Continuo

The Caldeira-Leggett Hamiltonian describes the interaction of a discrete harmonic oscillator with a continuous bath of harmonic oscillators. This system is a standard model of dissipation in macroscopic low temperature physics, and has applications to superconductors, quantum computing, and macroscopic quantum tunneling. The similarities between the Caldeira-Leggett model and the linearized Vlasov-Poisson equation are analyzed, and it is shown that the damping in the Caldeira-Leggett model is analogous to that of Landau damping in plasmas (Landau, 1946 [1]). An invertible linear transformation (Morrison and Pfirsch, 1992 [18]; Morrison, 2000 [19]) is presented that converts solutions of the Caldeira-Leggett model into solutions of the linearized Vlasov-Poisson system.

The objective of this review article is to provide a concise discussion of atomistic modeling efforts aimed at understanding the nanoscale behavior and the role of grain boundaries in plasticity of metallic polycrystalline materials. Atomistic simulations of grain boundary behavior during plastic deformation have focused mainly on three distinct configurations: (i) bicrystal models, (ii) columnar nanocrystalline models, and (iii) 3D nanocrystalline models. Bicrystal models facilitate the isolation of specific mechanisms that occur at the grain boundary during plastic deformation, whereas columnar and 3D nanocrystalline models allow for an evaluation of triple junctions and complex stress states characteristic of polycrystalline microstructures. Ultimately, both sets of calculations have merits and are necessary to determine the role of grain boundary structure on material properties. Future directions in grain boundary modeling are discussed, including studies focused on the role of...

OBJECTIVE—Recent studies have confirmed that improved glycemic control decreases the risk of diabetic complications in type 1 and type 2 diabetic patients. The Minimed glucose sensor allows continuous 72-h glucose monitoring and represents a potentially important tool to improve diabetes management. Its use is currently limited to the health care team. Our aim was to evaluate the reproducibility of data provided by the device by comparing data provided by two sensors worn simultaneously by the same subject. RESEARCH DESIGN AND METHODS—A total of 11 subjects (6 type 1 and 3 type 2 diabetic patients and 2 healthy subjects) agreed to wear two sensors and perform at least four daily finger-stick glucose determinations during 72 h. The simultaneous glucose values provided by the sensors were compared. To determine the clinical implications of the glucose data, each day was divided into eight periods, and for each period the glucose range was rated as satisfactory, too high, or too low by...

This paper makes the case that a perspective called “Gradualism” could serve as a foundation for building a therapeutic continuum between the harm reduction and abstinence-oriented treatment worlds. In contrast to other integrationist writers (Denning, 2001; Marlatt, Blume, & Parks, 2001), this paper argues for the incorporation of abstinence into harm reduction approaches. The goal is to build on the strengths of both perspectives while reducing their weaknesses, and examples of each are provided. Lastly, with the frequent occurrence of relapse among addicted patients, building a continuum could also serve to provide a therapeutic “safety net” for those in need.

City size distributions, defined on the basis of population, are often described by power laws. Zipf's Law states that the exponent of the power law for rank-size distributions of cities is near −1. Verification of power law scaling for city size distributions at continental and global scales is complicated by small sample sizes, inappropriate estimation techniques, inconsistent definitions of urban

Soil aggregation plays a crucial role in soil physicochemical and biological processes, thus influencing soil nutrient retention. It is possible to improve soil aggregation by choosing appropriate agricultural practices. The objective of this study was to evaluate the effects of tillage, crops and fertilizer sources on size distribution of water-stable aggregates (WSA) and nutrient concentrations in aggregate fractions. Soil samples

Leaf Area Index (LAI) is an important variable that governs canopy processes and can be monitored by satellites. The current study aims at exploring the potential and limitations of using the red-edge spectral bands of the forthcoming superspectral satellites, namely—Vegetation and Environmental New micro Spacecraft (VENμS) and Sentinel-2, for assessing LAI in field crops. The research was conducted in experimental plots of wheat and potato in the northwestern Negev, Israel. Continuous spectral data were collected by a field spectrometer and LAI data were obtained by a ceptometer. The spectral data were resampled to the superspectral VENμS and Sentinel-2 resolutions. The data were divided into seven datasets (four seasons, two crops, and one including all data). The LAI prediction abilities by Partial Least Squares (PLS) models for continuous spectra and the resampled spectra were compared and evaluated. For wheat and potato of the continuous, VENμS, and Sentinel-2 data formations, the PLS correlation coefficients (r) values were 0.93, 0.93, and 0.92, respectively. In most cases, the red-edge region was found to be the most important spectral region for the three data formations, according to the Variable Importance in Projection (VIP) analysis. Additionally, Normalized Difference Vegetation Index (NDVI) and the Red-Edge Inflection Point (REIP) were computed for the three data formations in order to observe relation to as well as prediction accuracy in retrieving LAI values. The prediction abilities of the calculated indices by the data formations were compared, peaking for wheat, with r values of 0.91 for the REIP for the three data formations. Therefore, it is concluded that VENμS and Sentinel-2 can spectrally assess LAI as good as a hyperspectral sensor. The REIP was found to be a significantly better predictor than NDVI for wheat data and therefore can potentially be implemented for future LAI monitoring applications by superspectral sensors that contain four red-edge bands.► Superspectral band settings can predict LAI as good as continuous spectra. ► REIP can predict LAI for relatively high biomass and fractional cover crops. ► On ground level, REIP is a better LAI predictor for wheat than for potato.

In Greek, the word “nature” derives from the verb phyō, to come forth, to grow, to become. It is life independent of thought, and non-constructed. Aristotle calls physis “the coming-to-be what it is” (1960: 193a). Nature as physis contains both the movement of emergence and the specific growth, becoming and being, productivity and product. Growth in this context implies that withering and demise belong to it; genesis is always phthora, decay is integral to the act of coming-to-light. In pre-Socratic thought, the human being is seen as part of physis, which contains the human as a whole and in his/her individuality. The focus of the Roman words nasci and natura is, however, on being conceived and being born. Natura now means “native” and “inherent,” but is also defined in terms of the right of disposal, which influenced the formation of the modern term of object (cf. Picht 1998: 90). Nature as the quintessence of objects is nature as the sum of everything that is at our disposal in thought and action.