Electrode for biological recording

Electrochemically reversible silver-silver chloride electrode for detecting bioelectric potential differences generated by human muscles and organ

The Importance of Pulsed Physical Events for Sustainability of Louisiana Coastal Forested Wetlands

A number of freshwater diversions from the Mississippi River into Louisiana’s coastal wetlands are currently in operation or in the planning stage. These diversions have multiple objectives including maintaining a desirable salinity gradient, restoring deteriorating wetlands, and enhancing fisheries. The extensive freshwater forested wetlands surrounding the western end of Lake Pontchartrain receive little or no sediment input and are currently deteriorating due to continuous flooding. Diverting nutrient-rich water through wetlands can lead to substantial nutrient removal and to enhanced accretion. The objective of this paper is to compare the impacts on freshwater wetland ecology, accretion, and water quality of several scenarios for diverting freshwater from the Mississippi River. Accretion will be increased so that the area will become progressively less flooded, enhancing productivity and seedling recruitment. With overland flow, about 73% of N and 48% of P will be retained in the wetland, while other alternatives are estimated to remove 0-33% of N and 0-40% of P. Productivity of the forested wetland will decrease by at least 20-50% over the next 50 years if nothing is done, but there would be a substantial increase in productivity if river water is diverted into the area. We recommend that a 45-55 m3/s diversion be placed in the southern portion of the swamps of Lake Maurepas and that the diversion be operated annually from winter to early spring. There are indications that a diversion in late summer and fall would be beneficial, as that is when salt pulses typically occur

Inclusive versus Exclusive EM Processes in Relativistic Nuclear Systems

Connections are explored between exclusive and inclusive electron scattering within the framework of the relativistic plane-wave impulse approximation, beginning with an analysis of the model-independent kinematical constraints to be found in the missing energy--missing momentum plane. From the interplay between these constraints and the spectral function basic features of the exclusive and inclusive nuclear responses are seen to arise. In particular, the responses of the relativistic Fermi gas and of a specific hybrid model with confined nucleons in the initial state are compared in this work. As expected, the exclusive responses are significantly different in the two models, whereas the inclusive ones are rather similar. By extending previous work on the relativistic Fermi gas, a reduced response is introduced for the hybrid model such that it fulfills the Coulomb and the higher-power energy-weighted sum rules. While incorporating specific classes of off-shellness for the struck nucleons, it is found that the reducing factor required is largely model-independent and, as such, yields a reduced response that is useful for extracting the Coulomb sum rule from experimental data. Finally, guided by the difference between the energy-weighted sum rules of the two models, a version of the relativistic Fermi gas is devised which has the 0$^{\rm th}$, 1$^{\rm st}$ and 2$^{\rm nd}$ moments of the charge response which agree rather well with those of the hybrid model: this version thus incorporates {\em a priori} the binding and confinement effects of the stuck nucleons while retaining the simplicity of the original Fermi gas.Comment: LaTex file with 15 .ps figure

Relativistic Effects in the Electromagnetic Current at GeV Energies

We employ a recent approach to the non-relativistic reduction of the electromagnetic current operator in calculations of electronuclear reactions. In contrast to the traditional scheme, where approximations are made for the transferred momentum, transferred energy and initial momentum of the struck nucleon in obtaining an on-shell inspired form for the current, we treat the problem exactly for the transferred energy and transferred momentum. We calculate response functions for the reaction $^2H(e,e'p)n$ at CEBAF (TJNAF) energies and find large relativistic corrections. We also show that in Plane Wave Impulse Approximation, it is always possible to use the full operator, and we present a comparison of such a limiting case with the results incorporating relativistic effects to the first order in the initial momentum of the struck nucleon.Comment: 31 pages, 8 figures, Revte

Origin of Relativistic Effects in the Reaction D(e,e'p)n at GeV Energies

In a series of recent publications, a new approach to the non-relativistic reduction of the electromagnetic current operator in calculations of electro-nuclear reactions has been introduced. In one of these papers, the conjecture that at energies of a few GeV, the bulk of the relativistic effects comes from the current and not from the nuclear dynamics was made, based on the large relativistic effects in the transverse-longitudinal response. Here, we explicitly compare a fully relativistic, manifestly covariant calculation performed with the Gross equation, with a calculation that uses a non-relativistic wave function and a fully relativistic current operator. We find very good agreement up to missing momenta of 400 MeV/c, thus confirming the previous conjecture. We discuss slight deviations in cross sections for higher missing momenta and their possible origin, namely p-wave contributions and off-shell effects.Comment: 25 pages, 11 figure

