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In the 2015 review paper ‘Petawatt Class Lasers Worldwide’ a comprehensive overview of the current status of high-power facilities of
was presented. This was largely based on facility specifications, with some description of their uses, for instance in fundamental ultra-high-intensity interactions, secondary source generation, and inertial confinement fusion (ICF). With the 2018 Nobel Prize in Physics being awarded to Professors Donna Strickland and Gerard Mourou for the development of the technique of chirped pulse amplification (CPA), which made these lasers possible, we celebrate by providing a comprehensive update of the current status of ultra-high-power lasers and demonstrate how the technology has developed. We are now in the era of multi-petawatt facilities coming online, with 100 PW lasers being proposed and even under construction. In addition to this there is a pull towards development of industrial and multi-disciplinary applications, which demands much higher repetition rates, delivering high-average powers with higher efficiencies and the use of alternative wavelengths: mid-IR facilities. So apart from a comprehensive update of the current global status, we want to look at what technologies are to be deployed to get to these new regimes, and some of the critical issues facing their development.
Glyphosate-resistant (GR) goosegrass [Eleusine indica (L.) Gaertn.] was recently identified in Brazil, but its resistance mechanism was unknown. This study elucidated the resistance mechanism in this species and developed a molecular marker for rapid detection of this target-site resistance trait. The resistance factor for the resistant biotype was 4.4-fold compared with the glyphosate-susceptible (GS) in greenhouse dose–response experiments. This was accompanied by a similar (4-fold) difference in the levels of in vitro and in planta shikimate accumulation in these biotypes. However, there was no difference in uptake, translocation, or metabolism of glyphosate between the GS and GR biotypes. Moreover, both biotypes showed similar values for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) copy number and transcription. Sequencing of a 330-bp fragment of the EPSPS gene identified a single-nucleotide polymorphism that led to a Pro-106-Ser amino acid substitution in the enzyme from the GR biotype. This mutation imparted a 3.8-fold increase in the amount of glyphosate required to inhibit 50% of EPSPS activity, confirming the role of this amino acid substitution in resistance to glyphosate. A quantitative PCR–based genotyping assay was developed for the rapid detection of resistant plants containing this Pro-106-Ser mutation.
We present a new experimental platform for studying laboratory astrophysics that combines a high-intensity, high-repetition-rate laser with the Large Plasma Device at the University of California, Los Angeles. To demonstrate the utility of this platform, we show the first results of volumetric, highly repeatable magnetic field and electrostatic potential measurements, along with derived quantities of electric field, charge density and current density, of the interaction between a super-Alfvénic laser-produced plasma and an ambient, magnetized plasma.
We have previously shown that the minor alleles of vascular endothelial growth factor A (VEGFA) single-nucleotide polymorphism rs833069 and superoxide dismutase 2 (SOD2) single-nucleotide polymorphism rs2758331 are both associated with improved transplant-free survival after surgery for CHD in infants, but the underlying mechanisms are unknown. We hypothesised that one or both of these minor alleles are associated with better systemic ventricular function, resulting in improved survival.
This study is a follow-up analysis of 422 non-syndromic CHD patients who underwent neonatal cardiac surgery with cardiopulmonary bypass. Echocardiographic reports were reviewed. Systemic ventricular function was subjectively categorised as normal, or as mildly, moderately, or severely depressed. The change in function was calculated as the change from the preoperative study to the last available study. Stepwise linear regression, adjusting for covariates, was performed for the outcome of change in ventricular function. Model comparison was performed using Akaike’s information criterion. Only variables that improved the model prediction of change in systemic ventricular function were retained in the final model.
Genetic and echocardiographic data were available for 335/422 subjects (79%). Of them, 33 (9.9%) developed worse systemic ventricular function during a mean follow-up period of 13.5 years. After covariate adjustment, the presence of the VEGFA minor allele was associated with preserved ventricular function (p=0.011).
These data support the hypothesis that the mechanism by which the VEGFA single-nucleotide polymorphism rs833069 minor allele improves survival may be the preservation of ventricular function. Further studies are needed to validate this genotype–phenotype association and to determine whether this mechanism is related to increased vascular endothelial growth factor production.
