. Direct wavefront evolution within the filament, measured for the first time, is used to characterize the role of energy reservoir in filament formation. This information provides new insights into the filament process and phase sensitive applications such as engineered plasma waveguides.

Nanosecond laser coupling for increased filament ablation.

Laser filaments can project intensities sufficient to ablate materials at long ranges, but the clamping of a filament's intensity to ∼10  W/cm limits the effective ablation of targets with which the laser pulses interact. We seek to identify regimes in which auxiliary radiation can be used to augment the ablation created by single filaments. In this work, the combination of an 800 nm, 50 fs beam at single filament intensity and a 1064 nm, 8 ns laser pulse is studied.

Broadband space-time wave packets propagating 70 m.

The propagation distance of a pulsed beam in free space is ultimately limited by diffraction and space-time coupling. "Space-time" (ST) wave packets are pulsed beams endowed with tight spatio-temporal spectral correlations that render them propagation-invariant. Here we explore the limits of the propagation distance for ST wave packets.

Sins of omission are more likely to be forgiven in non-native speakers.

Utterances produced by foreign-accented speakers are often judged as less credible, more vague, and more difficult to understand compared to those produced by native speakers. Some theoretical accounts argue that listeners have different expectations about the speech of non-native speakers. Other accounts argue that non-native speech is processed differently to the extent that a foreign accent taxes intelligibility and introduces additional processing load.

Synthesizing broadband propagation-invariant space-time wave packets using transmissive phase plates.

Space-time wave packets are a class of pulsed optical beams that are diffraction-free and dispersion-free in free space by virtue of introducing a tight correlation between the spatial and temporal degrees of freedom of the field. Such wave packets have been recently synthesized in a novel configuration that makes use of a spatial light modulator to realize the required spatio-temporal correlations. This arrangement combines pulse-modulation and beam-shaping to assign one spatial frequency to each wavelength according to a prescribed correlation function.

Rationale for routine collection of patient reported outcomes during integrative medicine consultation visits.

Objectives: Integrative medicine (IM) is whole-person care utilizing complementary health approaches to address numerous physical or emotional influences that can impact an individual's health. Patient-reported outcomes (PRO) are subjective measures that quantify patients' perception of their quality of life. While PRO measures have been routinely assessed in specific oncology clinics, our objective was to assess the ability and utility of routine collection of PRO measures in an IM clinic.

Work function characterization of directionally solidified LaB-VB eutectic.

With its low work function and high mechanical strength, the LaB/VB eutectic system is an interesting candidate for high performance thermionic emitters. For the development of device applications, it is important to understand the origin, value, and spatial distribution of the work function in this system. Here we combine thermal emission electron microscopy and low energy electron microscopy with Auger electron spectroscopy and physical vapor deposition of the constituent elements to explore physical and chemical conditions governing the work function of these surfaces.

Learning words from speakers with false beliefs.

During communication, hearers try to infer the speaker's intentions to be able to understand what the speaker means. Nevertheless, whether (and how early) preschoolers track their interlocutors' mental states is still a matter of debate. Furthermore, there is disagreement about how children's ability to consult a speaker's belief in communicative contexts relates to their ability to track someone's belief in non-communicative contexts.

Approach to multifunctional device platform with epitaxial graphene on transition metal oxide.

Heterostructures consisting of two-dimensional materials have shown new physical phenomena, novel electronic and optical properties, and new device concepts not observed in bulk material systems or purely three dimensional heterostructures. These new effects originated mostly from the van der Waals interaction between the different layers. Here we report that a new optical and electronic device platform can be provided by heterostructures of 2D graphene with a metal oxide (TiO2).

Morphology dependent field emission of acid-spun carbon nanotube fibers.

Acid spun carbon nanotube (CNT) fibers were investigated for their field emission properties and performance was determined to be dependent on fiber morphology. The fibers were fabricated by wet-spinning of pre-made CNTs. Fiber morphology was controlled by a fabrication method and processing conditions, as well as purity, size, and type of the CNT starting material.

