Creating topological interfaces and detecting chiral edge modes in a 2D optical lattice

We propose and analyze a general scheme to create chiral topological edge modes within the bulk of two-dimensional engineered quantum systems. Our method is based on the implementation of topological interfaces, designed within the bulk of the system, where topologically-protected edge modes localize and freely propagate in a unidirectional manner. This scheme is illustrated through an optical-lattice realization of the Haldane model for cold atoms, where an additional spatially-varying lattice potential induces distinct topological phases in separated regions of space. We present two realistic experimental configurations, which lead to linear and radial-symmetric topological interfaces, which both allows one to significantly reduce the effects of external confinement on topological edge properties. Furthermore, the versatility of our method opens the possibility of tuning the position, the localization length and the chirality of the edge modes, through simple adjustments of the lattice potentials. In order to demonstrate the unique detectability offered by engineered interfaces, we numerically investigate the time-evolution of wave packets, indicating how topological transport unambiguously manifests itself within the lattice. Finally, we analyze the effects of disorder on the dynamics of chiral and non-chiral states present in the system. Interestingly, engineered disorder is shown to provide a powerful tool for the detection of topological edge modes in cold-atom setups.Comment: 18 pages, 21 figure

Decoding Water Law: Ten Areas of Texas Water Law Every Ag Lawyer Should Know

Texas water law is not a model of clarity. As a body of law, it is riddled with jargon, double-meaning, and esoteric context that can sometimes read and work like a Rube Goldberg device. Landowners not trained in the dark arts of Texas water rights and regulation are often (rightfully) frustrated with attempts to understand, exercise, market, and simply explain one of the most important property rights in Texas agriculture. Fear not. While not a categorical truth, much of Texas’ water law can be translated into a language that is helpful to those involved in Texas agriculture. The authors give no guarantee that this Article will be a precise decoder ring for growers, ranchers, lenders, brokers, and the like, but hopefully it will be useful to these important groups, nonetheless. This Article will include quick tips for ag practitioners dealing with water law issues in Texas. While each one of these topics could be a paper in itself, the topics will conclude with links/resources for addi- tional information

HLA-G: expression in human keratinocytes in vitro and in human skin in vivo

Classical, polymorphic major histocompatibility complex class I molecules are expressed on most nucleated cells.They present peptides at the cell surface and, thus, enable the immune system to scan peptides for their antigenicity. The function of the other, nonclassical class I molecules in man is controversial. HLA-G which has been shown by transfection experiments to be expressed at the cell surface, is only transcribed in placental tissue and in the fetal eye.Therefore, a role of HLA-G in the control of rejection of the allogeneic fetus has been discussed. We found that HLA-G expression is induced in keratinocytes by culture in vitro. Three different alternative splicing products of HLA-G can be detected: a full length transcript, an mRNA lacking exon 3 and a transcript devoid of exon 3 and 4. Reverse transcription followed by polymerase chain reaction also revealed the presence of HLA-G mRNA in vivo in biopsies of either diseased or healthy skin

What Does a Sage-Grouse Eat?

Although sage-grouse may eat only sagebrush during the winter, knowing that they need to eat other foods at other times of the year helps wildlife managers implement projects that will ensure a balanced diet. By knowing what a sage-grouse eats and when, we can determine what we need to do to maintain and improve populations and their habitats

Fiscal Consequences of Paying Interest on Reserves

We review the role of the central bank's balance sheet in a textbook monetary model and explore what changes if the central bank is allowed to pay interest on its liabilities. When the central bank (CB) cannot pay interest, away from the zero lower bound its (real) balance sheet is limited by the demand for money. Furthermore, if securities are not marked to market and the central bank holds its bonds to maturity, it is impossible for the CB to make losses, and it always obtains profits from being a monopoly provider of money. When the option of paying interest on liabilities is allowed, the limit on the CB's balance sheet is lifted. In this case, the CB is free to take on interest-rate risk – for example, by buying long-term securities and financing those purchases with short-term debt that pays the market interest rate. This is a risky enterprise that can lead to additional profits but also to losses. To the extent that losses exceed the profits of the monopoly operations, the CB faces two options: either it is recapitalised by Treasury or it increases its monopoly profits by raising the inflation tax

Construction of an Environmental Quality Index for Public Health Research

Background A more comprehensive estimate of environmental quality would improve our understanding of the relationship between environmental conditions and human health. An environmental quality index (EQI) for all counties in the U.S. was developed. Methods The EQI was developed in four parts: domain identification; data source acquisition; variable construction; and data reduction. Five environmental domains (air, water, land, built and sociodemographic) were recognized. Within each domain, data sources were identified; each was temporally (years 2000–2005) and geographically (county) restricted. Variables were constructed for each domain and assessed for missingness, collinearity, and normality. Domain-specific data reduction was accomplished using principal components analysis (PCA), resulting in domain-specific indices. Domain-specific indices were then combined into an overall EQI using PCA. In each PCA procedure, the first principal component was retained. Both domain-specific indices and overall EQI were stratified by four rural–urban continuum codes (RUCC). Higher values for each index were set to correspond to areas with poorer environmental quality. Results Concentrations of included variables differed across rural–urban strata, as did within-domain variable loadings, and domain index loadings for the EQI. In general, higher values of the air and sociodemographic indices were found in the more metropolitan areas and the most thinly populated areas have the lowest values of each of the domain indices. The less-urbanized counties (RUCC 3) demonstrated the greatest heterogeneity and range of EQI scores (−4.76, 3.57) while the thinly populated strata (RUCC 4) contained counties with the most positive scores (EQI score ranges from −5.86, 2.52). Conclusion The EQI holds promise for improving our characterization of the overall environment for public health. The EQI describes the non-residential ambient county-level conditions to which residents are exposed and domain-specific EQI loadings indicate which of the environmental domains account for the largest portion of the variability in the EQI environment. The EQI was constructed for all counties in the United States, incorporating a variety of data to provide a broad picture of environmental conditions. We undertook a reproducible approach that primarily utilized publically-available data sources

Evolution of three streambanks before and after stabilization and record flooding

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of stabilization has been insufficiently measured. Sound monitoring practices inform adjustments in implementation and maintenance, which improve engineered effectiveness. Thus, the objectives of this study were to: 1) measure streambank migration from in three reaches stabilized with wooden jetties following a major flooding event, and 2) quantify deposition around the jetties between pre-flood and post-flood. Streambank deposition was measured in 2019 with a River Surveyor and Global Positioning System (GPS). Bank erosion rates in Reaches 1, 2 and 3 were 0.41, 0.96 and 0.07 m2 m–1 yr–1, respectively, from pre-installation of wooden jetties. After streambanks in these reaches were stabilized, Reach 1 experienced 0.11 m2 m–1 yr–1 of erosion while Reaches 2 and 3 had 0.13 and 0.01 m2 m–1 yr–1 of deposition. Deposition increased in 2019 (1.61 and 0.81 m2 m–1) following a high magnitude flood. We utilized a new method for quantifying accumulated sediment in stream beds and banks. Our application of this new method demonstrates that jetties in the Cedar River have decreased streambank migration and increased sediment deposition at the point of implementation. The quantification of stream-sediment dynamics near jetties provides crucial information for stream-restoration design and decision-making, specifically for bioengineering design implementation