Using a one-layer quasi-geostrophic model, we study the effect of random monoscale topography on forced beta-plane turbulence. The forcing is a uniform steady wind stress that produces both a uniform large-scale zonal flow
and smaller-scale macroturbulence characterized by standing and transient eddies. The large-scale flow
is retarded by a combination of Ekman drag and the domain-averaged topographic form stress produced by the eddies. The topographic form stress typically balances most of the applied wind stress, while the Ekman drag provides all of the energy dissipation required to balance the wind work. A collection of statistically equilibrated numerical solutions delineate the main flow regimes and the dependence of the time average of
on parameters such as the planetary potential vorticity (PV) gradient
and the statistical properties of the topography. We obtain asymptotic scaling laws for the strength of the large-scale flow
in the limiting cases of weak and strong forcing. If
is significantly smaller than the topographic PV gradient, the flow consists of stagnant pools attached to pockets of closed geostrophic contours. The stagnant dead zones are bordered by jets and the flow through the domain is concentrated into a narrow channel of open geostrophic contours. In most of the domain, the flow is weak and thus the large-scale flow
is an unoccupied mean. If
is comparable to, or larger than, the topographic PV gradient, then all geostrophic contours are open and the flow is uniformly distributed throughout the domain. In this open-contour case, there is an ‘eddy saturation’ regime in which
is insensitive to large changes in the wind stress. We show that eddy saturation requires strong transient eddies that act effectively as PV diffusion. This PV diffusion does not alter the kinetic energy of the standing eddies, but it does increase the topographic form stress by enhancing the correlation between the topographic slope and the standing-eddy pressure field. Using bounds based on the energy and enstrophy power integrals, we show that as the strength of the wind stress increases, the flow transitions from a regime in which the form stress balances most of the wind stress to a regime in which the form stress is very small and large transport ensues.
Introduction: Emergency Medicine Physicians have been incorporating Point-of-Care Ultrasound (POCUS) into their practice for over twenty years. Only recently has its use become more widespread in the practice of Pediatric Emergency Medicine (PEM). Recent guidelines have described the scope of applications for PEM physicians. However, no consensus exists as to which applications should be prioritized and routinely taught to PEM fellowship trainees and therefore expected of PEM graduates as they enter practice. The PEM POCUS Network, a multinational group of Physicians with POCUS expertise formed in 2014, set out to reach expert consensus as to which applications should be incorporated into PEM fellowship training curricula. Methods: A multinational group of PEM POCUS experts was recruited from the PEM POCUS Network via a screening process that identified PEM physicians who have performed over 1000 pediatric POCUS scans and met any of one of the following criteria: having 3 years or more experience teaching POCUS to PEM fellows, being local academic POCUS leaders or had completed a dedicated PEM POCUS fellowship. These experts rated each of the 60 possible PEM POCUS applications using a modified Delphi consensus building technique for their importance in inclusion into a PEM Fellowship curriculum. Consensus was reached when >80% of respondents agreed to include or exclude each item. Results: In the first round, 66 out of 92 (72%) PEM POCUS Network members responded to the survey email, of whom 45 met expert criteria and completed the first round. During round 1, consensus was reached to include 18 of the 60 applications in a PEM fellowship curriculum and to exclude 2 applications from a PEM fellowship curriculum. Eighty-two percent (37 /45) of the experts completed Round 2 where 40 items were rated; consensus was reached to include 3 additional applications and exclude 5 applications. The decision was made not to carry on with future rounds after this stage, since no significant changes were observed between the two rounds, with regard to items that had not reached consensus. Conclusion: This project of the PEM POCUS Network reached consensus on 21 applications that should be included in a PEM Fellowship curriculum. This project will have significant impact on how PEM fellowships teach POCUS to their trainees.
Owing to advances in micro- and nanofabrication methods over the last two decades, the degree of sophistication with which solid surfaces can be engineered today has caused a resurgence of interest in the topic of engineering surfaces for phase change heat transfer. This review aims at bridging the gap between the material sciences and heat transfer communities. It makes the argument that optimum surfaces need to address the specificities of phase change heat transfer in the way that a key matches its lock. This calls for the design and fabrication of adaptive surfaces with multiscale textures and non-uniform wettability.
Among numerous challenges to meet the rising global energy demand in a sustainable manner, improving phase change heat transfer has been at the forefront of engineering research for decades. The high heat transfer rates associated with phase change heat transfer are essential to energy and industry applications; but phase change is also inherently associated with poor thermodynamic efficiency at low heat flux, and violent instabilities at high heat flux. Engineers have tried since the 1930s to fabricate solid surfaces that improve phase change heat transfer. The development of micro and nanotechnologies has made feasible the high-resolution control of surface texture and chemistry over length scales ranging from molecular levels to centimeters. This paper reviews the fabrication techniques available for metallic and silicon-based surfaces, considering sintered and polymeric coatings. The influence of such surfaces in multiphase processes of high practical interest, e.g., boiling, condensation, freezing, and the associated physical phenomena are reviewed. The case is made that while engineers are in principle able to manufacture surfaces with optimum nucleation or thermofluid transport characteristics, more theoretical and experimental efforts are needed to guide the design and cost-effective fabrication of surfaces that not only satisfy the existing technological needs, but also catalyze new discoveries.
