High power femtosecond source based on passively mode-locked 1055nm VECSEL and Yb-fibre power amplifier

We report 5 ns pulses at 160 W average power and 910 repetition rate from a passively mode-locked VECSEL source seeding an Yb-doped fibre power amplifier. The amplified pulses were compressed to 291 fs duration

Quark gap equation within the analytic approach to QCD

The compatibility between the QCD analytic invariant charge and chiral symmetry breaking is examined in detail. The coupling in question incorporates asymptotic freedom and infrared enhancement into a single expression, and contains only one adjustable parameter with dimension of mass. When inserted into the standard form of the quark gap-equation it gives rise to solutions displaying singular confining behavior at the origin. By relating these solutions to the pion decay constant, a rough estimate of about 880 MeV is obtained for the aforementioned mass-scale.Comment: Talk given by J.P. at 12th International QCD Conference (QCD05), 4 - 9 July 2005, Montpellier, France; 4 pages, 3 figure

Looking into the matter of light-quark hadrons

In tackling QCD, a constructive feedback between theory and extant and forthcoming experiments is necessary in order to place constraints on the infrared behaviour of QCD's \beta-function, a key nonperturbative quantity in hadron physics. The Dyson-Schwinger equations provide a tool with which to work toward this goal. They connect confinement with dynamical chiral symmetry breaking, both with the observable properties of hadrons, and hence provide a means of elucidating the material content of real-world QCD. This contribution illustrates these points via comments on: in-hadron condensates; dressed-quark anomalous chromo- and electro-magnetic moments; the spectra of mesons and baryons, and the critical role played by hadron-hadron interactions in producing these spectra.Comment: 11 pages, 7 figures. Contribution to the Proceedings of "Applications of light-cone coordinates to highly relativistic systems - LIGHTCONE 2011," 23-27 May, 2011, Dallas. The Proceedings will be published in Few Body System

Magneto-Acoustic Wave Oscillations in Solar Spicules

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of kink waves. For this purposes, the oscillations of a magnetic cylinder embedded in a field-free environment is investigated. Finally, diagnostic diagrams displaying the oscillatory period in terms of some equilibrium parameters are provided to allow a comparison between theoretical results and those coming from observations.Comment: 10 pages, 4 fig

Are Asian elephants afraid of honeybees? Experimental studies in northern Thailand

This research article published Springer Nature Switzerland AG., 2020In many parts of South and Southeast Asia, rural farmers living at the borders of protected areas frequently encounter Asian elephants (Elephas maximus) raiding their crops and threatening farmers lives and livelihoods. Traditional deterrent methods often have limited success as elephants become habituated or alternate their movement and behavior. While African bees (Apis mellifera scutellate) have been shown to effectively and sustainably deter African elephants (Loxodonta africana) little is known about their Asian counterparts. We conducted two experiments to estimate the effectiveness of bees as an Asian elephant deterrent method. We analyzed the behavioral reaction of seven captive Asian elephants when confronted with a fence of A. mellifera hives blocking their way to a desired source of food. In addition, we explored the defensive reaction of five A. cerana hives and six A. mellifera hives to an artificial disturbance during both day and night time. The elephants crossed the beehive fence in 51% of the cases, the probability of crossing increased over time and the number of exposures had a significant effect on an elephant’s crossing probability, indicating that elephants became habituated to the presence of the beehive fence. In the bee experiment, only one out of five A. cerana hives and one out of six A. mellifera hives reacted to the disturbance during the daytime, while during nighttime, none of them reacted defensively after being disturbed. We, therefore, conclude that neither A. mellifera nor A. cerana bees are likely to be effective in deterring wild Asian elephants from entering crop fields

Evaluation of a Medicaid Lock-in Program

Background: "Lock-in" programs (LIPs) identify beneficiaries demonstrating potential overutilization of opioids, and other controlled substances, and restrict their access to these medications. LIPs are expanding to address the opioid crisis and could be an effective tool for connecting people to opioid use disorder treatment. We examined the immediate and sustained effects of a Medicaid LIP on overdose risk and use of medication-assisted treatment (MAT) for opioid use disorder. Methods: We analyzed North Carolina Medicaid claims from July 2009 through June 2013. We estimated daily risk differences and ratios of MAT use and overdose during lock-in and following release from the program, compared with periods before program enrollment. Results: The daily probability of MAT use during lock-in and following release was greater, when compared with a period just before LIP enrollment [daily risk ratios: 1.50, 95% confidence interval (CI): 1.18-1.91; 2.27, 95% CI: 1.07-4.80; respectively]. Beneficiaries' average overdose risk while enrolled in the program and following release was similar to their risk just before enrollment (daily risk ratios: 1.01, 95% CI: 0.79-1.28; 1.12, 95% CI: 0.82-1.54; respectively). Discussion: North Carolina's Medicaid LIP was associated with increased use of MAT during enrollment, and this increase was sustained in the year following release from the program. However, we did not observe parallel reductions in overdose risk during lock-in and following release. Identifying facilitators of MAT access and use among this population, as well as potential barriers to overdose reduction are important next steps to ensuring effective LIP design

Domain Wall Resistance in Perpendicular (Ga,Mn)As: dependence on pinning

We have investigated the domain wall resistance for two types of domain walls in a (Ga,Mn)As Hall bar with perpendicular magnetization. A sizeable positive intrinsic DWR is inferred for domain walls that are pinned at an etching step, which is quite consistent with earlier observations. However, much lower intrinsic domain wall resistance is obtained when domain walls are formed by pinning lines in unetched material. This indicates that the spin transport across a domain wall is strongly influenced by the nature of the pinning.Comment: 9 pages, 3 figure

Formation of giant iron oxide-copper-gold deposits by superimposed, episodic hydrothermal pulses

Iron oxide-copper-gold deposits are a globally important source of copper, gold and critical commodities. However, they possess a range of characteristics related to a variety of tectono-magmatic settings that make development of a general genetic model challenging. Here we investigate micro-textural and compositional variations in actinolite, to constrain the thermal evolution of the Candelaria iron oxide-copper-gold deposit in Chile. We identify at least two mineralization stages comprising an early 675–800 °C iron oxide-apatite type mineralization overprinted by a later copper-rich fluid at around 550–700 °C. We propose that these distinct stages were caused by episodic pulses of injection of magmatic-hydrothermal fluids from crystallizing magmas at depth. We suggest that the mineralisation stages we identify were the result of temperature gradients attributable to changes in the magmatic source, rather than variations in formation depth, and that actinolite chemistry can be used as a proxy for formation temperature in iron oxide-copper-gold systems

Editorial expression of concern: Formation of giant iron oxide-copper-gold deposits by superimposed, episodic hydrothermal pulses

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