Near-bottom seismic profiling: High lateral variability, anomalous amplitudes, and estimates of attenuation

For almost a decade the Marine Physical Laboratory of Scripps Institution of Oceanography has been conducting near‐bottom geophysical surveys involving quantitative seismic profiling. Operating initially at 4 kHz and more recently at 6 kHz, this system has provided a wealth of fine scale quantitative data on the acoustic properties of ocean sediments. Over lateral distances of a few meters, 7‐dB changes in overall reflected energy as well as 10‐dB changes from individual reflectors have been observed. Anomalously high amplitudes from deep reflectors have been commonly observed, suggesting that multilayer interference is prevalent in records from such pulsed cw profilers. This conclusion is supported by results from sediment core physical property work and related convolution modeling, as well as by the significant differences observed between 4‐ and 6‐kHz profiles. In general, however, lateral consistency has been adequate in most areas surveyed to permit good estimates of acoustic attenuation from returns from dipping reflectors and sediment wedges

Book Reviews

Reviews of the following books: To the Webster-Ashburton Treaty: A Study in Anglo-American Relations, 1783-1843 by Howard Jones; The Journals of John Edwards Godfrey, Bangor, Maine 1863-1869; The Archaeology of New England by Dean R. Sno

NiO gas sensing element prepared on needle-shaped silicon substrate

Abstract This study presents a new approach to enhancing the gas sensor properties based on increasing the sensing area by a structured substrate. Two types of needle-shaped silicon substrates with surface areas of 40 and 14 μm 2 were used as substrate for the preparation of NiO gas sensing element with a thickness of 25 nm. The surface morphology and composition of the prepared samples were examined by SEM, FIB-SEM, and GD OES methods. Deposited NiO films were continuous consisting of an agglomeration of small nanosized grains with arbitrary forms created on each Si needle. It was found that NiO had a polycrystalline nature. The gas sensing measurements revealed that hydrogen responses were better for NiO sensing elements prepared on needle-shape Si substrates with 40 μm 2 surface area than those with 14 μm 2 for all investigated concentrations and temperatures. The maximum relative sensitivity of 26% was measured at 250 ppm of hydrogen

Current and Future Strategies in the Diagnosis and Management of Penile Cancer

Penile cancer is an uncommon malignancy that has a devastating effect on the patient while also being challenging to diagnose and treat. By implementing preventive measures, we can decrease the incidence of this disease and improve the quality of life of our patients. Early detection plays an important role in disease control and proper diagnostic modalities must be used in order to accurately identify the cancer and its progression. Primary penile lesions should be initially approached when surgically feasible and clinically appropriate with penile preserving surgical techniques. Advances in inguinal lymph node detection and management, has improved the clinical outcome of penile cancer. Advanced penile cancer still portends a poor prognosis and should be approached via a multimodal treatment regimen. In this review, we address the importance of prevention, early detection, and the contemporary management of primary penile lesions, as well as the advances in inguinal lymph node disease detection and surgical treatment, for both localized and advanced disease

Current and Future Strategies in the Diagnosis and Management of Penile Cancer

Penile cancer is an uncommon malignancy that has a devastating effect on the patient while also being challenging to diagnose and treat. By implementing preventive measures, we can decrease the incidence of this disease and improve the quality of life of our patients. Early detection plays an important role in disease control and proper diagnostic modalities must be used in order to accurately identify the cancer and its progression. Primary penile lesions should be initially approached when surgically feasible and clinically appropriate with penile preserving surgical techniques. Advances in inguinal lymph node detection and management, has improved the clinical outcome of penile cancer. Advanced penile cancer still portends a poor prognosis and should be approached via a multimodal treatment regimen. In this review, we address the importance of prevention, early detection, and the contemporary management of primary penile lesions, as well as the advances in inguinal lymph node disease detection and surgical treatment, for both localized and advanced disease

Obtenção, caracterização e avaliação do potencial antioxidante de farinha de endosperma e de casca de pinhão para fins alimentícios.

