Theory and simulation of multi-GeV laser wakefield acceleration at kHz repetition rates

Deploying both analytic methods and particle-in-cell (PIC) simulations, we investigate the operating regime and performance of the Plasma-Modulated Plasma Accelerator (P-MoPA) [1]. This new approach offers the potential for GeV-scale laser wakefield accelerators (LWFA) at kHz repetition rates by taking advantage of preexisting thin-disk laser technology [2–4], overcoming the 100 mm) pre-formed plasma channels, and benchmark our theory with particle-in-cell (PIC) simulations. We identify a self-modulational transverse mode instability (TMI) that limits the energy of the drive pulse accepted by the modulator stage of the P-MoPA, and find that our theory agrees well. This shows that the TMI is the limiting factor of the plasma modulator, but still allows multi-joule drive pulses corresponding to multi-GeV electron beams. Extended 3D non-paraxial theory in conjunction with further PIC simulations then demonstrate the viability of multi-GeV LWFA driven by these plasma-modulated pulses. Finally, we evaluate the P-MoPA for a potential application as a kHz driver for a water-window X-ray free electron laser (XFEL)

Does environmental education benefit environmental outcomes in children and adolescents? A meta-analysis

Young people can be agents of sustainable change. To this end, environmental education programs aim to promote their environmental knowledge, attitudes, intentions, and behaviors. We synthesized five decades of research into the effectiveness of environmental education for children and adolescents. We searched PsycINFO, ERIC, and Scopus and identified 169 studies (512 effect sizes; 176,007 participants) conducted in 43 countries, across 6 continents. Environmental education significantly improved environmental knowledge (g = 0.953), attitudes (g = 0.384), intentions (g = 0.256), and—mostly self-reported—behavior (g = 0.410). Heterogeneity in effect sizes was substantial; none of the tested moderators (including participant age, educational approach, and study design) accounted for this variance. Our findings demonstrate the potential for environmental education to improve students’ environmental knowledge, attitudes, intentions, and behavior. They also reveal methodo- logical challenges for the field. Future research priorities include identifying effective environmental education components and approaches

Rationale and effect of reduction of immunosuppressive load in organ transplant recipients

Giving a patient immunosuppressive medication is creating an environment in which a transplanted organ will be accepted and rejection will be prevented. Unfortunately, the use of immunosuppression is complicated by serious side effects. After dealing with acute rejection in solid organ transplantation and reducing the incidence of infections in the early days of transplantation, other serious complications became more and more clear. The development of, for example, cardiovascular disease, diabetes mellitus, nephrotoxicity and malignancies after solid organ transplantation is a well known problem for every transplant clinician

Multi-GeV wakefield acceleration in a plasma-modulated plasma accelerator

We investigate the accelerator stage of a plasma-modulated plasma accelerator (P-MoPA) [Jakobsson et al., Phys. Rev. Lett. 127, 184801 (2021)] using both the paraxial wave equation and particle-in-cell (PIC) simulations. We show that adjusting the laser and plasma parameters of the modulator stage of a P-MoPA allows the temporal profile of pulses within the pulse train to be controlled, which in turn allows the wake amplitude in the accelerator stage to be as much as 72% larger than that generated by a plasma beat-wave accelerator with the same total drive laser energy. Our analysis shows that Rosenbluth-Liu detuning is unimportant in a P-MoPA if the number of pulses in the train is less than ∼30, and that this detuning is also partially counteracted by increased red-shifting, and hence increased pulse spacing, towards the back of the train. An analysis of transverse mode oscillations of the driving pulse train is found to be in good agreement with 2D (Cartesian) PIC simulations. PIC simulations demonstrating energy gains of ∼1.5GeV (∼2.5GeV) for drive pulse energies of 2.4J (5.0J) are presented. Our results suggest that P-MoPAs driven by few-joule, picosecond pulses, such as those provided by high-repetition-rate thin-disk lasers, could accelerate electron bunches to multi-GeV energies at pulse repetition rates in the kilohertz range

Cardiac and metabolic effects in patients who present with a multinodular goitre

Twenty-six consecutive patients who presented with clinically euthyroid multinodular goitre were studied for an overnight fasting serum lipid profile and 24 h Holter monitoring. Mean serum TSH was 0.6 +/- 0.4 vs 2.4 +/- 1.3 mU/l (p < 0.0001) and mean TT3 2.4 +/- 0.4 vs 2.0 +/- 0.5 nmol/l (p = 0.009) in patients vs controls (n = 15) while mean FT4 was not different from controls. Total serum HDL, LDL cholesterol and triglycerides were lower in patients but creatinine, ferritin and SHBG levels did not differ between patients and controls. The 24-hour ambulatory continuous ECG recordings did not demonstrate significant differences in mean, minimal and maximal heart rate between the study and the control group. Nocturnal heart rate, measured between 23.00 and 06.00 hours, also showed no differences between the two groups. Atrial fibrillation was absent in both the study and the control group. Premature atrial and ventricular complexes occurred equally frequently in both groups. Comparison of patients with a serum TSH below 0.4 mU/l (n = 11) and patients with a TSH above 0.4 mU/l revealed no differences. In conclusion, in consecutive patients who present with multinodular goitre, effects were found on the lipid profile, but not on the heart. It is argued that in this type of patients, cardiac effects depend on the degree of subclinical hyperthyroidism

Aspects of life history characteristics and physiological processes in smolting Pacific Lamprey, Lampetra tridentata, in a central Oregon coast stream

Rotary screw traps were used to estimate Pacific lamprey smolt yield, outmigration timing, age structure and sex ratio for Tenmile Creek basin, Lane County, Oregon. Traps were fished March to June and August to December 1994 and March to June and October to December 1995. Lamprey smolts caught in the traps were marked and released upstream. Recaptured fish were used to calculate trap efficiencies and daily and weekly estimates of outmigrating smolts. Little movement of smolts occurred before November. Outmigration peaked in late November and was complete both years by 2 December. Ages of smolts were determined using length-frequency analysis and by reading statoliths. Tenmile Creek Pacific lamprey smolts have an extended freshwater residency. Male to female ratios were approximately 1:1 both years. Larval, metamorphosing and smolting Pacific lamprey were examined for changes in skin guanine concentrations, gill (Na+K)-ATPase activities and plasma thyroid hormone levels during a 14 mo period. Seasonal peaks were observed in gill (Na+K)-ATPase activities and plasma thyroid hormone levels in larvae. Metamorphosing and smolting lamprey showed increases in skin guanine concentrations and gill (Na+K)-ATPase activities along with decreases in plasma thyroid hormone levels. Smolting lamprey challenged with artificial seawater showed no significant changes in the parameters observed