Background: Increased heartbeat perception accuracy (HBP-accuracy) may contribute to the pathogenesis of Panic Disorder (PD) without or with Agoraphobia (PDA). Extant research suggests that HBP-accuracy is a rather stable individual characteristic, moreover predictive of worse long-term outcome in PD/PDA patients. However, it remains still unexplored whether HBP-accuracy adversely affects patients’ short-term outcome after structured cognitive behaviour therapy (CBT) for PD/PDA. Aim: To explore the potential association between HBP-accuracy and the short-term outcome of a structured brief-CBT for the acute treatment of PDA. Method: We assessed baseline HBP-accuracy using the “mental tracking” paradigm in 25 consecutive medication-free, CBT-naive PDA patients. Patients then underwent a structured, protocol-based, 8-session CBT by the same therapist. Outcome measures included the number of panic attacks during the past week, the Agoraphobic Cognitions Questionnaire (ACQ), and the Mobility Inventory-Alone subscale (MI-alone). Results: No association emerged between baseline HBP-accuracy and posttreatment changes concerning number of panic attacks. Moreover, higher baseline HBP-accuracy was associated with significantly larger reductions in the scores of the ACQ and the MI-alone scales. Conclusion: Our results suggest that in PDA patients undergoing structured brief-CBT for the acute treatment of their symptoms, higher baseline HBP-accuracy is not associated with worse short-term outcome concerning panic attacks. Furthermore, higher baseline HBP-accuracy may be associated with enhanced therapeutic gains in agoraphobic cognitions and behaviours.
Ten ice-sheet models are used to study sensitivity of the Greenland and Antarctic ice sheets to prescribed changes of surface mass balance, sub-ice-shelf melting and basal sliding. Results exhibit a large range in projected contributions to sea-level change. In most cases, the ice volume above flotation lost is linearly dependent on the strength of the forcing. Combinations of forcings can be closely approximated by linearly summing the contributions from single forcing experiments, suggesting that nonlinear feedbacks are modest. Our models indicate that Greenland is more sensitive than Antarctica to likely atmospheric changes in temperature and precipitation, while Antarctica is more sensitive to increased ice-shelf basal melting. An experiment approximating the Intergovernmental Panel on Climate Change’s RCP8.5 scenario produces additional first-century contributions to sea level of 22.3 and 8.1 cm from Greenland and Antarctica, respectively, with a range among models of 62 and 14 cm, respectively. By 200 years, projections increase to 53.2 and 26.7 cm, respectively, with ranges of 79 and 43 cm. Linear interpolation of the sensitivity results closely approximates these projections, revealing the relative contributions of the individual forcings on the combined volume change and suggesting that total ice-sheet response to complicated forcings over 200 years can be linearized.
Nanotechnology and nanoscience have a strong potential to impact society and the commercial sector. It is critical to introduce this area to high school classrooms as a teaching tool. Here, we report the development of ferrofluid-based experimental modules in a team effort including a high school student and a high school teacher. The basic experimental modules were developed as follows: A) Electric motor-based patterning of magnetic nanoparticles and carbon nanotubes on a silicon wafer. Electromagnetically activated or ‘spiked’-ferrofluid was utilized here. B) Basic concepts of wettability, hydrophobicity, and oleophilicity were demonstrated by combining hydrophobic CNTs, water, and ferrofluids. C) Finally, the utility of ferrofluid-based environmental remediation was demonstrated for oil removal from oil-water mixture and organic dye separation from water-dye mixture. It is envisioned that the integration of the developed experimental modules into high school curriculum will motivate high school students to pursue degrees in science, engineering, and nanotechnology. Thus, this will assist in the development of future workforce in the area of nanotechnology and materials science.
