Cascaded Nondegenerate Four-Wave Mixing Technique for High-Power Single-Cycle Pulse Synthesis in the Visible and Ultraviolet Ranges

We present a new technique to synthesize high-power single-cycle pulses in the visible and ultraviolet ranges by coherent superposition of a multiband octave-spanning spectrum obtained by highly-nondegenerate cascaded four-wave mixing of femtosecond pulses in bulk isotropic nonresonant media. The generation of coherent spectra spanning over two octaves in bandwidth is experimentally demonstrated using a thin fused silica slide. Full characterization of the intervening multicolored fields using frequency-resolved optical gating, where multiple cascaded orders have been measured simultaneously for the first time, supports the possibility of direct synthesis of near-single-cycle 2.2 fs visible-UV pulses without recurring to complex amplitude or phase control, which should enable many applications in science and technology.Comment: 13 pages, 4 figures. Submitted to Physical Review

Nontimber Forest Products in the United States

A quiet revolution is taking place in America\u27s forests. Once seen primarily as stands of timber, our woodlands are now prized as a rich source of a wide range of commodities, from wild mushrooms and maple sugar to hundreds of medicinal plants whose uses have only begun to be fully realized. Now as timber harvesting becomes more mechanized and requires less labor, the image of the lumberjack is being replaced by that of the forager. This book provides the first comprehensive examination of nontimber forest products (NTFPs) in the United States, illustrating their diverse importance, describing the people who harvest them, and outlining the steps that are being taken to ensure access to them. As the first extensive national overview of NTFP policy and management specific to the United States, it brings together research from numerous disciplines and analytical perspectives-such as economics, mycology, history, ecology, law, entomology, forestry, geography, and anthropology—in order to provide a cohesive picture of the current and potential role of NTFPs. The contributors review the state of scientific knowledge of NTFPs by offering a survey of commercial and noncommercial products, an overview of uses and users, and discussions of sustainable management issues associated with ecology, cultural traditions, forest policy, and commerce. They examine some of the major social, economic, and biological benefits of NTFPs, while also addressing the potential negative consequences of NTFP harvesting on forest ecosystems and on NTFP species populations. Within this wealth of information are rich accounts of NTFP use drawn from all parts of the American landscape—from the Pacific Northwest to the Caribbean. From honey production to a review of nontimber forest economies still active in the United States—such as the Ojibway harvest of plants recounted here—the book takes in the whole breadth of recent NTFP issues, including ecological concerns associated with the expansion of NTFP markets and NTFP tenure issues on federally managed lands. No other volume offers such a comprehensive overview of NTFPs in North America. By examining all aspects of these products, it contributes to the development of more sophisticated policy and management frameworks for not only ensuring their ongoing use but also protecting the future of our forests. Description Eric T. Jones is an instructor and research professor in the Department of Forest Ecosystems and Society at Oregon State University. Rebecca J. McLain is director of research at the National Policy Consensus Center at Portland State University. Susan Charnley is a research social scientist at the Pacific Northwest Research Station of the USDA Forest Service. James Weigand is an ecologist at the US Department of the Interior, Bureau of Land Management. With a New Preface by Eric T. Jones, Rebecca J. McLain, Susan Charnley, and James Weigand. This Kansas Open Books title is funded by a grant from the National Endowment for the Humanities and the Andrew W. Mellon Foundation Humanities Open Book Program.https://digitalcommons.pittstate.edu/kansas_open_books/1035/thumbnail.jp

A numerical and experimental study of wavy ice structure in a parallel plate channel

The paper presents a numerical model for predicting steady-state ice formation inside a cooled, parallel plate channel. The study takes into account the strong interactions occuring between the turbulent flow, the shape of the ice and the heat transfer at the ice-water interface, which lead to the formation of wavy ice layers. The presented model is found to be able to predict realistic variations of the ice layer thickness for a wide range of Reynolds numbers and cooling parameters. The numerical results were verified by comparing with own measurements and good agreement was found

High-Resolution Kinoform X-Ray Optics Printed via 405 nm 3D Laser Lithography

Efficient focusing of X-rays is essential for high-resolution X-ray microscopy. Diffractive X-ray optics called kinoforms offer the highest focusing efficiencies in theory. However, they have long remained unavailable due to their challenging nanofabrication. Recently, various X-ray optic geometries including kinoforms have been realized using 3D laser lithography at near-infrared wavelengths. As the smallest features (period) of the kinoform determines the resolving power, there is a natural drive to find ways to fabricate kinoforms with ever smaller features. Here, a custom-built 3D laser lithography setup with an excitation wavelength of 405 nm is used, which allows to half the smallest period of the kinoforms compared to previous work. A 40% improvement in scanning transmission X-ray microscopy image resolution, that is, a cutoff resolution of 145 nm, and an efficiency of 7.6% at 700 eV is achieved. A reconstructed pixel size of 18.5 nm, reaching the limit imposed by the design of the microscopy set-up, is demonstrated through ptychographic imaging of a magnetic sample which has a strongly reduced contrast mechanism. Moreover, X-ray lenses manufactured by 405 nm 3D laser lithography have the potential to become much less expensive than X-ray lenses made by other means

The 63^{63}Ni(n,γ\gamma) cross section measured with DANCE

The neutron capture cross section of the s-process branch nucleus $^{63}$Ni affects the abundances of other nuclei in its region, especially $^{63}$Cu and $^{64}$Zn. In order to determine the energy dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4$\pi$ BaF$_2$ array DANCE. The (n,$\gamma$) cross section of $^{63}$Ni has been determined relative to the well known $^{197}$Au standard with uncertainties below 15%. Various $^{63}$Ni resonances have been identified based on the Q-value. Furthermore, the s-process sensitivity of the new values was analyzed with the new network calculation tool NETZ.Comment: 11 pages, 13 page