Inelastic nucleon contributions in (e,e′)(e,e^\prime) nuclear response functions

We estimate the contribution of inelastic nucleon excitations to the $(e,e^\prime)$ inclusive cross section in the CEBAF kinematic range. Calculations are based upon parameterizations of the nucleon structure functions measured at SLAC. Nuclear binding effects are included in a vector-scalar field theory, and are assumed have a minimal effect on the nucleon excitation spectrum. We find that for q\lsim 1 GeV the elastic and inelastic nucleon contributions to the nuclear response functions are comparable, and can be separated, but with roughly a factor of two uncertainty in the latter from the extrapolation from data. In contrast, for q\rsim 2 GeV this uncertainty is greatly reduced but the elastic nucleon contribution is heavily dominated by the inelastic nucleon background.Comment: 20 pages, 7 figures available from the authors at Department of Physics and Astronomy, University of Rochester, Rochester NY 1462

The Influence of Enhanced Post-Glacial Coastal Margin Productivity on the Emergence of Complex Societies

Abstract We analyze the dynamics of post-glacial coastal margin (CM) productivity and explore how it affected the emergence of six complex CM societies. Following deglaciation, global relative sea level stabilized after ~7000 BP and CM productivity significantly increased in many areas. Primary and secondary productivity (fish) likely increased by an order of magnitude or more. Aquatic animals were readily available in the CM providing sources of polyunsaturated omega-3 fatty acids, high quality protein, and nutrients, especially essential to human nutrition. In all six case studies, mature CMs appear to have been occupied by Neolithic agricultural and fishing villages within ~500 years of sea-level stabilization. Within a few hundred years population densities increased and roughly a millennium later social ranking and monumental architecture appeared. Sea-level stabilization and increased CM productivity in conjunction with agricultural intensification in lower alluvial floodplains were major contributors to the origins of many complex CM societies. Keyword

Early respiratory viral infections in infants with cystic fibrosis

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background Viral infections contribute to morbidity in cystic fibrosis (CF), but the impact of respiratory viruses on the development of airway disease is poorly understood. Methods Infants with CF identified by newborn screening were enrolled prior to 4 months of age to participate in a prospective observational study at 4 centers. Clinical data were collected at clinic visits and weekly phone calls. Multiplex PCR assays were performed on nasopharyngeal swabs to detect respiratory viruses during routine visits and when symptomatic. Participants underwent bronchoscopy with bronchoalveolar lavage (BAL) and a subset underwent pulmonary function testing. We present findings through 8.5 months of life. Results Seventy infants were enrolled, mean age 3.1 ± 0.8 months. Rhinovirus was the most prevalent virus (66%), followed by parainfluenza (19%), and coronavirus (16%). Participants had a median of 1.5 viral positive swabs (range 0–10). Past viral infection was associated with elevated neutrophil concentrations and bacterial isolates in BAL fluid, including recovery of classic CF bacterial pathogens. When antibiotics were prescribed for respiratory-related indications, viruses were identified in 52% of those instances. Conclusions Early viral infections were associated with greater neutrophilic inflammation and bacterial pathogens. Early viral infections appear to contribute to initiation of lower airway inflammation in infants with CF. Antibiotics were commonly prescribed in the setting of a viral infection. Future investigations examining longitudinal relationships between viral infections, airway microbiome, and antibiotic use will allow us to elucidate the interplay between these factors in young children with CF

Exponential Kleisli monoids as Eilenberg-Moore algebras

Lax monoidal powerset-enriched monads yield a monoidal structure on the category of monoids in the Kleisli category of a monad. Exponentiable objects in this category are identified as those Kleisli monoids with algebraic structure. This result generalizes the classical identification of exponentiable topological spaces as those whose lattice of open subsets forms a continuous lattice.Comment: v2: minor typos correcte

Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch

Growth in fundamental drivers—energy use, economic productivity and population—can provide quantitative indications of the proposed boundary between the Holocene Epoch and the Anthropocene. Human energy expenditure in the Anthropocene, ~22 zetajoules (ZJ), exceeds that across the prior 11,700 years of the Holocene (~14.6 ZJ), largely through combustion of fossil fuels. The global warming effect during the Anthropocene is more than an order of magnitude greater still. Global human population, their productivity and energy consumption, and most changes impacting the global environment, are highly correlated. This extraordinary outburst of consumption and productivity demonstrates how the Earth System has departed from its Holocene state since ~1950 CE, forcing abrupt physical, chemical and biological changes to the Earth’s stratigraphic record that can be used to justify the proposal for naming a new epoch—the Anthropocene