We examined impacts from effective predator management on nesting success of marine turtles in an exceptional nesting year at Hobe Sound National Wildlife Refuge, Florida, USA, a beach with a high density of nesting marine turtles that has a history of severe nest predation. Historically up to 95% of nests were predated, primarily by raccoons Procyon lotor and, more recently, armadillos Dasypus novemcinctus. Predator control was identified as the most important conservation tool for marine turtle reproduction. Predator management by refuge staff as ancillary duties typically only held predation levels to c. 50%. However, when experts in predator control were employed predation was substantially reduced. An extraordinary opportunity to evaluate the biological and economic benefits of this management approach occurred in 2008, a year with exceptionally heavy nesting. Loggerhead turtle Caretta caretta nesting resurged, green Chelonia mydas and leatherback Dermochelys coriacea turtles nested in record numbers, producing twice or more than their median number of nests, and the first Kemp’s ridley Lepidochelys kempii nest was observed. Overall predation was 14.7%, resulting in an estimated > 128,000 additional hatchlings emerging compared to estimates had no predator management been in place and historical predation rates occurred, and > 56,000 hatchlings more than expected had predator management been conducted as ancillary duties rather than by experts. The USD 12,000 investment for expert predator management equated to only USD 0.09 spent for each additional hatchling produced compared to the scenario of no predator control and only USD 0.21 compared to the scenario of predator control as ancillary duties.
During the last decades, an increasing number of predators were found to use specific prey pheromones as chemical cues. Beyond its ecological relevance, this knowledge has practical applications on insect conservation and pest control. In this study, we present first evidence that two species of the family Dasytidae (Coleoptera) Aplocnemus brevis Rosenhauer and A. raymondi Sainte-Claire Deville use the sex pheromone of the pine bast scale Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae) as kairomone to locate this prey. The feeding habits and biology of Aplocnemus species are practically unknown. In the laboratory, the adults of Aplocnemus sp. accepted M. feytaudi egg masses as food source as well as other diets. Females represented more than 90% of Aplocnemus sp. attracted to the pheromone lures. We believe that females use this olfactory cue to locate suitable places for oviposition and that larvae are the predators of Matsucoccus. This study further demonstrates that the response to the kairomone elicited short prey searching times, about 23% of the individuals appeared less than 12 min after lure exposure, being consistent with the hypothesis of prey specialization. Habitat and geographical distribution predict an ancestral association of A. brevis with M. feytaudi and of A. raymondi with M. pini. Nevertheless, a recent prey shift of A. raymondi to the invasive M. feytaudi in Corsica is in progress.
The structural, magnetic, and electronic properties of dilute Mn-doped scandium nitride thin films grown by radio frequency N-plasma molecular beam epitaxy are explored. The results indicate a small magnetization extending up to as high as 350K. There is a slight dependence on the manganese concentration, with the lower Mn concentration showing a larger saturation magnetization.
The combination of the molecular beam epitaxy growth method with the in-situ reflection high energy electron diffraction measurements currently offers unprecedented control of crystalline growth materials. We present here a stoichiometric study of MnxSc(1-x) [x = 0, 0.03, 0.05, 0.15, 0.25, 0.35, and 0.50] thin films grown on MgO(001) substrates with this growth method. Reflection high energy electron diffraction and atomic force microscopy measurements reveal alloy behavior for all of our samples. In addition, we found that samples Mn0.10Sc0.90 and Mn0.50Sc0.50 display surface self-assembled nanowires with a length/width ratio of ~ 800 – 2000.
Inertial cavitation, namely the rapid expansion and subsequent violent collapse of micron-sized cavities under the effect of ultrasound-induced pressure variations, has widely been considered as an undesirable phenomenon for in-vivo biomedical applications. This is mainly because of its highly stochastic nature and difficulties in its reliable initiation in vivo using moderate ultrasound pressure levels. Methods of lowering the pressure required to initiate cavitation, which is known as the cavitation threshold, has been previously addressed with the use of ultrasound contrast agents in form of encapsulated stabilized micron sized bubbles. However, such agents do not readily extravasate into tumours and other target tissues due to their relatively large size. This paper investigates the engineering of core-shell nanoparticles and examines their ability to initiate inertial cavitation in the context of ultrasound-enhanced local drug delivery. The nanoparticulate formulations are size-engineered to target tumour vasculature whilst presenting high surface roughness, facilitating surface air entrapment upon drying. The core-shell nanoparticles have been demonstrated to substantially lower the cavitation threshold in aqueous solution, allowing the initiation of inertial cavitation with moderate ultrasound amplitudes and the low energy levels typically deployed by diagnostic systems. The peak focal pressure where the probability of cavitation is greater than 0.5 was found to decrease by factors of five to ten fold, dependant on particle size, total surface area and surface morphology.