Topsoil Selling - extreme anthropogenic erosion and its consequences for paddy soil quality (Mekong Delta, Vietnam)

Increasing urbanization and industrialization leads to rising demands for construction material, particularly in low-income countries. Thus, agricultural topsoil is sometimes removed and used as raw material e.g. for brick production. Topsoil selling (TSS) is practiced around the world from America, Europe, and Afrika to Asia. In the Mekong, Delta farmers sell the topsoil from their paddy fields to contractors. The temporal effects of topsoil removal on soil quality are not yet fully understood. We hypothesized that after soil removal, soil quality is significantly lower compared to the original topsoil. To test this hypothesis, we sampled paddy soil chronosequences in two different provinces, ranging between 1 and 8 years after TSS. Soil organic carbon (Corg) stocks at TSS sites were up to 20 t/ha lower than at control sites (control: 50 t/ha) in Sóc Trăng and up to 15 t/ha lower in Trà Vinh (control: 30 t/ha). The C/N ratio was nearly constant around 10. Analysis of inorganic nutrients (e.g. P, K, Na, S, Zn, Cu) showed that changes are variable in space, time and among nutrients. Annual average changes ranged from less than a kg per hectare and year for micronutrients (e.g. Cu, Zn) to several tens and hundreds of kg for macronutrients (e.g. P, S). The so far available data revealed that TSS induces mainly a dramatic loss of soil organic matter. It was ongoing up to the 8th year of the chronosequences but was not necessarily accompanied by losses in inorganic nutrients. As a result, there appears to be a chance for farmers in the Mekong Delta to overcome risks of soil quality decline after topsoil removal. Within the next months, we will receive the results from P- and S fractionation and also results from lignin analysis (lignin-derived phenols) will complement to the available data. Thus, we will gain further insights into soil evolution after topsoil selling shortly

Continuous infusion of physostigmine in patients with perioperative septic shock: A pharmacokinetic/pharmacodynamic study with population pharmacokinetic modeling

Background In the context of the cholinergic anti-inflammatory pathway, the clinical trial Anticholium® per Se (EudraCT Number: 2012-001650-26, ClinicalTrials.gov NCT03013322) addressed the possibility of taking adjunctive physostigmine salicylate treatment in septic shock from bench to bedside. Pharmacokinetics (PK) are likely altered in critically ill patients; data on physostigmine PK and target concentrations are sparse, particularly for continuous infusion. Our objective was to build a population PK (popPK) model for physostigmine, and further evaluate pharmacodynamics (PD) and concentration-response relationship in this setting. Methods In the randomized, double-blind, placebo-controlled trial, 20 patients with perioperative septic shock either received an initial dose of 0.04 mg/kg physostigmine salicylate, followed by continuous infusion of 1 mg/h for up to 120 h, or equivalent volumes of 0.9% sodium chloride (placebo group). Physostigmine plasma concentrations and acetylcholinesterase (AChE) activity were measured; concentration-response associations were evaluated, and popPK and PD modeling was performed with NONMEM. Results Steady state physostigmine plasma concentrations reached 7.60 ± 2.81 ng/mL (mean ± standard deviation [SD]). PK was best described by a two-compartment model with linear clearance. Significant covariate effects were detected for body weight and age on clearance, as well as a high inter-individual variability of the central volume of distribution. AChE activity was significantly reduced to 30.5%–50.6% of baseline activity during physostigmine salicylate infusion. A sigmoidal direct effect PD model best described enzyme inhibition by physostigmine, with an estimated half maximal effective concentration (EC50) of 5.99 ng/mL. Conclusions PK of physostigmine in patients with septic shock displayed substantial inter-individual variability with body weight and age influencing the clearance. Physostigmine inhibited AChE activity with a sigmoidal concentration-response effect

Preliminary Results on Evaluation of Chickpea, Cicer arietinum, Genotypes for Resistance to the Pulse Beetle, Callosobruchus maculatus

The chickpea, Cicer arietinum L. (Fabales: Fabaceae), seeds are vulnerable, both in the field and in storage, to attack by seed-beetles. Beetles of the genus Callosobruchus are major storage pests of chickpea crops and cause considerable economic losses. In the present study, a total of 11 chickpea genotypes including five ‘kabuli’ (Mexican white, Diyar, CA 2969, ILC 8617 and ACC 245) and six ‘desi’ chickpeas (ICC 1069, ICC 12422, ICC 14336, ICC 4957, ICC 4969 and ICC 7509) were evaluated for resistance to the pulse beetle Callosobruchus maculatus F. (Coleoptera: Bruchidae). Resistance was evaluated by measuring percent damage to seeds. Damage to seeds by C. maculatus was manifested by the round exit holes with the ‘flap’ of seed coat made by emerging adults. Of the 11 genotypes tested, only one (ICC 4969) exhibited a complete resistance to C. maculatus in both free-choice and no-choice tests; no seed damage was found over the test period. In general, the ‘desi’ chickpeas were more resistant to C. maculatus than the ‘kabuli’ chickpeas. Among the tested chickpea genotypes, only ICC 4969 can be used as a source of C. maculatus resistance in breeding programmes that could then be grown in organic cultivation free from pesticides