Resumo. Disponível online. MIPE

The small GTPase Arf1 regulates ATP synthesis and mitochondria homeostasis by modulating fatty acid metabolism

Lipid mobilization through fatty acid β-oxidation is a central process essential for energy 36 production during nutrient shortage. In yeast, this catabolic process starts in the peroxisome from where β-oxidation products enter mitochondria and fuel the TCA cycle. Little is known about the physical and metabolic cooperation between these organelles. We found that expression of fatty acid transporters and of the rate-limiting enzyme involved in β-oxidation are decreased in cells expressing a hyperactive mutant of the small GTPase Arf1, leading to an accumulation of fatty acids in lipid droplets. As a consequence, mitochondria became fragmented and ATP synthesis decreased. Genetic and pharmacological depletion of fatty acids phenocopied the arf1 mutant mitochondrial phenotype. Although β-oxidation occurs mainly in mitochondria in mammals, Arf1's role in fatty acid metabolism is conserved. Together, our results indicate that Arf1 integrates metabolism into energy production by regulating fatty acid storage and utilization, and presumably organelle contact-sites

Adsorbing vs. nonadsorbing tracers for assessing pesticide transport in arable soils

The suitability of two different tracers to mimic the behavior of pesticides in agricultural soils and to evidence the potential for preferential flow was evaluated in outdoor lysimeter experiments. The herbicide atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] was used as a model compound. Two tracers were used: a nonadsorbing tracer (bromide) and a weakly adsorbing dye tracer (uranine). Two soils that are expected to show a different extent of macropore preferential flow were used: a well‐drained sandy‐loamy Cambisol (gravel soil) and a poorly drained loamy Cambisol (moraine soil). Conditions for preferential flow were promoted by applying heavy simulated rainfall shortly after pesticide application. In some of the experiments, preferential flow was also artificially simulated by injecting the solutes through a narrow tube below the root zone. With depth injection, preferential leaching of atrazine occurred shortly after application in both soil types, whereas with surface application, it occurred only in the moraine soil. Thereafter, atrazine transport was mainly through the porous soil matrix, although contributions of preferential flow were also observed. For all the application approaches and soil types, after 900 d, <3% of the applied amount of atrazine was recovered in the drainage water. Only uranine realistically illustrated the early atrazine breakthrough by transport through preferential flow. Uranine broke through during the first intense irrigation at the same time as atrazine. Bromide, however, appeared earlier than atrazine in some cases. The use of dye tracers as pesticide surrogates might assist in making sustainable decisions with respect to pesticide application timing relative to rainfall or soil potential for preferential flow

Increasing 3D Supramolecular Order by Decreasing Molecular Order. A Comparative Study of Helical Assemblies of Dendronized Nonchlorinated and Tetrachlorinated Perylene Bisimides

A nonplanar, twisted, and flexible tetrachlorinated perylene bisimide (Cl4PBI) was functionalized with two AB3 minidendrons containing hydrogenated or semifluorinated dodecyl groups. The hydrogenated dendron was attached to the imide groups of Cl4PBI via m = 0, 1, and 2 methylenic units, whereas the dendron containing semifluorinated groups was attached via m = 3 or a di(ethylene oxide) linker (m = 2EO). The supramolecular structures of these compounds, determined by a combination of differential scanning calorimetry, X-ray diffraction, and solid-state NMR, were compared with those of nonchlorinated planar and rigid PBI reported previously, which demonstrated the thermodynamically controlled formation of 2D periodic arrays at high temperatures and 3D arrays at low temperatures. The molecularly less ordered Cl4PBI containing hydrogenated dendrons self-organize into exclusively 3D crystalline periodic arrays under thermodynamic control for m = 0 and 2, while the more highly molecularly ordered PBI produced less stable and ordered 3D crystals and also 2D assemblies. This induction of a higher degree of 3D order in supramolecular assemblies of the less well-ordered molecular building blocks was unanticipated. The semifluorinated dendronized Cl4PBI with m = 3 formed a 2D columnar hexagonal array under kinetic control, whereas the compound with m = 2EO formed an unusual 2D honeycomb-like hexagonal phase under thermodynamic control. These Cl4PBI compounds provide a new route to stable crystalline assemblies via thermodynamic control at lower temperatures than previously obtained with PBI, thus generating 3D order in an accessible range of temperature of interest for structural analysis and for technological applications

A dynamic route choice model for public transport networks with boarding queues

The concepts of optimal strategy and hyperpath were born within the framework of static frequency-based public transport assignment, where it is assumed that travel times and frequencies do not change over time and no overcrowding occurs. However, the formation of queues at public transport stops can prevent passengers from boarding the first vehicle approaching and can thus lead to additional delays in their trip. Assuming that passengers know from previous experience that for certain stops/lines they will have to wait for the arrival of the 2nd, 3rd, …, k-th vehicle, they may alter their route choices, thus resulting in a different assignment of flows across the network. The aim of this paper is to investigate route choice behaviour changes as a result of the formation and dispersion of queues at stops within the framework of optimal travel strategies. A new model is developed, based on modifications of existing algorithms