Pulsed-laser deposited transition-metal carbides for field-emission cathode coatings.

Thin films of transition-metal carbides ZrC, HfC, and TiC were deposited by pulsed-laser deposition under vacuum. The surface chemistry of the films was characterized with ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy in situ. X-ray diffraction was used to characterize the film structure.

Utilization of a benchmarking database to inform NICHE implementation.

An integral part of NICHE (Nurses Improving Care for Healthsystem Elders) is a benchmarking service that provides member sites with the ability to evaluate staff perceptions of the care environment compared with other NICHE sites. The NICHE Database includes more than 100,000 surveys (Geriatric Institutional Assessment Profile). This study aimed to explain how secondary analyses of this aggregate database can inform effective geriatric programming in hospitals.

Strong, light, multifunctional fibers of carbon nanotubes with ultrahigh conductivity.

Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers.

VX hydrolysis by human serum paraoxonase 1: a comparison of experimental and computational results.

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown.

Computational characterization of how the VX nerve agent binds human serum paraoxonase 1.

Human serum paraoxonase 1 (HuPON1) is an enzyme that can hydrolyze various chemical warfare nerve agents including VX. A previous study has suggested that increasing HuPON1's VX hydrolysis activity one to two orders of magnitude would make the enzyme an effective countermeasure for in vivo use against VX. This study helps facilitate further engineering of HuPON1 for enhanced VX-hydrolase activity by computationally characterizing HuPON1's tertiary structure and how HuPON1 binds VX.

New nurses' views of quality improvement education.

Background: Quality improvement (QI) is a focus of hospital managers and policymakers. The role of registered nurses (RNs) in QI in hospitals is vital because most hospital-based RNs provide direct care to patients. QI skills are necessary to identify gaps between current care and best practice and to design, implement, test, and evaluate changes and are essential for R.

Factor structure of the geriatric institutional assessment profile's professional issues scales.

The Geriatric Institutional Assessment Profile (GIAP) is a self-administered survey of hospital nurses, designed to assess a hospital's readiness to implement geriatric programs. A sample of 2,211 direct care RNs in 24 hospitals was randomly split in half to analyze the Geriatric Professional Issues scales of the GIAP, using one sample for exploratory factor analysis and one for confirmatory factor analysis. An exploratory factor analysis of the six Geriatric Professional Issue scales (staff disagreement, staff/family/patient disagreement, use of geriatric services, perceived legal vulnerability, perceived upsetting behaviors, and burden of upsetting behaviors) demonstrated very good internal consistency both as a whole (Cronbach's alpha coefficient = 0.

Predicting Raman spectra using density functional theory.

Accurately computing molecular Raman spectra would enable rapid development of inexpensive and extensive Raman libraries. This is especially beneficial for chemicals that are regulated, toxic, or otherwise difficult to handle. Numerous quantum mechanical methods have been developed that enable computation of Raman spectra.

Understanding new registered nurses' intent to stay at their jobs.

Nursing turnover is costly for health care organizations. Newly licensed registered nurses work behavior is a complex process, influenced by their attitudes toward their work, personal characteristics, job opportunities, and workplace attributes. Several characteristics are significant in predicting satisfaction (ethnicity, gender) and organizational commitment (patient load, mandatory overtime, shift, and unit type) and intent to stay (income, age) over and above work attitudes.

Test--retest reliability of the Geriatric Institutional Assessment Profile.

The Geriatric Institutional Assessment Profile (GIAP) is a self-administered survey of hospital nurses designed to assess a hospital's readiness to implement geriatric programs. The GIAP measures nurses' knowledge and attitudes toward older adults as well as the organizational attributes that support or constrain geriatric best practices. Test-retest reliability estimates of the GIAP were conducted with a sample of 166 direct care nurses in three urban, university-affiliated hospitals over a 3-week time period.